libexec/ftpd/ftpd.c

   1 /*
   2  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if 0
  31 #ifndef lint
  32 static char copyright[] =
  33 "@(#) Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994\n\
  34         The Regents of the University of California.  All rights reserved.\n";
  35 #endif /* not lint */
  36 #endif
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)ftpd.c      8.4 (Berkeley) 4/16/94";
  41 #endif
  42 #endif /* not lint */
  43
  44 #include <sys/cdefs.h>
  45 __FBSDID("$FreeBSD$");
  46
  47 /*
  48  * FTP server.
  49  */
  50 #include <sys/param.h>
  51 #include <sys/ioctl.h>
  52 #include <sys/mman.h>
  53 #include <sys/socket.h>
  54 #include <sys/stat.h>
  55 #include <sys/time.h>
  56 #include <sys/wait.h>
  57
  58 #include <netinet/in.h>
  59 #include <netinet/in_systm.h>
  60 #include <netinet/ip.h>
  61 #include <netinet/tcp.h>
  62
  63 #define FTP_NAMES
  64 #include <arpa/ftp.h>
  65 #include <arpa/inet.h>
  66 #include <arpa/telnet.h>
  67
  68 #include <ctype.h>
  69 #include <dirent.h>
  70 #include <err.h>
  71 #include <errno.h>
  72 #include <fcntl.h>
  73 #include <glob.h>
  74 #include <limits.h>
  75 #include <netdb.h>
  76 #include <pwd.h>
  77 #include <grp.h>
  78 #include <opie.h>
  79 #include <signal.h>
  80 #include <stdint.h>
  81 #include <stdio.h>
  82 #include <stdlib.h>
  83 #include <string.h>
  84 #include <syslog.h>
  85 #include <time.h>
  86 #include <unistd.h>
  87 #include <libutil.h>
  88 #ifdef  LOGIN_CAP
  89 #include <login_cap.h>
  90 #endif
  91
  92 #ifdef USE_PAM
  93 #include <security/pam_appl.h>
  94 #endif
  95
  96 #include "pathnames.h"
  97 #include "extern.h"
  98
  99 #include <stdarg.h>
 100
 101 static char version[] = "Version 6.00LS";
 102 #undef main
 103
 104 union sockunion ctrl_addr;
 105 union sockunion data_source;
 106 union sockunion data_dest;
 107 union sockunion his_addr;
 108 union sockunion pasv_addr;
 109
 110 int     daemon_mode;
 111 int     data;
 112 int     dataport;
 113 int     hostinfo = 1;   /* print host-specific info in messages */
 114 int     logged_in;
 115 struct  passwd *pw;
 116 char    *homedir;
 117 int     ftpdebug;
 118 int     timeout = 900;    /* timeout after 15 minutes of inactivity */
 119 int     maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
 120 int     logging;
 121 int     restricted_data_ports = 1;
 122 int     paranoid = 1;     /* be extra careful about security */
 123 int     anon_only = 0;    /* Only anonymous ftp allowed */
 124 int     assumeutf8 = 0;   /* Assume that server file names are in UTF-8 */
 125 int     guest;
 126 int     dochroot;
 127 char    *chrootdir;
 128 int     dowtmp = 1;
 129 int     stats;
 130 int     statfd = -1;
 131 int     type;
 132 int     form;
 133 int     stru;                   /* avoid C keyword */
 134 int     mode;
 135 int     usedefault = 1;         /* for data transfers */
 136 int     pdata = -1;             /* for passive mode */
 137 int     readonly = 0;           /* Server is in readonly mode.  */
 138 int     noepsv = 0;             /* EPSV command is disabled.    */
 139 int     noretr = 0;             /* RETR command is disabled.    */
 140 int     noguestretr = 0;        /* RETR command is disabled for anon users. */
 141 int     noguestmkd = 0;         /* MKD command is disabled for anon users. */
 142 int     noguestmod = 1;         /* anon users may not modify existing files. */
 143
 144 off_t   file_size;
 145 off_t   byte_count;
 146 #if !defined(CMASK) || CMASK == 0
 147 #undef CMASK
 148 #define CMASK 027
 149 #endif
 150 int     defumask = CMASK;               /* default umask value */
 151 char    tmpline[7];
 152 char    *hostname;
 153 int     epsvall = 0;
 154
 155 #ifdef VIRTUAL_HOSTING
 156 char    *ftpuser;
 157
 158 static struct ftphost {
 159         struct ftphost  *next;
 160         struct addrinfo *hostinfo;
 161         char            *hostname;
 162         char            *anonuser;
 163         char            *statfile;
 164         char            *welcome;
 165         char            *loginmsg;
 166 } *thishost, *firsthost;
 167
 168 #endif
 169 char    remotehost[NI_MAXHOST];
 170 char    *ident = NULL;
 171
 172 static char     wtmpid[20];
 173
 174 #ifdef USE_PAM
 175 static int      auth_pam(struct passwd**, const char*);
 176 pam_handle_t    *pamh = NULL;
 177 #endif
 178
 179 static struct opie      opiedata;
 180 static char             opieprompt[OPIE_CHALLENGE_MAX+1];
 181 static int              pwok;
 182
 183 char    *pid_file = NULL; /* means default location to pidfile(3) */
 184
 185 /*
 186  * Limit number of pathnames that glob can return.
 187  * A limit of 0 indicates the number of pathnames is unlimited.
 188  */
 189 #define MAXGLOBARGS     16384
 190 #
 191
 192 /*
 193  * Timeout intervals for retrying connections
 194  * to hosts that don't accept PORT cmds.  This
 195  * is a kludge, but given the problems with TCP...
 196  */
 197 #define SWAITMAX        90      /* wait at most 90 seconds */
 198 #define SWAITINT        5       /* interval between retries */
 199
 200 int     swaitmax = SWAITMAX;
 201 int     swaitint = SWAITINT;
 202
 203 #ifdef SETPROCTITLE
 204 #ifdef OLD_SETPROCTITLE
 205 char    **Argv = NULL;          /* pointer to argument vector */
 206 char    *LastArgv = NULL;       /* end of argv */
 207 #endif /* OLD_SETPROCTITLE */
 208 char    proctitle[LINE_MAX];    /* initial part of title */
 209 #endif /* SETPROCTITLE */
 210
 211 #define LOGCMD(cmd, file)               logcmd((cmd), (file), NULL, -1)
 212 #define LOGCMD2(cmd, file1, file2)      logcmd((cmd), (file1), (file2), -1)
 213 #define LOGBYTES(cmd, file, cnt)        logcmd((cmd), (file), NULL, (cnt))
 214
 215 static  volatile sig_atomic_t recvurg;
 216 static  int transflag;          /* NB: for debugging only */
 217
 218 #define STARTXFER       flagxfer(1)
 219 #define ENDXFER         flagxfer(0)
 220
 221 #define START_UNSAFE    maskurg(1)
 222 #define END_UNSAFE      maskurg(0)
 223
 224 /* It's OK to put an `else' clause after this macro. */
 225 #define CHECKOOB(action)                                                \
 226         if (recvurg) {                                                  \
 227                 recvurg = 0;                                            \
 228                 if (myoob()) {                                          \
 229                         ENDXFER;                                        \
 230                         action;                                         \
 231                 }                                                       \
 232         }
 233
 234 #ifdef VIRTUAL_HOSTING
 235 static void      inithosts(int);
 236 static void      selecthost(union sockunion *);
 237 #endif
 238 static void      ack(char *);
 239 static void      sigurg(int);
 240 static void      maskurg(int);
 241 static void      flagxfer(int);
 242 static int       myoob(void);
 243 static int       checkuser(char *, char *, int, char **, int *);
 244 static FILE     *dataconn(char *, off_t, char *);
 245 static void      dolog(struct sockaddr *);
 246 static void      end_login(void);
 247 static FILE     *getdatasock(char *);
 248 static int       guniquefd(char *, char **);
 249 static void      lostconn(int);
 250 static void      sigquit(int);
 251 static int       receive_data(FILE *, FILE *);
 252 static int       send_data(FILE *, FILE *, size_t, off_t, int);
 253 static struct passwd *
 254                  sgetpwnam(char *);
 255 static char     *sgetsave(char *);
 256 static void      reapchild(int);
 257 static void      appendf(char **, char *, ...) __printflike(2, 3);
 258 static void      logcmd(char *, char *, char *, off_t);
 259 static void      logxfer(char *, off_t, time_t);
 260 static char     *doublequote(char *);
 261 static int      *socksetup(int, char *, const char *);
 262
 263 int
 264 main(int argc, char *argv[], char **envp)
 265 {
 266         socklen_t addrlen;
 267         int ch, on = 1, tos;
 268         char *cp, line[LINE_MAX];
 269         FILE *fd;
 270         char    *bindname = NULL;
 271         const char *bindport = "ftp";
 272         int     family = AF_UNSPEC;
 273         struct sigaction sa;
 274
 275         tzset();                /* in case no timezone database in ~ftp */
 276         sigemptyset(&sa.sa_mask);
 277         sa.sa_flags = SA_RESTART;
 278
 279 #ifdef OLD_SETPROCTITLE
 280         /*
 281          *  Save start and extent of argv for setproctitle.
 282          */
 283         Argv = argv;
 284         while (*envp)
 285                 envp++;
 286         LastArgv = envp[-1] + strlen(envp[-1]);
 287 #endif /* OLD_SETPROCTITLE */
 288
 289         /*
 290          * Prevent diagnostic messages from appearing on stderr.
 291          * We run as a daemon or from inetd; in both cases, there's
 292          * more reason in logging to syslog.
 293          */
 294         (void) freopen(_PATH_DEVNULL, "w", stderr);
 295         opterr = 0;
 296
 297         /*
 298          * LOG_NDELAY sets up the logging connection immediately,
 299          * necessary for anonymous ftp's that chroot and can't do it later.
 300          */
 301         openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
 302
 303         while ((ch = getopt(argc, argv,
 304                             "468a:AdDEhlmMoOp:P:rRSt:T:u:UvW")) != -1) {
 305                 switch (ch) {
 306                 case '4':
 307                         family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
 308                         break;
 309
 310                 case '6':
 311                         family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
 312                         break;
 313
 314                 case '8':
 315                         assumeutf8 = 1;
 316                         break;
 317
 318                 case 'a':
 319                         bindname = optarg;
 320                         break;
 321
 322                 case 'A':
 323                         anon_only = 1;
 324                         break;
 325
 326                 case 'd':
 327                         ftpdebug++;
 328                         break;
 329
 330                 case 'D':
 331                         daemon_mode++;
 332                         break;
 333
 334                 case 'E':
 335                         noepsv = 1;
 336                         break;
 337
 338                 case 'h':
 339                         hostinfo = 0;
 340                         break;
 341
 342                 case 'l':
 343                         logging++;      /* > 1 == extra logging */
 344                         break;
 345
 346                 case 'm':
 347                         noguestmod = 0;
 348                         break;
 349
 350                 case 'M':
 351                         noguestmkd = 1;
 352                         break;
 353
 354                 case 'o':
 355                         noretr = 1;
 356                         break;
 357
 358                 case 'O':
 359                         noguestretr = 1;
 360                         break;
 361
 362                 case 'p':
 363                         pid_file = optarg;
 364                         break;
 365
 366                 case 'P':
 367                         bindport = optarg;
 368                         break;
 369
 370                 case 'r':
 371                         readonly = 1;
 372                         break;
 373
 374                 case 'R':
 375                         paranoid = 0;
 376                         break;
 377
 378                 case 'S':
 379                         stats++;
 380                         break;
 381
 382                 case 't':
 383                         timeout = atoi(optarg);
 384                         if (maxtimeout < timeout)
 385                                 maxtimeout = timeout;
 386                         break;
 387
 388                 case 'T':
 389                         maxtimeout = atoi(optarg);
 390                         if (timeout > maxtimeout)
 391                                 timeout = maxtimeout;
 392                         break;
 393
 394                 case 'u':
 395                     {
 396                         long val = 0;
 397
 398                         val = strtol(optarg, &optarg, 8);
 399                         if (*optarg != '\0' || val < 0)
 400                                 syslog(LOG_WARNING, "bad value for -u");
 401                         else
 402                                 defumask = val;
 403                         break;
 404                     }
 405                 case 'U':
 406                         restricted_data_ports = 0;
 407                         break;
 408
 409                 case 'v':
 410                         ftpdebug++;
 411                         break;
 412
 413                 case 'W':
 414                         dowtmp = 0;
 415                         break;
 416
 417                 default:
 418                         syslog(LOG_WARNING, "unknown flag -%c ignored", optopt);
 419                         break;
 420                 }
 421         }
 422
 423         /* handle filesize limit gracefully */
 424         sa.sa_handler = SIG_IGN;
 425         (void)sigaction(SIGXFSZ, &sa, NULL);
 426
 427         if (daemon_mode) {
 428                 int *ctl_sock, fd, maxfd = -1, nfds, i;
 429                 fd_set defreadfds, readfds;
 430                 pid_t pid;
 431                 struct pidfh *pfh;
 432
 433                 if ((pfh = pidfile_open(pid_file, 0600, &pid)) == NULL) {
 434                         if (errno == EEXIST) {
 435                                 syslog(LOG_ERR, "%s already running, pid %d",
 436                                        getprogname(), (int)pid);
 437                                 exit(1);
 438                         }
 439                         syslog(LOG_WARNING, "pidfile_open: %m");
 440                 }
 441
 442                 /*
 443                  * Detach from parent.
 444                  */
 445                 if (daemon(1, 1) < 0) {
 446                         syslog(LOG_ERR, "failed to become a daemon");
 447                         exit(1);
 448                 }
 449
 450                 if (pfh != NULL && pidfile_write(pfh) == -1)
 451                         syslog(LOG_WARNING, "pidfile_write: %m");
 452
 453                 sa.sa_handler = reapchild;
 454                 (void)sigaction(SIGCHLD, &sa, NULL);
 455
 456 #ifdef VIRTUAL_HOSTING
 457                 inithosts(family);
 458 #endif
 459
 460                 /*
 461                  * Open a socket, bind it to the FTP port, and start
 462                  * listening.
 463                  */
 464                 ctl_sock = socksetup(family, bindname, bindport);
 465                 if (ctl_sock == NULL)
 466                         exit(1);
 467
 468                 FD_ZERO(&defreadfds);
 469                 for (i = 1; i <= *ctl_sock; i++) {
 470                         FD_SET(ctl_sock[i], &defreadfds);
 471                         if (listen(ctl_sock[i], 32) < 0) {
 472                                 syslog(LOG_ERR, "control listen: %m");
 473                                 exit(1);
 474                         }
 475                         if (maxfd < ctl_sock[i])
 476                                 maxfd = ctl_sock[i];
 477                 }
 478
 479                 /*
 480                  * Loop forever accepting connection requests and forking off
 481                  * children to handle them.
 482                  */
 483                 while (1) {
 484                         FD_COPY(&defreadfds, &readfds);
 485                         nfds = select(maxfd + 1, &readfds, NULL, NULL, 0);
 486                         if (nfds <= 0) {
 487                                 if (nfds < 0 && errno != EINTR)
 488                                         syslog(LOG_WARNING, "select: %m");
 489                                 continue;
 490                         }
 491
 492                         pid = -1;
 493                         for (i = 1; i <= *ctl_sock; i++)
 494                                 if (FD_ISSET(ctl_sock[i], &readfds)) {
 495                                         addrlen = sizeof(his_addr);
 496                                         fd = accept(ctl_sock[i],
 497                                             (struct sockaddr *)&his_addr,
 498                                             &addrlen);
 499                                         if (fd == -1) {
 500                                                 syslog(LOG_WARNING,
 501                                                        "accept: %m");
 502                                                 continue;
 503                                         }
 504                                         switch (pid = fork()) {
 505                                         case 0:
 506                                                 /* child */
 507                                                 (void) dup2(fd, 0);
 508                                                 (void) dup2(fd, 1);
 509                                                 (void) close(fd);
 510                                                 for (i = 1; i <= *ctl_sock; i++)
 511                                                         close(ctl_sock[i]);
 512                                                 if (pfh != NULL)
 513                                                         pidfile_close(pfh);
 514                                                 goto gotchild;
 515                                         case -1:
 516                                                 syslog(LOG_WARNING, "fork: %m");
 517                                                 /* FALLTHROUGH */
 518                                         default:
 519                                                 close(fd);
 520                                         }
 521                                 }
 522                 }
 523         } else {
 524                 addrlen = sizeof(his_addr);
 525                 if (getpeername(0, (struct sockaddr *)&his_addr, &addrlen) < 0) {
 526                         syslog(LOG_ERR, "getpeername (%s): %m",argv[0]);
 527                         exit(1);
 528                 }
 529
 530 #ifdef VIRTUAL_HOSTING
 531                 if (his_addr.su_family == AF_INET6 &&
 532                     IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr))
 533                         family = AF_INET;
 534                 else
 535                         family = his_addr.su_family;
 536                 inithosts(family);
 537 #endif
 538         }
 539
 540 gotchild:
 541         sa.sa_handler = SIG_DFL;
 542         (void)sigaction(SIGCHLD, &sa, NULL);
 543
 544         sa.sa_handler = sigurg;
 545         sa.sa_flags = 0;                /* don't restart syscalls for SIGURG */
 546         (void)sigaction(SIGURG, &sa, NULL);
 547
 548         sigfillset(&sa.sa_mask);        /* block all signals in handler */
 549         sa.sa_flags = SA_RESTART;
 550         sa.sa_handler = sigquit;
 551         (void)sigaction(SIGHUP, &sa, NULL);
 552         (void)sigaction(SIGINT, &sa, NULL);
 553         (void)sigaction(SIGQUIT, &sa, NULL);
 554         (void)sigaction(SIGTERM, &sa, NULL);
 555
 556         sa.sa_handler = lostconn;
 557         (void)sigaction(SIGPIPE, &sa, NULL);
 558
 559         addrlen = sizeof(ctrl_addr);
 560         if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
 561                 syslog(LOG_ERR, "getsockname (%s): %m",argv[0]);
 562                 exit(1);
 563         }
 564         dataport = ntohs(ctrl_addr.su_port) - 1; /* as per RFC 959 */
 565 #ifdef VIRTUAL_HOSTING
 566         /* select our identity from virtual host table */
 567         selecthost(&ctrl_addr);
 568 #endif
 569 #ifdef IP_TOS
 570         if (ctrl_addr.su_family == AF_INET)
 571       {
 572         tos = IPTOS_LOWDELAY;
 573         if (setsockopt(0, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
 574                 syslog(LOG_WARNING, "control setsockopt (IP_TOS): %m");
 575       }
 576 #endif
 577         /*
 578          * Disable Nagle on the control channel so that we don't have to wait
 579          * for peer's ACK before issuing our next reply.
 580          */
 581         if (setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
 582                 syslog(LOG_WARNING, "control setsockopt (TCP_NODELAY): %m");
 583
 584         data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
 585
 586         (void)snprintf(wtmpid, sizeof(wtmpid), "%xftpd", getpid());
 587
 588         /* Try to handle urgent data inline */
 589 #ifdef SO_OOBINLINE
 590         if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) < 0)
 591                 syslog(LOG_WARNING, "control setsockopt (SO_OOBINLINE): %m");
 592 #endif
 593
 594 #ifdef  F_SETOWN
 595         if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
 596                 syslog(LOG_ERR, "fcntl F_SETOWN: %m");
 597 #endif
 598         dolog((struct sockaddr *)&his_addr);
 599         /*
 600          * Set up default state
 601          */
 602         data = -1;
 603         type = TYPE_A;
 604         form = FORM_N;
 605         stru = STRU_F;
 606         mode = MODE_S;
 607         tmpline[0] = '\0';
 608
 609         /* If logins are disabled, print out the message. */
 610         if ((fd = fopen(_PATH_NOLOGIN,"r")) != NULL) {
 611                 while (fgets(line, sizeof(line), fd) != NULL) {
 612                         if ((cp = strchr(line, '\n')) != NULL)
 613                                 *cp = '\0';
 614                         lreply(530, "%s", line);
 615                 }
 616                 (void) fflush(stdout);
 617                 (void) fclose(fd);
 618                 reply(530, "System not available.");
 619                 exit(0);
 620         }
 621 #ifdef VIRTUAL_HOSTING
 622         fd = fopen(thishost->welcome, "r");
 623 #else
 624         fd = fopen(_PATH_FTPWELCOME, "r");
 625 #endif
 626         if (fd != NULL) {
 627                 while (fgets(line, sizeof(line), fd) != NULL) {
 628                         if ((cp = strchr(line, '\n')) != NULL)
 629                                 *cp = '\0';
 630                         lreply(220, "%s", line);
 631                 }
 632                 (void) fflush(stdout);
 633                 (void) fclose(fd);
 634                 /* reply(220,) must follow */
 635         }
 636 #ifndef VIRTUAL_HOSTING
 637         if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
 638                 fatalerror("Ran out of memory.");
 639         if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
 640                 hostname[0] = '\0';
 641         hostname[MAXHOSTNAMELEN - 1] = '\0';
 642 #endif
 643         if (hostinfo)
 644                 reply(220, "%s FTP server (%s) ready.", hostname, version);
 645         else
 646                 reply(220, "FTP server ready.");
 647         for (;;)
 648                 (void) yyparse();
 649         /* NOTREACHED */
 650 }
 651
 652 static void
 653 lostconn(int signo)
 654 {
 655
 656         if (ftpdebug)
 657                 syslog(LOG_DEBUG, "lost connection");
 658         dologout(1);
 659 }
 660
 661 static void
 662 sigquit(int signo)
 663 {
 664
 665         syslog(LOG_ERR, "got signal %d", signo);
 666         dologout(1);
 667 }
 668
 669 #ifdef VIRTUAL_HOSTING
 670 /*
 671  * read in virtual host tables (if they exist)
 672  */
 673
 674 static void
 675 inithosts(int family)
 676 {
 677         int insert;
 678         size_t len;
 679         FILE *fp;
 680         char *cp, *mp, *line;
 681         char *hostname;
 682         char *vhost, *anonuser, *statfile, *welcome, *loginmsg;
 683         struct ftphost *hrp, *lhrp;
 684         struct addrinfo hints, *res, *ai;
 685
 686         /*
 687          * Fill in the default host information
 688          */
 689         if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
 690                 fatalerror("Ran out of memory.");
 691         if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
 692                 hostname[0] = '\0';
 693         hostname[MAXHOSTNAMELEN - 1] = '\0';
 694         if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
 695                 fatalerror("Ran out of memory.");
 696         hrp->hostname = hostname;
 697         hrp->hostinfo = NULL;
 698
 699         memset(&hints, 0, sizeof(hints));
 700         hints.ai_flags = AI_PASSIVE;
 701         hints.ai_family = family;
 702         hints.ai_socktype = SOCK_STREAM;
 703         if (getaddrinfo(hrp->hostname, NULL, &hints, &res) == 0)
 704                 hrp->hostinfo = res;
 705         hrp->statfile = _PATH_FTPDSTATFILE;
 706         hrp->welcome  = _PATH_FTPWELCOME;
 707         hrp->loginmsg = _PATH_FTPLOGINMESG;
 708         hrp->anonuser = "ftp";
 709         hrp->next = NULL;
 710         thishost = firsthost = lhrp = hrp;
 711         if ((fp = fopen(_PATH_FTPHOSTS, "r")) != NULL) {
 712                 int addrsize, gothost;
 713                 void *addr;
 714                 struct hostent *hp;
 715
 716                 while ((line = fgetln(fp, &len)) != NULL) {
 717                         int     i, hp_error;
 718
 719                         /* skip comments */
 720                         if (line[0] == '#')
 721                                 continue;
 722                         if (line[len - 1] == '\n') {
 723                                 line[len - 1] = '\0';
 724                                 mp = NULL;
 725                         } else {
 726                                 if ((mp = malloc(len + 1)) == NULL)
 727                                         fatalerror("Ran out of memory.");
 728                                 memcpy(mp, line, len);
 729                                 mp[len] = '\0';
 730                                 line = mp;
 731                         }
 732                         cp = strtok(line, " \t");
 733                         /* skip empty lines */
 734                         if (cp == NULL)
 735                                 goto nextline;
 736                         vhost = cp;
 737
 738                         /* set defaults */
 739                         anonuser = "ftp";
 740                         statfile = _PATH_FTPDSTATFILE;
 741                         welcome  = _PATH_FTPWELCOME;
 742                         loginmsg = _PATH_FTPLOGINMESG;
 743
 744                         /*
 745                          * Preparse the line so we can use its info
 746                          * for all the addresses associated with
 747                          * the virtual host name.
 748                          * Field 0, the virtual host name, is special:
 749                          * it's already parsed off and will be strdup'ed
 750                          * later, after we know its canonical form.
 751                          */
 752                         for (i = 1; i < 5 && (cp = strtok(NULL, " \t")); i++)
 753                                 if (*cp != '-' && (cp = strdup(cp)))
 754                                         switch (i) {
 755                                         case 1: /* anon user permissions */
 756                                                 anonuser = cp;
 757                                                 break;
 758                                         case 2: /* statistics file */
 759                                                 statfile = cp;
 760                                                 break;
 761                                         case 3: /* welcome message */
 762                                                 welcome  = cp;
 763                                                 break;
 764                                         case 4: /* login message */
 765                                                 loginmsg = cp;
 766                                                 break;
 767                                         default: /* programming error */
 768                                                 abort();
 769                                                 /* NOTREACHED */
 770                                         }
 771
 772                         hints.ai_flags = AI_PASSIVE;
 773                         hints.ai_family = family;
 774                         hints.ai_socktype = SOCK_STREAM;
 775                         if (getaddrinfo(vhost, NULL, &hints, &res) != 0)
 776                                 goto nextline;
 777                         for (ai = res; ai != NULL && ai->ai_addr != NULL;
 778                              ai = ai->ai_next) {
 779
 780                         gothost = 0;
 781                         for (hrp = firsthost; hrp != NULL; hrp = hrp->next) {
 782                                 struct addrinfo *hi;
 783
 784                                 for (hi = hrp->hostinfo; hi != NULL;
 785                                      hi = hi->ai_next)
 786                                         if (hi->ai_addrlen == ai->ai_addrlen &&
 787                                             memcmp(hi->ai_addr,
 788                                                    ai->ai_addr,
 789                                                    ai->ai_addr->sa_len) == 0) {
 790                                                 gothost++;
 791                                                 break;
 792                                         }
 793                                 if (gothost)
 794                                         break;
 795                         }
 796                         if (hrp == NULL) {
 797                                 if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
 798                                         goto nextline;
 799                                 hrp->hostname = NULL;
 800                                 insert = 1;
 801                         } else {
 802                                 if (hrp->hostinfo && hrp->hostinfo != res)
 803                                         freeaddrinfo(hrp->hostinfo);
 804                                 insert = 0; /* host already in the chain */
 805                         }
 806                         hrp->hostinfo = res;
 807
 808                         /*
 809                          * determine hostname to use.
 810                          * force defined name if there is a valid alias
 811                          * otherwise fallback to primary hostname
 812                          */
 813                         /* XXX: getaddrinfo() can't do alias check */
 814                         switch(hrp->hostinfo->ai_family) {
 815                         case AF_INET:
 816                                 addr = &((struct sockaddr_in *)hrp->hostinfo->ai_addr)->sin_addr;
 817                                 addrsize = sizeof(struct in_addr);
 818                                 break;
 819                         case AF_INET6:
 820                                 addr = &((struct sockaddr_in6 *)hrp->hostinfo->ai_addr)->sin6_addr;
 821                                 addrsize = sizeof(struct in6_addr);
 822                                 break;
 823                         default:
 824                                 /* should not reach here */
 825                                 freeaddrinfo(hrp->hostinfo);
 826                                 if (insert)
 827                                         free(hrp); /*not in chain, can free*/
 828                                 else
 829                                         hrp->hostinfo = NULL; /*mark as blank*/
 830                                 goto nextline;
 831                                 /* NOTREACHED */
 832                         }
 833                         if ((hp = getipnodebyaddr(addr, addrsize,
 834                                                   hrp->hostinfo->ai_family,
 835                                                   &hp_error)) != NULL) {
 836                                 if (strcmp(vhost, hp->h_name) != 0) {
 837                                         if (hp->h_aliases == NULL)
 838                                                 vhost = hp->h_name;
 839                                         else {
 840                                                 i = 0;
 841                                                 while (hp->h_aliases[i] &&
 842                                                        strcmp(vhost, hp->h_aliases[i]) != 0)
 843                                                         ++i;
 844                                                 if (hp->h_aliases[i] == NULL)
 845                                                         vhost = hp->h_name;
 846                                         }
 847                                 }
 848                         }
 849                         if (hrp->hostname &&
 850                             strcmp(hrp->hostname, vhost) != 0) {
 851                                 free(hrp->hostname);
 852                                 hrp->hostname = NULL;
 853                         }
 854                         if (hrp->hostname == NULL &&
 855                             (hrp->hostname = strdup(vhost)) == NULL) {
 856                                 freeaddrinfo(hrp->hostinfo);
 857                                 hrp->hostinfo = NULL; /* mark as blank */
 858                                 if (hp)
 859                                         freehostent(hp);
 860                                 goto nextline;
 861                         }
 862                         hrp->anonuser = anonuser;
 863                         hrp->statfile = statfile;
 864                         hrp->welcome  = welcome;
 865                         hrp->loginmsg = loginmsg;
 866                         if (insert) {
 867                                 hrp->next  = NULL;
 868                                 lhrp->next = hrp;
 869                                 lhrp = hrp;
 870                         }
 871                         if (hp)
 872                                 freehostent(hp);
 873                       }
 874 nextline:
 875                         if (mp)
 876                                 free(mp);
 877                 }
 878                 (void) fclose(fp);
 879         }
 880 }
 881
 882 static void
 883 selecthost(union sockunion *su)
 884 {
 885         struct ftphost  *hrp;
 886         u_int16_t port;
 887 #ifdef INET6
 888         struct in6_addr *mapped_in6 = NULL;
 889 #endif
 890         struct addrinfo *hi;
 891
 892 #ifdef INET6
 893         /*
 894          * XXX IPv4 mapped IPv6 addr consideraton,
 895          * specified in rfc2373.
 896          */
 897         if (su->su_family == AF_INET6 &&
 898             IN6_IS_ADDR_V4MAPPED(&su->su_sin6.sin6_addr))
 899                 mapped_in6 = &su->su_sin6.sin6_addr;
 900 #endif
 901
 902         hrp = thishost = firsthost;     /* default */
 903         port = su->su_port;
 904         su->su_port = 0;
 905         while (hrp != NULL) {
 906             for (hi = hrp->hostinfo; hi != NULL; hi = hi->ai_next) {
 907                 if (memcmp(su, hi->ai_addr, hi->ai_addrlen) == 0) {
 908                         thishost = hrp;
 909                         goto found;
 910                 }
 911 #ifdef INET6
 912                 /* XXX IPv4 mapped IPv6 addr consideraton */
 913                 if (hi->ai_addr->sa_family == AF_INET && mapped_in6 != NULL &&
 914                     (memcmp(&mapped_in6->s6_addr[12],
 915                             &((struct sockaddr_in *)hi->ai_addr)->sin_addr,
 916                             sizeof(struct in_addr)) == 0)) {
 917                         thishost = hrp;
 918                         goto found;
 919                 }
 920 #endif
 921             }
 922             hrp = hrp->next;
 923         }
 924 found:
 925         su->su_port = port;
 926         /* setup static variables as appropriate */
 927         hostname = thishost->hostname;
 928         ftpuser = thishost->anonuser;
 929 }
 930 #endif
 931
 932 /*
 933  * Helper function for sgetpwnam().
 934  */
 935 static char *
 936 sgetsave(char *s)
 937 {
 938         char *new = malloc(strlen(s) + 1);
 939
 940         if (new == NULL) {
 941                 reply(421, "Ran out of memory.");
 942                 dologout(1);
 943                 /* NOTREACHED */
 944         }
 945         (void) strcpy(new, s);
 946         return (new);
 947 }
 948
 949 /*
 950  * Save the result of a getpwnam.  Used for USER command, since
 951  * the data returned must not be clobbered by any other command
 952  * (e.g., globbing).
 953  * NB: The data returned by sgetpwnam() will remain valid until
 954  * the next call to this function.  Its difference from getpwnam()
 955  * is that sgetpwnam() is known to be called from ftpd code only.
 956  */
 957 static struct passwd *
 958 sgetpwnam(char *name)
 959 {
 960         static struct passwd save;
 961         struct passwd *p;
 962
 963         if ((p = getpwnam(name)) == NULL)
 964                 return (p);
 965         if (save.pw_name) {
 966                 free(save.pw_name);
 967                 free(save.pw_passwd);
 968                 free(save.pw_class);
 969                 free(save.pw_gecos);
 970                 free(save.pw_dir);
 971                 free(save.pw_shell);
 972         }
 973         save = *p;
 974         save.pw_name = sgetsave(p->pw_name);
 975         save.pw_passwd = sgetsave(p->pw_passwd);
 976         save.pw_class = sgetsave(p->pw_class);
 977         save.pw_gecos = sgetsave(p->pw_gecos);
 978         save.pw_dir = sgetsave(p->pw_dir);
 979         save.pw_shell = sgetsave(p->pw_shell);
 980         return (&save);
 981 }
 982
 983 static int login_attempts;      /* number of failed login attempts */
 984 static int askpasswd;           /* had user command, ask for passwd */
 985 static char curname[MAXLOGNAME];        /* current USER name */
 986
 987 /*
 988  * USER command.
 989  * Sets global passwd pointer pw if named account exists and is acceptable;
 990  * sets askpasswd if a PASS command is expected.  If logged in previously,
 991  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
 992  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
 993  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
 994  * requesting login privileges.  Disallow anyone who does not have a standard
 995  * shell as returned by getusershell().  Disallow anyone mentioned in the file
 996  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
 997  */
 998 void
 999 user(char *name)
1000 {
1001         int ecode;
1002         char *cp, *shell;
1003
1004         if (logged_in) {
1005                 if (guest) {
1006                         reply(530, "Can't change user from guest login.");
1007                         return;
1008                 } else if (dochroot) {
1009                         reply(530, "Can't change user from chroot user.");
1010                         return;
1011                 }
1012                 end_login();
1013         }
1014
1015         guest = 0;
1016 #ifdef VIRTUAL_HOSTING
1017         pw = sgetpwnam(thishost->anonuser);
1018 #else
1019         pw = sgetpwnam("ftp");
1020 #endif
1021         if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
1022                 if (checkuser(_PATH_FTPUSERS, "ftp", 0, NULL, &ecode) ||
1023                     (ecode != 0 && ecode != ENOENT))
1024                         reply(530, "User %s access denied.", name);
1025                 else if (checkuser(_PATH_FTPUSERS, "anonymous", 0, NULL, &ecode) ||
1026                     (ecode != 0 && ecode != ENOENT))
1027                         reply(530, "User %s access denied.", name);
1028                 else if (pw != NULL) {
1029                         guest = 1;
1030                         askpasswd = 1;
1031                         reply(331,
1032                         "Guest login ok, send your email address as password.");
1033                 } else
1034                         reply(530, "User %s unknown.", name);
1035                 if (!askpasswd && logging)
1036                         syslog(LOG_NOTICE,
1037                             "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
1038                 return;
1039         }
1040         if (anon_only != 0) {
1041                 reply(530, "Sorry, only anonymous ftp allowed.");
1042                 return;
1043         }
1044
1045         if ((pw = sgetpwnam(name))) {
1046                 if ((shell = pw->pw_shell) == NULL || *shell == 0)
1047                         shell = _PATH_BSHELL;
1048                 setusershell();
1049                 while ((cp = getusershell()) != NULL)
1050                         if (strcmp(cp, shell) == 0)
1051                                 break;
1052                 endusershell();
1053
1054                 if (cp == NULL ||
1055                     (checkuser(_PATH_FTPUSERS, name, 1, NULL, &ecode) ||
1056                     (ecode != 0 && ecode != ENOENT))) {
1057                         reply(530, "User %s access denied.", name);
1058                         if (logging)
1059                                 syslog(LOG_NOTICE,
1060                                     "FTP LOGIN REFUSED FROM %s, %s",
1061                                     remotehost, name);
1062                         pw = NULL;
1063                         return;
1064                 }
1065         }
1066         if (logging)
1067                 strlcpy(curname, name, sizeof(curname));
1068
1069         pwok = 0;
1070 #ifdef USE_PAM
1071         /* XXX Kluge! The conversation mechanism needs to be fixed. */
1072 #endif
1073         if (opiechallenge(&opiedata, name, opieprompt) == 0) {
1074                 pwok = (pw != NULL) &&
1075                        opieaccessfile(remotehost) &&
1076                        opiealways(pw->pw_dir);
1077                 reply(331, "Response to %s %s for %s.",
1078                       opieprompt, pwok ? "requested" : "required", name);
1079         } else {
1080                 pwok = 1;
1081                 reply(331, "Password required for %s.", name);
1082         }
1083         askpasswd = 1;
1084         /*
1085          * Delay before reading passwd after first failed
1086          * attempt to slow down passwd-guessing programs.
1087          */
1088         if (login_attempts)
1089                 sleep(login_attempts);
1090 }
1091
1092 /*
1093  * Check if a user is in the file "fname",
1094  * return a pointer to a malloc'd string with the rest
1095  * of the matching line in "residue" if not NULL.
1096  */
1097 static int
1098 checkuser(char *fname, char *name, int pwset, char **residue, int *ecode)
1099 {
1100         FILE *fd;
1101         int found = 0;
1102         size_t len;
1103         char *line, *mp, *p;
1104
1105         if (ecode != NULL)
1106                 *ecode = 0;
1107         if ((fd = fopen(fname, "r")) != NULL) {
1108                 while (!found && (line = fgetln(fd, &len)) != NULL) {
1109                         /* skip comments */
1110                         if (line[0] == '#')
1111                                 continue;
1112                         if (line[len - 1] == '\n') {
1113                                 line[len - 1] = '\0';
1114                                 mp = NULL;
1115                         } else {
1116                                 if ((mp = malloc(len + 1)) == NULL)
1117                                         fatalerror("Ran out of memory.");
1118                                 memcpy(mp, line, len);
1119                                 mp[len] = '\0';
1120                                 line = mp;
1121                         }
1122                         /* avoid possible leading and trailing whitespace */
1123                         p = strtok(line, " \t");
1124                         /* skip empty lines */
1125                         if (p == NULL)
1126                                 goto nextline;
1127                         /*
1128                          * if first chr is '@', check group membership
1129                          */
1130                         if (p[0] == '@') {
1131                                 int i = 0;
1132                                 struct group *grp;
1133
1134                                 if (p[1] == '\0') /* single @ matches anyone */
1135                                         found = 1;
1136                                 else {
1137                                         if ((grp = getgrnam(p+1)) == NULL)
1138                                                 goto nextline;
1139                                         /*
1140                                          * Check user's default group
1141                                          */
1142                                         if (pwset && grp->gr_gid == pw->pw_gid)
1143                                                 found = 1;
1144                                         /*
1145                                          * Check supplementary groups
1146                                          */
1147                                         while (!found && grp->gr_mem[i])
1148                                                 found = strcmp(name,
1149                                                         grp->gr_mem[i++])
1150                                                         == 0;
1151                                 }
1152                         }
1153                         /*
1154                          * Otherwise, just check for username match
1155                          */
1156                         else
1157                                 found = strcmp(p, name) == 0;
1158                         /*
1159                          * Save the rest of line to "residue" if matched
1160                          */
1161                         if (found && residue) {
1162                                 if ((p = strtok(NULL, "")) != NULL)
1163                                         p += strspn(p, " \t");
1164                                 if (p && *p) {
1165                                         if ((*residue = strdup(p)) == NULL)
1166                                                 fatalerror("Ran out of memory.");
1167                                 } else
1168                                         *residue = NULL;
1169                         }
1170 nextline:
1171                         if (mp)
1172                                 free(mp);
1173                 }
1174                 (void) fclose(fd);
1175         } else if (ecode != NULL)
1176                 *ecode = errno;
1177         return (found);
1178 }
1179
1180 /*
1181  * Terminate login as previous user, if any, resetting state;
1182  * used when USER command is given or login fails.
1183  */
1184 static void
1185 end_login(void)
1186 {
1187 #ifdef USE_PAM
1188         int e;
1189 #endif
1190
1191         (void) seteuid(0);
1192 #ifdef  LOGIN_CAP
1193         setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
1194                        LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
1195                        LOGIN_SETENV));
1196 #endif
1197         if (logged_in && dowtmp)
1198                 ftpd_logwtmp(wtmpid, NULL, NULL);
1199         pw = NULL;
1200 #ifdef USE_PAM
1201         if (pamh) {
1202                 if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS)
1203                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1204                 if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS)
1205                         syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e));
1206                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS)
1207                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1208                 pamh = NULL;
1209         }
1210 #endif
1211         logged_in = 0;
1212         guest = 0;
1213         dochroot = 0;
1214 }
1215
1216 #ifdef USE_PAM
1217
1218 /*
1219  * the following code is stolen from imap-uw PAM authentication module and
1220  * login.c
1221  */
1222 #define COPY_STRING(s) (s ? strdup(s) : NULL)
1223
1224 struct cred_t {
1225         const char *uname;              /* user name */
1226         const char *pass;               /* password */
1227 };
1228 typedef struct cred_t cred_t;
1229
1230 static int
1231 auth_conv(int num_msg, const struct pam_message **msg,
1232           struct pam_response **resp, void *appdata)
1233 {
1234         int i;
1235         cred_t *cred = (cred_t *) appdata;
1236         struct pam_response *reply;
1237
1238         reply = calloc(num_msg, sizeof *reply);
1239         if (reply == NULL)
1240                 return PAM_BUF_ERR;
1241
1242         for (i = 0; i < num_msg; i++) {
1243                 switch (msg[i]->msg_style) {
1244                 case PAM_PROMPT_ECHO_ON:        /* assume want user name */
1245                         reply[i].resp_retcode = PAM_SUCCESS;
1246                         reply[i].resp = COPY_STRING(cred->uname);
1247                         /* PAM frees resp. */
1248                         break;
1249                 case PAM_PROMPT_ECHO_OFF:       /* assume want password */
1250                         reply[i].resp_retcode = PAM_SUCCESS;
1251                         reply[i].resp = COPY_STRING(cred->pass);
1252                         /* PAM frees resp. */
1253                         break;
1254                 case PAM_TEXT_INFO:
1255                 case PAM_ERROR_MSG:
1256                         reply[i].resp_retcode = PAM_SUCCESS;
1257                         reply[i].resp = NULL;
1258                         break;
1259                 default:                        /* unknown message style */
1260                         free(reply);
1261                         return PAM_CONV_ERR;
1262                 }
1263         }
1264
1265         *resp = reply;
1266         return PAM_SUCCESS;
1267 }
1268
1269 /*
1270  * Attempt to authenticate the user using PAM.  Returns 0 if the user is
1271  * authenticated, or 1 if not authenticated.  If some sort of PAM system
1272  * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
1273  * function returns -1.  This can be used as an indication that we should
1274  * fall back to a different authentication mechanism.
1275  */
1276 static int
1277 auth_pam(struct passwd **ppw, const char *pass)
1278 {
1279         const char *tmpl_user;
1280         const void *item;
1281         int rval;
1282         int e;
1283         cred_t auth_cred = { (*ppw)->pw_name, pass };
1284         struct pam_conv conv = { &auth_conv, &auth_cred };
1285
1286         e = pam_start("ftpd", (*ppw)->pw_name, &conv, &pamh);
1287         if (e != PAM_SUCCESS) {
1288                 /*
1289                  * In OpenPAM, it's OK to pass NULL to pam_strerror()
1290                  * if context creation has failed in the first place.
1291                  */
1292                 syslog(LOG_ERR, "pam_start: %s", pam_strerror(NULL, e));
1293                 return -1;
1294         }
1295
1296         e = pam_set_item(pamh, PAM_RHOST, remotehost);
1297         if (e != PAM_SUCCESS) {
1298                 syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
1299                         pam_strerror(pamh, e));
1300                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1301                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1302                 }
1303                 pamh = NULL;
1304                 return -1;
1305         }
1306
1307         e = pam_authenticate(pamh, 0);
1308         switch (e) {
1309         case PAM_SUCCESS:
1310                 /*
1311                  * With PAM we support the concept of a "template"
1312                  * user.  The user enters a login name which is
1313                  * authenticated by PAM, usually via a remote service
1314                  * such as RADIUS or TACACS+.  If authentication
1315                  * succeeds, a different but related "template" name
1316                  * is used for setting the credentials, shell, and
1317                  * home directory.  The name the user enters need only
1318                  * exist on the remote authentication server, but the
1319                  * template name must be present in the local password
1320                  * database.
1321                  *
1322                  * This is supported by two various mechanisms in the
1323                  * individual modules.  However, from the application's
1324                  * point of view, the template user is always passed
1325                  * back as a changed value of the PAM_USER item.
1326                  */
1327                 if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
1328                     PAM_SUCCESS) {
1329                         tmpl_user = (const char *) item;
1330                         if (strcmp((*ppw)->pw_name, tmpl_user) != 0)
1331                                 *ppw = getpwnam(tmpl_user);
1332                 } else
1333                         syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
1334                             pam_strerror(pamh, e));
1335                 rval = 0;
1336                 break;
1337
1338         case PAM_AUTH_ERR:
1339         case PAM_USER_UNKNOWN:
1340         case PAM_MAXTRIES:
1341                 rval = 1;
1342                 break;
1343
1344         default:
1345                 syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
1346                 rval = -1;
1347                 break;
1348         }
1349
1350         if (rval == 0) {
1351                 e = pam_acct_mgmt(pamh, 0);
1352                 if (e != PAM_SUCCESS) {
1353                         syslog(LOG_ERR, "pam_acct_mgmt: %s",
1354                                                 pam_strerror(pamh, e));
1355                         rval = 1;
1356                 }
1357         }
1358
1359         if (rval != 0) {
1360                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1361                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1362                 }
1363                 pamh = NULL;
1364         }
1365         return rval;
1366 }
1367
1368 #endif /* USE_PAM */
1369
1370 void
1371 pass(char *passwd)
1372 {
1373         int rval, ecode;
1374         FILE *fd;
1375 #ifdef  LOGIN_CAP
1376         login_cap_t *lc = NULL;
1377 #endif
1378 #ifdef USE_PAM
1379         int e;
1380 #endif
1381         char *residue = NULL;
1382         char *xpasswd;
1383
1384         if (logged_in || askpasswd == 0) {
1385                 reply(503, "Login with USER first.");
1386                 return;
1387         }
1388         askpasswd = 0;
1389         if (!guest) {           /* "ftp" is only account allowed no password */
1390                 if (pw == NULL) {
1391                         rval = 1;       /* failure below */
1392                         goto skip;
1393                 }
1394 #ifdef USE_PAM
1395                 rval = auth_pam(&pw, passwd);
1396                 if (rval >= 0) {
1397                         opieunlock();
1398                         goto skip;
1399                 }
1400 #endif
1401                 if (opieverify(&opiedata, passwd) == 0)
1402                         xpasswd = pw->pw_passwd;
1403                 else if (pwok) {
1404                         xpasswd = crypt(passwd, pw->pw_passwd);
1405                         if (passwd[0] == '\0' && pw->pw_passwd[0] != '\0')
1406                                 xpasswd = ":";
1407                 } else {
1408                         rval = 1;
1409                         goto skip;
1410                 }
1411                 rval = strcmp(pw->pw_passwd, xpasswd);
1412                 if (pw->pw_expire && time(NULL) >= pw->pw_expire)
1413                         rval = 1;       /* failure */
1414 skip:
1415                 /*
1416                  * If rval == 1, the user failed the authentication check
1417                  * above.  If rval == 0, either PAM or local authentication
1418                  * succeeded.
1419                  */
1420                 if (rval) {
1421                         reply(530, "Login incorrect.");
1422                         if (logging) {
1423                                 syslog(LOG_NOTICE,
1424                                     "FTP LOGIN FAILED FROM %s",
1425                                     remotehost);
1426                                 syslog(LOG_AUTHPRIV | LOG_NOTICE,
1427                                     "FTP LOGIN FAILED FROM %s, %s",
1428                                     remotehost, curname);
1429                         }
1430                         pw = NULL;
1431                         if (login_attempts++ >= 5) {
1432                                 syslog(LOG_NOTICE,
1433                                     "repeated login failures from %s",
1434                                     remotehost);
1435                                 exit(0);
1436                         }
1437                         return;
1438                 }
1439         }
1440         login_attempts = 0;             /* this time successful */
1441         if (setegid(pw->pw_gid) < 0) {
1442                 reply(550, "Can't set gid.");
1443                 return;
1444         }
1445         /* May be overridden by login.conf */
1446         (void) umask(defumask);
1447 #ifdef  LOGIN_CAP
1448         if ((lc = login_getpwclass(pw)) != NULL) {
1449                 char    remote_ip[NI_MAXHOST];
1450
1451                 if (getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1452                         remote_ip, sizeof(remote_ip) - 1, NULL, 0,
1453                         NI_NUMERICHOST))
1454                                 *remote_ip = 0;
1455                 remote_ip[sizeof(remote_ip) - 1] = 0;
1456                 if (!auth_hostok(lc, remotehost, remote_ip)) {
1457                         syslog(LOG_INFO|LOG_AUTH,
1458                             "FTP LOGIN FAILED (HOST) as %s: permission denied.",
1459                             pw->pw_name);
1460                         reply(530, "Permission denied.");
1461                         pw = NULL;
1462                         return;
1463                 }
1464                 if (!auth_timeok(lc, time(NULL))) {
1465                         reply(530, "Login not available right now.");
1466                         pw = NULL;
1467                         return;
1468                 }
1469         }
1470         setusercontext(lc, pw, 0, LOGIN_SETALL &
1471                        ~(LOGIN_SETRESOURCES | LOGIN_SETUSER | LOGIN_SETPATH | LOGIN_SETENV));
1472 #else
1473         setlogin(pw->pw_name);
1474         (void) initgroups(pw->pw_name, pw->pw_gid);
1475 #endif
1476
1477 #ifdef USE_PAM
1478         if (pamh) {
1479                 if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
1480                         syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, e));
1481                 } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
1482                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1483                 }
1484         }
1485 #endif
1486
1487         dochroot =
1488                 checkuser(_PATH_FTPCHROOT, pw->pw_name, 1, &residue, &ecode)
1489 #ifdef  LOGIN_CAP       /* Allow login.conf configuration as well */
1490                 || login_getcapbool(lc, "ftp-chroot", 0)
1491 #endif
1492         ;
1493         /*
1494          * It is possible that checkuser() failed to open the chroot file.
1495          * If this is the case, report that logins are un-available, since we
1496          * have no way of checking whether or not the user should be chrooted.
1497          * We ignore ENOENT since it is not required that this file be present.
1498          */
1499         if (ecode != 0 && ecode != ENOENT) {
1500                 reply(530, "Login not available right now.");
1501                 return;
1502         }
1503         chrootdir = NULL;
1504
1505         /* Disable wtmp logging when chrooting. */
1506         if (dochroot || guest)
1507                 dowtmp = 0;
1508         if (dowtmp)
1509                 ftpd_logwtmp(wtmpid, pw->pw_name,
1510                     (struct sockaddr *)&his_addr);
1511         logged_in = 1;
1512
1513 #ifdef  LOGIN_CAP
1514         setusercontext(lc, pw, 0, LOGIN_SETRESOURCES);
1515 #endif
1516
1517         if (guest && stats && statfd < 0)
1518 #ifdef VIRTUAL_HOSTING
1519                 statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1520 #else
1521                 statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1522 #endif
1523                 if (statfd < 0)
1524                         stats = 0;
1525
1526         /*
1527          * For a chrooted local user,
1528          * a) see whether ftpchroot(5) specifies a chroot directory,
1529          * b) extract the directory pathname from the line,
1530          * c) expand it to the absolute pathname if necessary.
1531          */
1532         if (dochroot && residue &&
1533             (chrootdir = strtok(residue, " \t")) != NULL) {
1534                 if (chrootdir[0] != '/')
1535                         asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1536                 else
1537                         chrootdir = strdup(chrootdir); /* make it permanent */
1538                 if (chrootdir == NULL)
1539                         fatalerror("Ran out of memory.");
1540         }
1541         if (guest || dochroot) {
1542                 /*
1543                  * If no chroot directory set yet, use the login directory.
1544                  * Copy it so it can be modified while pw->pw_dir stays intact.
1545                  */
1546                 if (chrootdir == NULL &&
1547                     (chrootdir = strdup(pw->pw_dir)) == NULL)
1548                         fatalerror("Ran out of memory.");
1549                 /*
1550                  * Check for the "/chroot/./home" syntax,
1551                  * separate the chroot and home directory pathnames.
1552                  */
1553                 if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1554                         *(homedir++) = '\0';    /* wipe '/' */
1555                         homedir++;              /* skip '.' */
1556                 } else {
1557                         /*
1558                          * We MUST do a chdir() after the chroot. Otherwise
1559                          * the old current directory will be accessible as "."
1560                          * outside the new root!
1561                          */
1562                         homedir = "/";
1563                 }
1564                 /*
1565                  * Finally, do chroot()
1566                  */
1567                 if (chroot(chrootdir) < 0) {
1568                         reply(550, "Can't change root.");
1569                         goto bad;
1570                 }
1571                 __FreeBSD_libc_enter_restricted_mode();
1572         } else  /* real user w/o chroot */
1573                 homedir = pw->pw_dir;
1574         /*
1575          * Set euid *before* doing chdir() so
1576          * a) the user won't be carried to a directory that he couldn't reach
1577          *    on his own due to no permission to upper path components,
1578          * b) NFS mounted homedirs w/restrictive permissions will be accessible
1579          *    (uid 0 has no root power over NFS if not mapped explicitly.)
1580          */
1581         if (seteuid(pw->pw_uid) < 0) {
1582                 reply(550, "Can't set uid.");
1583                 goto bad;
1584         }
1585         if (chdir(homedir) < 0) {
1586                 if (guest || dochroot) {
1587                         reply(550, "Can't change to base directory.");
1588                         goto bad;
1589                 } else {
1590                         if (chdir("/") < 0) {
1591                                 reply(550, "Root is inaccessible.");
1592                                 goto bad;
1593                         }
1594                         lreply(230, "No directory! Logging in with home=/.");
1595                 }
1596         }
1597
1598         /*
1599          * Display a login message, if it exists.
1600          * N.B. reply(230,) must follow the message.
1601          */
1602 #ifdef VIRTUAL_HOSTING
1603         fd = fopen(thishost->loginmsg, "r");
1604 #else
1605         fd = fopen(_PATH_FTPLOGINMESG, "r");
1606 #endif
1607         if (fd != NULL) {
1608                 char *cp, line[LINE_MAX];
1609
1610                 while (fgets(line, sizeof(line), fd) != NULL) {
1611                         if ((cp = strchr(line, '\n')) != NULL)
1612                                 *cp = '\0';
1613                         lreply(230, "%s", line);
1614                 }
1615                 (void) fflush(stdout);
1616                 (void) fclose(fd);
1617         }
1618         if (guest) {
1619                 if (ident != NULL)
1620                         free(ident);
1621                 ident = strdup(passwd);
1622                 if (ident == NULL)
1623                         fatalerror("Ran out of memory.");
1624
1625                 reply(230, "Guest login ok, access restrictions apply.");
1626 #ifdef SETPROCTITLE
1627 #ifdef VIRTUAL_HOSTING
1628                 if (thishost != firsthost)
1629                         snprintf(proctitle, sizeof(proctitle),
1630                                  "%s: anonymous(%s)/%s", remotehost, hostname,
1631                                  passwd);
1632                 else
1633 #endif
1634                         snprintf(proctitle, sizeof(proctitle),
1635                                  "%s: anonymous/%s", remotehost, passwd);
1636                 setproctitle("%s", proctitle);
1637 #endif /* SETPROCTITLE */
1638                 if (logging)
1639                         syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1640                             remotehost, passwd);
1641         } else {
1642                 if (dochroot)
1643                         reply(230, "User %s logged in, "
1644                                    "access restrictions apply.", pw->pw_name);
1645                 else
1646                         reply(230, "User %s logged in.", pw->pw_name);
1647
1648 #ifdef SETPROCTITLE
1649                 snprintf(proctitle, sizeof(proctitle),
1650                          "%s: user/%s", remotehost, pw->pw_name);
1651                 setproctitle("%s", proctitle);
1652 #endif /* SETPROCTITLE */
1653                 if (logging)
1654                         syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1655                             remotehost, pw->pw_name);
1656         }
1657         if (logging && (guest || dochroot))
1658                 syslog(LOG_INFO, "session root changed to %s", chrootdir);
1659 #ifdef  LOGIN_CAP
1660         login_close(lc);
1661 #endif
1662         if (residue)
1663                 free(residue);
1664         return;
1665 bad:
1666         /* Forget all about it... */
1667 #ifdef  LOGIN_CAP
1668         login_close(lc);
1669 #endif
1670         if (residue)
1671                 free(residue);
1672         end_login();
1673 }
1674
1675 void
1676 retrieve(char *cmd, char *name)
1677 {
1678         FILE *fin, *dout;
1679         struct stat st;
1680         int (*closefunc)(FILE *);
1681         time_t start;
1682         char line[BUFSIZ];
1683
1684         if (cmd == 0) {
1685                 fin = fopen(name, "r"), closefunc = fclose;
1686                 st.st_size = 0;
1687         } else {
1688                 (void) snprintf(line, sizeof(line), cmd, name);
1689                 name = line;
1690                 fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1691                 st.st_size = -1;
1692                 st.st_blksize = BUFSIZ;
1693         }
1694         if (fin == NULL) {
1695                 if (errno != 0) {
1696                         perror_reply(550, name);
1697                         if (cmd == 0) {
1698                                 LOGCMD("get", name);
1699                         }
1700                 }
1701                 return;
1702         }
1703         byte_count = -1;
1704         if (cmd == 0) {
1705                 if (fstat(fileno(fin), &st) < 0) {
1706                         perror_reply(550, name);
1707                         goto done;
1708                 }
1709                 if (!S_ISREG(st.st_mode)) {
1710                         /*
1711                          * Never sending a raw directory is a workaround
1712                          * for buggy clients that will attempt to RETR
1713                          * a directory before listing it, e.g., Mozilla.
1714                          * Preventing a guest from getting irregular files
1715                          * is a simple security measure.
1716                          */
1717                         if (S_ISDIR(st.st_mode) || guest) {
1718                                 reply(550, "%s: not a plain file.", name);
1719                                 goto done;
1720                         }
1721                         st.st_size = -1;
1722                         /* st.st_blksize is set for all descriptor types */
1723                 }
1724         }
1725         if (restart_point) {
1726                 if (type == TYPE_A) {
1727                         off_t i, n;
1728                         int c;
1729
1730                         n = restart_point;
1731                         i = 0;
1732                         while (i++ < n) {
1733                                 if ((c=getc(fin)) == EOF) {
1734                                         perror_reply(550, name);
1735                                         goto done;
1736                                 }
1737                                 if (c == '\n')
1738                                         i++;
1739                         }
1740                 } else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1741                         perror_reply(550, name);
1742                         goto done;
1743                 }
1744         }
1745         dout = dataconn(name, st.st_size, "w");
1746         if (dout == NULL)
1747                 goto done;
1748         time(&start);
1749         send_data(fin, dout, st.st_blksize, st.st_size,
1750                   restart_point == 0 && cmd == 0 && S_ISREG(st.st_mode));
1751         if (cmd == 0 && guest && stats && byte_count > 0)
1752                 logxfer(name, byte_count, start);
1753         (void) fclose(dout);
1754         data = -1;
1755         pdata = -1;
1756 done:
1757         if (cmd == 0)
1758                 LOGBYTES("get", name, byte_count);
1759         (*closefunc)(fin);
1760 }
1761
1762 void
1763 store(char *name, char *mode, int unique)
1764 {
1765         int fd;
1766         FILE *fout, *din;
1767         int (*closefunc)(FILE *);
1768
1769         if (*mode == 'a') {             /* APPE */
1770                 if (unique) {
1771                         /* Programming error */
1772                         syslog(LOG_ERR, "Internal: unique flag to APPE");
1773                         unique = 0;
1774                 }
1775                 if (guest && noguestmod) {
1776                         reply(550, "Appending to existing file denied.");
1777                         goto err;
1778                 }
1779                 restart_point = 0;      /* not affected by preceding REST */
1780         }
1781         if (unique)                     /* STOU overrides REST */
1782                 restart_point = 0;
1783         if (guest && noguestmod) {
1784                 if (restart_point) {    /* guest STOR w/REST */
1785                         reply(550, "Modifying existing file denied.");
1786                         goto err;
1787                 } else                  /* treat guest STOR as STOU */
1788                         unique = 1;
1789         }
1790
1791         if (restart_point)
1792                 mode = "r+";    /* so ASCII manual seek can work */
1793         if (unique) {
1794                 if ((fd = guniquefd(name, &name)) < 0)
1795                         goto err;
1796                 fout = fdopen(fd, mode);
1797         } else
1798                 fout = fopen(name, mode);
1799         closefunc = fclose;
1800         if (fout == NULL) {
1801                 perror_reply(553, name);
1802                 goto err;
1803         }
1804         byte_count = -1;
1805         if (restart_point) {
1806                 if (type == TYPE_A) {
1807                         off_t i, n;
1808                         int c;
1809
1810                         n = restart_point;
1811                         i = 0;
1812                         while (i++ < n) {
1813                                 if ((c=getc(fout)) == EOF) {
1814                                         perror_reply(550, name);
1815                                         goto done;
1816                                 }
1817                                 if (c == '\n')
1818                                         i++;
1819                         }
1820                         /*
1821                          * We must do this seek to "current" position
1822                          * because we are changing from reading to
1823                          * writing.
1824                          */
1825                         if (fseeko(fout, 0, SEEK_CUR) < 0) {
1826                                 perror_reply(550, name);
1827                                 goto done;
1828                         }
1829                 } else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1830                         perror_reply(550, name);
1831                         goto done;
1832                 }
1833         }
1834         din = dataconn(name, -1, "r");
1835         if (din == NULL)
1836                 goto done;
1837         if (receive_data(din, fout) == 0) {
1838                 if (unique)
1839                         reply(226, "Transfer complete (unique file name:%s).",
1840                             name);
1841                 else
1842                         reply(226, "Transfer complete.");
1843         }
1844         (void) fclose(din);
1845         data = -1;
1846         pdata = -1;
1847 done:
1848         LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1849         (*closefunc)(fout);
1850         return;
1851 err:
1852         LOGCMD(*mode == 'a' ? "append" : "put" , name);
1853         return;
1854 }
1855
1856 static FILE *
1857 getdatasock(char *mode)
1858 {
1859         int on = 1, s, t, tries;
1860
1861         if (data >= 0)
1862                 return (fdopen(data, mode));
1863
1864         s = socket(data_dest.su_family, SOCK_STREAM, 0);
1865         if (s < 0)
1866                 goto bad;
1867         if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1868                 syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1869         /* anchor socket to avoid multi-homing problems */
1870         data_source = ctrl_addr;
1871         data_source.su_port = htons(dataport);
1872         (void) seteuid(0);
1873         for (tries = 1; ; tries++) {
1874                 /*
1875                  * We should loop here since it's possible that
1876                  * another ftpd instance has passed this point and is
1877                  * trying to open a data connection in active mode now.
1878                  * Until the other connection is opened, we'll be getting
1879                  * EADDRINUSE because no SOCK_STREAM sockets in the system
1880                  * can share both local and remote addresses, localIP:20
1881                  * and *:* in this case.
1882                  */
1883                 if (bind(s, (struct sockaddr *)&data_source,
1884                     data_source.su_len) >= 0)
1885                         break;
1886                 if (errno != EADDRINUSE || tries > 10)
1887                         goto bad;
1888                 sleep(tries);
1889         }
1890         (void) seteuid(pw->pw_uid);
1891 #ifdef IP_TOS
1892         if (data_source.su_family == AF_INET)
1893       {
1894         on = IPTOS_THROUGHPUT;
1895         if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1896                 syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1897       }
1898 #endif
1899 #ifdef TCP_NOPUSH
1900         /*
1901          * Turn off push flag to keep sender TCP from sending short packets
1902          * at the boundaries of each write().
1903          */
1904         on = 1;
1905         if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1906                 syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1907 #endif
1908         return (fdopen(s, mode));
1909 bad:
1910         /* Return the real value of errno (close may change it) */
1911         t = errno;
1912         (void) seteuid(pw->pw_uid);
1913         (void) close(s);
1914         errno = t;
1915         return (NULL);
1916 }
1917
1918 static FILE *
1919 dataconn(char *name, off_t size, char *mode)
1920 {
1921         char sizebuf[32];
1922         FILE *file;
1923         int retry = 0, tos, conerrno;
1924
1925         file_size = size;
1926         byte_count = 0;
1927         if (size != -1)
1928                 (void) snprintf(sizebuf, sizeof(sizebuf),
1929                                 " (%jd bytes)", (intmax_t)size);
1930         else
1931                 *sizebuf = '\0';
1932         if (pdata >= 0) {
1933                 union sockunion from;
1934                 socklen_t fromlen = ctrl_addr.su_len;
1935                 int flags, s;
1936                 struct timeval timeout;
1937                 fd_set set;
1938
1939                 FD_ZERO(&set);
1940                 FD_SET(pdata, &set);
1941
1942                 timeout.tv_usec = 0;
1943                 timeout.tv_sec = 120;
1944
1945                 /*
1946                  * Granted a socket is in the blocking I/O mode,
1947                  * accept() will block after a successful select()
1948                  * if the selected connection dies in between.
1949                  * Therefore set the non-blocking I/O flag here.
1950                  */
1951                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1952                     fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1953                         goto pdata_err;
1954                 if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1955                     (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1956                         goto pdata_err;
1957                 (void) close(pdata);
1958                 pdata = s;
1959                 /*
1960                  * Unset the inherited non-blocking I/O flag
1961                  * on the child socket so stdio can work on it.
1962                  */
1963                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1964                     fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1965                         goto pdata_err;
1966 #ifdef IP_TOS
1967                 if (from.su_family == AF_INET)
1968               {
1969                 tos = IPTOS_THROUGHPUT;
1970                 if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1971                         syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1972               }
1973 #endif
1974                 reply(150, "Opening %s mode data connection for '%s'%s.",
1975                      type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1976                 return (fdopen(pdata, mode));
1977 pdata_err:
1978                 reply(425, "Can't open data connection.");
1979                 (void) close(pdata);
1980                 pdata = -1;
1981                 return (NULL);
1982         }
1983         if (data >= 0) {
1984                 reply(125, "Using existing data connection for '%s'%s.",
1985                     name, sizebuf);
1986                 usedefault = 1;
1987                 return (fdopen(data, mode));
1988         }
1989         if (usedefault)
1990                 data_dest = his_addr;
1991         usedefault = 1;
1992         do {
1993                 file = getdatasock(mode);
1994                 if (file == NULL) {
1995                         char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
1996
1997                         if (getnameinfo((struct sockaddr *)&data_source,
1998                                 data_source.su_len,
1999                                 hostbuf, sizeof(hostbuf) - 1,
2000                                 portbuf, sizeof(portbuf) - 1,
2001                                 NI_NUMERICHOST|NI_NUMERICSERV))
2002                                         *hostbuf = *portbuf = 0;
2003                         hostbuf[sizeof(hostbuf) - 1] = 0;
2004                         portbuf[sizeof(portbuf) - 1] = 0;
2005                         reply(425, "Can't create data socket (%s,%s): %s.",
2006                                 hostbuf, portbuf, strerror(errno));
2007                         return (NULL);
2008                 }
2009                 data = fileno(file);
2010                 conerrno = 0;
2011                 if (connect(data, (struct sockaddr *)&data_dest,
2012                     data_dest.su_len) == 0)
2013                         break;
2014                 conerrno = errno;
2015                 (void) fclose(file);
2016                 data = -1;
2017                 if (conerrno == EADDRINUSE) {
2018                         sleep(swaitint);
2019                         retry += swaitint;
2020                 } else {
2021                         break;
2022                 }
2023         } while (retry <= swaitmax);
2024         if (conerrno != 0) {
2025                 reply(425, "Can't build data connection: %s.",
2026                            strerror(conerrno));
2027                 return (NULL);
2028         }
2029         reply(150, "Opening %s mode data connection for '%s'%s.",
2030              type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
2031         return (file);
2032 }
2033
2034 /*
2035  * A helper macro to avoid code duplication
2036  * in send_data() and receive_data().
2037  *
2038  * XXX We have to block SIGURG during putc() because BSD stdio
2039  * is unable to restart interrupted write operations and hence
2040  * the entire buffer contents will be lost as soon as a write()
2041  * call indicates EINTR to stdio.
2042  */
2043 #define FTPD_PUTC(ch, file, label)                                      \
2044         do {                                                            \
2045                 int ret;                                                \
2046                                                                         \
2047                 do {                                                    \
2048                         START_UNSAFE;                                   \
2049                         ret = putc((ch), (file));                       \
2050                         END_UNSAFE;                                     \
2051                         CHECKOOB(return (-1))                           \
2052                         else if (ferror(file))                          \
2053                                 goto label;                             \
2054                         clearerr(file);                                 \
2055                 } while (ret == EOF);                                   \
2056         } while (0)
2057
2058 /*
2059  * Tranfer the contents of "instr" to "outstr" peer using the appropriate
2060  * encapsulation of the data subject to Mode, Structure, and Type.
2061  *
2062  * NB: Form isn't handled.
2063  */
2064 static int
2065 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2066 {
2067         int c, cp, filefd, netfd;
2068         char *buf;
2069
2070         STARTXFER;
2071
2072         switch (type) {
2073
2074         case TYPE_A:
2075                 cp = EOF;
2076                 for (;;) {
2077                         c = getc(instr);
2078                         CHECKOOB(return (-1))
2079                         else if (c == EOF && ferror(instr))
2080                                 goto file_err;
2081                         if (c == EOF) {
2082                                 if (ferror(instr)) {    /* resume after OOB */
2083                                         clearerr(instr);
2084                                         continue;
2085                                 }
2086                                 if (feof(instr))        /* EOF */
2087                                         break;
2088                                 syslog(LOG_ERR, "Internal: impossible condition"
2089                                                 " on file after getc()");
2090                                 goto file_err;
2091                         }
2092                         if (c == '\n' && cp != '\r') {
2093                                 FTPD_PUTC('\r', outstr, data_err);
2094                                 byte_count++;
2095                         }
2096                         FTPD_PUTC(c, outstr, data_err);
2097                         byte_count++;
2098                         cp = c;
2099                 }
2100 #ifdef notyet   /* BSD stdio isn't ready for that */
2101                 while (fflush(outstr) == EOF) {
2102                         CHECKOOB(return (-1))
2103                         else
2104                                 goto data_err;
2105                         clearerr(outstr);
2106                 }
2107                 ENDXFER;
2108 #else
2109                 ENDXFER;
2110                 if (fflush(outstr) == EOF)
2111                         goto data_err;
2112 #endif
2113                 reply(226, "Transfer complete.");
2114                 return (0);
2115
2116         case TYPE_I:
2117         case TYPE_L:
2118                 /*
2119                  * isreg is only set if we are not doing restart and we
2120                  * are sending a regular file
2121                  */
2122                 netfd = fileno(outstr);
2123                 filefd = fileno(instr);
2124
2125                 if (isreg) {
2126                         char *msg = "Transfer complete.";
2127                         off_t cnt, offset;
2128                         int err;
2129
2130                         cnt = offset = 0;
2131
2132                         while (filesize > 0) {
2133                                 err = sendfile(filefd, netfd, offset, 0,
2134                                                NULL, &cnt, 0);
2135                                 /*
2136                                  * Calculate byte_count before OOB processing.
2137                                  * It can be used in myoob() later.
2138                                  */
2139                                 byte_count += cnt;
2140                                 offset += cnt;
2141                                 filesize -= cnt;
2142                                 CHECKOOB(return (-1))
2143                                 else if (err == -1) {
2144                                         if (errno != EINTR &&
2145                                             cnt == 0 && offset == 0)
2146                                                 goto oldway;
2147                                         goto data_err;
2148                                 }
2149                                 if (err == -1)  /* resume after OOB */
2150                                         continue;
2151                                 /*
2152                                  * We hit the EOF prematurely.
2153                                  * Perhaps the file was externally truncated.
2154                                  */
2155                                 if (cnt == 0) {
2156                                         msg = "Transfer finished due to "
2157                                               "premature end of file.";
2158                                         break;
2159                                 }
2160                         }
2161                         ENDXFER;
2162                         reply(226, "%s", msg);
2163                         return (0);
2164                 }
2165
2166 oldway:
2167                 if ((buf = malloc(blksize)) == NULL) {
2168                         ENDXFER;
2169                         reply(451, "Ran out of memory.");
2170                         return (-1);
2171                 }
2172
2173                 for (;;) {
2174                         int cnt, len;
2175                         char *bp;
2176
2177                         cnt = read(filefd, buf, blksize);
2178                         CHECKOOB(free(buf); return (-1))
2179                         else if (cnt < 0) {
2180                                 free(buf);
2181                                 goto file_err;
2182                         }
2183                         if (cnt < 0)    /* resume after OOB */
2184                                 continue;
2185                         if (cnt == 0)   /* EOF */
2186                                 break;
2187                         for (len = cnt, bp = buf; len > 0;) {
2188                                 cnt = write(netfd, bp, len);
2189                                 CHECKOOB(free(buf); return (-1))
2190                                 else if (cnt < 0) {
2191                                         free(buf);
2192                                         goto data_err;
2193                                 }
2194                                 if (cnt <= 0)
2195                                         continue;
2196                                 len -= cnt;
2197                                 bp += cnt;
2198                                 byte_count += cnt;
2199                         }
2200                 }
2201                 ENDXFER;
2202                 free(buf);
2203                 reply(226, "Transfer complete.");
2204                 return (0);
2205         default:
2206                 ENDXFER;
2207                 reply(550, "Unimplemented TYPE %d in send_data.", type);
2208                 return (-1);
2209         }
2210
2211 data_err:
2212         ENDXFER;
2213         perror_reply(426, "Data connection");
2214         return (-1);
2215
2216 file_err:
2217         ENDXFER;
2218         perror_reply(551, "Error on input file");
2219         return (-1);
2220 }
2221
2222 /*
2223  * Transfer data from peer to "outstr" using the appropriate encapulation of
2224  * the data subject to Mode, Structure, and Type.
2225  *
2226  * N.B.: Form isn't handled.
2227  */
2228 static int
2229 receive_data(FILE *instr, FILE *outstr)
2230 {
2231         int c, cp;
2232         int bare_lfs = 0;
2233
2234         STARTXFER;
2235
2236         switch (type) {
2237
2238         case TYPE_I:
2239         case TYPE_L:
2240                 for (;;) {
2241                         int cnt, len;
2242                         char *bp;
2243                         char buf[BUFSIZ];
2244
2245                         cnt = read(fileno(instr), buf, sizeof(buf));
2246                         CHECKOOB(return (-1))
2247                         else if (cnt < 0)
2248                                 goto data_err;
2249                         if (cnt < 0)    /* resume after OOB */
2250                                 continue;
2251                         if (cnt == 0)   /* EOF */
2252                                 break;
2253                         for (len = cnt, bp = buf; len > 0;) {
2254                                 cnt = write(fileno(outstr), bp, len);
2255                                 CHECKOOB(return (-1))
2256                                 else if (cnt < 0)
2257                                         goto file_err;
2258                                 if (cnt <= 0)
2259                                         continue;
2260                                 len -= cnt;
2261                                 bp += cnt;
2262                                 byte_count += cnt;
2263                         }
2264                 }
2265                 ENDXFER;
2266                 return (0);
2267
2268         case TYPE_E:
2269                 ENDXFER;
2270                 reply(553, "TYPE E not implemented.");
2271                 return (-1);
2272
2273         case TYPE_A:
2274                 cp = EOF;
2275                 for (;;) {
2276                         c = getc(instr);
2277                         CHECKOOB(return (-1))
2278                         else if (c == EOF && ferror(instr))
2279                                 goto data_err;
2280                         if (c == EOF && ferror(instr)) { /* resume after OOB */
2281                                 clearerr(instr);
2282                                 continue;
2283                         }
2284
2285                         if (cp == '\r') {
2286                                 if (c != '\n')
2287                                         FTPD_PUTC('\r', outstr, file_err);
2288                         } else
2289                                 if (c == '\n')
2290                                         bare_lfs++;
2291                         if (c == '\r') {
2292                                 byte_count++;
2293                                 cp = c;
2294                                 continue;
2295                         }
2296
2297                         /* Check for EOF here in order not to lose last \r. */
2298                         if (c == EOF) {
2299                                 if (feof(instr))        /* EOF */
2300                                         break;
2301                                 syslog(LOG_ERR, "Internal: impossible condition"
2302                                                 " on data stream after getc()");
2303                                 goto data_err;
2304                         }
2305
2306                         byte_count++;
2307                         FTPD_PUTC(c, outstr, file_err);
2308                         cp = c;
2309                 }
2310 #ifdef notyet   /* BSD stdio isn't ready for that */
2311                 while (fflush(outstr) == EOF) {
2312                         CHECKOOB(return (-1))
2313                         else
2314                                 goto file_err;
2315                         clearerr(outstr);
2316                 }
2317                 ENDXFER;
2318 #else
2319                 ENDXFER;
2320                 if (fflush(outstr) == EOF)
2321                         goto file_err;
2322 #endif
2323                 if (bare_lfs) {
2324                         lreply(226,
2325                 "WARNING! %d bare linefeeds received in ASCII mode.",
2326                             bare_lfs);
2327                 (void)printf("   File may not have transferred correctly.\r\n");
2328                 }
2329                 return (0);
2330         default:
2331                 ENDXFER;
2332                 reply(550, "Unimplemented TYPE %d in receive_data.", type);
2333                 return (-1);
2334         }
2335
2336 data_err:
2337         ENDXFER;
2338         perror_reply(426, "Data connection");
2339         return (-1);
2340
2341 file_err:
2342         ENDXFER;
2343         perror_reply(452, "Error writing to file");
2344         return (-1);
2345 }
2346
2347 void
2348 statfilecmd(char *filename)
2349 {
2350         FILE *fin;
2351         int atstart;
2352         int c, code;
2353         char line[LINE_MAX];
2354         struct stat st;
2355
2356         code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2357         (void)snprintf(line, sizeof(line), _PATH_LS " -lgA %s", filename);
2358         fin = ftpd_popen(line, "r");
2359         if (fin == NULL) {
2360                 perror_reply(551, filename);
2361                 return;
2362         }
2363         lreply(code, "Status of %s:", filename);
2364         atstart = 1;
2365         while ((c = getc(fin)) != EOF) {
2366                 if (c == '\n') {
2367                         if (ferror(stdout)){
2368                                 perror_reply(421, "Control connection");
2369                                 (void) ftpd_pclose(fin);
2370                                 dologout(1);
2371                                 /* NOTREACHED */
2372                         }
2373                         if (ferror(fin)) {
2374                                 perror_reply(551, filename);
2375                                 (void) ftpd_pclose(fin);
2376                                 return;
2377                         }
2378                         (void) putc('\r', stdout);
2379                 }
2380                 /*
2381                  * RFC 959 says neutral text should be prepended before
2382                  * a leading 3-digit number followed by whitespace, but
2383                  * many ftp clients can be confused by any leading digits,
2384                  * as a matter of fact.
2385                  */
2386                 if (atstart && isdigit(c))
2387                         (void) putc(' ', stdout);
2388                 (void) putc(c, stdout);
2389                 atstart = (c == '\n');
2390         }
2391         (void) ftpd_pclose(fin);
2392         reply(code, "End of status.");
2393 }
2394
2395 void
2396 statcmd(void)
2397 {
2398         union sockunion *su;
2399         u_char *a, *p;
2400         char hname[NI_MAXHOST];
2401         int ispassive;
2402
2403         if (hostinfo) {
2404                 lreply(211, "%s FTP server status:", hostname);
2405                 printf("     %s\r\n", version);
2406         } else
2407                 lreply(211, "FTP server status:");
2408         printf("     Connected to %s", remotehost);
2409         if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2410                          hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2411                 hname[sizeof(hname) - 1] = 0;
2412                 if (strcmp(hname, remotehost) != 0)
2413                         printf(" (%s)", hname);
2414         }
2415         printf("\r\n");
2416         if (logged_in) {
2417                 if (guest)
2418                         printf("     Logged in anonymously\r\n");
2419                 else
2420                         printf("     Logged in as %s\r\n", pw->pw_name);
2421         } else if (askpasswd)
2422                 printf("     Waiting for password\r\n");
2423         else
2424                 printf("     Waiting for user name\r\n");
2425         printf("     TYPE: %s", typenames[type]);
2426         if (type == TYPE_A || type == TYPE_E)
2427                 printf(", FORM: %s", formnames[form]);
2428         if (type == TYPE_L)
2429 #if CHAR_BIT == 8
2430                 printf(" %d", CHAR_BIT);
2431 #else
2432                 printf(" %d", bytesize);        /* need definition! */
2433 #endif
2434         printf("; STRUcture: %s; transfer MODE: %s\r\n",
2435             strunames[stru], modenames[mode]);
2436         if (data != -1)
2437                 printf("     Data connection open\r\n");
2438         else if (pdata != -1) {
2439                 ispassive = 1;
2440                 su = &pasv_addr;
2441                 goto printaddr;
2442         } else if (usedefault == 0) {
2443                 ispassive = 0;
2444                 su = &data_dest;
2445 printaddr:
2446 #define UC(b) (((int) b) & 0xff)
2447                 if (epsvall) {
2448                         printf("     EPSV only mode (EPSV ALL)\r\n");
2449                         goto epsvonly;
2450                 }
2451
2452                 /* PORT/PASV */
2453                 if (su->su_family == AF_INET) {
2454                         a = (u_char *) &su->su_sin.sin_addr;
2455                         p = (u_char *) &su->su_sin.sin_port;
2456                         printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2457                                 ispassive ? "PASV" : "PORT",
2458                                 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2459                                 UC(p[0]), UC(p[1]));
2460                 }
2461
2462                 /* LPRT/LPSV */
2463             {
2464                 int alen, af, i;
2465
2466                 switch (su->su_family) {
2467                 case AF_INET:
2468                         a = (u_char *) &su->su_sin.sin_addr;
2469                         p = (u_char *) &su->su_sin.sin_port;
2470                         alen = sizeof(su->su_sin.sin_addr);
2471                         af = 4;
2472                         break;
2473                 case AF_INET6:
2474                         a = (u_char *) &su->su_sin6.sin6_addr;
2475                         p = (u_char *) &su->su_sin6.sin6_port;
2476                         alen = sizeof(su->su_sin6.sin6_addr);
2477                         af = 6;
2478                         break;
2479                 default:
2480                         af = 0;
2481                         break;
2482                 }
2483                 if (af) {
2484                         printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2485                                 af, alen);
2486                         for (i = 0; i < alen; i++)
2487                                 printf("%d,", UC(a[i]));
2488                         printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2489                 }
2490             }
2491
2492 epsvonly:;
2493                 /* EPRT/EPSV */
2494             {
2495                 int af;
2496
2497                 switch (su->su_family) {
2498                 case AF_INET:
2499                         af = 1;
2500                         break;
2501                 case AF_INET6:
2502                         af = 2;
2503                         break;
2504                 default:
2505                         af = 0;
2506                         break;
2507                 }
2508                 if (af) {
2509                         union sockunion tmp;
2510
2511                         tmp = *su;
2512                         if (tmp.su_family == AF_INET6)
2513                                 tmp.su_sin6.sin6_scope_id = 0;
2514                         if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2515                                         hname, sizeof(hname) - 1, NULL, 0,
2516                                         NI_NUMERICHOST)) {
2517                                 hname[sizeof(hname) - 1] = 0;
2518                                 printf("     %s |%d|%s|%d|\r\n",
2519                                         ispassive ? "EPSV" : "EPRT",
2520                                         af, hname, htons(tmp.su_port));
2521                         }
2522                 }
2523             }
2524 #undef UC
2525         } else
2526                 printf("     No data connection\r\n");
2527         reply(211, "End of status.");
2528 }
2529
2530 void
2531 fatalerror(char *s)
2532 {
2533
2534         reply(451, "Error in server: %s", s);
2535         reply(221, "Closing connection due to server error.");
2536         dologout(0);
2537         /* NOTREACHED */
2538 }
2539
2540 void
2541 reply(int n, const char *fmt, ...)
2542 {
2543         va_list ap;
2544
2545         (void)printf("%d ", n);
2546         va_start(ap, fmt);
2547         (void)vprintf(fmt, ap);
2548         va_end(ap);
2549         (void)printf("\r\n");
2550         (void)fflush(stdout);
2551         if (ftpdebug) {
2552                 syslog(LOG_DEBUG, "<--- %d ", n);
2553                 va_start(ap, fmt);
2554                 vsyslog(LOG_DEBUG, fmt, ap);
2555                 va_end(ap);
2556         }
2557 }
2558
2559 void
2560 lreply(int n, const char *fmt, ...)
2561 {
2562         va_list ap;
2563
2564         (void)printf("%d- ", n);
2565         va_start(ap, fmt);
2566         (void)vprintf(fmt, ap);
2567         va_end(ap);
2568         (void)printf("\r\n");
2569         (void)fflush(stdout);
2570         if (ftpdebug) {
2571                 syslog(LOG_DEBUG, "<--- %d- ", n);
2572                 va_start(ap, fmt);
2573                 vsyslog(LOG_DEBUG, fmt, ap);
2574                 va_end(ap);
2575         }
2576 }
2577
2578 static void
2579 ack(char *s)
2580 {
2581
2582         reply(250, "%s command successful.", s);
2583 }
2584
2585 void
2586 nack(char *s)
2587 {
2588
2589         reply(502, "%s command not implemented.", s);
2590 }
2591
2592 /* ARGSUSED */
2593 void
2594 yyerror(char *s)
2595 {
2596         char *cp;
2597
2598         if ((cp = strchr(cbuf,'\n')))
2599                 *cp = '\0';
2600         reply(500, "%s: command not understood.", cbuf);
2601 }
2602
2603 void
2604 delete(char *name)
2605 {
2606         struct stat st;
2607
2608         LOGCMD("delete", name);
2609         if (lstat(name, &st) < 0) {
2610                 perror_reply(550, name);
2611                 return;
2612         }
2613         if (S_ISDIR(st.st_mode)) {
2614                 if (rmdir(name) < 0) {
2615                         perror_reply(550, name);
2616                         return;
2617                 }
2618                 goto done;
2619         }
2620         if (guest && noguestmod) {
2621                 reply(550, "Operation not permitted.");
2622                 return;
2623         }
2624         if (unlink(name) < 0) {
2625                 perror_reply(550, name);
2626                 return;
2627         }
2628 done:
2629         ack("DELE");
2630 }
2631
2632 void
2633 cwd(char *path)
2634 {
2635
2636         if (chdir(path) < 0)
2637                 perror_reply(550, path);
2638         else
2639                 ack("CWD");
2640 }
2641
2642 void
2643 makedir(char *name)
2644 {
2645         char *s;
2646
2647         LOGCMD("mkdir", name);
2648         if (guest && noguestmkd)
2649                 reply(550, "Operation not permitted.");
2650         else if (mkdir(name, 0777) < 0)
2651                 perror_reply(550, name);
2652         else {
2653                 if ((s = doublequote(name)) == NULL)
2654                         fatalerror("Ran out of memory.");
2655                 reply(257, "\"%s\" directory created.", s);
2656                 free(s);
2657         }
2658 }
2659
2660 void
2661 removedir(char *name)
2662 {
2663
2664         LOGCMD("rmdir", name);
2665         if (rmdir(name) < 0)
2666                 perror_reply(550, name);
2667         else
2668                 ack("RMD");
2669 }
2670
2671 void
2672 pwd(void)
2673 {
2674         char *s, path[MAXPATHLEN + 1];
2675
2676         if (getcwd(path, sizeof(path)) == NULL)
2677                 perror_reply(550, "Get current directory");
2678         else {
2679                 if ((s = doublequote(path)) == NULL)
2680                         fatalerror("Ran out of memory.");
2681                 reply(257, "\"%s\" is current directory.", s);
2682                 free(s);
2683         }
2684 }
2685
2686 char *
2687 renamefrom(char *name)
2688 {
2689         struct stat st;
2690
2691         if (guest && noguestmod) {
2692                 reply(550, "Operation not permitted.");
2693                 return (NULL);
2694         }
2695         if (lstat(name, &st) < 0) {
2696                 perror_reply(550, name);
2697                 return (NULL);
2698         }
2699         reply(350, "File exists, ready for destination name.");
2700         return (name);
2701 }
2702
2703 void
2704 renamecmd(char *from, char *to)
2705 {
2706         struct stat st;
2707
2708         LOGCMD2("rename", from, to);
2709
2710         if (guest && (stat(to, &st) == 0)) {
2711                 reply(550, "%s: permission denied.", to);
2712                 return;
2713         }
2714
2715         if (rename(from, to) < 0)
2716                 perror_reply(550, "rename");
2717         else
2718                 ack("RNTO");
2719 }
2720
2721 static void
2722 dolog(struct sockaddr *who)
2723 {
2724         char who_name[NI_MAXHOST];
2725
2726         realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2727         remotehost[sizeof(remotehost) - 1] = 0;
2728         if (getnameinfo(who, who->sa_len,
2729                 who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2730                         *who_name = 0;
2731         who_name[sizeof(who_name) - 1] = 0;
2732
2733 #ifdef SETPROCTITLE
2734 #ifdef VIRTUAL_HOSTING
2735         if (thishost != firsthost)
2736                 snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2737                          remotehost, hostname);
2738         else
2739 #endif
2740                 snprintf(proctitle, sizeof(proctitle), "%s: connected",
2741                          remotehost);
2742         setproctitle("%s", proctitle);
2743 #endif /* SETPROCTITLE */
2744
2745         if (logging) {
2746 #ifdef VIRTUAL_HOSTING
2747                 if (thishost != firsthost)
2748                         syslog(LOG_INFO, "connection from %s (%s) to %s",
2749                                remotehost, who_name, hostname);
2750                 else
2751 #endif
2752                         syslog(LOG_INFO, "connection from %s (%s)",
2753                                remotehost, who_name);
2754         }
2755 }
2756
2757 /*
2758  * Record logout in wtmp file
2759  * and exit with supplied status.
2760  */
2761 void
2762 dologout(int status)
2763 {
2764
2765         if (logged_in && dowtmp) {
2766                 (void) seteuid(0);
2767 #ifdef          LOGIN_CAP
2768                 setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
2769                        LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
2770                        LOGIN_SETENV));
2771 #endif
2772                 ftpd_logwtmp(wtmpid, NULL, NULL);
2773         }
2774         /* beware of flushing buffers after a SIGPIPE */
2775         _exit(status);
2776 }
2777
2778 static void
2779 sigurg(int signo)
2780 {
2781
2782         recvurg = 1;
2783 }
2784
2785 static void
2786 maskurg(int flag)
2787 {
2788         int oerrno;
2789         sigset_t sset;
2790
2791         if (!transflag) {
2792                 syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2793                 return;
2794         }
2795         oerrno = errno;
2796         sigemptyset(&sset);
2797         sigaddset(&sset, SIGURG);
2798         sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2799         errno = oerrno;
2800 }
2801
2802 static void
2803 flagxfer(int flag)
2804 {
2805
2806         if (flag) {
2807                 if (transflag)
2808                         syslog(LOG_ERR, "Internal: flagxfer(1): "
2809                                         "transfer already under way");
2810                 transflag = 1;
2811                 maskurg(0);
2812                 recvurg = 0;
2813         } else {
2814                 if (!transflag)
2815                         syslog(LOG_ERR, "Internal: flagxfer(0): "
2816                                         "no active transfer");
2817                 maskurg(1);
2818                 transflag = 0;
2819         }
2820 }
2821
2822 /*
2823  * Returns 0 if OK to resume or -1 if abort requested.
2824  */
2825 static int
2826 myoob(void)
2827 {
2828         char *cp;
2829         int ret;
2830
2831         if (!transflag) {
2832                 syslog(LOG_ERR, "Internal: myoob() while no transfer");
2833                 return (0);
2834         }
2835         cp = tmpline;
2836         ret = getline(cp, 7, stdin);
2837         if (ret == -1) {
2838                 reply(221, "You could at least say goodbye.");
2839                 dologout(0);
2840         } else if (ret == -2) {
2841                 /* Ignore truncated command. */
2842                 return (0);
2843         }
2844         upper(cp);
2845         if (strcmp(cp, "ABOR\r\n") == 0) {
2846                 tmpline[0] = '\0';
2847                 reply(426, "Transfer aborted. Data connection closed.");
2848                 reply(226, "Abort successful.");
2849                 return (-1);
2850         }
2851         if (strcmp(cp, "STAT\r\n") == 0) {
2852                 tmpline[0] = '\0';
2853                 if (file_size != -1)
2854                         reply(213, "Status: %jd of %jd bytes transferred.",
2855                                    (intmax_t)byte_count, (intmax_t)file_size);
2856                 else
2857                         reply(213, "Status: %jd bytes transferred.",
2858                                    (intmax_t)byte_count);
2859         }
2860         return (0);
2861 }
2862
2863 /*
2864  * Note: a response of 425 is not mentioned as a possible response to
2865  *      the PASV command in RFC959. However, it has been blessed as
2866  *      a legitimate response by Jon Postel in a telephone conversation
2867  *      with Rick Adams on 25 Jan 89.
2868  */
2869 void
2870 passive(void)
2871 {
2872         socklen_t len;
2873         int on;
2874         char *p, *a;
2875
2876         if (pdata >= 0)         /* close old port if one set */
2877                 close(pdata);
2878
2879         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2880         if (pdata < 0) {
2881                 perror_reply(425, "Can't open passive connection");
2882                 return;
2883         }
2884         on = 1;
2885         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2886                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2887
2888         (void) seteuid(0);
2889
2890 #ifdef IP_PORTRANGE
2891         if (ctrl_addr.su_family == AF_INET) {
2892             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2893                                        : IP_PORTRANGE_DEFAULT;
2894
2895             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2896                             &on, sizeof(on)) < 0)
2897                     goto pasv_error;
2898         }
2899 #endif
2900 #ifdef IPV6_PORTRANGE
2901         if (ctrl_addr.su_family == AF_INET6) {
2902             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2903                                        : IPV6_PORTRANGE_DEFAULT;
2904
2905             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2906                             &on, sizeof(on)) < 0)
2907                     goto pasv_error;
2908         }
2909 #endif
2910
2911         pasv_addr = ctrl_addr;
2912         pasv_addr.su_port = 0;
2913         if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2914                 goto pasv_error;
2915
2916         (void) seteuid(pw->pw_uid);
2917
2918         len = sizeof(pasv_addr);
2919         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2920                 goto pasv_error;
2921         if (listen(pdata, 1) < 0)
2922                 goto pasv_error;
2923         if (pasv_addr.su_family == AF_INET)
2924                 a = (char *) &pasv_addr.su_sin.sin_addr;
2925         else if (pasv_addr.su_family == AF_INET6 &&
2926                  IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2927                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2928         else
2929                 goto pasv_error;
2930
2931         p = (char *) &pasv_addr.su_port;
2932
2933 #define UC(b) (((int) b) & 0xff)
2934
2935         reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2936                 UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2937         return;
2938
2939 pasv_error:
2940         (void) seteuid(pw->pw_uid);
2941         (void) close(pdata);
2942         pdata = -1;
2943         perror_reply(425, "Can't open passive connection");
2944         return;
2945 }
2946
2947 /*
2948  * Long Passive defined in RFC 1639.
2949  *     228 Entering Long Passive Mode
2950  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2951  */
2952
2953 void
2954 long_passive(char *cmd, int pf)
2955 {
2956         socklen_t len;
2957         int on;
2958         char *p, *a;
2959
2960         if (pdata >= 0)         /* close old port if one set */
2961                 close(pdata);
2962
2963         if (pf != PF_UNSPEC) {
2964                 if (ctrl_addr.su_family != pf) {
2965                         switch (ctrl_addr.su_family) {
2966                         case AF_INET:
2967                                 pf = 1;
2968                                 break;
2969                         case AF_INET6:
2970                                 pf = 2;
2971                                 break;
2972                         default:
2973                                 pf = 0;
2974                                 break;
2975                         }
2976                         /*
2977                          * XXX
2978                          * only EPRT/EPSV ready clients will understand this
2979                          */
2980                         if (strcmp(cmd, "EPSV") == 0 && pf) {
2981                                 reply(522, "Network protocol mismatch, "
2982                                         "use (%d)", pf);
2983                         } else
2984                                 reply(501, "Network protocol mismatch."); /*XXX*/
2985
2986                         return;
2987                 }
2988         }
2989
2990         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2991         if (pdata < 0) {
2992                 perror_reply(425, "Can't open passive connection");
2993                 return;
2994         }
2995         on = 1;
2996         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2997                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2998
2999         (void) seteuid(0);
3000
3001         pasv_addr = ctrl_addr;
3002         pasv_addr.su_port = 0;
3003         len = pasv_addr.su_len;
3004
3005 #ifdef IP_PORTRANGE
3006         if (ctrl_addr.su_family == AF_INET) {
3007             on = restricted_data_ports ? IP_PORTRANGE_HIGH
3008                                        : IP_PORTRANGE_DEFAULT;
3009
3010             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
3011                             &on, sizeof(on)) < 0)
3012                     goto pasv_error;
3013         }
3014 #endif
3015 #ifdef IPV6_PORTRANGE
3016         if (ctrl_addr.su_family == AF_INET6) {
3017             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
3018                                        : IPV6_PORTRANGE_DEFAULT;
3019
3020             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
3021                             &on, sizeof(on)) < 0)
3022                     goto pasv_error;
3023         }
3024 #endif
3025
3026         if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
3027                 goto pasv_error;
3028
3029         (void) seteuid(pw->pw_uid);
3030
3031         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
3032                 goto pasv_error;
3033         if (listen(pdata, 1) < 0)
3034                 goto pasv_error;
3035
3036 #define UC(b) (((int) b) & 0xff)
3037
3038         if (strcmp(cmd, "LPSV") == 0) {
3039                 p = (char *)&pasv_addr.su_port;
3040                 switch (pasv_addr.su_family) {
3041                 case AF_INET:
3042                         a = (char *) &pasv_addr.su_sin.sin_addr;
3043                 v4_reply:
3044                         reply(228,
3045 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3046                               4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3047                               2, UC(p[0]), UC(p[1]));
3048                         return;
3049                 case AF_INET6:
3050                         if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
3051                                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
3052                                 goto v4_reply;
3053                         }
3054                         a = (char *) &pasv_addr.su_sin6.sin6_addr;
3055                         reply(228,
3056 "Entering Long Passive Mode "
3057 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3058                               6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3059                               UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
3060                               UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
3061                               UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
3062                               2, UC(p[0]), UC(p[1]));
3063                         return;
3064                 }
3065         } else if (strcmp(cmd, "EPSV") == 0) {
3066                 switch (pasv_addr.su_family) {
3067                 case AF_INET:
3068                 case AF_INET6:
3069                         reply(229, "Entering Extended Passive Mode (|||%d|)",
3070                                 ntohs(pasv_addr.su_port));
3071                         return;
3072                 }
3073         } else {
3074                 /* more proper error code? */
3075         }
3076
3077 pasv_error:
3078         (void) seteuid(pw->pw_uid);
3079         (void) close(pdata);
3080         pdata = -1;
3081         perror_reply(425, "Can't open passive connection");
3082         return;
3083 }
3084
3085 /*
3086  * Generate unique name for file with basename "local"
3087  * and open the file in order to avoid possible races.
3088  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3089  * Return descriptor to the file, set "name" to its name.
3090  *
3091  * Generates failure reply on error.
3092  */
3093 static int
3094 guniquefd(char *local, char **name)
3095 {
3096         static char new[MAXPATHLEN];
3097         struct stat st;
3098         char *cp;
3099         int count;
3100         int fd;
3101
3102         cp = strrchr(local, '/');
3103         if (cp)
3104                 *cp = '\0';
3105         if (stat(cp ? local : ".", &st) < 0) {
3106                 perror_reply(553, cp ? local : ".");
3107                 return (-1);
3108         }
3109         if (cp) {
3110                 /*
3111                  * Let not overwrite dirname with counter suffix.
3112                  * -4 is for /nn\0
3113                  * In this extreme case dot won't be put in front of suffix.
3114                  */
3115                 if (strlen(local) > sizeof(new) - 4) {
3116                         reply(553, "Pathname too long.");
3117                         return (-1);
3118                 }
3119                 *cp = '/';
3120         }
3121         /* -4 is for the .nn<null> we put on the end below */
3122         (void) snprintf(new, sizeof(new) - 4, "%s", local);
3123         cp = new + strlen(new);
3124         /*
3125          * Don't generate dotfile unless requested explicitly.
3126          * This covers the case when basename gets truncated off
3127          * by buffer size.
3128          */
3129         if (cp > new && cp[-1] != '/')
3130                 *cp++ = '.';
3131         for (count = 0; count < 100; count++) {
3132                 /* At count 0 try unmodified name */
3133                 if (count)
3134                         (void)sprintf(cp, "%d", count);
3135                 if ((fd = open(count ? new : local,
3136                     O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3137                         *name = count ? new : local;
3138                         return (fd);
3139                 }
3140                 if (errno != EEXIST) {
3141                         perror_reply(553, count ? new : local);
3142                         return (-1);
3143                 }
3144         }
3145         reply(452, "Unique file name cannot be created.");
3146         return (-1);
3147 }
3148
3149 /*
3150  * Format and send reply containing system error number.
3151  */
3152 void
3153 perror_reply(int code, char *string)
3154 {
3155
3156         reply(code, "%s: %s.", string, strerror(errno));
3157 }
3158
3159 static char *onefile[] = {
3160         "",
3161         0
3162 };
3163
3164 void
3165 send_file_list(char *whichf)
3166 {
3167         struct stat st;
3168         DIR *dirp = NULL;
3169         struct dirent *dir;
3170         FILE *dout = NULL;
3171         char **dirlist, *dirname;
3172         int simple = 0;
3173         int freeglob = 0;
3174         glob_t gl;
3175
3176         if (strpbrk(whichf, "~{[*?") != NULL) {
3177                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3178
3179                 memset(&gl, 0, sizeof(gl));
3180                 gl.gl_matchc = MAXGLOBARGS;
3181                 flags |= GLOB_LIMIT;
3182                 freeglob = 1;
3183                 if (glob(whichf, flags, 0, &gl)) {
3184                         reply(550, "No matching files found.");
3185                         goto out;
3186                 } else if (gl.gl_pathc == 0) {
3187                         errno = ENOENT;
3188                         perror_reply(550, whichf);
3189                         goto out;
3190                 }
3191                 dirlist = gl.gl_pathv;
3192         } else {
3193                 onefile[0] = whichf;
3194                 dirlist = onefile;
3195                 simple = 1;
3196         }
3197
3198         while ((dirname = *dirlist++)) {
3199                 if (stat(dirname, &st) < 0) {
3200                         /*
3201                          * If user typed "ls -l", etc, and the client
3202                          * used NLST, do what the user meant.
3203                          */
3204                         if (dirname[0] == '-' && *dirlist == NULL &&
3205                             dout == NULL)
3206                                 retrieve(_PATH_LS " %s", dirname);
3207                         else
3208                                 perror_reply(550, whichf);
3209                         goto out;
3210                 }
3211
3212                 if (S_ISREG(st.st_mode)) {
3213                         if (dout == NULL) {
3214                                 dout = dataconn("file list", -1, "w");
3215                                 if (dout == NULL)
3216                                         goto out;
3217                                 STARTXFER;
3218                         }
3219                         START_UNSAFE;
3220                         fprintf(dout, "%s%s\n", dirname,
3221                                 type == TYPE_A ? "\r" : "");
3222                         END_UNSAFE;
3223                         if (ferror(dout))
3224                                 goto data_err;
3225                         byte_count += strlen(dirname) +
3226                                       (type == TYPE_A ? 2 : 1);
3227                         CHECKOOB(goto abrt);
3228                         continue;
3229                 } else if (!S_ISDIR(st.st_mode))
3230                         continue;
3231
3232                 if ((dirp = opendir(dirname)) == NULL)
3233                         continue;
3234
3235                 while ((dir = readdir(dirp)) != NULL) {
3236                         char nbuf[MAXPATHLEN];
3237
3238                         CHECKOOB(goto abrt);
3239
3240                         if (dir->d_name[0] == '.' && dir->d_namlen == 1)
3241                                 continue;
3242                         if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
3243                             dir->d_namlen == 2)
3244                                 continue;
3245
3246                         snprintf(nbuf, sizeof(nbuf),
3247                                 "%s/%s", dirname, dir->d_name);
3248
3249                         /*
3250                          * We have to do a stat to insure it's
3251                          * not a directory or special file.
3252                          */
3253                         if (simple || (stat(nbuf, &st) == 0 &&
3254                             S_ISREG(st.st_mode))) {
3255                                 if (dout == NULL) {
3256                                         dout = dataconn("file list", -1, "w");
3257                                         if (dout == NULL)
3258                                                 goto out;
3259                                         STARTXFER;
3260                                 }
3261                                 START_UNSAFE;
3262                                 if (nbuf[0] == '.' && nbuf[1] == '/')
3263                                         fprintf(dout, "%s%s\n", &nbuf[2],
3264                                                 type == TYPE_A ? "\r" : "");
3265                                 else
3266                                         fprintf(dout, "%s%s\n", nbuf,
3267                                                 type == TYPE_A ? "\r" : "");
3268                                 END_UNSAFE;
3269                                 if (ferror(dout))
3270                                         goto data_err;
3271                                 byte_count += strlen(nbuf) +
3272                                               (type == TYPE_A ? 2 : 1);
3273                                 CHECKOOB(goto abrt);
3274                         }
3275                 }
3276                 (void) closedir(dirp);
3277                 dirp = NULL;
3278         }
3279
3280         if (dout == NULL)
3281                 reply(550, "No files found.");
3282         else if (ferror(dout))
3283 data_err:       perror_reply(550, "Data connection");
3284         else
3285                 reply(226, "Transfer complete.");
3286 out:
3287         if (dout) {
3288                 ENDXFER;
3289 abrt:
3290                 (void) fclose(dout);
3291                 data = -1;
3292                 pdata = -1;
3293         }
3294         if (dirp)
3295                 (void) closedir(dirp);
3296         if (freeglob) {
3297                 freeglob = 0;
3298                 globfree(&gl);
3299         }
3300 }
3301
3302 void
3303 reapchild(int signo)
3304 {
3305         while (waitpid(-1, NULL, WNOHANG) > 0);
3306 }
3307
3308 #ifdef OLD_SETPROCTITLE
3309 /*
3310  * Clobber argv so ps will show what we're doing.  (Stolen from sendmail.)
3311  * Warning, since this is usually started from inetd.conf, it often doesn't
3312  * have much of an environment or arglist to overwrite.
3313  */
3314 void
3315 setproctitle(const char *fmt, ...)
3316 {
3317         int i;
3318         va_list ap;
3319         char *p, *bp, ch;
3320         char buf[LINE_MAX];
3321
3322         va_start(ap, fmt);
3323         (void)vsnprintf(buf, sizeof(buf), fmt, ap);
3324
3325         /* make ps print our process name */
3326         p = Argv[0];
3327         *p++ = '-';
3328
3329         i = strlen(buf);
3330         if (i > LastArgv - p - 2) {
3331                 i = LastArgv - p - 2;
3332                 buf[i] = '\0';
3333         }
3334         bp = buf;
3335         while (ch = *bp++)
3336                 if (ch != '\n' && ch != '\r')
3337                         *p++ = ch;
3338         while (p < LastArgv)
3339                 *p++ = ' ';
3340 }
3341 #endif /* OLD_SETPROCTITLE */
3342
3343 static void
3344 appendf(char **strp, char *fmt, ...)
3345 {
3346         va_list ap;
3347         char *ostr, *p;
3348
3349         va_start(ap, fmt);
3350         vasprintf(&p, fmt, ap);
3351         va_end(ap);
3352         if (p == NULL)
3353                 fatalerror("Ran out of memory.");
3354         if (*strp == NULL)
3355                 *strp = p;
3356         else {
3357                 ostr = *strp;
3358                 asprintf(strp, "%s%s", ostr, p);
3359                 if (*strp == NULL)
3360                         fatalerror("Ran out of memory.");
3361                 free(ostr);
3362         }
3363 }
3364
3365 static void
3366 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3367 {
3368         char *msg = NULL;
3369         char wd[MAXPATHLEN + 1];
3370
3371         if (logging <= 1)
3372                 return;
3373
3374         if (getcwd(wd, sizeof(wd) - 1) == NULL)
3375                 strcpy(wd, strerror(errno));
3376
3377         appendf(&msg, "%s", cmd);
3378         if (file1)
3379                 appendf(&msg, " %s", file1);
3380         if (file2)
3381                 appendf(&msg, " %s", file2);
3382         if (cnt >= 0)
3383                 appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3384         appendf(&msg, " (wd: %s", wd);
3385         if (guest || dochroot)
3386                 appendf(&msg, "; chrooted");
3387         appendf(&msg, ")");
3388         syslog(LOG_INFO, "%s", msg);
3389         free(msg);
3390 }
3391
3392 static void
3393 logxfer(char *name, off_t size, time_t start)
3394 {
3395         char buf[MAXPATHLEN + 1024];
3396         char path[MAXPATHLEN + 1];
3397         time_t now;
3398
3399         if (statfd >= 0) {
3400                 time(&now);
3401                 if (realpath(name, path) == NULL) {
3402                         syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3403                         return;
3404                 }
3405                 snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3406                         ctime(&now)+4, ident, remotehost,
3407                         path, (intmax_t)size,
3408                         (long)(now - start + (now == start)));
3409                 write(statfd, buf, strlen(buf));
3410         }
3411 }
3412
3413 static char *
3414 doublequote(char *s)
3415 {
3416         int n;
3417         char *p, *s2;
3418
3419         for (p = s, n = 0; *p; p++)
3420                 if (*p == '"')
3421                         n++;
3422
3423         if ((s2 = malloc(p - s + n + 1)) == NULL)
3424                 return (NULL);
3425
3426         for (p = s2; *s; s++, p++) {
3427                 if ((*p = *s) == '"')
3428                         *(++p) = '"';
3429         }
3430         *p = '\0';
3431
3432         return (s2);
3433 }
3434
3435 /* setup server socket for specified address family */
3436 /* if af is PF_UNSPEC more than one socket may be returned */
3437 /* the returned list is dynamically allocated, so caller needs to free it */
3438 static int *
3439 socksetup(int af, char *bindname, const char *bindport)
3440 {
3441         struct addrinfo hints, *res, *r;
3442         int error, maxs, *s, *socks;
3443         const int on = 1;
3444
3445         memset(&hints, 0, sizeof(hints));
3446         hints.ai_flags = AI_PASSIVE;
3447         hints.ai_family = af;
3448         hints.ai_socktype = SOCK_STREAM;
3449         error = getaddrinfo(bindname, bindport, &hints, &res);
3450         if (error) {
3451                 syslog(LOG_ERR, "%s", gai_strerror(error));
3452                 if (error == EAI_SYSTEM)
3453                         syslog(LOG_ERR, "%s", strerror(errno));
3454                 return NULL;
3455         }
3456
3457         /* Count max number of sockets we may open */
3458         for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3459                 ;
3460         socks = malloc((maxs + 1) * sizeof(int));
3461         if (!socks) {
3462                 freeaddrinfo(res);
3463                 syslog(LOG_ERR, "couldn't allocate memory for sockets");
3464                 return NULL;
3465         }
3466
3467         *socks = 0;   /* num of sockets counter at start of array */
3468         s = socks + 1;
3469         for (r = res; r; r = r->ai_next) {
3470                 *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3471                 if (*s < 0) {
3472                         syslog(LOG_DEBUG, "control socket: %m");
3473                         continue;
3474                 }
3475                 if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3476                     &on, sizeof(on)) < 0)
3477                         syslog(LOG_WARNING,
3478                             "control setsockopt (SO_REUSEADDR): %m");
3479                 if (r->ai_family == AF_INET6) {
3480                         if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3481                             &on, sizeof(on)) < 0)
3482                                 syslog(LOG_WARNING,
3483                                     "control setsockopt (IPV6_V6ONLY): %m");
3484                 }
3485                 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3486                         syslog(LOG_DEBUG, "control bind: %m");
3487                         close(*s);
3488                         continue;
3489                 }
3490                 (*socks)++;
3491                 s++;
3492         }
3493
3494         if (res)
3495                 freeaddrinfo(res);
3496
3497         if (*socks == 0) {
3498                 syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3499                 free(socks);
3500                 return NULL;
3501         }
3502         return(socks);
3503 }