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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if 0
  35 #ifndef lint
  36 static char copyright[] =
  37 "@(#) Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994\n\
  38         The Regents of the University of California.  All rights reserved.\n";
  39 #endif /* not lint */
  40 #endif
  41
  42 #ifndef lint
  43 #if 0
  44 static char sccsid[] = "@(#)ftpd.c      8.4 (Berkeley) 4/16/94";
  45 #endif
  46 #endif /* not lint */
  47
  48 #include <sys/cdefs.h>
  49 __FBSDID("$FreeBSD$");
  50
  51 /*
  52  * FTP server.
  53  */
  54 #include <sys/param.h>
  55 #include <sys/ioctl.h>
  56 #include <sys/mman.h>
  57 #include <sys/socket.h>
  58 #include <sys/stat.h>
  59 #include <sys/time.h>
  60 #include <sys/wait.h>
  61
  62 #include <netinet/in.h>
  63 #include <netinet/in_systm.h>
  64 #include <netinet/ip.h>
  65 #include <netinet/tcp.h>
  66
  67 #define FTP_NAMES
  68 #include <arpa/ftp.h>
  69 #include <arpa/inet.h>
  70 #include <arpa/telnet.h>
  71
  72 #include <ctype.h>
  73 #include <dirent.h>
  74 #include <err.h>
  75 #include <errno.h>
  76 #include <fcntl.h>
  77 #include <glob.h>
  78 #include <limits.h>
  79 #include <netdb.h>
  80 #include <pwd.h>
  81 #include <grp.h>
  82 #include <opie.h>
  83 #include <signal.h>
  84 #include <stdint.h>
  85 #include <stdio.h>
  86 #include <stdlib.h>
  87 #include <string.h>
  88 #include <syslog.h>
  89 #include <time.h>
  90 #include <unistd.h>
  91 #include <libutil.h>
  92 #ifdef  LOGIN_CAP
  93 #include <login_cap.h>
  94 #endif
  95
  96 #ifdef USE_PAM
  97 #include <security/pam_appl.h>
  98 #endif
  99
 100 #include "pathnames.h"
 101 #include "extern.h"
 102
 103 #include <stdarg.h>
 104
 105 static char version[] = "Version 6.00LS";
 106 #undef main
 107
 108 union sockunion ctrl_addr;
 109 union sockunion data_source;
 110 union sockunion data_dest;
 111 union sockunion his_addr;
 112 union sockunion pasv_addr;
 113
 114 int     daemon_mode;
 115 int     data;
 116 int     dataport;
 117 int     hostinfo = 1;   /* print host-specific info in messages */
 118 int     logged_in;
 119 struct  passwd *pw;
 120 char    *homedir;
 121 int     ftpdebug;
 122 int     timeout = 900;    /* timeout after 15 minutes of inactivity */
 123 int     maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
 124 int     logging;
 125 int     restricted_data_ports = 1;
 126 int     paranoid = 1;     /* be extra careful about security */
 127 int     anon_only = 0;    /* Only anonymous ftp allowed */
 128 int     assumeutf8 = 0;   /* Assume that server file names are in UTF-8 */
 129 int     guest;
 130 int     dochroot;
 131 char    *chrootdir;
 132 int     dowtmp = 1;
 133 int     stats;
 134 int     statfd = -1;
 135 int     type;
 136 int     form;
 137 int     stru;                   /* avoid C keyword */
 138 int     mode;
 139 int     usedefault = 1;         /* for data transfers */
 140 int     pdata = -1;             /* for passive mode */
 141 int     readonly = 0;           /* Server is in readonly mode.  */
 142 int     noepsv = 0;             /* EPSV command is disabled.    */
 143 int     noretr = 0;             /* RETR command is disabled.    */
 144 int     noguestretr = 0;        /* RETR command is disabled for anon users. */
 145 int     noguestmkd = 0;         /* MKD command is disabled for anon users. */
 146 int     noguestmod = 1;         /* anon users may not modify existing files. */
 147
 148 off_t   file_size;
 149 off_t   byte_count;
 150 #if !defined(CMASK) || CMASK == 0
 151 #undef CMASK
 152 #define CMASK 027
 153 #endif
 154 int     defumask = CMASK;               /* default umask value */
 155 char    tmpline[7];
 156 char    *hostname;
 157 int     epsvall = 0;
 158
 159 #ifdef VIRTUAL_HOSTING
 160 char    *ftpuser;
 161
 162 static struct ftphost {
 163         struct ftphost  *next;
 164         struct addrinfo *hostinfo;
 165         char            *hostname;
 166         char            *anonuser;
 167         char            *statfile;
 168         char            *welcome;
 169         char            *loginmsg;
 170 } *thishost, *firsthost;
 171
 172 #endif
 173 char    remotehost[NI_MAXHOST];
 174 char    *ident = NULL;
 175
 176 static char     wtmpid[20];
 177
 178 #ifdef USE_PAM
 179 static int      auth_pam(struct passwd**, const char*);
 180 pam_handle_t    *pamh = NULL;
 181 #endif
 182
 183 static struct opie      opiedata;
 184 static char             opieprompt[OPIE_CHALLENGE_MAX+1];
 185 static int              pwok;
 186
 187 char    *pid_file = NULL; /* means default location to pidfile(3) */
 188
 189 /*
 190  * Limit number of pathnames that glob can return.
 191  * A limit of 0 indicates the number of pathnames is unlimited.
 192  */
 193 #define MAXGLOBARGS     16384
 194 #
 195
 196 /*
 197  * Timeout intervals for retrying connections
 198  * to hosts that don't accept PORT cmds.  This
 199  * is a kludge, but given the problems with TCP...
 200  */
 201 #define SWAITMAX        90      /* wait at most 90 seconds */
 202 #define SWAITINT        5       /* interval between retries */
 203
 204 int     swaitmax = SWAITMAX;
 205 int     swaitint = SWAITINT;
 206
 207 #ifdef SETPROCTITLE
 208 #ifdef OLD_SETPROCTITLE
 209 char    **Argv = NULL;          /* pointer to argument vector */
 210 char    *LastArgv = NULL;       /* end of argv */
 211 #endif /* OLD_SETPROCTITLE */
 212 char    proctitle[LINE_MAX];    /* initial part of title */
 213 #endif /* SETPROCTITLE */
 214
 215 #define LOGCMD(cmd, file)               logcmd((cmd), (file), NULL, -1)
 216 #define LOGCMD2(cmd, file1, file2)      logcmd((cmd), (file1), (file2), -1)
 217 #define LOGBYTES(cmd, file, cnt)        logcmd((cmd), (file), NULL, (cnt))
 218
 219 static  volatile sig_atomic_t recvurg;
 220 static  int transflag;          /* NB: for debugging only */
 221
 222 #define STARTXFER       flagxfer(1)
 223 #define ENDXFER         flagxfer(0)
 224
 225 #define START_UNSAFE    maskurg(1)
 226 #define END_UNSAFE      maskurg(0)
 227
 228 /* It's OK to put an `else' clause after this macro. */
 229 #define CHECKOOB(action)                                                \
 230         if (recvurg) {                                                  \
 231                 recvurg = 0;                                            \
 232                 if (myoob()) {                                          \
 233                         ENDXFER;                                        \
 234                         action;                                         \
 235                 }                                                       \
 236         }
 237
 238 #ifdef VIRTUAL_HOSTING
 239 static void      inithosts(int);
 240 static void      selecthost(union sockunion *);
 241 #endif
 242 static void      ack(char *);
 243 static void      sigurg(int);
 244 static void      maskurg(int);
 245 static void      flagxfer(int);
 246 static int       myoob(void);
 247 static int       checkuser(char *, char *, int, char **, int *);
 248 static FILE     *dataconn(char *, off_t, char *);
 249 static void      dolog(struct sockaddr *);
 250 static void      end_login(void);
 251 static FILE     *getdatasock(char *);
 252 static int       guniquefd(char *, char **);
 253 static void      lostconn(int);
 254 static void      sigquit(int);
 255 static int       receive_data(FILE *, FILE *);
 256 static int       send_data(FILE *, FILE *, size_t, off_t, int);
 257 static struct passwd *
 258                  sgetpwnam(char *);
 259 static char     *sgetsave(char *);
 260 static void      reapchild(int);
 261 static void      appendf(char **, char *, ...) __printflike(2, 3);
 262 static void      logcmd(char *, char *, char *, off_t);
 263 static void      logxfer(char *, off_t, time_t);
 264 static char     *doublequote(char *);
 265 static int      *socksetup(int, char *, const char *);
 266
 267 int
 268 main(int argc, char *argv[], char **envp)
 269 {
 270         socklen_t addrlen;
 271         int ch, on = 1, tos;
 272         char *cp, line[LINE_MAX];
 273         FILE *fd;
 274         char    *bindname = NULL;
 275         const char *bindport = "ftp";
 276         int     family = AF_UNSPEC;
 277         struct sigaction sa;
 278
 279         tzset();                /* in case no timezone database in ~ftp */
 280         sigemptyset(&sa.sa_mask);
 281         sa.sa_flags = SA_RESTART;
 282
 283 #ifdef OLD_SETPROCTITLE
 284         /*
 285          *  Save start and extent of argv for setproctitle.
 286          */
 287         Argv = argv;
 288         while (*envp)
 289                 envp++;
 290         LastArgv = envp[-1] + strlen(envp[-1]);
 291 #endif /* OLD_SETPROCTITLE */
 292
 293         /*
 294          * Prevent diagnostic messages from appearing on stderr.
 295          * We run as a daemon or from inetd; in both cases, there's
 296          * more reason in logging to syslog.
 297          */
 298         (void) freopen(_PATH_DEVNULL, "w", stderr);
 299         opterr = 0;
 300
 301         /*
 302          * LOG_NDELAY sets up the logging connection immediately,
 303          * necessary for anonymous ftp's that chroot and can't do it later.
 304          */
 305         openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
 306
 307         while ((ch = getopt(argc, argv,
 308                             "468a:AdDEhlmMoOp:P:rRSt:T:u:UvW")) != -1) {
 309                 switch (ch) {
 310                 case '4':
 311                         family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
 312                         break;
 313
 314                 case '6':
 315                         family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
 316                         break;
 317
 318                 case '8':
 319                         assumeutf8 = 1;
 320                         break;
 321
 322                 case 'a':
 323                         bindname = optarg;
 324                         break;
 325
 326                 case 'A':
 327                         anon_only = 1;
 328                         break;
 329
 330                 case 'd':
 331                         ftpdebug++;
 332                         break;
 333
 334                 case 'D':
 335                         daemon_mode++;
 336                         break;
 337
 338                 case 'E':
 339                         noepsv = 1;
 340                         break;
 341
 342                 case 'h':
 343                         hostinfo = 0;
 344                         break;
 345
 346                 case 'l':
 347                         logging++;      /* > 1 == extra logging */
 348                         break;
 349
 350                 case 'm':
 351                         noguestmod = 0;
 352                         break;
 353
 354                 case 'M':
 355                         noguestmkd = 1;
 356                         break;
 357
 358                 case 'o':
 359                         noretr = 1;
 360                         break;
 361
 362                 case 'O':
 363                         noguestretr = 1;
 364                         break;
 365
 366                 case 'p':
 367                         pid_file = optarg;
 368                         break;
 369
 370                 case 'P':
 371                         bindport = optarg;
 372                         break;
 373
 374                 case 'r':
 375                         readonly = 1;
 376                         break;
 377
 378                 case 'R':
 379                         paranoid = 0;
 380                         break;
 381
 382                 case 'S':
 383                         stats++;
 384                         break;
 385
 386                 case 't':
 387                         timeout = atoi(optarg);
 388                         if (maxtimeout < timeout)
 389                                 maxtimeout = timeout;
 390                         break;
 391
 392                 case 'T':
 393                         maxtimeout = atoi(optarg);
 394                         if (timeout > maxtimeout)
 395                                 timeout = maxtimeout;
 396                         break;
 397
 398                 case 'u':
 399                     {
 400                         long val = 0;
 401
 402                         val = strtol(optarg, &optarg, 8);
 403                         if (*optarg != '\0' || val < 0)
 404                                 syslog(LOG_WARNING, "bad value for -u");
 405                         else
 406                                 defumask = val;
 407                         break;
 408                     }
 409                 case 'U':
 410                         restricted_data_ports = 0;
 411                         break;
 412
 413                 case 'v':
 414                         ftpdebug++;
 415                         break;
 416
 417                 case 'W':
 418                         dowtmp = 0;
 419                         break;
 420
 421                 default:
 422                         syslog(LOG_WARNING, "unknown flag -%c ignored", optopt);
 423                         break;
 424                 }
 425         }
 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                 strncpy(curname, name, sizeof(curname)-1);
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         if (logged_in && dowtmp)
1193                 ftpd_logwtmp(wtmpid, NULL, NULL);
1194         pw = NULL;
1195 #ifdef  LOGIN_CAP
1196         setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
1197                        LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
1198                        LOGIN_SETENV));
1199 #endif
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_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         if (guest && stats && statfd < 0)
1514 #ifdef VIRTUAL_HOSTING
1515                 statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1516 #else
1517                 statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1518 #endif
1519                 if (statfd < 0)
1520                         stats = 0;
1521
1522         /*
1523          * For a chrooted local user,
1524          * a) see whether ftpchroot(5) specifies a chroot directory,
1525          * b) extract the directory pathname from the line,
1526          * c) expand it to the absolute pathname if necessary.
1527          */
1528         if (dochroot && residue &&
1529             (chrootdir = strtok(residue, " \t")) != NULL) {
1530                 if (chrootdir[0] != '/')
1531                         asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1532                 else
1533                         chrootdir = strdup(chrootdir); /* make it permanent */
1534                 if (chrootdir == NULL)
1535                         fatalerror("Ran out of memory.");
1536         }
1537         if (guest || dochroot) {
1538                 /*
1539                  * If no chroot directory set yet, use the login directory.
1540                  * Copy it so it can be modified while pw->pw_dir stays intact.
1541                  */
1542                 if (chrootdir == NULL &&
1543                     (chrootdir = strdup(pw->pw_dir)) == NULL)
1544                         fatalerror("Ran out of memory.");
1545                 /*
1546                  * Check for the "/chroot/./home" syntax,
1547                  * separate the chroot and home directory pathnames.
1548                  */
1549                 if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1550                         *(homedir++) = '\0';    /* wipe '/' */
1551                         homedir++;              /* skip '.' */
1552                 } else {
1553                         /*
1554                          * We MUST do a chdir() after the chroot. Otherwise
1555                          * the old current directory will be accessible as "."
1556                          * outside the new root!
1557                          */
1558                         homedir = "/";
1559                 }
1560                 /*
1561                  * Finally, do chroot()
1562                  */
1563                 if (chroot(chrootdir) < 0) {
1564                         reply(550, "Can't change root.");
1565                         goto bad;
1566                 }
1567                 __FreeBSD_libc_enter_restricted_mode();
1568         } else  /* real user w/o chroot */
1569                 homedir = pw->pw_dir;
1570         /*
1571          * Set euid *before* doing chdir() so
1572          * a) the user won't be carried to a directory that he couldn't reach
1573          *    on his own due to no permission to upper path components,
1574          * b) NFS mounted homedirs w/restrictive permissions will be accessible
1575          *    (uid 0 has no root power over NFS if not mapped explicitly.)
1576          */
1577         if (seteuid(pw->pw_uid) < 0) {
1578                 reply(550, "Can't set uid.");
1579                 goto bad;
1580         }
1581         if (chdir(homedir) < 0) {
1582                 if (guest || dochroot) {
1583                         reply(550, "Can't change to base directory.");
1584                         goto bad;
1585                 } else {
1586                         if (chdir("/") < 0) {
1587                                 reply(550, "Root is inaccessible.");
1588                                 goto bad;
1589                         }
1590                         lreply(230, "No directory! Logging in with home=/.");
1591                 }
1592         }
1593
1594         /*
1595          * Display a login message, if it exists.
1596          * N.B. reply(230,) must follow the message.
1597          */
1598 #ifdef VIRTUAL_HOSTING
1599         fd = fopen(thishost->loginmsg, "r");
1600 #else
1601         fd = fopen(_PATH_FTPLOGINMESG, "r");
1602 #endif
1603         if (fd != NULL) {
1604                 char *cp, line[LINE_MAX];
1605
1606                 while (fgets(line, sizeof(line), fd) != NULL) {
1607                         if ((cp = strchr(line, '\n')) != NULL)
1608                                 *cp = '\0';
1609                         lreply(230, "%s", line);
1610                 }
1611                 (void) fflush(stdout);
1612                 (void) fclose(fd);
1613         }
1614         if (guest) {
1615                 if (ident != NULL)
1616                         free(ident);
1617                 ident = strdup(passwd);
1618                 if (ident == NULL)
1619                         fatalerror("Ran out of memory.");
1620
1621                 reply(230, "Guest login ok, access restrictions apply.");
1622 #ifdef SETPROCTITLE
1623 #ifdef VIRTUAL_HOSTING
1624                 if (thishost != firsthost)
1625                         snprintf(proctitle, sizeof(proctitle),
1626                                  "%s: anonymous(%s)/%s", remotehost, hostname,
1627                                  passwd);
1628                 else
1629 #endif
1630                         snprintf(proctitle, sizeof(proctitle),
1631                                  "%s: anonymous/%s", remotehost, passwd);
1632                 setproctitle("%s", proctitle);
1633 #endif /* SETPROCTITLE */
1634                 if (logging)
1635                         syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1636                             remotehost, passwd);
1637         } else {
1638                 if (dochroot)
1639                         reply(230, "User %s logged in, "
1640                                    "access restrictions apply.", pw->pw_name);
1641                 else
1642                         reply(230, "User %s logged in.", pw->pw_name);
1643
1644 #ifdef SETPROCTITLE
1645                 snprintf(proctitle, sizeof(proctitle),
1646                          "%s: user/%s", remotehost, pw->pw_name);
1647                 setproctitle("%s", proctitle);
1648 #endif /* SETPROCTITLE */
1649                 if (logging)
1650                         syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1651                             remotehost, pw->pw_name);
1652         }
1653         if (logging && (guest || dochroot))
1654                 syslog(LOG_INFO, "session root changed to %s", chrootdir);
1655 #ifdef  LOGIN_CAP
1656         login_close(lc);
1657 #endif
1658         if (residue)
1659                 free(residue);
1660         return;
1661 bad:
1662         /* Forget all about it... */
1663 #ifdef  LOGIN_CAP
1664         login_close(lc);
1665 #endif
1666         if (residue)
1667                 free(residue);
1668         end_login();
1669 }
1670
1671 void
1672 retrieve(char *cmd, char *name)
1673 {
1674         FILE *fin, *dout;
1675         struct stat st;
1676         int (*closefunc)(FILE *);
1677         time_t start;
1678
1679         if (cmd == 0) {
1680                 fin = fopen(name, "r"), closefunc = fclose;
1681                 st.st_size = 0;
1682         } else {
1683                 char line[BUFSIZ];
1684
1685                 (void) snprintf(line, sizeof(line), cmd, name), name = line;
1686                 fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1687                 st.st_size = -1;
1688                 st.st_blksize = BUFSIZ;
1689         }
1690         if (fin == NULL) {
1691                 if (errno != 0) {
1692                         perror_reply(550, name);
1693                         if (cmd == 0) {
1694                                 LOGCMD("get", name);
1695                         }
1696                 }
1697                 return;
1698         }
1699         byte_count = -1;
1700         if (cmd == 0) {
1701                 if (fstat(fileno(fin), &st) < 0) {
1702                         perror_reply(550, name);
1703                         goto done;
1704                 }
1705                 if (!S_ISREG(st.st_mode)) {
1706                         /*
1707                          * Never sending a raw directory is a workaround
1708                          * for buggy clients that will attempt to RETR
1709                          * a directory before listing it, e.g., Mozilla.
1710                          * Preventing a guest from getting irregular files
1711                          * is a simple security measure.
1712                          */
1713                         if (S_ISDIR(st.st_mode) || guest) {
1714                                 reply(550, "%s: not a plain file.", name);
1715                                 goto done;
1716                         }
1717                         st.st_size = -1;
1718                         /* st.st_blksize is set for all descriptor types */
1719                 }
1720         }
1721         if (restart_point) {
1722                 if (type == TYPE_A) {
1723                         off_t i, n;
1724                         int c;
1725
1726                         n = restart_point;
1727                         i = 0;
1728                         while (i++ < n) {
1729                                 if ((c=getc(fin)) == EOF) {
1730                                         perror_reply(550, name);
1731                                         goto done;
1732                                 }
1733                                 if (c == '\n')
1734                                         i++;
1735                         }
1736                 } else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1737                         perror_reply(550, name);
1738                         goto done;
1739                 }
1740         }
1741         dout = dataconn(name, st.st_size, "w");
1742         if (dout == NULL)
1743                 goto done;
1744         time(&start);
1745         send_data(fin, dout, st.st_blksize, st.st_size,
1746                   restart_point == 0 && cmd == 0 && S_ISREG(st.st_mode));
1747         if (cmd == 0 && guest && stats && byte_count > 0)
1748                 logxfer(name, byte_count, start);
1749         (void) fclose(dout);
1750         data = -1;
1751         pdata = -1;
1752 done:
1753         if (cmd == 0)
1754                 LOGBYTES("get", name, byte_count);
1755         (*closefunc)(fin);
1756 }
1757
1758 void
1759 store(char *name, char *mode, int unique)
1760 {
1761         int fd;
1762         FILE *fout, *din;
1763         int (*closefunc)(FILE *);
1764
1765         if (*mode == 'a') {             /* APPE */
1766                 if (unique) {
1767                         /* Programming error */
1768                         syslog(LOG_ERR, "Internal: unique flag to APPE");
1769                         unique = 0;
1770                 }
1771                 if (guest && noguestmod) {
1772                         reply(550, "Appending to existing file denied.");
1773                         goto err;
1774                 }
1775                 restart_point = 0;      /* not affected by preceding REST */
1776         }
1777         if (unique)                     /* STOU overrides REST */
1778                 restart_point = 0;
1779         if (guest && noguestmod) {
1780                 if (restart_point) {    /* guest STOR w/REST */
1781                         reply(550, "Modifying existing file denied.");
1782                         goto err;
1783                 } else                  /* treat guest STOR as STOU */
1784                         unique = 1;
1785         }
1786
1787         if (restart_point)
1788                 mode = "r+";    /* so ASCII manual seek can work */
1789         if (unique) {
1790                 if ((fd = guniquefd(name, &name)) < 0)
1791                         goto err;
1792                 fout = fdopen(fd, mode);
1793         } else
1794                 fout = fopen(name, mode);
1795         closefunc = fclose;
1796         if (fout == NULL) {
1797                 perror_reply(553, name);
1798                 goto err;
1799         }
1800         byte_count = -1;
1801         if (restart_point) {
1802                 if (type == TYPE_A) {
1803                         off_t i, n;
1804                         int c;
1805
1806                         n = restart_point;
1807                         i = 0;
1808                         while (i++ < n) {
1809                                 if ((c=getc(fout)) == EOF) {
1810                                         perror_reply(550, name);
1811                                         goto done;
1812                                 }
1813                                 if (c == '\n')
1814                                         i++;
1815                         }
1816                         /*
1817                          * We must do this seek to "current" position
1818                          * because we are changing from reading to
1819                          * writing.
1820                          */
1821                         if (fseeko(fout, 0, SEEK_CUR) < 0) {
1822                                 perror_reply(550, name);
1823                                 goto done;
1824                         }
1825                 } else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1826                         perror_reply(550, name);
1827                         goto done;
1828                 }
1829         }
1830         din = dataconn(name, -1, "r");
1831         if (din == NULL)
1832                 goto done;
1833         if (receive_data(din, fout) == 0) {
1834                 if (unique)
1835                         reply(226, "Transfer complete (unique file name:%s).",
1836                             name);
1837                 else
1838                         reply(226, "Transfer complete.");
1839         }
1840         (void) fclose(din);
1841         data = -1;
1842         pdata = -1;
1843 done:
1844         LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1845         (*closefunc)(fout);
1846         return;
1847 err:
1848         LOGCMD(*mode == 'a' ? "append" : "put" , name);
1849         return;
1850 }
1851
1852 static FILE *
1853 getdatasock(char *mode)
1854 {
1855         int on = 1, s, t, tries;
1856
1857         if (data >= 0)
1858                 return (fdopen(data, mode));
1859
1860         s = socket(data_dest.su_family, SOCK_STREAM, 0);
1861         if (s < 0)
1862                 goto bad;
1863         if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1864                 syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1865         /* anchor socket to avoid multi-homing problems */
1866         data_source = ctrl_addr;
1867         data_source.su_port = htons(dataport);
1868         (void) seteuid(0);
1869         for (tries = 1; ; tries++) {
1870                 /*
1871                  * We should loop here since it's possible that
1872                  * another ftpd instance has passed this point and is
1873                  * trying to open a data connection in active mode now.
1874                  * Until the other connection is opened, we'll be getting
1875                  * EADDRINUSE because no SOCK_STREAM sockets in the system
1876                  * can share both local and remote addresses, localIP:20
1877                  * and *:* in this case.
1878                  */
1879                 if (bind(s, (struct sockaddr *)&data_source,
1880                     data_source.su_len) >= 0)
1881                         break;
1882                 if (errno != EADDRINUSE || tries > 10)
1883                         goto bad;
1884                 sleep(tries);
1885         }
1886         (void) seteuid(pw->pw_uid);
1887 #ifdef IP_TOS
1888         if (data_source.su_family == AF_INET)
1889       {
1890         on = IPTOS_THROUGHPUT;
1891         if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1892                 syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1893       }
1894 #endif
1895 #ifdef TCP_NOPUSH
1896         /*
1897          * Turn off push flag to keep sender TCP from sending short packets
1898          * at the boundaries of each write().
1899          */
1900         on = 1;
1901         if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1902                 syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1903 #endif
1904         return (fdopen(s, mode));
1905 bad:
1906         /* Return the real value of errno (close may change it) */
1907         t = errno;
1908         (void) seteuid(pw->pw_uid);
1909         (void) close(s);
1910         errno = t;
1911         return (NULL);
1912 }
1913
1914 static FILE *
1915 dataconn(char *name, off_t size, char *mode)
1916 {
1917         char sizebuf[32];
1918         FILE *file;
1919         int retry = 0, tos, conerrno;
1920
1921         file_size = size;
1922         byte_count = 0;
1923         if (size != -1)
1924                 (void) snprintf(sizebuf, sizeof(sizebuf),
1925                                 " (%jd bytes)", (intmax_t)size);
1926         else
1927                 *sizebuf = '\0';
1928         if (pdata >= 0) {
1929                 union sockunion from;
1930                 socklen_t fromlen = ctrl_addr.su_len;
1931                 int flags, s;
1932                 struct timeval timeout;
1933                 fd_set set;
1934
1935                 FD_ZERO(&set);
1936                 FD_SET(pdata, &set);
1937
1938                 timeout.tv_usec = 0;
1939                 timeout.tv_sec = 120;
1940
1941                 /*
1942                  * Granted a socket is in the blocking I/O mode,
1943                  * accept() will block after a successful select()
1944                  * if the selected connection dies in between.
1945                  * Therefore set the non-blocking I/O flag here.
1946                  */
1947                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1948                     fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1949                         goto pdata_err;
1950                 if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1951                     (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1952                         goto pdata_err;
1953                 (void) close(pdata);
1954                 pdata = s;
1955                 /*
1956                  * Unset the inherited non-blocking I/O flag
1957                  * on the child socket so stdio can work on it.
1958                  */
1959                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1960                     fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1961                         goto pdata_err;
1962 #ifdef IP_TOS
1963                 if (from.su_family == AF_INET)
1964               {
1965                 tos = IPTOS_THROUGHPUT;
1966                 if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1967                         syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1968               }
1969 #endif
1970                 reply(150, "Opening %s mode data connection for '%s'%s.",
1971                      type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1972                 return (fdopen(pdata, mode));
1973 pdata_err:
1974                 reply(425, "Can't open data connection.");
1975                 (void) close(pdata);
1976                 pdata = -1;
1977                 return (NULL);
1978         }
1979         if (data >= 0) {
1980                 reply(125, "Using existing data connection for '%s'%s.",
1981                     name, sizebuf);
1982                 usedefault = 1;
1983                 return (fdopen(data, mode));
1984         }
1985         if (usedefault)
1986                 data_dest = his_addr;
1987         usedefault = 1;
1988         do {
1989                 file = getdatasock(mode);
1990                 if (file == NULL) {
1991                         char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
1992
1993                         if (getnameinfo((struct sockaddr *)&data_source,
1994                                 data_source.su_len,
1995                                 hostbuf, sizeof(hostbuf) - 1,
1996                                 portbuf, sizeof(portbuf) - 1,
1997                                 NI_NUMERICHOST|NI_NUMERICSERV))
1998                                         *hostbuf = *portbuf = 0;
1999                         hostbuf[sizeof(hostbuf) - 1] = 0;
2000                         portbuf[sizeof(portbuf) - 1] = 0;
2001                         reply(425, "Can't create data socket (%s,%s): %s.",
2002                                 hostbuf, portbuf, strerror(errno));
2003                         return (NULL);
2004                 }
2005                 data = fileno(file);
2006                 conerrno = 0;
2007                 if (connect(data, (struct sockaddr *)&data_dest,
2008                     data_dest.su_len) == 0)
2009                         break;
2010                 conerrno = errno;
2011                 (void) fclose(file);
2012                 data = -1;
2013                 if (conerrno == EADDRINUSE) {
2014                         sleep(swaitint);
2015                         retry += swaitint;
2016                 } else {
2017                         break;
2018                 }
2019         } while (retry <= swaitmax);
2020         if (conerrno != 0) {
2021                 reply(425, "Can't build data connection: %s.",
2022                            strerror(conerrno));
2023                 return (NULL);
2024         }
2025         reply(150, "Opening %s mode data connection for '%s'%s.",
2026              type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
2027         return (file);
2028 }
2029
2030 /*
2031  * A helper macro to avoid code duplication
2032  * in send_data() and receive_data().
2033  *
2034  * XXX We have to block SIGURG during putc() because BSD stdio
2035  * is unable to restart interrupted write operations and hence
2036  * the entire buffer contents will be lost as soon as a write()
2037  * call indicates EINTR to stdio.
2038  */
2039 #define FTPD_PUTC(ch, file, label)                                      \
2040         do {                                                            \
2041                 int ret;                                                \
2042                                                                         \
2043                 do {                                                    \
2044                         START_UNSAFE;                                   \
2045                         ret = putc((ch), (file));                       \
2046                         END_UNSAFE;                                     \
2047                         CHECKOOB(return (-1))                           \
2048                         else if (ferror(file))                          \
2049                                 goto label;                             \
2050                         clearerr(file);                                 \
2051                 } while (ret == EOF);                                   \
2052         } while (0)
2053
2054 /*
2055  * Tranfer the contents of "instr" to "outstr" peer using the appropriate
2056  * encapsulation of the data subject to Mode, Structure, and Type.
2057  *
2058  * NB: Form isn't handled.
2059  */
2060 static int
2061 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2062 {
2063         int c, cp, filefd, netfd;
2064         char *buf;
2065
2066         STARTXFER;
2067
2068         switch (type) {
2069
2070         case TYPE_A:
2071                 cp = EOF;
2072                 for (;;) {
2073                         c = getc(instr);
2074                         CHECKOOB(return (-1))
2075                         else if (c == EOF && ferror(instr))
2076                                 goto file_err;
2077                         if (c == EOF) {
2078                                 if (ferror(instr)) {    /* resume after OOB */
2079                                         clearerr(instr);
2080                                         continue;
2081                                 }
2082                                 if (feof(instr))        /* EOF */
2083                                         break;
2084                                 syslog(LOG_ERR, "Internal: impossible condition"
2085                                                 " on file after getc()");
2086                                 goto file_err;
2087                         }
2088                         if (c == '\n' && cp != '\r') {
2089                                 FTPD_PUTC('\r', outstr, data_err);
2090                                 byte_count++;
2091                         }
2092                         FTPD_PUTC(c, outstr, data_err);
2093                         byte_count++;
2094                         cp = c;
2095                 }
2096 #ifdef notyet   /* BSD stdio isn't ready for that */
2097                 while (fflush(outstr) == EOF) {
2098                         CHECKOOB(return (-1))
2099                         else
2100                                 goto data_err;
2101                         clearerr(outstr);
2102                 }
2103                 ENDXFER;
2104 #else
2105                 ENDXFER;
2106                 if (fflush(outstr) == EOF)
2107                         goto data_err;
2108 #endif
2109                 reply(226, "Transfer complete.");
2110                 return (0);
2111
2112         case TYPE_I:
2113         case TYPE_L:
2114                 /*
2115                  * isreg is only set if we are not doing restart and we
2116                  * are sending a regular file
2117                  */
2118                 netfd = fileno(outstr);
2119                 filefd = fileno(instr);
2120
2121                 if (isreg) {
2122                         char *msg = "Transfer complete.";
2123                         off_t cnt, offset;
2124                         int err;
2125
2126                         cnt = offset = 0;
2127
2128                         while (filesize > 0) {
2129                                 err = sendfile(filefd, netfd, offset, 0,
2130                                                NULL, &cnt, 0);
2131                                 /*
2132                                  * Calculate byte_count before OOB processing.
2133                                  * It can be used in myoob() later.
2134                                  */
2135                                 byte_count += cnt;
2136                                 offset += cnt;
2137                                 filesize -= cnt;
2138                                 CHECKOOB(return (-1))
2139                                 else if (err == -1) {
2140                                         if (errno != EINTR &&
2141                                             cnt == 0 && offset == 0)
2142                                                 goto oldway;
2143                                         goto data_err;
2144                                 }
2145                                 if (err == -1)  /* resume after OOB */
2146                                         continue;
2147                                 /*
2148                                  * We hit the EOF prematurely.
2149                                  * Perhaps the file was externally truncated.
2150                                  */
2151                                 if (cnt == 0) {
2152                                         msg = "Transfer finished due to "
2153                                               "premature end of file.";
2154                                         break;
2155                                 }
2156                         }
2157                         ENDXFER;
2158                         reply(226, "%s", msg);
2159                         return (0);
2160                 }
2161
2162 oldway:
2163                 if ((buf = malloc(blksize)) == NULL) {
2164                         ENDXFER;
2165                         reply(451, "Ran out of memory.");
2166                         return (-1);
2167                 }
2168
2169                 for (;;) {
2170                         int cnt, len;
2171                         char *bp;
2172
2173                         cnt = read(filefd, buf, blksize);
2174                         CHECKOOB(free(buf); return (-1))
2175                         else if (cnt < 0) {
2176                                 free(buf);
2177                                 goto file_err;
2178                         }
2179                         if (cnt < 0)    /* resume after OOB */
2180                                 continue;
2181                         if (cnt == 0)   /* EOF */
2182                                 break;
2183                         for (len = cnt, bp = buf; len > 0;) {
2184                                 cnt = write(netfd, bp, len);
2185                                 CHECKOOB(free(buf); return (-1))
2186                                 else if (cnt < 0) {
2187                                         free(buf);
2188                                         goto data_err;
2189                                 }
2190                                 if (cnt <= 0)
2191                                         continue;
2192                                 len -= cnt;
2193                                 bp += cnt;
2194                                 byte_count += cnt;
2195                         }
2196                 }
2197                 ENDXFER;
2198                 free(buf);
2199                 reply(226, "Transfer complete.");
2200                 return (0);
2201         default:
2202                 ENDXFER;
2203                 reply(550, "Unimplemented TYPE %d in send_data.", type);
2204                 return (-1);
2205         }
2206
2207 data_err:
2208         ENDXFER;
2209         perror_reply(426, "Data connection");
2210         return (-1);
2211
2212 file_err:
2213         ENDXFER;
2214         perror_reply(551, "Error on input file");
2215         return (-1);
2216 }
2217
2218 /*
2219  * Transfer data from peer to "outstr" using the appropriate encapulation of
2220  * the data subject to Mode, Structure, and Type.
2221  *
2222  * N.B.: Form isn't handled.
2223  */
2224 static int
2225 receive_data(FILE *instr, FILE *outstr)
2226 {
2227         int c, cp;
2228         int bare_lfs = 0;
2229
2230         STARTXFER;
2231
2232         switch (type) {
2233
2234         case TYPE_I:
2235         case TYPE_L:
2236                 for (;;) {
2237                         int cnt, len;
2238                         char *bp;
2239                         char buf[BUFSIZ];
2240
2241                         cnt = read(fileno(instr), buf, sizeof(buf));
2242                         CHECKOOB(return (-1))
2243                         else if (cnt < 0)
2244                                 goto data_err;
2245                         if (cnt < 0)    /* resume after OOB */
2246                                 continue;
2247                         if (cnt == 0)   /* EOF */
2248                                 break;
2249                         for (len = cnt, bp = buf; len > 0;) {
2250                                 cnt = write(fileno(outstr), bp, len);
2251                                 CHECKOOB(return (-1))
2252                                 else if (cnt < 0)
2253                                         goto file_err;
2254                                 if (cnt <= 0)
2255                                         continue;
2256                                 len -= cnt;
2257                                 bp += cnt;
2258                                 byte_count += cnt;
2259                         }
2260                 }
2261                 ENDXFER;
2262                 return (0);
2263
2264         case TYPE_E:
2265                 ENDXFER;
2266                 reply(553, "TYPE E not implemented.");
2267                 return (-1);
2268
2269         case TYPE_A:
2270                 cp = EOF;
2271                 for (;;) {
2272                         c = getc(instr);
2273                         CHECKOOB(return (-1))
2274                         else if (c == EOF && ferror(instr))
2275                                 goto data_err;
2276                         if (c == EOF && ferror(instr)) { /* resume after OOB */
2277                                 clearerr(instr);
2278                                 continue;
2279                         }
2280
2281                         if (cp == '\r') {
2282                                 if (c != '\n')
2283                                         FTPD_PUTC('\r', outstr, file_err);
2284                         } else
2285                                 if (c == '\n')
2286                                         bare_lfs++;
2287                         if (c == '\r') {
2288                                 byte_count++;
2289                                 cp = c;
2290                                 continue;
2291                         }
2292
2293                         /* Check for EOF here in order not to lose last \r. */
2294                         if (c == EOF) {
2295                                 if (feof(instr))        /* EOF */
2296                                         break;
2297                                 syslog(LOG_ERR, "Internal: impossible condition"
2298                                                 " on data stream after getc()");
2299                                 goto data_err;
2300                         }
2301
2302                         byte_count++;
2303                         FTPD_PUTC(c, outstr, file_err);
2304                         cp = c;
2305                 }
2306 #ifdef notyet   /* BSD stdio isn't ready for that */
2307                 while (fflush(outstr) == EOF) {
2308                         CHECKOOB(return (-1))
2309                         else
2310                                 goto file_err;
2311                         clearerr(outstr);
2312                 }
2313                 ENDXFER;
2314 #else
2315                 ENDXFER;
2316                 if (fflush(outstr) == EOF)
2317                         goto file_err;
2318 #endif
2319                 if (bare_lfs) {
2320                         lreply(226,
2321                 "WARNING! %d bare linefeeds received in ASCII mode.",
2322                             bare_lfs);
2323                 (void)printf("   File may not have transferred correctly.\r\n");
2324                 }
2325                 return (0);
2326         default:
2327                 ENDXFER;
2328                 reply(550, "Unimplemented TYPE %d in receive_data.", type);
2329                 return (-1);
2330         }
2331
2332 data_err:
2333         ENDXFER;
2334         perror_reply(426, "Data connection");
2335         return (-1);
2336
2337 file_err:
2338         ENDXFER;
2339         perror_reply(452, "Error writing to file");
2340         return (-1);
2341 }
2342
2343 void
2344 statfilecmd(char *filename)
2345 {
2346         FILE *fin;
2347         int atstart;
2348         int c, code;
2349         char line[LINE_MAX];
2350         struct stat st;
2351
2352         code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2353         (void)snprintf(line, sizeof(line), _PATH_LS " -lgA %s", filename);
2354         fin = ftpd_popen(line, "r");
2355         if (fin == NULL) {
2356                 perror_reply(551, filename);
2357                 return;
2358         }
2359         lreply(code, "Status of %s:", filename);
2360         atstart = 1;
2361         while ((c = getc(fin)) != EOF) {
2362                 if (c == '\n') {
2363                         if (ferror(stdout)){
2364                                 perror_reply(421, "Control connection");
2365                                 (void) ftpd_pclose(fin);
2366                                 dologout(1);
2367                                 /* NOTREACHED */
2368                         }
2369                         if (ferror(fin)) {
2370                                 perror_reply(551, filename);
2371                                 (void) ftpd_pclose(fin);
2372                                 return;
2373                         }
2374                         (void) putc('\r', stdout);
2375                 }
2376                 /*
2377                  * RFC 959 says neutral text should be prepended before
2378                  * a leading 3-digit number followed by whitespace, but
2379                  * many ftp clients can be confused by any leading digits,
2380                  * as a matter of fact.
2381                  */
2382                 if (atstart && isdigit(c))
2383                         (void) putc(' ', stdout);
2384                 (void) putc(c, stdout);
2385                 atstart = (c == '\n');
2386         }
2387         (void) ftpd_pclose(fin);
2388         reply(code, "End of status.");
2389 }
2390
2391 void
2392 statcmd(void)
2393 {
2394         union sockunion *su;
2395         u_char *a, *p;
2396         char hname[NI_MAXHOST];
2397         int ispassive;
2398
2399         if (hostinfo) {
2400                 lreply(211, "%s FTP server status:", hostname);
2401                 printf("     %s\r\n", version);
2402         } else
2403                 lreply(211, "FTP server status:");
2404         printf("     Connected to %s", remotehost);
2405         if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2406                          hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2407                 hname[sizeof(hname) - 1] = 0;
2408                 if (strcmp(hname, remotehost) != 0)
2409                         printf(" (%s)", hname);
2410         }
2411         printf("\r\n");
2412         if (logged_in) {
2413                 if (guest)
2414                         printf("     Logged in anonymously\r\n");
2415                 else
2416                         printf("     Logged in as %s\r\n", pw->pw_name);
2417         } else if (askpasswd)
2418                 printf("     Waiting for password\r\n");
2419         else
2420                 printf("     Waiting for user name\r\n");
2421         printf("     TYPE: %s", typenames[type]);
2422         if (type == TYPE_A || type == TYPE_E)
2423                 printf(", FORM: %s", formnames[form]);
2424         if (type == TYPE_L)
2425 #if CHAR_BIT == 8
2426                 printf(" %d", CHAR_BIT);
2427 #else
2428                 printf(" %d", bytesize);        /* need definition! */
2429 #endif
2430         printf("; STRUcture: %s; transfer MODE: %s\r\n",
2431             strunames[stru], modenames[mode]);
2432         if (data != -1)
2433                 printf("     Data connection open\r\n");
2434         else if (pdata != -1) {
2435                 ispassive = 1;
2436                 su = &pasv_addr;
2437                 goto printaddr;
2438         } else if (usedefault == 0) {
2439                 ispassive = 0;
2440                 su = &data_dest;
2441 printaddr:
2442 #define UC(b) (((int) b) & 0xff)
2443                 if (epsvall) {
2444                         printf("     EPSV only mode (EPSV ALL)\r\n");
2445                         goto epsvonly;
2446                 }
2447
2448                 /* PORT/PASV */
2449                 if (su->su_family == AF_INET) {
2450                         a = (u_char *) &su->su_sin.sin_addr;
2451                         p = (u_char *) &su->su_sin.sin_port;
2452                         printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2453                                 ispassive ? "PASV" : "PORT",
2454                                 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2455                                 UC(p[0]), UC(p[1]));
2456                 }
2457
2458                 /* LPRT/LPSV */
2459             {
2460                 int alen, af, i;
2461
2462                 switch (su->su_family) {
2463                 case AF_INET:
2464                         a = (u_char *) &su->su_sin.sin_addr;
2465                         p = (u_char *) &su->su_sin.sin_port;
2466                         alen = sizeof(su->su_sin.sin_addr);
2467                         af = 4;
2468                         break;
2469                 case AF_INET6:
2470                         a = (u_char *) &su->su_sin6.sin6_addr;
2471                         p = (u_char *) &su->su_sin6.sin6_port;
2472                         alen = sizeof(su->su_sin6.sin6_addr);
2473                         af = 6;
2474                         break;
2475                 default:
2476                         af = 0;
2477                         break;
2478                 }
2479                 if (af) {
2480                         printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2481                                 af, alen);
2482                         for (i = 0; i < alen; i++)
2483                                 printf("%d,", UC(a[i]));
2484                         printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2485                 }
2486             }
2487
2488 epsvonly:;
2489                 /* EPRT/EPSV */
2490             {
2491                 int af;
2492
2493                 switch (su->su_family) {
2494                 case AF_INET:
2495                         af = 1;
2496                         break;
2497                 case AF_INET6:
2498                         af = 2;
2499                         break;
2500                 default:
2501                         af = 0;
2502                         break;
2503                 }
2504                 if (af) {
2505                         union sockunion tmp;
2506
2507                         tmp = *su;
2508                         if (tmp.su_family == AF_INET6)
2509                                 tmp.su_sin6.sin6_scope_id = 0;
2510                         if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2511                                         hname, sizeof(hname) - 1, NULL, 0,
2512                                         NI_NUMERICHOST)) {
2513                                 hname[sizeof(hname) - 1] = 0;
2514                                 printf("     %s |%d|%s|%d|\r\n",
2515                                         ispassive ? "EPSV" : "EPRT",
2516                                         af, hname, htons(tmp.su_port));
2517                         }
2518                 }
2519             }
2520 #undef UC
2521         } else
2522                 printf("     No data connection\r\n");
2523         reply(211, "End of status.");
2524 }
2525
2526 void
2527 fatalerror(char *s)
2528 {
2529
2530         reply(451, "Error in server: %s", s);
2531         reply(221, "Closing connection due to server error.");
2532         dologout(0);
2533         /* NOTREACHED */
2534 }
2535
2536 void
2537 reply(int n, const char *fmt, ...)
2538 {
2539         va_list ap;
2540
2541         (void)printf("%d ", n);
2542         va_start(ap, fmt);
2543         (void)vprintf(fmt, ap);
2544         va_end(ap);
2545         (void)printf("\r\n");
2546         (void)fflush(stdout);
2547         if (ftpdebug) {
2548                 syslog(LOG_DEBUG, "<--- %d ", n);
2549                 va_start(ap, fmt);
2550                 vsyslog(LOG_DEBUG, fmt, ap);
2551                 va_end(ap);
2552         }
2553 }
2554
2555 void
2556 lreply(int n, const char *fmt, ...)
2557 {
2558         va_list ap;
2559
2560         (void)printf("%d- ", n);
2561         va_start(ap, fmt);
2562         (void)vprintf(fmt, ap);
2563         va_end(ap);
2564         (void)printf("\r\n");
2565         (void)fflush(stdout);
2566         if (ftpdebug) {
2567                 syslog(LOG_DEBUG, "<--- %d- ", n);
2568                 va_start(ap, fmt);
2569                 vsyslog(LOG_DEBUG, fmt, ap);
2570                 va_end(ap);
2571         }
2572 }
2573
2574 static void
2575 ack(char *s)
2576 {
2577
2578         reply(250, "%s command successful.", s);
2579 }
2580
2581 void
2582 nack(char *s)
2583 {
2584
2585         reply(502, "%s command not implemented.", s);
2586 }
2587
2588 /* ARGSUSED */
2589 void
2590 yyerror(char *s)
2591 {
2592         char *cp;
2593
2594         if ((cp = strchr(cbuf,'\n')))
2595                 *cp = '\0';
2596         reply(500, "%s: command not understood.", cbuf);
2597 }
2598
2599 void
2600 delete(char *name)
2601 {
2602         struct stat st;
2603
2604         LOGCMD("delete", name);
2605         if (lstat(name, &st) < 0) {
2606                 perror_reply(550, name);
2607                 return;
2608         }
2609         if (S_ISDIR(st.st_mode)) {
2610                 if (rmdir(name) < 0) {
2611                         perror_reply(550, name);
2612                         return;
2613                 }
2614                 goto done;
2615         }
2616         if (guest && noguestmod) {
2617                 reply(550, "Operation not permitted.");
2618                 return;
2619         }
2620         if (unlink(name) < 0) {
2621                 perror_reply(550, name);
2622                 return;
2623         }
2624 done:
2625         ack("DELE");
2626 }
2627
2628 void
2629 cwd(char *path)
2630 {
2631
2632         if (chdir(path) < 0)
2633                 perror_reply(550, path);
2634         else
2635                 ack("CWD");
2636 }
2637
2638 void
2639 makedir(char *name)
2640 {
2641         char *s;
2642
2643         LOGCMD("mkdir", name);
2644         if (guest && noguestmkd)
2645                 reply(550, "Operation not permitted.");
2646         else if (mkdir(name, 0777) < 0)
2647                 perror_reply(550, name);
2648         else {
2649                 if ((s = doublequote(name)) == NULL)
2650                         fatalerror("Ran out of memory.");
2651                 reply(257, "\"%s\" directory created.", s);
2652                 free(s);
2653         }
2654 }
2655
2656 void
2657 removedir(char *name)
2658 {
2659
2660         LOGCMD("rmdir", name);
2661         if (rmdir(name) < 0)
2662                 perror_reply(550, name);
2663         else
2664                 ack("RMD");
2665 }
2666
2667 void
2668 pwd(void)
2669 {
2670         char *s, path[MAXPATHLEN + 1];
2671
2672         if (getcwd(path, sizeof(path)) == NULL)
2673                 perror_reply(550, "Get current directory");
2674         else {
2675                 if ((s = doublequote(path)) == NULL)
2676                         fatalerror("Ran out of memory.");
2677                 reply(257, "\"%s\" is current directory.", s);
2678                 free(s);
2679         }
2680 }
2681
2682 char *
2683 renamefrom(char *name)
2684 {
2685         struct stat st;
2686
2687         if (guest && noguestmod) {
2688                 reply(550, "Operation not permitted.");
2689                 return (NULL);
2690         }
2691         if (lstat(name, &st) < 0) {
2692                 perror_reply(550, name);
2693                 return (NULL);
2694         }
2695         reply(350, "File exists, ready for destination name.");
2696         return (name);
2697 }
2698
2699 void
2700 renamecmd(char *from, char *to)
2701 {
2702         struct stat st;
2703
2704         LOGCMD2("rename", from, to);
2705
2706         if (guest && (stat(to, &st) == 0)) {
2707                 reply(550, "%s: permission denied.", to);
2708                 return;
2709         }
2710
2711         if (rename(from, to) < 0)
2712                 perror_reply(550, "rename");
2713         else
2714                 ack("RNTO");
2715 }
2716
2717 static void
2718 dolog(struct sockaddr *who)
2719 {
2720         char who_name[NI_MAXHOST];
2721
2722         realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2723         remotehost[sizeof(remotehost) - 1] = 0;
2724         if (getnameinfo(who, who->sa_len,
2725                 who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2726                         *who_name = 0;
2727         who_name[sizeof(who_name) - 1] = 0;
2728
2729 #ifdef SETPROCTITLE
2730 #ifdef VIRTUAL_HOSTING
2731         if (thishost != firsthost)
2732                 snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2733                          remotehost, hostname);
2734         else
2735 #endif
2736                 snprintf(proctitle, sizeof(proctitle), "%s: connected",
2737                          remotehost);
2738         setproctitle("%s", proctitle);
2739 #endif /* SETPROCTITLE */
2740
2741         if (logging) {
2742 #ifdef VIRTUAL_HOSTING
2743                 if (thishost != firsthost)
2744                         syslog(LOG_INFO, "connection from %s (%s) to %s",
2745                                remotehost, who_name, hostname);
2746                 else
2747 #endif
2748                         syslog(LOG_INFO, "connection from %s (%s)",
2749                                remotehost, who_name);
2750         }
2751 }
2752
2753 /*
2754  * Record logout in wtmp file
2755  * and exit with supplied status.
2756  */
2757 void
2758 dologout(int status)
2759 {
2760
2761         if (logged_in && dowtmp) {
2762                 (void) seteuid(0);
2763                 ftpd_logwtmp(wtmpid, NULL, NULL);
2764         }
2765         /* beware of flushing buffers after a SIGPIPE */
2766         _exit(status);
2767 }
2768
2769 static void
2770 sigurg(int signo)
2771 {
2772
2773         recvurg = 1;
2774 }
2775
2776 static void
2777 maskurg(int flag)
2778 {
2779         int oerrno;
2780         sigset_t sset;
2781
2782         if (!transflag) {
2783                 syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2784                 return;
2785         }
2786         oerrno = errno;
2787         sigemptyset(&sset);
2788         sigaddset(&sset, SIGURG);
2789         sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2790         errno = oerrno;
2791 }
2792
2793 static void
2794 flagxfer(int flag)
2795 {
2796
2797         if (flag) {
2798                 if (transflag)
2799                         syslog(LOG_ERR, "Internal: flagxfer(1): "
2800                                         "transfer already under way");
2801                 transflag = 1;
2802                 maskurg(0);
2803                 recvurg = 0;
2804         } else {
2805                 if (!transflag)
2806                         syslog(LOG_ERR, "Internal: flagxfer(0): "
2807                                         "no active transfer");
2808                 maskurg(1);
2809                 transflag = 0;
2810         }
2811 }
2812
2813 /*
2814  * Returns 0 if OK to resume or -1 if abort requested.
2815  */
2816 static int
2817 myoob(void)
2818 {
2819         char *cp;
2820         int ret;
2821
2822         if (!transflag) {
2823                 syslog(LOG_ERR, "Internal: myoob() while no transfer");
2824                 return (0);
2825         }
2826         cp = tmpline;
2827         ret = getline(cp, 7, stdin);
2828         if (ret == -1) {
2829                 reply(221, "You could at least say goodbye.");
2830                 dologout(0);
2831         } else if (ret == -2) {
2832                 /* Ignore truncated command. */
2833                 return (0);
2834         }
2835         upper(cp);
2836         if (strcmp(cp, "ABOR\r\n") == 0) {
2837                 tmpline[0] = '\0';
2838                 reply(426, "Transfer aborted. Data connection closed.");
2839                 reply(226, "Abort successful.");
2840                 return (-1);
2841         }
2842         if (strcmp(cp, "STAT\r\n") == 0) {
2843                 tmpline[0] = '\0';
2844                 if (file_size != -1)
2845                         reply(213, "Status: %jd of %jd bytes transferred.",
2846                                    (intmax_t)byte_count, (intmax_t)file_size);
2847                 else
2848                         reply(213, "Status: %jd bytes transferred.",
2849                                    (intmax_t)byte_count);
2850         }
2851         return (0);
2852 }
2853
2854 /*
2855  * Note: a response of 425 is not mentioned as a possible response to
2856  *      the PASV command in RFC959. However, it has been blessed as
2857  *      a legitimate response by Jon Postel in a telephone conversation
2858  *      with Rick Adams on 25 Jan 89.
2859  */
2860 void
2861 passive(void)
2862 {
2863         socklen_t len;
2864         int on;
2865         char *p, *a;
2866
2867         if (pdata >= 0)         /* close old port if one set */
2868                 close(pdata);
2869
2870         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2871         if (pdata < 0) {
2872                 perror_reply(425, "Can't open passive connection");
2873                 return;
2874         }
2875         on = 1;
2876         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2877                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2878
2879         (void) seteuid(0);
2880
2881 #ifdef IP_PORTRANGE
2882         if (ctrl_addr.su_family == AF_INET) {
2883             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2884                                        : IP_PORTRANGE_DEFAULT;
2885
2886             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2887                             &on, sizeof(on)) < 0)
2888                     goto pasv_error;
2889         }
2890 #endif
2891 #ifdef IPV6_PORTRANGE
2892         if (ctrl_addr.su_family == AF_INET6) {
2893             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2894                                        : IPV6_PORTRANGE_DEFAULT;
2895
2896             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2897                             &on, sizeof(on)) < 0)
2898                     goto pasv_error;
2899         }
2900 #endif
2901
2902         pasv_addr = ctrl_addr;
2903         pasv_addr.su_port = 0;
2904         if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2905                 goto pasv_error;
2906
2907         (void) seteuid(pw->pw_uid);
2908
2909         len = sizeof(pasv_addr);
2910         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2911                 goto pasv_error;
2912         if (listen(pdata, 1) < 0)
2913                 goto pasv_error;
2914         if (pasv_addr.su_family == AF_INET)
2915                 a = (char *) &pasv_addr.su_sin.sin_addr;
2916         else if (pasv_addr.su_family == AF_INET6 &&
2917                  IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2918                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2919         else
2920                 goto pasv_error;
2921
2922         p = (char *) &pasv_addr.su_port;
2923
2924 #define UC(b) (((int) b) & 0xff)
2925
2926         reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2927                 UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2928         return;
2929
2930 pasv_error:
2931         (void) seteuid(pw->pw_uid);
2932         (void) close(pdata);
2933         pdata = -1;
2934         perror_reply(425, "Can't open passive connection");
2935         return;
2936 }
2937
2938 /*
2939  * Long Passive defined in RFC 1639.
2940  *     228 Entering Long Passive Mode
2941  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2942  */
2943
2944 void
2945 long_passive(char *cmd, int pf)
2946 {
2947         socklen_t len;
2948         int on;
2949         char *p, *a;
2950
2951         if (pdata >= 0)         /* close old port if one set */
2952                 close(pdata);
2953
2954         if (pf != PF_UNSPEC) {
2955                 if (ctrl_addr.su_family != pf) {
2956                         switch (ctrl_addr.su_family) {
2957                         case AF_INET:
2958                                 pf = 1;
2959                                 break;
2960                         case AF_INET6:
2961                                 pf = 2;
2962                                 break;
2963                         default:
2964                                 pf = 0;
2965                                 break;
2966                         }
2967                         /*
2968                          * XXX
2969                          * only EPRT/EPSV ready clients will understand this
2970                          */
2971                         if (strcmp(cmd, "EPSV") == 0 && pf) {
2972                                 reply(522, "Network protocol mismatch, "
2973                                         "use (%d)", pf);
2974                         } else
2975                                 reply(501, "Network protocol mismatch."); /*XXX*/
2976
2977                         return;
2978                 }
2979         }
2980
2981         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2982         if (pdata < 0) {
2983                 perror_reply(425, "Can't open passive connection");
2984                 return;
2985         }
2986         on = 1;
2987         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2988                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2989
2990         (void) seteuid(0);
2991
2992         pasv_addr = ctrl_addr;
2993         pasv_addr.su_port = 0;
2994         len = pasv_addr.su_len;
2995
2996 #ifdef IP_PORTRANGE
2997         if (ctrl_addr.su_family == AF_INET) {
2998             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2999                                        : IP_PORTRANGE_DEFAULT;
3000
3001             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
3002                             &on, sizeof(on)) < 0)
3003                     goto pasv_error;
3004         }
3005 #endif
3006 #ifdef IPV6_PORTRANGE
3007         if (ctrl_addr.su_family == AF_INET6) {
3008             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
3009                                        : IPV6_PORTRANGE_DEFAULT;
3010
3011             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
3012                             &on, sizeof(on)) < 0)
3013                     goto pasv_error;
3014         }
3015 #endif
3016
3017         if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
3018                 goto pasv_error;
3019
3020         (void) seteuid(pw->pw_uid);
3021
3022         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
3023                 goto pasv_error;
3024         if (listen(pdata, 1) < 0)
3025                 goto pasv_error;
3026
3027 #define UC(b) (((int) b) & 0xff)
3028
3029         if (strcmp(cmd, "LPSV") == 0) {
3030                 p = (char *)&pasv_addr.su_port;
3031                 switch (pasv_addr.su_family) {
3032                 case AF_INET:
3033                         a = (char *) &pasv_addr.su_sin.sin_addr;
3034                 v4_reply:
3035                         reply(228,
3036 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3037                               4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3038                               2, UC(p[0]), UC(p[1]));
3039                         return;
3040                 case AF_INET6:
3041                         if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
3042                                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
3043                                 goto v4_reply;
3044                         }
3045                         a = (char *) &pasv_addr.su_sin6.sin6_addr;
3046                         reply(228,
3047 "Entering Long Passive Mode "
3048 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3049                               6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3050                               UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
3051                               UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
3052                               UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
3053                               2, UC(p[0]), UC(p[1]));
3054                         return;
3055                 }
3056         } else if (strcmp(cmd, "EPSV") == 0) {
3057                 switch (pasv_addr.su_family) {
3058                 case AF_INET:
3059                 case AF_INET6:
3060                         reply(229, "Entering Extended Passive Mode (|||%d|)",
3061                                 ntohs(pasv_addr.su_port));
3062                         return;
3063                 }
3064         } else {
3065                 /* more proper error code? */
3066         }
3067
3068 pasv_error:
3069         (void) seteuid(pw->pw_uid);
3070         (void) close(pdata);
3071         pdata = -1;
3072         perror_reply(425, "Can't open passive connection");
3073         return;
3074 }
3075
3076 /*
3077  * Generate unique name for file with basename "local"
3078  * and open the file in order to avoid possible races.
3079  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3080  * Return descriptor to the file, set "name" to its name.
3081  *
3082  * Generates failure reply on error.
3083  */
3084 static int
3085 guniquefd(char *local, char **name)
3086 {
3087         static char new[MAXPATHLEN];
3088         struct stat st;
3089         char *cp;
3090         int count;
3091         int fd;
3092
3093         cp = strrchr(local, '/');
3094         if (cp)
3095                 *cp = '\0';
3096         if (stat(cp ? local : ".", &st) < 0) {
3097                 perror_reply(553, cp ? local : ".");
3098                 return (-1);
3099         }
3100         if (cp) {
3101                 /*
3102                  * Let not overwrite dirname with counter suffix.
3103                  * -4 is for /nn\0
3104                  * In this extreme case dot won't be put in front of suffix.
3105                  */
3106                 if (strlen(local) > sizeof(new) - 4) {
3107                         reply(553, "Pathname too long.");
3108                         return (-1);
3109                 }
3110                 *cp = '/';
3111         }
3112         /* -4 is for the .nn<null> we put on the end below */
3113         (void) snprintf(new, sizeof(new) - 4, "%s", local);
3114         cp = new + strlen(new);
3115         /*
3116          * Don't generate dotfile unless requested explicitly.
3117          * This covers the case when basename gets truncated off
3118          * by buffer size.
3119          */
3120         if (cp > new && cp[-1] != '/')
3121                 *cp++ = '.';
3122         for (count = 0; count < 100; count++) {
3123                 /* At count 0 try unmodified name */
3124                 if (count)
3125                         (void)sprintf(cp, "%d", count);
3126                 if ((fd = open(count ? new : local,
3127                     O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3128                         *name = count ? new : local;
3129                         return (fd);
3130                 }
3131                 if (errno != EEXIST) {
3132                         perror_reply(553, count ? new : local);
3133                         return (-1);
3134                 }
3135         }
3136         reply(452, "Unique file name cannot be created.");
3137         return (-1);
3138 }
3139
3140 /*
3141  * Format and send reply containing system error number.
3142  */
3143 void
3144 perror_reply(int code, char *string)
3145 {
3146
3147         reply(code, "%s: %s.", string, strerror(errno));
3148 }
3149
3150 static char *onefile[] = {
3151         "",
3152         0
3153 };
3154
3155 void
3156 send_file_list(char *whichf)
3157 {
3158         struct stat st;
3159         DIR *dirp = NULL;
3160         struct dirent *dir;
3161         FILE *dout = NULL;
3162         char **dirlist, *dirname;
3163         int simple = 0;
3164         int freeglob = 0;
3165         glob_t gl;
3166
3167         if (strpbrk(whichf, "~{[*?") != NULL) {
3168                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3169
3170                 memset(&gl, 0, sizeof(gl));
3171                 gl.gl_matchc = MAXGLOBARGS;
3172                 flags |= GLOB_LIMIT;
3173                 freeglob = 1;
3174                 if (glob(whichf, flags, 0, &gl)) {
3175                         reply(550, "No matching files found.");
3176                         goto out;
3177                 } else if (gl.gl_pathc == 0) {
3178                         errno = ENOENT;
3179                         perror_reply(550, whichf);
3180                         goto out;
3181                 }
3182                 dirlist = gl.gl_pathv;
3183         } else {
3184                 onefile[0] = whichf;
3185                 dirlist = onefile;
3186                 simple = 1;
3187         }
3188
3189         while ((dirname = *dirlist++)) {
3190                 if (stat(dirname, &st) < 0) {
3191                         /*
3192                          * If user typed "ls -l", etc, and the client
3193                          * used NLST, do what the user meant.
3194                          */
3195                         if (dirname[0] == '-' && *dirlist == NULL &&
3196                             dout == NULL)
3197                                 retrieve(_PATH_LS " %s", dirname);
3198                         else
3199                                 perror_reply(550, whichf);
3200                         goto out;
3201                 }
3202
3203                 if (S_ISREG(st.st_mode)) {
3204                         if (dout == NULL) {
3205                                 dout = dataconn("file list", -1, "w");
3206                                 if (dout == NULL)
3207                                         goto out;
3208                                 STARTXFER;
3209                         }
3210                         START_UNSAFE;
3211                         fprintf(dout, "%s%s\n", dirname,
3212                                 type == TYPE_A ? "\r" : "");
3213                         END_UNSAFE;
3214                         if (ferror(dout))
3215                                 goto data_err;
3216                         byte_count += strlen(dirname) +
3217                                       (type == TYPE_A ? 2 : 1);
3218                         CHECKOOB(goto abrt);
3219                         continue;
3220                 } else if (!S_ISDIR(st.st_mode))
3221                         continue;
3222
3223                 if ((dirp = opendir(dirname)) == NULL)
3224                         continue;
3225
3226                 while ((dir = readdir(dirp)) != NULL) {
3227                         char nbuf[MAXPATHLEN];
3228
3229                         CHECKOOB(goto abrt);
3230
3231                         if (dir->d_name[0] == '.' && dir->d_namlen == 1)
3232                                 continue;
3233                         if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
3234                             dir->d_namlen == 2)
3235                                 continue;
3236
3237                         snprintf(nbuf, sizeof(nbuf),
3238                                 "%s/%s", dirname, dir->d_name);
3239
3240                         /*
3241                          * We have to do a stat to insure it's
3242                          * not a directory or special file.
3243                          */
3244                         if (simple || (stat(nbuf, &st) == 0 &&
3245                             S_ISREG(st.st_mode))) {
3246                                 if (dout == NULL) {
3247                                         dout = dataconn("file list", -1, "w");
3248                                         if (dout == NULL)
3249                                                 goto out;
3250                                         STARTXFER;
3251                                 }
3252                                 START_UNSAFE;
3253                                 if (nbuf[0] == '.' && nbuf[1] == '/')
3254                                         fprintf(dout, "%s%s\n", &nbuf[2],
3255                                                 type == TYPE_A ? "\r" : "");
3256                                 else
3257                                         fprintf(dout, "%s%s\n", nbuf,
3258                                                 type == TYPE_A ? "\r" : "");
3259                                 END_UNSAFE;
3260                                 if (ferror(dout))
3261                                         goto data_err;
3262                                 byte_count += strlen(nbuf) +
3263                                               (type == TYPE_A ? 2 : 1);
3264                                 CHECKOOB(goto abrt);
3265                         }
3266                 }
3267                 (void) closedir(dirp);
3268                 dirp = NULL;
3269         }
3270
3271         if (dout == NULL)
3272                 reply(550, "No files found.");
3273         else if (ferror(dout))
3274 data_err:       perror_reply(550, "Data connection");
3275         else
3276                 reply(226, "Transfer complete.");
3277 out:
3278         if (dout) {
3279                 ENDXFER;
3280 abrt:
3281                 (void) fclose(dout);
3282                 data = -1;
3283                 pdata = -1;
3284         }
3285         if (dirp)
3286                 (void) closedir(dirp);
3287         if (freeglob) {
3288                 freeglob = 0;
3289                 globfree(&gl);
3290         }
3291 }
3292
3293 void
3294 reapchild(int signo)
3295 {
3296         while (waitpid(-1, NULL, WNOHANG) > 0);
3297 }
3298
3299 #ifdef OLD_SETPROCTITLE
3300 /*
3301  * Clobber argv so ps will show what we're doing.  (Stolen from sendmail.)
3302  * Warning, since this is usually started from inetd.conf, it often doesn't
3303  * have much of an environment or arglist to overwrite.
3304  */
3305 void
3306 setproctitle(const char *fmt, ...)
3307 {
3308         int i;
3309         va_list ap;
3310         char *p, *bp, ch;
3311         char buf[LINE_MAX];
3312
3313         va_start(ap, fmt);
3314         (void)vsnprintf(buf, sizeof(buf), fmt, ap);
3315
3316         /* make ps print our process name */
3317         p = Argv[0];
3318         *p++ = '-';
3319
3320         i = strlen(buf);
3321         if (i > LastArgv - p - 2) {
3322                 i = LastArgv - p - 2;
3323                 buf[i] = '\0';
3324         }
3325         bp = buf;
3326         while (ch = *bp++)
3327                 if (ch != '\n' && ch != '\r')
3328                         *p++ = ch;
3329         while (p < LastArgv)
3330                 *p++ = ' ';
3331 }
3332 #endif /* OLD_SETPROCTITLE */
3333
3334 static void
3335 appendf(char **strp, char *fmt, ...)
3336 {
3337         va_list ap;
3338         char *ostr, *p;
3339
3340         va_start(ap, fmt);
3341         vasprintf(&p, fmt, ap);
3342         va_end(ap);
3343         if (p == NULL)
3344                 fatalerror("Ran out of memory.");
3345         if (*strp == NULL)
3346                 *strp = p;
3347         else {
3348                 ostr = *strp;
3349                 asprintf(strp, "%s%s", ostr, p);
3350                 if (*strp == NULL)
3351                         fatalerror("Ran out of memory.");
3352                 free(ostr);
3353         }
3354 }
3355
3356 static void
3357 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3358 {
3359         char *msg = NULL;
3360         char wd[MAXPATHLEN + 1];
3361
3362         if (logging <= 1)
3363                 return;
3364
3365         if (getcwd(wd, sizeof(wd) - 1) == NULL)
3366                 strcpy(wd, strerror(errno));
3367
3368         appendf(&msg, "%s", cmd);
3369         if (file1)
3370                 appendf(&msg, " %s", file1);
3371         if (file2)
3372                 appendf(&msg, " %s", file2);
3373         if (cnt >= 0)
3374                 appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3375         appendf(&msg, " (wd: %s", wd);
3376         if (guest || dochroot)
3377                 appendf(&msg, "; chrooted");
3378         appendf(&msg, ")");
3379         syslog(LOG_INFO, "%s", msg);
3380         free(msg);
3381 }
3382
3383 static void
3384 logxfer(char *name, off_t size, time_t start)
3385 {
3386         char buf[MAXPATHLEN + 1024];
3387         char path[MAXPATHLEN + 1];
3388         time_t now;
3389
3390         if (statfd >= 0) {
3391                 time(&now);
3392                 if (realpath(name, path) == NULL) {
3393                         syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3394                         return;
3395                 }
3396                 snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3397                         ctime(&now)+4, ident, remotehost,
3398                         path, (intmax_t)size,
3399                         (long)(now - start + (now == start)));
3400                 write(statfd, buf, strlen(buf));
3401         }
3402 }
3403
3404 static char *
3405 doublequote(char *s)
3406 {
3407         int n;
3408         char *p, *s2;
3409
3410         for (p = s, n = 0; *p; p++)
3411                 if (*p == '"')
3412                         n++;
3413
3414         if ((s2 = malloc(p - s + n + 1)) == NULL)
3415                 return (NULL);
3416
3417         for (p = s2; *s; s++, p++) {
3418                 if ((*p = *s) == '"')
3419                         *(++p) = '"';
3420         }
3421         *p = '\0';
3422
3423         return (s2);
3424 }
3425
3426 /* setup server socket for specified address family */
3427 /* if af is PF_UNSPEC more than one socket may be returned */
3428 /* the returned list is dynamically allocated, so caller needs to free it */
3429 static int *
3430 socksetup(int af, char *bindname, const char *bindport)
3431 {
3432         struct addrinfo hints, *res, *r;
3433         int error, maxs, *s, *socks;
3434         const int on = 1;
3435
3436         memset(&hints, 0, sizeof(hints));
3437         hints.ai_flags = AI_PASSIVE;
3438         hints.ai_family = af;
3439         hints.ai_socktype = SOCK_STREAM;
3440         error = getaddrinfo(bindname, bindport, &hints, &res);
3441         if (error) {
3442                 syslog(LOG_ERR, "%s", gai_strerror(error));
3443                 if (error == EAI_SYSTEM)
3444                         syslog(LOG_ERR, "%s", strerror(errno));
3445                 return NULL;
3446         }
3447
3448         /* Count max number of sockets we may open */
3449         for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3450                 ;
3451         socks = malloc((maxs + 1) * sizeof(int));
3452         if (!socks) {
3453                 freeaddrinfo(res);
3454                 syslog(LOG_ERR, "couldn't allocate memory for sockets");
3455                 return NULL;
3456         }
3457
3458         *socks = 0;   /* num of sockets counter at start of array */
3459         s = socks + 1;
3460         for (r = res; r; r = r->ai_next) {
3461                 *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3462                 if (*s < 0) {
3463                         syslog(LOG_DEBUG, "control socket: %m");
3464                         continue;
3465                 }
3466                 if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3467                     &on, sizeof(on)) < 0)
3468                         syslog(LOG_WARNING,
3469                             "control setsockopt (SO_REUSEADDR): %m");
3470                 if (r->ai_family == AF_INET6) {
3471                         if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3472                             &on, sizeof(on)) < 0)
3473                                 syslog(LOG_WARNING,
3474                                     "control setsockopt (IPV6_V6ONLY): %m");
3475                 }
3476                 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3477                         syslog(LOG_DEBUG, "control bind: %m");
3478                         close(*s);
3479                         continue;
3480                 }
3481                 (*socks)++;
3482                 s++;
3483         }
3484
3485         if (res)
3486                 freeaddrinfo(res);
3487
3488         if (*socks == 0) {
3489                 syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3490                 free(socks);
3491                 return NULL;
3492         }
3493         return(socks);
3494 }