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_gecos);
 969                 free(save.pw_dir);
 970                 free(save.pw_shell);
 971         }
 972         save = *p;
 973         save.pw_name = sgetsave(p->pw_name);
 974         save.pw_passwd = sgetsave(p->pw_passwd);
 975         save.pw_gecos = sgetsave(p->pw_gecos);
 976         save.pw_dir = sgetsave(p->pw_dir);
 977         save.pw_shell = sgetsave(p->pw_shell);
 978         return (&save);
 979 }
 980
 981 static int login_attempts;      /* number of failed login attempts */
 982 static int askpasswd;           /* had user command, ask for passwd */
 983 static char curname[MAXLOGNAME];        /* current USER name */
 984
 985 /*
 986  * USER command.
 987  * Sets global passwd pointer pw if named account exists and is acceptable;
 988  * sets askpasswd if a PASS command is expected.  If logged in previously,
 989  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
 990  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
 991  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
 992  * requesting login privileges.  Disallow anyone who does not have a standard
 993  * shell as returned by getusershell().  Disallow anyone mentioned in the file
 994  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
 995  */
 996 void
 997 user(char *name)
 998 {
 999         int ecode;
1000         char *cp, *shell;
1001
1002         if (logged_in) {
1003                 if (guest) {
1004                         reply(530, "Can't change user from guest login.");
1005                         return;
1006                 } else if (dochroot) {
1007                         reply(530, "Can't change user from chroot user.");
1008                         return;
1009                 }
1010                 end_login();
1011         }
1012
1013         guest = 0;
1014 #ifdef VIRTUAL_HOSTING
1015         pw = sgetpwnam(thishost->anonuser);
1016 #else
1017         pw = sgetpwnam("ftp");
1018 #endif
1019         if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
1020                 if (checkuser(_PATH_FTPUSERS, "ftp", 0, NULL, &ecode) ||
1021                     (ecode != 0 && ecode != ENOENT))
1022                         reply(530, "User %s access denied.", name);
1023                 else if (checkuser(_PATH_FTPUSERS, "anonymous", 0, NULL, &ecode) ||
1024                     (ecode != 0 && ecode != ENOENT))
1025                         reply(530, "User %s access denied.", name);
1026                 else if (pw != NULL) {
1027                         guest = 1;
1028                         askpasswd = 1;
1029                         reply(331,
1030                         "Guest login ok, send your email address as password.");
1031                 } else
1032                         reply(530, "User %s unknown.", name);
1033                 if (!askpasswd && logging)
1034                         syslog(LOG_NOTICE,
1035                             "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
1036                 return;
1037         }
1038         if (anon_only != 0) {
1039                 reply(530, "Sorry, only anonymous ftp allowed.");
1040                 return;
1041         }
1042
1043         if ((pw = sgetpwnam(name))) {
1044                 if ((shell = pw->pw_shell) == NULL || *shell == 0)
1045                         shell = _PATH_BSHELL;
1046                 setusershell();
1047                 while ((cp = getusershell()) != NULL)
1048                         if (strcmp(cp, shell) == 0)
1049                                 break;
1050                 endusershell();
1051
1052                 if (cp == NULL ||
1053                     (checkuser(_PATH_FTPUSERS, name, 1, NULL, &ecode) ||
1054                     (ecode != 0 && ecode != ENOENT))) {
1055                         reply(530, "User %s access denied.", name);
1056                         if (logging)
1057                                 syslog(LOG_NOTICE,
1058                                     "FTP LOGIN REFUSED FROM %s, %s",
1059                                     remotehost, name);
1060                         pw = NULL;
1061                         return;
1062                 }
1063         }
1064         if (logging)
1065                 strncpy(curname, name, sizeof(curname)-1);
1066
1067         pwok = 0;
1068 #ifdef USE_PAM
1069         /* XXX Kluge! The conversation mechanism needs to be fixed. */
1070 #endif
1071         if (opiechallenge(&opiedata, name, opieprompt) == 0) {
1072                 pwok = (pw != NULL) &&
1073                        opieaccessfile(remotehost) &&
1074                        opiealways(pw->pw_dir);
1075                 reply(331, "Response to %s %s for %s.",
1076                       opieprompt, pwok ? "requested" : "required", name);
1077         } else {
1078                 pwok = 1;
1079                 reply(331, "Password required for %s.", name);
1080         }
1081         askpasswd = 1;
1082         /*
1083          * Delay before reading passwd after first failed
1084          * attempt to slow down passwd-guessing programs.
1085          */
1086         if (login_attempts)
1087                 sleep(login_attempts);
1088 }
1089
1090 /*
1091  * Check if a user is in the file "fname",
1092  * return a pointer to a malloc'd string with the rest
1093  * of the matching line in "residue" if not NULL.
1094  */
1095 static int
1096 checkuser(char *fname, char *name, int pwset, char **residue, int *ecode)
1097 {
1098         FILE *fd;
1099         int found = 0;
1100         size_t len;
1101         char *line, *mp, *p;
1102
1103         if (ecode != NULL)
1104                 *ecode = 0;
1105         if ((fd = fopen(fname, "r")) != NULL) {
1106                 while (!found && (line = fgetln(fd, &len)) != NULL) {
1107                         /* skip comments */
1108                         if (line[0] == '#')
1109                                 continue;
1110                         if (line[len - 1] == '\n') {
1111                                 line[len - 1] = '\0';
1112                                 mp = NULL;
1113                         } else {
1114                                 if ((mp = malloc(len + 1)) == NULL)
1115                                         fatalerror("Ran out of memory.");
1116                                 memcpy(mp, line, len);
1117                                 mp[len] = '\0';
1118                                 line = mp;
1119                         }
1120                         /* avoid possible leading and trailing whitespace */
1121                         p = strtok(line, " \t");
1122                         /* skip empty lines */
1123                         if (p == NULL)
1124                                 goto nextline;
1125                         /*
1126                          * if first chr is '@', check group membership
1127                          */
1128                         if (p[0] == '@') {
1129                                 int i = 0;
1130                                 struct group *grp;
1131
1132                                 if (p[1] == '\0') /* single @ matches anyone */
1133                                         found = 1;
1134                                 else {
1135                                         if ((grp = getgrnam(p+1)) == NULL)
1136                                                 goto nextline;
1137                                         /*
1138                                          * Check user's default group
1139                                          */
1140                                         if (pwset && grp->gr_gid == pw->pw_gid)
1141                                                 found = 1;
1142                                         /*
1143                                          * Check supplementary groups
1144                                          */
1145                                         while (!found && grp->gr_mem[i])
1146                                                 found = strcmp(name,
1147                                                         grp->gr_mem[i++])
1148                                                         == 0;
1149                                 }
1150                         }
1151                         /*
1152                          * Otherwise, just check for username match
1153                          */
1154                         else
1155                                 found = strcmp(p, name) == 0;
1156                         /*
1157                          * Save the rest of line to "residue" if matched
1158                          */
1159                         if (found && residue) {
1160                                 if ((p = strtok(NULL, "")) != NULL)
1161                                         p += strspn(p, " \t");
1162                                 if (p && *p) {
1163                                         if ((*residue = strdup(p)) == NULL)
1164                                                 fatalerror("Ran out of memory.");
1165                                 } else
1166                                         *residue = NULL;
1167                         }
1168 nextline:
1169                         if (mp)
1170                                 free(mp);
1171                 }
1172                 (void) fclose(fd);
1173         } else if (ecode != NULL)
1174                 *ecode = errno;
1175         return (found);
1176 }
1177
1178 /*
1179  * Terminate login as previous user, if any, resetting state;
1180  * used when USER command is given or login fails.
1181  */
1182 static void
1183 end_login(void)
1184 {
1185 #ifdef USE_PAM
1186         int e;
1187 #endif
1188
1189         (void) seteuid(0);
1190         if (logged_in && dowtmp)
1191                 ftpd_logwtmp(wtmpid, NULL, NULL);
1192         pw = NULL;
1193 #ifdef  LOGIN_CAP
1194         setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
1195                        LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
1196                        LOGIN_SETENV));
1197 #endif
1198 #ifdef USE_PAM
1199         if (pamh) {
1200                 if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS)
1201                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1202                 if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS)
1203                         syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e));
1204                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS)
1205                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1206                 pamh = NULL;
1207         }
1208 #endif
1209         logged_in = 0;
1210         guest = 0;
1211         dochroot = 0;
1212 }
1213
1214 #ifdef USE_PAM
1215
1216 /*
1217  * the following code is stolen from imap-uw PAM authentication module and
1218  * login.c
1219  */
1220 #define COPY_STRING(s) (s ? strdup(s) : NULL)
1221
1222 struct cred_t {
1223         const char *uname;              /* user name */
1224         const char *pass;               /* password */
1225 };
1226 typedef struct cred_t cred_t;
1227
1228 static int
1229 auth_conv(int num_msg, const struct pam_message **msg,
1230           struct pam_response **resp, void *appdata)
1231 {
1232         int i;
1233         cred_t *cred = (cred_t *) appdata;
1234         struct pam_response *reply;
1235
1236         reply = calloc(num_msg, sizeof *reply);
1237         if (reply == NULL)
1238                 return PAM_BUF_ERR;
1239
1240         for (i = 0; i < num_msg; i++) {
1241                 switch (msg[i]->msg_style) {
1242                 case PAM_PROMPT_ECHO_ON:        /* assume want user name */
1243                         reply[i].resp_retcode = PAM_SUCCESS;
1244                         reply[i].resp = COPY_STRING(cred->uname);
1245                         /* PAM frees resp. */
1246                         break;
1247                 case PAM_PROMPT_ECHO_OFF:       /* assume want password */
1248                         reply[i].resp_retcode = PAM_SUCCESS;
1249                         reply[i].resp = COPY_STRING(cred->pass);
1250                         /* PAM frees resp. */
1251                         break;
1252                 case PAM_TEXT_INFO:
1253                 case PAM_ERROR_MSG:
1254                         reply[i].resp_retcode = PAM_SUCCESS;
1255                         reply[i].resp = NULL;
1256                         break;
1257                 default:                        /* unknown message style */
1258                         free(reply);
1259                         return PAM_CONV_ERR;
1260                 }
1261         }
1262
1263         *resp = reply;
1264         return PAM_SUCCESS;
1265 }
1266
1267 /*
1268  * Attempt to authenticate the user using PAM.  Returns 0 if the user is
1269  * authenticated, or 1 if not authenticated.  If some sort of PAM system
1270  * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
1271  * function returns -1.  This can be used as an indication that we should
1272  * fall back to a different authentication mechanism.
1273  */
1274 static int
1275 auth_pam(struct passwd **ppw, const char *pass)
1276 {
1277         const char *tmpl_user;
1278         const void *item;
1279         int rval;
1280         int e;
1281         cred_t auth_cred = { (*ppw)->pw_name, pass };
1282         struct pam_conv conv = { &auth_conv, &auth_cred };
1283
1284         e = pam_start("ftpd", (*ppw)->pw_name, &conv, &pamh);
1285         if (e != PAM_SUCCESS) {
1286                 /*
1287                  * In OpenPAM, it's OK to pass NULL to pam_strerror()
1288                  * if context creation has failed in the first place.
1289                  */
1290                 syslog(LOG_ERR, "pam_start: %s", pam_strerror(NULL, e));
1291                 return -1;
1292         }
1293
1294         e = pam_set_item(pamh, PAM_RHOST, remotehost);
1295         if (e != PAM_SUCCESS) {
1296                 syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
1297                         pam_strerror(pamh, e));
1298                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1299                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1300                 }
1301                 pamh = NULL;
1302                 return -1;
1303         }
1304
1305         e = pam_authenticate(pamh, 0);
1306         switch (e) {
1307         case PAM_SUCCESS:
1308                 /*
1309                  * With PAM we support the concept of a "template"
1310                  * user.  The user enters a login name which is
1311                  * authenticated by PAM, usually via a remote service
1312                  * such as RADIUS or TACACS+.  If authentication
1313                  * succeeds, a different but related "template" name
1314                  * is used for setting the credentials, shell, and
1315                  * home directory.  The name the user enters need only
1316                  * exist on the remote authentication server, but the
1317                  * template name must be present in the local password
1318                  * database.
1319                  *
1320                  * This is supported by two various mechanisms in the
1321                  * individual modules.  However, from the application's
1322                  * point of view, the template user is always passed
1323                  * back as a changed value of the PAM_USER item.
1324                  */
1325                 if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
1326                     PAM_SUCCESS) {
1327                         tmpl_user = (const char *) item;
1328                         if (strcmp((*ppw)->pw_name, tmpl_user) != 0)
1329                                 *ppw = getpwnam(tmpl_user);
1330                 } else
1331                         syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
1332                             pam_strerror(pamh, e));
1333                 rval = 0;
1334                 break;
1335
1336         case PAM_AUTH_ERR:
1337         case PAM_USER_UNKNOWN:
1338         case PAM_MAXTRIES:
1339                 rval = 1;
1340                 break;
1341
1342         default:
1343                 syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
1344                 rval = -1;
1345                 break;
1346         }
1347
1348         if (rval == 0) {
1349                 e = pam_acct_mgmt(pamh, 0);
1350                 if (e != PAM_SUCCESS) {
1351                         syslog(LOG_ERR, "pam_acct_mgmt: %s",
1352                                                 pam_strerror(pamh, e));
1353                         rval = 1;
1354                 }
1355         }
1356
1357         if (rval != 0) {
1358                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1359                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1360                 }
1361                 pamh = NULL;
1362         }
1363         return rval;
1364 }
1365
1366 #endif /* USE_PAM */
1367
1368 void
1369 pass(char *passwd)
1370 {
1371         int rval, ecode;
1372         FILE *fd;
1373 #ifdef  LOGIN_CAP
1374         login_cap_t *lc = NULL;
1375 #endif
1376 #ifdef USE_PAM
1377         int e;
1378 #endif
1379         char *residue = NULL;
1380         char *xpasswd;
1381
1382         if (logged_in || askpasswd == 0) {
1383                 reply(503, "Login with USER first.");
1384                 return;
1385         }
1386         askpasswd = 0;
1387         if (!guest) {           /* "ftp" is only account allowed no password */
1388                 if (pw == NULL) {
1389                         rval = 1;       /* failure below */
1390                         goto skip;
1391                 }
1392 #ifdef USE_PAM
1393                 rval = auth_pam(&pw, passwd);
1394                 if (rval >= 0) {
1395                         opieunlock();
1396                         goto skip;
1397                 }
1398 #endif
1399                 if (opieverify(&opiedata, passwd) == 0)
1400                         xpasswd = pw->pw_passwd;
1401                 else if (pwok) {
1402                         xpasswd = crypt(passwd, pw->pw_passwd);
1403                         if (passwd[0] == '\0' && pw->pw_passwd[0] != '\0')
1404                                 xpasswd = ":";
1405                 } else {
1406                         rval = 1;
1407                         goto skip;
1408                 }
1409                 rval = strcmp(pw->pw_passwd, xpasswd);
1410                 if (pw->pw_expire && time(NULL) >= pw->pw_expire)
1411                         rval = 1;       /* failure */
1412 skip:
1413                 /*
1414                  * If rval == 1, the user failed the authentication check
1415                  * above.  If rval == 0, either PAM or local authentication
1416                  * succeeded.
1417                  */
1418                 if (rval) {
1419                         reply(530, "Login incorrect.");
1420                         if (logging) {
1421                                 syslog(LOG_NOTICE,
1422                                     "FTP LOGIN FAILED FROM %s",
1423                                     remotehost);
1424                                 syslog(LOG_AUTHPRIV | LOG_NOTICE,
1425                                     "FTP LOGIN FAILED FROM %s, %s",
1426                                     remotehost, curname);
1427                         }
1428                         pw = NULL;
1429                         if (login_attempts++ >= 5) {
1430                                 syslog(LOG_NOTICE,
1431                                     "repeated login failures from %s",
1432                                     remotehost);
1433                                 exit(0);
1434                         }
1435                         return;
1436                 }
1437         }
1438         login_attempts = 0;             /* this time successful */
1439         if (setegid(pw->pw_gid) < 0) {
1440                 reply(550, "Can't set gid.");
1441                 return;
1442         }
1443         /* May be overridden by login.conf */
1444         (void) umask(defumask);
1445 #ifdef  LOGIN_CAP
1446         if ((lc = login_getpwclass(pw)) != NULL) {
1447                 char    remote_ip[NI_MAXHOST];
1448
1449                 if (getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1450                         remote_ip, sizeof(remote_ip) - 1, NULL, 0,
1451                         NI_NUMERICHOST))
1452                                 *remote_ip = 0;
1453                 remote_ip[sizeof(remote_ip) - 1] = 0;
1454                 if (!auth_hostok(lc, remotehost, remote_ip)) {
1455                         syslog(LOG_INFO|LOG_AUTH,
1456                             "FTP LOGIN FAILED (HOST) as %s: permission denied.",
1457                             pw->pw_name);
1458                         reply(530, "Permission denied.");
1459                         pw = NULL;
1460                         return;
1461                 }
1462                 if (!auth_timeok(lc, time(NULL))) {
1463                         reply(530, "Login not available right now.");
1464                         pw = NULL;
1465                         return;
1466                 }
1467         }
1468         setusercontext(lc, pw, 0, LOGIN_SETALL &
1469                        ~(LOGIN_SETUSER | LOGIN_SETPATH | LOGIN_SETENV));
1470 #else
1471         setlogin(pw->pw_name);
1472         (void) initgroups(pw->pw_name, pw->pw_gid);
1473 #endif
1474
1475 #ifdef USE_PAM
1476         if (pamh) {
1477                 if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
1478                         syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, e));
1479                 } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
1480                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1481                 }
1482         }
1483 #endif
1484
1485         dochroot =
1486                 checkuser(_PATH_FTPCHROOT, pw->pw_name, 1, &residue, &ecode)
1487 #ifdef  LOGIN_CAP       /* Allow login.conf configuration as well */
1488                 || login_getcapbool(lc, "ftp-chroot", 0)
1489 #endif
1490         ;
1491         /*
1492          * It is possible that checkuser() failed to open the chroot file.
1493          * If this is the case, report that logins are un-available, since we
1494          * have no way of checking whether or not the user should be chrooted.
1495          * We ignore ENOENT since it is not required that this file be present.
1496          */
1497         if (ecode != 0 && ecode != ENOENT) {
1498                 reply(530, "Login not available right now.");
1499                 return;
1500         }
1501         chrootdir = NULL;
1502
1503         /* Disable wtmp logging when chrooting. */
1504         if (dochroot || guest)
1505                 dowtmp = 0;
1506         if (dowtmp)
1507                 ftpd_logwtmp(wtmpid, pw->pw_name,
1508                     (struct sockaddr *)&his_addr);
1509         logged_in = 1;
1510
1511         if (guest && stats && statfd < 0)
1512 #ifdef VIRTUAL_HOSTING
1513                 statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1514 #else
1515                 statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1516 #endif
1517                 if (statfd < 0)
1518                         stats = 0;
1519
1520         /*
1521          * For a chrooted local user,
1522          * a) see whether ftpchroot(5) specifies a chroot directory,
1523          * b) extract the directory pathname from the line,
1524          * c) expand it to the absolute pathname if necessary.
1525          */
1526         if (dochroot && residue &&
1527             (chrootdir = strtok(residue, " \t")) != NULL) {
1528                 if (chrootdir[0] != '/')
1529                         asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1530                 else
1531                         chrootdir = strdup(chrootdir); /* make it permanent */
1532                 if (chrootdir == NULL)
1533                         fatalerror("Ran out of memory.");
1534         }
1535         if (guest || dochroot) {
1536                 /*
1537                  * If no chroot directory set yet, use the login directory.
1538                  * Copy it so it can be modified while pw->pw_dir stays intact.
1539                  */
1540                 if (chrootdir == NULL &&
1541                     (chrootdir = strdup(pw->pw_dir)) == NULL)
1542                         fatalerror("Ran out of memory.");
1543                 /*
1544                  * Check for the "/chroot/./home" syntax,
1545                  * separate the chroot and home directory pathnames.
1546                  */
1547                 if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1548                         *(homedir++) = '\0';    /* wipe '/' */
1549                         homedir++;              /* skip '.' */
1550                 } else {
1551                         /*
1552                          * We MUST do a chdir() after the chroot. Otherwise
1553                          * the old current directory will be accessible as "."
1554                          * outside the new root!
1555                          */
1556                         homedir = "/";
1557                 }
1558                 /*
1559                  * Finally, do chroot()
1560                  */
1561                 if (chroot(chrootdir) < 0) {
1562                         reply(550, "Can't change root.");
1563                         goto bad;
1564                 }
1565         } else  /* real user w/o chroot */
1566                 homedir = pw->pw_dir;
1567         /*
1568          * Set euid *before* doing chdir() so
1569          * a) the user won't be carried to a directory that he couldn't reach
1570          *    on his own due to no permission to upper path components,
1571          * b) NFS mounted homedirs w/restrictive permissions will be accessible
1572          *    (uid 0 has no root power over NFS if not mapped explicitly.)
1573          */
1574         if (seteuid(pw->pw_uid) < 0) {
1575                 reply(550, "Can't set uid.");
1576                 goto bad;
1577         }
1578         if (chdir(homedir) < 0) {
1579                 if (guest || dochroot) {
1580                         reply(550, "Can't change to base directory.");
1581                         goto bad;
1582                 } else {
1583                         if (chdir("/") < 0) {
1584                                 reply(550, "Root is inaccessible.");
1585                                 goto bad;
1586                         }
1587                         lreply(230, "No directory! Logging in with home=/.");
1588                 }
1589         }
1590
1591         /*
1592          * Display a login message, if it exists.
1593          * N.B. reply(230,) must follow the message.
1594          */
1595 #ifdef VIRTUAL_HOSTING
1596         fd = fopen(thishost->loginmsg, "r");
1597 #else
1598         fd = fopen(_PATH_FTPLOGINMESG, "r");
1599 #endif
1600         if (fd != NULL) {
1601                 char *cp, line[LINE_MAX];
1602
1603                 while (fgets(line, sizeof(line), fd) != NULL) {
1604                         if ((cp = strchr(line, '\n')) != NULL)
1605                                 *cp = '\0';
1606                         lreply(230, "%s", line);
1607                 }
1608                 (void) fflush(stdout);
1609                 (void) fclose(fd);
1610         }
1611         if (guest) {
1612                 if (ident != NULL)
1613                         free(ident);
1614                 ident = strdup(passwd);
1615                 if (ident == NULL)
1616                         fatalerror("Ran out of memory.");
1617
1618                 reply(230, "Guest login ok, access restrictions apply.");
1619 #ifdef SETPROCTITLE
1620 #ifdef VIRTUAL_HOSTING
1621                 if (thishost != firsthost)
1622                         snprintf(proctitle, sizeof(proctitle),
1623                                  "%s: anonymous(%s)/%s", remotehost, hostname,
1624                                  passwd);
1625                 else
1626 #endif
1627                         snprintf(proctitle, sizeof(proctitle),
1628                                  "%s: anonymous/%s", remotehost, passwd);
1629                 setproctitle("%s", proctitle);
1630 #endif /* SETPROCTITLE */
1631                 if (logging)
1632                         syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1633                             remotehost, passwd);
1634         } else {
1635                 if (dochroot)
1636                         reply(230, "User %s logged in, "
1637                                    "access restrictions apply.", pw->pw_name);
1638                 else
1639                         reply(230, "User %s logged in.", pw->pw_name);
1640
1641 #ifdef SETPROCTITLE
1642                 snprintf(proctitle, sizeof(proctitle),
1643                          "%s: user/%s", remotehost, pw->pw_name);
1644                 setproctitle("%s", proctitle);
1645 #endif /* SETPROCTITLE */
1646                 if (logging)
1647                         syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1648                             remotehost, pw->pw_name);
1649         }
1650         if (logging && (guest || dochroot))
1651                 syslog(LOG_INFO, "session root changed to %s", chrootdir);
1652 #ifdef  LOGIN_CAP
1653         login_close(lc);
1654 #endif
1655         if (residue)
1656                 free(residue);
1657         return;
1658 bad:
1659         /* Forget all about it... */
1660 #ifdef  LOGIN_CAP
1661         login_close(lc);
1662 #endif
1663         if (residue)
1664                 free(residue);
1665         end_login();
1666 }
1667
1668 void
1669 retrieve(char *cmd, char *name)
1670 {
1671         FILE *fin, *dout;
1672         struct stat st;
1673         int (*closefunc)(FILE *);
1674         time_t start;
1675
1676         if (cmd == 0) {
1677                 fin = fopen(name, "r"), closefunc = fclose;
1678                 st.st_size = 0;
1679         } else {
1680                 char line[BUFSIZ];
1681
1682                 (void) snprintf(line, sizeof(line), cmd, name), name = line;
1683                 fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1684                 st.st_size = -1;
1685                 st.st_blksize = BUFSIZ;
1686         }
1687         if (fin == NULL) {
1688                 if (errno != 0) {
1689                         perror_reply(550, name);
1690                         if (cmd == 0) {
1691                                 LOGCMD("get", name);
1692                         }
1693                 }
1694                 return;
1695         }
1696         byte_count = -1;
1697         if (cmd == 0) {
1698                 if (fstat(fileno(fin), &st) < 0) {
1699                         perror_reply(550, name);
1700                         goto done;
1701                 }
1702                 if (!S_ISREG(st.st_mode)) {
1703                         /*
1704                          * Never sending a raw directory is a workaround
1705                          * for buggy clients that will attempt to RETR
1706                          * a directory before listing it, e.g., Mozilla.
1707                          * Preventing a guest from getting irregular files
1708                          * is a simple security measure.
1709                          */
1710                         if (S_ISDIR(st.st_mode) || guest) {
1711                                 reply(550, "%s: not a plain file.", name);
1712                                 goto done;
1713                         }
1714                         st.st_size = -1;
1715                         /* st.st_blksize is set for all descriptor types */
1716                 }
1717         }
1718         if (restart_point) {
1719                 if (type == TYPE_A) {
1720                         off_t i, n;
1721                         int c;
1722
1723                         n = restart_point;
1724                         i = 0;
1725                         while (i++ < n) {
1726                                 if ((c=getc(fin)) == EOF) {
1727                                         perror_reply(550, name);
1728                                         goto done;
1729                                 }
1730                                 if (c == '\n')
1731                                         i++;
1732                         }
1733                 } else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1734                         perror_reply(550, name);
1735                         goto done;
1736                 }
1737         }
1738         dout = dataconn(name, st.st_size, "w");
1739         if (dout == NULL)
1740                 goto done;
1741         time(&start);
1742         send_data(fin, dout, st.st_blksize, st.st_size,
1743                   restart_point == 0 && cmd == 0 && S_ISREG(st.st_mode));
1744         if (cmd == 0 && guest && stats && byte_count > 0)
1745                 logxfer(name, byte_count, start);
1746         (void) fclose(dout);
1747         data = -1;
1748         pdata = -1;
1749 done:
1750         if (cmd == 0)
1751                 LOGBYTES("get", name, byte_count);
1752         (*closefunc)(fin);
1753 }
1754
1755 void
1756 store(char *name, char *mode, int unique)
1757 {
1758         int fd;
1759         FILE *fout, *din;
1760         int (*closefunc)(FILE *);
1761
1762         if (*mode == 'a') {             /* APPE */
1763                 if (unique) {
1764                         /* Programming error */
1765                         syslog(LOG_ERR, "Internal: unique flag to APPE");
1766                         unique = 0;
1767                 }
1768                 if (guest && noguestmod) {
1769                         reply(550, "Appending to existing file denied.");
1770                         goto err;
1771                 }
1772                 restart_point = 0;      /* not affected by preceding REST */
1773         }
1774         if (unique)                     /* STOU overrides REST */
1775                 restart_point = 0;
1776         if (guest && noguestmod) {
1777                 if (restart_point) {    /* guest STOR w/REST */
1778                         reply(550, "Modifying existing file denied.");
1779                         goto err;
1780                 } else                  /* treat guest STOR as STOU */
1781                         unique = 1;
1782         }
1783
1784         if (restart_point)
1785                 mode = "r+";    /* so ASCII manual seek can work */
1786         if (unique) {
1787                 if ((fd = guniquefd(name, &name)) < 0)
1788                         goto err;
1789                 fout = fdopen(fd, mode);
1790         } else
1791                 fout = fopen(name, mode);
1792         closefunc = fclose;
1793         if (fout == NULL) {
1794                 perror_reply(553, name);
1795                 goto err;
1796         }
1797         byte_count = -1;
1798         if (restart_point) {
1799                 if (type == TYPE_A) {
1800                         off_t i, n;
1801                         int c;
1802
1803                         n = restart_point;
1804                         i = 0;
1805                         while (i++ < n) {
1806                                 if ((c=getc(fout)) == EOF) {
1807                                         perror_reply(550, name);
1808                                         goto done;
1809                                 }
1810                                 if (c == '\n')
1811                                         i++;
1812                         }
1813                         /*
1814                          * We must do this seek to "current" position
1815                          * because we are changing from reading to
1816                          * writing.
1817                          */
1818                         if (fseeko(fout, 0, SEEK_CUR) < 0) {
1819                                 perror_reply(550, name);
1820                                 goto done;
1821                         }
1822                 } else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1823                         perror_reply(550, name);
1824                         goto done;
1825                 }
1826         }
1827         din = dataconn(name, -1, "r");
1828         if (din == NULL)
1829                 goto done;
1830         if (receive_data(din, fout) == 0) {
1831                 if (unique)
1832                         reply(226, "Transfer complete (unique file name:%s).",
1833                             name);
1834                 else
1835                         reply(226, "Transfer complete.");
1836         }
1837         (void) fclose(din);
1838         data = -1;
1839         pdata = -1;
1840 done:
1841         LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1842         (*closefunc)(fout);
1843         return;
1844 err:
1845         LOGCMD(*mode == 'a' ? "append" : "put" , name);
1846         return;
1847 }
1848
1849 static FILE *
1850 getdatasock(char *mode)
1851 {
1852         int on = 1, s, t, tries;
1853
1854         if (data >= 0)
1855                 return (fdopen(data, mode));
1856
1857         s = socket(data_dest.su_family, SOCK_STREAM, 0);
1858         if (s < 0)
1859                 goto bad;
1860         if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1861                 syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1862         /* anchor socket to avoid multi-homing problems */
1863         data_source = ctrl_addr;
1864         data_source.su_port = htons(dataport);
1865         (void) seteuid(0);
1866         for (tries = 1; ; tries++) {
1867                 /*
1868                  * We should loop here since it's possible that
1869                  * another ftpd instance has passed this point and is
1870                  * trying to open a data connection in active mode now.
1871                  * Until the other connection is opened, we'll be getting
1872                  * EADDRINUSE because no SOCK_STREAM sockets in the system
1873                  * can share both local and remote addresses, localIP:20
1874                  * and *:* in this case.
1875                  */
1876                 if (bind(s, (struct sockaddr *)&data_source,
1877                     data_source.su_len) >= 0)
1878                         break;
1879                 if (errno != EADDRINUSE || tries > 10)
1880                         goto bad;
1881                 sleep(tries);
1882         }
1883         (void) seteuid(pw->pw_uid);
1884 #ifdef IP_TOS
1885         if (data_source.su_family == AF_INET)
1886       {
1887         on = IPTOS_THROUGHPUT;
1888         if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1889                 syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1890       }
1891 #endif
1892 #ifdef TCP_NOPUSH
1893         /*
1894          * Turn off push flag to keep sender TCP from sending short packets
1895          * at the boundaries of each write().
1896          */
1897         on = 1;
1898         if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1899                 syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1900 #endif
1901         return (fdopen(s, mode));
1902 bad:
1903         /* Return the real value of errno (close may change it) */
1904         t = errno;
1905         (void) seteuid(pw->pw_uid);
1906         (void) close(s);
1907         errno = t;
1908         return (NULL);
1909 }
1910
1911 static FILE *
1912 dataconn(char *name, off_t size, char *mode)
1913 {
1914         char sizebuf[32];
1915         FILE *file;
1916         int retry = 0, tos, conerrno;
1917
1918         file_size = size;
1919         byte_count = 0;
1920         if (size != -1)
1921                 (void) snprintf(sizebuf, sizeof(sizebuf),
1922                                 " (%jd bytes)", (intmax_t)size);
1923         else
1924                 *sizebuf = '\0';
1925         if (pdata >= 0) {
1926                 union sockunion from;
1927                 socklen_t fromlen = ctrl_addr.su_len;
1928                 int flags, s;
1929                 struct timeval timeout;
1930                 fd_set set;
1931
1932                 FD_ZERO(&set);
1933                 FD_SET(pdata, &set);
1934
1935                 timeout.tv_usec = 0;
1936                 timeout.tv_sec = 120;
1937
1938                 /*
1939                  * Granted a socket is in the blocking I/O mode,
1940                  * accept() will block after a successful select()
1941                  * if the selected connection dies in between.
1942                  * Therefore set the non-blocking I/O flag here.
1943                  */
1944                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1945                     fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1946                         goto pdata_err;
1947                 if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1948                     (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1949                         goto pdata_err;
1950                 (void) close(pdata);
1951                 pdata = s;
1952                 /*
1953                  * Unset the inherited non-blocking I/O flag
1954                  * on the child socket so stdio can work on it.
1955                  */
1956                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1957                     fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1958                         goto pdata_err;
1959 #ifdef IP_TOS
1960                 if (from.su_family == AF_INET)
1961               {
1962                 tos = IPTOS_THROUGHPUT;
1963                 if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1964                         syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1965               }
1966 #endif
1967                 reply(150, "Opening %s mode data connection for '%s'%s.",
1968                      type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1969                 return (fdopen(pdata, mode));
1970 pdata_err:
1971                 reply(425, "Can't open data connection.");
1972                 (void) close(pdata);
1973                 pdata = -1;
1974                 return (NULL);
1975         }
1976         if (data >= 0) {
1977                 reply(125, "Using existing data connection for '%s'%s.",
1978                     name, sizebuf);
1979                 usedefault = 1;
1980                 return (fdopen(data, mode));
1981         }
1982         if (usedefault)
1983                 data_dest = his_addr;
1984         usedefault = 1;
1985         do {
1986                 file = getdatasock(mode);
1987                 if (file == NULL) {
1988                         char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
1989
1990                         if (getnameinfo((struct sockaddr *)&data_source,
1991                                 data_source.su_len,
1992                                 hostbuf, sizeof(hostbuf) - 1,
1993                                 portbuf, sizeof(portbuf) - 1,
1994                                 NI_NUMERICHOST|NI_NUMERICSERV))
1995                                         *hostbuf = *portbuf = 0;
1996                         hostbuf[sizeof(hostbuf) - 1] = 0;
1997                         portbuf[sizeof(portbuf) - 1] = 0;
1998                         reply(425, "Can't create data socket (%s,%s): %s.",
1999                                 hostbuf, portbuf, strerror(errno));
2000                         return (NULL);
2001                 }
2002                 data = fileno(file);
2003                 conerrno = 0;
2004                 if (connect(data, (struct sockaddr *)&data_dest,
2005                     data_dest.su_len) == 0)
2006                         break;
2007                 conerrno = errno;
2008                 (void) fclose(file);
2009                 data = -1;
2010                 if (conerrno == EADDRINUSE) {
2011                         sleep(swaitint);
2012                         retry += swaitint;
2013                 } else {
2014                         break;
2015                 }
2016         } while (retry <= swaitmax);
2017         if (conerrno != 0) {
2018                 reply(425, "Can't build data connection: %s.",
2019                            strerror(conerrno));
2020                 return (NULL);
2021         }
2022         reply(150, "Opening %s mode data connection for '%s'%s.",
2023              type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
2024         return (file);
2025 }
2026
2027 /*
2028  * A helper macro to avoid code duplication
2029  * in send_data() and receive_data().
2030  *
2031  * XXX We have to block SIGURG during putc() because BSD stdio
2032  * is unable to restart interrupted write operations and hence
2033  * the entire buffer contents will be lost as soon as a write()
2034  * call indicates EINTR to stdio.
2035  */
2036 #define FTPD_PUTC(ch, file, label)                                      \
2037         do {                                                            \
2038                 int ret;                                                \
2039                                                                         \
2040                 do {                                                    \
2041                         START_UNSAFE;                                   \
2042                         ret = putc((ch), (file));                       \
2043                         END_UNSAFE;                                     \
2044                         CHECKOOB(return (-1))                           \
2045                         else if (ferror(file))                          \
2046                                 goto label;                             \
2047                         clearerr(file);                                 \
2048                 } while (ret == EOF);                                   \
2049         } while (0)
2050
2051 /*
2052  * Tranfer the contents of "instr" to "outstr" peer using the appropriate
2053  * encapsulation of the data subject to Mode, Structure, and Type.
2054  *
2055  * NB: Form isn't handled.
2056  */
2057 static int
2058 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2059 {
2060         int c, cp, filefd, netfd;
2061         char *buf;
2062
2063         STARTXFER;
2064
2065         switch (type) {
2066
2067         case TYPE_A:
2068                 cp = EOF;
2069                 for (;;) {
2070                         c = getc(instr);
2071                         CHECKOOB(return (-1))
2072                         else if (c == EOF && ferror(instr))
2073                                 goto file_err;
2074                         if (c == EOF) {
2075                                 if (ferror(instr)) {    /* resume after OOB */
2076                                         clearerr(instr);
2077                                         continue;
2078                                 }
2079                                 if (feof(instr))        /* EOF */
2080                                         break;
2081                                 syslog(LOG_ERR, "Internal: impossible condition"
2082                                                 " on file after getc()");
2083                                 goto file_err;
2084                         }
2085                         if (c == '\n' && cp != '\r') {
2086                                 FTPD_PUTC('\r', outstr, data_err);
2087                                 byte_count++;
2088                         }
2089                         FTPD_PUTC(c, outstr, data_err);
2090                         byte_count++;
2091                         cp = c;
2092                 }
2093 #ifdef notyet   /* BSD stdio isn't ready for that */
2094                 while (fflush(outstr) == EOF) {
2095                         CHECKOOB(return (-1))
2096                         else
2097                                 goto data_err;
2098                         clearerr(outstr);
2099                 }
2100                 ENDXFER;
2101 #else
2102                 ENDXFER;
2103                 if (fflush(outstr) == EOF)
2104                         goto data_err;
2105 #endif
2106                 reply(226, "Transfer complete.");
2107                 return (0);
2108
2109         case TYPE_I:
2110         case TYPE_L:
2111                 /*
2112                  * isreg is only set if we are not doing restart and we
2113                  * are sending a regular file
2114                  */
2115                 netfd = fileno(outstr);
2116                 filefd = fileno(instr);
2117
2118                 if (isreg) {
2119                         char *msg = "Transfer complete.";
2120                         off_t cnt, offset;
2121                         int err;
2122
2123                         cnt = offset = 0;
2124
2125                         while (filesize > 0) {
2126                                 err = sendfile(filefd, netfd, offset, 0,
2127                                                NULL, &cnt, 0);
2128                                 /*
2129                                  * Calculate byte_count before OOB processing.
2130                                  * It can be used in myoob() later.
2131                                  */
2132                                 byte_count += cnt;
2133                                 offset += cnt;
2134                                 filesize -= cnt;
2135                                 CHECKOOB(return (-1))
2136                                 else if (err == -1) {
2137                                         if (errno != EINTR &&
2138                                             cnt == 0 && offset == 0)
2139                                                 goto oldway;
2140                                         goto data_err;
2141                                 }
2142                                 if (err == -1)  /* resume after OOB */
2143                                         continue;
2144                                 /*
2145                                  * We hit the EOF prematurely.
2146                                  * Perhaps the file was externally truncated.
2147                                  */
2148                                 if (cnt == 0) {
2149                                         msg = "Transfer finished due to "
2150                                               "premature end of file.";
2151                                         break;
2152                                 }
2153                         }
2154                         ENDXFER;
2155                         reply(226, "%s", msg);
2156                         return (0);
2157                 }
2158
2159 oldway:
2160                 if ((buf = malloc(blksize)) == NULL) {
2161                         ENDXFER;
2162                         reply(451, "Ran out of memory.");
2163                         return (-1);
2164                 }
2165
2166                 for (;;) {
2167                         int cnt, len;
2168                         char *bp;
2169
2170                         cnt = read(filefd, buf, blksize);
2171                         CHECKOOB(free(buf); return (-1))
2172                         else if (cnt < 0) {
2173                                 free(buf);
2174                                 goto file_err;
2175                         }
2176                         if (cnt < 0)    /* resume after OOB */
2177                                 continue;
2178                         if (cnt == 0)   /* EOF */
2179                                 break;
2180                         for (len = cnt, bp = buf; len > 0;) {
2181                                 cnt = write(netfd, bp, len);
2182                                 CHECKOOB(free(buf); return (-1))
2183                                 else if (cnt < 0) {
2184                                         free(buf);
2185                                         goto data_err;
2186                                 }
2187                                 if (cnt <= 0)
2188                                         continue;
2189                                 len -= cnt;
2190                                 bp += cnt;
2191                                 byte_count += cnt;
2192                         }
2193                 }
2194                 ENDXFER;
2195                 free(buf);
2196                 reply(226, "Transfer complete.");
2197                 return (0);
2198         default:
2199                 ENDXFER;
2200                 reply(550, "Unimplemented TYPE %d in send_data.", type);
2201                 return (-1);
2202         }
2203
2204 data_err:
2205         ENDXFER;
2206         perror_reply(426, "Data connection");
2207         return (-1);
2208
2209 file_err:
2210         ENDXFER;
2211         perror_reply(551, "Error on input file");
2212         return (-1);
2213 }
2214
2215 /*
2216  * Transfer data from peer to "outstr" using the appropriate encapulation of
2217  * the data subject to Mode, Structure, and Type.
2218  *
2219  * N.B.: Form isn't handled.
2220  */
2221 static int
2222 receive_data(FILE *instr, FILE *outstr)
2223 {
2224         int c, cp;
2225         int bare_lfs = 0;
2226
2227         STARTXFER;
2228
2229         switch (type) {
2230
2231         case TYPE_I:
2232         case TYPE_L:
2233                 for (;;) {
2234                         int cnt, len;
2235                         char *bp;
2236                         char buf[BUFSIZ];
2237
2238                         cnt = read(fileno(instr), buf, sizeof(buf));
2239                         CHECKOOB(return (-1))
2240                         else if (cnt < 0)
2241                                 goto data_err;
2242                         if (cnt < 0)    /* resume after OOB */
2243                                 continue;
2244                         if (cnt == 0)   /* EOF */
2245                                 break;
2246                         for (len = cnt, bp = buf; len > 0;) {
2247                                 cnt = write(fileno(outstr), bp, len);
2248                                 CHECKOOB(return (-1))
2249                                 else if (cnt < 0)
2250                                         goto file_err;
2251                                 if (cnt <= 0)
2252                                         continue;
2253                                 len -= cnt;
2254                                 bp += cnt;
2255                                 byte_count += cnt;
2256                         }
2257                 }
2258                 ENDXFER;
2259                 return (0);
2260
2261         case TYPE_E:
2262                 ENDXFER;
2263                 reply(553, "TYPE E not implemented.");
2264                 return (-1);
2265
2266         case TYPE_A:
2267                 cp = EOF;
2268                 for (;;) {
2269                         c = getc(instr);
2270                         CHECKOOB(return (-1))
2271                         else if (c == EOF && ferror(instr))
2272                                 goto data_err;
2273                         if (c == EOF && ferror(instr)) { /* resume after OOB */
2274                                 clearerr(instr);
2275                                 continue;
2276                         }
2277
2278                         if (cp == '\r') {
2279                                 if (c != '\n')
2280                                         FTPD_PUTC('\r', outstr, file_err);
2281                         } else
2282                                 if (c == '\n')
2283                                         bare_lfs++;
2284                         if (c == '\r') {
2285                                 byte_count++;
2286                                 cp = c;
2287                                 continue;
2288                         }
2289
2290                         /* Check for EOF here in order not to lose last \r. */
2291                         if (c == EOF) {
2292                                 if (feof(instr))        /* EOF */
2293                                         break;
2294                                 syslog(LOG_ERR, "Internal: impossible condition"
2295                                                 " on data stream after getc()");
2296                                 goto data_err;
2297                         }
2298
2299                         byte_count++;
2300                         FTPD_PUTC(c, outstr, file_err);
2301                         cp = c;
2302                 }
2303 #ifdef notyet   /* BSD stdio isn't ready for that */
2304                 while (fflush(outstr) == EOF) {
2305                         CHECKOOB(return (-1))
2306                         else
2307                                 goto file_err;
2308                         clearerr(outstr);
2309                 }
2310                 ENDXFER;
2311 #else
2312                 ENDXFER;
2313                 if (fflush(outstr) == EOF)
2314                         goto file_err;
2315 #endif
2316                 if (bare_lfs) {
2317                         lreply(226,
2318                 "WARNING! %d bare linefeeds received in ASCII mode.",
2319                             bare_lfs);
2320                 (void)printf("   File may not have transferred correctly.\r\n");
2321                 }
2322                 return (0);
2323         default:
2324                 ENDXFER;
2325                 reply(550, "Unimplemented TYPE %d in receive_data.", type);
2326                 return (-1);
2327         }
2328
2329 data_err:
2330         ENDXFER;
2331         perror_reply(426, "Data connection");
2332         return (-1);
2333
2334 file_err:
2335         ENDXFER;
2336         perror_reply(452, "Error writing to file");
2337         return (-1);
2338 }
2339
2340 void
2341 statfilecmd(char *filename)
2342 {
2343         FILE *fin;
2344         int atstart;
2345         int c, code;
2346         char line[LINE_MAX];
2347         struct stat st;
2348
2349         code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2350         (void)snprintf(line, sizeof(line), _PATH_LS " -lgA %s", filename);
2351         fin = ftpd_popen(line, "r");
2352         if (fin == NULL) {
2353                 perror_reply(551, filename);
2354                 return;
2355         }
2356         lreply(code, "Status of %s:", filename);
2357         atstart = 1;
2358         while ((c = getc(fin)) != EOF) {
2359                 if (c == '\n') {
2360                         if (ferror(stdout)){
2361                                 perror_reply(421, "Control connection");
2362                                 (void) ftpd_pclose(fin);
2363                                 dologout(1);
2364                                 /* NOTREACHED */
2365                         }
2366                         if (ferror(fin)) {
2367                                 perror_reply(551, filename);
2368                                 (void) ftpd_pclose(fin);
2369                                 return;
2370                         }
2371                         (void) putc('\r', stdout);
2372                 }
2373                 /*
2374                  * RFC 959 says neutral text should be prepended before
2375                  * a leading 3-digit number followed by whitespace, but
2376                  * many ftp clients can be confused by any leading digits,
2377                  * as a matter of fact.
2378                  */
2379                 if (atstart && isdigit(c))
2380                         (void) putc(' ', stdout);
2381                 (void) putc(c, stdout);
2382                 atstart = (c == '\n');
2383         }
2384         (void) ftpd_pclose(fin);
2385         reply(code, "End of status.");
2386 }
2387
2388 void
2389 statcmd(void)
2390 {
2391         union sockunion *su;
2392         u_char *a, *p;
2393         char hname[NI_MAXHOST];
2394         int ispassive;
2395
2396         if (hostinfo) {
2397                 lreply(211, "%s FTP server status:", hostname);
2398                 printf("     %s\r\n", version);
2399         } else
2400                 lreply(211, "FTP server status:");
2401         printf("     Connected to %s", remotehost);
2402         if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2403                          hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2404                 hname[sizeof(hname) - 1] = 0;
2405                 if (strcmp(hname, remotehost) != 0)
2406                         printf(" (%s)", hname);
2407         }
2408         printf("\r\n");
2409         if (logged_in) {
2410                 if (guest)
2411                         printf("     Logged in anonymously\r\n");
2412                 else
2413                         printf("     Logged in as %s\r\n", pw->pw_name);
2414         } else if (askpasswd)
2415                 printf("     Waiting for password\r\n");
2416         else
2417                 printf("     Waiting for user name\r\n");
2418         printf("     TYPE: %s", typenames[type]);
2419         if (type == TYPE_A || type == TYPE_E)
2420                 printf(", FORM: %s", formnames[form]);
2421         if (type == TYPE_L)
2422 #if CHAR_BIT == 8
2423                 printf(" %d", CHAR_BIT);
2424 #else
2425                 printf(" %d", bytesize);        /* need definition! */
2426 #endif
2427         printf("; STRUcture: %s; transfer MODE: %s\r\n",
2428             strunames[stru], modenames[mode]);
2429         if (data != -1)
2430                 printf("     Data connection open\r\n");
2431         else if (pdata != -1) {
2432                 ispassive = 1;
2433                 su = &pasv_addr;
2434                 goto printaddr;
2435         } else if (usedefault == 0) {
2436                 ispassive = 0;
2437                 su = &data_dest;
2438 printaddr:
2439 #define UC(b) (((int) b) & 0xff)
2440                 if (epsvall) {
2441                         printf("     EPSV only mode (EPSV ALL)\r\n");
2442                         goto epsvonly;
2443                 }
2444
2445                 /* PORT/PASV */
2446                 if (su->su_family == AF_INET) {
2447                         a = (u_char *) &su->su_sin.sin_addr;
2448                         p = (u_char *) &su->su_sin.sin_port;
2449                         printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2450                                 ispassive ? "PASV" : "PORT",
2451                                 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2452                                 UC(p[0]), UC(p[1]));
2453                 }
2454
2455                 /* LPRT/LPSV */
2456             {
2457                 int alen, af, i;
2458
2459                 switch (su->su_family) {
2460                 case AF_INET:
2461                         a = (u_char *) &su->su_sin.sin_addr;
2462                         p = (u_char *) &su->su_sin.sin_port;
2463                         alen = sizeof(su->su_sin.sin_addr);
2464                         af = 4;
2465                         break;
2466                 case AF_INET6:
2467                         a = (u_char *) &su->su_sin6.sin6_addr;
2468                         p = (u_char *) &su->su_sin6.sin6_port;
2469                         alen = sizeof(su->su_sin6.sin6_addr);
2470                         af = 6;
2471                         break;
2472                 default:
2473                         af = 0;
2474                         break;
2475                 }
2476                 if (af) {
2477                         printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2478                                 af, alen);
2479                         for (i = 0; i < alen; i++)
2480                                 printf("%d,", UC(a[i]));
2481                         printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2482                 }
2483             }
2484
2485 epsvonly:;
2486                 /* EPRT/EPSV */
2487             {
2488                 int af;
2489
2490                 switch (su->su_family) {
2491                 case AF_INET:
2492                         af = 1;
2493                         break;
2494                 case AF_INET6:
2495                         af = 2;
2496                         break;
2497                 default:
2498                         af = 0;
2499                         break;
2500                 }
2501                 if (af) {
2502                         union sockunion tmp;
2503
2504                         tmp = *su;
2505                         if (tmp.su_family == AF_INET6)
2506                                 tmp.su_sin6.sin6_scope_id = 0;
2507                         if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2508                                         hname, sizeof(hname) - 1, NULL, 0,
2509                                         NI_NUMERICHOST)) {
2510                                 hname[sizeof(hname) - 1] = 0;
2511                                 printf("     %s |%d|%s|%d|\r\n",
2512                                         ispassive ? "EPSV" : "EPRT",
2513                                         af, hname, htons(tmp.su_port));
2514                         }
2515                 }
2516             }
2517 #undef UC
2518         } else
2519                 printf("     No data connection\r\n");
2520         reply(211, "End of status.");
2521 }
2522
2523 void
2524 fatalerror(char *s)
2525 {
2526
2527         reply(451, "Error in server: %s", s);
2528         reply(221, "Closing connection due to server error.");
2529         dologout(0);
2530         /* NOTREACHED */
2531 }
2532
2533 void
2534 reply(int n, const char *fmt, ...)
2535 {
2536         va_list ap;
2537
2538         (void)printf("%d ", n);
2539         va_start(ap, fmt);
2540         (void)vprintf(fmt, ap);
2541         va_end(ap);
2542         (void)printf("\r\n");
2543         (void)fflush(stdout);
2544         if (ftpdebug) {
2545                 syslog(LOG_DEBUG, "<--- %d ", n);
2546                 va_start(ap, fmt);
2547                 vsyslog(LOG_DEBUG, fmt, ap);
2548                 va_end(ap);
2549         }
2550 }
2551
2552 void
2553 lreply(int n, const char *fmt, ...)
2554 {
2555         va_list ap;
2556
2557         (void)printf("%d- ", n);
2558         va_start(ap, fmt);
2559         (void)vprintf(fmt, ap);
2560         va_end(ap);
2561         (void)printf("\r\n");
2562         (void)fflush(stdout);
2563         if (ftpdebug) {
2564                 syslog(LOG_DEBUG, "<--- %d- ", n);
2565                 va_start(ap, fmt);
2566                 vsyslog(LOG_DEBUG, fmt, ap);
2567                 va_end(ap);
2568         }
2569 }
2570
2571 static void
2572 ack(char *s)
2573 {
2574
2575         reply(250, "%s command successful.", s);
2576 }
2577
2578 void
2579 nack(char *s)
2580 {
2581
2582         reply(502, "%s command not implemented.", s);
2583 }
2584
2585 /* ARGSUSED */
2586 void
2587 yyerror(char *s)
2588 {
2589         char *cp;
2590
2591         if ((cp = strchr(cbuf,'\n')))
2592                 *cp = '\0';
2593         reply(500, "%s: command not understood.", cbuf);
2594 }
2595
2596 void
2597 delete(char *name)
2598 {
2599         struct stat st;
2600
2601         LOGCMD("delete", name);
2602         if (lstat(name, &st) < 0) {
2603                 perror_reply(550, name);
2604                 return;
2605         }
2606         if (S_ISDIR(st.st_mode)) {
2607                 if (rmdir(name) < 0) {
2608                         perror_reply(550, name);
2609                         return;
2610                 }
2611                 goto done;
2612         }
2613         if (guest && noguestmod) {
2614                 reply(550, "Operation not permitted.");
2615                 return;
2616         }
2617         if (unlink(name) < 0) {
2618                 perror_reply(550, name);
2619                 return;
2620         }
2621 done:
2622         ack("DELE");
2623 }
2624
2625 void
2626 cwd(char *path)
2627 {
2628
2629         if (chdir(path) < 0)
2630                 perror_reply(550, path);
2631         else
2632                 ack("CWD");
2633 }
2634
2635 void
2636 makedir(char *name)
2637 {
2638         char *s;
2639
2640         LOGCMD("mkdir", name);
2641         if (guest && noguestmkd)
2642                 reply(550, "Operation not permitted.");
2643         else if (mkdir(name, 0777) < 0)
2644                 perror_reply(550, name);
2645         else {
2646                 if ((s = doublequote(name)) == NULL)
2647                         fatalerror("Ran out of memory.");
2648                 reply(257, "\"%s\" directory created.", s);
2649                 free(s);
2650         }
2651 }
2652
2653 void
2654 removedir(char *name)
2655 {
2656
2657         LOGCMD("rmdir", name);
2658         if (rmdir(name) < 0)
2659                 perror_reply(550, name);
2660         else
2661                 ack("RMD");
2662 }
2663
2664 void
2665 pwd(void)
2666 {
2667         char *s, path[MAXPATHLEN + 1];
2668
2669         if (getcwd(path, sizeof(path)) == NULL)
2670                 perror_reply(550, "Get current directory");
2671         else {
2672                 if ((s = doublequote(path)) == NULL)
2673                         fatalerror("Ran out of memory.");
2674                 reply(257, "\"%s\" is current directory.", s);
2675                 free(s);
2676         }
2677 }
2678
2679 char *
2680 renamefrom(char *name)
2681 {
2682         struct stat st;
2683
2684         if (guest && noguestmod) {
2685                 reply(550, "Operation not permitted.");
2686                 return (NULL);
2687         }
2688         if (lstat(name, &st) < 0) {
2689                 perror_reply(550, name);
2690                 return (NULL);
2691         }
2692         reply(350, "File exists, ready for destination name.");
2693         return (name);
2694 }
2695
2696 void
2697 renamecmd(char *from, char *to)
2698 {
2699         struct stat st;
2700
2701         LOGCMD2("rename", from, to);
2702
2703         if (guest && (stat(to, &st) == 0)) {
2704                 reply(550, "%s: permission denied.", to);
2705                 return;
2706         }
2707
2708         if (rename(from, to) < 0)
2709                 perror_reply(550, "rename");
2710         else
2711                 ack("RNTO");
2712 }
2713
2714 static void
2715 dolog(struct sockaddr *who)
2716 {
2717         char who_name[NI_MAXHOST];
2718
2719         realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2720         remotehost[sizeof(remotehost) - 1] = 0;
2721         if (getnameinfo(who, who->sa_len,
2722                 who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2723                         *who_name = 0;
2724         who_name[sizeof(who_name) - 1] = 0;
2725
2726 #ifdef SETPROCTITLE
2727 #ifdef VIRTUAL_HOSTING
2728         if (thishost != firsthost)
2729                 snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2730                          remotehost, hostname);
2731         else
2732 #endif
2733                 snprintf(proctitle, sizeof(proctitle), "%s: connected",
2734                          remotehost);
2735         setproctitle("%s", proctitle);
2736 #endif /* SETPROCTITLE */
2737
2738         if (logging) {
2739 #ifdef VIRTUAL_HOSTING
2740                 if (thishost != firsthost)
2741                         syslog(LOG_INFO, "connection from %s (%s) to %s",
2742                                remotehost, who_name, hostname);
2743                 else
2744 #endif
2745                         syslog(LOG_INFO, "connection from %s (%s)",
2746                                remotehost, who_name);
2747         }
2748 }
2749
2750 /*
2751  * Record logout in wtmp file
2752  * and exit with supplied status.
2753  */
2754 void
2755 dologout(int status)
2756 {
2757
2758         if (logged_in && dowtmp) {
2759                 (void) seteuid(0);
2760                 ftpd_logwtmp(wtmpid, NULL, NULL);
2761         }
2762         /* beware of flushing buffers after a SIGPIPE */
2763         _exit(status);
2764 }
2765
2766 static void
2767 sigurg(int signo)
2768 {
2769
2770         recvurg = 1;
2771 }
2772
2773 static void
2774 maskurg(int flag)
2775 {
2776         int oerrno;
2777         sigset_t sset;
2778
2779         if (!transflag) {
2780                 syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2781                 return;
2782         }
2783         oerrno = errno;
2784         sigemptyset(&sset);
2785         sigaddset(&sset, SIGURG);
2786         sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2787         errno = oerrno;
2788 }
2789
2790 static void
2791 flagxfer(int flag)
2792 {
2793
2794         if (flag) {
2795                 if (transflag)
2796                         syslog(LOG_ERR, "Internal: flagxfer(1): "
2797                                         "transfer already under way");
2798                 transflag = 1;
2799                 maskurg(0);
2800                 recvurg = 0;
2801         } else {
2802                 if (!transflag)
2803                         syslog(LOG_ERR, "Internal: flagxfer(0): "
2804                                         "no active transfer");
2805                 maskurg(1);
2806                 transflag = 0;
2807         }
2808 }
2809
2810 /*
2811  * Returns 0 if OK to resume or -1 if abort requested.
2812  */
2813 static int
2814 myoob(void)
2815 {
2816         char *cp;
2817         int ret;
2818
2819         if (!transflag) {
2820                 syslog(LOG_ERR, "Internal: myoob() while no transfer");
2821                 return (0);
2822         }
2823         cp = tmpline;
2824         ret = getline(cp, 7, stdin);
2825         if (ret == -1) {
2826                 reply(221, "You could at least say goodbye.");
2827                 dologout(0);
2828         } else if (ret == -2) {
2829                 /* Ignore truncated command. */
2830                 return (0);
2831         }
2832         upper(cp);
2833         if (strcmp(cp, "ABOR\r\n") == 0) {
2834                 tmpline[0] = '\0';
2835                 reply(426, "Transfer aborted. Data connection closed.");
2836                 reply(226, "Abort successful.");
2837                 return (-1);
2838         }
2839         if (strcmp(cp, "STAT\r\n") == 0) {
2840                 tmpline[0] = '\0';
2841                 if (file_size != -1)
2842                         reply(213, "Status: %jd of %jd bytes transferred.",
2843                                    (intmax_t)byte_count, (intmax_t)file_size);
2844                 else
2845                         reply(213, "Status: %jd bytes transferred.",
2846                                    (intmax_t)byte_count);
2847         }
2848         return (0);
2849 }
2850
2851 /*
2852  * Note: a response of 425 is not mentioned as a possible response to
2853  *      the PASV command in RFC959. However, it has been blessed as
2854  *      a legitimate response by Jon Postel in a telephone conversation
2855  *      with Rick Adams on 25 Jan 89.
2856  */
2857 void
2858 passive(void)
2859 {
2860         socklen_t len;
2861         int on;
2862         char *p, *a;
2863
2864         if (pdata >= 0)         /* close old port if one set */
2865                 close(pdata);
2866
2867         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2868         if (pdata < 0) {
2869                 perror_reply(425, "Can't open passive connection");
2870                 return;
2871         }
2872         on = 1;
2873         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2874                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2875
2876         (void) seteuid(0);
2877
2878 #ifdef IP_PORTRANGE
2879         if (ctrl_addr.su_family == AF_INET) {
2880             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2881                                        : IP_PORTRANGE_DEFAULT;
2882
2883             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2884                             &on, sizeof(on)) < 0)
2885                     goto pasv_error;
2886         }
2887 #endif
2888 #ifdef IPV6_PORTRANGE
2889         if (ctrl_addr.su_family == AF_INET6) {
2890             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2891                                        : IPV6_PORTRANGE_DEFAULT;
2892
2893             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2894                             &on, sizeof(on)) < 0)
2895                     goto pasv_error;
2896         }
2897 #endif
2898
2899         pasv_addr = ctrl_addr;
2900         pasv_addr.su_port = 0;
2901         if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2902                 goto pasv_error;
2903
2904         (void) seteuid(pw->pw_uid);
2905
2906         len = sizeof(pasv_addr);
2907         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2908                 goto pasv_error;
2909         if (listen(pdata, 1) < 0)
2910                 goto pasv_error;
2911         if (pasv_addr.su_family == AF_INET)
2912                 a = (char *) &pasv_addr.su_sin.sin_addr;
2913         else if (pasv_addr.su_family == AF_INET6 &&
2914                  IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2915                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2916         else
2917                 goto pasv_error;
2918
2919         p = (char *) &pasv_addr.su_port;
2920
2921 #define UC(b) (((int) b) & 0xff)
2922
2923         reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2924                 UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2925         return;
2926
2927 pasv_error:
2928         (void) seteuid(pw->pw_uid);
2929         (void) close(pdata);
2930         pdata = -1;
2931         perror_reply(425, "Can't open passive connection");
2932         return;
2933 }
2934
2935 /*
2936  * Long Passive defined in RFC 1639.
2937  *     228 Entering Long Passive Mode
2938  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2939  */
2940
2941 void
2942 long_passive(char *cmd, int pf)
2943 {
2944         socklen_t len;
2945         int on;
2946         char *p, *a;
2947
2948         if (pdata >= 0)         /* close old port if one set */
2949                 close(pdata);
2950
2951         if (pf != PF_UNSPEC) {
2952                 if (ctrl_addr.su_family != pf) {
2953                         switch (ctrl_addr.su_family) {
2954                         case AF_INET:
2955                                 pf = 1;
2956                                 break;
2957                         case AF_INET6:
2958                                 pf = 2;
2959                                 break;
2960                         default:
2961                                 pf = 0;
2962                                 break;
2963                         }
2964                         /*
2965                          * XXX
2966                          * only EPRT/EPSV ready clients will understand this
2967                          */
2968                         if (strcmp(cmd, "EPSV") == 0 && pf) {
2969                                 reply(522, "Network protocol mismatch, "
2970                                         "use (%d)", pf);
2971                         } else
2972                                 reply(501, "Network protocol mismatch."); /*XXX*/
2973
2974                         return;
2975                 }
2976         }
2977
2978         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2979         if (pdata < 0) {
2980                 perror_reply(425, "Can't open passive connection");
2981                 return;
2982         }
2983         on = 1;
2984         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2985                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2986
2987         (void) seteuid(0);
2988
2989         pasv_addr = ctrl_addr;
2990         pasv_addr.su_port = 0;
2991         len = pasv_addr.su_len;
2992
2993 #ifdef IP_PORTRANGE
2994         if (ctrl_addr.su_family == AF_INET) {
2995             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2996                                        : IP_PORTRANGE_DEFAULT;
2997
2998             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2999                             &on, sizeof(on)) < 0)
3000                     goto pasv_error;
3001         }
3002 #endif
3003 #ifdef IPV6_PORTRANGE
3004         if (ctrl_addr.su_family == AF_INET6) {
3005             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
3006                                        : IPV6_PORTRANGE_DEFAULT;
3007
3008             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
3009                             &on, sizeof(on)) < 0)
3010                     goto pasv_error;
3011         }
3012 #endif
3013
3014         if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
3015                 goto pasv_error;
3016
3017         (void) seteuid(pw->pw_uid);
3018
3019         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
3020                 goto pasv_error;
3021         if (listen(pdata, 1) < 0)
3022                 goto pasv_error;
3023
3024 #define UC(b) (((int) b) & 0xff)
3025
3026         if (strcmp(cmd, "LPSV") == 0) {
3027                 p = (char *)&pasv_addr.su_port;
3028                 switch (pasv_addr.su_family) {
3029                 case AF_INET:
3030                         a = (char *) &pasv_addr.su_sin.sin_addr;
3031                 v4_reply:
3032                         reply(228,
3033 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3034                               4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3035                               2, UC(p[0]), UC(p[1]));
3036                         return;
3037                 case AF_INET6:
3038                         if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
3039                                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
3040                                 goto v4_reply;
3041                         }
3042                         a = (char *) &pasv_addr.su_sin6.sin6_addr;
3043                         reply(228,
3044 "Entering Long Passive Mode "
3045 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3046                               6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3047                               UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
3048                               UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
3049                               UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
3050                               2, UC(p[0]), UC(p[1]));
3051                         return;
3052                 }
3053         } else if (strcmp(cmd, "EPSV") == 0) {
3054                 switch (pasv_addr.su_family) {
3055                 case AF_INET:
3056                 case AF_INET6:
3057                         reply(229, "Entering Extended Passive Mode (|||%d|)",
3058                                 ntohs(pasv_addr.su_port));
3059                         return;
3060                 }
3061         } else {
3062                 /* more proper error code? */
3063         }
3064
3065 pasv_error:
3066         (void) seteuid(pw->pw_uid);
3067         (void) close(pdata);
3068         pdata = -1;
3069         perror_reply(425, "Can't open passive connection");
3070         return;
3071 }
3072
3073 /*
3074  * Generate unique name for file with basename "local"
3075  * and open the file in order to avoid possible races.
3076  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3077  * Return descriptor to the file, set "name" to its name.
3078  *
3079  * Generates failure reply on error.
3080  */
3081 static int
3082 guniquefd(char *local, char **name)
3083 {
3084         static char new[MAXPATHLEN];
3085         struct stat st;
3086         char *cp;
3087         int count;
3088         int fd;
3089
3090         cp = strrchr(local, '/');
3091         if (cp)
3092                 *cp = '\0';
3093         if (stat(cp ? local : ".", &st) < 0) {
3094                 perror_reply(553, cp ? local : ".");
3095                 return (-1);
3096         }
3097         if (cp) {
3098                 /*
3099                  * Let not overwrite dirname with counter suffix.
3100                  * -4 is for /nn\0
3101                  * In this extreme case dot won't be put in front of suffix.
3102                  */
3103                 if (strlen(local) > sizeof(new) - 4) {
3104                         reply(553, "Pathname too long.");
3105                         return (-1);
3106                 }
3107                 *cp = '/';
3108         }
3109         /* -4 is for the .nn<null> we put on the end below */
3110         (void) snprintf(new, sizeof(new) - 4, "%s", local);
3111         cp = new + strlen(new);
3112         /*
3113          * Don't generate dotfile unless requested explicitly.
3114          * This covers the case when basename gets truncated off
3115          * by buffer size.
3116          */
3117         if (cp > new && cp[-1] != '/')
3118                 *cp++ = '.';
3119         for (count = 0; count < 100; count++) {
3120                 /* At count 0 try unmodified name */
3121                 if (count)
3122                         (void)sprintf(cp, "%d", count);
3123                 if ((fd = open(count ? new : local,
3124                     O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3125                         *name = count ? new : local;
3126                         return (fd);
3127                 }
3128                 if (errno != EEXIST) {
3129                         perror_reply(553, count ? new : local);
3130                         return (-1);
3131                 }
3132         }
3133         reply(452, "Unique file name cannot be created.");
3134         return (-1);
3135 }
3136
3137 /*
3138  * Format and send reply containing system error number.
3139  */
3140 void
3141 perror_reply(int code, char *string)
3142 {
3143
3144         reply(code, "%s: %s.", string, strerror(errno));
3145 }
3146
3147 static char *onefile[] = {
3148         "",
3149         0
3150 };
3151
3152 void
3153 send_file_list(char *whichf)
3154 {
3155         struct stat st;
3156         DIR *dirp = NULL;
3157         struct dirent *dir;
3158         FILE *dout = NULL;
3159         char **dirlist, *dirname;
3160         int simple = 0;
3161         int freeglob = 0;
3162         glob_t gl;
3163
3164         if (strpbrk(whichf, "~{[*?") != NULL) {
3165                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3166
3167                 memset(&gl, 0, sizeof(gl));
3168                 gl.gl_matchc = MAXGLOBARGS;
3169                 flags |= GLOB_LIMIT;
3170                 freeglob = 1;
3171                 if (glob(whichf, flags, 0, &gl)) {
3172                         reply(550, "No matching files found.");
3173                         goto out;
3174                 } else if (gl.gl_pathc == 0) {
3175                         errno = ENOENT;
3176                         perror_reply(550, whichf);
3177                         goto out;
3178                 }
3179                 dirlist = gl.gl_pathv;
3180         } else {
3181                 onefile[0] = whichf;
3182                 dirlist = onefile;
3183                 simple = 1;
3184         }
3185
3186         while ((dirname = *dirlist++)) {
3187                 if (stat(dirname, &st) < 0) {
3188                         /*
3189                          * If user typed "ls -l", etc, and the client
3190                          * used NLST, do what the user meant.
3191                          */
3192                         if (dirname[0] == '-' && *dirlist == NULL &&
3193                             dout == NULL)
3194                                 retrieve(_PATH_LS " %s", dirname);
3195                         else
3196                                 perror_reply(550, whichf);
3197                         goto out;
3198                 }
3199
3200                 if (S_ISREG(st.st_mode)) {
3201                         if (dout == NULL) {
3202                                 dout = dataconn("file list", -1, "w");
3203                                 if (dout == NULL)
3204                                         goto out;
3205                                 STARTXFER;
3206                         }
3207                         START_UNSAFE;
3208                         fprintf(dout, "%s%s\n", dirname,
3209                                 type == TYPE_A ? "\r" : "");
3210                         END_UNSAFE;
3211                         if (ferror(dout))
3212                                 goto data_err;
3213                         byte_count += strlen(dirname) +
3214                                       (type == TYPE_A ? 2 : 1);
3215                         CHECKOOB(goto abrt);
3216                         continue;
3217                 } else if (!S_ISDIR(st.st_mode))
3218                         continue;
3219
3220                 if ((dirp = opendir(dirname)) == NULL)
3221                         continue;
3222
3223                 while ((dir = readdir(dirp)) != NULL) {
3224                         char nbuf[MAXPATHLEN];
3225
3226                         CHECKOOB(goto abrt);
3227
3228                         if (dir->d_name[0] == '.' && dir->d_namlen == 1)
3229                                 continue;
3230                         if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
3231                             dir->d_namlen == 2)
3232                                 continue;
3233
3234                         snprintf(nbuf, sizeof(nbuf),
3235                                 "%s/%s", dirname, dir->d_name);
3236
3237                         /*
3238                          * We have to do a stat to insure it's
3239                          * not a directory or special file.
3240                          */
3241                         if (simple || (stat(nbuf, &st) == 0 &&
3242                             S_ISREG(st.st_mode))) {
3243                                 if (dout == NULL) {
3244                                         dout = dataconn("file list", -1, "w");
3245                                         if (dout == NULL)
3246                                                 goto out;
3247                                         STARTXFER;
3248                                 }
3249                                 START_UNSAFE;
3250                                 if (nbuf[0] == '.' && nbuf[1] == '/')
3251                                         fprintf(dout, "%s%s\n", &nbuf[2],
3252                                                 type == TYPE_A ? "\r" : "");
3253                                 else
3254                                         fprintf(dout, "%s%s\n", nbuf,
3255                                                 type == TYPE_A ? "\r" : "");
3256                                 END_UNSAFE;
3257                                 if (ferror(dout))
3258                                         goto data_err;
3259                                 byte_count += strlen(nbuf) +
3260                                               (type == TYPE_A ? 2 : 1);
3261                                 CHECKOOB(goto abrt);
3262                         }
3263                 }
3264                 (void) closedir(dirp);
3265                 dirp = NULL;
3266         }
3267
3268         if (dout == NULL)
3269                 reply(550, "No files found.");
3270         else if (ferror(dout))
3271 data_err:       perror_reply(550, "Data connection");
3272         else
3273                 reply(226, "Transfer complete.");
3274 out:
3275         if (dout) {
3276                 ENDXFER;
3277 abrt:
3278                 (void) fclose(dout);
3279                 data = -1;
3280                 pdata = -1;
3281         }
3282         if (dirp)
3283                 (void) closedir(dirp);
3284         if (freeglob) {
3285                 freeglob = 0;
3286                 globfree(&gl);
3287         }
3288 }
3289
3290 void
3291 reapchild(int signo)
3292 {
3293         while (waitpid(-1, NULL, WNOHANG) > 0);
3294 }
3295
3296 #ifdef OLD_SETPROCTITLE
3297 /*
3298  * Clobber argv so ps will show what we're doing.  (Stolen from sendmail.)
3299  * Warning, since this is usually started from inetd.conf, it often doesn't
3300  * have much of an environment or arglist to overwrite.
3301  */
3302 void
3303 setproctitle(const char *fmt, ...)
3304 {
3305         int i;
3306         va_list ap;
3307         char *p, *bp, ch;
3308         char buf[LINE_MAX];
3309
3310         va_start(ap, fmt);
3311         (void)vsnprintf(buf, sizeof(buf), fmt, ap);
3312
3313         /* make ps print our process name */
3314         p = Argv[0];
3315         *p++ = '-';
3316
3317         i = strlen(buf);
3318         if (i > LastArgv - p - 2) {
3319                 i = LastArgv - p - 2;
3320                 buf[i] = '\0';
3321         }
3322         bp = buf;
3323         while (ch = *bp++)
3324                 if (ch != '\n' && ch != '\r')
3325                         *p++ = ch;
3326         while (p < LastArgv)
3327                 *p++ = ' ';
3328 }
3329 #endif /* OLD_SETPROCTITLE */
3330
3331 static void
3332 appendf(char **strp, char *fmt, ...)
3333 {
3334         va_list ap;
3335         char *ostr, *p;
3336
3337         va_start(ap, fmt);
3338         vasprintf(&p, fmt, ap);
3339         va_end(ap);
3340         if (p == NULL)
3341                 fatalerror("Ran out of memory.");
3342         if (*strp == NULL)
3343                 *strp = p;
3344         else {
3345                 ostr = *strp;
3346                 asprintf(strp, "%s%s", ostr, p);
3347                 if (*strp == NULL)
3348                         fatalerror("Ran out of memory.");
3349                 free(ostr);
3350         }
3351 }
3352
3353 static void
3354 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3355 {
3356         char *msg = NULL;
3357         char wd[MAXPATHLEN + 1];
3358
3359         if (logging <= 1)
3360                 return;
3361
3362         if (getcwd(wd, sizeof(wd) - 1) == NULL)
3363                 strcpy(wd, strerror(errno));
3364
3365         appendf(&msg, "%s", cmd);
3366         if (file1)
3367                 appendf(&msg, " %s", file1);
3368         if (file2)
3369                 appendf(&msg, " %s", file2);
3370         if (cnt >= 0)
3371                 appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3372         appendf(&msg, " (wd: %s", wd);
3373         if (guest || dochroot)
3374                 appendf(&msg, "; chrooted");
3375         appendf(&msg, ")");
3376         syslog(LOG_INFO, "%s", msg);
3377         free(msg);
3378 }
3379
3380 static void
3381 logxfer(char *name, off_t size, time_t start)
3382 {
3383         char buf[MAXPATHLEN + 1024];
3384         char path[MAXPATHLEN + 1];
3385         time_t now;
3386
3387         if (statfd >= 0) {
3388                 time(&now);
3389                 if (realpath(name, path) == NULL) {
3390                         syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3391                         return;
3392                 }
3393                 snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3394                         ctime(&now)+4, ident, remotehost,
3395                         path, (intmax_t)size,
3396                         (long)(now - start + (now == start)));
3397                 write(statfd, buf, strlen(buf));
3398         }
3399 }
3400
3401 static char *
3402 doublequote(char *s)
3403 {
3404         int n;
3405         char *p, *s2;
3406
3407         for (p = s, n = 0; *p; p++)
3408                 if (*p == '"')
3409                         n++;
3410
3411         if ((s2 = malloc(p - s + n + 1)) == NULL)
3412                 return (NULL);
3413
3414         for (p = s2; *s; s++, p++) {
3415                 if ((*p = *s) == '"')
3416                         *(++p) = '"';
3417         }
3418         *p = '\0';
3419
3420         return (s2);
3421 }
3422
3423 /* setup server socket for specified address family */
3424 /* if af is PF_UNSPEC more than one socket may be returned */
3425 /* the returned list is dynamically allocated, so caller needs to free it */
3426 static int *
3427 socksetup(int af, char *bindname, const char *bindport)
3428 {
3429         struct addrinfo hints, *res, *r;
3430         int error, maxs, *s, *socks;
3431         const int on = 1;
3432
3433         memset(&hints, 0, sizeof(hints));
3434         hints.ai_flags = AI_PASSIVE;
3435         hints.ai_family = af;
3436         hints.ai_socktype = SOCK_STREAM;
3437         error = getaddrinfo(bindname, bindport, &hints, &res);
3438         if (error) {
3439                 syslog(LOG_ERR, "%s", gai_strerror(error));
3440                 if (error == EAI_SYSTEM)
3441                         syslog(LOG_ERR, "%s", strerror(errno));
3442                 return NULL;
3443         }
3444
3445         /* Count max number of sockets we may open */
3446         for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3447                 ;
3448         socks = malloc((maxs + 1) * sizeof(int));
3449         if (!socks) {
3450                 freeaddrinfo(res);
3451                 syslog(LOG_ERR, "couldn't allocate memory for sockets");
3452                 return NULL;
3453         }
3454
3455         *socks = 0;   /* num of sockets counter at start of array */
3456         s = socks + 1;
3457         for (r = res; r; r = r->ai_next) {
3458                 *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3459                 if (*s < 0) {
3460                         syslog(LOG_DEBUG, "control socket: %m");
3461                         continue;
3462                 }
3463                 if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3464                     &on, sizeof(on)) < 0)
3465                         syslog(LOG_WARNING,
3466                             "control setsockopt (SO_REUSEADDR): %m");
3467                 if (r->ai_family == AF_INET6) {
3468                         if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3469                             &on, sizeof(on)) < 0)
3470                                 syslog(LOG_WARNING,
3471                                     "control setsockopt (IPV6_V6ONLY): %m");
3472                 }
3473                 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3474                         syslog(LOG_DEBUG, "control bind: %m");
3475                         close(*s);
3476                         continue;
3477                 }
3478                 (*socks)++;
3479                 s++;
3480         }
3481
3482         if (res)
3483                 freeaddrinfo(res);
3484
3485         if (*socks == 0) {
3486                 syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3487                 free(socks);
3488                 return NULL;
3489         }
3490         return(socks);
3491 }