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