libexec/ftpd/ftpd.c

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