appl/push/push.c

   1 /*
   2  * Copyright (c) 1997-2004 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "push_locl.h"
  35 RCSID("$Id$");
  36
  37 #ifdef KRB4
  38 static int use_v4 = -1;
  39 #endif
  40
  41 #ifdef KRB5
  42 static int use_v5 = -1;
  43 static krb5_context context;
  44 #endif
  45
  46 static char *port_str;
  47 static int verbose_level;
  48 static int do_fork;
  49 static int do_leave;
  50 static int do_version;
  51 static int do_help;
  52 static int do_from;
  53 static int do_count;
  54 static char *header_str;
  55
  56 struct getargs args[] = {
  57 #ifdef KRB4
  58     { "krb4",   '4', arg_flag,          &use_v4,        "Use Kerberos V4",
  59       NULL },
  60 #endif
  61 #ifdef KRB5
  62     { "krb5",   '5', arg_flag,          &use_v5,        "Use Kerberos V5",
  63       NULL },
  64 #endif
  65     { "verbose",'v', arg_counter,       &verbose_level, "Verbose",
  66       NULL },
  67     { "fork",   'f', arg_flag,          &do_fork,       "Fork deleting proc",
  68       NULL },
  69     { "leave",  'l', arg_flag,          &do_leave,      "Leave mail on server",
  70       NULL },
  71     { "port",   'p', arg_string,        &port_str,      "Use this port",
  72       "number-or-service" },
  73     { "from",    0,  arg_flag,          &do_from,       "Behave like from",
  74       NULL },
  75     { "headers", 0,  arg_string,        &header_str,    "Headers to print", NULL },
  76     { "count", 'c',  arg_flag,          &do_count,      "Print number of messages", NULL},
  77     { "version", 0,  arg_flag,          &do_version,    "Print version",
  78       NULL },
  79     { "help",    0,  arg_flag,          &do_help,       NULL,
  80       NULL }
  81
  82 };
  83
  84 static void
  85 usage (int ret)
  86 {
  87     arg_printusage (args,
  88                     sizeof(args) / sizeof(args[0]),
  89                     NULL,
  90                     "[[{po:username[@hostname] | hostname[:username]}] ...] "
  91                     "filename");
  92     exit (ret);
  93 }
  94
  95 static int
  96 do_connect (const char *hostname, int port, int nodelay)
  97 {
  98     struct addrinfo *ai, *a;
  99     struct addrinfo hints;
 100     int error;
 101     int s = -1;
 102     char portstr[NI_MAXSERV];
 103
 104     memset (&hints, 0, sizeof(hints));
 105     hints.ai_socktype = SOCK_STREAM;
 106     hints.ai_protocol = IPPROTO_TCP;
 107
 108     snprintf (portstr, sizeof(portstr), "%u", ntohs(port));
 109
 110     error = getaddrinfo (hostname, portstr, &hints, &ai);
 111     if (error)
 112         errx (1, "getaddrinfo(%s): %s", hostname, gai_strerror(error));
 113
 114     for (a = ai; a != NULL; a = a->ai_next) {
 115         s = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
 116         if (s < 0)
 117             continue;
 118         if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
 119             warn ("connect(%s)", hostname);
 120             close (s);
 121             continue;
 122         }
 123         break;
 124     }
 125     freeaddrinfo (ai);
 126     if (a == NULL) {
 127         warnx ("failed to contact %s", hostname);
 128         return -1;
 129     }
 130
 131     if(setsockopt(s, IPPROTO_TCP, TCP_NODELAY,
 132                   (void *)&nodelay, sizeof(nodelay)) < 0)
 133         err (1, "setsockopt TCP_NODELAY");
 134     return s;
 135 }
 136
 137 typedef enum { INIT = 0, GREET, USER, PASS, STAT, RETR, TOP,
 138                DELE, XDELE, QUIT} pop_state;
 139
 140 static char *pop_state_string[] = {
 141     "INIT", "GREET", "USER", "PASS", "STAT", "RETR", "TOP",
 142     "DELE", "XDELE", "QUIT"
 143 };
 144
 145 #define PUSH_BUFSIZ 65536
 146
 147 #define STEP 16
 148
 149 struct write_state {
 150     struct iovec *iovecs;
 151     size_t niovecs, maxiovecs, allociovecs;
 152     int fd;
 153 };
 154
 155 static void
 156 write_state_init (struct write_state *w, int fd)
 157 {
 158 #ifdef UIO_MAXIOV
 159     w->maxiovecs = UIO_MAXIOV;
 160 #else
 161     w->maxiovecs = 16;
 162 #endif
 163     w->allociovecs = min(STEP, w->maxiovecs);
 164     w->niovecs = 0;
 165     w->iovecs = emalloc(w->allociovecs * sizeof(*w->iovecs));
 166     w->fd = fd;
 167 }
 168
 169 static void
 170 write_state_add (struct write_state *w, void *v, size_t len)
 171 {
 172     if(w->niovecs == w->allociovecs) {
 173         if(w->niovecs == w->maxiovecs) {
 174             if(writev (w->fd, w->iovecs, w->niovecs) < 0)
 175                 err(1, "writev");
 176             w->niovecs = 0;
 177         } else {
 178             w->allociovecs = min(w->allociovecs + STEP, w->maxiovecs);
 179             w->iovecs = erealloc (w->iovecs,
 180                                   w->allociovecs * sizeof(*w->iovecs));
 181         }
 182     }
 183     w->iovecs[w->niovecs].iov_base = v;
 184     w->iovecs[w->niovecs].iov_len  = len;
 185     ++w->niovecs;
 186 }
 187
 188 static void
 189 write_state_flush (struct write_state *w)
 190 {
 191     if (w->niovecs) {
 192         if (writev (w->fd, w->iovecs, w->niovecs) < 0)
 193             err (1, "writev");
 194         w->niovecs = 0;
 195     }
 196 }
 197
 198 static void
 199 write_state_destroy (struct write_state *w)
 200 {
 201     free (w->iovecs);
 202 }
 203
 204 static int
 205 doit(int s,
 206      const char *host,
 207      const char *user,
 208      const char *outfilename,
 209      const char *header_str,
 210      int leavep,
 211      int verbose,
 212      int forkp)
 213 {
 214     int ret;
 215     char out_buf[PUSH_BUFSIZ];
 216     int out_len = 0;
 217     char *in_buf;
 218     size_t in_buf_size;
 219     size_t in_len = 0;
 220     char *in_ptr;
 221     pop_state state = INIT;
 222     unsigned count, bytes;
 223     unsigned asked_for = 0, retrieved = 0, asked_deleted = 0, deleted = 0;
 224     unsigned sent_xdele = 0;
 225     int out_fd;
 226     char from_line[128];
 227     size_t from_line_length;
 228     time_t now;
 229     struct write_state write_state;
 230     unsigned int numheaders = 1;
 231     char **headers = NULL;
 232     int i;
 233     char *tmp = NULL;
 234
 235     in_buf = emalloc(PUSH_BUFSIZ + 1);
 236     in_ptr = in_buf;
 237     in_buf_size = PUSH_BUFSIZ;
 238
 239     if (do_from) {
 240         char *tmp2;
 241
 242         tmp2 = tmp = estrdup(header_str);
 243
 244         out_fd = -1;
 245         if (verbose)
 246             fprintf (stderr, "%s@%s\n", user, host);
 247         while (*tmp != '\0') {
 248             tmp = strchr(tmp, ',');
 249             if (tmp == NULL)
 250                 break;
 251             tmp++;
 252             numheaders++;
 253         }
 254
 255         headers = emalloc(sizeof(char *) * (numheaders + 1));
 256         for (i = 0; i < numheaders; i++) {
 257             headers[i] = strtok_r(tmp2, ",", &tmp2);
 258         }
 259         headers[numheaders] = NULL;
 260     } else {
 261         out_fd = open(outfilename, O_WRONLY | O_APPEND | O_CREAT, 0666);
 262         if (out_fd < 0)
 263             err (1, "open %s", outfilename);
 264         if (verbose)
 265             fprintf (stderr, "%s@%s -> %s\n", user, host, outfilename);
 266     }
 267
 268     now = time(NULL);
 269     from_line_length = snprintf (from_line, sizeof(from_line),
 270                                  "From %s %s", "push", ctime(&now));
 271     if (from_line_length < 0 || from_line_length > sizeof(from_line))
 272         errx (1, "snprintf failed");
 273
 274     out_len = snprintf (out_buf, sizeof(out_buf),
 275                         "USER %s\r\nPASS hej\r\nSTAT\r\n",
 276                         user);
 277     if (out_len < 0 || out_len > sizeof(out_buf))
 278         errx (1, "snprintf failed");
 279     if (net_write (s, out_buf, out_len) != out_len)
 280         err (1, "write");
 281     if (verbose > 1)
 282         fprintf (stderr, "%s", out_buf);
 283
 284     if (!do_from)
 285         write_state_init (&write_state, out_fd);
 286
 287     while(state != QUIT) {
 288         fd_set readset, writeset;
 289
 290         FD_ZERO(&readset);
 291         FD_ZERO(&writeset);
 292         if (s >= FD_SETSIZE)
 293             errx (1, "fd too large");
 294         FD_SET(s,&readset);
 295
 296         if (verbose > 1)
 297             fprintf (stderr, "state: %s count: %d asked_for: %d "
 298                      "retrieved: %d asked_deleted: %d\n",
 299                      pop_state_string[state],
 300                      count, asked_for, retrieved, asked_deleted);
 301
 302         if (((state == STAT || state == RETR || state == TOP)
 303              && asked_for < count)
 304             || (state == XDELE && !sent_xdele)
 305             || (state == DELE && asked_deleted < count))
 306             FD_SET(s,&writeset);
 307         ret = select (s + 1, &readset, &writeset, NULL, NULL);
 308         if (ret < 0) {
 309             if (errno == EAGAIN)
 310                 continue;
 311             else
 312                 err (1, "select");
 313         }
 314
 315         if (FD_ISSET(s, &readset)) {
 316             char *beg, *p;
 317             size_t rem;
 318             int blank_line = 0;
 319
 320             if(in_len >= in_buf_size) {
 321                 char *tmp = erealloc(in_buf, in_buf_size + PUSH_BUFSIZ + 1);
 322                 in_ptr = tmp + (in_ptr - in_buf);
 323                 in_buf = tmp;
 324                 in_buf_size += PUSH_BUFSIZ;
 325             }
 326
 327             ret = read (s, in_ptr, in_buf_size - in_len);
 328             if (ret < 0)
 329                 err (1, "read");
 330             else if (ret == 0)
 331                 errx (1, "EOF during read");
 332
 333             in_len += ret;
 334             in_ptr += ret;
 335             *in_ptr = '\0';
 336
 337             beg = in_buf;
 338             rem = in_len;
 339             while(rem > 1
 340                   && (p = strstr(beg, "\r\n")) != NULL) {
 341                 if (state == TOP) {
 342                     char *copy = beg;
 343
 344                     for (i = 0; i < numheaders; i++) {
 345                         size_t len;
 346
 347                         len = min(p - copy + 1, strlen(headers[i]));
 348                         if (strncasecmp(copy, headers[i], len) == 0) {
 349                             fprintf (stdout, "%.*s\n", (int)(p - copy), copy);
 350                         }
 351                     }
 352                     if (beg[0] == '.' && beg[1] == '\r' && beg[2] == '\n') {
 353                         if (numheaders > 1)
 354                             fprintf (stdout, "\n");
 355                         state = STAT;
 356                         if (++retrieved == count) {
 357                             state = QUIT;
 358                             net_write (s, "QUIT\r\n", 6);
 359                             if (verbose > 1)
 360                                 fprintf (stderr, "QUIT\r\n");
 361                         }
 362                     }
 363                     rem -= p - beg + 2;
 364                     beg = p + 2;
 365                 } else if (state == RETR) {
 366                     char *copy = beg;
 367                     if (beg[0] == '.') {
 368                         if (beg[1] == '\r' && beg[2] == '\n') {
 369                             if(!blank_line)
 370                                 write_state_add(&write_state, "\n", 1);
 371                             state = STAT;
 372                             rem -= p - beg + 2;
 373                             beg = p + 2;
 374                             if (++retrieved == count) {
 375                                 write_state_flush (&write_state);
 376                                 if (fsync (out_fd) < 0)
 377                                     err (1, "fsync");
 378                                 close(out_fd);
 379                                 if (leavep) {
 380                                     state = QUIT;
 381                                     net_write (s, "QUIT\r\n", 6);
 382                                     if (verbose > 1)
 383                                         fprintf (stderr, "QUIT\r\n");
 384                                 } else {
 385                                     if (forkp) {
 386                                         pid_t pid;
 387
 388                                         pid = fork();
 389                                         if (pid < 0)
 390                                             warn ("fork");
 391                                         else if(pid != 0) {
 392                                             if(verbose)
 393                                                 fprintf (stderr,
 394                                                          "(exiting)");
 395                                             return 0;
 396                                         }
 397                                     }
 398
 399                                     state = XDELE;
 400                                     if (verbose)
 401                                         fprintf (stderr, "deleting... ");
 402                                 }
 403                             }
 404                             continue;
 405                         } else
 406                             ++copy;
 407                     }
 408                     *p = '\n';
 409                     if(blank_line &&
 410                        strncmp(copy, "From ", min(p - copy + 1, 5)) == 0)
 411                         write_state_add(&write_state, ">", 1);
 412                     write_state_add(&write_state, copy, p - copy + 1);
 413                     blank_line = (*copy == '\n');
 414                     rem -= p - beg + 2;
 415                     beg = p + 2;
 416                 } else if (rem >= 3 && strncmp (beg, "+OK", 3) == 0) {
 417                     if (state == STAT) {
 418                         if (!do_from)
 419                             write_state_add(&write_state,
 420                                             from_line, from_line_length);
 421                         blank_line = 0;
 422                         if (do_from)
 423                             state = TOP;
 424                         else
 425                             state = RETR;
 426                     } else if (state == XDELE) {
 427                         state = QUIT;
 428                         net_write (s, "QUIT\r\n", 6);
 429                         if (verbose > 1)
 430                             fprintf (stderr, "QUIT\r\n");
 431                         break;
 432                     } else if (state == DELE) {
 433                         if (++deleted == count) {
 434                             state = QUIT;
 435                             net_write (s, "QUIT\r\n", 6);
 436                             if (verbose > 1)
 437                                 fprintf (stderr, "QUIT\r\n");
 438                             break;
 439                         }
 440                     } else if (++state == STAT) {
 441                         if(sscanf (beg + 4, "%u %u", &count, &bytes) != 2)
 442                             errx(1, "Bad STAT-line: %.*s", (int)(p - beg), beg);
 443                         if (verbose) {
 444                             fprintf (stderr, "%u message(s) (%u bytes). "
 445                                      "fetching... ",
 446                                      count, bytes);
 447                             if (do_from)
 448                                 fprintf (stderr, "\n");
 449                         } else if (do_count) {
 450                             fprintf (stderr, "%u message(s) (%u bytes).\n",
 451                                      count, bytes);
 452                         }
 453                         if (count == 0) {
 454                             state = QUIT;
 455                             net_write (s, "QUIT\r\n", 6);
 456                             if (verbose > 1)
 457                                 fprintf (stderr, "QUIT\r\n");
 458                             break;
 459                         }
 460                     }
 461
 462                     rem -= p - beg + 2;
 463                     beg = p + 2;
 464                 } else {
 465                     if(state == XDELE) {
 466                         state = DELE;
 467                         rem -= p - beg + 2;
 468                         beg = p + 2;
 469                     } else
 470                         errx (1, "Bad response: %.*s", (int)(p - beg), beg);
 471                 }
 472             }
 473             if (!do_from)
 474                 write_state_flush (&write_state);
 475
 476             memmove (in_buf, beg, rem);
 477             in_len = rem;
 478             in_ptr = in_buf + rem;
 479         }
 480         if (FD_ISSET(s, &writeset)) {
 481             if ((state == STAT && !do_from) || state == RETR)
 482                 out_len = snprintf (out_buf, sizeof(out_buf),
 483                                     "RETR %u\r\n", ++asked_for);
 484             else if ((state == STAT && do_from) || state == TOP)
 485                 out_len = snprintf (out_buf, sizeof(out_buf),
 486                                     "TOP %u 0\r\n", ++asked_for);
 487             else if(state == XDELE) {
 488                 out_len = snprintf(out_buf, sizeof(out_buf),
 489                                    "XDELE %u %u\r\n", 1, count);
 490                 sent_xdele++;
 491             }
 492             else if(state == DELE)
 493                 out_len = snprintf (out_buf, sizeof(out_buf),
 494                                     "DELE %u\r\n", ++asked_deleted);
 495             if (out_len < 0 || out_len > sizeof(out_buf))
 496                 errx (1, "snprintf failed");
 497             if (net_write (s, out_buf, out_len) != out_len)
 498                 err (1, "write");
 499             if (verbose > 1)
 500                 fprintf (stderr, "%s", out_buf);
 501         }
 502     }
 503     if (verbose)
 504         fprintf (stderr, "Done\n");
 505     if (do_from) {
 506         free (tmp);
 507         free (headers);
 508     } else {
 509         write_state_destroy (&write_state);
 510     }
 511     return 0;
 512 }
 513
 514 #ifdef KRB5
 515 static int
 516 do_v5 (const char *host,
 517        int port,
 518        const char *user,
 519        const char *filename,
 520        const char *header_str,
 521        int leavep,
 522        int verbose,
 523        int forkp)
 524 {
 525     krb5_error_code ret;
 526     krb5_auth_context auth_context = NULL;
 527     krb5_principal server;
 528     int s;
 529
 530     s = do_connect (host, port, 1);
 531     if (s < 0)
 532         return 1;
 533
 534     ret = krb5_sname_to_principal (context,
 535                                    host,
 536                                    "pop",
 537                                    KRB5_NT_SRV_HST,
 538                                    &server);
 539     if (ret) {
 540         warnx ("krb5_sname_to_principal: %s",
 541                krb5_get_err_text (context, ret));
 542         return 1;
 543     }
 544
 545     ret = krb5_sendauth (context,
 546                          &auth_context,
 547                          &s,
 548                          "KPOPV1.0",
 549                          NULL,
 550                          server,
 551                          0,
 552                          NULL,
 553                          NULL,
 554                          NULL,
 555                          NULL,
 556                          NULL,
 557                          NULL);
 558     krb5_free_principal (context, server);
 559     if (ret) {
 560         warnx ("krb5_sendauth: %s",
 561                krb5_get_err_text (context, ret));
 562         return 1;
 563     }
 564     return doit (s, host, user, filename, header_str, leavep, verbose, forkp);
 565 }
 566 #endif
 567
 568 #ifdef KRB4
 569 static int
 570 do_v4 (const char *host,
 571        int port,
 572        const char *user,
 573        const char *filename,
 574        const char *header_str,
 575        int leavep,
 576        int verbose,
 577        int forkp)
 578 {
 579     KTEXT_ST ticket;
 580     MSG_DAT msg_data;
 581     CREDENTIALS cred;
 582     des_key_schedule sched;
 583     int s;
 584     int ret;
 585
 586     s = do_connect (host, port, 1);
 587     if (s < 0)
 588         return 1;
 589     ret = krb_sendauth(0,
 590                        s,
 591                        &ticket,
 592                        "pop",
 593                        (char *)host,
 594                        krb_realmofhost(host),
 595                        getpid(),
 596                        &msg_data,
 597                        &cred,
 598                        sched,
 599                        NULL,
 600                        NULL,
 601                        "KPOPV0.1");
 602     if(ret) {
 603         warnx("krb_sendauth: %s", krb_get_err_text(ret));
 604         return 1;
 605     }
 606     return doit (s, host, user, filename, header_str, leavep, verbose, forkp);
 607 }
 608 #endif /* KRB4 */
 609
 610 #ifdef HESIOD
 611
 612 #ifdef HESIOD_INTERFACES
 613
 614 static char *
 615 hesiod_get_pobox (const char **user)
 616 {
 617     void *context;
 618     struct hesiod_postoffice *hpo;
 619     char *ret = NULL;
 620
 621     if(hesiod_init (&context) != 0)
 622         err (1, "hesiod_init");
 623
 624     hpo = hesiod_getmailhost (context, *user);
 625     if (hpo == NULL) {
 626         warn ("hesiod_getmailhost %s", *user);
 627     } else {
 628         if (strcasecmp(hpo->hesiod_po_type, "pop") != 0)
 629             errx (1, "Unsupported po type %s", hpo->hesiod_po_type);
 630
 631         ret = estrdup(hpo->hesiod_po_host);
 632         *user = estrdup(hpo->hesiod_po_name);
 633         hesiod_free_postoffice (context, hpo);
 634     }
 635     hesiod_end (context);
 636     return ret;
 637 }
 638
 639 #else /* !HESIOD_INTERFACES */
 640
 641 static char *
 642 hesiod_get_pobox (const char **user)
 643 {
 644     char *ret = NULL;
 645     struct hes_postoffice *hpo;
 646
 647     hpo = hes_getmailhost (*user);
 648     if (hpo == NULL) {
 649         warn ("hes_getmailhost %s", *user);
 650     } else {
 651         if (strcasecmp(hpo->po_type, "pop") != 0)
 652             errx (1, "Unsupported po type %s", hpo->po_type);
 653
 654         ret = estrdup(hpo->po_host);
 655         *user = estrdup(hpo->po_name);
 656     }
 657     return ret;
 658 }
 659
 660 #endif /* HESIOD_INTERFACES */
 661
 662 #endif /* HESIOD */
 663
 664 static char *
 665 get_pobox (const char **user)
 666 {
 667     char *ret = NULL;
 668
 669 #ifdef HESIOD
 670     ret = hesiod_get_pobox (user);
 671 #endif
 672
 673     if (ret == NULL)
 674         ret = getenv("MAILHOST");
 675     if (ret == NULL)
 676         errx (1, "MAILHOST not set");
 677     return ret;
 678 }
 679
 680 static void
 681 parse_pobox (char *a0, const char **host, const char **user)
 682 {
 683     const char *h, *u;
 684     char *p;
 685     int po = 0;
 686
 687     if (a0 == NULL) {
 688
 689         *user = getenv ("USERNAME");
 690         if (*user == NULL) {
 691             struct passwd *pwd = getpwuid (getuid ());
 692
 693             if (pwd == NULL)
 694                 errx (1, "Who are you?");
 695             *user = estrdup (pwd->pw_name);
 696         }
 697         *host = get_pobox (user);
 698         return;
 699     }
 700
 701     /* if the specification starts with po:, remember this information */
 702     if(strncmp(a0, "po:", 3) == 0) {
 703         a0 += 3;
 704         po++;
 705     }
 706     /* if there is an `@', the hostname is after it, otherwise at the
 707        beginning of the string */
 708     p = strchr(a0, '@');
 709     if(p != NULL) {
 710         *p++ = '\0';
 711         h = p;
 712     } else {
 713         h = a0;
 714     }
 715     /* if there is a `:', the username comes before it, otherwise at
 716        the beginning of the string */
 717     p = strchr(a0, ':');
 718     if(p != NULL) {
 719         *p++ = '\0';
 720         u = p;
 721     } else {
 722         u = a0;
 723     }
 724     if(h == u) {
 725         /* some inconsistent compatibility with various mailers */
 726         if(po) {
 727             h = get_pobox (&u);
 728         } else {
 729             u = get_default_username ();
 730             if (u == NULL)
 731                 errx (1, "Who are you?");
 732         }
 733     }
 734     *host = h;
 735     *user = u;
 736 }
 737
 738 int
 739 main(int argc, char **argv)
 740 {
 741     int port = 0;
 742     int optind = 0;
 743     int ret = 1;
 744     const char *host, *user, *filename = NULL;
 745     char *pobox = NULL;
 746
 747     setprogname (argv[0]);
 748
 749 #ifdef KRB5
 750     {
 751         krb5_error_code ret;
 752
 753         ret = krb5_init_context (&context);
 754         if (ret)
 755             errx (1, "krb5_init_context failed: %d", ret);
 756     }
 757 #endif
 758
 759     if (getarg (args, sizeof(args) / sizeof(args[0]), argc, argv,
 760                 &optind))
 761         usage (1);
 762
 763     argc -= optind;
 764     argv += optind;
 765
 766 #if defined(KRB4) && defined(KRB5)
 767     if(use_v4 == -1 && use_v5 == 1)
 768         use_v4 = 0;
 769     if(use_v5 == -1 && use_v4 == 1)
 770         use_v5 = 0;
 771 #endif
 772
 773     if (do_help)
 774         usage (0);
 775
 776     if (do_version) {
 777         print_version(NULL);
 778         return 0;
 779     }
 780
 781     if (do_from && header_str == NULL)
 782         header_str = "From:";
 783     else if (header_str != NULL)
 784         do_from = 1;
 785
 786     if (do_from) {
 787         if (argc == 0)
 788             pobox = NULL;
 789         else if (argc == 1)
 790             pobox = argv[0];
 791         else
 792             usage (1);
 793     } else {
 794         if (argc == 1) {
 795             filename = argv[0];
 796             pobox    = NULL;
 797         } else if (argc == 2) {
 798             filename = argv[1];
 799             pobox    = argv[0];
 800         } else
 801             usage (1);
 802     }
 803
 804     if (port_str) {
 805         struct servent *s = roken_getservbyname (port_str, "tcp");
 806
 807         if (s)
 808             port = s->s_port;
 809         else {
 810             char *ptr;
 811
 812             port = strtol (port_str, &ptr, 10);
 813             if (port == 0 && ptr == port_str)
 814                 errx (1, "Bad port `%s'", port_str);
 815             port = htons(port);
 816         }
 817     }
 818     if (port == 0) {
 819 #ifdef KRB5
 820         port = krb5_getportbyname (context, "kpop", "tcp", 1109);
 821 #elif defined(KRB4)
 822         port = k_getportbyname ("kpop", "tcp", htons(1109));
 823 #else
 824 #error must define KRB4 or KRB5
 825 #endif
 826     }
 827
 828     parse_pobox (pobox, &host, &user);
 829
 830 #ifdef KRB5
 831     if (ret && use_v5) {
 832         ret = do_v5 (host, port, user, filename, header_str,
 833                      do_leave, verbose_level, do_fork);
 834     }
 835 #endif
 836
 837 #ifdef KRB4
 838     if (ret && use_v4) {
 839         ret = do_v4 (host, port, user, filename, header_str,
 840                      do_leave, verbose_level, do_fork);
 841     }
 842 #endif /* KRB4 */
 843     return ret;
 844 }