xref: /freebsd/crypto/heimdal/appl/push/push.c (revision 95eb4b873b6a8b527c5bd78d7191975dfca38998)
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 #if defined(_AIX) && defined(STAT)
38 /*
39  * AIX defines STAT to 1 in sys/dir.h
40  */
41 #  undef STAT
42 #endif
43 
44 #ifdef KRB5
45 static int use_v5 = -1;
46 static krb5_context context;
47 #endif
48 
49 static char *port_str;
50 static int verbose_level;
51 static int do_fork;
52 static int do_leave;
53 static int do_version;
54 static int do_help;
55 static int do_from;
56 static int do_count;
57 static char *header_str;
58 
59 struct getargs args[] = {
60 #ifdef KRB5
61     { "krb5",	'5', arg_flag,		&use_v5,	"Use Kerberos V5",
62       NULL },
63 #endif
64     { "verbose",'v', arg_counter,	&verbose_level,	"Verbose",
65       NULL },
66     { "fork",	'f', arg_flag,		&do_fork,	"Fork deleting proc",
67       NULL },
68     { "leave",	'l', arg_flag,		&do_leave,	"Leave mail on server",
69       NULL },
70     { "port",	'p', arg_string,	&port_str,	"Use this port",
71       "number-or-service" },
72     { "from",	 0,  arg_flag,		&do_from,	"Behave like from",
73       NULL },
74     { "headers", 0,  arg_string,	&header_str,	"Headers to print", NULL },
75     { "count", 'c',  arg_flag,		&do_count,	"Print number of messages", NULL},
76     { "version", 0,  arg_flag,		&do_version,	"Print version",
77       NULL },
78     { "help",	 0,  arg_flag,		&do_help,	NULL,
79       NULL }
80 
81 };
82 
83 static void
84 usage (int ret)
85 {
86     arg_printusage (args,
87 		    sizeof(args) / sizeof(args[0]),
88 		    NULL,
89 		    "[[{po:username[@hostname] | hostname[:username]}] ...] "
90 		    "filename");
91     exit (ret);
92 }
93 
94 static int
95 do_connect (const char *hostname, int port, int nodelay)
96 {
97     struct addrinfo *ai, *a;
98     struct addrinfo hints;
99     int error;
100     int s = -1;
101     char portstr[NI_MAXSERV];
102 
103     memset (&hints, 0, sizeof(hints));
104     hints.ai_socktype = SOCK_STREAM;
105     hints.ai_protocol = IPPROTO_TCP;
106 
107     snprintf (portstr, sizeof(portstr), "%u", ntohs(port));
108 
109     error = getaddrinfo (hostname, portstr, &hints, &ai);
110     if (error)
111 	errx (1, "getaddrinfo(%s): %s", hostname, gai_strerror(error));
112 
113     for (a = ai; a != NULL; a = a->ai_next) {
114 	s = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
115 	if (s < 0)
116 	    continue;
117 	if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
118 	    warn ("connect(%s)", hostname);
119  	    close (s);
120  	    continue;
121 	}
122 	break;
123     }
124     freeaddrinfo (ai);
125     if (a == NULL) {
126 	warnx ("failed to contact %s", hostname);
127 	return -1;
128     }
129 
130     if(setsockopt(s, IPPROTO_TCP, TCP_NODELAY,
131 		  (void *)&nodelay, sizeof(nodelay)) < 0)
132 	err (1, "setsockopt TCP_NODELAY");
133     return s;
134 }
135 
136 typedef enum { INIT = 0, GREET, USER, PASS, STAT, RETR, TOP,
137 	       DELE, XDELE, QUIT} pop_state;
138 
139 static char *pop_state_string[] = {
140     "INIT", "GREET", "USER", "PASS", "STAT", "RETR", "TOP",
141     "DELE", "XDELE", "QUIT"
142 };
143 
144 #define PUSH_BUFSIZ 65536
145 
146 #define STEP 16
147 
148 struct write_state {
149     struct iovec *iovecs;
150     size_t niovecs, maxiovecs, allociovecs;
151     int fd;
152 };
153 
154 static void
155 write_state_init (struct write_state *w, int fd)
156 {
157 #ifdef UIO_MAXIOV
158     w->maxiovecs = UIO_MAXIOV;
159 #else
160     w->maxiovecs = 16;
161 #endif
162     w->allociovecs = min(STEP, w->maxiovecs);
163     w->niovecs = 0;
164     w->iovecs = emalloc(w->allociovecs * sizeof(*w->iovecs));
165     w->fd = fd;
166 }
167 
168 static void
169 write_state_add (struct write_state *w, void *v, size_t len)
170 {
171     if(w->niovecs == w->allociovecs) {
172 	if(w->niovecs == w->maxiovecs) {
173 	    if(writev (w->fd, w->iovecs, w->niovecs) < 0)
174 		err(1, "writev");
175 	    w->niovecs = 0;
176 	} else {
177 	    w->allociovecs = min(w->allociovecs + STEP, w->maxiovecs);
178 	    w->iovecs = erealloc (w->iovecs,
179 				  w->allociovecs * sizeof(*w->iovecs));
180 	}
181     }
182     w->iovecs[w->niovecs].iov_base = v;
183     w->iovecs[w->niovecs].iov_len  = len;
184     ++w->niovecs;
185 }
186 
187 static void
188 write_state_flush (struct write_state *w)
189 {
190     if (w->niovecs) {
191 	if (writev (w->fd, w->iovecs, w->niovecs) < 0)
192 	    err (1, "writev");
193 	w->niovecs = 0;
194     }
195 }
196 
197 static void
198 write_state_destroy (struct write_state *w)
199 {
200     free (w->iovecs);
201 }
202 
203 static int
204 doit(int s,
205      const char *host,
206      const char *user,
207      const char *outfilename,
208      const char *header_str,
209      int leavep,
210      int verbose,
211      int forkp)
212 {
213     int ret;
214     char out_buf[PUSH_BUFSIZ];
215     int out_len = 0;
216     char *in_buf;
217     size_t in_buf_size;
218     size_t in_len = 0;
219     char *in_ptr;
220     pop_state state = INIT;
221     unsigned count = 0, bytes;
222     unsigned asked_for = 0, retrieved = 0, asked_deleted = 0, deleted = 0;
223     unsigned sent_xdele = 0;
224     int out_fd;
225     char from_line[128];
226     size_t from_line_length;
227     time_t now;
228     struct write_state write_state;
229     unsigned int numheaders = 1;
230     char **headers = NULL;
231     int i;
232     char *tmp = NULL;
233 
234     in_buf = emalloc(PUSH_BUFSIZ + 1);
235     in_ptr = in_buf;
236     in_buf_size = PUSH_BUFSIZ;
237 
238     if (do_from) {
239 	char *tmp2;
240 
241 	tmp2 = tmp = estrdup(header_str);
242 
243 	out_fd = -1;
244 	if (verbose)
245 	    fprintf (stderr, "%s@%s\n", user, host);
246 	while (*tmp != '\0') {
247 	    tmp = strchr(tmp, ',');
248 	    if (tmp == NULL)
249 		break;
250 	    tmp++;
251 	    numheaders++;
252 	}
253 
254 	headers = emalloc(sizeof(char *) * (numheaders + 1));
255 	for (i = 0; i < numheaders; i++) {
256 	    headers[i] = strtok_r(tmp2, ",", &tmp2);
257 	}
258 	headers[numheaders] = NULL;
259     } else {
260 	out_fd = open(outfilename, O_WRONLY | O_APPEND | O_CREAT, 0666);
261 	if (out_fd < 0)
262 	    err (1, "open %s", outfilename);
263 	if (verbose)
264 	    fprintf (stderr, "%s@%s -> %s\n", user, host, outfilename);
265     }
266 
267     now = time(NULL);
268     from_line_length = snprintf (from_line, sizeof(from_line),
269 				 "From %s %s", "push", ctime(&now));
270     if (from_line_length < 0 || from_line_length > sizeof(from_line))
271 	errx (1, "snprintf failed");
272 
273     out_len = snprintf (out_buf, sizeof(out_buf),
274 			"USER %s\r\nPASS hej\r\nSTAT\r\n",
275 			user);
276     if (out_len < 0 || out_len > sizeof(out_buf))
277 	errx (1, "snprintf failed");
278     if (net_write (s, out_buf, out_len) != out_len)
279 	err (1, "write");
280     if (verbose > 1)
281 	fprintf (stderr, "%s", out_buf);
282 
283     if (!do_from)
284 	write_state_init (&write_state, out_fd);
285 
286     while(state != QUIT) {
287 	fd_set readset, writeset;
288 
289 	FD_ZERO(&readset);
290 	FD_ZERO(&writeset);
291 	if (s >= FD_SETSIZE)
292 	    errx (1, "fd too large");
293 	FD_SET(s,&readset);
294 
295 	if (verbose > 1)
296 	    fprintf (stderr, "state: %s count: %d asked_for: %d "
297 		     "retrieved: %d asked_deleted: %d\n",
298 		     pop_state_string[state],
299 		     count, asked_for, retrieved, asked_deleted);
300 
301 	if (((state == STAT || state == RETR || state == TOP)
302 	     && asked_for < count)
303 	    || (state == XDELE && !sent_xdele)
304 	    || (state == DELE && asked_deleted < count))
305 	    FD_SET(s,&writeset);
306 	ret = select (s + 1, &readset, &writeset, NULL, NULL);
307 	if (ret < 0) {
308 	    if (errno == EAGAIN)
309 		continue;
310 	    else
311 		err (1, "select");
312 	}
313 
314 	if (FD_ISSET(s, &readset)) {
315 	    char *beg, *p;
316 	    size_t rem;
317 	    int blank_line = 0;
318 
319 	    if(in_len >= in_buf_size) {
320 		char *tmp = erealloc(in_buf, in_buf_size + PUSH_BUFSIZ + 1);
321 		in_ptr = tmp + (in_ptr - in_buf);
322 		in_buf = tmp;
323 		in_buf_size += PUSH_BUFSIZ;
324 	    }
325 
326 	    ret = read (s, in_ptr, in_buf_size - in_len);
327 	    if (ret < 0)
328 		err (1, "read");
329 	    else if (ret == 0)
330 		errx (1, "EOF during read");
331 
332 	    in_len += ret;
333 	    in_ptr += ret;
334 	    *in_ptr = '\0';
335 
336 	    beg = in_buf;
337 	    rem = in_len;
338 	    while(rem > 1
339 		  && (p = strstr(beg, "\r\n")) != NULL) {
340 		if (state == TOP) {
341 		    char *copy = beg;
342 
343 		    for (i = 0; i < numheaders; i++) {
344 			size_t len;
345 
346 			len = min(p - copy + 1, strlen(headers[i]));
347 			if (strncasecmp(copy, headers[i], len) == 0) {
348 			    fprintf (stdout, "%.*s\n", (int)(p - copy), copy);
349 			}
350 		    }
351 		    if (beg[0] == '.' && beg[1] == '\r' && beg[2] == '\n') {
352 			if (numheaders > 1)
353 			    fprintf (stdout, "\n");
354 			state = STAT;
355 			if (++retrieved == count) {
356 			    state = QUIT;
357 			    net_write (s, "QUIT\r\n", 6);
358 			    if (verbose > 1)
359 				fprintf (stderr, "QUIT\r\n");
360 			}
361 		    }
362 		    rem -= p - beg + 2;
363 		    beg = p + 2;
364 		} else if (state == RETR) {
365 		    char *copy = beg;
366 		    if (beg[0] == '.') {
367 			if (beg[1] == '\r' && beg[2] == '\n') {
368 			    if(!blank_line)
369 				write_state_add(&write_state, "\n", 1);
370 			    state = STAT;
371 			    rem -= p - beg + 2;
372 			    beg = p + 2;
373 			    if (++retrieved == count) {
374 				write_state_flush (&write_state);
375 				if (fsync (out_fd) < 0)
376 				    err (1, "fsync");
377 				close(out_fd);
378 				if (leavep) {
379 				    state = QUIT;
380 				    net_write (s, "QUIT\r\n", 6);
381 				    if (verbose > 1)
382 					fprintf (stderr, "QUIT\r\n");
383 				} else {
384 				    if (forkp) {
385 					pid_t pid;
386 
387 					pid = fork();
388 					if (pid < 0)
389 					    warn ("fork");
390 					else if(pid != 0) {
391 					    if(verbose)
392 						fprintf (stderr,
393 							 "(exiting)");
394 					    return 0;
395 					}
396 				    }
397 
398 				    state = XDELE;
399 				    if (verbose)
400 					fprintf (stderr, "deleting... ");
401 				}
402 			    }
403 			    continue;
404 			} else
405 			    ++copy;
406 		    }
407 		    *p = '\n';
408 		    if(blank_line &&
409 		       strncmp(copy, "From ", min(p - copy + 1, 5)) == 0)
410 			write_state_add(&write_state, ">", 1);
411 		    write_state_add(&write_state, copy, p - copy + 1);
412 		    blank_line = (*copy == '\n');
413 		    rem -= p - beg + 2;
414 		    beg = p + 2;
415 		} else if (rem >= 3 && strncmp (beg, "+OK", 3) == 0) {
416 		    if (state == STAT) {
417 			if (!do_from)
418 			    write_state_add(&write_state,
419 					    from_line, from_line_length);
420 			blank_line = 0;
421 			if (do_from)
422 			    state = TOP;
423 			else
424 			    state = RETR;
425 		    } else if (state == XDELE) {
426 			state = QUIT;
427 			net_write (s, "QUIT\r\n", 6);
428 			if (verbose > 1)
429 			    fprintf (stderr, "QUIT\r\n");
430 			break;
431 		    } else if (state == DELE) {
432 			if (++deleted == count) {
433 			    state = QUIT;
434 			    net_write (s, "QUIT\r\n", 6);
435 			    if (verbose > 1)
436 				fprintf (stderr, "QUIT\r\n");
437 			    break;
438 			}
439 		    } else if (++state == STAT) {
440 			if(sscanf (beg + 4, "%u %u", &count, &bytes) != 2)
441 			    errx(1, "Bad STAT-line: %.*s", (int)(p - beg), beg);
442 			if (verbose) {
443 			    fprintf (stderr, "%u message(s) (%u bytes). "
444 				     "fetching... ",
445 				     count, bytes);
446 			    if (do_from)
447 				fprintf (stderr, "\n");
448 			} else if (do_count) {
449 			    fprintf (stderr, "%u message(s) (%u bytes).\n",
450 				     count, bytes);
451 			}
452 			if (count == 0) {
453 			    state = QUIT;
454 			    net_write (s, "QUIT\r\n", 6);
455 			    if (verbose > 1)
456 				fprintf (stderr, "QUIT\r\n");
457 			    break;
458 			}
459 		    }
460 
461 		    rem -= p - beg + 2;
462 		    beg = p + 2;
463 		} else {
464 		    if(state == XDELE) {
465 			state = DELE;
466 			rem -= p - beg + 2;
467 			beg = p + 2;
468 		    } else
469 			errx (1, "Bad response: %.*s", (int)(p - beg), beg);
470 		}
471 	    }
472 	    if (!do_from)
473 		write_state_flush (&write_state);
474 
475 	    memmove (in_buf, beg, rem);
476 	    in_len = rem;
477 	    in_ptr = in_buf + rem;
478 	}
479 	if (FD_ISSET(s, &writeset)) {
480 	    if ((state == STAT && !do_from) || state == RETR)
481 		out_len = snprintf (out_buf, sizeof(out_buf),
482 				    "RETR %u\r\n", ++asked_for);
483 	    else if ((state == STAT && do_from) || state == TOP)
484 		out_len = snprintf (out_buf, sizeof(out_buf),
485 				    "TOP %u 0\r\n", ++asked_for);
486 	    else if(state == XDELE) {
487 		out_len = snprintf(out_buf, sizeof(out_buf),
488 				   "XDELE %u %u\r\n", 1, count);
489 		sent_xdele++;
490 	    }
491 	    else if(state == DELE)
492 		out_len = snprintf (out_buf, sizeof(out_buf),
493 				    "DELE %u\r\n", ++asked_deleted);
494 	    if (out_len < 0 || out_len > sizeof(out_buf))
495 		errx (1, "snprintf failed");
496 	    if (net_write (s, out_buf, out_len) != out_len)
497 		err (1, "write");
498 	    if (verbose > 1)
499 		fprintf (stderr, "%s", out_buf);
500 	}
501     }
502     if (verbose)
503 	fprintf (stderr, "Done\n");
504     if (do_from) {
505 	free (tmp);
506 	free (headers);
507     } else {
508 	write_state_destroy (&write_state);
509     }
510     return 0;
511 }
512 
513 #ifdef KRB5
514 static int
515 do_v5 (const char *host,
516        int port,
517        const char *user,
518        const char *filename,
519        const char *header_str,
520        int leavep,
521        int verbose,
522        int forkp)
523 {
524     krb5_error_code ret;
525     krb5_auth_context auth_context = NULL;
526     krb5_principal server;
527     int s;
528 
529     s = do_connect (host, port, 1);
530     if (s < 0)
531 	return 1;
532 
533     ret = krb5_sname_to_principal (context,
534 				   host,
535 				   "pop",
536 				   KRB5_NT_SRV_HST,
537 				   &server);
538     if (ret) {
539 	warnx ("krb5_sname_to_principal: %s",
540 	       krb5_get_err_text (context, ret));
541 	return 1;
542     }
543 
544     ret = krb5_sendauth (context,
545 			 &auth_context,
546 			 &s,
547 			 "KPOPV1.0",
548 			 NULL,
549 			 server,
550 			 0,
551 			 NULL,
552 			 NULL,
553 			 NULL,
554 			 NULL,
555 			 NULL,
556 			 NULL);
557     krb5_free_principal (context, server);
558     if (ret) {
559 	warnx ("krb5_sendauth: %s",
560 	       krb5_get_err_text (context, ret));
561 	return 1;
562     }
563     return doit (s, host, user, filename, header_str, leavep, verbose, forkp);
564 }
565 #endif
566 
567 #ifdef HESIOD
568 
569 #ifdef HESIOD_INTERFACES
570 
571 static char *
572 hesiod_get_pobox (const char **user)
573 {
574     void *context;
575     struct hesiod_postoffice *hpo;
576     char *ret = NULL;
577 
578     if(hesiod_init (&context) != 0)
579 	err (1, "hesiod_init");
580 
581     hpo = hesiod_getmailhost (context, *user);
582     if (hpo == NULL) {
583 	warn ("hesiod_getmailhost %s", *user);
584     } else {
585 	if (strcasecmp(hpo->hesiod_po_type, "pop") != 0)
586 	    errx (1, "Unsupported po type %s", hpo->hesiod_po_type);
587 
588 	ret = estrdup(hpo->hesiod_po_host);
589 	*user = estrdup(hpo->hesiod_po_name);
590 	hesiod_free_postoffice (context, hpo);
591     }
592     hesiod_end (context);
593     return ret;
594 }
595 
596 #else /* !HESIOD_INTERFACES */
597 
598 static char *
599 hesiod_get_pobox (const char **user)
600 {
601     char *ret = NULL;
602     struct hes_postoffice *hpo;
603 
604     hpo = hes_getmailhost (*user);
605     if (hpo == NULL) {
606 	warn ("hes_getmailhost %s", *user);
607     } else {
608 	if (strcasecmp(hpo->po_type, "pop") != 0)
609 	    errx (1, "Unsupported po type %s", hpo->po_type);
610 
611 	ret = estrdup(hpo->po_host);
612 	*user = estrdup(hpo->po_name);
613     }
614     return ret;
615 }
616 
617 #endif /* HESIOD_INTERFACES */
618 
619 #endif /* HESIOD */
620 
621 static char *
622 get_pobox (const char **user)
623 {
624     char *ret = NULL;
625 
626 #ifdef HESIOD
627     ret = hesiod_get_pobox (user);
628 #endif
629 
630     if (ret == NULL)
631 	ret = getenv("MAILHOST");
632     if (ret == NULL)
633 	errx (1, "MAILHOST not set");
634     return ret;
635 }
636 
637 static void
638 parse_pobox (char *a0, const char **host, const char **user)
639 {
640     const char *h, *u;
641     char *p;
642     int po = 0;
643 
644     if (a0 == NULL) {
645 
646 	*user = getenv ("USERNAME");
647 	if (*user == NULL) {
648 	    struct passwd *pwd = getpwuid (getuid ());
649 
650 	    if (pwd == NULL)
651 		errx (1, "Who are you?");
652 	    *user = estrdup (pwd->pw_name);
653 	}
654 	*host = get_pobox (user);
655 	return;
656     }
657 
658     /* if the specification starts with po:, remember this information */
659     if(strncmp(a0, "po:", 3) == 0) {
660 	a0 += 3;
661 	po++;
662     }
663     /* if there is an `@', the hostname is after it, otherwise at the
664        beginning of the string */
665     p = strchr(a0, '@');
666     if(p != NULL) {
667 	*p++ = '\0';
668 	h = p;
669     } else {
670 	h = a0;
671     }
672     /* if there is a `:', the username comes before it, otherwise at
673        the beginning of the string */
674     p = strchr(a0, ':');
675     if(p != NULL) {
676 	*p++ = '\0';
677 	u = p;
678     } else {
679 	u = a0;
680     }
681     if(h == u) {
682 	/* some inconsistent compatibility with various mailers */
683 	if(po) {
684 	    h = get_pobox (&u);
685 	} else {
686 	    u = get_default_username ();
687 	    if (u == NULL)
688 		errx (1, "Who are you?");
689 	}
690     }
691     *host = h;
692     *user = u;
693 }
694 
695 int
696 main(int argc, char **argv)
697 {
698     int port = 0;
699     int optind = 0;
700     int ret = 1;
701     const char *host, *user, *filename = NULL;
702     char *pobox = NULL;
703 
704     setprogname (argv[0]);
705 
706 #ifdef KRB5
707     {
708 	krb5_error_code ret;
709 
710 	ret = krb5_init_context (&context);
711 	if (ret)
712 	    errx (1, "krb5_init_context failed: %d", ret);
713     }
714 #endif
715 
716     if (getarg (args, sizeof(args) / sizeof(args[0]), argc, argv,
717 		&optind))
718 	usage (1);
719 
720     argc -= optind;
721     argv += optind;
722 
723     if (do_help)
724 	usage (0);
725 
726     if (do_version) {
727 	print_version(NULL);
728 	return 0;
729     }
730 
731     if (do_from && header_str == NULL)
732 	header_str = "From:";
733     else if (header_str != NULL)
734 	do_from = 1;
735 
736     if (do_from) {
737 	if (argc == 0)
738 	    pobox = NULL;
739 	else if (argc == 1)
740 	    pobox = argv[0];
741 	else
742 	    usage (1);
743     } else {
744 	if (argc == 1) {
745 	    filename = argv[0];
746 	    pobox    = NULL;
747 	} else if (argc == 2) {
748 	    filename = argv[1];
749 	    pobox    = argv[0];
750 	} else
751 	    usage (1);
752     }
753 
754     if (port_str) {
755 	struct servent *s = roken_getservbyname (port_str, "tcp");
756 
757 	if (s)
758 	    port = s->s_port;
759 	else {
760 	    char *ptr;
761 
762 	    port = strtol (port_str, &ptr, 10);
763 	    if (port == 0 && ptr == port_str)
764 		errx (1, "Bad port `%s'", port_str);
765 	    port = htons(port);
766 	}
767     }
768     if (port == 0) {
769 #ifdef KRB5
770 	port = krb5_getportbyname (context, "kpop", "tcp", 1109);
771 #else
772 #error must define KRB5
773 #endif
774     }
775 
776     parse_pobox (pobox, &host, &user);
777 
778 #ifdef KRB5
779     if (ret && use_v5) {
780 	ret = do_v5 (host, port, user, filename, header_str,
781 		     do_leave, verbose_level, do_fork);
782     }
783 #endif
784     return ret;
785 }
786