summaryrefslogtreecommitdiff
path: root/qmail-smtpd.c
blob: 23f9c898fb32d746a1be431a03033742181399ac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
#include "sig.h"
#include "readwrite.h"
#include "stralloc.h"
#include "substdio.h"
#include "alloc.h"
#include "auto_qmail.h"
#include "control.h"
#include "received.h"
#include "constmap.h"
#include "error.h"
#include "ipme.h"
#include "ip.h"
#include "qmail.h"
#include "str.h"
#include "fmt.h"
#include "scan.h"
#include "byte.h"
#include "case.h"
#include "env.h"
#include "now.h"
#include "exit.h"
#include "rcpthosts.h"
#include "timeoutread.h"
#include "timeoutwrite.h"
#include "commands.h"
#include "wait.h"
#include "fd.h"

//  AUTHCRAM is not #defined for now, because:
//  1) It requires cmd5checkpw (not just checkpassword), and
//    a) cmd5checkpw requires separate administration of the poppasswed file.
//    b) cmd5checkpw requires leaving plaintext passwords on disk, yecchhhh.
//  2) We don't need the added security if we only offer auth
//    over channels that are already protected by ssl.

#define MAXHOPS 100
unsigned int databytes = 0;
int timeout = 1200;

int safewrite(fd,buf,len) int fd; char *buf; int len;
{
  int r;
  r = timeoutwrite(timeout,fd,buf,len);
  if (r <= 0) _exit(1);
  return r;
}

char ssoutbuf[512];
substdio ssout = SUBSTDIO_FDBUF(safewrite,1,ssoutbuf,sizeof ssoutbuf);

void flush() { substdio_flush(&ssout); }
void out(s) char *s; { substdio_puts(&ssout,s); }

void die_read() { _exit(1); }
void die_alarm() { out("451 timeout (#4.4.2)\r\n"); flush(); _exit(1); }
void die_nomem() { out("421 out of memory (#4.3.0)\r\n"); flush(); _exit(1); }
void die_control() { out("421 unable to read controls (#4.3.0)\r\n"); flush(); _exit(1); }
void die_ipme() { out("421 unable to figure out my IP addresses (#4.3.0)\r\n"); flush(); _exit(1); }
void straynewline() { out("451 See http://pobox.com/~djb/docs/smtplf.html.\r\n"); flush(); _exit(1); }

void err_badbounce() { out("550 sorry, bounce messages should have a single envelope recipient (#5.7.1)\r\n"); }
void err_bmf() { out("553 sorry, your envelope sender is in my badmailfrom list (#5.7.1)\r\n"); }
void err_nogateway() { out("553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)\r\n"); }
void err_unimpl(arg) char *arg; { out("502 unimplemented (#5.5.1)\r\n"); }
void err_syntax() { out("555 syntax error (#5.5.4)\r\n"); }
void err_relay() { out("553 we don't relay (#5.7.1)\r\n"); }
void err_wantmail() { out("503 MAIL first (#5.5.1)\r\n"); }
void err_wantrcpt() { out("503 RCPT first (#5.5.1)\r\n"); }
void err_noop(arg) char *arg; { out("250 ok\r\n"); }
void err_vrfy(arg) char *arg; { out("252 send some mail, i'll try my best\r\n"); }
void err_qqt() { out("451 qqt failure (#4.3.0)\r\n"); }

int err_child() { out("454 oops, problem with child and I can't auth (#4.3.0)\r\n"); return -1; }
int err_fork() { out("454 oops, child won't start and I can't auth (#4.3.0)\r\n"); return -1; }
int err_pipe() { out("454 oops, unable to open pipe and I can't auth (#4.3.0)\r\n"); return -1; }
int err_write() { out("454 oops, unable to write pipe and I can't auth (#4.3.0)\r\n"); return -1; }
void err_authd() { out("503 you're already authenticated (#5.5.0)\r\n"); }
void err_authmail() { out("503 no auth during mail transaction (#5.5.0)\r\n"); }
int err_noauth() { out("504 auth type unimplemented (#5.5.1)\r\n"); return -1; }
int err_authabrt() { out("501 auth exchange cancelled (#5.0.0)\r\n"); return -1; }
int err_input() { out("501 malformed auth input (#5.5.4)\r\n"); return -1; }

stralloc greeting = {0};

void smtp_greet(code) char *code;
{
  substdio_puts(&ssout,code);
  substdio_put(&ssout,greeting.s,greeting.len);
}
void smtp_help(arg) char *arg;
{
  out("214 netqmail home page: http://qmail.org/netqmail\r\n");
}
void smtp_quit(arg) char *arg;
{
  smtp_greet("221 "); out("\r\n"); flush(); _exit(0);
}

char *remoteip;
char *remotehost;
char *remoteinfo;
char *local;
char *relayclient;

stralloc helohost = {0};
char *fakehelo; /* pointer into helohost, or 0 */

void dohelo(arg) char *arg; {
  if (!stralloc_copys(&helohost,arg)) die_nomem();
  if (!stralloc_0(&helohost)) die_nomem();
  fakehelo = case_diffs(remotehost,helohost.s) ? helohost.s : 0;
}

int liphostok = 0;
stralloc liphost = {0};
int bmfok = 0;
stralloc bmf = {0};
struct constmap mapbmf;

void setup()
{
  char *x;
  unsigned long u;

  if (control_init() == -1) die_control();
  if (control_rldef(&greeting,"control/smtpgreeting",1,(char *) 0) != 1)
    die_control();
  liphostok = control_rldef(&liphost,"control/localiphost",1,(char *) 0);
  if (liphostok == -1) die_control();
  if (control_readint(&timeout,"control/timeoutsmtpd") == -1) die_control();
  if (timeout <= 0) timeout = 1;

  if (rcpthosts_init() == -1) die_control();

  bmfok = control_readfile(&bmf,"control/badmailfrom",0);
  if (bmfok == -1) die_control();
  if (bmfok)
    if (!constmap_init(&mapbmf,bmf.s,bmf.len,0)) die_nomem();

  if (control_readint(&databytes,"control/databytes") == -1) die_control();
  x = env_get("DATABYTES");
  if (x) { scan_ulong(x,&u); databytes = u; }
  if (!(databytes + 1)) --databytes;

  remoteip = env_get("TCPREMOTEIP");
  if (!remoteip) remoteip = "unknown";
  local = env_get("TCPLOCALHOST");
  if (!local) local = env_get("TCPLOCALIP");
  if (!local) local = "unknown";
  remotehost = env_get("TCPREMOTEHOST");
  if (!remotehost) remotehost = "unknown";
  remoteinfo = env_get("TCPREMOTEINFO");
  relayclient = env_get("RELAYCLIENT");
  dohelo(remotehost);
}


stralloc addr = {0}; /* will be 0-terminated, if addrparse returns 1 */

int addrparse(arg)
char *arg;
{
  int i;
  char ch;
  char terminator;
  struct ip_address ip;
  int flagesc;
  int flagquoted;

  terminator = '>';
  i = str_chr(arg,'<');
  if (arg[i])
    arg += i + 1;
  else { /* partner should go read rfc 821 */
    terminator = ' ';
/* The following fails insidiously if there's no ':' */
    arg += str_chr(arg,':');
    if (*arg == ':') ++arg;
    while (*arg == ' ') ++arg;
  }

  /* strip source route */
  if (*arg == '@') while (*arg) if (*arg++ == ':') break;

  if (!stralloc_copys(&addr,"")) die_nomem();
  flagesc = 0;
  flagquoted = 0;
  for (i = 0;ch = arg[i];++i) { /* copy arg to addr, stripping quotes */
    if (flagesc) {
      if (!stralloc_append(&addr,&ch)) die_nomem();
      flagesc = 0;
    }
    else {
      if (!flagquoted && (ch == terminator)) break;
      switch(ch) {
        case '\\': flagesc = 1; break;
        case '"': flagquoted = !flagquoted; break;
        default: if (!stralloc_append(&addr,&ch)) die_nomem();
      }
    }
  }
  /* could check for termination failure here, but why bother? */
  if (!stralloc_append(&addr,"")) die_nomem();

  if (liphostok) {
    i = byte_rchr(addr.s,addr.len,'@');
    if (i < addr.len) /* if not, partner should go read rfc 821 */
      if (addr.s[i + 1] == '[')
        if (!addr.s[i + 1 + ip_scanbracket(addr.s + i + 1,&ip)])
          if (ipme_is(&ip)) {
            addr.len = i + 1;
            if (!stralloc_cat(&addr,&liphost)) die_nomem();
            if (!stralloc_0(&addr)) die_nomem();
          }
  }

/* returning 0 will provoke a "555 syntax error" */
  if (addr.len > 900) return 0;
  if (addr.len == 0 || addr.s[0] == 0) return 0;
  return 1;
}

int bmfcheck()
{
  int j;
  if (!bmfok) return 0;
  if (constmap(&mapbmf,addr.s,addr.len - 1)) return 1;
  j = byte_rchr(addr.s,addr.len,'@');
  if (j < addr.len)
    if (constmap(&mapbmf,addr.s + j,addr.len - j - 1)) return 1;
  return 0;
}

int addrallowed()
{
  int r;
  r = rcpthosts(addr.s,str_len(addr.s));
  if (r == -1) die_control();
  return r;
}

int addrrelay()
{
  int j;
  j = addr.len;
  while(--j >= 0)
    if (addr.s[j] == '@') break;
  if (j < 0) j = addr.len;
  while(--j >= 0) {
    if (addr.s[j] == '@') return 1;
    if (addr.s[j] == '%') return 1;
    if (addr.s[j] == '!') return 1;
  }
  return 0;
}


int seenmail = 0;
int flagbarf; /* defined if seenmail */
stralloc mailfrom = {0};
stralloc rcptto = {0};
int recipcount;
char *hostname;
char **childargs;

void smtp_helo(arg) char *arg;
{
  smtp_greet("250 "); out("\r\n");
  seenmail = 0; dohelo(arg);
}
void smtp_ehlo(arg) char *arg;
{
  smtp_greet("250-");    out("\r\n");
  if (hostname && childargs) {
#ifdef AUTHCRAM
    out("250-AUTH LOGIN CRAM-MD5 PLAIN\r\n");
    out("250-AUTH=LOGIN CRAM-MD5 PLAIN\r\n");
#else
    out("250-AUTH LOGIN PLAIN\r\n");
    out("250-AUTH=LOGIN PLAIN\r\n");
#endif
  }
  out("250-PIPELINING\r\n250 8BITMIME\r\n");
  seenmail = 0; dohelo(arg);
}
void smtp_rset(arg) char *arg;
{
  seenmail = 0;
  out("250 flushed\r\n");
}
void smtp_mail(arg) char *arg;
{
  if (!addrparse(arg)) { err_syntax(); return; }
  flagbarf = bmfcheck();
  seenmail = 1;
  if (!stralloc_copys(&rcptto,"")) die_nomem();
  if (!stralloc_copys(&mailfrom,addr.s)) die_nomem();
  if (!stralloc_0(&mailfrom)) die_nomem();
  out("250 ok\r\n");
}
void smtp_rcpt(arg) char *arg; {
  if (!seenmail) { err_wantmail(); return; }
  if (!addrparse(arg)) { err_syntax(); return; }
  if (addrrelay()) { err_relay(); return; }
  if (flagbarf) { err_bmf(); return; }
  if (relayclient) {
    --addr.len;
    if (!stralloc_cats(&addr,relayclient)) die_nomem();
    if (!stralloc_0(&addr)) die_nomem();
  }
  else
    if (!addrallowed()) { err_nogateway(); return; }
  if (!stralloc_cats(&rcptto,"T")) die_nomem();
  if (!stralloc_cats(&rcptto,addr.s)) die_nomem();
  if (!stralloc_0(&rcptto)) die_nomem();
  recipcount++;
  out("250 ok\r\n");
}


int saferead(fd,buf,len) int fd; char *buf; int len;
{
  int r;
  flush();
  r = timeoutread(timeout,fd,buf,len);
  if (r == -1) if (errno == error_timeout) die_alarm();
  if (r <= 0) die_read();
  return r;
}

char ssinbuf[1024];
substdio ssin = SUBSTDIO_FDBUF(saferead,0,ssinbuf,sizeof ssinbuf);

struct qmail qqt;
unsigned int bytestooverflow = 0;

void put(ch)
char *ch;
{
  if (bytestooverflow)
    if (!--bytestooverflow)
      qmail_fail(&qqt);
  qmail_put(&qqt,ch,1);
}

void blast(hops)
int *hops;
{
  char ch;
  int state;
  int flaginheader;
  int pos; /* number of bytes since most recent \n, if fih */
  int flagmaybex; /* 1 if this line might match RECEIVED, if fih */
  int flagmaybey; /* 1 if this line might match \r\n, if fih */
  int flagmaybez; /* 1 if this line might match DELIVERED, if fih */

  state = 1;
  *hops = 0;
  flaginheader = 1;
  pos = 0; flagmaybex = flagmaybey = flagmaybez = 1;
  for (;;) {
    substdio_get(&ssin,&ch,1);
    if (flaginheader) {
      if (pos < 9) {
        if (ch != "delivered"[pos]) if (ch != "DELIVERED"[pos]) flagmaybez = 0;
        if (flagmaybez) if (pos == 8) ++*hops;
        if (pos < 8)
          if (ch != "received"[pos]) if (ch != "RECEIVED"[pos]) flagmaybex = 0;
        if (flagmaybex) if (pos == 7) ++*hops;
        if (pos < 2) if (ch != "\r\n"[pos]) flagmaybey = 0;
        if (flagmaybey) if (pos == 1) flaginheader = 0;
	++pos;
      }
      if (ch == '\n') { pos = 0; flagmaybex = flagmaybey = flagmaybez = 1; }
    }
    switch(state) {
      case 0:
        if (ch == '\n') straynewline();
        if (ch == '\r') { state = 4; continue; }
        break;
      case 1: /* \r\n */
        if (ch == '\n') straynewline();
        if (ch == '.') { state = 2; continue; }
        if (ch == '\r') { state = 4; continue; }
        state = 0;
        break;
      case 2: /* \r\n + . */
        if (ch == '\n') straynewline();
        if (ch == '\r') { state = 3; continue; }
        state = 0;
        break;
      case 3: /* \r\n + .\r */
        if (ch == '\n') return;
        put(".");
        put("\r");
        if (ch == '\r') { state = 4; continue; }
        state = 0;
        break;
      case 4: /* + \r */
        if (ch == '\n') { state = 1; break; }
        if (ch != '\r') { put("\r"); state = 0; }
    }
    put(&ch);
  }
}

char accept_buf[FMT_ULONG];
void acceptmessage(qp) unsigned long qp;
{
  datetime_sec when;
  when = now();
  out("250 ok ");
  accept_buf[fmt_ulong(accept_buf,(unsigned long) when)] = 0;
  out(accept_buf);
  out(" qp ");
  accept_buf[fmt_ulong(accept_buf,qp)] = 0;
  out(accept_buf);
  out("\r\n");
}

void smtp_data(arg) char *arg; {
  int hops;
  unsigned long qp;
  char *qqx;

  if (!seenmail) { err_wantmail(); return; }
  if (!rcptto.len) { err_wantrcpt(); return; }
  if (mailfrom.len == 1 && recipcount > 1) { err_badbounce(); return; }
  seenmail = 0;
  if (databytes) bytestooverflow = databytes + 1;
  if (qmail_open(&qqt) == -1) { err_qqt(); return; }
  qp = qmail_qp(&qqt);
  out("354 go ahead\r\n");

  received(&qqt,"SMTP",local,remoteip,remotehost,remoteinfo,fakehelo);
  blast(&hops);
  hops = (hops >= MAXHOPS);
  if (hops) qmail_fail(&qqt);
  qmail_from(&qqt,mailfrom.s);
  qmail_put(&qqt,rcptto.s,rcptto.len);

  qqx = qmail_close(&qqt);
  if (!*qqx) { acceptmessage(qp); return; }
  if (hops) { out("554 too many hops, this message is looping (#5.4.6)\r\n"); return; }
  if (databytes) if (!bytestooverflow) { out("552 sorry, that message size exceeds my databytes limit (#5.3.4)\r\n"); return; }
  if (*qqx == 'D') out("554 "); else out("451 ");
  out(qqx + 1);
  out("\r\n");
}


char unique[FMT_ULONG + FMT_ULONG + 3];
static stralloc authin = {0};
static stralloc user = {0};
static stralloc pass = {0};
static stralloc resp = {0};
static stralloc slop = {0};
substdio ssup;
char upbuf[128];
int authd = 0;

int authgetl(void) {
  int i;

  if (!stralloc_copys(&authin, "")) die_nomem();

  for (;;) {
    if (!stralloc_readyplus(&authin,1)) die_nomem(); /* XXX */
    i = substdio_get(&ssin,authin.s + authin.len,1);
    if (i != 1) die_read();
    if (authin.s[authin.len] == '\n') break;
    ++authin.len;
  }

  if (authin.len > 0) if (authin.s[authin.len - 1] == '\r') --authin.len;
  authin.s[authin.len] = 0;

  if (*authin.s == '*' && *(authin.s + 1) == 0) { return err_authabrt(); }
  if (authin.len == 0) { return err_input(); }
  return authin.len;
}

int authenticate(void)
{
  int child;
  int wstat;
  int pi[2];

  if (!stralloc_0(&user)) die_nomem();
  if (!stralloc_0(&pass)) die_nomem();
  if (!stralloc_0(&resp)) die_nomem();

  if (fd_copy(2,1) == -1) return err_pipe();
  if (pipe(pi) == -1) return err_pipe();
  switch(child = fork()) {
    case -1:
      return err_fork();
    case 0:
      close(pi[1]);
      if (0 > fd_copy(3,pi[0])) _exit(1);
      sig_pipedefault();
      execvp(*childargs, childargs);
      _exit(1);
  }
  close(pi[0]);

  substdio_fdbuf(&ssup,write,pi[1],upbuf,sizeof upbuf);
  if (substdio_put(&ssup,user.s,user.len) == -1) return err_write();
  if (substdio_put(&ssup,pass.s,pass.len) == -1) return err_write();
  if (substdio_put(&ssup,resp.s,resp.len) == -1) return err_write();
  if (substdio_flush(&ssup) == -1) return err_write();

  close(pi[1]);
  byte_zero(pass.s,pass.len);
  byte_zero(upbuf,sizeof upbuf);
  if (wait_pid(&wstat,child) == -1) return err_child();
  if (wait_crashed(wstat)) return err_child();
  if (wait_exitcode(wstat)) { sleep(5); return 1; } /* no */
  return 0; /* yes */
}

int auth_login(arg) char *arg;
{
  int r;

  if (*arg) {
    if (r = b64decode(arg,str_len(arg),&user) == 1) return err_input();
  }
  else {
    out("334 VXNlcm5hbWU6\r\n"); flush(); /* Username: */
    if (authgetl() < 0) return -1;
    if (r = b64decode(authin.s,authin.len,&user) == 1) return err_input();
  }
  if (r == -1) die_nomem();

  out("334 UGFzc3dvcmQ6\r\n"); flush(); /* Password: */

  if (authgetl() < 0) return -1;
  if (r = b64decode(authin.s,authin.len,&pass) == 1) return err_input();
  if (r == -1) die_nomem();

  if (!user.len || !pass.len) return err_input();
  return authenticate();
}

int auth_plain(arg) char *arg;
{
  int r, id = 0;

  if (*arg) {
    if (r = b64decode(arg,str_len(arg),&slop) == 1) return err_input();
  }
  else {
    out("334 \r\n"); flush();
    if (authgetl() < 0) return -1;
    if (r = b64decode(authin.s,authin.len,&slop) == 1) return err_input();
  }
  if (r == -1 || !stralloc_0(&slop)) die_nomem();
  while (slop.s[id]) id++; /* ignore authorize-id */

  if (slop.len > id + 1)
    if (!stralloc_copys(&user,slop.s + id + 1)) die_nomem();
  if (slop.len > id + user.len + 2)
    if (!stralloc_copys(&pass,slop.s + id + user.len + 2)) die_nomem();

  if (!user.len || !pass.len) return err_input();
  return authenticate();
}

#ifdef AUTHCRAM
int auth_cram()
{
  int i, r;
  char *s;

  s = unique;
  s += fmt_uint(s,getpid());
  *s++ = '.';
  s += fmt_ulong(s,(unsigned long) now());
  *s++ = '@';
  *s++ = 0;

  if (!stralloc_copys(&pass,"<")) die_nomem();
  if (!stralloc_cats(&pass,unique)) die_nomem();
  if (!stralloc_cats(&pass,hostname)) die_nomem();
  if (!stralloc_cats(&pass,">")) die_nomem();
  if (b64encode(&pass,&slop) < 0) die_nomem();
  if (!stralloc_0(&slop)) die_nomem();

  out("334 ");
  out(slop.s);
  out("\r\n");
  flush();

  if (authgetl() < 0) return -1;
  if (r = b64decode(authin.s,authin.len,&slop) == 1) return err_input();
  if (r == -1 || !stralloc_0(&slop)) die_nomem();

  i = str_chr(slop.s,' ');
  s = slop.s + i;
  while (*s == ' ') ++s;
  slop.s[i] = 0;
  if (!stralloc_copys(&user,slop.s)) die_nomem();
  if (!stralloc_copys(&resp,s)) die_nomem();

  if (!user.len || !resp.len) return err_input();
  return authenticate();
}
#endif

struct authcmd {
  char *text;
  int (*fun)();
} authcmds[] = {
  { "login", auth_login }
, { "plain", auth_plain }
#ifdef AUTHCRAM
, { "cram-md5", auth_cram }
#endif
, { 0, err_noauth }
};

void smtp_auth(arg)
char *arg;
{
  int i;
  char *cmd = arg;

  if (!hostname || !*childargs)
  {
    out("503 auth not available (#5.3.3)\r\n");
    return;
  }
  if (authd) { err_authd(); return; }
  if (seenmail) { err_authmail(); return; }

  if (!stralloc_copys(&user,"")) die_nomem();
  if (!stralloc_copys(&pass,"")) die_nomem();
  if (!stralloc_copys(&resp,"")) die_nomem();

  i = str_chr(cmd,' ');
  arg = cmd + i;
  while (*arg == ' ') ++arg;
  cmd[i] = 0;

  for (i = 0;authcmds[i].text;++i)
    if (case_equals(authcmds[i].text,cmd)) break;

  switch (authcmds[i].fun(arg)) {
    case 0:
      authd = 1;
      relayclient = "";
      remoteinfo = user.s;
      if (!env_unset("TCPREMOTEINFO")) die_read();
      if (!env_put2("TCPREMOTEINFO",remoteinfo)) die_nomem();
      out("235 ok, go ahead (#2.0.0)\r\n");
      break;
    case 1:
      out("535 authorization failed (#5.7.0)\r\n");
  }
}

struct commands smtpcommands[] = {
  { "rcpt", smtp_rcpt, 0 }
, { "mail", smtp_mail, 0 }
, { "data", smtp_data, flush }
, { "auth", smtp_auth, flush }
, { "quit", smtp_quit, flush }
, { "helo", smtp_helo, flush }
, { "ehlo", smtp_ehlo, flush }
, { "rset", smtp_rset, 0 }
, { "help", smtp_help, flush }
, { "noop", err_noop, flush }
, { "vrfy", err_vrfy, flush }
, { 0, err_unimpl, flush }
} ;

void main(argc,argv)
int argc;
char **argv;
{
  hostname = "";
  if (argc > 1) hostname = argv[1];
  childargs = 0;
  if (argc > 2) childargs = argv + 2;

  sig_pipeignore();
  if (chdir(auto_qmail) == -1) die_control();
  setup();
  if (ipme_init() != 1) die_ipme();
  smtp_greet("220 ");
  out(" ESMTP\r\n");
  if (commands(&ssin,&smtpcommands) == 0) die_read();
  die_nomem();
}