mdw@git.distorted.org.uk Git - qmail/blob - qmail-smtpd.c

   1 #include "sig.h"
   2 #include "readwrite.h"
   3 #include "getln.h"
   4 #include "stralloc.h"
   5 #include "substdio.h"
   6 #include "alloc.h"
   7 #include "auto_qmail.h"
   8 #include "control.h"
   9 #include "received.h"
  10 #include "constmap.h"
  11 #include "error.h"
  12 #include "ipme.h"
  13 #include "ip.h"
  14 #include "qmail.h"
  15 #include "str.h"
  16 #include "fmt.h"
  17 #include "byte.h"
  18 #include "case.h"
  19 #include "env.h"
  20 #include "now.h"
  21 #include "exit.h"
  22
  23 #define MAXHOPS 100
  24 int timeout = 1200;
  25
  26 char ssoutbuf[512];
  27 substdio ssout = SUBSTDIO_FDBUF(write,1,ssoutbuf,sizeof(ssoutbuf));
  28
  29 void die() { substdio_flush(&ssout); _exit(1); }
  30 void flush() { if (substdio_flush(&ssout) == -1) _exit(1); }
  31 void out(s) char *s; { if (substdio_puts(&ssout,s) == -1) die(); }
  32
  33 int timeoutread(fd,buf,n) int fd; char *buf; int n;
  34 {
  35  int r; int saveerrno;
  36  flush();
  37  alarm(timeout);
  38  r = read(fd,buf,n); saveerrno = errno;
  39  alarm(0);
  40  errno = saveerrno; return r;
  41 }
  42
  43 char ssinbuf[1024];
  44 substdio ssin = SUBSTDIO_FDBUF(timeoutread,0,ssinbuf,sizeof(ssinbuf));
  45
  46
  47 void outofmem() { out("421 out of memory (#4.3.0)\r\n"); die(); }
  48 void sigalrm() { out("451 timeout (#4.4.2)\r\n"); die(); }
  49
  50 struct qmail qqt;
  51 stralloc greeting = {0};
  52 int liphostok = 0;
  53 stralloc liphost = {0};
  54 int rhok = 0;
  55 stralloc rcpthosts = {0};
  56 struct constmap maprcpthosts;
  57 int bmfok = 0;
  58 stralloc bmf = {0};
  59 struct constmap mapbmf;
  60 int flagbarf; /* defined if seenmail */
  61
  62 stralloc helohost = {0};
  63 stralloc mailfrom = {0};
  64 stralloc rcptto = {0};
  65 int seenmail = 0;
  66
  67 stralloc addr = {0}; /* will be 0-terminated, if addrparse returns 1 */
  68
  69 char *remoteip;
  70 char *remotehost;
  71 char *remoteinfo;
  72 char *local;
  73 char *relayclient;
  74
  75 void dohelo(arg) char *arg;
  76 {
  77  if (!stralloc_copys(&helohost,arg)) outofmem();
  78  if (!stralloc_0(&helohost)) outofmem();
  79 }
  80
  81 void getenvs()
  82 {
  83  remoteip = env_get("TCPREMOTEIP");
  84  if (!remoteip) remoteip = "unknown";
  85  local = env_get("TCPLOCALHOST");
  86  if (!local) local = env_get("TCPLOCALIP");
  87  if (!local) local = "unknown";
  88  remotehost = env_get("TCPREMOTEHOST");
  89  if (!remotehost) remotehost = "unknown";
  90  remoteinfo = env_get("TCPREMOTEINFO");
  91  relayclient = env_get("RELAYCLIENT");
  92  dohelo(remotehost);
  93 }
  94
  95 void straynewline()
  96 {
  97  out("451 \
  98 Put ,E=\\r\\n at the end of Mether, Mtcp, or Msmtp in sendmail.cf \
  99 if you are using Solaris 2.5 (fixed in 2.5.1). \
 100 I cannot accept messages with stray newlines. \
 101 Many SMTP servers will time out waiting for \\r\\n.\\r\\n.\
 102 \r\n");
 103  die();
 104 }
 105
 106 void blast(ssfrom,hops)
 107 substdio *ssfrom;
 108 int *hops;
 109 {
 110  char ch;
 111  int state;
 112  int flaginheader;
 113  int pos; /* number of bytes since most recent \n, if fih */
 114  int flagmaybex; /* 1 if this line might match RECEIVED, if fih */
 115  int flagmaybey; /* 1 if this line might match \r\n, if fih */
 116  int flagmaybez; /* 1 if this line might match DELIVERED, if fih */
 117
 118  state = 1;
 119  *hops = 0;
 120  flaginheader = 1;
 121  pos = 0; flagmaybex = flagmaybey = flagmaybez = 1;
 122  for (;;)
 123   {
 124    if (substdio_get(ssfrom,&ch,1) <= 0) die();
 125    if (flaginheader)
 126     {
 127      if (pos < 9)
 128       {
 129        if (ch != "delivered"[pos]) if (ch != "DELIVERED"[pos]) flagmaybez = 0;
 130        if (flagmaybez) if (pos == 8) ++*hops;
 131        if (pos < 8)
 132          if (ch != "received"[pos]) if (ch != "RECEIVED"[pos]) flagmaybex = 0;
 133        if (flagmaybex) if (pos == 7) ++*hops;
 134        if (pos < 2) if (ch != "\r\n"[pos]) flagmaybey = 0;
 135        if (flagmaybey) if (pos == 1) flaginheader = 0;
 136       }
 137      ++pos;
 138      if (ch == '\n') { pos = 0; flagmaybex = flagmaybey = flagmaybez = 1; }
 139     }
 140    switch(state)
 141     {
 142      case 0:
 143        if (ch == '\n') straynewline();
 144        if (ch == '\r') { state = 4; continue; }
 145        break;
 146      case 1: /* \r\n */
 147        if (ch == '\n') straynewline();
 148        if (ch == '.') { state = 2; continue; }
 149        if (ch == '\r') { state = 4; continue; }
 150        state = 0;
 151        break;
 152      case 2: /* \r\n + . */
 153        if (ch == '\n') straynewline();
 154        if (ch == '\r') { state = 3; continue; }
 155        state = 0;
 156        break;
 157      case 3: /* \r\n + .\r */
 158        if (ch == '\n') return;
 159        qmail_put(&qqt,".\r",2);
 160        if (ch == '\r') { state = 4; continue; }
 161        state = 0;
 162        break;
 163      case 4: /* + \r */
 164        if (ch == '\n') { state = 1; break; }
 165        if (ch != '\r') { qmail_put(&qqt,"\r",1); state = 0; }
 166     }
 167    qmail_put(&qqt,&ch,1);
 168   }
 169 }
 170
 171 int addrparse(arg)
 172 char *arg;
 173 {
 174  int i;
 175  char ch;
 176  struct ip_address ip;
 177  int flagesc;
 178  int flagquoted;
 179
 180  arg += str_chr(arg,'<');
 181  if (*arg != '<') return 0;
 182  ++arg;
 183
 184  /* strip source route */
 185  if (*arg == '@') while (*arg) if (*arg++ == ':') break;
 186
 187  if (!*arg) return 0;
 188  if (!stralloc_copys(&addr,"")) outofmem();
 189  flagesc = 0;
 190  flagquoted = 0;
 191  for (i = 0;ch = arg[i];++i) /* copy arg to addr, stripping quotes */
 192   {
 193    if (flagesc)
 194     { if (!stralloc_append(&addr,&ch)) outofmem(); flagesc = 0; }
 195    else
 196     {
 197      if (!flagquoted && (ch == '>')) break;
 198      switch(ch)
 199       {
 200        case '\\': flagesc = 1; break;
 201        case '"': flagquoted = !flagquoted; break;
 202        default: if (!stralloc_append(&addr,&ch)) outofmem();
 203       }
 204     }
 205   }
 206  if (!ch) return 0;
 207  if (!stralloc_append(&addr,"")) outofmem();
 208  ++i;
 209  while (arg[i])
 210   {
 211    if (!case_diffs(arg + i," BODY=8BITMIME")) i += 14;
 212    else if (!case_diffs(arg + i," BODY=7BIT")) i += 10;
 213    else return 0;
 214   }
 215
 216  if (liphostok)
 217   {
 218    i = byte_rchr(addr.s,addr.len,'@');
 219    if (i < addr.len) /* if not, partner should go read rfc 821 */
 220      if (addr.s[i + 1] == '[')
 221        if (!addr.s[i + 1 + ip_scanbracket(addr.s + i + 1,&ip)])
 222          if (ipme_is(&ip))
 223           {
 224            addr.len = i + 1;
 225            if (!stralloc_cat(&addr,&liphost)) outofmem();
 226            if (!stralloc_0(&addr)) outofmem();
 227           }
 228   }
 229
 230  return 1;
 231 }
 232
 233 int addrallowed()
 234 {
 235  int j;
 236  if (!rhok) return 1;
 237  j = byte_rchr(addr.s,addr.len,'@');
 238  if (j >= addr.len) return 1; /* can be taken care of by envnoathost */
 239  if (constmap(&maprcpthosts,addr.s + j + 1,addr.len - j - 2)) return 1;
 240  for (;j < addr.len;++j)
 241    if (addr.s[j] == '.')
 242      if (constmap(&maprcpthosts,addr.s + j,addr.len - j - 1)) return 1;
 243  return 0;
 244 }
 245
 246 void bmfcheck()
 247 {
 248  int j;
 249  flagbarf = 0;
 250  if (!bmfok) return;
 251  if (constmap(&mapbmf,addr.s,addr.len - 1)) { flagbarf = 1; return; }
 252  j = byte_rchr(addr.s,addr.len,'@');
 253  if (j < addr.len)
 254    if (constmap(&mapbmf,addr.s + j,addr.len - j - 1)) flagbarf = 1;
 255 }
 256
 257 void smtp_greet(code) char *code; {
 258  if (substdio_puts(&ssout,code) == -1) die();
 259  if (substdio_put(&ssout,greeting.s,greeting.len) == -1) die(); }
 260 void smtp_quit() { smtp_greet("221 "); out("\r\n"); die(); }
 261 void smtp_help() { out("214-qmail home page: http://pobox.com/~djb/qmail.html\r\n214 send comments to qmail@pobox.com\r\n"); }
 262 void err_syntax() { out("555 syntax error (#5.5.4)\r\n"); }
 263 void err_bmf() { out("553 sorry, your envelope sender is in my badmailfrom list (#5.7.1)\r\n"); }
 264 void err_nogateway() { out("553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)\r\n"); }
 265 void err_unimpl() { out("502 unimplemented (#5.5.1)\r\n"); }
 266 void err_seenmail() { out("503 one MAIL per message (#5.5.1)\r\n"); }
 267 void err_wantmail() { out("503 MAIL first (#5.5.1)\r\n"); }
 268 void err_wantrcpt() { out("503 RCPT first (#5.5.1)\r\n"); }
 269 void err_noop() { out("250 ok\r\n"); }
 270 void err_vrfy() { out("252 send some mail, i'll try my best\r\n"); }
 271 void err_qqt() { out("451 qqt failure (#4.3.0)\r\n"); }
 272 void smtp_helo(arg) char *arg; {
 273  smtp_greet("250-"); out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n");
 274  seenmail = 0;
 275  dohelo(arg ? arg : ""); }
 276 void smtp_rset() {
 277  seenmail = 0;
 278  out("250 flushed\r\n"); }
 279 void smtp_mail(arg) char *arg; {
 280  if (seenmail) { err_seenmail(); return; }
 281  if (!arg) { err_syntax(); return; }
 282  if (!addrparse(arg)) { err_syntax(); return; }
 283  bmfcheck();
 284  seenmail = 1; out("250 ok\r\n");
 285  if (!stralloc_copys(&rcptto,"")) outofmem();
 286  if (!stralloc_copys(&mailfrom,addr.s)) outofmem();
 287  if (!stralloc_0(&mailfrom)) outofmem(); }
 288 void smtp_rcpt(arg) char *arg; {
 289  if (!seenmail) { err_wantmail(); return; }
 290  if (!arg) { err_syntax(); return; }
 291  if (!addrparse(arg)) { err_syntax(); return; }
 292  if (flagbarf) { err_bmf(); return; }
 293  if (relayclient)
 294   {
 295    --addr.len;
 296    if (!stralloc_cats(&addr,relayclient)) outofmem();
 297    if (!stralloc_0(&addr)) outofmem();
 298   }
 299  else
 300    if (!addrallowed()) { err_nogateway(); return; }
 301  out("250 ok\r\n");
 302  if (!stralloc_cats(&rcptto,"T")) outofmem();
 303  if (!stralloc_cats(&rcptto,addr.s)) outofmem();
 304  if (!stralloc_0(&rcptto)) outofmem(); }
 305
 306 char accept_buf[FMT_ULONG];
 307 void acceptmessage(qp) unsigned long qp;
 308 {
 309  datetime_sec when;
 310  when = now();
 311  out("250 ok ");
 312  accept_buf[fmt_ulong(accept_buf,(unsigned long) when)] = 0;
 313  out(accept_buf);
 314  out(" qp ");
 315  accept_buf[fmt_ulong(accept_buf,qp)] = 0;
 316  out(accept_buf);
 317  out("\r\n");
 318 }
 319
 320 void smtp_data() {
 321  int hops; int r; unsigned long qp;
 322  if (!seenmail) { err_wantmail(); return; }
 323  if (!rcptto.len) { err_wantrcpt(); return; }
 324  seenmail = 0;
 325  if (qmail_open(&qqt) == -1) { err_qqt(); return; }
 326  qp = qmail_qp(&qqt);
 327  out("354 go ahead\r\n");
 328
 329  received(&qqt,"SMTP",local,remoteip,remotehost,remoteinfo,case_diffs(remotehost,helohost.s) ? helohost.s : 0);
 330  blast(&ssin,&hops);
 331  hops = (hops >= MAXHOPS);
 332  if (hops) qmail_fail(&qqt);
 333  qmail_from(&qqt,mailfrom.s);
 334  qmail_put(&qqt,rcptto.s,rcptto.len);
 335
 336  r = qmail_close(&qqt);
 337  if (!r) { acceptmessage(qp); return; }
 338  if (hops) { out("554 too many hops, this message is looping (#5.4.6)\r\n"); return; }
 339  switch(r)
 340   {
 341    case QMAIL_TOOLONG: out("554 address too long (#5.1.3)\r\n"); return;
 342    case QMAIL_SYS: out("451 qq system error (#4.3.0)\r\n"); return;
 343    case QMAIL_READ: out("451 qq read error (#4.3.0)\r\n"); return;
 344    case QMAIL_WRITE: out("451 qq write error or disk full (#4.3.0)\r\n"); return;
 345    case QMAIL_NOMEM: out("451 qq out of memory (#4.3.0)\r\n"); return;
 346    case QMAIL_EXECSOFT: out("451 could not exec qq (#4.3.0)\r\n"); return;
 347    case QMAIL_TIMEOUT: out("451 qq timeout (#4.3.0)\r\n"); return;
 348    case QMAIL_WAITPID: out("451 qq waitpid surprise (#4.3.0)\r\n"); return;
 349    case QMAIL_CRASHED: out("451 qq crashed (#4.3.0)\r\n"); return;
 350    case QMAIL_USAGE: out("451 qq usage surprise (#4.3.0)\r\n"); return;
 351    default: out("451 qq internal bug (#4.3.0)\r\n"); return;
 352   }
 353 }
 354
 355 static struct { void (*fun)(); char *text; int flagflush; } smtpcmd[] = {
 356   { smtp_rcpt, "rcpt", 0 }
 357 , { smtp_mail, "mail", 0 }
 358 , { smtp_data, "data", 1 }
 359 , { smtp_quit, "quit", 1 }
 360 , { smtp_helo, "helo", 1 }
 361 , { smtp_helo, "ehlo", 1 }
 362 , { smtp_rset, "rset", 0 }
 363 , { smtp_help, "help", 1 }
 364 , { err_noop, "noop", 1 }
 365 , { err_vrfy, "vrfy", 1 }
 366 , { 0, 0, 0 }
 367 };
 368
 369 void doit(cmd)
 370 char *cmd;
 371 {
 372  int i;
 373  int j;
 374  char ch;
 375
 376  for (i = 0;smtpcmd[i].fun;++i)
 377   {
 378    for (j = 0;ch = smtpcmd[i].text[j];++j)
 379      if ((cmd[j] != ch) && (cmd[j] != ch - 32))
 380        break;
 381    if (!ch)
 382      if (!cmd[j] || (cmd[j] == ' '))
 383       {
 384        while (cmd[j] == ' ') ++j;
 385        if (!cmd[j])
 386          smtpcmd[i].fun((char *) 0);
 387        else
 388          smtpcmd[i].fun(cmd + j);
 389        if (smtpcmd[i].flagflush) flush();
 390        return;
 391       }
 392   }
 393  err_unimpl();
 394  flush();
 395 }
 396
 397 void getcontrols()
 398 {
 399  if (control_init() == -1) die();
 400  if (control_rldef(&greeting,"control/smtpgreeting",1,(char *) 0) != 1) die();
 401  switch(control_rldef(&liphost,"control/localiphost",1,(char *) 0))
 402   { case -1: die(); case 1: liphostok = 1; }
 403  if (control_readint(&timeout,"control/timeoutsmtpd") == -1) die();
 404  if (timeout <= 0) timeout = 1;
 405  switch(control_readfile(&rcpthosts,"control/rcpthosts",0))
 406   {
 407    case -1: die();
 408    case 1:
 409      rhok = 1;
 410      if (!constmap_init(&maprcpthosts,rcpthosts.s,rcpthosts.len,0)) die();
 411   }
 412  switch(control_readfile(&bmf,"control/badmailfrom",0))
 413   {
 414    case -1: die();
 415    case 1:
 416      bmfok = 1;
 417      if (!constmap_init(&mapbmf,bmf.s,bmf.len,0)) die();
 418   }
 419 }
 420
 421 void main()
 422 {
 423  static stralloc cmd = {0};
 424  int match;
 425
 426  sig_alarmcatch(sigalrm);
 427  sig_pipeignore();
 428
 429  if (chdir(auto_qmail) == -1) die();
 430  getcontrols();
 431  getenvs();
 432
 433  if (ipme_init() != 1) die();
 434
 435  smtp_greet("220 ");
 436  out(" ESMTP\r\n");
 437
 438  for (;;)
 439   {
 440    /* XXX: recipient can contain quoted lf. aargh. */
 441    if (getln(&ssin,&cmd,&match,'\n') == -1) die();
 442    if (!match) die();
 443    if (cmd.len == 0) die();
 444    if (cmd.s[--cmd.len] != '\n') die();
 445    if ((cmd.len > 0) && (cmd.s[cmd.len - 1] == '\r')) --cmd.len;
 446    cmd.s[cmd.len++] = 0;
 447    doit(cmd.s);
 448   }
 449 }