1 #include "sig.h"

     2 #include "readwrite.h"

     3 #include "stralloc.h"

     4 #include "substdio.h"

     5 #include "alloc.h"

     6 #include "auto_qmail.h"

     7 #include "control.h"

     8 #include "received.h"

     9 #include "constmap.h"

    10 #include "error.h"

    11 #include "ipme.h"

    12 #include "ip.h"

    13 #include "qmail.h"

    14 #include "str.h"

    15 #include "fmt.h"

    16 #include "scan.h"

    17 #include "byte.h"

    18 #include "case.h"

    19 #include "env.h"

    20 #include "now.h"

    21 #include "exit.h"

    22 #include "rcpthosts.h"

    23 #include "timeoutread.h"

    24 #include "timeoutwrite.h"

    25 #include "commands.h"

    26 

    27 #define MAXHOPS 100

    28 unsigned int databytes = 0;

    29 int timeout = 1200;

    30 

    31 int safewrite(fd,buf,len) int fd; char *buf; int len;

    32 {

    33   int r;

    34   r = timeoutwrite(timeout,fd,buf,len);

    35   if (r <= 0) _exit(1);

    36   return r;

    37 }

    38 

    39 char ssoutbuf[512];

    40 substdio ssout = SUBSTDIO_FDBUF(safewrite,1,ssoutbuf,sizeof ssoutbuf);

    41 

    42 void flush() { substdio_flush(&ssout); }

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

    44 

    45 void die_read() { _exit(1); }

    46 void die_alarm() { out("451 timeout (#4.4.2)\r\n"); flush(); _exit(1); }

    47 void die_nomem() { out("421 out of memory (#4.3.0)\r\n"); flush(); _exit(1); }

    48 void die_control() { out("421 unable to read controls (#4.3.0)\r\n"); flush(); _exit(1); }

    49 void die_ipme() { out("421 unable to figure out my IP addresses (#4.3.0)\r\n"); flush(); _exit(1); }

    50 void straynewline() { out("451 See http://pobox.com/~djb/docs/smtplf.html.\r\n"); flush(); _exit(1); }

    51 

    52 void err_bmf() { out("553 sorry, your envelope sender is in my badmailfrom list (#5.7.1)\r\n"); }

    53 void err_nogateway() { out("553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)\r\n"); }

    54 void err_unimpl() { out("502 unimplemented (#5.5.1)\r\n"); }

    55 void err_syntax() { out("555 syntax error (#5.5.4)\r\n"); }

    56 void err_wantmail() { out("503 MAIL first (#5.5.1)\r\n"); }

    57 void err_wantrcpt() { out("503 RCPT first (#5.5.1)\r\n"); }

    58 void err_noop() { out("250 ok\r\n"); }

    59 void err_vrfy() { out("252 send some mail, i'll try my best\r\n"); }

    60 void err_qqt() { out("451 qqt failure (#4.3.0)\r\n"); }

    61 

    62 

    63 stralloc greeting = {0};

    64 

    65 void smtp_greet(code) char *code;

    66 {

    67   substdio_puts(&ssout,code);

    68   substdio_put(&ssout,greeting.s,greeting.len);

    69 }

    70 void smtp_help()

    71 {

    72   out("214 qmail home page: http://pobox.com/~djb/qmail.html\r\n");

    73 }

    74 void smtp_quit()

    75 {

    76   smtp_greet("221 "); out("\r\n"); flush(); _exit(0);

    77 }

    78 

    79 char *remoteip;

    80 char *remotehost;

    81 char *remoteinfo;

    82 char *local;

    83 char *relayclient;

    84 

    85 stralloc helohost = {0};

    86 char *fakehelo; /* pointer into helohost, or 0 */

    87 

    88 void dohelo(arg) char *arg; {

    89   if (!stralloc_copys(&helohost,arg)) die_nomem(); 

    90   if (!stralloc_0(&helohost)) die_nomem(); 

    91   fakehelo = case_diffs(remotehost,helohost.s) ? helohost.s : 0;

    92 }

    93 

    94 int liphostok = 0;

    95 stralloc liphost = {0};

    96 int bmfok = 0;

    97 stralloc bmf = {0};

    98 struct constmap mapbmf;

    99 

   100 void setup()

   101 {

   102   char *x;

   103   unsigned long u;

   104  

   105   if (control_init() == -1) die_control();

   106   if (control_rldef(&greeting,"control/smtpgreeting",1,(char *) 0) != 1)

   107     die_control();

   108   liphostok = control_rldef(&liphost,"control/localiphost",1,(char *) 0);

   109   if (liphostok == -1) die_control();

   110   if (control_readint(&timeout,"control/timeoutsmtpd") == -1) die_control();

   111   if (timeout <= 0) timeout = 1;

   112 

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

   114 

   115   bmfok = control_readfile(&bmf,"control/badmailfrom",0);

   116   if (bmfok == -1) die_control();

   117   if (bmfok)

   118     if (!constmap_init(&mapbmf,bmf.s,bmf.len,0)) die_nomem();

   119  

   120   if (control_readint(&databytes,"control/databytes") == -1) die_control();

   121   x = env_get("DATABYTES");

   122   if (x) { scan_ulong(x,&u); databytes = u; }

   123   if (!(databytes + 1)) --databytes;

   124  

   125   remoteip = env_get("TCPREMOTEIP");

   126   if (!remoteip) remoteip = "unknown";

   127   local = env_get("TCPLOCALHOST");

   128   if (!local) local = env_get("TCPLOCALIP");

   129   if (!local) local = "unknown";

   130   remotehost = env_get("TCPREMOTEHOST");

   131   if (!remotehost) remotehost = "unknown";

   132   remoteinfo = env_get("TCPREMOTEINFO");

   133   relayclient = env_get("RELAYCLIENT");

   134   dohelo(remotehost);

   135 }

   136 

   137 

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

   139 

   140 int addrparse(arg)

   141 char *arg;

   142 {

   143   int i;

   144   char ch;

   145   char terminator;

   146   struct ip_address ip;

   147   int flagesc;

   148   int flagquoted;

   149  

   150   terminator = '>';

   151   i = str_chr(arg,'<');

   152   if (arg[i])

   153     arg += i + 1;

   154   else { /* partner should go read rfc 821 */

   155     terminator = ' ';

   156     arg += str_chr(arg,':');

   157     if (*arg == ':') ++arg;

   158     while (*arg == ' ') ++arg;

   159   }

   160 

   161   /* strip source route */

   162   if (*arg == '@') while (*arg) if (*arg++ == ':') break;

   163 

   164   if (!stralloc_copys(&addr,"")) die_nomem();

   165   flagesc = 0;

   166   flagquoted = 0;

   167   for (i = 0;ch = arg[i];++i) { /* copy arg to addr, stripping quotes */

   168     if (flagesc) {

   169       if (!stralloc_append(&addr,&ch)) die_nomem();

   170       flagesc = 0;

   171     }

   172     else {

   173       if (!flagquoted && (ch == terminator)) break;

   174       switch(ch) {

   175         case '\\': flagesc = 1; break;

   176         case '"': flagquoted = !flagquoted; break;

   177         default: if (!stralloc_append(&addr,&ch)) die_nomem();

   178       }

   179     }

   180   }

   181   /* could check for termination failure here, but why bother? */

   182   if (!stralloc_append(&addr,"")) die_nomem();

   183 

   184   if (liphostok) {

   185     i = byte_rchr(addr.s,addr.len,'@');

   186     if (i < addr.len) /* if not, partner should go read rfc 821 */

   187       if (addr.s[i + 1] == '[')

   188         if (!addr.s[i + 1 + ip_scanbracket(addr.s + i + 1,&ip)])

   189           if (ipme_is(&ip)) {

   190             addr.len = i + 1;

   191             if (!stralloc_cat(&addr,&liphost)) die_nomem();

   192             if (!stralloc_0(&addr)) die_nomem();

   193           }

   194   }

   195 

   196   if (addr.len > 900) return 0;

   197   return 1;

   198 }

   199 

   200 int bmfcheck()

   201 {

   202   int j;

   203   if (!bmfok) return 0;

   204   if (constmap(&mapbmf,addr.s,addr.len - 1)) return 1;

   205   j = byte_rchr(addr.s,addr.len,'@');

   206   if (j < addr.len)

   207     if (constmap(&mapbmf,addr.s + j,addr.len - j - 1)) return 1;

   208   return 0;

   209 }

   210 

   211 int addrallowed()

   212 {

   213   int r;

   214   r = rcpthosts(addr.s,str_len(addr.s));

   215   if (r == -1) die_control();

   216   return r;

   217 }

   218 

   219 

   220 int seenmail = 0;

   221 int flagbarf; /* defined if seenmail */

   222 stralloc mailfrom = {0};

   223 stralloc rcptto = {0};

   224 

   225 void smtp_helo(arg) char *arg;

   226 {

   227   smtp_greet("250 "); out("\r\n");

   228   seenmail = 0; dohelo(arg);

   229 }

   230 void smtp_ehlo(arg) char *arg;

   231 {

   232   smtp_greet("250-"); out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n");

   233   seenmail = 0; dohelo(arg);

   234 }

   235 void smtp_rset()

   236 {

   237   seenmail = 0;

   238   out("250 flushed\r\n");

   239 }

   240 void smtp_mail(arg) char *arg;

   241 {

   242   if (!addrparse(arg)) { err_syntax(); return; }

   243   flagbarf = bmfcheck();

   244   seenmail = 1;

   245   if (!stralloc_copys(&rcptto,"")) die_nomem();

   246   if (!stralloc_copys(&mailfrom,addr.s)) die_nomem();

   247   if (!stralloc_0(&mailfrom)) die_nomem();

   248   out("250 ok\r\n");

   249 }

   250 void smtp_rcpt(arg) char *arg; {

   251   if (!seenmail) { err_wantmail(); return; }

   252   if (!addrparse(arg)) { err_syntax(); return; }

   253   if (flagbarf) { err_bmf(); return; }

   254   if (relayclient) {

   255     --addr.len;

   256     if (!stralloc_cats(&addr,relayclient)) die_nomem();

   257     if (!stralloc_0(&addr)) die_nomem();

   258   }

   259   else

   260     if (!addrallowed()) { err_nogateway(); return; }

   261   if (!stralloc_cats(&rcptto,"T")) die_nomem();

   262   if (!stralloc_cats(&rcptto,addr.s)) die_nomem();

   263   if (!stralloc_0(&rcptto)) die_nomem();

   264   out("250 ok\r\n");

   265 }

   266 

   267 

   268 int saferead(fd,buf,len) int fd; char *buf; int len;

   269 {

   270   int r;

   271   flush();

   272   r = timeoutread(timeout,fd,buf,len);

   273   if (r == -1) if (errno == error_timeout) die_alarm();

   274   if (r <= 0) die_read();

   275   return r;

   276 }

   277 

   278 char ssinbuf[1024];

   279 substdio ssin = SUBSTDIO_FDBUF(saferead,0,ssinbuf,sizeof ssinbuf);

   280 

   281 struct qmail qqt;

   282 unsigned int bytestooverflow = 0;

   283 

   284 void put(ch)

   285 char *ch;

   286 {

   287   if (bytestooverflow)

   288     if (!--bytestooverflow)

   289       qmail_fail(&qqt);

   290   qmail_put(&qqt,ch,1);

   291 }

   292 

   293 void blast(hops)

   294 int *hops;

   295 {

   296   char ch;

   297   int state;

   298   int flaginheader;

   299   int pos; /* number of bytes since most recent \n, if fih */

   300   int flagmaybex; /* 1 if this line might match RECEIVED, if fih */

   301   int flagmaybey; /* 1 if this line might match \r\n, if fih */

   302   int flagmaybez; /* 1 if this line might match DELIVERED, if fih */

   303  

   304   state = 1;

   305   *hops = 0;

   306   flaginheader = 1;

   307   pos = 0; flagmaybex = flagmaybey = flagmaybez = 1;

   308   for (;;) {

   309     substdio_get(&ssin,&ch,1);

   310     if (flaginheader) {

   311       if (pos < 9) {

   312         if (ch != "delivered"[pos]) if (ch != "DELIVERED"[pos]) flagmaybez = 0;

   313         if (flagmaybez) if (pos == 8) ++*hops;

   314         if (pos < 8)

   315           if (ch != "received"[pos]) if (ch != "RECEIVED"[pos]) flagmaybex = 0;

   316         if (flagmaybex) if (pos == 7) ++*hops;

   317         if (pos < 2) if (ch != "\r\n"[pos]) flagmaybey = 0;

   318         if (flagmaybey) if (pos == 1) flaginheader = 0;

   319       }

   320       ++pos;

   321       if (ch == '\n') { pos = 0; flagmaybex = flagmaybey = flagmaybez = 1; }

   322     }

   323     switch(state) {

   324       case 0:

   325         if (ch == '\n') straynewline();

   326         if (ch == '\r') { state = 4; continue; }

   327         break;

   328       case 1: /* \r\n */

   329         if (ch == '\n') straynewline();

   330         if (ch == '.') { state = 2; continue; }

   331         if (ch == '\r') { state = 4; continue; }

   332         state = 0;

   333         break;

   334       case 2: /* \r\n + . */

   335         if (ch == '\n') straynewline();

   336         if (ch == '\r') { state = 3; continue; }

   337         state = 0;

   338         break;

   339       case 3: /* \r\n + .\r */

   340         if (ch == '\n') return;

   341         put(".");

   342         put("\r");

   343         if (ch == '\r') { state = 4; continue; }

   344         state = 0;

   345         break;

   346       case 4: /* + \r */

   347         if (ch == '\n') { state = 1; break; }

   348         if (ch != '\r') { put("\r"); state = 0; }

   349     }

   350     put(&ch);

   351   }

   352 }

   353 

   354 char accept_buf[FMT_ULONG];

   355 void acceptmessage(qp) unsigned long qp;

   356 {

   357   datetime_sec when;

   358   when = now();

   359   out("250 ok ");

   360   accept_buf[fmt_ulong(accept_buf,(unsigned long) when)] = 0;

   361   out(accept_buf);

   362   out(" qp ");

   363   accept_buf[fmt_ulong(accept_buf,qp)] = 0;

   364   out(accept_buf);

   365   out("\r\n");

   366 }

   367 

   368 void smtp_data() {

   369   int hops;

   370   unsigned long qp;

   371   char *qqx;

   372  

   373   if (!seenmail) { err_wantmail(); return; }

   374   if (!rcptto.len) { err_wantrcpt(); return; }

   375   seenmail = 0;

   376   if (databytes) bytestooverflow = databytes + 1;

   377   if (qmail_open(&qqt) == -1) { err_qqt(); return; }

   378   qp = qmail_qp(&qqt);

   379   out("354 go ahead\r\n");

   380  

   381   received(&qqt,"SMTP",local,remoteip,remotehost,remoteinfo,fakehelo);

   382   blast(&hops);

   383   hops = (hops >= MAXHOPS);

   384   if (hops) qmail_fail(&qqt);

   385   qmail_from(&qqt,mailfrom.s);

   386   qmail_put(&qqt,rcptto.s,rcptto.len);

   387  

   388   qqx = qmail_close(&qqt);

   389   if (!*qqx) { acceptmessage(qp); return; }

   390   if (hops) { out("554 too many hops, this message is looping (#5.4.6)\r\n"); return; }

   391   if (databytes) if (!bytestooverflow) { out("552 sorry, that message size exceeds my databytes limit (#5.3.4)\r\n"); return; }

   392   if (*qqx == 'D') out("554 "); else out("451 ");

   393   out(qqx + 1);

   394   out("\r\n");

   395 }

   396 

   397 struct commands smtpcommands[] = {

   398   { "rcpt", smtp_rcpt, 0 }

   399 , { "mail", smtp_mail, 0 }

   400 , { "data", smtp_data, flush }

   401 , { "quit", smtp_quit, flush }

   402 , { "helo", smtp_helo, flush }

   403 , { "ehlo", smtp_ehlo, flush }

   404 , { "rset", smtp_rset, 0 }

   405 , { "help", smtp_help, flush }

   406 , { "noop", err_noop, flush }

   407 , { "vrfy", err_vrfy, flush }

   408 , { 0, err_unimpl, flush }

   409 } ;

   410 

   411 void main()

   412 {

   413   sig_pipeignore();

   414   if (chdir(auto_qmail) == -1) die_control();

   415   setup();

   416   if (ipme_init() != 1) die_ipme();

   417   smtp_greet("220 ");

   418   out(" ESMTP\r\n");

   419   if (commands(&ssin,&smtpcommands) == 0) die_read();

   420   die_nomem();

   421 }