| 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 relayhostsok = 0; |
| 97 | stralloc relayhosts = {0}; |
| 98 | struct constmap maprelayhosts; |
| 99 | int bmfok = 0; |
| 100 | stralloc bmf = {0}; |
| 101 | struct constmap mapbmf; |
| 102 | |
| 103 | void setup() |
| 104 | { |
| 105 | char *x; |
| 106 | unsigned long u; |
| 107 | |
| 108 | if (control_init() == -1) die_control(); |
| 109 | if (control_rldef(&greeting,"control/smtpgreeting",1,(char *) 0) != 1) |
| 110 | die_control(); |
| 111 | liphostok = control_rldef(&liphost,"control/localiphost",1,(char *) 0); |
| 112 | if (liphostok == -1) die_control(); |
| 113 | if (control_readint(&timeout,"control/timeoutsmtpd") == -1) die_control(); |
| 114 | if (timeout <= 0) timeout = 1; |
| 115 | |
| 116 | if (rcpthosts_init() == -1) die_control(); |
| 117 | |
| 118 | bmfok = control_readfile(&bmf,"control/badmailfrom",0); |
| 119 | if (bmfok == -1) die_control(); |
| 120 | if (bmfok) |
| 121 | if (!constmap_init(&mapbmf,bmf.s,bmf.len,0)) die_nomem(); |
| 122 | |
| 123 | switch (control_readfile(&relayhosts, "control/relayhosts", 0)) { |
| 124 | case -1: |
| 125 | die_control(); |
| 126 | case 1: |
| 127 | relayhostsok = 1; |
| 128 | if (!constmap_init(&maprelayhosts, relayhosts.s, relayhosts.len, 1)) |
| 129 | die_nomem(); |
| 130 | } |
| 131 | |
| 132 | |
| 133 | if (control_readint(&databytes,"control/databytes") == -1) die_control(); |
| 134 | x = env_get("DATABYTES"); |
| 135 | if (x) { scan_ulong(x,&u); databytes = u; } |
| 136 | if (!(databytes + 1)) --databytes; |
| 137 | |
| 138 | remoteip = env_get("TCPREMOTEIP"); |
| 139 | if (!remoteip) remoteip = "unknown"; |
| 140 | local = env_get("TCPLOCALHOST"); |
| 141 | if (!local) local = env_get("TCPLOCALIP"); |
| 142 | if (!local) local = "unknown"; |
| 143 | remotehost = env_get("TCPREMOTEHOST"); |
| 144 | if (!remotehost) remotehost = "unknown"; |
| 145 | remoteinfo = env_get("TCPREMOTEINFO"); |
| 146 | relayclient = env_get("RELAYCLIENT"); |
| 147 | if (!relayclient && relayhostsok) { |
| 148 | int j; |
| 149 | int l = str_len(remotehost); |
| 150 | relayclient = constmap(&maprelayhosts, remotehost, l); |
| 151 | if (!relayclient) for (j = 0; j < l; ++j) { |
| 152 | if (remotehost[j] == '.' && |
| 153 | (relayclient = constmap(&maprelayhosts, |
| 154 | remotehost + j, |
| 155 | l - j)) != 0) |
| 156 | break; |
| 157 | } |
| 158 | } |
| 159 | dohelo(remotehost); |
| 160 | } |
| 161 | |
| 162 | |
| 163 | stralloc addr = {0}; /* will be 0-terminated, if addrparse returns 1 */ |
| 164 | |
| 165 | int addrparse(arg) |
| 166 | char *arg; |
| 167 | { |
| 168 | int i; |
| 169 | char ch; |
| 170 | char terminator; |
| 171 | struct ip_address ip; |
| 172 | int flagesc; |
| 173 | int flagquoted; |
| 174 | |
| 175 | terminator = '>'; |
| 176 | i = str_chr(arg,'<'); |
| 177 | if (arg[i]) |
| 178 | arg += i + 1; |
| 179 | else { /* partner should go read rfc 821 */ |
| 180 | terminator = ' '; |
| 181 | arg += str_chr(arg,':'); |
| 182 | if (*arg == ':') ++arg; |
| 183 | while (*arg == ' ') ++arg; |
| 184 | } |
| 185 | |
| 186 | /* strip source route */ |
| 187 | if (*arg == '@') while (*arg) if (*arg++ == ':') break; |
| 188 | |
| 189 | if (!stralloc_copys(&addr,"")) die_nomem(); |
| 190 | flagesc = 0; |
| 191 | flagquoted = 0; |
| 192 | for (i = 0;ch = arg[i];++i) { /* copy arg to addr, stripping quotes */ |
| 193 | if (flagesc) { |
| 194 | if (!stralloc_append(&addr,&ch)) die_nomem(); |
| 195 | flagesc = 0; |
| 196 | } |
| 197 | else { |
| 198 | if (!flagquoted && (ch == terminator)) break; |
| 199 | switch(ch) { |
| 200 | case '\\': flagesc = 1; break; |
| 201 | case '"': flagquoted = !flagquoted; break; |
| 202 | default: if (!stralloc_append(&addr,&ch)) die_nomem(); |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | /* could check for termination failure here, but why bother? */ |
| 207 | if (!stralloc_append(&addr,"")) die_nomem(); |
| 208 | |
| 209 | if (liphostok) { |
| 210 | i = byte_rchr(addr.s,addr.len,'@'); |
| 211 | if (i < addr.len) /* if not, partner should go read rfc 821 */ |
| 212 | if (addr.s[i + 1] == '[') |
| 213 | if (!addr.s[i + 1 + ip_scanbracket(addr.s + i + 1,&ip)]) |
| 214 | if (ipme_is(&ip)) { |
| 215 | addr.len = i + 1; |
| 216 | if (!stralloc_cat(&addr,&liphost)) die_nomem(); |
| 217 | if (!stralloc_0(&addr)) die_nomem(); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | if (addr.len > 900) return 0; |
| 222 | return 1; |
| 223 | } |
| 224 | |
| 225 | int bmfcheck() |
| 226 | { |
| 227 | int j; |
| 228 | if (!bmfok) return 0; |
| 229 | if (constmap(&mapbmf,addr.s,addr.len - 1)) return 1; |
| 230 | j = byte_rchr(addr.s,addr.len,'@'); |
| 231 | if (j < addr.len) |
| 232 | if (constmap(&mapbmf,addr.s + j,addr.len - j - 1)) return 1; |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | int addrallowed() |
| 237 | { |
| 238 | int r; |
| 239 | r = rcpthosts(addr.s,str_len(addr.s)); |
| 240 | if (r == -1) die_control(); |
| 241 | return r; |
| 242 | } |
| 243 | |
| 244 | |
| 245 | int seenmail = 0; |
| 246 | int flagbarf; /* defined if seenmail */ |
| 247 | stralloc mailfrom = {0}; |
| 248 | stralloc rcptto = {0}; |
| 249 | |
| 250 | void smtp_helo(arg) char *arg; |
| 251 | { |
| 252 | smtp_greet("250 "); out("\r\n"); |
| 253 | seenmail = 0; dohelo(arg); |
| 254 | } |
| 255 | void smtp_ehlo(arg) char *arg; |
| 256 | { |
| 257 | smtp_greet("250-"); out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n"); |
| 258 | seenmail = 0; dohelo(arg); |
| 259 | } |
| 260 | void smtp_rset() |
| 261 | { |
| 262 | seenmail = 0; |
| 263 | out("250 flushed\r\n"); |
| 264 | } |
| 265 | void smtp_mail(arg) char *arg; |
| 266 | { |
| 267 | if (!addrparse(arg)) { err_syntax(); return; } |
| 268 | flagbarf = bmfcheck(); |
| 269 | seenmail = 1; |
| 270 | if (!stralloc_copys(&rcptto,"")) die_nomem(); |
| 271 | if (!stralloc_copys(&mailfrom,addr.s)) die_nomem(); |
| 272 | if (!stralloc_0(&mailfrom)) die_nomem(); |
| 273 | out("250 ok\r\n"); |
| 274 | } |
| 275 | void smtp_rcpt(arg) char *arg; { |
| 276 | if (!seenmail) { err_wantmail(); return; } |
| 277 | if (!addrparse(arg)) { err_syntax(); return; } |
| 278 | if (flagbarf) { err_bmf(); return; } |
| 279 | if (relayclient) { |
| 280 | --addr.len; |
| 281 | if (!stralloc_cats(&addr,relayclient)) die_nomem(); |
| 282 | if (!stralloc_0(&addr)) die_nomem(); |
| 283 | } |
| 284 | else |
| 285 | if (!addrallowed()) { err_nogateway(); return; } |
| 286 | if (!stralloc_cats(&rcptto,"T")) die_nomem(); |
| 287 | if (!stralloc_cats(&rcptto,addr.s)) die_nomem(); |
| 288 | if (!stralloc_0(&rcptto)) die_nomem(); |
| 289 | out("250 ok\r\n"); |
| 290 | } |
| 291 | |
| 292 | |
| 293 | int saferead(fd,buf,len) int fd; char *buf; int len; |
| 294 | { |
| 295 | int r; |
| 296 | flush(); |
| 297 | r = timeoutread(timeout,fd,buf,len); |
| 298 | if (r == -1) if (errno == error_timeout) die_alarm(); |
| 299 | if (r <= 0) die_read(); |
| 300 | return r; |
| 301 | } |
| 302 | |
| 303 | char ssinbuf[1024]; |
| 304 | substdio ssin = SUBSTDIO_FDBUF(saferead,0,ssinbuf,sizeof ssinbuf); |
| 305 | |
| 306 | struct qmail qqt; |
| 307 | unsigned int bytestooverflow = 0; |
| 308 | |
| 309 | void put(ch) |
| 310 | char *ch; |
| 311 | { |
| 312 | if (bytestooverflow) |
| 313 | if (!--bytestooverflow) |
| 314 | qmail_fail(&qqt); |
| 315 | qmail_put(&qqt,ch,1); |
| 316 | } |
| 317 | |
| 318 | void blast(hops) |
| 319 | int *hops; |
| 320 | { |
| 321 | char ch; |
| 322 | int state; |
| 323 | int flaginheader; |
| 324 | int pos; /* number of bytes since most recent \n, if fih */ |
| 325 | int flagmaybex; /* 1 if this line might match RECEIVED, if fih */ |
| 326 | int flagmaybey; /* 1 if this line might match \r\n, if fih */ |
| 327 | int flagmaybez; /* 1 if this line might match DELIVERED, if fih */ |
| 328 | |
| 329 | state = 1; |
| 330 | *hops = 0; |
| 331 | flaginheader = 1; |
| 332 | pos = 0; flagmaybex = flagmaybey = flagmaybez = 1; |
| 333 | for (;;) { |
| 334 | substdio_get(&ssin,&ch,1); |
| 335 | if (flaginheader) { |
| 336 | if (pos < 9) { |
| 337 | if (ch != "delivered"[pos]) if (ch != "DELIVERED"[pos]) flagmaybez = 0; |
| 338 | if (flagmaybez) if (pos == 8) ++*hops; |
| 339 | if (pos < 8) |
| 340 | if (ch != "received"[pos]) if (ch != "RECEIVED"[pos]) flagmaybex = 0; |
| 341 | if (flagmaybex) if (pos == 7) ++*hops; |
| 342 | if (pos < 2) if (ch != "\r\n"[pos]) flagmaybey = 0; |
| 343 | if (flagmaybey) if (pos == 1) flaginheader = 0; |
| 344 | } |
| 345 | ++pos; |
| 346 | if (ch == '\n') { pos = 0; flagmaybex = flagmaybey = flagmaybez = 1; } |
| 347 | } |
| 348 | switch(state) { |
| 349 | case 0: |
| 350 | if (ch == '\n') straynewline(); |
| 351 | if (ch == '\r') { state = 4; continue; } |
| 352 | break; |
| 353 | case 1: /* \r\n */ |
| 354 | if (ch == '\n') straynewline(); |
| 355 | if (ch == '.') { state = 2; continue; } |
| 356 | if (ch == '\r') { state = 4; continue; } |
| 357 | state = 0; |
| 358 | break; |
| 359 | case 2: /* \r\n + . */ |
| 360 | if (ch == '\n') straynewline(); |
| 361 | if (ch == '\r') { state = 3; continue; } |
| 362 | state = 0; |
| 363 | break; |
| 364 | case 3: /* \r\n + .\r */ |
| 365 | if (ch == '\n') return; |
| 366 | put("."); |
| 367 | put("\r"); |
| 368 | if (ch == '\r') { state = 4; continue; } |
| 369 | state = 0; |
| 370 | break; |
| 371 | case 4: /* + \r */ |
| 372 | if (ch == '\n') { state = 1; break; } |
| 373 | if (ch != '\r') { put("\r"); state = 0; } |
| 374 | } |
| 375 | put(&ch); |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | char accept_buf[FMT_ULONG]; |
| 380 | void acceptmessage(qp) unsigned long qp; |
| 381 | { |
| 382 | datetime_sec when; |
| 383 | when = now(); |
| 384 | out("250 ok "); |
| 385 | accept_buf[fmt_ulong(accept_buf,(unsigned long) when)] = 0; |
| 386 | out(accept_buf); |
| 387 | out(" qp "); |
| 388 | accept_buf[fmt_ulong(accept_buf,qp)] = 0; |
| 389 | out(accept_buf); |
| 390 | out("\r\n"); |
| 391 | } |
| 392 | |
| 393 | void smtp_data() { |
| 394 | int hops; |
| 395 | unsigned long qp; |
| 396 | char *qqx; |
| 397 | |
| 398 | if (!seenmail) { err_wantmail(); return; } |
| 399 | if (!rcptto.len) { err_wantrcpt(); return; } |
| 400 | seenmail = 0; |
| 401 | if (databytes) bytestooverflow = databytes + 1; |
| 402 | if (qmail_open(&qqt) == -1) { err_qqt(); return; } |
| 403 | qp = qmail_qp(&qqt); |
| 404 | out("354 go ahead\r\n"); |
| 405 | |
| 406 | received(&qqt,"SMTP",local,remoteip,remotehost,remoteinfo,fakehelo); |
| 407 | blast(&hops); |
| 408 | hops = (hops >= MAXHOPS); |
| 409 | if (hops) qmail_fail(&qqt); |
| 410 | qmail_from(&qqt,mailfrom.s); |
| 411 | qmail_put(&qqt,rcptto.s,rcptto.len); |
| 412 | |
| 413 | qqx = qmail_close(&qqt); |
| 414 | if (!*qqx) { acceptmessage(qp); return; } |
| 415 | if (hops) { out("554 too many hops, this message is looping (#5.4.6)\r\n"); return; } |
| 416 | if (databytes) if (!bytestooverflow) { out("552 sorry, that message size exceeds my databytes limit (#5.3.4)\r\n"); return; } |
| 417 | if (*qqx == 'D') out("554 "); else out("451 "); |
| 418 | out(qqx + 1); |
| 419 | out("\r\n"); |
| 420 | } |
| 421 | |
| 422 | struct commands smtpcommands[] = { |
| 423 | { "rcpt", smtp_rcpt, 0 } |
| 424 | , { "mail", smtp_mail, 0 } |
| 425 | , { "data", smtp_data, flush } |
| 426 | , { "quit", smtp_quit, flush } |
| 427 | , { "helo", smtp_helo, flush } |
| 428 | , { "ehlo", smtp_ehlo, flush } |
| 429 | , { "rset", smtp_rset, 0 } |
| 430 | , { "help", smtp_help, flush } |
| 431 | , { "noop", err_noop, flush } |
| 432 | , { "vrfy", err_vrfy, flush } |
| 433 | , { 0, err_unimpl, flush } |
| 434 | } ; |
| 435 | |
| 436 | void main() |
| 437 | { |
| 438 | sig_pipeignore(); |
| 439 | if (chdir(auto_qmail) == -1) die_control(); |
| 440 | setup(); |
| 441 | if (ipme_init() != 1) die_ipme(); |
| 442 | smtp_greet("220 "); |
| 443 | out(" ESMTP\r\n"); |
| 444 | if (commands(&ssin,&smtpcommands) == 0) die_read(); |
| 445 | die_nomem(); |
| 446 | } |