diff options
Diffstat (limited to 'qmail-smtpd.c')
| -rw-r--r-- | qmail-smtpd.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/qmail-smtpd.c b/qmail-smtpd.c new file mode 100644 index 0000000..54df00c --- /dev/null +++ b/qmail-smtpd.c @@ -0,0 +1,421 @@ +#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" + +#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_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_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"); } + + +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 = ' '; + 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(); + } + } + + if (addr.len > 900) 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 seenmail = 0; +int flagbarf; /* defined if seenmail */ +stralloc mailfrom = {0}; +stralloc rcptto = {0}; + +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\n250-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 (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(); + 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; } + 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"); +} + +struct commands smtpcommands[] = { + { "rcpt", smtp_rcpt, 0 } +, { "mail", smtp_mail, 0 } +, { "data", smtp_data, 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() +{ + 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(); +} |