4.4BSD/usr/src/usr.sbin/sendmail/src/srvrsmtp.c
/*
* Copyright (c) 1983 Eric P. Allman
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
# include "sendmail.h"
#ifndef lint
#ifdef SMTP
static char sccsid[] = "@(#)srvrsmtp.c 8.1 (Berkeley) 6/7/93 (with SMTP)";
#else
static char sccsid[] = "@(#)srvrsmtp.c 8.1 (Berkeley) 6/7/93 (without SMTP)";
#endif
#endif /* not lint */
# include <errno.h>
# include <signal.h>
# ifdef SMTP
/*
** SMTP -- run the SMTP protocol.
**
** Parameters:
** none.
**
** Returns:
** never.
**
** Side Effects:
** Reads commands from the input channel and processes
** them.
*/
struct cmd
{
char *cmdname; /* command name */
int cmdcode; /* internal code, see below */
};
/* values for cmdcode */
# define CMDERROR 0 /* bad command */
# define CMDMAIL 1 /* mail -- designate sender */
# define CMDRCPT 2 /* rcpt -- designate recipient */
# define CMDDATA 3 /* data -- send message text */
# define CMDRSET 4 /* rset -- reset state */
# define CMDVRFY 5 /* vrfy -- verify address */
# define CMDEXPN 6 /* expn -- expand address */
# define CMDNOOP 7 /* noop -- do nothing */
# define CMDQUIT 8 /* quit -- close connection and die */
# define CMDHELO 9 /* helo -- be polite */
# define CMDHELP 10 /* help -- give usage info */
# define CMDEHLO 11 /* ehlo -- extended helo (RFC 1425) */
/* non-standard commands */
# define CMDONEX 16 /* onex -- sending one transaction only */
# define CMDVERB 17 /* verb -- go into verbose mode */
/* debugging-only commands, only enabled if SMTPDEBUG is defined */
# define CMDDBGQSHOW 24 /* showq -- show send queue */
# define CMDDBGDEBUG 25 /* debug -- set debug mode */
static struct cmd CmdTab[] =
{
"mail", CMDMAIL,
"rcpt", CMDRCPT,
"data", CMDDATA,
"rset", CMDRSET,
"vrfy", CMDVRFY,
"expn", CMDEXPN,
"help", CMDHELP,
"noop", CMDNOOP,
"quit", CMDQUIT,
"helo", CMDHELO,
"ehlo", CMDEHLO,
"verb", CMDVERB,
"onex", CMDONEX,
/*
* remaining commands are here only
* to trap and log attempts to use them
*/
"showq", CMDDBGQSHOW,
"debug", CMDDBGDEBUG,
NULL, CMDERROR,
};
bool InChild = FALSE; /* true if running in a subprocess */
bool OneXact = FALSE; /* one xaction only this run */
#define EX_QUIT 22 /* special code for QUIT command */
smtp(e)
register ENVELOPE *e;
{
register char *p;
register struct cmd *c;
char *cmd;
static char *skipword();
auto ADDRESS *vrfyqueue;
ADDRESS *a;
bool gotmail; /* mail command received */
bool gothello; /* helo command received */
bool vrfy; /* set if this is a vrfy command */
char *protocol; /* sending protocol */
char *sendinghost; /* sending hostname */
long msize; /* approximate maximum message size */
auto char *delimptr;
char *id;
int nrcpts; /* number of RCPT commands */
char inp[MAXLINE];
char cmdbuf[MAXLINE];
extern char Version[];
extern ENVELOPE BlankEnvelope;
if (fileno(OutChannel) != fileno(stdout))
{
/* arrange for debugging output to go to remote host */
(void) dup2(fileno(OutChannel), fileno(stdout));
}
settime(e);
CurHostName = RealHostName;
setproctitle("server %s startup", CurHostName);
expand("\201e", inp, &inp[sizeof inp], e);
message("220-%s", inp);
message("220 ESMTP spoken here");
protocol = NULL;
sendinghost = macvalue('s', e);
gothello = FALSE;
gotmail = FALSE;
for (;;)
{
/* arrange for backout */
if (setjmp(TopFrame) > 0 && InChild)
{
QuickAbort = FALSE;
SuprErrs = TRUE;
finis();
}
QuickAbort = FALSE;
HoldErrs = FALSE;
LogUsrErrs = FALSE;
e->e_flags &= ~EF_VRFYONLY;
/* setup for the read */
e->e_to = NULL;
Errors = 0;
(void) fflush(stdout);
/* read the input line */
SmtpPhase = "server cmd read";
setproctitle("server %s cmd read", CurHostName);
p = sfgets(inp, sizeof inp, InChannel, TimeOuts.to_nextcommand,
SmtpPhase);
/* handle errors */
if (p == NULL)
{
/* end of file, just die */
message("421 %s Lost input channel from %s",
MyHostName, CurHostName);
#ifdef LOG
if (LogLevel > 1)
syslog(LOG_NOTICE, "lost input channel from %s",
CurHostName);
#endif
if (InChild)
ExitStat = EX_QUIT;
finis();
}
/* clean up end of line */
fixcrlf(inp, TRUE);
/* echo command to transcript */
if (e->e_xfp != NULL)
fprintf(e->e_xfp, "<<< %s\n", inp);
if (e->e_id == NULL)
setproctitle("%s: %s", CurHostName, inp);
else
setproctitle("%s %s: %s", e->e_id, CurHostName, inp);
/* break off command */
for (p = inp; isascii(*p) && isspace(*p); p++)
continue;
cmd = cmdbuf;
while (*p != '\0' &&
!(isascii(*p) && isspace(*p)) &&
cmd < &cmdbuf[sizeof cmdbuf - 2])
*cmd++ = *p++;
*cmd = '\0';
/* throw away leading whitespace */
while (isascii(*p) && isspace(*p))
p++;
/* decode command */
for (c = CmdTab; c->cmdname != NULL; c++)
{
if (!strcasecmp(c->cmdname, cmdbuf))
break;
}
/* reset errors */
errno = 0;
/* process command */
switch (c->cmdcode)
{
case CMDHELO: /* hello -- introduce yourself */
case CMDEHLO: /* extended hello */
if (c->cmdcode == CMDEHLO)
{
protocol = "ESMTP";
SmtpPhase = "server EHLO";
}
else
{
protocol = "SMTP";
SmtpPhase = "server HELO";
}
sendinghost = newstr(p);
if (strcasecmp(p, RealHostName) != 0)
{
auth_warning(e, "Host %s claimed to be %s",
RealHostName, p);
}
p = macvalue('_', e);
if (p == NULL)
p = RealHostName;
gothello = TRUE;
if (c->cmdcode != CMDEHLO)
{
/* print old message and be done with it */
message("250 %s Hello %s, pleased to meet you",
MyHostName, p);
break;
}
/* print extended message and brag */
message("250-%s Hello %s, pleased to meet you",
MyHostName, p);
if (!bitset(PRIV_NOEXPN, PrivacyFlags))
message("250-EXPN");
if (MaxMessageSize > 0)
message("250-SIZE %ld", MaxMessageSize);
else
message("250-SIZE");
message("250 HELP");
break;
case CMDMAIL: /* mail -- designate sender */
SmtpPhase = "server MAIL";
/* check for validity of this command */
if (!gothello)
{
/* set sending host to our known value */
if (sendinghost == NULL)
sendinghost = RealHostName;
if (bitset(PRIV_NEEDMAILHELO, PrivacyFlags))
{
message("503 Polite people say HELO first");
break;
}
else
{
auth_warning(e,
"Host %s didn't use HELO protocol",
RealHostName);
}
}
if (gotmail)
{
message("503 Sender already specified");
break;
}
if (InChild)
{
errno = 0;
syserr("503 Nested MAIL command: MAIL %s", p);
finis();
}
/* fork a subprocess to process this command */
if (runinchild("SMTP-MAIL", e) > 0)
break;
if (protocol == NULL)
protocol = "SMTP";
define('r', protocol, e);
define('s', sendinghost, e);
initsys(e);
nrcpts = 0;
setproctitle("%s %s: %s", e->e_id, CurHostName, inp);
/* child -- go do the processing */
p = skipword(p, "from");
if (p == NULL)
break;
if (setjmp(TopFrame) > 0)
{
/* this failed -- undo work */
if (InChild)
{
QuickAbort = FALSE;
SuprErrs = TRUE;
finis();
}
break;
}
QuickAbort = TRUE;
/* must parse sender first */
delimptr = NULL;
setsender(p, e, &delimptr, FALSE);
p = delimptr;
if (p != NULL && *p != '\0')
*p++ = '\0';
/* now parse ESMTP arguments */
msize = 0;
for (; p != NULL && *p != '\0'; p++)
{
char *kp;
char *vp;
/* locate the beginning of the keyword */
while (isascii(*p) && isspace(*p))
p++;
if (*p == '\0')
break;
kp = p;
/* skip to the value portion */
while (isascii(*p) && isalnum(*p) || *p == '-')
p++;
if (*p == '=')
{
*p++ = '\0';
vp = p;
/* skip to the end of the value */
while (*p != '\0' && *p != ' ' &&
!(isascii(*p) && iscntrl(*p)) &&
*p != '=')
p++;
}
if (*p != '\0')
*p++ = '\0';
if (tTd(19, 1))
printf("MAIL: got arg %s=%s\n", kp,
vp == NULL ? "<null>" : vp);
if (strcasecmp(kp, "size") == 0)
{
if (vp == NULL)
{
usrerr("501 SIZE requires a value");
/* NOTREACHED */
}
msize = atol(vp);
}
else if (strcasecmp(kp, "body") == 0)
{
if (vp == NULL)
{
usrerr("501 BODY requires a value");
/* NOTREACHED */
}
# ifdef MIME
if (strcasecmp(vp, "8bitmime") == 0)
{
e->e_bodytype = "8BITMIME";
SevenBit = FALSE;
}
else if (strcasecmp(vp, "7bit") == 0)
{
e->e_bodytype = "7BIT";
SevenBit = TRUE;
}
else
{
usrerr("501 Unknown BODY type %s",
vp);
}
# endif
}
else
{
usrerr("501 %s parameter unrecognized", kp);
/* NOTREACHED */
}
}
if (MaxMessageSize > 0 && msize > MaxMessageSize)
{
usrerr("552 Message size exceeds fixed maximum message size (%ld)",
MaxMessageSize);
/* NOTREACHED */
}
if (!enoughspace(msize))
{
message("452 Insufficient disk space; try again later");
break;
}
message("250 Sender ok");
gotmail = TRUE;
break;
case CMDRCPT: /* rcpt -- designate recipient */
if (!gotmail)
{
usrerr("503 Need MAIL before RCPT");
break;
}
SmtpPhase = "server RCPT";
if (setjmp(TopFrame) > 0)
{
e->e_flags &= ~EF_FATALERRS;
break;
}
QuickAbort = TRUE;
LogUsrErrs = TRUE;
if (e->e_sendmode != SM_DELIVER)
e->e_flags |= EF_VRFYONLY;
p = skipword(p, "to");
if (p == NULL)
break;
a = parseaddr(p, (ADDRESS *) NULL, 1, ' ', NULL, e);
if (a == NULL)
break;
a->q_flags |= QPRIMARY;
a = recipient(a, &e->e_sendqueue, e);
if (Errors != 0)
break;
/* no errors during parsing, but might be a duplicate */
e->e_to = p;
if (!bitset(QBADADDR, a->q_flags))
{
message("250 Recipient ok");
nrcpts++;
}
else
{
/* punt -- should keep message in ADDRESS.... */
message("550 Addressee unknown");
}
e->e_to = NULL;
break;
case CMDDATA: /* data -- text of mail */
SmtpPhase = "server DATA";
if (!gotmail)
{
message("503 Need MAIL command");
break;
}
else if (e->e_nrcpts <= 0)
{
message("503 Need RCPT (recipient)");
break;
}
/* check to see if we need to re-expand aliases */
for (a = e->e_sendqueue; a != NULL; a = a->q_next)
{
if (bitset(QVERIFIED, a->q_flags))
break;
}
/* collect the text of the message */
SmtpPhase = "collect";
collect(TRUE, a != NULL, e);
e->e_flags &= ~EF_FATALERRS;
if (Errors != 0)
goto abortmessage;
/*
** Arrange to send to everyone.
** If sending to multiple people, mail back
** errors rather than reporting directly.
** In any case, don't mail back errors for
** anything that has happened up to
** now (the other end will do this).
** Truncate our transcript -- the mail has gotten
** to us successfully, and if we have
** to mail this back, it will be easier
** on the reader.
** Then send to everyone.
** Finally give a reply code. If an error has
** already been given, don't mail a
** message back.
** We goose error returns by clearing error bit.
*/
SmtpPhase = "delivery";
if (nrcpts != 1 && a == NULL)
{
HoldErrs = TRUE;
e->e_errormode = EM_MAIL;
}
e->e_xfp = freopen(queuename(e, 'x'), "w", e->e_xfp);
id = e->e_id;
/* send to all recipients */
sendall(e, a == NULL ? SM_DEFAULT : SM_QUEUE);
e->e_to = NULL;
/* save statistics */
markstats(e, (ADDRESS *) NULL);
/* issue success if appropriate and reset */
if (Errors == 0 || HoldErrs)
message("250 %s Message accepted for delivery", id);
if (bitset(EF_FATALERRS, e->e_flags) && !HoldErrs)
{
/* avoid sending back an extra message */
e->e_flags &= ~EF_FATALERRS;
e->e_flags |= EF_CLRQUEUE;
}
else
{
/* from now on, we have to operate silently */
HoldErrs = TRUE;
e->e_errormode = EM_MAIL;
/* if we just queued, poke it */
if (a != NULL && e->e_sendmode != SM_QUEUE)
{
unlockqueue(e);
dowork(id, TRUE, TRUE, e);
e->e_id = NULL;
}
}
abortmessage:
/* if in a child, pop back to our parent */
if (InChild)
finis();
/* clean up a bit */
gotmail = FALSE;
dropenvelope(e);
CurEnv = e = newenvelope(e, CurEnv);
e->e_flags = BlankEnvelope.e_flags;
break;
case CMDRSET: /* rset -- reset state */
message("250 Reset state");
if (InChild)
finis();
/* clean up a bit */
gotmail = FALSE;
dropenvelope(e);
CurEnv = e = newenvelope(e, CurEnv);
break;
case CMDVRFY: /* vrfy -- verify address */
case CMDEXPN: /* expn -- expand address */
vrfy = c->cmdcode == CMDVRFY;
if (bitset(vrfy ? PRIV_NOVRFY : PRIV_NOEXPN,
PrivacyFlags))
{
if (vrfy)
message("252 Who's to say?");
else
message("502 That's none of your business");
break;
}
else if (!gothello &&
bitset(vrfy ? PRIV_NEEDVRFYHELO : PRIV_NEEDEXPNHELO,
PrivacyFlags))
{
message("503 I demand that you introduce yourself first");
break;
}
if (runinchild(vrfy ? "SMTP-VRFY" : "SMTP-EXPN", e) > 0)
break;
#ifdef LOG
if (LogLevel > 5)
syslog(LOG_INFO, "%s: %s", CurHostName, inp);
#endif
vrfyqueue = NULL;
QuickAbort = TRUE;
if (vrfy)
e->e_flags |= EF_VRFYONLY;
while (*p != '\0' && isascii(*p) && isspace(*p))
*p++;
if (*p == '\0')
{
message("501 Argument required");
Errors++;
}
else
{
(void) sendtolist(p, (ADDRESS *) NULL,
&vrfyqueue, e);
}
if (Errors != 0)
{
if (InChild)
finis();
break;
}
if (vrfyqueue == NULL)
{
message("554 Nothing to %s", vrfy ? "VRFY" : "EXPN");
}
while (vrfyqueue != NULL)
{
register ADDRESS *a = vrfyqueue->q_next;
while (a != NULL && bitset(QDONTSEND|QBADADDR, a->q_flags))
a = a->q_next;
if (!bitset(QDONTSEND|QBADADDR, vrfyqueue->q_flags))
printvrfyaddr(vrfyqueue, a == NULL);
else if (a == NULL)
message("554 Self destructive alias loop");
vrfyqueue = a;
}
if (InChild)
finis();
break;
case CMDHELP: /* help -- give user info */
help(p);
break;
case CMDNOOP: /* noop -- do nothing */
message("200 OK");
break;
case CMDQUIT: /* quit -- leave mail */
message("221 %s closing connection", MyHostName);
/* avoid future 050 messages */
Verbose = FALSE;
if (InChild)
ExitStat = EX_QUIT;
finis();
case CMDVERB: /* set verbose mode */
if (bitset(PRIV_NOEXPN, PrivacyFlags))
{
/* this would give out the same info */
message("502 Verbose unavailable");
break;
}
Verbose = TRUE;
e->e_sendmode = SM_DELIVER;
message("250 Verbose mode");
break;
case CMDONEX: /* doing one transaction only */
OneXact = TRUE;
message("250 Only one transaction");
break;
# ifdef SMTPDEBUG
case CMDDBGQSHOW: /* show queues */
printf("Send Queue=");
printaddr(e->e_sendqueue, TRUE);
break;
case CMDDBGDEBUG: /* set debug mode */
tTsetup(tTdvect, sizeof tTdvect, "0-99.1");
tTflag(p);
message("200 Debug set");
break;
# else /* not SMTPDEBUG */
case CMDDBGQSHOW: /* show queues */
case CMDDBGDEBUG: /* set debug mode */
# ifdef LOG
if (LogLevel > 0)
syslog(LOG_NOTICE,
"\"%s\" command from %s (%s)",
c->cmdname, RealHostName,
anynet_ntoa(&RealHostAddr));
# endif
/* FALL THROUGH */
# endif /* SMTPDEBUG */
case CMDERROR: /* unknown command */
message("500 Command unrecognized");
break;
default:
errno = 0;
syserr("500 smtp: unknown code %d", c->cmdcode);
break;
}
}
}
/*
** SKIPWORD -- skip a fixed word.
**
** Parameters:
** p -- place to start looking.
** w -- word to skip.
**
** Returns:
** p following w.
** NULL on error.
**
** Side Effects:
** clobbers the p data area.
*/
static char *
skipword(p, w)
register char *p;
char *w;
{
register char *q;
/* find beginning of word */
while (isascii(*p) && isspace(*p))
p++;
q = p;
/* find end of word */
while (*p != '\0' && *p != ':' && !(isascii(*p) && isspace(*p)))
p++;
while (isascii(*p) && isspace(*p))
*p++ = '\0';
if (*p != ':')
{
syntax:
message("501 Syntax error in parameters");
Errors++;
return (NULL);
}
*p++ = '\0';
while (isascii(*p) && isspace(*p))
p++;
if (*p == '\0')
goto syntax;
/* see if the input word matches desired word */
if (strcasecmp(q, w))
goto syntax;
return (p);
}
/*
** PRINTVRFYADDR -- print an entry in the verify queue
**
** Parameters:
** a -- the address to print
** last -- set if this is the last one.
**
** Returns:
** none.
**
** Side Effects:
** Prints the appropriate 250 codes.
*/
printvrfyaddr(a, last)
register ADDRESS *a;
bool last;
{
char fmtbuf[20];
strcpy(fmtbuf, "250");
fmtbuf[3] = last ? ' ' : '-';
if (a->q_fullname == NULL)
{
if (strchr(a->q_user, '@') == NULL)
strcpy(&fmtbuf[4], "<%s@%s>");
else
strcpy(&fmtbuf[4], "<%s>");
message(fmtbuf, a->q_user, MyHostName);
}
else
{
if (strchr(a->q_user, '@') == NULL)
strcpy(&fmtbuf[4], "%s <%s@%s>");
else
strcpy(&fmtbuf[4], "%s <%s>");
message(fmtbuf, a->q_fullname, a->q_user, MyHostName);
}
}
/*
** HELP -- implement the HELP command.
**
** Parameters:
** topic -- the topic we want help for.
**
** Returns:
** none.
**
** Side Effects:
** outputs the help file to message output.
*/
help(topic)
char *topic;
{
register FILE *hf;
int len;
char buf[MAXLINE];
bool noinfo;
if (HelpFile == NULL || (hf = fopen(HelpFile, "r")) == NULL)
{
/* no help */
errno = 0;
message("502 HELP not implemented");
return;
}
if (topic == NULL || *topic == '\0')
topic = "smtp";
else
makelower(topic);
len = strlen(topic);
noinfo = TRUE;
while (fgets(buf, sizeof buf, hf) != NULL)
{
if (strncmp(buf, topic, len) == 0)
{
register char *p;
p = strchr(buf, '\t');
if (p == NULL)
p = buf;
else
p++;
fixcrlf(p, TRUE);
message("214-%s", p);
noinfo = FALSE;
}
}
if (noinfo)
message("504 HELP topic unknown");
else
message("214 End of HELP info");
(void) fclose(hf);
}
/*
** RUNINCHILD -- return twice -- once in the child, then in the parent again
**
** Parameters:
** label -- a string used in error messages
**
** Returns:
** zero in the child
** one in the parent
**
** Side Effects:
** none.
*/
runinchild(label, e)
char *label;
register ENVELOPE *e;
{
int childpid;
if (!OneXact)
{
childpid = dofork();
if (childpid < 0)
{
syserr("%s: cannot fork", label);
return (1);
}
if (childpid > 0)
{
auto int st;
/* parent -- wait for child to complete */
setproctitle("server %s child wait", CurHostName);
st = waitfor(childpid);
if (st == -1)
syserr("%s: lost child", label);
/* if we exited on a QUIT command, complete the process */
if (st == (EX_QUIT << 8))
finis();
return (1);
}
else
{
/* child */
InChild = TRUE;
QuickAbort = FALSE;
clearenvelope(e, FALSE);
}
}
/* open alias database */
initmaps(FALSE, e);
return (0);
}
# endif /* SMTP */