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|
/*
* Copyright (c) 1998 Sendmail, Inc. All rights reserved.
* Copyright (c) 1983, 1995-1997 Eric P. Allman. All rights reserved.
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the sendmail distribution.
*
*/
# include "sendmail.h"
#ifndef lint
#if SMTP
static char sccsid[] = "@(#)srvrsmtp.c 8.181 (Berkeley) 6/15/98 (with SMTP)";
#else
static char sccsid[] = "@(#)srvrsmtp.c 8.181 (Berkeley) 6/15/98 (without SMTP)";
#endif
#endif /* not lint */
# include <errno.h>
# if SMTP
/*
** SMTP -- run the SMTP protocol.
**
** Parameters:
** nullserver -- if non-NULL, rejection message for
** all SMTP commands.
** e -- the envelope.
**
** 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) */
# define CMDETRN 12 /* etrn -- flush queue */
/* non-standard commands */
# define CMDONEX 16 /* onex -- sending one transaction only */
# define CMDVERB 17 /* verb -- go into verbose mode */
# define CMDXUSR 18 /* xusr -- initial (user) submission */
/* use this to catch and log "door handle" attempts on your system */
# define CMDLOGBOGUS 23 /* bogus command that should be logged */
/* 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 },
{ "etrn", CMDETRN },
{ "verb", CMDVERB },
{ "onex", CMDONEX },
{ "xusr", CMDXUSR },
/* remaining commands are here only to trap and log attempts to use them */
{ "showq", CMDDBGQSHOW },
{ "debug", CMDDBGDEBUG },
{ "wiz", CMDLOGBOGUS },
{ NULL, CMDERROR }
};
bool OneXact = FALSE; /* one xaction only this run */
char *CurSmtpClient; /* who's at the other end of channel */
static char *skipword __P((char *volatile, char *));
#define MAXBADCOMMANDS 25 /* maximum number of bad commands */
#define MAXNOOPCOMMANDS 20 /* max "noise" commands before slowdown */
#define MAXHELOCOMMANDS 3 /* max HELO/EHLO commands before slowdown */
#define MAXVRFYCOMMANDS 6 /* max VRFY/EXPN commands before slowdown */
#define MAXETRNCOMMANDS 8 /* max ETRN commands before slowdown */
void
smtp(nullserver, e)
char *nullserver;
register ENVELOPE *volatile e;
{
register char *volatile p;
register struct cmd *c;
char *cmd;
auto ADDRESS *vrfyqueue;
ADDRESS *a;
volatile bool gotmail; /* mail command received */
volatile bool gothello; /* helo command received */
bool vrfy; /* set if this is a vrfy command */
char *volatile protocol; /* sending protocol */
char *volatile sendinghost; /* sending hostname */
char *volatile peerhostname; /* name of SMTP peer or "localhost" */
auto char *delimptr;
char *id;
volatile int nrcpts = 0; /* number of RCPT commands */
bool doublequeue;
bool discard;
volatile int badcommands = 0; /* count of bad commands */
volatile int nverifies = 0; /* count of VRFY/EXPN commands */
volatile int n_etrn = 0; /* count of ETRN commands */
volatile int n_noop = 0; /* count of NOOP/VERB/ONEX etc cmds */
volatile int n_helo = 0; /* count of HELO/EHLO commands */
bool ok;
volatile int lognullconnection = TRUE;
register char *q;
QUEUE_CHAR *new;
char inp[MAXLINE];
char cmdbuf[MAXLINE];
extern ENVELOPE BlankEnvelope;
extern void help __P((char *));
extern void settime __P((ENVELOPE *));
extern bool enoughdiskspace __P((long));
extern int runinchild __P((char *, ENVELOPE *));
extern void checksmtpattack __P((volatile int *, int, char *, ENVELOPE *));
if (fileno(OutChannel) != fileno(stdout))
{
/* arrange for debugging output to go to remote host */
(void) dup2(fileno(OutChannel), fileno(stdout));
}
settime(e);
peerhostname = RealHostName;
if (peerhostname == NULL)
peerhostname = "localhost";
CurHostName = peerhostname;
CurSmtpClient = macvalue('_', e);
if (CurSmtpClient == NULL)
CurSmtpClient = CurHostName;
/* check_relay may have set discard bit, save for later */
discard = bitset(EF_DISCARD, e->e_flags);
setproctitle("server %s startup", CurSmtpClient);
#if DAEMON
if (LogLevel > 11)
{
/* log connection information */
sm_syslog(LOG_INFO, NOQID,
"SMTP connect from %.100s (%.100s)",
CurSmtpClient, anynet_ntoa(&RealHostAddr));
}
#endif
/* output the first line, inserting "ESMTP" as second word */
expand(SmtpGreeting, inp, sizeof inp, e);
p = strchr(inp, '\n');
if (p != NULL)
*p++ = '\0';
id = strchr(inp, ' ');
if (id == NULL)
id = &inp[strlen(inp)];
cmd = p == NULL ? "220 %.*s ESMTP%s" : "220-%.*s ESMTP%s";
message(cmd, id - inp, inp, id);
/* output remaining lines */
while ((id = p) != NULL && (p = strchr(id, '\n')) != NULL)
{
*p++ = '\0';
if (isascii(*id) && isspace(*id))
id++;
message("220-%s", id);
}
if (id != NULL)
{
if (isascii(*id) && isspace(*id))
id++;
message("220 %s", id);
}
protocol = NULL;
sendinghost = macvalue('s', e);
gothello = FALSE;
gotmail = FALSE;
for (;;)
{
/* arrange for backout */
(void) setjmp(TopFrame);
QuickAbort = FALSE;
HoldErrs = FALSE;
SuprErrs = FALSE;
LogUsrErrs = FALSE;
OnlyOneError = TRUE;
e->e_flags &= ~(EF_VRFYONLY|EF_GLOBALERRS);
/* 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", CurSmtpClient);
p = sfgets(inp, sizeof inp, InChannel, TimeOuts.to_nextcommand,
SmtpPhase);
/* handle errors */
if (p == NULL)
{
/* end of file, just die */
disconnect(1, e);
message("421 %s Lost input channel from %s",
MyHostName, CurSmtpClient);
if (LogLevel > (gotmail ? 1 : 19))
sm_syslog(LOG_NOTICE, e->e_id,
"lost input channel from %.100s",
CurSmtpClient);
if (lognullconnection && LogLevel > 5)
sm_syslog(LOG_INFO, NULL,
"Null connection from %.100s",
CurSmtpClient);
/*
** If have not accepted mail (DATA), do not bounce
** bad addresses back to sender.
*/
if (bitset(EF_CLRQUEUE, e->e_flags))
e->e_sendqueue = NULL;
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 (LogLevel >= 15)
sm_syslog(LOG_INFO, e->e_id,
"<-- %s",
inp);
if (e->e_id == NULL)
setproctitle("%s: %.80s", CurSmtpClient, inp);
else
setproctitle("%s %s: %.80s", e->e_id, CurSmtpClient, 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.
**
** If we are running as a null server, return 550
** to everything.
*/
if (nullserver != NULL)
{
switch (c->cmdcode)
{
case CMDQUIT:
case CMDHELO:
case CMDEHLO:
case CMDNOOP:
/* process normally */
break;
default:
if (++badcommands > MAXBADCOMMANDS)
sleep(1);
usrerr("550 %s", nullserver);
continue;
}
}
/* non-null server */
switch (c->cmdcode)
{
case CMDMAIL:
case CMDEXPN:
case CMDVRFY:
case CMDETRN:
lognullconnection = FALSE;
}
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";
}
/* avoid denial-of-service */
checksmtpattack(&n_helo, MAXHELOCOMMANDS, "HELO/EHLO", e);
/* check for duplicate HELO/EHLO per RFC 1651 4.2 */
if (gothello)
{
usrerr("503 %s Duplicate HELO/EHLO",
MyHostName);
break;
}
/* check for valid domain name (re 1123 5.2.5) */
if (*p == '\0' && !AllowBogusHELO)
{
usrerr("501 %s requires domain address",
cmdbuf);
break;
}
/* check for long domain name (hides Received: info) */
if (strlen(p) > MAXNAME)
{
usrerr("501 Invalid domain name");
break;
}
for (q = p; *q != '\0'; q++)
{
if (!isascii(*q))
break;
if (isalnum(*q))
continue;
if (isspace(*q))
{
*q = '\0';
break;
}
if (strchr("[].-_#", *q) == NULL)
break;
}
if (*q == '\0')
{
q = "pleased to meet you";
sendinghost = newstr(p);
}
else if (!AllowBogusHELO)
{
usrerr("501 Invalid domain name");
break;
}
else
{
q = "accepting invalid domain name";
}
gothello = TRUE;
/* print HELO response message */
if (c->cmdcode != CMDEHLO || nullserver != NULL)
{
message("250 %s Hello %s, %s",
MyHostName, CurSmtpClient, q);
break;
}
message("250-%s Hello %s, %s",
MyHostName, CurSmtpClient, q);
/* print EHLO features list */
if (!bitset(PRIV_NOEXPN, PrivacyFlags))
{
message("250-EXPN");
if (!bitset(PRIV_NOVERB, PrivacyFlags))
message("250-VERB");
}
#if MIME8TO7
message("250-8BITMIME");
#endif
if (MaxMessageSize > 0)
message("250-SIZE %ld", MaxMessageSize);
else
message("250-SIZE");
#if DSN
if (SendMIMEErrors)
message("250-DSN");
#endif
message("250-ONEX");
if (!bitset(PRIV_NOETRN, PrivacyFlags))
message("250-ETRN");
message("250-XUSR");
message("250 HELP");
break;
case CMDMAIL: /* mail -- designate sender */
SmtpPhase = "server MAIL";
/* check for validity of this command */
if (!gothello && bitset(PRIV_NEEDMAILHELO, PrivacyFlags))
{
usrerr("503 Polite people say HELO first");
break;
}
if (gotmail)
{
usrerr("503 Sender already specified");
break;
}
if (InChild)
{
errno = 0;
syserr("503 Nested MAIL command: MAIL %s", p);
finis();
}
/* make sure we know who the sending host is */
if (sendinghost == NULL)
sendinghost = peerhostname;
p = skipword(p, "from");
if (p == NULL)
break;
/* fork a subprocess to process this command */
if (runinchild("SMTP-MAIL", e) > 0)
break;
if (Errors > 0)
goto undo_subproc_no_pm;
if (!gothello)
{
auth_warning(e,
"%s didn't use HELO protocol",
CurSmtpClient);
}
#ifdef PICKY_HELO_CHECK
if (strcasecmp(sendinghost, peerhostname) != 0 &&
(strcasecmp(peerhostname, "localhost") != 0 ||
strcasecmp(sendinghost, MyHostName) != 0))
{
auth_warning(e, "Host %s claimed to be %s",
CurSmtpClient, sendinghost);
}
#endif
if (protocol == NULL)
protocol = "SMTP";
define('r', protocol, e);
define('s', sendinghost, e);
initsys(e);
if (Errors > 0)
goto undo_subproc_no_pm;
nrcpts = 0;
e->e_flags |= EF_LOGSENDER|EF_CLRQUEUE;
setproctitle("%s %s: %.80s", e->e_id, CurSmtpClient, inp);
/* child -- go do the processing */
if (setjmp(TopFrame) > 0)
{
/* this failed -- undo work */
undo_subproc_no_pm:
e->e_flags &= ~EF_PM_NOTIFY;
undo_subproc:
if (InChild)
{
QuickAbort = FALSE;
SuprErrs = TRUE;
e->e_flags &= ~EF_FATALERRS;
finis();
}
break;
}
QuickAbort = TRUE;
/* must parse sender first */
delimptr = NULL;
setsender(p, e, &delimptr, ' ', FALSE);
if (delimptr != NULL && *delimptr != '\0')
*delimptr++ = '\0';
if (Errors > 0)
goto undo_subproc_no_pm;
/* do config file checking of the sender */
if (rscheck("check_mail", p, NULL, e) != EX_OK ||
Errors > 0)
goto undo_subproc_no_pm;
/* check for possible spoofing */
if (RealUid != 0 && OpMode == MD_SMTP &&
!wordinclass(RealUserName, 't') &&
!bitnset(M_LOCALMAILER, e->e_from.q_mailer->m_flags) &&
strcmp(e->e_from.q_user, RealUserName) != 0)
{
auth_warning(e, "%s owned process doing -bs",
RealUserName);
}
/* now parse ESMTP arguments */
e->e_msgsize = 0;
p = delimptr;
while (p != NULL && *p != '\0')
{
char *kp;
char *vp = NULL;
extern void mail_esmtp_args __P((char *, char *, ENVELOPE *));
/* 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);
mail_esmtp_args(kp, vp, e);
if (Errors > 0)
goto undo_subproc_no_pm;
}
if (Errors > 0)
goto undo_subproc_no_pm;
if (MaxMessageSize > 0 && e->e_msgsize > MaxMessageSize)
{
usrerr("552 Message size exceeds fixed maximum message size (%ld)",
MaxMessageSize);
goto undo_subproc_no_pm;
}
if (!enoughdiskspace(e->e_msgsize))
{
usrerr("452 Insufficient disk space; try again later");
goto undo_subproc_no_pm;
}
if (Errors > 0)
goto undo_subproc_no_pm;
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;
/* limit flooding of our machine */
if (MaxRcptPerMsg > 0 && nrcpts >= MaxRcptPerMsg)
{
usrerr("452 Too many recipients");
break;
}
if (e->e_sendmode != SM_DELIVER)
e->e_flags |= EF_VRFYONLY;
p = skipword(p, "to");
if (p == NULL)
break;
a = parseaddr(p, NULLADDR, RF_COPYALL, ' ', &delimptr, e);
if (a == NULL || Errors > 0)
break;
if (delimptr != NULL && *delimptr != '\0')
*delimptr++ = '\0';
/* do config file checking of the recipient */
if (rscheck("check_rcpt", p, NULL, e) != EX_OK ||
Errors > 0)
break;
/* now parse ESMTP arguments */
p = delimptr;
while (p != NULL && *p != '\0')
{
char *kp;
char *vp = NULL;
extern void rcpt_esmtp_args __P((ADDRESS *, char *, char *, ENVELOPE *));
/* 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("RCPT: got arg %s=\"%s\"\n", kp,
vp == NULL ? "<null>" : vp);
rcpt_esmtp_args(a, kp, vp, e);
if (Errors > 0)
break;
}
if (Errors > 0)
break;
/* save in recipient list after ESMTP mods */
a = recipient(a, &e->e_sendqueue, 0, e);
if (Errors > 0)
break;
/* no errors during parsing, but might be a duplicate */
e->e_to = a->q_paddr;
if (!bitset(QBADADDR, a->q_flags))
{
message("250 Recipient ok%s",
bitset(QQUEUEUP, a->q_flags) ?
" (will queue)" : "");
nrcpts++;
}
else
{
/* punt -- should keep message in ADDRESS.... */
usrerr("550 Addressee unknown");
}
break;
case CMDDATA: /* data -- text of mail */
SmtpPhase = "server DATA";
if (!gotmail)
{
usrerr("503 Need MAIL command");
break;
}
else if (nrcpts <= 0)
{
usrerr("503 Need RCPT (recipient)");
break;
}
/* put back discard bit */
if (discard)
e->e_flags |= EF_DISCARD;
/* check to see if we need to re-expand aliases */
/* also reset QBADADDR on already-diagnosted addrs */
doublequeue = FALSE;
for (a = e->e_sendqueue; a != NULL; a = a->q_next)
{
if (bitset(QVERIFIED, a->q_flags) &&
!bitset(EF_DISCARD, e->e_flags))
{
/* need to re-expand aliases */
doublequeue = TRUE;
}
if (bitset(QBADADDR, a->q_flags))
{
/* make this "go away" */
a->q_flags |= QDONTSEND;
a->q_flags &= ~QBADADDR;
}
}
/* collect the text of the message */
SmtpPhase = "collect";
buffer_errors();
collect(InChannel, TRUE, NULL, e);
if (Errors > 0)
{
flush_errors(TRUE);
buffer_errors();
goto abortmessage;
}
/* make sure we actually do delivery */
e->e_flags &= ~EF_CLRQUEUE;
/* from now on, we have to operate silently */
buffer_errors();
e->e_errormode = EM_MAIL;
/*
** 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";
e->e_xfp = freopen(queuename(e, 'x'), "w", e->e_xfp);
id = e->e_id;
if (doublequeue)
{
/* make sure it is in the queue */
queueup(e, FALSE);
}
else
{
/* send to all recipients */
sendall(e, SM_DEFAULT);
}
e->e_to = NULL;
/* issue success message */
message("250 %s Message accepted for delivery", id);
/* if we just queued, poke it */
if (doublequeue &&
e->e_sendmode != SM_QUEUE &&
e->e_sendmode != SM_DEFER)
{
CurrentLA = getla();
if (!shouldqueue(e->e_msgpriority, e->e_ctime))
{
extern pid_t dowork __P((char *, bool, bool, ENVELOPE *));
unlockqueue(e);
(void) dowork(id, TRUE, TRUE, e);
}
}
abortmessage:
/* if in a child, pop back to our parent */
if (InChild)
finis();
/* clean up a bit */
gotmail = FALSE;
dropenvelope(e, TRUE);
CurEnv = e = newenvelope(e, CurEnv);
e->e_flags = BlankEnvelope.e_flags;
break;
case CMDRSET: /* rset -- reset state */
if (tTd(94, 100))
message("451 Test failure");
else
message("250 Reset state");
/* arrange to ignore any current send list */
e->e_sendqueue = NULL;
e->e_flags |= EF_CLRQUEUE;
if (InChild)
finis();
/* clean up a bit */
gotmail = FALSE;
SuprErrs = TRUE;
dropenvelope(e, TRUE);
CurEnv = e = newenvelope(e, CurEnv);
break;
case CMDVRFY: /* vrfy -- verify address */
case CMDEXPN: /* expn -- expand address */
checksmtpattack(&nverifies, MAXVRFYCOMMANDS,
c->cmdcode == CMDVRFY ? "VRFY" : "EXPN", e);
vrfy = c->cmdcode == CMDVRFY;
if (bitset(vrfy ? PRIV_NOVRFY : PRIV_NOEXPN,
PrivacyFlags))
{
if (vrfy)
message("252 Cannot VRFY user; try RCPT to attempt delivery (or try finger)");
else
message("502 Sorry, we do not allow this operation");
if (LogLevel > 5)
sm_syslog(LOG_INFO, e->e_id,
"%.100s: %s [rejected]",
CurSmtpClient,
shortenstring(inp, MAXSHORTSTR));
break;
}
else if (!gothello &&
bitset(vrfy ? PRIV_NEEDVRFYHELO : PRIV_NEEDEXPNHELO,
PrivacyFlags))
{
usrerr("503 I demand that you introduce yourself first");
break;
}
if (runinchild(vrfy ? "SMTP-VRFY" : "SMTP-EXPN", e) > 0)
break;
if (Errors > 0)
goto undo_subproc;
if (LogLevel > 5)
sm_syslog(LOG_INFO, e->e_id,
"%.100s: %s",
CurSmtpClient,
shortenstring(inp, MAXSHORTSTR));
if (setjmp(TopFrame) > 0)
goto undo_subproc;
QuickAbort = TRUE;
vrfyqueue = NULL;
if (vrfy)
e->e_flags |= EF_VRFYONLY;
while (*p != '\0' && isascii(*p) && isspace(*p))
p++;
if (*p == '\0')
{
usrerr("501 Argument required");
}
else
{
(void) sendtolist(p, NULLADDR, &vrfyqueue, 0, e);
}
if (Errors > 0)
goto undo_subproc;
if (vrfyqueue == NULL)
{
usrerr("554 Nothing to %s", vrfy ? "VRFY" : "EXPN");
}
while (vrfyqueue != NULL)
{
extern void printvrfyaddr __P((ADDRESS *, bool, bool));
a = vrfyqueue;
while ((a = a->q_next) != NULL &&
bitset(QDONTSEND|QBADADDR, a->q_flags))
continue;
if (!bitset(QDONTSEND|QBADADDR, vrfyqueue->q_flags))
printvrfyaddr(vrfyqueue, a == NULL, vrfy);
vrfyqueue = vrfyqueue->q_next;
}
if (InChild)
finis();
break;
case CMDETRN: /* etrn -- force queue flush */
if (bitset(PRIV_NOETRN, PrivacyFlags))
{
message("502 Sorry, we do not allow this operation");
if (LogLevel > 5)
sm_syslog(LOG_INFO, e->e_id,
"%.100s: %s [rejected]",
CurSmtpClient,
shortenstring(inp, MAXSHORTSTR));
break;
}
if (strlen(p) <= 0)
{
usrerr("500 Parameter required");
break;
}
/* crude way to avoid denial-of-service attacks */
checksmtpattack(&n_etrn, MAXETRNCOMMANDS, "ETRN", e);
if (LogLevel > 5)
sm_syslog(LOG_INFO, e->e_id,
"%.100s: ETRN %s",
CurSmtpClient,
shortenstring(p, MAXSHORTSTR));
id = p;
if (*id == '@')
id++;
else
*--id = '@';
if ((new = (QUEUE_CHAR *)malloc(sizeof(QUEUE_CHAR))) == NULL)
{
syserr("500 ETRN out of memory");
break;
}
new->queue_match = id;
new->queue_next = NULL;
QueueLimitRecipient = new;
ok = runqueue(TRUE, TRUE);
free(QueueLimitRecipient);
QueueLimitRecipient = NULL;
if (ok && Errors == 0)
message("250 Queuing for node %s started", p);
break;
case CMDHELP: /* help -- give user info */
help(p);
break;
case CMDNOOP: /* noop -- do nothing */
checksmtpattack(&n_noop, MAXNOOPCOMMANDS, "NOOP", e);
message("250 OK");
break;
case CMDQUIT: /* quit -- leave mail */
message("221 %s closing connection", MyHostName);
doquit:
/* arrange to ignore any current send list */
e->e_sendqueue = NULL;
/* avoid future 050 messages */
disconnect(1, e);
if (InChild)
ExitStat = EX_QUIT;
if (lognullconnection && LogLevel > 5)
sm_syslog(LOG_INFO, NULL,
"Null connection from %.100s",
CurSmtpClient);
finis();
case CMDVERB: /* set verbose mode */
if (bitset(PRIV_NOEXPN, PrivacyFlags) ||
bitset(PRIV_NOVERB, PrivacyFlags))
{
/* this would give out the same info */
message("502 Verbose unavailable");
break;
}
checksmtpattack(&n_noop, MAXNOOPCOMMANDS, "VERB", e);
Verbose = 1;
e->e_sendmode = SM_DELIVER;
message("250 Verbose mode");
break;
case CMDONEX: /* doing one transaction only */
checksmtpattack(&n_noop, MAXNOOPCOMMANDS, "ONEX", e);
OneXact = TRUE;
message("250 Only one transaction");
break;
case CMDXUSR: /* initial (user) submission */
checksmtpattack(&n_noop, MAXNOOPCOMMANDS, "XUSR", e);
UserSubmission = TRUE;
message("250 Initial submission");
break;
# if 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 */
# endif /* SMTPDEBUG */
case CMDLOGBOGUS: /* bogus command */
if (LogLevel > 0)
sm_syslog(LOG_CRIT, e->e_id,
"\"%s\" command from %.100s (%.100s)",
c->cmdname, CurSmtpClient,
anynet_ntoa(&RealHostAddr));
/* FALL THROUGH */
case CMDERROR: /* unknown command */
if (++badcommands > MAXBADCOMMANDS)
{
message("421 %s Too many bad commands; closing connection",
MyHostName);
goto doquit;
}
usrerr("500 Command unrecognized: \"%s\"",
shortenstring(inp, MAXSHORTSTR));
break;
default:
errno = 0;
syserr("500 smtp: unknown code %d", c->cmdcode);
break;
}
}
}
/*
** CHECKSMTPATTACK -- check for denial-of-service attack by repetition
**
** Parameters:
** pcounter -- pointer to a counter for this command.
** maxcount -- maximum value for this counter before we
** slow down.
** cname -- command name for logging.
** e -- the current envelope.
**
** Returns:
** none.
**
** Side Effects:
** Slows down if we seem to be under attack.
*/
void
checksmtpattack(pcounter, maxcount, cname, e)
volatile int *pcounter;
int maxcount;
char *cname;
ENVELOPE *e;
{
if (++(*pcounter) >= maxcount)
{
if (*pcounter == maxcount && LogLevel > 5)
{
sm_syslog(LOG_INFO, e->e_id,
"%.100s: %.40s attack?",
CurSmtpClient, cname);
}
sleep(*pcounter / maxcount);
}
}
/*
** 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 *volatile p;
char *w;
{
register char *q;
char *firstp = p;
/* 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:
usrerr("501 Syntax error in parameters scanning \"%s\"",
shortenstring(firstp, MAXSHORTSTR));
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);
}
/*
** MAIL_ESMTP_ARGS -- process ESMTP arguments from MAIL line
**
** Parameters:
** kp -- the parameter key.
** vp -- the value of that parameter.
** e -- the envelope.
**
** Returns:
** none.
*/
void
mail_esmtp_args(kp, vp, e)
char *kp;
char *vp;
ENVELOPE *e;
{
if (strcasecmp(kp, "size") == 0)
{
if (vp == NULL)
{
usrerr("501 SIZE requires a value");
/* NOTREACHED */
}
# if defined(__STDC__) && !defined(BROKEN_ANSI_LIBRARY)
e->e_msgsize = strtoul(vp, (char **) NULL, 10);
# else
e->e_msgsize = strtol(vp, (char **) NULL, 10);
# endif
}
else if (strcasecmp(kp, "body") == 0)
{
if (vp == NULL)
{
usrerr("501 BODY requires a value");
/* NOTREACHED */
}
else if (strcasecmp(vp, "8bitmime") == 0)
{
SevenBitInput = FALSE;
}
else if (strcasecmp(vp, "7bit") == 0)
{
SevenBitInput = TRUE;
}
else
{
usrerr("501 Unknown BODY type %s",
vp);
/* NOTREACHED */
}
e->e_bodytype = newstr(vp);
}
else if (strcasecmp(kp, "envid") == 0)
{
if (vp == NULL)
{
usrerr("501 ENVID requires a value");
/* NOTREACHED */
}
if (!xtextok(vp))
{
usrerr("501 Syntax error in ENVID parameter value");
/* NOTREACHED */
}
if (e->e_envid != NULL)
{
usrerr("501 Duplicate ENVID parameter");
/* NOTREACHED */
}
e->e_envid = newstr(vp);
}
else if (strcasecmp(kp, "ret") == 0)
{
if (vp == NULL)
{
usrerr("501 RET requires a value");
/* NOTREACHED */
}
if (bitset(EF_RET_PARAM, e->e_flags))
{
usrerr("501 Duplicate RET parameter");
/* NOTREACHED */
}
e->e_flags |= EF_RET_PARAM;
if (strcasecmp(vp, "hdrs") == 0)
e->e_flags |= EF_NO_BODY_RETN;
else if (strcasecmp(vp, "full") != 0)
{
usrerr("501 Bad argument \"%s\" to RET", vp);
/* NOTREACHED */
}
}
else
{
usrerr("501 %s parameter unrecognized", kp);
/* NOTREACHED */
}
}
/*
** RCPT_ESMTP_ARGS -- process ESMTP arguments from RCPT line
**
** Parameters:
** a -- the address corresponding to the To: parameter.
** kp -- the parameter key.
** vp -- the value of that parameter.
** e -- the envelope.
**
** Returns:
** none.
*/
void
rcpt_esmtp_args(a, kp, vp, e)
ADDRESS *a;
char *kp;
char *vp;
ENVELOPE *e;
{
if (strcasecmp(kp, "notify") == 0)
{
char *p;
if (vp == NULL)
{
usrerr("501 NOTIFY requires a value");
/* NOTREACHED */
}
a->q_flags &= ~(QPINGONSUCCESS|QPINGONFAILURE|QPINGONDELAY);
a->q_flags |= QHASNOTIFY;
if (strcasecmp(vp, "never") == 0)
return;
for (p = vp; p != NULL; vp = p)
{
p = strchr(p, ',');
if (p != NULL)
*p++ = '\0';
if (strcasecmp(vp, "success") == 0)
a->q_flags |= QPINGONSUCCESS;
else if (strcasecmp(vp, "failure") == 0)
a->q_flags |= QPINGONFAILURE;
else if (strcasecmp(vp, "delay") == 0)
a->q_flags |= QPINGONDELAY;
else
{
usrerr("501 Bad argument \"%s\" to NOTIFY",
vp);
/* NOTREACHED */
}
}
}
else if (strcasecmp(kp, "orcpt") == 0)
{
if (vp == NULL)
{
usrerr("501 ORCPT requires a value");
/* NOTREACHED */
}
if (strchr(vp, ';') == NULL || !xtextok(vp))
{
usrerr("501 Syntax error in ORCPT parameter value");
/* NOTREACHED */
}
if (a->q_orcpt != NULL)
{
usrerr("501 Duplicate ORCPT parameter");
/* NOTREACHED */
}
a->q_orcpt = newstr(vp);
}
else
{
usrerr("501 %s parameter unrecognized", kp);
/* NOTREACHED */
}
}
/*
** PRINTVRFYADDR -- print an entry in the verify queue
**
** Parameters:
** a -- the address to print
** last -- set if this is the last one.
** vrfy -- set if this is a VRFY command.
**
** Returns:
** none.
**
** Side Effects:
** Prints the appropriate 250 codes.
*/
void
printvrfyaddr(a, last, vrfy)
register ADDRESS *a;
bool last;
bool vrfy;
{
char fmtbuf[20];
if (vrfy && a->q_mailer != NULL &&
!bitnset(M_VRFY250, a->q_mailer->m_flags))
strcpy(fmtbuf, "252");
else
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);
}
}
/*
** 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.
*/
int
runinchild(label, e)
char *label;
register ENVELOPE *e;
{
pid_t childpid;
if (!OneXact)
{
/*
** Disable child process reaping, in case ETRN has preceeded
** MAIL command, and then fork.
*/
(void) blocksignal(SIGCHLD);
childpid = dofork();
if (childpid < 0)
{
syserr("451 %s: cannot fork", label);
(void) releasesignal(SIGCHLD);
return (1);
}
if (childpid > 0)
{
auto int st;
/* parent -- wait for child to complete */
setproctitle("server %s child wait", CurSmtpClient);
st = waitfor(childpid);
if (st == -1)
syserr("451 %s: lost child", label);
else if (!WIFEXITED(st))
syserr("451 %s: died on signal %d",
label, st & 0177);
/* if we exited on a QUIT command, complete the process */
if (WEXITSTATUS(st) == EX_QUIT)
{
disconnect(1, e);
finis();
}
/* restore the child signal */
(void) releasesignal(SIGCHLD);
return (1);
}
else
{
/* child */
InChild = TRUE;
QuickAbort = FALSE;
clearenvelope(e, FALSE);
(void) setsignal(SIGCHLD, SIG_DFL);
(void) releasesignal(SIGCHLD);
}
}
/* open alias database */
initmaps(FALSE, e);
return (0);
}
# endif /* SMTP */
/*
** HELP -- implement the HELP command.
**
** Parameters:
** topic -- the topic we want help for.
**
** Returns:
** none.
**
** Side Effects:
** outputs the help file to message output.
*/
void
help(topic)
char *topic;
{
register FILE *hf;
int len;
bool noinfo;
int sff = SFF_OPENASROOT|SFF_REGONLY;
char buf[MAXLINE];
extern char Version[];
if (DontLockReadFiles)
sff |= SFF_NOLOCK;
if (!bitset(DBS_HELPFILEINUNSAFEDIRPATH, DontBlameSendmail))
sff |= SFF_SAFEDIRPATH;
if (HelpFile == NULL ||
(hf = safefopen(HelpFile, O_RDONLY, 0444, sff)) == NULL)
{
/* no help */
errno = 0;
message("502 Sendmail %s -- HELP not implemented", Version);
return;
}
if (topic == NULL || *topic == '\0')
{
topic = "smtp";
message("214-This is Sendmail version %s", Version);
noinfo = FALSE;
}
else
{
makelower(topic);
noinfo = TRUE;
}
len = strlen(topic);
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 \"%.10s\" unknown", topic);
else
message("214 End of HELP info");
(void) fclose(hf);
}
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