2.11BSD/src/usr.sbin/sendmail.MX/src/srvrsmtp.c
/*
* Copyright (c) 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of California at Berkeley. The name of the University
* may not be used to endorse or promote products derived from this
* software without specific prior written permission. This software
* is provided ``as is'' without express or implied warranty.
*
* Sendmail
* Copyright (c) 1983 Eric P. Allman
* Berkeley, California
*/
# include "sendmail.h"
#if !defined(lint) && !defined(NOSCCS)
#ifdef SMTP
static char sccsid[] = "@(#)srvrsmtp.c 5.21.1 (2.11BSD) 1997/10/3 (with SMTP)";
#else
static char sccsid[] = "@(#)srvrsmtp.c 5.21 (2.11BSD) 1997/10/3 (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 CMDHELP 6 /* help -- give usage info */
# define CMDNOOP 7 /* noop -- do nothing */
# define CMDQUIT 8 /* quit -- close connection and die */
# define CMDHELO 9 /* helo -- be polite */
# define CMDDBGQSHOW 10 /* showq -- show send queue (DEBUG) */
# define CMDDBGDEBUG 11 /* debug -- set debug mode */
# define CMDVERB 12 /* verb -- go into verbose mode */
# define CMDDBGKILL 13 /* kill -- kill sendmail */
# define CMDDBGWIZ 14 /* wiz -- become a wizard */
# define CMDONEX 15 /* onex -- sending one transaction only */
static struct cmd CmdTab[] =
{
"mail", CMDMAIL,
"rcpt", CMDRCPT,
"data", CMDDATA,
"rset", CMDRSET,
"vrfy", CMDVRFY,
"expn", CMDVRFY,
"help", CMDHELP,
"noop", CMDNOOP,
"quit", CMDQUIT,
"helo", CMDHELO,
"verb", CMDVERB,
"onex", CMDONEX,
# ifdef DEBUG
"showq", CMDDBGQSHOW,
# ifdef notdef
"debug", CMDDBGDEBUG,
# endif notdef
# endif DEBUG
# ifdef WIZ
"kill", CMDDBGKILL,
# endif WIZ
"wiz", CMDDBGWIZ,
NULL, CMDERROR,
};
# ifdef WIZ
bool IsWiz = FALSE; /* set if we are a wizard */
# endif WIZ
char *WizWord; /* the wizard word to compare against */
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()
{
register char *p;
register struct cmd *c;
char *cmd;
extern char *skipword();
bool hasmail; /* mail command received */
auto ADDRESS *vrfyqueue;
ADDRESS *a;
char *sendinghost;
char inp[MAXLINE];
char cmdbuf[100];
extern tick();
extern bool iswiz();
extern char *arpadate();
extern char *macvalue();
extern ADDRESS *recipient();
extern ENVELOPE BlankEnvelope;
extern ENVELOPE *newenvelope();
hasmail = FALSE;
if (OutChannel != stdout)
{
/* arrange for debugging output to go to remote host */
(void) close(1);
(void) dup(fileno(OutChannel));
}
settime();
if (RealHostName != NULL)
{
CurHostName = RealHostName;
setproctitle("srvrsmtp %s", CurHostName);
}
else
{
/* this must be us!! */
CurHostName = MyHostName;
}
expand("\001e", inp, &inp[sizeof inp], CurEnv);
message("220", inp);
SmtpPhase = "startup";
sendinghost = NULL;
for (;;)
{
/* arrange for backout */
if (setjmp(TopFrame) > 0 && InChild)
finis();
QuickAbort = FALSE;
HoldErrs = FALSE;
/* setup for the read */
CurEnv->e_to = NULL;
Errors = 0;
(void) fflush(stdout);
/* read the input line */
p = sfgets(inp, sizeof inp, InChannel);
/* handle errors */
if (p == NULL)
{
/* end of file, just die */
message("421", "%s Lost input channel to %s",
MyHostName, CurHostName);
finis();
}
/* clean up end of line */
fixcrlf(inp, TRUE);
/* echo command to transcript */
if (CurEnv->e_xfp != NULL)
fprintf(CurEnv->e_xfp, "<<< %s\n", inp);
/* break off command */
for (p = inp; isspace(*p); p++)
continue;
cmd = p;
for (cmd = cmdbuf; *p != '\0' && !isspace(*p); )
*cmd++ = *p++;
*cmd = '\0';
/* throw away leading whitespace */
while (isspace(*p))
p++;
/* decode command */
for (c = CmdTab; c->cmdname != NULL; c++)
{
if (!strcasecmp(c->cmdname, cmdbuf))
break;
}
/* process command */
switch (c->cmdcode)
{
case CMDHELO: /* hello -- introduce yourself */
SmtpPhase = "HELO";
setproctitle("%s: %s", CurHostName, inp);
if (!strcasecmp(p, MyHostName))
{
/* connected to an echo server */
message("553", "%s I refuse to talk to myself",
MyHostName);
break;
}
if (RealHostName != NULL && strcasecmp(p, RealHostName))
{
char hostbuf[MAXNAME];
(void) sprintf(hostbuf, "%s (%s)", p, RealHostName);
sendinghost = newstr(hostbuf);
}
else
sendinghost = newstr(p);
message("250", "%s Hello %s, pleased to meet you",
MyHostName, p);
break;
case CMDMAIL: /* mail -- designate sender */
SmtpPhase = "MAIL";
/* force a sending host even if no HELO given */
if (RealHostName != NULL && macvalue('s', CurEnv) == NULL)
sendinghost = RealHostName;
/* check for validity of this command */
if (hasmail)
{
message("503", "Sender already specified");
break;
}
if (InChild)
{
syserr("Nested MAIL command");
exit(0);
}
/* fork a subprocess to process this command */
if (runinchild("SMTP-MAIL") > 0)
break;
define('s', sendinghost, CurEnv);
initsys();
setproctitle("%s %s: %s", CurEnv->e_id,
CurHostName, inp);
/* child -- go do the processing */
p = skipword(p, "from");
if (p == NULL)
break;
setsender(p);
if (Errors == 0)
{
message("250", "Sender ok");
hasmail = TRUE;
}
else if (InChild)
finis();
break;
case CMDRCPT: /* rcpt -- designate recipient */
SmtpPhase = "RCPT";
setproctitle("%s %s: %s", CurEnv->e_id,
CurHostName, inp);
if (setjmp(TopFrame) > 0)
{
CurEnv->e_flags &= ~EF_FATALERRS;
break;
}
QuickAbort = TRUE;
p = skipword(p, "to");
if (p == NULL)
break;
a = parseaddr(p, (ADDRESS *) NULL, 1, '\0');
if (a == NULL)
break;
a->q_flags |= QPRIMARY;
a = recipient(a, &CurEnv->e_sendqueue);
if (Errors != 0)
break;
/* no errors during parsing, but might be a duplicate */
CurEnv->e_to = p;
if (!bitset(QBADADDR, a->q_flags))
message("250", "Recipient ok");
else
{
/* punt -- should keep message in ADDRESS.... */
message("550", "Addressee unknown");
}
CurEnv->e_to = NULL;
break;
case CMDDATA: /* data -- text of mail */
SmtpPhase = "DATA";
if (!hasmail)
{
message("503", "Need MAIL command");
break;
}
else if (CurEnv->e_nrcpts <= 0)
{
message("503", "Need RCPT (recipient)");
break;
}
/* collect the text of the message */
SmtpPhase = "collect";
setproctitle("%s %s: %s", CurEnv->e_id,
CurHostName, inp);
collect(TRUE);
if (Errors != 0)
break;
/*
** 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 (CurEnv->e_nrcpts != 1)
{
HoldErrs = TRUE;
ErrorMode = EM_MAIL;
}
CurEnv->e_flags &= ~EF_FATALERRS;
CurEnv->e_xfp = freopen(queuename(CurEnv, 'x'), "w", CurEnv->e_xfp);
/* send to all recipients */
sendall(CurEnv, SM_DEFAULT);
CurEnv->e_to = NULL;
/* save statistics */
markstats(CurEnv, (ADDRESS *) NULL);
/* issue success if appropriate and reset */
if (Errors == 0 || HoldErrs)
message("250", "Ok");
else
CurEnv->e_flags &= ~EF_FATALERRS;
/* if in a child, pop back to our parent */
if (InChild)
finis();
/* clean up a bit */
hasmail = 0;
dropenvelope(CurEnv);
CurEnv = newenvelope(CurEnv);
CurEnv->e_flags = BlankEnvelope.e_flags;
break;
case CMDRSET: /* rset -- reset state */
message("250", "Reset state");
if (InChild)
finis();
break;
case CMDVRFY: /* vrfy -- verify address */
if (runinchild("SMTP-VRFY") > 0)
break;
setproctitle("%s: %s", CurHostName, inp);
vrfyqueue = NULL;
QuickAbort = TRUE;
sendtolist(p, (ADDRESS *) NULL, &vrfyqueue);
if (Errors != 0)
{
if (InChild)
finis();
break;
}
while (vrfyqueue != NULL)
{
register ADDRESS *a = vrfyqueue->q_next;
char *code;
while (a != NULL && bitset(QDONTSEND|QBADADDR, a->q_flags))
a = a->q_next;
if (!bitset(QDONTSEND|QBADADDR, vrfyqueue->q_flags))
{
if (a != NULL)
code = "250-";
else
code = "250";
if (vrfyqueue->q_fullname == NULL)
message(code, "<%s>", vrfyqueue->q_paddr);
else
message(code, "%s <%s>",
vrfyqueue->q_fullname, vrfyqueue->q_paddr);
}
else if (a == NULL)
message("554", "Self destructive alias loop");
vrfyqueue = a;
}
if (InChild)
finis();
break;
case CMDHELP: /* help -- give user info */
if (*p == '\0')
p = "SMTP";
help(p);
break;
case CMDNOOP: /* noop -- do nothing */
message("200", "OK");
break;
case CMDQUIT: /* quit -- leave mail */
message("221", "%s closing connection", MyHostName);
if (InChild)
ExitStat = EX_QUIT;
finis();
case CMDVERB: /* set verbose mode */
Verbose = TRUE;
SendMode = SM_DELIVER;
message("200", "Verbose mode");
break;
case CMDONEX: /* doing one transaction only */
OneXact = TRUE;
message("200", "Only one transaction");
break;
# ifdef DEBUG
case CMDDBGQSHOW: /* show queues */
printf("Send Queue=");
printaddr(CurEnv->e_sendqueue, TRUE);
break;
case CMDDBGDEBUG: /* set debug mode */
tTsetup(tTdvect, sizeof tTdvect, "0-99.1");
tTflag(p);
message("200", "Debug set");
break;
# endif DEBUG
# ifdef WIZ
case CMDDBGKILL: /* kill the parent */
if (!iswiz())
break;
if (kill(MotherPid, SIGTERM) >= 0)
message("200", "Mother is dead");
else
message("500", "Can't kill Mom");
break;
case CMDDBGWIZ: /* become a wizard */
if (WizWord != NULL)
{
char seed[3];
extern char *crypt();
(void) strncpy(seed, WizWord, 2);
if (strcmp(WizWord, crypt(p, seed)) == 0)
{
IsWiz = TRUE;
message("200", "Please pass, oh mighty wizard");
break;
}
}
message("500", "You are no wizard!");
break;
# else WIZ
case CMDDBGWIZ: /* try to become a wizard */
message("500", "You wascal wabbit! Wandering wizards won't win!");
break;
# endif WIZ
case CMDERROR: /* unknown command */
message("500", "Command unrecognized");
break;
default:
syserr("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 (isspace(*p))
p++;
q = p;
/* find end of word */
while (*p != '\0' && *p != ':' && !isspace(*p))
p++;
while (isspace(*p))
*p++ = '\0';
if (*p != ':')
{
syntax:
message("501", "Syntax error");
Errors++;
return (NULL);
}
*p++ = '\0';
while (isspace(*p))
p++;
/* see if the input word matches desired word */
if (strcasecmp(q, w))
goto syntax;
return (p);
}
/*
** 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;
}
len = strlen(topic);
makelower(topic);
noinfo = TRUE;
while (fgets(buf, sizeof buf, hf) != NULL)
{
if (strncmp(buf, topic, len) == 0)
{
register char *p;
p = index(buf, '\t');
if (p == NULL)
p = buf;
else
p++;
fixcrlf(p, TRUE);
message("214-", p);
noinfo = FALSE;
}
}
if (noinfo)
message("504", "HELP topic unknown");
else
message("214", "End of HELP info");
(void) fclose(hf);
}
/*
** ISWIZ -- tell us if we are a wizard
**
** If not, print a nasty message.
**
** Parameters:
** none.
**
** Returns:
** TRUE if we are a wizard.
** FALSE if we are not a wizard.
**
** Side Effects:
** Prints a 500 exit stat if we are not a wizard.
*/
#ifdef WIZ
bool
iswiz()
{
if (!IsWiz)
message("500", "Mere mortals musn't mutter that mantra");
return (IsWiz);
}
#endif WIZ
/*
** 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)
char *label;
{
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 */
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(CurEnv, FALSE);
}
}
/* open alias database */
initaliases(AliasFile, FALSE);
return (0);
}
# endif SMTP