deliver.c

早期freebsd实现

	ADDRESS *ctladdr;
	register MCI *mci;
	register ADDRESS *to = firstto;
	bool clever = FALSE;		/* running user smtp to this mailer */
	ADDRESS *tochain = NULL;	/* chain of users in this mailer call */
	int rcode;			/* response code */
	char *firstsig;			/* signature of firstto */
	int pid;
	char *curhost;
	int mpvect[2];
	int rpvect[2];
	char *pv[MAXPV+1];
	char tobuf[TOBUFSIZE];		/* text line of to people */
	char buf[MAXNAME];
	char rpathbuf[MAXNAME];		/* translated return path */
	extern int checkcompat();

	errno = 0;
	if (bitset(QDONTSEND|QBADADDR|QQUEUEUP, to->q_flags))
		return (0);

#if NAMED_BIND
	/* unless interactive, try twice, over a minute */
	if (OpMode == MD_DAEMON || OpMode == MD_SMTP)
	{
		_res.retrans = 30;
		_res.retry = 2;
	}
#endif 

	m = to->q_mailer;
	host = to->q_host;
	CurEnv = e;			/* just in case */
	e->e_statmsg = NULL;
	SmtpError[0] = '\0';

	if (tTd(10, 1))
		printf("\n--deliver, id=%s, mailer=%s, host=`%s', first user=`%s'\n",
			e->e_id, m->m_name, host, to->q_user);
	if (tTd(10, 100))
		printopenfds(FALSE);

	/*
	**  If this mailer is expensive, and if we don't want to make
	**  connections now, just mark these addresses and return.
	**	This is useful if we want to batch connections to
	**	reduce load.  This will cause the messages to be
	**	queued up, and a daemon will come along to send the
	**	messages later.
	**		This should be on a per-mailer basis.
	*/

	if (NoConnect && bitnset(M_EXPENSIVE, m->m_flags) && !Verbose)
	{
		for (; to != NULL; to = to->q_next)
		{
			if (bitset(QDONTSEND|QBADADDR|QQUEUEUP, to->q_flags) ||
			    to->q_mailer != m)
				continue;
			to->q_flags |= QQUEUEUP;
			e->e_to = to->q_paddr;
			message("queued");
			if (LogLevel > 8)
				logdelivery(m, NULL, "queued", NULL, e);
		}
		e->e_to = NULL;
		return (0);
	}

	/*
	**  Do initial argv setup.
	**	Insert the mailer name.  Notice that $x expansion is
	**	NOT done on the mailer name.  Then, if the mailer has
	**	a picky -f flag, we insert it as appropriate.  This
	**	code does not check for 'pv' overflow; this places a
	**	manifest lower limit of 4 for MAXPV.
	**		The from address rewrite is expected to make
	**		the address relative to the other end.
	*/

	/* rewrite from address, using rewriting rules */
	rcode = EX_OK;
	(void) strcpy(rpathbuf, remotename(e->e_from.q_paddr, m,
					   RF_SENDERADDR|RF_CANONICAL,
					   &rcode, e));
	define('g', rpathbuf, e);		/* translated return path */
	define('h', host, e);			/* to host */
	Errors = 0;
	pvp = pv;
	*pvp++ = m->m_argv[0];

	/* insert -f or -r flag as appropriate */
	if (FromFlag && (bitnset(M_FOPT, m->m_flags) || bitnset(M_ROPT, m->m_flags)))
	{
		if (bitnset(M_FOPT, m->m_flags))
			*pvp++ = "-f";
		else
			*pvp++ = "-r";
		*pvp++ = newstr(rpathbuf);
	}

	/*
	**  Append the other fixed parts of the argv.  These run
	**  up to the first entry containing "$u".  There can only
	**  be one of these, and there are only a few more slots
	**  in the pv after it.
	*/

	for (mvp = m->m_argv; (p = *++mvp) != NULL; )
	{
		/* can't use strchr here because of sign extension problems */
		while (*p != '\0')
		{
			if ((*p++ & 0377) == MACROEXPAND)
			{
				if (*p == 'u')
					break;
			}
		}

		if (*p != '\0')
			break;

		/* this entry is safe -- go ahead and process it */
		expand(*mvp, buf, &buf[sizeof buf - 1], e);
		*pvp++ = newstr(buf);
		if (pvp >= &pv[MAXPV - 3])
		{
			syserr("554 Too many parameters to %s before $u", pv[0]);
			return (-1);
		}
	}

	/*
	**  If we have no substitution for the user name in the argument
	**  list, we know that we must supply the names otherwise -- and
	**  SMTP is the answer!!
	*/

	if (*mvp == NULL)
	{
		/* running SMTP */
# ifdef SMTP
		clever = TRUE;
		*pvp = NULL;
# else /* SMTP */
		/* oops!  we don't implement SMTP */
		syserr("554 SMTP style mailer not implemented");
		return (EX_SOFTWARE);
# endif /* SMTP */
	}

	/*
	**  At this point *mvp points to the argument with $u.  We
	**  run through our address list and append all the addresses
	**  we can.  If we run out of space, do not fret!  We can
	**  always send another copy later.
	*/

	tobuf[0] = '\0';
	e->e_to = tobuf;
	ctladdr = NULL;
	firstsig = hostsignature(firstto->q_mailer, firstto->q_host, e);
	for (; to != NULL; to = to->q_next)
	{
		/* avoid sending multiple recipients to dumb mailers */
		if (tobuf[0] != '\0' && !bitnset(M_MUSER, m->m_flags))
			break;

		/* if already sent or not for this host, don't send */
		if (bitset(QDONTSEND|QBADADDR|QQUEUEUP, to->q_flags) ||
		    to->q_mailer != firstto->q_mailer ||
		    strcmp(hostsignature(to->q_mailer, to->q_host, e), firstsig) != 0)
			continue;

		/* avoid overflowing tobuf */
		if (sizeof tobuf < (strlen(to->q_paddr) + strlen(tobuf) + 2))
			break;

		if (tTd(10, 1))
		{
			printf("\nsend to ");
			printaddr(to, FALSE);
		}

		/* compute effective uid/gid when sending */
		/* XXX perhaps this should be to->q_mailer != LocalMailer ?? */
		/* XXX perhaps it should be a mailer flag? */
		if (to->q_mailer == ProgMailer || to->q_mailer == FileMailer)
			ctladdr = getctladdr(to);

		user = to->q_user;
		e->e_to = to->q_paddr;
		if (tTd(10, 5))
		{
			printf("deliver: QDONTSEND ");
			printaddr(to, FALSE);
		}
		to->q_flags |= QDONTSEND;

		/*
		**  Check to see that these people are allowed to
		**  talk to each other.
		*/

		if (m->m_maxsize != 0 && e->e_msgsize > m->m_maxsize)
		{
			NoReturn = TRUE;
			usrerr("552 Message is too large; %ld bytes max", m->m_maxsize);
			giveresponse(EX_UNAVAILABLE, m, NULL, ctladdr, e);
			continue;
		}
		rcode = checkcompat(to, e);
		if (rcode != EX_OK)
		{
			markfailure(e, to, rcode);
			giveresponse(rcode, m, NULL, ctladdr, e);
			continue;
		}

		/*
		**  Strip quote bits from names if the mailer is dumb
		**	about them.
		*/

		if (bitnset(M_STRIPQ, m->m_flags))
		{
			stripquotes(user);
			stripquotes(host);
		}

		/* hack attack -- delivermail compatibility */
		if (m == ProgMailer && *user == '|')
			user++;

		/*
		**  If an error message has already been given, don't
		**	bother to send to this address.
		**
		**	>>>>>>>>>> This clause assumes that the local mailer
		**	>> NOTE >> cannot do any further aliasing; that
		**	>>>>>>>>>> function is subsumed by sendmail.
		*/

		if (bitset(QBADADDR|QQUEUEUP, to->q_flags))
			continue;

		/* save statistics.... */
		markstats(e, to);

		/*
		**  See if this user name is "special".
		**	If the user name has a slash in it, assume that this
		**	is a file -- send it off without further ado.  Note
		**	that this type of addresses is not processed along
		**	with the others, so we fudge on the To person.
		*/

		if (m == FileMailer)
		{
			rcode = mailfile(user, ctladdr, e);
			giveresponse(rcode, m, NULL, ctladdr, e);
			if (rcode == EX_OK)
				to->q_flags |= QSENT;
			continue;
		}

		/*
		**  Address is verified -- add this user to mailer
		**  argv, and add it to the print list of recipients.
		*/

		/* link together the chain of recipients */
		to->q_tchain = tochain;
		tochain = to;

		/* create list of users for error messages */
		(void) strcat(tobuf, ",");
		(void) strcat(tobuf, to->q_paddr);
		define('u', user, e);		/* to user */
		p = to->q_home;
		if (p == NULL && ctladdr != NULL)
			p = ctladdr->q_home;
		define('z', p, e);	/* user's home */

		/*
		**  Expand out this user into argument list.
		*/

		if (!clever)
		{
			expand(*mvp, buf, &buf[sizeof buf - 1], e);
			*pvp++ = newstr(buf);
			if (pvp >= &pv[MAXPV - 2])
			{
				/* allow some space for trailing parms */
				break;
			}
		}
	}

	/* see if any addresses still exist */
	if (tobuf[0] == '\0')
	{
		define('g', (char *) NULL, e);
		return (0);
	}

	/* print out messages as full list */
	e->e_to = tobuf + 1;

	/*
	**  Fill out any parameters after the $u parameter.
	*/

	while (!clever && *++mvp != NULL)
	{
		expand(*mvp, buf, &buf[sizeof buf - 1], e);
		*pvp++ = newstr(buf);
		if (pvp >= &pv[MAXPV])
			syserr("554 deliver: pv overflow after $u for %s", pv[0]);
	}
	*pvp++ = NULL;

	/*
	**  Call the mailer.
	**	The argument vector gets built, pipes
	**	are created as necessary, and we fork & exec as
	**	appropriate.
	**	If we are running SMTP, we just need to clean up.
	*/

	/*XXX this seems a bit wierd */
	if (ctladdr == NULL && m != ProgMailer &&
	    bitset(QGOODUID, e->e_from.q_flags))
		ctladdr = &e->e_from;

#if NAMED_BIND
	if (ConfigLevel < 2)
		_res.options &= ~(RES_DEFNAMES | RES_DNSRCH);	/* XXX */
#endif

	if (tTd(11, 1))
	{
		printf("openmailer:");
		printav(pv);
	}
	errno = 0;

	CurHostName = m->m_mailer;

	/*
	**  Deal with the special case of mail handled through an IPC
	**  connection.
	**	In this case we don't actually fork.  We must be
	**	running SMTP for this to work.  We will return a
	**	zero pid to indicate that we are running IPC.
	**  We also handle a debug version that just talks to stdin/out.
	*/

	curhost = NULL;
	SmtpPhase = NULL;
	mci = NULL;

#ifdef XDEBUG
	{
		char wbuf[MAXLINE];

		/* make absolutely certain 0, 1, and 2 are in use */
		sprintf(wbuf, "%s... openmailer(%s)", e->e_to, m->m_name);
		checkfd012(wbuf);
	}
#endif

	/* check for Local Person Communication -- not for mortals!!! */
	if (strcmp(m->m_mailer, "[LPC]") == 0)
	{
		mci = (MCI *) xalloc(sizeof *mci);
		bzero((char *) mci, sizeof *mci);
		mci->mci_in = stdin;
		mci->mci_out = stdout;
		mci->mci_state = clever ? MCIS_OPENING : MCIS_OPEN;
		mci->mci_mailer = m;
	}
	else if (strcmp(m->m_mailer, "[IPC]") == 0 ||
		 strcmp(m->m_mailer, "[TCP]") == 0)
	{
#ifdef DAEMON
		register int i;
		register u_short port;

		if (pv[0] == NULL || pv[1] == NULL || pv[1][0] == '\0')
		{
			syserr("null host name for %s mailer", m->m_mailer);
			rcode = EX_CONFIG;
			goto give_up;
		}

		CurHostName = pv[1];
		curhost = hostsignature(m, pv[1], e);

		if (curhost == NULL || curhost[0] == '\0')
		{
			syserr("null host signature for %s", pv[1]);
			rcode = EX_OSERR;
			goto give_up;
		}

		if (!clever)
		{
			syserr("554 non-clever IPC");
			rcode = EX_CONFIG;
			goto give_up;
		}
		if (pv[2] != NULL)
			port = atoi(pv[2]);
		else
			port = 0;
tryhost:
		while (*curhost != '\0')
		{
			register char *p;
			static char hostbuf[MAXNAME];

			/* pull the next host from the signature */
			p = strchr(curhost, ':');
			if (p == NULL)
				p = &curhost[strlen(curhost)];
			if (p == curhost)
			{
				syserr("deliver: null host name in signature");
				curhost++;
				continue;
			}
			strncpy(hostbuf, curhost, p - curhost);
			hostbuf[p - curhost] = '\0';
			if (*p != '\0')
				p++;
			curhost = p;

			/* see if we already know that this host is fried */
			CurHostName = hostbuf;
			mci = mci_get(hostbuf, m);
			if (mci->mci_state != MCIS_CLOSED)
			{
				if (tTd(11, 1))
				{
					printf("openmailer: ");
					mci_dump(mci, FALSE);
				}
				CurHostName = mci->mci_host;
				break;
			}
			mci->mci_mailer = m;
			if (mci->mci_exitstat != EX_OK)
				continue;

			/* try the connection */
			setproctitle("%s %s: %s", e->e_id, hostbuf, "user open");
			message("Connecting to %s (%s)...",
				hostbuf, m->m_name);
			i = makeconnection(hostbuf, port, mci,
				bitnset(M_SECURE_PORT, m->m_flags));
			mci->mci_exitstat = i;
			mci->mci_errno = errno;
#if NAMED_BIND
			mci->mci_herrno = h_errno;
#endif
			if (i == EX_OK)
			{
				mci->mci_state = MCIS_OPENING;
				mci_cache(mci);
				if (TrafficLogFile != NULL)
					fprintf(TrafficLogFile, "%05d == CONNECT %s\n",
						getpid(), hostbuf);
				break;
			}
			else if (tTd(11, 1))
				printf("openmailer: makeconnection => stat=%d, errno=%d\n",
					i, errno);

			/* enter status of this host */
			setstat(i);

			/* should print some message here for -v mode */
		}
		if (mci == NULL)
		{
			syserr("deliver: no host name");
			rcode = EX_OSERR;
			goto give_up;
		}
		mci->mci_pid = 0;
#else /* no DAEMON */
		syserr("554 openmailer: no IPC");
		if (tTd(11, 1))
			printf("openmailer: NULL\n");
		rcode = EX_UNAVAILABLE;
		goto give_up;
#endif /* DAEMON */
	}
	else
	{
		if (TrafficLogFile != NULL)
		{
			char **av;

			fprintf(TrafficLogFile, "%05d === EXEC", getpid());
			for (av = pv; *av != NULL; av++)
				fprintf(TrafficLogFile, " %s", *av);
			fprintf(TrafficLogFile, "\n");
		}

		/* create a pipe to shove the mail through */
		if (pipe(mpvect) < 0)
		{
			syserr("%s... openmailer(%s): pipe (to mailer)",
				e->e_to, m->m_name);
			if (tTd(11, 1))
				printf("openmailer: NULL\n");
			rcode = EX_OSERR;
			goto give_up;
		}

		/* if this mailer speaks smtp, create a return pipe */
		if (clever && pipe(rpvect) < 0)
		{
			syserr("%s... openmailer(%s): pipe (from mailer)",
				e->e_to, m->m_name);
			(void) close(mpvect[0]);
			(void) close(mpvect[1]);
			if (tTd(11, 1))
				printf("openmailer: NULL\n");
			rcode = EX_OSERR;
			goto give_up;
		}

		/*
		**  Actually fork the mailer process.
		**	DOFORK is clever about retrying.
		**
		**	Dispose of SIGCHLD signal catchers that may be laying
		**	around so that endmail will get it.
		*/

		if (e->e_xfp != NULL)
			(void) fflush(e->e_xfp);		/* for debugging */
		(void) fflush(stdout);
# ifdef SIGCHLD
		(void) setsignal(SIGCHLD, SIG_DFL);
# endif /* SIGCHLD */
		DOFORK(FORK);
		/* pid is set by DOFORK */
		if (pid < 0)
		{
			/* failure */
			syserr("%s... openmailer(%s): cannot fork",
				e->e_to, m->m_name);
			(void) close(mpvect[0]);
			(void) close(mpvect[1]);
			if (clever)
			{
				(void) close(rpvect[0]);
				(void) close(rpvect[1]);
			}
			if (tTd(11, 1))
				printf("openmailer: NULL\n");
			rcode = EX_OSERR;
			goto give_up;
		}
		else if (pid == 0)
		{
			int i;
			int saveerrno;
			char **ep;
			char *env[MAXUSERENVIRON];
			extern char **environ;
			extern int DtableSize;

			/* child -- set up input & exec mailer */
			(void) setsignal(SIGINT, SIG_IGN);
			(void) setsignal(SIGHUP, SIG_IGN);
			(void) setsignal(SIGTERM, SIG_DFL);

			/* reset user and group */
			if (!bitnset(M_RESTR, m->m_flags))
			{
				if (ctladdr == NULL || ctladdr->q_uid == 0)
				{
					(void) initgroups(DefUser, DefGid);
					(void) setgid(DefGid);
					(void) setuid(DefUid);
				}
				else
				{
					(void) initgroups(ctladdr->q_ruser?
						ctladdr->q_ruser: ctladdr->q_user,
						ctladdr->q_gid);
					(void) setgid(ctladdr->q_gid);
					(void) setuid(ctladdr->q_uid);
				}
			}