[people/ms/dma.git] / local.c

/*
 * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Simon 'corecode' Schubert <corecode@fs.ei.tum.de>.
 *
 * 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. Neither the name of The DragonFly Project 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 COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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 <sys/types.h>
#include <sys/wait.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <stdint.h>
#include <stdio.h>
#include <syslog.h>
#include <unistd.h>

#include "dma.h"

static int
create_mbox(const char *name)
{
	struct sigaction sa, osa;
	pid_t child, waitchild;
	int status;
	int i;
	long maxfd;
	int e;
	int r = -1;

	/*
	 * We need to enable SIGCHLD temporarily so that waitpid works.
	 */
	bzero(&sa, sizeof(sa));
	sa.sa_handler = SIG_DFL;
	sigaction(SIGCHLD, &sa, &osa);

	do_timeout(100, 0);

	child = fork();
	switch (child) {
	case 0:
		/* child */
		maxfd = sysconf(_SC_OPEN_MAX);
		if (maxfd == -1)
			maxfd = 1024;	/* what can we do... */

		for (i = 3; i <= maxfd; ++i)
			close(i);

		execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL);
		syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m");
		exit(1);

	default:
		/* parent */
		waitchild = waitpid(child, &status, 0);

		e = errno;

		do_timeout(0, 0);

		if (waitchild == -1 && e == EINTR) {
			syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name);
			break;
		}

		if (waitchild == -1) {
			syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name);
			break;
		}

		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
			syslog(LOG_ERR, "error creating mbox `%s'", name);
			break;
		}

		/* success */
		r = 0;
		break;

	case -1:
		/* error */
		syslog(LOG_ERR, "error creating mbox");
		break;
	}

	sigaction(SIGCHLD, &osa, NULL);

	return (r);
}

int
deliver_local(struct qitem *it)
{
	char fn[PATH_MAX+1];
	char line[1000];
	const char *sender;
	const char *newline = "\n";
	size_t linelen;
	int tries = 0;
	int mbox;
	int error;
	int hadnl = 0;
	off_t mboxlen;
	time_t now = time(NULL);

	error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr);
	if (error < 0 || (size_t)error >= sizeof(fn)) {
		syslog(LOG_NOTICE, "local delivery deferred: %m");
		return (1);
	}

retry:
	/* wait for a maximum of 100s to get the lock to the file */
	do_timeout(100, 0);

	/* don't use O_CREAT here, because we might be running as the wrong user. */
	mbox = open_locked(fn, O_WRONLY|O_APPEND);
	if (mbox < 0) {
		int e = errno;

		do_timeout(0, 0);

		switch (e) {
		case EACCES:
		case ENOENT:
			/*
			 * The file does not exist or we can't access it.
			 * Call dma-mbox-create to create it and fix permissions.
			 */
			if (tries > 0 || create_mbox(it->addr) != 0) {
				syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn);
				return (1);
			}
			++tries;
			goto retry;

		case EINTR:
			syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn);
			break;

		default:
			syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn);
			break;
		}
		return (1);
	}
	do_timeout(0, 0);

	mboxlen = lseek(mbox, 0, SEEK_END);

	/* New mails start with \nFrom ...., unless we're at the beginning of the mbox */
	if (mboxlen == 0)
		newline = "";

	/* If we're bouncing a message, claim it comes from MAILER-DAEMON */
	sender = it->sender;
	if (strcmp(sender, "") == 0)
		sender = "MAILER-DAEMON";

	if (fseek(it->mailf, 0, SEEK_SET) != 0) {
		syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m");
		goto out;
	}

	error = snprintf(line, sizeof(line), "%sFrom %s\t%s", newline, sender, ctime(&now));
	if (error < 0 || (size_t)error >= sizeof(line)) {
		syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m");
		goto out;
	}
	if (write(mbox, line, error) != error)
		goto wrerror;

	while (!feof(it->mailf)) {
		if (fgets(line, sizeof(line), it->mailf) == NULL)
			break;
		linelen = strlen(line);
		if (linelen == 0 || line[linelen - 1] != '\n') {
			syslog(LOG_CRIT, "local delivery failed: corrupted queue file");
			snprintf(errmsg, sizeof(errmsg), "corrupted queue file");
			error = -1;
			goto chop;
		}

		if (hadnl && strncmp(line, "From ", 5) == 0) {
			const char *gt = ">";

			if (write(mbox, gt, 1) != 1)
				goto wrerror;
			hadnl = 0;
		} else if (strcmp(line, "\n") == 0) {
			hadnl = 1;
		} else {
			hadnl = 0;
		}
		if ((size_t)write(mbox, line, linelen) != linelen)
			goto wrerror;
	}
	close(mbox);
	return (0);

wrerror:
	syslog(LOG_ERR, "local delivery failed: write error: %m");
	error = 1;
chop:
	if (ftruncate(mbox, mboxlen) != 0)
		syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn);
out:
	close(mbox);
	return (error);
}
Commit	Line	Data
c1ebccb4 SS	1	/*
	2	* Copyright (c) 2008 The DragonFly Project. All rights reserved.
	3	*
	4	* This code is derived from software contributed to The DragonFly Project
	5	* by Simon 'corecode' Schubert <corecode@fs.ei.tum.de>.
	6	*
	7	* Redistribution and use in source and binary forms, with or without
	8	* modification, are permitted provided that the following conditions
	9	* are met:
	10	*
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in
	15	* the documentation and/or other materials provided with the
	16	* distribution.
	17	* 3. Neither the name of The DragonFly Project nor the names of its
	18	* contributors may be used to endorse or promote products derived
	19	* from this software without specific, prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	22	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	23	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	24	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	25	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	26	* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
	27	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	28	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	29	* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	30	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	31	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	* SUCH DAMAGE.
	33	*/
	34
	35	#include <sys/types.h>
	36	#include <sys/wait.h>
	37
fd1de51a SS	38	#include <err.h>
	39	#include <errno.h>
	40	#include <fcntl.h>
c1ebccb4	41	#include <limits.h>
fd1de51a SS	42	#include <paths.h>
	43	#include <stdint.h>
	44	#include <stdio.h>
	45	#include <syslog.h>
	46	#include <unistd.h>
	47
	48	#include "dma.h"
	49
c1ebccb4 SS	50	static int
	51	create_mbox(const char *name)
	52	{
	53	struct sigaction sa, osa;
	54	pid_t child, waitchild;
	55	int status;
	56	int i;
	57	long maxfd;
	58	int e;
	59	int r = -1;
	60
	61	/*
	62	* We need to enable SIGCHLD temporarily so that waitpid works.
	63	*/
	64	bzero(&sa, sizeof(sa));
	65	sa.sa_handler = SIG_DFL;
	66	sigaction(SIGCHLD, &sa, &osa);
	67
	68	do_timeout(100, 0);
	69
	70	child = fork();
	71	switch (child) {
	72	case 0:
	73	/* child */
	74	maxfd = sysconf(_SC_OPEN_MAX);
	75	if (maxfd == -1)
	76	maxfd = 1024; /* what can we do... */
	77
	78	for (i = 3; i <= maxfd; ++i)
	79	close(i);
	80
	81	execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL);
	82	syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m");
	83	exit(1);
	84
	85	default:
	86	/* parent */
	87	waitchild = waitpid(child, &status, 0);
	88
	89	e = errno;
	90
	91	do_timeout(0, 0);
	92
	93	if (waitchild == -1 && e == EINTR) {
	94	syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name);
	95	break;
	96	}
	97
	98	if (waitchild == -1) {
	99	syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name);
	100	break;
	101	}
	102
	103	if (!WIFEXITED(status) \|\| WEXITSTATUS(status) != 0) {
	104	syslog(LOG_ERR, "error creating mbox `%s'", name);
	105	break;
	106	}
	107
	108	/* success */
	109	r = 0;
	110	break;
	111
	112	case -1:
	113	/* error */
114	syslog(LOG_ERR, "error creating mbox");
115	break;
116	}
117
118	sigaction(SIGCHLD, &osa, NULL);
119
120	return (r);
121	}
122
fd1de51a	123	int
249ee966	124	deliver_local(struct qitem *it)
fd1de51a SS	125	{
	126	char fn[PATH_MAX+1];
	127	char line[1000];
5a96b98a SS	128	const char *sender;
5a96b98a SS	129	const char *newline = "\n";
fd1de51a	130	size_t linelen;
c1ebccb4	131	int tries = 0;
fd1de51a SS	132	int mbox;
fd1de51a SS	133	int error;
5a96b98a	134	int hadnl = 0;
fd1de51a SS	135	off_t mboxlen;
	136	time_t now = time(NULL);
	137
	138	error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr);
	139	if (error < 0 \|\| (size_t)error >= sizeof(fn)) {
4d5af2b0	140	syslog(LOG_NOTICE, "local delivery deferred: %m");
fd1de51a SS	141	return (1);
	142	}
	143
c1ebccb4	144	retry:
f54b5114 SS	145	/* wait for a maximum of 100s to get the lock to the file */
	146	do_timeout(100, 0);
	147
c1ebccb4 SS	148	/* don't use O_CREAT here, because we might be running as the wrong user. */
c1ebccb4 SS	149	mbox = open_locked(fn, O_WRONLY\|O_APPEND);
fd1de51a	150	if (mbox < 0) {
f54b5114 SS	151	int e = errno;
	152
	153	do_timeout(0, 0);
c1ebccb4 SS	154
	155	switch (e) {
	156	case EACCES:
	157	case ENOENT:
	158	/*
	159	* The file does not exist or we can't access it.
	160	* Call dma-mbox-create to create it and fix permissions.
	161	*/
	162	if (tries > 0 \|\| create_mbox(it->addr) != 0) {
	163	syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn);
	164	return (1);
	165	}
	166	++tries;
	167	goto retry;
	168
	169	case EINTR:
f54b5114	170	syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn);
c1ebccb4 SS	171	break;
	172
	173	default:
f54b5114	174	syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn);
c1ebccb4 SS	175	break;
c1ebccb4 SS	176	}
fd1de51a SS	177	return (1);
fd1de51a SS	178	}
f54b5114 SS	179	do_timeout(0, 0);
f54b5114 SS	180
5a96b98a SS	181	mboxlen = lseek(mbox, 0, SEEK_END);
	182
	183	/* New mails start with \nFrom ...., unless we're at the beginning of the mbox */
	184	if (mboxlen == 0)
	185	newline = "";
	186
	187	/* If we're bouncing a message, claim it comes from MAILER-DAEMON */
	188	sender = it->sender;
	189	if (strcmp(sender, "") == 0)
	190	sender = "MAILER-DAEMON";
fd1de51a	191
6ddd63e1	192	if (fseek(it->mailf, 0, SEEK_SET) != 0) {
4d5af2b0	193	syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m");
f54b5114	194	goto out;
fd1de51a SS	195	}
fd1de51a SS	196
5a96b98a	197	error = snprintf(line, sizeof(line), "%sFrom %s\t%s", newline, sender, ctime(&now));
fd1de51a	198	if (error < 0 \|\| (size_t)error >= sizeof(line)) {
4d5af2b0	199	syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m");
f54b5114	200	goto out;
fd1de51a SS	201	}
	202	if (write(mbox, line, error) != error)
	203	goto wrerror;
	204
	205	while (!feof(it->mailf)) {
	206	if (fgets(line, sizeof(line), it->mailf) == NULL)
	207	break;
	208	linelen = strlen(line);
	209	if (linelen == 0 \|\| line[linelen - 1] != '\n') {
4d5af2b0	210	syslog(LOG_CRIT, "local delivery failed: corrupted queue file");
249ee966	211	snprintf(errmsg, sizeof(errmsg), "corrupted queue file");
fd1de51a SS	212	error = -1;
	213	goto chop;
	214	}
	215
5a96b98a	216	if (hadnl && strncmp(line, "From ", 5) == 0) {
fd1de51a SS	217	const char *gt = ">";
	218
	219	if (write(mbox, gt, 1) != 1)
	220	goto wrerror;
5a96b98a SS	221	hadnl = 0;
	222	} else if (strcmp(line, "\n") == 0) {
	223	hadnl = 1;
	224	} else {
	225	hadnl = 0;
fd1de51a SS	226	}
	227	if ((size_t)write(mbox, line, linelen) != linelen)
	228	goto wrerror;
	229	}
fd1de51a SS	230	close(mbox);
	231	return (0);
	232
	233	wrerror:
4d5af2b0	234	syslog(LOG_ERR, "local delivery failed: write error: %m");
fd1de51a SS	235	error = 1;
	236	chop:
	237	if (ftruncate(mbox, mboxlen) != 0)
4d5af2b0	238	syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn);
f54b5114	239	out:
fd1de51a SS	240	close(mbox);
	241	return (error);
	242	}