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

/*
 * Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>.
 * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Simon Schubert <2@0x2c.org>.
 *
 * 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 <signal.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(EX_SOFTWARE);

	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 %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;
		}

		/*
		 * mboxro processing:
		 * - escape lines that start with "From " with a > sign.
		 * - be reversable by escaping lines that contain an arbitrary
		 *   number of > signs, followed by "From ", i.e. />*From / in regexp.
		 * - strict mbox processing only requires escaping after empty lines,
		 *   yet most MUAs seem to relax this requirement and will treat any
		 *   line starting with "From " as the beginning of a new mail.
		 */
		if ((!MBOX_STRICT || hadnl) &&
		    strncmp(&line[strspn(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	1	/*
e458e5f0	2	* Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>.
c1ebccb4 SS	3	* Copyright (c) 2008 The DragonFly Project. All rights reserved.
	4	*
	5	* This code is derived from software contributed to The DragonFly Project
e458e5f0	6	* by Simon Schubert <2@0x2c.org>.
c1ebccb4 SS	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	*
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in
	16	* the documentation and/or other materials provided with the
	17	* distribution.
	18	* 3. Neither the name of The DragonFly Project nor the names of its
	19	* contributors may be used to endorse or promote products derived
	20	* from this software without specific, prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	23	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	24	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	25	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	26	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	27	* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
	28	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	29	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	30	* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	31	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	32	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	33	* SUCH DAMAGE.
	34	*/
	35
	36	#include <sys/types.h>
	37	#include <sys/wait.h>
	38
fd1de51a SS	39	#include <err.h>
	40	#include <errno.h>
	41	#include <fcntl.h>
c1ebccb4	42	#include <limits.h>
fd1de51a	43	#include <paths.h>
6ec95705	44	#include <signal.h>
fd1de51a SS	45	#include <stdint.h>
	46	#include <stdio.h>
	47	#include <syslog.h>
	48	#include <unistd.h>
	49
	50	#include "dma.h"
	51
c1ebccb4 SS	52	static int
	53	create_mbox(const char *name)
	54	{
	55	struct sigaction sa, osa;
	56	pid_t child, waitchild;
	57	int status;
	58	int i;
	59	long maxfd;
	60	int e;
	61	int r = -1;
	62
	63	/*
	64	* We need to enable SIGCHLD temporarily so that waitpid works.
	65	*/
	66	bzero(&sa, sizeof(sa));
	67	sa.sa_handler = SIG_DFL;
	68	sigaction(SIGCHLD, &sa, &osa);
	69
	70	do_timeout(100, 0);
	71
	72	child = fork();
	73	switch (child) {
	74	case 0:
	75	/* child */
	76	maxfd = sysconf(_SC_OPEN_MAX);
	77	if (maxfd == -1)
	78	maxfd = 1024; /* what can we do... */
	79
	80	for (i = 3; i <= maxfd; ++i)
	81	close(i);
	82
	83	execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL);
	84	syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m");
de196e33	85	exit(EX_SOFTWARE);
c1ebccb4 SS	86
	87	default:
	88	/* parent */
	89	waitchild = waitpid(child, &status, 0);
	90
	91	e = errno;
	92
	93	do_timeout(0, 0);
	94
	95	if (waitchild == -1 && e == EINTR) {
	96	syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name);
	97	break;
	98	}
	99
	100	if (waitchild == -1) {
	101	syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name);
	102	break;
	103	}
	104
	105	if (!WIFEXITED(status) \|\| WEXITSTATUS(status) != 0) {
	106	syslog(LOG_ERR, "error creating mbox `%s'", name);
	107	break;
	108	}
	109
	110	/* success */
	111	r = 0;
	112	break;
	113
	114	case -1:
	115	/* error */
	116	syslog(LOG_ERR, "error creating mbox");
	117	break;
	118	}
	119
	120	sigaction(SIGCHLD, &osa, NULL);
	121
	122	return (r);
	123	}
	124
fd1de51a	125	int
249ee966	126	deliver_local(struct qitem *it)
fd1de51a SS	127	{
	128	char fn[PATH_MAX+1];
	129	char line[1000];
5a96b98a SS	130	const char *sender;
5a96b98a SS	131	const char *newline = "\n";
fd1de51a	132	size_t linelen;
c1ebccb4	133	int tries = 0;
fd1de51a SS	134	int mbox;
fd1de51a SS	135	int error;
5a96b98a	136	int hadnl = 0;
fd1de51a SS	137	off_t mboxlen;
	138	time_t now = time(NULL);
	139
	140	error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr);
	141	if (error < 0 \|\| (size_t)error >= sizeof(fn)) {
4d5af2b0	142	syslog(LOG_NOTICE, "local delivery deferred: %m");
fd1de51a SS	143	return (1);
	144	}
	145
c1ebccb4	146	retry:
f54b5114 SS	147	/* wait for a maximum of 100s to get the lock to the file */
	148	do_timeout(100, 0);
	149
c1ebccb4 SS	150	/* don't use O_CREAT here, because we might be running as the wrong user. */
c1ebccb4 SS	151	mbox = open_locked(fn, O_WRONLY\|O_APPEND);
fd1de51a	152	if (mbox < 0) {
f54b5114 SS	153	int e = errno;
	154
	155	do_timeout(0, 0);
c1ebccb4 SS	156
	157	switch (e) {
	158	case EACCES:
	159	case ENOENT:
	160	/*
	161	* The file does not exist or we can't access it.
	162	* Call dma-mbox-create to create it and fix permissions.
	163	*/
	164	if (tries > 0 \|\| create_mbox(it->addr) != 0) {
	165	syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn);
	166	return (1);
	167	}
	168	++tries;
	169	goto retry;
	170
	171	case EINTR:
f54b5114	172	syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn);
c1ebccb4 SS	173	break;
	174
	175	default:
f54b5114	176	syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn);
c1ebccb4 SS	177	break;
c1ebccb4 SS	178	}
fd1de51a SS	179	return (1);
fd1de51a SS	180	}
f54b5114 SS	181	do_timeout(0, 0);
f54b5114 SS	182
5a96b98a SS	183	mboxlen = lseek(mbox, 0, SEEK_END);
	184
	185	/* New mails start with \nFrom ...., unless we're at the beginning of the mbox */
	186	if (mboxlen == 0)
	187	newline = "";
	188
	189	/* If we're bouncing a message, claim it comes from MAILER-DAEMON */
	190	sender = it->sender;
	191	if (strcmp(sender, "") == 0)
	192	sender = "MAILER-DAEMON";
fd1de51a	193
6ddd63e1	194	if (fseek(it->mailf, 0, SEEK_SET) != 0) {
4d5af2b0	195	syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m");
f54b5114	196	goto out;
fd1de51a SS	197	}
fd1de51a SS	198
5b135cce	199	error = snprintf(line, sizeof(line), "%sFrom %s %s", newline, sender, ctime(&now));
fd1de51a	200	if (error < 0 \|\| (size_t)error >= sizeof(line)) {
4d5af2b0	201	syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m");
f54b5114	202	goto out;
fd1de51a SS	203	}
	204	if (write(mbox, line, error) != error)
	205	goto wrerror;
	206
	207	while (!feof(it->mailf)) {
	208	if (fgets(line, sizeof(line), it->mailf) == NULL)
	209	break;
	210	linelen = strlen(line);
	211	if (linelen == 0 \|\| line[linelen - 1] != '\n') {
4d5af2b0	212	syslog(LOG_CRIT, "local delivery failed: corrupted queue file");
249ee966	213	snprintf(errmsg, sizeof(errmsg), "corrupted queue file");
fd1de51a SS	214	error = -1;
	215	goto chop;
	216	}
	217
fedbe711 SS	218	/*
	219	* mboxro processing:
	220	* - escape lines that start with "From " with a > sign.
	221	* - be reversable by escaping lines that contain an arbitrary
	222	* number of > signs, followed by "From ", i.e. />*From / in regexp.
	223	* - strict mbox processing only requires escaping after empty lines,
	224	* yet most MUAs seem to relax this requirement and will treat any
	225	* line starting with "From " as the beginning of a new mail.
	226	*/
	227	if ((!MBOX_STRICT \|\| hadnl) &&
	228	strncmp(&line[strspn(line, ">")], "From ", 5) == 0) {
fd1de51a SS	229	const char *gt = ">";
	230
	231	if (write(mbox, gt, 1) != 1)
	232	goto wrerror;
5a96b98a SS	233	hadnl = 0;
	234	} else if (strcmp(line, "\n") == 0) {
	235	hadnl = 1;
	236	} else {
	237	hadnl = 0;
fd1de51a SS	238	}
	239	if ((size_t)write(mbox, line, linelen) != linelen)
	240	goto wrerror;
	241	}
fd1de51a SS	242	close(mbox);
	243	return (0);
	244
	245	wrerror:
4d5af2b0	246	syslog(LOG_ERR, "local delivery failed: write error: %m");
fd1de51a SS	247	error = 1;
	248	chop:
	249	if (ftruncate(mbox, mboxlen) != 0)
4d5af2b0	250	syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn);
f54b5114	251	out:
fd1de51a SS	252	close(mbox);
	253	return (error);
	254	}