[projects/setup.git] / joinpasswd.c

/*
 * $Id$
 * 
 * Copyright (c) 2001 Michal Moskal <malekith@pld-linux.org>.
 * All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Michal Moskal.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY MICHAL MOSKAL 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 REGENTS 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.
 *
 *
 * 
 * USAGE: joinpasswd
 *
 * Add entries from freshly created {passwd,shadow,group}.rpmnew to existing
 * {passwd,shadow,group}. It is usable as part of setup package, during upgrade
 * where new system user/group is to be added. If entry is already found in 
 * system database, it is left, otherwise it is added. UIDs/GIDs are *not* 
 * checked anyhow. 
 *
 * For typical sizes of files in setup package, it takes about 1 second per
 * 20000 users in system database on Pentium class machine. After static link
 * against uClibc it is under 2k on x86. Stdio hasn't been used intentionally.
 * 
 * Written for PLD Linux (http://www.pld-linux.org/) setup package.
 *
 * Compilation against uClibc:
 * UCROOT=/usr/lib/bootdisk/usr
 * gcc -I$UCROOT/include -nostdlib -O2 joinpasswd.c $UCROOT/lib/crt0.o \
 * 		$UCROOT/lib/libc.a -lgcc -o joinpasswd
 * strip -R .comment -R .note joinpasswd
 *
 * The idea of this program comes from Lukasz Dobrek <dobrek@pld-linux.org>.
 * 
 */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdarg.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>

#define FILE1 "/etc/passwd"
#define FILE2 "/etc/shadow"
#define FILE3 "/etc/group"
#define FILE4 "/etc/gshadow"

/* #define OLD_LOCK */

#define LOCK_FILE "/etc/.pwd.lock"

#define SUFFIX ".rpmnew"
/* maybe "-" or sth? */
#define BACKUP ".old"

/* #define SILENT */

void eputs(const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	vfprintf(stderr, fmt, args);
	va_end(args);
}

void fatal(const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	eputs(fmt, args);
	va_end(args);

	eputs("\n");
	exit(1);
}

char *map_file(const char *name, int *sz)
{
	int fd;
	void *ptr;
	struct stat st;

	fd = open(name, O_RDONLY);
	if (fd == -1)
		return NULL;
	if (fstat(fd, &st) < 0)
		return NULL;
	*sz = st.st_size;
	ptr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	if (ptr == MAP_FAILED)
		return NULL;

	return ptr;
}

int exist(char *id, int id_len, char *ptr, int sz)
{
	int i;

	for (i = 0; i < sz; ) {
		if (sz - i > id_len && memcmp(id, ptr + i, id_len + 1) == 0)
			return 1;
		while (i < sz && ptr[i] != '\n')
			i++;
		i++;
	}

	return 0;
}

void itoa(char *buf, long i)
{
	char tmp[32];
	char *p;

	if (i < 0) {
		strcpy(buf, "-");
		buf++;
		i = -i;
	}
	if (i == 0) {
		strcpy(buf, "0"); 
		return;
	}
	for (p = tmp; i; i /= 10)
		*p++ = (i % 10) + '0';
	while (p > tmp)
		*buf++ = *--p;
	*buf = 0;
}

#ifndef OLD_LOCK
int lock_fd = -1;
void noop(int x)
{
	(void)x;
}
#endif

int try_lock(const char *name)
{
#ifdef OLD_LOCK
	char file[strlen(name) + 32], lock[strlen(name) + 32];
	char buf[32];
	int fd;
	long pid;

	strcpy(lock, name);
	strcpy(file, name);
	strcat(lock, ".lock");
	itoa(buf, (long)getpid());
	strcat(file, ".");
	strcat(file, buf);
	
	fd = open(file, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600);
	if (fd < 0)
		return -1;
	if (write(fd, buf, strlen(buf)) < 0) {
		close(fd);
		return -1;
	}
	if (close(fd) < 0)
		return -1;

	if (link(file, lock) == 0) {
		unlink(file);
		return 0;
	}

	fd = open(lock, O_RDONLY);
	if (fd < 0)
		goto oops;
	memset(buf, 0, sizeof(buf));
	read(fd, buf, sizeof(buf));
	pid = atol(buf);
	if (pid == 0 || kill(pid, 0) != 0) {
		/* stale lock */
		unlink(file);
		unlink(lock);
		/* try again */
		return try_lock(name);
	}

oops:
	unlink(file);
	return -1;
#else
	struct flock fl;
	
	if (lock_fd != -1)
		return -1;
	lock_fd = open(LOCK_FILE, O_RDWR|O_CREAT, 0600);
	if (lock_fd == -1)
		return -1;
	signal(SIGALRM, noop);
	alarm(15);
	memset(&fl, 0, sizeof(fl));
	fl.l_type = F_WRLCK;
	fl.l_whence = SEEK_SET;
	if (fcntl(lock_fd, F_SETLKW, &fl) != 0) {
		alarm(0);
		close(lock_fd);
		lock_fd = -1;
		return -1;
	}
	alarm(0);
	
	return 0;
#endif
}

void unlock(const char *name)
{
#ifdef OLD_LOCK
	char lock[strlen(name) + 32];

	strcpy(lock, name);
	strcat(lock, ".lock");
	unlink(lock);
#else
	if (lock_fd != -1)
		close(lock_fd);
	lock_fd = -1;
#endif
}

void lock(const char *name)
{
	int n;

	n = 5;
	while (n--) {
		if (try_lock(name) == 0)
			return;
		eputs("waiting for lock...\n");
		sleep(1);
	}
	fatal("cannot get lock");
}

int join(const char *old_name, const char *new_name, const char *backup_name)
{
	char *old, *new, *id;
	int i, fd;
	int old_sz, new_sz;

	new = map_file(new_name, &new_sz);
	if (new == NULL)
		return -1;
	
	lock(old_name);
	old = map_file(old_name, &old_sz);
	if (old == NULL)
		fatal("cannot mmap file `%s': %m", old_name);
	
	fd = open(backup_name, O_WRONLY|O_CREAT|O_TRUNC, 0600);
	if (fd < 0)
		fatal("cannot create backup file `%s': %m", backup_name);
	if (write(fd, old, old_sz) < 0)
		fatal("writting to backup file `%s' failed: %m", backup_name);
	if (fsync(fd) < 0)
		fatal("syncing backup file `%s' failed: %m", backup_name);
	if (close(fd) < 0)
		fatal("closing backup file `%s' failed: %m", backup_name);
	
#ifndef SILENT
	eputs("merging content of `");
	eputs(old_name);
	eputs("' with `");
	eputs(new_name);
	eputs("'\n");
#endif /* SILENT */

	fd = open(old_name, O_WRONLY|O_APPEND);
	if (fd < 0)
		fatal("cannot open old file `%s': %m", old_name);
	
	for (i = 0; i < new_sz; ) {
		id = new + i;
		while (i < new_sz && new[i] != ':' && new[i] != '\n')
			i++;
		if (i < new_sz && new[i] == ':') {
			int id_len, line_len;

			id_len = i - (id - new);
			while (i < new_sz && new[i] != '\n')
				i++;
			if (i < new_sz)
				i++;
			line_len = i - (id - new);
			
			if (!exist(id, id_len, old, old_sz)) {
#ifndef SILENT
				eputs(old_name);
				eputs(": adding `");
				write(2, id, id_len);
				eputs("'\n");
#endif /* SILENT */
				if (write(fd, id, line_len) < 0)
					fatal("writting line to `%s' failed, check backup file: %m", old_name);
			}
		} else if (i < new_sz)
			i++;
	}
	fsync(fd);
	close(fd);

#if 0
	/* user may want to exime this file... */
	unlink(new_name);
#endif
	unlock(old_name);

	return 0;
}

int main()
{
#if 1
	join(FILE1, FILE1 SUFFIX, FILE1 BACKUP);
	join(FILE2, FILE2 SUFFIX, FILE2 BACKUP);
	join(FILE3, FILE3 SUFFIX, FILE3 BACKUP);
	join(FILE4, FILE4 SUFFIX, FILE4 BACKUP);
#else
	join("test", "test.new", "test.old");
#endif
	return 0;
}
Commit	Line	Data
31aff165 MM	1	/*
	2	* $Id$
	3	*
e040c79e	4	* Copyright (c) 2001 Michal Moskal <malekith@pld-linux.org>.
31aff165 MM	5	* All rights reserved.
	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	* 1. Redistributions of source code must retain the above copyright
	11	* notice, this list of conditions and the following disclaimer.
	12	* 2. Redistributions in binary form must reproduce the above copyright
	13	* notice, this list of conditions and the following disclaimer in the
	14	* documentation and/or other materials provided with the distribution.
	15	* 3. All advertising materials mentioning features or use of this software
	16	* must display the following acknowledgement:
	17	* This product includes software developed by Michal Moskal.
	18	* 4. Neither the name of the author nor the names of any co-contributors
	19	* may be used to endorse or promote products derived from this software
	20	* without specific prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED BY MICHAL MOSKAL AND CONTRIBUTORS ``AS IS'' AND
	23	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	* SUCH DAMAGE.
	33	*
	34	*
	35	*
	36	* USAGE: joinpasswd
	37	*
	38	* Add entries from freshly created {passwd,shadow,group}.rpmnew to existing
	39	* {passwd,shadow,group}. It is usable as part of setup package, during upgrade
	40	* where new system user/group is to be added. If entry is already found in
3da0d83f MM	41	* system database, it is left, otherwise it is added. UIDs/GIDs are not
3da0d83f MM	42	* checked anyhow.
31aff165 MM	43	*
	44	* For typical sizes of files in setup package, it takes about 1 second per
	45	* 20000 users in system database on Pentium class machine. After static link
	46	* against uClibc it is under 2k on x86. Stdio hasn't been used intentionally.
	47	*
e040c79e	48	* Written for PLD Linux (http://www.pld-linux.org/) setup package.
31aff165 MM	49	*
	50	* Compilation against uClibc:
	51	* UCROOT=/usr/lib/bootdisk/usr
	52	* gcc -I$UCROOT/include -nostdlib -O2 joinpasswd.c $UCROOT/lib/crt0.o \
	53	* $UCROOT/lib/libc.a -lgcc -o joinpasswd
	54	* strip -R .comment -R .note joinpasswd
	55	*
e040c79e	56	* The idea of this program comes from Lukasz Dobrek <dobrek@pld-linux.org>.
31aff165 MM	57	*
	58	*/
	59
	60	#include <sys/types.h>
	61	#include <sys/mman.h>
	62	#include <sys/stat.h>
cbc25e75	63	#include <stdio.h>
8356227d	64	#include <errno.h>
31aff165	65	#include <unistd.h>
cbc25e75	66	#include <stdarg.h>
31aff165 MM	67	#include <fcntl.h>
	68	#include <stdlib.h>
	69	#include <string.h>
507b603d	70	#include <signal.h>
31aff165 MM	71
	72	#define FILE1 "/etc/passwd"
	73	#define FILE2 "/etc/shadow"
	74	#define FILE3 "/etc/group"
1a43487e	75	#define FILE4 "/etc/gshadow"
31aff165	76
507b603d MM	77	/* #define OLD_LOCK */
	78
	79	#define LOCK_FILE "/etc/.pwd.lock"
	80
31aff165	81	#define SUFFIX ".rpmnew"
f88ff4b9 MM	82	/* maybe "-" or sth? */
f88ff4b9 MM	83	#define BACKUP ".old"
31aff165 MM	84
	85	/* #define SILENT */
	86
cbc25e75	87	void eputs(const char *fmt, ...)
31aff165	88	{
cbc25e75 AM	89	va_list args;
	90
	91	va_start(args, fmt);
	92	vfprintf(stderr, fmt, args);
	93	va_end(args);
31aff165 MM	94	}
31aff165 MM	95
cbc25e75	96	void fatal(const char *fmt, ...)
31aff165	97	{
cbc25e75 AM	98	va_list args;
	99
	100	va_start(args, fmt);
	101	eputs(fmt, args);
	102	va_end(args);
	103
31aff165 MM	104	eputs("\n");
	105	exit(1);
	106	}
	107
	108	char map_file(const char name, int *sz)
	109	{
	110	int fd;
	111	void *ptr;
	112	struct stat st;
	113
	114	fd = open(name, O_RDONLY);
	115	if (fd == -1)
	116	return NULL;
bd3b57f6 AM	117	if (fstat(fd, &st) < 0)
bd3b57f6 AM	118	return NULL;
31aff165 MM	119	*sz = st.st_size;
	120	ptr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	121	if (ptr == MAP_FAILED)
	122	return NULL;
	123
	124	return ptr;
	125	}
	126
	127	int exist(char id, int id_len, char ptr, int sz)
	128	{
	129	int i;
	130
	131	for (i = 0; i < sz; ) {
	132	if (sz - i > id_len && memcmp(id, ptr + i, id_len + 1) == 0)
	133	return 1;
	134	while (i < sz && ptr[i] != '\n')
	135	i++;
	136	i++;
	137	}
	138
	139	return 0;
	140	}
	141
3da0d83f MM	142	void itoa(char *buf, long i)
	143	{
	144	char tmp[32];
	145	char *p;
	146
	147	if (i < 0) {
	148	strcpy(buf, "-");
	149	buf++;
	150	i = -i;
	151	}
	152	if (i == 0) {
	153	strcpy(buf, "0");
	154	return;
	155	}
	156	for (p = tmp; i; i /= 10)
	157	*p++ = (i % 10) + '0';
	158	while (p > tmp)
	159	buf++ = --p;
	160	*buf = 0;
	161	}
	162
507b603d MM	163	#ifndef OLD_LOCK
	164	int lock_fd = -1;
	165	void noop(int x)
	166	{
	167	(void)x;
	168	}
	169	#endif
	170
3da0d83f MM	171	int try_lock(const char *name)
3da0d83f MM	172	{
507b603d	173	#ifdef OLD_LOCK
3da0d83f MM	174	char file[strlen(name) + 32], lock[strlen(name) + 32];
	175	char buf[32];
	176	int fd;
	177	long pid;
	178
	179	strcpy(lock, name);
	180	strcpy(file, name);
	181	strcat(lock, ".lock");
	182	itoa(buf, (long)getpid());
	183	strcat(file, ".");
	184	strcat(file, buf);
	185
	186	fd = open(file, O_WRONLY\|O_CREAT\|O_EXCL\|O_TRUNC, 0600);
	187	if (fd < 0)
	188	return -1;
ed0f82b9 AM	189	if (write(fd, buf, strlen(buf)) < 0) {
	190	close(fd);
	191	return -1;
	192	}
	193	if (close(fd) < 0)
	194	return -1;
3da0d83f MM	195
	196	if (link(file, lock) == 0) {
	197	unlink(file);
	198	return 0;
	199	}
	200
	201	fd = open(lock, O_RDONLY);
	202	if (fd < 0)
	203	goto oops;
	204	memset(buf, 0, sizeof(buf));
	205	read(fd, buf, sizeof(buf));
	206	pid = atol(buf);
	207	if (pid == 0 \|\| kill(pid, 0) != 0) {
	208	/* stale lock */
	209	unlink(file);
	210	unlink(lock);
	211	/* try again */
	212	return try_lock(name);
	213	}
	214
	215	oops:
	216	unlink(file);
	217	return -1;
507b603d MM	218	#else
	219	struct flock fl;
	220
	221	if (lock_fd != -1)
	222	return -1;
	223	lock_fd = open(LOCK_FILE, O_RDWR\|O_CREAT, 0600);
	224	if (lock_fd == -1)
	225	return -1;
	226	signal(SIGALRM, noop);
	227	alarm(15);
	228	memset(&fl, 0, sizeof(fl));
	229	fl.l_type = F_WRLCK;
	230	fl.l_whence = SEEK_SET;
	231	if (fcntl(lock_fd, F_SETLKW, &fl) != 0) {
	232	alarm(0);
	233	close(lock_fd);
	234	lock_fd = -1;
	235	return -1;
	236	}
	237	alarm(0);
	238
	239	return 0;
	240	#endif
3da0d83f MM	241	}
	242
	243	void unlock(const char *name)
	244	{
507b603d	245	#ifdef OLD_LOCK
3da0d83f MM	246	char lock[strlen(name) + 32];
	247
	248	strcpy(lock, name);
	249	strcat(lock, ".lock");
	250	unlink(lock);
507b603d MM	251	#else
	252	if (lock_fd != -1)
	253	close(lock_fd);
	254	lock_fd = -1;
	255	#endif
3da0d83f MM	256	}
	257
	258	void lock(const char *name)
	259	{
	260	int n;
	261
	262	n = 5;
	263	while (n--) {
	264	if (try_lock(name) == 0)
	265	return;
	266	eputs("waiting for lock...\n");
	267	sleep(1);
	268	}
	269	fatal("cannot get lock");
	270	}
	271
f88ff4b9	272	int join(const char old_name, const char new_name, const char *backup_name)
31aff165 MM	273	{
	274	char old, new, *id;
	275	int i, fd;
	276	int old_sz, new_sz;
	277
	278	new = map_file(new_name, &new_sz);
	279	if (new == NULL)
	280	return -1;
3da0d83f MM	281
3da0d83f MM	282	lock(old_name);
31aff165 MM	283	old = map_file(old_name, &old_sz);
31aff165 MM	284	if (old == NULL)
cbc25e75	285	fatal("cannot mmap file `%s': %m", old_name);
f88ff4b9 MM	286
	287	fd = open(backup_name, O_WRONLY\|O_CREAT\|O_TRUNC, 0600);
	288	if (fd < 0)
cbc25e75	289	fatal("cannot create backup file `%s': %m", backup_name);
8356227d	290	if (write(fd, old, old_sz) < 0)
cbc25e75	291	fatal("writting to backup file `%s' failed: %m", backup_name);
8356227d	292	if (fsync(fd) < 0)
cbc25e75	293	fatal("syncing backup file `%s' failed: %m", backup_name);
8356227d	294	if (close(fd) < 0)
cbc25e75	295	fatal("closing backup file `%s' failed: %m", backup_name);
f88ff4b9	296
31aff165	297	#ifndef SILENT
128250fd	298	eputs("merging content of `");
31aff165 MM	299	eputs(old_name);
	300	eputs("' with `");
	301	eputs(new_name);
	302	eputs("'\n");
	303	#endif /* SILENT */
	304
	305	fd = open(old_name, O_WRONLY\|O_APPEND);
bd3b57f6	306	if (fd < 0)
cbc25e75	307	fatal("cannot open old file `%s': %m", old_name);
31aff165 MM	308
	309	for (i = 0; i < new_sz; ) {
	310	id = new + i;
	311	while (i < new_sz && new[i] != ':' && new[i] != '\n')
	312	i++;
	313	if (i < new_sz && new[i] == ':') {
	314	int id_len, line_len;
	315
	316	id_len = i - (id - new);
	317	while (i < new_sz && new[i] != '\n')
	318	i++;
	319	if (i < new_sz)
	320	i++;
	321	line_len = i - (id - new);
	322
	323	if (!exist(id, id_len, old, old_sz)) {
	324	#ifndef SILENT
	325	eputs(old_name);
	326	eputs(": adding `");
	327	write(2, id, id_len);
	328	eputs("'\n");
	329	#endif /* SILENT */
8356227d	330	if (write(fd, id, line_len) < 0)
cbc25e75	331	fatal("writting line to `%s' failed, check backup file: %m", old_name);
31aff165 MM	332	}
	333	} else if (i < new_sz)
	334	i++;
	335	}
bd9aee69 AM	336	fsync(fd);
bd9aee69 AM	337	close(fd);
31aff165 MM	338
	339	#if 0
	340	/* user may want to exime this file... */
	341	unlink(new_name);
	342	#endif
3da0d83f	343	unlock(old_name);
31aff165 MM	344
	345	return 0;
	346	}
	347
	348	int main()
	349	{
1a43487e	350	#if 1
3da0d83f MM	351	join(FILE1, FILE1 SUFFIX, FILE1 BACKUP);
	352	join(FILE2, FILE2 SUFFIX, FILE2 BACKUP);
	353	join(FILE3, FILE3 SUFFIX, FILE3 BACKUP);
1a43487e	354	join(FILE4, FILE4 SUFFIX, FILE4 BACKUP);
31aff165	355	#else
3da0d83f	356	join("test", "test.new", "test.old");
31aff165 MM	357	#endif
	358	return 0;
	359	}