[projects/setup.git] / joinpasswd.c

/*
 * 
 * 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, ssize_t *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, ssize_t sz)
{
	ssize_t 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;
	ssize_t 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	1	/*
31aff165	2	*
e040c79e	3	* Copyright (c) 2001 Michal Moskal <malekith@pld-linux.org>.
31aff165 MM	4	* All rights reserved.
	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions
	8	* are met:
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* 2. Redistributions in binary form must reproduce the above copyright
	12	* notice, this list of conditions and the following disclaimer in the
	13	* documentation and/or other materials provided with the distribution.
	14	* 3. All advertising materials mentioning features or use of this software
	15	* must display the following acknowledgement:
	16	* This product includes software developed by Michal Moskal.
	17	* 4. Neither the name of the author nor the names of any co-contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY MICHAL MOSKAL AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*
	33	*
	34	*
	35	* USAGE: joinpasswd
	36	*
	37	* Add entries from freshly created {passwd,shadow,group}.rpmnew to existing
	38	* {passwd,shadow,group}. It is usable as part of setup package, during upgrade
	39	* where new system user/group is to be added. If entry is already found in
3da0d83f MM	40	* system database, it is left, otherwise it is added. UIDs/GIDs are not
3da0d83f MM	41	* checked anyhow.
31aff165 MM	42	*
	43	* For typical sizes of files in setup package, it takes about 1 second per
	44	* 20000 users in system database on Pentium class machine. After static link
	45	* against uClibc it is under 2k on x86. Stdio hasn't been used intentionally.
	46	*
e040c79e	47	* Written for PLD Linux (http://www.pld-linux.org/) setup package.
31aff165 MM	48	*
	49	* Compilation against uClibc:
	50	* UCROOT=/usr/lib/bootdisk/usr
	51	* gcc -I$UCROOT/include -nostdlib -O2 joinpasswd.c $UCROOT/lib/crt0.o \
	52	* $UCROOT/lib/libc.a -lgcc -o joinpasswd
	53	* strip -R .comment -R .note joinpasswd
	54	*
e040c79e	55	* The idea of this program comes from Lukasz Dobrek <dobrek@pld-linux.org>.
31aff165 MM	56	*
	57	*/
	58
	59	#include <sys/types.h>
	60	#include <sys/mman.h>
	61	#include <sys/stat.h>
cbc25e75	62	#include <stdio.h>
8356227d	63	#include <errno.h>
31aff165	64	#include <unistd.h>
cbc25e75	65	#include <stdarg.h>
31aff165 MM	66	#include <fcntl.h>
	67	#include <stdlib.h>
	68	#include <string.h>
507b603d	69	#include <signal.h>
31aff165 MM	70
	71	#define FILE1 "/etc/passwd"
	72	#define FILE2 "/etc/shadow"
	73	#define FILE3 "/etc/group"
1a43487e	74	#define FILE4 "/etc/gshadow"
31aff165	75
507b603d MM	76	/* #define OLD_LOCK */
	77
	78	#define LOCK_FILE "/etc/.pwd.lock"
	79
31aff165	80	#define SUFFIX ".rpmnew"
f88ff4b9 MM	81	/* maybe "-" or sth? */
f88ff4b9 MM	82	#define BACKUP ".old"
31aff165 MM	83
	84	/* #define SILENT */
	85
cbc25e75	86	void eputs(const char *fmt, ...)
31aff165	87	{
cbc25e75 AM	88	va_list args;
	89
	90	va_start(args, fmt);
	91	vfprintf(stderr, fmt, args);
	92	va_end(args);
31aff165 MM	93	}
31aff165 MM	94
cbc25e75	95	void fatal(const char *fmt, ...)
31aff165	96	{
cbc25e75 AM	97	va_list args;
	98
	99	va_start(args, fmt);
	100	eputs(fmt, args);
	101	va_end(args);
	102
31aff165 MM	103	eputs("\n");
	104	exit(1);
	105	}
	106
db127c35	107	char map_file(const char name, ssize_t *sz)
31aff165 MM	108	{
	109	int fd;
	110	void *ptr;
	111	struct stat st;
	112
	113	fd = open(name, O_RDONLY);
	114	if (fd == -1)
	115	return NULL;
bd3b57f6 AM	116	if (fstat(fd, &st) < 0)
bd3b57f6 AM	117	return NULL;
31aff165 MM	118	*sz = st.st_size;
	119	ptr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	120	if (ptr == MAP_FAILED)
	121	return NULL;
	122
	123	return ptr;
	124	}
	125
db127c35	126	int exist(char id, int id_len, char ptr, ssize_t sz)
31aff165	127	{
db127c35	128	ssize_t i;
31aff165 MM	129
	130	for (i = 0; i < sz; ) {
	131	if (sz - i > id_len && memcmp(id, ptr + i, id_len + 1) == 0)
	132	return 1;
	133	while (i < sz && ptr[i] != '\n')
	134	i++;
	135	i++;
	136	}
	137
	138	return 0;
	139	}
	140
3da0d83f MM	141	void itoa(char *buf, long i)
	142	{
	143	char tmp[32];
	144	char *p;
	145
	146	if (i < 0) {
	147	strcpy(buf, "-");
	148	buf++;
	149	i = -i;
	150	}
	151	if (i == 0) {
	152	strcpy(buf, "0");
	153	return;
	154	}
	155	for (p = tmp; i; i /= 10)
	156	*p++ = (i % 10) + '0';
	157	while (p > tmp)
	158	buf++ = --p;
	159	*buf = 0;
	160	}
	161
507b603d MM	162	#ifndef OLD_LOCK
	163	int lock_fd = -1;
	164	void noop(int x)
	165	{
	166	(void)x;
	167	}
	168	#endif
	169
3da0d83f MM	170	int try_lock(const char *name)
3da0d83f MM	171	{
507b603d	172	#ifdef OLD_LOCK
3da0d83f MM	173	char file[strlen(name) + 32], lock[strlen(name) + 32];
	174	char buf[32];
	175	int fd;
	176	long pid;
	177
	178	strcpy(lock, name);
	179	strcpy(file, name);
	180	strcat(lock, ".lock");
	181	itoa(buf, (long)getpid());
	182	strcat(file, ".");
	183	strcat(file, buf);
	184
	185	fd = open(file, O_WRONLY\|O_CREAT\|O_EXCL\|O_TRUNC, 0600);
	186	if (fd < 0)
	187	return -1;
ed0f82b9 AM	188	if (write(fd, buf, strlen(buf)) < 0) {
	189	close(fd);
	190	return -1;
	191	}
	192	if (close(fd) < 0)
	193	return -1;
3da0d83f MM	194
	195	if (link(file, lock) == 0) {
	196	unlink(file);
	197	return 0;
	198	}
	199
	200	fd = open(lock, O_RDONLY);
	201	if (fd < 0)
	202	goto oops;
	203	memset(buf, 0, sizeof(buf));
	204	read(fd, buf, sizeof(buf));
	205	pid = atol(buf);
	206	if (pid == 0 \|\| kill(pid, 0) != 0) {
	207	/* stale lock */
	208	unlink(file);
	209	unlink(lock);
	210	/* try again */
	211	return try_lock(name);
	212	}
	213
	214	oops:
	215	unlink(file);
	216	return -1;
507b603d MM	217	#else
	218	struct flock fl;
	219
	220	if (lock_fd != -1)
	221	return -1;
	222	lock_fd = open(LOCK_FILE, O_RDWR\|O_CREAT, 0600);
	223	if (lock_fd == -1)
	224	return -1;
	225	signal(SIGALRM, noop);
	226	alarm(15);
	227	memset(&fl, 0, sizeof(fl));
	228	fl.l_type = F_WRLCK;
	229	fl.l_whence = SEEK_SET;
	230	if (fcntl(lock_fd, F_SETLKW, &fl) != 0) {
	231	alarm(0);
	232	close(lock_fd);
	233	lock_fd = -1;
	234	return -1;
	235	}
	236	alarm(0);
	237
	238	return 0;
	239	#endif
3da0d83f MM	240	}
	241
	242	void unlock(const char *name)
	243	{
507b603d	244	#ifdef OLD_LOCK
3da0d83f MM	245	char lock[strlen(name) + 32];
	246
	247	strcpy(lock, name);
	248	strcat(lock, ".lock");
	249	unlink(lock);
507b603d MM	250	#else
	251	if (lock_fd != -1)
	252	close(lock_fd);
	253	lock_fd = -1;
	254	#endif
3da0d83f MM	255	}
	256
	257	void lock(const char *name)
	258	{
	259	int n;
	260
	261	n = 5;
	262	while (n--) {
	263	if (try_lock(name) == 0)
	264	return;
	265	eputs("waiting for lock...\n");
	266	sleep(1);
	267	}
	268	fatal("cannot get lock");
	269	}
	270
f88ff4b9	271	int join(const char old_name, const char new_name, const char *backup_name)
31aff165 MM	272	{
	273	char old, new, *id;
	274	int i, fd;
db127c35	275	ssize_t old_sz, new_sz;
31aff165 MM	276
	277	new = map_file(new_name, &new_sz);
	278	if (new == NULL)
	279	return -1;
3da0d83f MM	280
3da0d83f MM	281	lock(old_name);
31aff165 MM	282	old = map_file(old_name, &old_sz);
31aff165 MM	283	if (old == NULL)
cbc25e75	284	fatal("cannot mmap file `%s': %m", old_name);
f88ff4b9 MM	285
	286	fd = open(backup_name, O_WRONLY\|O_CREAT\|O_TRUNC, 0600);
	287	if (fd < 0)
cbc25e75	288	fatal("cannot create backup file `%s': %m", backup_name);
8356227d	289	if (write(fd, old, old_sz) < 0)
cbc25e75	290	fatal("writting to backup file `%s' failed: %m", backup_name);
8356227d	291	if (fsync(fd) < 0)
cbc25e75	292	fatal("syncing backup file `%s' failed: %m", backup_name);
8356227d	293	if (close(fd) < 0)
cbc25e75	294	fatal("closing backup file `%s' failed: %m", backup_name);
f88ff4b9	295
31aff165	296	#ifndef SILENT
128250fd	297	eputs("merging content of `");
31aff165 MM	298	eputs(old_name);
	299	eputs("' with `");
	300	eputs(new_name);
	301	eputs("'\n");
	302	#endif /* SILENT */
	303
	304	fd = open(old_name, O_WRONLY\|O_APPEND);
bd3b57f6	305	if (fd < 0)
cbc25e75	306	fatal("cannot open old file `%s': %m", old_name);
31aff165 MM	307
	308	for (i = 0; i < new_sz; ) {
	309	id = new + i;
	310	while (i < new_sz && new[i] != ':' && new[i] != '\n')
	311	i++;
	312	if (i < new_sz && new[i] == ':') {
	313	int id_len, line_len;
	314
	315	id_len = i - (id - new);
	316	while (i < new_sz && new[i] != '\n')
	317	i++;
	318	if (i < new_sz)
	319	i++;
	320	line_len = i - (id - new);
	321
	322	if (!exist(id, id_len, old, old_sz)) {
	323	#ifndef SILENT
	324	eputs(old_name);
	325	eputs(": adding `");
	326	write(2, id, id_len);
	327	eputs("'\n");
	328	#endif /* SILENT */
8356227d	329	if (write(fd, id, line_len) < 0)
cbc25e75	330	fatal("writting line to `%s' failed, check backup file: %m", old_name);
31aff165 MM	331	}
	332	} else if (i < new_sz)
	333	i++;
	334	}
bd9aee69 AM	335	fsync(fd);
bd9aee69 AM	336	close(fd);
31aff165 MM	337
	338	#if 0
	339	/* user may want to exime this file... */
	340	unlink(new_name);
	341	#endif
3da0d83f	342	unlock(old_name);
31aff165 MM	343
	344	return 0;
	345	}
	346
	347	int main()
	348	{
1a43487e	349	#if 1
3da0d83f MM	350	join(FILE1, FILE1 SUFFIX, FILE1 BACKUP);
	351	join(FILE2, FILE2 SUFFIX, FILE2 BACKUP);
	352	join(FILE3, FILE3 SUFFIX, FILE3 BACKUP);
1a43487e	353	join(FILE4, FILE4 SUFFIX, FILE4 BACKUP);
31aff165	354	#else
3da0d83f	355	join("test", "test.new", "test.old");
31aff165 MM	356	#endif
	357	return 0;
	358	}