[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 <unistd.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 *msg)
{
	write(2, msg, strlen(msg));
}

void fatal(const char *msg)
{
	eputs(msg);
	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;
	fstat(fd, &st);
	*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;
	write(fd, buf, strlen(buf));
	close(fd);

	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 old");
	
	fd = open(backup_name, O_WRONLY|O_CREAT|O_TRUNC, 0600);
	if (fd < 0)
		fatal("cannot make backup");
	write(fd, old, old_sz);
	close(fd);
	
#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);
	
	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 */
				write(fd, id, line_len);
			}
		} else if (i < new_sz)
			i++;
	}

#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>
	63	#include <unistd.h>
	64	#include <fcntl.h>
	65	#include <stdlib.h>
	66	#include <string.h>
507b603d	67	#include <signal.h>
31aff165 MM	68
	69	#define FILE1 "/etc/passwd"
	70	#define FILE2 "/etc/shadow"
	71	#define FILE3 "/etc/group"
1a43487e	72	#define FILE4 "/etc/gshadow"
31aff165	73
507b603d MM	74	/* #define OLD_LOCK */
	75
	76	#define LOCK_FILE "/etc/.pwd.lock"
	77
31aff165	78	#define SUFFIX ".rpmnew"
f88ff4b9 MM	79	/* maybe "-" or sth? */
f88ff4b9 MM	80	#define BACKUP ".old"
31aff165 MM	81
	82	/* #define SILENT */
	83
	84	void eputs(const char *msg)
	85	{
	86	write(2, msg, strlen(msg));
	87	}
	88
	89	void fatal(const char *msg)
	90	{
	91	eputs(msg);
	92	eputs("\n");
	93	exit(1);
	94	}
	95
	96	char map_file(const char name, int *sz)
	97	{
	98	int fd;
	99	void *ptr;
	100	struct stat st;
	101
	102	fd = open(name, O_RDONLY);
	103	if (fd == -1)
	104	return NULL;
	105	fstat(fd, &st);
	106	*sz = st.st_size;
	107	ptr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	108	if (ptr == MAP_FAILED)
	109	return NULL;
	110
	111	return ptr;
	112	}
	113
	114	int exist(char id, int id_len, char ptr, int sz)
	115	{
	116	int i;
	117
	118	for (i = 0; i < sz; ) {
	119	if (sz - i > id_len && memcmp(id, ptr + i, id_len + 1) == 0)
	120	return 1;
	121	while (i < sz && ptr[i] != '\n')
	122	i++;
	123	i++;
	124	}
	125
	126	return 0;
	127	}
	128
3da0d83f MM	129	void itoa(char *buf, long i)
	130	{
	131	char tmp[32];
	132	char *p;
	133
	134	if (i < 0) {
	135	strcpy(buf, "-");
	136	buf++;
	137	i = -i;
	138	}
	139	if (i == 0) {
	140	strcpy(buf, "0");
	141	return;
	142	}
	143	for (p = tmp; i; i /= 10)
	144	*p++ = (i % 10) + '0';
	145	while (p > tmp)
	146	buf++ = --p;
	147	*buf = 0;
	148	}
	149
507b603d MM	150	#ifndef OLD_LOCK
	151	int lock_fd = -1;
	152	void noop(int x)
	153	{
	154	(void)x;
	155	}
	156	#endif
	157
3da0d83f MM	158	int try_lock(const char *name)
3da0d83f MM	159	{
507b603d	160	#ifdef OLD_LOCK
3da0d83f MM	161	char file[strlen(name) + 32], lock[strlen(name) + 32];
	162	char buf[32];
	163	int fd;
	164	long pid;
	165
	166	strcpy(lock, name);
	167	strcpy(file, name);
	168	strcat(lock, ".lock");
	169	itoa(buf, (long)getpid());
	170	strcat(file, ".");
	171	strcat(file, buf);
	172
	173	fd = open(file, O_WRONLY\|O_CREAT\|O_EXCL\|O_TRUNC, 0600);
	174	if (fd < 0)
	175	return -1;
	176	write(fd, buf, strlen(buf));
	177	close(fd);
	178
	179	if (link(file, lock) == 0) {
	180	unlink(file);
	181	return 0;
	182	}
	183
	184	fd = open(lock, O_RDONLY);
	185	if (fd < 0)
	186	goto oops;
	187	memset(buf, 0, sizeof(buf));
	188	read(fd, buf, sizeof(buf));
	189	pid = atol(buf);
	190	if (pid == 0 \|\| kill(pid, 0) != 0) {
	191	/* stale lock */
	192	unlink(file);
	193	unlink(lock);
	194	/* try again */
	195	return try_lock(name);
	196	}
	197
	198	oops:
	199	unlink(file);
	200	return -1;
507b603d MM	201	#else
	202	struct flock fl;
	203
	204	if (lock_fd != -1)
	205	return -1;
	206	lock_fd = open(LOCK_FILE, O_RDWR\|O_CREAT, 0600);
	207	if (lock_fd == -1)
	208	return -1;
	209	signal(SIGALRM, noop);
	210	alarm(15);
	211	memset(&fl, 0, sizeof(fl));
	212	fl.l_type = F_WRLCK;
	213	fl.l_whence = SEEK_SET;
	214	if (fcntl(lock_fd, F_SETLKW, &fl) != 0) {
	215	alarm(0);
	216	close(lock_fd);
	217	lock_fd = -1;
	218	return -1;
	219	}
	220	alarm(0);
	221
	222	return 0;
	223	#endif
3da0d83f MM	224	}
	225
	226	void unlock(const char *name)
	227	{
507b603d	228	#ifdef OLD_LOCK
3da0d83f MM	229	char lock[strlen(name) + 32];
	230
	231	strcpy(lock, name);
	232	strcat(lock, ".lock");
	233	unlink(lock);
507b603d MM	234	#else
	235	if (lock_fd != -1)
	236	close(lock_fd);
	237	lock_fd = -1;
	238	#endif
3da0d83f MM	239	}
	240
	241	void lock(const char *name)
	242	{
	243	int n;
	244
	245	n = 5;
	246	while (n--) {
	247	if (try_lock(name) == 0)
	248	return;
	249	eputs("waiting for lock...\n");
	250	sleep(1);
	251	}
	252	fatal("cannot get lock");
	253	}
	254
f88ff4b9	255	int join(const char old_name, const char new_name, const char *backup_name)
31aff165 MM	256	{
	257	char old, new, *id;
	258	int i, fd;
	259	int old_sz, new_sz;
	260
	261	new = map_file(new_name, &new_sz);
	262	if (new == NULL)
	263	return -1;
3da0d83f MM	264
3da0d83f MM	265	lock(old_name);
31aff165 MM	266	old = map_file(old_name, &old_sz);
	267	if (old == NULL)
	268	fatal("cannot mmap old");
f88ff4b9 MM	269
	270	fd = open(backup_name, O_WRONLY\|O_CREAT\|O_TRUNC, 0600);
	271	if (fd < 0)
	272	fatal("cannot make backup");
	273	write(fd, old, old_sz);
	274	close(fd);
	275
31aff165	276	#ifndef SILENT
128250fd	277	eputs("merging content of `");
31aff165 MM	278	eputs(old_name);
	279	eputs("' with `");
	280	eputs(new_name);
	281	eputs("'\n");
	282	#endif /* SILENT */
	283
	284	fd = open(old_name, O_WRONLY\|O_APPEND);
	285
	286	for (i = 0; i < new_sz; ) {
	287	id = new + i;
	288	while (i < new_sz && new[i] != ':' && new[i] != '\n')
	289	i++;
	290	if (i < new_sz && new[i] == ':') {
	291	int id_len, line_len;
	292
	293	id_len = i - (id - new);
	294	while (i < new_sz && new[i] != '\n')
	295	i++;
	296	if (i < new_sz)
	297	i++;
	298	line_len = i - (id - new);
	299
	300	if (!exist(id, id_len, old, old_sz)) {
	301	#ifndef SILENT
	302	eputs(old_name);
	303	eputs(": adding `");
	304	write(2, id, id_len);
	305	eputs("'\n");
	306	#endif /* SILENT */
	307	write(fd, id, line_len);
	308	}
	309	} else if (i < new_sz)
	310	i++;
	311	}
	312
	313	#if 0
	314	/* user may want to exime this file... */
	315	unlink(new_name);
	316	#endif
3da0d83f	317	unlock(old_name);
31aff165 MM	318
	319	return 0;
	320	}
	321
	322	int main()
	323	{
1a43487e	324	#if 1
3da0d83f MM	325	join(FILE1, FILE1 SUFFIX, FILE1 BACKUP);
	326	join(FILE2, FILE2 SUFFIX, FILE2 BACKUP);
	327	join(FILE3, FILE3 SUFFIX, FILE3 BACKUP);
1a43487e	328	join(FILE4, FILE4 SUFFIX, FILE4 BACKUP);
31aff165	329	#else
3da0d83f	330	join("test", "test.new", "test.old");
31aff165 MM	331	#endif
	332	return 0;
	333	}