Diff of /trunk/mkinitrd-magellan/busybox/libbb/update_passwd.c

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	revision 983 by niro, Fri Apr 24 18:33:46 2009 UTC	revision 984 by niro, Sun May 30 11:32:42 2010 UTC
#	Line 7	Line 7
7	* /etc/shadow) for a given user and password.	* /etc/shadow) for a given user and password.
8	*	*
9	* Moved from loginutils/passwd.c by Alexander Shishkin <virtuoso@slind.org>	* Moved from loginutils/passwd.c by Alexander Shishkin <virtuoso@slind.org>
10		*
11		* Modified to be able to add or delete users, groups and users to/from groups
12		* by Tito Ragusa <farmatito@tiscali.it>
13		*
14		* Licensed under GPLv2, see file LICENSE in this tarball for details.
15	*/	*/
16	#include "libbb.h"	#include "libbb.h"
17
18	#if ENABLE_SELINUX	#if ENABLE_SELINUX
#	Line 33  static void check_selinux_update_passwd(	Line 37  static void check_selinux_update_passwd(
37	freecon(context);	freecon(context);
38	}	}
39	#else	#else
40	#define check_selinux_update_passwd(username) ((void)0)	# define check_selinux_update_passwd(username) ((void)0)
41	#endif	#endif
42
43	int FAST_FUNC update_passwd(const char *filename, const char *username,	/*
44	const char *new_pw)	1) add a user: update_passwd(FILE, USER, REMAINING_PWLINE, NULL)
45		only if CONFIG_ADDUSER=y and applet_name[0] == 'a' like in adduser
46
47		2) add a group: update_passwd(FILE, GROUP, REMAINING_GRLINE, NULL)
48		only if CONFIG_ADDGROUP=y and applet_name[0] == 'a' like in addgroup
49
50		3) add a user to a group: update_passwd(FILE, GROUP, NULL, MEMBER)
51		only if CONFIG_FEATURE_ADDUSER_TO_GROUP=y, applet_name[0] == 'a'
52		like in addgroup and member != NULL
53
54		4) delete a user: update_passwd(FILE, USER, NULL, NULL)
55
56		5) delete a group: update_passwd(FILE, GROUP, NULL, NULL)
57
58		6) delete a user from a group: update_passwd(FILE, GROUP, NULL, MEMBER)
59		only if CONFIG_FEATURE_DEL_USER_FROM_GROUP=y and member != NULL
60
61		7) change user's passord: update_passwd(FILE, USER, NEW_PASSWD, NULL)
62		only if CONFIG_PASSWD=y and applet_name[0] == 'p' like in passwd
63		or if CONFIG_CHPASSWD=y and applet_name[0] == 'c' like in chpasswd
64
65		This function does not validate the arguments fed to it
66		so the calling program should take care of that.
67
68		Returns number of lines changed, or -1 on error.
69		*/
70		int FAST_FUNC update_passwd(const char *filename,
71		const char *name,
72		const char *new_passwd,
73		const char *member)
74	{	{
75		#if !(ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP)
76		#define member NULL
77		#endif
78	struct stat sb;	struct stat sb;
79	struct flock lock;	struct flock lock;
80	FILE *old_fp;	FILE *old_fp;
81	FILE *new_fp;	FILE *new_fp;
82	char *fnamesfx;	char *fnamesfx;
83	char *sfx_char;	char *sfx_char;
84		char *name_colon;
85	unsigned user_len;	unsigned user_len;
86	int old_fd;	int old_fd;
87	int new_fd;	int new_fd;
88	int i;	int i;
89	int cnt = 0;	int changed_lines;
90	int ret = -1; /* failure */	int ret = -1; /* failure */
91		/* used as a bool: "are we modifying /etc/shadow?" */
92		#if ENABLE_FEATURE_SHADOWPASSWDS
93		const char *shadow = strstr(filename, "shadow");
94		#else
95		# define shadow NULL
96		#endif
97
98	filename = xmalloc_follow_symlinks(filename);	filename = xmalloc_follow_symlinks(filename);
99	if (filename == NULL)	if (filename == NULL)
100	return -1;	return ret;
101
102	check_selinux_update_passwd(username);	check_selinux_update_passwd(name);
103
104	/* New passwd file, "/etc/passwd+" for now */	/* New passwd file, "/etc/passwd+" for now */
105	fnamesfx = xasprintf("%s+", filename);	fnamesfx = xasprintf("%s+", filename);
106	sfx_char = &fnamesfx[strlen(fnamesfx)-1];	sfx_char = &fnamesfx[strlen(fnamesfx)-1];
107	username = xasprintf("%s:", username);	name_colon = xasprintf("%s:", name);
108	user_len = strlen(username);	user_len = strlen(name_colon);
109
110	old_fp = fopen(filename, "r+");	if (shadow)
111	if (!old_fp)	old_fp = fopen(filename, "r+");
112		else
113		old_fp = fopen_or_warn(filename, "r+");
114		if (!old_fp) {
115		if (shadow)
116		ret = 0; /* missing shadow is not an error */
117	goto free_mem;	goto free_mem;
118		}
119	old_fd = fileno(old_fp);	old_fd = fileno(old_fp);
120
121	selinux_preserve_fcontext(old_fd);	selinux_preserve_fcontext(old_fd);
#	Line 80  int FAST_FUNC update_passwd(const char *	Line 129  int FAST_FUNC update_passwd(const char *
129	if (errno != EEXIST) break;	if (errno != EEXIST) break;
130	usleep(100000); /* 0.1 sec */	usleep(100000); /* 0.1 sec */
131	} while (--i);	} while (--i);
132	bb_perror_msg("cannot create '%s'", fnamesfx);	bb_perror_msg("can't create '%s'", fnamesfx);
133	goto close_old_fp;	goto close_old_fp;
134
135	created:	created:
#	Line 88  int FAST_FUNC update_passwd(const char *	Line 137  int FAST_FUNC update_passwd(const char *
137	fchmod(new_fd, sb.st_mode & 0777); /* ignore errors */	fchmod(new_fd, sb.st_mode & 0777); /* ignore errors */
138	fchown(new_fd, sb.st_uid, sb.st_gid);	fchown(new_fd, sb.st_uid, sb.st_gid);
139	}	}
140	new_fp = fdopen(new_fd, "w");	errno = 0;
141	if (!new_fp) {	new_fp = xfdopen_for_write(new_fd);
	close(new_fd);
	goto unlink_new;
	}
142
143	/* Backup file is "/etc/passwd-" */	/* Backup file is "/etc/passwd-" */
144	*sfx_char = '-';	*sfx_char = '-';
#	Line 100  int FAST_FUNC update_passwd(const char *	Line 146  int FAST_FUNC update_passwd(const char *
146	i = (unlink(fnamesfx) && errno != ENOENT);	i = (unlink(fnamesfx) && errno != ENOENT);
147	/* Create backup as a hardlink to current */	/* Create backup as a hardlink to current */
148	if (i || link(filename, fnamesfx))	if (i || link(filename, fnamesfx))
149	bb_perror_msg("warning: cannot create backup copy '%s'", fnamesfx);	bb_perror_msg("warning: can't create backup copy '%s'",
150		fnamesfx);
151	*sfx_char = '+';	*sfx_char = '+';
152
153	/* Lock the password file before updating */	/* Lock the password file before updating */
#	Line 109  int FAST_FUNC update_passwd(const char *	Line 156  int FAST_FUNC update_passwd(const char *
156	lock.l_start = 0;	lock.l_start = 0;
157	lock.l_len = 0;	lock.l_len = 0;
158	if (fcntl(old_fd, F_SETLK, &lock) < 0)	if (fcntl(old_fd, F_SETLK, &lock) < 0)
159	bb_perror_msg("warning: cannot lock '%s'", filename);	bb_perror_msg("warning: can't lock '%s'", filename);
160	lock.l_type = F_UNLCK;	lock.l_type = F_UNLCK;
161
162	/* Read current password file, write updated /etc/passwd+ */	/* Read current password file, write updated /etc/passwd+ */
163		changed_lines = 0;
164	while (1) {	while (1) {
165	char *line = xmalloc_fgets(old_fp);	char *cp, *line;
166	if (!line) break; /* EOF/error */
167	if (strncmp(username, line, user_len) == 0) {	line = xmalloc_fgetline(old_fp);
168	/* we have a match with "username:"... */	if (!line) /* EOF/error */
169	const char *cp = line + user_len;	break;
170	/* now cp -> old passwd, skip it: */	if (strncmp(name_colon, line, user_len) != 0) {
171	cp = strchrnul(cp, ':');	fprintf(new_fp, "%s\n", line);
172	/* now cp -> ':' after old passwd or -> "" */	goto next;
173	fprintf(new_fp, "%s%s%s", username, new_pw, cp);	}
174	cnt++;
175		/* We have a match with "name:"... */
176		cp = line + user_len; /* move past name: */
177
178		#if ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP
179		if (member) {
180		/* It's actually /etc/group+, not /etc/passwd+ */
181		if (ENABLE_FEATURE_ADDUSER_TO_GROUP
182		&& applet_name[0] == 'a'
183		) {
184		/* Add user to group */
185		fprintf(new_fp, "%s%s%s\n", line,
186		last_char_is(line, ':') ? "" : ",",
187		member);
188		changed_lines++;
189		} else if (ENABLE_FEATURE_DEL_USER_FROM_GROUP
190		/* && applet_name[0] == 'd' */
191		) {
192		/* Delete user from group */
193		char *tmp;
194		const char *fmt = "%s";
195
196		/* find the start of the member list: last ':' */
197		cp = strrchr(line, ':');
198		/* cut it */
199		*cp++ = '\0';
200		/* write the cut line name:passwd:gid:
201		* or name:!:: */
202		fprintf(new_fp, "%s:", line);
203		/* parse the tokens of the member list */
204		tmp = cp;
205		while ((cp = strsep(&tmp, ",")) != NULL) {
206		if (strcmp(member, cp) != 0) {
207		fprintf(new_fp, fmt, cp);
208		fmt = ",%s";
209		} else {
210		/* found member, skip it */
211		changed_lines++;
212		}
213		}
214		fprintf(new_fp, "\n");
215		}
216	} else	} else
217	fputs(line, new_fp);	#endif
218		if ((ENABLE_PASSWD && applet_name[0] == 'p')
219		|| (ENABLE_CHPASSWD && applet_name[0] == 'c')
220		) {
221		/* Change passwd */
222		cp = strchrnul(cp, ':'); /* move past old passwd */
223
224		if (shadow && *cp == ':') {
225		/* /etc/shadow's field 3 (passwd change date) needs updating */
226		/* move past old change date */
227		cp = strchrnul(cp + 1, ':');
228		/* "name:" + "new_passwd" + ":" + "change date" + ":rest of line" */
229		fprintf(new_fp, "%s%s:%u%s\n", name_colon, new_passwd,
230		(unsigned)(time(NULL)) / (24*60*60), cp);
231		} else {
232		/* "name:" + "new_passwd" + ":rest of line" */
233		fprintf(new_fp, "%s%s%s\n", name_colon, new_passwd, cp);
234		}
235		changed_lines++;
236		} /* else delete user or group: skip the line */
237		next:
238	free(line);	free(line);
239	}	}
240
241		if (changed_lines == 0) {
242		#if ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP
243		if (member) {
244		if (ENABLE_ADDGROUP && applet_name[0] == 'a')
245		bb_error_msg("can't find %s in %s", name, filename);
246		if (ENABLE_DELGROUP && applet_name[0] == 'd')
247		bb_error_msg("can't find %s in %s", member, filename);
248		}
249		#endif
250		if ((ENABLE_ADDUSER || ENABLE_ADDGROUP)
251		&& applet_name[0] == 'a' && !member
252		) {
253		/* add user or group */
254		fprintf(new_fp, "%s%s\n", name_colon, new_passwd);
255		changed_lines++;
256		}
257		}
258
259	fcntl(old_fd, F_SETLK, &lock);	fcntl(old_fd, F_SETLK, &lock);
260
261	/* We do want all of them to execute, thus | instead of || */	/* We do want all of them to execute, thus | instead of || */
262		errno = 0;
263	if ((ferror(old_fp) | fflush(new_fp) | fsync(new_fd) | fclose(new_fp))	if ((ferror(old_fp) | fflush(new_fp) | fsync(new_fd) | fclose(new_fp))
264	|| rename(fnamesfx, filename)	|| rename(fnamesfx, filename)
265	) {	) {
266	/* At least one of those failed */	/* At least one of those failed */
267		bb_perror_nomsg();
268	goto unlink_new;	goto unlink_new;
269	}	}
270	ret = cnt; /* whee, success! */	/* Success: ret >= 0 */
271		ret = changed_lines;
272
273	unlink_new:	unlink_new:
274	if (ret < 0) unlink(fnamesfx);	if (ret < 0)
275		unlink(fnamesfx);
276
277	close_old_fp:	close_old_fp:
278	fclose(old_fp);	fclose(old_fp);
#	Line 148  int FAST_FUNC update_passwd(const char *	Line 280  int FAST_FUNC update_passwd(const char *
280	free_mem:	free_mem:
281	free(fnamesfx);	free(fnamesfx);
282	free((char *)filename);	free((char *)filename);
283	free((char *)username);	free(name_colon);
284	return ret;	return ret;
285	}	}

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Legend: Removed from v.983   changed lines   Added in v.984