* /etc/shadow) for a given user and password.
*
* Moved from loginutils/passwd.c by Alexander Shishkin <virtuoso@slind.org>
+ *
+ * Modified to be able to add or delete users, groups and users to/from groups
+ * by Tito Ragusa <farmatito@tiscali.it>
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
-
#include "libbb.h"
#if ENABLE_SELINUX
char *seuser;
if (getuid() != (uid_t)0 || is_selinux_enabled() == 0)
- return; /* No need to check */
+ return; /* No need to check */
if (getprevcon_raw(&context) < 0)
- bb_perror_msg_and_die("getprevcon failed");
+ bb_simple_perror_msg_and_die("getprevcon failed");
seuser = strtok(context, ":");
if (!seuser)
bb_error_msg_and_die("invalid context '%s'", context);
if (strcmp(seuser, username) != 0) {
- if (checkPasswdAccess(PASSWD__PASSWD) != 0)
- bb_error_msg_and_die("SELinux: access denied");
+ security_class_t tclass;
+ access_vector_t av;
+
+ tclass = string_to_security_class("passwd");
+ if (tclass == 0)
+ goto die;
+ av = string_to_av_perm(tclass, "passwd");
+ if (av == 0)
+ goto die;
+
+ if (selinux_check_passwd_access(av) != 0)
+ die:
+ bb_simple_error_msg_and_die("SELinux: access denied");
}
if (ENABLE_FEATURE_CLEAN_UP)
freecon(context);
}
#else
-#define check_selinux_update_passwd(username) ((void)0)
+# define check_selinux_update_passwd(username) ((void)0)
#endif
-int update_passwd(const char *filename, const char *username,
- const char *new_pw)
+/*
+ 1) add a user: update_passwd(FILE, USER, REMAINING_PWLINE, NULL)
+ only if CONFIG_ADDUSER=y and applet_name[0] == 'a' like in adduser
+
+ 2) add a group: update_passwd(FILE, GROUP, REMAINING_GRLINE, NULL)
+ only if CONFIG_ADDGROUP=y and applet_name[0] == 'a' like in addgroup
+
+ 3) add a user to a group: update_passwd(FILE, GROUP, NULL, MEMBER)
+ only if CONFIG_FEATURE_ADDUSER_TO_GROUP=y, applet_name[0] == 'a'
+ like in addgroup and member != NULL
+
+ 4) delete a user: update_passwd(FILE, USER, NULL, NULL)
+
+ 5) delete a group: update_passwd(FILE, GROUP, NULL, NULL)
+
+ 6) delete a user from a group: update_passwd(FILE, GROUP, NULL, MEMBER)
+ only if CONFIG_FEATURE_DEL_USER_FROM_GROUP=y and member != NULL
+
+ 7) change user's password: update_passwd(FILE, USER, NEW_PASSWD, NULL)
+ only if CONFIG_PASSWD=y and applet_name[0] == 'p' like in passwd
+ or if CONFIG_CHPASSWD=y and applet_name[0] == 'c' like in chpasswd
+
+ 8) delete a user from all groups: update_passwd(FILE, NULL, NULL, MEMBER)
+
+ This function does not validate the arguments fed to it
+ so the calling program should take care of that.
+
+ Returns number of lines changed, or -1 on error.
+*/
+int FAST_FUNC update_passwd(const char *filename,
+ const char *name,
+ const char *new_passwd,
+ const char *member)
{
+#if !(ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP)
+#define member NULL
+#endif
struct stat sb;
struct flock lock;
FILE *old_fp;
FILE *new_fp;
char *fnamesfx;
char *sfx_char;
- unsigned user_len;
+ char *name_colon;
int old_fd;
int new_fd;
int i;
- int cnt = 0;
+ int changed_lines;
int ret = -1; /* failure */
+ /* used as a bool: "are we modifying /etc/shadow?" */
+#if ENABLE_FEATURE_SHADOWPASSWDS
+ const char *shadow = strstr(filename, "shadow");
+#else
+# define shadow NULL
+#endif
filename = xmalloc_follow_symlinks(filename);
if (filename == NULL)
- return -1;
+ return ret;
- check_selinux_update_passwd(username);
+ if (name)
+ check_selinux_update_passwd(name);
/* New passwd file, "/etc/passwd+" for now */
fnamesfx = xasprintf("%s+", filename);
sfx_char = &fnamesfx[strlen(fnamesfx)-1];
- username = xasprintf("%s:", username);
- user_len = strlen(username);
+ name_colon = xasprintf("%s:", name ? name : "");
- old_fp = fopen(filename, "r+");
- if (!old_fp)
+ if (shadow)
+ old_fp = fopen(filename, "r+");
+ else
+ old_fp = fopen_or_warn(filename, "r+");
+ if (!old_fp) {
+ if (shadow)
+ ret = 0; /* missing shadow is not an error */
goto free_mem;
+ }
old_fd = fileno(old_fp);
selinux_preserve_fcontext(old_fd);
if (errno != EEXIST) break;
usleep(100000); /* 0.1 sec */
} while (--i);
- bb_perror_msg("cannot create '%s'", fnamesfx);
+ bb_perror_msg("can't create '%s'", fnamesfx);
goto close_old_fp;
created:
- if (!fstat(old_fd, &sb)) {
+ if (fstat(old_fd, &sb) == 0) {
fchmod(new_fd, sb.st_mode & 0777); /* ignore errors */
fchown(new_fd, sb.st_uid, sb.st_gid);
}
- new_fp = fdopen(new_fd, "w");
- if (!new_fp) {
- close(new_fd);
- goto unlink_new;
- }
+ errno = 0;
+ new_fp = xfdopen_for_write(new_fd);
/* Backup file is "/etc/passwd-" */
*sfx_char = '-';
i = (unlink(fnamesfx) && errno != ENOENT);
/* Create backup as a hardlink to current */
if (i || link(filename, fnamesfx))
- bb_perror_msg("warning: cannot create backup copy '%s'", fnamesfx);
+ bb_perror_msg("warning: can't create backup copy '%s'",
+ fnamesfx);
*sfx_char = '+';
/* Lock the password file before updating */
lock.l_start = 0;
lock.l_len = 0;
if (fcntl(old_fd, F_SETLK, &lock) < 0)
- bb_perror_msg("warning: cannot lock '%s'", filename);
+ bb_perror_msg("warning: can't lock '%s'", filename);
lock.l_type = F_UNLCK;
/* Read current password file, write updated /etc/passwd+ */
+ changed_lines = 0;
while (1) {
- char *line = xmalloc_fgets(old_fp);
- if (!line) break; /* EOF/error */
- if (strncmp(username, line, user_len) == 0) {
- /* we have a match with "username:"... */
- const char *cp = line + user_len;
- /* now cp -> old passwd, skip it: */
- cp = strchrnul(cp, ':');
- /* now cp -> ':' after old passwd or -> "" */
- fprintf(new_fp, "%s%s%s", username, new_pw, cp);
- cnt++;
+ char *cp, *line;
+
+ line = xmalloc_fgetline(old_fp);
+ if (!line) /* EOF/error */
+ break;
+
+#if ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP
+ if (!name && member) {
+ /* Delete member from all groups */
+ /* line is "GROUP:PASSWD:[member1[,member2]...]" */
+ unsigned member_len = strlen(member);
+ char *list = strrchr(line, ':');
+ while (list) {
+ list++;
+ next_list_element:
+ if (is_prefixed_with(list, member)) {
+ char c;
+ changed_lines++;
+ c = list[member_len];
+ if (c == '\0') {
+ if (list[-1] == ',')
+ list--;
+ *list = '\0';
+ break;
+ }
+ if (c == ',') {
+ overlapping_strcpy(list, list + member_len + 1);
+ goto next_list_element;
+ }
+ changed_lines--;
+ }
+ list = strchr(list, ',');
+ }
+ fprintf(new_fp, "%s\n", line);
+ goto next;
+ }
+#endif
+
+ cp = is_prefixed_with(line, name_colon);
+ if (!cp) {
+ fprintf(new_fp, "%s\n", line);
+ goto next;
+ }
+
+ /* We have a match with "name:"... */
+ /* cp points past "name:" */
+
+#if ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP
+ if (member) {
+ /* It's actually /etc/group+, not /etc/passwd+ */
+ if (ENABLE_FEATURE_ADDUSER_TO_GROUP
+ && applet_name[0] == 'a'
+ ) {
+ /* Add user to group */
+ fprintf(new_fp, "%s%s%s\n", line,
+ last_char_is(line, ':') ? "" : ",",
+ member);
+ changed_lines++;
+ } else if (ENABLE_FEATURE_DEL_USER_FROM_GROUP
+ /* && applet_name[0] == 'd' */
+ ) {
+ /* Delete user from group */
+ char *tmp;
+ const char *fmt = "%s";
+
+ /* find the start of the member list: last ':' */
+ cp = strrchr(line, ':');
+ /* cut it */
+ *cp++ = '\0';
+ /* write the cut line name:passwd:gid:
+ * or name:!:: */
+ fprintf(new_fp, "%s:", line);
+ /* parse the tokens of the member list */
+ tmp = cp;
+ while ((cp = strsep(&tmp, ",")) != NULL) {
+ if (strcmp(member, cp) != 0) {
+ fprintf(new_fp, fmt, cp);
+ fmt = ",%s";
+ } else {
+ /* found member, skip it */
+ changed_lines++;
+ }
+ }
+ fprintf(new_fp, "\n");
+ }
} else
- fputs(line, new_fp);
+#endif
+ if ((ENABLE_PASSWD && applet_name[0] == 'p')
+ || (ENABLE_CHPASSWD && applet_name[0] == 'c')
+ ) {
+ /* Change passwd */
+ cp = strchrnul(cp, ':'); /* move past old passwd */
+
+ if (shadow && *cp == ':') {
+ /* /etc/shadow's field 3 (passwd change date) needs updating */
+ /* move past old change date */
+ unsigned time_days = (unsigned long)(time(NULL)) / (24*60*60);
+
+ if (time_days == 0) {
+ /* 0 as change date has special meaning, avoid it */
+ time_days = 1;
+ }
+ cp = strchrnul(cp + 1, ':');
+ /* "name:" + "new_passwd" + ":" + "change date" + ":rest of line" */
+ fprintf(new_fp, "%s%s:%u%s\n", name_colon, new_passwd,
+ time_days, cp);
+ } else {
+ /* "name:" + "new_passwd" + ":rest of line" */
+ fprintf(new_fp, "%s%s%s\n", name_colon, new_passwd, cp);
+ }
+ changed_lines++;
+ } /* else delete user or group: skip the line */
+ next:
free(line);
}
+
+ if (changed_lines == 0) {
+#if ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP
+ if (member) {
+ if (ENABLE_ADDGROUP && applet_name[0] == 'a')
+ bb_error_msg("can't find %s in %s", name, filename);
+ if (ENABLE_DELGROUP && applet_name[0] == 'd')
+ bb_error_msg("can't find %s in %s", member, filename);
+ }
+#endif
+ if ((ENABLE_ADDUSER || ENABLE_ADDGROUP)
+ && applet_name[0] == 'a' && !member
+ ) {
+ /* add user or group */
+ fprintf(new_fp, "%s%s\n", name_colon, new_passwd);
+ changed_lines++;
+ }
+ }
+
fcntl(old_fd, F_SETLK, &lock);
/* We do want all of them to execute, thus | instead of || */
+ errno = 0;
if ((ferror(old_fp) | fflush(new_fp) | fsync(new_fd) | fclose(new_fp))
|| rename(fnamesfx, filename)
) {
/* At least one of those failed */
+ bb_perror_nomsg();
goto unlink_new;
}
- ret = cnt; /* whee, success! */
+ /* Success: ret >= 0 */
+ ret = changed_lines;
unlink_new:
- if (ret < 0) unlink(fnamesfx);
+ if (ret < 0)
+ unlink(fnamesfx);
close_old_fp:
fclose(old_fp);
free_mem:
free(fnamesfx);
free((char *)filename);
- free((char *)username);
+ free(name_colon);
return ret;
}
projects / oweals / busybox.git / blobdiff