tftpd: options -c (allow _new_ files to be uploaded) and -u USER
[oweals/busybox.git] / loginutils / addgroup.c
index af1cd7a8353de89cd04edaaa3b200d99f546ec42..b25f8171df7416f2baacf03052b5aa7740b0644d 100644 (file)
 /* vi: set sw=4 ts=4: */
 /*
- * addgroup - add users to /etc/passwd and /etc/shadow
+ * addgroup - add groups to /etc/group and /etc/gshadow
  *
  * Copyright (C) 1999 by Lineo, inc. and John Beppu
  * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
+ * Copyright (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  *
  */
 
-#include <errno.h>
-#include <fcntl.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/param.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include "busybox.h"
-#include "pwd_.h"
-#include "grp_.h"
-
-
-/* structs __________________________ */
-
-/* data _____________________________ */
+#include "libbb.h"
 
-/* defaults : should this be in an external file? */
-static const char default_passwd[] = "x";
-
-
-/* make sure gr_name isn't taken, make sure gid is kosher
- * return 1 on failure */
-static int group_study(const char *filename, struct group *g)
+static void xgroup_study(struct group *g)
 {
-       FILE *etc_group;
-       gid_t desired;
-
-       struct group *grp;
-       const int max = 65000;
-
-       etc_group = bb_xfopen(filename, "r");
+       /* Make sure gr_name is unused */
+       if (getgrnam(g->gr_name)) {
+               goto error;
+       }
 
-       /* make sure gr_name isn't taken, make sure gid is kosher */
-       desired = g->gr_gid;
-       while ((grp = fgetgrent(etc_group))) {
-               if ((strcmp(grp->gr_name, g->gr_name)) == 0) {
-                       bb_error_msg_and_die("%s: group already in use\n", g->gr_name);
+       /* Check if the desired gid is free
+        * or find the first free one */
+       while (1) {
+               if (!getgrgid(g->gr_gid)) {
+                       return; /* found free group: return */
                }
-               if ((desired) && grp->gr_gid == desired) {
-                       bb_error_msg_and_die("%d: gid has already been allocated\n",
-                                                         desired);
+               if (option_mask32) {
+                       /* -g N, cannot pick gid other than N: error */
+                       g->gr_name = itoa(g->gr_gid);
+                       goto error;
                }
-               if ((grp->gr_gid > g->gr_gid) && (grp->gr_gid < max)) {
-                       g->gr_gid = grp->gr_gid;
+               g->gr_gid++;
+               if (g->gr_gid <= 0) {
+                       /* overflowed: error */
+                       bb_error_msg_and_die("no gids left");
                }
        }
-       fclose(etc_group);
 
-       /* gid */
-       if (desired) {
-               g->gr_gid = desired;
-       } else {
-               g->gr_gid++;
-       }
-       /* return 1; */
-       return 0;
+ error:
+       /* exit */
+       bb_error_msg_and_die("group %s already exists", g->gr_name);
 }
 
 /* append a new user to the passwd file */
-static int addgroup(const char *filename, char *group, gid_t gid, const char *user)
+static void new_group(char *group, gid_t gid)
 {
-       FILE *etc_group;
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
-       FILE *etc_gshadow;
-#endif
-
+       FILE *file;
        struct group gr;
 
-       /* group:passwd:gid:userlist */
-       static const char entryfmt[] = "%s:%s:%d:%s\n";
-
        /* make sure gid and group haven't already been allocated */
        gr.gr_gid = gid;
        gr.gr_name = group;
-       if (group_study(filename, &gr))
-               return 1;
+       xgroup_study(&gr);
 
        /* add entry to group */
-       etc_group = bb_xfopen(filename, "a");
-
-       fprintf(etc_group, entryfmt, group, default_passwd, gr.gr_gid, user);
-       fclose(etc_group);
-
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
-       /* add entry to gshadow if necessary */
-       if (access(bb_path_gshadow_file, F_OK|W_OK) == 0) {
-               etc_gshadow = bb_xfopen(bb_path_gshadow_file, "a");
-               fprintf(etc_gshadow, "%s:!::\n", group);
-               fclose(etc_gshadow);
+       file = xfopen(bb_path_group_file, "a");
+       /* group:passwd:gid:userlist */
+       fprintf(file, "%s:x:%u:\n", group, (unsigned)gr.gr_gid);
+       if (ENABLE_FEATURE_CLEAN_UP)
+               fclose(file);
+#if ENABLE_FEATURE_SHADOWPASSWDS
+       file = fopen_or_warn(bb_path_gshadow_file, "a");
+       if (file) {
+               fprintf(file, "%s:!::\n", group);
+               if (ENABLE_FEATURE_CLEAN_UP)
+                       fclose(file);
        }
 #endif
-
-       /* return 1; */
-       return 0;
 }
 
-#ifndef CONFIG_ADDUSER
-static inline void if_i_am_not_root(void)
+#if ENABLE_FEATURE_ADDUSER_TO_GROUP
+static void add_user_to_group(char **args,
+               const char *path,
+               FILE *(*fopen_func)(const char *fileName, const char *mode))
 {
-       if (geteuid()) {
-               bb_error_msg_and_die( "Only root may add a user or group to the system.");
+       char *line;
+       int len = strlen(args[1]);
+       llist_t *plist = NULL;
+       FILE *group_file;
+
+       group_file = fopen_func(path, "r");
+
+       if (!group_file) return;
+
+       while ((line = xmalloc_getline(group_file))) {
+               /* Find the group */
+               if (!strncmp(line, args[1], len)
+                && line[len] == ':'
+               ) {
+                       /* Add the new user */
+                       line = xasprintf("%s%s%s", line,
+                                               last_char_is(line, ':') ? "" : ",",
+                                               args[0]);
+               }
+               llist_add_to_end(&plist, line);
+       }
+
+       if (ENABLE_FEATURE_CLEAN_UP) {
+               fclose(group_file);
+               group_file = fopen_func(path, "w");
+               while ((line = llist_pop(&plist))) {
+                       if (group_file)
+                               fprintf(group_file, "%s\n", line);
+                       free(line);
+               }
+               if (group_file)
+                       fclose(group_file);
+       } else {
+               group_file = fopen_func(path, "w");
+               if (group_file)
+                       while ((line = llist_pop(&plist)))
+                               fprintf(group_file, "%s\n", line);
        }
 }
-#else
-extern void if_i_am_not_root(void);
 #endif
 
 /*
  * addgroup will take a login_name as its first parameter.
  *
- * gid 
- *
- * can be customized via command-line parameters.
- * ________________________________________________________________________ */
-int addgroup_main(int argc, char **argv)
+ * gid can be customized via command-line parameters.
+ * If called with two non-option arguments, addgroup
+ * will add an existing user to an existing group.
+ */
+int addgroup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int addgroup_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
        char *group;
-       char *user;
        gid_t gid = 0;
 
-       /* get remaining args */
-       if(bb_getopt_ulflags(argc, argv, "g:", &group)) {
-               gid = strtol(group, NULL, 10);
+       /* need to be root */
+       if (geteuid()) {
+               bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
        }
 
-       if (optind < argc) {
-               group = argv[optind];
-               optind++;
-       } else {
-               bb_show_usage();
-       }
-       
-       if (optind < argc) {
-               user = argv[optind];
-               optind++;
-       } else {
-               user = "";
+       /* Syntax:
+        *  addgroup group
+        *  addgroup -g num group
+        *  addgroup user group
+        * Check for min, max and missing args */
+       opt_complementary = "-1:?2";
+       if (getopt32(argv, "g:", &group)) {
+               gid = xatoul_range(group, 0, ((unsigned long)(gid_t)ULONG_MAX) >> 1);
        }
-       if_i_am_not_root();
+       /* move past the commandline options */
+       argv += optind;
+       //argc -= optind;
+
+#if ENABLE_FEATURE_ADDUSER_TO_GROUP
+       if (argv[1]) {
+               struct group *gr;
+
+               if (option_mask32) {
+                       /* -g was there, but "addgroup -g num user group"
+                        * is a no-no */
+                       bb_show_usage();
+               }
+
+               /* check if group and user exist */
+               xuname2uid(argv[0]); /* unknown user: exit */
+               xgroup2gid(argv[1]); /* unknown group: exit */
+               /* check if user is already in this group */
+               gr = getgrnam(argv[1]);
+               for (; *(gr->gr_mem) != NULL; (gr->gr_mem)++) {
+                       if (!strcmp(argv[0], *(gr->gr_mem))) {
+                               /* user is already in group: do nothing */
+                               return EXIT_SUCCESS;
+                       }
+               }
+               add_user_to_group(argv, bb_path_group_file, xfopen);
+#if ENABLE_FEATURE_SHADOWPASSWDS
+               add_user_to_group(argv, bb_path_gshadow_file, fopen_or_warn);
+#endif
+       } else
+#endif /* ENABLE_FEATURE_ADDUSER_TO_GROUP */
+               new_group(argv[0], gid);
 
-       /* werk */
-       return addgroup(bb_path_group_file, group, gid, user);
+       /* Reached only on success */
+       return EXIT_SUCCESS;
 }