/* * Copyright (c) 1991 - 1994, Julianne Frances Haugh * Copyright (c) 2008 , Nicolas François * 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. The name of the copyright holders or contributors may not be used to * endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT * HOLDERS 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. */ #include #include #include #include "prototypes.h" #include "pwio.h" #include "groupio.h" #include "getdef.h" /* * find_new_uid - Find a new unused UID. * * If successful, find_new_uid provides an unused user ID in the * [UID_MIN:UID_MAX] range. * This ID should be higher than all the used UID, but if not possible, * the lowest unused ID in the range will be returned. * * Return 0 on success, -1 if no unused UIDs are available. */ int find_new_uid (int sys_user, uid_t *uid, uid_t const *preferred_uid) { const struct passwd *pwd; uid_t uid_min, uid_max, user_id; assert (uid != NULL); if (sys_user == 0) { uid_min = getdef_unum ("UID_MIN", 1000); uid_max = getdef_unum ("UID_MAX", 60000); } else { uid_min = getdef_unum ("SYS_UID_MIN", 1); uid_max = getdef_unum ("UID_MIN", 1000) - 1; uid_max = getdef_unum ("SYS_UID_MAX", uid_max); } if ( (NULL != preferred_uid) && (*preferred_uid >= uid_min) && (*preferred_uid <= uid_max) /* Check if the user exists according to NSS */ && (getpwuid (*preferred_uid) == NULL) /* Check also the local database in case of uncommitted * changes */ && (pw_locate_uid (*preferred_uid) == NULL)) { *uid = *preferred_uid; return 0; } user_id = uid_min; /* * Search the entire password file, * looking for the largest unused value. * * We check the list of users according to NSS (setpwent/getpwent), * but we also check the local database (pw_rewind/pw_next) in case * some users were created but the changes were not committed yet. */ setpwent (); pw_rewind (); while ( ((pwd = getpwent ()) != NULL) || ((pwd = pw_next ()) != NULL)) { if ((pwd->pw_uid >= user_id) && (pwd->pw_uid <= uid_max)) { user_id = pwd->pw_uid + 1; } } endpwent (); /* * If a user with UID equal to UID_MAX exists, the above algorithm * will give us UID_MAX+1 even if not unique. Search for the first * free UID starting with UID_MIN (it's O(n*n) but can be avoided * by not having users with UID equal to UID_MAX). --marekm */ if (user_id == uid_max + 1) { for (user_id = uid_min; user_id < uid_max; user_id++) { /* local, no need for xgetpwuid */ if ( (getpwuid (user_id) == NULL) && (pw_locate_uid (user_id) == NULL)) { break; } } if (user_id == uid_max) { fputs (_("Can't get unique UID (no more available UIDs)\n"), stderr); return -1; } } *uid = user_id; return 0; } /* * find_new_gid - Find a new unused GID. * * If successful, find_new_gid provides an unused group ID in the * [GID_MIN:GID_MAX] range. * This ID should be higher than all the used GID, but if not possible, * the lowest unused ID in the range will be returned. * * Return 0 on success, -1 if no unused GIDs are available. */ int find_new_gid (int sys_group, gid_t *gid, gid_t const *preferred_gid) { const struct group *grp; gid_t gid_min, gid_max, group_id; assert (gid != NULL); if (sys_group == 0) { gid_min = getdef_unum ("GID_MIN", 1000); gid_max = getdef_unum ("GID_MAX", 60000); } else { gid_min = getdef_unum ("SYS_GID_MIN", 1); gid_max = getdef_unum ("GID_MIN", 1000) - 1; gid_max = getdef_unum ("SYS_GID_MAX", gid_max); } if ( (NULL != preferred_gid) && (*preferred_gid >= gid_min) && (*preferred_gid <= gid_max) /* Check if the user exists according to NSS */ && (getgrgid (*preferred_gid) == NULL) /* Check also the local database in case of uncommitted * changes */ && (gr_locate_gid (*preferred_gid) == NULL)) { *gid = *preferred_gid; return 0; } group_id = gid_min; /* * Search the entire group file, * looking for the largest unused value. * * We check the list of users according to NSS (setpwent/getpwent), * but we also check the local database (pw_rewind/pw_next) in case * some groups were created but the changes were not committed yet. */ setgrent (); gr_rewind (); while ( ((grp = getgrent ()) != NULL) || ((grp = gr_next ()) != NULL)) { if ((grp->gr_gid >= group_id) && (grp->gr_gid <= gid_max)) { group_id = grp->gr_gid + 1; } } endgrent (); /* * If a group with GID equal to GID_MAX exists, the above algorithm * will give us GID_MAX+1 even if not unique. Search for the first * free GID starting with GID_MIN (it's O(n*n) but can be avoided * by not having users with GID equal to GID_MAX). --marekm */ if (group_id == gid_max + 1) { for (group_id = gid_min; group_id < gid_max; group_id++) { /* local, no need for xgetgrgid */ if ( (getgrgid (group_id) == NULL) && (gr_locate_gid (group_id) == NULL)) { break; } } if (group_id == gid_max) { fputs (_("Can't get unique GID (no more available GIDs)\n"), stderr); return -1; } } *gid = group_id; return 0; }