2 * Handle the mapping of uid/gid and user/group names between systems.
4 * Copyright (C) 1996 Andrew Tridgell
5 * Copyright (C) 1996 Paul Mackerras
6 * Copyright (C) 2004-2007 Wayne Davison
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
22 /* If the source username/group does not exist on the target then use
23 * the numeric IDs. Never do any mapping for uid=0 or gid=0 as these
30 # define GETGROUPS_T gid_t
36 extern int preserve_uid;
37 extern int preserve_gid;
38 extern int numeric_ids;
46 static struct idlist *uidlist;
47 static struct idlist *gidlist;
49 static struct idlist *add_to_list(struct idlist **root, int id, char *name,
52 struct idlist *node = new(struct idlist);
54 out_of_memory("add_to_list");
63 /* turn a uid into a user name */
64 static char *uid_to_name(uid_t uid)
66 struct passwd *pass = getpwuid(uid);
68 return strdup(pass->pw_name);
72 /* turn a gid into a group name */
73 static char *gid_to_name(gid_t gid)
75 struct group *grp = getgrgid(gid);
77 return strdup(grp->gr_name);
81 static uid_t map_uid(uid_t id, char *name)
84 if (id != 0 && name_to_uid(name, &uid))
89 static gid_t map_gid(gid_t id, char *name)
92 if (id != 0 && name_to_gid(name, &gid))
97 static int is_in_group(gid_t gid)
100 static gid_t last_in = GID_NONE, last_out;
101 static int ngroups = -2;
102 static GETGROUPS_T *gidset;
108 gid_t mygid = MY_GID();
109 if ((ngroups = getgroups(0, NULL)) < 0)
111 gidset = new_array(GETGROUPS_T, ngroups+1);
113 out_of_memory("is_in_group");
115 ngroups = getgroups(ngroups, gidset);
116 /* The default gid might not be in the list on some systems. */
117 for (n = 0; n < ngroups; n++) {
118 if (gidset[n] == mygid)
122 gidset[ngroups++] = mygid;
125 char *gidbuf = new_array(char, ngroups*21+32);
127 out_of_memory("is_in_group");
128 pos = snprintf(gidbuf, 32, "process has %d gid%s: ",
129 ngroups, ngroups == 1? "" : "s");
130 for (n = 0; n < ngroups; n++) {
131 pos += snprintf(gidbuf+pos, 21, " %d", (int)gidset[n]);
133 rprintf(FINFO, "%s\n", gidbuf);
139 for (n = 0; n < ngroups; n++) {
140 if (gidset[n] == gid)
146 static gid_t mygid = GID_NONE;
147 if (mygid == GID_NONE) {
150 rprintf(FINFO, "process has gid %d\n", (int)mygid);
156 /* Add a uid to the list of uids. Only called on receiving side. */
157 static uid_t recv_add_uid(uid_t id, char *name)
159 uid_t id2 = name ? map_uid(id, name) : id;
162 node = add_to_list(&uidlist, (int)id, name, (int)id2);
165 rprintf(FINFO, "uid %d(%s) maps to %d\n",
166 (int)id, name ? name : "", (int)id2);
172 /* Add a gid to the list of gids. Only called on receiving side. */
173 static gid_t recv_add_gid(gid_t id, char *name)
175 gid_t id2 = name ? map_gid(id, name) : id;
178 if (!am_root && !is_in_group(id2))
180 node = add_to_list(&gidlist, (int)id, name, (int)id2);
183 rprintf(FINFO, "gid %d(%s) maps to %d\n",
184 (int)id, name ? name : "", (int)id2);
190 /* this function is a definate candidate for a faster algorithm */
191 uid_t match_uid(uid_t uid)
193 static uid_t last_in, last_out;
204 for (list = uidlist; list; list = list->next) {
205 if (list->id == (int)uid)
206 return last_out = (uid_t)list->id2;
209 return last_out = uid;
212 gid_t match_gid(gid_t gid)
214 static gid_t last_in = GID_NONE, last_out = GID_NONE;
225 for (list = gidlist; list; list = list->next) {
226 if (list->id == (int)gid)
227 return last_out = (gid_t)list->id2;
230 return last_out = recv_add_gid(gid, NULL);
233 /* Add a uid to the list of uids. Only called on sending side. */
234 char *add_uid(uid_t uid)
239 if (uid == 0) /* don't map root */
242 for (list = uidlist; list; list = list->next) {
243 if (list->id == (int)uid)
247 node = add_to_list(&uidlist, (int)uid, uid_to_name(uid), 0);
251 /* Add a gid to the list of gids. Only called on sending side. */
252 char *add_gid(gid_t gid)
257 if (gid == 0) /* don't map root */
260 for (list = gidlist; list; list = list->next) {
261 if (list->id == (int)gid)
265 node = add_to_list(&gidlist, (int)gid, gid_to_name(gid), 0);
269 /* send a complete uid/gid mapping to the peer */
270 void send_uid_list(int f)
276 /* we send sequences of uid/byte-length/name */
277 for (list = uidlist; list; list = list->next) {
280 len = strlen(list->name);
281 write_int(f, list->id);
283 write_buf(f, list->name, len);
286 /* terminate the uid list with a 0 uid. We explicitly exclude
293 for (list = gidlist; list; list = list->next) {
296 len = strlen(list->name);
297 write_int(f, list->id);
299 write_buf(f, list->name, len);
305 uid_t recv_user_name(int f, uid_t uid)
307 int len = read_byte(f);
308 char *name = new_array(char, len+1);
310 out_of_memory("recv_user_name");
311 read_sbuf(f, name, len);
312 return recv_add_uid(uid, name); /* node keeps name's memory */
315 gid_t recv_group_name(int f, gid_t gid)
317 int len = read_byte(f);
318 char *name = new_array(char, len+1);
320 out_of_memory("recv_group_name");
321 read_sbuf(f, name, len);
322 return recv_add_gid(gid, name); /* node keeps name's memory */
325 /* recv a complete uid/gid mapping from the peer and map the uid/gid
326 * in the file list to local names */
327 void recv_uid_list(int f, struct file_list *flist)
331 if (preserve_uid && !numeric_ids) {
332 /* read the uid list */
333 while ((id = read_int(f)) != 0)
334 recv_user_name(f, (uid_t)id);
337 if (preserve_gid && !numeric_ids) {
338 /* read the gid list */
339 while ((id = read_int(f)) != 0)
340 recv_group_name(f, (gid_t)id);
343 /* Now convert all the uids/gids from sender values to our values. */
344 if (am_root && preserve_uid && !numeric_ids) {
345 for (i = 0; i < flist->count; i++)
346 F_OWNER(flist->files[i]) = match_uid(F_UID(flist->files[i]));
348 if (preserve_gid && (!am_root || !numeric_ids)) {
349 for (i = 0; i < flist->count; i++)
350 F_GROUP(flist->files[i]) = match_gid(F_GID(flist->files[i]));