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
31 extern int preserve_uid;
32 extern int preserve_gid;
33 extern int preserve_acls;
34 extern int numeric_ids;
38 # define GETGROUPS_T gid_t
42 #define GID_NONE ((gid_t)-1)
51 static struct idlist *uidlist;
52 static struct idlist *gidlist;
54 static struct idlist *add_to_list(struct idlist **root, id_t id, char *name,
55 id_t id2, uint16 flags)
57 struct idlist *node = new(struct idlist);
59 out_of_memory("add_to_list");
69 /* turn a uid into a user name */
70 static char *uid_to_name(uid_t uid)
72 struct passwd *pass = getpwuid(uid);
74 return strdup(pass->pw_name);
78 /* turn a gid into a group name */
79 static char *gid_to_name(gid_t gid)
81 struct group *grp = getgrgid(gid);
83 return strdup(grp->gr_name);
87 static uid_t map_uid(uid_t id, char *name)
90 if (id != 0 && name_to_uid(name, &uid))
95 static gid_t map_gid(gid_t id, char *name)
98 if (id != 0 && name_to_gid(name, &gid))
103 static int is_in_group(gid_t gid)
105 #ifdef HAVE_GETGROUPS
106 static gid_t last_in = GID_NONE, last_out;
107 static int ngroups = -2;
108 static GETGROUPS_T *gidset;
114 gid_t mygid = MY_GID();
115 if ((ngroups = getgroups(0, NULL)) < 0)
117 gidset = new_array(GETGROUPS_T, ngroups+1);
119 out_of_memory("is_in_group");
121 ngroups = getgroups(ngroups, gidset);
122 /* The default gid might not be in the list on some systems. */
123 for (n = 0; n < ngroups; n++) {
124 if (gidset[n] == mygid)
128 gidset[ngroups++] = mygid;
131 char *gidbuf = new_array(char, ngroups*21+32);
133 out_of_memory("is_in_group");
134 pos = snprintf(gidbuf, 32, "process has %d gid%s: ",
135 ngroups, ngroups == 1? "" : "s");
136 for (n = 0; n < ngroups; n++) {
137 pos += snprintf(gidbuf+pos, 21, " %d", (int)gidset[n]);
139 rprintf(FINFO, "%s\n", gidbuf);
145 for (n = 0; n < ngroups; n++) {
146 if (gidset[n] == gid)
152 static gid_t mygid = GID_NONE;
153 if (mygid == GID_NONE) {
156 rprintf(FINFO, "process has gid %u\n", (unsigned)mygid);
162 /* Add a uid to the list of uids. Only called on receiving side. */
163 static struct idlist *recv_add_uid(uid_t id, char *name)
165 uid_t id2 = name ? map_uid(id, name) : id;
168 node = add_to_list(&uidlist, id, name, id2, 0);
171 rprintf(FINFO, "uid %u(%s) maps to %u\n",
172 (unsigned)id, name ? name : "", (unsigned)id2);
178 /* Add a gid to the list of gids. Only called on receiving side. */
179 static struct idlist *recv_add_gid(gid_t id, char *name)
181 gid_t id2 = name ? map_gid(id, name) : id;
184 node = add_to_list(&gidlist, id, name, id2,
185 !am_root && !is_in_group(id2) ? FLAG_SKIP_GROUP : 0);
188 rprintf(FINFO, "gid %u(%s) maps to %u\n",
189 (unsigned)id, name ? name : "", (unsigned)id2);
195 /* this function is a definate candidate for a faster algorithm */
196 uid_t match_uid(uid_t uid)
198 static uid_t last_in, last_out;
209 for (list = uidlist; list; list = list->next) {
211 return last_out = list->id2;
214 return last_out = uid;
217 gid_t match_gid(gid_t gid, uint16 *flags_ptr)
219 static gid_t last_in = GID_NONE, last_out = GID_NONE;
227 for (list = gidlist; list; list = list->next) {
233 list = recv_add_gid(gid, NULL);
235 if (flags_ptr && list->flags & FLAG_SKIP_GROUP)
236 *flags_ptr |= FLAG_SKIP_GROUP;
237 return last_out = list->id2;
240 /* Add a uid to the list of uids. Only called on sending side. */
241 char *add_uid(uid_t uid)
246 if (uid == 0) /* don't map root */
249 for (list = uidlist; list; list = list->next) {
254 node = add_to_list(&uidlist, uid, uid_to_name(uid), 0, 0);
258 /* Add a gid to the list of gids. Only called on sending side. */
259 char *add_gid(gid_t gid)
264 if (gid == 0) /* don't map root */
267 for (list = gidlist; list; list = list->next) {
272 node = add_to_list(&gidlist, gid, gid_to_name(gid), 0, 0);
276 /* send a complete uid/gid mapping to the peer */
277 void send_id_list(int f)
281 if (preserve_uid || preserve_acls) {
283 /* we send sequences of uid/byte-length/name */
284 for (list = uidlist; list; list = list->next) {
287 len = strlen(list->name);
288 write_varint30(f, list->id);
290 write_buf(f, list->name, len);
293 /* terminate the uid list with a 0 uid. We explicitly exclude
295 write_varint30(f, 0);
298 if (preserve_gid || preserve_acls) {
300 for (list = gidlist; list; list = list->next) {
303 len = strlen(list->name);
304 write_varint30(f, list->id);
306 write_buf(f, list->name, len);
308 write_varint30(f, 0);
312 uid_t recv_user_name(int f, uid_t uid)
315 int len = read_byte(f);
316 char *name = new_array(char, len+1);
318 out_of_memory("recv_user_name");
319 read_sbuf(f, name, len);
320 node = recv_add_uid(uid, name); /* node keeps name's memory */
324 gid_t recv_group_name(int f, gid_t gid, uint16 *flags_ptr)
327 int len = read_byte(f);
328 char *name = new_array(char, len+1);
330 out_of_memory("recv_group_name");
331 read_sbuf(f, name, len);
332 node = recv_add_gid(gid, name); /* node keeps name's memory */
333 if (flags_ptr && node->flags & FLAG_SKIP_GROUP)
334 *flags_ptr |= FLAG_SKIP_GROUP;
338 /* recv a complete uid/gid mapping from the peer and map the uid/gid
339 * in the file list to local names */
340 void recv_id_list(int f, struct file_list *flist)
345 if ((preserve_uid || preserve_acls) && !numeric_ids) {
346 /* read the uid list */
347 while ((id = read_varint30(f)) != 0)
348 recv_user_name(f, id);
351 if ((preserve_gid || preserve_acls) && !numeric_ids) {
352 /* read the gid list */
353 while ((id = read_varint30(f)) != 0)
354 recv_group_name(f, id, NULL);
357 /* Now convert all the uids/gids from sender values to our values. */
359 if (preserve_acls && !numeric_ids)
362 if (am_root && preserve_uid && !numeric_ids) {
363 for (i = 0; i < flist->count; i++)
364 F_OWNER(flist->files[i]) = match_uid(F_OWNER(flist->files[i]));
366 if (preserve_gid && (!am_root || !numeric_ids)) {
367 for (i = 0; i < flist->count; i++) {
368 F_GROUP(flist->files[i]) = match_gid(F_GROUP(flist->files[i]),
369 &flist->files[i]->flags);