| 1 | /* |
| 2 | Copyright (C) Andrew Tridgell 1996 |
| 3 | Copyright (C) Paul Mackerras 1996 |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 2 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, write to the Free Software |
| 17 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 18 | */ |
| 19 | |
| 20 | /* handle the mapping of uid/gid and user/group names between systems. |
| 21 | If the source username/group does not exist on the target then use |
| 22 | the numeric ids. Never do any mapping for uid=0 or gid=0 as these |
| 23 | are special. |
| 24 | */ |
| 25 | |
| 26 | #include "rsync.h" |
| 27 | |
| 28 | #ifdef GETGROUPS_T |
| 29 | # ifndef NGROUPS_MAX |
| 30 | /* It ought to be defined, but just in case. */ |
| 31 | # define NGROUPS_MAX 32 |
| 32 | # endif |
| 33 | #endif |
| 34 | |
| 35 | extern int preserve_uid; |
| 36 | extern int preserve_gid; |
| 37 | extern int numeric_ids; |
| 38 | extern int am_root; |
| 39 | |
| 40 | struct idlist { |
| 41 | struct idlist *next; |
| 42 | int id, id2; |
| 43 | char *name; |
| 44 | }; |
| 45 | |
| 46 | static struct idlist *uidlist; |
| 47 | static struct idlist *gidlist; |
| 48 | |
| 49 | static struct idlist *add_list(int id, char *name) |
| 50 | { |
| 51 | struct idlist *list = new(struct idlist); |
| 52 | if (!list) out_of_memory("add_list"); |
| 53 | list->next = NULL; |
| 54 | list->name = strdup(name); |
| 55 | if (!list->name) out_of_memory("add_list"); |
| 56 | list->id = (int)id; |
| 57 | return list; |
| 58 | } |
| 59 | |
| 60 | |
| 61 | |
| 62 | /* turn a uid into a user name */ |
| 63 | static char *uid_to_name(uid_t uid) |
| 64 | { |
| 65 | struct passwd *pass = getpwuid(uid); |
| 66 | if (pass) return(pass->pw_name); |
| 67 | return NULL; |
| 68 | } |
| 69 | |
| 70 | /* turn a gid into a group name */ |
| 71 | static char *gid_to_name(gid_t gid) |
| 72 | { |
| 73 | struct group *grp = getgrgid(gid); |
| 74 | if (grp) return(grp->gr_name); |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | static int map_uid(int id, char *name) |
| 79 | { |
| 80 | uid_t uid; |
| 81 | if (uid != 0 && name_to_uid(name, &uid)) |
| 82 | return uid; |
| 83 | return id; |
| 84 | } |
| 85 | |
| 86 | static int map_gid(int id, char *name) |
| 87 | { |
| 88 | gid_t gid; |
| 89 | if (gid != 0 && name_to_gid(name, &gid)) |
| 90 | return gid; |
| 91 | return id; |
| 92 | } |
| 93 | |
| 94 | /* this function is a definate candidate for a faster algorithm */ |
| 95 | static uid_t match_uid(uid_t uid) |
| 96 | { |
| 97 | static uid_t last_in, last_out; |
| 98 | struct idlist *list = uidlist; |
| 99 | |
| 100 | if (uid == last_in) return last_out; |
| 101 | |
| 102 | last_in = uid; |
| 103 | |
| 104 | while (list) { |
| 105 | if (list->id == (int)uid) { |
| 106 | last_out = (uid_t)list->id2; |
| 107 | return last_out; |
| 108 | } |
| 109 | list = list->next; |
| 110 | } |
| 111 | |
| 112 | last_out = uid; |
| 113 | return last_out; |
| 114 | } |
| 115 | |
| 116 | static int is_in_group(gid_t gid) |
| 117 | { |
| 118 | #ifdef GETGROUPS_T |
| 119 | static gid_t last_in = (gid_t) -2, last_out; |
| 120 | static int ngroups = -2; |
| 121 | static GETGROUPS_T *gidset; |
| 122 | int n; |
| 123 | |
| 124 | if (gid == last_in) |
| 125 | return last_out; |
| 126 | if (ngroups < -1) { |
| 127 | gid_t mygid = getgid(); |
| 128 | ngroups = getgroups(0, 0); |
| 129 | /* If that didn't work, perhaps 0 isn't treated specially? */ |
| 130 | if (ngroups < 0) |
| 131 | ngroups = NGROUPS_MAX; |
| 132 | gidset = new_array(GETGROUPS_T, ngroups+1); |
| 133 | if (ngroups > 0) |
| 134 | ngroups = getgroups(ngroups, gidset); |
| 135 | /* The default gid might not be in the list on some systems. */ |
| 136 | for (n = 0; n < ngroups; n++) { |
| 137 | if (gidset[n] == mygid) |
| 138 | break; |
| 139 | } |
| 140 | if (n == ngroups) |
| 141 | gidset[ngroups++] = mygid; |
| 142 | } |
| 143 | |
| 144 | last_in = gid; |
| 145 | last_out = 0; |
| 146 | for (n = 0; n < ngroups; n++) { |
| 147 | if (gidset[n] == gid) { |
| 148 | last_out = 1; |
| 149 | break; |
| 150 | } |
| 151 | } |
| 152 | return last_out; |
| 153 | |
| 154 | #else |
| 155 | return 0; |
| 156 | #endif |
| 157 | } |
| 158 | |
| 159 | static gid_t match_gid(gid_t gid) |
| 160 | { |
| 161 | static gid_t last_in = (gid_t) -2, last_out; |
| 162 | struct idlist *list = gidlist; |
| 163 | |
| 164 | if (gid == last_in) return last_out; |
| 165 | |
| 166 | last_in = gid; |
| 167 | |
| 168 | while (list) { |
| 169 | if (list->id == (int)gid) { |
| 170 | last_out = (gid_t)list->id2; |
| 171 | return last_out; |
| 172 | } |
| 173 | list = list->next; |
| 174 | } |
| 175 | |
| 176 | if (am_root) |
| 177 | last_out = gid; |
| 178 | else |
| 179 | last_out = GID_NONE; |
| 180 | return last_out; |
| 181 | } |
| 182 | |
| 183 | /* add a uid to the list of uids */ |
| 184 | void add_uid(uid_t uid) |
| 185 | { |
| 186 | struct idlist *list = uidlist; |
| 187 | char *name; |
| 188 | |
| 189 | if (numeric_ids) return; |
| 190 | |
| 191 | /* don't map root */ |
| 192 | if (uid==0) return; |
| 193 | |
| 194 | if (!list) { |
| 195 | if (!(name = uid_to_name(uid))) return; |
| 196 | uidlist = add_list((int)uid, name); |
| 197 | return; |
| 198 | } |
| 199 | |
| 200 | while (list->next) { |
| 201 | if (list->id == (int)uid) return; |
| 202 | list = list->next; |
| 203 | } |
| 204 | |
| 205 | if (list->id == (int)uid) return; |
| 206 | |
| 207 | if (!(name = uid_to_name(uid))) return; |
| 208 | |
| 209 | list->next = add_list((int)uid, name); |
| 210 | } |
| 211 | |
| 212 | /* add a gid to the list of gids */ |
| 213 | void add_gid(gid_t gid) |
| 214 | { |
| 215 | struct idlist *list = gidlist; |
| 216 | char *name; |
| 217 | |
| 218 | if (numeric_ids) return; |
| 219 | |
| 220 | /* don't map root */ |
| 221 | if (gid==0) return; |
| 222 | |
| 223 | if (!list) { |
| 224 | if (!(name = gid_to_name(gid))) return; |
| 225 | gidlist = add_list((int)gid, name); |
| 226 | return; |
| 227 | } |
| 228 | |
| 229 | while (list->next) { |
| 230 | if (list->id == (int)gid) return; |
| 231 | list = list->next; |
| 232 | } |
| 233 | |
| 234 | if (list->id == (int)gid) return; |
| 235 | |
| 236 | if (!(name = gid_to_name(gid))) return; |
| 237 | |
| 238 | list->next = add_list((int)gid, name); |
| 239 | } |
| 240 | |
| 241 | |
| 242 | /* send a complete uid/gid mapping to the peer */ |
| 243 | void send_uid_list(int f) |
| 244 | { |
| 245 | struct idlist *list; |
| 246 | |
| 247 | if (numeric_ids) return; |
| 248 | |
| 249 | if (preserve_uid) { |
| 250 | /* we send sequences of uid/byte-length/name */ |
| 251 | list = uidlist; |
| 252 | while (list) { |
| 253 | int len = strlen(list->name); |
| 254 | write_int(f, list->id); |
| 255 | write_byte(f, len); |
| 256 | write_buf(f, list->name, len); |
| 257 | list = list->next; |
| 258 | } |
| 259 | |
| 260 | /* terminate the uid list with a 0 uid. We explicitly exclude |
| 261 | 0 from the list */ |
| 262 | write_int(f, 0); |
| 263 | } |
| 264 | |
| 265 | if (preserve_gid) { |
| 266 | list = gidlist; |
| 267 | while (list) { |
| 268 | int len = strlen(list->name); |
| 269 | write_int(f, list->id); |
| 270 | write_byte(f, len); |
| 271 | write_buf(f, list->name, len); |
| 272 | list = list->next; |
| 273 | } |
| 274 | write_int(f, 0); |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | /* recv a complete uid/gid mapping from the peer and map the uid/gid |
| 279 | in the file list to local names */ |
| 280 | void recv_uid_list(int f, struct file_list *flist) |
| 281 | { |
| 282 | int id, i; |
| 283 | char *name; |
| 284 | struct idlist *list; |
| 285 | |
| 286 | if (numeric_ids) return; |
| 287 | |
| 288 | if (preserve_uid) { |
| 289 | /* read the uid list */ |
| 290 | list = uidlist; |
| 291 | while ((id = read_int(f)) != 0) { |
| 292 | int len = read_byte(f); |
| 293 | name = new_array(char, len+1); |
| 294 | if (!name) out_of_memory("recv_uid_list"); |
| 295 | read_sbuf(f, name, len); |
| 296 | if (!list) { |
| 297 | uidlist = add_list(id, name); |
| 298 | list = uidlist; |
| 299 | } else { |
| 300 | list->next = add_list(id, name); |
| 301 | list = list->next; |
| 302 | } |
| 303 | list->id2 = map_uid(id, name); |
| 304 | free(name); |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | |
| 309 | if (preserve_gid) { |
| 310 | /* and the gid list */ |
| 311 | list = gidlist; |
| 312 | while ((id = read_int(f)) != 0) { |
| 313 | int len = read_byte(f); |
| 314 | name = new_array(char, len+1); |
| 315 | if (!name) out_of_memory("recv_uid_list"); |
| 316 | read_sbuf(f, name, len); |
| 317 | if (!list) { |
| 318 | gidlist = add_list(id, name); |
| 319 | list = gidlist; |
| 320 | } else { |
| 321 | list->next = add_list(id, name); |
| 322 | list = list->next; |
| 323 | } |
| 324 | list->id2 = map_gid(id, name); |
| 325 | if (!am_root && !is_in_group(list->id2)) |
| 326 | list->id2 = GID_NONE; |
| 327 | free(name); |
| 328 | } |
| 329 | } |
| 330 | |
| 331 | if (!(am_root && preserve_uid) && !preserve_gid) return; |
| 332 | |
| 333 | /* now convert the uid/gid of all files in the list to the mapped |
| 334 | uid/gid */ |
| 335 | for (i = 0; i < flist->count; i++) { |
| 336 | if (am_root && preserve_uid && flist->files[i]->uid != 0) |
| 337 | flist->files[i]->uid = match_uid(flist->files[i]->uid); |
| 338 | if (preserve_gid && (!am_root || flist->files[i]->gid != 0)) |
| 339 | flist->files[i]->gid = match_gid(flist->files[i]->gid); |
| 340 | } |
| 341 | } |