1 /* $NetBSD: sftp-usergroup.c,v 1.3 2023/10/25 20:19:57 christos Exp $ */
2
3 /*
4 * Copyright (c) 2022 Damien Miller <djm@mindrot.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /* sftp client user/group lookup and caching */
20 #include "includes.h"
21 __RCSID("$NetBSD: sftp-usergroup.c,v 1.3 2023/10/25 20:19:57 christos Exp $");
22
23 #include <sys/types.h>
24 #include <sys/tree.h>
25
26 #include <glob.h>
27 #include <stdlib.h>
28 #include <stdarg.h>
29 #include <string.h>
30
31 #include "log.h"
32 #include "xmalloc.h"
33
34 #include "sftp-common.h"
35 #include "sftp-client.h"
36 #include "sftp-usergroup.h"
37
38 /* Tree of id, name */
39 struct idname {
40 u_int id;
41 char *name;
42 RB_ENTRY(idname) entry;
43 /* XXX implement bounded cache as TAILQ */
44 };
45 static int
idname_cmp(struct idname * a,struct idname * b)46 idname_cmp(struct idname *a, struct idname *b)
47 {
48 if (a->id == b->id)
49 return 0;
50 return a->id > b->id ? 1 : -1;
51 }
52 RB_HEAD(idname_tree, idname);
53 RB_GENERATE_STATIC(idname_tree, idname, entry, idname_cmp)
54
55 static struct idname_tree user_idname = RB_INITIALIZER(&user_idname);
56 static struct idname_tree group_idname = RB_INITIALIZER(&group_idname);
57
58 static void
idname_free(struct idname * idname)59 idname_free(struct idname *idname)
60 {
61 if (idname == NULL)
62 return;
63 free(idname->name);
64 free(idname);
65 }
66
67 static void
idname_enter(struct idname_tree * tree,u_int id,const char * name)68 idname_enter(struct idname_tree *tree, u_int id, const char *name)
69 {
70 struct idname *idname;
71
72 if ((idname = xcalloc(1, sizeof(*idname))) == NULL)
73 fatal_f("alloc");
74 idname->id = id;
75 idname->name = xstrdup(name);
76 if (RB_INSERT(idname_tree, tree, idname) != NULL)
77 idname_free(idname);
78 }
79
80 static const char *
idname_lookup(struct idname_tree * tree,u_int id)81 idname_lookup(struct idname_tree *tree, u_int id)
82 {
83 struct idname idname, *found;
84
85 memset(&idname, 0, sizeof(idname));
86 idname.id = id;
87 if ((found = RB_FIND(idname_tree, tree, &idname)) != NULL)
88 return found->name;
89 return NULL;
90 }
91
92 static void
freenames(char ** names,u_int nnames)93 freenames(char **names, u_int nnames)
94 {
95 u_int i;
96
97 if (names == NULL)
98 return;
99 for (i = 0; i < nnames; i++)
100 free(names[i]);
101 free(names);
102 }
103
104 static void
lookup_and_record(struct sftp_conn * conn,u_int * uids,u_int nuids,u_int * gids,u_int ngids)105 lookup_and_record(struct sftp_conn *conn,
106 u_int *uids, u_int nuids, u_int *gids, u_int ngids)
107 {
108 int r;
109 u_int i;
110 char **usernames = NULL, **groupnames = NULL;
111
112 if ((r = sftp_get_users_groups_by_id(conn, uids, nuids, gids, ngids,
113 &usernames, &groupnames)) != 0) {
114 debug_fr(r, "sftp_get_users_groups_by_id");
115 return;
116 }
117 for (i = 0; i < nuids; i++) {
118 if (usernames[i] == NULL) {
119 debug3_f("uid %u not resolved", uids[i]);
120 continue;
121 }
122 debug3_f("record uid %u => \"%s\"", uids[i], usernames[i]);
123 idname_enter(&user_idname, uids[i], usernames[i]);
124 }
125 for (i = 0; i < ngids; i++) {
126 if (groupnames[i] == NULL) {
127 debug3_f("gid %u not resolved", gids[i]);
128 continue;
129 }
130 debug3_f("record gid %u => \"%s\"", gids[i], groupnames[i]);
131 idname_enter(&group_idname, gids[i], groupnames[i]);
132 }
133 freenames(usernames, nuids);
134 freenames(groupnames, ngids);
135 }
136
137 static int
has_id(u_int id,u_int * ids,u_int nids)138 has_id(u_int id, u_int *ids, u_int nids)
139 {
140 u_int i;
141
142 if (nids == 0)
143 return 0;
144
145 /* XXX O(N^2) */
146 for (i = 0; i < nids; i++) {
147 if (ids[i] == id)
148 break;
149 }
150 return i < nids;
151 }
152
153 static void
collect_ids_from_glob(glob_t * g,int user,u_int ** idsp,u_int * nidsp)154 collect_ids_from_glob(glob_t *g, int user, u_int **idsp, u_int *nidsp)
155 {
156 u_int id, i, n = 0, *ids = NULL;
157
158 for (i = 0; g->gl_pathv[i] != NULL; i++) {
159 struct stat *stp;
160 #if GLOB_KEEPSTAT != 0
161 stp = g->gl_statv[i];
162 #else
163 struct stat st;
164 if (lstat(g->gl_pathv[i], stp = &st) == -1) {
165 error("no stat information for %s", g->gl_pathv[i]);
166 continue;
167 }
168 #endif
169 if (user) {
170 if (ruser_name(stp->st_uid) != NULL)
171 continue; /* Already seen */
172 id = (u_int)stp->st_uid;
173 } else {
174 if (rgroup_name(stp->st_gid) != NULL)
175 continue; /* Already seen */
176 id = (u_int)stp->st_gid;
177 }
178 if (has_id(id, ids, n))
179 continue;
180 ids = xrecallocarray(ids, n, n + 1, sizeof(*ids));
181 ids[n++] = id;
182 }
183 *idsp = ids;
184 *nidsp = n;
185 }
186
187 void
get_remote_user_groups_from_glob(struct sftp_conn * conn,glob_t * g)188 get_remote_user_groups_from_glob(struct sftp_conn *conn, glob_t *g)
189 {
190 u_int *uids = NULL, nuids = 0, *gids = NULL, ngids = 0;
191
192 if (!sftp_can_get_users_groups_by_id(conn))
193 return;
194
195 collect_ids_from_glob(g, 1, &uids, &nuids);
196 collect_ids_from_glob(g, 0, &gids, &ngids);
197 lookup_and_record(conn, uids, nuids, gids, ngids);
198 free(uids);
199 free(gids);
200 }
201
202 static void
collect_ids_from_dirents(SFTP_DIRENT ** d,int user,u_int ** idsp,u_int * nidsp)203 collect_ids_from_dirents(SFTP_DIRENT **d, int user, u_int **idsp, u_int *nidsp)
204 {
205 u_int id, i, n = 0, *ids = NULL;
206
207 for (i = 0; d[i] != NULL; i++) {
208 if (user) {
209 if (ruser_name((uid_t)(d[i]->a.uid)) != NULL)
210 continue; /* Already seen */
211 id = d[i]->a.uid;
212 } else {
213 if (rgroup_name((gid_t)(d[i]->a.gid)) != NULL)
214 continue; /* Already seen */
215 id = d[i]->a.gid;
216 }
217 if (has_id(id, ids, n))
218 continue;
219 ids = xrecallocarray(ids, n, n + 1, sizeof(*ids));
220 ids[n++] = id;
221 }
222 *idsp = ids;
223 *nidsp = n;
224 }
225
226 void
get_remote_user_groups_from_dirents(struct sftp_conn * conn,SFTP_DIRENT ** d)227 get_remote_user_groups_from_dirents(struct sftp_conn *conn, SFTP_DIRENT **d)
228 {
229 u_int *uids = NULL, nuids = 0, *gids = NULL, ngids = 0;
230
231 if (!sftp_can_get_users_groups_by_id(conn))
232 return;
233
234 collect_ids_from_dirents(d, 1, &uids, &nuids);
235 collect_ids_from_dirents(d, 0, &gids, &ngids);
236 lookup_and_record(conn, uids, nuids, gids, ngids);
237 free(uids);
238 free(gids);
239 }
240
241 const char *
ruser_name(uid_t uid)242 ruser_name(uid_t uid)
243 {
244 return idname_lookup(&user_idname, (u_int)uid);
245 }
246
247 const char *
rgroup_name(uid_t gid)248 rgroup_name(uid_t gid)
249 {
250 return idname_lookup(&group_idname, (u_int)gid);
251 }
252
253