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