1 /*
2 * Copyright (C) Igor Sysoev
3 * Copyright (C) NGINX, Inc.
4 */
5
6 #include <nxt_main.h>
7
8
9 static nxt_int_t nxt_credential_groups_get(nxt_task_t *task, nxt_mp_t *mp,
10 nxt_credential_t *uc);
11
12
13 nxt_int_t
nxt_credential_get(nxt_task_t * task,nxt_mp_t * mp,nxt_credential_t * uc,const char * group)14 nxt_credential_get(nxt_task_t *task, nxt_mp_t *mp, nxt_credential_t *uc,
15 const char *group)
16 {
17 struct group *grp;
18 struct passwd *pwd;
19
20 nxt_errno = 0;
21
22 pwd = getpwnam(uc->user);
23
24 if (nxt_slow_path(pwd == NULL)) {
25
26 if (nxt_errno == 0) {
27 nxt_alert(task, "getpwnam(\"%s\") failed, user \"%s\" not found",
28 uc->user, uc->user);
29 } else {
30 nxt_alert(task, "getpwnam(\"%s\") failed %E", uc->user, nxt_errno);
31 }
32
33 return NXT_ERROR;
34 }
35
36 uc->uid = pwd->pw_uid;
37 uc->base_gid = pwd->pw_gid;
38
39 if (group != NULL && group[0] != '\0') {
40 nxt_errno = 0;
41
42 grp = getgrnam(group);
43
44 if (nxt_slow_path(grp == NULL)) {
45
46 if (nxt_errno == 0) {
47 nxt_alert(task,
48 "getgrnam(\"%s\") failed, group \"%s\" not found",
49 group, group);
50 } else {
51 nxt_alert(task, "getgrnam(\"%s\") failed %E", group, nxt_errno);
52 }
53
54 return NXT_ERROR;
55 }
56
57 uc->base_gid = grp->gr_gid;
58 }
59
60 nxt_debug(task, "about to get \"%s\" groups (uid:%d, base gid:%d)",
61 uc->user, uc->uid, uc->base_gid);
62
63 if (nxt_credential_groups_get(task, mp, uc) != NXT_OK) {
64 return NXT_ERROR;
65 }
66
67 #if (NXT_DEBUG)
68 {
69 u_char *p, *end;
70 nxt_uint_t i;
71 u_char msg[NXT_MAX_ERROR_STR];
72
73 p = msg;
74 end = msg + NXT_MAX_ERROR_STR;
75
76 for (i = 0; i < uc->ngroups; i++) {
77 p = nxt_sprintf(p, end, "%d%c", uc->gids[i],
78 i+1 < uc->ngroups ? ',' : '\0');
79 }
80
81 nxt_debug(task, "user \"%s\" has gids:%*s", uc->user, p - msg, msg);
82 }
83 #endif
84
85 return NXT_OK;
86 }
87
88
89 #if (NXT_HAVE_GETGROUPLIST && !NXT_MACOSX)
90
91 #define NXT_NGROUPS nxt_min(256, NGROUPS_MAX)
92
93
94 static nxt_int_t
nxt_credential_groups_get(nxt_task_t * task,nxt_mp_t * mp,nxt_credential_t * uc)95 nxt_credential_groups_get(nxt_task_t *task, nxt_mp_t *mp,
96 nxt_credential_t *uc)
97 {
98 int ngroups;
99 gid_t groups[NXT_NGROUPS];
100
101 ngroups = NXT_NGROUPS;
102
103 if (getgrouplist(uc->user, uc->base_gid, groups, &ngroups) < 0) {
104 if (nxt_slow_path(ngroups <= NXT_NGROUPS)) {
105 nxt_alert(task, "getgrouplist(\"%s\", %d, ...) failed %E", uc->user,
106 uc->base_gid, nxt_errno);
107
108 return NXT_ERROR;
109 }
110 }
111
112 if (ngroups > NXT_NGROUPS) {
113 if (ngroups > NGROUPS_MAX) {
114 ngroups = NGROUPS_MAX;
115 }
116
117 uc->ngroups = ngroups;
118
119 uc->gids = nxt_mp_alloc(mp, ngroups * sizeof(gid_t));
120 if (nxt_slow_path(uc->gids == NULL)) {
121 return NXT_ERROR;
122 }
123
124 if (nxt_slow_path(getgrouplist(uc->user, uc->base_gid, uc->gids,
125 &ngroups) < 0)) {
126
127 nxt_alert(task, "getgrouplist(\"%s\", %d) failed %E", uc->user,
128 uc->base_gid, nxt_errno);
129
130 return NXT_ERROR;
131 }
132
133 return NXT_OK;
134 }
135
136 uc->ngroups = ngroups;
137
138 uc->gids = nxt_mp_alloc(mp, ngroups * sizeof(gid_t));
139 if (nxt_slow_path(uc->gids == NULL)) {
140 return NXT_ERROR;
141 }
142
143 nxt_memcpy(uc->gids, groups, ngroups * sizeof(gid_t));
144
145 return NXT_OK;
146 }
147
148
149 #else
150
151 /*
152 * For operating systems that lack getgrouplist(3) or it's buggy (MacOS),
153 * nxt_credential_groups_get() stores an array of groups IDs which should be
154 * set by the setgroups() function for a given user. The initgroups()
155 * may block a just forked worker process for some time if LDAP or NDIS+
156 * is used, so nxt_credential_groups_get() allows to get worker user groups in
157 * main process. In a nutshell the initgroups() calls getgrouplist()
158 * followed by setgroups(). However older Solaris lacks the getgrouplist().
159 * Besides getgrouplist() does not allow to query the exact number of
160 * groups in some platforms, while NGROUPS_MAX can be quite large (e.g.
161 * 65536 on Linux).
162 * So nxt_credential_groups_get() emulates getgrouplist(): at first the
163 * function saves the super-user groups IDs, then calls initgroups() and saves
164 * the specified user groups IDs, and then restores the super-user groups IDs.
165 * This works at least on Linux, FreeBSD, and Solaris, but does not work
166 * on MacOSX, getgroups(2):
167 *
168 * To provide compatibility with applications that use getgroups() in
169 * environments where users may be in more than {NGROUPS_MAX} groups,
170 * a variant of getgroups(), obtained when compiling with either the
171 * macros _DARWIN_UNLIMITED_GETGROUPS or _DARWIN_C_SOURCE defined, can
172 * be used that is not limited to {NGROUPS_MAX} groups. However, this
173 * variant only returns the user's default group access list and not
174 * the group list modified by a call to setgroups(2).
175 *
176 * For such cases initgroups() is used in worker process as fallback.
177 */
178
179 static nxt_int_t
nxt_credential_groups_get(nxt_task_t * task,nxt_mp_t * mp,nxt_credential_t * uc)180 nxt_credential_groups_get(nxt_task_t *task, nxt_mp_t *mp, nxt_credential_t *uc)
181 {
182 int nsaved, ngroups;
183 nxt_int_t ret;
184 nxt_gid_t *saved;
185
186 nsaved = getgroups(0, NULL);
187
188 if (nxt_slow_path(nsaved == -1)) {
189 nxt_alert(task, "getgroups(0, NULL) failed %E", nxt_errno);
190 return NXT_ERROR;
191 }
192
193 nxt_debug(task, "getgroups(0, NULL): %d", nsaved);
194
195 if (nsaved > NGROUPS_MAX) {
196 /* MacOSX case. */
197
198 uc->gids = NULL;
199 uc->ngroups = 0;
200
201 return NXT_OK;
202 }
203
204 saved = nxt_mp_alloc(mp, nsaved * sizeof(nxt_gid_t));
205
206 if (nxt_slow_path(saved == NULL)) {
207 return NXT_ERROR;
208 }
209
210 ret = NXT_ERROR;
211
212 nsaved = getgroups(nsaved, saved);
213
214 if (nxt_slow_path(nsaved == -1)) {
215 nxt_alert(task, "getgroups(%d) failed %E", nsaved, nxt_errno);
216 goto free;
217 }
218
219 nxt_debug(task, "getgroups(): %d", nsaved);
220
221 if (initgroups(uc->user, uc->base_gid) != 0) {
222 if (nxt_errno == NXT_EPERM) {
223 nxt_log(task, NXT_LOG_NOTICE,
224 "initgroups(%s, %d) failed %E, ignored",
225 uc->user, uc->base_gid, nxt_errno);
226
227 ret = NXT_OK;
228
229 goto free;
230
231 } else {
232 nxt_alert(task, "initgroups(%s, %d) failed %E",
233 uc->user, uc->base_gid, nxt_errno);
234 goto restore;
235 }
236 }
237
238 ngroups = getgroups(0, NULL);
239
240 if (nxt_slow_path(ngroups == -1)) {
241 nxt_alert(task, "getgroups(0, NULL) failed %E", nxt_errno);
242 goto restore;
243 }
244
245 nxt_debug(task, "getgroups(0, NULL): %d", ngroups);
246
247 uc->gids = nxt_mp_alloc(mp, ngroups * sizeof(nxt_gid_t));
248
249 if (nxt_slow_path(uc->gids == NULL)) {
250 goto restore;
251 }
252
253 ngroups = getgroups(ngroups, uc->gids);
254
255 if (nxt_slow_path(ngroups == -1)) {
256 nxt_alert(task, "getgroups(%d) failed %E", ngroups, nxt_errno);
257 goto restore;
258 }
259
260 uc->ngroups = ngroups;
261
262 ret = NXT_OK;
263
264 restore:
265
266 if (nxt_slow_path(setgroups(nsaved, saved) != 0)) {
267 nxt_alert(task, "setgroups(%d) failed %E", nsaved, nxt_errno);
268 ret = NXT_ERROR;
269 }
270
271 free:
272
273 nxt_mp_free(mp, saved);
274
275 return ret;
276 }
277
278
279 #endif
280
281
282 nxt_int_t
nxt_credential_setuid(nxt_task_t * task,nxt_credential_t * uc)283 nxt_credential_setuid(nxt_task_t *task, nxt_credential_t *uc)
284 {
285 nxt_debug(task, "user cred set: \"%s\" uid:%d", uc->user, uc->uid);
286
287 if (setuid(uc->uid) != 0) {
288
289 #if (NXT_HAVE_CLONE)
290 if (nxt_errno == EINVAL) {
291 nxt_log(task, NXT_LOG_ERR, "The uid %d (user \"%s\") isn't "
292 "valid in the application namespace.", uc->uid, uc->user);
293 return NXT_ERROR;
294 }
295 #endif
296
297 nxt_alert(task, "setuid(%d) failed %E", uc->uid, nxt_errno);
298 return NXT_ERROR;
299 }
300
301 return NXT_OK;
302 }
303
304
305 nxt_int_t
nxt_credential_setgids(nxt_task_t * task,nxt_credential_t * uc)306 nxt_credential_setgids(nxt_task_t *task, nxt_credential_t *uc)
307 {
308 nxt_runtime_t *rt;
309
310 nxt_debug(task, "user cred set gids: base gid:%d, ngroups: %d",
311 uc->base_gid, uc->ngroups);
312
313 rt = task->thread->runtime;
314
315 if (setgid(uc->base_gid) != 0) {
316
317 #if (NXT_HAVE_CLONE)
318 if (nxt_errno == EINVAL) {
319 nxt_log(task, NXT_LOG_ERR, "The gid %d isn't valid in the "
320 "application namespace.", uc->base_gid);
321 return NXT_ERROR;
322 }
323 #endif
324
325 nxt_alert(task, "setgid(%d) failed %E", uc->base_gid, nxt_errno);
326 return NXT_ERROR;
327 }
328
329 if (!rt->capabilities.setid) {
330 return NXT_OK;
331 }
332
333 if (nxt_slow_path(uc->ngroups > 0
334 && setgroups(uc->ngroups, uc->gids) != 0)) {
335
336 #if (NXT_HAVE_CLONE)
337 if (nxt_errno == EINVAL) {
338 nxt_log(task, NXT_LOG_ERR, "The user \"%s\" (uid: %d) has "
339 "supplementary group ids not valid in the application "
340 "namespace.", uc->user, uc->uid);
341 return NXT_ERROR;
342 }
343 #endif
344
345 nxt_alert(task, "setgroups(%i) failed %E", uc->ngroups, nxt_errno);
346 return NXT_ERROR;
347 }
348
349 return NXT_OK;
350 }
351