@@ -5604,6 +5604,163 @@ void send_flush_mdlog(struct ceph_mds_session *s)
mutex_unlock(&s->s_mutex);
}
+static int ceph_mds_auth_match(struct ceph_mds_client *mdsc,
+ struct ceph_mds_cap_auth *auth,
+ char *tpath)
+{
+ const struct cred *cred = get_current_cred();
+ uint32_t caller_uid = from_kuid(&init_user_ns, cred->fsuid);
+ uint32_t caller_gid = from_kgid(&init_user_ns, cred->fsgid);
+ struct ceph_client *cl = mdsc->fsc->client;
+ const char *path = mdsc->fsc->mount_options->server_path;
+ bool gid_matched = false;
+ uint32_t gid, tlen, len;
+ int i, j;
+
+ doutc(cl, "match.uid %lld\n", auth->match.uid);
+ if (auth->match.uid != MDS_AUTH_UID_ANY) {
+ if (auth->match.uid != caller_uid)
+ return 0;
+ if (auth->match.num_gids) {
+ for (i = 0; i < auth->match.num_gids; i++) {
+ if (caller_gid == auth->match.gids[i])
+ gid_matched = true;
+ }
+ if (!gid_matched && cred->group_info->ngroups) {
+ for (i = 0; i < cred->group_info->ngroups; i++) {
+ gid = from_kgid(&init_user_ns, cred->group_info->gid[i]);
+ for (j = 0; j < auth->match.num_gids; j++) {
+ if (gid == auth->match.gids[j]) {
+ gid_matched = true;
+ break;
+ }
+ }
+ if (gid_matched)
+ break;
+ }
+ }
+ if (!gid_matched)
+ return 0;
+ }
+ }
+
+ /* path match */
+ if (auth->match.path) {
+ if (!tpath)
+ return 0;
+
+ tlen = strlen(tpath);
+ len = strlen(auth->match.path);
+ if (len) {
+ char *_tpath = tpath;
+ bool free_tpath = false;
+ int m, n;
+
+ doutc(cl, "server path %s, tpath %s, match.path %s\n",
+ path, tpath, auth->match.path);
+ if (path && (m = strlen(path)) != 1) {
+ /* mount path + '/' + tpath + an extra space */
+ n = m + 1 + tlen + 1;
+ _tpath = kmalloc(n, GFP_NOFS);
+ if (!_tpath)
+ return -ENOMEM;
+ /* remove the leading '/' */
+ snprintf(_tpath, n, "%s/%s", path + 1, tpath);
+ free_tpath = true;
+ tlen = strlen(_tpath);
+ }
+
+ /* Remove the tailing '/' */
+ while (tlen && _tpath[tlen - 1] == '/') {
+ _tpath[tlen - 1] = '\0';
+ tlen -= 1;
+ }
+ doutc(cl, "_tpath %s\n", _tpath);
+
+ /* In case first == _tpath && tlen == len:
+ * path=/foo --> /foo target_path=/foo --> match
+ * path=/foo/ --> /foo target_path=/foo/ --> match
+ * path=/foo/ --> /foo target_path=/foo --> match
+ *
+ * In case first == _tpath && tlen > len:
+ * path=/foo --> /foo target_path=/foo/ --> match
+ * path=/foo/ --> /foo target_path=/foo/d --> match
+ * path=/foo --> /foo target_path=/food --> mismatch
+ *
+ * All the other cases --> mismatch
+ */
+ char *first = strstr(_tpath, auth->match.path);
+ if (first != _tpath) {
+ if (free_tpath)
+ kfree(_tpath);
+ return 0;
+ }
+
+ if (tlen > len && _tpath[len] != '/') {
+ if (free_tpath)
+ kfree(_tpath);
+ return 0;
+ }
+ }
+ }
+
+ doutc(cl, "matched\n");
+ return 1;
+}
+
+int ceph_mds_check_access(struct ceph_mds_client *mdsc, char *tpath, int mask)
+{
+ const struct cred *cred = get_current_cred();
+ uint32_t caller_uid = from_kuid(&init_user_ns, cred->fsuid);
+ uint32_t caller_gid = from_kgid(&init_user_ns, cred->fsgid);
+ struct ceph_mds_cap_auth *rw_perms_s = NULL;
+ struct ceph_client *cl = mdsc->fsc->client;
+ bool root_squash_perms = true;
+ int i, err;
+
+ doutc(cl, "tpath '%s', mask %d, caller_uid %d, caller_gid %d\n",
+ tpath, mask, caller_uid, caller_gid);
+
+ for (i = 0; i < mdsc->s_cap_auths_num; i++) {
+ struct ceph_mds_cap_auth *s = &mdsc->s_cap_auths[i];
+
+ err = ceph_mds_auth_match(mdsc, s, tpath);
+ if (err < 0) {
+ return err;
+ } else if (err > 0) {
+ // always follow the last auth caps' permision
+ root_squash_perms = true;
+ rw_perms_s = NULL;
+ if ((mask & MAY_WRITE) && s->writeable &&
+ s->match.root_squash && (!caller_uid || !caller_gid))
+ root_squash_perms = false;
+
+ if (((mask & MAY_WRITE) && !s->writeable) ||
+ ((mask & MAY_READ) && !s->readable))
+ rw_perms_s = s;
+ }
+ }
+
+ doutc(cl, "root_squash_perms %d, rw_perms_s %p\n", root_squash_perms,
+ rw_perms_s);
+ if (root_squash_perms && rw_perms_s == NULL) {
+ doutc(cl, "access allowed\n");
+ return 0;
+ }
+
+ if (!root_squash_perms) {
+ doutc(cl, "root_squash is enabled and user(%d %d) isn't allowed to write",
+ caller_uid, caller_gid);
+ }
+ if (rw_perms_s) {
+ doutc(cl, "mds auth caps readable/writeable %d/%d while request r/w %d/%d",
+ rw_perms_s->readable, rw_perms_s->writeable, !!(mask & MAY_READ),
+ !!(mask & MAY_WRITE));
+ }
+ doutc(cl, "access denied\n");
+ return -EACCES;
+}
+
/*
* called before mount is ro, and before dentries are torn down.
* (hmm, does this still race with new lookups?)
@@ -602,6 +602,9 @@ extern void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr);
extern int ceph_iterate_session_caps(struct ceph_mds_session *session,
int (*cb)(struct inode *, int mds, void *),
void *arg);
+extern int ceph_mds_check_access(struct ceph_mds_client *mdsc, char *tpath,
+ int mask);
+
extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
static inline void ceph_mdsc_free_path(char *path, int len)