glusterd: make peerfile parsing more robust

Differential Revision: https://phabricator.intern.facebook.com/D5498639

Change-Id: I3184ed8f3dadbdcffd46f4ade855fa93131efa82
BUG: 1462969
Signed-off-by: Jeff Darcy <jdarcy@fb.com>
Reviewed-on: https://review.gluster.org/17885
Smoke: Gluster Build System <jenkins@build.gluster.org>
Tested-by: Jeff Darcy <jeff@pl.atyp.us>
Reviewed-by: Prashanth Pai <ppai@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>

2 files changed, 90 insertions, 14 deletions

diff --git a/tests/basic/peer-parsing.t b/tests/basic/peer-parsing.t
new file mode 100644
index 00000000000..210ec8ccd90
--- /dev/null
+++ b/tests/basic/peer-parsing.t
@@ -0,0 +1,52 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+
+PEER_DIR=/var/lib/glusterd/peers
+TEST mkdir -p $PEER_DIR
+
+declare -i HOST_NUM=100
+
+create_random_peer_files() {
+        for i in $(seq 0 9); do
+                local peer_uuid=$(uuidgen)
+                # The rules for quoting and variable substitution in
+                # here documents would force this to be even less
+                # readable that way.
+                (
+                        echo "state=1"
+                        echo "uuid=$peer_uuid"
+                        echo "hostname=127.0.0.$HOST_NUM"
+                ) > $PEER_DIR/$peer_uuid
+                HOST_NUM+=1
+        done
+}
+
+create_non_peer_file() {
+        echo "random stuff" > $PEER_DIR/not_a_peer_file
+}
+
+create_malformed_peer_file() {
+        echo "more random stuff" > $PEER_DIR/$(uuidgen)
+}
+
+# We create lots of files, in batches, to ensure that our bogus ones are
+# properly interspersed with the valid ones.
+
+TEST create_random_peer_files
+TEST create_non_peer_file
+TEST create_random_peer_files
+TEST create_malformed_peer_file
+TEST create_random_peer_files
+
+# There should be 30 peers, not counting the two bogus files.
+TEST glusterd
+N_PEERS=$($CLI peer status | grep ^Uuid: | wc -l)
+TEST [ "$N_PEERS" = "30" ]
+
+# For extra credit, check the logs for messages about bogus files.
+
+cleanup
+
+
+
diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c
index 8eb301f040f..2dc35174f95 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.c
+++ b/xlators/mgmt/glusterd/src/glusterd-store.c
@@ -4293,6 +4293,8 @@ glusterd_store_retrieve_peers (xlator_t *this)
         glusterd_peerctx_args_t   args               = {0};
         gf_store_op_errno_t       op_errno           = GD_STORE_SUCCESS;
         glusterd_peer_hostname_t *address            = NULL;
+        uuid_t                    tmp_uuid;
+        gf_boolean_t              is_ok;
 
         GF_ASSERT (this);
         priv = this->private;
@@ -4312,21 +4314,29 @@ glusterd_store_retrieve_peers (xlator_t *this)
                 goto out;
         }
 
-        GF_FOR_EACH_ENTRY_IN_DIR (entry, dir, scratch);
-
-        while (entry) {
+        for (;;) {
+                GF_FOR_EACH_ENTRY_IN_DIR (entry, dir, scratch);
+                if (!entry) {
+                        break;
+                }
+                if (gf_uuid_parse (entry->d_name, tmp_uuid) != 0) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "skipping non-peer file %s", entry->d_name);
+                        continue;
+                }
+                is_ok = _gf_false;
                 snprintf (filepath, PATH_MAX, "%s/%s", path, entry->d_name);
                 ret = gf_store_handle_retrieve (filepath, &shandle);
                 if (ret)
-                        goto out;
+                        goto next;
 
                 ret = gf_store_iter_new (shandle, &iter);
                 if (ret)
-                        goto out;
+                        goto next;
 
                 ret = gf_store_iter_get_next (iter, &key, &value, &op_errno);
                 if (ret)
-                        goto out;
+                        goto next;
 
                 /* Create an empty peerinfo object before reading in the
                  * details
@@ -4335,7 +4345,7 @@ glusterd_store_retrieve_peers (xlator_t *this)
                                                   NULL, 0);
                 if (peerinfo == NULL) {
                         ret = -1;
-                        goto out;
+                        goto next;
                 }
 
                 while (!ret) {
@@ -4367,11 +4377,18 @@ glusterd_store_retrieve_peers (xlator_t *this)
                                                       &op_errno);
                 }
                 if (op_errno != GD_STORE_EOF) {
-                        goto out;
+                        goto next;
                 }
 
                 (void) gf_store_iter_destroy (iter);
 
+                if (gf_uuid_is_null (peerinfo->uuid)) {
+                        gf_log ("", GF_LOG_ERROR,
+                            "Null UUID while attempting to read peer from '%s'",
+                            filepath);
+                        goto next;
+                }
+
                 /* Set first hostname from peerinfo->hostnames to
                  * peerinfo->hostname
                  */
@@ -4380,17 +4397,27 @@ glusterd_store_retrieve_peers (xlator_t *this)
                                           hostname_list);
                 if (!address) {
                         ret = -1;
-                        goto out;
+                        goto next;
                 }
                 peerinfo->hostname = gf_strdup (address->hostname);
 
                 ret = glusterd_friend_add_from_peerinfo (peerinfo, 1, NULL);
                 if (ret)
-                        goto out;
+                        goto next;
 
                 peerinfo->shandle = shandle;
+                is_ok = _gf_true;
+
+next:
+                if (!is_ok) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "skipping malformed peer file %s",
+                                entry->d_name);
+                        if (peerinfo) {
+                                glusterd_peerinfo_cleanup (peerinfo);
+                        }
+                }
                 peerinfo = NULL;
-                GF_FOR_EACH_ENTRY_IN_DIR (entry, dir, scratch);
         }
 
         args.mode = GD_MODE_ON;
@@ -4405,9 +4432,6 @@ glusterd_store_retrieve_peers (xlator_t *this)
         peerinfo = NULL;
 
 out:
-        if (peerinfo)
-                glusterd_peerinfo_cleanup (peerinfo);
-
         if (dir)
                 sys_closedir (dir);
         gf_msg_debug (this->name, 0, "Returning with %d", ret);