bgpd: Fix graceful-restart JSON outputs and the crash

Without this patch:

```
donatas-pc# show bgp neighbors graceful-restart json
vtysh: error reading from bgpd: Resource temporarily unavailable (11)Warning: closing connection to bgpd because of an I/O error!
donatas-pc#
```

And, invalid JSON generated when multiple neighbors exist due to json_neighbor
being freed in a loop.

After the patch:

```
donatas-pc# show bgp ipv4 neighbors 192.168.10.124 graceful-restart json
{
  "192.168.10.124":{
    "neighborAddr":"192.168.10.124",
    "localGrMode":"Helper*",
    "remoteGrMode":"Restart",
    "rBit":false,
    "nBit":true,
    "timers":{
      "configuredRestartTimer":120,
      "receivedRestartTimer":120
    },
    "ipv4Unicast":{
      "fBit":true,
      "endOfRibStatus":{
        "endOfRibSend":true,
        "endOfRibSentAfterUpdate":false,
        "endOfRibRecv":true
      },
      "timers":{
        "stalePathTimer":360
      }
    }
  }
}
donatas-pc# show bgp neighbors graceful-restart json
{
  "192.168.10.124":{
    "neighborAddr":"192.168.10.124",
    "localGrMode":"Helper*",
    "remoteGrMode":"Restart",
    "rBit":false,
    "nBit":true,
    "timers":{
      "configuredRestartTimer":120,
      "receivedRestartTimer":120
    },
    "ipv4Unicast":{
      "fBit":true,
      "endOfRibStatus":{
        "endOfRibSend":true,
        "endOfRibSentAfterUpdate":false,
        "endOfRibRecv":true
      },
      "timers":{
        "stalePathTimer":360
      }
    }
  },
  "2a02:4780:abc::2":{
    "neighborAddr":"2a02:4780:abc::2",
    "localGrMode":"Helper*",
    "remoteGrMode":"Restart",
    "rBit":false,
    "nBit":true,
    "timers":{
      "configuredRestartTimer":120,
      "receivedRestartTimer":120
    },
    "ipv4Unicast":{
      "fBit":true,
      "endOfRibStatus":{
        "endOfRibSend":true,
        "endOfRibSentAfterUpdate":false,
        "endOfRibRecv":true
      },
      "timers":{
        "stalePathTimer":360
      }
    },
    "ipv6Unicast":{
      "fBit":true,
      "endOfRibStatus":{
        "endOfRibSend":true,
        "endOfRibSentAfterUpdate":true,
        "endOfRibRecv":true
      },
      "timers":{
        "stalePathTimer":360
      }
    }
  }
}
donatas-pc#
```

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

2 files changed, 65 insertions, 83 deletions

diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index 7b9400118b..64e3295a89 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -158,9 +158,7 @@ static struct peer_group *listen_range_exists(struct bgp *bgp,
 					      struct prefix *range, int exact);
 
 static void bgp_show_global_graceful_restart_mode_vty(struct vty *vty,
-						      struct bgp *bgp,
-						      bool use_json,
-						      json_object *json);
+						      struct bgp *bgp);
 
 static int bgp_show_neighbor_graceful_restart_afi_all(struct vty *vty,
 						      enum show_type type,
@@ -11856,7 +11854,6 @@ static void bgp_show_peer_afi_orf_cap(struct vty *vty, struct peer *p,
 
 static void bgp_show_neighnor_graceful_restart_flags(struct vty *vty,
 						     struct peer *p,
-						     bool use_json,
 						     json_object *json)
 {
 	bool rbit = false;
@@ -11869,7 +11866,7 @@ static void bgp_show_neighnor_graceful_restart_flags(struct vty *vty,
 		nbit = CHECK_FLAG(p->cap, PEER_CAP_GRACEFUL_RESTART_N_BIT_RCV);
 	}
 
-	if (use_json) {
+	if (json) {
 		json_object_boolean_add(json, "rBit", rbit);
 		json_object_boolean_add(json, "nBit", nbit);
 	} else {
@@ -11880,12 +11877,11 @@ static void bgp_show_neighnor_graceful_restart_flags(struct vty *vty,
 
 static void bgp_show_neighbor_graceful_restart_remote_mode(struct vty *vty,
 							   struct peer *peer,
-							   bool use_json,
 							   json_object *json)
 {
 	const char *mode = "NotApplicable";
 
-	if (!use_json)
+	if (!json)
 		vty_out(vty, "\n    Remote GR Mode: ");
 
 	if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_ADV)
@@ -11908,20 +11904,19 @@ static void bgp_show_neighbor_graceful_restart_remote_mode(struct vty *vty,
 		}
 	}
 
-	if (use_json) {
+	if (json)
 		json_object_string_add(json, "remoteGrMode", mode);
-	} else
+	else
 		vty_out(vty, mode, "\n");
 }
 
 static void bgp_show_neighbor_graceful_restart_local_mode(struct vty *vty,
 							  struct peer *p,
-							  bool use_json,
 							  json_object *json)
 {
 	const char *mode = "Invalid";
 
-	if (!use_json)
+	if (!json)
 		vty_out(vty, "    Local GR Mode: ");
 
 	if (bgp_peer_gr_mode_get(p) == PEER_HELPER)
@@ -11941,15 +11936,14 @@ static void bgp_show_neighbor_graceful_restart_local_mode(struct vty *vty,
 			mode = "Invalid*";
 	}
 
-	if (use_json) {
+	if (json)
 		json_object_string_add(json, "localGrMode", mode);
-	} else {
+	else
 		vty_out(vty, mode, "\n");
-	}
 }
 
 static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
-	struct vty *vty, struct peer *peer, bool use_json, json_object *json)
+	struct vty *vty, struct peer *peer, json_object *json)
 {
 	afi_t afi;
 	safi_t safi;
@@ -11966,7 +11960,7 @@ static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
 		    !CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV))
 			continue;
 
-		if (use_json) {
+		if (json) {
 			json_afi_safi = json_object_new_object();
 			json_endofrib_status = json_object_new_object();
 			json_timer = json_object_new_object();
@@ -11977,7 +11971,7 @@ static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
 		else
 			eor_flag = false;
 
-		if (!use_json) {
+		if (!json) {
 			vty_out(vty, "    %s:\n",
 				get_afi_safi_str(afi, safi, false));
 
@@ -11988,25 +11982,25 @@ static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
 		    CHECK_FLAG(peer->af_cap[afi][safi],
 			       PEER_CAP_RESTART_AF_PRESERVE_RCV)) {
 
-			if (use_json) {
+			if (json) {
 				json_object_boolean_true_add(json_afi_safi,
 							     "fBit");
 			} else
 				vty_out(vty, "True\n");
 		} else {
-			if (use_json)
+			if (json)
 				json_object_boolean_false_add(json_afi_safi,
 							      "fBit");
 			else
 				vty_out(vty, "False\n");
 		}
 
-		if (!use_json)
+		if (!json)
 			vty_out(vty, "      End-of-RIB sent: ");
 
 		if (CHECK_FLAG(peer->af_sflags[afi][safi],
 			       PEER_STATUS_EOR_SEND)) {
-			if (use_json) {
+			if (json) {
 				json_object_boolean_true_add(
 					json_endofrib_status, "endOfRibSend");
 
@@ -12019,7 +12013,7 @@ static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
 				PRINT_EOR(eor_flag);
 			}
 		} else {
-			if (use_json) {
+			if (json) {
 				json_object_boolean_false_add(
 					json_endofrib_status, "endOfRibSend");
 				json_object_boolean_false_add(
@@ -12033,25 +12027,25 @@ static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
 			}
 		}
 
-		if (!use_json)
+		if (!json)
 			vty_out(vty, "      End-of-RIB received: ");
 
 		if (CHECK_FLAG(peer->af_sflags[afi][safi],
 			       PEER_STATUS_EOR_RECEIVED)) {
-			if (use_json)
+			if (json)
 				json_object_boolean_true_add(
 					json_endofrib_status, "endOfRibRecv");
 			else
 				vty_out(vty, "Yes\n");
 		} else {
-			if (use_json)
+			if (json)
 				json_object_boolean_false_add(
 					json_endofrib_status, "endOfRibRecv");
 			else
 				vty_out(vty, "No\n");
 		}
 
-		if (use_json) {
+		if (json) {
 			json_object_int_add(json_timer, "stalePathTimer",
 					    peer->bgp->stalepath_time);
 
@@ -12111,7 +12105,7 @@ static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
 						peer->bgp->gr_info[afi][safi]
 							.t_select_deferral));
 		}
-		if (use_json) {
+		if (json) {
 			json_object_object_add(json_afi_safi, "endOfRibStatus",
 					       json_endofrib_status);
 			json_object_object_add(json_afi_safi, "timers",
@@ -12125,10 +12119,9 @@ static void bgp_show_neighbor_graceful_restart_capability_per_afi_safi(
 
 static void bgp_show_neighbor_graceful_restart_time(struct vty *vty,
 						    struct peer *p,
-						    bool use_json,
 						    json_object *json)
 {
-	if (use_json) {
+	if (json) {
 		json_object *json_timer = NULL;
 
 		json_timer = json_object_new_object();
@@ -12164,7 +12157,7 @@ static void bgp_show_neighbor_graceful_restart_time(struct vty *vty,
 }
 
 static void bgp_show_peer_gr_status(struct vty *vty, struct peer *p,
-				    bool use_json, json_object *json)
+				    json_object *json)
 {
 	char dn_flag[2] = {0};
 	/* '*' + v6 address of neighbor */
@@ -12174,7 +12167,7 @@ static void bgp_show_peer_gr_status(struct vty *vty, struct peer *p,
 		dn_flag[0] = '*';
 
 	if (p->conf_if) {
-		if (use_json)
+		if (json)
 			json_object_string_addf(json, "neighborAddr", "%pSU",
 						&p->su);
 		else
@@ -12184,7 +12177,7 @@ static void bgp_show_peer_gr_status(struct vty *vty, struct peer *p,
 		snprintf(neighborAddr, sizeof(neighborAddr), "%s%s", dn_flag,
 			 p->host);
 
-		if (use_json)
+		if (json)
 			json_object_string_add(json, "neighborAddr",
 					       neighborAddr);
 		else
@@ -12192,7 +12185,7 @@ static void bgp_show_peer_gr_status(struct vty *vty, struct peer *p,
 	}
 
 	/* more gr info in new format */
-	BGP_SHOW_PEER_GR_CAPABILITY(vty, p, use_json, json);
+	BGP_SHOW_PEER_GR_CAPABILITY(vty, p, json);
 }
 
 static void bgp_show_peer_afi(struct vty *vty, struct peer *p, afi_t afi,
@@ -14174,7 +14167,7 @@ static void bgp_show_peer(struct vty *vty, struct peer *p, bool use_json,
 				thread_timer_remain_second(p->t_gr_stale) *
 					1000);
 		/* more gr info in new format */
-		BGP_SHOW_PEER_GR_CAPABILITY(vty, p, use_json, json_grace);
+		BGP_SHOW_PEER_GR_CAPABILITY(vty, p, json_grace);
 		json_object_object_add(json_neigh, "gracefulRestartInfo",
 				       json_grace);
 	} else {
@@ -14220,7 +14213,7 @@ static void bgp_show_peer(struct vty *vty, struct peer *p, bool use_json,
 				thread_timer_remain_second(p->t_gr_stale));
 
 		/* more gr info in new format */
-		BGP_SHOW_PEER_GR_CAPABILITY(vty, p, use_json, NULL);
+		BGP_SHOW_PEER_GR_CAPABILITY(vty, p, NULL);
 	}
 
 	if (use_json) {
@@ -14682,20 +14675,14 @@ static int bgp_show_neighbor_graceful_restart(struct vty *vty, struct bgp *bgp,
 					      enum show_type type,
 					      union sockunion *su,
 					      const char *conf_if, afi_t afi,
-					      bool use_json)
+					      json_object *json)
 {
 	struct listnode *node, *nnode;
 	struct peer *peer;
 	int find = 0;
 	safi_t safi = SAFI_UNICAST;
-	json_object *json = NULL;
 	json_object *json_neighbor = NULL;
 
-	if (use_json) {
-		json = json_object_new_object();
-		json_neighbor = json_object_new_object();
-	}
-
 	for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
 
 		if (!CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE))
@@ -14704,15 +14691,15 @@ static int bgp_show_neighbor_graceful_restart(struct vty *vty, struct bgp *bgp,
 		if ((peer->afc[afi][safi]) == 0)
 			continue;
 
+		if (json)
+			json_neighbor = json_object_new_object();
+
 		if (type == show_all) {
-			bgp_show_peer_gr_status(vty, peer, use_json,
-						json_neighbor);
+			bgp_show_peer_gr_status(vty, peer, json_neighbor);
 
-			if (use_json) {
+			if (json)
 				json_object_object_add(json, peer->host,
 						       json_neighbor);
-				json_neighbor = NULL;
-			}
 
 		} else if (type == show_peer) {
 			if (conf_if) {
@@ -14722,41 +14709,33 @@ static int bgp_show_neighbor_graceful_restart(struct vty *vty, struct bgp *bgp,
 					&& !strcmp(peer->hostname, conf_if))) {
 					find = 1;
 					bgp_show_peer_gr_status(vty, peer,
-								use_json,
 								json_neighbor);
 				}
 			} else {
 				if (sockunion_same(&peer->su, su)) {
 					find = 1;
 					bgp_show_peer_gr_status(vty, peer,
-								use_json,
 								json_neighbor);
 				}
 			}
-			if (use_json && find)
+			if (json && find)
 				json_object_object_add(json, peer->host,
 						       json_neighbor);
 		}
 
-		if (find) {
-			json_neighbor = NULL;
+		if (find)
 			break;
-		}
 	}
 
 	if (type == show_peer && !find) {
-		if (use_json)
+		if (json)
 			json_object_boolean_true_add(json, "bgpNoSuchNeighbor");
 		else
 			vty_out(vty, "%% No such neighbor\n");
 	}
-	if (use_json) {
-		if (json_neighbor)
-			json_object_free(json_neighbor);
-		vty_json(vty, json);
-	} else {
+
+	if (!json)
 		vty_out(vty, "\n");
-	}
 
 	return CMD_SUCCESS;
 }
@@ -14869,7 +14848,7 @@ static int bgp_show_neighbor(struct vty *vty, struct bgp *bgp,
 static void bgp_show_neighbor_graceful_restart_vty(struct vty *vty,
 						   enum show_type type,
 						   const char *ip_str,
-						   afi_t afi, bool use_json)
+						   afi_t afi, json_object *json)
 {
 
 	int ret;
@@ -14881,21 +14860,20 @@ static void bgp_show_neighbor_graceful_restart_vty(struct vty *vty,
 	if (!bgp)
 		return;
 
-	if (!use_json)
-		bgp_show_global_graceful_restart_mode_vty(vty, bgp, use_json,
-							  NULL);
+	if (!json)
+		bgp_show_global_graceful_restart_mode_vty(vty, bgp);
 
 	if (ip_str) {
 		ret = str2sockunion(ip_str, &su);
 		if (ret < 0)
-			bgp_show_neighbor_graceful_restart(
-				vty, bgp, type, NULL, ip_str, afi, use_json);
+			bgp_show_neighbor_graceful_restart(vty, bgp, type, NULL,
+							   ip_str, afi, json);
 		else
 			bgp_show_neighbor_graceful_restart(vty, bgp, type, &su,
-							   NULL, afi, use_json);
+							   NULL, afi, json);
 	} else
 		bgp_show_neighbor_graceful_restart(vty, bgp, type, NULL, NULL,
-						   afi, use_json);
+						   afi, json);
 }
 
 static void bgp_show_all_instances_neighbors_vty(struct vty *vty,
@@ -15215,9 +15193,7 @@ DEFUN (show_ip_bgp_lcommunity_info,
 /* Graceful Restart */
 
 static void bgp_show_global_graceful_restart_mode_vty(struct vty *vty,
-						      struct bgp *bgp,
-						      bool use_json,
-						      json_object *json)
+						      struct bgp *bgp)
 {
 
 
@@ -15252,22 +15228,32 @@ static int bgp_show_neighbor_graceful_restart_afi_all(struct vty *vty,
 						      const char *ip_str,
 						      afi_t afi, bool use_json)
 {
+	json_object *json = NULL;
+
+	if (use_json)
+		json = json_object_new_object();
+
 	if ((afi == AFI_MAX) && (ip_str == NULL)) {
 		afi = AFI_IP;
 
 		while ((afi != AFI_L2VPN) && (afi < AFI_MAX)) {
 
 			bgp_show_neighbor_graceful_restart_vty(
-				vty, type, ip_str, afi, use_json);
+				vty, type, ip_str, afi, json);
 			afi++;
 		}
 	} else if (afi != AFI_MAX) {
 		bgp_show_neighbor_graceful_restart_vty(vty, type, ip_str, afi,
-						       use_json);
+						       json);
 	} else {
+		if (json)
+			json_object_free(json);
 		return CMD_ERR_INCOMPLETE;
 	}
 
+	if (json)
+		vty_json(vty, json);
+
 	return CMD_SUCCESS;
 }
 /* Graceful Restart */
diff --git a/bgpd/bgp_vty.h b/bgpd/bgp_vty.h
index 9526b50fb9..019789dff8 100644
--- a/bgpd/bgp_vty.h
+++ b/bgpd/bgp_vty.h
@@ -56,18 +56,14 @@ struct bgp;
 	"V         AS    LocalAS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down State/PfxRcd   PfxSnt Desc\n"
 #define BGP_SHOW_SUMMARY_HEADER_FAILED "EstdCnt DropCnt ResetTime Reason\n"
 
-#define BGP_SHOW_PEER_GR_CAPABILITY(vty, p, use_json, json)                    \
+#define BGP_SHOW_PEER_GR_CAPABILITY(vty, p, json)                              \
 	do {                                                                   \
-		bgp_show_neighbor_graceful_restart_local_mode(vty, p,          \
-							      use_json, json); \
-		bgp_show_neighbor_graceful_restart_remote_mode(                \
-			vty, p, use_json, json);                               \
-		bgp_show_neighnor_graceful_restart_flags(vty, p, use_json,     \
-							 json);                \
-		bgp_show_neighbor_graceful_restart_time(vty, p, use_json,      \
-							json);                 \
+		bgp_show_neighbor_graceful_restart_local_mode(vty, p, json);   \
+		bgp_show_neighbor_graceful_restart_remote_mode(vty, p, json);  \
+		bgp_show_neighnor_graceful_restart_flags(vty, p, json);        \
+		bgp_show_neighbor_graceful_restart_time(vty, p, json);         \
 		bgp_show_neighbor_graceful_restart_capability_per_afi_safi(    \
-			vty, p, use_json, json);                               \
+			vty, p, json);                                         \
 	} while (0)
 
 #define VTY_BGP_GR_DEFINE_LOOP_VARIABLE                                        \