bgpd: implement draft-ietf-grow-bgp-gshut-10

Signed-off-by: Daniel Walton <dwalton@cumulusnetworks.com>

11 files changed, 218 insertions, 37 deletions

diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index b03b408f7..0487cb4e3 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -848,10 +848,24 @@ struct attr *bgp_attr_aggregate_intern(struct bgp *bgp, u_char origin,
 	attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
 
 	if (community) {
+		u_int32_t gshut = COMMUNITY_GSHUT;
+
+		/* If we are not shutting down ourselves and we are
+		 * aggregating a route that contains the GSHUT community we
+		 * need to remove that community when creating the aggregate */
+		if (!bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN) &&
+		    community_include(community, gshut)) {
+			community_del_val(community, &gshut);
+		}
+
 		attr.community = community;
 		attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES);
 	}
 
+	if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
+		bgp_attr_add_gshut_community(&attr);
+	}
+
 	attr.label_index = BGP_INVALID_LABEL_INDEX;
 	attr.label = MPLS_INVALID_LABEL;
 	attr.weight = BGP_ATTR_DEFAULT_WEIGHT;
@@ -1400,7 +1414,7 @@ bgp_attr_local_pref(struct bgp_attr_parser_args *args)
 
 	attr->local_pref = stream_getl(peer->ibuf);
 
-	/* Set atomic aggregate flag. */
+	/* Set the local-pref flag. */
 	attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
 
 	return BGP_ATTR_PARSE_PROCEED;
diff --git a/bgpd/bgp_clist.c b/bgpd/bgp_clist.c
index 13587b359..94ea35fa0 100644
--- a/bgpd/bgp_clist.c
+++ b/bgpd/bgp_clist.c
@@ -355,6 +355,9 @@ static char *community_str_get(struct community *com, int i)
 	case COMMUNITY_LOCAL_AS:
 		len = strlen(" local-AS");
 		break;
+	case COMMUNITY_GSHUT:
+		len = strlen(" graceful-shutdown");
+		break;
 	default:
 		len = strlen(" 65536:65535");
 		break;
@@ -380,6 +383,10 @@ static char *community_str_get(struct community *com, int i)
 		strcpy(pnt, "local-AS");
 		pnt += strlen("local-AS");
 		break;
+	case COMMUNITY_GSHUT:
+		strcpy(pnt, "graceful-shutdown");
+		pnt += strlen("graceful-shutdown");
+		break;
 	default:
 		as = (comval >> 16) & 0xFFFF;
 		val = comval & 0xFFFF;
diff --git a/bgpd/bgp_community.c b/bgpd/bgp_community.c
index 389d723e0..7e8411b6a 100644
--- a/bgpd/bgp_community.c
+++ b/bgpd/bgp_community.c
@@ -191,6 +191,7 @@ struct community *community_uniq_sort(struct community *com)
    0xFFFFFF01      "no-export"
    0xFFFFFF02      "no-advertise"
    0xFFFFFF03      "local-AS"
+   0xFFFF0000      "graceful-shutdown"
 
    For other values, "AS:VAL" format is used.  */
 static void set_community_string(struct community *com)
@@ -244,6 +245,9 @@ static void set_community_string(struct community *com)
 		case COMMUNITY_LOCAL_AS:
 			len += strlen(" local-AS");
 			break;
+		case COMMUNITY_GSHUT:
+			len += strlen(" graceful-shutdown");
+			break;
 		default:
 			len += strlen(" 65536:65535");
 			break;
@@ -289,6 +293,12 @@ static void set_community_string(struct community *com)
 			json_string = json_object_new_string("localAs");
 			json_object_array_add(json_community_list, json_string);
 			break;
+		case COMMUNITY_GSHUT:
+			strcpy(pnt, "graceful-shutdown");
+			pnt += strlen("graceful-shutdown");
+			json_string = json_object_new_string("gracefulShutdown");
+			json_object_array_add(json_community_list, json_string);
+			break;
 		default:
 			as = (comval >> 16) & 0xFFFF;
 			val = comval & 0xFFFF;
@@ -480,6 +490,7 @@ enum community_token {
 	community_token_no_export,
 	community_token_no_advertise,
 	community_token_local_as,
+	community_token_gshut,
 	community_token_unknown
 };
 
@@ -523,6 +534,12 @@ community_gettoken(const char *buf, enum community_token *token, u_int32_t *val)
 			p += strlen("local-AS");
 			return p;
 		}
+		if (strncmp(p, "graceful-shutdown", strlen("graceful-shutdown")) == 0) {
+			*val = COMMUNITY_GSHUT;
+			*token = community_token_gshut;
+			p += strlen("graceful-shutdown");
+			return p;
+		}
 
 		/* Unknown string. */
 		*token = community_token_unknown;
@@ -595,6 +612,7 @@ struct community *community_str2com(const char *str)
 		case community_token_no_export:
 		case community_token_no_advertise:
 		case community_token_local_as:
+		case community_token_gshut:
 			if (com == NULL) {
 				com = community_new();
 				com->json = NULL;
diff --git a/bgpd/bgp_community.h b/bgpd/bgp_community.h
index c59eebf2e..f728debdb 100644
--- a/bgpd/bgp_community.h
+++ b/bgpd/bgp_community.h
@@ -48,6 +48,7 @@ struct community {
 #define COMMUNITY_NO_ADVERTISE          0xFFFFFF02
 #define COMMUNITY_NO_EXPORT_SUBCONFED   0xFFFFFF03
 #define COMMUNITY_LOCAL_AS              0xFFFFFF03
+#define COMMUNITY_GSHUT                 0xFFFF0000
 
 /* Macros of community attribute.  */
 #define com_length(X)    ((X)->size * 4)
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index bb204b01f..e12c6fb7d 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -1267,6 +1267,39 @@ static void bgp_peer_as_override(struct bgp *bgp, afi_t afi, safi_t safi,
 	}
 }
 
+void bgp_attr_add_gshut_community(struct attr *attr)
+{
+	struct community *old;
+	struct community *new;
+	struct community *merge;
+	struct community *gshut;
+
+	old = attr->community;
+	gshut = community_str2com("graceful-shutdown");
+
+	if (old) {
+		merge = community_merge(community_dup(old), gshut);
+
+		if (old->refcnt== 0)
+			community_free(old);
+
+		new = community_uniq_sort(merge);
+		community_free(merge);
+	} else {
+		new = community_dup(gshut);
+	}
+
+	community_free(gshut);
+	attr->community = new;
+	attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES);
+
+	/* When we add the graceful-shutdown community we must also
+	 * lower the local-preference */
+	attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
+	attr->local_pref = BGP_GSHUT_LOCAL_PREF;
+}
+
+
 static void subgroup_announce_reset_nhop(u_char family, struct attr *attr)
 {
 	if (family == AF_INET)
@@ -1623,6 +1656,15 @@ int subgroup_announce_check(struct bgp_node *rn, struct bgp_info *ri,
 		}
 	}
 
+	if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
+		if (peer->sort == BGP_PEER_IBGP || peer->sort == BGP_PEER_CONFED) {
+			attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
+			attr->local_pref = BGP_GSHUT_LOCAL_PREF;
+		} else {
+			bgp_attr_add_gshut_community(attr);
+		}
+	}
+
 	/* After route-map has been applied, we check to see if the nexthop to
 	 * be carried in the attribute (that is used for the announcement) can
 	 * be cleared off or not. We do this in all cases where we would be
@@ -2725,6 +2767,22 @@ int bgp_update(struct peer *peer, struct prefix *p, u_int32_t addpath_id,
 		goto filtered;
 	}
 
+	if (peer->sort == BGP_PEER_EBGP) {
+
+		/* If we receive the graceful-shutdown community from an eBGP peer we
+		 * must lower local-preference */
+		if (new_attr.community &&
+		    community_include(new_attr.community, COMMUNITY_GSHUT)) {
+			new_attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
+			new_attr.local_pref = BGP_GSHUT_LOCAL_PREF;
+
+		/* If graceful-shutdown is configured then add the GSHUT community to
+		 * all paths received from eBGP peers */
+		} else if (bgp_flag_check(peer->bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
+			bgp_attr_add_gshut_community(&new_attr);
+		}
+	}
+
 	/* next hop check.  */
 	if (bgp_update_martian_nexthop(bgp, afi, safi, &new_attr)) {
 		reason = "martian or self next-hop;";
@@ -4044,9 +4102,18 @@ void bgp_static_update(struct bgp *bgp, struct prefix *p,
 			bgp_static_withdraw(bgp, p, afi, safi);
 			return;
 		}
+
+		if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN))
+			bgp_attr_add_gshut_community(&attr_tmp);
+
 		attr_new = bgp_attr_intern(&attr_tmp);
-	} else
+	} else {
+
+		if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN))
+			bgp_attr_add_gshut_community(&attr);
+
 		attr_new = bgp_attr_intern(&attr);
+	}
 
 	for (ri = rn->info; ri; ri = ri->next)
 		if (ri->peer == bgp->peer_self && ri->type == ZEBRA_ROUTE_BGP
@@ -6152,6 +6219,9 @@ void bgp_redistribute_add(struct bgp *bgp, struct prefix *p,
 			}
 		}
 
+		if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN))
+			bgp_attr_add_gshut_community(&attr_new);
+
 		bn = bgp_afi_node_get(bgp->rib[afi][SAFI_UNICAST], afi,
 				      SAFI_UNICAST, p, NULL);
 
@@ -8019,8 +8089,8 @@ static int bgp_show_prefix_longer(struct vty *vty, struct bgp *bgp,
 				  enum bgp_show_type type);
 static int bgp_show_regexp(struct vty *vty, const char *regstr, afi_t afi,
 			   safi_t safi, enum bgp_show_type type);
-static int bgp_show_community(struct vty *vty, struct bgp *bgp, int argc,
-			      struct cmd_token **argv, int exact, afi_t afi,
+static int bgp_show_community(struct vty *vty, struct bgp *bgp,
+			      const char *comstr, int exact, afi_t afi,
 			      safi_t safi);
 
 static int bgp_show_table(struct vty *vty, struct bgp *bgp,
@@ -8846,7 +8916,7 @@ DEFUN (show_ip_bgp,
              |prefix-list WORD\
              |filter-list WORD\
              |statistics\
-             |community [<AA:NN|local-AS|no-advertise|no-export> [exact-match]]\
+             |community [<AA:NN|local-AS|no-advertise|no-export|graceful-shutdown> [exact-match]]\
              |community-list <(1-500)|WORD> [exact-match]\
              |A.B.C.D/M longer-prefixes\
              |X:X::X:X/M longer-prefixes>\
@@ -8874,6 +8944,7 @@ DEFUN (show_ip_bgp,
        "Do not send outside local AS (well-known community)\n"
        "Do not advertise to any peer (well-known community)\n"
        "Do not export to next AS (well-known community)\n"
+       "Graceful shutdown (well-known community)\n"
        "Exact match of the communities\n"
        "Display routes matching the community-list\n"
        "community-list number\n"
@@ -8891,6 +8962,7 @@ DEFUN (show_ip_bgp,
 	enum bgp_show_type sh_type = bgp_show_type_normal;
 	struct bgp *bgp = NULL;
 	int idx = 0;
+	int idx_community_type = 0;
 
 	bgp_vty_find_and_parse_afi_safi_bgp(vty, argv, argc, &idx, &afi, &safi,
 					    &bgp);
@@ -8934,12 +9006,15 @@ DEFUN (show_ip_bgp,
 
 	if (argv_find(argv, argc, "community", &idx)) {
 		/* show a specific community */
-		if (argv_find(argv, argc, "local-AS", &idx)
-		    || argv_find(argv, argc, "no-advertise", &idx)
-		    || argv_find(argv, argc, "no-export", &idx)) {
-			if (argv_find(argv, argc, "exact_match", &idx))
+		if (argv_find(argv, argc, "local-AS", &idx_community_type)
+		    || argv_find(argv, argc, "no-advertise", &idx_community_type)
+		    || argv_find(argv, argc, "no-export", &idx_community_type)
+		    || argv_find(argv, argc, "graceful-shutdown", &idx_community_type)
+		    || argv_find(argv, argc, "AA:NN", &idx_community_type)) {
+
+			if (argv_find(argv, argc, "exact-match", &idx))
 				exact_match = 1;
-			return bgp_show_community(vty, bgp, argc, argv,
+			return bgp_show_community(vty, bgp, argv[idx_community_type]->arg,
 						  exact_match, afi, safi);
 		}
 		/* show all communities */
@@ -9170,39 +9245,16 @@ static int bgp_show_route_map(struct vty *vty, struct bgp *bgp,
 	return bgp_show(vty, bgp, afi, safi, type, rmap, 0);
 }
 
-static int bgp_show_community(struct vty *vty, struct bgp *bgp, int argc,
-			      struct cmd_token **argv, int exact, afi_t afi,
+static int bgp_show_community(struct vty *vty, struct bgp *bgp,
+			      const char *comstr, int exact, afi_t afi,
 			      safi_t safi)
 {
 	struct community *com;
-	struct buffer *b;
-	int i;
-	char *str;
-	int first = 0;
 	int ret = 0;
 
-	b = buffer_new(1024);
-	for (i = 0; i < argc; i++) {
-		if (first)
-			buffer_putc(b, ' ');
-		else {
-			if (strmatch(argv[i]->text, "unicast")
-			    || strmatch(argv[i]->text, "multicast"))
-				continue;
-			first = 1;
-		}
-
-		buffer_putstr(b, argv[i]->arg);
-	}
-	buffer_putc(b, '\0');
-
-	str = buffer_getstr(b);
-	buffer_free(b);
-
-	com = community_str2com(str);
-	XFREE(MTYPE_TMP, str);
+	com = community_str2com(comstr);
 	if (!com) {
-		vty_out(vty, "%% Community malformed: \n");
+		vty_out(vty, "%% Community malformed: %s\n", comstr);
 		return CMD_WARNING;
 	}
 
diff --git a/bgpd/bgp_route.h b/bgpd/bgp_route.h
index 1a1817bad..b9d7957c6 100644
--- a/bgpd/bgp_route.h
+++ b/bgpd/bgp_route.h
@@ -423,6 +423,7 @@ extern void bgp_info_restore(struct bgp_node *, struct bgp_info *);
 extern int bgp_info_cmp_compatible(struct bgp *, struct bgp_info *,
 				   struct bgp_info *, char *pfx_buf, afi_t afi,
 				   safi_t safi);
+extern void bgp_attr_add_gshut_community(struct attr *attr);
 
 extern void bgp_best_selection(struct bgp *bgp, struct bgp_node *rn,
 			       struct bgp_maxpaths_cfg *mpath_cfg,
diff --git a/bgpd/bgp_routemap.c b/bgpd/bgp_routemap.c
index 5a5d2a5d5..dce18a73d 100644
--- a/bgpd/bgp_routemap.c
+++ b/bgpd/bgp_routemap.c
@@ -3768,6 +3768,11 @@ DEFUN (set_community,
 			buffer_putstr(b, "no-export");
 			continue;
 		}
+		if (strncmp(argv[i]->arg, "graceful-shutdown", strlen(argv[i]->arg))
+		    == 0) {
+			buffer_putstr(b, "graceful-shutdown");
+			continue;
+		}
 		buffer_putstr(b, argv[i]->arg);
 	}
 	buffer_putc(b, '\0');
diff --git a/bgpd/bgp_updgrp_adv.c b/bgpd/bgp_updgrp_adv.c
index 0a33fa5ed..1bd6fb8b3 100644
--- a/bgpd/bgp_updgrp_adv.c
+++ b/bgpd/bgp_updgrp_adv.c
@@ -691,6 +691,7 @@ void subgroup_default_originate(struct update_subgroup *subgrp, int withdraw)
 
 	bgp_attr_default_set(&attr, BGP_ORIGIN_IGP);
 	aspath = attr.aspath;
+
 	attr.local_pref = bgp->default_local_pref;
 
 	if (afi == AFI_IP)
@@ -749,6 +750,11 @@ void subgroup_default_originate(struct update_subgroup *subgrp, int withdraw)
 	} else {
 		if (!CHECK_FLAG(subgrp->sflags,
 				SUBGRP_STATUS_DEFAULT_ORIGINATE)) {
+
+			if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
+				bgp_attr_add_gshut_community(&attr);
+			}
+
 			SET_FLAG(subgrp->sflags,
 				 SUBGRP_STATUS_DEFAULT_ORIGINATE);
 			subgroup_default_update_packet(subgrp, &attr, from);
diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index 2e18a6d44..d9117deaf 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -1804,6 +1804,69 @@ DEFUN (no_bgp_graceful_restart_preserve_fw,
 	return CMD_SUCCESS;
 }
 
+static void bgp_redistribute_redo(struct bgp *bgp)
+{
+	afi_t afi;
+	int i;
+	struct list *red_list;
+	struct listnode *node;
+	struct bgp_redist *red;
+
+        for (afi = AFI_IP; afi < AFI_MAX; afi++) {
+                for (i = 0; i < ZEBRA_ROUTE_MAX; i++) {
+
+                        red_list = bgp->redist[afi][i];
+                        if (!red_list)
+                                continue;
+
+                        for (ALL_LIST_ELEMENTS_RO(red_list, node, red)) {
+				bgp_redistribute_resend(bgp, afi, i,
+							red->instance);
+			}
+		}
+	}
+}
+
+/* "bgp graceful-shutdown" configuration */
+DEFUN (bgp_graceful_shutdown,
+       bgp_graceful_shutdown_cmd,
+       "bgp graceful-shutdown",
+       BGP_STR
+       "Graceful shutdown parameters\n")
+{
+	VTY_DECLVAR_CONTEXT(bgp, bgp);
+
+	if (!bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
+		bgp_flag_set(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN);
+		bgp_static_redo_import_check(bgp);
+		bgp_redistribute_redo(bgp);
+		bgp_clear_star_soft_out(vty, bgp->name);
+		bgp_clear_star_soft_in(vty, bgp->name);
+	}
+
+	return CMD_SUCCESS;
+}
+
+DEFUN (no_bgp_graceful_shutdown,
+       no_bgp_graceful_shutdown_cmd,
+       "no bgp graceful-shutdown",
+       NO_STR
+       BGP_STR
+       "Graceful shutdown parameters\n")
+{
+	VTY_DECLVAR_CONTEXT(bgp, bgp);
+
+	if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
+		bgp_flag_unset(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN);
+		bgp_static_redo_import_check(bgp);
+		bgp_redistribute_redo(bgp);
+		bgp_clear_star_soft_out(vty, bgp->name);
+		bgp_clear_star_soft_in(vty, bgp->name);
+	}
+
+	return CMD_SUCCESS;
+}
+
 /* "bgp fast-external-failover" configuration. */
 DEFUN (bgp_fast_external_failover,
        bgp_fast_external_failover_cmd,
@@ -10459,6 +10522,7 @@ DEFUN (bgp_redistribute_ipv4,
 		vty_out(vty, "%% Invalid route type\n");
 		return CMD_WARNING_CONFIG_FAILED;
 	}
+
 	bgp_redist_add(bgp, AFI_IP, type, 0);
 	return bgp_redistribute_set(bgp, AFI_IP, type, 0);
 }
@@ -11335,6 +11399,10 @@ void bgp_vty_init(void)
 	install_element(BGP_NODE, &bgp_graceful_restart_preserve_fw_cmd);
 	install_element(BGP_NODE, &no_bgp_graceful_restart_preserve_fw_cmd);
 
+	/* "bgp graceful-shutdown" commands */
+	install_element(BGP_NODE, &bgp_graceful_shutdown_cmd);
+	install_element(BGP_NODE, &no_bgp_graceful_shutdown_cmd);
+
 	/* "bgp fast-external-failover" commands */
 	install_element(BGP_NODE, &bgp_fast_external_failover_cmd);
 	install_element(BGP_NODE, &no_bgp_fast_external_failover_cmd);
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 9d7c38c87..258d650d2 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -7190,6 +7190,10 @@ int bgp_config_write(struct vty *vty)
 		if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_RESTART))
 			vty_out(vty, " bgp graceful-restart\n");
 
+		/* BGP graceful-shutdown */
+		if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN))
+			vty_out(vty, " bgp graceful-shutdown\n");
+
 		/* BGP graceful-restart Preserve State F bit. */
 		if (bgp_flag_check(bgp, BGP_FLAG_GR_PRESERVE_FWD))
 			vty_out(vty,
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index f6e7b2277..da30ecd96 100644
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -303,6 +303,7 @@ struct bgp {
 #define BGP_FLAG_FORCE_STATIC_PROCESS     (1 << 18)
 #define BGP_FLAG_SHOW_HOSTNAME            (1 << 19)
 #define BGP_FLAG_GR_PRESERVE_FWD          (1 << 20)
+#define BGP_FLAG_GRACEFUL_SHUTDOWN        (1 << 21)
 
 	/* BGP Per AF flags */
 	u_int16_t af_flags[AFI_MAX][SAFI_MAX];
@@ -1091,6 +1092,10 @@ struct bgp_nlri {
 /* BGP default local preference.  */
 #define BGP_DEFAULT_LOCAL_PREF                 100
 
+/* BGP local-preference to send when 'bgp graceful-shutdown'
+ * is configured */
+#define BGP_GSHUT_LOCAL_PREF                     0
+
 /* BGP default subgroup packet queue max .  */
 #define BGP_DEFAULT_SUBGROUP_PKT_QUEUE_MAX      40