bgpd: add 'default hostname-capability'

The BGP capability option 72 defines the hostname option as per draft-walton-bgp-hostname-capability. It is a draft, and some equipements do not support this option. Add the 'bgp default hostname-capability' command to change the behaviour. Signed-off-by: Philippe Guibert <[email protected]>
FRRouting · Jan 11, 2024 · 8fe025a · 8fe025a
1 parent 5fbf0cc
commit 8fe025a
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Showing 4 changed files with 40 additions and 1 deletion.
diff --git a/bgpd/bgp_open.c b/bgpd/bgp_open.c
@@ -1896,7 +1896,8 @@ uint16_t bgp_open_capability(struct stream *s, struct peer *peer,
 	}
 
 	/* Hostname capability */
-	if (cmd_hostname_get()) {
+	if (CHECK_FLAG(peer->bgp->flags, BGP_FLAG_HOSTNAME_CAPABILITY) &&
+	    cmd_hostname_get()) {
 		SET_FLAG(peer->cap, PEER_CAP_HOSTNAME_ADV);
 		stream_putc(s, BGP_OPEN_OPT_CAP);
 		rcapp = stream_get_endp(s); /* Ptr to length placeholder */

diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
@@ -126,6 +126,7 @@ FRR_CFG_DEFAULT_BOOL(BGP_SOFT_VERSION_CAPABILITY,
 	{ .val_bool = true, .match_profile = "datacenter", },
 	{ .val_bool = false },
 );
+FRR_CFG_DEFAULT_BOOL(BGP_HOSTNAME_CAPABILITY, { .val_bool = true }, );
 FRR_CFG_DEFAULT_BOOL(BGP_ENFORCE_FIRST_AS,
 	{ .val_bool = false, .match_version = "< 9.1", },
 	{ .val_bool = true },
@@ -623,6 +624,8 @@ int bgp_get_vty(struct bgp **bgp, as_t *as, const char *name,
 		if (DFLT_BGP_SOFT_VERSION_CAPABILITY)
 			SET_FLAG((*bgp)->flags,
 				 BGP_FLAG_SOFT_VERSION_CAPABILITY);
+		if (DFLT_BGP_HOSTNAME_CAPABILITY)
+			SET_FLAG((*bgp)->flags, BGP_FLAG_HOSTNAME_CAPABILITY);
 		if (DFLT_BGP_ENFORCE_FIRST_AS)
 			SET_FLAG((*bgp)->flags, BGP_FLAG_ENFORCE_FIRST_AS);
 
@@ -4287,6 +4290,24 @@ DEFPY (bgp_default_software_version_capability,
 	return CMD_SUCCESS;
 }
 
+DEFPY (bgp_default_hostname_capability,
+       bgp_default_hostname_capability_cmd,
+       "[no] bgp default hostname-capability",
+       NO_STR
+       BGP_STR
+       "Configure BGP defaults\n"
+       "Advertise hostname capability for all neighbors\n")
+{
+	VTY_DECLVAR_CONTEXT(bgp, bgp);
+
+	if (no)
+		UNSET_FLAG(bgp->flags, BGP_FLAG_HOSTNAME_CAPABILITY);
+	else
+		SET_FLAG(bgp->flags, BGP_FLAG_HOSTNAME_CAPABILITY);
+
+	return CMD_SUCCESS;
+}
+
 /* "bgp network import-check" configuration.  */
 DEFUN (bgp_network_import_check,
        bgp_network_import_check_cmd,
@@ -18829,6 +18850,14 @@ int bgp_config_write(struct vty *vty)
 					? ""
 					: "no ");
 
+		if (!!CHECK_FLAG(bgp->flags, BGP_FLAG_HOSTNAME_CAPABILITY) !=
+		    SAVE_BGP_HOSTNAME_CAPABILITY)
+			vty_out(vty, " %sbgp default hostname-capability\n",
+				CHECK_FLAG(bgp->flags,
+					   BGP_FLAG_HOSTNAME_CAPABILITY)
+					? ""
+					: "no ");
+
 		/* BGP default subgroup-pkt-queue-max. */
 		if (bgp->default_subgroup_pkt_queue_max
 		    != BGP_DEFAULT_SUBGROUP_PKT_QUEUE_MAX)
@@ -19877,6 +19906,9 @@ void bgp_vty_init(void)
 	/* bgp default software-version-capability */
 	install_element(BGP_NODE, &bgp_default_software_version_capability_cmd);
 
+	/* bgp default hostname-capability */
+	install_element(BGP_NODE, &bgp_default_hostname_capability_cmd);
+
 	/* "bgp default subgroup-pkt-queue-max" commands. */
 	install_element(BGP_NODE, &bgp_default_subgroup_pkt_queue_max_cmd);
 	install_element(BGP_NODE, &no_bgp_default_subgroup_pkt_queue_max_cmd);

diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
@@ -519,6 +519,7 @@ struct bgp {
 #define BGP_FLAG_LU_IPV6_EXPLICIT_NULL (1ULL << 34)
 #define BGP_FLAG_SOFT_VERSION_CAPABILITY (1ULL << 35)
 #define BGP_FLAG_ENFORCE_FIRST_AS (1ULL << 36)
+#define BGP_FLAG_HOSTNAME_CAPABILITY	 (1ULL << 36)
 
 	/* BGP default address-families.
 	 * New peers inherit enabled afi/safis from bgp instance.

diff --git a/doc/user/bgp.rst b/doc/user/bgp.rst
@@ -1913,6 +1913,11 @@ Configuring Peers
    outputs. It's easier to troubleshoot if you have a number of BGP peers
    and a number of routes to check.
 
+.. clicmd:: bgp default hostname-capability
+
+   This command enables hostname capability advertisement by default
+   for all the neighbors. This is enabled by default.
+
 .. clicmd:: bgp default software-version-capability
 
    This command enables software version capability advertisement by default