From ad36d216b10e1c53b692131f5a5bc1d4537ec10a Mon Sep 17 00:00:00 2001
From: Donald Sharp <sharpd@cumulusnetworks.com>
Date: Thu, 7 May 2020 10:03:31 -0400
Subject: [PATCH] bgpd: `bgp bestpath bandwidth` should not be a legal command

The `bgp bestpath bandwidth` command should not be a legal
command.  Pull out the `no` form to allow this.  Allow
`no bgp bestpath bandwidth` to work as we would expect.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
---
 bgpd/bgp_vty.c | 56 +++++++++++++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 17 deletions(-)

diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index 0f09369860..8266b76111 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -2987,8 +2987,7 @@ DEFUN (no_bgp_bestpath_med,
 /* "bgp bestpath bandwidth" configuration. */
 DEFPY (bgp_bestpath_bw,
        bgp_bestpath_bw_cmd,
-       "[no$no] bgp bestpath bandwidth [<ignore|skip-missing|default-weight-for-missing>$bw_cfg]",
-       NO_STR
+       "bgp bestpath bandwidth <ignore|skip-missing|default-weight-for-missing>$bw_cfg",
        "BGP specific commands\n"
        "Change the default bestpath selection\n"
        "Link Bandwidth attribute\n"
@@ -3000,22 +2999,18 @@ DEFPY (bgp_bestpath_bw,
 	afi_t afi;
 	safi_t safi;
 
-	if (no) {
-		bgp->lb_handling = BGP_LINK_BW_ECMP;
-	} else {
-		if (!bw_cfg) {
-			vty_out(vty, "%% Bandwidth configuration must be specified\n");
-			return CMD_ERR_INCOMPLETE;
-		}
-		if (!strcmp(bw_cfg, "ignore"))
-			bgp->lb_handling = BGP_LINK_BW_IGNORE_BW;
-		else if (!strcmp(bw_cfg, "skip-missing"))
-			bgp->lb_handling = BGP_LINK_BW_SKIP_MISSING;
-		else if (!strcmp(bw_cfg, "default-weight-for-missing"))
-			bgp->lb_handling = BGP_LINK_BW_DEFWT_4_MISSING;
-		else
-			return CMD_ERR_NO_MATCH;
+	if (!bw_cfg) {
+		vty_out(vty, "%% Bandwidth configuration must be specified\n");
+		return CMD_ERR_INCOMPLETE;
 	}
+	if (!strcmp(bw_cfg, "ignore"))
+		bgp->lb_handling = BGP_LINK_BW_IGNORE_BW;
+	else if (!strcmp(bw_cfg, "skip-missing"))
+		bgp->lb_handling = BGP_LINK_BW_SKIP_MISSING;
+	else if (!strcmp(bw_cfg, "default-weight-for-missing"))
+		bgp->lb_handling = BGP_LINK_BW_DEFWT_4_MISSING;
+	else
+		return CMD_ERR_NO_MATCH;
 
 	/* This config is used in route install, so redo that. */
 	FOREACH_AFI_SAFI (afi, safi) {
@@ -3027,6 +3022,32 @@ DEFPY (bgp_bestpath_bw,
 	return CMD_SUCCESS;
 }
 
+DEFPY (no_bgp_bestpath_bw,
+       no_bgp_bestpath_bw_cmd,
+       "no bgp bestpath bandwidth [<ignore|skip-missing|default-weight-for-missing>$bw_cfg]",
+       NO_STR
+       "BGP specific commands\n"
+       "Change the default bestpath selection\n"
+       "Link Bandwidth attribute\n"
+       "Ignore link bandwidth (i.e., do regular ECMP, not weighted)\n"
+       "Ignore paths without link bandwidth for ECMP (if other paths have it)\n"
+       "Assign a low default weight (value 1) to paths not having link bandwidth\n")
+{
+	VTY_DECLVAR_CONTEXT(bgp, bgp);
+	afi_t afi;
+	safi_t safi;
+
+	bgp->lb_handling = BGP_LINK_BW_ECMP;
+
+	/* This config is used in route install, so redo that. */
+	FOREACH_AFI_SAFI (afi, safi) {
+		if (!bgp_fibupd_safi(safi))
+			continue;
+		bgp_zebra_announce_table(bgp, afi, safi);
+	}
+	return CMD_SUCCESS;
+}
+
 /* "no bgp default ipv4-unicast". */
 DEFUN (no_bgp_default_ipv4_unicast,
        no_bgp_default_ipv4_unicast_cmd,
@@ -15757,6 +15778,7 @@ void bgp_vty_init(void)
 
 	/* "bgp bestpath bandwidth" commands */
 	install_element(BGP_NODE, &bgp_bestpath_bw_cmd);
+	install_element(BGP_NODE, &no_bgp_bestpath_bw_cmd);
 
 	/* "no bgp default ipv4-unicast" commands. */
 	install_element(BGP_NODE, &no_bgp_default_ipv4_unicast_cmd);
-- 
2.39.5