bgpd, zebra: Allow setting ecmp from daemon cli

When starting up bgp and zebra now, you can specify
-e <number> or --ecmp <number>
and that number will be used as the maximum ecmp
that can be used.

The <number specified must be >= 1 and <= MULTIPATH_NUM
that Quagga is compiled with.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

6 files changed, 27 insertions, 7 deletions

diff --git a/bgpd/bgp_main.c b/bgpd/bgp_main.c
index 9607d381d..fbbcda591 100644
--- a/bgpd/bgp_main.c
+++ b/bgpd/bgp_main.c
@@ -75,6 +75,7 @@ static const struct option longopts[] =
   { "vty_socket",  required_argument, NULL, OPTION_VTYSOCK },
   { "retain",      no_argument,       NULL, 'r'},
   { "no_kernel",   no_argument,       NULL, 'n'},
+  { "ecmp",        required_argument, NULL, 'e'},
   { "user",        required_argument, NULL, 'u'},
   { "group",       required_argument, NULL, 'g'},
   { "skip_runas",  no_argument,       NULL, 'S'},
@@ -176,6 +177,7 @@ redistribution between different routing protocols.\n\n\
     --vty_socket   Override vty socket path\n\
 -r, --retain       When program terminates, retain added route by bgpd.\n\
 -n, --no_kernel    Do not install route to kernel.\n\
+-e, --ecmp         Specify ECMP to use.\n\
 -u, --user         User to run as\n\
 -g, --group        Group to run as\n\
 -S, --skip_runas   Skip user and group run as\n\
@@ -468,6 +470,14 @@ main (int argc, char **argv)
 	case 'A':
 	  vty_addr = optarg;
 	  break;
+        case 'e':
+          multipath_num = atoi (optarg);
+          if (multipath_num > MULTIPATH_NUM || multipath_num <= 0)
+            {
+              zlog_err ("Multipath Number specified must be less than %d and greater than 0", MULTIPATH_NUM);
+              return 1;
+            }
+          break;
 	case 'P':
           /* Deal with atoi() returning 0 on failure, and bgpd not
              listening on bgp port... */
diff --git a/bgpd/bgp_mpath.c b/bgpd/bgp_mpath.c
index f564ff169..a95c4a008 100644
--- a/bgpd/bgp_mpath.c
+++ b/bgpd/bgp_mpath.c
@@ -84,11 +84,11 @@ bgp_maximum_paths_unset (struct bgp *bgp, afi_t afi, safi_t safi,
   switch (peertype)
     {
     case BGP_PEER_IBGP:
-      bgp->maxpaths[afi][safi].maxpaths_ibgp = MULTIPATH_NUM;
+      bgp->maxpaths[afi][safi].maxpaths_ibgp = multipath_num;
       bgp->maxpaths[afi][safi].ibgp_flags = 0;
       break;
     case BGP_PEER_EBGP:
-      bgp->maxpaths[afi][safi].maxpaths_ebgp = MULTIPATH_NUM;
+      bgp->maxpaths[afi][safi].maxpaths_ebgp = multipath_num;
       break;
     default:
       return -1;
@@ -436,7 +436,7 @@ bgp_info_mpath_update (struct bgp_node *rn, struct bgp_info *new_best,
   char path_buf[PATH_ADDPATH_STR_BUFFER];
 
   mpath_changed = 0;
-  maxpaths = MULTIPATH_NUM;
+  maxpaths = multipath_num;
   mpath_count = 0;
   cur_mpath = NULL;
   old_mpath_count = 0;
diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index aa8c3145f..07f2d5945 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -1144,6 +1144,13 @@ bgp_maxpaths_config_vty (struct vty *vty, int peer_type, const char *mpaths,
   if (set)
   {
     maxpaths = strtol(mpaths, NULL, 10);
+    if (maxpaths > multipath_num)
+      {
+        vty_out (vty,
+                 "%% Maxpaths Specified: %d is > than multipath num specified on bgp command line %d",
+                 maxpaths, multipath_num);
+        return CMD_WARNING;
+      }
     ret = bgp_maximum_paths_set (bgp, afi, safi, peer_type, maxpaths, options);
   }
   else
diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index 822f459c2..2a513dda2 100644
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -69,7 +69,7 @@ struct stream *bgp_ifindices_buf = NULL;
    Number of supported next-hops are finite, use of arrays should be ok. */
 struct attr attr_cp[MULTIPATH_NUM];
 struct attr_extra attr_extra_cp[MULTIPATH_NUM];
-int    attr_index = 0;
+unsigned int attr_index = 0;
 
 /* Once per address-family initialization of the attribute array */
 #define BGP_INFO_ATTR_BUF_INIT()\
@@ -82,7 +82,7 @@ do {\
 #define BGP_INFO_ATTR_BUF_COPY(info_src, info_dst)\
 do { \
   *info_dst = *info_src; \
-  assert(attr_index != MULTIPATH_NUM);\
+  assert(attr_index != multipath_num);\
   attr_cp[attr_index].extra = &attr_extra_cp[attr_index]; \
   bgp_attr_dup (&attr_cp[attr_index], info_src->attr); \
   bgp_attr_deep_dup (&attr_cp[attr_index], info_src->attr); \
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 3512167b0..9b779e5d3 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -93,6 +93,8 @@ struct bgp_master *bm;
 /* BGP community-list.  */
 struct community_list_handler *bgp_clist;
 
+unsigned int multipath_num = MULTIPATH_NUM;
+
 static void bgp_if_init (struct bgp *bgp);
 static void bgp_if_finish (struct bgp *bgp);
 
@@ -2918,8 +2920,8 @@ bgp_create (as_t *as, const char *name, enum bgp_instance_type inst_type)
 	bgp->rib[afi][safi] = bgp_table_init (afi, safi);
 
         /* Enable maximum-paths */
-        bgp_maximum_paths_set (bgp, afi, safi, BGP_PEER_EBGP, MULTIPATH_NUM, 0);
-        bgp_maximum_paths_set (bgp, afi, safi, BGP_PEER_IBGP, MULTIPATH_NUM, 0);
+        bgp_maximum_paths_set (bgp, afi, safi, BGP_PEER_EBGP, multipath_num, 0);
+        bgp_maximum_paths_set (bgp, afi, safi, BGP_PEER_IBGP, multipath_num, 0);
       }
 
   bgp->v_update_delay = BGP_UPDATE_DELAY_DEF;
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index 09c64aa33..f0f2ed87b 100644
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -1161,6 +1161,7 @@ typedef enum
 } bgp_policy_type_e;
 
 extern struct bgp_master *bm;
+extern unsigned int multipath_num;
 
 /* Prototypes. */
 extern void bgp_terminate (void);