tunneling: Handle multiple ip address for given device.

Device can have multiple IP address but netdev_get_in4/6()
returns only one configured IPv6 address. Following
patch fixes it.
OVS router is also updated to return source ip address for
given destination, This is required when interface has multiple
IP address configured.

Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>

1 files changed, 71 insertions, 8 deletions

diff --git a/lib/ovs-router.c b/lib/ovs-router.c
index f10901605..82923ff26 100644
--- a/lib/ovs-router.c
+++ b/lib/ovs-router.c
@@ -42,6 +42,9 @@
 #include "tnl-ports.h"
 #include "unixctl.h"
 #include "util.h"
+#include "unaligned.h"
+#include "unixctl.h"
+#include "util.h"
 
 static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
 static struct classifier cls;
@@ -51,6 +54,7 @@ struct ovs_router_entry {
     char output_bridge[IFNAMSIZ];
     struct in6_addr gw;
     struct in6_addr nw_addr;
+    struct in6_addr src_addr;
     uint8_t plen;
     uint8_t priority;
 };
@@ -67,7 +71,7 @@ ovs_router_entry_cast(const struct cls_rule *cr)
 
 bool
 ovs_router_lookup(const struct in6_addr *ip6_dst, char output_bridge[],
-                  struct in6_addr *gw)
+                  struct in6_addr *src, struct in6_addr *gw)
 {
     const struct cls_rule *cr;
     struct flow flow = {.ipv6_dst = *ip6_dst};
@@ -78,6 +82,9 @@ ovs_router_lookup(const struct in6_addr *ip6_dst, char output_bridge[],
 
         ovs_strlcpy(output_bridge, p->output_bridge, IFNAMSIZ);
         *gw = p->gw;
+        if (src) {
+            *src = p->src_addr;
+        }
         return true;
     }
     return false;
@@ -89,7 +96,7 @@ ovs_router_lookup4(ovs_be32 ip_dst, char output_bridge[], ovs_be32 *gw)
     struct in6_addr ip6_dst = in6_addr_mapped_ipv4(ip_dst);
     struct in6_addr gw6;
 
-    if (ovs_router_lookup(&ip6_dst, output_bridge, &gw6)) {
+    if (ovs_router_lookup(&ip6_dst, output_bridge, NULL, &gw6)) {
         *gw = in6_addr_get_mapped_ipv4(&gw6);
         return true;
     }
@@ -117,7 +124,48 @@ static void rt_init_match(struct match *match, const struct in6_addr *ip6_dst,
     match->wc.masks.ipv6_dst = mask;
 }
 
-static void
+static int
+get_src_addr(const struct in6_addr *ip6_dst,
+             const char output_bridge[], struct in6_addr *psrc)
+{
+    struct in6_addr *mask, *addr6;
+    int err, n_in6, i, max_plen = -1;
+    struct netdev *dev;
+
+    err = netdev_open(output_bridge, NULL, &dev);
+    if (err) {
+        return err;
+    }
+
+    err = netdev_get_addr_list(dev, &addr6, &mask, &n_in6);
+    if (err) {
+        goto out;
+    }
+
+    for (i = 0; i < n_in6; i++) {
+        struct in6_addr a1, a2;
+        int mask_bits;
+
+        a1 = ipv6_addr_bitand(ip6_dst, &mask[i]);
+        a2 = ipv6_addr_bitand(&addr6[i], &mask[i]);
+        mask_bits = bitmap_count1(ALIGNED_CAST(const unsigned long *, &mask[i]), 128);
+
+        if (!memcmp(&a1, &a2, sizeof (a1)) && mask_bits > max_plen) {
+            *psrc = addr6[i];
+            max_plen = mask_bits;
+        }
+    }
+    if (max_plen == -1) {
+        err = ENOENT;
+    }
+out:
+    free(addr6);
+    free(mask);
+    netdev_close(dev);
+    return err;
+}
+
+static int
 ovs_router_insert__(uint8_t priority, const struct in6_addr *ip6_dst,
                     uint8_t plen, const char output_bridge[],
                     const struct in6_addr *gw)
@@ -125,6 +173,7 @@ ovs_router_insert__(uint8_t priority, const struct in6_addr *ip6_dst,
     const struct cls_rule *cr;
     struct ovs_router_entry *p;
     struct match match;
+    int err;
 
     rt_init_match(&match, ip6_dst, plen);
 
@@ -136,6 +185,10 @@ ovs_router_insert__(uint8_t priority, const struct in6_addr *ip6_dst,
     p->nw_addr = match.flow.ipv6_dst;
     p->plen = plen;
     p->priority = priority;
+    err = get_src_addr(ip6_dst, output_bridge, &p->src_addr);
+    if (err) {
+        return err;
+    }
     /* Longest prefix matches first. */
     cls_rule_init(&p->cr, &match, priority);
 
@@ -149,6 +202,7 @@ ovs_router_insert__(uint8_t priority, const struct in6_addr *ip6_dst,
     }
     tnl_port_map_insert_ipdev(output_bridge);
     seq_change(tnl_conf_seq);
+    return 0;
 }
 
 void
@@ -226,6 +280,7 @@ ovs_router_add(struct unixctl_conn *conn, int argc,
     unsigned int plen;
     struct in6_addr ip6;
     struct in6_addr gw6;
+    int err;
 
     if (scan_ipv4_route(argv[1], &ip, &plen)) {
         ovs_be32 gw = 0;
@@ -246,8 +301,12 @@ ovs_router_add(struct unixctl_conn *conn, int argc,
         unixctl_command_reply_error(conn, "Invalid parameters");
         return;
     }
-    ovs_router_insert__(plen + 32, &ip6, plen, argv[2], &gw6);
-    unixctl_command_reply(conn, "OK");
+    err = ovs_router_insert__(plen + 32, &ip6, plen, argv[2], &gw6);
+    if (err) {
+        unixctl_command_reply(conn, "Error while inserting route.");
+    } else {
+        unixctl_command_reply(conn, "OK");
+    }
 }
 
 static void
@@ -298,6 +357,8 @@ ovs_router_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
             ds_put_format(&ds, " GW ");
             ipv6_format_mapped(&rt->gw, &ds);
         }
+        ds_put_format(&ds, " SRC ");
+        ipv6_format_mapped(&rt->src_addr, &ds);
         ds_put_format(&ds, "\n");
     }
     unixctl_command_reply(conn, ds_cstr(&ds));
@@ -312,7 +373,7 @@ ovs_router_lookup_cmd(struct unixctl_conn *conn, int argc OVS_UNUSED,
     struct in6_addr ip6;
     unsigned int plen;
     char iface[IFNAMSIZ];
-    struct in6_addr gw;
+    struct in6_addr gw, src;
 
     if (scan_ipv4_route(argv[1], &ip, &plen) && plen == 32) {
         in6_addr_set_mapped_ipv4(&ip6, ip);
@@ -321,10 +382,12 @@ ovs_router_lookup_cmd(struct unixctl_conn *conn, int argc OVS_UNUSED,
         return;
     }
 
-    if (ovs_router_lookup(&ip6, iface, &gw)) {
+    if (ovs_router_lookup(&ip6, iface, &src, &gw)) {
         struct ds ds = DS_EMPTY_INITIALIZER;
+        ds_put_format(&ds, "src ");
+        ipv6_format_mapped(&src, &ds);
         ds_put_format(&ds, "gateway ");
-        ipv6_format_mapped(&ip6, &ds);
+        ipv6_format_mapped(&gw, &ds);
         ds_put_format(&ds, "\ndev %s\n", iface);
         unixctl_command_reply(conn, ds_cstr(&ds));
         ds_destroy(&ds);