batman-adv: move and restructure batadv_v_ogm_forward

To match our code better to the protocol description of B.A.T.M.A.N. V,
move batadv_v_ogm_forward() out into batadv_v_ogm_process_per_outif()
and move all checks directly deciding whether the OGM should be
forwarded into batadv_v_ogm_forward().

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
index d9bcbe6..07c9997 100644 (file)
--- a/net/batman-adv/bat_v_ogm.c
+++ b/net/batman-adv/bat_v_ogm.c
@@ -347,10 +347,12 @@ static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 }
 
 /**
- * batadv_v_ogm_forward - forward an OGM to the given outgoing interface
+ * batadv_v_ogm_forward - check conditions and forward an OGM to the given
+ *  outgoing interface
  * @bat_priv: the bat priv with all the soft interface information
  * @ogm_received: previously received OGM to be forwarded
- * @throughput: throughput to announce, may vary per outgoing interface
+ * @orig_node: the originator which has been updated
+ * @neigh_node: the neigh_node through with the OGM has been received
  * @if_incoming: the interface on which this OGM was received on
  * @if_outgoing: the interface to which the OGM has to be forwarded to
  *
@@ -359,28 +361,57 @@ static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
  */
 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
                                 const struct batadv_ogm2_packet *ogm_received,
-                                u32 throughput,
+                                struct batadv_orig_node *orig_node,
+                                struct batadv_neigh_node *neigh_node,
                                 struct batadv_hard_iface *if_incoming,
                                 struct batadv_hard_iface *if_outgoing)
 {
+       struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
+       struct batadv_orig_ifinfo *orig_ifinfo = NULL;
+       struct batadv_neigh_node *router = NULL;
        struct batadv_ogm2_packet *ogm_forward;
        unsigned char *skb_buff;
        struct sk_buff *skb;
        size_t packet_len;
        u16 tvlv_len;
 
+       /* only forward for specific interfaces, not for the default one. */
+       if (if_outgoing == BATADV_IF_DEFAULT)
+               goto out;
+
+       orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
+       if (!orig_ifinfo)
+               goto out;
+
+       /* acquire possibly updated router */
+       router = batadv_orig_router_get(orig_node, if_outgoing);
+
+       /* strict rule: forward packets coming from the best next hop only */
+       if (neigh_node != router)
+               goto out;
+
+       /* don't forward the same seqno twice on one interface */
+       if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
+               goto out;
+
+       orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
+
        if (ogm_received->ttl <= 1) {
                batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
-               return;
+               goto out;
        }
 
+       neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
+       if (!neigh_ifinfo)
+               goto out;
+
        tvlv_len = ntohs(ogm_received->tvlv_len);
 
        packet_len = BATADV_OGM2_HLEN + tvlv_len;
        skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
                                        ETH_HLEN + packet_len);
        if (!skb)
-               return;
+               goto out;
 
        skb_reserve(skb, ETH_HLEN);
        skb_buff = skb_put(skb, packet_len);
@@ -388,15 +419,23 @@ static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 
        /* apply forward penalty */
        ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
-       ogm_forward->throughput = htonl(throughput);
+       ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
        ogm_forward->ttl--;
 
        batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
                   "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
-                  if_outgoing->net_dev->name, throughput, ogm_forward->ttl,
-                  if_incoming->net_dev->name);
+                  if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
+                  ogm_forward->ttl, if_incoming->net_dev->name);
 
        batadv_v_ogm_send_to_if(skb, if_outgoing);
+
+out:
+       if (orig_ifinfo)
+               batadv_orig_ifinfo_put(orig_ifinfo);
+       if (router)
+               batadv_neigh_node_put(router);
+       if (neigh_ifinfo)
+               batadv_neigh_ifinfo_put(neigh_ifinfo);
 }
 
 /**
@@ -493,8 +532,10 @@ out:
  * @neigh_node: the neigh_node through with the OGM has been received
  * @if_incoming: the interface where this packet was received
  * @if_outgoing: the interface for which the packet should be considered
+ *
+ * Return: true if the packet should be forwarded, false otherwise
  */
-static void batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
+static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
                                      const struct ethhdr *ethhdr,
                                      const struct batadv_ogm2_packet *ogm2,
                                      struct batadv_orig_node *orig_node,
@@ -503,14 +544,9 @@ static void batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
                                      struct batadv_hard_iface *if_outgoing)
 {
        struct batadv_neigh_node *router = NULL;
-       struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
        struct batadv_orig_node *orig_neigh_node = NULL;
-       struct batadv_orig_ifinfo *orig_ifinfo = NULL;
        struct batadv_neigh_node *orig_neigh_router = NULL;
-
-       neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
-       if (!neigh_ifinfo)
-               goto out;
+       bool forward = false;
 
        orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
        if (!orig_neigh_node)
@@ -529,47 +565,20 @@ static void batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
                goto out;
        }
 
-       if (router)
-               batadv_neigh_node_put(router);
-
        /* Update routes, and check if the OGM is from the best next hop */
        batadv_v_ogm_orig_update(bat_priv, orig_node, neigh_node, ogm2,
                                 if_outgoing);
 
-       orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
-       if (!orig_ifinfo)
-               goto out;
-
-       /* don't forward the same seqno twice on one interface */
-       if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm2->seqno))
-               goto out;
-
-       /* acquire possibly updated router */
-       router = batadv_orig_router_get(orig_node, if_outgoing);
-
-       /* strict rule: forward packets coming from the best next hop only */
-       if (neigh_node != router)
-               goto out;
-
-       /* only forward for specific interface, not for the default one. */
-       if (if_outgoing != BATADV_IF_DEFAULT) {
-               orig_ifinfo->last_seqno_forwarded = ntohl(ogm2->seqno);
-               batadv_v_ogm_forward(bat_priv, ogm2,
-                                    neigh_ifinfo->bat_v.throughput,
-                                    if_incoming, if_outgoing);
-       }
-
+       forward = true;
 out:
-       if (orig_ifinfo)
-               batadv_orig_ifinfo_put(orig_ifinfo);
        if (router)
                batadv_neigh_node_put(router);
        if (orig_neigh_router)
                batadv_neigh_node_put(orig_neigh_router);
        if (orig_neigh_node)
                batadv_orig_node_put(orig_neigh_node);
-       if (neigh_ifinfo)
-               batadv_neigh_ifinfo_put(neigh_ifinfo);
+
+       return forward;
 }
 
 /**
@@ -592,6 +601,7 @@ batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
                               struct batadv_hard_iface *if_outgoing)
 {
        int seqno_age;
+       bool forward;
 
        /* first, update the metric with according sanity checks */
        seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
@@ -610,8 +620,14 @@ batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
                                               ntohs(ogm2->tvlv_len));
 
        /* if the metric update went through, update routes if needed */
-       batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
-                                 neigh_node, if_incoming, if_outgoing);
+       forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
+                                           neigh_node, if_incoming,
+                                           if_outgoing);
+
+       /* if the routes have been processed correctly, check and forward */
+       if (forward)
+               batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
+                                    if_incoming, if_outgoing);
 }
 
 /**