batman-adv: Add wrapper to look up neighbor and send skb

By adding batadv_send_skb_to_orig() in send.c, we can remove duplicate
code that looks up the next hop and then calls batadv_send_skb_packet().

Furthermore, this prepares the upcoming new implementation of
fragmentation, which requires the next hop to route packets.

Please note that this doesn't entirely remove the next-hop lookup in
routing.c and unicast.c, since it is used by the current fragmentation
code.

Also note that the next-hop info is removed from debug messages in
translation-table.c, since it is looked up elsewhere.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

6 files changed, 74 insertions, 107 deletions

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 78d657264cbf..8d64348e3cc0 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -285,7 +285,6 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 {
         struct batadv_hard_iface *primary_if = NULL;
         struct batadv_orig_node *orig_node = NULL;
-        struct batadv_neigh_node *router = NULL;
         struct batadv_icmp_packet_rr *icmp_packet;
         int ret = NET_RX_DROP;
 
@@ -307,10 +306,6 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
         if (!orig_node)
                 goto out;
 
-        router = batadv_orig_node_get_router(orig_node);
-        if (!router)
-                goto out;
-
         /* create a copy of the skb, if needed, to modify it. */
         if (skb_cow(skb, ETH_HLEN) < 0)
                 goto out;
@@ -322,14 +317,12 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
         icmp_packet->msg_type = BATADV_ECHO_REPLY;
         icmp_packet->header.ttl = BATADV_TTL;
 
-        batadv_send_skb_packet(skb, router->if_incoming, router->addr);
-        ret = NET_RX_SUCCESS;
+        if (batadv_send_skb_to_orig(skb, orig_node, NULL))
+                ret = NET_RX_SUCCESS;
 
 out:
         if (primary_if)
                 batadv_hardif_free_ref(primary_if);
-        if (router)
-                batadv_neigh_node_free_ref(router);
         if (orig_node)
                 batadv_orig_node_free_ref(orig_node);
         return ret;
@@ -340,7 +333,6 @@ static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 {
         struct batadv_hard_iface *primary_if = NULL;
         struct batadv_orig_node *orig_node = NULL;
-        struct batadv_neigh_node *router = NULL;
         struct batadv_icmp_packet *icmp_packet;
         int ret = NET_RX_DROP;
 
@@ -362,10 +354,6 @@ static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
         if (!orig_node)
                 goto out;
 
-        router = batadv_orig_node_get_router(orig_node);
-        if (!router)
-                goto out;
-
         /* create a copy of the skb, if needed, to modify it. */
         if (skb_cow(skb, ETH_HLEN) < 0)
                 goto out;
@@ -377,14 +365,12 @@ static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
         icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
         icmp_packet->header.ttl = BATADV_TTL;
 
-        batadv_send_skb_packet(skb, router->if_incoming, router->addr);
-        ret = NET_RX_SUCCESS;
+        if (batadv_send_skb_to_orig(skb, orig_node, NULL))
+                ret = NET_RX_SUCCESS;
 
 out:
         if (primary_if)
                 batadv_hardif_free_ref(primary_if);
-        if (router)
-                batadv_neigh_node_free_ref(router);
         if (orig_node)
                 batadv_orig_node_free_ref(orig_node);
         return ret;
@@ -398,7 +384,6 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
         struct batadv_icmp_packet_rr *icmp_packet;
         struct ethhdr *ethhdr;
         struct batadv_orig_node *orig_node = NULL;
-        struct batadv_neigh_node *router = NULL;
         int hdr_size = sizeof(struct batadv_icmp_packet);
         int ret = NET_RX_DROP;
 
@@ -447,10 +432,6 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
         if (!orig_node)
                 goto out;
 
-        router = batadv_orig_node_get_router(orig_node);
-        if (!router)
-                goto out;
-
         /* create a copy of the skb, if needed, to modify it. */
         if (skb_cow(skb, ETH_HLEN) < 0)
                 goto out;
@@ -461,12 +442,10 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
         icmp_packet->header.ttl--;
 
         /* route it */
-        batadv_send_skb_packet(skb, router->if_incoming, router->addr);
-        ret = NET_RX_SUCCESS;
+        if (batadv_send_skb_to_orig(skb, orig_node, recv_if))
+                ret = NET_RX_SUCCESS;
 
 out:
-        if (router)
-                batadv_neigh_node_free_ref(router);
         if (orig_node)
                 batadv_orig_node_free_ref(orig_node);
         return ret;
@@ -882,8 +861,8 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,
                            skb->len + ETH_HLEN);
 
         /* route it */
-        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
-        ret = NET_RX_SUCCESS;
+        if (batadv_send_skb_to_orig(skb, orig_node, recv_if))
+                ret = NET_RX_SUCCESS;
 
 out:
         if (neigh_node)
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index 660d9bf7d219..c7f702376535 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -78,6 +78,39 @@ send_skb_err:
         return NET_XMIT_DROP;
 }
 
+/**
+ * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
+ * @skb: Packet to be transmitted.
+ * @orig_node: Final destination of the packet.
+ * @recv_if: Interface used when receiving the packet (can be NULL).
+ *
+ * Looks up the best next-hop towards the passed originator and passes the
+ * skb on for preparation of MAC header. If the packet originated from this
+ * host, NULL can be passed as recv_if and no interface alternating is
+ * attempted.
+ *
+ * Returns TRUE on success; FALSE otherwise.
+ */
+bool batadv_send_skb_to_orig(struct sk_buff *skb,
+                             struct batadv_orig_node *orig_node,
+                             struct batadv_hard_iface *recv_if)
+{
+        struct batadv_priv *bat_priv = orig_node->bat_priv;
+        struct batadv_neigh_node *neigh_node;
+
+        /* batadv_find_router() increases neigh_nodes refcount if found. */
+        neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
+        if (!neigh_node)
+                return false;
+
+        /* route it */
+        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
+
+        batadv_neigh_node_free_ref(neigh_node);
+
+        return true;
+}
+
 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 {
         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
diff --git a/net/batman-adv/send.h b/net/batman-adv/send.h
index 643329b787ed..0078dece1abc 100644
--- a/net/batman-adv/send.h
+++ b/net/batman-adv/send.h
@@ -23,6 +23,9 @@
 int batadv_send_skb_packet(struct sk_buff *skb,
                            struct batadv_hard_iface *hard_iface,
                            const uint8_t *dst_addr);
+bool batadv_send_skb_to_orig(struct sk_buff *skb,
+                             struct batadv_orig_node *orig_node,
+                             struct batadv_hard_iface *recv_if);
 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface);
 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
                                     const struct sk_buff *skb,
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index cdad824a0014..22457a7952ba 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1642,7 +1642,6 @@ static int batadv_send_tt_request(struct batadv_priv *bat_priv,
 {
         struct sk_buff *skb = NULL;
         struct batadv_tt_query_packet *tt_request;
-        struct batadv_neigh_node *neigh_node = NULL;
         struct batadv_hard_iface *primary_if;
         struct batadv_tt_req_node *tt_req_node = NULL;
         int ret = 1;
@@ -1680,23 +1679,15 @@ static int batadv_send_tt_request(struct batadv_priv *bat_priv,
         if (full_table)
                 tt_request->flags |= BATADV_TT_FULL_TABLE;
 
-        neigh_node = batadv_orig_node_get_router(dst_orig_node);
-        if (!neigh_node)
-                goto out;
-
-        batadv_dbg(BATADV_DBG_TT, bat_priv,
-                   "Sending TT_REQUEST to %pM via %pM [%c]\n",
-                   dst_orig_node->orig, neigh_node->addr,
-                   (full_table ? 'F' : '.'));
+        batadv_dbg(BATADV_DBG_TT, bat_priv, "Sending TT_REQUEST to %pM [%c]\n",
+                   dst_orig_node->orig, (full_table ? 'F' : '.'));
 
         batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_TX);
 
-        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
-        ret = 0;
+        if (batadv_send_skb_to_orig(skb, dst_orig_node, NULL))
+                ret = 0;
 
 out:
-        if (neigh_node)
-                batadv_neigh_node_free_ref(neigh_node);
         if (primary_if)
                 batadv_hardif_free_ref(primary_if);
         if (ret)
@@ -1716,7 +1707,6 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
 {
         struct batadv_orig_node *req_dst_orig_node;
         struct batadv_orig_node *res_dst_orig_node = NULL;
-        struct batadv_neigh_node *neigh_node = NULL;
         struct batadv_hard_iface *primary_if = NULL;
         uint8_t orig_ttvn, req_ttvn, ttvn;
         int ret = false;
@@ -1742,10 +1732,6 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
         if (!res_dst_orig_node)
                 goto out;
 
-        neigh_node = batadv_orig_node_get_router(res_dst_orig_node);
-        if (!neigh_node)
-                goto out;
-
         primary_if = batadv_primary_if_get_selected(bat_priv);
         if (!primary_if)
                 goto out;
@@ -1817,14 +1803,13 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
                 tt_response->flags |= BATADV_TT_FULL_TABLE;
 
         batadv_dbg(BATADV_DBG_TT, bat_priv,
-                   "Sending TT_RESPONSE %pM via %pM for %pM (ttvn: %u)\n",
-                   res_dst_orig_node->orig, neigh_node->addr,
-                   req_dst_orig_node->orig, req_ttvn);
+                   "Sending TT_RESPONSE %pM for %pM (ttvn: %u)\n",
+                   res_dst_orig_node->orig, req_dst_orig_node->orig, req_ttvn);
 
         batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_TX);
 
-        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
-        ret = true;
+        if (batadv_send_skb_to_orig(skb, res_dst_orig_node, NULL))
+                ret = true;
         goto out;
 
 unlock:
@@ -1835,8 +1820,6 @@ out:
                 batadv_orig_node_free_ref(res_dst_orig_node);
         if (req_dst_orig_node)
                 batadv_orig_node_free_ref(req_dst_orig_node);
-        if (neigh_node)
-                batadv_neigh_node_free_ref(neigh_node);
         if (primary_if)
                 batadv_hardif_free_ref(primary_if);
         if (!ret)
@@ -1850,7 +1833,6 @@ batadv_send_my_tt_response(struct batadv_priv *bat_priv,
                            struct batadv_tt_query_packet *tt_request)
 {
         struct batadv_orig_node *orig_node;
-        struct batadv_neigh_node *neigh_node = NULL;
         struct batadv_hard_iface *primary_if = NULL;
         uint8_t my_ttvn, req_ttvn, ttvn;
         int ret = false;
@@ -1875,10 +1857,6 @@ batadv_send_my_tt_response(struct batadv_priv *bat_priv,
         if (!orig_node)
                 goto out;
 
-        neigh_node = batadv_orig_node_get_router(orig_node);
-        if (!neigh_node)
-                goto out;
-
         primary_if = batadv_primary_if_get_selected(bat_priv);
         if (!primary_if)
                 goto out;
@@ -1942,14 +1920,14 @@ batadv_send_my_tt_response(struct batadv_priv *bat_priv,
                 tt_response->flags |= BATADV_TT_FULL_TABLE;
 
         batadv_dbg(BATADV_DBG_TT, bat_priv,
-                   "Sending TT_RESPONSE to %pM via %pM [%c]\n",
-                   orig_node->orig, neigh_node->addr,
+                   "Sending TT_RESPONSE to %pM [%c]\n",
+                   orig_node->orig,
                    (tt_response->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
 
         batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_TX);
 
-        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
-        ret = true;
+        if (batadv_send_skb_to_orig(skb, orig_node, NULL))
+                ret = true;
         goto out;
 
 unlock:
@@ -1957,8 +1935,6 @@ unlock:
 out:
         if (orig_node)
                 batadv_orig_node_free_ref(orig_node);
-        if (neigh_node)
-                batadv_neigh_node_free_ref(neigh_node);
         if (primary_if)
                 batadv_hardif_free_ref(primary_if);
         if (!ret)
@@ -2223,7 +2199,6 @@ unlock:
 static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
                                  struct batadv_orig_node *orig_node)
 {
-        struct batadv_neigh_node *neigh_node = NULL;
         struct sk_buff *skb = NULL;
         struct batadv_roam_adv_packet *roam_adv_packet;
         int ret = 1;
@@ -2256,23 +2231,17 @@ static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
         memcpy(roam_adv_packet->dst, orig_node->orig, ETH_ALEN);
         memcpy(roam_adv_packet->client, client, ETH_ALEN);
 
-        neigh_node = batadv_orig_node_get_router(orig_node);
-        if (!neigh_node)
-                goto out;
-
         batadv_dbg(BATADV_DBG_TT, bat_priv,
-                   "Sending ROAMING_ADV to %pM (client %pM) via %pM\n",
-                   orig_node->orig, client, neigh_node->addr);
+                   "Sending ROAMING_ADV to %pM (client %pM)\n",
+                   orig_node->orig, client);
 
         batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_TX);
 
-        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
-        ret = 0;
+        if (batadv_send_skb_to_orig(skb, orig_node, NULL))
+                ret = 0;
 
 out:
-        if (neigh_node)
-                batadv_neigh_node_free_ref(neigh_node);
-        if (ret)
+        if (ret && skb)
                 kfree_skb(skb);
         return;
 }
diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
index c9a1f6523c36..10aff49fcf25 100644
--- a/net/batman-adv/unicast.c
+++ b/net/batman-adv/unicast.c
@@ -402,7 +402,7 @@ int batadv_unicast_generic_send_skb(struct batadv_priv *bat_priv,
         struct batadv_orig_node *orig_node;
         struct batadv_neigh_node *neigh_node;
         int data_len = skb->len;
-        int ret = 1;
+        int ret = NET_RX_DROP;
         unsigned int dev_mtu;
 
         /* get routing information */
@@ -466,15 +466,15 @@ find_router:
                 goto out;
         }
 
-        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
-        ret = 0;
+        if (batadv_send_skb_to_orig(skb, orig_node, NULL))
+                ret = 0;
 
 out:
         if (neigh_node)
                 batadv_neigh_node_free_ref(neigh_node);
         if (orig_node)
                 batadv_orig_node_free_ref(orig_node);
-        if (ret == 1)
+        if (ret == NET_RX_DROP)
                 kfree_skb(skb);
         return ret;
 }
diff --git a/net/batman-adv/vis.c b/net/batman-adv/vis.c
index ad14a6c91d6a..0f65a9de5f74 100644
--- a/net/batman-adv/vis.c
+++ b/net/batman-adv/vis.c
@@ -698,15 +698,12 @@ static void batadv_purge_vis_packets(struct batadv_priv *bat_priv)
 static void batadv_broadcast_vis_packet(struct batadv_priv *bat_priv,
                                         struct batadv_vis_info *info)
 {
-        struct batadv_neigh_node *router;
         struct batadv_hashtable *hash = bat_priv->orig_hash;
         struct hlist_node *node;
         struct hlist_head *head;
         struct batadv_orig_node *orig_node;
         struct batadv_vis_packet *packet;
         struct sk_buff *skb;
-        struct batadv_hard_iface *hard_iface;
-        uint8_t dstaddr[ETH_ALEN];
         uint32_t i;
 
 
@@ -722,30 +719,20 @@ static void batadv_broadcast_vis_packet(struct batadv_priv *bat_priv,
                         if (!(orig_node->flags & BATADV_VIS_SERVER))
                                 continue;
 
-                        router = batadv_orig_node_get_router(orig_node);
-                        if (!router)
-                                continue;
-
                         /* don't send it if we already received the packet from
                          * this node.
                          */
                         if (batadv_recv_list_is_in(bat_priv, &info->recv_list,
-                                                   orig_node->orig)) {
-                                batadv_neigh_node_free_ref(router);
+                                                   orig_node->orig))
                                 continue;
-                        }
 
                         memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
-                        hard_iface = router->if_incoming;
-                        memcpy(dstaddr, router->addr, ETH_ALEN);
-
-                        batadv_neigh_node_free_ref(router);
-
                         skb = skb_clone(info->skb_packet, GFP_ATOMIC);
-                        if (skb)
-                                batadv_send_skb_packet(skb, hard_iface,
-                                                       dstaddr);
+                        if (!skb)
+                                continue;
 
+                        if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
+                                kfree_skb(skb);
                 }
                 rcu_read_unlock();
         }
@@ -755,7 +742,6 @@ static void batadv_unicast_vis_packet(struct batadv_priv *bat_priv,
                                       struct batadv_vis_info *info)
 {
         struct batadv_orig_node *orig_node;
-        struct batadv_neigh_node *router = NULL;
         struct sk_buff *skb;
         struct batadv_vis_packet *packet;
 
@@ -765,17 +751,14 @@ static void batadv_unicast_vis_packet(struct batadv_priv *bat_priv,
         if (!orig_node)
                 goto out;
 
-        router = batadv_orig_node_get_router(orig_node);
-        if (!router)
+        skb = skb_clone(info->skb_packet, GFP_ATOMIC);
+        if (!skb)
                 goto out;
 
-        skb = skb_clone(info->skb_packet, GFP_ATOMIC);
-        if (skb)
-                batadv_send_skb_packet(skb, router->if_incoming, router->addr);
+        if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
+                kfree_skb(skb);
 
 out:
-        if (router)
-                batadv_neigh_node_free_ref(router);
         if (orig_node)
                 batadv_orig_node_free_ref(orig_node);
 }