[B.A.T.M.A.N.] [PATCH 1/6] batman-adv: implement an helper function to forge unicast packets

A new function named prepare_unicast_packet() has been implemented so that it can do all the needed operations to set up a skb for unicast sending. It is general enough to be used in every context. Helpful for later developments Signed-off-by: Antonio Quartulli &lt;ordex(a)autistici.org&gt; --- unicast.c | 48 ++++++++++++++++++++++++++++++++---------------- unicast.h | 2 ++ 2 files changed, 34 insertions(+), 16 deletions(-) diff --git a/unicast.c b/unicast.c index 07d1c1d..ee7bceb 100644 --- a/unicast.c +++ b/unicast.c @@ -283,6 +283,33 @@ out: return ret; } +struct sk_buff *prepare_unicast_packet(struct sk_buff *skb, + struct orig_node *orig_node) +{ + struct unicast_packet *unicast_packet; + + if (my_skb_head_push(skb, sizeof(*unicast_packet)) < 0) + goto out; + + unicast_packet = (struct unicast_packet *)skb->data; + + unicast_packet->version = COMPAT_VERSION; + /* batman packet type: unicast */ + unicast_packet->packet_type = BAT_UNICAST; + /* set unicast ttl */ + unicast_packet->ttl = TTL; + /* copy the destination for faster routing */ + memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN); + /* set the destination tt version number */ + unicast_packet->ttvn = + (uint8_t)atomic_read(&orig_node->last_ttvn); + + return skb; +out: + kfree(skb); + return NULL; +} + int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv) { struct ethhdr *ethhdr = (struct ethhdr *)skb->data; @@ -296,7 +323,7 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv) if (is_multicast_ether_addr(ethhdr->h_dest)) { orig_node = gw_get_selected_orig(bat_priv); if (orig_node) - goto find_router; + goto prepare_packet; } /* check for tt host - increases orig_node refcount. @@ -304,33 +331,22 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv) orig_node = transtable_search(bat_priv, ethhdr->h_source, ethhdr->h_dest); -find_router: +prepare_packet: /** * find_router(): * - if orig_node is NULL it returns NULL * - increases neigh_nodes refcount if found. */ neigh_node = find_router(bat_priv, orig_node, NULL); - if (!neigh_node) goto out; - if (my_skb_head_push(skb, sizeof(*unicast_packet)) < 0) + skb = prepare_unicast_packet(skb, orig_node); + if (!skb) goto out; unicast_packet = (struct unicast_packet *)skb->data; - unicast_packet->version = COMPAT_VERSION; - /* batman packet type: unicast */ - unicast_packet->packet_type = BAT_UNICAST; - /* set unicast ttl */ - unicast_packet->ttl = TTL; - /* copy the destination for faster routing */ - memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN); - /* set the destination tt version number */ - unicast_packet->ttvn = - (uint8_t)atomic_read(&orig_node->last_ttvn); - if (atomic_read(&bat_priv->fragmentation) && data_len + sizeof(*unicast_packet) > neigh_node->if_incoming->net_dev->mtu) { @@ -350,7 +366,7 @@ out: neigh_node_free_ref(neigh_node); if (orig_node) orig_node_free_ref(orig_node); - if (ret == 1) + if (ret == 1 && skb) kfree_skb(skb); return ret; } diff --git a/unicast.h b/unicast.h index 8fd5535..f53a735 100644 --- a/unicast.h +++ b/unicast.h @@ -33,6 +33,8 @@ void frag_list_free(struct list_head *head); int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv); int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv, struct hard_iface *hard_iface, const uint8_t dstaddr[]); +struct sk_buff *prepare_unicast_packet(struct sk_buff *skb, + struct orig_node *orig_node); static inline int frag_can_reassemble(const struct sk_buff *skb, int mtu) { -- 1.7.3.4