diff options
Diffstat (limited to 'net/batman-adv/fragmentation.c')
| -rw-r--r-- | net/batman-adv/fragmentation.c | 41 |
1 files changed, 27 insertions, 14 deletions
diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 9751b207b01f..371f50804fc2 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -394,9 +394,10 @@ out: /** * batadv_frag_create - create a fragment from skb + * @net_dev: outgoing device for fragment * @skb: skb to create fragment from * @frag_head: header to use in new fragment - * @mtu: size of new fragment + * @fragment_size: size of new fragment * * Split the passed skb into two fragments: A new one with size matching the * passed mtu and the old one with the rest. The new skb contains data from the @@ -404,22 +405,25 @@ out: * * Returns the new fragment, NULL on error. */ -static struct sk_buff *batadv_frag_create(struct sk_buff *skb, +static struct sk_buff *batadv_frag_create(struct net_device *net_dev, + struct sk_buff *skb, struct batadv_frag_packet *frag_head, - unsigned int mtu) + unsigned int fragment_size) { + unsigned int ll_reserved = LL_RESERVED_SPACE(net_dev); + unsigned int tailroom = net_dev->needed_tailroom; struct sk_buff *skb_fragment; unsigned header_size = sizeof(*frag_head); - unsigned fragment_size = mtu - header_size; + unsigned mtu = fragment_size + header_size; - skb_fragment = netdev_alloc_skb(NULL, mtu + ETH_HLEN); + skb_fragment = dev_alloc_skb(ll_reserved + mtu + tailroom); if (!skb_fragment) goto err; skb->priority = TC_PRIO_CONTROL; /* Eat the last mtu-bytes of the skb */ - skb_reserve(skb_fragment, header_size + ETH_HLEN); + skb_reserve(skb_fragment, ll_reserved + header_size); skb_split(skb, skb_fragment, skb->len - fragment_size); /* Add the header */ @@ -442,13 +446,14 @@ bool batadv_frag_send_packet(struct sk_buff *skb, struct batadv_orig_node *orig_node, struct batadv_neigh_node *neigh_node) { + struct net_device *net_dev = neigh_node->if_incoming->net_dev; struct batadv_priv *bat_priv; struct batadv_hard_iface *primary_if = NULL; struct batadv_frag_packet frag_header; struct sk_buff *skb_fragment; - unsigned mtu = neigh_node->if_incoming->net_dev->mtu; + unsigned mtu = net_dev->mtu; unsigned header_size = sizeof(frag_header); - unsigned max_fragment_size, max_packet_size; + unsigned max_fragment_size, num_fragments; bool ret = false; /* To avoid merge and refragmentation at next-hops we never send @@ -456,10 +461,15 @@ bool batadv_frag_send_packet(struct sk_buff *skb, */ mtu = min_t(unsigned, mtu, BATADV_FRAG_MAX_FRAG_SIZE); max_fragment_size = mtu - header_size; - max_packet_size = max_fragment_size * BATADV_FRAG_MAX_FRAGMENTS; + + if (skb->len == 0 || max_fragment_size == 0) + goto out_err; + + num_fragments = (skb->len - 1) / max_fragment_size + 1; + max_fragment_size = (skb->len - 1) / num_fragments + 1; /* Don't even try to fragment, if we need more than 16 fragments */ - if (skb->len > max_packet_size) + if (num_fragments > BATADV_FRAG_MAX_FRAGMENTS) goto out_err; bat_priv = orig_node->bat_priv; @@ -484,7 +494,8 @@ bool batadv_frag_send_packet(struct sk_buff *skb, if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) goto out_err; - skb_fragment = batadv_frag_create(skb, &frag_header, mtu); + skb_fragment = batadv_frag_create(net_dev, skb, &frag_header, + max_fragment_size); if (!skb_fragment) goto out_err; @@ -496,11 +507,13 @@ bool batadv_frag_send_packet(struct sk_buff *skb, frag_header.no++; } - /* Make room for the fragment header. */ - if (batadv_skb_head_push(skb, header_size) < 0 || - pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0) + /* make sure that there is at least enough head for the fragmentation + * and ethernet headers + */ + if (skb_cow_head(skb, ETH_HLEN + header_size) < 0) goto out_err; + skb_push(skb, header_size); memcpy(skb->data, &frag_header, header_size); /* Send the last fragment */ |