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author | 2011-07-05 01:43:20 -0700 | |
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committer | 2011-07-05 22:34:52 -0700 | |
commit | 7736d33f4262d437c51ed7a28114eacbfca236ff (patch) | |
tree | fdefc344c66940773982d23203a7fc07aa94e1ef /net/packet/af_packet.c | |
parent | ipv4: Add ip_defrag() agent IP_DEFRAG_AF_PACKET. (diff) | |
download | linux-7736d33f4262d437c51ed7a28114eacbfca236ff.tar.gz linux-7736d33f4262d437c51ed7a28114eacbfca236ff.tar.bz2 linux-7736d33f4262d437c51ed7a28114eacbfca236ff.zip |
packet: Add pre-defragmentation support for ipv4 fanouts.
The skb->rxhash cannot be properly computed if the
packet is a fragment. To alleviate this, allow the
AF_PACKET client to ask for defragmentation to be
done at demux time.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/packet/af_packet.c')
-rw-r--r-- | net/packet/af_packet.c | 50 |
1 files changed, 48 insertions, 2 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 3350f1d3c9aa..7ba6871a1942 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -223,7 +223,7 @@ struct packet_fanout { unsigned int num_members; u16 id; u8 type; - u8 pad; + u8 defrag; atomic_t rr_cur; struct list_head list; struct sock *arr[PACKET_FANOUT_MAX]; @@ -447,6 +447,41 @@ static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb return f->arr[cur]; } +static struct sk_buff *fanout_check_defrag(struct sk_buff *skb) +{ + const struct iphdr *iph; + u32 len; + + if (skb->protocol != htons(ETH_P_IP)) + return skb; + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + return skb; + + iph = ip_hdr(skb); + if (iph->ihl < 5 || iph->version != 4) + return skb; + if (!pskb_may_pull(skb, iph->ihl*4)) + return skb; + iph = ip_hdr(skb); + len = ntohs(iph->tot_len); + if (skb->len < len || len < (iph->ihl * 4)) + return skb; + + if (ip_is_fragment(ip_hdr(skb))) { + skb = skb_clone(skb, GFP_ATOMIC); + if (skb) { + if (pskb_trim_rcsum(skb, len)) + return skb; + memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); + if (ip_defrag(skb, IP_DEFRAG_AF_PACKET)) + return NULL; + skb->rxhash = 0; + } + } + return skb; +} + static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { @@ -461,6 +496,12 @@ static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev, return 0; } + if (f->defrag) { + skb = fanout_check_defrag(skb); + if (!skb) + return 0; + } + skb_get_rxhash(skb); sk = fanout_demux_hash(f, skb, num); @@ -519,10 +560,12 @@ static void __fanout_unlink(struct sock *sk, struct packet_sock *po) spin_unlock(&f->lock); } -static int fanout_add(struct sock *sk, u16 id, u8 type) +static int fanout_add(struct sock *sk, u16 id, u16 type_flags) { struct packet_sock *po = pkt_sk(sk); struct packet_fanout *f, *match; + u8 type = type_flags & 0xff; + u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0; int err; switch (type) { @@ -548,12 +591,15 @@ static int fanout_add(struct sock *sk, u16 id, u8 type) break; } } + if (match && match->defrag != defrag) + return -EINVAL; if (!match) { match = kzalloc(sizeof(*match), GFP_KERNEL); if (match) { write_pnet(&match->net, sock_net(sk)); match->id = id; match->type = type; + match->defrag = defrag; atomic_set(&match->rr_cur, 0); INIT_LIST_HEAD(&match->list); spin_lock_init(&match->lock); |