From: Bill Sommerfeld Date: Tue, 19 Jul 2011 15:22:33 +0000 (+0000) Subject: ipv4: Constrain UFO fragment sizes to multiples of 8 bytes X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=d9be4f7a6f5a8da3133b832eca41c3591420b1ca;p=openwrt%2Fstaging%2Fblogic.git ipv4: Constrain UFO fragment sizes to multiples of 8 bytes Because the ip fragment offset field counts 8-byte chunks, ip fragments other than the last must contain a multiple of 8 bytes of payload. ip_ufo_append_data wasn't respecting this constraint and, depending on the MTU and ip option sizes, could create malformed non-final fragments. Google-Bug-Id: 5009328 Signed-off-by: Bill Sommerfeld Signed-off-by: David S. Miller --- diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index be27e609a98b..ccaaa851ab42 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -734,7 +734,7 @@ static inline int ip_ufo_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb), void *from, int length, int hh_len, int fragheaderlen, - int transhdrlen, int mtu, unsigned int flags) + int transhdrlen, int maxfraglen, unsigned int flags) { struct sk_buff *skb; int err; @@ -767,7 +767,7 @@ static inline int ip_ufo_append_data(struct sock *sk, skb->csum = 0; /* specify the length of each IP datagram fragment */ - skb_shinfo(skb)->gso_size = mtu - fragheaderlen; + skb_shinfo(skb)->gso_size = maxfraglen - fragheaderlen; skb_shinfo(skb)->gso_type = SKB_GSO_UDP; __skb_queue_tail(queue, skb); } @@ -831,7 +831,7 @@ static int __ip_append_data(struct sock *sk, (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len) { err = ip_ufo_append_data(sk, queue, getfrag, from, length, hh_len, fragheaderlen, transhdrlen, - mtu, flags); + maxfraglen, flags); if (err) goto error; return 0;