diff options
author | Sridhar Samudrala <sri@us.ibm.com> | 2009-07-09 08:09:47 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2009-07-12 14:29:21 -0700 |
commit | d7ca4cc01fd154f2da30ae6dae160fa5800af758 (patch) | |
tree | 8e772bbb2320f4b109e20e9e588345bd1a51fb12 /net | |
parent | 30ffee8480c13fbcf8ab6c28e31f79dfff683117 (diff) | |
download | op-kernel-dev-d7ca4cc01fd154f2da30ae6dae160fa5800af758.zip op-kernel-dev-d7ca4cc01fd154f2da30ae6dae160fa5800af758.tar.gz |
udpv4: Handle large incoming UDP/IPv4 packets and support software UFO.
- validate and forward GSO UDP/IPv4 packets from untrusted sources.
- do software UFO if the outgoing device doesn't support UFO.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/ipv4/af_inet.c | 12 | ||||
-rw-r--r-- | net/ipv4/udp.c | 61 |
2 files changed, 72 insertions, 1 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 566ea6c..197d024 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1187,6 +1187,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features) int proto; int ihl; int id; + unsigned int offset = 0; if (!(features & NETIF_F_V4_CSUM)) features &= ~NETIF_F_SG; @@ -1229,7 +1230,14 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features) skb = segs; do { iph = ip_hdr(skb); - iph->id = htons(id++); + if (proto == IPPROTO_UDP) { + iph->id = htons(id); + iph->frag_off = htons(offset >> 3); + if (skb->next != NULL) + iph->frag_off |= htons(IP_MF); + offset += (skb->len - skb->mac_len - iph->ihl * 4); + } else + iph->id = htons(id++); iph->tot_len = htons(skb->len - skb->mac_len); iph->check = 0; iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl); @@ -1425,6 +1433,8 @@ static struct net_protocol tcp_protocol = { static struct net_protocol udp_protocol = { .handler = udp_rcv, .err_handler = udp_err, + .gso_send_check = udp4_ufo_send_check, + .gso_segment = udp4_ufo_fragment, .no_policy = 1, .netns_ok = 1, }; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 80e3812..7bc2d08 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1816,6 +1816,67 @@ void __init udp_init(void) sysctl_udp_wmem_min = SK_MEM_QUANTUM; } +int udp4_ufo_send_check(struct sk_buff *skb) +{ + const struct iphdr *iph; + struct udphdr *uh; + + if (!pskb_may_pull(skb, sizeof(*uh))) + return -EINVAL; + + iph = ip_hdr(skb); + uh = udp_hdr(skb); + + uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, + IPPROTO_UDP, 0); + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + skb->ip_summed = CHECKSUM_PARTIAL; + return 0; +} + +struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + unsigned int mss; + int offset; + __wsum csum; + + mss = skb_shinfo(skb)->gso_size; + if (unlikely(skb->len <= mss)) + goto out; + + if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { + /* Packet is from an untrusted source, reset gso_segs. */ + int type = skb_shinfo(skb)->gso_type; + + if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) || + !(type & (SKB_GSO_UDP)))) + goto out; + + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); + + segs = NULL; + goto out; + } + + /* Do software UFO. Complete and fill in the UDP checksum as HW cannot + * do checksum of UDP packets sent as multiple IP fragments. + */ + offset = skb->csum_start - skb_headroom(skb); + csum = skb_checksum(skb, offset, skb->len- offset, 0); + offset += skb->csum_offset; + *(__sum16 *)(skb->data + offset) = csum_fold(csum); + skb->ip_summed = CHECKSUM_NONE; + + /* Fragment the skb. IP headers of the fragments are updated in + * inet_gso_segment() + */ + segs = skb_segment(skb, features); +out: + return segs; +} + EXPORT_SYMBOL(udp_disconnect); EXPORT_SYMBOL(udp_ioctl); EXPORT_SYMBOL(udp_prot); |