diff options
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 80e3812837ad..7bc2d082a49e 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); |