diff options
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 062dd1a0d8a..0e029c4e290 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -258,6 +258,7 @@ #include <linux/random.h> #include <linux/bootmem.h> #include <linux/cache.h> +#include <linux/err.h> #include <net/icmp.h> #include <net/tcp.h> @@ -2144,6 +2145,67 @@ int compat_tcp_getsockopt(struct sock *sk, int level, int optname, EXPORT_SYMBOL(compat_tcp_getsockopt); #endif +struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int sg) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + struct tcphdr *th; + unsigned thlen; + unsigned int seq; + unsigned int delta; + unsigned int oldlen; + unsigned int len; + + if (!pskb_may_pull(skb, sizeof(*th))) + goto out; + + th = skb->h.th; + thlen = th->doff * 4; + if (thlen < sizeof(*th)) + goto out; + + if (!pskb_may_pull(skb, thlen)) + goto out; + + oldlen = ~htonl(skb->len); + __skb_pull(skb, thlen); + + segs = skb_segment(skb, sg); + if (IS_ERR(segs)) + goto out; + + len = skb_shinfo(skb)->gso_size; + delta = csum_add(oldlen, htonl(thlen + len)); + + skb = segs; + th = skb->h.th; + seq = ntohl(th->seq); + + do { + th->fin = th->psh = 0; + + if (skb->ip_summed == CHECKSUM_NONE) { + th->check = csum_fold(csum_partial( + skb->h.raw, thlen, csum_add(skb->csum, delta))); + } + + seq += len; + skb = skb->next; + th = skb->h.th; + + th->seq = htonl(seq); + th->cwr = 0; + } while (skb->next); + + if (skb->ip_summed == CHECKSUM_NONE) { + delta = csum_add(oldlen, htonl(skb->tail - skb->h.raw)); + th->check = csum_fold(csum_partial( + skb->h.raw, thlen, csum_add(skb->csum, delta))); + } + +out: + return segs; +} + extern void __skb_cb_too_small_for_tcp(int, int); extern struct tcp_congestion_ops tcp_reno; |