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authorHerbert Xu <herbert@gondor.apana.org.au>2006-06-26 02:55:46 -0400
committerDavid S. Miller <davem@davemloft.net>2006-06-26 02:55:46 -0400
commit0718bcc09b3597c51e87f265c72135a4928d3c0b (patch)
treefd4a686629488bad28f3c780e6b2b52803698877 /net/ipv4/tcp.c
parent3ba07e65b288f00cc4d2420f1da46309b1cb5a0c (diff)
[NET]: Fix CHECKSUM_HW GSO problems.
Fix checksum problems in the GSO code path for CHECKSUM_HW packets. The ipv4 TCP pseudo header checksum has to be adjusted for GSO segmented packets. The adjustment is needed because the length field in the pseudo-header changes. However, because we have the inequality oldlen > newlen, we know that delta = (u16)~oldlen + newlen is still a 16-bit quantity. This also means that htonl(delta) + th->check still fits in 32 bits. Therefore we don't have to use csum_add on this operations. This is based on a patch by Michael Chan <mchan@broadcom.com>. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c22
1 files changed, 11 insertions, 11 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 0e029c4e2903..c04176be7ed1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2166,7 +2166,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int sg)
2166 if (!pskb_may_pull(skb, thlen)) 2166 if (!pskb_may_pull(skb, thlen))
2167 goto out; 2167 goto out;
2168 2168
2169 oldlen = ~htonl(skb->len); 2169 oldlen = (u16)~skb->len;
2170 __skb_pull(skb, thlen); 2170 __skb_pull(skb, thlen);
2171 2171
2172 segs = skb_segment(skb, sg); 2172 segs = skb_segment(skb, sg);
@@ -2174,7 +2174,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int sg)
2174 goto out; 2174 goto out;
2175 2175
2176 len = skb_shinfo(skb)->gso_size; 2176 len = skb_shinfo(skb)->gso_size;
2177 delta = csum_add(oldlen, htonl(thlen + len)); 2177 delta = htonl(oldlen + (thlen + len));
2178 2178
2179 skb = segs; 2179 skb = segs;
2180 th = skb->h.th; 2180 th = skb->h.th;
@@ -2183,10 +2183,10 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int sg)
2183 do { 2183 do {
2184 th->fin = th->psh = 0; 2184 th->fin = th->psh = 0;
2185 2185
2186 if (skb->ip_summed == CHECKSUM_NONE) { 2186 th->check = ~csum_fold(th->check + delta);
2187 th->check = csum_fold(csum_partial( 2187 if (skb->ip_summed != CHECKSUM_HW)
2188 skb->h.raw, thlen, csum_add(skb->csum, delta))); 2188 th->check = csum_fold(csum_partial(skb->h.raw, thlen,
2189 } 2189 skb->csum));
2190 2190
2191 seq += len; 2191 seq += len;
2192 skb = skb->next; 2192 skb = skb->next;
@@ -2196,11 +2196,11 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int sg)
2196 th->cwr = 0; 2196 th->cwr = 0;
2197 } while (skb->next); 2197 } while (skb->next);
2198 2198
2199 if (skb->ip_summed == CHECKSUM_NONE) { 2199 delta = htonl(oldlen + (skb->tail - skb->h.raw) + skb->data_len);
2200 delta = csum_add(oldlen, htonl(skb->tail - skb->h.raw)); 2200 th->check = ~csum_fold(th->check + delta);
2201 th->check = csum_fold(csum_partial( 2201 if (skb->ip_summed != CHECKSUM_HW)
2202 skb->h.raw, thlen, csum_add(skb->csum, delta))); 2202 th->check = csum_fold(csum_partial(skb->h.raw, thlen,
2203 } 2203 skb->csum));
2204 2204
2205out: 2205out:
2206 return segs; 2206 return segs;