From fb286bb2990a107009dbf25f6ffebeb7df77f9be Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 10 Nov 2005 13:01:24 -0800 Subject: [NET]: Detect hardware rx checksum faults correctly Here is the patch that introduces the generic skb_checksum_complete which also checks for hardware RX checksum faults. If that happens, it'll call netdev_rx_csum_fault which currently prints out a stack trace with the device name. In future it can turn off RX checksum. I've converted every spot under net/ that does RX checksum checks to use skb_checksum_complete or __skb_checksum_complete with the exceptions of: * Those places where checksums are done bit by bit. These will call netdev_rx_csum_fault directly. * The following have not been completely checked/converted: ipmr ip_vs netfilter dccp This patch is based on patches and suggestions from Stephen Hemminger and David S. Miller. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 634dabb558fd..ac1fcf5b4ebc 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1110,24 +1110,18 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) static int tcp_v4_checksum_init(struct sk_buff *skb) { if (skb->ip_summed == CHECKSUM_HW) { - skb->ip_summed = CHECKSUM_UNNECESSARY; if (!tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr, - skb->nh.iph->daddr, skb->csum)) + skb->nh.iph->daddr, skb->csum)) { + skb->ip_summed = CHECKSUM_UNNECESSARY; return 0; - - LIMIT_NETDEBUG(KERN_DEBUG "hw tcp v4 csum failed\n"); - skb->ip_summed = CHECKSUM_NONE; + } } + + skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr, skb->nh.iph->daddr, + skb->len, IPPROTO_TCP, 0); + if (skb->len <= 76) { - if (tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr, - skb->nh.iph->daddr, - skb_checksum(skb, 0, skb->len, 0))) - return -1; - skb->ip_summed = CHECKSUM_UNNECESSARY; - } else { - skb->csum = ~tcp_v4_check(skb->h.th, skb->len, - skb->nh.iph->saddr, - skb->nh.iph->daddr, 0); + return __skb_checksum_complete(skb); } return 0; } @@ -1219,7 +1213,7 @@ int tcp_v4_rcv(struct sk_buff *skb) * provided case of th->doff==0 is elimineted. * So, we defer the checks. */ if ((skb->ip_summed != CHECKSUM_UNNECESSARY && - tcp_v4_checksum_init(skb) < 0)) + tcp_v4_checksum_init(skb))) goto bad_packet; th = skb->h.th; -- cgit v1.2.1