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/icmp.c | 6 +++--- net/ipv4/igmp.c | 19 ++++++++++++++----- net/ipv4/ip_gre.c | 15 ++++++++------- net/ipv4/netfilter/ip_conntrack_proto_icmp.c | 11 ++++------- net/ipv4/tcp_ipv4.c | 24 +++++++++--------------- net/ipv4/udp.c | 7 ++----- 6 files changed, 40 insertions(+), 42 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 175e093..e3eceec 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -934,11 +934,11 @@ int icmp_rcv(struct sk_buff *skb) case CHECKSUM_HW: if (!(u16)csum_fold(skb->csum)) break; - LIMIT_NETDEBUG(KERN_DEBUG "icmp v4 hw csum failure\n"); + /* fall through */ case CHECKSUM_NONE: - if ((u16)csum_fold(skb_checksum(skb, 0, skb->len, 0))) + skb->csum = 0; + if (__skb_checksum_complete(skb)) goto error; - default:; } if (!pskb_pull(skb, sizeof(struct icmphdr))) diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index c6247fc..c04607b 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -872,11 +872,18 @@ int igmp_rcv(struct sk_buff *skb) return 0; } - if (!pskb_may_pull(skb, sizeof(struct igmphdr)) || - (u16)csum_fold(skb_checksum(skb, 0, len, 0))) { - in_dev_put(in_dev); - kfree_skb(skb); - return 0; + if (!pskb_may_pull(skb, sizeof(struct igmphdr))) + goto drop; + + switch (skb->ip_summed) { + case CHECKSUM_HW: + if (!(u16)csum_fold(skb->csum)) + break; + /* fall through */ + case CHECKSUM_NONE: + skb->csum = 0; + if (__skb_checksum_complete(skb)) + goto drop; } ih = skb->h.igmph; @@ -906,6 +913,8 @@ int igmp_rcv(struct sk_buff *skb) default: NETDEBUG(KERN_DEBUG "New IGMP type=%d, why we do not know about it?\n", ih->type); } + +drop: in_dev_put(in_dev); kfree_skb(skb); return 0; diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 896ce3f..4e9c74b 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -577,15 +577,16 @@ static int ipgre_rcv(struct sk_buff *skb) goto drop_nolock; if (flags&GRE_CSUM) { - if (skb->ip_summed == CHECKSUM_HW) { + switch (skb->ip_summed) { + case CHECKSUM_HW: csum = (u16)csum_fold(skb->csum); - if (csum) - skb->ip_summed = CHECKSUM_NONE; - } - if (skb->ip_summed == CHECKSUM_NONE) { - skb->csum = skb_checksum(skb, 0, skb->len, 0); + if (!csum) + break; + /* fall through */ + case CHECKSUM_NONE: + skb->csum = 0; + csum = __skb_checksum_complete(skb); skb->ip_summed = CHECKSUM_HW; - csum = (u16)csum_fold(skb->csum); } offset += 4; } diff --git a/net/ipv4/netfilter/ip_conntrack_proto_icmp.c b/net/ipv4/netfilter/ip_conntrack_proto_icmp.c index 5198f3a..e4d6b26 100644 --- a/net/ipv4/netfilter/ip_conntrack_proto_icmp.c +++ b/net/ipv4/netfilter/ip_conntrack_proto_icmp.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -230,19 +231,15 @@ icmp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo, case CHECKSUM_HW: if (!(u16)csum_fold(skb->csum)) break; - if (LOG_INVALID(IPPROTO_ICMP)) - nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL, - "ip_ct_icmp: bad HW ICMP checksum "); - return -NF_ACCEPT; + /* fall through */ case CHECKSUM_NONE: - if ((u16)csum_fold(skb_checksum(skb, 0, skb->len, 0))) { + skb->csum = 0; + if (__skb_checksum_complete(skb)) { if (LOG_INVALID(IPPROTO_ICMP)) nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL, "ip_ct_icmp: bad ICMP checksum "); return -NF_ACCEPT; } - default: - break; } checksum_skipped: diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 634dabb..ac1fcf5 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; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index e0bd101..2422a5f 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -761,7 +761,7 @@ int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) static __inline__ int __udp_checksum_complete(struct sk_buff *skb) { - return (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)); + return __skb_checksum_complete(skb); } static __inline__ int udp_checksum_complete(struct sk_buff *skb) @@ -1100,11 +1100,8 @@ static int udp_checksum_init(struct sk_buff *skb, struct udphdr *uh, if (uh->check == 0) { skb->ip_summed = CHECKSUM_UNNECESSARY; } else if (skb->ip_summed == CHECKSUM_HW) { - skb->ip_summed = CHECKSUM_UNNECESSARY; if (!udp_check(uh, ulen, saddr, daddr, skb->csum)) - return 0; - LIMIT_NETDEBUG(KERN_DEBUG "udp v4 hw csum failure.\n"); - skb->ip_summed = CHECKSUM_NONE; + skb->ip_summed = CHECKSUM_UNNECESSARY; } if (skb->ip_summed != CHECKSUM_UNNECESSARY) skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); -- cgit v1.1