[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 <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 23e5403..1bdf0fb 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -585,17 +585,16 @@
daddr = &skb->nh.ipv6h->daddr;
/* Perform checksum. */
- if (skb->ip_summed == CHECKSUM_HW) {
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
- skb->csum)) {
- LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 hw checksum failed\n");
- skb->ip_summed = CHECKSUM_NONE;
- }
- }
- if (skb->ip_summed == CHECKSUM_NONE) {
- if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
- skb_checksum(skb, 0, skb->len, 0))) {
+ switch (skb->ip_summed) {
+ case CHECKSUM_HW:
+ if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
+ skb->csum))
+ break;
+ /* fall through */
+ case CHECKSUM_NONE:
+ skb->csum = ~csum_ipv6_magic(saddr, daddr, skb->len,
+ IPPROTO_ICMPV6, 0);
+ if (__skb_checksum_complete(skb)) {
LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x > %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]\n",
NIP6(*saddr), NIP6(*daddr));
goto discard_it;
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 651c79b..8e9628f 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -298,13 +298,10 @@
static inline int rawv6_rcv_skb(struct sock * sk, struct sk_buff * skb)
{
if ((raw6_sk(sk)->checksum || sk->sk_filter) &&
- skb->ip_summed != CHECKSUM_UNNECESSARY) {
- if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
- /* FIXME: increment a raw6 drops counter here */
- kfree_skb(skb);
- return 0;
- }
- skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb_checksum_complete(skb)) {
+ /* FIXME: increment a raw6 drops counter here */
+ kfree_skb(skb);
+ return 0;
}
/* Charge it to the socket. */
@@ -337,32 +334,25 @@
if (!rp->checksum)
skb->ip_summed = CHECKSUM_UNNECESSARY;
- if (skb->ip_summed != CHECKSUM_UNNECESSARY) {
- if (skb->ip_summed == CHECKSUM_HW) {
- skb_postpull_rcsum(skb, skb->nh.raw,
- skb->h.raw - skb->nh.raw);
+ if (skb->ip_summed == CHECKSUM_HW) {
+ skb_postpull_rcsum(skb, skb->nh.raw,
+ skb->h.raw - skb->nh.raw);
+ if (!csum_ipv6_magic(&skb->nh.ipv6h->saddr,
+ &skb->nh.ipv6h->daddr,
+ skb->len, inet->num, skb->csum))
skb->ip_summed = CHECKSUM_UNNECESSARY;
- if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,
- skb->len, inet->num, skb->csum)) {
- LIMIT_NETDEBUG(KERN_DEBUG "raw v6 hw csum failure.\n");
- skb->ip_summed = CHECKSUM_NONE;
- }
- }
- if (skb->ip_summed == CHECKSUM_NONE)
- skb->csum = ~csum_ipv6_magic(&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,
- skb->len, inet->num, 0);
}
+ if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+ skb->csum = ~csum_ipv6_magic(&skb->nh.ipv6h->saddr,
+ &skb->nh.ipv6h->daddr,
+ skb->len, inet->num, 0);
if (inet->hdrincl) {
- if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
- (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
+ if (skb_checksum_complete(skb)) {
/* FIXME: increment a raw6 drops counter here */
kfree_skb(skb);
return 0;
}
- skb->ip_summed = CHECKSUM_UNNECESSARY;
}
rawv6_rcv_skb(sk, skb);
@@ -407,7 +397,7 @@
if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
} else if (msg->msg_flags&MSG_TRUNC) {
- if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
+ if (__skb_checksum_complete(skb))
goto csum_copy_err;
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
} else {
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d746d3b..62c0e5b 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1401,20 +1401,18 @@
static int tcp_v6_checksum_init(struct sk_buff *skb)
{
if (skb->ip_summed == CHECKSUM_HW) {
- skb->ip_summed = CHECKSUM_UNNECESSARY;
if (!tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,skb->csum))
+ &skb->nh.ipv6h->daddr,skb->csum)) {
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
return 0;
- LIMIT_NETDEBUG(KERN_DEBUG "hw tcp v6 csum failed\n");
+ }
}
+
+ skb->csum = ~tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
+ &skb->nh.ipv6h->daddr, 0);
+
if (skb->len <= 76) {
- if (tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,skb_checksum(skb, 0, skb->len, 0)))
- return -1;
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- } else {
- skb->csum = ~tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,
- &skb->nh.ipv6h->daddr,0);
+ return __skb_checksum_complete(skb);
}
return 0;
}
@@ -1575,7 +1573,7 @@
goto discard_it;
if ((skb->ip_summed != CHECKSUM_UNNECESSARY &&
- tcp_v6_checksum_init(skb) < 0))
+ tcp_v6_checksum_init(skb)))
goto bad_packet;
th = skb->h.th;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index bf95193..e671153 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -248,7 +248,7 @@
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
copied);
} else if (msg->msg_flags&MSG_TRUNC) {
- if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
+ if (__skb_checksum_complete(skb))
goto csum_copy_err;
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
copied);
@@ -363,13 +363,10 @@
return -1;
}
- if (skb->ip_summed != CHECKSUM_UNNECESSARY) {
- if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
- UDP6_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return 0;
- }
- skb->ip_summed = CHECKSUM_UNNECESSARY;
+ if (skb_checksum_complete(skb)) {
+ UDP6_INC_STATS_BH(UDP_MIB_INERRORS);
+ kfree_skb(skb);
+ return 0;
}
if (sock_queue_rcv_skb(sk,skb)<0) {
@@ -491,13 +488,10 @@
uh = skb->h.uh;
}
- if (skb->ip_summed==CHECKSUM_HW) {
+ if (skb->ip_summed == CHECKSUM_HW &&
+ !csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, skb->csum))
skb->ip_summed = CHECKSUM_UNNECESSARY;
- if (csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, skb->csum)) {
- LIMIT_NETDEBUG(KERN_DEBUG "udp v6 hw csum failure.\n");
- skb->ip_summed = CHECKSUM_NONE;
- }
- }
+
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
skb->csum = ~csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, 0);
@@ -521,8 +515,7 @@
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard;
- if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
- (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
+ if (skb_checksum_complete(skb))
goto discard;
UDP6_INC_STATS_BH(UDP_MIB_NOPORTS);