From 9f37c604d4d2fa491ce9c1dbfd631d731a61e9b0 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Wed, 19 Aug 2015 17:07:32 -0700 Subject: [PATCH] gro: Fix remcsum offload to deal with frags in GRO The remote checksum offload GRO did not consider the case that frag0 might be in use. This patch fixes that by accessing headers using the skb_gro functions and not saving offsets relative to skb->head. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 23 ++++++++------------ include/linux/netdevice.h | 44 ++++++++++++++++++++++++++++----------- net/ipv4/fou.c | 28 +++++++++++-------------- 3 files changed, 53 insertions(+), 42 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 54615bb9d9163..64fcd2402562c 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -519,10 +519,10 @@ static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb, u32 data, struct gro_remcsum *grc, bool nopartial) { - size_t start, offset, plen; + size_t start, offset; if (skb->remcsum_offload) - return NULL; + return vh; if (!NAPI_GRO_CB(skb)->csum_valid) return NULL; @@ -532,17 +532,8 @@ static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb, offsetof(struct udphdr, check) : offsetof(struct tcphdr, check)); - plen = hdrlen + offset + sizeof(u16); - - /* Pull checksum that will be written */ - if (skb_gro_header_hard(skb, off + plen)) { - vh = skb_gro_header_slow(skb, off + plen, off); - if (!vh) - return NULL; - } - - skb_gro_remcsum_process(skb, (void *)vh + hdrlen, - start, offset, grc, nopartial); + vh = skb_gro_remcsum_process(skb, (void *)vh, off, hdrlen, + start, offset, grc, nopartial); skb->remcsum_offload = 1; @@ -573,7 +564,6 @@ static struct sk_buff **vxlan_gro_receive(struct sk_buff **head, goto out; } - skb_gro_pull(skb, sizeof(struct vxlanhdr)); /* pull vxlan header */ skb_gro_postpull_rcsum(skb, vh, sizeof(struct vxlanhdr)); flags = ntohl(vh->vx_flags); @@ -588,6 +578,8 @@ static struct sk_buff **vxlan_gro_receive(struct sk_buff **head, goto out; } + skb_gro_pull(skb, sizeof(struct vxlanhdr)); /* pull vxlan header */ + flush = 0; for (p = *head; p; p = p->next) { @@ -1110,6 +1102,9 @@ static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh, { size_t start, offset, plen; + if (skb->remcsum_offload) + return vh; + start = (data & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT; offset = start + ((data & VXLAN_RCO_UDP) ? offsetof(struct udphdr, check) : diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 4bd177faa90ce..6abe0d6f1e1d4 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2311,8 +2311,7 @@ __sum16 __skb_gro_checksum_complete(struct sk_buff *skb); static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb) { - return (NAPI_GRO_CB(skb)->gro_remcsum_start - skb_headroom(skb) == - skb_gro_offset(skb)); + return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb)); } static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb, @@ -2408,37 +2407,58 @@ static inline void skb_gro_remcsum_init(struct gro_remcsum *grc) grc->delta = 0; } -static inline void skb_gro_remcsum_process(struct sk_buff *skb, void *ptr, - int start, int offset, - struct gro_remcsum *grc, - bool nopartial) +static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr, + unsigned int off, size_t hdrlen, + int start, int offset, + struct gro_remcsum *grc, + bool nopartial) { __wsum delta; + size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start); BUG_ON(!NAPI_GRO_CB(skb)->csum_valid); if (!nopartial) { - NAPI_GRO_CB(skb)->gro_remcsum_start = - ((unsigned char *)ptr + start) - skb->head; - return; + NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start; + return ptr; + } + + ptr = skb_gro_header_fast(skb, off); + if (skb_gro_header_hard(skb, off + plen)) { + ptr = skb_gro_header_slow(skb, off + plen, off); + if (!ptr) + return NULL; } - delta = remcsum_adjust(ptr, NAPI_GRO_CB(skb)->csum, start, offset); + delta = remcsum_adjust(ptr + hdrlen, NAPI_GRO_CB(skb)->csum, + start, offset); /* Adjust skb->csum since we changed the packet */ NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta); - grc->offset = (ptr + offset) - (void *)skb->head; + grc->offset = off + hdrlen + offset; grc->delta = delta; + + return ptr; } static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb, struct gro_remcsum *grc) { + void *ptr; + size_t plen = grc->offset + sizeof(u16); + if (!grc->delta) return; - remcsum_unadjust((__sum16 *)(skb->head + grc->offset), grc->delta); + ptr = skb_gro_header_fast(skb, grc->offset); + if (skb_gro_header_hard(skb, grc->offset + sizeof(u16))) { + ptr = skb_gro_header_slow(skb, plen, grc->offset); + if (!ptr) + return; + } + + remcsum_unadjust((__sum16 *)ptr, grc->delta); } static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev, diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index 34968cd5c1464..eb11f95068946 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -79,7 +79,11 @@ static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr, __be16 *pd = data; size_t start = ntohs(pd[0]); size_t offset = ntohs(pd[1]); - size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start); + size_t plen = sizeof(struct udphdr) + hdrlen + + max_t(size_t, offset + sizeof(u16), start); + + if (skb->remcsum_offload) + return guehdr; if (!pskb_may_pull(skb, plen)) return NULL; @@ -221,29 +225,21 @@ out_unlock: static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off, struct guehdr *guehdr, void *data, - size_t hdrlen, u8 ipproto, - struct gro_remcsum *grc, bool nopartial) + size_t hdrlen, struct gro_remcsum *grc, + bool nopartial) { __be16 *pd = data; size_t start = ntohs(pd[0]); size_t offset = ntohs(pd[1]); - size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start); if (skb->remcsum_offload) - return NULL; + return guehdr; if (!NAPI_GRO_CB(skb)->csum_valid) return NULL; - /* Pull checksum that will be written */ - if (skb_gro_header_hard(skb, off + plen)) { - guehdr = skb_gro_header_slow(skb, off + plen, off); - if (!guehdr) - return NULL; - } - - skb_gro_remcsum_process(skb, (void *)guehdr + hdrlen, - start, offset, grc, nopartial); + guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen, + start, offset, grc, nopartial); skb->remcsum_offload = 1; @@ -307,10 +303,10 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head, if (flags & GUE_PFLAG_REMCSUM) { guehdr = gue_gro_remcsum(skb, off, guehdr, - data + doffset, hdrlen, - guehdr->proto_ctype, &grc, + data + doffset, hdrlen, &grc, !!(fou->flags & FOU_F_REMCSUM_NOPARTIAL)); + if (!guehdr) goto out; -- 2.39.5