lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <57ac3460731bc73c849bfde39537123c446cc995.camel@redhat.com> Date: Sun, 02 Oct 2022 16:13:51 +0200 From: Paolo Abeni <pabeni@...hat.com> To: Eric Dumazet <eric.dumazet@...il.com>, "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org> Cc: netdev <netdev@...r.kernel.org>, Eric Dumazet <edumazet@...gle.com>, Coco Li <lixiaoyan@...gle.com> Subject: Re: [PATCH v2 net-next] gro: add support of (hw)gro packets to gro stack On Fri, 2022-09-30 at 15:09 -0700, Eric Dumazet wrote: > From: Coco Li <lixiaoyan@...gle.com> > > Current GRO stack only supports incoming packets containing > one frame/MSS. > > This patch changes GRO to accept packets that are already GRO. > > HW-GRO (aka RSC for some vendors) is very often limited in presence > of interleaved packets. Linux SW GRO stack can complete the job > and provide larger GRO packets, thus reducing rate of ACK packets > and cpu overhead. > > This also means BIG TCP can still be used, even if HW-GRO/RSC was > able to cook ~64 KB GRO packets. > > v2: fix logic in tcp_gro_receive() > > Only support TCP for the moment (Paolo) > > Co-Developed-by: Eric Dumazet <edumazet@...gle.com> > Signed-off-by: Eric Dumazet <edumazet@...gle.com> > Signed-off-by: Coco Li <lixiaoyan@...gle.com> > --- > net/core/gro.c | 18 ++++++++++++++---- > net/ipv4/tcp_offload.c | 17 +++++++++++++++-- > 2 files changed, 29 insertions(+), 6 deletions(-) > > diff --git a/net/core/gro.c b/net/core/gro.c > index b4190eb084672fb4f2be8b437eccb4e8507ff63f..bc9451743307bc380cca96ae6995aa0a3b83d185 100644 > --- a/net/core/gro.c > +++ b/net/core/gro.c > @@ -160,6 +160,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) > unsigned int gro_max_size; > unsigned int new_truesize; > struct sk_buff *lp; > + int segs; > > /* pairs with WRITE_ONCE() in netif_set_gro_max_size() */ > gro_max_size = READ_ONCE(p->dev->gro_max_size); > @@ -175,6 +176,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) > return -E2BIG; > } > > + segs = NAPI_GRO_CB(skb)->count; > lp = NAPI_GRO_CB(p)->last; > pinfo = skb_shinfo(lp); > > @@ -265,7 +267,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) > lp = p; > > done: > - NAPI_GRO_CB(p)->count++; > + NAPI_GRO_CB(p)->count += segs; > p->data_len += len; > p->truesize += delta_truesize; > p->len += len; > @@ -496,8 +498,15 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff > BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed), > sizeof(u32))); /* Avoid slow unaligned acc */ > *(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0; > - NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb); > + NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb); > NAPI_GRO_CB(skb)->is_atomic = 1; > + NAPI_GRO_CB(skb)->count = 1; > + if (unlikely(skb_is_gso(skb))) { > + NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs; > + /* Only support TCP at the moment. */ > + if (!skb_is_gso_tcp(skb)) > + NAPI_GRO_CB(skb)->flush = 1; > + } > > /* Setup for GRO checksum validation */ > switch (skb->ip_summed) { > @@ -545,10 +554,10 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff > else > gro_list->count++; > > - NAPI_GRO_CB(skb)->count = 1; > NAPI_GRO_CB(skb)->age = jiffies; > NAPI_GRO_CB(skb)->last = skb; > - skb_shinfo(skb)->gso_size = skb_gro_len(skb); > + if (!skb_is_gso(skb)) > + skb_shinfo(skb)->gso_size = skb_gro_len(skb); > list_add(&skb->list, &gro_list->list); > ret = GRO_HELD; > > @@ -660,6 +669,7 @@ static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) > > skb->encapsulation = 0; > skb_shinfo(skb)->gso_type = 0; > + skb_shinfo(skb)->gso_size = 0; > if (unlikely(skb->slow_gro)) { > skb_orphan(skb); > skb_ext_reset(skb); > diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c > index a844a0d38482d916251f3aca4555c75c9770820c..45dda788938704c3f762256266d9ea29b6ded4a5 100644 > --- a/net/ipv4/tcp_offload.c > +++ b/net/ipv4/tcp_offload.c > @@ -255,7 +255,15 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) > > mss = skb_shinfo(p)->gso_size; > > - flush |= (len - 1) >= mss; > + /* If skb is a GRO packet, make sure its gso_size matches prior packet mss. > + * If it is a single frame, do not aggregate it if its length > + * is bigger than our mss. > + */ > + if (unlikely(skb_is_gso(skb))) > + flush |= (mss != skb_shinfo(skb)->gso_size); > + else > + flush |= (len - 1) >= mss; > + > flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); > #ifdef CONFIG_TLS_DEVICE > flush |= p->decrypted ^ skb->decrypted; > @@ -269,7 +277,12 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) > tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); > > out_check_final: > - flush = len < mss; > + /* Force a flush if last segment is smaller than mss. */ > + if (unlikely(skb_is_gso(skb))) > + flush = len != NAPI_GRO_CB(skb)->count * skb_shinfo(skb)->gso_size; > + else > + flush = len < mss; > + > flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | > TCP_FLAG_RST | TCP_FLAG_SYN | > TCP_FLAG_FIN)); LGTM, thanks! Acked-by: Paolo Abeni <pabeni@...hat.com>
Powered by blists - more mailing lists