linux.git/net/core/gro.c, branch v6.5

gro: move the tc_ext comparison to a helper

2023-06-18T17:08:35+00:00

The double ifdefs (one for the variable declaration and
one around the code) are quite aesthetically displeasing.
Factor this code out into a helper for easier wrapping.

This will become even more ugly when another skb ext
comparison is added in the future.

The resulting machine code looks the same, the compiler
seems to try to use %rax more and some blocks more around
but I haven't spotted minor differences.

Reviewed-by: Simon Horman 
Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

net: move gso declarations and functions to their own files

2023-06-10T07:11:41+00:00

Move declarations into include/net/gso.h and code into net/core/gso.c

Signed-off-by: Eric Dumazet 
Cc: Stanislav Fomichev 
Reviewed-by: Simon Horman 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

gro: decrease size of CB

2023-06-06T09:12:20+00:00

The GRO control block (NAPI_GRO_CB) is currently at its maximum size.
This commit reduces its size by putting two groups of fields that are
used only at different times into a union.

Specifically, the fields frag0 and frag0_len are the fields that make up
the frag0 optimisation mechanism, which is used during the initial
parsing of the SKB.

The fields last and age are used after the initial parsing, while the
SKB is stored in the GRO list, waiting for other packets to arrive.

There was one location in dev_gro_receive that modified the frag0 fields
after setting last and age. I changed this accordingly without altering
the code behaviour.

Signed-off-by: Richard Gobert 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20230601161407.GA9253@debian
Signed-off-by: Paolo Abeni

net: introduce and use skb_frag_fill_page_desc()

2023-05-13T18:47:56+00:00

Most users use __skb_frag_set_page()/skb_frag_off_set()/
skb_frag_size_set() to fill the page desc for a skb frag.

Introduce skb_frag_fill_page_desc() to do that.

net/bpf/test_run.c does not call skb_frag_off_set() to
set the offset, "copy_from_user(page_address(page), ...)"
and 'shinfo' being part of the 'data' kzalloced in
bpf_test_init() suggest that it is assuming offset to be
initialized as zero, so call skb_frag_fill_page_desc()
with offset being zero for this case.

Also, skb_frag_set_page() is not used anymore, so remove
it.

Signed-off-by: Yunsheng Lin 
Reviewed-by: Leon Romanovsky 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller

net: skbuff: update and rename __kfree_skb_defer()

2023-04-21T02:25:08+00:00

__kfree_skb_defer() uses the old naming where "defer" meant
slab bulk free/alloc APIs. In the meantime we also made
__kfree_skb_defer() feed the per-NAPI skb cache, which
implies bulk APIs. So take away the 'defer' and add 'napi'.

While at it add a drop reason. This only matters on the
tx_action path, if the skb has a frag_list. But getting
rid of a SKB_DROP_REASON_NOT_SPECIFIED seems like a net
benefit so why not.

Reviewed-by: Alexander Lobakin 
Link: https://lore.kernel.org/r/20230420020005.815854-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-02-02T22:49:55+00:00

net/core/gro.c
  7d2c89b32587 ("skb: Do mix page pool and page referenced frags in GRO")
  b1a78b9b9886 ("net: add support for ipv4 big tcp")
https://lore.kernel.org/all/20230203094454.5766f160@canb.auug.org.au/

Signed-off-by: Jakub Kicinski

net: add support for ipv4 big tcp

2023-02-02T04:54:27+00:00

Similar to Eric's IPv6 BIG TCP, this patch is to enable IPv4 BIG TCP.

Firstly, allow sk->sk_gso_max_size to be set to a value greater than
GSO_LEGACY_MAX_SIZE by not trimming gso_max_size in sk_trim_gso_size()
for IPv4 TCP sockets.

Then on TX path, set IP header tot_len to 0 when skb->len > IP_MAX_MTU
in __ip_local_out() to allow to send BIG TCP packets, and this implies
that skb->len is the length of a IPv4 packet; On RX path, use skb->len
as the length of the IPv4 packet when the IP header tot_len is 0 and
skb->len > IP_MAX_MTU in ip_rcv_core(). As the API iph_set_totlen() and
skb_ip_totlen() are used in __ip_local_out() and ip_rcv_core(), we only
need to update these APIs.

Also in GRO receive, add the check for ETH_P_IP/IPPROTO_TCP, and allows
the merged packet size >= GRO_LEGACY_MAX_SIZE in skb_gro_receive(). In
GRO complete, set IP header tot_len to 0 when the merged packet size
greater than IP_MAX_MTU in iph_set_totlen() so that it can be processed
on RX path.

Note that by checking skb_is_gso_tcp() in API iph_totlen(), it makes
this implementation safe to use iph->len == 0 indicates IPv4 BIG TCP
packets.

Signed-off-by: Xin Long 
Reviewed-by: David Ahern 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

skb: Do mix page pool and page referenced frags in GRO

2023-01-28T07:21:27+00:00

GSO should not merge page pool recycled frames with standard reference
counted frames. Traditionally this didn't occur, at least not often.
However as we start looking at adding support for wireless adapters there
becomes the potential to mix the two due to A-MSDU repartitioning frames in
the receive path. There are possibly other places where this may have
occurred however I suspect they must be few and far between as we have not
seen this issue until now.

Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool")
Reported-by: Felix Fietkau 
Signed-off-by: Alexander Duyck 
Acked-by: Ilias Apalodimas 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/167475990764.1934330.11960904198087757911.stgit@localhost.localdomain
Signed-off-by: Jakub Kicinski

gro: take care of DODGY packets

2023-01-09T07:37:07+00:00

Jaroslav reported a recent throughput regression with virtio_net
caused by blamed commit.

It is unclear if DODGY GSO packets coming from user space
can be accepted by GRO engine in the future with minimal
changes, and if there is any expected gain from it.

In the meantime, make sure to detect and flush DODGY packets.

Fixes: 5eddb24901ee ("gro: add support of (hw)gro packets to gro stack")
Signed-off-by: Eric Dumazet 
Reported-and-bisected-by: Jaroslav Pulchart 
Cc: Coco Li 
Cc: Paolo Abeni 
Signed-off-by: David S. Miller

net: gro: no longer use skb_vlan_tag_present()

2022-11-12T02:18:05+00:00

We can remove a conditional test in gro_list_prepare()
by comparing vlan_all fields of the two skbs.

Notes:

While comparing the vlan_proto is not strictly needed,
because part of the following compare_ether_header() call,
using 32bit word is actually faster than using 16bit values.

napi_reuse_skb() makes sure to clear skb->vlan_all,
as it already calls __vlan_hwaccel_clear_tag()

Signed-off-by: Eric Dumazet 
Acked-by: Martin KaFai Lau 
Signed-off-by: Jakub Kicinski