kernel.git/net/core/gro.c, branch linux-6.8.y

net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb

2024-05-17T10:14:34Z

[ Upstream commit 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 ] Commits a602456 ("udp: Add GRO functions to UDP socket") and 57c67ff ("udp: additional GRO support") introduce incorrect usage of {ip,ipv6}_hdr in the complete phase of gro. The functions always return skb->network_header, which in the case of encapsulated packets at the gro complete phase, is always set to the innermost L3 of the packet. That means that calling {ip,ipv6}_hdr for skbs which completed the GRO receive phase (both in gro_list and *_gro_complete) when parsing an encapsulated packet's _outer_ L3/L4 may return an unexpected value. This incorrect usage leads to a bug in GRO's UDP socket lookup. udp{4,6}_lib_lookup_skb functions use ip_hdr/ipv6_hdr respectively. These *_hdr functions return network_header which will point to the innermost L3, resulting in the wrong offset being used in __udp{4,6}_lib_lookup with encapsulated packets. This patch adds network_offset and inner_network_offset to napi_gro_cb, and makes sure both are set correctly. To fix the issue, network_offsets union is used inside napi_gro_cb, in which both the outer and the inner network offsets are saved. Reproduction example: Endpoint configuration example (fou + local address bind) # ip fou add port 6666 ipproto 4 # ip link add name tun1 type ipip remote 2.2.2.1 local 2.2.2.2 encap fou encap-dport 5555 encap-sport 6666 mode ipip # ip link set tun1 up # ip a add 1.1.1.2/24 dev tun1 Netperf TCP_STREAM result on net-next before patch is applied: net-next main, GRO enabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.28 2.37 net-next main, GRO disabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.01 2745.06 patch applied, GRO enabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.01 2877.38 Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket") Signed-off-by: Richard Gobert Reviewed-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

gro: fix ownership transfer

2024-04-10T14:38:05Z

commit ed4cccef64c1d0d5b91e69f7a8a6697c3a865486 upstream. If packets are GROed with fraglist they might be segmented later on and continue their journey in the stack. In skb_segment_list those skbs can be reused as-is. This is an issue as their destructor was removed in skb_gro_receive_list but not the reference to their socket, and then they can't be orphaned. Fix this by also removing the reference to the socket. For example this could be observed, kernel BUG at include/linux/skbuff.h:3131! (skb_orphan) RIP: 0010:ip6_rcv_core+0x11bc/0x19a0 Call Trace: ipv6_list_rcv+0x250/0x3f0 __netif_receive_skb_list_core+0x49d/0x8f0 netif_receive_skb_list_internal+0x634/0xd40 napi_complete_done+0x1d2/0x7d0 gro_cell_poll+0x118/0x1f0 A similar construction is found in skb_gro_receive, apply the same change there. Fixes: 5e10da5385d2 ("skbuff: allow 'slow_gro' for skb carring sock reference") Signed-off-by: Antoine Tenart Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

gro: move the tc_ext comparison to a helper

2023-06-18T17:08:35Z

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

2023-06-10T07:11:41Z

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

2023-06-06T09:12:20Z

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()

2023-05-13T18:47:56Z

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()

2023-04-21T02:25:08Z

__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

2023-02-02T22:49:55Z

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

2023-02-02T04:54:27Z

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

2023-01-28T07:21:27Z

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