kernel/linux.git/include/linux/udp.h, branch v6.12.80

Merge tag 'printk-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2024-05-15T19:34:46+00:00

Pull printk updates from Petr Mladek: - Use no_printk() instead of "if (0) printk()" constructs to avoid generating printk index for messages disabled at compile time - Remove deprecated strncpy/strcpy from printk.c - Remove redundant CONFIG_BASE_FULL in favor of CONFIG_BASE_SMALL * tag 'printk-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: cleanup deprecated uses of strncpy/strcpy printk: Remove redundant CONFIG_BASE_FULL printk: Change type of CONFIG_BASE_SMALL to bool printk: Fix LOG_CPU_MAX_BUF_SHIFT when BASE_SMALL is enabled ceph: Use no_printk() helper dyndbg: Use *no_printk() helpers dev_printk: Add and use dev_no_printk() printk: Let no_printk() use _printk()

printk: Change type of CONFIG_BASE_SMALL to bool

2024-05-06T15:39:09+00:00

CONFIG_BASE_SMALL is currently a type int but is only used as a boolean. So, change its type to bool and adapt all usages: CONFIG_BASE_SMALL == 0 becomes !IS_ENABLED(CONFIG_BASE_SMALL) and CONFIG_BASE_SMALL != 0 becomes IS_ENABLED(CONFIG_BASE_SMALL). Reviewed-by: Petr Mladek Reviewed-by: Greg Kroah-Hartman Reviewed-by: Masahiro Yamada Signed-off-by: Yoann Congal Link: https://lore.kernel.org/r/20240505080343.1471198-3-yoann.congal@smile.fr Signed-off-by: Petr Mladek

net: change maximum number of UDP segments to 128

2024-04-14T16:05:08+00:00

The commit fc8b2a619469 ("net: more strict VIRTIO_NET_HDR_GSO_UDP_L4 validation") adds check of potential number of UDP segments vs UDP_MAX_SEGMENTS in linux/virtio_net.h. After this change certification test of USO guest-to-guest transmit on Windows driver for virtio-net device fails, for example with packet size of ~64K and mss of 536 bytes. In general the USO should not be more restrictive than TSO. Indeed, in case of unreasonably small mss a lot of segments can cause queue overflow and packet loss on the destination. Limit of 128 segments is good for any practical purpose, with minimal meaningful mss of 536 the maximal UDP packet will be divided to ~120 segments. The number of segments for UDP packets is validated vs UDP_MAX_SEGMENTS also in udp.c (v4,v6), this does not affect quest-to-guest path but does affect packets sent to host, for example. It is important to mention that UDP_MAX_SEGMENTS is kernel-only define and not available to user mode socket applications. In order to request MSS smaller than MTU the applications just uses setsockopt with SOL_UDP and UDP_SEGMENT and there is no limitations on socket API level. Fixes: fc8b2a619469 ("net: more strict VIRTIO_NET_HDR_GSO_UDP_L4 validation") Signed-off-by: Yuri Benditovich Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller

udp: do not accept non-tunnel GSO skbs landing in a tunnel

2024-03-29T11:30:43+00:00

When rx-udp-gro-forwarding is enabled UDP packets might be GROed when being forwarded. If such packets might land in a tunnel this can cause various issues and udp_gro_receive makes sure this isn't the case by looking for a matching socket. This is performed in udp4/6_gro_lookup_skb but only in the current netns. This is an issue with tunneled packets when the endpoint is in another netns. In such cases the packets will be GROed at the UDP level, which leads to various issues later on. The same thing can happen with rx-gro-list. We saw this with geneve packets being GROed at the UDP level. In such case gso_size is set; later the packet goes through the geneve rx path, the geneve header is pulled, the offset are adjusted and frag_list skbs are not adjusted with regard to geneve. When those skbs hit skb_fragment, it will misbehave. Different outcomes are possible depending on what the GROed skbs look like; from corrupted packets to kernel crashes. One example is a BUG_ON[1] triggered in skb_segment while processing the frag_list. Because gso_size is wrong (geneve header was pulled) skb_segment thinks there is "geneve header size" of data in frag_list, although it's in fact the next packet. The BUG_ON itself has nothing to do with the issue. This is only one of the potential issues. Looking up for a matching socket in udp_gro_receive is fragile: the lookup could be extended to all netns (not speaking about performances) but nothing prevents those packets from being modified in between and we could still not find a matching socket. It's OK to keep the current logic there as it should cover most cases but we also need to make sure we handle tunnel packets being GROed too early. This is done by extending the checks in udp_unexpected_gso: GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits and landing in a tunnel must be segmented. [1] kernel BUG at net/core/skbuff.c:4408! RIP: 0010:skb_segment+0xd2a/0xf70 __udp_gso_segment+0xaa/0x560 Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Fixes: 36707061d6ba ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets") Signed-off-by: Antoine Tenart Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller

udp: add local "peek offset enabled" flag

2024-02-22T01:05:01+00:00

We want to re-organize the struct sock layout. The sk_peek_off field location is problematic, as most protocols want it in the RX read area, while UDP wants it on a cacheline different from sk_receive_queue. Create a local (inside udp_sock) copy of the 'peek offset is enabled' flag and place it inside the same cacheline of reader_queue. Check such flag before reading sk_peek_off. This will save potential false sharing and cache misses in the fast-path. Tested under UDP flood with small packets. The struct sock layout update causes a 4% performance drop, and this patch restores completely the original tput. Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/r/67ab679c15fbf49fa05b3ffe05d91c47ab84f147.1708426665.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski

udplite: fix various data-races

2023-09-14T14:16:36+00:00

udp->pcflag, udp->pcslen and udp->pcrlen reads/writes are racy. Move udp->pcflag to udp->udp_flags for atomicity, and add READ_ONCE()/WRITE_ONCE() annotations for pcslen and pcrlen. Fixes: ba4e58eca8aa ("[NET]: Supporting UDP-Lite (RFC 3828) in Linux") Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni

udplite: remove UDPLITE_BIT

2023-09-14T14:16:36+00:00

This flag is set but never read, we can remove it. Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni

udp: lockless UDP_ENCAP_L2TPINUDP / UDP_GRO

2023-09-14T14:16:36+00:00

Move udp->encap_enabled to udp->udp_flags. Add udp_test_and_set_bit() helper to allow lockless udp_tunnel_encap_enable() implementation. Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni

udp: move udp->accept_udp_{l4|fraglist} to udp->udp_flags

2023-09-14T14:16:36+00:00

These are read locklessly, move them to udp_flags to fix data-races. Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni

udp: move udp->gro_enabled to udp->udp_flags

2023-09-14T14:16:36+00:00

syzbot reported that udp->gro_enabled can be read locklessly. Use one atomic bit from udp->udp_flags. Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni