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2025-11-27netmem, devmem, tcp: access pp fields through @desc in net_iovByungchul Park
Convert all the legacy code directly accessing the pp fields in net_iov to access them through @desc in net_iov. Signed-off-by: Byungchul Park <byungchul@sk.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-10net: Helper to move packet data and metadata after skb_push/pullJakub Sitnicki
Lay groundwork for fixing BPF helpers available to TC(X) programs. When skb_push() or skb_pull() is called in a TC(X) ingress BPF program, the skb metadata must be kept in front of the MAC header. Otherwise, BPF programs using the __sk_buff->data_meta pseudo-pointer lose access to it. Introduce a helper that moves both metadata and a specified number of packet data bytes together, suitable as a drop-in replacement for memmove(). Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20251105-skb-meta-rx-path-v4-1-5ceb08a9b37b@cloudflare.com
2025-10-23net: datagram: introduce datagram_poll_queue for custom receive queuesRalf Lici
Some protocols using TCP encapsulation (e.g., espintcp, openvpn) deliver userspace-bound packets through a custom skb queue rather than the standard sk_receive_queue. Introduce datagram_poll_queue that accepts an explicit receive queue, and convert datagram_poll into a wrapper around datagram_poll_queue. This allows protocols with custom skb queues to reuse the core polling logic without relying on sk_receive_queue. Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: Antonio Quartulli <antonio@openvpn.net> Signed-off-by: Ralf Lici <ralf@mandelbit.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Antonio Quartulli <antonio@openvpn.net> Link: https://patch.msgid.link/20251021100942.195010-2-ralf@mandelbit.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-25net: gso: restore ids of outer ip headers correctlyRichard Gobert
Currently, NETIF_F_TSO_MANGLEID indicates that the inner-most ID can be mangled. Outer IDs can always be mangled. Make GSO preserve outer IDs by default, with NETIF_F_TSO_MANGLEID allowing both inner and outer IDs to be mangled. This commit also modifies a few drivers that use SKB_GSO_FIXEDID directly. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> # for sfc Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-4-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18net: modify core data structures for PSP datapath supportJakub Kicinski
Add pointers to psp data structures to core networking structs, and an SKB extension to carry the PSP information from the drivers to the socket layer. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-4-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.17-rc4). No conflicts. Adjacent changes: drivers/net/ethernet/intel/idpf/idpf_txrx.c 02614eee26fb ("idpf: do not linearize big TSO packets") 6c4e68480238 ("idpf: remove obsolete stashing code") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-21net: Introduce skb_copy_datagram_from_iter_full()Will Deacon
In a similar manner to copy_from_iter()/copy_from_iter_full(), introduce skb_copy_datagram_from_iter_full() which reverts the iterator to its initial state when returning an error. A subsequent fix for a vsock regression will make use of this new function. Cc: Christian Brauner <brauner@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Will Deacon <will@kernel.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://patch.msgid.link/20250818180355.29275-2-will@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net: Add skb_dst_check_unsetStanislav Fomichev
To prevent dst_entry leaks, add warning when the non-NULL dst_entry is rewritten. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250818154032.3173645-8-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net: Add skb_dstref_steal and skb_dstref_restoreStanislav Fomichev
Going forward skb_dst_set will assert that skb dst_entry is empty during skb_dst_set to prevent potential leaks. There are few places that still manually manage dst_entry not using the helpers. Convert them to the following new helpers: - skb_dstref_steal that resets dst_entry and returns previous dst_entry value - skb_dstref_restore that restores dst_entry previously reset via skb_dstref_steal Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250818154032.3173645-2-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-01ipv6: reject malicious packets in ipv6_gso_segment()Eric Dumazet
syzbot was able to craft a packet with very long IPv6 extension headers leading to an overflow of skb->transport_header. This 16bit field has a limited range. Add skb_reset_transport_header_careful() helper and use it from ipv6_gso_segment() WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 skb_reset_transport_header include/linux/skbuff.h:3032 [inline] WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Modules linked in: CPU: 0 UID: 0 PID: 5871 Comm: syz-executor211 Not tainted 6.16.0-rc6-syzkaller-g7abc678e3084 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:skb_reset_transport_header include/linux/skbuff.h:3032 [inline] RIP: 0010:ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Call Trace: <TASK> skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 nsh_gso_segment+0x54a/0xe10 net/nsh/nsh.c:110 skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 __skb_gso_segment+0x342/0x510 net/core/gso.c:124 skb_gso_segment include/net/gso.h:83 [inline] validate_xmit_skb+0x857/0x11b0 net/core/dev.c:3950 validate_xmit_skb_list+0x84/0x120 net/core/dev.c:4000 sch_direct_xmit+0xd3/0x4b0 net/sched/sch_generic.c:329 __dev_xmit_skb net/core/dev.c:4102 [inline] __dev_queue_xmit+0x17b6/0x3a70 net/core/dev.c:4679 Fixes: d1da932ed4ec ("ipv6: Separate ipv6 offload support") Reported-by: syzbot+af43e647fd835acc02df@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/688a1a05.050a0220.5d226.0008.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Dawid Osuchowski <dawid.osuchowski@linux.intel.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250730131738.3385939-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08net: splice: Drop unused @gfpMichal Luczaj
Since its introduction in commit 2e910b95329c ("net: Add a function to splice pages into an skbuff for MSG_SPLICE_PAGES"), skb_splice_from_iter() never used the @gfp argument. Remove it and adapt callers. No functional change intended. Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Michal Luczaj <mhal@rbox.co> Link: https://patch.msgid.link/20250702-splice-drop-unused-v3-2-55f68b60d2b7@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-21netmem: fix skb_frag_address_safe with unreadable skbsMina Almasry
skb_frag_address_safe() needs a check that the skb_frag_page exists check similar to skb_frag_address(). Cc: ap420073@gmail.com Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250619175239.3039329-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-17net: Add skb_can_coalesce for netmemDragos Tatulea
Allow drivers that have moved over to netmem to do fragment coalescing. Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com> Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Mark Bloch <mbloch@nvidia.com> Link: https://patch.msgid.link/20250616141441.1243044-3-mbloch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-21net: remove skb_copy_and_hash_datagram_iter()Eric Biggers
Now that skb_copy_and_hash_datagram_iter() is no longer used, remove it. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://patch.msgid.link/20250519175012.36581-11-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-21net: add skb_copy_and_crc32c_datagram_iter()Eric Biggers
Since skb_copy_and_hash_datagram_iter() is used only with CRC32C, the crypto_ahash abstraction provides no value. Add skb_copy_and_crc32c_datagram_iter() which just calls crc32c() directly. This is faster and simpler. It also doesn't have the weird dependency issue where skb_copy_and_hash_datagram_iter() depends on CONFIG_CRYPTO_HASH=y without that being expressed explicitly in the kconfig (presumably because it was too heavyweight for NET to select). The new function is conditional on the hidden boolean symbol NET_CRC32C, which selects CRC32. So it gets compiled only when something that actually needs CRC32C packet checksums is enabled, it has no implicit dependency, and it doesn't depend on the heavyweight crypto layer. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://patch.msgid.link/20250519175012.36581-9-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-21net: fold __skb_checksum() into skb_checksum()Eric Biggers
Now that the only remaining caller of __skb_checksum() is skb_checksum(), fold __skb_checksum() into skb_checksum(). This makes struct skb_checksum_ops unnecessary, so remove that too and simply do the "regular" net checksum. It also makes the wrapper functions csum_partial_ext() and csum_block_add_ext() unnecessary, so remove those too and just use the underlying functions. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://patch.msgid.link/20250519175012.36581-7-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-21net: add skb_crc32c()Eric Biggers
Add skb_crc32c(), which calculates the CRC32C of a sk_buff. It will replace __skb_checksum(), which unnecessarily supports arbitrary checksums. Compared to __skb_checksum(), skb_crc32c(): - Uses the correct type for CRC32C values (u32, not __wsum). - Does not require the caller to provide a skb_checksum_ops struct. - Is faster because it does not use indirect calls and does not use the very slow crc32c_combine(). According to commit 2817a336d4d5 ("net: skb_checksum: allow custom update/combine for walking skb") which added __skb_checksum(), the original motivation for the abstraction layer was to avoid code duplication for CRC32C and other checksums in the future. However: - No additional checksums showed up after CRC32C. __skb_checksum() is only used with the "regular" net checksum and CRC32C. - Indirect calls are expensive. Commit 2544af0344ba ("net: avoid indirect calls in L4 checksum calculation") worked around this using the INDIRECT_CALL_1 macro. But that only avoided the indirect call for the net checksum, and at the cost of an extra branch. - The checksums use different types (__wsum and u32), causing casts to be needed. - It made the checksums of fragments be combined (rather than chained) for both checksums, despite this being highly counterproductive for CRC32C due to how slow crc32c_combine() is. This can clearly be seen in commit 4c2f24549644 ("sctp: linearize early if it's not GSO") which tried to work around this performance bug. With a dedicated function for each checksum, we can instead just use the proper strategy for each checksum. As shown by the following tables, the new function skb_crc32c() is faster than __skb_checksum(), with the improvement varying greatly from 5% to 2500% depending on the case. The largest improvements come from fragmented packets, mainly due to eliminating the inefficient crc32c_combine(). But linear packets are improved too, especially shorter ones, mainly due to eliminating indirect calls. These benchmarks were done on AMD Zen 5. On that CPU, Linux uses IBRS instead of retpoline; an even greater improvement might be seen with retpoline: Linear sk_buffs Length in bytes __skb_checksum cycles skb_crc32c cycles =============== ===================== ================= 64 43 18 256 94 77 1420 204 161 16384 1735 1642 Nonlinear sk_buffs (even split between head and one fragment) Length in bytes __skb_checksum cycles skb_crc32c cycles =============== ===================== ================= 64 579 22 256 829 77 1420 1506 194 16384 4365 1682 Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://patch.msgid.link/20250519175012.36581-3-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-13net: devmem: Implement TX pathMina Almasry
Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-06Merge tag 'wireless-next-2025-05-06' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next Johannes Berg says: ==================== wireless features, notably * stack - free SKBTX_WIFI_STATUS flag - fixes for VLAN multicast in multi-link - improve codel parameters (revert some old twiddling) * ath12k - Enable AHB support for IPQ5332. - Add monitor interface support to QCN9274. - Add MLO support to WCN7850. - Add 802.11d scan offload support to WCN7850. * ath11k - Restore hibernation support * iwlwifi - EMLSR on two 5 GHz links * mwifiex - cleanups/refactoring along with many other small features/cleanups * tag 'wireless-next-2025-05-06' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next: (177 commits) Revert "wifi: iwlwifi: clean up config macro" wifi: iwlwifi: move phy_filters to fw_runtime wifi: iwlwifi: pcie: make sure to lock rxq->read wifi: iwlwifi: add definitions for iwl_mac_power_cmd version 2 wifi: iwlwifi: clean up config macro wifi: iwlwifi: mld: simplify iwl_mld_rx_fill_status() wifi: iwlwifi: mld: rx: simplify channel handling wifi: iwlwifi: clean up band in RX metadata wifi: iwlwifi: mld: skip unknown FW channel load values wifi: iwlwifi: define API for external FSEQ images wifi: iwlwifi: mld: allow EMLSR on separated 5 GHz subbands wifi: iwlwifi: mld: use cfg80211_chandef_get_width() wifi: iwlwifi: mld: fix iwl_mld_emlsr_disallowed_with_link() return wifi: iwlwifi: mld: clarify variable type wifi: iwlwifi: pcie: add support for the reset handshake in MSI wifi: mac80211_hwsim: Prevent tsf from setting if beacon is disabled wifi: mac80211: restructure tx profile retrieval for MLO MBSSID wifi: nl80211: add link id of transmitted profile for MLO MBSSID wifi: ieee80211: Add helpers to fetch EMLSR delay and timeout values wifi: mac80211: update ML STA with EML capabilities ... ==================== Link: https://patch.msgid.link/20250506174656.119970-3-johannes@sipsolutions.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-23wifi: free SKBTX_WIFI_STATUS skb tx_flags flagJohannes Berg
Jason mentioned at netdevconf that we've run out of tx_flags in the skb_shinfo(). Gain one bit back by removing the wifi bit. We can do that because the only userspace application for it (hostapd) doesn't change the setting on the socket, it just uses different sockets, and normally doesn't even use this any more, sending the frames over nl80211 instead. Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20250313134942.52ff54a140ec.If390bbdc46904cf451256ba989d7a056c457af6e@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2025-04-17skb: implement skb_send_sock_locked_with_flags()Antonio Quartulli
When sending an skb over a socket using skb_send_sock_locked(), it is currently not possible to specify any flag to be set in msghdr->msg_flags. However, we may want to pass flags the user may have specified, like MSG_NOSIGNAL. Extend __skb_send_sock() with a new argument 'flags' and add a new interface named skb_send_sock_locked_with_flags(). Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Signed-off-by: Antonio Quartulli <antonio@openvpn.net> Link: https://patch.msgid.link/20250415-b4-ovpn-v26-12-577f6097b964@openvpn.net Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-08net: Drop unused @sk of __skb_try_recv_from_queue()Michal Luczaj
__skb_try_recv_from_queue() deals with a queue, @sk is not used since commit e427cad6eee4 ("net: datagram: drop 'destructor' argument from several helpers"). Remove sk from function parameters, adapt callers. No functional change intended. Signed-off-by: Michal Luczaj <mhal@rbox.co> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250407-cleanup-drop-param-sk-v1-1-cd076979afac@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-25net-timestamp: COMPLETION timestamp on packet tx completionPauli Virtanen
Add SOF_TIMESTAMPING_TX_COMPLETION, for requesting a software timestamp when hardware reports a packet completed. Completion tstamp is useful for Bluetooth, as hardware timestamps do not exist in the HCI specification except for ISO packets, and the hardware has a queue where packets may wait. In this case the software SND timestamp only reflects the kernel-side part of the total latency (usually small) and queue length (usually 0 unless HW buffers congested), whereas the completion report time is more informative of the true latency. It may also be useful in other cases where HW TX timestamps cannot be obtained and user wants to estimate an upper bound to when the TX probably happened. Signed-off-by: Pauli Virtanen <pav@iki.fi> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-03-18net: skbuff: Remove unused skb_add_data()Yue Haibing
Since commit a4ea4c477619 ("rxrpc: Don't use a ring buffer for call Tx queue") this function is not used anymore. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250312063450.183652-1-yuehaibing@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-17gso: AccECN supportIlpo Järvinen
Handling the CWR flag differs between RFC 3168 ECN and AccECN. With RFC 3168 ECN aware TSO (NETIF_F_TSO_ECN) CWR flag is cleared starting from 2nd segment which is incompatible how AccECN handles the CWR flag. Such super-segments are indicated by SKB_GSO_TCP_ECN. With AccECN, CWR flag (or more accurately, the ACE field that also includes ECE & AE flags) changes only when new packet(s) with CE mark arrives so the flag should not be changed within a super-skb. The new skb/feature flags are necessary to prevent such TSO engines corrupting AccECN ACE counters by clearing the CWR flag (if the CWR handling feature cannot be turned off). If NIC is completely unaware of RFC3168 ECN (doesn't support NETIF_F_TSO_ECN) or its TSO engine can be set to not touch CWR flag despite supporting also NETIF_F_TSO_ECN, TSO could be safely used with AccECN on such NIC. This should be evaluated per NIC basis (not done in this patch series for any NICs). For the cases, where TSO cannot keep its hands off the CWR flag, a GSO fallback is provided by this patch. Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-02-27net: skbuff: introduce napi_skb_cache_get_bulk()Alexander Lobakin
Add a function to get an array of skbs from the NAPI percpu cache. It's supposed to be a drop-in replacement for kmem_cache_alloc_bulk(skbuff_head_cache, GFP_ATOMIC) and xdp_alloc_skb_bulk(GFP_ATOMIC). The difference (apart from the requirement to call it only from the BH) is that it tries to use as many NAPI cache entries for skbs as possible, and allocate new ones only if needed. The logic is as follows: * there is enough skbs in the cache: decache them and return to the caller; * not enough: try refilling the cache first. If there is now enough skbs, return; * still not enough: try allocating skbs directly to the output array with %GFP_ZERO, maybe we'll be able to get some. If there's now enough, return; * still not enough: return as many as we were able to obtain. Most of times, if called from the NAPI polling loop, the first one will be true, sometimes (rarely) the second one. The third and the fourth -- only under heavy memory pressure. It can save significant amounts of CPU cycles if there are GRO cycles and/or Tx completion cycles (anything that descends to napi_skb_cache_put()) happening on this CPU. Tested-by: Daniel Xu <dxu@dxuuu.xyz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-02-26net: skb: free up one bit in tx_flagsWillem de Bruijn
The linked series wants to add skb tx completion timestamps. That needs a bit in skb_shared_info.tx_flags, but all are in use. A per-skb bit is only needed for features that are configured on a per packet basis. Per socket features can be read from sk->sk_tsflags. Per packet tsflags can be set in sendmsg using cmsg, but only those in SOF_TIMESTAMPING_TX_RECORD_MASK. Per packet tsflags can also be set without cmsg by sandwiching a send inbetween two setsockopts: val |= SOF_TIMESTAMPING_$FEATURE; setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &val, sizeof(val)); write(fd, buf, sz); val &= ~SOF_TIMESTAMPING_$FEATURE; setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &val, sizeof(val)); Changing a datapath test from skb_shinfo(skb)->tx_flags to skb->sk->sk_tsflags can change behavior in that case, as the tx_flags is written before the second setsockopt updates sk_tsflags. Therefore, only bits can be reclaimed that cannot be set by cmsg and are also highly unlikely to be used to target individual packets otherwise. Free up the bit currently used for SKBTX_HW_TSTAMP_USE_CYCLES. This selects between clock and free running counter source for HW TX timestamps. It is probable that all packets of the same socket will always use the same source. Link: https://lore.kernel.org/netdev/cover.1739988644.git.pav@iki.fi/ Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com> Link: https://patch.msgid.link/20250225023416.2088705-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-24net: remove '__' from __skb_flow_get_ports()Nicolas Dichtel
Only one version of skb_flow_get_ports() exists after the previous commit, so let's remove the useless '__'. Suggested-by: Simon Horman <horms@kernel.org> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Link: https://patch.msgid.link/20250221110941.2041629-3-nicolas.dichtel@6wind.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-24skbuff: kill skb_flow_get_ports()Nicolas Dichtel
Since commit a815bde56b15 ("net, bonding: Refactor bond_xmit_hash for use with xdp_buff"), this function is not used anymore. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250221110941.2041629-2-nicolas.dichtel@6wind.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-20bpf: Add BPF_SOCK_OPS_TSTAMP_SND_HW_CB callbackJason Xing
Support hw SCM_TSTAMP_SND case for bpf timestamping. Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SND_HW_CB. This callback will occur at the same timestamping point as the user space's hardware SCM_TSTAMP_SND. The BPF program can use it to get the same SCM_TSTAMP_SND timestamp without modifying the user-space application. To avoid increasing the code complexity, replace SKBTX_HW_TSTAMP with SKBTX_HW_TSTAMP_NOBPF instead of changing numerous callers from driver side using SKBTX_HW_TSTAMP. The new definition of SKBTX_HW_TSTAMP means the combination tests of socket timestamping and bpf timestamping. After this patch, drivers can work under the bpf timestamping. Considering some drivers don't assign the skb with hardware timestamp, this patch does the assignment and then BPF program can acquire the hwstamp from skb directly. Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250220072940.99994-9-kerneljasonxing@gmail.com
2025-02-20bpf: Add BPF_SOCK_OPS_TSTAMP_SND_SW_CB callbackJason Xing
Support sw SCM_TSTAMP_SND case for bpf timestamping. Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SND_SW_CB. This callback will occur at the same timestamping point as the user space's software SCM_TSTAMP_SND. The BPF program can use it to get the same SCM_TSTAMP_SND timestamp without modifying the user-space application. Based on this patch, BPF program will get the software timestamp when the driver is ready to send the skb. In the sebsequent patch, the hardware timestamp will be supported. Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250220072940.99994-8-kerneljasonxing@gmail.com
2025-02-20bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callbackJason Xing
Support SCM_TSTAMP_SCHED case for bpf timestamping. Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SCHED_CB. This callback will occur at the same timestamping point as the user space's SCM_TSTAMP_SCHED. The BPF program can use it to get the same SCM_TSTAMP_SCHED timestamp without modifying the user-space application. A new SKBTX_BPF flag is added to mark skb_shinfo(skb)->tx_flags, ensuring that the new BPF timestamping and the current user space's SO_TIMESTAMPING do not interfere with each other. Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250220072940.99994-7-kerneljasonxing@gmail.com
2024-12-19xdp: add generic xdp_buff_add_frag()Alexander Lobakin
The code piece which would attach a frag to &xdp_buff is almost identical across the drivers supporting XDP multi-buffer on Rx. Make it a generic elegant "oneliner". Also, I see lots of drivers calculating frags_truesize as `xdp->frame_sz * nr_frags`. I can't say this is fully correct, since frags might be backed by chunks of different sizes, especially with stuff like the header split. Even page_pool_alloc() can give you two different truesizes on two subsequent requests to allocate the same buffer size. Add a field to &skb_shared_info (unionized as there's no free slot currently on x86_64) to track the "true" truesize. It can be used later when updating the skb. Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Link: https://patch.msgid.link/20241218174435.1445282-3-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-12skbuff: allow 2-4-argument skb_frag_dma_map()Alexander Lobakin
skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag), DMA_TO_DEVICE) is repeated across dozens of drivers and really wants a shorthand. Add a macro which will count args and handle all possible number from 2 to 5. Semantics: skb_frag_dma_map(dev, frag) -> __skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag), DMA_TO_DEVICE) skb_frag_dma_map(dev, frag, offset) -> __skb_frag_dma_map(dev, frag, offset, skb_frag_size(frag) - offset, DMA_TO_DEVICE) skb_frag_dma_map(dev, frag, offset, size) -> __skb_frag_dma_map(dev, frag, offset, size, DMA_TO_DEVICE) skb_frag_dma_map(dev, frag, offset, size, dir) -> __skb_frag_dma_map(dev, frag, offset, size, dir) No object code size changes for the existing callers. Users passing less arguments also won't have bigger size comparing to the full equivalent call. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Link: https://patch.msgid.link/20241211172649.761483-11-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-09net: reformat kdoc return statementsJakub Kicinski
kernel-doc -Wall warns about missing Return: statement for non-void functions. We have a number of kdocs in our headers which are missing the colon, IOW they use * Return some value or * Returns some value Having the colon makes some sense, it should help kdoc parser avoid false positives. So add them. This is mostly done with a sed script, and removing the unnecessary cases (mostly the comments which aren't kdoc). Acked-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Sergey Ryazanov <ryazanov.s.a@gmail.com> Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> Acked-by: Alexandra Winter <wintera@linux.ibm.com> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Link: https://patch.msgid.link/20241205165914.1071102-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-05bpf, xdp: constify some bpf_prog * function argumentsAlexander Lobakin
In lots of places, bpf_prog pointer is used only for tracing or other stuff that doesn't modify the structure itself. Same for net_device. Address at least some of them and add `const` attributes there. The object code didn't change, but that may prevent unwanted data modifications and also allow more helpers to have const arguments. Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-12net: Implement fault injection forcing skb reallocationBreno Leitao
Introduce a fault injection mechanism to force skb reallocation. The primary goal is to catch bugs related to pointer invalidation after potential skb reallocation. The fault injection mechanism aims to identify scenarios where callers retain pointers to various headers in the skb but fail to reload these pointers after calling a function that may reallocate the data. This type of bug can lead to memory corruption or crashes if the old, now-invalid pointers are used. By forcing reallocation through fault injection, we can stress-test code paths and ensure proper pointer management after potential skb reallocations. Add a hook for fault injection in the following functions: * pskb_trim_rcsum() * pskb_may_pull_reason() * pskb_trim() As the other fault injection mechanism, protect it under a debug Kconfig called CONFIG_FAIL_SKB_REALLOC. This patch was *heavily* inspired by Jakub's proposal from: https://lore.kernel.org/all/20240719174140.47a868e6@kernel.org/ CC: Akinobu Mita <akinobu.mita@gmail.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/20241107-fault_v6-v6-1-1b82cb6ecacd@debian.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-11mm: move the page fragment allocator from page_alloc into its own fileYunsheng Lin
Inspired by [1], move the page fragment allocator from page_alloc into its own c file and header file, as we are about to make more change for it to replace another page_frag implementation in sock.c As this patchset is going to replace 'struct page_frag' with 'struct page_frag_cache' in sched.h, including page_frag_cache.h in sched.h has a compiler error caused by interdependence between mm_types.h and mm.h for asm-offsets.c, see [2]. So avoid the compiler error by moving 'struct page_frag_cache' to mm_types_task.h as suggested by Alexander, see [3]. 1. https://lore.kernel.org/all/20230411160902.4134381-3-dhowells@redhat.com/ 2. https://lore.kernel.org/all/15623dac-9358-4597-b3ee-3694a5956920@gmail.com/ 3. https://lore.kernel.org/all/CAKgT0UdH1yD=LSCXFJ=YM_aiA4OomD-2wXykO42bizaWMt_HOA@mail.gmail.com/ CC: David Howells <dhowells@redhat.com> CC: Linux-MM <linux-mm@kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://patch.msgid.link/20241028115343.3405838-3-linyunsheng@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-06net: add debug check in skb_reset_mac_header()Eric Dumazet
Make sure (skb->data - skb->head) can fit in skb->mac_header This needs CONFIG_DEBUG_NET=y. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://patch.msgid.link/20241105174403.850330-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-06net: add debug check in skb_reset_network_header()Eric Dumazet
Make sure (skb->data - skb->head) can fit in skb->network_header This needs CONFIG_DEBUG_NET=y. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://patch.msgid.link/20241105174403.850330-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-06net: add debug check in skb_reset_transport_header()Eric Dumazet
Make sure (skb->data - skb->head) can fit in skb->transport_header This needs CONFIG_DEBUG_NET=y. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://patch.msgid.link/20241105174403.850330-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-06net: add debug check in skb_reset_inner_mac_header()Eric Dumazet
Make sure (skb->data - skb->head) can fit in skb->inner_mac_header This needs CONFIG_DEBUG_NET=y. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://patch.msgid.link/20241105174403.850330-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-06net: add debug check in skb_reset_inner_network_header()Eric Dumazet
Make sure (skb->data - skb->head) can fit in skb->inner_network_header This needs CONFIG_DEBUG_NET=y. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://patch.msgid.link/20241105174403.850330-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-06net: add debug check in skb_reset_inner_transport_header()Eric Dumazet
Make sure (skb->data - skb->head) can fit in skb->inner_transport_header This needs CONFIG_DEBUG_NET=y. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://patch.msgid.link/20241105174403.850330-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-06net: skb_reset_mac_len() must check if mac_header was setEric Dumazet
Recent discussions show that skb_reset_mac_len() should be more careful. We expect the MAC header being set. If not, clear skb->mac_len and fire a warning for CONFIG_DEBUG_NET=y builds. If after investigations we find that not having a MAC header was okay, we can remove the warning. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/CANn89iJZGH+yEfJxfPWa3Hm7jxb-aeY2Up4HufmLMnVuQXt38A@mail.gmail.com/T/ Cc: En-Wei Wu <en-wei.wu@canonical.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://patch.msgid.link/20241105174403.850330-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-13net: skb: add pskb_network_may_pull_reason() helperMenglong Dong
Introduce the function pskb_network_may_pull_reason() and make pskb_network_may_pull() a simple inline call to it. The drop reasons of it just come from pskb_may_pull_reason. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-09-11net: add support for skbs with unreadable fragsMina Almasry
For device memory TCP, we expect the skb headers to be available in host memory for access, and we expect the skb frags to be in device memory and unaccessible to the host. We expect there to be no mixing and matching of device memory frags (unaccessible) with host memory frags (accessible) in the same skb. Add a skb->devmem flag which indicates whether the frags in this skb are device memory frags or not. __skb_fill_netmem_desc() now checks frags added to skbs for net_iov, and marks the skb as skb->devmem accordingly. Add checks through the network stack to avoid accessing the frags of devmem skbs and avoid coalescing devmem skbs with non devmem skbs. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-9-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-11net: support non paged skb fragsMina Almasry
Make skb_frag_page() fail in the case where the frag is not backed by a page, and fix its relevant callers to handle this case. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-8-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10Merge tag 'ipsec-next-2024-09-10' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2024-09-10 1) Remove an unneeded WARN_ON on packet offload. From Patrisious Haddad. 2) Add a copy from skb_seq_state to buffer function. This is needed for the upcomming IPTFS patchset. From Christian Hopps. 3) Spelling fix in xfrm.h. From Simon Horman. 4) Speed up xfrm policy insertions. From Florian Westphal. 5) Add and revert a patch to support xfrm interfaces for packet offload. This patch was just half cooked. 6) Extend usage of the new xfrm_policy_is_dead_or_sk helper. From Florian Westphal. 7) Update comments on sdb and xfrm_policy. From Florian Westphal. 8) Fix a null pointer dereference in the new policy insertion code From Florian Westphal. 9) Fix an uninitialized variable in the new policy insertion code. From Nathan Chancellor. * tag 'ipsec-next-2024-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next: xfrm: policy: Restore dir assignments in xfrm_hash_rebuild() xfrm: policy: fix null dereference Revert "xfrm: add SA information to the offloaded packet" xfrm: minor update to sdb and xfrm_policy comments xfrm: policy: use recently added helper in more places xfrm: add SA information to the offloaded packet xfrm: policy: remove remaining use of inexact list xfrm: switch migrate to xfrm_policy_lookup_bytype xfrm: policy: don't iterate inexact policies twice at insert time selftests: add xfrm policy insertion speed test script xfrm: Correct spelling in xfrm.h net: add copy from skb_seq_state to buffer function xfrm: Remove documentation WARN_ON to limit return values for offloaded SA ==================== Link: https://patch.msgid.link/20240910065507.2436394-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-20net: add copy from skb_seq_state to buffer functionChristian Hopps
Add an skb helper function to copy a range of bytes from within an existing skb_seq_state. Signed-off-by: Christian Hopps <chopps@labn.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>