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path: root/net/ipv4/route.c
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2025-07-14net: ipv4: fix incorrect MTU in broadcast routesOscar Maes
Currently, __mkroute_output overrules the MTU value configured for broadcast routes. This buggy behaviour can be reproduced with: ip link set dev eth1 mtu 9000 ip route del broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2 ip route add broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2 mtu 1500 The maximum packet size should be 1500, but it is actually 8000: ping -b 192.168.0.255 -s 8000 Fix __mkroute_output to allow MTU values to be configured for for broadcast routes (to support a mixed-MTU local-area-network). Signed-off-by: Oscar Maes <oscmaes92@gmail.com> Link: https://patch.msgid.link/20250710142714.12986-1-oscmaes92@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02ipv4: adopt dst_dev, skb_dst_dev and skb_dst_dev_net[_rcu]Eric Dumazet
Use the new helpers as a first step to deal with potential dst->dev races. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250630121934.3399505-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02net: dst: annotate data-races around dst->outputEric Dumazet
dst_dev_put() can overwrite dst->output while other cpus might read this field (for instance from dst_output()) Add READ_ONCE()/WRITE_ONCE() annotations to suppress potential issues. We will likely need RCU protection in the future. Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250630121934.3399505-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02net: dst: annotate data-races around dst->inputEric Dumazet
dst_dev_put() can overwrite dst->input while other cpus might read this field (for instance from dst_input()) Add READ_ONCE()/WRITE_ONCE() annotations to suppress potential issues. We will likely need full RCU protection later. Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250630121934.3399505-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02net: dst: annotate data-races around dst->expiresEric Dumazet
(dst_entry)->expires is read and written locklessly, add corresponding annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250630121934.3399505-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02net: dst: annotate data-races around dst->obsoleteEric Dumazet
(dst_entry)->obsolete is read locklessly, add corresponding annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250630121934.3399505-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-25net: Remove unnecessary NULL check for lwtunnel_fill_encap()Yue Haibing
lwtunnel_fill_encap() has NULL check and return 0, so no need to check before call it. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250624140015.3929241-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-23net: annotate races around sk->sk_uidEric Dumazet
sk->sk_uid can be read while another thread changes its value in sockfs_setattr(). Add sk_uid(const struct sock *sk) helper to factorize the needed READ_ONCE() annotations, and add corresponding WRITE_ONCE() where needed. Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Link: https://patch.msgid.link/20250620133001.4090592-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-17net: ipv4: Add ip_mr_output()Petr Machata
Multicast routing is today handled in the input path. Locally generated MC packets don't hit the IPMR code today. Thus if a VXLAN remote address is multicast, the driver needs to set an OIF during route lookup. Thus MC routing configuration needs to be kept in sync with the VXLAN FDB and MDB. Ideally, the VXLAN packets would be routed by the MC routing code instead. To that end, this patch adds support to route locally generated multicast packets. The newly-added routines do largely what ip_mr_input() and ip_mr_forward() do: make an MR cache lookup to find where to send the packets, and use ip_mc_output() to send each of them. When no cache entry is found, the packet is punted to the daemon for resolution. However, an installation that uses a VXLAN underlay netdevice for which it also has matching MC routes, would get a different routing with this patch. Previously, the MC packets would be delivered directly to the underlay port, whereas now they would be MC-routed. In order to avoid this change in behavior, introduce an IPCB flag. Only if the flag is set will ip_mr_output() actually engage, otherwise it reverts to ip_mc_output(). This code is based on work by Roopa Prabhu and Nikolay Aleksandrov. Signed-off-by: Roopa Prabhu <roopa@nvidia.com> Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/0aadbd49330471c0f758d54afb05eb3b6e3a6b65.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-15ipv4/route: Use this_cpu_inc() for stats on PREEMPT_RTSebastian Andrzej Siewior
The statistics are incremented with raw_cpu_inc() assuming it always happens with bottom half disabled. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this is no longer true. Use this_cpu_inc() on PREEMPT_RT for the increment to not worry about preemption. Cc: David Ahern <dsahern@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20250512092736.229935-4-bigeasy@linutronix.de Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-29ip: load balance tcp connections to single dst addr and portWillem de Bruijn
Load balance new TCP connections across nexthops also when they connect to the same service at a single remote address and port. This affects only port-based multipath hashing: fib_multipath_hash_policy 1 or 3. Local connections must choose both a source address and port when connecting to a remote service, in ip_route_connect. This "chicken-and-egg problem" (commit 2d7192d6cbab ("ipv4: Sanitize and simplify ip_route_{connect,newports}()")) is resolved by first selecting a source address, by looking up a route using the zero wildcard source port and address. As a result multiple connections to the same destination address and port have no entropy in fib_multipath_hash. This is not a problem when forwarding, as skb-based hashing has a 4-tuple. Nor when establishing UDP connections, as autobind there selects a port before reaching ip_route_connect. Load balance also TCP, by using a random port in fib_multipath_hash. Port assignment in inet_hash_connect is not atomic with ip_route_connect. Thus ports are unpredictable, effectively random. Implementation details: Do not actually pass a random fl4_sport, as that affects not only hashing, but routing more broadly, and can match a source port based policy route, which existing wildcard port 0 will not. Instead, define a new wildcard flowi flag that is used only for hashing. Selecting a random source is equivalent to just selecting a random hash entirely. But for code clarity, follow the normal 4-tuple hash process and only update this field. fib_multipath_hash can be reached with zero sport from other code paths, so explicitly pass this flowi flag, rather than trying to infer this case in the function itself. Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250424143549.669426-3-willemdebruijn.kernel@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-29ipv4: prefer multipath nexthop that matches source addressWillem de Bruijn
With multipath routes, try to ensure that packets leave on the device that is associated with the source address. Avoid the following tcpdump example: veth0 Out IP 10.1.0.2.38640 > 10.2.0.3.8000: Flags [S] veth1 Out IP 10.1.0.2.38648 > 10.2.0.3.8000: Flags [S] Which can happen easily with the most straightforward setup: ip addr add 10.0.0.1/24 dev veth0 ip addr add 10.1.0.1/24 dev veth1 ip route add 10.2.0.3 nexthop via 10.0.0.2 dev veth0 \ nexthop via 10.1.0.2 dev veth1 This is apparently considered WAI, based on the comment in ip_route_output_key_hash_rcu: * 2. Moreover, we are allowed to send packets with saddr * of another iface. --ANK It may be ok for some uses of multipath, but not all. For instance, when using two ISPs, a router may drop packets with unknown source. The behavior occurs because tcp_v4_connect makes three route lookups when establishing a connection: 1. ip_route_connect calls to select a source address, with saddr zero. 2. ip_route_connect calls again now that saddr and daddr are known. 3. ip_route_newports calls again after a source port is also chosen. With a route with multiple nexthops, each lookup may make a different choice depending on available entropy to fib_select_multipath. So it is possible for 1 to select the saddr from the first entry, but 3 to select the second entry. Leading to the above situation. Address this by preferring a match that matches the flowi4 saddr. This will make 2 and 3 make the same choice as 1. Continue to update the backup choice until a choice that matches saddr is found. Do this in fib_select_multipath itself, rather than passing an fl4_oif constraint, to avoid changing non-multipath route selection. Commit e6b45241c57a ("ipv4: reset flowi parameters on route connect") shows how that may cause regressions. Also read ipv4.sysctl_fib_multipath_use_neigh only once. No need to refresh in the loop. This does not happen in IPv6, which performs only one lookup. Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250424143549.669426-2-willemdebruijn.kernel@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-16ipv4: Use nlmsg_payload in route fileBreno Leitao
Leverage the new nlmsg_payload() helper to avoid checking for message size and then reading the nlmsg data. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250415-nlmsg_v2-v1-6-a1c75d493fd7@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-10ipv4: remove unnecessary judgment in ip_route_output_key_hash_rcuZhengchao Shao
In the ip_route_output_key_cash_rcu function, the input fl4 member saddr is first checked to be non-zero before entering multicast, broadcast and arbitrary IP address checks. However, the fact that the IP address is not 0 has already ruled out the possibility of any address, so remove unnecessary judgment. Signed-off-by: Zhengchao Shao <shaozhengchao@163.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250409033321.108244-1-shaozhengchao@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-06ipv4: use RCU protection in __ip_rt_update_pmtu()Eric Dumazet
__ip_rt_update_pmtu() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: 2fbc6e89b2f1 ("ipv4: Update exception handling for multipath routes via same device") Fixes: 1de6b15a434c ("Namespaceify min_pmtu sysctl") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250205155120.1676781-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-06ipv4: use RCU protection in rt_is_expired()Eric Dumazet
rt_is_expired() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: e84f84f27647 ("netns: place rt_genid into struct net") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250205155120.1676781-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-06ipv4: use RCU protection in ipv4_default_advmss()Eric Dumazet
ipv4_default_advmss() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: 2e9589ff809e ("ipv4: Namespaceify min_adv_mss sysctl knob") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250205155120.1676781-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-16ipv4: Prepare inet_rtm_getroute() to .flowi4_tos conversion.Guillaume Nault
Store rtm->rtm_tos in a dscp_t variable, which can then be used for setting fl4.flowi4_tos and also be passed as parameter of ip_route_input_rcu(). The .flowi4_tos field is going to be converted to dscp_t to ensure ECN bits aren't erroneously taken into account during route lookups. Having a dscp_t variable available will simplify that conversion, as we'll just have to drop the inet_dscp_to_dsfield() call. Note that we can't just convert rtm->rtm_tos to dscp_t because this structure is exported to user space. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/7bc1c7dc47ad1393569095d334521fae59af5bc7.1736944951.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.13-rc8). Conflicts: drivers/net/ethernet/realtek/r8169_main.c 1f691a1fc4be ("r8169: remove redundant hwmon support") 152d00a91396 ("r8169: simplify setting hwmon attribute visibility") https://lore.kernel.org/20250115122152.760b4e8d@canb.auug.org.au Adjacent changes: drivers/net/ethernet/broadcom/bnxt/bnxt.c 152f4da05aee ("bnxt_en: add support for rx-copybreak ethtool command") f0aa6a37a3db ("eth: bnxt: always recalculate features after XDP clearing, fix null-deref") drivers/net/ethernet/intel/ice/ice_type.h 50327223a8bb ("ice: add lock to protect low latency interface") dc26548d729e ("ice: Fix quad registers read on E825") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-09ipv4: route: fix drop reason being overridden in ip_route_input_slowAntoine Tenart
When jumping to 'martian_destination' a drop reason is always set but that label falls-through the 'e_nobufs' one, overriding the value. The behavior was introduced by the mentioned commit. The logic went from, goto martian_destination; ... martian_destination: ... e_inval: err = -EINVAL; goto out; e_nobufs: err = -ENOBUFS; goto out; to, reason = ...; goto martian_destination; ... martian_destination: ... e_nobufs: reason = SKB_DROP_REASON_NOMEM; goto out; A 'goto out' is clearly missing now after 'martian_destination' to avoid overriding the drop reason. Fixes: 5b92112acd8e ("net: ip: make ip_route_input_slow() return drop reasons") Reported-by: Sabrina Dubroca <sd@queasysnail.net> Cc: Menglong Dong <menglong8.dong@gmail.com> Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250108165725.404564-1-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-17inetpeer: do not get a refcount in inet_getpeer()Eric Dumazet
All inet_getpeer() callers except ip4_frag_init() don't need to acquire a permanent refcount on the inetpeer. They can switch to full RCU protection. Move the refcount_inc_not_zero() into ip4_frag_init(), so that all the other callers no longer have to perform a pair of expensive atomic operations on a possibly contended cache line. inet_putpeer() no longer needs to be exported. After this patch, my DUT can receive 8,400,000 UDP packets per second targeting closed ports, using 50% less cpu cycles than before. Also change two calls to l3mdev_master_ifindex() by l3mdev_master_ifindex_rcu() (Ido ideas) Fixes: 8c2bd38b95f7 ("icmp: change the order of rate limits") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241215175629.1248773-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-17inetpeer: remove create argument of inet_getpeer_v[46]()Eric Dumazet
All callers of inet_getpeer_v4() and inet_getpeer_v6() want to create an inetpeer. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241215175629.1248773-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-07ip: Return drop reason if in_dev is NULL in ip_route_input_rcu().Kuniyuki Iwashima
syzkaller reported a warning in __sk_skb_reason_drop(). Commit 61b95c70f344 ("net: ip: make ip_route_input_rcu() return drop reasons") missed a path where -EINVAL is returned. Then, the cited commit started to trigger the warning with the invalid error. Let's fix it by returning SKB_DROP_REASON_NOT_SPECIFIED. [0]: WARNING: CPU: 0 PID: 10 at net/core/skbuff.c:1216 __sk_skb_reason_drop net/core/skbuff.c:1216 [inline] WARNING: CPU: 0 PID: 10 at net/core/skbuff.c:1216 sk_skb_reason_drop+0x97/0x1b0 net/core/skbuff.c:1241 Modules linked in: CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.12.0-10686-gbb18265c3aba #10 1c308307628619808b5a4a0495c4aab5637b0551 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 Workqueue: wg-crypt-wg2 wg_packet_decrypt_worker RIP: 0010:__sk_skb_reason_drop net/core/skbuff.c:1216 [inline] RIP: 0010:sk_skb_reason_drop+0x97/0x1b0 net/core/skbuff.c:1241 Code: 5d 41 5c 41 5d 41 5e e9 e7 9e 95 fd e8 e2 9e 95 fd 31 ff 44 89 e6 e8 58 a1 95 fd 45 85 e4 0f 85 a2 00 00 00 e8 ca 9e 95 fd 90 <0f> 0b 90 e8 c1 9e 95 fd 44 89 e6 bf 01 00 00 00 e8 34 a1 95 fd 41 RSP: 0018:ffa0000000007650 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 000000000000ffff RCX: ffffffff83bc3592 RDX: ff110001002a0000 RSI: ffffffff83bc34d6 RDI: 0000000000000007 RBP: ff11000109ee85f0 R08: 0000000000000001 R09: ffe21c00213dd0da R10: 000000000000ffff R11: 0000000000000000 R12: 00000000ffffffea R13: 0000000000000000 R14: ff11000109ee86d4 R15: ff11000109ee8648 FS: 0000000000000000(0000) GS:ff1100011a000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020177000 CR3: 0000000108a3d006 CR4: 0000000000771ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: <IRQ> kfree_skb_reason include/linux/skbuff.h:1263 [inline] ip_rcv_finish_core.constprop.0+0x896/0x2320 net/ipv4/ip_input.c:424 ip_list_rcv_finish.constprop.0+0x1b2/0x710 net/ipv4/ip_input.c:610 ip_sublist_rcv net/ipv4/ip_input.c:636 [inline] ip_list_rcv+0x34a/0x460 net/ipv4/ip_input.c:670 __netif_receive_skb_list_ptype net/core/dev.c:5715 [inline] __netif_receive_skb_list_core+0x536/0x900 net/core/dev.c:5762 __netif_receive_skb_list net/core/dev.c:5814 [inline] netif_receive_skb_list_internal+0x77c/0xdc0 net/core/dev.c:5905 gro_normal_list include/net/gro.h:515 [inline] gro_normal_list include/net/gro.h:511 [inline] napi_complete_done+0x219/0x8c0 net/core/dev.c:6256 wg_packet_rx_poll+0xbff/0x1e40 drivers/net/wireguard/receive.c:488 __napi_poll.constprop.0+0xb3/0x530 net/core/dev.c:6877 napi_poll net/core/dev.c:6946 [inline] net_rx_action+0x9eb/0xe30 net/core/dev.c:7068 handle_softirqs+0x1ac/0x740 kernel/softirq.c:554 do_softirq kernel/softirq.c:455 [inline] do_softirq+0x48/0x80 kernel/softirq.c:442 </IRQ> <TASK> __local_bh_enable_ip+0xed/0x110 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline] wg_packet_decrypt_worker+0x3ba/0x580 drivers/net/wireguard/receive.c:499 process_one_work+0x940/0x1a70 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x639/0xe30 kernel/workqueue.c:3391 kthread+0x283/0x350 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244 </TASK> Fixes: 82d9983ebeb8 ("net: ip: make ip_route_input_noref() return drop reasons") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20241206020715.80207-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-12net: ip: make ip_route_use_hint() return drop reasonsMenglong Dong
In this commit, we make ip_route_use_hint() return drop reasons. The drop reasons that we return are similar to what we do in ip_route_input_slow(), and no drop reasons are added in this commit. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-12net: ip: make ip_mkroute_input/__mkroute_input return drop reasonsMenglong Dong
In this commit, we make ip_mkroute_input() and __mkroute_input() return drop reasons. The drop reason "SKB_DROP_REASON_ARP_PVLAN_DISABLE" is introduced for the case: the packet which is not IP is forwarded to the in_dev, and the proxy_arp_pvlan is not enabled. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-12net: ip: make ip_route_input_noref() return drop reasonsMenglong Dong
In this commit, we make ip_route_input_noref() return drop reasons, which come from ip_route_input_rcu(). We need adjust the callers of ip_route_input_noref() to make sure the return value of ip_route_input_noref() is used properly. The errno that ip_route_input_noref() returns comes from ip_route_input and bpf_lwt_input_reroute in the origin logic, and we make them return -EINVAL on error instead. In the following patch, we will make ip_route_input() returns drop reasons too. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-12net: ip: make ip_route_input_rcu() return drop reasonsMenglong Dong
In this commit, we make ip_route_input_rcu() return drop reasons, which come from ip_route_input_mc() and ip_route_input_slow(). The only caller of ip_route_input_rcu() is ip_route_input_noref(). We adjust it by making it return -EINVAL on error and ignore the reasons that ip_route_input_rcu() returns. In the following patch, we will make ip_route_input_noref() returns the drop reasons. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-12net: ip: make ip_route_input_slow() return drop reasonsMenglong Dong
In this commit, we make ip_route_input_slow() return skb drop reasons, and following new skb drop reasons are added: SKB_DROP_REASON_IP_INVALID_DEST The only caller of ip_route_input_slow() is ip_route_input_rcu(), and we adjust it by making it return -EINVAL on error. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-12net: ip: make ip_mc_validate_source() return drop reasonMenglong Dong
Make ip_mc_validate_source() return drop reason, and adjust the call of it in ip_route_input_mc(). Another caller of it is ip_rcv_finish_core->udp_v4_early_demux, and the errno is not checked in detail, so we don't do more adjustment for it. The drop reason "SKB_DROP_REASON_IP_LOCALNET" is added in this commit. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-12net: ip: make ip_route_input_mc() return drop reasonMenglong Dong
Make ip_route_input_mc() return drop reason, and adjust the call of it in ip_route_input_rcu(). Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-12net: ip: make fib_validate_source() support drop reasonsMenglong Dong
In this commit, we make fib_validate_source() and __fib_validate_source() return -reason instead of errno on error. The return value of fib_validate_source can be -errno, 0, and 1. It's hard to make fib_validate_source() return drop reasons directly. The fib_validate_source() will return 1 if the scope of the source(revert) route is HOST. And the __mkroute_input() will mark the skb with IPSKB_DOREDIRECT in this case (combine with some other conditions). And then, a REDIRECT ICMP will be sent in ip_forward() if this flag exists. We can't pass this information to __mkroute_input if we make fib_validate_source() return drop reasons. Therefore, we introduce the wrapper fib_validate_source_reason() for fib_validate_source(), which will return the drop reasons on error. In the origin logic, LINUX_MIB_IPRPFILTER will be counted if fib_validate_source() return -EXDEV. And now, we need to adjust it by checking "reason == SKB_DROP_REASON_IP_RPFILTER". However, this will take effect only after the patch "net: ip: make ip_route_input_noref() return drop reasons", as we can't pass the drop reasons from fib_validate_source() to ip_rcv_finish_core() in this patch. Following new drop reasons are added in this patch: SKB_DROP_REASON_IP_LOCAL_SOURCE SKB_DROP_REASON_IP_INVALID_SOURCE Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-11net: ipv4: Cache pmtu for all packet paths if multipath enabledVladimir Vdovin
Check number of paths by fib_info_num_path(), and update_or_create_fnhe() for every path. Problem is that pmtu is cached only for the oif that has received icmp message "need to frag", other oifs will still try to use "default" iface mtu. An example topology showing the problem: | host1 +---------+ | dummy0 | 10.179.20.18/32 mtu9000 +---------+ +-----------+----------------+ +---------+ +---------+ | ens17f0 | 10.179.2.141/31 | ens17f1 | 10.179.2.13/31 +---------+ +---------+ | (all here have mtu 9000) | +------+ +------+ | ro1 | 10.179.2.140/31 | ro2 | 10.179.2.12/31 +------+ +------+ | | ---------+------------+-------------------+------ | +-----+ | ro3 | 10.10.10.10 mtu1500 +-----+ | ======================================== some networks ======================================== | +-----+ | eth0| 10.10.30.30 mtu9000 +-----+ | host2 host1 have enabled multipath and sysctl net.ipv4.fib_multipath_hash_policy = 1: default proto static src 10.179.20.18 nexthop via 10.179.2.12 dev ens17f1 weight 1 nexthop via 10.179.2.140 dev ens17f0 weight 1 When host1 tries to do pmtud from 10.179.20.18/32 to host2, host1 receives at ens17f1 iface an icmp packet from ro3 that ro3 mtu=1500. And host1 caches it in nexthop exceptions cache. Problem is that it is cached only for the iface that has received icmp, and there is no way that ro3 will send icmp msg to host1 via another path. Host1 now have this routes to host2: ip r g 10.10.30.30 sport 30000 dport 443 10.10.30.30 via 10.179.2.12 dev ens17f1 src 10.179.20.18 uid 0 cache expires 521sec mtu 1500 ip r g 10.10.30.30 sport 30033 dport 443 10.10.30.30 via 10.179.2.140 dev ens17f0 src 10.179.20.18 uid 0 cache So when host1 tries again to reach host2 with mtu>1500, if packet flow is lucky enough to be hashed with oif=ens17f1 its ok, if oif=ens17f0 it blackholes and still gets icmp msgs from ro3 to ens17f1, until lucky day when ro3 will send it through another flow to ens17f0. Signed-off-by: Vladimir Vdovin <deliran@verdict.gg> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20241108093427.317942-1-deliran@verdict.gg Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-11net: convert to nla_get_*_default()Johannes Berg
Most of the original conversion is from the spatch below, but I edited some and left out other instances that were either buggy after conversion (where default values don't fit into the type) or just looked strange. @@ expression attr, def; expression val; identifier fn =~ "^nla_get_.*"; fresh identifier dfn = fn ## "_default"; @@ ( -if (attr) - val = fn(attr); -else - val = def; +val = dfn(attr, def); | -if (!attr) - val = def; -else - val = fn(attr); +val = dfn(attr, def); | -if (!attr) - return def; -return fn(attr); +return dfn(attr, def); | -attr ? fn(attr) : def +dfn(attr, def) | -!attr ? def : fn(attr) +dfn(attr, def) ) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org> Link: https://patch.msgid.link/20241108114145.0580b8684e7f.I740beeaa2f70ebfc19bfca1045a24d6151992790@changeid Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-29ipv4: Prepare ip_rt_get_source() to future .flowi4_tos conversion.Guillaume Nault
Use ip4h_dscp() to get the DSCP from the IPv4 header, then convert the dscp_t value to __u8 with inet_dscp_to_dsfield(). Then, when we'll convert .flowi4_tos to dscp_t, we'll just have to drop the inet_dscp_to_dsfield() call. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/0a13a200f31809841975e38633914af1061e0c04.1729530028.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-15ipv4: Use rtnl_register_many().Kuniyuki Iwashima
We will remove rtnl_register() in favour of rtnl_register_many(). When it succeeds, rtnl_register_many() guarantees all rtnetlink types in the passed array are supported, and there is no chance that a part of message types is not supported. Let's use rtnl_register_many() instead. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241014201828.91221-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09ipv4: Convert fib_validate_source() to dscp_t.Guillaume Nault
Pass a dscp_t variable to fib_validate_source(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. All callers of fib_validate_source() already have a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversions. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/08612a4519bc5a3578bb493fbaad82437ebb73dc.1728302212.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09ipv4: Convert ip_mc_validate_source() to dscp_t.Guillaume Nault
Pass a dscp_t variable to ip_mc_validate_source(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_mc_validate_source() to consider are: * ip_route_input_mc() which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * udp_v4_early_demux() which gets the DSCP directly from the IPv4 header and can simply use the ip4h_dscp() helper. Also, stop including net/inet_dscp.h in udp.c as we don't use any of its declarations anymore. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/c91b2cca04718b7ee6cf5b9c1d5b40507d65a8d4.1728302212.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09ipv4: Convert ip_route_input_mc() to dscp_t.Guillaume Nault
Pass a dscp_t variable to ip_route_input_mc(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Only ip_route_input_rcu() actually calls ip_route_input_mc(). Since it already has a dscp_t variable to pass as parameter, we only need to remove the inet_dscp_to_dsfield() conversion. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/0cc653ef59bbc0a28881f706d34896c61eba9e01.1728302212.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09ipv4: Convert __mkroute_input() to dscp_t.Guillaume Nault
Pass a dscp_t variable to __mkroute_input(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Only ip_mkroute_input() actually calls __mkroute_input(). Since it already has a dscp_t variable to pass as parameter, we only need to remove the inet_dscp_to_dsfield() conversion. While there, reorganise the function parameters to fill up horizontal space. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/40853c720aee4d608e6b1b204982164c3b76697d.1728302212.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09ipv4: Convert ip_mkroute_input() to dscp_t.Guillaume Nault
Pass a dscp_t variable to ip_mkroute_input(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Only ip_route_input_slow() actually calls ip_mkroute_input(). Since it already has a dscp_t variable to pass as parameter, we only need to remove the inet_dscp_to_dsfield() conversion. While there, reorganise the function parameters to fill up horizontal space. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/6aa71e28f9ff681cbd70847080e1ab6b526f94f1.1728302212.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-09ipv4: Convert ip_route_use_hint() to dscp_t.Guillaume Nault
Pass a dscp_t variable to ip_route_use_hint(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Only ip_rcv_finish_core() actually calls ip_route_use_hint(). Use the ip4h_dscp() helper to get the DSCP from the IPv4 header. While there, modify the declaration of ip_route_use_hint() in include/net/route.h so that it matches the prototype of its implementation in net/ipv4/route.c. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/c40994fdf804db7a363d04fdee01bf48dddda676.1728302212.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03ipv4: Convert ip_route_input_slow() to dscp_t.Guillaume Nault
Pass a dscp_t variable to ip_route_input_slow(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Only ip_route_input_rcu() actually calls ip_route_input_slow(). Since it already has a dscp_t variable to pass as parameter, we only need to remove the inet_dscp_to_dsfield() conversion. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/d6bca5f87eea9e83a3861e6e05594cdd252583c9.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03ipv4: Convert ip_route_input_rcu() to dscp_t.Guillaume Nault
Pass a dscp_t variable to ip_route_input_rcu(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_route_input_rcu() to consider are: * ip_route_input_noref(), which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * inet_rtm_getroute(), which receives a u8 from user space and needs to convert it with inet_dsfield_to_dscp(). Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/c4dbb5aa9cbc79c4fcb317abbffa7c7156bc56a7.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03ipv4: Convert ip_route_input_noref() to dscp_t.Guillaume Nault
Pass a dscp_t variable to ip_route_input_noref(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_route_input_noref() to consider are: * arp_process() in net/ipv4/arp.c. This function sets the tos parameter to 0, which is already a valid dscp_t value, so it doesn't need to be adjusted for the new prototype. * ip_route_input(), which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * ipvlan_l3_rcv(), bpf_lwt_input_reroute(), ip_expire(), ip_rcv_finish_core(), xfrm4_rcv_encap_finish() and xfrm4_rcv_encap(), which get the DSCP directly from IPv4 headers and can simply use the ip4h_dscp() helper. While there, declare the IPv4 header pointers as const in ipvlan_l3_rcv() and bpf_lwt_input_reroute(). Also, modify the declaration of ip_route_input_noref() in include/net/route.h so that it matches the prototype of its implementation in net/ipv4/route.c. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/a8a747bed452519c4d0cc06af32c7e7795d7b627.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-31ipv4: Unmask upper DSCP bits when building flow keyIdo Schimmel
build_sk_flow_key() and __build_flow_key() are used to build an IPv4 flow key before calling one of the FIB lookup APIs. Unmask the upper DSCP bits so that in the future the lookup could be performed according to the full DSCP value. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-31ipv4: Unmask upper DSCP bits in ip_route_output_key_hash()Ido Schimmel
Unmask the upper DSCP bits so that in the future output routes could be looked up according to the full DSCP value. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-31ipv4: Unmask upper DSCP bits in RTM_GETROUTE output route lookupIdo Schimmel
Unmask the upper DSCP bits when looking up an output route via the RTM_GETROUTE netlink message so that in the future the lookup could be performed according to the full DSCP value. No functional changes intended since the upper DSCP bits are masked when comparing against the TOS selectors in FIB rules and routes. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-22ipv4: Unmask upper DSCP bits when using hintsIdo Schimmel
Unmask the upper DSCP bits when performing source validation and routing a packet using the same route from a previously processed packet (hint). In the future, this will allow us to perform the FIB lookup that is performed as part of source validation according to the full DSCP value. No functional changes intended since the upper DSCP bits are masked when comparing against the TOS selectors in FIB rules and routes. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20240821125251.1571445-13-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-22ipv4: Unmask upper DSCP bits in RTM_GETROUTE input route lookupIdo Schimmel
Unmask the upper DSCP bits when looking up an input route via the RTM_GETROUTE netlink message so that in the future the lookup could be performed according to the full DSCP value. No functional changes intended since the upper DSCP bits are masked when comparing against the TOS selectors in FIB rules and routes. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20240821125251.1571445-10-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-22ipv4: Unmask upper DSCP bits in input route lookupIdo Schimmel
Unmask the upper DSCP bits in input route lookup so that in the future the lookup could be performed according to the full DSCP value. No functional changes intended since the upper DSCP bits are masked when comparing against the TOS selectors in FIB rules and routes. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20240821125251.1571445-9-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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