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2020-11-28ipv4: Fix tos mask in inet_rtm_getroute()Guillaume Nault
When inet_rtm_getroute() was converted to use the RCU variants of ip_route_input() and ip_route_output_key(), the TOS parameters stopped being masked with IPTOS_RT_MASK before doing the route lookup. As a result, "ip route get" can return a different route than what would be used when sending real packets. For example: $ ip route add 192.0.2.11/32 dev eth0 $ ip route add unreachable 192.0.2.11/32 tos 2 $ ip route get 192.0.2.11 tos 2 RTNETLINK answers: No route to host But, packets with TOS 2 (ECT(0) if interpreted as an ECN bit) would actually be routed using the first route: $ ping -c 1 -Q 2 192.0.2.11 PING 192.0.2.11 (192.0.2.11) 56(84) bytes of data. 64 bytes from 192.0.2.11: icmp_seq=1 ttl=64 time=0.173 ms --- 192.0.2.11 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.173/0.173/0.173/0.000 ms This patch re-applies IPTOS_RT_MASK in inet_rtm_getroute(), to return results consistent with real route lookups. Fixes: 3765d35ed8b9 ("net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup") Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/b2d237d08317ca55926add9654a48409ac1b8f5b.1606412894.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Minor conflicts in net/mptcp/protocol.h and tools/testing/selftests/net/Makefile. In both cases code was added on both sides in the same place so just keep both. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10ipv4: Restore flowi4_oif update before call to xfrm_lookup_routeDavid Ahern
Tobias reported regressions in IPsec tests following the patch referenced by the Fixes tag below. The root cause is dropping the reset of the flowi4_oif after the fib_lookup. Apparently it is needed for xfrm cases, so restore the oif update to ip_route_output_flow right before the call to xfrm_lookup_route. Fixes: 2fbc6e89b2f1 ("ipv4: Update exception handling for multipath routes via same device") Reported-by: Tobias Brunner <tobias@strongswan.org> Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Two minor conflicts: 1) net/ipv4/route.c, adding a new local variable while moving another local variable and removing it's initial assignment. 2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes. One pretty prints the port mode differently, whilst another changes the driver to try and obtain the port mode from the port node rather than the switch node. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-15ipv4: Update exception handling for multipath routes via same deviceDavid Ahern
Kfir reported that pmtu exceptions are not created properly for deployments where multipath routes use the same device. After some digging I see 2 compounding problems: 1. ip_route_output_key_hash_rcu is updating the flowi4_oif *after* the route lookup. This is the second use case where this has been a problem (the first is related to use of vti devices with VRF). I can not find any reason for the oif to be changed after the lookup; the code goes back to the start of git. It does not seem logical so remove it. 2. fib_lookups for exceptions do not call fib_select_path to handle multipath route selection based on the hash. The end result is that the fib_lookup used to add the exception always creates it based using the first leg of the route. An example topology showing the problem: | host1 +------+ | eth0 | .209 +------+ | +------+ switch | br0 | +------+ | +---------+---------+ | host2 | host3 +------+ +------+ | eth0 | .250 | eth0 | 192.168.252.252 +------+ +------+ +-----+ +-----+ | vti | .2 | vti | 192.168.247.3 +-----+ +-----+ \ / ================================= tunnels 192.168.247.1/24 for h in host1 host2 host3; do ip netns add ${h} ip -netns ${h} link set lo up ip netns exec ${h} sysctl -wq net.ipv4.ip_forward=1 done ip netns add switch ip -netns switch li set lo up ip -netns switch link add br0 type bridge stp 0 ip -netns switch link set br0 up for n in 1 2 3; do ip -netns switch link add eth-sw type veth peer name eth-h${n} ip -netns switch li set eth-h${n} master br0 up ip -netns switch li set eth-sw netns host${n} name eth0 done ip -netns host1 addr add 192.168.252.209/24 dev eth0 ip -netns host1 link set dev eth0 up ip -netns host1 route add 192.168.247.0/24 \ nexthop via 192.168.252.250 dev eth0 nexthop via 192.168.252.252 dev eth0 ip -netns host2 addr add 192.168.252.250/24 dev eth0 ip -netns host2 link set dev eth0 up ip -netns host2 addr add 192.168.252.252/24 dev eth0 ip -netns host3 link set dev eth0 up ip netns add tunnel ip -netns tunnel li set lo up ip -netns tunnel li add br0 type bridge ip -netns tunnel li set br0 up for n in $(seq 11 20); do ip -netns tunnel addr add dev br0 192.168.247.${n}/24 done for n in 2 3 do ip -netns tunnel link add vti${n} type veth peer name eth${n} ip -netns tunnel link set eth${n} mtu 1360 master br0 up ip -netns tunnel link set vti${n} netns host${n} mtu 1360 up ip -netns host${n} addr add dev vti${n} 192.168.247.${n}/24 done ip -netns tunnel ro add default nexthop via 192.168.247.2 nexthop via 192.168.247.3 ip netns exec host1 ping -M do -s 1400 -c3 -I 192.168.252.209 192.168.247.11 ip netns exec host1 ping -M do -s 1400 -c3 -I 192.168.252.209 192.168.247.15 ip -netns host1 ro ls cache Before this patch the cache always shows exceptions against the first leg in the multipath route; 192.168.252.250 per this example. Since the hash has an initial random seed, you may need to vary the final octet more than what is listed. In my tests, using addresses between 11 and 19 usually found 1 that used both legs. With this patch, the cache will have exceptions for both legs. Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions") Reported-by: Kfir Itzhak <mastertheknife@gmail.com> Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14ipv4: Initialize flowi4_multipath_hash in data pathDavid Ahern
flowi4_multipath_hash was added by the commit referenced below for tunnels. Unfortunately, the patch did not initialize the new field for several fast path lookups that do not initialize the entire flow struct to 0. Fix those locations. Currently, flowi4_multipath_hash is random garbage and affects the hash value computed by fib_multipath_hash for multipath selection. Fixes: 24ba14406c5c ("route: Add multipath_hash in flowi_common to make user-define hash") Signed-off-by: David Ahern <dsahern@gmail.com> Cc: wenxu <wenxu@ucloud.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-31net: clean up codestyleMiaohe Lin
This is a pure codestyle cleanup patch. No functional change intended. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-25net: clean up codestyle for net/ipv4Miaohe Lin
This is a pure codestyle cleanup patch. Also add a blank line after declarations as warned by checkpatch.pl. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-25net: gain ipv4 mtu when mtu is not lockedMiaohe Lin
When mtu is locked, we should not obtain ipv4 mtu as we return immediately in this case and leave acquired ipv4 mtu unused. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-04ipv4: route: Ignore output interface in FIB lookup for PMTU routeStefano Brivio
Currently, processes sending traffic to a local bridge with an encapsulation device as a port don't get ICMP errors if they exceed the PMTU of the encapsulated link. David Ahern suggested this as a hack, but it actually looks like the correct solution: when we update the PMTU for a given destination by means of updating or creating a route exception, the encapsulation might trigger this because of PMTU discovery happening either on the encapsulation device itself, or its lower layer. This happens on bridged encapsulations only. The output interface shouldn't matter, because we already have a valid destination. Drop the output interface restriction from the associated route lookup. For UDP tunnels, we will now have a route exception created for the encapsulation itself, with a MTU value reflecting its headroom, which allows a bridge forwarding IP packets originated locally to deliver errors back to the sending socket. The behaviour is now consistent with IPv6 and verified with selftests pmtu_ipv{4,6}_br_{geneve,vxlan}{4,6}_exception introduced later in this series. v2: - reset output interface only for bridge ports (David Ahern) - add and use netif_is_any_bridge_port() helper (David Ahern) Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-27net: ipv4: Fix wrong type conversion from hint to rt in ip_route_use_hint()Miaohe Lin
We can't cast sk_buff to rtable by (struct rtable *)hint. Use skb_rtable(). Fixes: 02b24941619f ("ipv4: use dst hint for ipv4 list receive") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The MSCC bug fix in 'net' had to be slightly adjusted because the register accesses are done slightly differently in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17net: revert "net: get rid of an signed integer overflow in ip_idents_reserve()"Yuqi Jin
Commit adb03115f459 ("net: get rid of an signed integer overflow in ip_idents_reserve()") used atomic_cmpxchg to replace "atomic_add_return" inside the function "ip_idents_reserve". The reason was to avoid UBSAN warning. However, this change has caused performance degrade and in GCC-8, fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer and signed integer overflow is now undefined by default at all optimization levels[1]. Moreover, it was a bug in UBSAN vs -fwrapv /-fno-strict-overflow, so Let's revert it safely. [1] https://gcc.gnu.org/gcc-8/changes.html Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jiri Pirko <jiri@resnulli.us> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Jiong Wang <jiongwang@huawei.com> Signed-off-by: Yuqi Jin <jinyuqi@huawei.com> Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Move the bpf verifier trace check into the new switch statement in HEAD. Resolve the overlapping changes in hinic, where bug fixes overlap the addition of VF support. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-08net: ipv4: really enforce backoff for redirectsPaolo Abeni
In commit b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and rate_tokens usage") I missed the fact that a 0 'rate_tokens' will bypass the backoff algorithm. Since rate_tokens is cleared after a redirect silence, and never incremented on redirects, if the host keeps receiving packets requiring redirect it will reply ignoring the backoff. Additionally, the 'rate_last' field will be updated with the cadence of the ingress packet requiring redirect. If that rate is high enough, that will prevent the host from generating any other kind of ICMP messages The check for a zero 'rate_tokens' value was likely a shortcut to avoid the more complex backoff algorithm after a redirect silence period. Address the issue checking for 'n_redirects' instead, which is incremented on successful redirect, and does not interfere with other ICMP replies. Fixes: b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and rate_tokens usage") Reported-and-tested-by: Colin Walters <walters@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-04-27sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-23Remove DST_HOSTDavid Laight
Previous changes to the IP routing code have removed all the tests for the DS_HOST route flag. Remove the flags and all the code that sets it. Signed-off-by: David Laight <david.laight@aculab.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24net: UDP tunnel encapsulation module for tunnelling different protocols like ↵Martin Varghese
MPLS, IP, NSH etc. The Bareudp tunnel module provides a generic L3 encapsulation tunnelling module for tunnelling different protocols like MPLS, IP,NSH etc inside a UDP tunnel. Signed-off-by: Martin Varghese <martin.varghese@nokia.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-04proc: convert everything to "struct proc_ops"Alexey Dobriyan
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Minor conflict in mlx5 because changes happened to code that has moved meanwhile. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24rt_cpu_seq_next should increase position indexVasily Averin
if seq_file .next fuction does not change position index, read after some lseek can generate unexpected output. https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-14ipv4: Add "offload" and "trap" indications to routesIdo Schimmel
When performing L3 offload, routes and nexthops are usually programmed into two different tables in the underlying device. Therefore, the fact that a nexthop resides in hardware does not necessarily mean that all the associated routes also reside in hardware and vice-versa. While the kernel can signal to user space the presence of a nexthop in hardware (via 'RTNH_F_OFFLOAD'), it does not have a corresponding flag for routes. In addition, the fact that a route resides in hardware does not necessarily mean that the traffic is offloaded. For example, unreachable routes (i.e., 'RTN_UNREACHABLE') are programmed to trap packets to the CPU so that the kernel will be able to generate the appropriate ICMP error packet. This patch adds an "offload" and "trap" indications to IPv4 routes, so that users will have better visibility into the offload process. 'struct fib_alias' is extended with two new fields that indicate if the route resides in hardware or not and if it is offloading traffic from the kernel or trapping packets to it. Note that the new fields are added in the 6 bytes hole and therefore the struct still fits in a single cache line [1]. Capable drivers are expected to invoke fib_alias_hw_flags_set() with the route's key in order to set the flags. The indications are dumped to user space via a new flags (i.e., 'RTM_F_OFFLOAD' and 'RTM_F_TRAP') in the 'rtm_flags' field in the ancillary header. v2: * Make use of 'struct fib_rt_info' in fib_alias_hw_flags_set() [1] struct fib_alias { struct hlist_node fa_list; /* 0 16 */ struct fib_info * fa_info; /* 16 8 */ u8 fa_tos; /* 24 1 */ u8 fa_type; /* 25 1 */ u8 fa_state; /* 26 1 */ u8 fa_slen; /* 27 1 */ u32 tb_id; /* 28 4 */ s16 fa_default; /* 32 2 */ u8 offload:1; /* 34: 0 1 */ u8 trap:1; /* 34: 1 1 */ u8 unused:6; /* 34: 2 1 */ /* XXX 5 bytes hole, try to pack */ struct callback_head rcu __attribute__((__aligned__(8))); /* 40 16 */ /* size: 56, cachelines: 1, members: 12 */ /* sum members: 50, holes: 1, sum holes: 5 */ /* sum bitfield members: 8 bits (1 bytes) */ /* forced alignments: 1, forced holes: 1, sum forced holes: 5 */ /* last cacheline: 56 bytes */ } __attribute__((__aligned__(8))); Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-14ipv4: Encapsulate function arguments in a structIdo Schimmel
fib_dump_info() is used to prepare RTM_{NEW,DEL}ROUTE netlink messages using the passed arguments. Currently, the function takes 11 arguments, 6 of which are attributes of the route being dumped (e.g., prefix, TOS). The next patch will need the function to also dump to user space an indication if the route is present in hardware or not. Instead of passing yet another argument, change the function to take a struct containing the different route attributes. v2: * Name last argument of fib_dump_info() * Move 'struct fib_rt_info' to include/net/ip_fib.h so that it could later be passed to fib_alias_hw_flags_set() Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24net: add bool confirm_neigh parameter for dst_ops.update_pmtuHangbin Liu
The MTU update code is supposed to be invoked in response to real networking events that update the PMTU. In IPv6 PMTU update function __ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor confirmed time. But for tunnel code, it will call pmtu before xmit, like: - tnl_update_pmtu() - skb_dst_update_pmtu() - ip6_rt_update_pmtu() - __ip6_rt_update_pmtu() - dst_confirm_neigh() If the tunnel remote dst mac address changed and we still do the neigh confirm, we will not be able to update neigh cache and ping6 remote will failed. So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we should not be invoking dst_confirm_neigh() as we have no evidence of successful two-way communication at this point. On the other hand it is also important to keep the neigh reachability fresh for TCP flows, so we cannot remove this dst_confirm_neigh() call. To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu to choose whether we should do neigh update or not. I will add the parameter in this patch and set all the callers to true to comply with the previous way, and fix the tunnel code one by one on later patches. v5: No change. v4: No change. v3: Do not remove dst_confirm_neigh, but add a new bool parameter in dst_ops.update_pmtu to control whether we should do neighbor confirm. Also split the big patch to small ones for each area. v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu. Suggested-by: David Miller <davem@davemloft.net> Reviewed-by: Guillaume Nault <gnault@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-21ipv4: use dst hint for ipv4 list receivePaolo Abeni
This is alike the previous change, with some additional ipv4 specific quirk. Even when using the route hint we still have to do perform additional per packet checks about source address validity: a new helper is added to wrap them. Hints are explicitly disabled if the destination is a local broadcast, that keeps the code simple and local broadcast are a slower path anyway. UDP flood performances vs recvmmsg() receiver: vanilla patched delta Kpps Kpps % 1683 1871 +11 In the worst case scenario - each packet has a different destination address - the performance delta is within noise range. v3 -> v4: - re-enable hints for forward v2 -> v3: - really fix build (sic) and hint usage check - use fib4_has_custom_rules() helpers (David A.) - add ip_extract_route_hint() helper (Edward C.) - use prev skb as hint instead of copying data (Willem) v1 -> v2: - fix build issue with !CONFIG_IP_MULTIPLE_TABLES Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-05icmp: remove duplicate codeMatteo Croce
The same code which recognizes ICMP error packets is duplicated several times. Use the icmp_is_err() and icmpv6_is_err() helpers instead, which do the same thing. ip_multipath_l3_keys() and tcf_nat_act() didn't check for all the error types, assume that they should instead. Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-17ipv4: fix race condition between route lookup and invalidationWei Wang
Jesse and Ido reported the following race condition: <CPU A, t0> - Received packet A is forwarded and cached dst entry is taken from the nexthop ('nhc->nhc_rth_input'). Calls skb_dst_set() <t1> - Given Jesse has busy routers ("ingesting full BGP routing tables from multiple ISPs"), route is added / deleted and rt_cache_flush() is called <CPU B, t2> - Received packet B tries to use the same cached dst entry from t0, but rt_cache_valid() is no longer true and it is replaced in rt_cache_route() by the newer one. This calls dst_dev_put() on the original dst entry which assigns the blackhole netdev to 'dst->dev' <CPU A, t3> - dst_input(skb) is called on packet A and it is dropped due to 'dst->dev' being the blackhole netdev There are 2 issues in the v4 routing code: 1. A per-netns counter is used to do the validation of the route. That means whenever a route is changed in the netns, users of all routes in the netns needs to redo lookup. v6 has an implementation of only updating fn_sernum for routes that are affected. 2. When rt_cache_valid() returns false, rt_cache_route() is called to throw away the current cache, and create a new one. This seems unnecessary because as long as this route does not change, the route cache does not need to be recreated. To fully solve the above 2 issues, it probably needs quite some code changes and requires careful testing, and does not suite for net branch. So this patch only tries to add the deleted cached rt into the uncached list, so user could still be able to use it to receive packets until it's done. Fixes: 95c47f9cf5e0 ("ipv4: call dst_dev_put() properly") Signed-off-by: Wei Wang <weiwan@google.com> Reported-by: Ido Schimmel <idosch@idosch.org> Reported-by: Jesse Hathaway <jesse@mbuki-mvuki.org> Tested-by: Jesse Hathaway <jesse@mbuki-mvuki.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-17ipv4: Return -ENETUNREACH if we can't create route but saddr is validStefano Brivio
...instead of -EINVAL. An issue was found with older kernel versions while unplugging a NFS client with pending RPCs, and the wrong error code here prevented it from recovering once link is back up with a configured address. Incidentally, this is not an issue anymore since commit 4f8943f80883 ("SUNRPC: Replace direct task wakeups from softirq context"), included in 5.2-rc7, had the effect of decoupling the forwarding of this error by using SO_ERROR in xs_wake_error(), as pointed out by Benjamin Coddington. To the best of my knowledge, this isn't currently causing any further issue, but the error code doesn't look appropriate anyway, and we might hit this in other paths as well. In detail, as analysed by Gonzalo Siero, once the route is deleted because the interface is down, and can't be resolved and we return -EINVAL here, this ends up, courtesy of inet_sk_rebuild_header(), as the socket error seen by tcp_write_err(), called by tcp_retransmit_timer(). In turn, tcp_write_err() indirectly calls xs_error_report(), which wakes up the RPC pending tasks with a status of -EINVAL. This is then seen by call_status() in the SUN RPC implementation, which aborts the RPC call calling rpc_exit(), instead of handling this as a potentially temporary condition, i.e. as a timeout. Return -EINVAL only if the input parameters passed to ip_route_output_key_hash_rcu() are actually invalid (this is the case if the specified source address is multicast, limited broadcast or all zeroes), but return -ENETUNREACH in all cases where, at the given moment, the given source address doesn't allow resolving the route. While at it, drop the initialisation of err to -ENETUNREACH, which was added to __ip_route_output_key() back then by commit 0315e3827048 ("net: Fix behaviour of unreachable, blackhole and prohibit routes"), but actually had no effect, as it was, and is, overwritten by the fib_lookup() return code assignment, and anyway ignored in all other branches, including the if (fl4->saddr) one: I find this rather confusing, as it would look like -ENETUNREACH is the "default" error, while that statement has no effect. Also note that after commit fc75fc8339e7 ("ipv4: dont create routes on down devices"), we would get -ENETUNREACH if the device is down, but -EINVAL if the source address is specified and we can't resolve the route, and this appears to be rather inconsistent. Reported-by: Stefan Walter <walteste@inf.ethz.ch> Analysed-by: Benjamin Coddington <bcodding@redhat.com> Analysed-by: Gonzalo Siero <gsierohu@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-04net: ipv4: avoid mixed n_redirects and rate_tokens usagePaolo Abeni
Since commit c09551c6ff7f ("net: ipv4: use a dedicated counter for icmp_v4 redirect packets") we use 'n_redirects' to account for redirect packets, but we still use 'rate_tokens' to compute the redirect packets exponential backoff. If the device sent to the relevant peer any ICMP error packet after sending a redirect, it will also update 'rate_token' according to the leaking bucket schema; typically 'rate_token' will raise above BITS_PER_LONG and the redirect packets backoff algorithm will produce undefined behavior. Fix the issue using 'n_redirects' to compute the exponential backoff in ip_rt_send_redirect(). Note that we still clear rate_tokens after a redirect silence period, to avoid changing an established behaviour. The root cause predates git history; before the mentioned commit in the critical scenario, the kernel stopped sending redirects, after the mentioned commit the behavior more randomic. Reported-by: Xiumei Mu <xmu@redhat.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: c09551c6ff7f ("net: ipv4: use a dedicated counter for icmp_v4 redirect packets") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-20ipv4: Revert removal of rt_uses_gatewayDavid Ahern
Julian noted that rt_uses_gateway has a more subtle use than 'is gateway set': https://lore.kernel.org/netdev/alpine.LFD.2.21.1909151104060.2546@ja.home.ssi.bg/ Revert that part of the commit referenced in the Fixes tag. Currently, there are no u8 holes in 'struct rtable'. There is a 4-byte hole in the second cacheline which contains the gateway declaration. So move rt_gw_family down to the gateway declarations since they are always used together, and then re-use that u8 for rt_uses_gateway. End result is that rtable size is unchanged. Fixes: 1550c171935d ("ipv4: Prepare rtable for IPv6 gateway") Reported-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-08-24net: route dump netlink NLM_F_MULTI flag missingJohn Fastabend
An excerpt from netlink(7) man page, In multipart messages (multiple nlmsghdr headers with associated payload in one byte stream) the first and all following headers have the NLM_F_MULTI flag set, except for the last header which has the type NLMSG_DONE. but, after (ee28906) there is a missing NLM_F_MULTI flag in the middle of a FIB dump. The result is user space applications following above man page excerpt may get confused and may stop parsing msg believing something went wrong. In the golang netlink lib [0] the library logic stops parsing believing the message is not a multipart message. Found this running Cilium[1] against net-next while adding a feature to auto-detect routes. I noticed with multiple route tables we no longer could detect the default routes on net tree kernels because the library logic was not returning them. Fix this by handling the fib_dump_info_fnhe() case the same way the fib_dump_info() handles it by passing the flags argument through the call chain and adding a flags argument to rt_fill_info(). Tested with Cilium stack and auto-detection of routes works again. Also annotated libs to dump netlink msgs and inspected NLM_F_MULTI and NLMSG_DONE flags look correct after this. Note: In inet_rtm_getroute() pass rt_fill_info() '0' for flags the same as is done for fib_dump_info() so this looks correct to me. [0] https://github.com/vishvananda/netlink/ [1] https://github.com/cilium/ Fixes: ee28906fd7a14 ("ipv4: Dump route exceptions if requested") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Two cases of overlapping changes, nothing fancy. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-08ipv4: Multipath hashing on inner L3 needs to consider inner IPv6 pktsStephen Suryaputra
Commit 363887a2cdfe ("ipv4: Support multipath hashing on inner IP pkts for GRE tunnel") supports multipath policy value of 2, Layer 3 or inner Layer 3 if present, but it only considers inner IPv4. There is a use case of IPv6 is tunneled by IPv4 GRE, thus add the ability to hash on inner IPv6 addresses. Fixes: 363887a2cdfe ("ipv4: Support multipath hashing on inner IP pkts for GRE tunnel") Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-05ipv4: Fix NULL pointer dereference in ipv4_neigh_lookup()Ido Schimmel
Both ip_neigh_gw4() and ip_neigh_gw6() can return either a valid pointer or an error pointer, but the code currently checks that the pointer is not NULL. Fix this by checking that the pointer is not an error pointer, as this can result in a NULL pointer dereference [1]. Specifically, I believe that what happened is that ip_neigh_gw4() returned '-EINVAL' (0xffffffffffffffea) to which the offset of 'refcnt' (0x70) was added, which resulted in the address 0x000000000000005a. [1] BUG: KASAN: null-ptr-deref in refcount_inc_not_zero_checked+0x6e/0x180 Read of size 4 at addr 000000000000005a by task swapper/2/0 CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.2.0-rc6-custom-reg-179657-gaa32d89 #396 Hardware name: Mellanox Technologies Ltd. MSN2010/SA002610, BIOS 5.6.5 08/24/2017 Call Trace: <IRQ> dump_stack+0x73/0xbb __kasan_report+0x188/0x1ea kasan_report+0xe/0x20 refcount_inc_not_zero_checked+0x6e/0x180 ipv4_neigh_lookup+0x365/0x12c0 __neigh_update+0x1467/0x22f0 arp_process.constprop.6+0x82e/0x1f00 __netif_receive_skb_one_core+0xee/0x170 process_backlog+0xe3/0x640 net_rx_action+0x755/0xd90 __do_softirq+0x29b/0xae7 irq_exit+0x177/0x1c0 smp_apic_timer_interrupt+0x164/0x5e0 apic_timer_interrupt+0xf/0x20 </IRQ> Fixes: 5c9f7c1dfc2e ("ipv4: Add helpers for neigh lookup for nexthop") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Shalom Toledo <shalomt@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-01blackhole_netdev: use blackhole_netdev to invalidate dst entriesMahesh Bandewar
Use blackhole_netdev instead of 'lo' device with lower MTU when marking dst "dead". Signed-off-by: Mahesh Bandewar <maheshb@google.com> Tested-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-28ipv4: enable route flushing in network namespacesChristian Brauner
Tools such as vpnc try to flush routes when run inside network namespaces by writing 1 into /proc/sys/net/ipv4/route/flush. This currently does not work because flush is not enabled in non-initial network namespaces. Since routes are per network namespace it is safe to enable /proc/sys/net/ipv4/route/flush in there. Link: https://github.com/lxc/lxd/issues/4257 Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The new route handling in ip_mc_finish_output() from 'net' overlapped with the new support for returning congestion notifications from BPF programs. In order to handle this I had to take the dev_loopback_xmit() calls out of the switch statement. The aquantia driver conflicts were simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-26ipv4: reset rt_iif for recirculated mcast/bcast out pktsStephen Suryaputra
Multicast or broadcast egress packets have rt_iif set to the oif. These packets might be recirculated back as input and lookup to the raw sockets may fail because they are bound to the incoming interface (skb_iif). If rt_iif is not zero, during the lookup, inet_iif() function returns rt_iif instead of skb_iif. Hence, the lookup fails. v2: Make it non vrf specific (David Ahern). Reword the changelog to reflect it. Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-26ipv4: fix suspicious RCU usage in fib_dump_info_fnhe()Eric Dumazet
sysbot reported that we lack appropriate rcu_read_lock() protection in fib_dump_info_fnhe() net/ipv4/route.c:2875 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor609/8966: #0: 00000000b7dbe288 (rtnl_mutex){+.+.}, at: netlink_dump+0xe7/0xfb0 net/netlink/af_netlink.c:2199 stack backtrace: CPU: 0 PID: 8966 Comm: syz-executor609 Not tainted 5.2.0-rc5+ #43 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5250 fib_dump_info_fnhe+0x9d9/0x1080 net/ipv4/route.c:2875 fn_trie_dump_leaf net/ipv4/fib_trie.c:2141 [inline] fib_table_dump+0x64a/0xd00 net/ipv4/fib_trie.c:2175 inet_dump_fib+0x83c/0xa90 net/ipv4/fib_frontend.c:1004 rtnl_dump_all+0x295/0x490 net/core/rtnetlink.c:3445 netlink_dump+0x558/0xfb0 net/netlink/af_netlink.c:2244 __netlink_dump_start+0x5b1/0x7d0 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:226 [inline] rtnetlink_rcv_msg+0x73d/0xb00 net/core/rtnetlink.c:5182 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5237 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:665 sock_write_iter+0x27c/0x3e0 net/socket.c:994 call_write_iter include/linux/fs.h:1872 [inline] new_sync_write+0x4d3/0x770 fs/read_write.c:483 __vfs_write+0xe1/0x110 fs/read_write.c:496 vfs_write+0x20c/0x580 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4401b9 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc8e134978 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401b9 RDX: 000000000000001c RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 0000000000000010 R11: 0000000000000246 R12: 0000000000401a40 R13: 0000000000401ad0 R14: 0000000000000000 R15: 0000000000000000 Fixes: ee28906fd7a1 ("ipv4: Dump route exceptions if requested") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stefano Brivio <sbrivio@redhat.com> Cc: David Ahern <dsahern@gmail.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24ipv4: Dump route exceptions if requestedStefano Brivio
Since commit 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions."), cached exception routes are stored as a separate entity, so they are not dumped on a FIB dump, even if the RTM_F_CLONED flag is passed. This implies that the command 'ip route list cache' doesn't return any result anymore. If the RTM_F_CLONED is passed, and strict checking requested, retrieve nexthop exception routes and dump them. If no strict checking is requested, filtering can't be performed consistently: dump everything in that case. With this, we need to add an argument to the netlink callback in order to track how many entries were already dumped for the last leaf included in a partial netlink dump. A single additional argument is sufficient, even if we traverse logically nested structures (nexthop objects, hash table buckets, bucket chains): it doesn't matter if we stop in the middle of any of those, because they are always traversed the same way. As an example, s_i values in [], s_fa values in (): node (fa) #1 [1] nexthop #1 bucket #1 -> #0 in chain (1) bucket #2 -> #0 in chain (2) -> #1 in chain (3) -> #2 in chain (4) bucket #3 -> #0 in chain (5) -> #1 in chain (6) nexthop #2 bucket #1 -> #0 in chain (7) -> #1 in chain (8) bucket #2 -> #0 in chain (9) -- node (fa) #2 [2] nexthop #1 bucket #1 -> #0 in chain (1) -> #1 in chain (2) bucket #2 -> #0 in chain (3) it doesn't matter if we stop at (3), (4), (7) for "node #1", or at (2) for "node #2": walking flattens all that. It would even be possible to drop the distinction between the in-tree (s_i) and in-node (s_fa) counter, but a further improvement might advise against this. This is only as accurate as the existing tracking mechanism for leaves: if a partial dump is restarted after exceptions are removed or expired, we might skip some non-dumped entries. To improve this, we could attach a 'sernum' attribute (similar to the one used for IPv6) to nexthop entities, and bump this counter whenever exceptions change: having a distinction between the two counters would make this more convenient. Listing of exception routes (modified routes pre-3.5) was tested against these versions of kernel and iproute2: iproute2 kernel 4.14.0 4.15.0 4.19.0 5.0.0 5.1.0 3.5-rc4 + + + + + 4.4 4.9 4.14 4.15 4.19 5.0 5.1 fixed + + + + + v7: - Move loop over nexthop objects to route.c, and pass struct fib_info and table ID to it, not a struct fib_alias (suggested by David Ahern) - While at it, note that the NULL check on fa->fa_info is redundant, and the check on RTNH_F_DEAD is also not consistent with what's done with regular route listing: just keep it for nhc_flags - Rename entry point function for dumping exceptions to fib_dump_info_fnhe(), and rearrange arguments for consistency with fib_dump_info() - Rename fnhe_dump_buckets() to fnhe_dump_bucket() and make it handle one bucket at a time - Expand commit message to describe why we can have a single "skip" counter for all exceptions stored in bucket chains in nexthop objects (suggested by David Ahern) v6: - Rebased onto net-next - Loop over nexthop paths too. Move loop over fnhe buckets to route.c, avoids need to export rt_fill_info() and to touch exceptions from fib_trie.c. Pass NULL as flow to rt_fill_info(), it now allows that (suggested by David Ahern) Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24ipv4/route: Allow NULL flowinfo in rt_fill_info()Stefano Brivio
In the next patch, we're going to use rt_fill_info() to dump exception routes upon RTM_GETROUTE with NLM_F_ROOT, meaning userspace is requesting a dump and not a specific route selection, which in turn implies the input interface is not relevant. Update rt_fill_info() to handle a NULL flowinfo. v7: If fl4 is NULL, explicitly set r->rtm_tos to 0: it's not initialised otherwise (spotted by David Ahern) v6: New patch Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14ipv4: Support multipath hashing on inner IP pkts for GRE tunnelStephen Suryaputra
Multipath hash policy value of 0 isn't distributing since the outer IP dest and src aren't varied eventhough the inner ones are. Since the flow is on the inner ones in the case of tunneled traffic, hashing on them is desired. This is done mainly for IP over GRE, hence only tested for that. But anything else supported by flow dissection should work. v2: Use skb_flow_dissect_flow_keys() directly so that other tunneling can be supported through flow dissection (per Nikolay Aleksandrov). v3: Remove accidental inclusion of ports in the hash keys and clarify the documentation (Nikolay Alexandrov). Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Some ISDN files that got removed in net-next had some changes done in mainline, take the removals. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Free AF_PACKET po->rollover properly, from Willem de Bruijn. 2) Read SFP eeprom in max 16 byte increments to avoid problems with some SFP modules, from Russell King. 3) Fix UDP socket lookup wrt. VRF, from Tim Beale. 4) Handle route invalidation properly in s390 qeth driver, from Julian Wiedmann. 5) Memory leak on unload in RDS, from Zhu Yanjun. 6) sctp_process_init leak, from Neil HOrman. 7) Fix fib_rules rule insertion semantic change that broke Android, from Hangbin Liu. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (33 commits) pktgen: do not sleep with the thread lock held. net: mvpp2: Use strscpy to handle stat strings net: rds: fix memory leak in rds_ib_flush_mr_pool ipv6: fix EFAULT on sendto with icmpv6 and hdrincl ipv6: use READ_ONCE() for inet->hdrincl as in ipv4 Revert "fib_rules: return 0 directly if an exactly same rule exists when NLM_F_EXCL not supplied" net: aquantia: fix wol configuration not applied sometimes ethtool: fix potential userspace buffer overflow Fix memory leak in sctp_process_init net: rds: fix memory leak when unload rds_rdma ipv6: fix the check before getting the cookie in rt6_get_cookie ipv4: not do cache for local delivery if bc_forwarding is enabled s390/qeth: handle error when updating TX queue count s390/qeth: fix VLAN attribute in bridge_hostnotify udev event s390/qeth: check dst entry before use s390/qeth: handle limited IPv4 broadcast in L3 TX path net: fix indirect calls helpers for ptype list hooks. net: ipvlan: Fix ipvlan device tso disabled while NETIF_F_IP_CSUM is set udp: only choose unbound UDP socket for multicast when not in a VRF net/tls: replace the sleeping lock around RX resync with a bit lock ...
2019-06-05ipv4: not do cache for local delivery if bc_forwarding is enabledXin Long
With the topo: h1 ---| rp1 | | route rp3 |--- h3 (192.168.200.1) h2 ---| rp2 | If rp1 bc_forwarding is set while rp2 bc_forwarding is not, after doing "ping 192.168.200.255" on h1, then ping 192.168.200.255 on h2, and the packets can still be forwared. This issue was caused by the input route cache. It should only do the cache for either bc forwarding or local delivery. Otherwise, local delivery can use the route cache for bc forwarding of other interfaces. This patch is to fix it by not doing cache for local delivery if all.bc_forwarding is enabled. Note that we don't fix it by checking route cache local flag after rt_cache_valid() in "local_input:" and "ip_mkroute_input", as the common route code shouldn't be touched for bc_forwarding. Fixes: 5cbf777cfdf6 ("route: add support for directed broadcast forwarding") Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-04ipv4: Prepare for fib6_nh