kernel/linux.git/include/net/ip_tunnels.h, branch v4.19.302

ip_gre, ip6_gre: Fix race condition on o_seqno in collect_md mode

2023-05-30T11:42:10+00:00

[ Upstream commit 31c417c948d7f6909cb63f0ac3298f3c38f8ce20 ] As pointed out by Jakub Kicinski, currently using TUNNEL_SEQ in collect_md mode is racy for [IP6]GRE[TAP] devices. Consider the following sequence of events: 1. An [IP6]GRE[TAP] device is created in collect_md mode using "ip link add ... external". "ip" ignores "[o]seq" if "external" is specified, so TUNNEL_SEQ is off, and the device is marked as NETIF_F_LLTX (i.e. it uses lockless TX); 2. Someone sets TUNNEL_SEQ on outgoing skb's, using e.g. bpf_skb_set_tunnel_key() in an eBPF program attached to this device; 3. gre_fb_xmit() or __gre6_xmit() processes these skb's: gre_build_header(skb, tun_hlen, flags, protocol, tunnel_id_to_key32(tun_info->key.tun_id), (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); ^^^^^^^^^^^^^^^^^ Since we are not using the TX lock (&txq->_xmit_lock), multiple CPUs may try to do this tunnel->o_seqno++ in parallel, which is racy. Fix it by making o_seqno atomic_t. As mentioned by Eric Dumazet in commit b790e01aee74 ("ip_gre: lockless xmit"), making o_seqno atomic_t increases "chance for packets being out of order at receiver" when NETIF_F_LLTX is on. Maybe a better fix would be: 1. Do not ignore "oseq" in external mode. Users MUST specify "oseq" if they want the kernel to allow sequencing of outgoing packets; 2. Reject all outgoing TUNNEL_SEQ packets if the device was not created with "oseq". Unfortunately, that would break userspace. We could now make [IP6]GRE[TAP] devices always NETIF_F_LLTX, but let us do it in separate patches to keep this fix minimal. Suggested-by: Jakub Kicinski Fixes: 77a5196a804e ("gre: add sequence number for collect md mode.") Signed-off-by: Peilin Ye Acked-by: William Tu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

ip_tunnels: Set tunnel option flag when tunnel metadata is present

2020-11-24T12:27:21+00:00

[ Upstream commit 9c2e14b48119b39446031d29d994044ae958d8fc ] Currently, we may set the tunnel option flag when the size of metadata is zero. For example, we set TUNNEL_GENEVE_OPT in the receive function no matter the geneve option is present or not. As this may result in issues on the tunnel flags consumers, this patch fixes the issue. Related discussion: * https://lore.kernel.org/netdev/1604448694-19351-1-git-send-email-yihung.wei@gmail.com/T/#u Fixes: 256c87c17c53 ("net: check tunnel option type in tunnel flags") Signed-off-by: Yi-Hung Wei Link: https://lore.kernel.org/r/1605053800-74072-1-git-send-email-yihung.wei@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ip: validate header length on virtual device xmit

2019-01-09T16:38:31+00:00

[ Upstream commit cb9f1b783850b14cbd7f87d061d784a666dfba1f ] KMSAN detected read beyond end of buffer in vti and sit devices when passing truncated packets with PF_PACKET. The issue affects additional ip tunnel devices. Extend commit 76c0ddd8c3a6 ("ip6_tunnel: be careful when accessing the inner header") and commit ccfec9e5cb2d ("ip_tunnel: be careful when accessing the inner header"). Move the check to a separate helper and call at the start of each ndo_start_xmit function in net/ipv4 and net/ipv6. Minor changes: - convert dev_kfree_skb to kfree_skb on error path, as dev_kfree_skb calls consume_skb which is not for error paths. - use pskb_network_may_pull even though that is pedantic here, as the same as pskb_may_pull for devices without llheaders. - do not cache ipv6 hdrs if used only once (unsafe across pskb_may_pull, was more relevant to earlier patch) Reported-by: syzbot Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: check tunnel option type in tunnel flags

2018-06-29T14:50:26+00:00

Check the tunnel option type stored in tunnel flags when creating options for tunnels. Thereby ensuring we do not set geneve, vxlan or erspan tunnel options on interfaces that are not associated with them. Make sure all users of the infrastructure set correct flags, for the BPF helper we have to set all bits to keep backward compatibility. Signed-off-by: Pieter Jansen van Vuuren Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

net/ipv4: Update ip_tunnel_metadata_cnt static key to modern api

2018-05-10T19:13:33+00:00

No changes in refcount semantics -- key init is false; replace static_key_slow_inc|dec with static_branch_inc|dec static_key_false with static_branch_unlikely Signed-off-by: Davidlohr Bueso Signed-off-by: David S. Miller

vxlan: add ttl inherit support

2018-04-17T17:53:13+00:00

Like tos inherit, ttl inherit should also means inherit the inner protocol's ttl values, which actually not implemented in vxlan yet. But we could not treat ttl == 0 as "use the inner TTL", because that would be used also when the "ttl" option is not specified and that would be a behavior change, and breaking real use cases. So add a different attribute IFLA_VXLAN_TTL_INHERIT when "ttl inherit" is specified with ip cmd. Reported-by: Jianlin Shi Suggested-by: Jiri Benc Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller

net: do not create fallback tunnels for non-default namespaces

2018-03-09T16:23:11+00:00

fallback tunnels (like tunl0, gre0, gretap0, erspan0, sit0, ip6tnl0, ip6gre0) are automatically created when the corresponding module is loaded. These tunnels are also automatically created when a new network namespace is created, at a great cost. In many cases, netns are used for isolation purposes, and these extra network devices are a waste of resources. We are using thousands of netns per host, and hit the netns creation/delete bottleneck a lot. (Many thanks to Kirill for recent work on this) Add a new sysctl so that we can opt-out from this automatic creation. Note that these tunnels are still created for the initial namespace, to be the least intrusive for typical setups. Tested: lpk43:~# cat add_del_unshare.sh for i in `seq 1 40` do (for j in `seq 1 100` ; do unshare -n /bin/true >/dev/null ; done) & done wait lpk43:~# echo 0 >/proc/sys/net/core/fb_tunnels_only_for_init_net lpk43:~# time ./add_del_unshare.sh real 0m37.521s user 0m0.886s sys 7m7.084s lpk43:~# echo 1 >/proc/sys/net/core/fb_tunnels_only_for_init_net lpk43:~# time ./add_del_unshare.sh real 0m4.761s user 0m0.851s sys 1m8.343s lpk43:~# Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ip_tunnel: Rename & publish init_tunnel_flow

2018-02-27T19:46:26+00:00

Initializing struct flowi4 is useful for drivers that need to emulate routing decisions made by a tunnel interface. Publish the function (appropriately renamed) so that the drivers in question don't need to cut'n'paste it around. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller

net: erspan: introduce erspan v2 for ip_gre

2017-12-15T17:34:00+00:00

The patch adds support for erspan version 2. Not all features are supported in this patch. The SGT (security group tag), GRA (timestamp granularity), FT (frame type) are set to fixed value. Only hardware ID and direction are configurable. Optional subheader is also not supported. Signed-off-by: William Tu Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-11-04T00:26:51+00:00

Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller