kernel/linux.git/include/net/dst.h, branch v4.19.103

net/dst: do not confirm neighbor for vxlan and geneve pmtu update

2020-01-04T18:13:39+00:00

[ Upstream commit f081042d128a0c7acbd67611def62e1b52e2d294 ] When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end, we should not call dst_confirm_neigh() as there is no two-way communication. So disable the neigh confirm for vxlan and geneve pmtu update. 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. Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Reviewed-by: Guillaume Nault Tested-by: Guillaume Nault Acked-by: David Ahern Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/dst: add new function skb_dst_update_pmtu_no_confirm

2020-01-04T18:13:38+00:00

[ Upstream commit 07dc35c6e3cc3c001915d05f5bf21f80a39a0970 ] Add a new function skb_dst_update_pmtu_no_confirm() for callers who need update pmtu but should not do neighbor confirm. 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. Reviewed-by: Guillaume Nault Acked-by: David Ahern Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: add bool confirm_neigh parameter for dst_ops.update_pmtu

2020-01-04T18:13:37+00:00

[ Upstream commit bd085ef678b2cc8c38c105673dfe8ff8f5ec0c57 ] 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 Reviewed-by: Guillaume Nault Acked-by: David Ahern Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: dst: Force 4-byte alignment of dst_metrics

2019-12-31T15:34:37+00:00

[ Upstream commit 258a980d1ec23e2c786e9536a7dd260bea74bae6 ] When storing a pointer to a dst_metrics structure in dst_entry._metrics, two flags are added in the least significant bits of the pointer value. Hence this assumes all pointers to dst_metrics structures have at least 4-byte alignment. However, on m68k, the minimum alignment of 32-bit values is 2 bytes, not 4 bytes. Hence in some kernel builds, dst_default_metrics may be only 2-byte aligned, leading to obscure boot warnings like: WARNING: CPU: 0 PID: 7 at lib/refcount.c:28 refcount_warn_saturate+0x44/0x9a refcount_t: underflow; use-after-free. Modules linked in: CPU: 0 PID: 7 Comm: ksoftirqd/0 Tainted: G W 5.5.0-rc2-atari-01448-g114a1a1038af891d-dirty #261 Stack from 10835e6c: 10835e6c 0038134f 00023fa6 00394b0f 0000001c 00000009 00321560 00023fea 00394b0f 0000001c 001a70f8 00000009 00000000 10835eb4 00000001 00000000 04208040 0000000a 00394b4a 10835ed4 00043aa8 001a70f8 00394b0f 0000001c 00000009 00394b4a 0026aba8 003215a4 00000003 00000000 0026d5a8 00000001 003215a4 003a4361 003238d6 000001f0 00000000 003215a4 10aa3b00 00025e84 003ddb00 10834000 002416a8 10aa3b00 00000000 00000080 000aa038 0004854a Call Trace: [<00023fa6>] __warn+0xb2/0xb4 [<00023fea>] warn_slowpath_fmt+0x42/0x64 [<001a70f8>] refcount_warn_saturate+0x44/0x9a [<00043aa8>] printk+0x0/0x18 [<001a70f8>] refcount_warn_saturate+0x44/0x9a [<0026aba8>] refcount_sub_and_test.constprop.73+0x38/0x3e [<0026d5a8>] ipv4_dst_destroy+0x5e/0x7e [<00025e84>] __local_bh_enable_ip+0x0/0x8e [<002416a8>] dst_destroy+0x40/0xae Fix this by forcing 4-byte alignment of all dst_metrics structures. Fixes: e5fd387ad5b30ca3 ("ipv6: do not overwrite inetpeer metrics prematurely") Signed-off-by: Geert Uytterhoeven Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: make skb_dst_force return true when dst is refcounted

2019-07-28T06:29:24+00:00

[ Upstream commit b60a77386b1d4868f72f6353d35dabe5fbe981f2 ] netfilter did not expect that skb_dst_force() can cause skb to lose its dst entry. I got a bug report with a skb->dst NULL dereference in netfilter output path. The backtrace contains nf_reinject(), so the dst might have been cleared when skb got queued to userspace. Other users were fixed via if (skb_dst(skb)) { skb_dst_force(skb); if (!skb_dst(skb)) goto handle_err; } But I think its preferable to make the 'dst might be cleared' part of the function explicit. In netfilter case, skb with a null dst is expected when queueing in prerouting hook, so drop skb for the other hooks. v2: v1 of this patch returned true in case skb had no dst entry. Eric said: Say if we have two skb_dst_force() calls for some reason on the same skb, only the first one will return false. This now returns false even when skb had no dst, as per Erics suggestion, so callers might need to check skb_dst() first before skb_dst_force(). Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

geneve, vxlan: Don't set exceptions if skb->len < mtu

2018-10-18T04:51:13+00:00

We shouldn't abuse exceptions: if the destination MTU is already higher than what we're transmitting, no exception should be created. Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Signed-off-by: David S. Miller

xfrm: Remove xfrmi interface ID from flowi

2018-07-20T08:14:41+00:00

In order to remove performance impact of having the extra u32 in every single flowi, this change removes the flowi_xfrm struct, prefering to take the if_id as a method parameter where needed. In the inbound direction, if_id is only needed during the __xfrm_check_policy() function, and the if_id can be determined at that point based on the skb. As such, xfrmi_decode_session() is only called with the skb in __xfrm_check_policy(). In the outbound direction, the only place where if_id is needed is the xfrm_lookup() call in xfrmi_xmit2(). With this change, the if_id is directly passed into the xfrm_lookup_with_ifid() call. All existing callers can still call xfrm_lookup(), which uses a default if_id of 0. This change does not change any behavior of XFRMIs except for improving overall system performance via flowi size reduction. This change has been tested against the Android Kernel Networking Tests: https://android.googlesource.com/kernel/tests/+/master/net/test Signed-off-by: Benedict Wong Signed-off-by: Steffen Klassert

net: core: dst: Add kernel-doc for 'net' parameter

2018-03-05T17:52:45+00:00

This fixes the following kernel-doc warning: ./include/net/dst.h:366: warning: Function parameter or member 'net' not described in 'skb_tunnel_rx' Fixes: ea23192e8e57 ("tunnels: harmonize cleanup done on skb on rx path") Signed-off-by: Jonathan Neuschäfer Signed-off-by: David S. Miller

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

2018-01-29T15:15:51+00:00

Signed-off-by: David S. Miller

net: don't call update_pmtu unconditionally

2018-01-25T21:27:34+00:00

Some dst_ops (e.g. md_dst_ops)) doesn't set this handler. It may result to: "BUG: unable to handle kernel NULL pointer dereference at (null)" Let's add a helper to check if update_pmtu is available before calling it. Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") CC: Roman Kapl CC: Xin Long Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller