kernel/include/net/dst.h, branch linux-5.2.y

net: make skb_dst_force return true when dst is refcounted

2019-07-28T06:27:13Z

[ 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

net: dst: remove gc leftovers

2019-03-21T20:39:25Z

Get rid of some obsolete gc-related documentation and macros that were missed in commit 5b7c9a8ff828 ("net: remove dst gc related code"). CC: Wei Wang Signed-off-by: Julian Wiedmann Acked-by: Wei Wang Signed-off-by: David S. Miller

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

2018-10-18T04:51:13Z

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

2018-07-20T08:14:41Z

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

2018-03-05T17:52:45Z

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

2018-01-29T15:15:51Z

Signed-off-by: David S. Miller

net: don't call update_pmtu unconditionally

2018-01-25T21:27:34Z

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

net: Remove dst->next

2017-11-30T14:54:27Z

There are no more users. Signed-off-by: David S. Miller Reviewed-by: Eric Dumazet

net: Rearrange dst_entry layout to avoid useless padding.

2017-11-30T14:54:27Z

We have padding to try and align the refcount on a separate cache line. But after several simplifications the padding has increased substantially. So now it's easy to change the layout to get rid of the padding entirely. We group the write-heavy __refcnt and __use with less often used items such as the rcu_head and the error code. Signed-off-by: David S. Miller Reviewed-by: Eric Dumazet

xfrm: Move dst->path into struct xfrm_dst

2017-11-30T14:54:26Z

The first member of an IPSEC route bundle chain sets it's dst->path to the underlying ipv4/ipv6 route that carries the bundle. Stated another way, if one were to follow the xfrm_dst->child chain of the bundle, the final non-NULL pointer would be the path and point to either an ipv4 or an ipv6 route. This is largely used to make sure that PMTU events propagate down to the correct ipv4 or ipv6 route. When we don't have the top of an IPSEC bundle 'dst->path == dst'. Move it down into xfrm_dst and key off of dst->xfrm. Signed-off-by: David S. Miller Reviewed-by: Eric Dumazet