Jesper Dangaard Brouer 1d6e51e231 bpf: Fix bpf_fib_lookup helper MTU check for SKB ctx ... [ Upstream commit 2c0a10af688c02adcf127aad29e923e0056c6b69 ] BPF end-user on Cilium slack-channel (Carlo Carraro) wants to use bpf_fib_lookup for doing MTU-check, but *prior* to extending packet size, by adjusting fib_params 'tot_len' with the packet length plus the expected encap size. (Just like the bpf_check_mtu helper supports). He discovered that for SKB ctx the param->tot_len was not used, instead skb->len was used (via MTU check in is_skb_forwardable() that checks against netdev MTU). Fix this by using fib_params 'tot_len' for MTU check. If not provided (e.g. zero) then keep existing TC behaviour intact. Notice that 'tot_len' for MTU check is done like XDP code-path, which checks against FIB-dst MTU. V16: - Revert V13 optimization, 2nd lookup is against egress/resulting netdev V13: - Only do ifindex lookup one time, calling dev_get_by_index_rcu(). V10: - Use same method as XDP for 'tot_len' MTU check Fixes: 4c79579b44 ("bpf: Change bpf_fib_lookup to return lookup status") Reported-by: Carlo Carraro <colrack@gmail.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/161287789444.790810.15247494756551413508.stgit@firesoul Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-03-04 11:37:33 +01:00
..
bpf_sk_storage.c
datagram.c	udp: fix skb_copy_and_csum_datagram with odd segment sizes	2021-02-17 11:02:28 +01:00
datagram.h
dev_addr_lists.c
dev_ioctl.c
dev.c	net/sched: fix miss init the mru in qdisc_skb_cb	2021-02-23 15:53:23 +01:00
devlink.c	net: core: devlink: use right genl user_ptr when handling port param get/set	2021-01-27 11:55:26 +01:00
drop_monitor.c
dst_cache.c
dst.c
failover.c
fib_notifier.c
fib_rules.c
filter.c	bpf: Fix bpf_fib_lookup helper MTU check for SKB ctx	2021-03-04 11:37:33 +01:00
flow_dissector.c
flow_offload.c
gen_estimator.c	net_sched: gen_estimator: support large ewma log	2021-01-27 11:55:23 +01:00
gen_stats.c
gro_cells.c
hwbm.c
link_watch.c
lwt_bpf.c
lwtunnel.c
Makefile
neighbour.c	neighbour: Prevent a dead entry from updating gc_list	2021-02-10 09:29:22 +01:00
net_namespace.c
net-procfs.c
net-sysfs.c	net-sysfs: take the rtnl lock when accessing xps_rxqs_map and num_tc	2021-01-12 20:18:11 +01:00
net-sysfs.h
net-traces.c
netclassid_cgroup.c
netevent.c
netpoll.c
netprio_cgroup.c
page_pool.c
pktgen.c
ptp_classifier.c
request_sock.c
rtnetlink.c
scm.c
secure_seq.c
skbuff.c	skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too	2021-01-27 11:55:23 +01:00
skmsg.c
sock_diag.c
sock_map.c
sock_reuseport.c	udp: Prevent reuseport_select_sock from reading uninitialized socks	2021-01-23 16:03:59 +01:00
sock.c
stream.c
sysctl_net_core.c
timestamping.c
tso.c
utils.c
xdp.c