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| author | Willem de Bruijn <willemb@google.com> | 2017-04-11 14:08:08 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-04-11 14:54:19 -0400 |
| commit | 8f917bba0042f1e3b7693743fbe9782709e936e7 (patch) | |
| tree | 5adc788308ed37a25a9911c42149638052f24b47 | |
| parent | cb6bf9cfdb5e26dfb7eb9b955b2f24d82703e27d (diff) | |
| download | linux-8f917bba0042f1e3b7693743fbe9782709e936e7.tar.gz linux-8f917bba0042f1e3b7693743fbe9782709e936e7.tar.bz2 linux-8f917bba0042f1e3b7693743fbe9782709e936e7.zip | |
bpf: pass sk to helper functions
BPF helper functions access socket fields through skb->sk. This is not
set in ingress cgroup and socket filters. The association is only made
in skb_set_owner_r once the filter has accepted the packet. Sk is
available as socket lookup has taken place.
Temporarily set skb->sk to sk in these cases.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | kernel/bpf/cgroup.c | 5 | ||||
| -rw-r--r-- | net/core/filter.c | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index da0f53690295..ea6033cba947 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -154,7 +154,7 @@ int __cgroup_bpf_update(struct cgroup *cgrp, struct cgroup *parent, /** * __cgroup_bpf_run_filter_skb() - Run a program for packet filtering - * @sk: The socken sending or receiving traffic + * @sk: The socket sending or receiving traffic * @skb: The skb that is being sent or received * @type: The type of program to be exectuted * @@ -189,10 +189,13 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, prog = rcu_dereference(cgrp->bpf.effective[type]); if (prog) { unsigned int offset = skb->data - skb_network_header(skb); + struct sock *save_sk = skb->sk; + skb->sk = sk; __skb_push(skb, offset); ret = bpf_prog_run_save_cb(prog, skb) == 1 ? 0 : -EPERM; __skb_pull(skb, offset); + skb->sk = save_sk; } rcu_read_unlock(); diff --git a/net/core/filter.c b/net/core/filter.c index bbe0cf415105..ce2a19da8aa4 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -92,8 +92,13 @@ int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap) rcu_read_lock(); filter = rcu_dereference(sk->sk_filter); if (filter) { - unsigned int pkt_len = bpf_prog_run_save_cb(filter->prog, skb); + struct sock *save_sk = skb->sk; + unsigned int pkt_len; + + skb->sk = sk; + pkt_len = bpf_prog_run_save_cb(filter->prog, skb); err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM; + skb->sk = save_sk; } rcu_read_unlock(); |