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authorWillem de Bruijn <willemb@google.com>2017-04-11 14:08:08 -0400
committerDavid S. Miller <davem@davemloft.net>2017-04-11 14:54:19 -0400
commit8f917bba0042f1e3b7693743fbe9782709e936e7 (patch)
tree5adc788308ed37a25a9911c42149638052f24b47 /kernel/bpf
parentcb6bf9cfdb5e26dfb7eb9b955b2f24d82703e27d (diff)
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>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/cgroup.c5
1 files changed, 4 insertions, 1 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();