Commit e7a3160d authored by brakmo's avatar brakmo Committed by Alexei Starovoitov

bpf: Update __cgroup_bpf_run_filter_skb with cn

For egress packets, __cgroup_bpf_fun_filter_skb() will now call
BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY() instead of PROG_CGROUP_RUN_ARRAY()
in order to propagate congestion notifications (cn) requests to TCP
callers.

For egress packets, this function can return:
   NET_XMIT_SUCCESS    (0)    - continue with packet output
   NET_XMIT_DROP       (1)    - drop packet and notify TCP to call cwr
   NET_XMIT_CN         (2)    - continue with packet output and notify TCP
                                to call cwr
   -EPERM                     - drop packet

For ingress packets, this function will return -EPERM if any attached
program was found and if it returned != 1 during execution. Otherwise 0
is returned.
Signed-off-by: default avatarLawrence Brakmo <brakmo@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 5cf1e914
......@@ -587,8 +587,16 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr,
* The program type passed in via @type must be suitable for network
* filtering. No further check is performed to assert that.
*
* This function will return %-EPERM if any if an attached program was found
* and if it returned != 1 during execution. In all other cases, 0 is returned.
* For egress packets, this function can return:
* NET_XMIT_SUCCESS (0) - continue with packet output
* NET_XMIT_DROP (1) - drop packet and notify TCP to call cwr
* NET_XMIT_CN (2) - continue with packet output and notify TCP
* to call cwr
* -EPERM - drop packet
*
* For ingress packets, this function will return -EPERM if any
* attached program was found and if it returned != 1 during execution.
* Otherwise 0 is returned.
*/
int __cgroup_bpf_run_filter_skb(struct sock *sk,
struct sk_buff *skb,
......@@ -614,12 +622,19 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk,
/* compute pointers for the bpf prog */
bpf_compute_and_save_data_end(skb, &saved_data_end);
if (type == BPF_CGROUP_INET_EGRESS) {
ret = BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY(
cgrp->bpf.effective[type], skb, __bpf_prog_run_save_cb);
} else {
ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb,
__bpf_prog_run_save_cb);
ret = (ret == 1 ? 0 : -EPERM);
}
bpf_restore_data_end(skb, saved_data_end);
__skb_pull(skb, offset);
skb->sk = save_sk;
return ret == 1 ? 0 : -EPERM;
return ret;
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
......
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