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authorbrakmo <brakmo@fb.com>2019-05-28 16:59:37 -0700
committerAlexei Starovoitov <ast@kernel.org>2019-05-31 16:41:29 -0700
commite7a3160d092aa4dd7fb2ef23335cb3a98400aec6 (patch)
tree09c100a83ac1c6942ec343d9778933e75d5e764b
parent5cf1e91456301f8c4f6bbc63ff76cff12f92f31b (diff)
downloadlinux-e7a3160d092aa4dd7fb2ef23335cb3a98400aec6.tar.bz2
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: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--kernel/bpf/cgroup.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index ff594eb86fd7..1b65ab0df457 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -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);
- ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb,
- __bpf_prog_run_save_cb);
+ 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);