@@ -1039,6 +1039,10 @@ enum {
* Arg2: value of icsk_rto
* Arg3: whether RTO has expired
*/
+ BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted.
+ * Arg1: sequence number of 1st byte
+ * Arg2: # segments
+ */
};
#define TCP_BPF_IW 1001 /* Set TCP initial congestion window */
@@ -270,7 +270,8 @@ struct tcp_diag_md5sig {
/* Definitions for bpf_sock_ops_cb_flags */
#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0)
-#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x1 /* Mask of all currently
+#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1)
+#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x3 /* Mask of all currently
* supported cb flags
*/
@@ -2908,6 +2908,9 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
if (likely(!err)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS;
trace_tcp_retransmit_skb(sk, skb);
+ if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RETRANS_CB_FLAG))
+ tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_RETRANS_CB,
+ TCP_SKB_CB(skb)->seq, segs);
} else if (err != -EBUSY) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL);
}
Adds support for calling sock_ops BPF program when there is a retransmission. Two arguments are used; one for the sequence number and other for the number of segments retransmitted. Does not include syn-ack retransmissions. New op: BPF_SOCK_OPS_RETRANS_CB. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> --- include/uapi/linux/bpf.h | 4 ++++ include/uapi/linux/tcp.h | 3 ++- net/ipv4/tcp_output.c | 3 +++ 3 files changed, 9 insertions(+), 1 deletion(-)