On Sat, Oct 31, 2020 at 11:52:37AM -0700, Alexander Duyck wrote:
[ ... ]
> +struct tcpbpf_globals global = { 0 };
> int _version SEC("version") = 1;
>
> SEC("sockops")
> @@ -105,29 +72,15 @@ int bpf_testcb(struct bpf_sock_ops *skops)
>
> op = (int) skops->op;
>
> - update_event_map(op);
> + global.event_map |= (1 << op);
>
> switch (op) {
> case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
> /* Test failure to set largest cb flag (assumes not defined) */
> - bad_call_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
> + global.bad_cb_test_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
> /* Set callback */
> - good_call_rv = bpf_sock_ops_cb_flags_set(skops,
> + global.good_cb_test_rv = bpf_sock_ops_cb_flags_set(skops,
> BPF_SOCK_OPS_STATE_CB_FLAG);
> - /* Update results */
> - {
> - __u32 key = 0;
> - struct tcpbpf_globals g, *gp;
> -
> - gp = bpf_map_lookup_elem(&global_map, &key);
> - if (!gp)
> - break;
> - g = *gp;
> - g.bad_cb_test_rv = bad_call_rv;
> - g.good_cb_test_rv = good_call_rv;
> - bpf_map_update_elem(&global_map, &key, &g,
> - BPF_ANY);
> - }
> break;
> case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
> skops->sk_txhash = 0x12345f;
> @@ -143,10 +96,8 @@ int bpf_testcb(struct bpf_sock_ops *skops)
>
> thdr = (struct tcphdr *)(header + offset);
> v = thdr->syn;
> - __u32 key = 1;
>
> - bpf_map_update_elem(&sockopt_results, &key, &v,
> - BPF_ANY);
> + global.tcp_saved_syn = v;
> }
> }
> break;
> @@ -156,25 +107,16 @@ int bpf_testcb(struct bpf_sock_ops *skops)
> break;
> case BPF_SOCK_OPS_STATE_CB:
> if (skops->args[1] == BPF_TCP_CLOSE) {
> - __u32 key = 0;
> - struct tcpbpf_globals g, *gp;
> -
> - gp = bpf_map_lookup_elem(&global_map, &key);
> - if (!gp)
> - break;
> - g = *gp;
> if (skops->args[0] == BPF_TCP_LISTEN) {
> - g.num_listen++;
> + global.num_listen++;
> } else {
> - g.total_retrans = skops->total_retrans;
> - g.data_segs_in = skops->data_segs_in;
> - g.data_segs_out = skops->data_segs_out;
> - g.bytes_received = skops->bytes_received;
> - g.bytes_acked = skops->bytes_acked;
> + global.total_retrans = skops->total_retrans;
> + global.data_segs_in = skops->data_segs_in;
> + global.data_segs_out = skops->data_segs_out;
> + global.bytes_received = skops->bytes_received;
> + global.bytes_acked = skops->bytes_acked;
> }
> - g.num_close_events++;
> - bpf_map_update_elem(&global_map, &key, &g,
> - BPF_ANY);
It is interesting that there is no race in the original "g.num_close_events++"
followed by the bpf_map_update_elem(). It seems quite fragile though.
> + global.num_close_events++;
There is __sync_fetch_and_add().
not sure about the global.event_map though, may be use an individual
variable for each _CB. Thoughts?
> }
> break;
> case BPF_SOCK_OPS_TCP_LISTEN_CB:
> @@ -182,9 +124,7 @@ int bpf_testcb(struct bpf_sock_ops *skops)
> v = bpf_setsockopt(skops, IPPROTO_TCP, TCP_SAVE_SYN,
> &save_syn, sizeof(save_syn));
> /* Update global map w/ result of setsock opt */
> - __u32 key = 0;
> -
> - bpf_map_update_elem(&sockopt_results, &key, &v, BPF_ANY);
> + global.tcp_save_syn = v;
> break;
> default:
> rv = -1;
> diff --git a/tools/testing/selftests/bpf/test_tcpbpf.h b/tools/testing/selftests/bpf/test_tcpbpf.h
> index 6220b95cbd02..0ed33521cbbb 100644
> --- a/tools/testing/selftests/bpf/test_tcpbpf.h
> +++ b/tools/testing/selftests/bpf/test_tcpbpf.h
> @@ -14,5 +14,7 @@ struct tcpbpf_globals {
> __u64 bytes_acked;
> __u32 num_listen;
> __u32 num_close_events;
> + __u32 tcp_save_syn;
> + __u32 tcp_saved_syn;
> };
> #endif
>
>
