bpf/progs/test_tcpnotify_kern.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <stddef.h>
0003 #include <string.h>
0004 #include <netinet/in.h>
0005 #include <linux/bpf.h>
0006 #include <linux/if_ether.h>
0007 #include <linux/if_packet.h>
0008 #include <linux/ip.h>
0009 #include <linux/ipv6.h>
0010 #include <linux/types.h>
0011 #include <linux/socket.h>
0012 #include <linux/tcp.h>
0013 #include <bpf/bpf_helpers.h>
0014 #include <bpf/bpf_endian.h>
0015 #include "test_tcpnotify.h"
0016
0017 struct {
0018     __uint(type, BPF_MAP_TYPE_ARRAY);
0019     __uint(max_entries, 4);
0020     __type(key, __u32);
0021     __type(value, struct tcpnotify_globals);
0022 } global_map SEC(".maps");
0023
0024 struct {
0025     __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
0026     __uint(max_entries, 2);
0027     __type(key, int);
0028     __type(value, __u32);
0029 } perf_event_map SEC(".maps");
0030
0031 SEC("sockops")
0032 int bpf_testcb(struct bpf_sock_ops *skops)
0033 {
0034     int rv = -1;
0035     int op;
0036
0037     op = (int) skops->op;
0038
0039     if (bpf_ntohl(skops->remote_port) != TESTPORT) {
0040         skops->reply = -1;
0041         return 0;
0042     }
0043
0044     switch (op) {
0045     case BPF_SOCK_OPS_TIMEOUT_INIT:
0046     case BPF_SOCK_OPS_RWND_INIT:
0047     case BPF_SOCK_OPS_NEEDS_ECN:
0048     case BPF_SOCK_OPS_BASE_RTT:
0049     case BPF_SOCK_OPS_RTO_CB:
0050         rv = 1;
0051         break;
0052
0053     case BPF_SOCK_OPS_TCP_CONNECT_CB:
0054     case BPF_SOCK_OPS_TCP_LISTEN_CB:
0055     case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
0056     case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
0057         bpf_sock_ops_cb_flags_set(skops, (BPF_SOCK_OPS_RETRANS_CB_FLAG|
0058                       BPF_SOCK_OPS_RTO_CB_FLAG));
0059         rv = 1;
0060         break;
0061     case BPF_SOCK_OPS_RETRANS_CB: {
0062             __u32 key = 0;
0063             struct tcpnotify_globals g, *gp;
0064             struct tcp_notifier msg = {
0065                 .type = 0xde,
0066                 .subtype = 0xad,
0067                 .source = 0xbe,
0068                 .hash = 0xef,
0069             };
0070
0071             rv = 1;
0072
0073             /* Update results */
0074             gp = bpf_map_lookup_elem(&global_map, &key);
0075             if (!gp)
0076                 break;
0077             g = *gp;
0078             g.total_retrans = skops->total_retrans;
0079             g.ncalls++;
0080             bpf_map_update_elem(&global_map, &key, &g,
0081                         BPF_ANY);
0082             bpf_perf_event_output(skops, &perf_event_map,
0083                           BPF_F_CURRENT_CPU,
0084                           &msg, sizeof(msg));
0085         }
0086         break;
0087     default:
0088         rv = -1;
0089     }
0090     skops->reply = rv;
0091     return 1;
0092 }
0093 char _license[] SEC("license") = "GPL";