1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2
3 /*
4 * solisten Trace IPv4 and IPv6 listen syscalls
5 *
6 * Copyright (c) 2021 Hengqi Chen
7 *
8 * Based on solisten(8) from BCC by Jean-Tiare Le Bigot
9 * 31-May-2021 Hengqi Chen Created this.
10 */
11 #include <argp.h>
12 #include <arpa/inet.h>
13 #include <errno.h>
14 #include <signal.h>
15 #include <sys/socket.h>
16 #include <time.h>
17
18 #include <bpf/libbpf.h>
19 #include <bpf/bpf.h>
20 #include "solisten.h"
21 #include "solisten.skel.h"
22 #include "trace_helpers.h"
23
24 #define PERF_BUFFER_PAGES 16
25 #define PERF_POLL_TIMEOUT_MS 100
26 #define warn(...) fprintf(stderr, __VA_ARGS__)
27
28 static volatile sig_atomic_t exiting = 0;
29
30 static pid_t target_pid = 0;
31 static bool emit_timestamp = false;
32 static bool verbose = false;
33
34 const char *argp_program_version = "solisten 0.1";
35 const char *argp_program_bug_address =
36 "https://github.com/iovisor/bcc/tree/master/libbpf-tools";
37 const char argp_program_doc[] =
38 "Trace IPv4 and IPv6 listen syscalls.\n"
39 "\n"
40 "USAGE: solisten [-h] [-t] [-p PID]\n"
41 "\n"
42 "EXAMPLES:\n"
43 " solisten # trace listen syscalls\n"
44 " solisten -t # output with timestamp\n"
45 " solisten -p 1216 # only trace PID 1216\n";
46
47 static const struct argp_option opts[] = {
48 { "pid", 'p', "PID", 0, "Process ID to trace" },
49 { "timestamp", 't', NULL, 0, "Include timestamp on output" },
50 { "verbose", 'v', NULL, 0, "Verbose debug output" },
51 { NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
52 {},
53 };
54
parse_arg(int key,char * arg,struct argp_state * state)55 static error_t parse_arg(int key, char *arg, struct argp_state *state)
56 {
57 long pid;
58
59 switch (key) {
60 case 'p':
61 errno = 0;
62 pid = strtol(arg, NULL, 10);
63 if (errno || pid <= 0) {
64 warn("Invalid PID: %s\n", arg);
65 argp_usage(state);
66 }
67 target_pid = pid;
68 break;
69 case 't':
70 emit_timestamp = true;
71 break;
72 case 'v':
73 verbose = true;
74 break;
75 case 'h':
76 argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
77 break;
78 default:
79 return ARGP_ERR_UNKNOWN;
80 }
81 return 0;
82 }
83
libbpf_print_fn(enum libbpf_print_level level,const char * format,va_list args)84 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
85 {
86 if (level == LIBBPF_DEBUG && !verbose)
87 return 0;
88 return vfprintf(stderr, format, args);
89 }
90
sig_int(int signo)91 static void sig_int(int signo)
92 {
93 exiting = 1;
94 }
95
handle_event(void * ctx,int cpu,void * data,__u32 data_sz)96 static void handle_event(void *ctx, int cpu, void *data, __u32 data_sz)
97 {
98 const struct event *e = data;
99 time_t t;
100 struct tm *tm;
101 char ts[32], proto[16], addr[48] = {};
102 __u16 family = e->proto >> 16;
103 __u16 type = (__u16)e->proto;
104 const char *prot;
105
106 if (emit_timestamp) {
107 time(&t);
108 tm = localtime(&t);
109 strftime(ts, sizeof(ts), "%H:%M:%S", tm);
110 printf("%8s ", ts);
111 }
112
113 if (type == SOCK_STREAM)
114 prot = "TCP";
115 else if (type == SOCK_DGRAM)
116 prot = "UDP";
117 else
118 prot = "UNK";
119 if (family == AF_INET)
120 snprintf(proto, sizeof(proto), "%sv4", prot);
121 else /* family == AF_INET6 */
122 snprintf(proto, sizeof(proto), "%sv6", prot);
123 inet_ntop(family, e->addr, addr, sizeof(addr));
124 printf("%-7d %-16s %-3d %-7d %-5s %-5d %-32s\n",
125 e->pid, e->task, e->ret, e->backlog, proto, e->port, addr);
126 }
127
handle_lost_events(void * ctx,int cpu,__u64 lost_cnt)128 static void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
129 {
130 warn("lost %llu events on CPU #%d\n", lost_cnt, cpu);
131 }
132
main(int argc,char ** argv)133 int main(int argc, char **argv)
134 {
135 static const struct argp argp = {
136 .options = opts,
137 .parser = parse_arg,
138 .doc = argp_program_doc,
139 };
140 struct perf_buffer *pb = NULL;
141 struct solisten_bpf *obj;
142 int err;
143
144 err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
145 if (err)
146 return err;
147
148 libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
149 libbpf_set_print(libbpf_print_fn);
150
151 obj = solisten_bpf__open();
152 if (!obj) {
153 warn("failed to open BPF object\n");
154 return 1;
155 }
156
157 obj->rodata->target_pid = target_pid;
158
159 if (fentry_can_attach("inet_listen", NULL)) {
160 bpf_program__set_autoload(obj->progs.inet_listen_entry, false);
161 bpf_program__set_autoload(obj->progs.inet_listen_exit, false);
162 } else {
163 bpf_program__set_autoload(obj->progs.inet_listen_fexit, false);
164 }
165
166 err = solisten_bpf__load(obj);
167 if (err) {
168 warn("failed to load BPF object: %d\n", err);
169 goto cleanup;
170 }
171
172 err = solisten_bpf__attach(obj);
173 if (err) {
174 warn("failed to attach BPF programs: %d\n", err);
175 goto cleanup;
176 }
177
178 pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES,
179 handle_event, handle_lost_events, NULL, NULL);
180 if (!pb) {
181 err = -errno;
182 warn("failed to open perf buffer: %d\n", err);
183 goto cleanup;
184 }
185
186 if (signal(SIGINT, sig_int) == SIG_ERR) {
187 warn("can't set signal handler: %s\n", strerror(errno));
188 err = 1;
189 goto cleanup;
190 }
191
192 if (emit_timestamp)
193 printf("%-8s ", "TIME(s)");
194 printf("%-7s %-16s %-3s %-7s %-5s %-5s %-32s\n",
195 "PID", "COMM", "RET", "BACKLOG", "PROTO", "PORT", "ADDR");
196
197 while (!exiting) {
198 err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS);
199 if (err < 0 && err != -EINTR) {
200 warn("error polling perf buffer: %s\n", strerror(-err));
201 goto cleanup;
202 }
203 /* reset err to return 0 if exiting */
204 err = 0;
205 }
206
207 cleanup:
208 perf_buffer__free(pb);
209 solisten_bpf__destroy(obj);
210
211 return err != 0;
212 }
213