aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/tools/bpf/bpftool/net.c
blob: 77dd73dd9ade654d62d3a19af70e52e456b763c6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
// SPDX-License-Identifier: GPL-2.0+
// Copyright (C) 2018 Facebook

#define _GNU_SOURCE
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libbpf.h>
#include <net/if.h>
#include <linux/if.h>
#include <linux/rtnetlink.h>
#include <linux/tc_act/tc_bpf.h>
#include <sys/socket.h>

#include <bpf.h>
#include <nlattr.h>
#include "main.h"
#include "netlink_dumper.h"

struct bpf_netdev_t {
	int	*ifindex_array;
	int	used_len;
	int	array_len;
	int	filter_idx;
};

struct tc_kind_handle {
	char	kind[64];
	int	handle;
};

struct bpf_tcinfo_t {
	struct tc_kind_handle	*handle_array;
	int			used_len;
	int			array_len;
	bool			is_qdisc;
};

static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb)
{
	struct bpf_netdev_t *netinfo = cookie;
	struct ifinfomsg *ifinfo = msg;

	if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index)
		return 0;

	if (netinfo->used_len == netinfo->array_len) {
		netinfo->ifindex_array = realloc(netinfo->ifindex_array,
			(netinfo->array_len + 16) * sizeof(int));
		netinfo->array_len += 16;
	}
	netinfo->ifindex_array[netinfo->used_len++] = ifinfo->ifi_index;

	return do_xdp_dump(ifinfo, tb);
}

static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb)
{
	struct bpf_tcinfo_t *tcinfo = cookie;
	struct tcmsg *info = msg;

	if (tcinfo->is_qdisc) {
		/* skip clsact qdisc */
		if (tb[TCA_KIND] &&
		    strcmp(nla_data(tb[TCA_KIND]), "clsact") == 0)
			return 0;
		if (info->tcm_handle == 0)
			return 0;
	}

	if (tcinfo->used_len == tcinfo->array_len) {
		tcinfo->handle_array = realloc(tcinfo->handle_array,
			(tcinfo->array_len + 16) * sizeof(struct tc_kind_handle));
		tcinfo->array_len += 16;
	}
	tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle;
	snprintf(tcinfo->handle_array[tcinfo->used_len].kind,
		 sizeof(tcinfo->handle_array[tcinfo->used_len].kind),
		 "%s_%s",
		 tcinfo->is_qdisc ? "qdisc" : "class",
		 tb[TCA_KIND] ? nla_getattr_str(tb[TCA_KIND]) : "unknown");
	tcinfo->used_len++;

	return 0;
}

static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb)
{
	const char *kind = cookie;

	return do_filter_dump((struct tcmsg *)msg, tb, kind);
}

static int show_dev_tc_bpf(int sock, unsigned int nl_pid, int ifindex)
{
	struct bpf_tcinfo_t tcinfo;
	int i, handle, ret;

	tcinfo.handle_array = NULL;
	tcinfo.used_len = 0;
	tcinfo.array_len = 0;

	tcinfo.is_qdisc = false;
	ret = nl_get_class(sock, nl_pid, ifindex, dump_class_qdisc_nlmsg,
			   &tcinfo);
	if (ret)
		return ret;

	tcinfo.is_qdisc = true;
	ret = nl_get_qdisc(sock, nl_pid, ifindex, dump_class_qdisc_nlmsg,
			   &tcinfo);
	if (ret)
		return ret;

	for (i = 0; i < tcinfo.used_len; i++) {
		ret = nl_get_filter(sock, nl_pid, ifindex,
				    tcinfo.handle_array[i].handle,
				    dump_filter_nlmsg,
				    tcinfo.handle_array[i].kind);
		if (ret)
			return ret;
	}

	/* root, ingress and egress handle */
	handle = TC_H_ROOT;
	ret = nl_get_filter(sock, nl_pid, ifindex, handle, dump_filter_nlmsg,
			    "root");
	if (ret)
		return ret;

	handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
	ret = nl_get_filter(sock, nl_pid, ifindex, handle, dump_filter_nlmsg,
			    "qdisc_clsact_ingress");
	if (ret)
		return ret;

	handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);
	ret = nl_get_filter(sock, nl_pid, ifindex, handle, dump_filter_nlmsg,
			    "qdisc_clsact_egress");
	if (ret)
		return ret;

	return 0;
}

static int do_show(int argc, char **argv)
{
	int i, sock, ret, filter_idx = -1;
	struct bpf_netdev_t dev_array;
	unsigned int nl_pid;
	char err_buf[256];

	if (argc == 2) {
		if (strcmp(argv[0], "dev") != 0)
			usage();
		filter_idx = if_nametoindex(argv[1]);
		if (filter_idx == 0) {
			fprintf(stderr, "invalid dev name %s\n", argv[1]);
			return -1;
		}
	} else if (argc != 0) {
		usage();
	}

	sock = bpf_netlink_open(&nl_pid);
	if (sock < 0) {
		fprintf(stderr, "failed to open netlink sock\n");
		return -1;
	}

	dev_array.ifindex_array = NULL;
	dev_array.used_len = 0;
	dev_array.array_len = 0;
	dev_array.filter_idx = filter_idx;

	if (json_output)
		jsonw_start_array(json_wtr);
	NET_START_OBJECT;
	NET_START_ARRAY("xdp", "\n");
	ret = nl_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);
	NET_END_ARRAY("\n");

	if (!ret) {
		NET_START_ARRAY("tc_filters", "\n");
		for (i = 0; i < dev_array.used_len; i++) {
			ret = show_dev_tc_bpf(sock, nl_pid,
					      dev_array.ifindex_array[i]);
			if (ret)
				break;
		}
		NET_END_ARRAY("\n");
	}
	NET_END_OBJECT;
	if (json_output)
		jsonw_end_array(json_wtr);

	if (ret) {
		if (json_output)
			jsonw_null(json_wtr);
		libbpf_strerror(ret, err_buf, sizeof(err_buf));
		fprintf(stderr, "Error: %s\n", err_buf);
	}
	free(dev_array.ifindex_array);
	close(sock);
	return ret;
}

static int do_help(int argc, char **argv)
{
	if (json_output) {
		jsonw_null(json_wtr);
		return 0;
	}

	fprintf(stderr,
		"Usage: %s %s { show | list } [dev <devname>]\n"
		"       %s %s help\n",
		bin_name, argv[-2], bin_name, argv[-2]);

	return 0;
}

static const struct cmd cmds[] = {
	{ "show",	do_show },
	{ "list",	do_show },
	{ "help",	do_help },
	{ 0 }
};

int do_net(int argc, char **argv)
{
	return cmd_select(cmds, argc, argv, do_help);
}