1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>
  3 */
  4#include <linux/bpf.h>
  5#include <linux/if_link.h>
  6#include <assert.h>
  7#include <errno.h>
  8#include <signal.h>
  9#include <stdio.h>
 10#include <stdlib.h>
 11#include <stdbool.h>
 12#include <string.h>
 13#include <net/if.h>
 14#include <unistd.h>
 15#include <libgen.h>
 16#include <sys/resource.h>
 17
 18#include "bpf_util.h"
 19#include <bpf/bpf.h>
 20#include <bpf/libbpf.h>
 21
 22static int ifindex_in;
 23static int ifindex_out;
 24static bool ifindex_out_xdp_dummy_attached = true;
 25static __u32 prog_id;
 26static __u32 dummy_prog_id;
 27
 28static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 29static int rxcnt_map_fd;
 30
 31static void int_exit(int sig)
 32{
 33	__u32 curr_prog_id = 0;
 34
 35	if (bpf_get_link_xdp_id(ifindex_in, &curr_prog_id, xdp_flags)) {
 36		printf("bpf_get_link_xdp_id failed\n");
 37		exit(1);
 38	}
 39	if (prog_id == curr_prog_id)
 40		bpf_set_link_xdp_fd(ifindex_in, -1, xdp_flags);
 41	else if (!curr_prog_id)
 42		printf("couldn't find a prog id on iface IN\n");
 43	else
 44		printf("program on iface IN changed, not removing\n");
 45
 46	if (ifindex_out_xdp_dummy_attached) {
 47		curr_prog_id = 0;
 48		if (bpf_get_link_xdp_id(ifindex_out, &curr_prog_id,
 49					xdp_flags)) {
 50			printf("bpf_get_link_xdp_id failed\n");
 51			exit(1);
 52		}
 53		if (dummy_prog_id == curr_prog_id)
 54			bpf_set_link_xdp_fd(ifindex_out, -1, xdp_flags);
 55		else if (!curr_prog_id)
 56			printf("couldn't find a prog id on iface OUT\n");
 57		else
 58			printf("program on iface OUT changed, not removing\n");
 59	}
 60	exit(0);
 61}
 62
 63static void poll_stats(int interval, int ifindex)
 64{
 65	unsigned int nr_cpus = bpf_num_possible_cpus();
 66	__u64 values[nr_cpus], prev[nr_cpus];
 67
 68	memset(prev, 0, sizeof(prev));
 69
 70	while (1) {
 71		__u64 sum = 0;
 72		__u32 key = 0;
 73		int i;
 74
 75		sleep(interval);
 76		assert(bpf_map_lookup_elem(rxcnt_map_fd, &key, values) == 0);
 77		for (i = 0; i < nr_cpus; i++)
 78			sum += (values[i] - prev[i]);
 79		if (sum)
 80			printf("ifindex %i: %10llu pkt/s\n",
 81			       ifindex, sum / interval);
 82		memcpy(prev, values, sizeof(values));
 83	}
 84}
 85
 86static void usage(const char *prog)
 87{
 88	fprintf(stderr,
 89		"usage: %s [OPTS] <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n\n"
 90		"OPTS:\n"
 91		"    -S    use skb-mode\n"
 92		"    -N    enforce native mode\n"
 93		"    -F    force loading prog\n",
 94		prog);
 95}
 96
 97
 98int main(int argc, char **argv)
 99{
100	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
101	struct bpf_prog_load_attr prog_load_attr = {
102		.prog_type	= BPF_PROG_TYPE_XDP,
103	};
104	struct bpf_program *prog, *dummy_prog;
105	int prog_fd, tx_port_map_fd, opt;
106	struct bpf_prog_info info = {};
107	__u32 info_len = sizeof(info);
108	const char *optstr = "FSN";
109	struct bpf_object *obj;
110	char filename[256];
111	int dummy_prog_fd;
112	int ret, key = 0;
113
114	while ((opt = getopt(argc, argv, optstr)) != -1) {
115		switch (opt) {
116		case 'S':
117			xdp_flags |= XDP_FLAGS_SKB_MODE;
118			break;
119		case 'N':
120			/* default, set below */
121			break;
122		case 'F':
123			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
124			break;
125		default:
126			usage(basename(argv[0]));
127			return 1;
128		}
129	}
130
131	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
132		xdp_flags |= XDP_FLAGS_DRV_MODE;
133
134	if (optind == argc) {
135		printf("usage: %s <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n", argv[0]);
136		return 1;
137	}
138
139	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
140		perror("setrlimit(RLIMIT_MEMLOCK)");
141		return 1;
142	}
143
144	ifindex_in = if_nametoindex(argv[optind]);
145	if (!ifindex_in)
146		ifindex_in = strtoul(argv[optind], NULL, 0);
147
148	ifindex_out = if_nametoindex(argv[optind + 1]);
149	if (!ifindex_out)
150		ifindex_out = strtoul(argv[optind + 1], NULL, 0);
151
152	printf("input: %d output: %d\n", ifindex_in, ifindex_out);
153
154	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
155	prog_load_attr.file = filename;
156
157	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
158		return 1;
159
160	prog = bpf_program__next(NULL, obj);
161	dummy_prog = bpf_program__next(prog, obj);
162	if (!prog || !dummy_prog) {
163		printf("finding a prog in obj file failed\n");
164		return 1;
165	}
166	/* bpf_prog_load_xattr gives us the pointer to first prog's fd,
167	 * so we're missing only the fd for dummy prog
168	 */
169	dummy_prog_fd = bpf_program__fd(dummy_prog);
170	if (prog_fd < 0 || dummy_prog_fd < 0) {
171		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
172		return 1;
173	}
174
175	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
176	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
177	if (tx_port_map_fd < 0 || rxcnt_map_fd < 0) {
178		printf("bpf_object__find_map_fd_by_name failed\n");
179		return 1;
180	}
181
182	if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) {
183		printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
184		return 1;
185	}
186
187	ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
188	if (ret) {
189		printf("can't get prog info - %s\n", strerror(errno));
190		return ret;
191	}
192	prog_id = info.id;
193
194	/* Loading dummy XDP prog on out-device */
195	if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd,
196			    (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
197		printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
198		ifindex_out_xdp_dummy_attached = false;
199	}
200
201	memset(&info, 0, sizeof(info));
202	ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len);
203	if (ret) {
204		printf("can't get prog info - %s\n", strerror(errno));
205		return ret;
206	}
207	dummy_prog_id = info.id;
208
209	signal(SIGINT, int_exit);
210	signal(SIGTERM, int_exit);
211
212	/* bpf redirect port */
213	ret = bpf_map_update_elem(tx_port_map_fd, &key, &ifindex_out, 0);
214	if (ret) {
215		perror("bpf_update_elem");
216		goto out;
217	}
218
219	poll_stats(2, ifindex_out);
220
221out:
222	return 0;
223}