1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bpf.h>
3 #include <linux/if_link.h>
4 #include <assert.h>
5 #include <errno.h>
6 #include <signal.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <net/if.h>
11 #include <unistd.h>
12 #include <libgen.h>
13 #include <sys/ioctl.h>
14 #include <sys/types.h>
15 #include <sys/socket.h>
16 #include <netinet/in.h>
17 
18 #include "bpf_util.h"
19 #include <bpf/bpf.h>
20 #include <bpf/libbpf.h>
21 
22 #define MAX_IFACE_NUM 32
23 #define MAX_INDEX_NUM 1024
24 
25 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
26 static int ifaces[MAX_IFACE_NUM] = {};
27 
int_exit(int sig)28 static void int_exit(int sig)
29 {
30 	__u32 prog_id = 0;
31 	int i;
32 
33 	for (i = 0; ifaces[i] > 0; i++) {
34 		if (bpf_xdp_query_id(ifaces[i], xdp_flags, &prog_id)) {
35 			printf("bpf_xdp_query_id failed\n");
36 			exit(1);
37 		}
38 		if (prog_id)
39 			bpf_xdp_detach(ifaces[i], xdp_flags, NULL);
40 	}
41 
42 	exit(0);
43 }
44 
get_mac_addr(unsigned int ifindex,void * mac_addr)45 static int get_mac_addr(unsigned int ifindex, void *mac_addr)
46 {
47 	char ifname[IF_NAMESIZE];
48 	struct ifreq ifr;
49 	int fd, ret = -1;
50 
51 	fd = socket(AF_INET, SOCK_DGRAM, 0);
52 	if (fd < 0)
53 		return ret;
54 
55 	if (!if_indextoname(ifindex, ifname))
56 		goto err_out;
57 
58 	strcpy(ifr.ifr_name, ifname);
59 
60 	if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0)
61 		goto err_out;
62 
63 	memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));
64 	ret = 0;
65 
66 err_out:
67 	close(fd);
68 	return ret;
69 }
70 
usage(const char * prog)71 static void usage(const char *prog)
72 {
73 	fprintf(stderr,
74 		"usage: %s [OPTS] <IFNAME|IFINDEX> <IFNAME|IFINDEX> ...\n"
75 		"OPTS:\n"
76 		"    -S    use skb-mode\n"
77 		"    -N    enforce native mode\n"
78 		"    -F    force loading prog\n"
79 		"    -X    load xdp program on egress\n",
80 		prog);
81 }
82 
main(int argc,char ** argv)83 int main(int argc, char **argv)
84 {
85 	int prog_fd, group_all, mac_map;
86 	struct bpf_program *ingress_prog, *egress_prog;
87 	int i, err, ret, opt, egress_prog_fd = 0;
88 	struct bpf_devmap_val devmap_val;
89 	bool attach_egress_prog = false;
90 	unsigned char mac_addr[6];
91 	char ifname[IF_NAMESIZE];
92 	struct bpf_object *obj;
93 	unsigned int ifindex;
94 	char filename[256];
95 
96 	while ((opt = getopt(argc, argv, "SNFX")) != -1) {
97 		switch (opt) {
98 		case 'S':
99 			xdp_flags |= XDP_FLAGS_SKB_MODE;
100 			break;
101 		case 'N':
102 			/* default, set below */
103 			break;
104 		case 'F':
105 			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
106 			break;
107 		case 'X':
108 			attach_egress_prog = true;
109 			break;
110 		default:
111 			usage(basename(argv[0]));
112 			return 1;
113 		}
114 	}
115 
116 	if (!(xdp_flags & XDP_FLAGS_SKB_MODE)) {
117 		xdp_flags |= XDP_FLAGS_DRV_MODE;
118 	} else if (attach_egress_prog) {
119 		printf("Load xdp program on egress with SKB mode not supported yet\n");
120 		goto err_out;
121 	}
122 
123 	if (optind == argc) {
124 		printf("usage: %s <IFNAME|IFINDEX> <IFNAME|IFINDEX> ...\n", argv[0]);
125 		goto err_out;
126 	}
127 
128 	printf("Get interfaces:");
129 	for (i = 0; i < MAX_IFACE_NUM && argv[optind + i]; i++) {
130 		ifaces[i] = if_nametoindex(argv[optind + i]);
131 		if (!ifaces[i])
132 			ifaces[i] = strtoul(argv[optind + i], NULL, 0);
133 		if (!if_indextoname(ifaces[i], ifname)) {
134 			perror("Invalid interface name or i");
135 			goto err_out;
136 		}
137 		if (ifaces[i] > MAX_INDEX_NUM) {
138 			printf(" interface index too large\n");
139 			goto err_out;
140 		}
141 		printf(" %d", ifaces[i]);
142 	}
143 	printf("\n");
144 
145 	snprintf(filename, sizeof(filename), "%s_kern.bpf.o", argv[0]);
146 	obj = bpf_object__open_file(filename, NULL);
147 	err = libbpf_get_error(obj);
148 	if (err)
149 		goto err_out;
150 	err = bpf_object__load(obj);
151 	if (err)
152 		goto err_out;
153 	prog_fd = bpf_program__fd(bpf_object__next_program(obj, NULL));
154 
155 	if (attach_egress_prog)
156 		group_all = bpf_object__find_map_fd_by_name(obj, "map_egress");
157 	else
158 		group_all = bpf_object__find_map_fd_by_name(obj, "map_all");
159 	mac_map = bpf_object__find_map_fd_by_name(obj, "mac_map");
160 
161 	if (group_all < 0 || mac_map < 0) {
162 		printf("bpf_object__find_map_fd_by_name failed\n");
163 		goto err_out;
164 	}
165 
166 	if (attach_egress_prog) {
167 		/* Find ingress/egress prog for 2nd xdp prog */
168 		ingress_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_all_prog");
169 		egress_prog = bpf_object__find_program_by_name(obj, "xdp_devmap_prog");
170 		if (!ingress_prog || !egress_prog) {
171 			printf("finding ingress/egress_prog in obj file failed\n");
172 			goto err_out;
173 		}
174 		prog_fd = bpf_program__fd(ingress_prog);
175 		egress_prog_fd = bpf_program__fd(egress_prog);
176 		if (prog_fd < 0 || egress_prog_fd < 0) {
177 			printf("find egress_prog fd failed\n");
178 			goto err_out;
179 		}
180 	}
181 
182 	signal(SIGINT, int_exit);
183 	signal(SIGTERM, int_exit);
184 
185 	/* Init forward multicast groups and exclude group */
186 	for (i = 0; ifaces[i] > 0; i++) {
187 		ifindex = ifaces[i];
188 
189 		if (attach_egress_prog) {
190 			ret = get_mac_addr(ifindex, mac_addr);
191 			if (ret < 0) {
192 				printf("get interface %d mac failed\n", ifindex);
193 				goto err_out;
194 			}
195 			ret = bpf_map_update_elem(mac_map, &ifindex, mac_addr, 0);
196 			if (ret) {
197 				perror("bpf_update_elem mac_map failed\n");
198 				goto err_out;
199 			}
200 		}
201 
202 		/* Add all the interfaces to group all */
203 		devmap_val.ifindex = ifindex;
204 		devmap_val.bpf_prog.fd = egress_prog_fd;
205 		ret = bpf_map_update_elem(group_all, &ifindex, &devmap_val, 0);
206 		if (ret) {
207 			perror("bpf_map_update_elem");
208 			goto err_out;
209 		}
210 
211 		/* bind prog_fd to each interface */
212 		ret = bpf_xdp_attach(ifindex, prog_fd, xdp_flags, NULL);
213 		if (ret) {
214 			printf("Set xdp fd failed on %d\n", ifindex);
215 			goto err_out;
216 		}
217 	}
218 
219 	/* sleep some time for testing */
220 	sleep(999);
221 
222 	return 0;
223 
224 err_out:
225 	return 1;
226 }
227