1 /* vi: set sw=4 ts=4: */
2 /*
3  * Small implementation of brctl for busybox.
4  *
5  * Copyright (C) 2008 by Bernhard Reutner-Fischer
6  *
7  * Some helper functions from bridge-utils are
8  * Copyright (C) 2000 Lennert Buytenhek
9  *
10  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
11  */
12 /* This applet currently uses only the ioctl interface and no sysfs at all.
13  * At the time of this writing this was considered a feature.
14  */
15 //config:config BRCTL
16 //config:	bool "brctl"
17 //config:	default y
18 //config:	select PLATFORM_LINUX
19 //config:	help
20 //config:	  Manage ethernet bridges.
21 //config:	  Supports addbr/delbr and addif/delif.
22 //config:
23 //config:config FEATURE_BRCTL_FANCY
24 //config:	bool "Fancy options"
25 //config:	default y
26 //config:	depends on BRCTL
27 //config:	help
28 //config:	  Add support for extended option like:
29 //config:	    setageing, setfd, sethello, setmaxage,
30 //config:	    setpathcost, setportprio, setbridgeprio,
31 //config:	    stp
32 //config:	  This adds about 600 bytes.
33 //config:
34 //config:config FEATURE_BRCTL_SHOW
35 //config:	bool "Support show"
36 //config:	default y
37 //config:	depends on BRCTL && FEATURE_BRCTL_FANCY
38 //config:	help
39 //config:	  Add support for option which prints the current config:
40 //config:	    show
41 
42 //applet:IF_BRCTL(APPLET(brctl, BB_DIR_USR_SBIN, BB_SUID_DROP))
43 
44 //kbuild:lib-$(CONFIG_BRCTL) += brctl.o
45 
46 //usage:#define brctl_trivial_usage
47 //usage:       "COMMAND [BRIDGE [INTERFACE]]"
48 //usage:#define brctl_full_usage "\n\n"
49 //usage:       "Manage ethernet bridges\n"
50 //usage:     "\nCommands:"
51 //usage:	IF_FEATURE_BRCTL_SHOW(
52 //usage:     "\n	show			Show a list of bridges"
53 //usage:	)
54 //usage:     "\n	addbr BRIDGE		Create BRIDGE"
55 //usage:     "\n	delbr BRIDGE		Delete BRIDGE"
56 //usage:     "\n	addif BRIDGE IFACE	Add IFACE to BRIDGE"
57 //usage:     "\n	delif BRIDGE IFACE	Delete IFACE from BRIDGE"
58 //usage:	IF_FEATURE_BRCTL_FANCY(
59 //usage:     "\n	setageing BRIDGE TIME		Set ageing time"
60 //usage:     "\n	setfd BRIDGE TIME		Set bridge forward delay"
61 //usage:     "\n	sethello BRIDGE TIME		Set hello time"
62 //usage:     "\n	setmaxage BRIDGE TIME		Set max message age"
63 //usage:     "\n	setpathcost BRIDGE COST		Set path cost"
64 //usage:     "\n	setportprio BRIDGE PRIO		Set port priority"
65 //usage:     "\n	setbridgeprio BRIDGE PRIO	Set bridge priority"
66 //usage:     "\n	stp BRIDGE [1/yes/on|0/no/off]	STP on/off"
67 //usage:	)
68 
69 #include "libbb.h"
70 #include <linux/sockios.h>
71 #include <net/if.h>
72 
73 #ifndef SIOCBRADDBR
74 # define SIOCBRADDBR BRCTL_ADD_BRIDGE
75 #endif
76 #ifndef SIOCBRDELBR
77 # define SIOCBRDELBR BRCTL_DEL_BRIDGE
78 #endif
79 #ifndef SIOCBRADDIF
80 # define SIOCBRADDIF BRCTL_ADD_IF
81 #endif
82 #ifndef SIOCBRDELIF
83 # define SIOCBRDELIF BRCTL_DEL_IF
84 #endif
85 
86 
87 /* Maximum number of ports supported per bridge interface.  */
88 #ifndef MAX_PORTS
89 # define MAX_PORTS 32
90 #endif
91 
92 /* Use internal number parsing and not the "exact" conversion.  */
93 /* #define BRCTL_USE_INTERNAL 0 */ /* use exact conversion */
94 #define BRCTL_USE_INTERNAL 1
95 
96 #if ENABLE_FEATURE_BRCTL_FANCY
97 /* #include <linux/if_bridge.h>
98  * breaks on musl: we already included netinet/in.h in libbb.h,
99  * if we include <linux/if_bridge.h> here, we get this:
100  * In file included from /usr/include/linux/if_bridge.h:18,
101  *                  from networking/brctl.c:67:
102  * /usr/include/linux/in6.h:32: error: redefinition of 'struct in6_addr'
103  * /usr/include/linux/in6.h:49: error: redefinition of 'struct sockaddr_in6'
104  * /usr/include/linux/in6.h:59: error: redefinition of 'struct ipv6_mreq'
105  */
106 /* From <linux/if_bridge.h> */
107 #define BRCTL_GET_VERSION 0
108 #define BRCTL_GET_BRIDGES 1
109 #define BRCTL_ADD_BRIDGE 2
110 #define BRCTL_DEL_BRIDGE 3
111 #define BRCTL_ADD_IF 4
112 #define BRCTL_DEL_IF 5
113 #define BRCTL_GET_BRIDGE_INFO 6
114 #define BRCTL_GET_PORT_LIST 7
115 #define BRCTL_SET_BRIDGE_FORWARD_DELAY 8
116 #define BRCTL_SET_BRIDGE_HELLO_TIME 9
117 #define BRCTL_SET_BRIDGE_MAX_AGE 10
118 #define BRCTL_SET_AGEING_TIME 11
119 #define BRCTL_SET_GC_INTERVAL 12
120 #define BRCTL_GET_PORT_INFO 13
121 #define BRCTL_SET_BRIDGE_STP_STATE 14
122 #define BRCTL_SET_BRIDGE_PRIORITY 15
123 #define BRCTL_SET_PORT_PRIORITY 16
124 #define BRCTL_SET_PATH_COST 17
125 #define BRCTL_GET_FDB_ENTRIES 18
126 struct __bridge_info {
127 	uint64_t designated_root;
128 	uint64_t bridge_id;
129 	uint32_t root_path_cost;
130 	uint32_t max_age;
131 	uint32_t hello_time;
132 	uint32_t forward_delay;
133 	uint32_t bridge_max_age;
134 	uint32_t bridge_hello_time;
135 	uint32_t bridge_forward_delay;
136 	uint8_t  topology_change;
137 	uint8_t  topology_change_detected;
138 	uint8_t  root_port;
139 	uint8_t  stp_enabled;
140 	uint32_t ageing_time;
141 	uint32_t gc_interval;
142 	uint32_t hello_timer_value;
143 	uint32_t tcn_timer_value;
144 	uint32_t topology_change_timer_value;
145 	uint32_t gc_timer_value;
146 };
147 /* end <linux/if_bridge.h> */
148 
149 /* FIXME: These 4 funcs are not really clean and could be improved */
bb_strtotimeval(struct timeval * tv,const char * time_str)150 static ALWAYS_INLINE void bb_strtotimeval(struct timeval *tv,
151 		const char *time_str)
152 {
153 	double secs;
154 # if BRCTL_USE_INTERNAL
155 	char *endptr;
156 	secs = /*bb_*/strtod(time_str, &endptr);
157 	if (endptr == time_str)
158 # else
159 	if (sscanf(time_str, "%lf", &secs) != 1)
160 # endif
161 		bb_error_msg_and_die(bb_msg_invalid_arg_to, time_str, "timespec");
162 	tv->tv_sec = secs;
163 	tv->tv_usec = 1000000 * (secs - tv->tv_sec);
164 }
165 
tv_to_jiffies(const struct timeval * tv)166 static ALWAYS_INLINE unsigned long tv_to_jiffies(const struct timeval *tv)
167 {
168 	unsigned long long jif;
169 
170 	jif = 1000000ULL * tv->tv_sec + tv->tv_usec;
171 
172 	return jif/10000;
173 }
174 # if 0
175 static void jiffies_to_tv(struct timeval *tv, unsigned long jiffies)
176 {
177 	unsigned long long tvusec;
178 
179 	tvusec = 10000ULL*jiffies;
180 	tv->tv_sec = tvusec/1000000;
181 	tv->tv_usec = tvusec - 1000000 * tv->tv_sec;
182 }
183 # endif
str_to_jiffies(const char * time_str)184 static unsigned long str_to_jiffies(const char *time_str)
185 {
186 	struct timeval tv;
187 	bb_strtotimeval(&tv, time_str);
188 	return tv_to_jiffies(&tv);
189 }
190 
arm_ioctl(unsigned long * args,unsigned long arg0,unsigned long arg1,unsigned long arg2)191 static void arm_ioctl(unsigned long *args,
192 		unsigned long arg0, unsigned long arg1, unsigned long arg2)
193 {
194 	args[0] = arg0;
195 	args[1] = arg1;
196 	args[2] = arg2;
197 	args[3] = 0;
198 }
199 #endif
200 
201 
202 int brctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
brctl_main(int argc UNUSED_PARAM,char ** argv)203 int brctl_main(int argc UNUSED_PARAM, char **argv)
204 {
205 	static const char keywords[] ALIGN1 =
206 		"addbr\0" "delbr\0" "addif\0" "delif\0"
207 	IF_FEATURE_BRCTL_FANCY(
208 		"stp\0"
209 		"setageing\0" "setfd\0" "sethello\0" "setmaxage\0"
210 		"setpathcost\0" "setportprio\0" "setbridgeprio\0"
211 	)
212 	IF_FEATURE_BRCTL_SHOW("show\0");
213 
214 	enum { ARG_addbr = 0, ARG_delbr, ARG_addif, ARG_delif
215 		IF_FEATURE_BRCTL_FANCY(,
216 			ARG_stp,
217 			ARG_setageing, ARG_setfd, ARG_sethello, ARG_setmaxage,
218 			ARG_setpathcost, ARG_setportprio, ARG_setbridgeprio
219 		)
220 		IF_FEATURE_BRCTL_SHOW(, ARG_show)
221 	};
222 
223 	int fd;
224 	smallint key;
225 	struct ifreq ifr;
226 	char *br, *brif;
227 
228 	argv++;
229 	while (*argv) {
230 #if ENABLE_FEATURE_BRCTL_FANCY
231 		int ifidx[MAX_PORTS];
232 		unsigned long args[4];
233 		ifr.ifr_data = (char *) &args;
234 #endif
235 
236 		key = index_in_strings(keywords, *argv);
237 		if (key == -1) /* no match found in keywords array, bail out. */
238 			bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
239 		argv++;
240 		fd = xsocket(AF_INET, SOCK_STREAM, 0);
241 
242 #if ENABLE_FEATURE_BRCTL_SHOW
243 		if (key == ARG_show) { /* show */
244 			char brname[IFNAMSIZ];
245 			int bridx[MAX_PORTS];
246 			int i, num;
247 			arm_ioctl(args, BRCTL_GET_BRIDGES,
248 						(unsigned long) bridx, MAX_PORTS);
249 			num = xioctl(fd, SIOCGIFBR, args);
250 			puts("bridge name\tbridge id\t\tSTP enabled\tinterfaces");
251 			for (i = 0; i < num; i++) {
252 				char ifname[IFNAMSIZ];
253 				int j, tabs;
254 				struct __bridge_info bi;
255 				unsigned char *x;
256 
257 				if (!if_indextoname(bridx[i], brname))
258 					bb_perror_msg_and_die("can't get bridge name for index %d", i);
259 				strncpy_IFNAMSIZ(ifr.ifr_name, brname);
260 
261 				arm_ioctl(args, BRCTL_GET_BRIDGE_INFO,
262 							(unsigned long) &bi, 0);
263 				xioctl(fd, SIOCDEVPRIVATE, &ifr);
264 				printf("%s\t\t", brname);
265 
266 				/* print bridge id */
267 				x = (unsigned char *) &bi.bridge_id;
268 				for (j = 0; j < 8; j++) {
269 					printf("%02x", x[j]);
270 					if (j == 1)
271 						bb_putchar('.');
272 				}
273 				printf(bi.stp_enabled ? "\tyes" : "\tno");
274 
275 				/* print interface list */
276 				arm_ioctl(args, BRCTL_GET_PORT_LIST,
277 							(unsigned long) ifidx, MAX_PORTS);
278 				xioctl(fd, SIOCDEVPRIVATE, &ifr);
279 				tabs = 0;
280 				for (j = 0; j < MAX_PORTS; j++) {
281 					if (!ifidx[j])
282 						continue;
283 					if (!if_indextoname(ifidx[j], ifname))
284 						bb_perror_msg_and_die("can't get interface name for index %d", j);
285 					if (tabs)
286 						printf("\t\t\t\t\t");
287 					else
288 						tabs = 1;
289 					printf("\t\t%s\n", ifname);
290 				}
291 				if (!tabs)  /* bridge has no interfaces */
292 					bb_putchar('\n');
293 			}
294 			goto done;
295 		}
296 #endif
297 
298 		if (!*argv) /* all but 'show' need at least one argument */
299 			bb_show_usage();
300 
301 		br = *argv++;
302 
303 		if (key == ARG_addbr || key == ARG_delbr) { /* addbr or delbr */
304 			ioctl_or_perror_and_die(fd,
305 					key == ARG_addbr ? SIOCBRADDBR : SIOCBRDELBR,
306 					br, "bridge %s", br);
307 			goto done;
308 		}
309 
310 		if (!*argv) /* all but 'addbr/delbr' need at least two arguments */
311 			bb_show_usage();
312 
313 		strncpy_IFNAMSIZ(ifr.ifr_name, br);
314 		if (key == ARG_addif || key == ARG_delif) { /* addif or delif */
315 			brif = *argv;
316 			ifr.ifr_ifindex = if_nametoindex(brif);
317 			if (!ifr.ifr_ifindex) {
318 				bb_perror_msg_and_die("iface %s", brif);
319 			}
320 			ioctl_or_perror_and_die(fd,
321 					key == ARG_addif ? SIOCBRADDIF : SIOCBRDELIF,
322 					&ifr, "bridge %s", br);
323 			goto done_next_argv;
324 		}
325 #if ENABLE_FEATURE_BRCTL_FANCY
326 		if (key == ARG_stp) { /* stp */
327 			static const char no_yes[] ALIGN1 =
328 				"0\0" "off\0" "n\0" "no\0"   /* 0 .. 3 */
329 				"1\0" "on\0"  "y\0" "yes\0"; /* 4 .. 7 */
330 			int onoff = index_in_strings(no_yes, *argv);
331 			if (onoff < 0)
332 				bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
333 			onoff = (unsigned)onoff / 4;
334 			arm_ioctl(args, BRCTL_SET_BRIDGE_STP_STATE, onoff, 0);
335 			goto fire;
336 		}
337 		if ((unsigned)(key - ARG_setageing) < 4) { /* time related ops */
338 			static const uint8_t ops[] ALIGN1 = {
339 				BRCTL_SET_AGEING_TIME,          /* ARG_setageing */
340 				BRCTL_SET_BRIDGE_FORWARD_DELAY, /* ARG_setfd     */
341 				BRCTL_SET_BRIDGE_HELLO_TIME,    /* ARG_sethello  */
342 				BRCTL_SET_BRIDGE_MAX_AGE        /* ARG_setmaxage */
343 			};
344 			arm_ioctl(args, ops[key - ARG_setageing], str_to_jiffies(*argv), 0);
345 			goto fire;
346 		}
347 		if (key == ARG_setpathcost
348 		 || key == ARG_setportprio
349 		 || key == ARG_setbridgeprio
350 		) {
351 			static const uint8_t ops[] ALIGN1 = {
352 				BRCTL_SET_PATH_COST,      /* ARG_setpathcost   */
353 				BRCTL_SET_PORT_PRIORITY,  /* ARG_setportprio   */
354 				BRCTL_SET_BRIDGE_PRIORITY /* ARG_setbridgeprio */
355 			};
356 			int port = -1;
357 			unsigned arg1, arg2;
358 
359 			if (key != ARG_setbridgeprio) {
360 				/* get portnum */
361 				unsigned i;
362 
363 				port = if_nametoindex(*argv++);
364 				if (!port)
365 					bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, "port");
366 				memset(ifidx, 0, sizeof ifidx);
367 				arm_ioctl(args, BRCTL_GET_PORT_LIST, (unsigned long)ifidx,
368 						MAX_PORTS);
369 				xioctl(fd, SIOCDEVPRIVATE, &ifr);
370 				for (i = 0; i < MAX_PORTS; i++) {
371 					if (ifidx[i] == port) {
372 						port = i;
373 						break;
374 					}
375 				}
376 			}
377 			arg1 = port;
378 			arg2 = xatoi_positive(*argv);
379 			if (key == ARG_setbridgeprio) {
380 				arg1 = arg2;
381 				arg2 = 0;
382 			}
383 			arm_ioctl(args, ops[key - ARG_setpathcost], arg1, arg2);
384 		}
385  fire:
386 		/* Execute the previously set command */
387 		xioctl(fd, SIOCDEVPRIVATE, &ifr);
388 #endif
389  done_next_argv:
390 		argv++;
391  done:
392 		close(fd);
393 	}
394 
395 	return EXIT_SUCCESS;
396 }
397