1 /* This example is placed in the public domain. */
2 #include <errno.h>
3 #include <limits.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <unistd.h>
8 #include <time.h>
9
10 #include <libmnl/libmnl.h>
11 #include <linux/can/netlink.h>
12 #include <linux/if.h>
13 #include <linux/if_link.h>
14 #include <linux/rtnetlink.h>
15
16 static void incomplete_command(void) __attribute__((noreturn));
17
18 #define NEXT_ARG() \
19 do { \
20 if (argc <= 0) incomplete_command(); \
21 argv++; \
22 argc--; \
23 } while (0)
24
duparg2(const char * key,const char * arg)25 static void duparg2(const char *key, const char *arg)
26 {
27 fprintf(stderr,
28 "Error: either \"%s\" is duplicate, or \"%s\" is a garbage.\n",
29 key, arg);
30 exit(-1);
31 }
32
incomplete_command(void)33 static void incomplete_command(void)
34 {
35 fprintf(stderr, "Command line is not complete. Try option \"help\"\n");
36 exit(EXIT_FAILURE);
37 }
38
39 /* Returns false if 'prefix' is a not empty prefix of 'string'.
40 */
matches(const char * prefix,const char * string)41 static bool matches(const char *prefix, const char *string)
42 {
43 if (!*prefix)
44 return true;
45
46 while (*string && *prefix == *string) {
47 prefix++;
48 string++;
49 }
50
51 return !!*prefix;
52 }
53
get_u16(__u16 * val,const char * arg,int base)54 static int get_u16(__u16 *val, const char *arg, int base)
55 {
56 unsigned long res;
57 char *ptr;
58
59 if (!arg || !*arg)
60 return -1;
61
62 res = strtoul(arg, &ptr, base);
63
64 /* empty string or trailing non-digits */
65 if (!ptr || ptr == arg || *ptr)
66 return -1;
67
68 /* overflow */
69 if (res == ULONG_MAX && errno == ERANGE)
70 return -1;
71
72 if (res > 0xFFFFUL)
73 return -1;
74
75 *val = res;
76 return 0;
77 }
78
get_u32(__u32 * val,const char * arg,int base)79 static int get_u32(__u32 *val, const char *arg, int base)
80 {
81 unsigned long res;
82 char *ptr;
83
84 if (!arg || !*arg)
85 return -1;
86
87 res = strtoul(arg, &ptr, base);
88
89 /* empty string or trailing non-digits */
90 if (!ptr || ptr == arg || *ptr)
91 return -1;
92
93 /* overflow */
94 if (res == ULONG_MAX && errno == ERANGE)
95 return -1;
96
97 /* in case UL > 32 bits */
98 if (res > 0xFFFFFFFFUL)
99 return -1;
100
101 *val = res;
102 return 0;
103 }
104
get_float(float * val,const char * arg)105 static int get_float(float *val, const char *arg)
106 {
107 float res;
108 char *ptr;
109
110 if (!arg || !*arg)
111 return -1;
112
113 res = strtof(arg, &ptr);
114 if (!ptr || ptr == arg || *ptr)
115 return -1;
116
117 *val = res;
118 return 0;
119 }
120
set_ctrlmode(char * name,char * arg,struct can_ctrlmode * cm,__u32 flags)121 static void set_ctrlmode(char *name, char *arg,
122 struct can_ctrlmode *cm, __u32 flags)
123 {
124 if (strcmp(arg, "on") == 0) {
125 cm->flags |= flags;
126 } else if (strcmp(arg, "off") != 0) {
127 fprintf(stderr,
128 "Error: argument of \"%s\" must be \"on\" or \"off\", not \"%s\"\n",
129 name, arg);
130 exit(EXIT_FAILURE);
131 }
132
133 cm->mask |= flags;
134 }
135
invarg(const char * msg,const char * arg)136 static void invarg(const char *msg, const char *arg)
137 {
138 fprintf(stderr, "Error: argument \"%s\" is wrong: %s\n", arg, msg);
139 exit(-1);
140 }
141
print_usage(FILE * f)142 static void print_usage(FILE *f)
143 {
144 fprintf(f,
145 "Usage: ip link set DEVICE type can\n"
146 "\t[ bitrate BITRATE [ sample-point SAMPLE-POINT] ] |\n"
147 "\t[ tq TQ prop-seg PROP_SEG phase-seg1 PHASE-SEG1\n \t phase-seg2 PHASE-SEG2 [ sjw SJW ] ]\n"
148 "\n"
149 "\t[ dbitrate BITRATE [ dsample-point SAMPLE-POINT] ] |\n"
150 "\t[ dtq TQ dprop-seg PROP_SEG dphase-seg1 PHASE-SEG1\n \t dphase-seg2 PHASE-SEG2 [ dsjw SJW ] ]\n"
151 "\n"
152 "\t[ loopback { on | off } ]\n"
153 "\t[ listen-only { on | off } ]\n"
154 "\t[ triple-sampling { on | off } ]\n"
155 "\t[ one-shot { on | off } ]\n"
156 "\t[ berr-reporting { on | off } ]\n"
157 "\t[ fd { on | off } ]\n"
158 "\t[ fd-non-iso { on | off } ]\n"
159 "\t[ presume-ack { on | off } ]\n"
160 "\t[ cc-len8-dlc { on | off } ]\n"
161 "\n"
162 "\t[ restart-ms TIME-MS ]\n"
163 "\t[ restart ]\n"
164 "\n"
165 "\t[ termination { 0..65535 } ]\n"
166 "\n"
167 "\tWhere: BITRATE := { 1..1000000 }\n"
168 "\t SAMPLE-POINT := { 0.000..0.999 }\n"
169 "\t TQ := { NUMBER }\n"
170 "\t PROP-SEG := { 1..8 }\n"
171 "\t PHASE-SEG1 := { 1..8 }\n"
172 "\t PHASE-SEG2 := { 1..8 }\n"
173 "\t SJW := { 1..4 }\n"
174 "\t RESTART-MS := { 0 | NUMBER }\n"
175 );
176 }
177
usage(void)178 static void usage(void)
179 {
180 print_usage(stderr);
181 }
182
iplink_set_can_parse(int argc,char ** argv,struct nlmsghdr * nlh)183 static int iplink_set_can_parse(int argc, char **argv, struct nlmsghdr *nlh)
184 {
185 struct can_bittiming bt = {}, dbt = {};
186 struct can_ctrlmode cm = {};
187
188 while (argc > 0) {
189 if (matches(*argv, "bitrate") == 0) {
190 NEXT_ARG();
191 if (get_u32(&bt.bitrate, *argv, 0))
192 invarg("invalid \"bitrate\" value\n", *argv);
193 } else if (matches(*argv, "sample-point") == 0) {
194 float sp;
195
196 NEXT_ARG();
197 if (get_float(&sp, *argv))
198 invarg("invalid \"sample-point\" value\n",
199 *argv);
200
201 bt.sample_point = (__u32)(sp * 1000);
202 } else if (matches(*argv, "tq") == 0) {
203 NEXT_ARG();
204 if (get_u32(&bt.tq, *argv, 0))
205 invarg("invalid \"tq\" value\n", *argv);
206 } else if (matches(*argv, "prop-seg") == 0) {
207 NEXT_ARG();
208 if (get_u32(&bt.prop_seg, *argv, 0))
209 invarg("invalid \"prop-seg\" value\n", *argv);
210 } else if (matches(*argv, "phase-seg1") == 0) {
211 NEXT_ARG();
212 if (get_u32(&bt.phase_seg1, *argv, 0))
213 invarg("invalid \"phase-seg1\" value\n", *argv);
214 } else if (matches(*argv, "phase-seg2") == 0) {
215 NEXT_ARG();
216 if (get_u32(&bt.phase_seg2, *argv, 0))
217 invarg("invalid \"phase-seg2\" value\n", *argv);
218 } else if (matches(*argv, "sjw") == 0) {
219 NEXT_ARG();
220 if (get_u32(&bt.sjw, *argv, 0))
221 invarg("invalid \"sjw\" value\n", *argv);
222 } else if (matches(*argv, "dbitrate") == 0) {
223 NEXT_ARG();
224 if (get_u32(&dbt.bitrate, *argv, 0))
225 invarg("invalid \"dbitrate\" value\n", *argv);
226 } else if (matches(*argv, "dsample-point") == 0) {
227 float sp;
228
229 NEXT_ARG();
230 if (get_float(&sp, *argv))
231 invarg("invalid \"dsample-point\" value\n", *argv);
232 dbt.sample_point = (__u32)(sp * 1000);
233 } else if (matches(*argv, "dtq") == 0) {
234 NEXT_ARG();
235 if (get_u32(&dbt.tq, *argv, 0))
236 invarg("invalid \"dtq\" value\n", *argv);
237 } else if (matches(*argv, "dprop-seg") == 0) {
238 NEXT_ARG();
239 if (get_u32(&dbt.prop_seg, *argv, 0))
240 invarg("invalid \"dprop-seg\" value\n", *argv);
241 } else if (matches(*argv, "dphase-seg1") == 0) {
242 NEXT_ARG();
243 if (get_u32(&dbt.phase_seg1, *argv, 0))
244 invarg("invalid \"dphase-seg1\" value\n", *argv);
245 } else if (matches(*argv, "dphase-seg2") == 0) {
246 NEXT_ARG();
247 if (get_u32(&dbt.phase_seg2, *argv, 0))
248 invarg("invalid \"dphase-seg2\" value\n", *argv);
249 } else if (matches(*argv, "dsjw") == 0) {
250 NEXT_ARG();
251 if (get_u32(&dbt.sjw, *argv, 0))
252 invarg("invalid \"dsjw\" value\n", *argv);
253 } else if (matches(*argv, "loopback") == 0) {
254 NEXT_ARG();
255 set_ctrlmode("loopback", *argv, &cm,
256 CAN_CTRLMODE_LOOPBACK);
257 } else if (matches(*argv, "listen-only") == 0) {
258 NEXT_ARG();
259 set_ctrlmode("listen-only", *argv, &cm,
260 CAN_CTRLMODE_LISTENONLY);
261 } else if (matches(*argv, "triple-sampling") == 0) {
262 NEXT_ARG();
263 set_ctrlmode("triple-sampling", *argv, &cm,
264 CAN_CTRLMODE_3_SAMPLES);
265 } else if (matches(*argv, "one-shot") == 0) {
266 NEXT_ARG();
267 set_ctrlmode("one-shot", *argv, &cm,
268 CAN_CTRLMODE_ONE_SHOT);
269 } else if (matches(*argv, "berr-reporting") == 0) {
270 NEXT_ARG();
271 set_ctrlmode("berr-reporting", *argv, &cm,
272 CAN_CTRLMODE_BERR_REPORTING);
273 } else if (matches(*argv, "fd") == 0) {
274 NEXT_ARG();
275 set_ctrlmode("fd", *argv, &cm,
276 CAN_CTRLMODE_FD);
277 } else if (matches(*argv, "fd-non-iso") == 0) {
278 NEXT_ARG();
279 set_ctrlmode("fd-non-iso", *argv, &cm,
280 CAN_CTRLMODE_FD_NON_ISO);
281 } else if (matches(*argv, "presume-ack") == 0) {
282 NEXT_ARG();
283 set_ctrlmode("presume-ack", *argv, &cm,
284 CAN_CTRLMODE_PRESUME_ACK);
285 #if defined(CAN_CTRLMODE_CC_LEN8_DLC)
286 } else if (matches(*argv, "cc-len8-dlc") == 0) {
287 NEXT_ARG();
288 set_ctrlmode("cc-len8-dlc", *argv, &cm,
289 CAN_CTRLMODE_CC_LEN8_DLC);
290 #endif
291 } else if (matches(*argv, "restart") == 0) {
292 __u32 val = 1;
293
294 mnl_attr_put(nlh, IFLA_CAN_RESTART, sizeof(val), &val);
295 } else if (matches(*argv, "restart-ms") == 0) {
296 __u32 val;
297
298 NEXT_ARG();
299 if (get_u32(&val, *argv, 0))
300 invarg("invalid \"restart-ms\" value\n", *argv);
301
302 mnl_attr_put(nlh, IFLA_CAN_RESTART_MS, sizeof(val), &val);
303 } else if (matches(*argv, "termination") == 0) {
304 __u16 val;
305
306 NEXT_ARG();
307 if (get_u16(&val, *argv, 0))
308 invarg("invalid \"termination\" value\n",
309 *argv);
310
311 mnl_attr_put(nlh, IFLA_CAN_TERMINATION, sizeof(val), &val);
312 } else {
313 fprintf(stderr, "unknown option \"%s\"\n", *argv);
314 usage();
315 return -1;
316 }
317
318 NEXT_ARG();
319 }
320
321 if (bt.bitrate || bt.tq)
322 mnl_attr_put(nlh, IFLA_CAN_BITTIMING, sizeof(bt), &bt);
323
324 if (cm.mask)
325 mnl_attr_put(nlh, IFLA_CAN_CTRLMODE, sizeof(cm), &cm);
326
327 return 0;
328 }
329
main(int argc,char * argv[])330 int main(int argc, char *argv[])
331 {
332 char buf[MNL_SOCKET_BUFFER_SIZE];
333 struct mnl_socket *nl;
334 struct nlmsghdr *nlh;
335 struct ifinfomsg *ifm;
336 int ret;
337 unsigned int seq, portid;
338 struct nlattr *linkinfo, *data;
339 const char *signatures[] = {
340 "ip", "link", "set", ""
341 };
342 char *type = NULL;
343 char *dev = NULL;
344 int i;
345
346 NEXT_ARG();
347 for (i = 0; argc > 0 && signatures[i][0];) {
348 if (matches(*argv, signatures[i]))
349 incomplete_command();
350
351 NEXT_ARG();
352 i++;
353 }
354
355 if (argc == 0)
356 incomplete_command();
357
358 nlh = mnl_nlmsg_put_header(buf);
359 nlh->nlmsg_type = RTM_NEWLINK;
360 nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
361 nlh->nlmsg_seq = seq = time(NULL);
362 ifm = mnl_nlmsg_put_extra_header(nlh, sizeof(*ifm));
363 ifm->ifi_family = AF_UNSPEC;
364 ifm->ifi_change = 0;
365 ifm->ifi_flags = 0;
366
367 while (argc > 0) {
368 if (matches(*argv, "up") == 0) {
369 ifm->ifi_change |= IFF_UP;
370 ifm->ifi_flags |= IFF_UP;
371 } else if (matches(*argv, "down") == 0) {
372 ifm->ifi_change |= IFF_UP;
373 ifm->ifi_flags &= ~IFF_UP;
374 } else if (matches(*argv, "type") == 0) {
375 NEXT_ARG();
376 type = *argv;
377 NEXT_ARG();
378 break;
379 } else if (matches(*argv, "help") == 0) {
380 usage();
381 exit(EXIT_FAILURE);
382 } else {
383 if (matches(*argv, "dev") == 0)
384 NEXT_ARG();
385
386 if (dev)
387 duparg2("dev", *argv);
388
389 dev = *argv;
390 }
391
392 NEXT_ARG();
393 }
394
395 if (dev)
396 mnl_attr_put_str(nlh, IFLA_IFNAME, dev);
397
398 if (type) {
399 if (matches(type, "can")) {
400 fprintf(stderr, "unknown type \"%s\"\n", type);
401 usage();
402 exit(EXIT_FAILURE);
403 }
404
405 linkinfo = mnl_attr_nest_start(nlh, IFLA_LINKINFO);
406 mnl_attr_put_str(nlh, IFLA_INFO_KIND, "can");
407 data = mnl_attr_nest_start(nlh, IFLA_INFO_DATA);
408
409 if (iplink_set_can_parse(argc, argv, nlh))
410 return -1;
411
412 mnl_attr_nest_end(nlh, data);
413 mnl_attr_nest_end(nlh, linkinfo);
414 }
415
416 nl = mnl_socket_open(NETLINK_ROUTE);
417 if (nl == NULL) {
418 perror("mnl_socket_open");
419 exit(EXIT_FAILURE);
420 }
421
422 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
423 perror("mnl_socket_bind");
424 exit(EXIT_FAILURE);
425 }
426
427 portid = mnl_socket_get_portid(nl);
428
429 mnl_nlmsg_fprintf(stdout, nlh, nlh->nlmsg_len,
430 sizeof(struct ifinfomsg));
431
432 if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
433 perror("mnl_socket_sendto");
434 exit(EXIT_FAILURE);
435 }
436
437 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
438 if (ret == -1) {
439 perror("mnl_socket_recvfrom");
440 exit(EXIT_FAILURE);
441 }
442
443 ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL);
444 if (ret == -1) {
445 perror("mnl_cb_run");
446 exit(EXIT_FAILURE);
447 }
448
449 mnl_socket_close(nl);
450
451 return 0;
452 }
453