6 * cangw.c - manage PF_CAN netlink gateway
8 * Copyright (c) 2010 Volkswagen Group Electronic Research
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of Volkswagen nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * Alternatively, provided that this notice is retained in full, this
24 * software may be distributed under the terms of the GNU General
25 * Public License ("GPL") version 2, in which case the provisions of the
26 * GPL apply INSTEAD OF those given above.
28 * The provided data structures and external interfaces from this code
29 * are not restricted to be used by modules with a GPL compatible license.
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
41 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
44 * Send feedback to <socketcan-users@lists.berlios.de>
54 #include <sys/socket.h>
56 #include <linux/netlink.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/can/gw.h>
72 } __attribute__((packed));
75 #define RTCAN_RTA(r) ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct rtcanmsg))))
76 #define RTCAN_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct rtcanmsg))
78 /* some netlink helpers stolen from iproute2 package */
79 #define NLMSG_TAIL(nmsg) \
80 ((struct rtattr *)(((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
82 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
85 int len = RTA_LENGTH(alen);
88 if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
89 fprintf(stderr, "addattr_l: message exceeded bound of %d\n",
96 memcpy(RTA_DATA(rta), data, alen);
97 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
101 void printfilter(const void *data)
103 struct can_filter *filter = (struct can_filter *)data;
105 printf("-f %03X:%X ", filter->can_id, filter->can_mask);
108 void printmod(const char *type, const void *data)
113 memcpy (&mod, data, CGW_MODATTR_LEN);
115 printf("-m %s:", type);
117 if (mod.modtype & CGW_MOD_ID)
120 if (mod.modtype & CGW_MOD_DLC)
123 if (mod.modtype & CGW_MOD_DATA)
126 printf(":%03X.%X.", mod.cf.can_id, mod.cf.can_dlc);
128 for (i = 0; i < 8; i++)
129 printf("%02X", mod.cf.data[i]);
134 void print_cs_xor(struct cgw_csum_xor *cs_xor)
136 printf("-x %d:%d:%d:%02X ",
137 cs_xor->from_idx, cs_xor->to_idx,
138 cs_xor->result_idx, cs_xor->prefix_value);
141 void print_cs_crc8(struct cgw_csum_crc8 *cs_crc8)
145 printf("-c %d:%d:%d:",
146 cs_crc8->from_idx, cs_crc8->to_idx,
147 cs_crc8->result_idx);
149 for (i = 0; i < 256; i++)
150 printf("%02X", cs_crc8->crctab[i]);
155 void print_usage(char *prg)
157 fprintf(stderr, "\nUsage: %s [options]\n\n", prg);
158 fprintf(stderr, "Commands: -A (add a new rule)\n");
159 fprintf(stderr, " -D (delete a rule)\n");
160 fprintf(stderr, " -F (flush / delete all rules)\n");
161 fprintf(stderr, " -L (list all rules)\n");
162 fprintf(stderr, "Mandatory: -s <src_dev> (source netdevice)\n");
163 fprintf(stderr, " -d <dst_dev> (destination netdevice)\n");
164 fprintf(stderr, "Options: -t (preserve src_dev rx timestamp)\n");
165 fprintf(stderr, " -e (echo sent frames - recommended on vcanx)\n");
166 fprintf(stderr, " -f <filter> (set CAN filter)\n");
167 fprintf(stderr, " -m <mod> (set frame modifications)\n");
168 fprintf(stderr, "\nValues are given and expected in hexadecimal values. Leading 0s can be omitted.\n");
169 fprintf(stderr, "\n");
170 fprintf(stderr, "<filter> is a <value>:<mask> CAN identifier filter\n");
171 fprintf(stderr, "\n");
172 fprintf(stderr, "<mod> is a CAN frame modification instruction consisting of\n");
173 fprintf(stderr, "<instruction>:<can_frame-elements>:<can_id>.<can_dlc>.<can_data>\n");
174 fprintf(stderr, " - <instruction> is one of 'AND' 'OR' 'XOR' 'SET'\n");
175 fprintf(stderr, " - <can_frame-elements> is _one_ or _more_ of 'I'dentifier 'L'ength 'D'ata\n");
176 fprintf(stderr, " - <can_id> is an u32 value containing the CAN Identifier\n");
177 fprintf(stderr, " - <can_dlc> is an u8 value containing the data length code (0 .. 8)\n");
178 fprintf(stderr, " - <can_data> is always eight(!) u8 values containing the CAN frames data\n");
179 fprintf(stderr, "The max. four modifications are performed in the order AND -> OR -> XOR -> SET\n");
180 fprintf(stderr, "\n");
181 fprintf(stderr, "Example:\n");
182 fprintf(stderr, "%s -A -s can0 -d vcan3 -e -f 123:C00007FF -m SET:IL:333.4.1122334455667788\n", prg);
183 fprintf(stderr, "\n");
186 int b64hex(char *asc, unsigned char *bin, int len)
190 for (i = 0; i < len; i++) {
191 if (!sscanf(asc+(i*2), "%2hhx", bin+i))
197 int parse_mod(char *optarg, struct modattr *modmsg)
200 char hexdata[17] = {0};
203 nptr = strchr(ptr, ':');
205 if ((nptr - ptr > 3) || (nptr - ptr == 0))
208 if (!strncmp(ptr, "AND", 3))
209 modmsg->instruction = CGW_MOD_AND;
210 else if (!strncmp(ptr, "OR", 2))
211 modmsg->instruction = CGW_MOD_OR;
212 else if (!strncmp(ptr, "XOR", 3))
213 modmsg->instruction = CGW_MOD_XOR;
214 else if (!strncmp(ptr, "SET", 3))
215 modmsg->instruction = CGW_MOD_SET;
220 nptr = strchr(ptr, ':');
222 if ((nptr - ptr > 3) || (nptr - ptr == 0))
227 while (*ptr != ':') {
232 modmsg->modtype |= CGW_MOD_ID;
236 modmsg->modtype |= CGW_MOD_DLC;
240 modmsg->modtype |= CGW_MOD_DATA;
249 if ((sscanf(++ptr, "%lx.%hhd.%16s",
250 (long unsigned int *)&modmsg->cf.can_id,
251 (unsigned char *)&modmsg->cf.can_dlc, hexdata) != 3) ||
252 (modmsg->cf.can_dlc > 8))
255 if (strlen(hexdata) != 16)
258 if (b64hex(hexdata, &modmsg->cf.data[0], 8))
264 int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
266 char ifname[IF_NAMESIZE]; /* internface name for if_indextoname() */
267 struct rtcanmsg *rtc;
269 struct nlmsghdr *nlh;
270 unsigned int src_ifindex = 0;
271 unsigned int dst_ifindex = 0;
272 __u32 handled, dropped;
276 nlh = (struct nlmsghdr *)rxbuf;
279 if (!NLMSG_OK(nlh, len))
282 if (nlh->nlmsg_type == NLMSG_ERROR) {
283 printf("NLMSG_ERROR\n");
287 if (nlh->nlmsg_type == NLMSG_DONE) {
288 //printf("NLMSG_DONE\n");
292 rtc = (struct rtcanmsg *)NLMSG_DATA(nlh);
293 if (rtc->can_family != AF_CAN) {
294 printf("received msg from unknown family %d\n", rtc->can_family);
298 if (rtc->gwtype != CGW_TYPE_CAN_CAN) {
299 printf("received msg with unknown gwtype %d\n", rtc->gwtype);
304 * print list in a representation that
305 * can be used directly for start scripts.
307 * To order the mandatory and optional parameters in the
308 * output string, the NLMSG is parsed twice.
316 printf("%s -A ", basename(prgname));
318 /* first parse for mandatory options */
319 rta = (struct rtattr *) RTCAN_RTA(rtc);
320 rtlen = RTCAN_PAYLOAD(nlh);
321 for(;RTA_OK(rta, rtlen);rta=RTA_NEXT(rta,rtlen))
323 //printf("(A-%d)", rta->rta_type);
324 switch(rta->rta_type) {
336 src_ifindex = *(__u32 *)RTA_DATA(rta);
340 dst_ifindex = *(__u32 *)RTA_DATA(rta);
344 handled = *(__u32 *)RTA_DATA(rta);
348 dropped = *(__u32 *)RTA_DATA(rta);
352 printf("Unknown attribute %d!", rta->rta_type);
359 printf("-s %s ", if_indextoname(src_ifindex, ifname));
360 printf("-d %s ", if_indextoname(dst_ifindex, ifname));
362 if (rtc->flags & CGW_FLAGS_CAN_ECHO)
365 if (rtc->flags & CGW_FLAGS_CAN_SRC_TSTAMP)
368 /* second parse for mod attributes */
369 rta = (struct rtattr *) RTCAN_RTA(rtc);
370 rtlen = RTCAN_PAYLOAD(nlh);
371 for(;RTA_OK(rta, rtlen);rta=RTA_NEXT(rta,rtlen))
373 //printf("(B-%d)", rta->rta_type);
374 switch(rta->rta_type) {
377 printfilter(RTA_DATA(rta));
381 printmod("AND", RTA_DATA(rta));
385 printmod("OR", RTA_DATA(rta));
389 printmod("XOR", RTA_DATA(rta));
393 printmod("SET", RTA_DATA(rta));
397 print_cs_xor((struct cgw_csum_xor *)RTA_DATA(rta));
401 print_cs_crc8((struct cgw_csum_crc8 *)RTA_DATA(rta));
411 printf("Unknown attribute %d!", rta->rta_type);
417 printf("# %d handled %d dropped\n", handled, dropped); /* end of entry */
419 /* jump to next NLMSG in the given buffer */
420 nlh = NLMSG_NEXT(nlh, len);
424 int main(int argc, char **argv)
430 extern int optind, opterr, optopt;
435 int have_cs_crc8 = 0;
439 struct rtcanmsg rtcan;
444 unsigned char rxbuf[8192]; /* netlink receive buffer */
445 struct nlmsghdr *nlh;
446 struct nlmsgerr *rte;
447 unsigned int src_ifindex = 0;
448 unsigned int dst_ifindex = 0;
452 struct can_filter filter;
453 struct sockaddr_nl nladdr;
455 struct cgw_csum_xor cs_xor;
456 struct cgw_csum_crc8 cs_crc8;
457 char crc8tab[513] = {0};
459 struct modattr modmsg[CGW_MOD_FUNCS];
463 memset(&req, 0, sizeof(req));
465 while ((opt = getopt(argc, argv, "ADFLs:d:tef:c:x:m:?")) != -1) {
489 src_ifindex = if_nametoindex(optarg);
493 dst_ifindex = if_nametoindex(optarg);
497 flags |= CGW_FLAGS_CAN_SRC_TSTAMP;
501 flags |= CGW_FLAGS_CAN_ECHO;
505 if (sscanf(optarg, "%lx:%lx",
506 (long unsigned int *)&filter.can_id,
507 (long unsigned int *)&filter.can_mask) == 2) {
510 printf("Bad filter definition '%s'.\n", optarg);
516 if (sscanf(optarg, "%hhd:%hhd:%hhd:%hhx",
517 &cs_xor.from_idx, &cs_xor.to_idx,
518 &cs_xor.result_idx, &cs_xor.prefix_value) == 4) {
521 printf("Bad XOR checksum definition '%s'.\n", optarg);
527 if ((sscanf(optarg, "%hhd:%hhd:%hhd:%512s",
528 &cs_crc8.from_idx, &cs_crc8.to_idx,
529 &cs_crc8.result_idx, crc8tab) == 4) &&
530 (strlen(crc8tab) == 512) &&
531 (b64hex(crc8tab, (unsigned char *)&cs_crc8.crctab, 256) == 0)) {
534 printf("Bad CRC8 checksum definition '%s'.\n", optarg);
540 /* may be triggered by each of the CGW_MOD_FUNCS functions */
541 if ((modidx < CGW_MOD_FUNCS) && (err = parse_mod(optarg, &modmsg[modidx++]))) {
542 printf("Problem %d with modification definition '%s'.\n", err, optarg);
548 print_usage(basename(argv[0]));
553 fprintf(stderr, "Unknown option %c\n", opt);
554 print_usage(basename(argv[0]));
560 if ((argc - optind != 0) || (cmd == UNSPEC)) {
561 print_usage(basename(argv[0]));
565 if ((cmd == ADD || cmd == DEL) &&
566 ((!src_ifindex) || (!dst_ifindex))) {
567 print_usage(basename(argv[0]));
571 s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
576 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
577 req.nh.nlmsg_type = RTM_NEWROUTE;
581 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
582 req.nh.nlmsg_type = RTM_DELROUTE;
586 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
587 req.nh.nlmsg_type = RTM_DELROUTE;
588 /* if_index set to 0 => remove all entries */
594 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
595 req.nh.nlmsg_type = RTM_GETROUTE;
599 printf("This function is not yet implemented.\n");
604 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtcanmsg));
605 req.nh.nlmsg_seq = 0;
607 req.rtcan.can_family = AF_CAN;
608 req.rtcan.gwtype = CGW_TYPE_CAN_CAN;
609 req.rtcan.flags = flags;
611 addattr_l(&req.nh, sizeof(req), CGW_SRC_IF, &src_ifindex, sizeof(src_ifindex));
612 addattr_l(&req.nh, sizeof(req), CGW_DST_IF, &dst_ifindex, sizeof(dst_ifindex));
614 /* add new attributes here */
617 addattr_l(&req.nh, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
620 addattr_l(&req.nh, sizeof(req), CGW_CS_XOR, &cs_xor, sizeof(cs_xor));
623 addattr_l(&req.nh, sizeof(req), CGW_CS_CRC8, &cs_crc8, sizeof(cs_crc8));
626 * a better example code
627 * modmsg.modtype = CGW_MOD_ID;
628 * addattr_l(&req.n, sizeof(req), CGW_MOD_SET, &modmsg, CGW_MODATTR_LEN);
631 /* add up to CGW_MOD_FUNCS modification definitions */
632 for (i = 0; i < modidx; i++)
633 addattr_l(&req.nh, sizeof(req), modmsg[i].instruction, &modmsg[i], CGW_MODATTR_LEN);
635 memset(&nladdr, 0, sizeof(nladdr));
636 nladdr.nl_family = AF_NETLINK;
638 nladdr.nl_groups = 0;
640 err = sendto(s, &req, req.nh.nlmsg_len, 0,
641 (struct sockaddr*)&nladdr, sizeof(nladdr));
643 perror("netlink sendto");
647 /* clean netlink receive buffer */
648 bzero(rxbuf, sizeof(rxbuf));
653 * cmd == ADD || cmd == DEL || cmd == FLUSH
655 * Parse the requested netlink acknowledge return values.
658 err = recv(s, &rxbuf, sizeof(rxbuf), 0);
660 perror("netlink recv");
663 nlh = (struct nlmsghdr *)rxbuf;
664 if (nlh->nlmsg_type != NLMSG_ERROR) {
665 fprintf(stderr, "unexpected netlink answer of type %d\n", nlh->nlmsg_type);
668 rte = (struct nlmsgerr *)NLMSG_DATA(nlh);
671 fprintf(stderr, "netlink error %d (%s)\n", err, strerror(abs(err)));
678 len = recv(s, &rxbuf, sizeof(rxbuf), 0);
680 perror("netlink recv");
684 printf("received msg len %d\n", len);
686 for (i = 0; i < len; i++)
687 printf("%02X ", rxbuf[i]);
691 /* leave on errors or NLMSG_DONE */
692 if (parse_rtlist(argv[0], rxbuf, len))