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 <linux-can@vger.kernel.org>
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->init_xor_val);
141 void print_cs_crc8_profile(struct cgw_csum_crc8 *cs_crc8)
145 printf("-p %d:", cs_crc8->profile);
147 switch (cs_crc8->profile) {
149 case CGW_CRC8PRF_1U8:
151 printf("%02X", cs_crc8->profile_data[0]);
154 case CGW_CRC8PRF_16U8:
156 for (i = 0; i < 16; i++)
157 printf("%02X", cs_crc8->profile_data[i]);
160 case CGW_CRC8PRF_SFFID_XOR:
164 printf("<unknown profile #%d>", cs_crc8->profile);
170 void print_cs_crc8(struct cgw_csum_crc8 *cs_crc8)
174 printf("-c %d:%d:%d:%02X:%02X:",
175 cs_crc8->from_idx, cs_crc8->to_idx,
176 cs_crc8->result_idx, cs_crc8->init_crc_val,
177 cs_crc8->final_xor_val);
179 for (i = 0; i < 256; i++)
180 printf("%02X", cs_crc8->crctab[i]);
184 if (cs_crc8->profile != CGW_CRC8PRF_UNSPEC)
185 print_cs_crc8_profile(cs_crc8);
188 void print_usage(char *prg)
190 fprintf(stderr, "\nUsage: %s [options]\n\n", prg);
191 fprintf(stderr, "Commands: -A (add a new rule)\n");
192 fprintf(stderr, " -D (delete a rule)\n");
193 fprintf(stderr, " -F (flush / delete all rules)\n");
194 fprintf(stderr, " -L (list all rules)\n");
195 fprintf(stderr, "Mandatory: -s <src_dev> (source netdevice)\n");
196 fprintf(stderr, " -d <dst_dev> (destination netdevice)\n");
197 fprintf(stderr, "Options: -t (preserve src_dev rx timestamp)\n");
198 fprintf(stderr, " -e (echo sent frames - recommended on vcanx)\n");
199 fprintf(stderr, " -f <filter> (set CAN filter)\n");
200 fprintf(stderr, " -m <mod> (set frame modifications)\n");
201 fprintf(stderr, " -x <from_idx>:<to_idx>:<result_idx>:<init_xor_val> (XOR checksum)\n");
202 fprintf(stderr, " -c <from>:<to>:<result>:<init_val>:<xor_val>:<crctab[256]> (CRC8 cs)\n");
203 fprintf(stderr, " -p <profile>:[<profile_data>] (CRC8 checksum profile & parameters)\n");
204 fprintf(stderr, "\nValues are given and expected in hexadecimal values. Leading 0s can be omitted.\n");
205 fprintf(stderr, "\n");
206 fprintf(stderr, "<filter> is a <value><mask> CAN identifier filter\n");
207 fprintf(stderr, " <can_id>:<can_mask> (matches when <received_can_id> & mask == can_id & mask)\n");
208 fprintf(stderr, " <can_id>~<can_mask> (matches when <received_can_id> & mask != can_id & mask)\n");
209 fprintf(stderr, "\n");
210 fprintf(stderr, "<mod> is a CAN frame modification instruction consisting of\n");
211 fprintf(stderr, "<instruction>:<can_frame-elements>:<can_id>.<can_dlc>.<can_data>\n");
212 fprintf(stderr, " - <instruction> is one of 'AND' 'OR' 'XOR' 'SET'\n");
213 fprintf(stderr, " - <can_frame-elements> is _one_ or _more_ of 'I'dentifier 'L'ength 'D'ata\n");
214 fprintf(stderr, " - <can_id> is an u32 value containing the CAN Identifier\n");
215 fprintf(stderr, " - <can_dlc> is an u8 value containing the data length code (0 .. 8)\n");
216 fprintf(stderr, " - <can_data> is always eight(!) u8 values containing the CAN frames data\n");
217 fprintf(stderr, "The max. four modifications are performed in the order AND -> OR -> XOR -> SET\n");
218 fprintf(stderr, "\n");
219 fprintf(stderr, "Example:\n");
220 fprintf(stderr, "%s -A -s can0 -d vcan3 -e -f 123:C00007FF -m SET:IL:333.4.1122334455667788\n", prg);
221 fprintf(stderr, "\n");
222 fprintf(stderr, "Supported CRC 8 profiles:\n");
223 fprintf(stderr, "Profile '%d' (1U8) - add one additional u8 value\n", CGW_CRC8PRF_1U8);
224 fprintf(stderr, "Profile '%d' (16U8) - add u8 value from table[16] indexed by (data[1] & 0xF)\n", CGW_CRC8PRF_16U8);
225 fprintf(stderr, "Profile '%d' (SFFID_XOR) - add u8 value (can_id & 0xFF) ^ (can_id >> 8 & 0xFF)\n", CGW_CRC8PRF_SFFID_XOR);
226 fprintf(stderr, "\n");
229 int b64hex(char *asc, unsigned char *bin, int len)
233 for (i = 0; i < len; i++) {
234 if (!sscanf(asc+(i*2), "%2hhx", bin+i))
240 int parse_crc8_profile(char *optarg, struct cgw_csum_crc8 *crc8)
245 if (sscanf(optarg, "%hhd:", &crc8->profile) != 1)
248 switch (crc8->profile) {
250 case CGW_CRC8PRF_1U8:
252 if (sscanf(optarg, "%hhd:%2hhx", &crc8->profile, &crc8->profile_data[0]) == 2)
257 case CGW_CRC8PRF_16U8:
259 ptr = strchr(optarg, ':');
261 /* check if length contains 16 base64 hex values */
263 strlen(ptr) == strlen(":00112233445566778899AABBCCDDEEFF") &&
264 b64hex(ptr+1, (unsigned char *)&crc8->profile_data[0], 16) == 0)
269 case CGW_CRC8PRF_SFFID_XOR:
271 /* no additional parameters needed */
279 int parse_mod(char *optarg, struct modattr *modmsg)
282 char hexdata[17] = {0};
285 nptr = strchr(ptr, ':');
287 if ((nptr - ptr > 3) || (nptr - ptr == 0))
290 if (!strncmp(ptr, "AND", 3))
291 modmsg->instruction = CGW_MOD_AND;
292 else if (!strncmp(ptr, "OR", 2))
293 modmsg->instruction = CGW_MOD_OR;
294 else if (!strncmp(ptr, "XOR", 3))
295 modmsg->instruction = CGW_MOD_XOR;
296 else if (!strncmp(ptr, "SET", 3))
297 modmsg->instruction = CGW_MOD_SET;
302 nptr = strchr(ptr, ':');
304 if ((nptr - ptr > 3) || (nptr - ptr == 0))
309 while (*ptr != ':') {
314 modmsg->modtype |= CGW_MOD_ID;
318 modmsg->modtype |= CGW_MOD_DLC;
322 modmsg->modtype |= CGW_MOD_DATA;
331 if (sscanf(++ptr, "%x.%hhx.%16s", &modmsg->cf.can_id,
332 (unsigned char *)&modmsg->cf.can_dlc, hexdata) != 3)
335 /* 4-bit masks can have values from 0 to 0xF */
336 if (modmsg->cf.can_dlc > 0xF)
339 /* but when setting CAN_DLC the value has to be limited to 8 */
340 if (modmsg->instruction == CGW_MOD_SET && modmsg->cf.can_dlc > 8)
343 if (strlen(hexdata) != 16)
346 if (b64hex(hexdata, &modmsg->cf.data[0], 8))
352 int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
354 char ifname[IF_NAMESIZE]; /* internface name for if_indextoname() */
355 struct rtcanmsg *rtc;
357 struct nlmsghdr *nlh;
358 unsigned int src_ifindex = 0;
359 unsigned int dst_ifindex = 0;
360 __u32 handled, dropped;
364 nlh = (struct nlmsghdr *)rxbuf;
367 if (!NLMSG_OK(nlh, len))
370 if (nlh->nlmsg_type == NLMSG_ERROR) {
371 printf("NLMSG_ERROR\n");
375 if (nlh->nlmsg_type == NLMSG_DONE) {
376 //printf("NLMSG_DONE\n");
380 rtc = (struct rtcanmsg *)NLMSG_DATA(nlh);
381 if (rtc->can_family != AF_CAN) {
382 printf("received msg from unknown family %d\n", rtc->can_family);
386 if (rtc->gwtype != CGW_TYPE_CAN_CAN) {
387 printf("received msg with unknown gwtype %d\n", rtc->gwtype);
392 * print list in a representation that
393 * can be used directly for start scripts.
395 * To order the mandatory and optional parameters in the
396 * output string, the NLMSG is parsed twice.
404 printf("%s -A ", basename(prgname));
406 /* first parse for mandatory options */
407 rta = (struct rtattr *) RTCAN_RTA(rtc);
408 rtlen = RTCAN_PAYLOAD(nlh);
409 for(;RTA_OK(rta, rtlen);rta=RTA_NEXT(rta,rtlen))
411 //printf("(A-%d)", rta->rta_type);
412 switch(rta->rta_type) {
424 src_ifindex = *(__u32 *)RTA_DATA(rta);
428 dst_ifindex = *(__u32 *)RTA_DATA(rta);
432 handled = *(__u32 *)RTA_DATA(rta);
436 dropped = *(__u32 *)RTA_DATA(rta);
440 printf("Unknown attribute %d!", rta->rta_type);
447 printf("-s %s ", if_indextoname(src_ifindex, ifname));
448 printf("-d %s ", if_indextoname(dst_ifindex, ifname));
450 if (rtc->flags & CGW_FLAGS_CAN_ECHO)
453 if (rtc->flags & CGW_FLAGS_CAN_SRC_TSTAMP)
456 /* second parse for mod attributes */
457 rta = (struct rtattr *) RTCAN_RTA(rtc);
458 rtlen = RTCAN_PAYLOAD(nlh);
459 for(;RTA_OK(rta, rtlen);rta=RTA_NEXT(rta,rtlen))
461 //printf("(B-%d)", rta->rta_type);
462 switch(rta->rta_type) {
465 printfilter(RTA_DATA(rta));
469 printmod("AND", RTA_DATA(rta));
473 printmod("OR", RTA_DATA(rta));
477 printmod("XOR", RTA_DATA(rta));
481 printmod("SET", RTA_DATA(rta));
485 print_cs_xor((struct cgw_csum_xor *)RTA_DATA(rta));
489 print_cs_crc8((struct cgw_csum_crc8 *)RTA_DATA(rta));
499 printf("Unknown attribute %d!", rta->rta_type);
505 printf("# %d handled %d dropped\n", handled, dropped); /* end of entry */
507 /* jump to next NLMSG in the given buffer */
508 nlh = NLMSG_NEXT(nlh, len);
512 int main(int argc, char **argv)
518 extern int optind, opterr, optopt;
523 int have_cs_crc8 = 0;
527 struct rtcanmsg rtcan;
532 unsigned char rxbuf[8192]; /* netlink receive buffer */
533 struct nlmsghdr *nlh;
534 struct nlmsgerr *rte;
535 unsigned int src_ifindex = 0;
536 unsigned int dst_ifindex = 0;
540 struct can_filter filter;
541 struct sockaddr_nl nladdr;
543 struct cgw_csum_xor cs_xor;
544 struct cgw_csum_crc8 cs_crc8;
545 char crc8tab[513] = {0};
547 struct modattr modmsg[CGW_MOD_FUNCS];
551 memset(&req, 0, sizeof(req));
552 memset(&cs_xor, 0, sizeof(cs_xor));
553 memset(&cs_crc8, 0, sizeof(cs_crc8));
555 while ((opt = getopt(argc, argv, "ADFLs:d:tef:c:p:x:m:?")) != -1) {
579 src_ifindex = if_nametoindex(optarg);
583 dst_ifindex = if_nametoindex(optarg);
587 flags |= CGW_FLAGS_CAN_SRC_TSTAMP;
591 flags |= CGW_FLAGS_CAN_ECHO;
595 if (sscanf(optarg, "%x:%x", &filter.can_id,
596 &filter.can_mask) == 2) {
598 } else if (sscanf(optarg, "%x~%x", &filter.can_id,
599 &filter.can_mask) == 2) {
600 filter.can_id |= CAN_INV_FILTER;
603 printf("Bad filter definition '%s'.\n", optarg);
609 if (sscanf(optarg, "%hhd:%hhd:%hhd:%hhx",
610 &cs_xor.from_idx, &cs_xor.to_idx,
611 &cs_xor.result_idx, &cs_xor.init_xor_val) == 4) {
614 printf("Bad XOR checksum definition '%s'.\n", optarg);
620 if ((sscanf(optarg, "%hhd:%hhd:%hhd:%hhx:%hhx:%512s",
621 &cs_crc8.from_idx, &cs_crc8.to_idx,
622 &cs_crc8.result_idx, &cs_crc8.init_crc_val,
623 &cs_crc8.final_xor_val, crc8tab) == 6) &&
624 (strlen(crc8tab) == 512) &&
625 (b64hex(crc8tab, (unsigned char *)&cs_crc8.crctab, 256) == 0)) {
628 printf("Bad CRC8 checksum definition '%s'.\n", optarg);
634 if (parse_crc8_profile(optarg, &cs_crc8)) {
635 printf("Bad CRC8 profile definition '%s'.\n", optarg);
641 /* may be triggered by each of the CGW_MOD_FUNCS functions */
642 if ((modidx < CGW_MOD_FUNCS) && (err = parse_mod(optarg, &modmsg[modidx++]))) {
643 printf("Problem %d with modification definition '%s'.\n", err, optarg);
649 print_usage(basename(argv[0]));
654 fprintf(stderr, "Unknown option %c\n", opt);
655 print_usage(basename(argv[0]));
661 if ((argc - optind != 0) || (cmd == UNSPEC)) {
662 print_usage(basename(argv[0]));
666 if ((cmd == ADD || cmd == DEL) &&
667 ((!src_ifindex) || (!dst_ifindex))) {
668 print_usage(basename(argv[0]));
672 if (!modidx && (have_cs_crc8 || have_cs_xor)) {
673 printf("-c or -x can only be used in conjunction with -m\n");
677 s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
682 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
683 req.nh.nlmsg_type = RTM_NEWROUTE;
687 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
688 req.nh.nlmsg_type = RTM_DELROUTE;
692 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
693 req.nh.nlmsg_type = RTM_DELROUTE;
694 /* if_index set to 0 => remove all entries */
700 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
701 req.nh.nlmsg_type = RTM_GETROUTE;
705 printf("This function is not yet implemented.\n");
710 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtcanmsg));
711 req.nh.nlmsg_seq = 0;
713 req.rtcan.can_family = AF_CAN;
714 req.rtcan.gwtype = CGW_TYPE_CAN_CAN;
715 req.rtcan.flags = flags;
717 addattr_l(&req.nh, sizeof(req), CGW_SRC_IF, &src_ifindex, sizeof(src_ifindex));
718 addattr_l(&req.nh, sizeof(req), CGW_DST_IF, &dst_ifindex, sizeof(dst_ifindex));
720 /* add new attributes here */
723 addattr_l(&req.nh, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
726 addattr_l(&req.nh, sizeof(req), CGW_CS_CRC8, &cs_crc8, sizeof(cs_crc8));
729 addattr_l(&req.nh, sizeof(req), CGW_CS_XOR, &cs_xor, sizeof(cs_xor));
732 * a better example code
733 * modmsg.modtype = CGW_MOD_ID;
734 * addattr_l(&req.n, sizeof(req), CGW_MOD_SET, &modmsg, CGW_MODATTR_LEN);
737 /* add up to CGW_MOD_FUNCS modification definitions */
738 for (i = 0; i < modidx; i++)
739 addattr_l(&req.nh, sizeof(req), modmsg[i].instruction, &modmsg[i], CGW_MODATTR_LEN);
741 memset(&nladdr, 0, sizeof(nladdr));
742 nladdr.nl_family = AF_NETLINK;
744 nladdr.nl_groups = 0;
746 err = sendto(s, &req, req.nh.nlmsg_len, 0,
747 (struct sockaddr*)&nladdr, sizeof(nladdr));
749 perror("netlink sendto");
753 /* clean netlink receive buffer */
754 memset(rxbuf, 0x0, sizeof(rxbuf));
759 * cmd == ADD || cmd == DEL || cmd == FLUSH
761 * Parse the requested netlink acknowledge return values.
764 err = recv(s, &rxbuf, sizeof(rxbuf), 0);
766 perror("netlink recv");
769 nlh = (struct nlmsghdr *)rxbuf;
770 if (nlh->nlmsg_type != NLMSG_ERROR) {
771 fprintf(stderr, "unexpected netlink answer of type %d\n", nlh->nlmsg_type);
774 rte = (struct nlmsgerr *)NLMSG_DATA(nlh);
777 fprintf(stderr, "netlink error %d (%s)\n", err, strerror(abs(err)));
784 len = recv(s, &rxbuf, sizeof(rxbuf), 0);
786 perror("netlink recv");
790 printf("received msg len %d\n", len);
792 for (i = 0; i < len; i++)
793 printf("%02X ", rxbuf[i]);
797 /* leave on errors or NLMSG_DONE */
798 if (parse_rtlist(argv[0], rxbuf, len))