--- /dev/null
+/*
+ * $Id$
+ */
+
+/*
+ * cangw.c - manage PF_CAN netlink gateway
+ *
+ * Copyright (c) 2010 Volkswagen Group Electronic Research
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <libgen.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/can/gw.h>
+
+enum {
+ UNSPEC,
+ ADD,
+ DEL,
+ FLUSH,
+ LIST
+};
+
+struct modattr {
+ struct can_frame cf;
+ __u8 modtype;
+ __u8 instruction;
+} __attribute__((packed));
+
+
+/* some netlink helpers stolen from iproute2 package */
+#define NLMSG_TAIL(nmsg) \
+ ((struct rtattr *)(((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
+
+int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
+ int alen)
+{
+ int len = RTA_LENGTH(alen);
+ struct rtattr *rta;
+
+ if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
+ fprintf(stderr, "addattr_l: message exceeded bound of %d\n",
+ maxlen);
+ return -1;
+ }
+ rta = NLMSG_TAIL(n);
+ rta->rta_type = type;
+ rta->rta_len = len;
+ memcpy(RTA_DATA(rta), data, alen);
+ n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
+ return 0;
+}
+
+void print_usage(char *prg)
+{
+ fprintf(stderr, "\nUsage: %s [options]\n\n", prg);
+ fprintf(stderr, "Commands: -A (add a new rule)\n");
+ fprintf(stderr, " -D (delete a rule) [not yet implemented]\n");
+ fprintf(stderr, " -F (flush - delete all rules) [not yet implemented]\n");
+ fprintf(stderr, " -L (list all rules) [not yet implemented]\n");
+ fprintf(stderr, "Mandatory: -s <src_dev> (source netdevice)\n");
+ fprintf(stderr, " -d <dst_dev> (destination netdevice)\n");
+ fprintf(stderr, "Options: -t (preserve src_dev rx timestamp)\n");
+ fprintf(stderr, " -e (echo sent frames - recommended on vcanx)\n");
+ fprintf(stderr, " -f <filter> (set CAN filter)\n");
+ fprintf(stderr, " -m <mod> (set frame modifications)\n");
+ fprintf(stderr, "\nValues are given and expected in hexadecimal values. Leading 0s can be omitted.\n");
+ fprintf(stderr, "\n");
+ fprintf(stderr, "<filter> is a <value>:<mask> CAN identifier filter\n");
+ fprintf(stderr, "\n");
+ fprintf(stderr, "<mod> is a CAN frame modification instruction consisting of\n");
+ fprintf(stderr, "<instruction>:<can_frame-elements>:<can_id>.<can_dlc>.<can_data>\n");
+ fprintf(stderr, " - <instruction> is one of 'AND' 'OR' 'XOR' 'SET'\n");
+ fprintf(stderr, " - <can_frame-elements> is _one_ or _more_ of 'I'dentifier 'L'ength 'D'ata\n");
+ fprintf(stderr, " - <can_id> is an u32 value containing the CAN Identifier\n");
+ fprintf(stderr, " - <can_dlc> is an u8 value containing the data length code (0 .. 8)\n");
+ fprintf(stderr, " - <can_data> is always eight(!) u8 values containing the CAN frames data\n");
+ fprintf(stderr, "The instructions are performed in the order 'AND' -> 'OR' -> 'XOR' -> 'SET'\n");
+ fprintf(stderr, "\n");
+ fprintf(stderr, "Example:\n");
+ fprintf(stderr, "%s -A -s can0 -d vcan3 -f 123:C00007FF -m SET:IL:80000333.4.1122334455667788\n", prg);
+ fprintf(stderr, "\n");
+}
+
+int parse_mod(char *optarg, struct modattr *modmsg)
+{
+ char *ptr, *nptr;
+ int i;
+
+ char hexdata[17] = {0};
+
+ ptr = optarg;
+ nptr = strchr(ptr, ':');
+
+ if ((nptr - ptr > 3) || (nptr - ptr == 0))
+ return 1;
+
+ if (!strncmp(ptr, "AND", 3))
+ modmsg->instruction = CGW_MOD_AND;
+ else if (!strncmp(ptr, "OR", 2))
+ modmsg->instruction = CGW_MOD_OR;
+ else if (!strncmp(ptr, "XOR", 3))
+ modmsg->instruction = CGW_MOD_XOR;
+ else if (!strncmp(ptr, "SET", 3))
+ modmsg->instruction = CGW_MOD_SET;
+ else
+ return 2;
+
+ ptr = nptr+1;
+ nptr = strchr(ptr, ':');
+
+ if ((nptr - ptr > 3) || (nptr - ptr == 0))
+ return 3;
+
+ modmsg->modtype = 0;
+
+ while (*ptr != ':') {
+
+ switch (*ptr) {
+
+ case 'I':
+ modmsg->modtype |= CGW_MOD_ID;
+ break;
+
+ case 'L':
+ modmsg->modtype |= CGW_MOD_DLC;
+ break;
+
+ case 'D':
+ modmsg->modtype |= CGW_MOD_DATA;
+ break;
+
+ default:
+ return 4;
+ }
+ ptr++;
+ }
+
+ if ((sscanf(++ptr, "%lx.%hhd.%16s",
+ (long unsigned int *)&modmsg->cf.can_id,
+ (unsigned char *)&modmsg->cf.can_dlc, hexdata) != 3) ||
+ (modmsg->cf.can_dlc > 8))
+ return 5;
+
+ if (strlen(hexdata) != 16)
+ return 6;
+
+ for (i = 0; i < 8; i++) {
+ if (!sscanf(&hexdata[i*2], "%2hhx", &modmsg->cf.data[i]))
+ return 7;
+ }
+
+ return 0; /* ok */
+}
+
+int main(int argc, char **argv)
+{
+ int s;
+ int err = 0;
+
+ int opt;
+ extern int optind, opterr, optopt;
+
+ int cmd = UNSPEC;
+ int have_filter = 0;
+
+ struct {
+ struct nlmsghdr n;
+ struct rtcanmsg r;
+ char buf[200];
+
+ } req;
+
+ struct can_filter filter;
+ struct sockaddr_nl nladdr;
+
+ struct modattr modmsg[CGW_MOD_FUNCS];
+ int modidx = 0;
+ int i;
+
+ memset(&req, 0, sizeof(req));
+
+ while ((opt = getopt(argc, argv, "ADFLs:d:tef:m:?")) != -1) {
+ switch (opt) {
+
+ case 'A':
+ if (cmd == UNSPEC)
+ cmd = ADD;
+ break;
+
+ case 'D':
+ if (cmd == UNSPEC)
+ cmd = DEL;
+ break;
+
+ case 'F':
+ if (cmd == UNSPEC)
+ cmd = FLUSH;
+ break;
+
+ case 'L':
+ if (cmd == UNSPEC)
+ cmd = LIST;
+ break;
+
+ case 's':
+ req.r.src_ifindex = if_nametoindex(optarg);
+ break;
+
+ case 'd':
+ req.r.dst_ifindex = if_nametoindex(optarg);
+ break;
+
+ case 't':
+ req.r.can_txflags |= CAN_GW_TXFLAGS_SRC_TSTAMP;
+ break;
+
+ case 'e':
+ req.r.can_txflags |= CAN_GW_TXFLAGS_ECHO;
+ break;
+
+ case 'f':
+ if (sscanf(optarg, "%lx:%lx",
+ (long unsigned int *)&filter.can_id,
+ (long unsigned int *)&filter.can_mask) == 2) {
+ have_filter = 1;
+ } else {
+ printf("Bad filter definition '%s'.\n", optarg);
+ exit(1);
+ }
+ break;
+
+ case 'm':
+ /* may be triggered by each of the CGW_MOD_FUNCS functions */
+ if ((modidx < CGW_MOD_FUNCS) && (err = parse_mod(optarg, &modmsg[modidx++]))) {
+ printf("Problem %d with modification definition '%s'.\n", err, optarg);
+ exit(1);
+ }
+ break;
+
+ case '?':
+ print_usage(basename(argv[0]));
+ exit(0);
+ break;
+
+ default:
+ fprintf(stderr, "Unknown option %c\n", opt);
+ print_usage(basename(argv[0]));
+ exit(1);
+ break;
+ }
+ }
+
+ if ((argc - optind != 0) || (cmd == UNSPEC) ||
+ (!req.r.src_ifindex) || (!req.r.dst_ifindex)) {
+ print_usage(basename(argv[0]));
+ exit(1);
+ }
+
+ s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+
+ switch (cmd) {
+
+ case ADD:
+ req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
+ req.n.nlmsg_type = RTM_NEWROUTE;
+ break;
+
+ default:
+ printf("This function is not yet implemented.\n");
+ exit(1);
+ break;
+ }
+
+ req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtcanmsg));
+ req.n.nlmsg_seq = 0;
+
+ req.r.can_family = AF_CAN;
+
+ /* add new attributes here */
+
+ if (have_filter)
+ addattr_l(&req.n, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
+
+ // a better example code
+ // modmsg.modtype = CGW_MOD_ID;
+ // addattr_l(&req.n, sizeof(req), CGW_MOD_SET, &modmsg, CGW_MODATTR_LEN);
+
+ /* add up to CGW_MOD_FUNCS modification definitions */
+ for (i = 0; i < modidx; i++)
+ addattr_l(&req.n, sizeof(req), modmsg[i].instruction, &modmsg[i], CGW_MODATTR_LEN);
+
+ memset(&nladdr, 0, sizeof(nladdr));
+ nladdr.nl_family = AF_NETLINK;
+ nladdr.nl_pid = 0;
+ nladdr.nl_groups = 0;
+
+ err = sendto(s, &req, req.n.nlmsg_len, 0,
+ (struct sockaddr*)&nladdr, sizeof(nladdr));
+
+ if (err < 0)
+ perror("PF_CAN netlink gateway answered ");
+
+ close(s);
+
+ return err;
+}
+
projects / sojka / can-utils.git / commitdiff