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can-utils
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Added netlink error message support to be able to provide return values. 

Renamed some structure elements. Updated usage text.
pull/7/head
Oliver Hartkopp 2010-02-21 12:34:34 +00:00
parent 0dc9fcc98e
commit bd1ebaaf28
1 changed files with 46 additions and 20 deletions
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64
cangw.c
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@ -99,7 +99,7 @@ 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, " -D (delete a rule)\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");
@ -209,12 +209,16 @@ int main(int argc, char **argv)
int have_filter = 0;
struct {
struct nlmsghdr n;
struct rtcanmsg r;
struct nlmsghdr nh;
struct rtcanmsg rtcan;
char buf[200];
} req;
char rxbuf[8192]; /* netlink receive buffer */
struct nlmsghdr *nlh;
struct nlmsgerr *rte;
struct can_filter filter;
struct sockaddr_nl nladdr;
@ -248,19 +252,19 @@ int main(int argc, char **argv)
break;
case 's':
req.r.src_ifindex = if_nametoindex(optarg);
req.rtcan.src_ifindex = if_nametoindex(optarg);
break;
case 'd':
req.r.dst_ifindex = if_nametoindex(optarg);
req.rtcan.dst_ifindex = if_nametoindex(optarg);
break;
case 't':
req.r.can_txflags |= CAN_GW_TXFLAGS_SRC_TSTAMP;
req.rtcan.can_txflags |= CAN_GW_TXFLAGS_SRC_TSTAMP;
break;
case 'e':
req.r.can_txflags |= CAN_GW_TXFLAGS_ECHO;
req.rtcan.can_txflags |= CAN_GW_TXFLAGS_ECHO;
break;
case 'f':
@ -296,7 +300,7 @@ int main(int argc, char **argv)
}
if ((argc - optind != 0) || (cmd == UNSPEC) ||
(!req.r.src_ifindex) || (!req.r.dst_ifindex)) {
(!req.rtcan.src_ifindex) || (!req.rtcan.dst_ifindex)) {
print_usage(basename(argv[0]));
exit(1);
}
@ -306,13 +310,13 @@ int main(int argc, char **argv)
switch (cmd) {
case ADD:
req.n.nlmsg_flags = NLM_F_REQUEST;
req.n.nlmsg_type = RTM_NEWROUTE;
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
req.nh.nlmsg_type = RTM_NEWROUTE;
break;
case DEL:
req.n.nlmsg_flags = NLM_F_REQUEST;
req.n.nlmsg_type = RTM_DELROUTE;
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
req.nh.nlmsg_type = RTM_DELROUTE;
break;
default:
@ -321,15 +325,15 @@ int main(int argc, char **argv)
break;
}
req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtcanmsg));
req.n.nlmsg_seq = 0;
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtcanmsg));
req.nh.nlmsg_seq = 0;
req.r.can_family = AF_CAN;
req.rtcan.can_family = AF_CAN;
/* add new attributes here */
if (have_filter)
addattr_l(&req.n, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
addattr_l(&req.nh, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
// a better example code
// modmsg.modtype = CGW_MOD_ID;
@ -337,18 +341,40 @@ int main(int argc, char **argv)
/* 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);
addattr_l(&req.nh, 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,
err = sendto(s, &req, req.nh.nlmsg_len, 0,
(struct sockaddr*)&nladdr, sizeof(nladdr));
if (err < 0) {
perror("netlink sendto");
return err;
}
// clean netlink receive buffer
bzero(rxbuf, sizeof(rxbuf));
if (cmd == ADD || cmd == DEL) {
err = recv(s, &rxbuf, sizeof(rxbuf), 0);
if (err < 0) {
perror("netlink recv");
return err;
}
nlh = (struct nlmsghdr *)rxbuf;
if (nlh->nlmsg_type != NLMSG_ERROR) {
fprintf(stderr, "unexpected netlink answer of type %d\n", nlh->nlmsg_type);
return -EINVAL;
}
rte = (struct nlmsgerr *)NLMSG_DATA(nlh);
err = rte->error;
if (err < 0)
perror("PF_CAN netlink gateway answered ");
fprintf(stderr, "netlink error %d (%s)\n", err, strerror(abs(err)));
}
close(s);