VALUE rb_rt_initialize(int argc, VALUE *argv, VALUE klass) {
rt_ctx *ctx;
VALUE binmode = Qnil;
int _bmode = 0;
rb_scan_args(argc, argv, "01", &binmode);
if ((binmode != Qnil) && (binmode != Qfalse)) {
Check_Type(binmode, T_TRUE);
_bmode=1;
}
if(!(ctx = rt_new()))
rb_sys_fail(0);
ctx->binary = _bmode;
return Data_Wrap_Struct(klass, rb_rt_mark, rt_free, ctx);
}
/* Our rt netlink filter */
int rt_filter(struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
struct rt_entry *rtarg;
struct rtmsg *r = NLMSG_DATA(n);
int len = n->nlmsg_len;
struct rtattr *tb[RTA_MAX+1];
struct rt_entry *entry;
rtarg = (struct rt_entry *)arg;
/* Just lookup the Main routing table */
if (r->rtm_table != RT_TABLE_MAIN)
return 0;
/* init len value */
len -= NLMSG_LENGTH(sizeof(*r));
if (len <0) {
printf("BUG: wrong nlmsg len %d\n", len);
return -1;
}
/* init the parse attribute space */
memset(tb, 0, sizeof(tb));
parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
/*
* we return from filter when route is
* cloned from another route, learn by an
* ICMP redirect or set by kernel.
* Return too when rt type != gateway or direct route.
*/
if (r->rtm_flags & RTM_F_CLONED)
return 0;
if (r->rtm_protocol == RTPROT_REDIRECT)
return 0;
if (r->rtm_protocol == RTPROT_KERNEL)
return 0;
if (r->rtm_type != RTN_UNICAST)
return 0;
if (tb[RTA_OIF]) {
/* alloc new memory entry */
entry = rt_new();
/* copy the rtmsg infos */
memcpy(entry->rtm, r, sizeof(struct rtmsg));
/*
* can use RTA_PAYLOAD(tb[RTA_SRC])
* but ipv4 addr are 4 bytes coded
*/
entry->oif = *(int *) RTA_DATA(tb[RTA_OIF]);
if (tb[RTA_SRC]) memcpy(&entry->src, RTA_DATA(tb[RTA_SRC]), 4);
if (tb[RTA_PREFSRC]) memcpy(&entry->psrc, RTA_DATA(tb[RTA_PREFSRC]), 4);
if (tb[RTA_DST]) memcpy(&entry->dest, RTA_DATA(tb[RTA_DST]), 4);
if (tb[RTA_GATEWAY]) memcpy(&entry->gate, RTA_DATA(tb[RTA_GATEWAY]), 4);
if (tb[RTA_FLOW]) memcpy(&entry->flow, RTA_DATA(tb[RTA_FLOW]), 4);
if (tb[RTA_IIF]) entry->iif = *(int *) RTA_DATA(tb[RTA_IIF]);
if (tb[RTA_PRIORITY]) entry->prio = *(int *) RTA_DATA(tb[RTA_PRIORITY]);
if (tb[RTA_METRICS]) entry->metrics = *(int *) RTA_DATA(tb[RTA_METRICS]);
/* save this entry */
rtarg = rt_append(rtarg, entry);
}
return 0;
}