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/* vi: set sw=4 ts=4: */
/*
* Copyright (C) 2011 Denys Vlasenko.
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
#include "common.h"
#include "d6_common.h"
#include <net/if.h>
#include <ifaddrs.h>
#include <netpacket/packet.h>
int FAST_FUNC d6_read_interface(
const char *interface,
int *ifindex,
struct in6_addr *nip6,
uint8_t *mac)
{
int retval = 3;
struct ifaddrs *ifap, *ifa;
getifaddrs(&ifap);
for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
struct sockaddr_in6 *sip6;
if (!ifa->ifa_addr || (strcmp(ifa->ifa_name, interface) != 0))
continue;
if (ifa->ifa_addr->sa_family == AF_PACKET) {
struct sockaddr_ll *sll = (void*)(ifa->ifa_addr);
memcpy(mac, sll->sll_addr, 6);
log2("MAC %02x:%02x:%02x:%02x:%02x:%02x",
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]
);
*ifindex = sll->sll_ifindex;
log2("ifindex %d", *ifindex);
retval &= (3 - (1<<0));
}
#if 0
if (ifa->ifa_addr->sa_family == AF_INET) {
*nip = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
log1("IP %s", inet_ntoa(((struct sockaddr_in *)ifa->ifa_addr)->sin_addr));
}
#endif
/* RFC 3315
* 16. Client Source Address and Interface Selection
*
* "When a client sends a DHCP message to the
* All_DHCP_Relay_Agents_and_Servers address, ... ... The client
* MUST use a link-local address assigned to the interface for which it
* is requesting configuration information as the source address in the
* header of the IP datagram."
*/
sip6 = (void*)(ifa->ifa_addr);
if (ifa->ifa_addr->sa_family == AF_INET6
&& IN6_IS_ADDR_LINKLOCAL(&sip6->sin6_addr)
) {
*nip6 = sip6->sin6_addr; /* struct copy */
log1(
"IPv6 %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x",
nip6->s6_addr[0], nip6->s6_addr[1],
nip6->s6_addr[2], nip6->s6_addr[3],
nip6->s6_addr[4], nip6->s6_addr[5],
nip6->s6_addr[6], nip6->s6_addr[7],
nip6->s6_addr[8], nip6->s6_addr[9],
nip6->s6_addr[10], nip6->s6_addr[11],
nip6->s6_addr[12], nip6->s6_addr[13],
nip6->s6_addr[14], nip6->s6_addr[15]
);
retval &= (3 - (1<<1));
}
}
freeifaddrs(ifap);
if (retval & (1<<0)) {
/* This iface has no MAC (e.g. ppp), generate a random one */
struct ifreq ifr;
int fd;
/*memset(&ifr, 0, sizeof(ifr)); - SIOCGIFINDEX does not need to clear all */
strncpy_IFNAMSIZ(ifr.ifr_name, interface);
fd = xsocket(AF_INET6, SOCK_RAW, IPPROTO_RAW);
if (ioctl(fd, SIOCGIFINDEX, &ifr) == 0) {
*ifindex = ifr.ifr_ifindex;
log2("ifindex %d", *ifindex);
if (((uint32_t*)mac)[0] == 0) {
/* invent a fictitious MAC (once) */
((uint32_t*)mac)[0] = rand();
((uint16_t*)mac)[2] = rand();
mac[0] &= 0xfc; /* make sure it's not bcast */
}
retval &= (3 - (1<<0));
}
close(fd);
}
if (retval == 0)
return retval;
if (retval & (1<<0))
bb_error_msg("can't get %s", "MAC");
if (retval & (1<<1))
bb_error_msg("can't get %s", "link-local IPv6 address");
return retval;
}
int FAST_FUNC d6_listen_socket(int port, const char *inf)
{
int fd;
struct sockaddr_in6 addr;
log1("opening listen socket on *:%d %s", port, inf);
fd = xsocket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
setsockopt_reuseaddr(fd);
if (setsockopt_broadcast(fd) == -1)
bb_simple_perror_msg_and_die("SO_BROADCAST");
/* NB: bug 1032 says this doesn't work on ethernet aliases (ethN:M) */
if (setsockopt_bindtodevice(fd, inf))
xfunc_die(); /* warning is already printed */
memset(&addr, 0, sizeof(addr));
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(port);
/* addr.sin6_addr is all-zeros */
xbind(fd, (struct sockaddr *)&addr, sizeof(addr));
return fd;
}
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