| /* 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 & (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; |
| char *colon; |
| |
| log2("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"); |
| |
| /* SO_BINDTODEVICE doesn't work on ethernet aliases (ethN:M) */ |
| colon = strrchr(inf, ':'); |
| if (colon) |
| *colon = '\0'; |
| |
| if (setsockopt_bindtodevice(fd, inf)) |
| xfunc_die(); /* warning is already printed */ |
| |
| if (colon) |
| *colon = ':'; |
| |
| 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; |
| } |