+ {
+ struct {
+ // interface setting
+ struct nlmsghdr nh;
+ union {
+ struct ifinfomsg ifinfo;
+ struct ifaddrmsg ifaddr;
+ } ifmsg __attribute__ ((aligned(NLMSG_ALIGNTO)));
+ char rtdata[32]; // 32 should be enough
+ } req;
+ uint32_t txqlen, mtu;
+ struct in_addr ip;
+
+ memset(&req, 0, sizeof(req));
+
+ req.nh.nlmsg_type = RTM_SETLINK;
+ req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_MULTI;
+ req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifinfo));
+
+ req.ifmsg.ifinfo = ifinfo;
+ req.ifmsg.ifinfo.ifi_flags |= IFF_UP; // set interface up
+ req.ifmsg.ifinfo.ifi_change = IFF_UP; // only change this flag
+
+ /* Bump up the qlen to deal with bursts from the network */
+ txqlen = 1000;
+ netlink_addattr(&req.nh, IFLA_TXQLEN, &txqlen, sizeof(txqlen));
+ /* set MTU to modem MRU */
+ mtu = MRU;
+ netlink_addattr(&req.nh, IFLA_MTU, &mtu, sizeof(mtu));
+
+ if (netlink_send(&req.nh) < 0)
+ goto senderror;
+
+ memset(&req, 0, sizeof(req));
+
+ req.nh.nlmsg_type = RTM_NEWADDR;
+ req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+ req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr));
+
+ req.ifmsg.ifaddr.ifa_family = AF_INET;
+ req.ifmsg.ifaddr.ifa_prefixlen = 32;
+ req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
+
+ if (config->bind_address)
+ ip.s_addr = config->bind_address;
+ else
+ ip.s_addr = 0x01010101, // 1.1.1.1
+ netlink_addattr(&req.nh, IFA_LOCAL, &ip, sizeof(ip));
+
+ if (netlink_send(&req.nh) < 0)
+ goto senderror;
+
+ // Only setup IPv6 on the tun device if we have a configured prefix
+ if (config->ipv6_prefix.s6_addr[0]) {
+ struct in6_addr ip6;
+
+ memset(&req, 0, sizeof(req));
+
+ req.nh.nlmsg_type = RTM_NEWADDR;
+ req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+ req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr));
+
+ req.ifmsg.ifaddr.ifa_family = AF_INET6;
+ req.ifmsg.ifaddr.ifa_prefixlen = 64;
+ req.ifmsg.ifaddr.ifa_scope = RT_SCOPE_LINK;
+ req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
+
+ // Link local address is FE80::1
+ memset(&ip6, 0, sizeof(ip6));
+ ip6.s6_addr[0] = 0xFE;
+ ip6.s6_addr[1] = 0x80;
+ ip6.s6_addr[15] = 1;
+ netlink_addattr(&req.nh, IFA_LOCAL, &ip6, sizeof(ip6));
+
+ if (netlink_send(&req.nh) < 0)
+ goto senderror;
+
+ memset(&req, 0, sizeof(req));
+
+ req.nh.nlmsg_type = RTM_NEWADDR;
+ req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+ req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr));
+
+ req.ifmsg.ifaddr.ifa_family = AF_INET6;
+ req.ifmsg.ifaddr.ifa_prefixlen = 64;
+ req.ifmsg.ifaddr.ifa_scope = RT_SCOPE_UNIVERSE;
+ req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
+
+ // Global address is prefix::1
+ ip6 = config->ipv6_prefix;
+ ip6.s6_addr[15] = 1;
+ netlink_addattr(&req.nh, IFA_LOCAL, &ip6, sizeof(ip6));
+
+ if (netlink_send(&req.nh) < 0)
+ goto senderror;
+ }
+
+ memset(&req, 0, sizeof(req));
+
+ req.nh.nlmsg_type = NLMSG_DONE;
+ req.nh.nlmsg_len = NLMSG_LENGTH(0);
+
+ if (netlink_send(&req.nh) < 0)
+ goto senderror;
+
+ // if we get an error for seqnum < min_initok_nlseqnum,
+ // we must exit as initialization went wrong
+ if (config->ipv6_prefix.s6_addr[0])
+ min_initok_nlseqnum = 5 + 1; // idx + if + addr + 2*addr6
+ else
+ min_initok_nlseqnum = 3 + 1; // idx + if + addr
+ }
+
+ return;
+
+senderror:
+ LOG(0, 0, 0, "Error while setting up tun device: %s\n", strerror(errno));
+ exit(1);