conf: Avoid getifaddrs(), split L2/L3 address fetching, get filtered dumps
getifaddrs() needs to allocate heap memory, and gets a ton of results we don't need. Use explicit netlink messages with "strict checking" instead. While at it, separate L2/L3 address handling, so that we don't fetch MAC addresses for IPv6, and also use netlink instead of ioctl() to get the MAC address. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio
parent
e871fa9f22
commit
580581fd96
2 changed files with 179 additions and 133 deletions
310
conf.c
310
conf.c
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@ -267,14 +267,27 @@ overlap:
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}
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/**
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* struct nl_request - Netlink request filled and sent by get_routes()
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* @nlh: Netlink message header
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* @rtm: Routing Netlink message
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* nl_req() - Send netlink request and read response, doesn't return on failure
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* @buf: Buffer for response (BUFSIZ long)
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* @req: Request with netlink header
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* @len: Request length
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*/
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struct nl_request {
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struct nlmsghdr nlh;
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struct rtmsg rtm;
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};
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static void nl_req(char *buf, void *req, ssize_t len)
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{
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int s = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE), v = 1;
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struct sockaddr_nl addr = { .nl_family = AF_NETLINK, };
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if (s < 0 ||
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setsockopt(s, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &v, sizeof(v)) ||
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bind(s, (struct sockaddr *)&addr, sizeof(addr)) ||
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(send(s, req, len, 0) < len) ||
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(recv(s, buf, BUFSIZ, 0) < 0)) {
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perror("netlink recv");
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exit(EXIT_FAILURE);
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}
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close(s);
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}
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/**
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* get_routes() - Get default route and fill in routable interface name
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@ -282,57 +295,33 @@ struct nl_request {
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*/
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static void get_routes(struct ctx *c)
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{
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struct nl_request req = {
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.nlh.nlmsg_type = RTM_GETROUTE,
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struct { struct nlmsghdr nlh; struct rtmsg rtm; } req = {
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.nlh.nlmsg_type = RTM_GETROUTE,
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.nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP | NLM_F_EXCL,
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.nlh.nlmsg_len = sizeof(struct nl_request),
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.nlh.nlmsg_seq = 1,
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.rtm.rtm_family = AF_INET,
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.rtm.rtm_table = RT_TABLE_MAIN,
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.rtm.rtm_scope = RT_SCOPE_UNIVERSE,
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.rtm.rtm_type = RTN_UNICAST,
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.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)),
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.nlh.nlmsg_seq = 1,
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.rtm.rtm_family = AF_INET,
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.rtm.rtm_table = RT_TABLE_MAIN,
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.rtm.rtm_scope = RT_SCOPE_UNIVERSE,
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.rtm.rtm_type = RTN_UNICAST,
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};
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struct sockaddr_nl addr = {
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.nl_family = AF_NETLINK,
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};
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struct nlmsghdr *nlh;
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int s, n, na, v4, v6;
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char ifn[IFNAMSIZ];
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char ifn[IFNAMSIZ], buf[BUFSIZ];
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struct nlmsghdr *nh;
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struct rtattr *rta;
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struct rtmsg *rtm;
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char buf[BUFSIZ];
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int n, na, v4, v6;
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if (!c->v4 && !c->v6)
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v4 = v6 = -1;
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else
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v6 = -!(v4 = -c->v4);
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s = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
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if (s < 0) {
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perror("netlink socket");
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goto out;
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}
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if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
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perror("netlink bind");
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goto out;
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}
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v6:
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if (send(s, &req, sizeof(req), 0) < 0) {
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perror("netlink send");
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goto out;
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}
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nl_req(buf, &req, sizeof(req));
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nh = (struct nlmsghdr *)buf;
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n = recv(s, &buf, sizeof(buf), 0);
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if (n < 0) {
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perror("netlink recv");
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goto out;
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}
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nlh = (struct nlmsghdr *)buf;
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for ( ; NLMSG_OK(nlh, n); nlh = NLMSG_NEXT(nlh, n)) {
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rtm = (struct rtmsg *)NLMSG_DATA(nlh);
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for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) {
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rtm = (struct rtmsg *)NLMSG_DATA(nh);
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if (rtm->rtm_dst_len ||
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(rtm->rtm_family != AF_INET && rtm->rtm_family != AF_INET6))
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@ -342,7 +331,7 @@ v6:
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if (*c->ifn) {
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*ifn = 0;
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for (rta = (struct rtattr *)RTM_RTA(rtm),
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na = RTM_PAYLOAD(nlh);
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na = RTM_PAYLOAD(nh);
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RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
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if (rta->rta_type != RTA_OIF)
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continue;
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@ -355,7 +344,7 @@ v6:
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goto next;
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}
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for (rta = (struct rtattr *)RTM_RTA(rtm), na = RTM_PAYLOAD(nlh);
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for (rta = (struct rtattr *)RTM_RTA(rtm), na = RTM_PAYLOAD(nh);
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RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
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if (!*c->ifn && rta->rta_type == RTA_OIF)
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if_indextoname(*(unsigned *)RTA_DATA(rta), ifn);
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@ -380,23 +369,18 @@ v6:
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}
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next:
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if (nlh->nlmsg_type == NLMSG_DONE)
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if (nh->nlmsg_type == NLMSG_DONE)
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break;
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}
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if (v6 == -1) {
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if (v6 < 0 && req.rtm.rtm_family == AF_INET) {
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req.rtm.rtm_family = AF_INET6;
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req.nlh.nlmsg_seq++;
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recv(s, &buf, sizeof(buf), 0);
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v6--;
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goto v6;
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} else if (v6 < 0) {
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v6 = 0;
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}
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out:
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close(s);
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if ((v4 <= 0 && v6 <= 0) || (!*c->ifn && !*ifn)) {
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err("No routing information");
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exit(EXIT_FAILURE);
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@ -409,80 +393,98 @@ out:
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}
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/**
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* get_addrs() - Fetch MAC, IP addresses, masks of external routable interface
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* get_l3_addrs() - Fetch IP addresses of external routable interface
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* @c: Execution context
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*/
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static void get_addrs(struct ctx *c)
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static void get_l3_addrs(struct ctx *c)
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{
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struct ifreq ifr = {
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.ifr_addr.sa_family = AF_INET,
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struct { struct nlmsghdr nlh; struct ifaddrmsg ifa; } req = {
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.nlh.nlmsg_type = RTM_GETADDR,
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.nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP,
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.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
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.nlh.nlmsg_seq = 1,
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.ifa.ifa_family = AF_INET,
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.ifa.ifa_index = if_nametoindex(c->ifn),
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};
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struct ifaddrs *ifaddr, *ifa;
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int s, v4 = 0, v6 = 0;
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struct ifaddrmsg *ifa;
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struct nlmsghdr *nh;
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struct rtattr *rta;
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int n, na, v4, v6;
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char buf[BUFSIZ];
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if (getifaddrs(&ifaddr) == -1) {
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perror("getifaddrs");
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goto out;
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}
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if (c->addr4) {
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c->addr4_seen = c->addr4;
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v4 = 1;
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}
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if (!IN6_IS_ADDR_UNSPECIFIED(&c->addr6)) {
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memcpy(&c->addr6_seen, &c->addr6, sizeof(c->addr6));
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memcpy(&c->addr6_ll_seen, &c->addr6, sizeof(c->addr6));
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v6 = 1;
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}
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/* Fill in any missing information */
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for (ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
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struct sockaddr_in *in_addr;
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struct sockaddr_in *in_mask;
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struct sockaddr_in6 *in6_addr;
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if (strcmp(ifa->ifa_name, c->ifn))
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continue;
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if (!ifa->ifa_addr)
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continue;
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in_addr = (struct sockaddr_in *)ifa->ifa_addr;
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if (ifa->ifa_addr->sa_family == AF_INET && !c->addr4) {
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c->addr4_seen = c->addr4 = in_addr->sin_addr.s_addr;
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if (c->v4) {
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v4 = -1;
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if ((c->addr4_seen = c->addr4))
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v4 = 1;
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}
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}
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if (ifa->ifa_addr->sa_family == AF_INET && !c->mask4 &&
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in_addr->sin_addr.s_addr == c->addr4) {
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in_mask = (struct sockaddr_in *)ifa->ifa_netmask;
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c->mask4 = in_mask->sin_addr.s_addr;
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if (c->v6) {
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v6 = -2;
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if (!IN6_IS_ADDR_UNSPECIFIED(&c->addr6)) {
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memcpy(&c->addr6_seen, &c->addr6, sizeof(c->addr6));
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memcpy(&c->addr6_ll_seen, &c->addr6, sizeof(c->addr6));
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v6 = -1;
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}
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}
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if (ifa->ifa_addr->sa_family == AF_INET6) {
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in6_addr = (struct sockaddr_in6 *)ifa->ifa_addr;
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if (IN6_IS_ADDR_LINKLOCAL(&in6_addr->sin6_addr) &&
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IN6_IS_ADDR_UNSPECIFIED(&c->addr6_ll)) {
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memcpy(&c->addr6_ll, &in6_addr->sin6_addr,
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sizeof(c->addr6_ll));
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} else if (IN6_IS_ADDR_UNSPECIFIED(&c->addr6)) {
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memcpy(&c->addr6, &in6_addr->sin6_addr,
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sizeof(c->addr6));
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memcpy(&c->addr6_seen, &in6_addr->sin6_addr,
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sizeof(c->addr6_seen));
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memcpy(&c->addr6_ll_seen, &in6_addr->sin6_addr,
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sizeof(c->addr6_seen));
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v6 = 1;
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next_v:
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if (v4 < 0)
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req.ifa.ifa_family = AF_INET;
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else if (v6 < 0)
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req.ifa.ifa_family = AF_INET6;
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else
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goto mask_only;
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nl_req(buf, &req, sizeof(req));
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nh = (struct nlmsghdr *)buf;
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for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) {
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if (nh->nlmsg_type != RTM_NEWADDR)
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goto next;
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ifa = (struct ifaddrmsg *)NLMSG_DATA(nh);
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for (rta = (struct rtattr *)IFA_RTA(ifa), na = RTM_PAYLOAD(nh);
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RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
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if (rta->rta_type != IFA_ADDRESS)
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continue;
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if (v4 < 0) {
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memcpy(&c->addr4, RTA_DATA(rta),
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sizeof(c->addr4));
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memcpy(&c->addr4_seen, RTA_DATA(rta),
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sizeof(c->addr4_seen));
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v4 = 1;
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} else if (v6 < 0) {
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if (v6 == -2 &&
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ifa->ifa_scope == RT_SCOPE_UNIVERSE) {
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memcpy(&c->addr6, RTA_DATA(rta),
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sizeof(c->addr6));
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memcpy(&c->addr6_seen, RTA_DATA(rta),
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sizeof(c->addr6_seen));
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memcpy(&c->addr6_ll_seen, RTA_DATA(rta),
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sizeof(c->addr6_ll_seen));
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} else if (ifa->ifa_scope == RT_SCOPE_LINK) {
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memcpy(&c->addr6_ll, RTA_DATA(rta),
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sizeof(c->addr6_ll));
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}
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if (!IN6_IS_ADDR_UNSPECIFIED(&c->addr6) &&
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!IN6_IS_ADDR_UNSPECIFIED(&c->addr6_ll))
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v6 = 1;
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}
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}
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next:
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if (nh->nlmsg_type == NLMSG_DONE)
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break;
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}
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freeifaddrs(ifaddr);
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if (v4 >= 0 && v6 < 0)
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goto next_v;
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if (v4 < c->v4 || v6 < c->v6)
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goto out;
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mask_only:
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if (v4 && !c->mask4) {
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if (IN_CLASSA(ntohl(c->addr4)))
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c->mask4 = htonl(IN_CLASSA_NET);
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@ -494,31 +496,71 @@ static void get_addrs(struct ctx *c)
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c->mask4 = 0xffffffff;
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}
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if (!memcmp(c->mac, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN)) {
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s = socket(AF_INET, SOCK_DGRAM, 0);
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if (s < 0) {
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perror("socket SIOCGIFHWADDR");
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goto out;
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}
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strncpy(ifr.ifr_name, c->ifn, IF_NAMESIZE);
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if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0) {
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perror("SIOCGIFHWADDR");
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goto out;
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}
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close(s);
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memcpy(c->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
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}
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memset(&c->mac_guest, 0xff, sizeof(c->mac_guest));
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return;
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out:
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err("Couldn't get addresses for routable interface");
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exit(EXIT_FAILURE);
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}
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/**
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* get_l2_addr() - Fetch hardware addresses of external routable interface
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* @c: Execution context
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*/
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static void get_l2_addr(struct ctx *c)
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{
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struct { struct nlmsghdr nlh; struct ifinfomsg ifi; } req = {
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.nlh.nlmsg_type = RTM_GETLINK,
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.nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP_FILTERED,
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.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
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.nlh.nlmsg_seq = 1,
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.ifi.ifi_family = AF_UNSPEC,
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.ifi.ifi_index = if_nametoindex(c->ifn),
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};
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struct ifinfomsg *ifi;
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struct nlmsghdr *nh;
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struct rtattr *rta;
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char buf[BUFSIZ];
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int n, na;
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if (memcmp(c->mac, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN))
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goto mac_guest;
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nl_req(buf, &req, sizeof(req));
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nh = (struct nlmsghdr *)buf;
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for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) {
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if (nh->nlmsg_type != RTM_NEWLINK)
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goto next;
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ifi = (struct ifinfomsg *)NLMSG_DATA(nh);
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for (rta = (struct rtattr *)IFLA_RTA(ifi), na = RTM_PAYLOAD(nh);
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RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
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if (rta->rta_type != IFLA_ADDRESS)
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continue;
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memcpy(c->mac, RTA_DATA(rta), ETH_ALEN);
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break;
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}
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next:
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if (nh->nlmsg_type == NLMSG_DONE)
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break;
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}
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if (!memcmp(c->mac, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN))
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goto out;
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mac_guest:
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if (memcmp(c->mac_guest, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN))
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memset(&c->mac_guest, 0xff, sizeof(c->mac_guest));
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return;
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out:
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err("Couldn't get hardware address for routable interface");
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exit(EXIT_FAILURE);
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}
|
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/**
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* get_dns() - Get nameserver addresses from local /etc/resolv.conf
|
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* @c: Execution context
|
||||
|
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@ -888,6 +930,8 @@ void conf_print(struct ctx *c)
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inet_ntop(AF_INET6, &c->addr6, buf6, sizeof(buf6)));
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info(" router: %s",
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inet_ntop(AF_INET6, &c->gw6, buf6, sizeof(buf6)));
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info(" our link-local: %s",
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inet_ntop(AF_INET6, &c->addr6_ll, buf6, sizeof(buf6)));
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|
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for (i = 0; !IN6_IS_ADDR_UNSPECIFIED(&c->dns6[i]); i++) {
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if (!i)
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|
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@ -1290,7 +1334,9 @@ void conf(struct ctx *c, int argc, char **argv)
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}
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|
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get_routes(c);
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get_addrs(c);
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get_l3_addrs(c);
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if (c->v4)
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get_l2_addr(c);
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|
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if (c->mode == MODE_PASTA && dns4 == c->dns4 && dns6 == c->dns6)
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c->no_dns = 1;
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|
|
|
|||
2
passt.h
2
passt.h
|
|
@ -98,7 +98,7 @@ enum passt_modes {
|
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* @fd_tap_listen: File descriptor for listening AF_UNIX socket, if any
|
||||
* @fd_tap: File descriptor for AF_UNIX socket or tuntap device
|
||||
* @mac: Host MAC address
|
||||
* @mac_guest: Guest MAC address
|
||||
* @mac_guest: MAC address of guest or namespace, seen or configured
|
||||
* @v4: Enable IPv4 transport
|
||||
* @addr4: IPv4 address for external, routable interface
|
||||
* @addr4_seen: Latest IPv4 address seen as source from tap
|
||||
|
|
|
|||
Loading…
Reference in a new issue