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Diffstat (limited to 'conf.c')
-rw-r--r--conf.c292
1 files changed, 169 insertions, 123 deletions
diff --git a/conf.c b/conf.c
index 3d07692..94ecf44 100644
--- a/conf.c
+++ b/conf.c
@@ -267,14 +267,27 @@ overlap:
}
/**
- * struct nl_request - Netlink request filled and sent by get_routes()
- * @nlh: Netlink message header
- * @rtm: Routing Netlink message
+ * nl_req() - Send netlink request and read response, doesn't return on failure
+ * @buf: Buffer for response (BUFSIZ long)
+ * @req: Request with netlink header
+ * @len: Request length
*/
-struct nl_request {
- struct nlmsghdr nlh;
- struct rtmsg rtm;
-};
+static void nl_req(char *buf, void *req, ssize_t len)
+{
+ int s = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE), v = 1;
+ struct sockaddr_nl addr = { .nl_family = AF_NETLINK, };
+
+ if (s < 0 ||
+ setsockopt(s, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &v, sizeof(v)) ||
+ bind(s, (struct sockaddr *)&addr, sizeof(addr)) ||
+ (send(s, req, len, 0) < len) ||
+ (recv(s, buf, BUFSIZ, 0) < 0)) {
+ perror("netlink recv");
+ exit(EXIT_FAILURE);
+ }
+
+ close(s);
+}
/**
* get_routes() - Get default route and fill in routable interface name
@@ -282,57 +295,33 @@ struct nl_request {
*/
static void get_routes(struct ctx *c)
{
- struct nl_request req = {
- .nlh.nlmsg_type = RTM_GETROUTE,
+ struct { struct nlmsghdr nlh; struct rtmsg rtm; } req = {
+ .nlh.nlmsg_type = RTM_GETROUTE,
.nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP | NLM_F_EXCL,
- .nlh.nlmsg_len = sizeof(struct nl_request),
- .nlh.nlmsg_seq = 1,
- .rtm.rtm_family = AF_INET,
- .rtm.rtm_table = RT_TABLE_MAIN,
- .rtm.rtm_scope = RT_SCOPE_UNIVERSE,
- .rtm.rtm_type = RTN_UNICAST,
+ .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)),
+ .nlh.nlmsg_seq = 1,
+ .rtm.rtm_family = AF_INET,
+ .rtm.rtm_table = RT_TABLE_MAIN,
+ .rtm.rtm_scope = RT_SCOPE_UNIVERSE,
+ .rtm.rtm_type = RTN_UNICAST,
};
- struct sockaddr_nl addr = {
- .nl_family = AF_NETLINK,
- };
- struct nlmsghdr *nlh;
- int s, n, na, v4, v6;
- char ifn[IFNAMSIZ];
+ char ifn[IFNAMSIZ], buf[BUFSIZ];
+ struct nlmsghdr *nh;
struct rtattr *rta;
struct rtmsg *rtm;
- char buf[BUFSIZ];
+ int n, na, v4, v6;
if (!c->v4 && !c->v6)
v4 = v6 = -1;
else
v6 = -!(v4 = -c->v4);
- s = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
- if (s < 0) {
- perror("netlink socket");
- goto out;
- }
-
- if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
- perror("netlink bind");
- goto out;
- }
-
v6:
- if (send(s, &req, sizeof(req), 0) < 0) {
- perror("netlink send");
- goto out;
- }
-
- n = recv(s, &buf, sizeof(buf), 0);
- if (n < 0) {
- perror("netlink recv");
- goto out;
- }
+ nl_req(buf, &req, sizeof(req));
+ nh = (struct nlmsghdr *)buf;
- nlh = (struct nlmsghdr *)buf;
- for ( ; NLMSG_OK(nlh, n); nlh = NLMSG_NEXT(nlh, n)) {
- rtm = (struct rtmsg *)NLMSG_DATA(nlh);
+ for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) {
+ rtm = (struct rtmsg *)NLMSG_DATA(nh);
if (rtm->rtm_dst_len ||
(rtm->rtm_family != AF_INET && rtm->rtm_family != AF_INET6))
@@ -342,7 +331,7 @@ v6:
if (*c->ifn) {
*ifn = 0;
for (rta = (struct rtattr *)RTM_RTA(rtm),
- na = RTM_PAYLOAD(nlh);
+ na = RTM_PAYLOAD(nh);
RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
if (rta->rta_type != RTA_OIF)
continue;
@@ -355,7 +344,7 @@ v6:
goto next;
}
- for (rta = (struct rtattr *)RTM_RTA(rtm), na = RTM_PAYLOAD(nlh);
+ for (rta = (struct rtattr *)RTM_RTA(rtm), na = RTM_PAYLOAD(nh);
RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
if (!*c->ifn && rta->rta_type == RTA_OIF)
if_indextoname(*(unsigned *)RTA_DATA(rta), ifn);
@@ -380,23 +369,18 @@ v6:
}
next:
- if (nlh->nlmsg_type == NLMSG_DONE)
+ if (nh->nlmsg_type == NLMSG_DONE)
break;
}
- if (v6 == -1) {
+ if (v6 < 0 && req.rtm.rtm_family == AF_INET) {
req.rtm.rtm_family = AF_INET6;
req.nlh.nlmsg_seq++;
- recv(s, &buf, sizeof(buf), 0);
- v6--;
goto v6;
} else if (v6 < 0) {
v6 = 0;
}
-out:
- close(s);
-
if ((v4 <= 0 && v6 <= 0) || (!*c->ifn && !*ifn)) {
err("No routing information");
exit(EXIT_FAILURE);
@@ -409,80 +393,98 @@ out:
}
/**
- * get_addrs() - Fetch MAC, IP addresses, masks of external routable interface
+ * get_l3_addrs() - Fetch IP addresses of external routable interface
* @c: Execution context
*/
-static void get_addrs(struct ctx *c)
+static void get_l3_addrs(struct ctx *c)
{
- struct ifreq ifr = {
- .ifr_addr.sa_family = AF_INET,
+ struct { struct nlmsghdr nlh; struct ifaddrmsg ifa; } req = {
+ .nlh.nlmsg_type = RTM_GETADDR,
+ .nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP,
+ .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
+ .nlh.nlmsg_seq = 1,
+ .ifa.ifa_family = AF_INET,
+ .ifa.ifa_index = if_nametoindex(c->ifn),
};
- struct ifaddrs *ifaddr, *ifa;
- int s, v4 = 0, v6 = 0;
-
- if (getifaddrs(&ifaddr) == -1) {
- perror("getifaddrs");
- goto out;
- }
+ struct ifaddrmsg *ifa;
+ struct nlmsghdr *nh;
+ struct rtattr *rta;
+ int n, na, v4, v6;
+ char buf[BUFSIZ];
- if (c->addr4) {
- c->addr4_seen = c->addr4;
- v4 = 1;
+ if (c->v4) {
+ v4 = -1;
+ if ((c->addr4_seen = c->addr4))
+ v4 = 1;
}
- if (!IN6_IS_ADDR_UNSPECIFIED(&c->addr6)) {
- memcpy(&c->addr6_seen, &c->addr6, sizeof(c->addr6));
- memcpy(&c->addr6_ll_seen, &c->addr6, sizeof(c->addr6));
- v6 = 1;
+ if (c->v6) {
+ v6 = -2;
+ if (!IN6_IS_ADDR_UNSPECIFIED(&c->addr6)) {
+ memcpy(&c->addr6_seen, &c->addr6, sizeof(c->addr6));
+ memcpy(&c->addr6_ll_seen, &c->addr6, sizeof(c->addr6));
+ v6 = -1;
+ }
}
- /* Fill in any missing information */
- for (ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
- struct sockaddr_in *in_addr;
- struct sockaddr_in *in_mask;
- struct sockaddr_in6 *in6_addr;
+next_v:
+ if (v4 < 0)
+ req.ifa.ifa_family = AF_INET;
+ else if (v6 < 0)
+ req.ifa.ifa_family = AF_INET6;
+ else
+ goto mask_only;
- if (strcmp(ifa->ifa_name, c->ifn))
- continue;
+ nl_req(buf, &req, sizeof(req));
+ nh = (struct nlmsghdr *)buf;
- if (!ifa->ifa_addr)
- continue;
+ for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) {
+ if (nh->nlmsg_type != RTM_NEWADDR)
+ goto next;
- in_addr = (struct sockaddr_in *)ifa->ifa_addr;
- if (ifa->ifa_addr->sa_family == AF_INET && !c->addr4) {
- c->addr4_seen = c->addr4 = in_addr->sin_addr.s_addr;
- v4 = 1;
- }
+ ifa = (struct ifaddrmsg *)NLMSG_DATA(nh);
- if (ifa->ifa_addr->sa_family == AF_INET && !c->mask4 &&
- in_addr->sin_addr.s_addr == c->addr4) {
- in_mask = (struct sockaddr_in *)ifa->ifa_netmask;
- c->mask4 = in_mask->sin_addr.s_addr;
- }
+ for (rta = (struct rtattr *)IFA_RTA(ifa), na = RTM_PAYLOAD(nh);
+ RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
+ if (rta->rta_type != IFA_ADDRESS)
+ continue;
- if (ifa->ifa_addr->sa_family == AF_INET6) {
- in6_addr = (struct sockaddr_in6 *)ifa->ifa_addr;
- if (IN6_IS_ADDR_LINKLOCAL(&in6_addr->sin6_addr) &&
- IN6_IS_ADDR_UNSPECIFIED(&c->addr6_ll)) {
- memcpy(&c->addr6_ll, &in6_addr->sin6_addr,
- sizeof(c->addr6_ll));
- } else if (IN6_IS_ADDR_UNSPECIFIED(&c->addr6)) {
- memcpy(&c->addr6, &in6_addr->sin6_addr,
- sizeof(c->addr6));
- memcpy(&c->addr6_seen, &in6_addr->sin6_addr,
- sizeof(c->addr6_seen));
- memcpy(&c->addr6_ll_seen, &in6_addr->sin6_addr,
- sizeof(c->addr6_seen));
- v6 = 1;
+ if (v4 < 0) {
+ memcpy(&c->addr4, RTA_DATA(rta),
+ sizeof(c->addr4));
+ memcpy(&c->addr4_seen, RTA_DATA(rta),
+ sizeof(c->addr4_seen));
+ v4 = 1;
+ } else if (v6 < 0) {
+ if (v6 == -2 &&
+ ifa->ifa_scope == RT_SCOPE_UNIVERSE) {
+ memcpy(&c->addr6, RTA_DATA(rta),
+ sizeof(c->addr6));
+ memcpy(&c->addr6_seen, RTA_DATA(rta),
+ sizeof(c->addr6_seen));
+ memcpy(&c->addr6_ll_seen, RTA_DATA(rta),
+ sizeof(c->addr6_ll_seen));
+ } else if (ifa->ifa_scope == RT_SCOPE_LINK) {
+ memcpy(&c->addr6_ll, RTA_DATA(rta),
+ sizeof(c->addr6_ll));
+ }
+ if (!IN6_IS_ADDR_UNSPECIFIED(&c->addr6) &&
+ !IN6_IS_ADDR_UNSPECIFIED(&c->addr6_ll))
+ v6 = 1;
}
}
+next:
+ if (nh->nlmsg_type == NLMSG_DONE)
+ break;
}
- freeifaddrs(ifaddr);
+ if (v4 >= 0 && v6 < 0)
+ goto next_v;
if (v4 < c->v4 || v6 < c->v6)
goto out;
+mask_only:
if (v4 && !c->mask4) {
if (IN_CLASSA(ntohl(c->addr4)))
c->mask4 = htonl(IN_CLASSA_NET);
@@ -494,28 +496,68 @@ static void get_addrs(struct ctx *c)
c->mask4 = 0xffffffff;
}
- if (!memcmp(c->mac, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN)) {
- s = socket(AF_INET, SOCK_DGRAM, 0);
- if (s < 0) {
- perror("socket SIOCGIFHWADDR");
- goto out;
- }
+ return;
+out:
+ err("Couldn't get addresses for routable interface");
+ exit(EXIT_FAILURE);
+}
- strncpy(ifr.ifr_name, c->ifn, IF_NAMESIZE);
- if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0) {
- perror("SIOCGIFHWADDR");
- goto out;
- }
+/**
+ * get_l2_addr() - Fetch hardware addresses of external routable interface
+ * @c: Execution context
+ */
+static void get_l2_addr(struct ctx *c)
+{
+ struct { struct nlmsghdr nlh; struct ifinfomsg ifi; } req = {
+ .nlh.nlmsg_type = RTM_GETLINK,
+ .nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP_FILTERED,
+ .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+ .nlh.nlmsg_seq = 1,
+ .ifi.ifi_family = AF_UNSPEC,
+ .ifi.ifi_index = if_nametoindex(c->ifn),
+ };
+ struct ifinfomsg *ifi;
+ struct nlmsghdr *nh;
+ struct rtattr *rta;
+ char buf[BUFSIZ];
+ int n, na;
+
+ if (memcmp(c->mac, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN))
+ goto mac_guest;
- close(s);
- memcpy(c->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
+ nl_req(buf, &req, sizeof(req));
+ nh = (struct nlmsghdr *)buf;
+
+ for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) {
+ if (nh->nlmsg_type != RTM_NEWLINK)
+ goto next;
+
+ ifi = (struct ifinfomsg *)NLMSG_DATA(nh);
+
+ for (rta = (struct rtattr *)IFLA_RTA(ifi), na = RTM_PAYLOAD(nh);
+ RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) {
+ if (rta->rta_type != IFLA_ADDRESS)
+ continue;
+
+ memcpy(c->mac, RTA_DATA(rta), ETH_ALEN);
+ break;
+ }
+next:
+ if (nh->nlmsg_type == NLMSG_DONE)
+ break;
}
- memset(&c->mac_guest, 0xff, sizeof(c->mac_guest));
+ if (!memcmp(c->mac, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN))
+ goto out;
+
+mac_guest:
+ if (memcmp(c->mac_guest, ((uint8_t [ETH_ALEN]){ 0 }), ETH_ALEN))
+ memset(&c->mac_guest, 0xff, sizeof(c->mac_guest));
return;
+
out:
- err("Couldn't get addresses for routable interface");
+ err("Couldn't get hardware address for routable interface");
exit(EXIT_FAILURE);
}
@@ -888,6 +930,8 @@ void conf_print(struct ctx *c)
inet_ntop(AF_INET6, &c->addr6, buf6, sizeof(buf6)));
info(" router: %s",
inet_ntop(AF_INET6, &c->gw6, buf6, sizeof(buf6)));
+ info(" our link-local: %s",
+ inet_ntop(AF_INET6, &c->addr6_ll, buf6, sizeof(buf6)));
for (i = 0; !IN6_IS_ADDR_UNSPECIFIED(&c->dns6[i]); i++) {
if (!i)
@@ -1290,7 +1334,9 @@ void conf(struct ctx *c, int argc, char **argv)
}
get_routes(c);
- get_addrs(c);
+ get_l3_addrs(c);
+ if (c->v4)
+ get_l2_addr(c);
if (c->mode == MODE_PASTA && dns4 == c->dns4 && dns6 == c->dns6)
c->no_dns = 1;