gluon-radvd: implement own radvd to reduce size

package/gluon-radvd/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=gluon-radvd
-PKG_VERSION:=2
+PKG_VERSION:=3
 
 PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
 
@@ -11,7 +11,7 @@ define Package/gluon-radvd
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=Advertise an IPv6 prefix from the node
-  DEPENDS:=+gluon-core +gluon-ebtables +gluon-mesh-batman-adv +radvd
+  DEPENDS:=+gluon-core +gluon-ebtables +gluon-mesh-batman-adv +librt
 endef
 
 define Package/gluon-radvd/description
@@ -20,16 +20,20 @@ endef
 
 define Build/Prepare
 	mkdir -p $(PKG_BUILD_DIR)
+	$(CP) ./src/* $(PKG_BUILD_DIR)/
 endef
 
 define Build/Configure
 endef
 
 define Build/Compile
+	CFLAGS="$(TARGET_CFLAGS)" CPPFLAGS="$(TARGET_CPPFLAGS)" $(MAKE) -C $(PKG_BUILD_DIR) $(TARGET_CONFIGURE_OPTS)
 endef
 
 define Package/gluon-radvd/install
 	$(CP) ./files/* $(1)/
+	$(INSTALL_DIR) $(1)/usr/sbin
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/gluon-radvd $(1)/usr/sbin/
 endef
 
 $(eval $(call BuildPackage,gluon-radvd))

package/gluon-radvd/files/etc/init.d/gluon-radvd

@@ -2,24 +2,14 @@
 
 START=50
 
-SERVICE_USE_PID=1
-SERVICE_NAME=gluon-radvd
-SERVICE_PID_DIR=/var/run/gluon-radvd
-SERVICE_PID_FILE="$SERVICE_PID_DIR"/gluon-radvd.pid
+SERVICE_WRITE_PID=1
+SERVICE_DAEMONIZE=1
 
-radvd_conf=/var/gluon/radvd/radvd.conf
 
 start() {
-	mkdir -p "$SERVICE_PID_DIR"
-	chown gluon-radvd "$SERVICE_PID_DIR"
-
-	mkdir -p "$(dirname "$radvd_conf")"
-	/lib/gluon/radvd/generate_config > "$radvd_conf"
-
-	service_start /usr/sbin/radvd -C "$radvd_conf" -m stderr_syslog -u gluon-radvd -p "$SERVICE_PID_FILE"
+	service_start /usr/sbin/gluon-radvd -i br-client -p $(lua -e 'print(require("gluon.site_config").prefix6)')
 }
 
 stop() {
-	service_stop /usr/sbin/radvd
-	rm "$radvd_conf"
+	service_stop /usr/sbin/gluon-radvd
 }

package/gluon-radvd/files/lib/gluon/radvd/generate_config

@@ -1,14 +0,0 @@
-#!/usr/bin/lua
-
-local site = require 'gluon.site_config'
-
-print([[
-interface br-client
-{
-	IgnoreIfMissing on;
-	AdvSendAdvert on;
-	AdvDefaultLifetime 0;
-
-	prefix ]] .. site.prefix6 .. [[ {};
-};
-]])

package/gluon-radvd/files/lib/gluon/upgrade/radvd/invariant/10-radvd-user

@@ -2,4 +2,4 @@
 
 local users = require 'gluon.users'
 
-users.add_user('gluon-radvd', 801, 100)
+users.remove_user('gluon-radvd')

package/gluon-radvd/src/Makefile

@@ -0,0 +1,4 @@
+all: gluon-radvd
+
+gluon-radvd: gluon-radvd.c
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -Wall -o $@ $^ $(LDLIBS) -lrt

package/gluon-radvd/src/gluon-radvd.c

@@ -0,0 +1,647 @@
+/*
+  Copyright (c) 2014, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <error.h>
+#include <ifaddrs.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <arpa/inet.h>
+
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include <net/if.h>
+
+#include <netinet/in.h>
+#include <netinet/icmp6.h>
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <sys/stat.h>
+
+
+#define MAX_PREFIXES 8
+
+/* These are in seconds */
+#define AdvValidLifetime 86400u
+#define AdvPreferredLifetime 14400u
+#define AdvDefaultLifetime 0u
+#define AdvCurHopLimit 64u
+
+#define MinRtrAdvInterval 200u
+#define MaxRtrAdvInterval 600u
+
+/* And these in milliseconds */
+#define MAX_RA_DELAY_TIME 500u
+#define MIN_DELAY_BETWEEN_RAS 3000u
+
+
+struct icmpv6_opt {
+	uint8_t type;
+	uint8_t length;
+	uint8_t data[6];
+};
+
+
+struct iface {
+	bool ok;
+	unsigned int ifindex;
+	struct in6_addr ifaddr;
+	uint8_t mac[6];
+};
+
+static struct global {
+	struct iface iface;
+
+	struct timespec time;
+	struct timespec next_advert;
+	struct timespec next_advert_earliest;
+
+	int icmp_sock;
+	int rtnl_sock;
+
+	const char *ifname;
+
+	size_t n_prefixes;
+	struct in6_addr prefixes[MAX_PREFIXES];
+} G = {
+	.rtnl_sock = -1,
+	.icmp_sock = -1,
+};
+
+
+static inline void exit_errno(const char *message) {
+	error(1, errno, "error: %s", message);
+}
+
+static inline void warn_errno(const char *message) {
+	error(0, errno, "warning: %s", message);
+}
+
+
+static inline void update_time(void) {
+	clock_gettime(CLOCK_MONOTONIC, &G.time);
+}
+
+/* Compares two timespecs and returns true if tp1 is after tp2 */
+static inline bool timespec_after(const struct timespec *tp1, const struct timespec *tp2) {
+	return (tp1->tv_sec > tp2->tv_sec ||
+		(tp1->tv_sec == tp2->tv_sec && tp1->tv_nsec > tp2->tv_nsec));
+}
+
+/* Returns (tp1 - tp2) in milliseconds  */
+static inline int timespec_diff(const struct timespec *tp1, const struct timespec *tp2) {
+	return ((tp1->tv_sec - tp2->tv_sec))*1000 + (tp1->tv_nsec - tp2->tv_nsec)/1e6;
+}
+
+static inline void timespec_add(struct timespec *tp, unsigned int ms) {
+	tp->tv_sec += ms/1000;
+	tp->tv_nsec += (ms%1000) * 1e6;
+
+	if (tp->tv_nsec >= 1e9) {
+		tp->tv_nsec -= 1e9;
+		tp->tv_sec++;
+	}
+}
+
+
+static inline int setsockopt_int(int socket, int level, int option, int value) {
+	return setsockopt(socket, level, option, &value, sizeof(value));
+}
+
+
+static void init_random(void) {
+	unsigned int seed;
+	int fd = open("/dev/urandom", O_RDONLY);
+	if (fd < 0)
+		exit_errno("can't open /dev/urandom");
+
+	if (read(fd, &seed, sizeof(seed)) != sizeof(seed))
+		exit_errno("can't read from /dev/urandom");
+
+	close(fd);
+
+	srandom(seed);
+}
+
+static inline int rand_range(int min, int max) {
+	unsigned int r = (unsigned int)random();
+	return (r%(max-min) + min);
+}
+
+static void init_icmp(void) {
+	G.icmp_sock = socket(AF_INET6, SOCK_RAW|SOCK_NONBLOCK, IPPROTO_ICMPV6);
+	if (G.icmp_sock < 0)
+		exit_errno("can't open ICMP socket");
+
+	setsockopt_int(G.icmp_sock, IPPROTO_RAW, IPV6_CHECKSUM, 2);
+
+	setsockopt_int(G.icmp_sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 255);
+	setsockopt_int(G.icmp_sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, 1);
+
+	setsockopt_int(G.icmp_sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, 1);
+
+	struct icmp6_filter filter;
+	ICMP6_FILTER_SETBLOCKALL(&filter);
+	ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filter);
+	setsockopt(G.icmp_sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filter, sizeof(filter));
+}
+
+static void init_rtnl(void) {
+	G.rtnl_sock = socket(AF_NETLINK, SOCK_DGRAM|SOCK_NONBLOCK, NETLINK_ROUTE);
+	if (G.rtnl_sock < 0)
+		exit_errno("can't open RTNL socket");
+
+	struct sockaddr_nl snl = {
+		.nl_family = AF_NETLINK,
+		.nl_groups = RTMGRP_LINK | RTMGRP_IPV6_IFADDR,
+	};
+	if (bind(G.rtnl_sock, (struct sockaddr *)&snl, sizeof(snl)) < 0)
+		exit_errno("can't bind RTNL socket");
+}
+
+
+static void schedule_advert(bool nodelay) {
+	struct timespec t = G.time;
+
+	if (nodelay)
+		timespec_add(&t, rand_range(0, MAX_RA_DELAY_TIME));
+	else
+		timespec_add(&t, rand_range(MinRtrAdvInterval*1000, MaxRtrAdvInterval*1000));
+
+	if (timespec_after(&G.next_advert_earliest, &t))
+		t = G.next_advert_earliest;
+
+	if (!nodelay || timespec_after(&G.next_advert, &t))
+		G.next_advert = t;
+}
+
+
+static int join_multicast(void) {
+	struct ipv6_mreq mreq = {
+		.ipv6mr_multiaddr = {
+			.s6_addr = {
+				/* all-routers address */
+				0xff, 0x02, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x02,
+			}
+		},
+		.ipv6mr_interface = G.iface.ifindex,
+	};
+
+	if (setsockopt(G.icmp_sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) == 0) {
+		return 2;
+	}
+	else if (errno != EADDRINUSE) {
+		warn_errno("can't join multicast group");
+		return 0;
+	}
+
+	return 1;
+}
+
+static void update_interface(void) {
+	struct iface old;
+
+	memcpy(&old, &G.iface, sizeof(struct iface));
+	memset(&G.iface, 0, sizeof(struct iface));
+
+	/* Update ifindex */
+	G.iface.ifindex = if_nametoindex(G.ifname);
+	if (!G.iface.ifindex)
+		return;
+
+	/* Update MAC address */
+	struct ifreq ifr = {};
+	strncpy(ifr.ifr_name, G.ifname, sizeof(ifr.ifr_name)-1);
+	if (ioctl(G.icmp_sock, SIOCGIFHWADDR, &ifr) < 0)
+		return;
+
+	memcpy(G.iface.mac, ifr.ifr_hwaddr.sa_data, sizeof(G.iface.mac));
+
+	struct ifaddrs *addrs, *addr;
+	if (getifaddrs(&addrs) < 0) {
+		warn_errno("getifaddrs");
+		return;
+	}
+
+	memset(&G.iface.ifaddr, 0, sizeof(G.iface.ifaddr));
+
+	for (addr = addrs; addr; addr = addr->ifa_next) {
+		if (addr->ifa_addr->sa_family != AF_INET6)
+			continue;
+
+		const struct sockaddr_in6 *in6 = (const struct sockaddr_in6 *)addr->ifa_addr;
+		if (!IN6_IS_ADDR_LINKLOCAL(&in6->sin6_addr))
+			continue;
+
+		if (strncmp(addr->ifa_name, G.ifname, IFNAMSIZ-1) != 0)
+			continue;
+
+		G.iface.ifaddr = in6->sin6_addr;
+	}
+
+	freeifaddrs(addrs);
+
+	if (IN6_IS_ADDR_UNSPECIFIED(&G.iface.ifaddr))
+		return;
+
+	int joined = join_multicast();
+	if (!joined)
+		return;
+
+	setsockopt(G.icmp_sock, SOL_SOCKET, SO_BINDTODEVICE, G.ifname, strnlen(G.ifname, IFNAMSIZ-1));
+
+	G.iface.ok = true;
+
+	if (memcmp(&old, &G.iface, sizeof(struct iface)) != 0 || joined == 2)
+		schedule_advert(true);
+}
+
+
+static bool handle_rtnl_link(uint16_t type, const struct ifinfomsg *msg) {
+	switch (type) {
+	case RTM_NEWLINK:
+		if (!G.iface.ok)
+			return true;
+
+		break;
+
+	case RTM_SETLINK:
+		if ((unsigned)msg->ifi_index == G.iface.ifindex)
+			return true;
+
+		if (!G.iface.ok)
+			return true;
+
+		break;
+
+	case RTM_DELLINK:
+		if (G.iface.ok && (unsigned)msg->ifi_index == G.iface.ifindex)
+			return true;
+	}
+
+	return false;
+}
+
+static bool handle_rtnl_addr(uint16_t type, const struct ifaddrmsg *msg) {
+	switch (type) {
+	case RTM_NEWADDR:
+		if (!G.iface.ok && (unsigned)msg->ifa_index == G.iface.ifindex)
+			return true;
+
+		break;
+
+	case RTM_DELADDR:
+		if (G.iface.ok && (unsigned)msg->ifa_index == G.iface.ifindex)
+			return true;
+	}
+
+	return false;
+}
+
+static bool handle_rtnl_msg(uint16_t type, const void *data) {
+	switch (type) {
+	case RTM_NEWLINK:
+	case RTM_DELLINK:
+	case RTM_SETLINK:
+		return handle_rtnl_link(type, data);
+
+	case RTM_NEWADDR:
+	case RTM_DELADDR:
+		return handle_rtnl_addr(type, data);
+
+	default:
+		return false;
+	}
+}
+
+static void handle_rtnl(void) {
+	char buffer[4096];
+
+	ssize_t len = recv(G.rtnl_sock, buffer, sizeof(buffer), 0);
+	if (len < 0) {
+		warn_errno("recv");
+		return;
+	}
+
+	const struct nlmsghdr *nh;
+	for (nh = (struct nlmsghdr *)buffer; NLMSG_OK(nh, len); nh = NLMSG_NEXT(nh, len)) {
+		switch (nh->nlmsg_type) {
+		case NLMSG_DONE:
+			return;
+
+		case NLMSG_ERROR:
+			error(1, 0, "error: netlink error");
+
+		default:
+			if (handle_rtnl_msg(nh->nlmsg_type, NLMSG_DATA(nh))) {
+				update_interface();
+				return;
+			}
+		}
+	}
+}
+
+static void add_pktinfo(struct msghdr *msg) {
+	struct cmsghdr *cmsg = (struct cmsghdr*)((char*)msg->msg_control + msg->msg_controllen);
+
+	cmsg->cmsg_level = IPPROTO_IPV6;
+	cmsg->cmsg_type = IPV6_PKTINFO;
+	cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
+
+	msg->msg_controllen += cmsg->cmsg_len;
+
+	struct in6_pktinfo pktinfo = {
+		.ipi6_addr = G.iface.ifaddr,
+		.ipi6_ifindex = G.iface.ifindex,
+	};
+
+	memcpy(CMSG_DATA(cmsg), &pktinfo, sizeof(pktinfo));
+}
+
+
+static void handle_solicit(void) {
+	struct sockaddr_in6 addr;
+
+	uint8_t buffer[1500] __attribute__((aligned(8)));
+	struct iovec vec = { .iov_base = buffer, .iov_len = sizeof(buffer) };
+
+	uint8_t cbuf[1024] __attribute__((aligned(8)));
+
+
+	struct msghdr msg = {
+		.msg_name = &addr,
+		.msg_namelen = sizeof(addr),
+		.msg_iov = &vec,
+		.msg_iovlen = 1,
+		.msg_control = cbuf,
+		.msg_controllen = sizeof(cbuf),
+	};
+
+	ssize_t len = recvmsg(G.icmp_sock, &msg, 0);
+	if (len < (ssize_t)sizeof(struct nd_router_solicit)) {
+		if (len < 0)
+			warn_errno("recvmsg");
+
+		return;
+	}
+
+	struct cmsghdr *cmsg;
+	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+		if (cmsg->cmsg_level != IPPROTO_IPV6)
+			continue;
+
+		if (cmsg->cmsg_type != IPV6_HOPLIMIT)
+			continue;
+
+		if (*(int*)CMSG_DATA(cmsg) != 255)
+			return;
+
+		break;
+	}
+
+	const struct nd_router_solicit *s = (struct nd_router_solicit *)buffer;
+	if (s->nd_rs_hdr.icmp6_type != ND_ROUTER_SOLICIT || s->nd_rs_hdr.icmp6_code != 0)
+		return;
+
+	const struct icmpv6_opt *opt = (struct icmpv6_opt *)(buffer + sizeof(struct nd_router_solicit)), *end = (struct icmpv6_opt *)(buffer+len);
+
+	for (; opt < end; opt += opt->length) {
+		if (opt+1 < end)
+			return;
+
+		if (!opt->length)
+			return;
+
+		if (opt+opt->length < end)
+			return;
+
+		if (opt->type == ND_OPT_SOURCE_LINKADDR && IN6_IS_ADDR_UNSPECIFIED(&addr.sin6_addr))
+			return;
+	}
+
+	if (opt != end)
+		return;
+
+	schedule_advert(true);
+}
+
+static void send_advert(void) {
+	if (!G.iface.ok)
+		return;
+
+	struct nd_router_advert advert = {
+		.nd_ra_hdr = {
+			.icmp6_type = ND_ROUTER_ADVERT,
+			.icmp6_dataun.icmp6_un_data8 = {AdvCurHopLimit, 0 /* Flags */, (AdvDefaultLifetime>>8) & 0xff, AdvDefaultLifetime & 0xff },
+		},
+	};
+
+	struct icmpv6_opt lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {}};
+	memcpy(lladdr.data, G.iface.mac, sizeof(G.iface.mac));
+
+	struct nd_opt_prefix_info prefixes[G.n_prefixes];
+
+	size_t i;
+	for (i = 0; i < G.n_prefixes; i++) {
+		prefixes[i] = (struct nd_opt_prefix_info){
+			.nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION,
+			.nd_opt_pi_len = 4,
+			.nd_opt_pi_prefix_len = 64,
+			.nd_opt_pi_flags_reserved = ND_OPT_PI_FLAG_AUTO|ND_OPT_PI_FLAG_ONLINK,
+			.nd_opt_pi_valid_time = htonl(AdvValidLifetime),
+			.nd_opt_pi_preferred_time = htonl(AdvPreferredLifetime),
+			.nd_opt_pi_prefix = G.prefixes[i],
+		};
+	}
+
+	struct iovec vec[3] = {
+		{ .iov_base = &advert, .iov_len = sizeof(advert) },
+		{ .iov_base = &lladdr, .iov_len = sizeof(lladdr) },
+		{ .iov_base = prefixes, .iov_len = sizeof(prefixes) },
+	};
+
+	struct sockaddr_in6 addr = {
+		.sin6_family = AF_INET6,
+		.sin6_addr = {
+			.s6_addr = {
+				/* all-nodes address */
+				0xff, 0x02, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x01,
+			}
+		},
+		.sin6_scope_id = G.iface.ifindex,
+	};
+
+	uint8_t cbuf[1024] __attribute__((aligned(8))) = {};
+
+	struct msghdr msg = {
+		.msg_name = &addr,
+		.msg_namelen = sizeof(addr),
+		.msg_iov = vec,
+		.msg_iovlen = 3,
+		.msg_control = cbuf,
+		.msg_controllen = 0,
+		.msg_flags = 0,
+	};
+
+	add_pktinfo(&msg);
+
+	if (sendmsg(G.icmp_sock, &msg, 0) < 0) {
+		G.iface.ok = false;
+		return;
+	}
+
+	G.next_advert_earliest = G.time;
+	timespec_add(&G.next_advert_earliest, MIN_DELAY_BETWEEN_RAS);
+
+	schedule_advert(false);
+}
+
+
+static void usage(void) {
+	fprintf(stderr, "Usage: gluon-radvd [-h] -i <interface> -p <prefix> [ -p <prefix> ... ]\n");
+}
+
+static void add_prefix(const char *prefix) {
+	if (G.n_prefixes == MAX_PREFIXES)
+		error(1, 0, "maximum number of prefixes is %i.", MAX_PREFIXES);
+
+	const size_t len = strlen(prefix)+1;
+	char prefix2[len];
+	memcpy(prefix2, prefix, len);
+
+	char *slash = strchr(prefix2, '/');
+	if (slash) {
+		*slash = 0;
+		if (strcmp(slash+1, "64") != 0)
+			goto error;
+	}
+
+	if (inet_pton(AF_INET6, prefix2, &G.prefixes[G.n_prefixes]) != 1)
+		goto error;
+
+	static const uint8_t zero[8] = {};
+	if (memcmp(G.prefixes[G.n_prefixes].s6_addr + 8, zero, 8) != 0)
+		goto error;
+
+	G.n_prefixes++;
+	return;
+
+  error:
+	error(1, 0, "invalid prefix %s (only prefixes of length 64 are supported).", prefix);
+}
+
+static void parse_cmdline(int argc, char *argv[]) {
+	int c;
+	while ((c = getopt(argc, argv, "i:p:h")) != -1) {
+		switch(c) {
+		case 'i':
+			if (G.ifname)
+				error(1, 0, "multiple interfaces are not supported.");
+
+			G.ifname = optarg;
+
+			break;
+
+		case 'p':
+			add_prefix(optarg);
+			break;
+
+		case 'h':
+			usage();
+			exit(0);
+
+		default:
+			usage();
+			exit(1);
+		}
+	}
+}
+
+int main(int argc, char *argv[]) {
+	parse_cmdline(argc, argv);
+
+	if (!G.ifname || !G.n_prefixes)
+		error(1, 0, "interface and prefix arguments are required.");
+
+	init_random();
+	init_icmp();
+	init_rtnl();
+
+	update_time();
+	G.next_advert = G.next_advert_earliest = G.time;
+
+	update_interface();
+
+	while (true) {
+		struct pollfd fds[2] = {
+			{ .fd = G.icmp_sock, .events = POLLIN },
+			{ .fd = G.rtnl_sock, .events = POLLIN },
+		};
+
+		int timeout = -1;
+
+		if (G.iface.ok) {
+			timeout = timespec_diff(&G.next_advert, &G.time);
+
+			if (timeout < 0)
+				timeout = 0;
+		}
+
+		int ret = poll(fds, 2, timeout);
+		if (ret < 0)
+			exit_errno("poll");
+
+		update_time();
+
+		if (fds[0].revents & POLLIN)
+			handle_solicit();
+		if (fds[1].revents & POLLIN)
+			handle_rtnl();
+
+		if (timespec_after(&G.time, &G.next_advert))
+			send_advert();
+	}
+}