/*	$OpenBSD: bgpd.c,v 1.233 2021/01/04 17:44:14 claudio Exp $ */

/*
 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "bgpd.h"
#include "session.h"
#include "log.h"

void		sighdlr(int);
__dead void	usage(void);
int		main(int, char *[]);
pid_t		start_child(enum bgpd_process, char *, int, int, int);
int		send_filterset(struct imsgbuf *, struct filter_set_head *);
int		reconfigure(char *, struct bgpd_config *);
int		send_config(struct bgpd_config *);
int		dispatch_imsg(struct imsgbuf *, int, struct bgpd_config *);
int		control_setup(struct bgpd_config *);
static void	getsockpair(int [2]);
int		imsg_send_sockets(struct imsgbuf *, struct imsgbuf *);

int			 cflags;
volatile sig_atomic_t	 mrtdump;
volatile sig_atomic_t	 quit;
volatile sig_atomic_t	 reconfig;
pid_t			 reconfpid;
int			 reconfpending;
struct imsgbuf		*ibuf_se;
struct imsgbuf		*ibuf_rde;
struct rib_names	 ribnames = SIMPLEQ_HEAD_INITIALIZER(ribnames);
char			*cname;
char			*rcname;

void
sighdlr(int sig)
{
	switch (sig) {
	case SIGTERM:
	case SIGINT:
		quit = 1;
		break;
	case SIGHUP:
		reconfig = 1;
		break;
	case SIGALRM:
	case SIGUSR1:
		mrtdump = 1;
		break;
	}
}

__dead void
usage(void)
{
	extern char *__progname;

	fprintf(stderr, "usage: %s [-cdnv] [-D macro=value] [-f file]\n",
	    __progname);
	exit(1);
}

#define PFD_PIPE_SESSION	0
#define PFD_PIPE_RDE		1
#define PFD_SOCK_ROUTE		2
#define PFD_SOCK_PFKEY		3
#define POLL_MAX		4
#define MAX_TIMEOUT		3600

int	 cmd_opts;

int
main(int argc, char *argv[])
{
	struct bgpd_config	*conf;
	enum bgpd_process	 proc = PROC_MAIN;
	struct rde_rib		*rr;
	struct peer		*p;
	struct pollfd		 pfd[POLL_MAX];
	time_t			 timeout;
	pid_t			 se_pid = 0, rde_pid = 0, pid;
	char			*conffile;
	char			*saved_argv0;
	int			 debug = 0;
	int			 rfd, keyfd;
	int			 ch, status;
	int			 pipe_m2s[2];
	int			 pipe_m2r[2];

	conffile = CONFFILE;

	log_init(1, LOG_DAEMON);	/* log to stderr until daemonized */
	log_procinit(log_procnames[PROC_MAIN]);
	log_setverbose(1);

	saved_argv0 = argv[0];
	if (saved_argv0 == NULL)
		saved_argv0 = "bgpd";

	while ((ch = getopt(argc, argv, "cdD:f:nRSv")) != -1) {
		switch (ch) {
		case 'c':
			cmd_opts |= BGPD_OPT_FORCE_DEMOTE;
			break;
		case 'd':
			debug = 1;
			break;
		case 'D':
			if (cmdline_symset(optarg) < 0)
				log_warnx("could not parse macro definition %s",
				    optarg);
			break;
		case 'f':
			conffile = optarg;
			break;
		case 'n':
			cmd_opts |= BGPD_OPT_NOACTION;
			break;
		case 'v':
			if (cmd_opts & BGPD_OPT_VERBOSE)
				cmd_opts |= BGPD_OPT_VERBOSE2;
			cmd_opts |= BGPD_OPT_VERBOSE;
			break;
		case 'R':
			proc = PROC_RDE;
			break;
		case 'S':
			proc = PROC_SE;
			break;
		default:
			usage();
			/* NOTREACHED */
		}
	}

	argc -= optind;
	argv += optind;
	if (argc > 0)
		usage();

	if (cmd_opts & BGPD_OPT_NOACTION) {
		if ((conf = parse_config(conffile, NULL)) == NULL)
			exit(1);

		if (cmd_opts & BGPD_OPT_VERBOSE)
			print_config(conf, &ribnames);
		else
			fprintf(stderr, "configuration OK\n");

		while ((rr = SIMPLEQ_FIRST(&ribnames)) != NULL) {
			SIMPLEQ_REMOVE_HEAD(&ribnames, entry);
			free(rr);
		}
		free_config(conf);
		exit(0);
	}

	switch (proc) {
	case PROC_MAIN:
		break;
	case PROC_RDE:
		rde_main(debug, cmd_opts & BGPD_OPT_VERBOSE);
		/* NOTREACHED */
	case PROC_SE:
		session_main(debug, cmd_opts & BGPD_OPT_VERBOSE);
		/* NOTREACHED */
	}

	if (geteuid())
		errx(1, "need root privileges");

	if (getpwnam(BGPD_USER) == NULL)
		errx(1, "unknown user %s", BGPD_USER);

	if ((conf = parse_config(conffile, NULL)) == NULL) {
		log_warnx("config file %s has errors", conffile);
		exit(1);
	}

	if (prepare_listeners(conf) == -1)
		exit(1);

	log_init(debug, LOG_DAEMON);
	log_setverbose(cmd_opts & BGPD_OPT_VERBOSE);

	if (!debug)
		daemon(1, 0);

	log_info("startup");

	getsockpair(pipe_m2s);
	getsockpair(pipe_m2r);

	/* fork children */
	rde_pid = start_child(PROC_RDE, saved_argv0, pipe_m2r[1], debug,
	    cmd_opts & BGPD_OPT_VERBOSE);
	se_pid = start_child(PROC_SE, saved_argv0, pipe_m2s[1], debug,
	    cmd_opts & BGPD_OPT_VERBOSE);

	signal(SIGTERM, sighdlr);
	signal(SIGINT, sighdlr);
	signal(SIGHUP, sighdlr);
	signal(SIGALRM, sighdlr);
	signal(SIGUSR1, sighdlr);
	signal(SIGPIPE, SIG_IGN);

	if ((ibuf_se = malloc(sizeof(struct imsgbuf))) == NULL ||
	    (ibuf_rde = malloc(sizeof(struct imsgbuf))) == NULL)
		fatal(NULL);
	imsg_init(ibuf_se, pipe_m2s[0]);
	imsg_init(ibuf_rde, pipe_m2r[0]);
	mrt_init(ibuf_rde, ibuf_se);
	if (kr_init(&rfd) == -1)
		quit = 1;
	keyfd = pfkey_init();

	/*
	 * rpath, read config file
	 * cpath, unlink control socket
	 * fattr, chmod on control socket
	 * wpath, needed if we are doing mrt dumps
	 *
	 * pledge placed here because kr_init() does a setsockopt on the
	 * routing socket thats not allowed at all.
	 */
#if 0
	/*
	 * disabled because we do ioctls on /dev/pf and SIOCSIFGATTR
	 * this needs some redesign of bgpd to be fixed.
	 */
BROKEN	if (pledge("stdio rpath wpath cpath fattr unix route recvfd sendfd",
	    NULL) == -1)
		fatal("pledge");
#endif

	if (imsg_send_sockets(ibuf_se, ibuf_rde))
		fatal("could not establish imsg links");
	/* control setup needs to happen late since it sends imsgs */
	if (control_setup(conf) == -1)
		quit = 1;
	if (send_config(conf) != 0)
		quit = 1;
	if (pftable_clear_all() != 0)
		quit = 1;

	while (quit == 0) {
		bzero(pfd, sizeof(pfd));

		timeout = mrt_timeout(conf->mrt);

		pfd[PFD_SOCK_ROUTE].fd = rfd;
		pfd[PFD_SOCK_ROUTE].events = POLLIN;

		pfd[PFD_SOCK_PFKEY].fd = keyfd;
		pfd[PFD_SOCK_PFKEY].events = POLLIN;

		set_pollfd(&pfd[PFD_PIPE_SESSION], ibuf_se);
		set_pollfd(&pfd[PFD_PIPE_RDE], ibuf_rde);

		if (timeout < 0 || timeout > MAX_TIMEOUT)
			timeout = MAX_TIMEOUT;
		if (poll(pfd, POLL_MAX, timeout * 1000) == -1)
			if (errno != EINTR) {
				log_warn("poll error");
				quit = 1;
			}

		if (handle_pollfd(&pfd[PFD_PIPE_SESSION], ibuf_se) == -1) {
			log_warnx("main: Lost connection to SE");
			msgbuf_clear(&ibuf_se->w);
			free(ibuf_se);
			ibuf_se = NULL;
			quit = 1;
		} else {
			if (dispatch_imsg(ibuf_se, PFD_PIPE_SESSION, conf) ==
			    -1)
				quit = 1;
		}

		if (handle_pollfd(&pfd[PFD_PIPE_RDE], ibuf_rde) == -1) {
			log_warnx("main: Lost connection to RDE");
			msgbuf_clear(&ibuf_rde->w);
			free(ibuf_rde);
			ibuf_rde = NULL;
			quit = 1;
		} else {
			if (dispatch_imsg(ibuf_rde, PFD_PIPE_RDE, conf) ==
			    -1)
				quit = 1;
		}

		if (pfd[PFD_SOCK_ROUTE].revents & POLLIN) {
			if (kr_dispatch_msg(conf->default_tableid) == -1)
				quit = 1;
		}

		if (pfd[PFD_SOCK_PFKEY].revents & POLLIN) {
			if (pfkey_read(keyfd, NULL) == -1) {
				log_warnx("pfkey_read failed, exiting...");
				quit = 1;
			}
		}

		if (reconfig) {
			u_int	error;

			reconfig = 0;
			switch (reconfigure(conffile, conf)) {
			case -1:	/* fatal error */
				quit = 1;
				break;
			case 0:		/* all OK */
				error = 0;
				break;
			case 2:
				log_info("previous reload still running");
				error = CTL_RES_PENDING;
				break;
			default:	/* parse error */
				log_warnx("config file %s has errors, "
				    "not reloading", conffile);
				error = CTL_RES_PARSE_ERROR;
				break;
			}
			if (reconfpid != 0) {
				send_imsg_session(IMSG_CTL_RESULT, reconfpid,
				    &error, sizeof(error));
				reconfpid = 0;
			}
		}

		if (mrtdump) {
			mrtdump = 0;
			mrt_handler(conf->mrt);
		}
	}

	/* close pipes */
	if (ibuf_se) {
		msgbuf_clear(&ibuf_se->w);
		close(ibuf_se->fd);
		free(ibuf_se);
		ibuf_se = NULL;
	}
	if (ibuf_rde) {
		msgbuf_clear(&ibuf_rde->w);
		close(ibuf_rde->fd);
		free(ibuf_rde);
		ibuf_rde = NULL;
	}

	/* cleanup kernel data structures */
	carp_demote_shutdown();
	kr_shutdown(conf->fib_priority, conf->default_tableid);
	pftable_clear_all();

	RB_FOREACH(p, peer_head, &conf->peers)
		pfkey_remove(p);

	while ((rr = SIMPLEQ_FIRST(&ribnames)) != NULL) {
		SIMPLEQ_REMOVE_HEAD(&ribnames, entry);
		free(rr);
	}
	free_config(conf);

	log_debug("waiting for children to terminate");
	do {
		pid = wait(&status);
		if (pid == -1) {
			if (errno != EINTR && errno != ECHILD)
				fatal("wait");
		} else if (WIFSIGNALED(status)) {
			char *name = "unknown process";
			if (pid == rde_pid)
				name = "route decision engine";
			else if (pid == se_pid)
				name = "session engine";
			log_warnx("%s terminated; signal %d", name,
				WTERMSIG(status));
		}
	} while (pid != -1 || (pid == -1 && errno == EINTR));

	free(rcname);
	free(cname);

	log_info("terminating");
	return (0);
}

pid_t
start_child(enum bgpd_process p, char *argv0, int fd, int debug, int verbose)
{
	char *argv[5];
	int argc = 0;
	pid_t pid;

	switch (pid = fork()) {
	case -1:
		fatal("cannot fork");
	case 0:
		break;
	default:
		close(fd);
		return (pid);
	}

	if (fd != 3) {
		if (dup2(fd, 3) == -1)
			fatal("cannot setup imsg fd");
	} else if (fcntl(fd, F_SETFD, 0) == -1)
		fatal("cannot setup imsg fd");

	argv[argc++] = argv0;
	switch (p) {
	case PROC_MAIN:
		fatalx("Can not start main process");
	case PROC_RDE:
		argv[argc++] = "-R";
		break;
	case PROC_SE:
		argv[argc++] = "-S";
		break;
	}
	if (debug)
		argv[argc++] = "-d";
	if (verbose)
		argv[argc++] = "-v";
	argv[argc++] = NULL;

	execvp(argv0, argv);
	fatal("execvp");
}

int
send_filterset(struct imsgbuf *i, struct filter_set_head *set)
{
	struct filter_set	*s;

	TAILQ_FOREACH(s, set, entry)
		if (imsg_compose(i, IMSG_FILTER_SET, 0, 0, -1, s,
		    sizeof(struct filter_set)) == -1)
			return (-1);
	return (0);
}

int
reconfigure(char *conffile, struct bgpd_config *conf)
{
	struct bgpd_config	*new_conf;

	if (reconfpending)
		return (2);

	log_info("rereading config");
	if ((new_conf = parse_config(conffile, &conf->peers)) == NULL)
		return (1);

	merge_config(conf, new_conf);

	if (prepare_listeners(conf) == -1) {
		return (1);
	}

	if (control_setup(conf) == -1) {
		return (1);
	}

	return send_config(conf);
}

int
send_config(struct bgpd_config *conf)
{
	struct peer		*p;
	struct filter_rule	*r;
	struct listen_addr	*la;
	struct rde_rib		*rr;
	struct l3vpn		*vpn;
	struct as_set		*aset;
	struct prefixset	*ps;
	struct prefixset_item	*psi, *npsi;
	struct roa		*roa, *nroa;

	reconfpending = 2;	/* one per child */

	expand_networks(conf);

	cflags = conf->flags;

	/* start reconfiguration */
	if (imsg_compose(ibuf_se, IMSG_RECONF_CONF, 0, 0, -1,
	    conf, sizeof(*conf)) == -1)
		return (-1);
	if (imsg_compose(ibuf_rde, IMSG_RECONF_CONF, 0, 0, -1,
	    conf, sizeof(*conf)) == -1)
		return (-1);

	TAILQ_FOREACH(la, conf->listen_addrs, entry) {
		if (imsg_compose(ibuf_se, IMSG_RECONF_LISTENER, 0, 0, la->fd,
		    la, sizeof(*la)) == -1)
			return (-1);
		la->fd = -1;
	}

	/* adjust fib syncing on reload */
	ktable_preload();

	/* RIBs for the RDE */
	while ((rr = SIMPLEQ_FIRST(&ribnames))) {
		SIMPLEQ_REMOVE_HEAD(&ribnames, entry);
		if (ktable_update(rr->rtableid, rr->name, rr->flags,
		    conf->fib_priority) == -1) {
			log_warnx("failed to load rdomain %d",
			    rr->rtableid);
			return (-1);
		}
		if (imsg_compose(ibuf_rde, IMSG_RECONF_RIB, 0, 0, -1,
		    rr, sizeof(*rr)) == -1)
			return (-1);
		free(rr);
	}

	/* send peer list to the SE */
	RB_FOREACH(p, peer_head, &conf->peers) {
		if (imsg_compose(ibuf_se, IMSG_RECONF_PEER, p->conf.id, 0, -1,
		    &p->conf, sizeof(p->conf)) == -1)
			return (-1);

		if (p->reconf_action == RECONF_REINIT)
			if (pfkey_establish(p) == -1)
				log_peer_warnx(&p->conf, "pfkey setup failed");
	}

	/* networks go via kroute to the RDE */
	kr_net_reload(conf->default_tableid, 0, &conf->networks);

	/* prefixsets for filters in the RDE */
	while ((ps = SIMPLEQ_FIRST(&conf->prefixsets)) != NULL) {
		SIMPLEQ_REMOVE_HEAD(&conf->prefixsets, entry);
		if (imsg_compose(ibuf_rde, IMSG_RECONF_PREFIX_SET, 0, 0, -1,
		    ps->name, sizeof(ps->name)) == -1)
			return (-1);
		RB_FOREACH_SAFE(psi, prefixset_tree, &ps->psitems, npsi) {
			RB_REMOVE(prefixset_tree, &ps->psitems, psi);
			if (imsg_compose(ibuf_rde, IMSG_RECONF_PREFIX_SET_ITEM,
			    0, 0, -1, psi, sizeof(*psi)) == -1)
				return (-1);
			free(psi);
		}
		free(ps);
	}

	/* originsets for filters in the RDE */
	while ((ps = SIMPLEQ_FIRST(&conf->originsets)) != NULL) {
		SIMPLEQ_REMOVE_HEAD(&conf->originsets, entry);
		if (imsg_compose(ibuf_rde, IMSG_RECONF_ORIGIN_SET, 0, 0, -1,
		    ps->name, sizeof(ps->name)) == -1)
			return (-1);
		RB_FOREACH_SAFE(roa, roa_tree, &ps->roaitems, nroa) {
			RB_REMOVE(roa_tree, &ps->roaitems, roa);
			if (imsg_compose(ibuf_rde, IMSG_RECONF_ROA_ITEM, 0, 0,
			    -1, roa, sizeof(*roa)) == -1)
				return (-1);
			free(roa);
		}
		free(ps);
	}

	if (!RB_EMPTY(&conf->roa)) {
		if (imsg_compose(ibuf_rde, IMSG_RECONF_ROA_SET, 0, 0, -1,
		    NULL, 0) == -1)
			return (-1);
		RB_FOREACH_SAFE(roa, roa_tree, &conf->roa, nroa) {
			RB_REMOVE(roa_tree, &conf->roa, roa);
			if (imsg_compose(ibuf_rde, IMSG_RECONF_ROA_ITEM, 0, 0,
			    -1, roa, sizeof(*roa)) == -1)
				return (-1);
			free(roa);
		}
	}

	/* as-sets for filters in the RDE */
	while ((aset = SIMPLEQ_FIRST(&conf->as_sets)) != NULL) {
		struct ibuf *wbuf;
		u_int32_t *as;
		size_t i, l, n;

		SIMPLEQ_REMOVE_HEAD(&conf->as_sets, entry);

		as = set_get(aset->set, &n);
		if ((wbuf = imsg_create(ibuf_rde, IMSG_RECONF_AS_SET, 0, 0,
		    sizeof(n) + sizeof(aset->name))) == NULL)
			return -1;
		if (imsg_add(wbuf, &n, sizeof(n)) == -1 ||
		    imsg_add(wbuf, aset->name, sizeof(aset->name)) == -1)
			return -1;
		imsg_close(ibuf_rde, wbuf);

		for (i = 0; i < n; i += l) {
			l = (n - i > 1024 ? 1024 : n - i);
			if (imsg_compose(ibuf_rde, IMSG_RECONF_AS_SET_ITEMS,
			    0, 0, -1, as + i, l * sizeof(*as)) == -1)
				return -1;
		}

		if (imsg_compose(ibuf_rde, IMSG_RECONF_AS_SET_DONE, 0, 0, -1,
		    NULL, 0) == -1)
			return -1;

		set_free(aset->set);
		free(aset);
	}

	/* filters for the RDE */
	while ((r = TAILQ_FIRST(conf->filters)) != NULL) {
		TAILQ_REMOVE(conf->filters, r, entry);
		if (send_filterset(ibuf_rde, &r->set) == -1)
			return (-1);
		if (imsg_compose(ibuf_rde, IMSG_RECONF_FILTER, 0, 0, -1,
		    r, sizeof(struct filter_rule)) == -1)
			return (-1);
		filterset_free(&r->set);
		free(r);
	}

	while ((vpn = SIMPLEQ_FIRST(&conf->l3vpns)) != NULL) {
		SIMPLEQ_REMOVE_HEAD(&conf->l3vpns, entry);
		if (ktable_update(vpn->rtableid, vpn->descr, vpn->flags,
		    conf->fib_priority) == -1) {
			log_warnx("failed to load rdomain %d",
			    vpn->rtableid);
			return (-1);
		}
		/* networks go via kroute to the RDE */
		kr_net_reload(vpn->rtableid, vpn->rd, &vpn->net_l);

		if (imsg_compose(ibuf_rde, IMSG_RECONF_VPN, 0, 0, -1,
		    vpn, sizeof(*vpn)) == -1)
			return (-1);

		/* export targets */
		if (send_filterset(ibuf_rde, &vpn->export) == -1)
			return (-1);
		if (imsg_compose(ibuf_rde, IMSG_RECONF_VPN_EXPORT, 0, 0,
		    -1, NULL, 0) == -1)
			return (-1);
		filterset_free(&vpn->export);

		/* import targets */
		if (send_filterset(ibuf_rde, &vpn->import) == -1)
			return (-1);
		if (imsg_compose(ibuf_rde, IMSG_RECONF_VPN_IMPORT, 0, 0,
		    -1, NULL, 0) == -1)
			return (-1);
		filterset_free(&vpn->import);

		if (imsg_compose(ibuf_rde, IMSG_RECONF_VPN_DONE, 0, 0,
		    -1, NULL, 0) == -1)
			return (-1);

		free(vpn);
	}

	/* send a drain message to know when all messages where processed */
	if (imsg_compose(ibuf_se, IMSG_RECONF_DRAIN, 0, 0, -1, NULL, 0) == -1)
		return (-1);
	if (imsg_compose(ibuf_rde, IMSG_RECONF_DRAIN, 0, 0, -1, NULL, 0) == -1)
		return (-1);

	/* mrt changes can be sent out of bound */
	mrt_reconfigure(conf->mrt);
	return (0);
}

int
dispatch_imsg(struct imsgbuf *ibuf, int idx, struct bgpd_config *conf)
{
	struct imsg		 imsg;
	struct peer		*p;
	ssize_t			 n;
	int			 rv, verbose;

	rv = 0;
	while (ibuf) {
		if ((n = imsg_get(ibuf, &imsg)) == -1)
			return (-1);

		if (n == 0)
			break;

		switch (imsg.hdr.type) {
		case IMSG_KROUTE_CHANGE:
			if (idx != PFD_PIPE_RDE)
				log_warnx("route request not from RDE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE +
			    sizeof(struct kroute_full))
				log_warnx("wrong imsg len");
			else if (kr_change(imsg.hdr.peerid, imsg.data,
			    conf->fib_priority))
				rv = -1;
			break;
		case IMSG_KROUTE_DELETE:
			if (idx != PFD_PIPE_RDE)
				log_warnx("route request not from RDE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE +
			    sizeof(struct kroute_full))
				log_warnx("wrong imsg len");
			else if (kr_delete(imsg.hdr.peerid, imsg.data,
			    conf->fib_priority))
				rv = -1;
			break;
		case IMSG_KROUTE_FLUSH:
			if (idx != PFD_PIPE_RDE)
				log_warnx("route request not from RDE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE)
				log_warnx("wrong imsg len");
			else if (kr_flush(imsg.hdr.peerid))
				rv = -1;
			break;
		case IMSG_NEXTHOP_ADD:
			if (idx != PFD_PIPE_RDE)
				log_warnx("nexthop request not from RDE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE +
			    sizeof(struct bgpd_addr))
				log_warnx("wrong imsg len");
			else if (kr_nexthop_add(imsg.hdr.peerid, imsg.data,
			    conf) == -1)
				rv = -1;
			break;
		case IMSG_NEXTHOP_REMOVE:
			if (idx != PFD_PIPE_RDE)
				log_warnx("nexthop request not from RDE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE +
			    sizeof(struct bgpd_addr))
				log_warnx("wrong imsg len");
			else
				kr_nexthop_delete(imsg.hdr.peerid, imsg.data,
				    conf);
			break;
		case IMSG_PFTABLE_ADD:
			if (idx != PFD_PIPE_RDE)
				log_warnx("pftable request not from RDE");
			else
				if (imsg.hdr.len != IMSG_HEADER_SIZE +
				    sizeof(struct pftable_msg))
					log_warnx("wrong imsg len");
				else if (pftable_addr_add(imsg.data) != 0)
					rv = -1;
			break;
		case IMSG_PFTABLE_REMOVE:
			if (idx != PFD_PIPE_RDE)
				log_warnx("pftable request not from RDE");
			else
				if (imsg.hdr.len != IMSG_HEADER_SIZE +
				    sizeof(struct pftable_msg))
					log_warnx("wrong imsg len");
				else if (pftable_addr_remove(imsg.data) != 0)
					rv = -1;
			break;
		case IMSG_PFTABLE_COMMIT:
			if (idx != PFD_PIPE_RDE)
				log_warnx("pftable request not from RDE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE)
				log_warnx("wrong imsg len");
			else if (pftable_commit() != 0)
				rv = -1;
			break;
		case IMSG_PFKEY_RELOAD:
			if (idx != PFD_PIPE_SESSION) {
				log_warnx("pfkey reload request not from SE");
				break;
			}
			p = getpeerbyid(conf, imsg.hdr.peerid);
			if (p != NULL) {
				if (pfkey_establish(p) == -1)
					log_peer_warnx(&p->conf,
					    "pfkey setup failed");
			}
			break;
		case IMSG_CTL_RELOAD:
			if (idx != PFD_PIPE_SESSION)
				log_warnx("reload request not from SE");
			else {
				reconfig = 1;
				reconfpid = imsg.hdr.pid;
				if (imsg.hdr.len == IMSG_HEADER_SIZE +
				    REASON_LEN && ((char *)imsg.data)[0])
					log_info("reload due to: %s",
					    log_reason(imsg.data));
			}
			break;
		case IMSG_CTL_FIB_COUPLE:
			if (idx != PFD_PIPE_SESSION)
				log_warnx("couple request not from SE");
			else
				kr_fib_couple(imsg.hdr.peerid,
				    conf->fib_priority);
			break;
		case IMSG_CTL_FIB_DECOUPLE:
			if (idx != PFD_PIPE_SESSION)
				log_warnx("decouple request not from SE");
			else
				kr_fib_decouple(imsg.hdr.peerid,
				    conf->fib_priority);
			break;
		case IMSG_CTL_KROUTE:
		case IMSG_CTL_KROUTE_ADDR:
		case IMSG_CTL_SHOW_NEXTHOP:
		case IMSG_CTL_SHOW_INTERFACE:
		case IMSG_CTL_SHOW_FIB_TABLES:
			if (idx != PFD_PIPE_SESSION)
				log_warnx("kroute request not from SE");
			else
				kr_show_route(&imsg);
			break;
		case IMSG_IFINFO:
			if (idx != PFD_PIPE_SESSION)
				log_warnx("IFINFO request not from SE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE + IFNAMSIZ)
				log_warnx("IFINFO request with wrong len");
			else
				kr_ifinfo(imsg.data);
			break;
		case IMSG_DEMOTE:
			if (idx != PFD_PIPE_SESSION)
				log_warnx("demote request not from SE");
			else if (imsg.hdr.len != IMSG_HEADER_SIZE +
			    sizeof(struct demote_msg))
				log_warnx("DEMOTE request with wrong len");
			else {
				struct demote_msg	*msg;

				msg = imsg.data;
				carp_demote_set(msg->demote_group, msg->level);
			}
			break;
		case IMSG_CTL_LOG_VERBOSE:
			/* already checked by SE */
			memcpy(&verbose, imsg.data, sizeof(verbose));
			log_setverbose(verbose);
			break;
		case IMSG_RECONF_DONE:
			if (reconfpending == 0) {
				log_warnx("unexpected RECONF_DONE received");
				break;
			}
			if (idx == PFD_PIPE_SESSION) {
				imsg_compose(ibuf_rde, IMSG_RECONF_DONE, 0,
				    0, -1, NULL, 0);

				/* finally fix kroute information */
				ktable_postload(conf->fib_priority);

				/* redistribute list needs to be reloaded too */
				kr_reload();
			}
			reconfpending--;
			break;
		case IMSG_RECONF_DRAIN:
			if (reconfpending == 0) {
				log_warnx("unexpected RECONF_DRAIN received");
				break;
			}
			reconfpending--;
			if (reconfpending == 0) {
				/*
				 * SE goes first to bring templated neighbors
				 * in sync.
				 */
				imsg_compose(ibuf_se, IMSG_RECONF_DONE, 0,
				    0, -1, NULL, 0);
				reconfpending = 2; /* expecting 2 DONE msg */
			}
			break;
		default:
			break;
		}
		imsg_free(&imsg);
		if (rv != 0)
			return (rv);
	}
	return (0);
}

void
send_nexthop_update(struct kroute_nexthop *msg)
{
	char	*gw = NULL;

	if (msg->gateway.aid)
		if (asprintf(&gw, ": via %s",
		    log_addr(&msg->gateway)) == -1) {
			log_warn("send_nexthop_update");
			quit = 1;
		}

	log_debug("nexthop %s now %s%s%s", log_addr(&msg->nexthop),
	    msg->valid ? "valid" : "invalid",
	    msg->connected ? ": directly connected" : "",
	    msg->gateway.aid ? gw : "");

	free(gw);

	if (imsg_compose(ibuf_rde, IMSG_NEXTHOP_UPDATE, 0, 0, -1,
	    msg, sizeof(struct kroute_nexthop)) == -1)
		quit = 1;
}

void
send_imsg_session(int type, pid_t pid, void *data, u_int16_t datalen)
{
	imsg_compose(ibuf_se, type, 0, pid, -1, data, datalen);
}

int
send_network(int type, struct network_config *net, struct filter_set_head *h)
{
	if (quit)
		return (0);
	if (imsg_compose(ibuf_rde, type, 0, 0, -1, net,
	    sizeof(struct network_config)) == -1)
		return (-1);
	/* networks that get deleted don't need to send the filter set */
	if (type == IMSG_NETWORK_REMOVE)
		return (0);
	if (send_filterset(ibuf_rde, h) == -1)
		return (-1);
	if (imsg_compose(ibuf_rde, IMSG_NETWORK_DONE, 0, 0, -1, NULL, 0) == -1)
		return (-1);

	return (0);
}

int
bgpd_filternexthop(struct kroute *kr, struct kroute6 *kr6)
{
	/* kernel routes are never filtered */
	if (kr && kr->flags & F_KERNEL && kr->prefixlen != 0)
		return (0);
	if (kr6 && kr6->flags & F_KERNEL && kr6->prefixlen != 0)
		return (0);

	if (cflags & BGPD_FLAG_NEXTHOP_BGP) {
		if (kr && kr->flags & F_BGPD_INSERTED)
			return (0);
		if (kr6 && kr6->flags & F_BGPD_INSERTED)
			return (0);
	}

	if (cflags & BGPD_FLAG_NEXTHOP_DEFAULT) {
		if (kr && kr->prefixlen == 0)
			return (0);
		if (kr6 && kr6->prefixlen == 0)
			return (0);
	}

	return (1);
}

int
control_setup(struct bgpd_config *conf)
{
	int fd, restricted;

	/* control socket is outside chroot */
	if (!cname || strcmp(cname, conf->csock)) {
		if (cname) {
			free(cname);
		}
		if ((cname = strdup(conf->csock)) == NULL)
			fatal("strdup");
		if (control_check(cname) == -1)
			return (-1);
		if ((fd = control_init(0, cname)) == -1)
			fatalx("control socket setup failed");
		if (control_listen(fd) == -1)
			fatalx("control socket setup failed");
		restricted = 0;
		if (imsg_compose(ibuf_se, IMSG_RECONF_CTRL, 0, 0, fd,
		    &restricted, sizeof(restricted)) == -1)
			return (-1);
	}
	if (!conf->rcsock) {
		/* remove restricted socket */
		free(rcname);
		rcname = NULL;
	} else if (!rcname || strcmp(rcname, conf->rcsock)) {
		if (rcname) {
			free(rcname);
		}
		if ((rcname = strdup(conf->rcsock)) == NULL)
			fatal("strdup");
		if (control_check(rcname) == -1)
			return (-1);
		if ((fd = control_init(1, rcname)) == -1)
			fatalx("control socket setup failed");
		if (control_listen(fd) == -1)
			fatalx("control socket setup failed");
		restricted = 1;
		if (imsg_compose(ibuf_se, IMSG_RECONF_CTRL, 0, 0, fd,
		    &restricted, sizeof(restricted)) == -1)
			return (-1);
	}
	return (0);
}

void
set_pollfd(struct pollfd *pfd, struct imsgbuf *i)
{
	if (i == NULL || i->fd == -1) {
		pfd->fd = -1;
		return;
	}
	pfd->fd = i->fd;
	pfd->events = POLLIN;
	if (i->w.queued > 0)
		pfd->events |= POLLOUT;
}

int
handle_pollfd(struct pollfd *pfd, struct imsgbuf *i)
{
	ssize_t n;

	if (i == NULL)
		return (0);

	if (pfd->revents & POLLOUT)
		if (msgbuf_write(&i->w) <= 0 && errno != EAGAIN) {
			log_warn("imsg write error");
			close(i->fd);
			i->fd = -1;
			return (-1);
		}

	if (pfd->revents & POLLIN) {
		if ((n = imsg_read(i)) == -1 && errno != EAGAIN) {
			log_warn("imsg read error");
			close(i->fd);
			i->fd = -1;
			return (-1);
		}
		if (n == 0) {
			log_warnx("peer closed imsg connection");
			close(i->fd);
			i->fd = -1;
			return (-1);
		}
	}
	return (0);
}

static void
getsockpair(int pipe[2])
{
	int bsize, i;

	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
	    PF_UNSPEC, pipe) == -1)
		fatal("socketpair");

	for (i = 0; i < 2; i++) {
		for (bsize = MAX_SOCK_BUF; bsize >= 16 * 1024; bsize /= 2) {
			if (setsockopt(pipe[i], SOL_SOCKET, SO_RCVBUF,
			    &bsize, sizeof(bsize)) == -1) {
				if (errno != ENOBUFS)
					fatal("setsockopt(SO_RCVBUF, %d)",
					    bsize);
				log_warn("setsockopt(SO_RCVBUF, %d)", bsize);
				continue;
			}
			break;
		}
	}
	for (i = 0; i < 2; i++) {
		for (bsize = MAX_SOCK_BUF; bsize >= 16 * 1024; bsize /= 2) {
			if (setsockopt(pipe[i], SOL_SOCKET, SO_SNDBUF,
			    &bsize, sizeof(bsize)) == -1) {
				if (errno != ENOBUFS)
					fatal("setsockopt(SO_SNDBUF, %d)",
					    bsize);
				log_warn("setsockopt(SO_SNDBUF, %d)", bsize);
				continue;
			}
			break;
		}
	}
}

int
imsg_send_sockets(struct imsgbuf *se, struct imsgbuf *rde)
{
	int pipe_s2r[2];
	int pipe_s2r_ctl[2];

	getsockpair(pipe_s2r);
	getsockpair(pipe_s2r_ctl);

	if (imsg_compose(se, IMSG_SOCKET_CONN, 0, 0, pipe_s2r[0],
	    NULL, 0) == -1)
		return (-1);
	if (imsg_compose(rde, IMSG_SOCKET_CONN, 0, 0, pipe_s2r[1],
	    NULL, 0) == -1)
		return (-1);

	if (imsg_compose(se, IMSG_SOCKET_CONN_CTL, 0, 0, pipe_s2r_ctl[0],
	    NULL, 0) == -1)
		return (-1);
	if (imsg_compose(rde, IMSG_SOCKET_CONN_CTL, 0, 0, pipe_s2r_ctl[1],
	    NULL, 0) == -1)
		return (-1);

	return (0);
}