Import hostated, the host status daemon. This daemon will monitor

remote hosts and dynamically alter pf(4) tables and redirection rules
for active server load balancing.  The daemon has been written by
Pierre-Yves Ritschard (pyr at spootnik.org) and was formerly known as
"slbd".

The daemon is fully functional but it still needs some work and
cleanup so we don't link it to the build yet.  Some TODOs are a
partial rewrite of the check_* routines (use libevent whenever we
can), improvement of the manpages, and general knf and cleanup.

ok deraadt@ claudio@

1 files changed, 497 insertions, 0 deletions

diff --git a/usr.sbin/relayd/pfe.c b/usr.sbin/relayd/pfe.c
new file mode 100644
index 00000000000..0a7ff43949f
--- /dev/null
+++ b/usr.sbin/relayd/pfe.c
@@ -0,0 +1,497 @@
+/*	$OpenBSD: pfe.c,v 1.1 2006/12/16 11:45:07 reyk Exp $	*/
+
+/*
+ * Copyright (c) 2006 Pierre-Yves Ritschard <pyr@spootnik.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/queue.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <net/if.h>
+#include <errno.h>
+#include <event.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#include "hostated.h"
+
+void	pfe_sig_handler(int sig, short, void *);
+void	pfe_shutdown(void);
+void	pfe_dispatch_imsg(int, short, void *);
+void	pfe_dispatch_parent(int, short, void *);
+
+void	pfe_sync(void);
+
+static struct hostated	*env = NULL;
+
+struct imsgbuf	*ibuf_main;
+struct imsgbuf	*ibuf_hce;
+
+void
+pfe_sig_handler(int sig, short event, void *arg)
+{
+	switch (sig) {
+	case SIGINT:
+	case SIGTERM:
+		pfe_shutdown();
+	default:
+		fatalx("pfe_sig_handler: unexpected signal");
+	}
+}
+
+pid_t
+pfe(struct hostated *x_env, int pipe_parent2pfe[2], int pipe_parent2hce[2],
+	int pipe_pfe2hce[2])
+{
+	pid_t		 pid;
+	struct passwd	*pw;
+	struct event	 ev_sigint;
+	struct event	 ev_sigterm;
+
+	switch (pid = fork()) {
+	case -1:
+		fatal("pfe: cannot fork");
+	case 0:
+		break;
+	default:
+		return (pid);
+	}
+
+	env = x_env;
+
+	if (control_init() == -1)
+		fatalx("pfe: control socket setup failed");
+
+	init_filter(env);
+	init_tables(env);
+
+	if ((pw = getpwnam(HOSTATED_USER)) == NULL)
+		fatal("pfe: getpwnam");
+
+	if (chroot(pw->pw_dir) == -1)
+		fatal("pfe: chroot");
+	if (chdir("/") == -1)
+		fatal("pfe: chdir(\"/\")");
+
+	setproctitle("pf update engine");
+	hostated_process = PROC_PFE;
+
+        if (setgroups(1, &pw->pw_gid) ||
+            setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
+            setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
+                fatal("pfe: cannot drop privileges");
+
+	event_init();
+
+	signal_set(&ev_sigint, SIGINT, pfe_sig_handler, NULL);
+	signal_set(&ev_sigterm, SIGTERM, pfe_sig_handler, NULL);
+	signal_add(&ev_sigint, NULL);
+	signal_add(&ev_sigterm, NULL);
+
+	/* setup pipes */
+	close(pipe_pfe2hce[0]);
+	close(pipe_parent2pfe[0]);
+	close(pipe_parent2hce[0]);
+	close(pipe_parent2hce[1]);
+
+	if ((ibuf_hce = calloc(1, sizeof(struct imsgbuf))) == NULL ||
+	    (ibuf_main = calloc(1, sizeof(struct imsgbuf))) == NULL)
+		fatal("pfe");
+	imsg_init(ibuf_hce, pipe_pfe2hce[1], pfe_dispatch_imsg); 
+	imsg_init(ibuf_main, pipe_parent2pfe[1], pfe_dispatch_parent); 
+
+	ibuf_hce->events = EV_READ;
+	event_set(&ibuf_hce->ev, ibuf_hce->fd, ibuf_hce->events,
+		ibuf_hce->handler, ibuf_hce);
+	event_add(&ibuf_hce->ev, NULL);
+
+	ibuf_main->events = EV_READ;
+	event_set(&ibuf_main->ev, ibuf_main->fd, ibuf_main->events,
+		ibuf_main->handler, ibuf_main);
+	event_add(&ibuf_main->ev, NULL);
+
+	TAILQ_INIT(&ctl_conns);
+	control_listen();
+
+	event_dispatch();
+	pfe_shutdown();
+
+	return (0);
+}
+
+void
+pfe_shutdown(void)
+{
+	flush_rulesets(env);
+	log_info("pf update engine exiting");
+	_exit(0);
+}
+
+void
+pfe_dispatch_imsg(int fd, short event, void *ptr)
+{
+	struct imsgbuf		*ibuf;
+	struct imsg		 imsg;
+	ssize_t			 n;
+
+	struct host		*host;
+	struct table		*table;
+	struct ctl_status	 st;
+
+	ibuf = ptr;
+	switch (event) {
+	case EV_READ:
+		if ((n = imsg_read(ibuf)) == -1)
+			fatal("pfe_dispatch_imsg: imsg_read_error");
+		if (n == 0)
+			fatalx("pfe_dispatch_imsg: pipe closed");
+		break;
+	case EV_WRITE:
+		if (msgbuf_write(&ibuf->w) == -1)
+			fatal("pfe_dispatch_imsg: msgbuf_write");
+		imsg_event_add(ibuf);
+		return;
+	default:
+		fatalx("pfe_dispatch_imsg: unknown event");
+	}
+
+	for (;;) {
+		if ((n = imsg_get(ibuf, &imsg)) == -1)
+			fatal("pfe_dispatch_imsg: imsg_read error");
+		if (n == 0)
+			break;
+
+		switch (imsg.hdr.type) {
+		case IMSG_HOST_STATUS:
+			if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(st))
+				fatalx("pfe_dispatch_imsg: invalid request");
+			memcpy(&st, imsg.data, sizeof(st));
+			if ((host = host_find(env, st.id)) == NULL)
+				fatalx("pfe_dispatch_imsg: invalid host id");
+			if (host->up == st.up) {
+				log_debug("pfe_dispatch_imsg: host %d => %d",
+					  host->id, host->up);
+				fatalx("pfe_dispatch_imsg: desynchronized");
+			}
+
+			if ((table = table_find(env, host->tableid)) == NULL)
+				fatalx("pfe_dispatch_imsg: invalid table id");
+
+			log_debug("pfe_dispatch_imsg: state %d for host %u %s",
+				  st.up, host->id, host->name);
+
+			if ((st.up == HOST_UNKNOWN && host->up == HOST_DOWN) ||
+			    (st.up == HOST_DOWN && host->up == HOST_UNKNOWN)) {
+				host->up = st.up;
+				break;
+			}
+
+			if (st.up == HOST_UP) {
+				table->flags |= F_CHANGED;
+				table->up++;
+				host->flags |= F_ADD;
+				host->flags &= ~(F_DEL);
+			} else {
+				table->up--;
+				table->flags |= F_CHANGED;
+				host->flags |= F_DEL;
+				host->flags &= ~(F_ADD);
+			}
+			host->up = st.up;
+			break;
+		case IMSG_SYNC:
+			pfe_sync();
+			break;
+		default:
+			log_debug("pfe_dispatch_imsg: unexpected imsg %d",
+				  imsg.hdr.type);
+			break;
+		}
+		imsg_free(&imsg);
+	}
+	imsg_event_add(ibuf);
+}
+
+void
+pfe_dispatch_parent(int fd, short event, void * ptr)
+{
+	struct imsgbuf	*ibuf;
+        struct imsg	 imsg;
+        ssize_t		 n;
+
+	ibuf = ptr;
+	switch (event) {
+        case EV_READ:
+                if ((n = imsg_read(ibuf)) == -1)
+                        fatal("imsg_read error");
+                if (n == 0)     /* connection closed */
+                        fatalx("pfe_dispatch_parent: pipe closed");
+                break;
+        case EV_WRITE:
+                if (msgbuf_write(&ibuf->w) == -1)
+                        fatal("msgbuf_write");
+                imsg_event_add(ibuf);
+                return;
+        default:
+                fatalx("pfe_dispatch_parent: unknown event");
+	}
+
+        for (;;) {
+                if ((n = imsg_get(ibuf, &imsg)) == -1)
+                        fatal("pfe_dispatch_parent: imsg_read error");
+                if (n == 0)
+                        break;
+
+                switch (imsg.hdr.type) {
+                default:
+                        log_debug("pfe_dispatch_parent: unexpected imsg %d", 
+                                imsg.hdr.type);
+                        break;
+                }
+                imsg_free(&imsg);
+        }
+}
+
+void
+show(struct ctl_conn *c)
+{
+	struct service	*service;
+	struct host	*host;
+
+	TAILQ_FOREACH(service, &env->services, entry) {
+		imsg_compose(&c->ibuf, IMSG_CTL_SERVICE, 0, 0,
+				service, sizeof(*service));
+		if (service->flags & F_DISABLE)
+			continue;
+
+		imsg_compose(&c->ibuf, IMSG_CTL_TABLE, 0, 0,
+			     service->table, sizeof(*service->table)); 
+		if (!(service->table->flags & F_DISABLE))
+			TAILQ_FOREACH(host, &service->table->hosts, entry)
+				imsg_compose(&c->ibuf, IMSG_CTL_HOST, 0, 0,
+					     host, sizeof(*host));
+
+		if (service->backup->id == EMPTY_TABLE)
+			continue;
+		imsg_compose(&c->ibuf, IMSG_CTL_TABLE, 0, 0,
+			     service->backup, sizeof(*service->backup)); 
+		if (!(service->backup->flags & F_DISABLE))
+			TAILQ_FOREACH(host, &service->backup->hosts, entry)
+				imsg_compose(&c->ibuf, IMSG_CTL_HOST, 0, 0,
+					     host, sizeof(*host));
+	}
+	imsg_compose(&c->ibuf, IMSG_CTL_END, 0, 0, NULL, 0);
+}
+
+
+int
+disable_service(struct ctl_conn *c, objid_t id)
+{
+	struct service	*service;
+
+	if ((service = service_find(env, id)) == NULL)
+		return (-1);
+
+	if (service->flags & F_DISABLE)
+		return (0);
+
+	service->flags |= F_DISABLE;
+	service->flags &= ~(F_ADD);
+	service->flags |= F_DEL;
+	service->table->flags |= F_DISABLE;
+	log_debug("disable_service: disabled service %d", service->id);
+	pfe_sync();
+	return (0);
+}
+
+int
+enable_service(struct ctl_conn *c, objid_t id)
+{
+	struct service	*service;
+
+	if ((service = service_find(env, id)) == NULL)
+		return (-1);
+
+	if (!(service->flags & F_DISABLE))
+		return (0);
+
+	service->flags &= ~(F_DISABLE);
+	service->flags &= ~(F_DEL);
+	service->flags |= F_ADD;
+	log_debug("enable_service: enabled service %d", service->id);
+
+	/* XXX: we're syncing twice */
+	if (enable_table(c, service->table->id))
+		return (-1);
+	if (enable_table(c, service->backup->id))
+		return (-1);
+	return (0);
+}
+
+int
+disable_table(struct ctl_conn *c, objid_t id)
+{
+	struct table	*table;
+	struct service	*service;
+	struct host	*host;
+
+	if (id == EMPTY_TABLE)
+		return (-1);
+	if ((table = table_find(env, id)) == NULL)
+		return (-1);
+	if ((service = service_find(env, table->serviceid)) == NULL)
+		fatalx("disable_table: desynchronised");
+
+	if (table->flags & F_DISABLE)
+		return (0);
+	table->flags |= (F_DISABLE|F_CHANGED);
+	table->up = 0;
+	TAILQ_FOREACH(host, &table->hosts, entry)
+		host->up = HOST_UNKNOWN;
+	imsg_compose(ibuf_hce, IMSG_TABLE_DISABLE, 0, 0, &id, sizeof(id));
+	log_debug("disable_table: disabled table %d", table->id);
+	pfe_sync();
+	return (0);
+}
+
+int
+enable_table(struct ctl_conn *c, objid_t id)
+{
+	struct service	*service;
+	struct table	*table;
+	struct host	*host;
+
+	if (id == EMPTY_TABLE)
+		return (-1);
+	if ((table = table_find(env, id)) == NULL)
+		return (-1);
+	if ((service = service_find(env, table->serviceid)) == NULL)
+		fatalx("enable_table: desynchronised");
+
+	if (!(table->flags & F_DISABLE))
+		return (0);
+	table->flags &= ~(F_DISABLE);
+	table->flags |= F_CHANGED;
+	table->up = 0;
+	TAILQ_FOREACH(host, &table->hosts, entry)
+		host->up = HOST_UNKNOWN;
+	imsg_compose(ibuf_hce, IMSG_TABLE_ENABLE, 0, 0, &id, sizeof(id));
+	log_debug("enable_table: enabled table %d", table->id);
+	pfe_sync();
+	return (0);
+}
+
+int
+disable_host(struct ctl_conn *c, objid_t id)
+{
+	struct host	*host;
+	struct table	*table;
+
+	if ((host = host_find(env, id)) == NULL)
+		return (-1);
+
+	if (host->flags & F_DISABLE)
+		return (0);
+
+	if (host->up == HOST_UP) {
+		if ((table = table_find(env, host->tableid)) == NULL)
+			fatalx("disable_host: invalid table id");
+		table->up--;
+		table->flags |= F_CHANGED;
+	}
+
+	host->up = HOST_UNKNOWN;
+	host->flags |= F_DISABLE;
+	host->flags |= F_DEL;
+	host->flags &= ~(F_ADD);
+
+	imsg_compose(ibuf_hce, IMSG_HOST_DISABLE, 0, 0, &id, sizeof (id));
+	log_debug("disable_host: disabled host %d", host->id);
+	pfe_sync();
+	return (0);
+}
+
+int
+enable_host(struct ctl_conn *c, objid_t id)
+{
+	struct host	*host;
+
+	if ((host = host_find(env, id)) == NULL)
+		return (-1);
+
+	if (!(host->flags & F_DISABLE))
+		return (0);
+
+	host->up = HOST_UNKNOWN;
+	host->flags &= ~(F_DISABLE);
+	host->flags &= ~(F_DEL);
+	host->flags &= ~(F_ADD);
+
+	imsg_compose(ibuf_hce, IMSG_HOST_ENABLE, 0, 0, &id, sizeof (id));
+	log_debug("enable_host: enabled host %d", host->id);
+	pfe_sync();
+	return (0);
+}
+
+void
+pfe_sync(void)
+{
+	struct service	*service;
+	struct table	*active;
+	int		 backup;
+
+	TAILQ_FOREACH(service, &env->services, entry) {
+		backup = (service->flags & F_BACKUP);
+		service->flags &= ~(F_BACKUP);
+		service->flags &= ~(F_DOWN);
+
+		if (service->flags & F_DISABLE ||
+		    (service->table->up == 0 && service->backup->up == 0)) {
+			service->flags |= F_DOWN;
+			active = NULL;
+		} else if (service->table->up == 0 && service->backup->up > 0) {
+			service->flags |= F_BACKUP;
+			active = service->backup;
+			active->flags |= service->table->flags & F_CHANGED;
+			active->flags |= service->backup->flags & F_CHANGED;
+		} else
+			active = service->table;
+
+		if (active != NULL && active->flags & F_CHANGED)
+			sync_table(env, service, active);
+
+		service->table->flags &= ~(F_CHANGED);
+		service->backup->flags &= ~(F_CHANGED);
+		
+		if (service->flags & F_DOWN) {
+			if (service->flags & F_ACTIVE_RULESET) {
+				flush_table(env, service);
+				log_debug("pfe_sync: disabling ruleset");
+				service->flags &= ~(F_ACTIVE_RULESET);
+				sync_ruleset(env, service, 0);
+			}
+		} else if (!(service->flags & F_ACTIVE_RULESET)) {
+			log_debug("pfe_sync: enabling ruleset");
+			service->flags |= F_ACTIVE_RULESET;
+			sync_ruleset(env, service, 1);
+		}
+	}
+}