NSD v3.2.4

1 files changed, 839 insertions, 0 deletions

diff --git a/usr.sbin/nsd/ipc.c b/usr.sbin/nsd/ipc.c
new file mode 100644
index 00000000000..449c0514fc1
--- /dev/null
+++ b/usr.sbin/nsd/ipc.c
@@ -0,0 +1,839 @@
+/*
+ * ipc.c - Interprocess communication routines. Handlers read and write.
+ *
+ * Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
+ *
+ * See LICENSE for the license.
+ *
+ */
+
+#include <config.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "ipc.h"
+#include "buffer.h"
+#include "xfrd-tcp.h"
+#include "nsd.h"
+#include "namedb.h"
+#include "xfrd.h"
+#include "xfrd-notify.h"
+
+/* set is_ok for the zone according to the zone message */
+static zone_type* handle_xfrd_zone_state(struct nsd* nsd, buffer_type* packet);
+/* write ipc ZONE_STATE message into the buffer */
+static void write_zone_state_packet(buffer_type* packet, zone_type* zone);
+/* attempt to send NSD_STATS command to child fd */
+static void send_stat_to_child(struct main_ipc_handler_data* data, int fd);
+/* write IPC expire notification msg to a buffer */
+static void xfrd_write_expire_notification(buffer_type* buffer, xfrd_zone_t* zone);
+/* send reload request over the IPC channel */
+static void xfrd_send_reload_req(xfrd_state_t* xfrd);
+/* send quit request over the IPC channel */
+static void xfrd_send_quit_req(xfrd_state_t* xfrd);
+/* get SOA INFO out of IPC packet buffer */
+static void xfrd_handle_ipc_SOAINFO(xfrd_state_t* xfrd, buffer_type* packet);
+/* perform read part of handle ipc for xfrd */
+static void xfrd_handle_ipc_read(netio_handler_type *handler, xfrd_state_t* xfrd);
+
+static zone_type*
+handle_xfrd_zone_state(struct nsd* nsd, buffer_type* packet)
+{
+	uint8_t ok;
+	const dname_type *dname;
+	domain_type *domain;
+	zone_type *zone;
+
+	ok = buffer_read_u8(packet);
+	dname = (dname_type*)buffer_current(packet);
+	DEBUG(DEBUG_IPC,1, (LOG_INFO, "handler zone state %s is %s",
+		dname_to_string(dname, NULL), ok?"ok":"expired"));
+	/* find in zone_types, if does not exist, we cannot serve anyway */
+	/* find zone in config, since that one always exists */
+	domain = domain_table_find(nsd->db->domains, dname);
+	if(!domain) {
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "zone state msg, empty zone (domain %s)",
+			dname_to_string(dname, NULL)));
+		return NULL;
+	}
+	zone = domain_find_zone(domain);
+	if(!zone || dname_compare(domain_dname(zone->apex), dname) != 0) {
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "zone state msg, empty zone (zone %s)",
+			dname_to_string(dname, NULL)));
+		return NULL;
+	}
+	assert(zone);
+	/* only update zone->is_ok if needed to minimize copy-on-write
+	   of memory pages shared after fork() */
+	if(ok && !zone->is_ok)
+		zone->is_ok = 1;
+	if(!ok && zone->is_ok)
+		zone->is_ok = 0;
+	return zone;
+}
+
+void
+child_handle_parent_command(netio_type *ATTR_UNUSED(netio),
+		      netio_handler_type *handler,
+		      netio_event_types_type event_types)
+{
+	sig_atomic_t mode;
+	int len;
+	struct ipc_handler_conn_data *data =
+		(struct ipc_handler_conn_data *) handler->user_data;
+	if (!(event_types & NETIO_EVENT_READ)) {
+		return;
+	}
+
+	if(data->conn->is_reading) {
+		int ret = conn_read(data->conn);
+		if(ret == -1) {
+			log_msg(LOG_ERR, "handle_parent_command: error in conn_read: %s",
+				strerror(errno));
+			data->conn->is_reading = 0;
+			return;
+		}
+		if(ret == 0) {
+			return; /* continue later */
+		}
+		/* completed */
+		data->conn->is_reading = 0;
+		buffer_flip(data->conn->packet);
+		(void)handle_xfrd_zone_state(data->nsd, data->conn->packet);
+		return;
+	}
+
+	if ((len = read(handler->fd, &mode, sizeof(mode))) == -1) {
+		log_msg(LOG_ERR, "handle_parent_command: read: %s",
+			strerror(errno));
+		return;
+	}
+	if (len == 0)
+	{
+		/* parent closed the connection. Quit */
+		data->nsd->mode = NSD_QUIT;
+		return;
+	}
+
+	switch (mode) {
+	case NSD_STATS:
+	case NSD_QUIT:
+		data->nsd->mode = mode;
+		break;
+	case NSD_ZONE_STATE:
+		data->conn->is_reading = 1;
+		data->conn->total_bytes = 0;
+		data->conn->msglen = 0;
+		data->conn->fd = handler->fd;
+		buffer_clear(data->conn->packet);
+		break;
+	default:
+		log_msg(LOG_ERR, "handle_parent_command: bad mode %d",
+			(int) mode);
+		break;
+	}
+}
+
+void
+parent_handle_xfrd_command(netio_type *ATTR_UNUSED(netio),
+		      netio_handler_type *handler,
+		      netio_event_types_type event_types)
+{
+	sig_atomic_t mode;
+	int len;
+	struct ipc_handler_conn_data *data =
+		(struct ipc_handler_conn_data *) handler->user_data;
+	if (!(event_types & NETIO_EVENT_READ)) {
+		return;
+	}
+
+	if(data->conn->is_reading) {
+		/* handle ZONE_STATE forward to children */
+		int ret = conn_read(data->conn);
+		size_t i;
+		zone_type* zone;
+		if(ret == -1) {
+			log_msg(LOG_ERR, "main xfrd listener: error in conn_read: %s",
+				strerror(errno));
+			data->conn->is_reading = 0;
+			return;
+		}
+		if(ret == 0) {
+			return; /* continue later */
+		}
+		/* completed */
+		data->conn->is_reading = 0;
+		buffer_flip(data->conn->packet);
+		zone = handle_xfrd_zone_state(data->nsd, data->conn->packet);
+		if(!zone)
+			return;
+		/* forward to all children */
+		for (i = 0; i < data->nsd->child_count; ++i) {
+			if(!zone->dirty[i]) {
+				zone->dirty[i] = 1;
+				stack_push(data->nsd->children[i].dirty_zones, zone);
+				data->nsd->children[i].handler->event_types |=
+					NETIO_EVENT_WRITE;
+			}
+		}
+		return;
+	}
+
+	if ((len = read(handler->fd, &mode, sizeof(mode))) == -1) {
+		log_msg(LOG_ERR, "handle_xfrd_command: read: %s",
+			strerror(errno));
+		return;
+	}
+	if (len == 0)
+	{
+		DEBUG(DEBUG_IPC,1, (LOG_ERR, "handle_xfrd_command: xfrd closed channel."));
+		close(handler->fd);
+		handler->fd = -1;
+		return;
+	}
+
+	switch (mode) {
+	case NSD_RELOAD:
+		data->nsd->signal_hint_reload = 1;
+		break;
+	case NSD_QUIT:
+		data->nsd->mode = mode;
+		break;
+	case NSD_REAP_CHILDREN:
+		data->nsd->signal_hint_child = 1;
+		break;
+	case NSD_ZONE_STATE:
+		data->conn->is_reading = 1;
+		data->conn->total_bytes = 0;
+		data->conn->msglen = 0;
+		data->conn->fd = handler->fd;
+		buffer_clear(data->conn->packet);
+		break;
+	default:
+		log_msg(LOG_ERR, "handle_xfrd_command: bad mode %d",
+			(int) mode);
+		break;
+	}
+}
+
+static void
+write_zone_state_packet(buffer_type* packet, zone_type* zone)
+{
+	sig_atomic_t cmd = NSD_ZONE_STATE;
+	uint8_t ok = zone->is_ok;
+	uint16_t sz;
+	if(!zone->apex) {
+		return;
+	}
+	sz = dname_total_size(domain_dname(zone->apex)) + 1;
+	sz = htons(sz);
+
+	buffer_clear(packet);
+	buffer_write(packet, &cmd, sizeof(cmd));
+	buffer_write(packet, &sz, sizeof(sz));
+	buffer_write(packet, &ok, sizeof(ok));
+	buffer_write(packet, domain_dname(zone->apex),
+		dname_total_size(domain_dname(zone->apex)));
+	buffer_flip(packet);
+}
+
+static void
+send_stat_to_child(struct main_ipc_handler_data* data, int fd)
+{
+	sig_atomic_t cmd = NSD_STATS;
+	if(write(fd, &cmd, sizeof(cmd)) == -1) {
+		if(errno == EAGAIN || errno == EINTR)
+			return; /* try again later */
+		log_msg(LOG_ERR, "svrmain: problems sending stats to child %d command: %s",
+			(int)data->child->pid, strerror(errno));
+		return;
+	}
+	data->child->need_to_send_STATS = 0;
+}
+
+int packet_read_query_section(buffer_type *packet, uint8_t* dest, uint16_t* qtype, uint16_t* qclass);
+static void
+debug_print_fwd_name(int ATTR_UNUSED(len), buffer_type* packet, int acl_num)
+{
+	uint8_t qnamebuf[MAXDOMAINLEN];
+	uint16_t qtype, qclass;
+	const dname_type* dname;
+	region_type* tempregion = region_create(xalloc, free);
+
+	size_t bufpos = buffer_position(packet);
+	buffer_rewind(packet);
+	buffer_skip(packet, 12);
+	if(packet_read_query_section(packet, qnamebuf, &qtype, &qclass)) {
+		dname = dname_make(tempregion, qnamebuf, 1);
+		log_msg(LOG_INFO, "main: fwd packet for %s, acl %d",
+			dname_to_string(dname,0), acl_num);
+	} else {
+		log_msg(LOG_INFO, "main: fwd packet badqname, acl %d", acl_num);
+	}
+	buffer_set_position(packet, bufpos);
+	region_destroy(tempregion);
+}
+
+static void
+send_quit_to_child(struct main_ipc_handler_data* data, int fd)
+{
+	sig_atomic_t cmd = NSD_QUIT;
+	if(write(fd, &cmd, sizeof(cmd)) == -1) {
+		if(errno == EAGAIN || errno == EINTR)
+			return; /* try again later */
+		log_msg(LOG_ERR, "svrmain: problems sending quit to child %d command: %s",
+			(int)data->child->pid, strerror(errno));
+		return;
+	}
+	data->child->need_to_send_QUIT = 0;
+	DEBUG(DEBUG_IPC,2, (LOG_INFO, "main: sent quit to child %d",
+		(int)data->child->pid));
+}
+
+void
+parent_handle_child_command(netio_type *ATTR_UNUSED(netio),
+		      netio_handler_type *handler,
+		      netio_event_types_type event_types)
+{
+	sig_atomic_t mode;
+	int len;
+	struct main_ipc_handler_data *data =
+		(struct main_ipc_handler_data*)handler->user_data;
+
+	/* do a nonblocking write to the child if it is ready. */
+	if (event_types & NETIO_EVENT_WRITE) {
+		if(!data->busy_writing_zone_state &&
+			!data->child->need_to_send_STATS &&
+			!data->child->need_to_send_QUIT &&
+			!data->child->need_to_exit &&
+			data->child->dirty_zones->num > 0) {
+			/* create packet from next dirty zone */
+			zone_type* zone = (zone_type*)stack_pop(data->child->dirty_zones);
+			assert(zone);
+			zone->dirty[data->child_num] = 0;
+			data->busy_writing_zone_state = 1;
+			write_zone_state_packet(data->write_conn->packet, zone);
+			data->write_conn->msglen = buffer_limit(data->write_conn->packet);
+			data->write_conn->total_bytes = sizeof(uint16_t); /* len bytes already in packet */
+			data->write_conn->fd = handler->fd;
+		}
+		if(data->busy_writing_zone_state) {
+			/* write more of packet */
+			int ret = conn_write(data->write_conn);
+			if(ret == -1) {
+				log_msg(LOG_ERR, "handle_child_cmd %d: could not write: %s",
+					(int)data->child->pid, strerror(errno));
+				data->busy_writing_zone_state = 0;
+			} else if(ret == 1) {
+				data->busy_writing_zone_state = 0; /* completed */
+			}
+		} else if(data->child->need_to_send_STATS &&
+			  !data->child->need_to_exit) {
+			send_stat_to_child(data, handler->fd);
+		} else if(data->child->need_to_send_QUIT) {
+			send_quit_to_child(data, handler->fd);
+			if(!data->child->need_to_send_QUIT)
+				handler->event_types = NETIO_EVENT_READ;
+		}
+		if(!data->busy_writing_zone_state &&
+			!data->child->need_to_send_STATS &&
+			!data->child->need_to_send_QUIT &&
+			data->child->dirty_zones->num == 0) {
+			handler->event_types = NETIO_EVENT_READ;
+		}
+	}
+
+	if (!(event_types & NETIO_EVENT_READ)) {
+		return;
+	}
+
+	if (data->forward_mode) {
+		int got_acl;
+		/* forward the data to xfrd */
+		DEBUG(DEBUG_IPC,2, (LOG_INFO,
+			"main passed packet readup %d", (int)data->got_bytes));
+		if(data->got_bytes < sizeof(data->total_bytes))
+		{
+			if ((len = read(handler->fd,
+				(char*)&data->total_bytes+data->got_bytes,
+				sizeof(data->total_bytes)-data->got_bytes)) == -1) {
+				log_msg(LOG_ERR, "handle_child_command: read: %s",
+					strerror(errno));
+				return;
+			}
+			if(len == 0) {
+				/* EOF */
+				data->forward_mode = 0;
+				return;
+			}
+			data->got_bytes += len;
+			if(data->got_bytes < sizeof(data->total_bytes))
+				return;
+			data->total_bytes = ntohs(data->total_bytes);
+			buffer_clear(data->packet);
+			if(data->total_bytes > buffer_capacity(data->packet)) {
+				log_msg(LOG_ERR, "internal error: ipc too large");
+				exit(1);
+			}
+			return;
+		}
+		/* read the packet */
+		if(data->got_bytes-sizeof(data->total_bytes) < data->total_bytes) {
+			if((len = read(handler->fd, buffer_current(data->packet),
+				data->total_bytes - (data->got_bytes-sizeof(data->total_bytes))
+				)) == -1 ) {
+				log_msg(LOG_ERR, "handle_child_command: read: %s",
+					strerror(errno));
+				return;
+			}
+			if(len == 0) {
+				/* EOF */
+				data->forward_mode = 0;
+				return;
+			}
+			data->got_bytes += len;
+			buffer_skip(data->packet, len);
+			/* read rest later */
+			return;
+		}
+		/* read the acl number */
+		got_acl = data->got_bytes - sizeof(data->total_bytes) - data->total_bytes;
+		if((len = read(handler->fd, (char*)&data->acl_num+got_acl,
+			sizeof(data->acl_num)-got_acl)) == -1 ) {
+			log_msg(LOG_ERR, "handle_child_command: read: %s",
+				strerror(errno));
+			return;
+		}
+		if(len == 0) {
+			/* EOF */
+			data->forward_mode = 0;
+			return;
+		}
+		got_acl += len;
+		data->got_bytes += len;
+		if(got_acl >= (int)sizeof(data->acl_num)) {
+			uint16_t len = htons(data->total_bytes);
+			DEBUG(DEBUG_IPC,2, (LOG_INFO,
+				"main fwd passed packet write %d", (int)data->got_bytes));
+#ifndef NDEBUG
+			if(nsd_debug_level >= 2)
+				debug_print_fwd_name(len, data->packet, data->acl_num);
+#endif
+			data->forward_mode = 0;
+			mode = NSD_PASS_TO_XFRD;
+			if(!write_socket(*data->xfrd_sock, &mode, sizeof(mode)) ||
+			   !write_socket(*data->xfrd_sock, &len, sizeof(len)) ||
+			   !write_socket(*data->xfrd_sock, buffer_begin(data->packet),
+				data->total_bytes) ||
+			   !write_socket(*data->xfrd_sock, &data->acl_num,
+			   	sizeof(data->acl_num))) {
+				log_msg(LOG_ERR, "error in ipc fwd main2xfrd: %s",
+					strerror(errno));
+			}
+		}
+		return;
+	}
+
+	/* read command from ipc */
+	if ((len = read(handler->fd, &mode, sizeof(mode))) == -1) {
+		log_msg(LOG_ERR, "handle_child_command: read: %s",
+			strerror(errno));
+		return;
+	}
+	if (len == 0)
+	{
+		size_t i;
+		if(handler->fd > 0) close(handler->fd);
+		for(i=0; i<data->nsd->child_count; ++i)
+			if(data->nsd->children[i].child_fd == handler->fd) {
+				data->nsd->children[i].child_fd = -1;
+				data->nsd->children[i].has_exited = 1;
+				DEBUG(DEBUG_IPC,1, (LOG_INFO,
+					"server %d closed cmd channel",
+					(int) data->nsd->children[i].pid));
+			}
+		handler->fd = -1;
+		parent_check_all_children_exited(data->nsd);
+		return;
+	}
+
+	switch (mode) {
+	case NSD_QUIT:
+		data->nsd->mode = mode;
+		break;
+	case NSD_STATS:
+		data->nsd->signal_hint_stats = 1;
+		break;
+	case NSD_REAP_CHILDREN:
+		data->nsd->signal_hint_child = 1;
+		break;
+	case NSD_PASS_TO_XFRD:
+		/* set mode for handle_child_command; echo to xfrd. */
+		data->forward_mode = 1;
+		data->got_bytes = 0;
+		data->total_bytes = 0;
+		break;
+	default:
+		log_msg(LOG_ERR, "handle_child_command: bad mode %d",
+			(int) mode);
+		break;
+	}
+}
+
+void
+parent_check_all_children_exited(struct nsd* nsd)
+{
+	size_t i;
+	for(i=0; i < nsd->child_count; i++) {
+		if(!nsd->children[i].need_to_exit)
+		      return;
+		if(!nsd->children[i].has_exited)
+		      return;
+	}
+	nsd->mode = NSD_QUIT_SYNC;
+	DEBUG(DEBUG_IPC,2, (LOG_INFO, "main: all children exited. quit sync."));
+}
+
+void
+parent_handle_reload_command(netio_type *ATTR_UNUSED(netio),
+		      netio_handler_type *handler,
+		      netio_event_types_type event_types)
+{
+	sig_atomic_t mode;
+	int len;
+	size_t i;
+	struct nsd *nsd = (struct nsd*) handler->user_data;
+	if (!(event_types & NETIO_EVENT_READ)) {
+		return;
+	}
+	/* read command from ipc */
+	if ((len = read(handler->fd, &mode, sizeof(mode))) == -1) {
+		log_msg(LOG_ERR, "handle_reload_command: read: %s",
+			strerror(errno));
+		return;
+	}
+	if (len == 0)
+	{
+		if(handler->fd > 0) {
+			close(handler->fd);
+			handler->fd = -1;
+		}
+		log_msg(LOG_ERR, "handle_reload_cmd: reload closed cmd channel");
+		return;
+	}
+	switch (mode) {
+	case NSD_QUIT_SYNC:
+		/* set all children to exit, only then notify xfrd. */
+		/* so that buffered packets to pass to xfrd can arrive. */
+		for(i=0; i < nsd->child_count; i++) {
+			nsd->children[i].need_to_exit = 1;
+			if(nsd->children[i].pid > 0 &&
+			   nsd->children[i].child_fd > 0) {
+				nsd->children[i].need_to_send_QUIT = 1;
+				nsd->children[i].handler->event_types
+					|= NETIO_EVENT_WRITE;
+			} else {
+				if(nsd->children[i].child_fd == -1)
+					nsd->children[i].has_exited = 1;
+			}
+		}
+		parent_check_all_children_exited(nsd);
+		break;
+	default:
+		log_msg(LOG_ERR, "handle_reload_command: bad mode %d",
+			(int) mode);
+		break;
+	}
+}
+
+static void
+xfrd_write_expire_notification(buffer_type* buffer, xfrd_zone_t* zone)
+{
+	sig_atomic_t cmd = NSD_ZONE_STATE;
+	uint8_t ok = 1;
+	uint16_t sz = dname_total_size(zone->apex) + 1;
+	sz = htons(sz);
+	if(zone->state == xfrd_zone_expired)
+		ok = 0;
+
+	DEBUG(DEBUG_IPC,1, (LOG_INFO,
+		"xfrd encoding ipc zone state msg for zone %s state %d.",
+		zone->apex_str, (int)zone->state));
+
+	buffer_clear(buffer);
+	buffer_write(buffer, &cmd, sizeof(cmd));
+	buffer_write(buffer, &sz, sizeof(sz));
+	buffer_write(buffer, &ok, sizeof(ok));
+	buffer_write(buffer, zone->apex, dname_total_size(zone->apex));
+	buffer_flip(buffer);
+}
+
+static void
+xfrd_send_reload_req(xfrd_state_t* xfrd)
+{
+	sig_atomic_t req = NSD_RELOAD;
+	/* ask server_main for a reload */
+	if(write(xfrd->ipc_handler.fd, &req, sizeof(req)) == -1) {
+		if(errno == EAGAIN || errno == EINTR)
+			return; /* try again later */
+		log_msg(LOG_ERR, "xfrd: problems sending reload command: %s",
+			strerror(errno));
+		return;
+	}
+	DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: asked nsd to reload new updates"));
+	xfrd_prepare_zones_for_reload();
+	xfrd->reload_cmd_last_sent = xfrd_time();
+	xfrd->need_to_send_reload = 0;
+	xfrd->can_send_reload = 0;
+}
+
+static void
+xfrd_send_quit_req(xfrd_state_t* xfrd)
+{
+	sig_atomic_t cmd = NSD_QUIT;
+	xfrd->ipc_send_blocked = 1;
+	xfrd->ipc_handler.event_types &= (~NETIO_EVENT_WRITE);
+	xfrd->sending_zone_state = 0;
+	DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: ipc send ackreload(quit)"));
+	if(write_socket(xfrd->ipc_handler.fd, &cmd, sizeof(cmd)) == -1) {
+		log_msg(LOG_ERR, "xfrd: error writing ack to main: %s",
+			strerror(errno));
+	}
+	xfrd->need_to_send_quit = 0;
+}
+
+static void
+xfrd_handle_ipc_SOAINFO(xfrd_state_t* xfrd, buffer_type* packet)
+{
+	xfrd_soa_t soa;
+	xfrd_soa_t* soa_ptr = &soa;
+	xfrd_zone_t* zone;
+	/* dname is sent in memory format */
+	const dname_type* dname = (const dname_type*)buffer_begin(packet);
+
+	/* find zone and decode SOA */
+	zone = (xfrd_zone_t*)rbtree_search(xfrd->zones, dname);
+	buffer_skip(packet, dname_total_size(dname));
+
+	if(!buffer_available(packet, sizeof(uint32_t)*6 + sizeof(uint8_t)*2)) {
+		/* NSD has zone without any info */
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "SOAINFO for %s lost zone",
+			dname_to_string(dname,0)));
+		soa_ptr = NULL;
+	} else {
+		/* read soa info */
+		memset(&soa, 0, sizeof(soa));
+		/* left out type, klass, count for speed */
+		soa.type = htons(TYPE_SOA);
+		soa.klass = htons(CLASS_IN);
+		soa.ttl = htonl(buffer_read_u32(packet));
+		soa.rdata_count = htons(7);
+		soa.prim_ns[0] = buffer_read_u8(packet);
+		if(!buffer_available(packet, soa.prim_ns[0]))
+			return;
+		buffer_read(packet, soa.prim_ns+1, soa.prim_ns[0]);
+		soa.email[0] = buffer_read_u8(packet);
+		if(!buffer_available(packet, soa.email[0]))
+			return;
+		buffer_read(packet, soa.email+1, soa.email[0]);
+
+		soa.serial = htonl(buffer_read_u32(packet));
+		soa.refresh = htonl(buffer_read_u32(packet));
+		soa.retry = htonl(buffer_read_u32(packet));
+		soa.expire = htonl(buffer_read_u32(packet));
+		soa.minimum = htonl(buffer_read_u32(packet));
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "SOAINFO for %s %u",
+			dname_to_string(dname,0), ntohl(soa.serial)));
+	}
+
+	if(!zone) {
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: zone %s master zone updated",
+			dname_to_string(dname,0)));
+		notify_handle_master_zone_soainfo(xfrd->notify_zones,
+			dname, soa_ptr);
+		return;
+	}
+	xfrd_handle_incoming_soa(zone, soa_ptr, xfrd_time());
+}
+
+void
+xfrd_handle_ipc(netio_type* ATTR_UNUSED(netio),
+	netio_handler_type *handler,
+	netio_event_types_type event_types)
+{
+	xfrd_state_t* xfrd = (xfrd_state_t*)handler->user_data;
+        if ((event_types & NETIO_EVENT_READ))
+	{
+		/* first attempt to read as a signal from main
+		 * could block further send operations */
+		xfrd_handle_ipc_read(handler, xfrd);
+	}
+        if ((event_types & NETIO_EVENT_WRITE))
+	{
+		if(xfrd->ipc_send_blocked) { /* wait for SOA_END */
+			handler->event_types = NETIO_EVENT_READ;
+			return;
+		}
+		/* if necessary prepare a packet */
+		if(!(xfrd->can_send_reload && xfrd->need_to_send_reload) &&
+			!xfrd->need_to_send_quit &&
+			!xfrd->sending_zone_state &&
+			xfrd->dirty_zones->num > 0) {
+			xfrd_zone_t* zone = (xfrd_zone_t*)stack_pop(xfrd->dirty_zones);
+			assert(zone);
+			zone->dirty = 0;
+			xfrd->sending_zone_state = 1;
+			xfrd_write_expire_notification(xfrd->ipc_conn_write->packet, zone);
+			xfrd->ipc_conn_write->msglen = buffer_limit(xfrd->ipc_conn_write->packet);
+			/* skip length bytes; they are encoded in the packet, after cmd */
+			xfrd->ipc_conn_write->total_bytes = sizeof(uint16_t);
+		}
+		/* write a bit */
+		if(xfrd->sending_zone_state) {
+			/* call conn_write */
+			int ret = conn_write(xfrd->ipc_conn_write);
+			if(ret == -1) {
+				log_msg(LOG_ERR, "xfrd: error in write ipc: %s", strerror(errno));
+				xfrd->sending_zone_state = 0;
+			}
+			else if(ret == 1) { /* done */
+				xfrd->sending_zone_state = 0;
+			}
+		} else if(xfrd->need_to_send_quit) {
+			xfrd_send_quit_req(xfrd);
+		} else if(xfrd->can_send_reload && xfrd->need_to_send_reload) {
+			xfrd_send_reload_req(xfrd);
+		}
+		if(!(xfrd->can_send_reload && xfrd->need_to_send_reload) &&
+			!xfrd->need_to_send_quit &&
+			!xfrd->sending_zone_state &&
+			xfrd->dirty_zones->num == 0) {
+			handler->event_types = NETIO_EVENT_READ; /* disable writing for now */
+		}
+	}
+
+}
+
+static void
+xfrd_handle_ipc_read(netio_handler_type *handler, xfrd_state_t* xfrd)
+{
+        sig_atomic_t cmd;
+        int len;
+
+	if(xfrd->ipc_conn->is_reading==2) {
+		buffer_type* tmp = xfrd->ipc_pass;
+		uint32_t acl_num;
+		/* read acl_num */
+		int ret = conn_read(xfrd->ipc_conn);
+		if(ret == -1) {
+			log_msg(LOG_ERR, "xfrd: error in read ipc: %s", strerror(errno));
+			xfrd->ipc_conn->is_reading = 0;
+			return;
+		}
+		if(ret == 0)
+			return;
+		buffer_flip(xfrd->ipc_conn->packet);
+		xfrd->ipc_pass = xfrd->ipc_conn->packet;
+		xfrd->ipc_conn->packet = tmp;
+		xfrd->ipc_conn->is_reading = 0;
+		acl_num = buffer_read_u32(xfrd->ipc_pass);
+		xfrd_handle_passed_packet(xfrd->ipc_conn->packet, acl_num);
+		return;
+	}
+	if(xfrd->ipc_conn->is_reading) {
+		/* reading an IPC message */
+		int ret = conn_read(xfrd->ipc_conn);
+		if(ret == -1) {
+			log_msg(LOG_ERR, "xfrd: error in read ipc: %s", strerror(errno));
+			xfrd->ipc_conn->is_reading = 0;
+			return;
+		}
+		if(ret == 0)
+			return;
+		buffer_flip(xfrd->ipc_conn->packet);
+		if(xfrd->ipc_is_soa) {
+			xfrd->ipc_conn->is_reading = 0;
+			xfrd_handle_ipc_SOAINFO(xfrd, xfrd->ipc_conn->packet);
+		} else 	{
+			/* use ipc_conn to read remaining data as well */
+			buffer_type* tmp = xfrd->ipc_pass;
+			xfrd->ipc_conn->is_reading=2;
+			xfrd->ipc_pass = xfrd->ipc_conn->packet;
+			xfrd->ipc_conn->packet = tmp;
+			xfrd->ipc_conn->total_bytes = sizeof(xfrd->ipc_conn->msglen);
+			xfrd->ipc_conn->msglen = sizeof(uint32_t);
+			buffer_clear(xfrd->ipc_conn->packet);
+			buffer_set_limit(xfrd->ipc_conn->packet, xfrd->ipc_conn->msglen);
+		}
+		return;
+	}
+
+        if((len = read(handler->fd, &cmd, sizeof(cmd))) == -1) {
+                log_msg(LOG_ERR, "xfrd_handle_ipc: read: %s",
+                        strerror(errno));
+                return;
+        }
+        if(len == 0)
+        {
+		/* parent closed the connection. Quit */
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: main closed connection."));
+		xfrd->shutdown = 1;
+		return;
+        }
+
+        switch(cmd) {
+        case NSD_QUIT:
+        case NSD_SHUTDOWN:
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: main send shutdown cmd."));
+                xfrd->shutdown = 1;
+                break;
+	case NSD_SOA_BEGIN:
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: ipc recv SOA_BEGIN"));
+		/* reload starts sending SOA INFOs; don't block */
+		xfrd->parent_soa_info_pass = 1;
+		/* reset the nonblocking ipc write;
+		   the new parent does not want half a packet */
+		xfrd->sending_zone_state = 0;
+		break;
+	case NSD_SOA_INFO:
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: ipc recv SOA_INFO"));
+		assert(xfrd->parent_soa_info_pass);
+		xfrd->ipc_is_soa = 1;
+		xfrd->ipc_conn->is_reading = 1;
+                break;
+	case NSD_SOA_END:
+		/* reload has finished */
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: ipc recv SOA_END"));
+		xfrd->can_send_reload = 1;
+		xfrd->parent_soa_info_pass = 0;
+		xfrd->ipc_send_blocked = 0;
+		handler->event_types |= NETIO_EVENT_WRITE;
+		xfrd_reopen_logfile();
+		xfrd_check_failed_updates();
+		xfrd_send_expy_all_zones();
+		break;
+	case NSD_PASS_TO_XFRD:
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: ipc recv PASS_TO_XFRD"));
+		xfrd->ipc_is_soa = 0;
+		xfrd->ipc_conn->is_reading = 1;
+		break;
+	case NSD_RELOAD:
+		/* main tells us that reload is done, stop ipc send to main */
+		DEBUG(DEBUG_IPC,1, (LOG_INFO, "xfrd: ipc recv RELOAD"));
+		handler->event_types |= NETIO_EVENT_WRITE;
+		xfrd->need_to_send_quit = 1;
+		break;
+        default:
+                log_msg(LOG_ERR, "xfrd_handle_ipc: bad mode %d (%d)", (int)cmd,
+			ntohl(cmd));
+                break;
+        }
+
+	if(xfrd->ipc_conn->is_reading) {
+		/* setup read of info */
+		xfrd->ipc_conn->total_bytes = 0;
+		xfrd->ipc_conn->msglen = 0;
+		buffer_clear(xfrd->ipc_conn->packet);
+	}
+}
+