curvetun: renamed client, server, and management files

Rename those files so that they are conform to the rest of the files
we have in our repository.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

1 files changed, 812 insertions, 0 deletions

diff --git a/curvetun_server.c b/curvetun_server.c
new file mode 100644
index 0000000..bb704b0
--- /dev/null
+++ b/curvetun_server.c
@@ -0,0 +1,812 @@
+/*
+ * curvetun - the cipherspace wormhole creator
+ * Part of the netsniff-ng project
+ * Copyright 2011 Daniel Borkmann <daniel@netsniff-ng.org>,
+ * Subject to the GPL, version 2.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <syslog.h>
+#include <signal.h>
+#include <netdb.h>
+#include <stdint.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <sys/poll.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/epoll.h>
+#include <arpa/inet.h>
+#include <linux/if_tun.h>
+
+#include "die.h"
+#include "epoll2.h"
+#include "ioops.h"
+#include "xmalloc.h"
+#include "curvetun.h"
+#include "curve.h"
+#include "ioexact.h"
+#include "corking.h"
+#include "cpus.h"
+#include "sock.h"
+#include "built_in.h"
+#include "curvetun_mgmt_users.h"
+#include "cpusched.h"
+#include "trie.h"
+
+struct parent_info {
+	int efd;
+	int refd;
+	int tunfd;
+	int ipv4;
+	int udp;
+};
+
+struct worker_struct {
+	pthread_t trid;
+	int efd[2];
+	unsigned int cpu;
+	struct parent_info parent;
+	int (*handler)(int fd, const struct worker_struct *ws,
+		       char *buff, size_t len);
+	struct curve25519_struct *c;
+};
+
+static struct worker_struct *threadpool = NULL;
+
+static int auth_log = 1;
+
+extern volatile sig_atomic_t sigint;
+
+static int handler_udp_tun_to_net(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len) __pure;
+static int handler_udp_net_to_tun(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len) __pure;
+static int handler_udp(int fd, const struct worker_struct *ws,
+		       char *buff, size_t len) __pure;
+static int handler_tcp_tun_to_net(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len) __pure;
+static int handler_tcp_net_to_tun(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len) __pure;
+static int handler_tcp(int fd, const struct worker_struct *ws,
+		       char *buff, size_t len) __pure;
+ssize_t handler_tcp_read(int fd, char *buff, size_t len);
+static void *worker(void *self) __pure;
+
+static int handler_udp_tun_to_net(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len)
+{
+	int dfd, keep = 1;
+	char *cbuff;
+	ssize_t rlen, err, clen;
+	struct ct_proto *hdr;
+	struct curve25519_proto *p;
+	struct sockaddr_storage naddr;
+	socklen_t nlen;
+	size_t off = sizeof(struct ct_proto) + crypto_box_zerobytes;
+
+	if (!buff || len <= off)
+		return 0;
+
+	memset(buff, 0, len);
+	while ((rlen = read(fd, buff + off, len - off)) > 0) {
+		dfd = -1; nlen = 0; p = NULL;
+
+		memset(&naddr, 0, sizeof(naddr));
+
+		hdr = (struct ct_proto *) buff;
+		memset(hdr, 0, sizeof(*hdr));
+		hdr->flags = 0;
+
+		trie_addr_lookup(buff + off, rlen, ws->parent.ipv4, &dfd, &naddr,
+				 (size_t *) &nlen);
+		if (unlikely(dfd < 0 || nlen == 0)) {
+			memset(buff, 0, len);
+			continue;
+		}
+
+		err = get_user_by_sockaddr(&naddr, nlen, &p);
+		if (unlikely(err || !p)) {
+			memset(buff, 0, len);
+			continue;
+		}
+
+		clen = curve25519_encode(ws->c, p, (unsigned char *) (buff + off -
+					 crypto_box_zerobytes), (rlen +
+					 crypto_box_zerobytes), (unsigned char **)
+					 &cbuff);
+		if (unlikely(clen <= 0)) {
+			memset(buff, 0, len);
+			continue;
+		}
+
+		hdr->payload = htons((uint16_t) clen);
+
+		set_udp_cork(dfd);
+
+		sendto(dfd, hdr, sizeof(struct ct_proto), 0, (struct sockaddr *)
+		       &naddr, nlen);
+		sendto(dfd, cbuff, clen, 0, (struct sockaddr *) &naddr, nlen);
+
+		set_udp_uncork(dfd);
+
+		memset(buff, 0, len);
+	}
+
+	return keep;
+}
+
+static void handler_udp_notify_close(int fd, struct sockaddr_storage *addr)
+{
+	struct ct_proto hdr;
+
+	memset(&hdr, 0, sizeof(hdr));
+	hdr.flags |= PROTO_FLAG_EXIT;
+	hdr.payload = 0;
+
+	sendto(fd, &hdr, sizeof(hdr), 0, (struct sockaddr *) addr,
+	       sizeof(*addr));
+}
+
+static int handler_udp_net_to_tun(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len)
+{
+	int keep = 1;
+	char *cbuff;
+	ssize_t rlen, err, clen;
+	struct ct_proto *hdr;
+	struct curve25519_proto *p;
+	struct sockaddr_storage naddr;
+	socklen_t nlen = sizeof(naddr);
+
+	if (!buff || !len)
+		return 0;
+
+	memset(&naddr, 0, sizeof(naddr));
+	while ((rlen = recvfrom(fd, buff, len, 0, (struct sockaddr *) &naddr,
+				&nlen)) > 0) {
+		p = NULL;
+
+		hdr = (struct ct_proto *) buff;
+
+		if (unlikely(rlen < sizeof(struct ct_proto)))
+			goto close;
+		if (unlikely(rlen - sizeof(*hdr) != ntohs(hdr->payload)))
+			goto close;
+		if (unlikely(ntohs(hdr->payload) == 0))
+			goto close;
+		if (hdr->flags & PROTO_FLAG_EXIT) {
+close:
+			remove_user_by_sockaddr(&naddr, nlen);
+			trie_addr_remove_addr(&naddr, nlen);
+			handler_udp_notify_close(fd, &naddr);
+
+			return keep;
+		}
+		if (hdr->flags & PROTO_FLAG_INIT) {
+			syslog_maybe(auth_log, LOG_INFO, "Got initial userhash "
+				     "from remote end!\n");
+
+			if (unlikely(rlen - sizeof(*hdr) <
+				     sizeof(struct username_struct)))
+				goto close;
+
+			err = try_register_user_by_sockaddr(ws->c,
+					buff + sizeof(struct ct_proto),
+					rlen - sizeof(struct ct_proto),
+					&naddr, nlen, auth_log);
+			if (unlikely(err))
+				goto close;
+
+			goto next;
+		}
+
+		err = get_user_by_sockaddr(&naddr, nlen, &p);
+		if (unlikely(err || !p))
+			goto close;
+
+		clen = curve25519_decode(ws->c, p, (unsigned char *) buff +
+					 sizeof(struct ct_proto),
+					 rlen - sizeof(struct ct_proto),
+					 (unsigned char **) &cbuff, NULL);
+                if (unlikely(clen <= 0))
+			goto close;
+
+		cbuff += crypto_box_zerobytes;
+		clen -= crypto_box_zerobytes;
+
+		err = trie_addr_maybe_update(cbuff, clen, ws->parent.ipv4,
+					     fd, &naddr, nlen);
+		if (unlikely(err))
+			goto next;
+
+		err = write(ws->parent.tunfd, cbuff, clen);
+next:
+		nlen = sizeof(naddr);
+		memset(&naddr, 0, sizeof(naddr));
+	}
+
+	return keep;
+}
+
+static int handler_udp(int fd, const struct worker_struct *ws,
+		       char *buff, size_t len)
+{
+	int ret = 0;
+
+	if (fd == ws->parent.tunfd)
+		ret = handler_udp_tun_to_net(fd, ws, buff, len);
+	else
+		ret = handler_udp_net_to_tun(fd, ws, buff, len);
+
+	return ret;
+}
+
+static int handler_tcp_tun_to_net(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len)
+{
+	int dfd, keep = 1;
+	char *cbuff;
+	ssize_t rlen, err, clen;
+	struct ct_proto *hdr;
+	struct curve25519_proto *p;
+	socklen_t nlen;
+	size_t off = sizeof(struct ct_proto) + crypto_box_zerobytes;
+
+	if (!buff || len <= off)
+		return 0;
+
+	memset(buff, 0, len);
+	while ((rlen = read(fd, buff + off, len - off)) > 0) {
+		dfd = -1; p = NULL;
+
+		hdr = (struct ct_proto *) buff;
+		memset(hdr, 0, sizeof(*hdr));
+		hdr->flags = 0;
+
+		trie_addr_lookup(buff + off, rlen, ws->parent.ipv4, &dfd, NULL,
+				 (size_t *) &nlen);
+		if (unlikely(dfd < 0)) {
+			memset(buff, 0, len);
+			continue;
+		}
+
+		err = get_user_by_socket(dfd, &p);
+		if (unlikely(err || !p)) {
+			memset(buff, 0, len);
+			continue;
+		}
+
+		clen = curve25519_encode(ws->c, p, (unsigned char *) (buff + off -
+					 crypto_box_zerobytes), (rlen +
+					 crypto_box_zerobytes), (unsigned char **)
+					 &cbuff);
+		if (unlikely(clen <= 0)) {
+			memset(buff, 0, len);
+			continue;
+		}
+
+		hdr->payload = htons((uint16_t) clen);
+
+		set_tcp_cork(dfd);
+
+		write_exact(dfd, hdr, sizeof(struct ct_proto), 0);
+		write_exact(dfd, cbuff, clen, 0);
+
+		set_tcp_uncork(dfd);
+
+		memset(buff, 0, len);
+	}
+
+	return keep;
+}
+
+ssize_t handler_tcp_read(int fd, char *buff, size_t len)
+{
+	ssize_t rlen;
+	struct ct_proto *hdr = (struct ct_proto *) buff;
+
+	if (!buff || !len)
+		return 0;
+
+	/* May exit on EAGAIN if 0 Byte read */
+	rlen = read_exact(fd, buff, sizeof(struct ct_proto), 1);
+	if (rlen < 0)
+		return rlen;
+	if (unlikely(ntohs(hdr->payload) > len - sizeof(struct ct_proto))) {
+		errno = ENOMEM;
+		return 1; /* Force server to close connection */
+	}
+
+	/* May not exit on EAGAIN if 0 Byte read */
+	rlen = read_exact(fd, buff + sizeof(struct ct_proto),
+			  ntohs(hdr->payload), 0);
+	if (rlen < 0)
+		return rlen;
+
+	return sizeof(struct ct_proto) + rlen;
+}
+
+static void handler_tcp_notify_close(int fd)
+{
+	struct ct_proto hdr;
+
+	memset(&hdr, 0, sizeof(hdr));
+	hdr.flags |= PROTO_FLAG_EXIT;
+	hdr.payload = 0;
+
+	if (write(fd, &hdr, sizeof(hdr))) { ; }
+}
+
+static int handler_tcp_net_to_tun(int fd, const struct worker_struct *ws,
+				  char *buff, size_t len)
+{
+	int keep = 1, count = 0;
+	char *cbuff;
+	ssize_t rlen, err, clen;
+	struct ct_proto *hdr;
+	struct curve25519_proto *p;
+
+	if (!buff || !len)
+		return 0;
+
+	while ((rlen = handler_tcp_read(fd, buff, len)) > 0) {
+		p = NULL;
+
+		hdr = (struct ct_proto *) buff;
+
+		if (unlikely(rlen < sizeof(struct ct_proto)))
+			goto close;
+		if (unlikely(rlen - sizeof(*hdr) != ntohs(hdr->payload)))
+			goto close;
+		if (unlikely(ntohs(hdr->payload) == 0))
+			goto close;
+		if (hdr->flags & PROTO_FLAG_EXIT) {
+close:
+			remove_user_by_socket(fd);
+			trie_addr_remove(fd);
+			handler_tcp_notify_close(fd);
+			rlen = write(ws->parent.efd, &fd, sizeof(fd));
+
+			keep = 0;
+			return keep;
+		}
+		if (hdr->flags & PROTO_FLAG_INIT) {
+			syslog_maybe(auth_log, LOG_INFO, "Got initial userhash "
+				     "from remote end!\n");
+
+			if (unlikely(rlen - sizeof(*hdr) <
+				     sizeof(struct username_struct)))
+				goto close;
+
+			err = try_register_user_by_socket(ws->c,
+					buff + sizeof(struct ct_proto),
+					rlen - sizeof(struct ct_proto),
+					fd, auth_log);
+			if (unlikely(err))
+				goto close;
+
+			continue;
+		}
+
+		err = get_user_by_socket(fd, &p);
+		if (unlikely(err || !p))
+			continue;
+
+		clen = curve25519_decode(ws->c, p, (unsigned char *) buff +
+					 sizeof(struct ct_proto),
+					 rlen - sizeof(struct ct_proto),
+					 (unsigned char **) &cbuff, NULL);
+                if (unlikely(clen <= 0))
+			continue;
+
+		cbuff += crypto_box_zerobytes;
+		clen -= crypto_box_zerobytes;
+
+		err = trie_addr_maybe_update(cbuff, clen, ws->parent.ipv4,
+					     fd, NULL, 0);
+		if (unlikely(err))
+			continue;
+
+		err = write(ws->parent.tunfd, cbuff, clen);
+
+		count++;
+		if (count == 10) {
+			write_exact(ws->efd[1], &fd, sizeof(fd), 1);
+			/* Read later next data and let others process */
+			return keep;
+		}
+	}
+
+	return keep;
+}
+
+static int handler_tcp(int fd, const struct worker_struct *ws,
+		       char *buff, size_t len)
+{
+	int ret = 0;
+
+	if (fd == ws->parent.tunfd)
+		ret = handler_tcp_tun_to_net(fd, ws, buff, len);
+	else
+		ret = handler_tcp_net_to_tun(fd, ws, buff, len);
+
+	return ret;
+}
+
+static void *worker(void *self)
+{
+	int fd, old_state;
+	ssize_t ret;
+	size_t blen = TUNBUFF_SIZ; //FIXME
+	struct worker_struct *ws = self;
+	struct pollfd fds;
+	char *buff;
+
+	fds.fd = ws->efd[0];
+	fds.events = POLLIN;
+
+	ws->c = curve25519_tfm_alloc();
+	buff = xmalloc_aligned(blen, 64);
+
+	syslog(LOG_INFO, "curvetun thread on CPU%u up!\n", ws->cpu);
+
+	pthread_cleanup_push(curve25519_tfm_free_void, ws->c);
+	pthread_cleanup_push(xfree_func, buff);
+
+	while (likely(!sigint)) {
+		poll(&fds, 1, -1);
+		if ((fds.revents & POLLIN) != POLLIN)
+			continue;
+
+		pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &old_state);
+
+		while ((ret = read_exact(ws->efd[0], &fd, sizeof(fd), 1)) > 0) {
+			if (ret != sizeof(fd)) {
+				sched_yield();
+				continue;
+			}
+
+			ret = ws->handler(fd, ws, buff, blen);
+			if (ret)
+				write_exact(ws->parent.refd, &fd, sizeof(fd), 1);
+		}
+
+		pthread_setcancelstate(old_state, NULL);
+	}
+
+	syslog(LOG_INFO, "curvetun thread on CPU%u down!\n", ws->cpu);
+
+	pthread_cleanup_pop(1);
+	pthread_cleanup_pop(1);
+
+	pthread_exit((void *) ((long) ws->cpu));
+}
+
+static void thread_spawn_or_panic(unsigned int cpus, int efd, int refd,
+				  int tunfd, int ipv4, int udp)
+{
+	int i, ret;
+	cpu_set_t cpuset;
+	unsigned int threads;
+
+	threads = cpus * THREADS_PER_CPU;
+
+	for (i = 0; i < threads; ++i) {
+		CPU_ZERO(&cpuset);
+		threadpool[i].cpu = i % cpus;
+		CPU_SET(threadpool[i].cpu, &cpuset);
+
+		ret = pipe2(threadpool[i].efd, O_NONBLOCK);
+		if (ret < 0)
+			syslog_panic("Cannot create event socket!\n");
+
+		threadpool[i].c = xmalloc_aligned(sizeof(*threadpool[i].c), 64);
+		threadpool[i].parent.efd = efd;
+		threadpool[i].parent.refd = refd;
+		threadpool[i].parent.tunfd = tunfd;
+		threadpool[i].parent.ipv4 = ipv4;
+		threadpool[i].parent.udp = udp;
+		threadpool[i].handler = udp ? handler_udp : handler_tcp;
+
+		ret = pthread_create(&threadpool[i].trid, NULL,
+				     worker, &threadpool[i]);
+		if (ret < 0)
+			syslog_panic("Thread creation failed!\n");
+
+		ret = pthread_setaffinity_np(threadpool[i].trid,
+					     sizeof(cpuset), &cpuset);
+		if (ret < 0)
+			syslog_panic("Thread CPU migration failed!\n");
+
+		pthread_detach(threadpool[i].trid);
+	}
+
+	sleep(1);
+}
+
+static void thread_finish(unsigned int cpus)
+{
+	int i;
+	unsigned int threads;
+
+	threads = cpus * THREADS_PER_CPU;
+
+	for (i = 0; i < threads; ++i) {
+		while (pthread_join(threadpool[i].trid, NULL) < 0)
+			;
+
+		close(threadpool[i].efd[0]);
+		close(threadpool[i].efd[1]);
+	}
+}
+
+int server_main(char *home, char *dev, char *port, int udp, int ipv4, int log)
+{
+	int lfd = -1, kdpfd, nfds, nfd, curfds, efd[2], refd[2], tunfd, i;
+	unsigned int cpus = 0, threads, udp_cpu = 0;
+	ssize_t ret;
+	struct epoll_event *events;
+	struct addrinfo hints, *ahead, *ai;
+
+	auth_log = !!log;
+	openlog("curvetun", LOG_PID | LOG_CONS | LOG_NDELAY, LOG_DAEMON);
+
+	syslog(LOG_INFO, "curvetun server booting!\n");
+	syslog_maybe(!auth_log, LOG_INFO, "curvetun user logging disabled!\n");
+
+	parse_userfile_and_generate_user_store_or_die(home);
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = PF_UNSPEC;
+	hints.ai_socktype = udp ? SOCK_DGRAM : SOCK_STREAM;
+	hints.ai_protocol = udp ? IPPROTO_UDP : IPPROTO_TCP;
+	hints.ai_flags = AI_PASSIVE;
+
+	ret = getaddrinfo(NULL, port, &hints, &ahead);
+	if (ret < 0)
+		syslog_panic("Cannot get address info!\n");
+
+	for (ai = ahead; ai != NULL && lfd < 0; ai = ai->ai_next) {
+		lfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+		if (lfd < 0)
+			continue;
+		if (ai->ai_family == AF_INET6) {
+#ifdef IPV6_V6ONLY
+			ret = set_ipv6_only(lfd);
+			if (ret < 0) {
+				close(lfd);
+				lfd = -1;
+				continue;
+			}
+#else
+			close(lfd);
+			lfd = -1;
+			continue;
+#endif /* IPV6_V6ONLY */
+		}
+
+		set_reuseaddr(lfd);
+		set_mtu_disc_dont(lfd);
+
+		ret = bind(lfd, ai->ai_addr, ai->ai_addrlen);
+		if (ret < 0) {
+			close(lfd);
+			lfd = -1;
+			continue;
+		}
+
+		if (!udp) {
+			ret = listen(lfd, 5);
+			if (ret < 0) {
+				close(lfd);
+				lfd = -1;
+				continue;
+			}
+		}
+
+		if (ipv4 == -1) {
+			ipv4 = (ai->ai_family == AF_INET6 ? 0 :
+				(ai->ai_family == AF_INET ? 1 : -1));
+		}
+
+		syslog_maybe(auth_log, LOG_INFO, "curvetun on IPv%d via %s "
+			     "on port %s!\n", ai->ai_family == AF_INET ? 4 : 6,
+			     udp ? "UDP" : "TCP", port);
+		syslog_maybe(auth_log, LOG_INFO, "Allowed overlay proto is "
+			     "IPv%d!\n", ipv4 ? 4 : 6);
+	}
+
+	freeaddrinfo(ahead);
+
+	if (lfd < 0 || ipv4 < 0)
+		syslog_panic("Cannot create socket!\n");
+
+	tunfd = tun_open_or_die(dev ? dev : DEVNAME_SERVER, IFF_TUN | IFF_NO_PI);
+
+	pipe_or_die(efd, O_NONBLOCK);
+	pipe_or_die(refd, O_NONBLOCK);
+
+	set_nonblocking(lfd);
+
+	events = xzmalloc(MAX_EPOLL_SIZE * sizeof(*events));
+	for (i = 0; i < MAX_EPOLL_SIZE; ++i)
+		events[i].data.fd = -1;
+
+	kdpfd = epoll_create(MAX_EPOLL_SIZE);
+	if (kdpfd < 0)
+		syslog_panic("Cannot create socket!\n");
+
+	set_epoll_descriptor(kdpfd, EPOLL_CTL_ADD, lfd,
+			     udp ? EPOLLIN | EPOLLET | EPOLLONESHOT : EPOLLIN);
+	set_epoll_descriptor(kdpfd, EPOLL_CTL_ADD, efd[0], EPOLLIN);
+	set_epoll_descriptor(kdpfd, EPOLL_CTL_ADD, refd[0], EPOLLIN);
+	set_epoll_descriptor(kdpfd, EPOLL_CTL_ADD, tunfd,
+			     EPOLLIN | EPOLLET | EPOLLONESHOT);
+	curfds = 4;
+
+	trie_init();
+
+	cpus = get_number_cpus_online();
+	threads = cpus * THREADS_PER_CPU;
+	if (!ispow2(threads))
+		syslog_panic("Thread number not power of two!\n");
+
+	threadpool = xzmalloc(sizeof(*threadpool) * threads);
+	thread_spawn_or_panic(cpus, efd[1], refd[1], tunfd, ipv4, udp);
+
+	init_cpusched(threads);
+
+	register_socket(tunfd);
+	register_socket(lfd);
+
+	syslog(LOG_INFO, "curvetun up and running!\n");
+
+	while (likely(!sigint)) {
+		nfds = epoll_wait(kdpfd, events, curfds, -1);
+		if (nfds < 0) {
+			syslog(LOG_ERR, "epoll_wait error: %s\n",
+			       strerror(errno));
+			break;
+		}
+
+		for (i = 0; i < nfds; ++i) {
+			if (unlikely(events[i].data.fd < 0))
+				continue;
+
+			if (events[i].data.fd == lfd && !udp) {
+				int ncpu;
+				char hbuff[256], sbuff[256];
+				struct sockaddr_storage taddr;
+				socklen_t tlen;
+
+				tlen = sizeof(taddr);
+				nfd = accept(lfd, (struct sockaddr *) &taddr,
+					     &tlen);
+				if (nfd < 0) {
+					syslog(LOG_ERR, "accept error: %s\n",
+					       strerror(errno));
+					continue;
+				}
+
+				if (curfds + 1 > MAX_EPOLL_SIZE) {
+					close(nfd);
+					continue;
+				}
+
+				curfds++;
+
+				ncpu = register_socket(nfd);
+
+				memset(hbuff, 0, sizeof(hbuff));
+				memset(sbuff, 0, sizeof(sbuff));
+				getnameinfo((struct sockaddr *) &taddr, tlen,
+					    hbuff, sizeof(hbuff),
+					    sbuff, sizeof(sbuff),
+					    NI_NUMERICHOST | NI_NUMERICSERV);
+
+				syslog_maybe(auth_log, LOG_INFO, "New connection "
+					     "from %s:%s (%d active client connections) -  id %d on CPU%d",
+					     hbuff, sbuff, curfds-4, nfd, ncpu);
+
+				set_nonblocking(nfd);
+				set_socket_keepalive(nfd);
+				set_tcp_nodelay(nfd);
+				ret = set_epoll_descriptor2(kdpfd, EPOLL_CTL_ADD,
+						nfd, EPOLLIN | EPOLLET | EPOLLONESHOT);
+				if (ret < 0) {
+					close(nfd);
+					curfds--;
+					continue;
+				}
+			} else if (events[i].data.fd == refd[0]) {
+				int fd_one;
+
+				ret = read_exact(refd[0], &fd_one,
+						 sizeof(fd_one), 1);
+				if (ret != sizeof(fd_one) || fd_one <= 0)
+					continue;
+
+				ret = set_epoll_descriptor2(kdpfd, EPOLL_CTL_MOD,
+						fd_one, EPOLLIN | EPOLLET | EPOLLONESHOT);
+				if (ret < 0) {
+					close(fd_one);
+					continue;
+				}
+			} else if (events[i].data.fd == efd[0]) {
+				int fd_del, test;
+
+				ret = read_exact(efd[0], &fd_del,
+						 sizeof(fd_del), 1);
+				if (ret != sizeof(fd_del) || fd_del <= 0)
+					continue;
+
+				ret = read(fd_del, &test, sizeof(test));
+				if (ret < 0 && errno == EBADF)
+					continue;
+
+				ret = set_epoll_descriptor2(kdpfd, EPOLL_CTL_DEL,
+						fd_del, 0);
+				if (ret < 0) {
+					close(fd_del);
+					continue;
+				}
+
+				close(fd_del);
+				curfds--;
+				unregister_socket(fd_del);
+
+				syslog_maybe(auth_log, LOG_INFO, "Closed connection "
+					     "with id %d (%d active client connections remain)\n", fd_del,
+					     curfds-4);
+			} else {
+				int cpu, fd_work = events[i].data.fd;
+
+				if (!udp)
+					cpu = socket_to_cpu(fd_work);
+				else
+					udp_cpu = (udp_cpu + 1) & (threads - 1);
+
+				write_exact(threadpool[udp ? udp_cpu : cpu].efd[1],
+					    &fd_work, sizeof(fd_work), 1);
+			}
+		}
+	}
+
+	syslog(LOG_INFO, "curvetun prepare shut down!\n");
+
+	close(lfd);
+	close(efd[0]);
+	close(efd[1]);
+	close(refd[0]);
+	close(refd[1]);
+	close(tunfd);
+
+	thread_finish(cpus);
+
+	xfree(threadpool);
+	xfree(events);
+
+	unregister_socket(lfd);
+	unregister_socket(tunfd);
+
+	destroy_cpusched();
+
+	trie_cleanup();
+
+	destroy_user_store();
+
+	syslog(LOG_INFO, "curvetun shut down!\n");
+	closelog();
+
+	return 0;
+}