stun

commit cd801d3eefc9654dd2f56d4944eaa245eb581c9f
parent 965324af5e5e7826cf87d5c760e8298f5e47161e
Author: sin <sin@2f30.org>
Date:   Tue, 12 Apr 2016 16:52:04 +0100

split out client/server code

Diffstat:
M
Makefile
 | 
6
+++---
A
client.c
 | 
53
+++++++++++++++++++++++++++++++++++++++++++++++++++++
A
server.c
 | 
75
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
stun.c
 | 
186
++++++++++++++++++-------------------------------------------------------------
M
stun.h
 | 
10
++++++++++

5 files changed, 182 insertions(+), 148 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,9 +1,9 @@
 include config.mk
 
 DISTFILES = Makefile README WHATSNEW UNLICENSE arg.h auth.c \
-	config.mk crypto.c dev_bsd.c dev_linux.c log.c \
-	netpkt.c stun.8 stun.c stun.h util.c
-OBJ = $(EXTRAOBJ) auth.o crypto.o log.o netpkt.o stun.o util.o
+	client.c config.mk crypto.c dev_bsd.c dev_linux.c log.c \
+	netpkt.c server.c stun.8 stun.c stun.h util.c
+OBJ = $(EXTRAOBJ) auth.o client.o crypto.o log.o netpkt.o server.o stun.o util.o
 BIN = stun
 
 all: $(BIN)
diff --git a/client.c b/client.c
@@ -0,0 +1,53 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "stun.h"
+
+int
+clientconnect(char *host, char *port)
+{
+	struct addrinfo hints, *ai, *p;
+	int ret, netfd;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET;
+	hints.ai_socktype = SOCK_STREAM;
+	if ((ret = getaddrinfo(host, port, &hints, &ai)))
+		logerr("getaddrinfo: %s", gai_strerror(ret));
+
+	for (p = ai; p; p = p->ai_next) {
+		if ((netfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+			continue;
+		if (connect(netfd, p->ai_addr, p->ai_addrlen) < 0) {
+			close(netfd);
+			continue;
+		}
+		break;
+	}
+	freeaddrinfo(ai);
+	if (!p) {
+		close(netfd);
+		logwarn("failed to connect to %s:%s", host, port);
+		return -1;
+	}
+
+	setnonblock(netfd, 1);
+	setsockopt(netfd, SOL_SOCKET, SO_KEEPALIVE, (int []){1}, sizeof(int));
+	setsockopt(netfd, IPPROTO_TCP, TCP_NODELAY, (int []){1}, sizeof(int));
+
+	if (response(netfd) < 0 || challenge(netfd) < 0) {
+		close(netfd);
+		logwarn("challenge-response failed");
+		return -1;
+	}
+	return netfd;
+}
diff --git a/server.c b/server.c
@@ -0,0 +1,75 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "stun.h"
+
+int
+serverinit(char *host, char *port)
+{
+	struct addrinfo hints, *ai, *p;
+	int ret, listenfd;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_PASSIVE;
+
+	if ((ret = getaddrinfo(host, port, &hints, &ai)))
+		logerr("getaddrinfo: %s", gai_strerror(ret));
+
+	for (p = ai; p; p = p->ai_next) {
+		if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+			continue;
+		setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, (int []){1},
+		           sizeof(int));
+		if (bind(listenfd, p->ai_addr, p->ai_addrlen) < 0) {
+			close(listenfd);
+			continue;
+		}
+		if (listen(listenfd, 5) < 0) {
+			close(listenfd);
+			continue;
+		}
+		break;
+	}
+	if (!p)
+		logerr("failed to bind socket");
+	freeaddrinfo(ai);
+	return listenfd;
+}
+
+int
+serveraccept(int listenfd)
+{
+	struct sockaddr_in remote;
+	int netfd;
+
+	netfd = accept(listenfd, (struct sockaddr *)&remote,
+	               (socklen_t []){sizeof(remote)});
+	if (netfd < 0) {
+		if (errno != ECONNABORTED)
+			logwarn("accept failed");
+		return -1;
+	}
+
+	setnonblock(netfd, 1);
+	setsockopt(netfd, SOL_SOCKET, SO_KEEPALIVE, (int []){1}, sizeof(int));
+	setsockopt(netfd, IPPROTO_TCP, TCP_NODELAY, (int []){1}, sizeof(int));
+
+	if (challenge(netfd) < 0 || response(netfd) < 0) {
+		close(netfd);
+		logwarn("challenge-response failed");
+		return -1;
+	}
+	return netfd;
+}
diff --git a/stun.c b/stun.c
@@ -41,17 +41,8 @@
  *
  */
 
-#include <sys/types.h>
 #include <sys/resource.h>
-#include <sys/socket.h>
 
-#include <netinet/in.h>
-#include <netinet/tcp.h>
-#include <arpa/inet.h>
-#include <netdb.h>
-
-#include <errno.h>
-#include <fcntl.h>
 #include <poll.h>
 #include <signal.h>
 #include <stdio.h>
@@ -106,124 +97,6 @@ tunnel(int netfd, int devfd)
 	return 0;
 }
 
-int
-serversetup(int devfd)
-{
-	struct addrinfo hints, *ai, *p;
-	struct sockaddr_in remote;
-	int ret, netfd, listenfd;
-
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_INET;
-	hints.ai_socktype = SOCK_STREAM;
-	hints.ai_flags = AI_PASSIVE;
-
-	if ((ret = getaddrinfo(bindaddr, port, &hints, &ai)))
-		logerr("getaddrinfo: %s", gai_strerror(ret));
-
-	for (p = ai; p; p = p->ai_next) {
-		if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
-			continue;
-		setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, (int []){1},
-		           sizeof(int));
-		if (bind(listenfd, p->ai_addr, p->ai_addrlen) < 0) {
-			close(listenfd);
-			continue;
-		}
-		if (listen(listenfd, 5) < 0) {
-			close(listenfd);
-			continue;
-		}
-		break;
-	}
-	if (!p)
-		logerr("failed to bind socket");
-	freeaddrinfo(ai);
-
-	revokeprivs();
-#if defined(__OpenBSD__)
-	if (pledge("stdio inet", NULL) < 0)
-		logerr("pledge failed");
-#endif
-
-	for (;;) {
-		netfd = accept(listenfd, (struct sockaddr *)&remote,
-		               (socklen_t []){sizeof(remote)});
-		if (netfd < 0) {
-			if (errno != ECONNABORTED)
-				logwarn("accept failed");
-			continue;
-		}
-		if (debug)
-			logdbg("remote peer connected: %s",
-			       inet_ntoa(remote.sin_addr));
-
-		setnonblock(netfd, 1);
-		setsockopt(netfd, SOL_SOCKET, SO_KEEPALIVE, (int []){1}, sizeof(int));
-		setsockopt(netfd, IPPROTO_TCP, TCP_NODELAY, (int []){1}, sizeof(int));
-
-		if (challenge(netfd) < 0 || response(netfd) < 0) {
-			logwarn("challenge-response failed");
-			goto err;
-		}
-
-		tunnel(netfd, devfd);
-err:
-		netreset();
-		close(netfd);
-		if (debug)
-			logdbg("remote peer disconnected: %s",
-			       inet_ntoa(remote.sin_addr));
-	}
-}
-
-int
-clientsetup(int devfd)
-{
-	struct addrinfo hints, *ai, *p;
-	int ret, netfd;
-
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_INET;
-	hints.ai_socktype = SOCK_STREAM;
-	if ((ret = getaddrinfo(host, port, &hints, &ai)))
-		logerr("getaddrinfo: %s", gai_strerror(ret));
-
-	for (p = ai; p; p = p->ai_next) {
-		if ((netfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
-			continue;
-		if (connect(netfd, p->ai_addr, p->ai_addrlen) < 0) {
-			close(netfd);
-			continue;
-		}
-		break;
-	}
-	freeaddrinfo(ai);
-	if (!p) {
-		close(netfd);
-		logwarn("failed to connect to %s:%s", host, port);
-		return -1;
-	}
-	if (debug)
-		logdbg("connected to %s:%s", host, port);
-
-	setnonblock(netfd, 1);
-	setsockopt(netfd, SOL_SOCKET, SO_KEEPALIVE, (int []){1}, sizeof(int));
-	setsockopt(netfd, IPPROTO_TCP, TCP_NODELAY, (int []){1}, sizeof(int));
-
-	if (response(netfd) < 0 || challenge(netfd) < 0) {
-		logwarn("challenge-response failed");
-		goto err;
-	}
-
-	tunnel(netfd, devfd);
-err:
-	netreset();
-	close(netfd);
-	logwarn("connection to %s:%s dropped", host, port);
-	return -1;
-}
-
 void
 usage(void)
 {
@@ -237,7 +110,7 @@ main(int argc, char *argv[])
 {
 	struct rlimit rlim;
 	char *arg, *pw;
-	int devfd;
+	int devfd, listenfd, netfd;
 
 	ARGBEGIN {
 	case 'd':
@@ -274,37 +147,60 @@ main(int argc, char *argv[])
 	if (argc != 1 || !(sflag ^ (host != NULL)))
 		usage();
 
+	/* disable core dumps as memory contains the pre-shared key */
+	rlim.rlim_cur = rlim.rlim_max = 0;
+	if (setrlimit(RLIMIT_CORE, &rlim) < 0)
+		logerr("failed to disable core dumps");
+
 	signal(SIGPIPE, SIG_IGN);
 	if (!debug)
 		daemon(0, 0);
 	loginit("stun");
-	devfd = devopen(argv[0]);
 
-	/* disable core dumps as memory contains the pre-shared key */
-	rlim.rlim_cur = rlim.rlim_max = 0;
-	if (setrlimit(RLIMIT_CORE, &rlim) < 0)
-		logerr("failed to disable core dumps");
+	/* initialize tun/tap device */
+	devfd = devopen(argv[0]);
 
+	/* initialize crypto engine */
 	if (!(pw = getenv("STUNPW")))
 		logerr("STUNPW is not set");
 	cryptoinit(pw);
 	memset(pw, 0, strlen(pw));
 
+	/* initialize networking engine */
 	netinit();
-
-	if (sflag)
-		return serversetup(devfd);
-
-	revokeprivs();
+	if (sflag) {
+		listenfd = serverinit(bindaddr, port);
+		revokeprivs();
 #if defined(__OpenBSD__)
-	if (pledge("stdio dns inet", NULL) < 0)
-		logerr("pledge failed");
+		if (pledge("stdio inet", NULL) < 0)
+			logerr("pledge failed");
 #endif
-
-	/* auto-reconnect client */
-	for (;;) {
-		clientsetup(devfd);
-		sleep(RECONNECTTIMEO);
+		for (;;) {
+			if ((netfd = serveraccept(listenfd)) < 0) {
+				netreset();
+				continue;
+			}
+			tunnel(netfd, devfd);
+			close(netfd);
+			netreset();
+		}
+	} else {
+		revokeprivs();
+#if defined(__OpenBSD__)
+		if (pledge("stdio dns inet", NULL) < 0)
+			logerr("pledge failed");
+#endif
+		for (;;) {
+			if ((netfd = clientconnect(host, port)) < 0) {
+				netreset();
+				sleep(RECONNECTTIMEO);
+				continue;
+			}
+			tunnel(netfd, devfd);
+			close(netfd);
+			netreset();
+			sleep(RECONNECTTIMEO);
+		}
 	}
 	return 0;
 }
diff --git a/stun.h b/stun.h
@@ -26,6 +26,9 @@ extern char *cipher;
 int challenge(int);
 int response(int);
 
+/* client.c */
+int clientconnect(char *, char *);
+
 /* crypto.c */
 void cryptoinit(char *);
 size_t cryptononcelen(void);
@@ -54,6 +57,13 @@ int netread(int, unsigned char *, size_t, size_t *);
 void netreset(void);
 void netinit(void);
 
+/* server.c */
+int serverinit(char *, char *);
+int serveraccept(int);
+
+/* stun.c */
+int tunnel(int, int);
+
 /* util.c */
 void pack16(unsigned char *, uint16_t);
 uint16_t unpack16(unsigned char *);