skel

9 files changed, 291 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..350c6e0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+tunnel
+*.o
+*~
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..365d550
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,19 @@
+PROGNAME = tunnel
+
+CFLAGS = -Wall -Wextra
+LDFLAGS =
+
+include libevent.mk
+
+SOURCES = $(wildcard *.c)
+OBJECTS = $(patsubst %.c,%.o,$(SOURCES))
+
+$(PROGNAME): $(OBJECTS)
+	gcc $(LDFLAGS) -o $@ $^
+
+%.o: %.c
+	gcc $(CFLAGS) -c -o $@ $<
+
+clean:
+	@echo cleaning...
+	@rm -f *.o *~
diff --git a/TODO b/TODO
index 511a63b..663f2ab 100644
--- a/TODO
+++ b/TODO
@@ -5,3 +5,15 @@ Usage:
 	tunnel route del ip[/mask]
 	tunnel route show
 	tunnel show
+
+	tunnel create http host port name proxy
+	tunnel route add port 80 via proxy
+	tunnel route del port 80 via proxy
+	tunnel route drop via proxy
+
+	tunnel add proxy httpconnect host port
+	tunnel route add proxy port 80
+	tunnel route add proxy port 22
+	tunnel show proxy
+	tunnel del proxy
+	tunnel list
diff --git a/daemon.c b/daemon.c
new file mode 100644
index 0000000..305755d
--- /dev/null
+++ b/daemon.c
@@ -0,0 +1,74 @@
+#include <sys/socket.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <err.h>
+
+#include "tunnel.h"
+#include "macro.h"
+
+static void sighandler(int signo __unused)
+{
+	unlink(TUNNEL_SOCK_PATH);
+	exit(EXIT_FAILURE);
+}
+
+static void tunnel_daemon_loop(int sock)
+{
+	for (;;) {
+		int fd = accept(sock, NULL, NULL);
+		if (fd < 0) {
+			warn("accept");
+			continue;
+		}
+
+		FILE *fp = fdopen(fd, "w");
+		if (fp) {
+			fprintf(fp, "hello from %d", getpid());
+			fclose(fp);
+		}
+	}
+}
+
+int tunnel_daemon(int sock)
+{
+	switch (fork()) {
+	case -1:
+		warn("fork");
+		return -1;
+	case 0:
+		break;
+	default:
+		return 0;
+	}
+
+	if (setsid() < 0)
+		err(EXIT_FAILURE, "setsid");
+
+	chdir("/");
+
+	struct sigaction sa = {
+		.sa_handler = sighandler
+	};
+
+	sigaction(SIGTERM, &sa, NULL);
+	sigaction(SIGINT, &sa, NULL);
+
+#if 0
+	int fd = open("/dev/null", O_RDWR);
+	if (fd < 0)
+		err(EXIT_FAILURE, "open /dev/null");
+
+	dup2(fd, STDIN_FILENO);
+	dup2(fd, STDOUT_FILENO);
+	dup2(fd, STDERR_FILENO);
+
+	if (fd > 2)
+		close(fd);
+#endif
+
+	tunnel_daemon_loop(sock);
+
+	return 0;
+}
diff --git a/libevent.mk b/libevent.mk
new file mode 100644
index 0000000..194a525
--- /dev/null
+++ b/libevent.mk
@@ -0,0 +1,2 @@
+CFLAGS	+= $(shell pkg-config --cflags libevent)
+LDFLAGS	+= $(shell pkg-config --libs libevent)
diff --git a/macro.h b/macro.h
new file mode 100644
index 0000000..c91b8cf
--- /dev/null
+++ b/macro.h
@@ -0,0 +1,25 @@
+#ifndef __TUNNEL_MACRO_H__
+#define __TUNNEL_MACRO_H__
+
+#include <stdlib.h>
+#include <string.h>
+
+#define _new(t)		memset(malloc(sizeof(t)), 0, sizeof(t))
+
+#define _copy(p, ...)	_copy_(p, ## __VA_ARGS__, sizeof(*p))
+#define _copy_(p, n, ...)	memcpy(malloc(n), p, n)
+
+#define __unused	__attribute__((unused))
+#define __cleanup(f)	__attribute__((cleanup(f)))
+
+#define CAT(a, b)	CAT_(a, b)
+#define CAT_(a, b)	a ## b
+
+#define UNIQ(name)	CAT(name, __LINE__)
+
+#define defer 								\
+	auto void UNIQ(defer_func)(int *);				\
+	int UNIQ(defer_var) __cleanup(UNIQ(defer_func));		\
+	void UNIQ(defer_func)(int *p __unused)
+
+#endif
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..5a43f51
--- /dev/null
+++ b/main.c
@@ -0,0 +1,31 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <err.h>
+
+#include "tunnel.h"
+#include "macro.h"
+
+int main(int argc __unused, char *argv[] __unused)
+{
+#if 0
+	if (geteuid() != 0)
+		errx(EXIT_FAILURE, "running as root required");
+#endif
+
+	int sock = tunnel_client();
+	if (sock < 0)
+		errx(EXIT_FAILURE, "tunnel_connect failed");
+
+	char buf[512];
+
+	int n = read(sock, buf, sizeof(buf));
+	if (n < 0)
+		err(EXIT_FAILURE, "read");
+
+	printf("%.*s\n", n, buf);
+
+	close(sock);
+
+	return 0;
+}
diff --git a/tunnel.c b/tunnel.c
new file mode 100644
index 0000000..56bdcdd
--- /dev/null
+++ b/tunnel.c
@@ -0,0 +1,116 @@
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <err.h>
+
+#include "tunnel.h"
+#include "macro.h"
+
+int tunnel_socket(struct sockaddr **sa, socklen_t *salen)
+{
+	int sock = socket(AF_UNIX, SOCK_SEQPACKET, 0);
+	if (sock < 0) {
+		warn("socket");
+		return -1;
+	}
+
+	struct sockaddr_un sun = {
+		.sun_family = AF_UNIX
+	};
+
+	const char *path = TUNNEL_SOCK_PATH;
+
+	int n = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", path);
+	socklen_t len = offsetof(struct sockaddr_un, sun_path) + n + 1;
+
+	if (len > sizeof(sun)) {
+		warnx("too large unix path");
+		close(sock);
+		return -1;
+	}
+
+	*sa = _copy(&sun, len);
+	*salen = len;
+
+	return sock;
+}
+
+int tunnel_listen(int sock, struct sockaddr *sa, socklen_t salen)
+{
+	if (bind(sock, sa, salen) < 0) {
+		warn("bind");
+		return -1;
+	}
+
+	if (listen(sock, 0) < 0) {
+		warn("listen");
+		return -1;
+	}
+
+	return 0;
+}
+
+int tunnel_server(void)
+{
+	struct sockaddr *sa = NULL;
+	socklen_t salen = 0;
+
+	int sock = tunnel_socket(&sa, &salen);
+	if (sock < 0)
+		return -1;
+
+	defer {
+		close(sock);
+		free(sa);
+	}
+
+	if (tunnel_listen(sock, sa, salen) < 0)
+		return -1;
+
+	if (tunnel_daemon(sock) < 0)
+		return -1;
+
+	return 0;
+}
+
+int tunnel_connect(int sock, struct sockaddr *sa, socklen_t salen)
+{
+	if (connect(sock, sa, salen) < 0) {
+		if (errno == ENOENT) {
+			if (tunnel_server() < 0)
+				return -1;
+		}
+
+		if (errno != ENOENT || connect(sock, sa, salen) < 0) {
+			warn("connect");
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int tunnel_client(void)
+{
+	struct sockaddr *sa = NULL;
+	socklen_t salen = 0;
+
+	int sock = tunnel_socket(&sa, &salen);
+	if (sock < 0)
+		return -1;
+
+	defer { free(sa); }
+
+	if (tunnel_connect(sock, sa, salen) < 0) {
+		close(sock);
+		return -1;
+	}
+
+	return sock;
+}
diff --git a/tunnel.h b/tunnel.h
new file mode 100644
index 0000000..d04bde5
--- /dev/null
+++ b/tunnel.h
@@ -0,0 +1,9 @@
+#ifndef __TUNNEL_H__
+#define __TUNNEL_H__
+
+#define TUNNEL_SOCK_PATH "/tmp/tunnel.sock"
+
+int tunnel_client(void);
+int tunnel_daemon(int sock);
+
+#endif