Working client and server comms

Signed-off-by: Tushar Pankaj <tushar.s.pankaj@gmail.com>

6 files changed, 138 insertions, 17 deletions

diff --git a/client.c b/client.c
index 1a839b9..ebef8b3 100644
--- a/client.c
+++ b/client.c
@@ -4,16 +4,16 @@
  */
 
 #include <stdlib.h>
-#include <stdio.h>
 #include <stdbool.h>
 #include <unistd.h>
+#include <errno.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <arpa/inet.h>
 #include "protocol.h"
 #include "client.h"
 
-bool is_server_in_allowed_ips(const char interface[])
+bool is_server_in_allowed_ips(const char iface[])
 {
 	/* TODO: check if IP is in wg allowed ips, etc */
 	return true;
@@ -22,21 +22,30 @@ bool is_server_in_allowed_ips(const char interface[])
 int connect_to_server()
 {
 	int sock = -1;
+	int ret;
 	struct sockaddr_in6 addr;
 
 	sock = socket(AF_INET6, SOCK_STREAM, 0);
+	if (sock < 0) {
+		return -errno;
+	}
 	addr.sin6_family = AF_INET6;
 	addr.sin6_port = htons(WG_DYNAMIC_SERVER_PORT);
 	inet_pton(AF_INET6, WG_DYNAMIC_SERVER_IP, &addr.sin6_addr);
-	connect(sock, (struct sockaddr *)&addr, sizeof(addr));
+	ret = connect(sock, (struct sockaddr *)&addr, sizeof(addr));
+	if (ret < 0) {
+		return -errno;
+	}
 
 	return sock;
 }
 
-void close_connection(int sock)
+int close_connection(int sock)
 {
-	if (close(sock) < 0) {
-		perror("error closing socket to server");
-		exit(EXIT_FAILURE);
+	int ret;
+	ret = close(sock);
+	if (ret < 0) {
+		return -errno;
 	}
+	return 0;
 }
diff --git a/client.h b/client.h
index 8dd35db..5a4b460 100644
--- a/client.h
+++ b/client.h
@@ -8,8 +8,8 @@
 
 #include <stdbool.h>
 
-bool is_server_in_allowed_ips(const char interface[]);
+bool is_server_in_allowed_ips(const char iface[]);
 int connect_to_server();
-void close_connection(int sock);
+int close_connection(int sock);
 
 #endif
diff --git a/server.c b/server.c
index 0315ccb..89a78c0 100644
--- a/server.c
+++ b/server.c
@@ -3,8 +3,78 @@
  * Copyright (C) 2018 Wireguard LLC
  */
 
-int setup_server(const char interface[])
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include "protocol.h"
+#include "server.h"
+
+bool is_wg_up_on_iface(const char iface[])
+{
+	/* TODO */
+	return true;
+}
+
+int setup_server()
+{
+	int sock = -1;
+	int reuseaddr = 1;
+	int ret;
+	struct sockaddr_in6 addr;
+
+	sock = socket(AF_INET6, SOCK_STREAM, 0);
+	if (sock < 0) {
+		return -errno;
+	}
+	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuseaddr,
+		   sizeof(reuseaddr));
+	addr.sin6_family = AF_INET6;
+	addr.sin6_port = htons(WG_DYNAMIC_SERVER_PORT);
+	inet_pton(AF_INET6, WG_DYNAMIC_SERVER_IP, &addr.sin6_addr);
+	ret = bind(sock, (struct sockaddr *)&addr, sizeof(addr));
+	if (ret < 0) {
+		return -errno;
+	}
+	ret = listen(sock, 5);
+	if (ret < 0) {
+		return -errno;
+	}
+	return sock;
+}
+
+static void handle_connection(int conn, struct sockaddr_in6 addr)
 {
 	/* TODO */
-	return -1;
+}
+
+int handle_connections(int sock)
+{
+	int conn = -1;
+	pid_t pid = -1;
+	struct sockaddr_in6 addr;
+	socklen_t addr_size = sizeof(addr);
+	;
+	while (1) {
+		conn = accept(sock, (struct sockaddr *)&addr, &addr_size);
+		if (conn < 0) {
+			return -errno;
+		}
+		pid = fork();
+		if (pid < 0) {
+			return -errno;
+		} else if (pid == 0) {
+			close(sock);
+			handle_connection(conn, addr);
+			close(conn);
+			exit(EXIT_SUCCESS);
+		} else {
+			close(conn);
+		}
+	}
+	return 0;
 }
diff --git a/server.h b/server.h
index 3ffa9c5..43f8af2 100644
--- a/server.h
+++ b/server.h
@@ -6,6 +6,10 @@
 #ifndef SERVER_H
 #define SERVER_H
 
-int setup_server(const char interface[]);
+#include <stdbool.h>
+
+bool is_wg_up_on_iface(const char iface[]);
+int setup_server();
+int handle_connections(int sock);
 
 #endif
diff --git a/wg_dynamic_client.c b/wg_dynamic_client.c
index 318714d..7862e9e 100644
--- a/wg_dynamic_client.c
+++ b/wg_dynamic_client.c
@@ -7,6 +7,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 const char *PROG_NAME;
 
@@ -17,6 +18,9 @@ static void show_usage()
 
 int main(int argc, char *argv[])
 {
+	const char *iface;
+	int sock;
+
 	PROG_NAME = argv[0];
 
 	if (argc == 1) {
@@ -24,8 +28,22 @@ int main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
-	if (connect_to_server(argv[1]) < 0) {
-		perror("error connecting to server");
+	iface = argv[1];
+
+	if (!is_server_in_allowed_ips(iface)) {
+		fprintf(stderr, "server is not in allowed IPs for tunnel %s\n",
+			iface);
+		return EXIT_FAILURE;
+	}
+
+	if ((sock = connect_to_server(argv[1])) < 0) {
+		fprintf(stderr, "error connecting to server: %s\n",
+			strerror(-sock));
+		return EXIT_FAILURE;
+	}
+
+	if ((sock = close_connection(sock)) < 0) {
+		fprintf(stderr, "error closing socket: %s\n", strerror(-sock));
 		return EXIT_FAILURE;
 	}
 
diff --git a/wg_dynamic_server.c b/wg_dynamic_server.c
index dcc7737..75bf3af 100644
--- a/wg_dynamic_server.c
+++ b/wg_dynamic_server.c
@@ -7,6 +7,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 const char *PROG_NAME;
 
@@ -17,6 +18,10 @@ static void show_usage()
 
 int main(int argc, char *argv[])
 {
+	const char *iface;
+	int sock;
+	int ret;
+
 	PROG_NAME = argv[0];
 
 	if (argc == 1) {
@@ -24,10 +29,25 @@ int main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
-	if (setup_server(argv[1]) < 0) {
-		perror("error setting up server");
+	iface = argv[1];
+
+	if (!is_wg_up_on_iface(iface)) {
+		fprintf(stderr, "no such wireguard iface %s\n", iface);
+		return EXIT_FAILURE;
+	}
+
+	if ((sock = setup_server(argv[1])) < 0) {
+		fprintf(stderr, "error setting up server: %s\n",
+			strerror(-sock));
+		return EXIT_FAILURE;
+	}
+
+	if ((ret = handle_connections(sock)) < 0) {
+		fprintf(stderr, "error while handling connections: %s\n",
+			strerror(-ret));
 		return EXIT_FAILURE;
 	}
 
-	return EXIT_SUCCESS;
+	/* unreachable */
+	return EXIT_FAILURE;
 }