Init tun interface and define some structures

6 files changed, 356 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index b25c15b..c344a07 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 *~
+*.o
+fastd
diff --git a/src/Makefile b/src/Makefile
new file mode 100644
index 0000000..90619ec
--- /dev/null
+++ b/src/Makefile
@@ -0,0 +1,10 @@
+all : fastd
+
+fastd : fastd.o method_null.o
+	gcc -Wall -o $@ $^
+
+fastd.o : fastd.c fastd.h packet.h
+	gcc -Wall -c -o $@ $<
+
+method_null.o : method_null.c fastd.h
+	gcc -Wall -c -o $@ $<
diff --git a/src/fastd.c b/src/fastd.c
index f500090..42478b2 100644
--- a/src/fastd.c
+++ b/src/fastd.c
@@ -23,3 +23,133 @@
   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
+
+
+#include <fcntl.h>
+#include <linux/if_ether.h>
+#include <linux/if_tun.h>
+#include <net/if.h>
+#include <poll.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "fastd.h"
+#include "packet.h"
+
+
+extern fastd_method fastd_method_null;
+
+
+static int init_tuntap(const fastd_context *ctx) {
+	int tunfd;
+	struct ifreq ifr;
+
+	pr_debug(ctx, "Initializing tun/tap device...");
+
+	if ((tunfd = open("/dev/net/tun", O_RDWR)) < 0)
+		exit_fatal_errno(ctx, "Could not open tun/tap device file");
+
+	memset(&ifr, 0, sizeof(ifr));
+	// strcpy(ifr.ifr_name, name);
+	ifr.ifr_flags = IFF_TAP;
+	ifr.ifr_flags |= IFF_NO_PI;
+	if (ioctl(tunfd, TUNSETIFF, (void *)&ifr) < 0)
+		exit_fatal_errno(ctx, "TUNSETIFF ioctl failed");
+
+	return tunfd;
+}
+
+static void configure(fastd_context *ctx, fastd_config *conf) {
+	conf->loglevel = LOG_DEBUG;
+	conf->mtu = 1500;
+	conf->protocol = PROTOCOL_ETHERNET;
+	conf->method = &fastd_method_null;
+	conf->n_peers = 0;
+	conf->peers = NULL;
+}
+
+static size_t get_max_packet_size(const fastd_context *ctx) {
+	switch (ctx->conf->protocol) {
+	case PROTOCOL_ETHERNET:
+		return ctx->conf->mtu+ETH_HLEN;
+	case PROTOCOL_IP:
+		return ctx->conf->mtu;
+	default:
+		exit_fatal_bug(ctx, "invalid protocol");
+	}
+}
+
+static void *get_source_address(const fastd_context *ctx, void *buffer) {
+	switch (ctx->conf->protocol) {
+	case PROTOCOL_ETHERNET:
+		return &((struct ethhdr*)buffer)->h_source;
+	case PROTOCOL_IP:
+		return NULL;
+	default:
+		exit_fatal_bug(ctx, "invalid protocol");
+	}
+}
+
+static void *get_dest_address(const fastd_context *ctx, void *buffer) {
+	switch (ctx->conf->protocol) {
+	case PROTOCOL_ETHERNET:
+		return &((struct ethhdr*)buffer)->h_dest;
+	case PROTOCOL_IP:
+		return NULL;
+	default:
+		exit_fatal_bug(ctx, "invalid protocol");
+	}
+}
+
+static void run(const fastd_context *ctx) {
+	int tunfd;
+
+	tunfd = init_tuntap(ctx);
+
+	struct pollfd fds[ctx->conf->n_peers+1];
+	fds[0].fd = tunfd;
+	fds[0].events = POLLIN;
+
+	while (1) {
+		int ret = poll(fds, 1, -1);
+		if (ret < 0)
+			exit_fatal_errno(ctx, "poll error");
+
+		if (fds[0].revents & POLLIN) {
+			size_t max_len = get_max_packet_size(ctx);
+			char buffer[max_len];
+
+			unsigned len = read(tunfd, buffer, max_len);
+			if (len < 0)
+				exit_fatal_errno(ctx, "read");
+
+			uint8_t *src_addr = get_source_address(ctx, buffer);
+			uint8_t *dest_addr = get_dest_address(ctx, buffer);
+
+			pr_debug(ctx, "A packet with length %u was received from %02x:%02x:%02x:%02x:%02x:%02x to %02x:%02x:%02x:%02x:%02x:%02x",
+				 len, src_addr[0], src_addr[1], src_addr[2], src_addr[3], src_addr[4], src_addr[5],
+				 dest_addr[0], dest_addr[1], dest_addr[2], dest_addr[3], dest_addr[4], dest_addr[5]);
+
+			ctx->conf->method->method_send(ctx, buffer, len);
+		}
+	}
+}
+
+
+int main()
+{
+	fastd_context ctx = {
+		.conf = NULL,
+	};
+
+	fastd_config conf;
+	configure(&ctx, &conf);
+	ctx.conf = &conf;
+
+	run(&ctx);
+
+	return 0;
+}
diff --git a/src/fastd.h b/src/fastd.h
new file mode 100644
index 0000000..06b69b2
--- /dev/null
+++ b/src/fastd.h
@@ -0,0 +1,102 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  Partly based on QuickTun Copyright (c) 2010, Ivo Smits <Ivo@UCIS.nl>.
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#ifndef _FASTD_FASTD_H_
+#define _FASTD_FASTD_H_
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+typedef enum _fastd_loglevel {
+	LOG_FATAL = 0,
+	LOG_ERROR,
+	LOG_WARN,
+	LOG_INFO,
+	LOG_DEBUG,
+} fastd_loglevel;
+
+
+typedef enum _fastd_protocol {
+	PROTOCOL_ETHERNET,
+	PROTOCOL_IP,
+} fastd_protocol;
+
+typedef struct _fastd_peer_config {
+	struct _fastd_peer_config *next;
+} fastd_peer_config;
+
+
+typedef struct _fastd_peer_state {
+	struct _fastd_peer_state *next;
+
+	const fastd_peer_config *config;
+} fastd_peer_state;
+
+typedef struct _fastd_context fastd_context;
+
+typedef struct _fastd_method {
+	const char *name;
+	void (*method_init)(const fastd_context *ctx);
+
+	void (*method_recv)(const fastd_context *ctx, void *buffer, size_t len);
+	void (*method_send)(const fastd_context *ctx, void *buffer, size_t len);
+} fastd_method;
+
+typedef struct _fastd_config {
+	fastd_loglevel loglevel;
+
+	uint16_t mtu;
+	fastd_protocol protocol;
+
+	fastd_method *method;
+
+	unsigned n_peers;
+	fastd_peer_config *peers;
+} fastd_config;
+
+struct _fastd_context {
+	const fastd_config *conf;
+};
+
+
+#define pr_log(context, level, args...) if ((context)->conf == NULL || (level) <= (context)->conf->loglevel) do { fprintf(stderr, args); fputs("\n", stderr); } while(0)
+
+#define pr_fatal(context, args...) pr_log(context, LOG_FATAL, args)
+#define pr_error(context, args...) pr_log(context, LOG_ERROR, args)
+#define pr_warn(context, args...) pr_log(context, LOG_WARN, args)
+#define pr_info(context, args...) pr_log(context, LOG_INFO, args)
+#define pr_debug(context, args...) pr_log(context, LOG_DEBUG, args)
+
+#define exit_fatal(context, args...) do { pr_fatal(context, args); exit(1); } while(0)
+#define exit_fatal_bug(context, message) exit_fatal(context, "BUG: %s", message)
+#define exit_fatal_errno(context, message) exit_fatal(context, "%s: %s", message, strerror(errno))
+
+#endif /* _FASTD_FASTD_H_ */
diff --git a/src/method_null.c b/src/method_null.c
new file mode 100644
index 0000000..fd41110
--- /dev/null
+++ b/src/method_null.c
@@ -0,0 +1,45 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  Partly based on QuickTun Copyright (c) 2010, Ivo Smits <Ivo@UCIS.nl>.
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "fastd.h"
+
+
+static void null_init(const fastd_context *ctx) {
+}
+
+static void null_recv(const fastd_context *ctx, void *buffer, size_t len) {
+}
+
+static void null_send(const fastd_context *ctx, void *buffer, size_t len) {
+}
+
+
+const fastd_method fastd_method_null = {
+	.name = "null",
+	.method_init = null_init,
+	.method_recv = null_recv,
+	.method_send = null_send,
+};
diff --git a/src/packet.h b/src/packet.h
new file mode 100644
index 0000000..79b1984
--- /dev/null
+++ b/src/packet.h
@@ -0,0 +1,67 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  Partly based on QuickTun Copyright (c) 2010, Ivo Smits <Ivo@UCIS.nl>.
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#ifndef _FASTD_PACKET_H_
+#define _FASTD_PACKET_H_
+
+
+typedef struct __attribute__ ((__packed__)) _fastd_packet_any {
+	unsigned type       : 8;
+	unsigned reply      : 1;
+	unsigned cp         : 1;
+	unsigned req_id     : 6;
+	unsigned rsv        : 8;
+} fastd_packet_any;
+
+typedef struct __attribute__ ((__packed__)) _fastd_packet_request {
+	unsigned type       : 8;
+	unsigned reply      : 1;
+	unsigned cp         : 1;
+	unsigned req_id     : 6;
+	unsigned rsv        : 8;
+	unsigned flags      : 8;
+	unsigned proto      : 8;
+	unsigned method_len : 8;
+	char     method_name[];
+} fastd_packet_request;
+
+typedef struct __attribute__ ((__packed__)) _fastd_packet_reply {
+	unsigned type       : 8;
+	unsigned reply      : 1;
+	unsigned cp         : 1;
+	unsigned req_id     : 6;
+	unsigned rsv        : 8;
+	unsigned reply_code : 8;
+} fastd_packet_reply;
+
+typedef union _fastd_packet {
+	fastd_packet_any any;
+	fastd_packet_request request;
+	fastd_packet_reply reply;
+} fastd_packet;
+
+#endif /* _FASTD_PACKET_H_ */