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authorMatthias Schiffer <mschiffer@universe-factory.net>2012-02-25 22:53:33 +0100
committerMatthias Schiffer <mschiffer@universe-factory.net>2012-02-25 22:53:33 +0100
commit57a63fc9304e71ddd2cf434cc4c8789a1a3a3c88 (patch)
tree081b9dc0d024f7b57dde74c6858274c3d62df9aa /src/fastd.c
parentd86a948a67c44ca1c484cfbe30261f1bf61c59ab (diff)
downloadfastd-57a63fc9304e71ddd2cf434cc4c8789a1a3a3c88.tar
fastd-57a63fc9304e71ddd2cf434cc4c8789a1a3a3c88.zip
Init tun interface and define some structures
Diffstat (limited to 'src/fastd.c')
-rw-r--r--src/fastd.c130
1 files changed, 130 insertions, 0 deletions
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;
+}