Add fd_device

[tinc] / src / fd_device.c

diff --git a/src/fd_device.c b/src/fd_device.c
new file mode 100644 (file)
index 0000000..67e0cb7
--- /dev/null
+++ b/src/fd_device.c
@@ -0,0 +1,123 @@
+/*
+    fd_device.c -- Interaction with Android tun fd
+    Copyright (C)   2001-2005   Ivo Timmermans,
+                    2001-2016   Guus Sliepen <guus@tinc-vpn.org>
+                    2009        Grzegorz Dymarek <gregd72002@googlemail.com>
+                    2016        Pacien TRAN-GIRARD <pacien@pacien.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "system.h"
+#include "conf.h"
+#include "device.h"
+#include "ethernet.h"
+#include "logger.h"
+#include "net.h"
+#include "route.h"
+#include "utils.h"
+
+static inline bool check_config(void) {
+       if(routing_mode == RMODE_SWITCH) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Switch mode not supported (requires unsupported TAP device)!");
+               return false;
+       }
+
+       if(!get_config_int(lookup_config(config_tree, "Device"), &device_fd)) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Could not read fd from configuration!");
+               return false;
+       }
+
+       return true;
+}
+
+static bool setup_device(void) {
+       if(!check_config()) {
+               return false;
+       }
+
+       if(device_fd < 0) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Could not open %s: %s!", device, strerror(errno));
+               return false;
+       }
+
+       logger(DEBUG_ALWAYS, LOG_INFO, "fd/%d adapter set up.", device_fd);
+
+       return true;
+}
+
+static void close_device(void) {
+       close(device_fd);
+       device_fd = -1;
+}
+
+static inline uint16_t get_ip_ethertype(vpn_packet_t *packet) {
+       switch (DATA(packet)[ETH_HLEN] >> 4) {
+       case 4:
+               return ETH_P_IP;
+
+       case 6:
+               return ETH_P_IPV6;
+
+       default:
+               return ETH_P_MAX;
+       }
+}
+
+static inline void set_etherheader(vpn_packet_t *packet, uint16_t ethertype) {
+       memset(DATA(packet), 0, ETH_HLEN - ETHER_TYPE_LEN);
+
+       DATA(packet)[ETH_HLEN - ETHER_TYPE_LEN] = (ethertype >> 8) & 0xFF;
+       DATA(packet)[ETH_HLEN - ETHER_TYPE_LEN + 1] = ethertype & 0xFF;
+}
+
+static bool read_packet(vpn_packet_t *packet) {
+       int lenin = read(device_fd, DATA(packet) + ETH_HLEN, MTU - ETH_HLEN);
+       if(lenin <= 0) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from fd/%d: %s!", device_fd, strerror(errno));
+               return false;
+       }
+
+       uint16_t ethertype = get_ip_ethertype(packet);
+       if(ethertype == ETH_P_MAX) {
+               logger(DEBUG_TRAFFIC, LOG_ERR, "Unknown IP version while reading packet from fd/%d!", device_fd);
+               return false;
+       }
+
+       set_etherheader(packet, ethertype);
+       packet->len = lenin + ETH_HLEN;
+
+       logger(DEBUG_TRAFFIC, LOG_DEBUG, "Read packet of %d bytes from fd/%d.", packet->len, device_fd);
+
+       return true;
+}
+
+static bool write_packet(vpn_packet_t *packet) {
+       logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to fd/%d.", packet->len, device_fd);
+
+       if(write(device_fd, DATA(packet) + ETH_HLEN, packet->len - ETH_HLEN) < 0) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to fd/%d: %s!", device_fd, strerror(errno));
+               return false;
+       }
+
+       return true;
+}
+
+const devops_t fd_devops = {
+       .setup = setup_device,
+       .close = close_device,
+       .read = read_packet,
+       .write = write_packet,
+};