X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/e6b06b6b61b4b877937d4a56ba704d3f18154dc2..786989941b7b4504f0234c4a318f929802e981ad:/server/tun-linux.c

diff --git a/server/tun-linux.c b/server/tun-linux.c
new file mode 100644
index 00000000..3cfa5d72
--- /dev/null
+++ b/server/tun-linux.c
@@ -0,0 +1,192 @@
+/* -*-c-*-
+ *
+ * $Id$
+ *
+ * Tunnel interface based on Linux TUN/TAP driver
+ *
+ * (c) 2003 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------* 
+ *
+ * This file is part of Trivial IP Encryption (TrIPE).
+ *
+ * TrIPE 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.
+ * 
+ * TrIPE 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 TrIPE; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#define TUN_INTERNALS
+
+#include "tripe.h"
+
+#ifdef TUN_LINUX
+#  include <sys/ioctl.h>
+#  include <linux/if.h>
+#  include <linux/if_tun.h>
+#endif
+
+/*----- Main code ---------------------------------------------------------*/
+
+#ifdef TUN_LINUX
+
+struct tunnel {
+  const tunnel_ops *ops;		/* Pointer to operations */
+  sel_file f;				/* Selector for TUN/TAP device */
+  struct peer *p;			/* Pointer to my peer */
+  char ifn[IFNAMSIZ];			/* Interface name buffer */
+};  
+
+/* --- @t_read@ --- *
+ *
+ * Arguments:	@int fd@ = file descriptor to read
+ *		@unsigned mode@ = what's happened
+ *		@void *v@ = pointer to tunnel block
+ *
+ * Returns:	---
+ *
+ * Use:		Reads data from the tunnel.
+ */
+
+static void t_read(int fd, unsigned mode, void *v)
+{
+  tunnel *t = v;
+  ssize_t n;
+  buf b;
+
+  n = read(fd, buf_i, sizeof(buf_i));
+  if (n < 0) {
+    a_warn("TUN", "%s", t->ifn, "read-error", "?ERRNO", A_END);
+    return;
+  }
+  IF_TRACING(T_TUNNEL, {
+    trace(T_TUNNEL, "tun-linux: packet arrived");
+    trace_block(T_PACKET, "tun-linux: packet contents", buf_i, n);
+  })
+  buf_init(&b, buf_i, n);
+  p_tun(t->p, &b);
+}
+
+/* --- @t_init@ --- *
+ *
+ * Arguments:	---
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes the tunneling system.  Maybe this will require
+ *		opening file descriptors or something.
+ */
+
+static void t_init(void) { return; }
+
+/* --- @t_create@ --- *
+ *
+ * Arguments:	@peer *p@ = pointer to peer block
+ *
+ * Returns:	A tunnel block if it worked, or null on failure.
+ *
+ * Use:		Initializes a new tunnel.
+ */
+
+static tunnel *t_create(peer *p)
+{
+  int fd;
+  int f;
+  struct ifreq iff;
+  tunnel *t;
+
+  if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
+    a_warn("TUN", "-", "linux",
+	    "open-error", "/dev/net/tun", "?ERRNO",
+	    A_END);
+    return (0);
+  }
+  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
+  memset(&iff, 0, sizeof(iff));
+  iff.ifr_name[0] = 0;
+  iff.ifr_flags = IFF_TUN | IFF_NO_PI;
+  if ((f = ioctl(fd, TUNSETIFF, &iff)) < 0) {
+    a_warn("TUN", "-", "linux", "config-error", "?ERRNO", A_END);
+    close(fd);
+    return (0);
+  }
+  t = CREATE(tunnel);
+  t->ops = &tun_linux;
+  t->p = p;
+  sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
+  sel_addfile(&t->f);
+  iff.ifr_name[IFNAMSIZ - 1] = 0;
+  strcpy(t->ifn, iff.ifr_name);
+  T( trace(T_TUNNEL, "tun-linux: attached interface %s to peer `%s'",
+	   t->ifn, p_name(p)); )
+  return (t);
+}
+
+/* --- @t_ifname@ --- *
+ *
+ * Arguments:	@tunnel *t@ = pointer to tunnel block
+ *
+ * Returns:	A pointer to the tunnel's interface name.
+ */
+
+static const char *t_ifname(tunnel *t) { return (t->ifn); }
+
+/* --- @t_inject@ --- *
+ *
+ * Arguments:	@tunnel *t@ = pointer to tunnel block
+ *		@buf *b@ = buffer to send
+ *
+ * Returns:	---
+ *
+ * Use:		Injects a packet into the local network stack.
+ */
+
+static void t_inject(tunnel *t, buf *b)
+{
+  IF_TRACING(T_TUNNEL, {
+    trace(T_TUNNEL, "tun-linux: inject decrypted packet");
+    trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
+  })
+  write(t->f.fd, BBASE(b), BLEN(b));
+}
+
+/* --- @t_destroy@ --- *
+ *
+ * Arguments:	@tunnel *t@ = pointer to tunnel block
+ *
+ * Returns:	---
+ *
+ * Use:		Destroys a tunnel.
+ */
+
+static void t_destroy(tunnel *t)
+{
+  sel_rmfile(&t->f);
+  close(t->f.fd);
+  DESTROY(t);
+}
+
+const tunnel_ops tun_linux = {
+  "linux",
+  t_init,
+  t_create,
+  t_ifname,
+  t_inject,
+  t_destroy
+};
+
+#endif
+
+/*----- That's all, folks -------------------------------------------------*/