server/tun-*.c: Factor out the (very similar) TUN-like drivers.

[tripe] / server / tun-std.c

diff --git a/server/tun-std.c b/server/tun-std.c
new file mode 100644 (file)
index 0000000..2983767
--- /dev/null
+++ b/server/tun-std.c
@@ -0,0 +1,167 @@
+/* -*-c-*-
+ *
+ * Tunnel interface for Linux-tun-shaped arrangements
+ *
+ * (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"
+
+/*----- Main code ---------------------------------------------------------*/
+
+#if defined(TUN_LINUX) || defined(TUN_BSD) || defined(TUN_UNET)
+
+struct tunnel {
+  const tunnel_ops *ops;               /* Pointer to operations */
+  sel_file f;                          /* Selector for TUN/TAP device */
+  struct peer *p;                      /* Pointer to my peer */
+};
+
+/* --- @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", p_ifname(t->p), "%s", t->ops->name,
+          "read-error", "?ERRNO", A_END);
+    return;
+  }
+  IF_TRACING(T_TUNNEL, {
+    trace(T_TUNNEL, "tun-%s: packet arrived", t->ops->name);
+    trace_block(T_PACKET, "tunnel: 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
+ *             @int fd@ = file descriptor of tunnel device
+ *             @char **ifn@ = where to put the interface name
+ *
+ * Returns:    A tunnel block if it worked, or null on failure.
+ *
+ * Use:                Initializes a new tunnel.
+ */
+
+static tunnel *t_create(peer *p, int fd, char **ifn, const tunnel_ops *ops)
+{
+  tunnel *t;
+
+  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
+  t = CREATE(tunnel);
+  t->ops = ops;
+  t->p = p;
+  sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
+  sel_addfile(&t->f);
+  return (t);
+}
+
+/* --- @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-%s: inject decrypted packet", t->ops->name);
+    trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
+  })
+  DISCARD(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); }
+
+#define DEFOPS(name)                                                   \
+                                                                       \
+static tunnel *t_create_##name(peer *p, int fd, char **ifn);           \
+                                                                       \
+const tunnel_ops tun_##name = {                                                \
+  #name, TUNF_PRIVOPEN,                                                        \
+  t_init, t_create_##name, 0, t_inject, t_destroy                      \
+};                                                                     \
+                                                                       \
+static tunnel *t_create_##name(peer *p, int fd, char **ifn)            \
+  { return t_create(p, fd, ifn, &tun_##name); }
+
+#ifdef TUN_LINUX
+  DEFOPS(linux)
+#endif
+
+#ifdef TUN_BSD
+  DEFOPS(bsd)
+#endif
+
+#ifdef TUN_UNET
+  DEFOPS(unet)
+#endif
+
+#endif
+
+/*----- That's all, folks -------------------------------------------------*/