Update mud

This allows to build easily with other libc.

.build.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+export CC="gcc -static"
+
+git clone https://github.com/jedisct1/libsodium --depth=1 --branch stable
+cd libsodium || exit 1
+./autogen.sh && ./configure --enable-minimal --disable-shared --prefix=/usr && make install
+cd ..
+
+./autogen.sh && ./configure && make
+[ -x glorytun ] || exit 1
+
+mkdir -p deploy
+
+cp glorytun deploy/glorytun-$(cat VERSION)-$(uname -m).debug.bin
+
+strip -s glorytun
+cp glorytun deploy/glorytun-$(cat VERSION)-$(uname -m).bin

.gitignore

@@ -1,9 +1,9 @@
 *.o
 *.log
 *.scan
-*.m4
 *.cache
 *.status
+aclocal.m4
 Makefile
 Makefile.in
 configure

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "mud"]
+	path = mud
+	url = https://github.com/angt/mud.git

.travis.yml

@@ -18,3 +18,18 @@ before_script:
 
 script:
     - ./configure --disable-dependency-tracking && make distcheck
+
+deploy:
+    provider: releases
+    api_key:
+        secure: Ira1jd3j+17QVFbJ7KlkytTNp0oMZLTqCWPQLxNHLEt32PVY/IPs/16BcvTbFpKrY+Ma7E3KCihfufTVG8T+jRlZ5hFO7HNpoQMgi7L7yZZAGScYO5pnMQvsr8O9hf7jzSi1DjFXgFHznbPJJ3lOSwegcqzSrbZflokiCR50GTLLWewHoPpfs+1gJ5XbtVyRhZlmXhMPC0NEH2sh33X2WdUiKUJUMOnlYC0atPBL+4n12qxnugF9YA9wPK5NHJSLiPHue7I2rHlSrOLX5NkN3vqnEvusiuIFQX1y0NuKtkpOscFD9n1CLHThGLuzMvPlwpdQfzRMVxwjYFGu6Ma5alf64ksFnMKl8Oo0yCXEA7WvHXz+qUai/a1gzYZLTGuasHtjrHN/mgKxM4QRSiHo8t5hj3CczUW+OFglytawZQyGjyUUiKdwx2kvlO96RVDIYEhUD4DeHzHR8rhvDLmlMlGAWqUPXq7d4D+bExqKmqWCCSkhrbubq5B1kChRmgw7/gly4SryqGy+R0xsC4oq9jUUxd7Sl801BIKcYDb5r5gFSw+hEhOzBb+uE2xJYFNO2KZ+eG69lkFeG3oNJMTy8afs8fRRUXq0poQJ39wFWerps3Md7h8Sxs61YLIAKHvLJJMfoMI+AORTcjnnpqujMhgWGWt8wLhJZdxaSycoQkU=
+    skip_cleanup: true
+    file_glob: true
+    file: glorytun-*.tar.gz
+    on:
+        tags: true
+        repo: angt/glorytun
+        condition: "${TRAVIS_OS_NAME}-${CC} == linux-gcc"
+
+after_deploy:
+    - md5sum glorytun-*.tar.gz

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2015, angt
+Copyright (c) 2015-2016, angt
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without

Makefile.am

@@ -1,13 +1,29 @@
+ACLOCAL_AMFLAGS = -I m4 --install
+
 bin_PROGRAMS = glorytun
+
 glorytun_CFLAGS = $(libsodium_CFLAGS)
 glorytun_LDADD = $(libsodium_LIBS)
 glorytun_SOURCES = \
     src/common.h \
-    src/common-static.h \
     src/common.c \
-    src/ip-static.h \
+    src/ip.h \
+    src/str.h \
     src/main.c \
     src/option.c \
     src/option.h \
     src/tun.c \
-    src/tun.h
+    src/tun.h \
+    src/db.c \
+    src/db.h
+
+glorytun_SOURCES += \
+    mud/mud.h \
+    mud/mud.c
+
+EXTRA_DIST = \
+    LICENSE \
+    README.md \
+    VERSION \
+    autogen.sh \
+    version.sh

README.md

@@ -1,20 +1,18 @@
-# glorytun
+# π₁(Glorytun)=0
 
-**Work In Progress:** Do not touch!
+Small, Simple and Stupid VPN over [mud](https://github.com/angt/mud).
 
-glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4
-and needs an AES-NI capable CPU.
+#### Build and Install
+
+Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4.
 
 To build and install the latest version:
 
-    $ git clone https://github.com/angt/glorytun
+    $ git clone https://github.com/angt/glorytun --recursive --branch mud
     $ cd glorytun
     $ ./autogen.sh
     $ ./configure
     $ make
     # make install
 
-To create and use a new secret key:
-
-    $ dd if=/dev/urandom of=glorytun.key bs=32 count=1
-    # glorytun keyfile glorytun.key [...]
+For feature requests and bug reports, please create an [issue](https://github.com/angt/glorytun/issues).

autogen.sh

@@ -1,2 +1,3 @@
 #!/bin/sh
+
 autoreconf -i -f

configure.ac

@@ -1,15 +1,22 @@
 AC_PREREQ([2.65])
-AC_INIT([glorytun], [0.0.2], [https://github.com/angt/glorytun/issues],
-        [glorytun], [https://github.com/angt/glorytun])
+AC_INIT([glorytun],
+        [m4_esyscmd([./version.sh])],
+        [https://github.com/angt/glorytun/issues],
+        [glorytun],
+        [https://github.com/angt/glorytun])
+AC_DEFINE_UNQUOTED([VERSION_MAJOR], [m4_esyscmd([./version.sh major])])
 AC_CONFIG_SRCDIR([src/common.h])
 AC_CONFIG_AUX_DIR([build-aux])
+AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([1.9 -Wall -Werror foreign tar-ustar subdir-objects])
 AM_DEP_TRACK
 AM_SILENT_RULES([yes])
+AM_PROG_CC_C_O
 AC_PROG_CC_C99
 AC_USE_SYSTEM_EXTENSIONS
-AC_SEARCH_LIBS([getaddrinfo], [resolv nsl])
 AC_SEARCH_LIBS([socket], [socket])
+AC_CHECK_LIB([rt], [clock_gettime])
+AC_CHECK_FUNCS([clock_gettime])
 PKG_CHECK_MODULES([libsodium], [libsodium >= 1.0.4])
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT

m4/pkg.m4

@@ -0,0 +1,275 @@
+dnl pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
+dnl serial 11 (pkg-config-0.29)
+dnl
+dnl Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
+dnl Copyright © 2012-2015 Dan Nicholson <dbn.lists@gmail.com>
+dnl
+dnl This program is free software; you can redistribute it and/or modify
+dnl it under the terms of the GNU General Public License as published by
+dnl the Free Software Foundation; either version 2 of the License, or
+dnl (at your option) any later version.
+dnl
+dnl This program is distributed in the hope that it will be useful, but
+dnl WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+dnl General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License
+dnl along with this program; if not, write to the Free Software
+dnl Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+dnl 02111-1307, USA.
+dnl
+dnl As a special exception to the GNU General Public License, if you
+dnl distribute this file as part of a program that contains a
+dnl configuration script generated by Autoconf, you may include it under
+dnl the same distribution terms that you use for the rest of that
+dnl program.
+
+dnl PKG_PREREQ(MIN-VERSION)
+dnl -----------------------
+dnl Since: 0.29
+dnl
+dnl Verify that the version of the pkg-config macros are at least
+dnl MIN-VERSION. Unlike PKG_PROG_PKG_CONFIG, which checks the user's
+dnl installed version of pkg-config, this checks the developer's version
+dnl of pkg.m4 when generating configure.
+dnl
+dnl To ensure that this macro is defined, also add:
+dnl m4_ifndef([PKG_PREREQ],
+dnl     [m4_fatal([must install pkg-config 0.29 or later before running autoconf/autogen])])
+dnl
+dnl See the "Since" comment for each macro you use to see what version
+dnl of the macros you require.
+m4_defun([PKG_PREREQ],
+[m4_define([PKG_MACROS_VERSION], [0.29])
+m4_if(m4_version_compare(PKG_MACROS_VERSION, [$1]), -1,
+    [m4_fatal([pkg.m4 version $1 or higher is required but ]PKG_MACROS_VERSION[ found])])
+])dnl PKG_PREREQ
+
+dnl PKG_PROG_PKG_CONFIG([MIN-VERSION])
+dnl ----------------------------------
+dnl Since: 0.16
+dnl
+dnl Search for the pkg-config tool and set the PKG_CONFIG variable to
+dnl first found in the path. Checks that the version of pkg-config found
+dnl is at least MIN-VERSION. If MIN-VERSION is not specified, 0.9.0 is
+dnl used since that's the first version where most current features of
+dnl pkg-config existed.
+AC_DEFUN([PKG_PROG_PKG_CONFIG],
+[m4_pattern_forbid([^_?PKG_[A-Z_]+$])
+m4_pattern_allow([^PKG_CONFIG(_(PATH|LIBDIR|SYSROOT_DIR|ALLOW_SYSTEM_(CFLAGS|LIBS)))?$])
+m4_pattern_allow([^PKG_CONFIG_(DISABLE_UNINSTALLED|TOP_BUILD_DIR|DEBUG_SPEW)$])
+AC_ARG_VAR([PKG_CONFIG], [path to pkg-config utility])
+AC_ARG_VAR([PKG_CONFIG_PATH], [directories to add to pkg-config's search path])
+AC_ARG_VAR([PKG_CONFIG_LIBDIR], [path overriding pkg-config's built-in search path])
+
+if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
+	AC_PATH_TOOL([PKG_CONFIG], [pkg-config])
+fi
+if test -n "$PKG_CONFIG"; then
+	_pkg_min_version=m4_default([$1], [0.9.0])
+	AC_MSG_CHECKING([pkg-config is at least version $_pkg_min_version])
+	if $PKG_CONFIG --atleast-pkgconfig-version $_pkg_min_version; then
+		AC_MSG_RESULT([yes])
+	else
+		AC_MSG_RESULT([no])
+		PKG_CONFIG=""
+	fi
+fi[]dnl
+])dnl PKG_PROG_PKG_CONFIG
+
+dnl PKG_CHECK_EXISTS(MODULES, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl -------------------------------------------------------------------
+dnl Since: 0.18
+dnl
+dnl Check to see whether a particular set of modules exists. Similar to
+dnl PKG_CHECK_MODULES(), but does not set variables or print errors.
+dnl
+dnl Please remember that m4 expands AC_REQUIRE([PKG_PROG_PKG_CONFIG])
+dnl only at the first occurence in configure.ac, so if the first place
+dnl it's called might be skipped (such as if it is within an "if", you
+dnl have to call PKG_CHECK_EXISTS manually
+AC_DEFUN([PKG_CHECK_EXISTS],
+[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
+if test -n "$PKG_CONFIG" && \
+    AC_RUN_LOG([$PKG_CONFIG --exists --print-errors "$1"]); then
+  m4_default([$2], [:])
+m4_ifvaln([$3], [else
+  $3])dnl
+fi])
+
+dnl _PKG_CONFIG([VARIABLE], [COMMAND], [MODULES])
+dnl ---------------------------------------------
+dnl Internal wrapper calling pkg-config via PKG_CONFIG and setting
+dnl pkg_failed based on the result.
+m4_define([_PKG_CONFIG],
+[if test -n "$$1"; then
+    pkg_cv_[]$1="$$1"
+ elif test -n "$PKG_CONFIG"; then
+    PKG_CHECK_EXISTS([$3],
+                     [pkg_cv_[]$1=`$PKG_CONFIG --[]$2 "$3" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes ],
+		     [pkg_failed=yes])
+ else
+    pkg_failed=untried
+fi[]dnl
+])dnl _PKG_CONFIG
+
+dnl _PKG_SHORT_ERRORS_SUPPORTED
+dnl ---------------------------
+dnl Internal check to see if pkg-config supports short errors.
+AC_DEFUN([_PKG_SHORT_ERRORS_SUPPORTED],
+[AC_REQUIRE([PKG_PROG_PKG_CONFIG])
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi[]dnl
+])dnl _PKG_SHORT_ERRORS_SUPPORTED
+
+
+dnl PKG_CHECK_MODULES(VARIABLE-PREFIX, MODULES, [ACTION-IF-FOUND],
+dnl   [ACTION-IF-NOT-FOUND])
+dnl --------------------------------------------------------------
+dnl Since: 0.4.0
+dnl
+dnl Note that if there is a possibility the first call to
+dnl PKG_CHECK_MODULES might not happen, you should be sure to include an
+dnl explicit call to PKG_PROG_PKG_CONFIG in your configure.ac
+AC_DEFUN([PKG_CHECK_MODULES],
+[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
+AC_ARG_VAR([$1][_CFLAGS], [C compiler flags for $1, overriding pkg-config])dnl
+AC_ARG_VAR([$1][_LIBS], [linker flags for $1, overriding pkg-config])dnl
+
+pkg_failed=no
+AC_MSG_CHECKING([for $1])
+
+_PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])
+_PKG_CONFIG([$1][_LIBS], [libs], [$2])
+
+m4_define([_PKG_TEXT], [Alternatively, you may set the environment variables $1[]_CFLAGS
+and $1[]_LIBS to avoid the need to call pkg-config.
+See the pkg-config man page for more details.])
+
+if test $pkg_failed = yes; then
+   	AC_MSG_RESULT([no])
+        _PKG_SHORT_ERRORS_SUPPORTED
+        if test $_pkg_short_errors_supported = yes; then
+	        $1[]_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "$2" 2>&1`
+        else 
+	        $1[]_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "$2" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$$1[]_PKG_ERRORS" >&AS_MESSAGE_LOG_FD
+
+	m4_default([$4], [AC_MSG_ERROR(
+[Package requirements ($2) were not met:
+
+$$1_PKG_ERRORS
+
+Consider adjusting the PKG_CONFIG_PATH environment variable if you
+installed software in a non-standard prefix.
+
+_PKG_TEXT])[]dnl
+        ])
+elif test $pkg_failed = untried; then
+     	AC_MSG_RESULT([no])
+	m4_default([$4], [AC_MSG_FAILURE(
+[The pkg-config script could not be found or is too old.  Make sure it
+is in your PATH or set the PKG_CONFIG environment variable to the full
+path to pkg-config.
+
+_PKG_TEXT
+
+To get pkg-config, see <http://pkg-config.freedesktop.org/>.])[]dnl
+        ])
+else
+	$1[]_CFLAGS=$pkg_cv_[]$1[]_CFLAGS
+	$1[]_LIBS=$pkg_cv_[]$1[]_LIBS
+        AC_MSG_RESULT([yes])
+	$3
+fi[]dnl
+])dnl PKG_CHECK_MODULES
+
+
+dnl PKG_CHECK_MODULES_STATIC(VARIABLE-PREFIX, MODULES, [ACTION-IF-FOUND],
+dnl   [ACTION-IF-NOT-FOUND])
+dnl ---------------------------------------------------------------------
+dnl Since: 0.29
+dnl
+dnl Checks for existence of MODULES and gathers its build flags with
+dnl static libraries enabled. Sets VARIABLE-PREFIX_CFLAGS from --cflags
+dnl and VARIABLE-PREFIX_LIBS from --libs.
+dnl
+dnl Note that if there is a possibility the first call to
+dnl PKG_CHECK_MODULES_STATIC might not happen, you should be sure to
+dnl include an explicit call to PKG_PROG_PKG_CONFIG in your
+dnl configure.ac.
+AC_DEFUN([PKG_CHECK_MODULES_STATIC],
+[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
+_save_PKG_CONFIG=$PKG_CONFIG
+PKG_CONFIG="$PKG_CONFIG --static"
+PKG_CHECK_MODULES($@)
+PKG_CONFIG=$_save_PKG_CONFIG[]dnl
+])dnl PKG_CHECK_MODULES_STATIC
+
+
+dnl PKG_INSTALLDIR([DIRECTORY])
+dnl -------------------------
+dnl Since: 0.27
+dnl
+dnl Substitutes the variable pkgconfigdir as the location where a module
+dnl should install pkg-config .pc files. By default the directory is
+dnl $libdir/pkgconfig, but the default can be changed by passing
+dnl DIRECTORY. The user can override through the --with-pkgconfigdir
+dnl parameter.
+AC_DEFUN([PKG_INSTALLDIR],
+[m4_pushdef([pkg_default], [m4_default([$1], ['${libdir}/pkgconfig'])])
+m4_pushdef([pkg_description],
+    [pkg-config installation directory @<:@]pkg_default[@:>@])
+AC_ARG_WITH([pkgconfigdir],
+    [AS_HELP_STRING([--with-pkgconfigdir], pkg_description)],,
+    [with_pkgconfigdir=]pkg_default)
+AC_SUBST([pkgconfigdir], [$with_pkgconfigdir])
+m4_popdef([pkg_default])
+m4_popdef([pkg_description])
+])dnl PKG_INSTALLDIR
+
+
+dnl PKG_NOARCH_INSTALLDIR([DIRECTORY])
+dnl --------------------------------
+dnl Since: 0.27
+dnl
+dnl Substitutes the variable noarch_pkgconfigdir as the location where a
+dnl module should install arch-independent pkg-config .pc files. By
+dnl default the directory is $datadir/pkgconfig, but the default can be
+dnl changed by passing DIRECTORY. The user can override through the
+dnl --with-noarch-pkgconfigdir parameter.
+AC_DEFUN([PKG_NOARCH_INSTALLDIR],
+[m4_pushdef([pkg_default], [m4_default([$1], ['${datadir}/pkgconfig'])])
+m4_pushdef([pkg_description],
+    [pkg-config arch-independent installation directory @<:@]pkg_default[@:>@])
+AC_ARG_WITH([noarch-pkgconfigdir],
+    [AS_HELP_STRING([--with-noarch-pkgconfigdir], pkg_description)],,
+    [with_noarch_pkgconfigdir=]pkg_default)
+AC_SUBST([noarch_pkgconfigdir], [$with_noarch_pkgconfigdir])
+m4_popdef([pkg_default])
+m4_popdef([pkg_description])
+])dnl PKG_NOARCH_INSTALLDIR
+
+
+dnl PKG_CHECK_VAR(VARIABLE, MODULE, CONFIG-VARIABLE,
+dnl [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl -------------------------------------------
+dnl Since: 0.28
+dnl
+dnl Retrieves the value of the pkg-config variable for the given module.
+AC_DEFUN([PKG_CHECK_VAR],
+[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
+AC_ARG_VAR([$1], [value of $3 for $2, overriding pkg-config])dnl
+
+_PKG_CONFIG([$1], [variable="][$3]["], [$2])
+AS_VAR_COPY([$1], [pkg_cv_][$1])
+
+AS_VAR_IF([$1], [""], [$5], [$4])dnl
+])dnl PKG_CHECK_VAR

src/common-static.h

@@ -1,142 +0,0 @@
-#pragma once
-
-#include "common.h"
-
-#include <unistd.h>
-#include <errno.h>
-
-static inline void byte_set (void *dst, const char value, size_t size)
-{
-    if (!dst)
-        return;
-
-    char *restrict d = dst;
-
-    while (size--)
-        *d++ = value;
-}
-
-static inline void byte_cpy (void *dst, const void *src, size_t size)
-{
-    if (!dst || !src)
-        return;
-
-    char *restrict d = dst;
-    const char *restrict s = src;
-
-    while (size--)
-        *d++ = *s++;
-}
-
-static inline size_t str_cpy (char *restrict dst, const char *restrict src, size_t len)
-{
-    if (!dst || !src)
-        return 0;
-
-    size_t i;
-
-    for (i=0; i<len && src[i]; i++)
-        dst[i] = src[i];
-
-    dst[i] = 0;
-
-    return i;
-}
-
-static inline int str_cmp (const char *restrict sa, const char *restrict sb)
-{
-    if (!sa || !sb)
-        return 1;
-
-     while (*sa==*sb++)
-         if (!*sa++)
-             return 0;
-
-    return 1;
-}
-
-static inline size_t str_len (const char *restrict str)
-{
-    if (!str)
-        return 0;
-
-    size_t i = 0;
-
-    while (str[i])
-        i++;
-
-    return i;
-}
-
-static inline char *str_cat (const char *const strs[], size_t count)
-{
-    size_t size = 1;
-
-    for (size_t i=0; i<count; i++)
-        size += str_len(strs[i]);
-
-    char *str = malloc(size);
-
-    if (!str)
-        return NULL;
-
-    char *p = str;
-
-    for (size_t i=0; i<count; i++) {
-        size_t len = str_len(strs[i]);
-        byte_cpy(p, strs[i], len);
-        p += len;
-    }
-
-    p[0] = 0;
-
-    return str;
-}
-
-static inline void buffer_setup (buffer_t *buffer, void *data, size_t size)
-{
-    if (!data)
-        data = malloc(ALIGN(size));
-
-    buffer->data  = data;
-    buffer->read  = data;
-    buffer->write = data;
-    buffer->end   = data;
-    buffer->end  += size;
-}
-
-static inline void buffer_format (buffer_t *buffer)
-{
-    buffer->write = buffer->data;
-    buffer->read  = buffer->data;
-}
-
-static inline size_t buffer_size (buffer_t *buffer)
-{
-    return buffer->end-buffer->data;
-}
-
-static inline size_t buffer_write_size (buffer_t *buffer)
-{
-    return buffer->end-buffer->write;
-}
-
-static inline size_t buffer_read_size (buffer_t *buffer)
-{
-    return buffer->write-buffer->read;
-}
-
-static inline void buffer_shift (buffer_t *buffer)
-{
-    if (buffer->read==buffer->write) {
-        buffer_format(buffer);
-    } else {
-        const uint8_t *src = PALIGN_DOWN(buffer->read);
-        const size_t size = ALIGN(buffer->write-src);
-        if (buffer->data+size<src) {
-            byte_cpy(buffer->data, src, size);
-            buffer->read  -= src-buffer->data;
-            buffer->write -= src-buffer->data;
-        }
-    }
-}

src/common.c

@@ -1,9 +1,24 @@
 #include "common.h"
 
-#include <stdio.h>
 #include <stdarg.h>
+#include <stdio.h>
 
-void gt_log (const char *fmt, ...)
+int
+gt_print(const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    int ret = vfprintf(stdout, fmt, ap);
+    va_end(ap);
+
+    if (ret < 0)
+        return 0;
+
+    return ret;
+}
+
+void
+gt_log(const char *fmt, ...)
 {
     va_list ap;
     va_start(ap, fmt);
@@ -11,7 +26,8 @@ void gt_log (const char *fmt, ...)
     va_end(ap);
 }
 
-void gt_fatal (const char *fmt, ...)
+void
+gt_fatal(const char *fmt, ...)
 {
     va_list ap;
     va_start(ap, fmt);
@@ -21,7 +37,66 @@ void gt_fatal (const char *fmt, ...)
     exit(EXIT_FAILURE);
 }
 
-void gt_na (const char *name)
+void
+gt_na(const char *name)
 {
-    gt_log("%s is not available on your platform!\n", name);
+    gt_log("%s is not available on your platform\n", name);
+}
+
+int
+gt_tohex(char *dst, size_t dst_size, const uint8_t *src, size_t src_size)
+{
+    if (_0_(!dst_size))
+        return -1;
+
+    if (_0_(((dst_size - 1) / 2) < src_size))
+        return -1;
+
+    static const char tbl[] = "0123456789ABCDEF";
+
+    for (size_t i = 0; i < src_size; i++) {
+        *dst++ = tbl[0xF & (src[i] >> 4)];
+        *dst++ = tbl[0xF & (src[i])];
+    }
+
+    *dst = 0;
+
+    return 0;
+}
+
+_const_ static inline int
+fromhex(const char c)
+{
+    if (c >= '0' && c <= '9')
+        return c - '0';
+
+    if (c >= 'A' && c <= 'F')
+        return c - 'A' + 10;
+
+    if (c >= 'a' && c <= 'f')
+        return c - 'a' + 10;
+
+    return -1;
+}
+
+int
+gt_fromhex(uint8_t *dst, size_t dst_size, const char *src, size_t src_size)
+{
+    if (_0_(src_size & 1))
+        return -1;
+
+    if (_0_(dst_size < (src_size / 2)))
+        return -1;
+
+    for (size_t i = 0; i < src_size; i += 2) {
+        const int a = fromhex(src[i]);
+        const int b = fromhex(src[i + 1]);
+
+        if (_0_(a == -1 || b == -1))
+            return -1;
+
+        *dst++ = (a << 4) | b;
+    }
+
+    return 0;
 }

src/common.h

@@ -2,8 +2,11 @@
 
 #include <stdlib.h>
 #include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
 
-#define COUNT(x) (sizeof(x)/sizeof(x[0]))
+#define COUNT(x)       (sizeof(x)/sizeof(x[0]))
 
 #define ALIGN_SIZE     (1<<4)
 #define ALIGN_MASK     (ALIGN_SIZE-1)
@@ -14,19 +17,28 @@
 #define PALIGN(x)      ((void *)ALIGN((size_t)(x)))
 #define PALIGN_DOWN(x) ((void *)ALIGN_DOWN((size_t)(x)))
 
-#define _printf_(A,B)  __attribute__((format(printf,A,B)))
-#define _noreturn_     __attribute__((noreturn))
-#define _unused_       __attribute__((unused))
+#define _1_(x)         (__builtin_expect((x), 1))
+#define _0_(x)         (__builtin_expect((x), 0))
 
-typedef struct buffer buffer_t;
+#define CLZ(x)         (__builtin_clz(x))
 
-struct buffer {
-    uint8_t *data;
-    uint8_t *read;
-    uint8_t *write;
-    uint8_t *end;
-};
+#define _printf_(A,B)  __attribute__ ((format(printf,A,B)))
+#define _noreturn_     __attribute__ ((noreturn))
+#define _unused_       __attribute__ ((unused))
+#define _pure_         __attribute__ ((pure))
+#define _const_        __attribute__ ((const))
+#define _align_(...)   __attribute__ ((aligned(__VA_ARGS__)))
 
+#undef MAX
+#define MAX(x,y) ({ __typeof__(x) X=(x); __typeof__(y) Y=(y); X > Y ? X : Y; })
+
+#undef MIN
+#define MIN(x,y) ({ __typeof__(x) X=(x); __typeof__(y) Y=(y); X < Y ? X : Y; })
+
+int  gt_print (const char *, ...) _printf_(1,2);
 void gt_log   (const char *, ...) _printf_(1,2);
 void gt_fatal (const char *, ...) _printf_(1,2) _noreturn_;
 void gt_na    (const char *);
+
+int gt_tohex   (char *, size_t, const uint8_t *, size_t);
+int gt_fromhex (uint8_t *, size_t, const char *, size_t);

src/db.c

@@ -0,0 +1,158 @@
+#include "common.h"
+
+#include "db.h"
+#include "str.h"
+
+#define CBIT(X) (1 & (intptr_t)(X))
+#define CBIT_PTR(X) (uint8_t *)(1 | (intptr_t)(X))
+#define CBIT_NODE(X) (struct node *)(1 ^ (intptr_t)(X))
+
+struct node {
+    uint8_t *child[2];
+    uint32_t point;
+};
+
+_pure_ static inline size_t
+db_size(const uint8_t *a)
+{
+    return (a[0] ?: str_len((char *)a + 1)) + 1;
+}
+
+_pure_ static inline size_t
+db_cmp(const uint8_t *a, const uint8_t *b)
+{
+    const size_t size = a[0];
+
+    if (size != b[0])
+        return 1;
+
+    if (!size) {
+        size_t i = str_cmp((char *)a + 1, (char *)b + 1);
+        return i ? i + 1 : 0;
+    }
+
+    for (size_t i = 1; i <= size; i++) {
+        if (a[i] != b[i])
+            return i + 1;
+    }
+
+    return 0;
+}
+
+_pure_ static inline int
+db_dir(const uint32_t point, uint8_t *data, const size_t size)
+{
+    const size_t pos = point >> 8;
+
+    if (pos >= size)
+        return 0;
+
+    return ((point | data[pos]) & 255) == 255;
+}
+
+uint8_t *
+db_search(uint8_t **p, uint8_t *data)
+{
+    if (_0_(!*p))
+        return NULL;
+
+    uint8_t *r = *p;
+    const size_t size = db_size(data);
+
+    while (CBIT(r)) {
+        struct node *node = CBIT_NODE(r);
+        r = node->child[db_dir(node->point, data, size)];
+    }
+
+    if (!db_cmp(r, data))
+        return r;
+
+    return NULL;
+}
+
+uint8_t *
+db_insert(uint8_t **p, uint8_t *data)
+{
+    if (_0_(CBIT(data)))
+        return NULL;
+
+    if (_0_(!*p)) {
+        *p = data;
+        return data;
+    }
+
+    uint8_t *r = *p;
+    size_t size = db_size(data);
+
+    while (CBIT(r)) {
+        struct node *node = CBIT_NODE(r);
+        r = node->child[db_dir(node->point, data, size)];
+    }
+
+    const size_t diff = db_cmp(r, data);
+
+    if (_0_(!diff))
+        return r;
+
+    const size_t pos = diff - 1;
+    const uint8_t mask = ~((1u << 31) >> CLZ(r[pos] ^ data[pos]));
+    const size_t point = (pos << 8) | mask;
+
+    while (CBIT(*p)) {
+        struct node *node = CBIT_NODE(*p);
+
+        if (node->point > point)
+            break;
+
+        p = node->child + db_dir(node->point, data, size);
+    }
+
+    struct node *node = malloc(sizeof(struct node));
+
+    if (_0_(!node))
+        return NULL;
+
+    const int dir = (mask | r[pos]) == 255;
+
+    node->child[dir] = *p;
+    node->child[1 - dir] = data;
+    node->point = point;
+
+    *p = CBIT_PTR(node);
+
+    return data;
+}
+
+uint8_t *
+db_remove(uint8_t **p, uint8_t *data)
+{
+    if (_0_(!*p))
+        return NULL;
+
+    const size_t size = db_size(data);
+
+    uint8_t **p_old = NULL;
+    struct node *node = NULL;
+    int dir = 0;
+
+    while (CBIT(*p)) {
+        p_old = p;
+        node = CBIT_NODE(*p);
+        dir = db_dir(node->point, data, size);
+        p = node->child + dir;
+    }
+
+    if (_0_(db_cmp(data, *p)))
+        return NULL;
+
+    uint8_t *r = *p;
+
+    if (p_old) {
+        *p_old = node->child[1 - dir];
+        free(node);
+    } else {
+        *p = NULL;
+    }
+
+    return r;
+}

src/db.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stdint.h>
+
+uint8_t *db_search (uint8_t **, uint8_t *);
+uint8_t *db_insert (uint8_t **, uint8_t *);
+uint8_t *db_remove (uint8_t **, uint8_t *);

src/ip-static.h

@@ -1,30 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-static inline int ip_get_version (const uint8_t *data, size_t size)
-{
-    if (size<20)   // XXX
-        return -1; // XXX
-
-    return data[0]>>4;
-}
-
-static inline void ip_set_size (uint8_t *data, size_t size)
-{
-    data[2] = 0xFF&(size>>8);
-    data[3] = 0xFF&(size);
-}
-
-static inline ssize_t ip_get_size (const uint8_t *data, size_t size)
-{
-    switch (ip_get_version(data, size)) {
-    case 4:
-        return (data[2]<<8)|data[3];
-    case -1:
-        return -1;
-    }
-
-    return 0;
-}
-

src/ip.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <stdint.h>
+
+struct ip_common {
+    uint8_t version;
+    uint8_t tc;
+    uint8_t proto;
+    uint8_t hdr_size;
+    uint16_t size;
+};
+
+_pure_ static inline uint8_t
+ip_get_version(const uint8_t *data, size_t size)
+{
+    if (size < 20)
+        return 0;
+
+    return data[0] >> 4;
+}
+
+static inline int
+ip_get_common(struct ip_common *ic, const uint8_t *data, size_t size)
+{
+    ic->version = ip_get_version(data, size);
+
+    switch (ic->version) {
+    case 4:
+        ic->tc = data[1];
+        ic->proto = data[9];
+        ic->hdr_size = (data[0] & 0xF) << 2;
+        ic->size = ((data[2] << 8) | data[3]);
+        if (ic->size >= 20)
+            return 0;
+        break;
+    case 6:
+        ic->tc = ((data[0] & 0xF) << 4) | (data[1] >> 4);
+        ic->proto = data[6];
+        ic->hdr_size = 40;
+        ic->size = ((data[4] << 8) | data[5]) + 40;
+        return 0;
+    }
+
+    return -1;
+}

src/option.c

@@ -1,34 +1,26 @@
-#include "common-static.h"
-
-#include <stdio.h>
-#include <stdlib.h>
+#include "common.h"
 
 #include "option.h"
+#include "str.h"
 
-int option_flag (void *data, _unused_ int argc, _unused_ char **argv)
+int
+option_str(void *data, int argc, char **argv)
 {
-    const int one = 1;
-    byte_cpy(data, &one, sizeof(one));
-
-    return 0;
-}
-
-int option_str (void *data, int argc, char **argv)
-{
-    if (argc<2 || !argv[1]) {
-        printf("option `%s' need a string argument\n", argv[0]);
+    if (argc < 2 || str_empty(argv[1])) {
+        gt_print("option `%s' need a string argument\n", argv[0]);
         return -1;
     }
 
-    byte_cpy(data, &argv[1], sizeof(argv[1]));
+    memcpy(data, &argv[1], sizeof(argv[1]));
 
     return 1;
 }
 
-int option_long (void *data, int argc, char **argv)
+int
+option_long(void *data, int argc, char **argv)
 {
-    if (argc<2 || !argv[1]) {
-        printf("option `%s' need an integer argument\n", argv[0]);
+    if (argc < 2 || str_empty(argv[1])) {
+        gt_print("option `%s' need an integer argument\n", argv[0]);
         return -1;
     }
 
@@ -36,38 +28,53 @@ int option_long (void *data, int argc, char **argv)
     char *end;
     long val = strtol(argv[1], &end, 0);
 
-    if (errno || argv[1]==end) {
-        printf("argument `%s' is not a valid integer\n", argv[1]);
+    if (errno || argv[1] == end) {
+        gt_print("argument `%s' is not a valid integer\n", argv[1]);
         return -1;
     }
 
-    byte_cpy(data, &val, sizeof(val));
+    memcpy(data, &val, sizeof(val));
 
     return 1;
 }
 
-int option_option (void *data, int argc, char **argv)
+int
+option_is_set(struct option *opts, const char *name)
 {
+    for (int k = 0; opts[k].name; k++) {
+        if (!str_cmp(opts[k].name, name))
+            return opts[k].set;
+    }
+
+    return 0;
+}
+
+int
+option_option(void *data, int argc, char **argv)
+{
+    if (!data)
+        return 0;
+
     struct option *opts = (struct option *)data;
 
-    for (int k=0; opts[k].name; k++)
+    for (int k = 0; opts[k].name; k++)
         opts[k].set = 0;
 
-    for (int i=1; i<argc; i++) {
+    for (int i = 1; i < argc; i++) {
         int found = 0;
 
-        for (int k=0; opts[k].name; k++) {
+        for (int k = 0; opts[k].name; k++) {
             if (str_cmp(opts[k].name, argv[i]))
                 continue;
 
             if (opts[k].set) {
-                printf("option `%s' is already set\n", opts[k].name);
+                gt_print("option `%s' is already set\n", opts[k].name);
                 return -1;
             }
 
-            int ret = opts[k].call(opts[k].data, argc-i, &argv[i]);
+            int ret = opts[k].call(opts[k].data, argc - i, &argv[i]);
 
-            if (ret<0)
+            if (ret < 0)
                 return -1;
 
             opts[k].set = 1;
@@ -78,51 +85,62 @@ int option_option (void *data, int argc, char **argv)
         }
 
         if (!found)
-            return i-1;
+            return i - 1;
     }
 
     return argc;
 }
 
-static void option_usage (struct option *opts, char *name)
+static int
+option_usage(struct option *opts, int slen)
 {
-    char *usage = "usage: ";
-    size_t slen = str_len(usage)+str_len(name);
-    size_t len = slen;
+    if (!opts)
+        return 0;
 
-    printf("%s%s", usage, name);
+    int len = 0;
 
-    if (slen>40)
-        slen = 12;
-
-    for (int k=0; opts[k].name; k++) {
-        char *arg = (opts[k].call==option_flag)?"":" ARG";
-        size_t inc = str_len(opts[k].name)+str_len(arg)+3;
-
-        if (len+inc>72) {
-            printf("\n%*s", (int)slen, "");
-            len = slen;
+    for (int k = 0; opts[k].name; k++) {
+        if (len > 40) {
+            gt_print("\n%*s", slen, "");
+            len = 0;
         }
 
-        printf(" [%s%s]", opts[k].name, arg);
-        len += inc;
+        len += gt_print(" [%s", opts[k].name);
+
+        if (opts[k].call == option_option) {
+            len += option_usage((struct option *)opts[k].data, slen + len);
+        } else {
+            len += gt_print(" ARG");
+        }
+
+        len += gt_print("]");
     }
 
-    printf("\n");
+    return len;
 }
 
-int option (struct option *opts, int argc, char **argv)
+int
+option(struct option *opts, int argc, char **argv)
 {
     int ret = option_option(opts, argc, argv);
 
-    if (ret==argc)
+    if (ret == argc)
         return 0;
 
-    if (ret<0 || ret+1>=argc)
+    if (ret < 0 || ret + 1 >= argc)
         return 1;
 
-    printf("option `%s' is unknown\n", argv[ret+1]);
-    option_usage(opts, argv[0]);
+    gt_print("option `%s' is unknown\n", argv[ret + 1]);
+
+    int slen = gt_print("usage: %s", argv[0]);
+
+    if (slen > 40) {
+        slen = 12;
+        gt_print("\n%*s", slen, "");
+    }
+
+    option_usage(opts, slen);
+    gt_print("\n");
 
     return 1;
 }

src/option.h

@@ -7,9 +7,9 @@ struct option {
     int set;
 };
 
-int option_flag   (void *, int, char **);
+int option_option (void *, int, char **);
 int option_str    (void *, int, char **);
 int option_long   (void *, int, char **);
-int option_option (void *, int, char **);
 
-int option (struct option *, int, char **);
+int option_is_set (struct option *, const char *);
+int option        (struct option *, int, char **);

src/str.h

@@ -0,0 +1,75 @@
+#pragma once
+
+#include "common.h"
+
+static inline size_t
+str_cpy(char *restrict dst, const char *restrict src, size_t len)
+{
+    if (!dst || !src)
+        return 0;
+
+    size_t i;
+
+    for (i = 0; i < len && src[i]; i++)
+        dst[i] = src[i];
+
+    dst[i] = 0;
+
+    return i;
+}
+
+_pure_ static inline int
+str_empty(const char *restrict str)
+{
+    return !str || !str[0];
+}
+
+_pure_ static inline size_t
+str_cmp(const char *restrict sa, const char *restrict sb)
+{
+    if (!sa || !sb)
+        return 1;
+
+    size_t i = 0;
+
+    while (sa[i] == sb[i])
+        if (!sa[i++])
+            return 0;
+
+    return i + 1;
+}
+
+_pure_ static inline size_t
+str_len(const char *restrict str)
+{
+    if (!str)
+        return 0;
+
+    return strlen(str);
+}
+
+static inline char *
+str_cat(const char **strs, size_t count)
+{
+    size_t size = 1;
+
+    for (size_t i = 0; i < count; i++)
+        size += str_len(strs[i]);
+
+    char *str = malloc(size);
+
+    if (!str)
+        return NULL;
+
+    char *p = str;
+
+    for (size_t i = 0; i < count; i++) {
+        size_t len = str_len(strs[i]);
+        memcpy(p, strs[i], len);
+        p += len;
+    }
+
+    p[0] = 0;
+
+    return str;
+}

src/tun.c

@@ -1,164 +1,202 @@
-#include "common-static.h"
-#include "ip-static.h"
+#include "common.h"
 
+#include "ip.h"
+#include "str.h"
 #include "tun.h"
 
-#include <stdio.h>
 #include <fcntl.h>
+#include <stdio.h>
 
 #include <sys/ioctl.h>
 #include <sys/socket.h>
 #include <sys/uio.h>
 
+#include <net/if.h>
+
 #ifdef __linux__
-# include <linux/if.h>
-# include <linux/if_tun.h>
+#define IFF_TUN 0x0001
+#define IFF_NO_PI 0x1000
+#define TUNSETIFF _IOW('T', 202, int)
 #endif
 
 #ifdef __APPLE__
-# include <sys/sys_domain.h>
-# include <sys/kern_control.h>
-# include <net/if_utun.h>
+#include <net/if_utun.h>
+#include <sys/kern_control.h>
+#include <sys/sys_domain.h>
 #endif
 
 #if defined(__APPLE__) || defined(__OpenBSD__)
-# define GT_BSD_TUN 1
+#define GT_BSD_TUN
 #endif
 
-#ifdef __linux__
-int tun_create (char *name, int multiqueue)
-{
-    int fd = open("/dev/net/tun", O_RDWR);
+#ifdef __APPLE__
 
-    if (fd<0) {
-        perror("open /dev/net/tun");
+static int
+tun_create_by_id(char *name, size_t size, unsigned id)
+{
+    int fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
+
+    if (fd == -1)
+        return -1;
+
+    struct ctl_info ci;
+
+    memset(&ci, 0, sizeof(ci));
+    str_cpy(ci.ctl_name, UTUN_CONTROL_NAME, sizeof(ci.ctl_name) - 1);
+
+    if (ioctl(fd, CTLIOCGINFO, &ci)) {
+        int err = errno;
+        close(fd);
+        errno = err;
         return -1;
     }
 
-    struct ifreq ifr = {
-        .ifr_flags = IFF_TUN|IFF_NO_PI,
+    struct sockaddr_ctl sc = {
+        .sc_id = ci.ctl_id,
+        .sc_len = sizeof(sc),
+        .sc_family = AF_SYSTEM,
+        .ss_sysaddr = AF_SYS_CONTROL,
+        .sc_unit = id + 1,
     };
 
-    if (multiqueue) {
-#ifdef IFF_MULTI_QUEUE
-        ifr.ifr_flags |= IFF_MULTI_QUEUE;
-#else
-        gt_na("IFF_MULTI_QUEUE");
-#endif
-    }
-
-    str_cpy(ifr.ifr_name, name, IFNAMSIZ-1);
-
-    int ret = ioctl(fd, TUNSETIFF, &ifr);
-
-    if (ret<0) {
-        perror("ioctl TUNSETIFF");
+    if (connect(fd, (struct sockaddr *)&sc, sizeof(sc))) {
+        int err = errno;
+        close(fd);
+        errno = err;
         return -1;
     }
 
-    printf("tun name: %s\n", ifr.ifr_name);
+    snprintf(name, size, "utun%u", id);
 
     return fd;
 }
-#elif defined(__APPLE__)
-int tun_create (_unused_ char *name, _unused_ int mq)
+
+static int
+tun_create_by_name(char *name, size_t size, char *dev_name)
 {
-    struct ctl_info ctlInfo;
-    struct sockaddr_ctl sc;
-    int fd;
+    unsigned id = 0;
 
-    for (unsigned dev_id = 0U; dev_id<32U; dev_id++) {
-        byte_set(&ctlInfo, 0, sizeof(ctlInfo));
-        str_cpy(ctlInfo.ctl_name, UTUN_CONTROL_NAME, sizeof(ctlInfo.ctl_name));
-        fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
-
-        if (fd==-1)
-            return -1;
-
-        if (ioctl(fd, CTLIOCGINFO, &ctlInfo)==-1) {
-            close(fd);
-            continue;
-        }
-
-        sc.sc_id = ctlInfo.ctl_id;
-        sc.sc_len = sizeof(sc);
-        sc.sc_family = AF_SYSTEM;
-        sc.ss_sysaddr = AF_SYS_CONTROL;
-        sc.sc_unit = dev_id+1;
-
-        if (connect(fd, (struct sockaddr *) &sc, sizeof(sc))==-1) {
-            close(fd);
-            continue;
-        }
-
-        printf("tun name: /dev/utun%u\n", dev_id);
-
-        return fd;
+    if (sscanf(dev_name, "utun%u", &id) != 1) {
+        errno = EINVAL;
+        return -1;
     }
 
-    return -1;
+    return tun_create_by_id(name, size, id);
 }
-#else
-int tun_create (_unused_ char *name, _unused_ int mq)
+
+#else /* not __APPLE__ */
+
+#ifdef __linux__
+
+static int
+tun_create_by_name(char *name, size_t size, char *dev_name)
 {
-    for (unsigned dev_id = 0U; dev_id<32U; dev_id++) {
-        char dev_path[11U];
+    int fd = open("/dev/net/tun", O_RDWR);
 
-        snprintf(dev_path, sizeof(dev_path), "/dev/tun%u", dev_id);
+    if (fd == -1)
+        return -1;
 
-        int fd = open(dev_path, O_RDWR);
+    struct ifreq ifr = {
+        .ifr_flags = IFF_TUN | IFF_NO_PI,
+    };
 
-        if (fd!=-1) {
-            printf("tun name: /dev/tun%u\n", dev_id);
-            return fd;
-        }
+    str_cpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
+
+    if (ioctl(fd, TUNSETIFF, &ifr)) {
+        close(fd);
+        return -1;
     }
 
-    return -1;
+    str_cpy(name, ifr.ifr_name, size - 1);
+
+    return fd;
 }
+
+#else /* not __linux__ not __APPLE__ */
+
+static int
+tun_create_by_name(char *name, size_t size, char *dev_name)
+{
+    char path[64];
+
+    snprintf(path, sizeof(path), "/dev/%s", dev_name);
+    str_cpy(name, dev_name, size - 1);
+
+    return open(path, O_RDWR);
+}
+
+#endif /* not __APPLE__ */
+
+static int
+tun_create_by_id(char *name, size_t size, unsigned id)
+{
+    char dev_name[64];
+
+    snprintf(dev_name, sizeof(dev_name), "tun%u", id);
+
+    return tun_create_by_name(name, size, dev_name);
+}
+
 #endif
 
-ssize_t tun_read (int fd, void *data, size_t size)
+int
+tun_create(char *dev_name, char **ret_name)
+{
+    char name[64] = {0};
+    int fd = -1;
+
+    if (str_empty(dev_name)) {
+        for (unsigned id = 0; id < 32 && fd == -1; id++)
+            fd = tun_create_by_id(name, sizeof(name), id);
+    } else {
+        fd = tun_create_by_name(name, sizeof(name), dev_name);
+    }
+
+    if (fd != -1 && ret_name)
+        *ret_name = strdup(name);
+
+    return fd;
+}
+
+int
+tun_read(int fd, void *data, size_t size)
 {
     if (!size)
-        return -2;
+        return 0;
 
 #ifdef GT_BSD_TUN
     uint32_t family;
+
     struct iovec iov[2] = {
-        { .iov_base = &family, .iov_len = sizeof(family) },
-        { .iov_base = data, .iov_len = size }
+        {
+            .iov_base = &family,
+            .iov_len = sizeof(family),
+        },
+        {
+            .iov_base = data,
+            .iov_len = size,
+        },
     };
 
     ssize_t ret = readv(fd, iov, 2);
-#else
-    ssize_t ret = read(fd, data, size);
-#endif
 
-    if (ret==-1) {
-        if (errno==EAGAIN || errno==EINTR)
-            return -1;
+    if (ret <= (ssize_t)0)
+        return ret;
 
-        if (errno)
-            perror("readv");
-
-        return 0;
-    }
-
-#ifdef GT_BSD_TUN
-    if (ret<(ssize_t) sizeof(family))
+    if (ret <= (ssize_t)sizeof(family))
         return 0;
 
-    return ret-sizeof(family);
+    return ret - sizeof(family);
 #else
-    return ret;
+    return read(fd, data, size);
 #endif
 }
 
-ssize_t tun_write (int fd, const void *data, size_t size)
+int
+tun_write(int fd, const void *data, size_t size)
 {
     if (!size)
-        return -2;
+        return 0;
 
 #ifdef GT_BSD_TUN
     uint32_t family;
@@ -171,35 +209,54 @@ ssize_t tun_write (int fd, const void *data, size_t size)
         family = htonl(AF_INET6);
         break;
     default:
+        errno = EINVAL;
         return -1;
     }
 
     struct iovec iov[2] = {
-        { .iov_base = &family, .iov_len = sizeof(family) },
-        { .iov_base = (void *) data, .iov_len = size },
+        {
+            .iov_base = &family,
+            .iov_len = sizeof(family),
+        },
+        {
+            .iov_base = (void *)data,
+            .iov_len = size,
+        },
     };
 
     ssize_t ret = writev(fd, iov, 2);
-#else
-    ssize_t ret = write(fd, data, size);
-#endif
 
-    if (ret==-1) {
-        if (errno==EAGAIN || errno==EINTR)
-            return -1;
+    if (ret <= (ssize_t)0)
+        return ret;
 
-        if (errno)
-            perror("write");
-
-        return 0;
-    }
-
-#ifdef GT_BSD_TUN
-    if (ret<(ssize_t) sizeof(family))
+    if (ret <= (ssize_t)sizeof(family))
         return 0;
 
-    return ret-sizeof(family);
+    return ret - sizeof(family);
 #else
-    return ret;
+    return write(fd, data, size);
 #endif
 }
+
+int
+tun_set_mtu(char *dev_name, int mtu)
+{
+    struct ifreq ifr = {
+        .ifr_mtu = mtu,
+    };
+
+    str_cpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
+
+    int fd = socket(AF_INET, SOCK_DGRAM, 0);
+
+    if (fd == -1)
+        return -1;
+
+    int ret = ioctl(fd, SIOCSIFMTU, &ifr);
+
+    int err = errno;
+    close(fd);
+    errno = err;
+
+    return ret;
+}

src/tun.h

@@ -1,7 +1,6 @@
 #pragma once
 
-#include <unistd.h>
-
-int     tun_create (char *, int);
-ssize_t tun_read   (int, void *, size_t);
-ssize_t tun_write  (int, const void *, size_t);
+int tun_create  (char *, char **);
+int tun_read    (int, void *, size_t);
+int tun_write   (int, const void *, size_t);
+int tun_set_mtu (char *, int);

version.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+[ -z "${VERSION}" ] && VERSION=`git describe --tags --match='v[0-9].*' 2>/dev/null` \
+                    && VERSION=${VERSION#v}
+
+[ -z "${VERSION}" ] && VERSION=`cat VERSION 2>/dev/null`
+
+[ -z "${VERSION}" ] && VERSION=0.0.0
+
+[ "$1" = "major"  ] && printf ${VERSION%%.*} \
+                    && exit 0
+
+printf ${VERSION} | tee VERSION