Skip ip rule errors for now

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>

.build.sh

@@ -1,18 +0,0 @@
-#!/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

@@ -11,3 +11,5 @@ build-aux
 .deps
 .dirstamp
 glorytun
+build*
+VERSION

Makefile.am

@@ -14,10 +14,10 @@ glorytun_SOURCES = \
     src/option.h \
     src/tun.c \
     src/tun.h \
+    src/iface.c \
+    src/iface.h \
     src/db.c \
-    src/db.h
-
-glorytun_SOURCES += \
+    src/db.h \
     mud/mud.h \
     mud/mud.c
 
@@ -25,5 +25,13 @@ EXTRA_DIST = \
     LICENSE \
     README.md \
     VERSION \
+    systemd/glorytun-client.network \
+    systemd/glorytun-run \
+    systemd/glorytun-setup \
+    systemd/glorytun.network \
+    systemd/glorytun@.service.in \
+    mud/LICENSE \
+    mud/README.md \
+    meson.build \
     autogen.sh \
     version.sh

README.md

@@ -1,18 +1,53 @@
-# π₁(Glorytun)=0
+# Glorytun
 
 Small, Simple and Stupid VPN over [mud](https://github.com/angt/mud).
 
-#### Build and Install
+### Build and Install
 
 Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4.
 
-To build and install the latest version:
+On Ubuntu, the following command should be sufficient:
 
-    $ git clone https://github.com/angt/glorytun --recursive --branch mud
+    $ sudo apt-get install meson libsodium-dev pkg-config
+
+Grab the latest release from github:
+
+    $ git clone https://github.com/angt/glorytun --recursive
     $ cd glorytun
-    $ ./autogen.sh
-    $ ./configure
-    $ make
-    # make install
+
+To build and install the latest version with [meson](http://mesonbuild.com):
+
+    $ meson build
+    $ sudo ninja -C build install
+
+The more classical autotools suite is also available.
+
+### Easy setup with systemd
+
+Just call `glorytun-setup` and follow the instructions.
+
+First, setup the server:
+
+    $ sudo glorytun-setup
+    Config filename (tun0):
+    Server ip (enter for server conf):
+    Server key (enter to generate a new one):
+    Your new key: NEW_KEY
+    Start glorytun now ? (enter to skip): y
+
+Copy the new generated key and use it when configuring the client:
+
+    $ sudo glorytun-setup
+    Config filename (tun0):
+    Server ip (enter for server conf): SERVER_IP
+    Server key (enter to generate a new one): NEW_KEY
+    Start glorytun now ? (enter to skip): y
+
+You can check easily if it works by looking at your public ip.
+To stop the service:
+
+    $ sudo systemctl stop glorytun@tun0
+
+---
 
 For feature requests and bug reports, please create an [issue](https://github.com/angt/glorytun/issues).

configure.ac

@@ -8,7 +8,7 @@ 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_INIT_AUTOMAKE([1.12 -Wall -Werror foreign tar-ustar subdir-objects])
 AM_DEP_TRACK
 AM_SILENT_RULES([yes])
 AM_PROG_CC_C_O

m4/pkg.m4

@@ -1,6 +1,6 @@
-dnl pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
-dnl serial 11 (pkg-config-0.29)
-dnl
+# pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
+# serial 12 (pkg-config-0.29.2)
+
 dnl Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
 dnl Copyright © 2012-2015 Dan Nicholson <dbn.lists@gmail.com>
 dnl
@@ -41,7 +41,7 @@ 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_define([PKG_MACROS_VERSION], [0.29.2])
 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
@@ -142,7 +142,7 @@ 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])
+AC_MSG_CHECKING([for $2])
 
 _PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])
 _PKG_CONFIG([$1][_LIBS], [libs], [$2])

meson.build

@@ -0,0 +1,49 @@
+project('glorytun', 'c',
+    version: run_command('./version.sh').stdout(),
+    license: 'BSD-3-Clause',
+    default_options : [ 'buildtype=debugoptimized' ]
+)
+
+prefix = get_option('prefix')
+bindir = join_paths(prefix, get_option('bindir'))
+
+conf_data = configuration_data()
+conf_data.set('prefix', prefix)
+conf_data.set('bindir', bindir)
+
+add_global_arguments('-DPACKAGE_VERSION="'+meson.project_version()+'"', language : 'c')
+
+src = [
+    'src/common.c',
+    'src/iface.c',
+    'src/option.c',
+    'src/tun.c',
+    'mud/mud.c',
+    'src/main.c'
+]
+
+deps = [
+    dependency('libsodium', version : '>=1.0.4')
+]
+
+executable('glorytun', install: true, sources: src, dependencies: deps)
+
+systemd = dependency('systemd', required: false)
+
+if systemd.found()
+  systemdutildir = systemd.get_pkgconfig_variable('systemdutildir')
+  configure_file(
+      input: 'systemd/glorytun@.service.in',
+      output: 'glorytun@.service',
+      configuration: conf_data,
+      install_dir: join_paths(systemdutildir, 'system')
+  )
+  install_data('systemd/glorytun.network',
+      install_dir: join_paths(systemdutildir, 'network'))
+  install_data('systemd/glorytun-client.network',
+      install_dir: join_paths(systemdutildir, 'network'))
+  install_data('systemd/glorytun-run',
+      install_dir: bindir)
+  install_data('systemd/glorytun-setup',
+      install_dir: bindir)
+endif

src/common.c

@@ -26,23 +26,6 @@ gt_log(const char *fmt, ...)
     va_end(ap);
 }
 
-void
-gt_fatal(const char *fmt, ...)
-{
-    va_list ap;
-    va_start(ap, fmt);
-    vfprintf(stderr, fmt, ap);
-    va_end(ap);
-
-    exit(EXIT_FAILURE);
-}
-
-void
-gt_na(const char *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)
 {

src/common.h

@@ -37,8 +37,6 @@
 
 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/iface.c

@@ -0,0 +1,30 @@
+#include "common.h"
+
+#include "str.h"
+#include "iface.h"
+
+#include <sys/ioctl.h>
+#include <net/if.h>
+
+int
+iface_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/iface.h

@@ -0,0 +1,3 @@
+#pragma once
+
+int iface_set_mtu (char *, int);

src/main.c

@@ -5,6 +5,7 @@
 #include "option.h"
 #include "str.h"
 #include "tun.h"
+#include "iface.h"
 
 #include <fcntl.h>
 #include <inttypes.h>
@@ -14,6 +15,7 @@
 #include <stdio.h>
 #include <sys/socket.h>
 #include <sys/time.h>
+#include <netinet/in.h>
 
 #include <arpa/inet.h>
 #include <netdb.h>
@@ -24,10 +26,15 @@
 #define O_CLOEXEC 0
 #endif
 
+#ifndef PACKAGE_VERSION
+#define PACKAGE_VERSION "unknown"
+#endif
+
 #define GT_MTU(X) ((X)-28)
 
 static struct {
     volatile sig_atomic_t quit;
+    volatile sig_atomic_t reload;
     char *dev;
     char *keyfile;
     char *host;
@@ -45,6 +52,12 @@ static struct {
     int mtu_auto;
     int chacha20;
     int version;
+    int keygen;
+    int persist;
+    struct {
+        unsigned char *data;
+        long size;
+    } buf;
 } gt = {
     .port = 5000,
     .bind = {
@@ -56,6 +69,9 @@ static struct {
 #ifdef __linux__
     .ipv6 = 1,
 #endif
+    .buf = {
+        .size = 64 * 1024,
+    },
 };
 
 static void
@@ -80,6 +96,7 @@ fd_set_nonblock(int fd)
 static void
 gt_quit_handler(int sig)
 {
+    gt.reload = (sig == SIGHUP);
     gt.quit = 1;
 }
 
@@ -96,9 +113,9 @@ gt_set_signal(void)
     sigaction(SIGINT, &sa, NULL);
     sigaction(SIGQUIT, &sa, NULL);
     sigaction(SIGTERM, &sa, NULL);
+    sigaction(SIGHUP, &sa, NULL);
 
     sa.sa_handler = SIG_IGN;
-    sigaction(SIGHUP, &sa, NULL);
     sigaction(SIGPIPE, &sa, NULL);
     sigaction(SIGUSR1, &sa, NULL);
     sigaction(SIGUSR2, &sa, NULL);
@@ -116,7 +133,7 @@ gt_print_secretkey(struct mud *mud)
     char buf[2 * sizeof(key) + 1];
 
     gt_tohex(buf, sizeof(buf), key, size);
-    gt_print("secret key: %s\n", buf);
+    gt_print("%s\n", buf);
 }
 
 static int
@@ -178,14 +195,17 @@ gt_setup_option(int argc, char **argv)
         { "bind-backup",    &gt.bind.backup,    option_str    },
         { "bind-port",      &gt.bind.port,      option_long   },
         { "dev",            &gt.dev,            option_str    },
+        { "persist",        NULL,               option_option },
         { "mtu",            &gt.mtu,            option_long   },
         { "mtu-auto",       NULL,               option_option },
         { "keyfile",        &gt.keyfile,        option_str    },
+        { "keygen",         NULL,               option_option },
         { "timeout",        &gt.timeout,        option_long   },
         { "time-tolerance", &gt.time_tolerance, option_long   },
         { "v4only",         NULL,               option_option },
         { "v6only",         NULL,               option_option },
         { "chacha20",       NULL,               option_option },
+        { "buf-size",       &gt.buf.size,       option_long   },
         { "version",        NULL,               option_option },
         {  NULL                                               },
     };
@@ -203,13 +223,13 @@ gt_setup_option(int argc, char **argv)
         return 1;
     }
 
-    if (gt.host && !option_is_set(opts, "keyfile")) {
-        gt_log("keyfile option must be set\n");
+    if ((int)gt.timeout <= 0) {
+        gt_log("bad timeout\n");
         return 1;
     }
 
-    if ((int)gt.timeout <= 0) {
-        gt_log("bad timeout\n");
+    if (gt.buf.size <= 0) {
+        gt_log("bad buf-size\n");
         return 1;
     }
 
@@ -226,6 +246,10 @@ gt_setup_option(int argc, char **argv)
     gt.mtu_auto = option_is_set(opts, "mtu-auto");
     gt.chacha20 = option_is_set(opts, "chacha20");
     gt.version = option_is_set(opts, "version");
+    gt.keygen = option_is_set(opts, "keygen");
+    gt.persist = option_is_set(opts, "persist");
+
+    gt.buf.data = malloc(gt.buf.size);
 
     return 0;
 }
@@ -242,7 +266,7 @@ gt_setup_mtu(struct mud *mud, char *tun_name)
 
     gt_log("setup MTU to %i on interface %s\n", mtu, tun_name);
 
-    if (tun_set_mtu(tun_name, mtu) == -1)
+    if (iface_set_mtu(tun_name, mtu) == -1)
         perror("tun_set_mtu");
 }
 
@@ -255,7 +279,7 @@ main(int argc, char **argv)
         return 1;
 
     if (gt.version) {
-        gt_print(PACKAGE_STRING "\n");
+        gt_print(PACKAGE_VERSION "\n");
         return 0;
     }
 
@@ -268,6 +292,36 @@ main(int argc, char **argv)
             gt_log("couldn't create ICMP socket\n");
     }
 
+    struct mud *mud = mud_create(gt.bind.port, gt.ipv4, gt.ipv6);
+
+    if (!mud) {
+        gt_log("couldn't create mud\n");
+        return 1;
+    }
+
+    if (gt.keygen || str_empty(gt.keyfile)) {
+        if (mud_new_key(mud)) {
+            gt_log("couldn't generate a new key\n");
+            return 1;
+        }
+    }
+
+    if (gt.keygen) {
+        gt_print_secretkey(mud);
+        return 0;
+    }
+
+    if (!gt.chacha20 && mud_set_aes(mud))
+        gt_log("AES is not available\n");
+
+    if (gt.timeout > 0)
+        mud_set_send_timeout_msec(mud, gt.timeout);
+
+    if (gt.time_tolerance > 0)
+        mud_set_time_tolerance_sec(mud, gt.time_tolerance);
+
+    mud_set_mtu(mud, GT_MTU(gt.mtu));
+
     char *tun_name = NULL;
 
     int tun_fd = tun_create(gt.dev, &tun_name);
@@ -277,26 +331,17 @@ main(int argc, char **argv)
         return 1;
     }
 
-    struct mud *mud = mud_create(gt.bind.port, gt.ipv4, gt.ipv6,
-                                 !gt.chacha20, GT_MTU(gt.mtu));
-
-    if (!mud) {
-        gt_log("couldn't create mud\n");
-        return 1;
-    }
+    if (tun_set_persist(tun_fd, gt.persist) == -1)
+        perror("tun_set_persist");
 
     if (str_empty(gt.keyfile)) {
+        gt_print("here is your new secret key:\n");
         gt_print_secretkey(mud);
     } else {
         if (gt_setup_secretkey(mud, gt.keyfile))
             return 1;
     }
 
-    mud_set_send_timeout_msec(mud, gt.timeout);
-
-    if (gt.time_tolerance > 0)
-        mud_set_time_tolerance_sec(mud, gt.time_tolerance);
-
     if (gt.host && gt.port) {
         if (gt.bind.backup) {
             if (mud_peer(mud, gt.bind.backup, gt.host, gt.port, 1)) {
@@ -345,8 +390,6 @@ main(int argc, char **argv)
     fd_set rfds;
     FD_ZERO(&rfds);
 
-    unsigned char buf[8 * 1024];
-
     int last_fd = 1 + MAX(tun_fd, MAX(mud_fd, icmp_fd));
 
     while (!gt.quit) {
@@ -366,12 +409,12 @@ main(int argc, char **argv)
         if (icmp_fd != -1 && FD_ISSET(icmp_fd, &rfds)) {
             struct sockaddr_storage ss;
             socklen_t sl = sizeof(ss);
-            ssize_t r = recvfrom(icmp_fd, buf, sizeof(buf), 0,
+            ssize_t r = recvfrom(icmp_fd, gt.buf.data, gt.buf.size, 0,
                                  (struct sockaddr *)&ss, &sl);
             if (r >= 8) {
                 struct ip_common ic;
-                if (!ip_get_common(&ic, buf, r) && ic.proto == 1) {
-                    unsigned char *data = &buf[ic.hdr_size];
+                if (!ip_get_common(&ic, gt.buf.data, r) && ic.proto == 1) {
+                    unsigned char *data = &gt.buf.data[ic.hdr_size];
                     if (data[0] == 3) {
                         int mtu = (data[6] << 8) | data[7];
                         if (mtu) {
@@ -386,15 +429,15 @@ main(int argc, char **argv)
         if (FD_ISSET(tun_fd, &rfds)) {
             size_t size = 0;
 
-            while (sizeof(buf) - size >= gt.mtu) {
-                const int r = tun_read(tun_fd, &buf[size], sizeof(buf) - size);
+            while (gt.buf.size - size >= gt.mtu) {
+                const int r = tun_read(tun_fd, &gt.buf.data[size], gt.buf.size - size);
 
                 if (r <= 0 || r > gt.mtu)
                     break;
 
                 struct ip_common ic;
 
-                if (ip_get_common(&ic, &buf[size], r) || ic.size != r)
+                if (ip_get_common(&ic, &gt.buf.data[size], r) || ic.size != r)
                     break;
 
                 size += r;
@@ -409,7 +452,7 @@ main(int argc, char **argv)
                 while (q < size) {
                     struct ip_common ic;
 
-                    if ((ip_get_common(&ic, &buf[q], size - q)) ||
+                    if ((ip_get_common(&ic, &gt.buf.data[q], size - q)) ||
                         (ic.size > size - q))
                         break;
 
@@ -425,7 +468,7 @@ main(int argc, char **argv)
                 if (p >= q)
                     break;
 
-                int r = mud_send(mud, &buf[p], q - p, tc);
+                int r = mud_send(mud, &gt.buf.data[p], q - p, tc);
 
                 if (r == -1 && errno == EMSGSIZE) {
                     gt_setup_mtu(mud, tun_name);
@@ -439,30 +482,39 @@ main(int argc, char **argv)
         }
 
         if (FD_ISSET(mud_fd, &rfds)) {
-            while (1) {
-                const int size = mud_recv(mud, buf, sizeof(buf));
+            size_t size = 0;
 
-                if (size <= 0) {
-                    if (size == -1 && errno != EAGAIN)
+            while (gt.buf.size - size >= gt.mtu) {
+                const int r = mud_recv(mud, &gt.buf.data[size], gt.buf.size - size);
+
+                if (r <= 0) {
+                    if (r == -1 && errno != EAGAIN)
                         perror("mud_recv");
                     break;
                 }
 
+                size += r;
+            }
+
             int p = 0;
 
             while (p < size) {
                 struct ip_common ic;
 
-                    if ((ip_get_common(&ic, &buf[p], size - p)) ||
+                if ((ip_get_common(&ic, &gt.buf.data[p], size - p)) ||
                     (ic.size > size - p))
                     break;
 
-                    tun_write(tun_fd, &buf[p], ic.size);
+                tun_write(tun_fd, &gt.buf.data[p], ic.size);
 
                 p += ic.size;
             }
         }
     }
+
+    if (gt.reload && tun_fd >= 0) {
+        if (tun_set_persist(tun_fd, 1) == -1)
+            perror("tun_set_persist");
     }
 
     return 0;

src/tun.c

@@ -17,6 +17,7 @@
 #define IFF_TUN 0x0001
 #define IFF_NO_PI 0x1000
 #define TUNSETIFF _IOW('T', 202, int)
+#define TUNSETPERSIST _IOW('T', 203, int)
 #endif
 
 #ifdef __APPLE__
@@ -239,24 +240,12 @@ tun_write(int fd, const void *data, size_t size)
 }
 
 int
-tun_set_mtu(char *dev_name, int mtu)
+tun_set_persist(int fd, int on)
 {
-    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)
+#ifdef TUNSETPERSIST
+    return ioctl(fd, TUNSETPERSIST, on);
+#else
+    errno = ENOSYS;
     return -1;
-
-    int ret = ioctl(fd, SIOCSIFMTU, &ifr);
-
-    int err = errno;
-    close(fd);
-    errno = err;
-
-    return ret;
+#endif
 }

src/tun.h

@@ -3,4 +3,4 @@
 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);
+int tun_set_persist (int, int);

systemd/glorytun-client.network

@@ -0,0 +1,10 @@
+[Match]
+Name=gtc-*
+
+[Network]
+Description=Glorytun client device
+DHCP=ipv4
+
+[DHCP]
+CriticalConnection=yes
+RouteTable=200

systemd/glorytun-run

@@ -0,0 +1,37 @@
+#!/bin/sh
+
+set -e
+
+if [ ! -f "$1" ]; then
+	echo "usage: $(basename "$0") FILE"
+	exit 1
+fi
+
+. "$(readlink -f "$1")"
+
+DEV="gt${HOST:+c}-$(basename "$1")"
+
+# Setting BIND is like going to 'expert mode'
+# This helper is pretty stupid and still needs some work
+if [ -n "$HOST" ]; then
+	if [ -z "$PREF" ]; then
+		PREF=$(ip rule | awk '/from all lookup main/{print $1; exit}' | tr -d :)
+		PREF=$((PREF-1))
+	fi
+	if [ -z "$BIND" ]; then
+		BIND=$(ip route get "$HOST" | awk '/src/{getline;print $0}' RS=' ')
+		ip rule add from "$BIND" table main pref "$((PREF-1))" || true
+	fi
+	ip rule add from all table 200 pref "$PREF" || true
+fi
+
+exec glorytun \
+	v4only \
+	keyfile "$1".key \
+	dev "$DEV" \
+	${HOST:+host "$HOST"} \
+	${PORT:+port "$PORT"} \
+	${BIND:+bind "$BIND"} \
+	${BIND_PORT:+bind-port "$BIND_PORT"} \
+	${MTU:+mtu "$MTU"} \
+	${MTU_AUTO:+mtu-auto}

systemd/glorytun-setup

@@ -0,0 +1,41 @@
+#!/bin/sh
+
+set -e
+
+_ask() {
+	printf "%s: " "$1"
+	read -r "$2"
+}
+
+_ask "Config filename (tun0)" NAME
+NAME=${NAME:-tun0}
+
+if [ -f /etc/glorytun/"$NAME" ]; then
+	echo "This config already exit!"
+	exit 1
+fi
+
+_ask "Server ip (enter for server conf)" HOST
+
+_ask "Server key (enter to generate a new one)" KEY
+if [ -z "$KEY" ]; then
+	KEY=$(glorytun keygen)
+	echo "Your new key: $KEY"
+fi
+
+# install files
+mkdir -p /etc/glorytun
+
+cat > /etc/glorytun/"$NAME" <<EOF
+${HOST:+HOST="$HOST"}
+MTU_AUTO=yes
+EOF
+
+( umask 077; echo "$KEY" > /etc/glorytun/"$NAME".key )
+
+# start services
+_ask "Start glorytun now ? (enter to skip)" START
+case "$START" in y*|Y*)
+	systemctl restart systemd-networkd
+	systemctl start glorytun@"$NAME" ;;
+esac

systemd/glorytun.network

@@ -0,0 +1,14 @@
+[Match]
+Name=gt-*
+
+[Network]
+Description=Glorytun server device
+Address=0.0.0.0/24
+DHCPServer=yes
+IPMasquerade=yes
+
+[DHCPServer]
+PoolOffset=2
+PoolSize=1
+EmitDNS=yes
+DNS=9.9.9.9

systemd/glorytun@.service.in

@@ -0,0 +1,12 @@
+[Unit]
+Description=Glorytun on %I
+After=network.target
+
+[Service]
+Type=simple
+Restart=always
+ExecStart=@bindir@/glorytun-run /etc/glorytun/%i
+CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_RAW
+
+[Install]
+WantedBy=multi-user.target