Update and fix MTU

This allows to build easily with other libc.

.build.sh

@@ -0,0 +1,15 @@
+#!/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
+strip -s glorytun
+mv glorytun deploy/glorytun-$(cat VERSION)-$(uname -m).bin

Makefile.am

@@ -7,7 +7,6 @@ glorytun_LDADD = $(libsodium_LIBS)
 glorytun_SOURCES = \
     src/common.h \
     src/common.c \
-    src/buffer.h \
     src/ip.h \
     src/str.h \
     src/main.c \
@@ -16,9 +15,7 @@ glorytun_SOURCES = \
     src/tun.c \
     src/tun.h \
     src/db.c \
-    src/db.h \
-    src/state.c \
-    src/state.h
+    src/db.h
 
 glorytun_CFLAGS  += -I$(srcdir)/mud
 glorytun_SOURCES += \

README.md

@@ -1,15 +1,10 @@
-# π₁(Glorytun)=ℤ²
+# π₁(Glorytun)=0
 
 Small, Simple and Stupid VPN over [mud](https://github.com/angt/mud).
 
-#### Work In Progress
-
-This code will probably format your harddisk!
-
 #### Build and Install
 
-Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4
-and needs an AES-NI capable CPU.
+Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4.
 
 To build and install the latest version:
 

configure.ac

@@ -14,8 +14,9 @@ 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

src/buffer.h

@@ -1,66 +0,0 @@
-#pragma once
-
-#include "common.h"
-
-typedef struct buffer buffer_t;
-
-struct buffer {
-    uint8_t *data;
-    uint8_t *read;
-    uint8_t *write;
-    uint8_t *end;
-};
-
-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;
-}
-
-_pure_
-static inline size_t buffer_size (buffer_t *buffer)
-{
-    return buffer->end-buffer->data;
-}
-
-_pure_
-static inline size_t buffer_write_size (buffer_t *buffer)
-{
-    return buffer->end-buffer->write;
-}
-
-_pure_
-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->data)
-        return;
-
-    if (buffer->read==buffer->write) {
-        buffer_format(buffer);
-        return;
-    }
-
-    const size_t size = buffer_read_size(buffer);
-
-    memmove(buffer->data, buffer->read, size);
-
-    buffer->read  = buffer->data;
-    buffer->write = buffer->data+size;
-}

src/common.c

@@ -1,9 +1,10 @@
 #include "common.h"
 
-#include <stdio.h>
 #include <stdarg.h>
+#include <stdio.h>
 
-int gt_print (const char *fmt, ...)
+int
+gt_print(const char *fmt, ...)
 {
     va_list ap;
     va_start(ap, fmt);
@@ -16,7 +17,8 @@ int gt_print (const char *fmt, ...)
     return ret;
 }
 
-void gt_log (const char *fmt, ...)
+void
+gt_log(const char *fmt, ...)
 {
     va_list ap;
     va_start(ap, fmt);
@@ -24,7 +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);
@@ -34,17 +37,19 @@ 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);
 }
 
-int gt_tohex (char *dst, size_t dst_size, const uint8_t *src, size_t src_size)
+int
+gt_tohex(char *dst, size_t dst_size, const uint8_t *src, size_t src_size)
 {
-    if _0_(!dst_size)
+    if (_0_(!dst_size))
         return -1;
 
-    if _0_(((dst_size-1)/2)<src_size)
+    if (_0_(((dst_size - 1) / 2) < src_size))
         return -1;
 
     static const char tbl[] = "0123456789ABCDEF";
@@ -59,8 +64,8 @@ int gt_tohex (char *dst, size_t dst_size, const uint8_t *src, size_t src_size)
     return 0;
 }
 
-_const_
-static inline int fromhex (const char c)
+_const_ static inline int
+fromhex(const char c)
 {
     if (c >= '0' && c <= '9')
         return c - '0';
@@ -74,19 +79,20 @@ static inline int fromhex (const char c)
     return -1;
 }
 
-int gt_fromhex (uint8_t *dst, size_t dst_size, const char *src, size_t src_size)
+int
+gt_fromhex(uint8_t *dst, size_t dst_size, const char *src, size_t src_size)
 {
-    if _0_(src_size&1)
+    if (_0_(src_size & 1))
         return -1;
 
-    if _0_(dst_size<(src_size/2))
+    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)
+        if (_0_(a == -1 || b == -1))
             return -1;
 
         *dst++ = (a << 4) | b;

src/common.h

@@ -29,6 +29,12 @@
 #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_;

src/db.c

@@ -12,14 +12,14 @@ struct node {
     uint32_t point;
 };
 
-_pure_
-static inline size_t db_size (const uint8_t *a)
+_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)
+_pure_ static inline size_t
+db_cmp(const uint8_t *a, const uint8_t *b)
 {
     const size_t size = a[0];
 
@@ -39,8 +39,8 @@ static inline size_t db_cmp (const uint8_t *a, const uint8_t *b)
     return 0;
 }
 
-_pure_
-static inline int db_dir (const uint32_t point, uint8_t *data, const size_t size)
+_pure_ static inline int
+db_dir(const uint32_t point, uint8_t *data, const size_t size)
 {
     const size_t pos = point >> 8;
 
@@ -50,9 +50,10 @@ static inline int db_dir (const uint32_t point, uint8_t *data, const size_t size
     return ((point | data[pos]) & 255) == 255;
 }
 
-uint8_t *db_search (uint8_t **p, uint8_t *data)
+uint8_t *
+db_search(uint8_t **p, uint8_t *data)
 {
-    if _0_(!*p)
+    if (_0_(!*p))
         return NULL;
 
     uint8_t *r = *p;
@@ -69,12 +70,13 @@ uint8_t *db_search (uint8_t **p, uint8_t *data)
     return NULL;
 }
 
-uint8_t *db_insert (uint8_t **p, uint8_t *data)
+uint8_t *
+db_insert(uint8_t **p, uint8_t *data)
 {
-    if _0_(CBIT(data))
+    if (_0_(CBIT(data)))
         return NULL;
 
-    if _0_(!*p) {
+    if (_0_(!*p)) {
         *p = data;
         return data;
     }
@@ -89,7 +91,7 @@ uint8_t *db_insert (uint8_t **p, uint8_t *data)
 
     const size_t diff = db_cmp(r, data);
 
-    if _0_(!diff)
+    if (_0_(!diff))
         return r;
 
     const size_t pos = diff - 1;
@@ -107,7 +109,7 @@ uint8_t *db_insert (uint8_t **p, uint8_t *data)
 
     struct node *node = malloc(sizeof(struct node));
 
-    if _0_(!node)
+    if (_0_(!node))
         return NULL;
 
     const int dir = (mask | r[pos]) == 255;
@@ -121,9 +123,10 @@ uint8_t *db_insert (uint8_t **p, uint8_t *data)
     return data;
 }
 
-uint8_t *db_remove (uint8_t **p, uint8_t *data)
+uint8_t *
+db_remove(uint8_t **p, uint8_t *data)
 {
-    if _0_(!*p)
+    if (_0_(!*p))
         return NULL;
 
     const size_t size = db_size(data);
@@ -139,7 +142,7 @@ uint8_t *db_remove (uint8_t **p, uint8_t *data)
         p = node->child + dir;
     }
 
-    if _0_(db_cmp(data, *p))
+    if (_0_(db_cmp(data, *p)))
         return NULL;
 
     uint8_t *r = *p;

src/ip.h

@@ -4,6 +4,7 @@
 
 struct ip_common {
     uint8_t version;
+    uint8_t tc;
     uint8_t proto;
     uint8_t hdr_size;
     uint16_t size;
@@ -24,11 +25,13 @@ static inline int ip_get_common (struct ip_common *ic, const uint8_t *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]);
         return 0;
     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;

src/main.c

@@ -1,41 +1,64 @@
 #include "common.h"
 
-#include "buffer.h"
-#include "ip.h"
-#include "str.h"
-#include "option.h"
-#include "tun.h"
 #include "db.h"
-#include "state.h"
+#include "ip.h"
+#include "option.h"
+#include "str.h"
+#include "tun.h"
 
+#include <fcntl.h>
 #include <inttypes.h>
 #include <limits.h>
-#include <stdio.h>
-#include <signal.h>
 #include <poll.h>
-#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
 #include <sys/socket.h>
 #include <sys/time.h>
 
 #include <arpa/inet.h>
 #include <netdb.h>
 
-#include <sodium.h>
-
 #include "mud.h"
 
 #ifndef O_CLOEXEC
 #define O_CLOEXEC 0
 #endif
 
-static struct {
-    int timeout;
-    volatile sig_atomic_t quit;
-    volatile sig_atomic_t info;
-    uint8_t key[crypto_generichash_KEYBYTES];
-} gt;
+#define GT_MTU(X) ((X) - 28)
 
-static void fd_set_nonblock (int fd)
+static struct {
+    volatile sig_atomic_t quit;
+    char *dev;
+    char *keyfile;
+    char *host;
+    long port;
+    struct {
+        char *list;
+        char *backup;
+        long port;
+    } bind;
+    long mtu;
+    long timeout;
+    long time_tolerance;
+    int ipv4;
+    int ipv6;
+    int mtu_auto;
+    int chacha20;
+    int version;
+} gt = {
+    .port = 5000,
+    .bind = {
+        .port = 5000,
+    },
+    .timeout = 5000,
+    .ipv4 = 1,
+#ifdef __linux__
+    .ipv6 = 1,
+#endif
+};
+
+static void
+fd_set_nonblock(int fd)
 {
     int ret;
 
@@ -53,21 +76,14 @@ static void fd_set_nonblock (int fd)
         perror("fcntl O_NONBLOCK");
 }
 
-static void gt_sa_handler (int sig)
+static void
+gt_quit_handler(int sig)
 {
-    switch (sig) {
-    case SIGINT:
-    case SIGQUIT:
-    case SIGTERM:
     gt.quit = 1;
-        break;
-    case SIGUSR1:
-        gt.info = 1;
-        break;
-    }
 }
 
-static void gt_set_signal (void)
+static void
+gt_set_signal(void)
 {
     struct sigaction sa = {
         .sa_flags = 0,
@@ -75,130 +91,36 @@ static void gt_set_signal (void)
 
     sigemptyset(&sa.sa_mask);
 
-    sa.sa_handler = gt_sa_handler;
+    sa.sa_handler = gt_quit_handler;
     sigaction(SIGINT, &sa, NULL);
     sigaction(SIGQUIT, &sa, NULL);
     sigaction(SIGTERM, &sa, NULL);
-    sigaction(SIGUSR1, &sa, NULL);
 
     sa.sa_handler = SIG_IGN;
     sigaction(SIGHUP, &sa, NULL);
     sigaction(SIGPIPE, &sa, NULL);
+    sigaction(SIGUSR1, &sa, NULL);
+    sigaction(SIGUSR2, &sa, NULL);
 }
 
-static ssize_t fd_read (int fd, void *data, size_t size)
+static void
+gt_print_secretkey(struct mud *mud)
 {
-    if ((fd==-1) || !size)
-        return -1;
+    unsigned char key[32];
+    size_t size = sizeof(key);
 
-    ssize_t ret = read(fd, data, size);
+    if (mud_get_key(mud, key, &size))
+        return;
 
-    if (ret==-1) {
-        if (errno==EAGAIN || errno==EINTR)
-            return -1;
+    char buf[2 * sizeof(key) + 1];
 
-        if (errno)
-            perror("read");
-
-        return 0;
+    gt_tohex(buf, sizeof(buf), key, size);
+    gt_print("secret key: %s\n", buf);
 }
 
-    return ret;
-}
-
-static ssize_t fd_write (int fd, const void *data, size_t size)
+static int
+gt_setup_secretkey(struct mud *mud, char *keyfile)
 {
-    if ((fd==-1) || !size)
-        return -1;
-
-    ssize_t ret = write(fd, data, size);
-
-    if (ret==-1) {
-        if (errno==EAGAIN || errno==EINTR)
-            return -1;
-
-        if (errno==EPIPE || errno==ECONNRESET)
-            return 0;
-
-        if (errno)
-            perror("write");
-
-        return 0;
-    }
-
-    return ret;
-}
-
-static size_t fd_read_all (int fd, void *data, size_t size)
-{
-    size_t done = 0;
-
-    while (done<size) {
-        ssize_t ret = fd_read(fd, (uint8_t *)data+done, size-done);
-
-        if (!ret)
-            break;
-
-        if (ret<0) {
-            struct pollfd pollfd = {
-                .fd = fd,
-                .events = POLLIN,
-            };
-
-            if (!poll(&pollfd, 1, gt.timeout))
-                break;
-
-            continue;
-        }
-
-        done += ret;
-    }
-
-    return done;
-}
-
-static size_t fd_write_all (int fd, const void *data, size_t size)
-{
-    size_t done = 0;
-
-    while (done<size) {
-        ssize_t ret = fd_write(fd, (const uint8_t *)data+done, size-done);
-
-        if (!ret)
-            break;
-
-        if (ret<0) {
-            struct pollfd pollfd = {
-                .fd = fd,
-                .events = POLLOUT,
-            };
-
-            if (!poll(&pollfd, 1, gt.timeout))
-                break;
-
-            continue;
-        }
-
-        done += ret;
-    }
-
-    return done;
-}
-
-static int gt_setup_secretkey (char *keyfile)
-{
-    const size_t size = sizeof(gt.key);
-
-    if (str_empty(keyfile)) {
-        char buf[2*size+1];
-
-        randombytes_buf(gt.key, size);
-        gt_tohex(buf, sizeof(buf), gt.key, size);
-        state("SECRETKEY", buf);
-
-        return 0;
-    }
-
     int fd;
 
     do {
@@ -210,211 +132,328 @@ static int gt_setup_secretkey (char *keyfile)
         return -1;
     }
 
-    char key[2*size];
-    size_t r = fd_read_all(fd, key, sizeof(key));
+    unsigned char key[32];
+    char buf[2 * sizeof(key)];
+    size_t size = 0;
+
+    while (size < sizeof(buf)) {
+        ssize_t r = read(fd, &buf[size], sizeof(buf) - size);
+
+        if (r <= (ssize_t)0) {
+            if (r && (errno == EAGAIN || errno == EINTR))
+                continue;
+            break;
+        }
+
+        size += r;
+    }
 
     close(fd);
 
-    if (r!=sizeof(key)) {
+    if (size != sizeof(buf)) {
         gt_log("unable to read secret key\n");
         return -1;
     }
 
-    if (gt_fromhex(gt.key, size, key, sizeof(key))) {
+    if (gt_fromhex(key, sizeof(key), buf, sizeof(buf))) {
         gt_log("secret key is not valid\n");
         return -1;
     }
 
+    mud_set_key(mud, key, sizeof(key));
+
     return 0;
 }
 
-int main (int argc, char **argv)
+static int
+gt_setup_option(int argc, char **argv)
 {
-    gt_set_signal();
-
-    char *host = NULL;
-    char *port = "5000";
-    char *bind_list = NULL;
-    char *bind_port = "5000";
-    char *dev = NULL;
-    char *keyfile = NULL;
-    char *statefile = NULL;
-
-    gt.timeout = 5000;
-
-    long time_tolerance = 0;
+    // clang-format off
 
     struct option opts[] = {
-        { "host",           &host,           option_str    },
-        { "port",           &port,           option_str    },
-        { "bind",           &bind_list,      option_str    },
-        { "bind-port",      &bind_port,      option_str    },
-        { "dev",            &dev,            option_str    },
-        { "keyfile",        &keyfile,        option_str    },
-        { "multiqueue",     NULL,            option_option },
-        { "statefile",      &statefile,      option_str    },
+        { "host",           &gt.host,           option_str    },
+        { "port",           &gt.port,           option_long   },
+        { "bind",           &gt.bind.list,      option_str    },
+        { "bind-backup",    &gt.bind.backup,    option_str    },
+        { "bind-port",      &gt.bind.port,      option_long   },
+        { "dev",            &gt.dev,            option_str    },
+        { "mtu",            &gt.mtu,            option_long   },
+        { "mtu-auto",       NULL,               option_option },
+        { "keyfile",        &gt.keyfile,        option_str    },
         { "timeout",        &gt.timeout,        option_long   },
-        { "time-tolerance", &time_tolerance, option_long   },
+        { "time-tolerance", &gt.time_tolerance, option_long   },
+        { "v4only",         NULL,               option_option },
+        { "v6only",         NULL,               option_option },
+        { "chacha20",       NULL,               option_option },
         { "version",        NULL,               option_option },
         {  NULL                                               },
     };
 
+    // clang-format on
+
     if (option(opts, argc, argv))
         return 1;
 
-    if (option_is_set(opts, "version")) {
-        gt_print(PACKAGE_STRING"\n");
-        return 0;
+    int v4only = option_is_set(opts, "v4only");
+    int v6only = option_is_set(opts, "v6only");
+
+    if (v4only && v6only) {
+        gt_log("v4only and v6only cannot be both set\n");
+        return 1;
     }
 
-    if (!option_is_set(opts, "keyfile")) {
+    if (gt.host && !option_is_set(opts, "keyfile")) {
         gt_log("keyfile option must be set\n");
         return 1;
     }
 
-    if (gt.timeout<=0 || gt.timeout>INT_MAX) {
+    if ((int)gt.timeout <= 0) {
         gt_log("bad timeout\n");
         return 1;
     }
 
-    if (sodium_init()==-1) {
-        gt_log("libsodium initialization has failed\n");
-        return 1;
+    if (v4only) {
+        gt.ipv4 = 1;
+        gt.ipv6 = 0;
     }
 
-    if (state_init(statefile))
+    if (v6only) {
+        gt.ipv4 = 0;
+        gt.ipv6 = 1;
+    }
+
+    gt.mtu_auto = option_is_set(opts, "mtu-auto");
+    gt.chacha20 = option_is_set(opts, "chacha20");
+    gt.version = option_is_set(opts, "version");
+
+    return 0;
+}
+
+int
+main(int argc, char **argv)
+{
+    gt_set_signal();
+
+    if (gt_setup_option(argc, argv))
         return 1;
 
+    if (gt.version) {
+        gt_print(PACKAGE_STRING "\n");
+        return 0;
+    }
+
+    int icmp_fd = -1;
+
+    if (gt.ipv4 && gt.mtu_auto) {
+        icmp_fd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
+
+        if (icmp_fd == -1)
+            gt_log("couldn't create ICMP socket\n");
+    }
+
     char *tun_name = NULL;
 
-    int tun_fd = tun_create(dev, &tun_name, option_is_set(opts, "multiqueue"));
+    int tun_fd = tun_create(gt.dev, &tun_name);
 
     if (tun_fd == -1) {
         gt_log("couldn't create tun device\n");
         return 1;
     }
 
-    fd_set_nonblock(tun_fd);
-
-    if (gt_setup_secretkey(keyfile))
-        return 1;
-
-    struct mud *mud = mud_create(bind_port);
+    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;
     }
 
-    mud_set_key(mud, gt.key, sizeof(gt.key));
+    if (str_empty(gt.keyfile)) {
+        gt_print_secretkey(mud);
+    } else {
+        if (gt_setup_secretkey(mud, gt.keyfile))
+            return 1;
+    }
 
     mud_set_send_timeout_msec(mud, gt.timeout);
 
-    if (time_tolerance > 0)
-        mud_set_time_tolerance_sec(mud, time_tolerance);
+    if (gt.time_tolerance > 0)
+        mud_set_time_tolerance_sec(mud, gt.time_tolerance);
 
-    if (bind_list) {
+    if (gt.host && gt.port) {
+        if (gt.bind.backup) {
+            if (mud_peer(mud, gt.bind.backup, gt.host, gt.port, 1)) {
+                perror("mud_peer (backup)");
+                return 1;
+            }
+        }
+
+        if (gt.bind.list) {
             char tmp[1024];
             char *name = &tmp[0];
 
-        size_t size = str_cpy(tmp, bind_list, sizeof(tmp)-1);
+            str_cpy(tmp, gt.bind.list, sizeof(tmp) - 1);
 
-        for (size_t i=0; i<size; i++) {
-            if (tmp[i]!=',')
-                continue;
+            while (*name) {
+                char *p = name;
 
-            tmp[i] = 0;
+                while (*p && *p != ',')
+                    p++;
 
-            if (mud_bind(mud, name))
-                return 1;
+                if (*p)
+                    *p++ = 0;
 
-            name = &tmp[i+1];
-        }
-
-        if (name[0] && mud_bind(mud, name))
+                if (mud_peer(mud, name, gt.host, gt.port, 0)) {
+                    perror("mud_peer");
                     return 1;
                 }
 
-    if (host && mud_peer(mud, host, port))
+                name = p;
+            }
+        }
+    }
+
+    gt.mtu = GT_MTU(mud_get_mtu(mud));
+
+    if (tun_set_mtu(tun_name, gt.mtu) == -1) {
+        perror("tun_set_mtu");
         return 1;
+    }
 
     int mud_fd = mud_get_fd(mud);
 
-    state("INITIALIZED", tun_name);
+    fd_set_nonblock(tun_fd);
+    fd_set_nonblock(mud_fd);
+
+    gt_log("running...\n");
 
     fd_set rfds;
     FD_ZERO(&rfds);
 
-    int started = 0;
-    unsigned char buf[2048];
+    unsigned char buf[8 * 1024];
+
+    int last_fd = 1 + MAX(tun_fd, MAX(mud_fd, icmp_fd));
 
     while (!gt.quit) {
         FD_SET(tun_fd, &rfds);
-
-        if (mud_can_pull(mud)) {
         FD_SET(mud_fd, &rfds);
-        } else {
-            FD_CLR(mud_fd, &rfds);
-        }
 
-        struct timeval timeout = {
-            .tv_usec = 100000,
-        };
+        if (icmp_fd != -1)
+            FD_SET(icmp_fd, &rfds);
 
-        if (mud_can_push(mud))
-            timeout.tv_usec = 1000;
-
-        if _0_(select(mud_fd+1, &rfds, NULL, NULL, &timeout)==-1) {
-            if (errno==EINTR)
+        if (select(last_fd, &rfds, NULL, NULL, NULL) == -1) {
+            if (errno != EBADF)
                 continue;
             perror("select");
             return 1;
         }
 
-        if (mud_is_up(mud)) {
-            if (!started) {
-                state("STARTED", tun_name);
-                started = 1;
+        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,
+                                 (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 (data[0] == 3) {
+                        int mtu = (data[6] << 8) | data[7];
+                        if (mtu) {
+                            gt_log("received MTU from ICMP: %i\n", mtu);
+                            mud_set_mtu(mud, GT_MTU(mtu));
+                        }
+                    }
                 }
-        } else {
-            if (started) {
-                state("STOPPED", tun_name);
-                started = 0;
             }
         }
 
         if (FD_ISSET(tun_fd, &rfds)) {
-            while (1) {
-                const ssize_t r = tun_read(tun_fd, buf, sizeof(buf));
+            size_t size = 0;
 
-                if (r<=0) {
-                    gt.quit |= !r;
+            while (sizeof(buf) - size > gt.mtu) {
+                const ssize_t r = tun_read(tun_fd, &buf[size],
+                                           sizeof(buf) - size);
+                if (r <= 0)
                     break;
-                }
 
                 struct ip_common ic;
 
-                if (!ip_get_common(&ic, buf, sizeof(buf)) && ic.size==r)
-                    mud_send(mud, buf, r);
+                if (ip_get_common(&ic, &buf[size], r) || ic.size != r)
+                    break;
+
+                size += r;
+            }
+
+            int p = 0;
+
+            while (p < size) {
+                int tc = 0;
+                int q = p;
+
+                while (q < size) {
+                    struct ip_common ic;
+
+                    if ((ip_get_common(&ic, &buf[q], size - q)) ||
+                        (ic.size > size - q)) {
+                        size = q;
+                        break;
+                    }
+
+                    if (q + ic.size > p + gt.mtu)
+                        break;
+
+                    q += ic.size;
+
+                    if (tc < (ic.tc & 0xFC))
+                        tc = ic.tc & 0xFC;
+                }
+
+                int r = mud_send(mud, &buf[p], q - p, tc);
+
+                if (r == -1 && errno == EMSGSIZE) {
+                    int mtu = GT_MTU(mud_get_mtu(mud));
+
+                    if (mtu != (int)gt.mtu) {
+                        gt.mtu = mtu;
+
+                        gt_log("setup MTU to %i on interface %s\n", mtu, tun_name);
+
+                        if (tun_set_mtu(tun_name, mtu) == -1)
+                            perror("tun_set_mtu");
+                    }
+                } else {
+                    if (r == -1 && errno != EAGAIN)
+                        perror("mud_send");
+                }
+
+                p = q;
             }
         }
 
-        mud_push(mud);
-
-        if (FD_ISSET(mud_fd, &rfds))
-            mud_pull(mud);
-
+        if (FD_ISSET(mud_fd, &rfds)) {
             while (1) {
                 const int size = mud_recv(mud, buf, sizeof(buf));
 
-            if (size<=0)
+                if (size <= 0) {
+                    if (size == -1 && errno != EAGAIN)
+                        perror("mud_recv");
+                    break;
+                }
+
+                int p = 0;
+
+                while (p < size) {
+                    struct ip_common ic;
+
+                    if ((ip_get_common(&ic, &buf[p], size - p)) ||
+                        (ic.size > size - p))
                         break;
 
-            const ssize_t r = tun_write(tun_fd, buf, size);
+                    tun_write(tun_fd, &buf[p], ic.size);
 
-            if (r<=0) {
-                gt.quit |= !r;
-                break;
+                    p += ic.size;
+                }
             }
         }
     }

src/option.c

@@ -3,7 +3,8 @@
 #include "option.h"
 #include "str.h"
 
-int option_str (void *data, int argc, char **argv)
+int
+option_str(void *data, int argc, char **argv)
 {
     if (argc < 2 || str_empty(argv[1])) {
         gt_print("option `%s' need a string argument\n", argv[0]);
@@ -15,7 +16,8 @@ int option_str (void *data, int argc, char **argv)
     return 1;
 }
 
-int option_long (void *data, int argc, char **argv)
+int
+option_long(void *data, int argc, char **argv)
 {
     if (argc < 2 || str_empty(argv[1])) {
         gt_print("option `%s' need an integer argument\n", argv[0]);
@@ -36,7 +38,8 @@ int option_long (void *data, int argc, char **argv)
     return 1;
 }
 
-int option_is_set (struct option *opts, const char *name)
+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))
@@ -46,7 +49,8 @@ int option_is_set (struct option *opts, const char *name)
     return 0;
 }
 
-int option_option (void *data, int argc, char **argv)
+int
+option_option(void *data, int argc, char **argv)
 {
     if (!data)
         return 0;
@@ -87,7 +91,8 @@ int option_option (void *data, int argc, char **argv)
     return argc;
 }
 
-static int option_usage (struct option *opts, int slen)
+static int
+option_usage(struct option *opts, int slen)
 {
     if (!opts)
         return 0;
@@ -114,7 +119,8 @@ static int option_usage (struct option *opts, int slen)
     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);
 

src/state.c

@@ -1,61 +0,0 @@
-#include "common.h"
-
-#include "state.h"
-#include "str.h"
-
-#include <stdio.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-
-static int state_fd = -1;
-
-int state_init (const char *filename)
-{
-    if (str_empty(filename))
-        return 0;
-
-    state_fd = open(filename, O_WRONLY);
-
-    if (state_fd==-1) {
-        if (errno!=EINTR)
-            perror("open");
-        return -1;
-    }
-
-    struct stat st = {0};
-
-    if (fstat(state_fd, &st)==-1) {
-        perror("fstat");
-        close(state_fd);
-        state_fd = -1;
-        return -1;
-    }
-
-    if (!S_ISFIFO(st.st_mode)) {
-        gt_log("`%s' is not a fifo\n", filename);
-        close(state_fd);
-        state_fd = -1;
-        return -1;
-    }
-
-    return 0;
-}
-
-void state (const char *state, const char *info)
-{
-    if (str_empty(state))
-        return;
-
-    const char *strs[] = { state, " ", info, "\n" };
-    char *str = str_cat(strs, COUNT(strs));
-
-    if (!str)
-        return;
-
-    if (state_fd==-1) {
-        gt_print("%s", str);
-    } else {
-        if (write(state_fd, str, str_len(str))==-1 && errno!=EINTR)
-            perror("write");
-    }
-}

src/state.h

@@ -1,4 +0,0 @@
-#pragma once
-
-int  state_init (const char *);
-void state      (const char *, const char *);

src/tun.c

@@ -1,25 +1,28 @@
 #include "common.h"
 
-#include "tun.h"
-#include "str.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 <sys/kern_control.h>
+#include <sys/sys_domain.h>
 #endif
 
 #if defined(__APPLE__) || defined(__OpenBSD__)
@@ -28,7 +31,8 @@
 
 #ifdef __APPLE__
 
-static int tun_create_by_id (char *name, size_t size, unsigned id, _unused_ int mq)
+static int
+tun_create_by_id(char *name, size_t size, unsigned id)
 {
     int fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
 
@@ -63,21 +67,23 @@ static int tun_create_by_id (char *name, size_t size, unsigned id, _unused_ int
     return fd;
 }
 
-static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
+static int
+tun_create_by_name(char *name, size_t size, char *dev_name)
 {
     unsigned id = 0;
 
     if (sscanf(dev_name, "utun%u", &id) != 1)
         return -1;
 
-    return tun_create_by_id(name, size, id, mq);
+    return tun_create_by_id(name, size, id);
 }
 
 #else /* not __APPLE__ */
 
 #ifdef __linux__
 
-static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
+static int
+tun_create_by_name(char *name, size_t size, char *dev_name)
 {
     int fd = open("/dev/net/tun", O_RDWR);
 
@@ -88,12 +94,6 @@ static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
         .ifr_flags = IFF_TUN | IFF_NO_PI,
     };
 
-    if (mq) {
-#ifdef IFF_MULTI_QUEUE
-        ifr.ifr_flags |= IFF_MULTI_QUEUE;
-#endif
-    }
-
     str_cpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
 
     if (ioctl(fd, TUNSETIFF, &ifr)) {
@@ -108,7 +108,8 @@ static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
 
 #else /* not __linux__ not __APPLE__ */
 
-static int tun_create_by_name (char *name, size_t size, char *dev_name, _unused_ int mq)
+static int
+tun_create_by_name(char *name, size_t size, char *dev_name)
 {
     char path[64];
 
@@ -120,32 +121,29 @@ static int tun_create_by_name (char *name, size_t size, char *dev_name, _unused_
 
 #endif /* not __APPLE__ */
 
-static int tun_create_by_id (char *name, size_t size, unsigned id, int mq)
+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, mq);
+    return tun_create_by_name(name, size, dev_name);
 }
 
 #endif
 
-int tun_create (char *dev_name, char **ret_name, int mq)
+int
+tun_create(char *dev_name, char **ret_name)
 {
     char name[64] = {0};
     int fd = -1;
 
-#ifndef IFF_MULTI_QUEUE
-    if (mq)
-        gt_na("IFF_MULTI_QUEUE");
-#endif
-
     if (str_empty(dev_name)) {
         for (unsigned id = 0; id < 32 && fd == -1; id++)
-            fd = tun_create_by_id(name, sizeof(name), id, mq);
+            fd = tun_create_by_id(name, sizeof(name), id);
     } else {
-        fd = tun_create_by_name(name, sizeof(name), dev_name, mq);
+        fd = tun_create_by_name(name, sizeof(name), dev_name);
     }
 
     if (fd != -1 && ret_name)
@@ -154,7 +152,8 @@ int tun_create (char *dev_name, char **ret_name, int mq)
     return fd;
 }
 
-ssize_t tun_read (int fd, void *data, size_t size)
+ssize_t
+tun_read(int fd, void *data, size_t size)
 {
     if (!size)
         return -1;
@@ -163,8 +162,14 @@ ssize_t tun_read (int fd, void *data, size_t size)
     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);
@@ -192,7 +197,8 @@ ssize_t tun_read (int fd, void *data, size_t size)
 #endif
 }
 
-ssize_t tun_write (int fd, const void *data, size_t size)
+ssize_t
+tun_write(int fd, const void *data, size_t size)
 {
     if (!size)
         return -1;
@@ -212,8 +218,14 @@ ssize_t tun_write (int fd, const void *data, size_t size)
     }
 
     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);
@@ -240,3 +252,26 @@ ssize_t tun_write (int fd, const void *data, size_t size)
     return ret;
 #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

@@ -2,6 +2,7 @@
 
 #include <unistd.h>
 
-int     tun_create (char *, char **, int);
+int     tun_create  (char *, char **);
 ssize_t tun_read    (int, void *, size_t);
 ssize_t tun_write   (int, const void *, size_t);
+int     tun_set_mtu (char *, int);