Add meson.build

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

.build.sh

@@ -11,5 +11,8 @@ cd ..
 [ -x glorytun ] || exit 1
 
 mkdir -p deploy
+
+cp glorytun deploy/glorytun-$(cat VERSION)-$(uname -m).debug.bin
+
 strip -s glorytun
-mv glorytun deploy/glorytun-$(cat VERSION)-$(uname -m).bin
+cp 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 \
@@ -15,12 +14,11 @@ glorytun_SOURCES = \
     src/option.h \
     src/tun.c \
     src/tun.h \
+    src/iface.c \
+    src/iface.h \
     src/db.c \
-    src/db.h \
+    src/db.h
-    src/state.c \
-    src/state.h
 
-glorytun_CFLAGS  += -I$(srcdir)/mud
 glorytun_SOURCES += \
     mud/mud.h \
     mud/mud.c

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
+Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4.
-and needs an AES-NI capable CPU.
 
 To build and install the latest version:
 

meson.build

@@ -0,0 +1,10 @@
+project('glorytun', 'c',
+    version: run_command('./version.sh').stdout()
+)
+
+add_global_arguments('-DPACKAGE_VERSION="'+meson.project_version()+'"', language : 'c')
+
+executable('glorytun', install: true,
+    sources: [ 'src/main.c', 'src/common.c', 'src/option.c', 'src/tun.c', 'src/iface.c', 'mud/mud.c' ],
+    dependencies: [ dependency('libsodium', version : '>=1.0.4') ]
+)

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

@@ -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

@@ -29,10 +29,14 @@
 #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/iface.c

@@ -0,0 +1,29 @@
+#include "common.h"
+
+#include "str.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/ip.h

@@ -10,16 +10,17 @@ struct ip_common {
     uint16_t size;
 };
 
-_pure_
+_pure_ static inline uint8_t
-static inline uint8_t ip_get_version (const uint8_t *data, size_t size)
+ip_get_version(const uint8_t *data, size_t size)
 {
-    if (size<20)
+    if (size < 20)
         return 0;
 
-    return data[0]>>4;
+    return data[0] >> 4;
 }
 
-static inline int ip_get_common (struct ip_common *ic, const uint8_t *data, size_t size)
+static inline int
+ip_get_common(struct ip_common *ic, const uint8_t *data, size_t size)
 {
     ic->version = ip_get_version(data, size);
 
@@ -27,14 +28,16 @@ static inline int ip_get_common (struct ip_common *ic, const uint8_t *data, size
     case 4:
         ic->tc = data[1];
         ic->proto = data[9];
-        ic->hdr_size = (data[0]&0xF)<<2;
+        ic->hdr_size = (data[0] & 0xF) << 2;
-        ic->size = ((data[2]<<8)|data[3]);
+        ic->size = ((data[2] << 8) | data[3]);
-        return 0;
+        if (ic->size >= 20)
+            return 0;
+        break;
     case 6:
-        ic->tc = ((data[0]&0xF)<<4)|(data[1]>>4);
+        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;
+        ic->size = ((data[4] << 8) | data[5]) + 40;
         return 0;
     }
 

src/main.c

@@ -1,12 +1,11 @@
 #include "common.h"
 
-#include "buffer.h"
 #include "db.h"
 #include "ip.h"
 #include "option.h"
-#include "state.h"
 #include "str.h"
 #include "tun.h"
+#include "iface.h"
 
 #include <fcntl.h>
 #include <inttypes.h>
@@ -20,18 +19,59 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 
-#include "mud.h"
+#include "../mud/mud.h"
 
 #ifndef O_CLOEXEC
 #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 info;
+    volatile sig_atomic_t reload;
-    int timeout;
+    char *dev;
-    int state_fd;
+    char *keyfile;
-} gt;
+    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;
+    int keygen;
+    int persist;
+    struct {
+        unsigned char *data;
+        long size;
+    } buf;
+} gt = {
+    .port = 5000,
+    .bind = {
+        .port = 5000,
+    },
+    .mtu = 1500,
+    .timeout = 5000,
+    .ipv4 = 1,
+#ifdef __linux__
+    .ipv6 = 1,
+#endif
+    .buf = {
+        .size = 64 * 1024,
+    },
+};
 
 static void
 fd_set_nonblock(int fd)
@@ -53,18 +93,10 @@ fd_set_nonblock(int fd)
 }
 
 static void
-gt_sa_handler(int sig)
+gt_quit_handler(int sig)
 {
-    switch (sig) {
+    gt.reload = (sig == SIGHUP);
-    case SIGINT:
+    gt.quit = 1;
-    case SIGQUIT:
-    case SIGTERM:
-        gt.quit = 1;
-        break;
-    case SIGUSR1:
-        gt.info = 1;
-        break;
-    }
 }
 
 static void
@@ -76,138 +108,36 @@ 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);
+    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);
 }
 
-static ssize_t
+static void
-fd_read(int fd, void *data, size_t size)
+gt_print_secretkey(struct mud *mud)
 {
-    if ((fd == -1) || !size)
+    unsigned char key[32];
-        return -1;
+    size_t size = sizeof(key);
 
-    ssize_t ret = read(fd, data, size);
+    if (mud_get_key(mud, key, &size))
+        return;
 
-    if (ret == -1) {
+    char buf[2 * sizeof(key) + 1];
-        if (errno == EAGAIN || errno == EINTR)
-            return -1;
 
-        if (errno)
+    gt_tohex(buf, sizeof(buf), key, size);
-            perror("read");
+    gt_print("%s\n", buf);
-
-        return 0;
-    }
-
-    return ret;
-}
-
-static ssize_t
-fd_write(int fd, const void *data, size_t size)
-{
-    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(struct mud *mud, char *keyfile)
 {
-    unsigned char key[32];
-
-    if (str_empty(keyfile)) {
-        char buf[2 * sizeof(key) + 1];
-        size_t size = sizeof(key);
-
-        if (mud_get_key(mud, key, &size))
-            return -1;
-
-        gt_tohex(buf, sizeof(buf), key, size);
-        state_send(gt.state_fd, "SECRETKEY", buf);
-
-        return 0;
-    }
-
     int fd;
 
     do {
@@ -219,12 +149,25 @@ gt_setup_secretkey(struct mud *mud, char *keyfile)
         return -1;
     }
 
+    unsigned char key[32];
     char buf[2 * sizeof(key)];
-    size_t r = fd_read_all(fd, buf, sizeof(buf));
+    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(buf)) {
+    if (size != sizeof(buf)) {
         gt_log("unable to read secret key\n");
         return -1;
     }
@@ -239,150 +182,178 @@ gt_setup_secretkey(struct mud *mud, char *keyfile)
     return 0;
 }
 
+static int
+gt_setup_option(int argc, char **argv)
+{
+    // clang-format off
+
+    struct option opts[] = {
+        { "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    },
+        { "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                                               },
+    };
+
+    // clang-format on
+
+    if (option(opts, argc, argv))
+        return 1;
+
+    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 ((int)gt.timeout <= 0) {
+        gt_log("bad timeout\n");
+        return 1;
+    }
+
+    if (gt.buf.size <= 0) {
+        gt_log("bad buf-size\n");
+        return 1;
+    }
+
+    if (v4only) {
+        gt.ipv4 = 1;
+        gt.ipv6 = 0;
+    }
+
+    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");
+    gt.keygen = option_is_set(opts, "keygen");
+    gt.persist = option_is_set(opts, "persist");
+
+    gt.buf.data = malloc(gt.buf.size);
+
+    return 0;
+}
+
+static void
+gt_setup_mtu(struct mud *mud, char *tun_name)
+{
+    int mtu = mud_get_mtu(mud);
+
+    if (mtu == (int)gt.mtu)
+        return;
+
+    gt.mtu = mtu;
+
+    gt_log("setup MTU to %i on interface %s\n", mtu, tun_name);
+
+    if (iface_set_mtu(tun_name, mtu) == -1)
+        perror("tun_set_mtu");
+}
+
 int
 main(int argc, char **argv)
 {
     gt_set_signal();
 
-    char *host = NULL;
+    if (gt_setup_option(argc, argv))
-    long port = 5000;
-
-    char *bind_list = NULL;
-    char *bind_backup = NULL;
-    long bind_port = 5000;
-
-    char *dev = NULL;
-    char *keyfile = NULL;
-    char *statefile = NULL;
-
-    long mtu = 1450;
-
-    gt.timeout = 5000;
-
-    long time_tolerance = 0;
-
-    int v4 = 1;
-    int v6 = 0;
-
-#ifdef __linux__
-    v6 = 1;
-#endif
-
-    struct option opts[] = {
-        // clang-format off
-        { "host",           &host,           option_str    },
-        { "port",           &port,           option_long   },
-        { "bind",           &bind_list,      option_str    },
-        { "bind-backup",    &bind_backup,    option_str    },
-        { "bind-port",      &bind_port,      option_long   },
-        { "dev",            &dev,            option_str    },
-        { "mtu",            &mtu,            option_long   },
-        { "keyfile",        &keyfile,        option_str    },
-        { "statefile",      &statefile,      option_str    },
-        { "timeout",        &gt.timeout,     option_long   },
-        { "time-tolerance", &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")) {
+    if (gt.version) {
-        gt_print(PACKAGE_STRING "\n");
+        gt_print(PACKAGE_VERSION "\n");
         return 0;
     }
 
-    if (option_is_set(opts, "v4only")) {
-        v4 = 1;
-        v6 = 0;
-    }
-
-    if (option_is_set(opts, "v6only")) {
-        v4 = 0;
-        v6 = 1;
-    }
-
-    if (option_is_set(opts, "v4only") &&
-        option_is_set(opts, "v6only")) {
-        gt_log("v4only and v6only are both set\n");
-        return 1;
-    }
-
-    if (host && !option_is_set(opts, "keyfile")) {
-        gt_log("keyfile option must be set\n");
-        return 1;
-    }
-
-    if (gt.timeout <= 0 || gt.timeout > INT_MAX) {
-        gt_log("bad timeout\n");
-        return 1;
-    }
-
     int icmp_fd = -1;
 
-    if (v4) {
+    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");
     }
 
-    gt.state_fd = state_create(statefile);
+    struct mud *mud = mud_create(gt.bind.port, gt.ipv4, gt.ipv6);
-
-    if (statefile && gt.state_fd == -1)
-        return 1;
-
-    char *tun_name = NULL;
-
-    int tun_fd = tun_create(dev, &tun_name);
-
-    if (tun_fd == -1) {
-        gt_log("couldn't create tun device\n");
-        return 1;
-    }
-
-    if (tun_set_mtu(tun_name, mtu) == -1) {
-        perror("tun_set_mtu");
-        return 1;
-    }
-
-    fd_set_nonblock(tun_fd);
-
-    int chacha = option_is_set(opts, "chacha20");
-
-    struct mud *mud = mud_create(bind_port, v4, v6, !chacha, mtu);
 
     if (!mud) {
         gt_log("couldn't create mud\n");
         return 1;
     }
 
-    if (gt_setup_secretkey(mud, keyfile))
+    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);
+
+    if (tun_fd == -1) {
+        gt_log("couldn't create tun device\n");
         return 1;
+    }
 
-    mud_set_send_timeout_msec(mud, gt.timeout);
+    if (tun_set_persist(tun_fd, gt.persist) == -1)
+        perror("tun_set_persist");
 
-    if (time_tolerance > 0)
+    if (str_empty(gt.keyfile)) {
-        mud_set_time_tolerance_sec(mud, time_tolerance);
+        gt_print("here is your new secret key:\n");
+        gt_print_secretkey(mud);
+    } else {
+        if (gt_setup_secretkey(mud, gt.keyfile))
+            return 1;
+    }
 
-    if (host && port) {
+    if (gt.host && gt.port) {
-        if (bind_backup) {
+        if (gt.bind.backup) {
-            if (mud_peer(mud, bind_backup, host, port, 1)) {
+            if (mud_peer(mud, gt.bind.backup, gt.host, gt.port, 1)) {
                 perror("mud_peer (backup)");
                 return 1;
             }
         }
 
-        if (bind_list) {
+        if (gt.bind.list) {
             char tmp[1024];
             char *name = &tmp[0];
 
-            str_cpy(tmp, bind_list, sizeof(tmp) - 1);
+            str_cpy(tmp, gt.bind.list, sizeof(tmp) - 1);
 
             while (*name) {
                 char *p = name;
@@ -393,7 +364,7 @@ main(int argc, char **argv)
                 if (*p)
                     *p++ = 0;
 
-                if (mud_peer(mud, name, host, port, 0)) {
+                if (mud_peer(mud, name, gt.host, gt.port, 0)) {
                     perror("mud_peer");
                     return 1;
                 }
@@ -403,16 +374,22 @@ main(int argc, char **argv)
         }
     }
 
+    gt_setup_mtu(mud, tun_name);
+
     int mud_fd = mud_get_fd(mud);
 
+    fd_set_nonblock(tun_fd);
     fd_set_nonblock(mud_fd);
 
-    state_send(gt.state_fd, "INITIALIZED", tun_name);
+    if (icmp_fd != -1)
+        fd_set_nonblock(icmp_fd);
+
+    gt_log("running...\n");
 
     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) {
         FD_SET(tun_fd, &rfds);
@@ -421,8 +398,8 @@ main(int argc, char **argv)
         if (icmp_fd != -1)
             FD_SET(icmp_fd, &rfds);
 
-        if (select(mud_fd + 1, &rfds, NULL, NULL, NULL) == -1) {
+        if (select(last_fd, &rfds, NULL, NULL, NULL) == -1) {
-            if (errno == EINTR)
+            if (errno != EBADF)
                 continue;
             perror("select");
             return 1;
@@ -431,17 +408,17 @@ 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) {
+                if (!ip_get_common(&ic, gt.buf.data, r) && ic.proto == 1) {
-                    unsigned char *data = &buf[ic.hdr_size];
+                    unsigned char *data = &gt.buf.data[ic.hdr_size];
                     if (data[0] == 3) {
-                        int new_mtu = (data[6] << 8) | data[7];
+                        int mtu = (data[6] << 8) | data[7];
-                        if (new_mtu) {
+                        if (mtu) {
-                            gt_log("received MTU from ICMP: %i\n", new_mtu);
+                            gt_log("received MTU from ICMP: %i\n", mtu);
-                            mud_set_mtu(mud, new_mtu - 50); // XXX
+                            mud_set_mtu(mud, GT_MTU(mtu));
                         }
                     }
                 }
@@ -451,15 +428,15 @@ main(int argc, char **argv)
         if (FD_ISSET(tun_fd, &rfds)) {
             size_t size = 0;
 
-            while (sizeof(buf) - size > mtu) {
+            while (gt.buf.size - size >= gt.mtu) {
-                const ssize_t r = tun_read(tun_fd, &buf[size],
+                const int r = tun_read(tun_fd, &gt.buf.data[size], gt.buf.size - size);
-                                           sizeof(buf) - size);
+
-                if (r <= 0)
+                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;
@@ -474,13 +451,11 @@ 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)) {
+                        (ic.size > size - q))
-                        size = q;
                         break;
-                    }
 
-                    if (q + ic.size > p + mtu)
+                    if (q + ic.size > p + gt.mtu)
                         break;
 
                     q += ic.size;
@@ -489,54 +464,57 @@ main(int argc, char **argv)
                         tc = ic.tc & 0xFC;
                 }
 
-                int r = mud_send(mud, &buf[p], q - p, tc);
+                if (p >= q)
+                    break;
+
+                int r = mud_send(mud, &gt.buf.data[p], q - p, tc);
 
                 if (r == -1 && errno == EMSGSIZE) {
-                    int new_mtu = mud_get_mtu(mud);
+                    gt_setup_mtu(mud, tun_name);
-
-                    if (new_mtu != mtu) {
-                        mtu = new_mtu;
-
-                        gt_log("MTU changed: %li\n", mtu);
-
-                        if (tun_set_mtu(tun_name, mtu) == -1)
-                            perror("tun_set_mtu");
-                    }
                 } else {
                     if (r == -1 && errno != EAGAIN)
                         perror("mud_send");
-
-                    p = q;
                 }
+
+                p = q;
             }
         }
 
         if (FD_ISSET(mud_fd, &rfds)) {
-            while (1) {
+            size_t size = 0;
-                const int size = mud_recv(mud, buf, sizeof(buf));
 
-                if (size <= 0) {
+            while (gt.buf.size - size >= gt.mtu) {
-                    if (size == -1 && errno != EAGAIN)
+                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;
                 }
 
-                int p = 0;
+                size += r;
+            }
 
-                while (p < size) {
+            int p = 0;
-                    struct ip_common ic;
 
-                    if ((ip_get_common(&ic, &buf[p], size - p)) ||
+            while (p < size) {
-                        (ic.size > size - p))
+                struct ip_common ic;
-                        break;
 
-                    tun_write(tun_fd, &buf[p], ic.size);
+                if ((ip_get_common(&ic, &gt.buf.data[p], size - p)) ||
+                    (ic.size > size - p))
+                    break;
 
-                    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/state.c

@@ -1,64 +0,0 @@
-#include "common.h"
-
-#include "state.h"
-#include "str.h"
-
-#include <fcntl.h>
-#include <stdio.h>
-#include <sys/stat.h>
-
-int
-state_create(const char *filename)
-{
-    if (str_empty(filename))
-        return -1;
-
-    int fd = open(filename, O_WRONLY);
-
-    if (fd == -1) {
-        if (errno != EINTR)
-            perror("open");
-        return -1;
-    }
-
-    struct stat st = {0};
-
-    if (fstat(fd, &st) == -1) {
-        perror("fstat");
-        close(fd);
-        return -1;
-    }
-
-    if (!S_ISFIFO(st.st_mode)) {
-        gt_log("`%s' is not a fifo\n", filename);
-        close(fd);
-        return -1;
-    }
-
-    return fd;
-}
-
-void
-state_send(int fd, const char *state, const char *info)
-{
-    if (str_empty(state))
-        return;
-
-    if (fd == -1) {
-        gt_print("%s %s\n", state, info);
-        return;
-    }
-
-    const char *strs[] = {state, " ", info, "\n"};
-    char *str = str_cat(strs, COUNT(strs));
-
-    if (!str) {
-        perror("str_cat");
-        return;
-    }
-
-    if (write(fd, str, str_len(str)) == -1 && errno != EINTR)
-        perror("write");
-
-    free(str);
-}

src/state.h

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

src/str.h

@@ -2,14 +2,15 @@
 
 #include "common.h"
 
-static inline size_t str_cpy (char *restrict dst, const char *restrict src, size_t len)
+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++)
+    for (i = 0; i < len && src[i]; i++)
         dst[i] = src[i];
 
     dst[i] = 0;
@@ -17,29 +18,29 @@ static inline size_t str_cpy (char *restrict dst, const char *restrict src, size
     return i;
 }
 
-_pure_
+_pure_ static inline int
-static inline int str_empty (const char *restrict str)
+str_empty(const char *restrict str)
 {
     return !str || !str[0];
 }
 
-_pure_
+_pure_ static inline size_t
-static inline size_t str_cmp (const char *restrict sa, const char *restrict sb)
+str_cmp(const char *restrict sa, const char *restrict sb)
 {
     if (!sa || !sb)
         return 1;
 
     size_t i = 0;
 
-    while (sa[i]==sb[i])
+    while (sa[i] == sb[i])
         if (!sa[i++])
             return 0;
 
-    return i+1;
+    return i + 1;
 }
 
-_pure_
+_pure_ static inline size_t
-static inline size_t str_len (const char *restrict str)
+str_len(const char *restrict str)
 {
     if (!str)
         return 0;
@@ -47,11 +48,12 @@ static inline size_t str_len (const char *restrict str)
     return strlen(str);
 }
 
-static inline char *str_cat (const char **strs, size_t count)
+static inline char *
+str_cat(const char **strs, size_t count)
 {
     size_t size = 1;
 
-    for (size_t i=0; i<count; i++)
+    for (size_t i = 0; i < count; i++)
         size += str_len(strs[i]);
 
     char *str = malloc(size);
@@ -61,7 +63,7 @@ static inline char *str_cat (const char **strs, size_t count)
 
     char *p = str;
 
-    for (size_t i=0; i<count; i++) {
+    for (size_t i = 0; i < count; i++) {
         size_t len = str_len(strs[i]);
         memcpy(p, strs[i], len);
         p += len;

src/tun.c

@@ -14,7 +14,10 @@
 #include <net/if.h>
 
 #ifdef __linux__
-#include <linux/if_tun.h>
+#define IFF_TUN 0x0001
+#define IFF_NO_PI 0x1000
+#define TUNSETIFF _IOW('T', 202, int)
+#define TUNSETPERSIST _IOW('T', 203, int)
 #endif
 
 #ifdef __APPLE__
@@ -43,7 +46,9 @@ tun_create_by_id(char *name, size_t size, unsigned id)
     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;
     }
 
@@ -56,7 +61,9 @@ tun_create_by_id(char *name, size_t size, unsigned id)
     };
 
     if (connect(fd, (struct sockaddr *)&sc, sizeof(sc))) {
+        int err = errno;
         close(fd);
+        errno = err;
         return -1;
     }
 
@@ -70,8 +77,10 @@ tun_create_by_name(char *name, size_t size, char *dev_name)
 {
     unsigned id = 0;
 
-    if (sscanf(dev_name, "utun%u", &id) != 1)
+    if (sscanf(dev_name, "utun%u", &id) != 1) {
+        errno = EINVAL;
         return -1;
+    }
 
     return tun_create_by_id(name, size, id);
 }
@@ -150,11 +159,11 @@ tun_create(char *dev_name, char **ret_name)
     return fd;
 }
 
-ssize_t
+int
 tun_read(int fd, void *data, size_t size)
 {
     if (!size)
-        return -1;
+        return 0;
 
 #ifdef GT_BSD_TUN
     uint32_t family;
@@ -171,35 +180,24 @@ tun_read(int fd, void *data, size_t size)
     };
 
     ssize_t ret = readv(fd, iov, 2);
-#else
-    ssize_t ret = read(fd, data, size);
-#endif
 
-    if (ret == -1) {
+    if (ret <= (ssize_t)0)
-        if (errno == EAGAIN || errno == EINTR)
+        return ret;
-            return -1;
 
-        if (errno)
+    if (ret <= (ssize_t)sizeof(family))
-            perror("tun read");
-
-        return 0;
-    }
-
-#ifdef GT_BSD_TUN
-    if (ret < (ssize_t)sizeof(family))
         return 0;
 
     return ret - sizeof(family);
 #else
-    return ret;
+    return read(fd, data, size);
 #endif
 }
 
-ssize_t
+int
 tun_write(int fd, const void *data, size_t size)
 {
     if (!size)
-        return -1;
+        return 0;
 
 #ifdef GT_BSD_TUN
     uint32_t family;
@@ -212,6 +210,7 @@ tun_write(int fd, const void *data, size_t size)
         family = htonl(AF_INET6);
         break;
     default:
+        errno = EINVAL;
         return -1;
     }
 
@@ -227,49 +226,26 @@ tun_write(int fd, const void *data, size_t size)
     };
 
     ssize_t ret = writev(fd, iov, 2);
-#else
-    ssize_t ret = write(fd, data, size);
-#endif
 
-    if (ret == -1) {
+    if (ret <= (ssize_t)0)
-        if (errno == EAGAIN || errno == EINTR)
+        return ret;
-            return -1;
 
-        if (errno)
+    if (ret <= (ssize_t)sizeof(family))
-            perror("tun write");
-
-        return 0;
-    }
-
-#ifdef GT_BSD_TUN
-    if (ret < (ssize_t)sizeof(family))
         return 0;
 
     return ret - sizeof(family);
 #else
-    return ret;
+    return write(fd, data, size);
 #endif
 }
 
 int
-tun_set_mtu(char *dev_name, int mtu)
+tun_set_persist(int fd, int on)
 {
-    struct ifreq ifr = {
+#ifdef TUNSETPERSIST
-        .ifr_mtu = mtu,
+    return ioctl(fd, TUNSETPERSIST, on);
-    };
+#else
-
+    errno = ENOSYS;
-    str_cpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
+    return -1;
-
+#endif
-    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

@@ -1,8 +1,6 @@
 #pragma once
 
-#include <unistd.h>
+int tun_create      (char *, char **);
-
+int tun_read        (int, void *, size_t);
-int     tun_create  (char *, char **);
+int tun_write       (int, const void *, size_t);
-ssize_t tun_read    (int, void *, size_t);
+int tun_set_persist (int, int);
-ssize_t tun_write   (int, const void *, size_t);
-int     tun_set_mtu (char *, int);