Update and fix MTU

This allows to build easily with other libc.

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/db.h
-    src/state.c \
-    src/state.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
+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:
 

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.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/main.c

@@ -1,10 +1,8 @@
 #include "common.h"
 
-#include "buffer.h"
 #include "db.h"
 #include "ip.h"
 #include "option.h"
-#include "state.h"
 #include "str.h"
 #include "tun.h"
 
@@ -26,12 +24,38 @@
 #define O_CLOEXEC 0
 #endif
 
+#define GT_MTU(X) ((X) - 28)
+
 static struct {
     volatile sig_atomic_t quit;
-    volatile sig_atomic_t info;
+    char *dev;
-    int timeout;
+    char *keyfile;
-    int state_fd;
+    char *host;
-} gt;
+    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)
@@ -53,18 +77,9 @@ fd_set_nonblock(int fd)
 }
 
 static void
-gt_sa_handler(int sig)
+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
@@ -76,138 +91,36 @@ 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);
 
     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("secret key: %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 +132,25 @@ 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 +165,134 @@ gt_setup_secretkey(struct mud *mud, char *keyfile)
     return 0;
 }
 
-int
+static int
-main(int argc, char **argv)
+gt_setup_option(int argc, char **argv)
 {
-    gt_set_signal();
+    // clang-format off
-
-    char *host = NULL;
-    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",           &gt.host,           option_str    },
-        { "host",           &host,           option_str    },
+        { "port",           &gt.port,           option_long   },
-        { "port",           &port,           option_long   },
+        { "bind",           &gt.bind.list,      option_str    },
-        { "bind",           &bind_list,      option_str    },
+        { "bind-backup",    &gt.bind.backup,    option_str    },
-        { "bind-backup",    &bind_backup,    option_str    },
+        { "bind-port",      &gt.bind.port,      option_long   },
-        { "bind-port",      &bind_port,      option_long   },
+        { "dev",            &gt.dev,            option_str    },
-        { "dev",            &dev,            option_str    },
+        { "mtu",            &gt.mtu,            option_long   },
-        { "mtu",            &mtu,            option_long   },
+        { "mtu-auto",       NULL,               option_option },
-        { "keyfile",        &keyfile,        option_str    },
+        { "keyfile",        &gt.keyfile,        option_str    },
-        { "statefile",      &statefile,      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
     };
 
+    // clang-format on
+
     if (option(opts, argc, argv))
         return 1;
 
-    if (option_is_set(opts, "version")) {
+    int v4only = option_is_set(opts, "v4only");
-        gt_print(PACKAGE_STRING "\n");
+    int v6only = option_is_set(opts, "v6only");
-        return 0;
-    }
 
-    if (option_is_set(opts, "v4only")) {
+    if (v4only && v6only) {
-        v4 = 1;
+        gt_log("v4only and v6only cannot be both set\n");
-        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")) {
+    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 (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");
+
+    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 (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);
-
-    if (statefile && gt.state_fd == -1)
-        return 1;
-
     char *tun_name = NULL;
 
-    int tun_fd = tun_create(dev, &tun_name);
+    int tun_fd = tun_create(gt.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) {
+    struct mud *mud = mud_create(gt.bind.port, gt.ipv4, gt.ipv6,
-        perror("tun_set_mtu");
+                                 !gt.chacha20, GT_MTU(gt.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 (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)
+    if (gt.time_tolerance > 0)
-        mud_set_time_tolerance_sec(mud, time_tolerance);
+        mud_set_time_tolerance_sec(mud, gt.time_tolerance);
 
-    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 +303,7 @@ 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;
                 }
@@ -403,17 +313,27 @@ main(int argc, char **argv)
         }
     }
 
+    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);
 
+    fd_set_nonblock(tun_fd);
     fd_set_nonblock(mud_fd);
 
-    state_send(gt.state_fd, "INITIALIZED", tun_name);
+    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);
         FD_SET(mud_fd, &rfds);
@@ -421,8 +341,8 @@ 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;
@@ -438,10 +358,10 @@ main(int argc, char **argv)
                 if (!ip_get_common(&ic, buf, r) && ic.proto == 1) {
                     unsigned char *data = &buf[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));
                         }
                     }
                 }
@@ -451,7 +371,7 @@ main(int argc, char **argv)
         if (FD_ISSET(tun_fd, &rfds)) {
             size_t size = 0;
 
-            while (sizeof(buf) - size > mtu) {
+            while (sizeof(buf) - size > gt.mtu) {
                 const ssize_t r = tun_read(tun_fd, &buf[size],
                                            sizeof(buf) - size);
                 if (r <= 0)
@@ -480,7 +400,7 @@ main(int argc, char **argv)
                         break;
                     }
 
-                    if (q + ic.size > p + mtu)
+                    if (q + ic.size > p + gt.mtu)
                         break;
 
                     q += ic.size;
@@ -492,12 +412,12 @@ main(int argc, char **argv)
                 int r = mud_send(mud, &buf[p], q - p, tc);
 
                 if (r == -1 && errno == EMSGSIZE) {
-                    int new_mtu = mud_get_mtu(mud);
+                    int mtu = GT_MTU(mud_get_mtu(mud));
 
-                    if (new_mtu != mtu) {
+                    if (mtu != (int)gt.mtu) {
-                        mtu = new_mtu;
+                        gt.mtu = mtu;
 
-                        gt_log("MTU changed: %li\n", 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");
@@ -505,11 +425,11 @@ main(int argc, char **argv)
                 } else {
                     if (r == -1 && errno != EAGAIN)
                         perror("mud_send");
+                }
 
                 p = q;
             }
         }
-        }
 
         if (FD_ISSET(mud_fd, &rfds)) {
             while (1) {

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/tun.c

@@ -14,7 +14,9 @@
 #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)
 #endif
 
 #ifdef __APPLE__