Use timeout in connect() too

Cope with branches that don't have tags

LICENSE

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

Makefile.am

@@ -6,19 +6,23 @@ glorytun_CFLAGS = $(libsodium_CFLAGS)
 glorytun_LDADD = $(libsodium_LIBS)
 glorytun_SOURCES = \
     src/common.h \
-    src/common-static.h \
     src/common.c \
-    src/ip-static.h \
+    src/buffer.h \
+    src/ip.h \
+    src/str.h \
     src/main.c \
     src/option.c \
     src/option.h \
     src/tun.c \
     src/tun.h \
     src/db.c \
-    src/db.h
+    src/db.h \
+    src/state.c \
+    src/state.h
 
 EXTRA_DIST = \
-	LICENSE \
-	README.md \
-	autogen.sh \
-	version.sh
+    LICENSE \
+    README.md \
+    VERSION \
+    autogen.sh \
+    version.sh

src/buffer.h

@@ -0,0 +1,66 @@
+#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-static.h

@@ -1,155 +0,0 @@
-#pragma once
-
-#include "common.h"
-
-#include <unistd.h>
-#include <errno.h>
-
-static inline void byte_set (void *dst, const char value, size_t size)
-{
-    if (!dst)
-        return;
-
-    char *restrict d = dst;
-
-    while (size--)
-        *d++ = value;
-}
-
-static inline void byte_cpy (void *dst, const void *src, size_t size)
-{
-    if (!dst)
-        return;
-
-    char *restrict d = dst;
-    const char *restrict s = src;
-
-    while (size--)
-        *d++ = *s++;
-}
-
-static inline size_t str_cpy (char *restrict dst, const char *restrict src, size_t len)
-{
-    if (!dst || !src)
-        return 0;
-
-    size_t i;
-
-    for (i=0; i<len && src[i]; i++)
-        dst[i] = src[i];
-
-    dst[i] = 0;
-
-    return i;
-}
-
-_pure_
-static inline int str_empty (const char *restrict str)
-{
-    return !str || !str[0];
-}
-
-_pure_
-static inline size_t str_cmp (const char *restrict sa, const char *restrict sb)
-{
-    if (!sa || !sb)
-        return 1;
-
-    size_t i = 0;
-
-    while (sa[i]==sb[i])
-        if (!sa[i++])
-            return 0;
-
-    return i+1;
-}
-
-_pure_
-static inline size_t str_len (const char *restrict str)
-{
-    if (!str)
-        return 0;
-
-    size_t i = 0;
-
-    while (str[i])
-        i++;
-
-    return i;
-}
-
-static inline char *str_cat (const char *const strs[], size_t count)
-{
-    size_t size = 1;
-
-    for (size_t i=0; i<count; i++)
-        size += str_len(strs[i]);
-
-    char *str = malloc(size);
-
-    if (!str)
-        return NULL;
-
-    char *p = str;
-
-    for (size_t i=0; i<count; i++) {
-        size_t len = str_len(strs[i]);
-        byte_cpy(p, strs[i], len);
-        p += len;
-    }
-
-    p[0] = 0;
-
-    return str;
-}
-
-static inline void buffer_setup (buffer_t *buffer, void *data, size_t size)
-{
-    if (!data)
-        data = malloc(ALIGN(size));
-
-    buffer->data  = data;
-    buffer->read  = data;
-    buffer->write = data;
-    buffer->end   = data;
-    buffer->end  += size;
-}
-
-static inline void buffer_format (buffer_t *buffer)
-{
-    buffer->write = buffer->data;
-    buffer->read  = buffer->data;
-}
-
-_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->write) {
-        buffer_format(buffer);
-    } else {
-        const uint8_t *src = PALIGN_DOWN(buffer->read);
-        const size_t size = ALIGN(buffer->write-src);
-        if (buffer->data+size<src) {
-            byte_cpy(buffer->data, src, size);
-            buffer->read  -= src-buffer->data;
-            buffer->write -= src-buffer->data;
-        }
-    }
-}

src/common.h

@@ -2,8 +2,11 @@
 
 #include <stdlib.h>
 #include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
 
-#define COUNT(x) (sizeof(x)/sizeof(x[0]))
+#define COUNT(x)       (sizeof(x)/sizeof(x[0]))
 
 #define ALIGN_SIZE     (1<<4)
 #define ALIGN_MASK     (ALIGN_SIZE-1)
@@ -26,15 +29,6 @@
 #define _const_        __attribute__ ((const))
 #define _align_(...)   __attribute__ ((aligned(__VA_ARGS__)))
 
-typedef struct buffer buffer_t;
-
-struct buffer {
-    uint8_t *data;
-    uint8_t *read;
-    uint8_t *write;
-    uint8_t *end;
-};
-
 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

@@ -1,5 +1,7 @@
+#include "common.h"
+
 #include "db.h"
-#include "common-static.h"
+#include "str.h"
 
 #define CBIT(X)      (1&(intptr_t)(X))
 #define CBIT_PTR(X)  (uint8_t *)(1|(intptr_t)(X))

src/ip-static.h

@@ -1,57 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-_pure_
-static inline int ip_get_version (const uint8_t *data, size_t size)
-{
-    if (size<20)   // XXX
-        return -1; // XXX
-
-    return data[0]>>4;
-}
-
-_pure_
-static inline ssize_t ip_get_size (const int ip_version, const uint8_t *data, size_t size)
-{
-    switch (ip_version) {
-    case 4:
-        return ((data[2]<<8)|data[3]);
-    case 6:
-        return ((data[4]<<8)|data[5])+40;
-    case -1:
-        return -1;
-    }
-
-    return 0;
-}
-
-_pure_
-static inline ssize_t ip_get_proto (const int ip_version, const uint8_t *data, size_t size)
-{
-    switch (ip_version) {
-    case 4:
-        return data[9];
-    case 6:
-        return data[6];
-    case -1:
-        return -1;
-    }
-
-    return 0;
-}
-
-_pure_
-static inline ssize_t ip_get_hdr_size (const int ip_version, const uint8_t *data, size_t size)
-{
-    switch (ip_version) {
-    case 4:
-        return (data[0]&0xF)<<2;
-    case 6:
-        return 40;
-    case -1:
-        return -1;
-    }
-
-    return 0;
-}

src/ip.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <stdint.h>
+
+struct ip_common {
+    uint8_t version;
+    uint8_t proto;
+    uint8_t hdr_size;
+    uint16_t size;
+};
+
+_pure_
+static inline uint8_t ip_get_version (const uint8_t *data, size_t size)
+{
+    if (size<20)
+        return 0;
+
+    return data[0]>>4;
+}
+
+static inline int ip_get_common (struct ip_common *ic, const uint8_t *data, size_t size)
+{
+    ic->version = ip_get_version(data, size);
+
+    switch (ic->version) {
+    case 4:
+        ic->proto = data[9];
+        ic->hdr_size = (data[0]&0xF)<<2;
+        ic->size = ((data[2]<<8)|data[3]);
+        return 0;
+    case 6:
+        ic->proto = data[6];
+        ic->hdr_size = 40;
+        ic->size = ((data[4]<<8)|data[5])+40;
+        return 0;
+    }
+
+    return -1;
+}

src/main.c

@@ -1,12 +1,21 @@
+#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 <inttypes.h>
 #include <limits.h>
 #include <stdio.h>
 #include <signal.h>
-#include <string.h>
 #include <poll.h>
+#include <fcntl.h>
+#include <sys/socket.h>
 #include <sys/time.h>
-#include <sys/fcntl.h>
-#include <sys/stat.h>
 
 #ifndef __FAVOR_BSD
 #define __FAVOR_BSD
@@ -27,21 +36,18 @@
 
 #include <sodium.h>
 
-#include "common-static.h"
-#include "ip-static.h"
-
-#include "option.h"
-#include "tun.h"
-
 #ifndef O_CLOEXEC
 #define O_CLOEXEC 0
 #endif
 
-#define GT_BUFFER_SIZE  (4*1024*1024)
-#define GT_TIMEOUT      (5000)
-#define GT_MTU_MAX      (1500)
-#define GT_TUNR_SIZE    (0x7FFF-16)
-#define GT_TUNW_SIZE    (0x7FFF)
+#define GT_MTU_MAX   (1500)
+#define GT_PKT_MAX   (32*1024)
+#define GT_TUNR_SIZE (GT_PKT_MAX-16-2)
+#define GT_TUNW_SIZE (GT_PKT_MAX)
+
+static struct {
+    int timeout;
+} gt;
 
 struct fdbuf {
     int fd;
@@ -49,11 +55,6 @@ struct fdbuf {
     buffer_t write;
 };
 
-struct blk {
-    size_t size;
-    uint8_t data[GT_MTU_MAX] _align_(16);
-};
-
 struct crypto_ctx {
     struct {
         crypto_aead_aes256gcm_state state;
@@ -102,6 +103,7 @@ enum sk_opt {
     sk_defer_accept,
     sk_acceptfilter,
     sk_quickack,
+    sk_user_timeout,
 };
 
 static void sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
@@ -151,6 +153,11 @@ static void sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
         [sk_acceptfilter] = { "SO_ACCEPTFILTER",
 #ifdef SO_ACCEPTFILTER
             1, SOL_SOCKET, SO_ACCEPTFILTER,
+#endif
+        },
+        [sk_user_timeout] = { "TCP_USER_TIMEOUT",
+#ifdef TCP_USER_TIMEOUT
+            1, IPPROTO_TCP, TCP_USER_TIMEOUT,
 #endif
         },
     };
@@ -184,10 +191,9 @@ static int sk_listen (int fd, struct addrinfo *ai)
     }
 
 #ifdef __linux__
-    sk_set_int(fd, sk_defer_accept, GT_TIMEOUT/1000);
+    sk_set_int(fd, sk_defer_accept, gt.timeout/1000);
 #else
-    char data[256] = {0};
-    str_cpy(data, "dataready", sizeof(data)-1);
+    char data[256] = "dataready";
     sk_set(fd, sk_acceptfilter, &data, sizeof(data));
 #endif
 
@@ -196,10 +202,34 @@ static int sk_listen (int fd, struct addrinfo *ai)
 
 static int sk_connect (int fd, struct addrinfo *ai)
 {
+    fd_set_nonblock(fd);
+
     int ret = connect(fd, ai->ai_addr, ai->ai_addrlen);
 
-    if (ret==-1 && errno==EINTR)
-        return 0;
+    if (ret==-1) {
+        if (errno==EINTR)
+            return 0;
+
+        if (errno==EINPROGRESS) {
+            struct pollfd pollfd = {
+                .fd = fd,
+                .events = POLLOUT,
+            };
+
+            if (!poll(&pollfd, 1, gt.timeout))
+                return -1;
+
+            int opt = 0;
+            socklen_t optlen = sizeof(opt);
+
+            getsockopt(fd, SOL_SOCKET, SO_ERROR, &opt, &optlen);
+
+            if (!opt)
+                return 0;
+
+            errno = opt;
+        }
+    }
 
     return ret;
 }
@@ -231,6 +261,8 @@ static int sk_accept (int fd)
     if (ret==-1 && errno!=EINTR)
         perror("accept");
 
+    fd_set_nonblock(ret);
+
     return ret;
 }
 
@@ -262,7 +294,7 @@ static char *sk_get_name (int fd)
         return NULL;
     }
 
-    const char *const strs[] = {
+    const char *strs[] = {
         host, ".", port
     };
 
@@ -271,7 +303,7 @@ static char *sk_get_name (int fd)
 
 static struct addrinfo *ai_create (const char *host, const char *port, int listener)
 {
-    if (!port || !port[0]) {
+    if (str_empty(port)) {
         gt_log("port is not valid\n");
         return NULL;
     }
@@ -384,11 +416,6 @@ static ssize_t fd_write (int fd, const void *data, size_t size)
     return ret;
 }
 
-static ssize_t fd_write_str (int fd, const char *str)
-{
-    return fd_write(fd, str, str_len(str));
-}
-
 static size_t fd_read_all (int fd, void *data, size_t size)
 {
     size_t done = 0;
@@ -405,7 +432,7 @@ static size_t fd_read_all (int fd, void *data, size_t size)
                 .events = POLLIN,
             };
 
-            if (!poll(&pollfd, 1, GT_TIMEOUT))
+            if (!poll(&pollfd, 1, gt.timeout))
                 break;
 
             continue;
@@ -433,7 +460,7 @@ static size_t fd_write_all (int fd, const void *data, size_t size)
                 .events = POLLOUT,
             };
 
-            if (!poll(&pollfd, 1, GT_TIMEOUT))
+            if (!poll(&pollfd, 1, gt.timeout))
                 break;
 
             continue;
@@ -533,20 +560,256 @@ static inline uint16_t sum16_final (uint32_t sum)
     return ~(sum+(sum>>16));
 }
 
-static void gt_print_hdr (const int ip_version, uint8_t *data, size_t ip_size)
-{
-    const ssize_t ip_proto = ip_get_proto(ip_version, data, ip_size);
-    const ssize_t ip_hdr_size = ip_get_hdr_size(ip_version, data, ip_size);
+struct seq_elem {
+    uint32_t seq;
+    uint32_t size;
+};
 
-    if (ip_proto<0 || ip_hdr_size<=0)
+struct seq_array {
+    struct seq_elem *elem;
+    uint32_t count;
+    uint32_t base;
+};
+
+struct tcp_entry {
+    uint8_t key[37];
+    struct {
+        struct seq_array sa;
+        size_t retrans;
+    } data[2];
+};
+
+void tcp_entry_free (struct tcp_entry *te)
+{
+    free(te->data[0].sa.elem);
+    free(te->data[1].sa.elem);
+    free(te);
+}
+
+void sa_insert_elem (struct seq_array *sa, uint32_t i, uint32_t seq, uint32_t size)
+{
+    if (sa->count<i)
         return;
 
-    uint32_t sum = (size_t)ip_proto+ip_size-(size_t)ip_hdr_size;
+    if (!(sa->count&7)) {
+        struct seq_elem *tmp = realloc(sa->elem, (sa->count+8)*sizeof(struct seq_elem));
+
+        if (!tmp) {
+            gt_log("couldn't realloc!\n");
+            return;
+        }
+
+        sa->elem = tmp;
+    }
+
+    memmove(&sa->elem[i+1], &sa->elem[i], (sa->count-i)*sizeof(struct seq_elem));
+
+    sa->elem[i].seq = seq;
+    sa->elem[i].size = size;
+    sa->count++;
+}
+
+void sa_remove_elem (struct seq_array *sa, uint32_t i)
+{
+    if (sa->count<i+1)
+        return;
+
+    sa->count--;
+
+    memmove(&sa->elem[i], &sa->elem[i+1], (sa->count-i)*sizeof(struct seq_elem));
+}
+
+int sa_have (struct seq_array *sa, uint32_t seq, uint32_t size)
+{
+    uint32_t i;
+    uint32_t seqa = seq-sa->base;
+
+    for (i=0; i<sa->count; i++) {
+        uint32_t seqb = sa->elem[i].seq-sa->base;
+
+        if (seqb>=seqa) {
+            uint32_t d = seqb-seqa;
+
+            if (d>size)
+                return 0;
+        } else {
+            uint32_t d = seqa-seqb;
+
+            if (d>=sa->elem[i].size)
+                continue;
+
+            if (d+size>sa->elem[i].size) {
+                gt_print("sa_have:part\n");
+                return 0; // XXX 0
+            }
+        }
+
+        return 1;
+    }
+
+    return 0;
+}
+
+void sa_rebase (struct seq_array *sa, uint32_t seq)
+{
+    if (!sa->count)
+        return;
+
+    if (seq==sa->base)
+        return;
+
+    uint32_t size = seq-sa->elem[0].seq;
+
+    if (size==sa->elem[0].size) {
+        sa_remove_elem(sa, 0);
+    } else {
+        if (size>sa->elem[0].size)
+            return;
+        sa->elem[0].seq = seq;
+        sa->elem[0].size -= size;
+    }
+
+    sa->base = seq;
+}
+
+void sa_insert (struct seq_array *sa, uint32_t seq, uint32_t size)
+{
+    uint32_t i;
+    uint32_t seqa = seq-sa->base;
+
+    for (i=0; i<sa->count; i++) {
+        uint32_t seqb = sa->elem[i].seq-sa->base;
+
+        if (seqb>=seqa) {
+            uint32_t d = seqb-seqa;
+
+            if (d>size)
+                break;
+
+            sa->elem[i].seq = seq;
+
+            uint32_t new_size = sa->elem[i].size+d;
+
+            if (new_size>size) {
+                sa->elem[i].size = new_size;
+            } else {
+                sa->elem[i].size = size;
+            }
+        } else {
+            uint32_t d = seqa-seqb;
+
+            if (d>sa->elem[i].size)
+                continue;
+
+            uint32_t new_size = size+d;
+
+            if (new_size>sa->elem[i].size)
+                sa->elem[i].size = new_size;
+        }
+
+        if (i+1<sa->count) {
+            if (seqb+sa->elem[i].size==sa->elem[i+1].seq-sa->base) {
+                sa->elem[i].size += sa->elem[i+1].size;
+                sa_remove_elem(sa, i+1);
+            }
+        }
+
+        return;
+    }
+
+    sa_insert_elem(sa, i, seq, size);
+}
+
+static int tcp_entry_set_key (struct tcp_entry *te, struct ip_common *ic, uint8_t *data)
+{
+    uint8_t *key = &te->key[1];
+    size_t size = 0;
+
+    switch (ic->version) {
+    case 4:
+        size = 8;
+        memcpy(key, &data[12], 8);
+        break;
+    case 6:
+        size = 32;
+        memcpy(key, &data[9], 32);
+        break;
+    }
+
+    memcpy(&key[size], &data[ic->hdr_size], 4);
+    te->key[0] = size+4;
+
+    return 0;
+}
+
+static int tcp_entry_set_key_rev (struct tcp_entry *te, struct ip_common *ic, uint8_t *data)
+{
+    uint8_t *key = &te->key[1];
+    size_t size = 0;
+
+    switch (ic->version) {
+    case 4:
+        size = 8;
+        memcpy(key, &data[12+4], 4);
+        memcpy(key+4, &data[12], 4);
+        break;
+    case 6:
+        size = 32;
+        memcpy(key, &data[9+16], 16);
+        memcpy(key+16, &data[9], 16);
+        break;
+    }
+
+    memcpy(&key[size], &data[ic->hdr_size+2], 2);
+    memcpy(&key[size+2], &data[ic->hdr_size], 2);
+    te->key[0] = size+4;
+
+    return 0;
+}
+
+static void gt_print_entry (struct tcp_entry *te)
+{
+    uint8_t *key = &te->key[1];
+    size_t size = te->key[0];
+
+    char ip0[INET6_ADDRSTRLEN];
+    char ip1[INET6_ADDRSTRLEN];
+
+    uint16_t port0, port1;
+
+    switch (size) {
+    case 8+4:
+        inet_ntop(AF_INET, key, ip0, sizeof(ip0));
+        inet_ntop(AF_INET, key+4, ip1, sizeof(ip1));
+        port0 = (key[8]<<8)|key[9];
+        port1 = (key[10]<<8)|key[11];
+        break;
+    case 32+4:
+        inet_ntop(AF_INET6, key,  ip0, sizeof(ip0));
+        inet_ntop(AF_INET6, key+16, ip1, sizeof(ip1));
+        port0 = (key[32]<<8)|key[33];
+        port1 = (key[34]<<8)|key[35];
+        break;
+    }
+
+    gt_print("connection:%s.%hu-%s.%hu\t"
+             "retrans:%zu, %zu\n",
+             ip0, port0, ip1, port1,
+             te->data[0].retrans,
+             te->data[1].retrans);
+}
+
+static void gt_print_hdr (struct ip_common *ic, uint8_t *data)
+{
+    if (!ic->hdr_size)
+        return;
+
+    uint32_t sum = ic->proto+ic->size-ic->hdr_size;
 
     char ip_src[INET6_ADDRSTRLEN];
     char ip_dst[INET6_ADDRSTRLEN];
 
-    switch (ip_version) {
+    switch (ic->version) {
     case 4:
         inet_ntop(AF_INET, &data[12], ip_src, sizeof(ip_src));
         inet_ntop(AF_INET, &data[16], ip_dst, sizeof(ip_dst));
@@ -559,16 +822,18 @@ static void gt_print_hdr (const int ip_version, uint8_t *data, size_t ip_size)
         break;
     }
 
-    if (ip_proto==IPPROTO_TCP) {
+    uint8_t *const packet = &data[ic->hdr_size];
+
+    if (ic->proto==IPPROTO_TCP) {
         struct tcphdr tcp;
 
-        byte_cpy(&tcp, &data[ip_hdr_size], sizeof(tcp));
+        memcpy(&tcp, packet, sizeof(tcp));
 
         uint16_t tcp_sum = ntohs(tcp.th_sum);
         tcp.th_sum = 0;
 
         sum = sum16(sum, (uint8_t *)&tcp, sizeof(tcp));
-        sum = sum16(sum, &data[ip_hdr_size+sizeof(tcp)], ip_size-ip_hdr_size-sizeof(tcp));
+        sum = sum16(sum, &packet[sizeof(tcp)], ic->size-ic->hdr_size-sizeof(tcp));
         uint16_t computed_sum = sum16_final(sum);
 
         tcp.th_sport = ntohs(tcp.th_sport);
@@ -577,9 +842,9 @@ static void gt_print_hdr (const int ip_version, uint8_t *data, size_t ip_size)
         tcp.th_ack = ntohl(tcp.th_ack);
         tcp.th_win = ntohs(tcp.th_win);
 
-        gt_print("proto:%zi\tsrc:%s.%u\tdst:%s.%u\tseq:%u\tack:%u\twin:%u\tsize:%zu\tflags:%c%c%c%c%c%c\tsum:%i\n",
-                ip_proto, ip_src, tcp.th_sport, ip_dst, tcp.th_dport,
-                tcp.th_seq, tcp.th_ack, tcp.th_win, ip_size-ip_hdr_size+tcp.th_off*4,
+        gt_print("proto:%hhu\tsrc:%s.%u\tdst:%s.%u\tseq:%u\tack:%u\twin:%u\tsize:%u\tflags:%c%c%c%c%c%c\tsum:%i\n",
+                ic->proto, ip_src, tcp.th_sport, ip_dst, tcp.th_dport,
+                tcp.th_seq, tcp.th_ack, tcp.th_win, ic->size-ic->hdr_size-tcp.th_off*4,
                 (tcp.th_flags&TH_FIN) ?'F':'.',
                 (tcp.th_flags&TH_SYN) ?'S':'.',
                 (tcp.th_flags&TH_RST) ?'R':'.',
@@ -588,34 +853,105 @@ static void gt_print_hdr (const int ip_version, uint8_t *data, size_t ip_size)
                 (tcp.th_flags&TH_URG) ?'U':'.',
                 (computed_sum==tcp_sum));
 
-    } else if (ip_proto==IPPROTO_UDP) {
+    } else if (ic->proto==IPPROTO_UDP) {
         struct udphdr udp;
 
-        byte_cpy(&udp, &data[ip_hdr_size], sizeof(udp));
+        memcpy(&udp, packet, sizeof(udp));
 
         udp.uh_sport = ntohs(udp.uh_sport);
         udp.uh_dport = ntohs(udp.uh_dport);
         udp.uh_ulen = ntohs(udp.uh_ulen);
 
-        gt_print("proto:%zi\tsrc:%s.%u\tdst:%s.%u\tsize:%u\n",
-                ip_proto, ip_src, udp.uh_sport, ip_dst, udp.uh_dport, udp.uh_ulen-8);
+        gt_print("proto:%hhu\tsrc:%s.%u\tdst:%s.%u\tsize:%u\n",
+                ic->proto, ip_src, udp.uh_sport, ip_dst, udp.uh_dport, udp.uh_ulen-8);
     } else {
-        gt_print("proto:%zi\tsrc:%s\tdst:%s\tsize:%zu\n",
-                ip_proto, ip_src, ip_dst, ip_size);
+        gt_print("proto:%hhu\tsrc:%s\tdst:%s\tsize:%hu\n",
+                ic->proto, ip_src, ip_dst, ic->size);
     }
 }
 
+static int gt_track (uint8_t **db, struct ip_common *ic, uint8_t *data, int rev)
+{
+    if (ic->proto!=IPPROTO_TCP)
+        return 0;
+
+    if (!ic->hdr_size)
+        return 1;
+
+    struct tcp_entry entry;
+
+    if (rev) {
+        tcp_entry_set_key_rev(&entry, ic, data);
+    } else {
+        tcp_entry_set_key(&entry, ic, data);
+    }
+
+    struct tcphdr tcp;
+    memcpy(&tcp, &data[ic->hdr_size], sizeof(tcp));
+    tcp.th_seq = ntohl(tcp.th_seq);
+    tcp.th_ack = ntohl(tcp.th_ack);
+
+    struct tcp_entry *r_entry = (void *)db_search(db, entry.key);
+
+    if (tcp.th_flags&(TH_FIN|TH_RST)) {
+        if (r_entry) {
+            gt_print_entry(r_entry);
+            db_remove(db, entry.key);
+            tcp_entry_free(r_entry);
+        }
+        return 0;
+    }
+
+    if (tcp.th_flags&TH_ACK) {
+        if (!r_entry) {
+            r_entry = calloc(1, sizeof(entry));
+
+            if (!r_entry)
+                return 0;
+
+            memcpy(r_entry->key, entry.key, sizeof(entry.key));
+
+            if (!db_insert(db, r_entry->key)) {
+                free(r_entry);
+                return 0;
+            }
+
+            gt_print_entry(r_entry);
+
+            r_entry->data[1-rev].sa.base = tcp.th_ack;
+            r_entry->data[rev].sa.base = tcp.th_seq;
+        } else {
+            sa_rebase(&r_entry->data[1-rev].sa, tcp.th_ack);
+        }
+    }
+
+    if (!r_entry)
+        return 0;
+
+    uint32_t size = ic->size-ic->hdr_size-tcp.th_off*4;
+
+    if (!size)
+        return 0;
+
+    if (sa_have(&r_entry->data[rev].sa, tcp.th_seq, size)) {
+        r_entry->data[rev].retrans++;
+    } else {
+        sa_insert(&r_entry->data[rev].sa, tcp.th_seq, size);
+    }
+
+    return 0;
+}
+
 static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 {
     const size_t size = sizeof(ctx->skey);
 
-    if (!keyfile) {
+    if (str_empty(keyfile)) {
         char buf[2*size+1];
 
         randombytes_buf(ctx->skey, size);
         gt_tohex(buf, sizeof(buf), ctx->skey, size);
-
-        gt_print("new secret key: %s\n", buf);
+        state("SECRETKEY", buf);
 
         return 0;
     }
@@ -669,13 +1005,13 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
 
     crypto_generichash_state state;
 
-    byte_set(data_w, 0, size);
+    memset(data_w, 0, size);
     randombytes_buf(data_w, nonce_size);
 
     randombytes_buf(secret, sizeof(secret));
     crypto_scalarmult_base(&data_w[nonce_size], secret);
 
-    byte_cpy(&data_w[size-hash_size-sizeof(gt)], gt, sizeof(gt));
+    memcpy(&data_w[size-hash_size-sizeof(gt)], gt, sizeof(gt));
 
     crypto_generichash(&data_w[size-hash_size], hash_size,
             data_w, size-hash_size, ctx->skey, sizeof(ctx->skey));
@@ -734,8 +1070,8 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
     sodium_memzero(shared, sizeof(shared));
     sodium_memzero(key, sizeof(key));
 
-    byte_cpy(ctx->read.nonce, data_r, nonce_size);
-    byte_cpy(ctx->write.nonce, data_w, nonce_size);
+    memcpy(ctx->read.nonce, data_r, nonce_size);
+    memcpy(ctx->write.nonce, data_w, nonce_size);
 
     return 0;
 }
@@ -751,7 +1087,7 @@ int main (int argc, char **argv)
     char *congestion = NULL;
     char *statefile = NULL;
 
-    long buffer_size = GT_BUFFER_SIZE;
+    long buffer_size = GT_PKT_MAX;
 
     long ka_count = -1;
     long ka_idle = -1;
@@ -762,6 +1098,8 @@ int main (int argc, char **argv)
     long retry_const = 0;
     long retry_limit = 1000000;
 
+    gt.timeout = 5000;
+
     struct option ka_opts[] = {
         { "count",    &ka_count,    option_long },
         { "idle",     &ka_idle,     option_long },
@@ -778,22 +1116,22 @@ int main (int argc, char **argv)
     };
 
     struct option opts[] = {
-        { "listener",    NULL,         option_option },
-        { "host",        &host,        option_str    },
-        { "port",        &port,        option_str    },
-        { "dev",         &dev,         option_str    },
-        { "keyfile",     &keyfile,     option_str    },
-        { "congestion",  &congestion,  option_str    },
-        { "delay",       NULL,         option_option },
-        { "multiqueue",  NULL,         option_option },
-        { "keepalive",   ka_opts,      option_option },
-        { "buffer-size", &buffer_size, option_long   },
-        { "noquickack",  NULL,         option_option },
-        { "retry",       &retry_opts,  option_option },
-        { "daemon",      NULL,         option_option },
-        { "statefile",   &statefile,   option_str    },
-        { "debug",       NULL,         option_option },
-        { "version",     NULL,         option_option },
+        { "listener",    NULL,          option_option },
+        { "host",        &host,         option_str    },
+        { "port",        &port,         option_str    },
+        { "dev",         &dev,          option_str    },
+        { "keyfile",     &keyfile,      option_str    },
+        { "congestion",  &congestion,   option_str    },
+        { "delay",       NULL,          option_option },
+        { "multiqueue",  NULL,          option_option },
+        { "keepalive",   ka_opts,       option_option },
+        { "buffer-size", &buffer_size,  option_long   },
+        { "noquickack",  NULL,          option_option },
+        { "retry",       &retry_opts,   option_option },
+        { "statefile",   &statefile,    option_str    },
+        { "timeout",     &gt.timeout,   option_long   },
+        { "debug",       NULL,          option_option },
+        { "version",     NULL,          option_option },
         { NULL },
     };
 
@@ -811,9 +1149,9 @@ int main (int argc, char **argv)
     const int noquickack = option_is_set(opts, "noquickack");
     const int debug = option_is_set(opts, "debug");
 
-    if (buffer_size < 2048) {
-        buffer_size = 2048;
-        gt_log("buffer size must be greater than 2048\n");
+    if (buffer_size < GT_PKT_MAX) {
+        buffer_size = GT_PKT_MAX;
+        gt_log("buffer size must be greater than or equal to %li\n", buffer_size);
     }
 
     if (!listener) {
@@ -826,8 +1164,8 @@ int main (int argc, char **argv)
             retry_count = 0;
     }
 
-    if (statefile && statefile[0]!='/') {
-        gt_log("statefile must be an absolute path\n");
+    if (gt.timeout<=0 || gt.timeout>INT_MAX) {
+        gt_log("bad timeout\n");
         return 1;
     }
 
@@ -846,24 +1184,21 @@ int main (int argc, char **argv)
     if (!ai)
         return 1;
 
+    if (state_init(statefile))
+        return 1;
+
     struct fdbuf tun  = { .fd = -1 };
     struct fdbuf sock = { .fd = -1 };
 
-    tun.fd = tun_create(dev, option_is_set(opts, "multiqueue"));
+    char *tun_name = NULL;
+
+    tun.fd = tun_create(dev, &tun_name, option_is_set(opts, "multiqueue"));
 
     if (tun.fd==-1) {
         gt_log("couldn't create tun device\n");
         return 1;
     }
 
-    struct blk *blks = calloc(256, sizeof(struct blk));
-    size_t blk_count = 0;
-    uint8_t blk_read = 0;
-    uint8_t blk_write = 0;
-
-    if (!blks)
-        return 1;
-
     fd_set_nonblock(tun.fd);
 
     buffer_setup(&tun.write, NULL, GT_TUNW_SIZE);
@@ -886,49 +1221,10 @@ int main (int argc, char **argv)
     if (gt_setup_secretkey(&ctx, keyfile))
         return 1;
 
-    if (option_is_set(opts, "daemon")) {
-        switch (fork()) {
-        case -1:
-            perror("fork");
-            return 1;
-        case 0:
-            if (setsid()==-1)
-                perror("setsid");
-            break;
-        default:
-            _exit(0);
-        }
-
-        chdir("/");
-    }
-
-    int state_fd = -1;
-
-    if (statefile) {
-        state_fd = open(statefile, O_WRONLY);
-
-        if (state_fd==-1) {
-            if (errno!=EINTR)
-                perror("open statefile");
-            return 1;
-        }
-
-        struct stat st = {0};
-
-        if (fstat(state_fd, &st)==-1) {
-            perror("stat statefile");
-            return 1;
-        }
-
-        if (!S_ISFIFO(st.st_mode)) {
-            gt_log("`%s' is not a fifo\n", statefile);
-            return 1;
-        }
-    }
-
     long retry = 0;
+    uint8_t *db = NULL;
 
-    fd_write_str(state_fd, "INITIALIZED");
+    state("INITIALIZED", tun_name);
 
     while (!gt_close) {
         if (retry_count>=0 && retry>=retry_count+1) {
@@ -957,15 +1253,13 @@ int main (int argc, char **argv)
 
         char *sockname = sk_get_name(sock.fd);
 
-        if (!sockname) {
+        if (str_empty(sockname)) {
             close(sock.fd);
             continue;
         }
 
         gt_log("%s: connected\n", sockname);
 
-        fd_set_nonblock(sock.fd);
-
         sk_set_int(sock.fd, sk_nodelay, !delay);
         sk_set_int(sock.fd, sk_keepalive, keepalive);
 
@@ -980,6 +1274,7 @@ int main (int argc, char **argv)
                 sk_set_int(sock.fd, sk_keepintvl, ka_interval);
         }
 
+        sk_set_int(sock.fd, sk_user_timeout, gt.timeout);
         sk_set(sock.fd, sk_congestion, congestion, str_len(congestion));
 
         switch (gt_setup_crypto(&ctx, sock.fd, listener)) {
@@ -995,7 +1290,7 @@ int main (int argc, char **argv)
 
         retry = 0;
 
-        fd_write_str(state_fd, "STARTED");
+        state("STARTED", sockname);
 
         fd_set rfds;
         FD_ZERO(&rfds);
@@ -1015,7 +1310,9 @@ int main (int argc, char **argv)
                     goto restart;
                 FD_CLR(tun.fd, &rfds);
             } else {
-                if (!blks[blk_write].size) {
+                buffer_shift(&tun.read);
+
+                if (buffer_write_size(&tun.read)>=GT_MTU_MAX) {
                     FD_SET(tun.fd, &rfds);
                 } else {
                     FD_CLR(tun.fd, &rfds);
@@ -1046,68 +1343,53 @@ int main (int argc, char **argv)
          // gettimeofday(&now, NULL);
 
             if (FD_ISSET(tun.fd, &rfds)) {
-                while (!blks[blk_write].size) {
-                    uint8_t *data = blks[blk_write].data;
-                    const ssize_t r = tun_read(tun.fd, data, GT_MTU_MAX);
+                while (1) {
+                    const size_t size = buffer_write_size(&tun.read);
+
+                    if (size<GT_MTU_MAX)
+                        break;
+
+                    const ssize_t r = tun_read(tun.fd, tun.read.write, GT_MTU_MAX);
 
                     if (r<=0) {
                         gt_close |= !r;
                         break;
                     }
 
-                    const int ip_version = ip_get_version(data, GT_MTU_MAX);
-                    const ssize_t ip_size = ip_get_size(ip_version, data, GT_MTU_MAX);
+                    struct ip_common ic;
 
-                    if _0_(ip_size<=0)
+                    if (ip_get_common(&ic, tun.read.write, GT_MTU_MAX))
                         continue;
 
-                    if _0_(ip_size!=r) {
+                    if _0_(ic.size!=r) {
                         char tmp[2*GT_MTU_MAX+1];
-                        gt_tohex(tmp, sizeof(tmp), data, r);
+                        gt_tohex(tmp, sizeof(tmp), tun.read.write, r);
                         gt_log("%s: DUMP %zi %s\n", sockname, r, tmp);
                         continue;
                     }
 
-                    if _0_(debug)
-                        gt_print_hdr(ip_version, data, ip_size);
+                    if _0_(debug) {
+                        if (gt_track(&db, &ic, tun.read.write, 0))
+                            continue;
+                    }
 
-                    blks[blk_write++].size = r;
-                    blk_count++;
+                    tun.read.write += r;
                 }
             }
 
-            while (1) {
-                buffer_shift(&tun.read);
+            buffer_shift(&sock.write);
 
-                if _0_(!stop_loop) {
-                    for (; blk_count; blk_read++) {
-                        const size_t size = blks[blk_read].size;
-
-                        if (!size || buffer_write_size(&tun.read)<size)
-                            break;
-
-                        byte_cpy(tun.read.write, blks[blk_read].data, size);
-                        tun.read.write += size;
-
-                        blks[blk_read].size = 0;
-                        blk_count--;
-                    }
-
-                    gt_encrypt(&ctx, &sock.write, &tun.read);
-                }
-
-                if (!buffer_read_size(&sock.write))
-                    break;
+            if _1_(!stop_loop)
+                gt_encrypt(&ctx, &sock.write, &tun.read);
 
+            if (buffer_read_size(&sock.write)) {
                 const ssize_t r = fd_write(sock.fd, sock.write.read,
                                            buffer_read_size(&sock.write));
 
                 if (r>0) {
                     sock.write.read += r;
-                } else {
-                    if (!r)
-                        stop_loop |= (1<<2);
-                    break;
+                } else if (!r) {
+                    stop_loop |= (1<<2);
                 }
             }
 
@@ -1119,8 +1401,6 @@ int main (int argc, char **argv)
                 }
             }
 
-            buffer_shift(&sock.write);
-
             if (FD_ISSET(sock.fd, &rfds)) {
                 if (noquickack)
                     sk_set_int(sock.fd, sk_quickack, 0);
@@ -1135,33 +1415,38 @@ int main (int argc, char **argv)
                 }
             }
 
+            buffer_shift(&tun.write);
+
+            if _0_(gt_decrypt(&ctx, &tun.write, &sock.read)) {
+                gt_log("%s: message could not be verified!\n", sockname);
+                goto restart;
+            }
+
             while (1) {
-                buffer_shift(&tun.write);
-
-                if _0_(gt_decrypt(&ctx, &tun.write, &sock.read)) {
-                    gt_log("%s: message could not be verified!\n", sockname);
-                    goto restart;
-                }
-
                 size_t size = buffer_read_size(&tun.write);
 
-                const int ip_version = ip_get_version(tun.write.read, size);
-                ssize_t ip_size = ip_get_size(ip_version, tun.write.read, size);
+                if (!size)
+                    break;
 
-                if _0_(!ip_size) {
+                struct ip_common ic;
+
+                if (ip_get_common(&ic, tun.write.read, size) || ic.size>size) {
                     gt_log("%s: bad packet!\n", sockname);
                     goto restart;
                 }
 
-                if (ip_size<0 || (size_t)ip_size>size)
-                    break;
+                if _0_(debug) {
+                    if (gt_track(&db, &ic, tun.write.read, 1)) {
+                        tun.write.read += ic.size;
+                        continue;
+                    }
+                }
 
-                ssize_t r = tun_write(tun.fd, tun.write.read, ip_size);
+                ssize_t r = tun_write(tun.fd, tun.write.read, ic.size);
 
                 if (r>0) {
-                    if _0_(debug)
-                        gt_print_hdr(ip_version, tun.write.read, ip_size);
-                    tun.write.read += r;
+                    if (r==ic.size)
+                        tun.write.read += r;
                 } else {
                     gt_close |= !r;
                     break;
@@ -1170,23 +1455,21 @@ int main (int argc, char **argv)
         }
 
     restart:
-        if (sockname) {
-            free(sockname);
-            sockname = NULL;
-        }
-
         if (sock.fd!=-1) {
             close(sock.fd);
             sock.fd = -1;
         }
 
-        fd_write_str(state_fd, "STOPPED");
+        state("STOPPED", sockname);
+
+        if (sockname) {
+            free(sockname);
+            sockname = NULL;
+        }
     }
 
     freeaddrinfo(ai);
 
-    free(blks);
-
     free(sock.write.data);
     free(sock.read.data);
 

src/option.c

@@ -1,25 +1,23 @@
-#include "common-static.h"
-
-#include <stdio.h>
-#include <stdlib.h>
+#include "common.h"
 
 #include "option.h"
+#include "str.h"
 
 int option_str (void *data, int argc, char **argv)
 {
-    if (argc<2 || !argv[1]) {
+    if (argc<2 || str_empty(argv[1])) {
         gt_print("option `%s' need a string argument\n", argv[0]);
         return -1;
     }
 
-    byte_cpy(data, &argv[1], sizeof(argv[1]));
+    memcpy(data, &argv[1], sizeof(argv[1]));
 
     return 1;
 }
 
 int option_long (void *data, int argc, char **argv)
 {
-    if (argc<2 || !argv[1]) {
+    if (argc<2 || str_empty(argv[1])) {
         gt_print("option `%s' need an integer argument\n", argv[0]);
         return -1;
     }
@@ -33,7 +31,7 @@ int option_long (void *data, int argc, char **argv)
         return -1;
     }
 
-    byte_cpy(data, &val, sizeof(val));
+    memcpy(data, &val, sizeof(val));
 
     return 1;
 }

src/state.c

@@ -0,0 +1,61 @@
+#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

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

src/str.h

@@ -0,0 +1,73 @@
+#pragma once
+
+#include "common.h"
+
+static inline size_t str_cpy (char *restrict dst, const char *restrict src, size_t len)
+{
+    if (!dst || !src)
+        return 0;
+
+    size_t i;
+
+    for (i=0; i<len && src[i]; i++)
+        dst[i] = src[i];
+
+    dst[i] = 0;
+
+    return i;
+}
+
+_pure_
+static inline int str_empty (const char *restrict str)
+{
+    return !str || !str[0];
+}
+
+_pure_
+static inline size_t str_cmp (const char *restrict sa, const char *restrict sb)
+{
+    if (!sa || !sb)
+        return 1;
+
+    size_t i = 0;
+
+    while (sa[i]==sb[i])
+        if (!sa[i++])
+            return 0;
+
+    return i+1;
+}
+
+_pure_
+static inline size_t str_len (const char *restrict str)
+{
+    if (!str)
+        return 0;
+
+    return strlen(str);
+}
+
+static inline char *str_cat (const char **strs, size_t count)
+{
+    size_t size = 1;
+
+    for (size_t i=0; i<count; i++)
+        size += str_len(strs[i]);
+
+    char *str = malloc(size);
+
+    if (!str)
+        return NULL;
+
+    char *p = str;
+
+    for (size_t i=0; i<count; i++) {
+        size_t len = str_len(strs[i]);
+        memcpy(p, strs[i], len);
+        p += len;
+    }
+
+    p[0] = 0;
+
+    return str;
+}

src/tun.c

@@ -1,7 +1,8 @@
-#include "common-static.h"
-#include "ip-static.h"
+#include "common.h"
 
 #include "tun.h"
+#include "str.h"
+#include "ip.h"
 
 #include <stdio.h>
 #include <fcntl.h>
@@ -36,7 +37,7 @@ static int tun_create_by_id (char *name, size_t size, unsigned id, _unused_ int
 
     struct ctl_info ci;
 
-    byte_set(&ci, 0, sizeof(ci));
+    memset(&ci, 0, sizeof(ci));
     str_cpy(ci.ctl_name, UTUN_CONTROL_NAME, sizeof(ci.ctl_name)-1);
 
     if (ioctl(fd, CTLIOCGINFO, &ci)) {
@@ -130,9 +131,9 @@ static int tun_create_by_id (char *name, size_t size, unsigned id, int mq)
 
 #endif
 
-int tun_create (char *dev_name, int mq)
+int tun_create (char *dev_name, char **ret_name, int mq)
 {
-    char name[64];
+    char name[64] = {0};
     int fd = -1;
 
 #ifndef IFF_MULTI_QUEUE
@@ -147,8 +148,8 @@ int tun_create (char *dev_name, int mq)
         fd = tun_create_by_name(name, sizeof(name), dev_name, mq);
     }
 
-    if (fd!=-1)
-        gt_print("tun name: %s\n", name);
+    if (fd!=-1 && ret_name)
+        *ret_name = strdup(name);
 
     return fd;
 }

src/tun.h

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

version.sh

@@ -1,11 +1,13 @@
 #!/bin/sh
 
-[ -z "${VERSION}" ] && VERSION=`git describe --tags --always 2>/dev/null` \
+[ -z "${VERSION}" ] && VERSION=`git describe --tags --match='v[0-9].*' 2>/dev/null` \
                     && VERSION=${VERSION#v}
 
-[ -z "${VERSION}" ] && VERSION=`basename \`pwd\`` \
-                    && VERSION=${VERSION#*-}
+[ -z "${VERSION}" ] && VERSION=`cat VERSION 2>/dev/null`
 
-[ "$1" = "major"  ] && VERSION=${VERSION%%.*}
+[ -z "${VERSION}" ] && VERSION=0.0.0
 
-printf ${VERSION}
+[ "$1" = "major"  ] && printf ${VERSION%%.*} \
+                    && exit 0
+
+printf ${VERSION} | tee VERSION