Key exchange may fail for several reasons

README.md

@@ -1,8 +1,9 @@
-# glorytun
+# Glorytun
+Small, Simple and Stupid **TCP** VPN.
 
-**Work In Progress:** Do not touch!
+**Work In Progress:** Do not touch! This code will probably format your harddisk!
 
-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:

configure.ac

@@ -1,11 +1,12 @@
 AC_PREREQ([2.65])
-AC_INIT([glorytun], [0.0.3], [https://github.com/angt/glorytun/issues],
+AC_INIT([glorytun], [0.0.11], [https://github.com/angt/glorytun/issues],
         [glorytun], [https://github.com/angt/glorytun])
 AC_CONFIG_SRCDIR([src/common.h])
 AC_CONFIG_AUX_DIR([build-aux])
 AM_INIT_AUTOMAKE([1.9 -Wall -Werror foreign tar-ustar subdir-objects])
 AM_DEP_TRACK
 AM_SILENT_RULES([yes])
+AM_PROG_CC_C_O
 AC_PROG_CC_C99
 AC_USE_SYSTEM_EXTENSIONS
 AC_SEARCH_LIBS([getaddrinfo], [resolv nsl])

src/common.h

@@ -14,9 +14,13 @@
 #define PALIGN(x)      ((void *)ALIGN((size_t)(x)))
 #define PALIGN_DOWN(x) ((void *)ALIGN_DOWN((size_t)(x)))
 
+#define _1_(x)         (__builtin_expect((x), 1))
+#define _0_(x)         (__builtin_expect((x), 0))
+
 #define _printf_(A,B)  __attribute__((format(printf,A,B)))
 #define _noreturn_     __attribute__((noreturn))
 #define _unused_       __attribute__((unused))
+#define _align_(...)   __attribute__((aligned(__VA_ARGS__)))
 
 typedef struct buffer buffer_t;
 

src/ip-static.h

@@ -28,3 +28,12 @@ static inline ssize_t ip_get_size (const uint8_t *data, size_t size)
     return 0;
 }
 
+static inline int ip_get_dscp (const uint8_t *data, size_t size)
+{
+    switch (ip_get_version(data, size)) {
+    case 4:
+        return data[1]>>2;
+    }
+
+    return 0;
+}

src/main.c

@@ -23,13 +23,20 @@
 #endif
 
 #define GT_BUFFER_SIZE  (4*1024*1024)
-#define GT_TIMEOUT     (1000)
+#define GT_TIMEOUT      (5000)
+#define GT_MTU_MAX      (1500)
+#define GT_TUNR_SIZE    (0x7FFF-16)
+#define GT_TUNW_SIZE    (0x7FFF)
 
-struct netio {
+struct fdbuf {
     int fd;
-    struct {
+    buffer_t read;
-        buffer_t buf;
+    buffer_t write;
-    } write, read;
+};
+
+struct blk {
+    size_t size;
+    uint8_t data[GT_MTU_MAX] _align_(16);
 };
 
 struct crypto_ctx {
@@ -41,6 +48,7 @@ struct crypto_ctx {
 };
 
 volatile sig_atomic_t gt_close = 0;
+volatile sig_atomic_t gt_info = 0;
 
 static int64_t dt_ms (struct timeval *ta, struct timeval *tb)
 {
@@ -67,54 +75,81 @@ static void fd_set_nonblock (int fd)
         perror("fcntl O_NONBLOCK");
 }
 
-static void sk_set (int fd, const char *name, const void *val, socklen_t len)
+enum sk_opt {
+    sk_nodelay,
+    sk_reuseaddr,
+    sk_keepalive,
+    sk_keepcnt,
+    sk_keepidle,
+    sk_keepintvl,
+    sk_congestion,
+    sk_defer_accept,
+    sk_quickack,
+};
+
+static void sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
 {
-    if (!name || !val || len<=0)
+    if (!val || len<=0)
         return;
 
     struct {
         const char *name;
+        const int present;
         const int level;
         const int option;
-    } ops[] = {
+    } opts[] = {
-        { "TCP_NODELAY",    IPPROTO_TCP, TCP_NODELAY    },
+        [sk_nodelay] = { "TCP_NODELAY", 1, IPPROTO_TCP, TCP_NODELAY, },
-        { "SO_REUSEADDR",   SOL_SOCKET,  SO_REUSEADDR   },
+        [sk_reuseaddr] = { "SO_REUSEADDR", 1, SOL_SOCKET, SO_REUSEADDR, },
-        { "SO_KEEPALIVE",   SOL_SOCKET,  SO_KEEPALIVE   },
+        [sk_keepalive] = { "SO_KEEPALIVE", 1, SOL_SOCKET, SO_KEEPALIVE, },
+        [sk_keepcnt] = { "TCP_KEEPCNT",
 #ifdef TCP_KEEPCNT
-        { "TCP_KEEPCNT",    IPPROTO_TCP, TCP_KEEPCNT    },
+            1, IPPROTO_TCP, TCP_KEEPCNT,
 #endif
+        },
+        [sk_keepidle] = { "TCP_KEEPIDLE",
 #ifdef TCP_KEEPIDLE
-        { "TCP_KEEPIDLE",   IPPROTO_TCP, TCP_KEEPIDLE   },
+            1, IPPROTO_TCP, TCP_KEEPIDLE,
 #endif
+        },
+        [sk_keepintvl] = { "TCP_KEEPINTVL",
 #ifdef TCP_KEEPINTVL
-        { "TCP_KEEPINTVL",  IPPROTO_TCP, TCP_KEEPINTVL  },
+            1, IPPROTO_TCP, TCP_KEEPINTVL,
 #endif
+        },
+        [sk_congestion] = { "TCP_CONGESTION",
 #ifdef TCP_CONGESTION
-        { "TCP_CONGESTION", IPPROTO_TCP, TCP_CONGESTION },
+            1, IPPROTO_TCP, TCP_CONGESTION,
 #endif
+        },
+        [sk_defer_accept] = { "TCP_DEFER_ACCEPT",
+#ifdef TCP_DEFER_ACCEPT
+            1, IPPROTO_TCP, TCP_DEFER_ACCEPT,
+#endif
+        },
+        [sk_quickack] = { "TCP_QUICKACK",
+#ifdef TCP_QUICKACK
+            1, IPPROTO_TCP, TCP_QUICKACK,
+#endif
+        },
     };
 
-    for (int k=0; k<COUNT(ops); k++) {
+    if (!opts[opt].present) {
-        if (str_cmp(ops[k].name, name))
+        gt_na(opts[opt].name);
-            continue;
-
-        if (setsockopt(fd, ops[k].level, ops[k].option, val, len)==-1)
-            gt_log("couldn't set socket option `%s'\n", name);
-
         return;
     }
 
-    gt_na(name);
+    if (setsockopt(fd, opts[opt].level, opts[opt].option, val, len)==-1)
+        gt_log("couldn't set socket option `%s'\n", opts[opt].name);
 }
 
-static void sk_set_int (int fd, const char *name, int val)
+static void sk_set_int (int fd, enum sk_opt opt, int val)
 {
-    return sk_set(fd, name, &val, sizeof(val));
+    return sk_set(fd, opt, &val, sizeof(val));
 }
 
 static int sk_listen (int fd, struct addrinfo *ai)
 {
-    sk_set_int(fd, "SO_REUSEADDR", 1);
+    sk_set_int(fd, sk_reuseaddr, 1);
 
     int ret = bind(fd, ai->ai_addr, ai->ai_addrlen);
 
@@ -123,13 +158,15 @@ static int sk_listen (int fd, struct addrinfo *ai)
         return -1;
     }
 
-    ret = listen(fd, 1);
+    ret = listen(fd, 8);
 
     if (ret==-1) {
         perror("listen");
         return -1;
     }
 
+    sk_set_int(fd, sk_defer_accept, GT_TIMEOUT/1000);
+
     return 0;
 }
 
@@ -279,34 +316,44 @@ static struct addrinfo *ai_create (const char *host, const char *port, int liste
     return NULL;
 }
 
-static void gt_sa_stop (int sig)
+static void gt_sa_handler (int sig)
 {
     switch (sig) {
     case SIGINT:
+    case SIGQUIT:
     case SIGTERM:
         gt_close = 1;
+        break;
+    case SIGUSR1:
+        gt_info = 1;
+        break;
     }
 }
 
 static void gt_set_signal (void)
 {
-    struct sigaction sa;
+    struct sigaction sa = {
+        .sa_flags = 0,
+    };
 
-    byte_set(&sa, 0, sizeof(sa));
+    sigemptyset(&sa.sa_mask);
 
-    sa.sa_handler = gt_sa_stop;
+    sa.sa_handler = gt_sa_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(SIGUSR2, &sa, NULL);
 }
 
 static ssize_t fd_read (int fd, void *data, size_t size)
 {
     if (!size)
-        return -2;
+        return -1;
 
     ssize_t ret = read(fd, data, size);
 
@@ -326,7 +373,7 @@ static ssize_t fd_read (int fd, void *data, size_t size)
 static ssize_t fd_write (int fd, const void *data, size_t size)
 {
     if (!size)
-        return -2;
+        return -1;
 
     ssize_t ret = write(fd, data, size);
 
@@ -397,52 +444,69 @@ static ssize_t fd_write_all (int fd, const void *data, size_t size)
     return done;
 }
 
-static int encrypt_packet (struct crypto_ctx *ctx, uint8_t *packet, size_t size, buffer_t *buffer)
+static int gt_encrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
 {
-    const size_t ws = size + crypto_aead_aes256gcm_ABYTES;
+    const size_t rs = buffer_read_size(src);
+    const size_t ws = buffer_write_size(dst);
 
-    if (buffer_write_size(buffer) < ws)
+    if (!rs || !ws)
-        return 1;
+        return 0;
 
-    const int hs = 4;
+    const size_t size = rs+crypto_aead_aes256gcm_ABYTES;
 
-    byte_cpy(buffer->write, packet, size);
+    if (size+2>ws)
+        return 0;
+
+    dst->write[0] = 0xFF&(size>>8);
+    dst->write[1] = 0xFF&(size);
 
     crypto_aead_aes256gcm_encrypt_afternm(
-            buffer->write + hs, NULL,
+            dst->write+2, NULL,
-            packet + hs, size - hs,
+            src->read, rs,
-            packet, hs,
+            dst->write, 2,
             NULL, ctx->write.nonce,
             (const crypto_aead_aes256gcm_state *)&ctx->write.state);
 
     sodium_increment(ctx->write.nonce, crypto_aead_aes256gcm_NPUBBYTES);
-    buffer->write += ws;
+
+    src->read += rs;
+    dst->write += size+2;
 
     return 0;
 }
 
-static int decrypt_packet (struct crypto_ctx *ctx, uint8_t *packet, size_t size, buffer_t *buffer)
+static int gt_decrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
 {
-    const size_t rs = size + crypto_aead_aes256gcm_ABYTES;
+    const size_t rs = buffer_read_size(src);
+    const size_t ws = buffer_write_size(dst);
 
-    if (buffer_read_size(buffer) < rs)
+    if (!rs || !ws)
-        return 1;
+        return 0;
 
-    const int hs = 4;
+    if (rs<=2+crypto_aead_aes256gcm_ABYTES)
+        return 0;
 
-    byte_cpy(packet, buffer->read, hs);
+    const size_t size = (src->read[0]<<8)|src->read[1];
+
+    if (size-crypto_aead_aes256gcm_ABYTES>ws)
+        return 0;
+
+    if (size+2>rs)
+        return 0;
 
     if (crypto_aead_aes256gcm_decrypt_afternm(
-                packet + hs, NULL,
+                dst->write, NULL,
                 NULL,
-                buffer->read + hs, rs - hs,
+                src->read+2, size,
-                packet, hs,
+                src->read, 2,
                 ctx->read.nonce,
                 (const crypto_aead_aes256gcm_state *)&ctx->read.state))
         return -1;
 
     sodium_increment(ctx->read.nonce, crypto_aead_aes256gcm_NPUBBYTES);
-    buffer->read += rs;
+
+    src->read += size+2;
+    dst->write += size-crypto_aead_aes256gcm_ABYTES;
 
     return 0;
 }
@@ -467,7 +531,7 @@ static void dump_ip_header (uint8_t *data, size_t size)
 
 static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 {
-    size_t size = sizeof(ctx->skey);
+    const size_t size = sizeof(ctx->skey);
 
     byte_set(ctx->skey, 1, size);
 
@@ -581,27 +645,22 @@ int main (int argc, char **argv)
 {
     gt_set_signal();
 
-    int listener = 0;
     char *host = NULL;
     char *port = "5000";
     char *dev = PACKAGE_NAME;
     char *keyfile = NULL;
     char *congestion = NULL;
+
     long buffer_size = GT_BUFFER_SIZE;
-    int delay = 0;
+
-    int multiqueue = 0;
     long ka_count = -1;
     long ka_idle = -1;
     long ka_interval = -1;
-    int version = 0;
-    int debug = 0;
 
-#ifdef TCP_INFO
+    long retry_count = 0;
-    struct {
+    long retry_slope = 1000;
-        struct timeval time;
+    long retry_const = 0;
-        struct tcp_info info;
+    long retry_limit = 1000000;
-    } tcpinfo = {0};
-#endif
 
     struct option ka_opts[] = {
         { "count",    &ka_count,    option_long },
@@ -610,31 +669,50 @@ int main (int argc, char **argv)
         { NULL },
     };
 
+    struct option daemon_opts[] = {
+        { "fake", NULL, option_option },
+        { NULL },
+    };
+
+    struct option retry_opts[] = {
+        { "count", &retry_count, option_long },
+        { "slope", &retry_slope, option_long },
+        { "const", &retry_const, option_long },
+        { "limit", &retry_limit, option_long },
+        { NULL },
+    };
+
     struct option opts[] = {
-        { "listener",    &listener,    option_flag   },
+        { "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",       &delay,       option_flag   },
+        { "delay",       NULL,         option_option },
-        { "multiqueue",  &multiqueue,  option_flag   },
+        { "multiqueue",  NULL,         option_option },
         { "keepalive",   ka_opts,      option_option },
         { "buffer-size", &buffer_size, option_long   },
-        { "debug",       &debug,       option_flag   },
+        { "noquickack",  NULL,         option_option },
-        { "version",     &version,     option_flag   },
+        { "retry",       &retry_opts,  option_option },
+        { "daemon",      &daemon_opts, option_option },
+        { "trap",        NULL,         option_option },
+        { "version",     NULL,         option_option },
         { NULL },
     };
 
     if (option(opts, argc, argv))
         return 1;
 
-    if (version) {
+    if (option_is_set(opts, "version")) {
         gt_print(PACKAGE_STRING"\n");
         return 0;
     }
 
-    int keepalive = option_is_set(opts, "keepalive");
+    const int listener = option_is_set(opts, "listener");
+    const int delay = option_is_set(opts, "delay");
+    const int keepalive = option_is_set(opts, "keepalive");
+    const int noquickack = option_is_set(opts, "noquickack");
 
     if (buffer_size < 2048) {
         buffer_size = 2048;
@@ -661,18 +739,29 @@ int main (int argc, char **argv)
     if (!ai)
         return 1;
 
-    struct netio tun  = { .fd = -1 };
+    struct fdbuf tun  = { .fd = -1 };
-    struct netio sock = { .fd = -1 };
+    struct fdbuf sock = { .fd = -1 };
 
-    tun.fd = tun_create(dev, multiqueue);
+    tun.fd = tun_create(dev, option_is_set(opts, "multiqueue"));
 
     if (tun.fd==-1)
         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(&sock.write.buf, NULL, buffer_size);
+    buffer_setup(&tun.write, NULL, GT_TUNW_SIZE);
-    buffer_setup(&sock.read.buf, NULL, buffer_size);
+    buffer_setup(&tun.read,  NULL, GT_TUNR_SIZE);
+
+    buffer_setup(&sock.write, NULL, buffer_size);
+    buffer_setup(&sock.read,  NULL, buffer_size);
 
     int fd = -1;
 
@@ -683,196 +772,271 @@ int main (int argc, char **argv)
             return 1;
     }
 
+    if (option_is_set(opts, "daemon")) {
+        switch (fork()) {
+        case -1:
+            perror("fork");
+            return 1;
+        case 0:
+            if (option_is_set(daemon_opts, "fake")) {
+                gt_log("running in fake daemon mode\n");
+            } else if (setsid()==-1) {
+                perror("setsid");
+            }
+            break;
+        default:
+            _exit(0);
+        }
+    }
+
+    long retry = 0;
+
     while (!gt_close) {
         sock.fd = listener?sk_accept(fd):sk_create(ai, sk_connect);
 
         if (sock.fd==-1) {
-            usleep(100000);
+            if (retry<LONG_MAX)
-            goto restart;
+                retry++;
+
+            long usec = retry*retry_slope+retry_const;
+
+            if (retry_count>=0 && retry>=retry_count) {
+                gt_log("couldn't %s (%d attempt%s)\n",
+                        listener?"listen":"connect",
+                        retry, (retry>1)?"s":"");
+                break;
+            }
+
+            if (usec>retry_limit)
+                usec = retry_limit;
+
+            if (usec<=0)
+                usec = 0;
+
+            if (usleep(usec)==-1 && errno==EINVAL)
+                sleep(usec/1000000);
+
+            continue;
         }
 
         char *sockname = sk_get_name(sock.fd);
 
-        if (!sockname)
+        if (!sockname) {
-            goto restart;
+            close(sock.fd);
+            continue;
+        }
 
         gt_log("%s: connected\n", sockname);
 
         fd_set_nonblock(sock.fd);
 
-        sk_set_int(sock.fd, "TCP_NODELAY", !delay);
+        sk_set_int(sock.fd, sk_nodelay, !delay);
-        sk_set_int(sock.fd, "SO_KEEPALIVE", keepalive);
+        sk_set_int(sock.fd, sk_keepalive, keepalive);
 
         if (keepalive) {
             if (ka_count>=0 && ka_count<=INT_MAX)
-                sk_set_int(sock.fd, "TCP_KEEPCNT", ka_count);
+                sk_set_int(sock.fd, sk_keepcnt, ka_count);
 
             if (ka_idle>=0 && ka_idle<=INT_MAX)
-                sk_set_int(sock.fd, "TCP_KEEPIDLE", ka_idle);
+                sk_set_int(sock.fd, sk_keepidle, ka_idle);
 
             if (ka_interval>=0 && ka_interval<=INT_MAX)
-                sk_set_int(sock.fd, "TCP_KEEPINTVL", ka_interval);
+                sk_set_int(sock.fd, sk_keepintvl, ka_interval);
         }
 
-        sk_set(sock.fd, "TCP_CONGESTION", congestion, str_len(congestion));
+        sk_set(sock.fd, sk_congestion, congestion, str_len(congestion));
 
         switch (gt_setup_crypto(&ctx, sock.fd, listener)) {
-            case -2: gt_log("%s: key exchange could not be verified!\n", sockname);
+        case -2:
-            case -1: goto restart;
+            gt_log("%s: key exchange could not be verified!\n", sockname);
-            default: break;
+            goto restart;
+        case -1:
+            gt_log("%s: key exchange failed\n", sockname);
+            goto restart;
+        default:
+            break;
         }
 
-        struct {
+        retry = 0;
-            uint8_t buf[2048];
-            size_t size;
-        } tunr, tunw;
 
-        tunr.size = 0;
+        if (option_is_set(opts, "trap"))
-        tunw.size = 0;
+            kill(0, SIGUSR2);
 
-        fd_set rfds, wfds;
+        gt_log("%s: running\n", sockname);
+
+        fd_set rfds;
         FD_ZERO(&rfds);
-        FD_ZERO(&wfds);
 
         int stop_loop = 0;
 
-        buffer_format(&sock.write.buf);
+        buffer_format(&sock.write);
-        buffer_format(&sock.read.buf);
+        buffer_format(&sock.read);
 
         while (1) {
-            if (gt_close)
+            if _0_(gt_close)
-                stop_loop = 1;
+                stop_loop |= 1;
 
-            if (stop_loop) {
+            if _0_(stop_loop) {
-                if (((stop_loop&(1<<2)) || !buffer_read_size(&sock.write.buf)) &&
+                if (((stop_loop&(1<<2)) || !buffer_read_size(&sock.write)) &&
-                    ((stop_loop&(1<<1)) || !buffer_read_size(&sock.read.buf)))
+                    ((stop_loop&(1<<1)) || !buffer_read_size(&sock.read)))
                     goto restart;
                 FD_CLR(tun.fd, &rfds);
             } else {
+                if (!blks[blk_write].size) {
                     FD_SET(tun.fd, &rfds);
+                } else {
+                    FD_CLR(tun.fd, &rfds);
+                }
             }
 
-            FD_SET(sock.fd, &rfds);
+            buffer_shift(&sock.read);
 
-            if (select(sock.fd+1, &rfds, &wfds, NULL, NULL)==-1) {
+            if (buffer_write_size(&sock.read)) {
+                FD_SET(sock.fd, &rfds);
+            } else {
+                FD_CLR(sock.fd, &rfds);
+            }
+
+            struct timeval timeout = {
+                .tv_usec = 1000,
+            };
+
+            if _0_(select(sock.fd+1, &rfds, NULL, NULL, &timeout)==-1) {
                 if (errno==EINTR)
                     continue;
                 perror("select");
                 return 1;
             }
 
-#ifdef TCP_INFO
+         // TODO
-            struct timeval now;
+         // struct timeval now;
-            gettimeofday(&now, NULL);
+         // gettimeofday(&now, NULL);
 
-            if (debug && dt_ms(&now, &tcpinfo.time)>1000LL) {
+#ifdef TCP_INFO
-                tcpinfo.time = now;
+            if _0_(gt_info) {
-                if (sk_get_info(sock.fd, &tcpinfo.info))
+                struct tcp_info ti;
-                    print_tcp_info(sockname, &tcpinfo.info);
+
+                if (sk_get_info(sock.fd, &ti))
+                    print_tcp_info(sockname, &ti);
+
+                gt_info = 0;
             }
 #endif
 
-            buffer_shift(&sock.write.buf);
-
             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);
+
+                    if (r<=0) {
+                        gt_close |= !r;
+                        break;
+                    }
+
+                    const ssize_t ip_size = ip_get_size(data, GT_MTU_MAX);
+
+                    if _0_(ip_size<=0)
+                        continue;
+
+                    if _0_(ip_size!=r) {
+                        dump_ip_header(data, r);
+
+                        if (r>ip_size)
+                            continue;
+
+                        ip_set_size(data, r);
+                    }
+
+                    blks[blk_write++].size = r;
+                    blk_count++;
+                }
+            }
+
             while (1) {
-                    if (buffer_write_size(&sock.write.buf)<sizeof(tunr.buf)+16)
+                buffer_shift(&tun.read);
+
+                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;
 
-                    ssize_t r = tun_read(tun.fd, tunr.buf, sizeof(tunr.buf));
+                        byte_cpy(tun.read.write, blks[blk_read].data, size);
+                        tun.read.write += size;
 
-                    if (!r)
+                        blks[blk_read].size = 0;
-                        return 2;
+                        blk_count--;
+                    }
 
-                    if (r<0)
+                    gt_encrypt(&ctx, &sock.write, &tun.read);
+                }
+
+                if (!buffer_read_size(&sock.write))
                     break;
 
-                    ssize_t ip_size = ip_get_size(tunr.buf, sizeof(tunr.buf));
+                const ssize_t r = fd_write(sock.fd, sock.write.read,
+                                           buffer_read_size(&sock.write));
 
-                    if (ip_size<=0)
+                if (r>0) {
-                        continue;
+                    sock.write.read += r;
-
-                    if (ip_size!=r) {
-                        dump_ip_header(tunr.buf, r);
-
-                        if (r<ip_size) {
-                            ip_set_size(tunr.buf, r);
                 } else {
-                            continue;
-                        }
-                    }
-
-                    encrypt_packet(&ctx, tunr.buf, r, &sock.write.buf);
-                }
-            }
-
-            if (FD_ISSET(sock.fd, &wfds))
-                FD_CLR(sock.fd, &wfds);
-
-            if (buffer_read_size(&sock.write.buf)) {
-                ssize_t r = fd_write(sock.fd, sock.write.buf.read,
-                                     buffer_read_size(&sock.write.buf));
-
-                if (r==-1)
-                    FD_SET(sock.fd, &wfds);
-
                     if (!r)
                         stop_loop |= (1<<2);
-
+                    break;
-                if (r>0)
+                }
-                    sock.write.buf.read += r;
-            } else {
-                if (stop_loop)
-                    shutdown(sock.fd, SHUT_WR);
             }
 
-            buffer_shift(&sock.read.buf);
+            if _0_(stop_loop && !buffer_read_size(&sock.write)) {
+                if (!(stop_loop&(1<<2))) {
+                    stop_loop |= (1<<2);
+                    shutdown(sock.fd, SHUT_WR);
+                    gt_log("%s: shutdown\n", sockname);
+                }
+            }
+
+            buffer_shift(&sock.write);
 
             if (FD_ISSET(sock.fd, &rfds)) {
-                ssize_t r = fd_read(sock.fd, sock.read.buf.write,
+                if (noquickack)
-                                    buffer_write_size(&sock.read.buf));
+                    sk_set_int(sock.fd, sk_quickack, 0);
 
-                if (!r)
+                const ssize_t r = fd_read(sock.fd, sock.read.write,
+                                          buffer_write_size(&sock.read));
+
+                if (r>0) {
+                    sock.read.write += r;
+                } else if (!r) {
                     stop_loop |= (1<<1);
-
+                }
-                if (r>0)
-                    sock.read.buf.write += r;
             }
 
-            if (FD_ISSET(tun.fd, &wfds))
-                FD_CLR(tun.fd, &wfds);
-
             while (1) {
-                if (!tunw.size) {
+                buffer_shift(&tun.write);
-                    size_t size = buffer_read_size(&sock.read.buf);
-                    ssize_t ip_size = ip_get_size(sock.read.buf.read, size);
 
-                    if (!ip_size)
+                if _0_(gt_decrypt(&ctx, &tun.write, &sock.read)) {
-                        goto restart;
-
-                    if (ip_size<0 || (size_t)ip_size+16>size)
-                        break;
-
-                    if (decrypt_packet(&ctx, tunw.buf, ip_size, &sock.read.buf)) {
                     gt_log("%s: message could not be verified!\n", sockname);
                     goto restart;
                 }
 
-                    tunw.size = ip_size;
+                size_t size = buffer_read_size(&tun.write);
+                ssize_t ip_size = ip_get_size(tun.write.read, size);
+
+                if _0_(!ip_size) {
+                    gt_log("%s: bad packet!\n", sockname);
+                    goto restart;
                 }
-                if (tunw.size) {
-                    ssize_t r = tun_write(tun.fd, tunw.buf, tunw.size);
 
-                    if (!r)
+                if (ip_size<0 || (size_t)ip_size>size)
-                        return 2;
-
-                    if (r==-1)
-                        FD_SET(tun.fd, &wfds);
-
-                    if (r<0)
                     break;
 
-                    tunw.size = 0;
+                ssize_t r = tun_write(tun.fd, tun.write.read, ip_size);
+
+                if (r>0) {
+                    tun.write.read += r;
+                } else {
+                    gt_close |= !r;
+                    break;
                 }
             }
         }
@@ -891,8 +1055,13 @@ int main (int argc, char **argv)
 
     freeaddrinfo(ai);
 
-    free(sock.write.buf.data);
+    free(blks);
-    free(sock.read.buf.data);
+
+    free(sock.write.data);
+    free(sock.read.data);
+
+    free(tun.write.data);
+    free(tun.read.data);
 
     return 0;
 }

src/option.c

@@ -5,14 +5,6 @@
 
 #include "option.h"
 
-int option_flag (void *data, _unused_ int argc, _unused_ char **argv)
-{
-    const int one = 1;
-    byte_cpy(data, &one, sizeof(one));
-
-    return 0;
-}
-
 int option_str (void *data, int argc, char **argv)
 {
     if (argc<2 || !argv[1]) {
@@ -58,6 +50,9 @@ int option_is_set (struct option *opts, const char *name)
 
 int option_option (void *data, int argc, char **argv)
 {
+    if (!data)
+        return 0;
+
     struct option *opts = (struct option *)data;
 
     for (int k=0; opts[k].name; k++)
@@ -96,23 +91,24 @@ int option_option (void *data, int argc, char **argv)
 
 static int option_usage (struct option *opts, int slen)
 {
-    int len = slen;
+    if (!opts)
+        return 0;
+
+    int len = 0;
 
     for (int k=0; opts[k].name; k++) {
-        if (len>60) {
+        if (len>40) {
-            gt_print("\n%*s", (int)slen, "");
+            gt_print("\n%*s", slen, "");
-            len = slen;
+            len = 0;
         }
 
         len += gt_print(" [%s", opts[k].name);
 
-        if (opts[k].call!=option_flag) {
         if (opts[k].call==option_option) {
-                len += option_usage((struct option *)opts[k].data, len);
+            len += option_usage((struct option *)opts[k].data, slen+len);
         } else {
             len += gt_print(" ARG");
         }
-        }
 
         len += gt_print("]");
     }
@@ -134,12 +130,13 @@ int option (struct option *opts, int argc, char **argv)
 
     int slen = gt_print("usage: %s", argv[0]);
 
-    if (slen>40)
+    if (slen>40) {
         slen = 12;
+        gt_print("\n%*s", slen, "");
+    }
 
     option_usage(opts, slen);
-
+    gt_print("\n");
-    printf("\n");
 
     return 1;
 }

src/option.h

@@ -7,10 +7,9 @@ struct option {
     int set;
 };
 
-int option_flag   (void *, int, char **);
+int option_option (void *, int, char **);
 int option_str    (void *, int, char **);
 int option_long   (void *, int, char **);
-int option_option (void *, int, char **);
 
 int option_is_set (struct option *, const char *);
 int option        (struct option *, int, char **);

src/tun.c

@@ -56,15 +56,16 @@ int tun_create (char *name, int multiqueue)
         return -1;
     }
 
-    gt_print("tun name: %s\n", ifr.ifr_name);
+    gt_log("tun name: %s\n", ifr.ifr_name);
 
     return fd;
 }
 #elif defined(__APPLE__)
 int tun_create (_unused_ char *name, _unused_ int mq)
 {
-    for (unsigned dev_id = 0U; dev_id<32U; dev_id++) {
+    for (unsigned dev_id = 0; dev_id < 32; dev_id++) {
         struct ctl_info ci;
+
         byte_set(&ci, 0, sizeof(ci));
         str_cpy(ci.ctl_name, UTUN_CONTROL_NAME, sizeof(ci.ctl_name)-1);
 
@@ -91,7 +92,7 @@ int tun_create (_unused_ char *name, _unused_ int mq)
             continue;
         }
 
-        gt_print("tun name: /dev/utun%u\n", dev_id);
+        gt_log("tun name: /dev/utun%u\n", dev_id);
 
         return fd;
     }
@@ -101,18 +102,20 @@ int tun_create (_unused_ char *name, _unused_ int mq)
 #else
 int tun_create (_unused_ char *name, _unused_ int mq)
 {
-    for (unsigned dev_id = 0U; dev_id<32U; dev_id++) {
+    for (unsigned dev_id = 0; dev_id < 32; dev_id++) {
-        char dev_path[11U];
+        char dev_path[11];
 
-        sngt_print(dev_path, sizeof(dev_path), "/dev/tun%u", dev_id);
+        snprintf(dev_path, sizeof(dev_path), "/dev/tun%u", dev_id);
 
         int fd = open(dev_path, O_RDWR);
 
-        if (fd!=-1) {
+        if (fd==-1)
-            gt_print("tun name: /dev/tun%u\n", dev_id);
+            continue;
+
+        gt_log("tun name: %s\n", dev_path);
+
         return fd;
     }
-    }
 
     return -1;
 }
@@ -121,10 +124,11 @@ int tun_create (_unused_ char *name, _unused_ int mq)
 ssize_t tun_read (int fd, void *data, size_t size)
 {
     if (!size)
-        return -2;
+        return -1;
 
 #ifdef GT_BSD_TUN
     uint32_t family;
+
     struct iovec iov[2] = {
         { .iov_base = &family, .iov_len = sizeof(family) },
         { .iov_base = data, .iov_len = size }
@@ -140,7 +144,7 @@ ssize_t tun_read (int fd, void *data, size_t size)
             return -1;
 
         if (errno)
-            perror("readv");
+            perror("tun read");
 
         return 0;
     }
@@ -158,7 +162,7 @@ ssize_t tun_read (int fd, void *data, size_t size)
 ssize_t tun_write (int fd, const void *data, size_t size)
 {
     if (!size)
-        return -2;
+        return -1;
 
 #ifdef GT_BSD_TUN
     uint32_t family;
@@ -189,7 +193,7 @@ ssize_t tun_write (int fd, const void *data, size_t size)
             return -1;
 
         if (errno)
-            perror("write");
+            perror("tun write");
 
         return 0;
     }