Version 0.0.7

configure.ac

@@ -1,5 +1,5 @@
 AC_PREREQ([2.65])
-AC_INIT([glorytun], [0.0.3], [https://github.com/angt/glorytun/issues],
+AC_INIT([glorytun], [0.0.7], [https://github.com/angt/glorytun/issues],
         [glorytun], [https://github.com/angt/glorytun])
 AC_CONFIG_SRCDIR([src/common.h])
 AC_CONFIG_AUX_DIR([build-aux])

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

@@ -22,14 +22,22 @@
 #define O_CLOEXEC 0
 #endif
 
-#define GT_BUFFER_SIZE (4*1024*1024)
-#define GT_TIMEOUT     (1000)
+#define GT_BUFFER_SIZE  (4*1024*1024)
+#define GT_TIMEOUT      (1000)
+#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 buf;
-    } write, read;
+    buffer_t read;
+    buffer_t write;
+};
+
+struct blk {
+    uint8_t prio;
+    size_t size;
+    uint8_t data[GT_MTU_MAX];
 };
 
 struct crypto_ctx {
@@ -67,54 +75,75 @@ 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,
+};
+
+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[] = {
-        { "TCP_NODELAY",    IPPROTO_TCP, TCP_NODELAY    },
-        { "SO_REUSEADDR",   SOL_SOCKET,  SO_REUSEADDR   },
-        { "SO_KEEPALIVE",   SOL_SOCKET,  SO_KEEPALIVE   },
+    } opts[] = {
+        [sk_nodelay] = { "TCP_NODELAY", 1, IPPROTO_TCP, TCP_NODELAY, },
+        [sk_reuseaddr] = { "SO_REUSEADDR", 1, SOL_SOCKET, SO_REUSEADDR, },
+        [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
+        },
     };
 
-    for (int k=0; k<COUNT(ops); k++) {
-        if (str_cmp(ops[k].name, name))
-            continue;
-
-        if (setsockopt(fd, ops[k].level, ops[k].option, val, len)==-1)
-            gt_log("couldn't set socket option `%s'\n", name);
-
+    if (!opts[opt].present) {
+        gt_na(opts[opt].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 +152,15 @@ 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;
 }
 
@@ -397,52 +428,69 @@ 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;
+    size_t rs = buffer_read_size(src);
+    size_t ws = buffer_write_size(dst);
 
-    if (buffer_write_size(buffer) < ws)
-        return 1;
+    if (!rs || !ws)
+        return 0;
 
-    const int hs = 4;
+    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,
-            packet + hs, size - hs,
-            packet, hs,
+            dst->write+2, NULL,
+            src->read, rs,
+            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;
+    size_t rs = buffer_read_size(src);
+    size_t ws = buffer_write_size(dst);
 
-    if (buffer_read_size(buffer) < rs)
-        return 1;
+    if (!rs || !ws)
+        return 0;
 
-    const int hs = 4;
+    if (rs<=2+16)
+        return 0;
 
-    byte_cpy(packet, buffer->read, hs);
+    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,
-                packet, hs,
+                src->read+2, size,
+                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;
 }
@@ -581,20 +629,17 @@ 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;
+    long prio_dscp = 46;
+    long prio_size = (GT_TUNR_SIZE*3)/4;
 
 #ifdef TCP_INFO
     struct {
@@ -610,30 +655,41 @@ int main (int argc, char **argv)
         { NULL },
     };
 
+    struct option prio_opts[] = {
+        { "dscp",  &prio_dscp, option_long },
+        { "size",  &prio_size, 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   },
-        { "multiqueue",  &multiqueue,  option_flag   },
+        { "delay",       NULL,         option_option },
+        { "multiqueue",  NULL,         option_option },
         { "keepalive",   ka_opts,      option_option },
         { "buffer-size", &buffer_size, option_long   },
-        { "debug",       &debug,       option_flag   },
-        { "version",     &version,     option_flag   },
+        { "priority",    prio_opts,    option_option },
+        { "daemon",      NULL,         option_option },
+        { "debug",       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 listener = option_is_set(opts, "listener");
+    int delay = option_is_set(opts, "delay");
+    int debug = option_is_set(opts, "debug");
     int keepalive = option_is_set(opts, "keepalive");
 
     if (buffer_size < 2048) {
@@ -641,6 +697,16 @@ int main (int argc, char **argv)
         gt_log("buffer size must be greater than 2048!\n");
     }
 
+    if (prio_size < 0) {
+        prio_size = 0;
+        gt_log("priority size must be positive!\n");
+    }
+
+    if (prio_size > GT_TUNR_SIZE) {
+        prio_size = GT_TUNR_SIZE;
+        gt_log("priority size must be less than or equal to %zu\n", GT_TUNR_SIZE);
+    }
+
     if (sodium_init()==-1) {
         gt_log("libsodium initialization has failed!\n");
         return 1;
@@ -661,18 +727,30 @@ int main (int argc, char **argv)
     if (!ai)
         return 1;
 
-    struct netio tun  = { .fd = -1 };
-    struct netio sock = { .fd = -1 };
+    struct fdbuf tun  = { .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;
+    size_t blk_prio = 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(&sock.read.buf, NULL, buffer_size);
+    buffer_setup(&tun.write, NULL, GT_TUNW_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;
 
@@ -683,38 +761,54 @@ 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 (setsid()==-1)
+                perror("setsid");
+            break;
+        default:
+            _exit(0);
+        }
+    }
+
     while (!gt_close) {
         sock.fd = listener?sk_accept(fd):sk_create(ai, sk_connect);
 
         if (sock.fd==-1) {
             usleep(100000);
-            goto restart;
+            continue;
         }
 
         char *sockname = sk_get_name(sock.fd);
 
-        if (!sockname)
-            goto restart;
+        if (!sockname) {
+            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, "SO_KEEPALIVE", keepalive);
+        sk_set_int(sock.fd, sk_nodelay, !delay);
+        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);
@@ -722,30 +816,22 @@ int main (int argc, char **argv)
             default: break;
         }
 
-        struct {
-            uint8_t buf[2048];
-            size_t size;
-        } tunr, tunw;
-
-        tunr.size = 0;
-        tunw.size = 0;
-
         fd_set rfds, wfds;
         FD_ZERO(&rfds);
         FD_ZERO(&wfds);
 
         int stop_loop = 0;
 
-        buffer_format(&sock.write.buf);
-        buffer_format(&sock.read.buf);
+        buffer_format(&sock.write);
+        buffer_format(&sock.read);
 
         while (1) {
             if (gt_close)
-                stop_loop = 1;
+                stop_loop |= 1;
 
             if (stop_loop) {
-                if (((stop_loop&(1<<2)) || !buffer_read_size(&sock.write.buf)) &&
-                    ((stop_loop&(1<<1)) || !buffer_read_size(&sock.read.buf)))
+                if (((stop_loop&(1<<2)) || !buffer_read_size(&sock.write)) &&
+                    ((stop_loop&(1<<1)) || !buffer_read_size(&sock.read)))
                     goto restart;
                 FD_CLR(tun.fd, &rfds);
             } else {
@@ -754,6 +840,12 @@ int main (int argc, char **argv)
 
             FD_SET(sock.fd, &rfds);
 
+            if (buffer_read_size(&tun.read) || blk_count)
+                FD_SET(sock.fd, &wfds);
+
+            if (buffer_read_size(&sock.read))
+                FD_SET(tun.fd, &wfds);
+
             if (select(sock.fd+1, &rfds, &wfds, NULL, NULL)==-1) {
                 if (errno==EINTR)
                     continue;
@@ -761,6 +853,9 @@ int main (int argc, char **argv)
                 return 1;
             }
 
+            FD_CLR(sock.fd, &wfds);
+            FD_CLR(tun.fd, &wfds);
+
 #ifdef TCP_INFO
             struct timeval now;
             gettimeofday(&now, NULL);
@@ -772,14 +867,10 @@ int main (int argc, char **argv)
             }
 #endif
 
-            buffer_shift(&sock.write.buf);
-
             if (FD_ISSET(tun.fd, &rfds)) {
-                while (1) {
-                    if (buffer_write_size(&sock.write.buf)<sizeof(tunr.buf)+16)
-                        break;
-
-                    ssize_t r = tun_read(tun.fd, tunr.buf, sizeof(tunr.buf));
+                while (!blks[blk_write].size) {
+                    uint8_t *data = blks[blk_write].data;
+                    ssize_t r = tun_read(tun.fd, data, GT_MTU_MAX);
 
                     if (!r)
                         return 2;
@@ -787,31 +878,85 @@ int main (int argc, char **argv)
                     if (r<0)
                         break;
 
-                    ssize_t ip_size = ip_get_size(tunr.buf, sizeof(tunr.buf));
+                    ssize_t ip_size = ip_get_size(data, GT_MTU_MAX);
 
                     if (ip_size<=0)
                         continue;
 
                     if (ip_size!=r) {
-                        dump_ip_header(tunr.buf, r);
+                        dump_ip_header(data, r);
 
                         if (r<ip_size) {
-                            ip_set_size(tunr.buf, r);
+                            ip_set_size(data, r);
                         } else {
                             continue;
                         }
                     }
 
-                    encrypt_packet(&ctx, tunr.buf, r, &sock.write.buf);
+                    if (ip_get_dscp(data, GT_MTU_MAX)==prio_dscp) {
+                        blks[blk_write].prio = 1;
+                        blk_prio++;
+                    } else {
+                        blks[blk_write].prio = 0;
+                    }
+
+                    blks[blk_write++].size = r;
+                    blk_count++;
                 }
             }
 
-            if (FD_ISSET(sock.fd, &wfds))
-                FD_CLR(sock.fd, &wfds);
+            buffer_shift(&tun.read);
 
-            if (buffer_read_size(&sock.write.buf)) {
-                ssize_t r = fd_write(sock.fd, sock.write.buf.read,
-                                     buffer_read_size(&sock.write.buf));
+            // XXX prio code needs a full rewrite :)
+
+            if (blk_prio) {
+                uint8_t k = blk_read;
+
+                while (blk_prio && buffer_read_size(&tun.read)<(size_t)prio_size) {
+                    while (!blks[k].prio || !blks[k].size)
+                        k++;
+
+                    if (buffer_write_size(&tun.read)<blks[k].size)
+                        break;
+
+                    byte_cpy(tun.read.write, blks[k].data, blks[k].size);
+                    tun.read.write += blks[k].size;
+
+                    blks[k].size = 0;
+                    blk_count--;
+                    blk_prio--;
+
+                    if (blk_read==k)
+                        blk_read++;
+
+                    k++;
+                }
+            }
+
+            while (blk_count) {
+                if (!blks[blk_read].size) {
+                    blk_read++;
+                    continue;
+                }
+
+                if (buffer_write_size(&tun.read)<blks[blk_read].size)
+                    break;
+
+                byte_cpy(tun.read.write, blks[blk_read].data, blks[blk_read].size);
+                tun.read.write += blks[blk_read].size;
+
+                if (blks[blk_read].prio)
+                    blk_prio--;
+
+                blks[blk_read++].size = 0;
+                blk_count--;
+            }
+
+            gt_encrypt(&ctx, &sock.write, &tun.read);
+
+            if (buffer_read_size(&sock.write)) {
+                ssize_t r = fd_write(sock.fd, sock.write.read,
+                                     buffer_read_size(&sock.write));
 
                 if (r==-1)
                     FD_SET(sock.fd, &wfds);
@@ -820,61 +965,58 @@ int main (int argc, char **argv)
                     stop_loop |= (1<<2);
 
                 if (r>0)
-                    sock.write.buf.read += r;
+                    sock.write.read += r;
             } else {
-                if (stop_loop)
+                if (stop_loop) {
+                    gt_log("%s: shutdown\n", sockname);
                     shutdown(sock.fd, SHUT_WR);
+                }
             }
 
-            buffer_shift(&sock.read.buf);
+            buffer_shift(&sock.write);
+            buffer_shift(&sock.read);
 
             if (FD_ISSET(sock.fd, &rfds)) {
-                ssize_t r = fd_read(sock.fd, sock.read.buf.write,
-                                    buffer_write_size(&sock.read.buf));
+                ssize_t r = fd_read(sock.fd, sock.read.write,
+                                    buffer_write_size(&sock.read));
 
                 if (!r)
                     stop_loop |= (1<<1);
 
                 if (r>0)
-                    sock.read.buf.write += r;
+                    sock.read.write += r;
             }
 
-            if (FD_ISSET(tun.fd, &wfds))
-                FD_CLR(tun.fd, &wfds);
-
             while (1) {
-                if (!tunw.size) {
-                    size_t size = buffer_read_size(&sock.read.buf);
-                    ssize_t ip_size = ip_get_size(sock.read.buf.read, size);
-
-                    if (!ip_size)
-                        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;
+                if (gt_decrypt(&ctx, &tun.write, &sock.read)) {
+                    gt_log("%s: message could not be verified!\n", sockname);
+                    goto restart;
                 }
-                if (tunw.size) {
-                    ssize_t r = tun_write(tun.fd, tunw.buf, tunw.size);
 
-                    if (!r)
-                        return 2;
+                size_t size = buffer_read_size(&tun.write);
+                ssize_t ip_size = ip_get_size(tun.write.read, size);
 
-                    if (r==-1)
-                        FD_SET(tun.fd, &wfds);
-
-                    if (r<0)
-                        break;
-
-                    tunw.size = 0;
+                if (!ip_size) {
+                    gt_log("%s: bad packet!\n", sockname);
+                    goto restart;
                 }
+
+                if (ip_size<0 || (size_t)ip_size>size)
+                    break;
+
+                ssize_t r = tun_write(tun.fd, tun.write.read, ip_size);
+
+                if (!r)
+                    return 2;
+
+                if (r==-1)
+                    FD_SET(tun.fd, &wfds);
+
+                if (r>0)
+                    tun.write.read += r;
             }
+
+            buffer_shift(&tun.write);
         }
 
     restart:
@@ -891,8 +1033,13 @@ int main (int argc, char **argv)
 
     freeaddrinfo(ai);
 
-    free(sock.write.buf.data);
-    free(sock.read.buf.data);
+    free(blks);
+
+    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++)
@@ -96,22 +91,23 @@ int option_option (void *data, int argc, char **argv)
 
 static int option_usage (struct option *opts, int slen)
 {
+    if (!opts)
+        return 0;
+
     int len = slen;
 
     for (int k=0; opts[k].name; k++) {
-        if (len>60) {
+        if (len>slen+40) {
             gt_print("\n%*s", (int)slen, "");
             len = slen;
         }
 
         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);
-            } else {
-                len += gt_print(" ARG");
-            }
+        if (opts[k].call==option_option) {
+            len += option_usage((struct option *)opts[k].data, len);
+        } else {
+            len += gt_print(" ARG");
         }
 
         len += gt_print("]");
@@ -134,8 +130,10 @@ 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", (int)slen, "");
+    }
 
     option_usage(opts, slen);
 

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;
     }
@@ -101,17 +102,19 @@ 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++) {
-        char dev_path[11U];
+    for (unsigned dev_id = 0; dev_id < 32; dev_id++) {
+        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) {
-            gt_print("tun name: /dev/tun%u\n", dev_id);
-            return fd;
-        }
+        if (fd==-1)
+            continue;
+
+        gt_log("tun name: %s\n", dev_path);
+
+        return fd;
     }
 
     return -1;
@@ -125,6 +128,7 @@ ssize_t tun_read (int fd, void *data, size_t size)
 
 #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;
     }
@@ -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;
     }