Try value 42 for mptcp (fallback to 26)

Chacha20 will be automatically used if aesni is not available.

.build.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+export CC="gcc -static"
+
+git clone https://github.com/jedisct1/libsodium --depth=1 --branch stable
+cd libsodium || exit 1
+./autogen.sh && ./configure --enable-minimal --disable-shared --prefix=/usr && make install
+cd ..
+
+./autogen.sh && ./configure && make
+[ -x glorytun ] || exit 1
+
+mkdir -p deploy
+strip -s glorytun
+mv glorytun deploy/glorytun-$(cat VERSION)-$(uname -m).bin

README.md

@@ -1,4 +1,4 @@
-# Glorytun
+# π₁(Glorytun)=ℤ²
 
 Small, Simple and Stupid TCP VPN.
 
@@ -8,8 +8,7 @@ This code will probably format your harddisk!
 
 #### Build and Install
 
-Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4
-and needs an AES-NI capable CPU.
+Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4.
 
 To build and install the latest version:
 

configure.ac

@@ -16,6 +16,8 @@ AC_PROG_CC_C99
 AC_USE_SYSTEM_EXTENSIONS
 AC_SEARCH_LIBS([getaddrinfo], [resolv nsl])
 AC_SEARCH_LIBS([socket], [socket])
+AC_CHECK_LIB([rt], [clock_gettime])
+AC_CHECK_FUNCS([clock_gettime])
 PKG_CHECK_MODULES([libsodium], [libsodium >= 1.0.4])
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT

m4/pkg.m4

@@ -1,6 +1,6 @@
-dnl pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
-dnl serial 11 (pkg-config-0.29)
-dnl
+# pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
+# serial 12 (pkg-config-0.29.2)
+
 dnl Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
 dnl Copyright © 2012-2015 Dan Nicholson <dbn.lists@gmail.com>
 dnl
@@ -41,7 +41,7 @@ dnl
 dnl See the "Since" comment for each macro you use to see what version
 dnl of the macros you require.
 m4_defun([PKG_PREREQ],
-[m4_define([PKG_MACROS_VERSION], [0.29])
+[m4_define([PKG_MACROS_VERSION], [0.29.2])
 m4_if(m4_version_compare(PKG_MACROS_VERSION, [$1]), -1,
     [m4_fatal([pkg.m4 version $1 or higher is required but ]PKG_MACROS_VERSION[ found])])
 ])dnl PKG_PREREQ
@@ -142,7 +142,7 @@ AC_ARG_VAR([$1][_CFLAGS], [C compiler flags for $1, overriding pkg-config])dnl
 AC_ARG_VAR([$1][_LIBS], [linker flags for $1, overriding pkg-config])dnl
 
 pkg_failed=no
-AC_MSG_CHECKING([for $1])
+AC_MSG_CHECKING([for $2])
 
 _PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])
 _PKG_CONFIG([$1][_LIBS], [libs], [$2])

src/main.c

@@ -14,6 +14,7 @@
 #include <signal.h>
 #include <poll.h>
 #include <fcntl.h>
+#include <time.h>
 #include <sys/socket.h>
 #include <sys/time.h>
 
@@ -36,6 +37,10 @@
 
 #include <sodium.h>
 
+#ifdef __APPLE__
+#include <mach/mach_time.h>
+#endif
+
 #ifndef O_CLOEXEC
 #define O_CLOEXEC 0
 #endif
@@ -45,8 +50,15 @@
 #define GT_TUNR_SIZE (GT_PKT_MAX-16-2)
 #define GT_TUNW_SIZE (GT_PKT_MAX)
 
+#define GT_ABYTES    (16)
+#define GT_KEYBYTES  (32)
+
 static struct {
-    int timeout;
+    volatile sig_atomic_t quit;
+    volatile sig_atomic_t info;
+    long timeout;
+    int mptcp;
+    int state_fd;
 } gt;
 
 struct fdbuf {
@@ -57,15 +69,13 @@ struct fdbuf {
 
 struct crypto_ctx {
     struct {
-        crypto_aead_aes256gcm_state state;
-        uint8_t nonce[crypto_aead_aes256gcm_NPUBBYTES];
+        uint8_t key[512] _align_(16);
+        uint8_t nonce[16];
     } write, read;
     uint8_t skey[crypto_generichash_KEYBYTES];
+    int chacha;
 };
 
-volatile sig_atomic_t gt_close = 0;
-volatile sig_atomic_t gt_info = 0;
-
 _pure_
 static int64_t dt_ms (struct timeval *ta, struct timeval *tb)
 {
@@ -104,12 +114,16 @@ enum sk_opt {
     sk_acceptfilter,
     sk_quickack,
     sk_user_timeout,
+    sk_mptcp_26,
+    sk_mptcp_42,
 };
 
-static void sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
+static int sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
 {
-    if (!val || len<=0)
-        return;
+    if (!val || len<=0) {
+        errno = EINVAL;
+        return -1;
+    }
 
     struct {
         const char *name;
@@ -160,26 +174,45 @@ static void sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
             1, IPPROTO_TCP, TCP_USER_TIMEOUT,
 #endif
         },
+        [sk_mptcp_26] = { "MPTCP_ENABLED (26)", 1, IPPROTO_TCP, 26 },
+        [sk_mptcp_42] = { "MPTCP_ENABLED (42)", 1, IPPROTO_TCP, 42 },
     };
 
     if (!opts[opt].present) {
         gt_na(opts[opt].name);
-        return;
+        errno = EINVAL;
+        return -1;
     }
 
-    if (setsockopt(fd, opts[opt].level, opts[opt].option, val, len)==-1)
+    int ret = setsockopt(fd, opts[opt].level, opts[opt].option, val, len);
+
+    if (ret==-1) {
+        int err = errno;
         gt_log("couldn't set socket option `%s'\n", opts[opt].name);
+        errno = err;
+    }
+
+    return ret;
 }
 
-static void sk_set_int (int fd, enum sk_opt opt, int val)
+static int sk_set_int (int fd, enum sk_opt opt, int val)
 {
     return sk_set(fd, opt, &val, sizeof(val));
 }
 
+static void sk_set_mptcp (int fd)
+{
+    if (sk_set_int(fd, sk_mptcp_42, 1)==-1)
+        sk_set_int(fd, sk_mptcp_26, 1);
+}
+
 static int sk_listen (int fd, struct addrinfo *ai)
 {
     sk_set_int(fd, sk_reuseaddr, 1);
 
+    if (gt.mptcp)
+        sk_set_mptcp(fd);
+
     if (bind(fd, ai->ai_addr, ai->ai_addrlen)==-1) {
         perror("bind");
         return -1;
@@ -204,6 +237,9 @@ static int sk_connect (int fd, struct addrinfo *ai)
 {
     fd_set_nonblock(fd);
 
+    if (gt.mptcp)
+        sk_set_mptcp(fd);
+
     int ret = connect(fd, ai->ai_addr, ai->ai_addrlen);
 
     if (ret==-1) {
@@ -258,8 +294,11 @@ static int sk_accept (int fd)
 
     int ret = accept(fd, (struct sockaddr *)&addr, &addr_size);
 
-    if (ret==-1 && errno!=EINTR)
+    if (ret==-1) {
+        if (errno!=EINTR)
             perror("accept");
+        return -1;
+    }
 
     fd_set_nonblock(ret);
 
@@ -346,10 +385,10 @@ static void gt_sa_handler (int sig)
     case SIGINT:
     case SIGQUIT:
     case SIGTERM:
-        gt_close = 1;
+        gt.quit = 1;
         break;
     case SIGUSR1:
-        gt_info = 1;
+        gt.info = 1;
         break;
     }
 }
@@ -480,7 +519,7 @@ static int gt_encrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
     if (!rs || !ws)
         return 0;
 
-    const size_t size = rs+crypto_aead_aes256gcm_ABYTES;
+    const size_t size = rs+GT_ABYTES;
 
     if (size+2>ws)
         return 0;
@@ -488,14 +527,25 @@ static int gt_encrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
     dst->write[0] = 0xFF&(size>>8);
     dst->write[1] = 0xFF&(size);
 
+    if (ctx->chacha) {
+        crypto_aead_chacha20poly1305_encrypt(
+                dst->write+2, NULL,
+                src->read, rs,
+                dst->write, 2,
+                NULL, ctx->write.nonce,
+                ctx->write.key);
+
+        sodium_increment(ctx->write.nonce, crypto_aead_chacha20poly1305_NPUBBYTES);
+    } else {
         crypto_aead_aes256gcm_encrypt_afternm(
                 dst->write+2, NULL,
                 src->read, rs,
                 dst->write, 2,
                 NULL, ctx->write.nonce,
-            (const crypto_aead_aes256gcm_state *)&ctx->write.state);
+                (const crypto_aead_aes256gcm_state *)ctx->write.key);
 
         sodium_increment(ctx->write.nonce, crypto_aead_aes256gcm_NPUBBYTES);
+    }
 
     src->read += rs;
     dst->write += size+2;
@@ -511,30 +561,43 @@ static int gt_decrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
     if (!rs || !ws)
         return 0;
 
-    if (rs<=2+crypto_aead_aes256gcm_ABYTES)
+    if (rs<=2+GT_ABYTES)
         return 0;
 
     const size_t size = (src->read[0]<<8)|src->read[1];
 
-    if (size-crypto_aead_aes256gcm_ABYTES>ws)
+    if (size-GT_ABYTES>ws)
         return 0;
 
     if (size+2>rs)
         return 0;
 
+    if (ctx->chacha) {
+        if (crypto_aead_chacha20poly1305_decrypt(
+                    dst->write, NULL,
+                    NULL,
+                    src->read+2, size,
+                    src->read, 2,
+                    ctx->read.nonce,
+                    ctx->read.key))
+            return -1;
+
+        sodium_increment(ctx->read.nonce, crypto_aead_chacha20poly1305_NPUBBYTES);
+    } else {
         if (crypto_aead_aes256gcm_decrypt_afternm(
                     dst->write, NULL,
                     NULL,
                     src->read+2, size,
                     src->read, 2,
                     ctx->read.nonce,
-                (const crypto_aead_aes256gcm_state *)&ctx->read.state))
+                    (const crypto_aead_aes256gcm_state *)ctx->read.key))
             return -1;
 
         sodium_increment(ctx->read.nonce, crypto_aead_aes256gcm_NPUBBYTES);
+    }
 
     src->read += size+2;
-    dst->write += size-crypto_aead_aes256gcm_ABYTES;
+    dst->write += size-GT_ABYTES;
 
     return 0;
 }
@@ -772,10 +835,11 @@ 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];
+    char ip0[INET6_ADDRSTRLEN] = {0};
+    char ip1[INET6_ADDRSTRLEN] = {0};
 
-    uint16_t port0, port1;
+    uint16_t port0 = 0;
+    uint16_t port1 = 0;
 
     switch (size) {
     case 8+4:
@@ -942,6 +1006,81 @@ static int gt_track (uint8_t **db, struct ip_common *ic, uint8_t *data, int rev)
     return 0;
 }
 
+static unsigned long long gt_now (void)
+{
+#if defined __APPLE__
+    static mach_timebase_info_data_t mtid;
+    if (!mtid.denom) mach_timebase_info(&mtid);
+    return (mach_absolute_time()*mtid.numer/mtid.denom)/1000ULL;
+#elif defined CLOCK_MONOTONIC
+    struct timespec tv;
+    clock_gettime(CLOCK_MONOTONIC, &tv);
+    return tv.tv_sec*1000000ULL+tv.tv_nsec/1000ULL;
+#else
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return tv.tv_sec*1000000ULL+tv.tv_usec;
+#endif
+}
+
+static void gt_bench (int chacha)
+{
+    unsigned char npub[crypto_aead_aes256gcm_NPUBBYTES];
+    memset(npub, 0, sizeof(npub));
+
+    unsigned char key[crypto_aead_aes256gcm_KEYBYTES];
+    memset(key, 1, sizeof(key));
+
+    crypto_aead_aes256gcm_state ctx;
+
+    if (!chacha)
+        crypto_aead_aes256gcm_beforenm(&ctx, key);
+
+    gt_print("bench: %s\n", chacha?"chacha20poly1305":"aes256gcm");
+
+    _align_(16) unsigned char buf[32*1024+crypto_aead_aes256gcm_ABYTES];
+
+    size_t bs = 8;
+
+    while (!gt.quit && bs<=sizeof(buf)) {
+        size_t total_size = 0;
+        unsigned long long total_dt = 0.0;
+        double mbps = 0.0;
+
+        while (!gt.quit) {
+            unsigned long long now = gt_now();
+
+            size_t size = 0;
+
+            while (!gt.quit && size<16*1024*1024) {
+                if (chacha) {
+                    crypto_aead_chacha20poly1305_encrypt(buf, NULL,
+                            buf, bs, NULL, 0, NULL, npub, key);
+                } else {
+                    crypto_aead_aes256gcm_encrypt_afternm(buf, NULL,
+                            buf, bs, NULL, 0, NULL, npub,
+                            (const crypto_aead_aes256gcm_state *)&ctx);
+                }
+                size += bs;
+            }
+
+            total_dt += gt_now()-now;
+            total_size += size;
+
+            double last_mbps = mbps;
+            mbps = total_size*8.0/total_dt;
+
+            double diff = mbps-last_mbps;
+
+            if (-0.1<diff && diff<0.1)
+                break;
+        }
+
+        gt_print("%6zu bytes %9.2f Mbps\n", bs, mbps);
+        bs *= 2;
+    }
+}
+
 static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 {
     const size_t size = sizeof(ctx->skey);
@@ -951,7 +1090,7 @@ static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 
         randombytes_buf(ctx->skey, size);
         gt_tohex(buf, sizeof(buf), ctx->skey, size);
-        state("SECRETKEY", buf);
+        state_send(gt.state_fd, "SECRETKEY", buf);
 
         return 0;
     }
@@ -987,17 +1126,16 @@ static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 
 static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
 {
-    const uint8_t gt[] = {'G', 'T', VERSION_MAJOR, 0 };
+    const uint8_t proto[] = {'G', 'T', VERSION_MAJOR, (uint8_t)ctx->chacha };
 
     const size_t size = 96;
     const size_t hash_size = 32;
 
-    const size_t nonce_size = crypto_aead_aes256gcm_NPUBBYTES;
-    const size_t public_size = crypto_scalarmult_SCALARBYTES;
-
     uint8_t secret[crypto_scalarmult_SCALARBYTES];
     uint8_t shared[crypto_scalarmult_BYTES];
-    uint8_t key[crypto_aead_aes256gcm_KEYBYTES];
+
+    uint8_t key_r[GT_KEYBYTES];
+    uint8_t key_w[GT_KEYBYTES];
 
     uint8_t data_r[size], data_w[size];
     uint8_t auth_r[hash_size], auth_w[hash_size];
@@ -1006,12 +1144,11 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
     crypto_generichash_state state;
 
     memset(data_w, 0, size);
-    randombytes_buf(data_w, nonce_size);
 
     randombytes_buf(secret, sizeof(secret));
-    crypto_scalarmult_base(&data_w[nonce_size], secret);
+    crypto_scalarmult_base(data_w, secret);
 
-    memcpy(&data_w[size-hash_size-sizeof(gt)], gt, sizeof(gt));
+    memcpy(&data_w[size-hash_size-sizeof(proto)], proto, sizeof(proto));
 
     crypto_generichash(&data_w[size-hash_size], hash_size,
             data_w, size-hash_size, ctx->skey, sizeof(ctx->skey));
@@ -1022,14 +1159,26 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
     if (fd_read_all(fd, data_r, size)!=size)
         return -1;
 
-    if (memcmp(&data_r[size-hash_size-sizeof(gt)], gt, sizeof(gt)))
+    if (memcmp(&data_r[size-hash_size-sizeof(proto)], proto, 3)) {
+        gt_log("bad packet [%02"PRIX8"%02"PRIX8"%02"PRIX8"] !\n",
+            &data_r[size-hash_size-sizeof(proto)+0],
+            &data_r[size-hash_size-sizeof(proto)+1],
+            &data_r[size-hash_size-sizeof(proto)+2]);
         return -2;
+    }
+
+    if (data_r[size-hash_size-sizeof(proto)+3] && !ctx->chacha) {
+        gt_log("peer wants chacha20\n");
+        ctx->chacha = 1;
+    }
 
     crypto_generichash(hash, hash_size,
             data_r, size-hash_size, ctx->skey, sizeof(ctx->skey));
 
-    if (sodium_memcmp(&data_r[size-hash_size], hash, hash_size))
+    if (sodium_memcmp(&data_r[size-hash_size], hash, hash_size)) {
+        gt_log("peer sends a bad hash!\n");
         return -2;
+    }
 
     if (listener && fd_write_all(fd, data_w, size)!=size)
         return -1;
@@ -1046,32 +1195,43 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
     crypto_generichash(hash, hash_size,
             data_w, size, ctx->skey, sizeof(ctx->skey));
 
-    if (sodium_memcmp(auth_r, hash, hash_size))
+    if (sodium_memcmp(auth_r, hash, hash_size)) {
+        gt_log("peer sends a bad hash (challenge-response)!\n");
         return -2;
+    }
 
-    if (crypto_scalarmult(shared, secret, &data_r[nonce_size]))
+    if (crypto_scalarmult(shared, secret, data_r)) {
+        gt_log("I'm just gonna hurt you really, really, BAD\n");
         return -2;
+    }
 
-    crypto_generichash_init(&state, ctx->skey, sizeof(ctx->skey), sizeof(key));
+    crypto_generichash_init(&state, ctx->skey, sizeof(ctx->skey), sizeof(key_r));
     crypto_generichash_update(&state, shared, sizeof(shared));
     crypto_generichash_update(&state, data_r, size);
     crypto_generichash_update(&state, data_w, size);
-    crypto_generichash_final(&state, key, sizeof(key));
-    crypto_aead_aes256gcm_beforenm(&ctx->read.state, key);
+    crypto_generichash_final(&state, key_r, sizeof(key_r));
 
-    crypto_generichash_init(&state, ctx->skey, sizeof(ctx->skey), sizeof(key));
+    crypto_generichash_init(&state, ctx->skey, sizeof(ctx->skey), sizeof(key_w));
     crypto_generichash_update(&state, shared, sizeof(shared));
     crypto_generichash_update(&state, data_w, size);
     crypto_generichash_update(&state, data_r, size);
-    crypto_generichash_final(&state, key, sizeof(key));
-    crypto_aead_aes256gcm_beforenm(&ctx->write.state, key);
+    crypto_generichash_final(&state, key_w, sizeof(key_w));
+
+    if (ctx->chacha) {
+        memcpy(ctx->read.key, key_r, sizeof(key_r));
+        memcpy(ctx->write.key, key_w, sizeof(key_w));
+    } else {
+        crypto_aead_aes256gcm_beforenm(&ctx->read.key, key_r);
+        crypto_aead_aes256gcm_beforenm(&ctx->write.key, key_w);
+    }
 
     sodium_memzero(secret, sizeof(secret));
     sodium_memzero(shared, sizeof(shared));
-    sodium_memzero(key, sizeof(key));
+    sodium_memzero(key_r, sizeof(key_r));
+    sodium_memzero(key_w, sizeof(key_w));
 
-    memcpy(ctx->read.nonce, data_r, nonce_size);
-    memcpy(ctx->write.nonce, data_w, nonce_size);
+    memset(ctx->read.nonce, 0, sizeof(ctx->read.nonce));
+    memset(ctx->write.nonce, 0, sizeof(ctx->write.nonce));
 
     return 0;
 }
@@ -1130,6 +1290,9 @@ int main (int argc, char **argv)
         { "retry",       &retry_opts,   option_option },
         { "statefile",   &statefile,    option_str    },
         { "timeout",     &gt.timeout,   option_long   },
+        { "bench",       NULL,          option_option },
+        { "chacha20",    NULL,          option_option },
+        { "mptcp",       NULL,          option_option },
         { "debug",       NULL,          option_option },
         { "version",     NULL,          option_option },
         { NULL },
@@ -1149,6 +1312,25 @@ int main (int argc, char **argv)
     const int noquickack = option_is_set(opts, "noquickack");
     const int debug = option_is_set(opts, "debug");
 
+    int chacha = option_is_set(opts, "chacha20");
+
+    gt.mptcp = option_is_set(opts, "mptcp");
+
+    if (sodium_init()==-1) {
+        gt_log("libsodium initialization has failed\n");
+        return 1;
+    }
+
+    if (!chacha && !crypto_aead_aes256gcm_is_available()) {
+        gt_na("AES-256-GCM");
+        chacha = 1;
+    }
+
+    if (option_is_set(opts, "bench")) {
+        gt_bench(chacha);
+        return 0;
+    }
+
     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);
@@ -1169,22 +1351,14 @@ int main (int argc, char **argv)
         return 1;
     }
 
-    if (sodium_init()==-1) {
-        gt_log("libsodium initialization has failed\n");
-        return 1;
-    }
-
-    if (!crypto_aead_aes256gcm_is_available()) {
-        gt_na("AES-256-GCM");
-        return 1;
-    }
-
     struct addrinfo *ai = ai_create(host, port, listener);
 
     if (!ai)
         return 1;
 
-    if (state_init(statefile))
+    gt.state_fd = state_create(statefile);
+
+    if (statefile && gt.state_fd==-1)
         return 1;
 
     struct fdbuf tun  = { .fd = -1 };
@@ -1224,9 +1398,9 @@ int main (int argc, char **argv)
     long retry = 0;
     uint8_t *db = NULL;
 
-    state("INITIALIZED", tun_name);
+    state_send(gt.state_fd, "INITIALIZED", tun_name);
 
-    while (!gt_close) {
+    while (!gt.quit) {
         if (retry_count>=0 && retry>=retry_count+1) {
             gt_log("couldn't %s (%d attempt%s)\n", listener?"listen":"connect",
                    (int)retry, (retry>1)?"s":"");
@@ -1277,20 +1451,16 @@ int main (int argc, char **argv)
         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)) {
-        case -2:
-            gt_log("%s: key exchange could not be verified!\n", sockname);
-            goto restart;
-        case -1:
+        ctx.chacha = chacha;
+
+        if (gt_setup_crypto(&ctx, sock.fd, listener)) {
             gt_log("%s: key exchange failed\n", sockname);
             goto restart;
-        default:
-            break;
         }
 
         retry = 0;
 
-        state("STARTED", sockname);
+        state_send(gt.state_fd, "STARTED", tun_name);
 
         fd_set rfds;
         FD_ZERO(&rfds);
@@ -1301,7 +1471,7 @@ int main (int argc, char **argv)
         buffer_format(&sock.read);
 
         while (1) {
-            if _0_(gt_close)
+            if _0_(gt.quit)
                 stop_loop |= 1;
 
             if _0_(stop_loop) {
@@ -1328,9 +1498,12 @@ int main (int argc, char **argv)
             }
 
             struct timeval timeout = {
-                .tv_usec = 1000,
+                .tv_usec = 100000,
             };
 
+            if (buffer_read_size(&sock.write))
+                timeout.tv_usec = 1000;
+
             if _0_(select(sock.fd+1, &rfds, NULL, NULL, &timeout)==-1) {
                 if (errno==EINTR)
                     continue;
@@ -1352,7 +1525,7 @@ int main (int argc, char **argv)
                     const ssize_t r = tun_read(tun.fd, tun.read.write, GT_MTU_MAX);
 
                     if (r<=0) {
-                        gt_close |= !r;
+                        gt.quit |= !r;
                         break;
                     }
 
@@ -1448,7 +1621,7 @@ int main (int argc, char **argv)
                     if (r==ic.size)
                         tun.write.read += r;
                 } else {
-                    gt_close |= !r;
+                    gt.quit |= !r;
                     break;
                 }
             }
@@ -1460,7 +1633,7 @@ int main (int argc, char **argv)
             sock.fd = -1;
         }
 
-        state("STOPPED", sockname);
+        state_send(gt.state_fd, "STOPPED", tun_name);
 
         if (sockname) {
             free(sockname);

src/state.c

@@ -7,16 +7,14 @@
 #include <fcntl.h>
 #include <sys/stat.h>
 
-static int state_fd = -1;
-
-int state_init (const char *filename)
+int state_create (const char *filename)
 {
     if (str_empty(filename))
-        return 0;
+        return -1;
 
-    state_fd = open(filename, O_WRONLY);
+    int fd = open(filename, O_WRONLY);
 
-    if (state_fd==-1) {
+    if (fd==-1) {
         if (errno!=EINTR)
             perror("open");
         return -1;
@@ -24,38 +22,41 @@ int state_init (const char *filename)
 
     struct stat st = {0};
 
-    if (fstat(state_fd, &st)==-1) {
+    if (fstat(fd, &st)==-1) {
         perror("fstat");
-        close(state_fd);
-        state_fd = -1;
+        close(fd);
         return -1;
     }
 
     if (!S_ISFIFO(st.st_mode)) {
         gt_log("`%s' is not a fifo\n", filename);
-        close(state_fd);
-        state_fd = -1;
+        close(fd);
         return -1;
     }
 
-    return 0;
+    return fd;
 }
 
-void state (const char *state, const char *info)
+void state_send (int fd, const char *state, const char *info)
 {
     if (str_empty(state))
         return;
 
+    if (fd==-1) {
+        gt_print("%s %s\n", state, info);
+        return;
+    }
+
     const char *strs[] = { state, " ", info, "\n" };
     char *str = str_cat(strs, COUNT(strs));
 
-    if (!str)
+    if (!str) {
+        perror("str_cat");
         return;
-
-    if (state_fd==-1) {
-        gt_print("%s", str);
-    } else {
-        if (write(state_fd, str, str_len(str))==-1 && errno!=EINTR)
-            perror("write");
     }
+
+    if (write(fd, str, str_len(str))==-1 && errno!=EINTR)
+        perror("write");
+
+    free(str);
 }

src/state.h

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