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], [0.0.9], [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/main.c

@@ -23,7 +23,7 @@
 #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)
@@ -316,7 +316,7 @@ 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:
@@ -338,7 +338,7 @@ static void gt_set_signal (void)
 
     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);
@@ -347,6 +347,7 @@ static void gt_set_signal (void)
     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)
@@ -445,13 +446,13 @@ static ssize_t fd_write_all (int fd, const void *data, size_t size)
 
 static int gt_encrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
 {
-    size_t rs = buffer_read_size(src);
-    size_t ws = buffer_write_size(dst);
+    const size_t rs = buffer_read_size(src);
+    const size_t ws = buffer_write_size(dst);
 
     if (!rs || !ws)
         return 0;
 
-    size_t size = rs+crypto_aead_aes256gcm_ABYTES;
+    const size_t size = rs+crypto_aead_aes256gcm_ABYTES;
 
     if (size+2>ws)
         return 0;
@@ -476,16 +477,16 @@ static int gt_encrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
 
 static int gt_decrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
 {
-    size_t rs = buffer_read_size(src);
-    size_t ws = buffer_write_size(dst);
+    const size_t rs = buffer_read_size(src);
+    const size_t ws = buffer_write_size(dst);
 
     if (!rs || !ws)
         return 0;
 
-    if (rs<=2+16)
+    if (rs<=2+crypto_aead_aes256gcm_ABYTES)
         return 0;
 
-    size_t size = (src->read[0]<<8)|src->read[1];
+    const size_t size = (src->read[0]<<8)|src->read[1];
 
     if (size-crypto_aead_aes256gcm_ABYTES>ws)
         return 0;
@@ -530,7 +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);
 
@@ -649,11 +650,18 @@ int main (int argc, char **argv)
     char *dev = PACKAGE_NAME;
     char *keyfile = NULL;
     char *congestion = NULL;
+
     long buffer_size = GT_BUFFER_SIZE;
+
     long ka_count = -1;
     long ka_idle = -1;
     long ka_interval = -1;
 
+    long retry_count = 0;
+    long retry_slope = 1000;
+    long retry_const = 0;
+    long retry_limit = 1000000;
+
     struct option ka_opts[] = {
         { "count",    &ka_count,    option_long },
         { "idle",     &ka_idle,     option_long },
@@ -661,6 +669,19 @@ 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",    NULL,         option_option },
         { "host",        &host,        option_str    },
@@ -673,7 +694,9 @@ int main (int argc, char **argv)
         { "keepalive",   ka_opts,      option_option },
         { "buffer-size", &buffer_size, option_long   },
         { "noquickack",  NULL,         option_option },
-        { "daemon",      NULL,         option_option },
+        { "retry",       &retry_opts,  option_option },
+        { "daemon",      &daemon_opts, option_option },
+        { "trap",        NULL,         option_option },
         { "version",     NULL,         option_option },
         { NULL },
     };
@@ -686,10 +709,10 @@ int main (int argc, char **argv)
         return 0;
     }
 
-    int listener = option_is_set(opts, "listener");
-    int delay = option_is_set(opts, "delay");
-    int keepalive = option_is_set(opts, "keepalive");
-    int noquickack = option_is_set(opts, "noquickack");
+    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;
@@ -755,19 +778,44 @@ int main (int argc, char **argv)
             perror("fork");
             return 1;
         case 0:
-            if (setsid()==-1)
+            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)
+                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;
         }
 
@@ -799,14 +847,25 @@ int main (int argc, char **argv)
         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 -1: goto restart;
-            default: break;
+        case -2:
+            gt_log("%s: key exchange could not be verified!\n", sockname);
+            goto restart;
+        case -1:
+            gt_log("%s: key exchange failed\n", sockname);
+            goto restart;
+        default:
+            break;
         }
 
-        fd_set rfds, wfds;
+        retry = 0;
+
+        if (option_is_set(opts, "trap"))
+            kill(0, SIGUSR2);
+
+        gt_log("%s: running\n", sockname);
+
+        fd_set rfds;
         FD_ZERO(&rfds);
-        FD_ZERO(&wfds);
 
         int stop_loop = 0;
 
@@ -814,36 +873,47 @@ int main (int argc, char **argv)
         buffer_format(&sock.read);
 
         while (1) {
-            if (gt_close)
+            if _0_(gt_close)
                 stop_loop |= 1;
 
-            if (stop_loop) {
+            if _0_(stop_loop) {
                 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 {
-                FD_SET(tun.fd, &rfds);
+                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;
             }
 
-            FD_CLR(sock.fd, &wfds);
-            FD_CLR(tun.fd, &wfds);
-
          // TODO
          // struct timeval now;
          // gettimeofday(&now, NULL);
 
 #ifdef TCP_INFO
-            if (gt_info) {
+            if _0_(gt_info) {
                 struct tcp_info ti;
 
                 if (sk_get_info(sock.fd, &ti))
@@ -856,26 +926,25 @@ int main (int argc, char **argv)
             if (FD_ISSET(tun.fd, &rfds)) {
                 while (!blks[blk_write].size) {
                     uint8_t *data = blks[blk_write].data;
-                    ssize_t r = tun_read(tun.fd, data, GT_MTU_MAX);
+                    const ssize_t r = tun_read(tun.fd, data, GT_MTU_MAX);
 
                     if (r<=0) {
                         gt_close |= !r;
                         break;
                     }
 
-                    ssize_t ip_size = ip_get_size(data, GT_MTU_MAX);
+                    const ssize_t ip_size = ip_get_size(data, GT_MTU_MAX);
 
-                    if (ip_size<=0)
+                    if _0_(ip_size<=0)
                         continue;
 
-                    if (ip_size!=r) {
+                    if _0_(ip_size!=r) {
                         dump_ip_header(data, r);
 
-                        if (r<ip_size) {
-                            ip_set_size(data, r);
-                        } else {
+                        if (r>ip_size)
                             continue;
-                        }
+
+                        ip_set_size(data, r);
                     }
 
                     blks[blk_write++].size = r;
@@ -886,16 +955,15 @@ int main (int argc, char **argv)
             while (1) {
                 buffer_shift(&tun.read);
 
-                if (!stop_loop) {
+                if _0_(!stop_loop) {
                     for (; blk_count; blk_read++) {
-                        if (!blks[blk_read].size)
+                        const size_t size = blks[blk_read].size;
+
+                        if (!size || buffer_write_size(&tun.read)<size)
                             break;
 
-                        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;
+                        byte_cpy(tun.read.write, blks[blk_read].data, size);
+                        tun.read.write += size;
 
                         blks[blk_read].size = 0;
                         blk_count--;
@@ -907,22 +975,19 @@ int main (int argc, char **argv)
                 if (!buffer_read_size(&sock.write))
                     break;
 
-                ssize_t r = fd_write(sock.fd, sock.write.read,
-                                     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) {
+                    if (!r)
                         stop_loop |= (1<<2);
-                    } else {
-                        FD_SET(sock.fd, &wfds);
-                    }
                     break;
                 }
             }
 
-            if (stop_loop && !buffer_read_size(&sock.write)) {
+            if _0_(stop_loop && !buffer_read_size(&sock.write)) {
                 if (!(stop_loop&(1<<2))) {
                     stop_loop |= (1<<2);
                     shutdown(sock.fd, SHUT_WR);
@@ -931,14 +996,13 @@ int main (int argc, char **argv)
             }
 
             buffer_shift(&sock.write);
-            buffer_shift(&sock.read);
 
             if (FD_ISSET(sock.fd, &rfds)) {
                 if (noquickack)
                     sk_set_int(sock.fd, sk_quickack, 0);
 
-                ssize_t r = fd_read(sock.fd, sock.read.write,
-                                    buffer_write_size(&sock.read));
+                const ssize_t r = fd_read(sock.fd, sock.read.write,
+                                          buffer_write_size(&sock.read));
 
                 if (r>0) {
                     sock.read.write += r;
@@ -948,7 +1012,9 @@ int main (int argc, char **argv)
             }
 
             while (1) {
-                if (gt_decrypt(&ctx, &tun.write, &sock.read)) {
+                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;
                 }
@@ -956,7 +1022,7 @@ int main (int argc, char **argv)
                 size_t size = buffer_read_size(&tun.write);
                 ssize_t ip_size = ip_get_size(tun.write.read, size);
 
-                if (!ip_size) {
+                if _0_(!ip_size) {
                     gt_log("%s: bad packet!\n", sockname);
                     goto restart;
                 }
@@ -970,12 +1036,9 @@ int main (int argc, char **argv)
                     tun.write.read += r;
                 } else {
                     gt_close |= !r;
-                    FD_SET(tun.fd, &wfds);
                     break;
                 }
             }
-
-            buffer_shift(&tun.write);
         }
 
     restart:

src/option.c

@@ -94,18 +94,18 @@ static int option_usage (struct option *opts, int slen)
     if (!opts)
         return 0;
 
-    int len = slen;
+    int len = 0;
 
     for (int k=0; opts[k].name; k++) {
-        if (len>slen+40) {
-            gt_print("\n%*s", (int)slen, "");
-            len = slen;
+        if (len>40) {
+            gt_print("\n%*s", slen, "");
+            len = 0;
         }
 
         len += gt_print(" [%s", opts[k].name);
 
         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");
         }
@@ -132,12 +132,11 @@ int option (struct option *opts, int argc, char **argv)
 
     if (slen>40) {
         slen = 12;
-        gt_print("\n%*s", (int)slen, "");
+        gt_print("\n%*s", slen, "");
     }
 
     option_usage(opts, slen);
-
-    printf("\n");
+    gt_print("\n");
 
     return 1;
 }