Don't wait too long when we have data to send

src/main.c

@@ -20,8 +20,6 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 
-#include <sodium.h>
-
 #include "mud.h"
 
 #ifndef O_CLOEXEC
@@ -29,10 +27,10 @@
 #endif
 
 static struct {
-    int timeout;
     volatile sig_atomic_t quit;
     volatile sig_atomic_t info;
-    uint8_t key[crypto_generichash_KEYBYTES];
+    int timeout;
+    int state_fd;
 } gt;
 
 static void fd_set_nonblock (int fd)
@@ -185,16 +183,19 @@ static size_t fd_write_all (int fd, const void *data, size_t size)
     return done;
 }
 
-static int gt_setup_secretkey (char *keyfile)
+static int gt_setup_secretkey (struct mud *mud, char *keyfile)
 {
-    const size_t size = sizeof(gt.key);
+    unsigned char key[32];
 
     if (str_empty(keyfile)) {
-        char buf[2*size+1];
+        char buf[2*sizeof(key)+1];
+        size_t size = sizeof(key);
 
-        randombytes_buf(gt.key, size);
-        gt_tohex(buf, sizeof(buf), gt.key, size);
-        state("SECRETKEY", buf);
+        if (mud_get_key(mud, key, &size))
+            return -1;
+
+        gt_tohex(buf, sizeof(buf), key, size);
+        state_send(gt.state_fd, "SECRETKEY", buf);
 
         return 0;
     }
@@ -210,21 +211,23 @@ static int gt_setup_secretkey (char *keyfile)
         return -1;
     }
 
-    char key[2*size];
-    size_t r = fd_read_all(fd, key, sizeof(key));
+    char buf[2*sizeof(key)];
+    size_t r = fd_read_all(fd, buf, sizeof(buf));
 
     close(fd);
 
-    if (r!=sizeof(key)) {
+    if (r!=sizeof(buf)) {
         gt_log("unable to read secret key\n");
         return -1;
     }
 
-    if (gt_fromhex(gt.key, size, key, sizeof(key))) {
+    if (gt_fromhex(key, sizeof(key), buf, sizeof(buf))) {
         gt_log("secret key is not valid\n");
         return -1;
     }
 
+    mud_set_key(mud, key, sizeof(key));
+
     return 0;
 }
 
@@ -233,28 +236,38 @@ int main (int argc, char **argv)
     gt_set_signal();
 
     char *host = NULL;
-    char *port = "5000";
+    long port = 5000;
+
     char *bind_list = NULL;
-    char *bind_port = "5000";
+    long bind_port = 5000;
+
     char *dev = NULL;
     char *keyfile = NULL;
     char *statefile = NULL;
 
+    long mtu = 1450;
+
     gt.timeout = 5000;
 
     long time_tolerance = 0;
 
+    int v4 = 1;
+    int v6 = 1;
+
     struct option opts[] = {
         { "host",           &host,           option_str    },
-        { "port",           &port,           option_str    },
+        { "port",           &port,           option_long   },
         { "bind",           &bind_list,      option_str    },
-        { "bind-port",      &bind_port,      option_str    },
+        { "bind-port",      &bind_port,      option_long   },
         { "dev",            &dev,            option_str    },
+        { "mtu",            &mtu,            option_long   },
         { "keyfile",        &keyfile,        option_str    },
         { "multiqueue",     NULL,            option_option },
         { "statefile",      &statefile,      option_str    },
         { "timeout",        &gt.timeout,     option_long   },
         { "time-tolerance", &time_tolerance, option_long   },
+        { "v4only",         NULL,            option_option },
+        { "v6only",         NULL,            option_option },
         { "version",        NULL,            option_option },
         { NULL },
     };
@@ -267,7 +280,18 @@ int main (int argc, char **argv)
         return 0;
     }
 
-    if (!option_is_set(opts, "keyfile")) {
+    if (option_is_set(opts, "v4only"))
+        v6 = 0;
+
+    if (option_is_set(opts, "v6only"))
+        v4 = 0;
+
+    if (!v4 && !v6) {
+        gt_log("v4only and v6only are both set\n");
+        return 1;
+    }
+
+    if (host && !option_is_set(opts, "keyfile")) {
         gt_log("keyfile option must be set\n");
         return 1;
     }
@@ -277,12 +301,9 @@ int main (int argc, char **argv)
         return 1;
     }
 
-    if (sodium_init()==-1) {
-        gt_log("libsodium initialization has failed\n");
-        return 1;
-    }
+    gt.state_fd = state_create(statefile);
 
-    if (state_init(statefile))
+    if (statefile && gt.state_fd==-1)
         return 1;
 
     char *tun_name = NULL;
@@ -296,24 +317,22 @@ int main (int argc, char **argv)
 
     fd_set_nonblock(tun_fd);
 
-    if (gt_setup_secretkey(keyfile))
-        return 1;
-
-    struct mud *mud = mud_create(bind_port);
+    struct mud *mud = mud_create(bind_port, v4, v6);
 
     if (!mud) {
         gt_log("couldn't create mud\n");
         return 1;
     }
 
-    mud_set_key(mud, gt.key, sizeof(gt.key));
+    if (gt_setup_secretkey(mud, keyfile))
+        return 1;
 
     mud_set_send_timeout_msec(mud, gt.timeout);
 
     if (time_tolerance > 0)
         mud_set_time_tolerance_sec(mud, time_tolerance);
 
-    if (bind_list) {
+    if (host && port && bind_list) {
         char tmp[1024];
         char *name = &tmp[0];
 
@@ -325,28 +344,34 @@ int main (int argc, char **argv)
 
             tmp[i] = 0;
 
-            if (mud_bind(mud, name))
+            if (mud_peer(mud, name, host, port))
                 return 1;
 
             name = &tmp[i+1];
         }
 
-        if (name[0] && mud_bind(mud, name))
+        if (name[0] && mud_peer(mud, name, host, port))
             return 1;
     }
 
-    if (host && mud_peer(mud, host, port))
-        return 1;
-
     int mud_fd = mud_get_fd(mud);
 
-    state("INITIALIZED", tun_name);
+    state_send(gt.state_fd, "INITIALIZED", tun_name);
 
     fd_set rfds;
     FD_ZERO(&rfds);
 
     int started = 0;
-    unsigned char buf[2048];
+
+    struct {
+        unsigned char *buf;
+    } send, recv;
+
+    send.buf = malloc(2*mtu);
+    recv.buf = malloc(mtu);
+
+    size_t send_size = 0;
+    size_t send_limit = 0;
 
     while (!gt.quit) {
         FD_SET(tun_fd, &rfds);
@@ -361,7 +386,7 @@ int main (int argc, char **argv)
             .tv_usec = 100000,
         };
 
-        if (mud_can_push(mud))
+        if (mud_can_push(mud) || send_size)
             timeout.tv_usec = 1000;
 
         if _0_(select(mud_fd+1, &rfds, NULL, NULL, &timeout)==-1) {
@@ -373,19 +398,19 @@ int main (int argc, char **argv)
 
         if (mud_is_up(mud)) {
             if (!started) {
-                state("STARTED", tun_name);
+                state_send(gt.state_fd, "STARTED", tun_name);
                 started = 1;
             }
         } else {
             if (started) {
-                state("STOPPED", tun_name);
+                state_send(gt.state_fd, "STOPPED", tun_name);
                 started = 0;
             }
         }
 
         if (FD_ISSET(tun_fd, &rfds)) {
-            while (1) {
-                const ssize_t r = tun_read(tun_fd, buf, sizeof(buf));
+            while (send_size<mtu) {
+                const ssize_t r = tun_read(tun_fd, send.buf+send_size, mtu);
 
                 if (r<=0) {
                     gt.quit |= !r;
@@ -394,9 +419,23 @@ int main (int argc, char **argv)
 
                 struct ip_common ic;
 
-                if (!ip_get_common(&ic, buf, sizeof(buf)) && ic.size==r)
-                    mud_send(mud, buf, r);
+                if (ip_get_common(&ic, send.buf+send_size, mtu) || ic.size!=r) {
+                    gt_log("packet dropped: malformed\n");
+                    continue;
                 }
+
+                send_size += r;
+
+                if (send_size<=mtu)
+                    send_limit = send_size;
+            }
+        }
+
+        if (send_limit && mud_send(mud, send.buf, send_limit)==send_limit) {
+            if (send_size>send_limit)
+                memmove(&send.buf[0], &send.buf[send_limit], send_size-send_limit);
+            send_size -= send_limit;
+            send_limit = send_size;
         }
 
         mud_push(mud);
@@ -404,18 +443,29 @@ int main (int argc, char **argv)
         if (FD_ISSET(mud_fd, &rfds))
             mud_pull(mud);
 
-        while (1) {
-            const int size = mud_recv(mud, buf, sizeof(buf));
+        while (!gt.quit) {
+            const int size = mud_recv(mud, recv.buf, mtu);
 
             if (size<=0)
                 break;
 
-            const ssize_t r = tun_write(tun_fd, buf, size);
+            int p = 0;
+
+            while (p<size) {
+                struct ip_common ic;
+
+                if (ip_get_common(&ic, recv.buf+p, size-p) || ic.size>size-p)
+                    break;
+
+                const ssize_t r = tun_write(tun_fd, recv.buf+p, ic.size);
 
                 if (r<=0) {
                     gt.quit |= !r;
                     break;
                 }
+
+                p += ic.size;
+            }
         }
     }
 

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 *);