Support TFO

desync.c

@@ -251,22 +251,24 @@ int send_disorder(int sfd,
         char *buffer, long pos, int fa)
 {
     int bttl = 1;
+    int status = 0;
+    
     if (setttl(sfd, bttl, fa) < 0) {
         return -1;
     }
     if (send(sfd, buffer, pos, 0) < 0) {
         uniperror("send");
-        return -1;
+        status = -1;
     }
     if (setttl(sfd, params.def_ttl, fa) < 0) {
         return -1;
     }
-    return 0;
+    return status;
 }
 
 
 int desync(int sfd, char *buffer, size_t bfsize,
-        ssize_t n, struct sockaddr *dst, int dp_c)
+        ssize_t n, ssize_t offset, struct sockaddr *dst, int dp_c)
 {
     struct desync_params dp = params.dp[dp_c];
     
@@ -324,7 +326,7 @@ int desync(int sfd, char *buffer, size_t bfsize,
             return -1;
         }
     }
-    long lp = 0;
+    long lp = offset;
     
     if (!type && params.de_known) {
     }
@@ -347,7 +349,11 @@ int desync(int sfd, char *buffer, size_t bfsize,
         else if (pos < 0) {
             pos += n;
         }
-        if (pos <= 0 || pos >= n || pos <= lp) {
+        // after EAGAIN
+        if (pos <= offset) {
+            continue;
+        }
+        else if (pos <= 0 || pos >= n || pos <= lp) {
             LOG(LOG_E, "split cancel: pos=%ld-%ld, n=%ld\n", lp, pos, n);
             break;
         }
@@ -373,12 +379,13 @@ int desync(int sfd, char *buffer, size_t bfsize,
             
         case DESYNC_SPLIT:
         default:
-            if (send(sfd, buffer + lp, pos - lp, 0) < 0) {
-                uniperror("send");
-                return -1;
-            }
+            s = send(sfd, buffer + lp, pos - lp, 0);
         }
-        if (s) {
+        if (s < 0) {
+            if (part.m != DESYNC_FAKE
+                    && get_e() == EAGAIN) {
+                return lp;
+            }
             return -1;
         }
         lp = pos;
@@ -386,9 +393,12 @@ int desync(int sfd, char *buffer, size_t bfsize,
     if (lp < n) {
         LOG((lp ? LOG_S : LOG_L), "send: pos=%ld-%ld\n", lp, n);
         if (send(sfd, buffer + lp, n - lp, 0) < 0) {
+            if (get_e() == EAGAIN) {
+                return lp;
+            }
             uniperror("send");
             return -1;
         }
     }
-    return 0;
+    return n;
 }

desync.h

@@ -1 +1 @@
-int desync(int sfd, char *buffer, size_t bfsize, ssize_t n, struct sockaddr *dst, int dp_c);
+int desync(int sfd, char *buffer, size_t bfsize, ssize_t n, ssize_t offset, struct sockaddr *dst, int dp_c);

main.c

@@ -16,6 +16,7 @@
     #include <unistd.h>
     #include <netdb.h>
     #include <fcntl.h>
+    #include <netinet/tcp.h>
 #else
     #include <ws2tcpip.h>
     #define close(fd) closesocket(fd)
@@ -42,6 +43,7 @@ struct params params = {
     .custom_ttl = 0,
     .de_known = 0,
     
+    .tfo = 0,
     .timeout = 0,
     .cache_ttl = 100800,
     .ipv6 = 1,
@@ -66,6 +68,9 @@ const char help_text[] = {
     "    -g, --def-ttl <num>       TTL for all outgoing connections\n"
     // desync options
     "    -K, --desync-known        Desync only HTTP and TLS with SNI\n"
+    #ifdef TCP_FASTOPEN_CONNECT
+    "    -F, --tfo                 Enable TCP Fast Open\n"
+    #endif
     "    -A, --auto                Try desync params after this option\n"
     "    -u, --cache-ttl <sec>     Lifetime of cached desync params for IP\n"
     #ifdef TIMEOUT_SUPPORT
@@ -103,6 +108,9 @@ const struct option options[] = {
     {"debug",         1, 0, 'x'},
     
     {"desync-known ", 0, 0, 'K'},
+    #ifdef TCP_FASTOPEN_CONNECT
+    {"tfo ",          0, 0, 'F'},
+    #endif
     {"auto",          0, 0, 'A'},
     {"cache-ttl",     1, 0, 'u'},
     #ifdef TIMEOUT_SUPPORT
@@ -391,6 +399,10 @@ int main(int argc, char **argv)
             params.de_known = 1;
             break;
             
+        case 'F':
+            params.tfo = 1;
+            break;
+            
         case 'A':
             dp = add((void *)&params.dp, &params.dp_count,
                 sizeof(struct desync_params));

params.h

@@ -46,6 +46,7 @@ struct params {
     int def_ttl;
     char custom_ttl;
     
+    char tfo;
     unsigned int timeout;
     long cache_ttl;
     int spos_n;

proxy.c

@@ -333,6 +333,15 @@ int create_conn(struct poolhd *pool,
         return -1;
     }
     #endif
+    #ifdef TCP_FASTOPEN_CONNECT
+    int yes = 1;
+    if (params.tfo && setsockopt(sfd, IPPROTO_TCP,
+            TCP_FASTOPEN_CONNECT, (char *)&yes, sizeof(yes))) {
+        uniperror("setsockopt TCP_FASTOPEN_CONNECT");
+        close(sfd);
+        return -1;
+    }
+    #endif
     int one = 1;
     if (setsockopt(sfd, IPPROTO_TCP,
             TCP_NODELAY, (char *)&one, sizeof(one))) {
@@ -633,7 +642,7 @@ int on_tunnel_check(struct poolhd *pool, struct eval *val,
     ssize_t n = recv(val->fd, buffer, bfsize, 0);
     if (n < 1) {
         uniperror("recv");
-        switch (unie(get_e())) {
+        switch (get_e()) {
             case ECONNRESET:
             case ETIMEDOUT: 
                 break;
@@ -719,10 +728,20 @@ int on_desync(struct poolhd *pool, struct eval *val,
             set_timeout(val->pair->fd, params.timeout)) {
         return -1;
     }
-    if (desync(val->pair->fd, buffer, bfsize, n,
-            (struct sockaddr *)&val->pair->in6, m)) {
+    ssize_t sn = desync(val->pair->fd, buffer, bfsize,
+        n, val->buff.offset, (struct sockaddr *)&val->pair->in6, m);
+    if (sn < 0) {
         return -1;
     }
+    if (sn != n) {
+        val->buff.offset = sn;
+        if (mod_etype(pool, val->pair, POLLOUT, 1)) {
+            uniperror("mod_etype");
+            return -1;
+        }
+        val->pair->type = EV_DESYNC;
+        return 0;
+    }
     val->type = EV_TUNNEL;
     val->pair->type = EV_PRE_TUNNEL;
     return 0;