fix the buff offset

src/udprelay.c

@@ -622,7 +622,6 @@ static void server_recv_cb (EV_P_ ev_io *w, int revents)
 
     if (remote_ctx == NULL)
     {
-
         struct addrinfo hints;
         struct addrinfo *result;
 
@@ -667,8 +666,8 @@ static void server_recv_cb (EV_P_ ev_io *w, int revents)
         freeaddrinfo(result);
     }
 
-    buf_len -= 3;
-    memmove(buf, buf + 3, buf_len);
+    buf_len -= offset;
+    memmove(buf, buf + offset, buf_len);
 
     buf = ss_encrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method);
 
@@ -681,9 +680,6 @@ static void server_recv_cb (EV_P_ ev_io *w, int revents)
 
 #else
 
-    buf_len -= (offset + addr_header_len);
-    memmove(buf, buf + (offset + addr_header_len), buf_len);
-
     if (remote_ctx == NULL)
     {
         struct addrinfo hints;
@@ -701,7 +697,8 @@ static void server_recv_cb (EV_P_ ev_io *w, int revents)
             goto CLEAN_UP;
         }
 
-        struct query_ctx *query_ctx = new_query_ctx(query, buf, buf_len);
+        struct query_ctx *query_ctx = new_query_ctx(query, buf + addr_header_len,
+                buf_len - addr_header_len);
         query_ctx->server_ctx = server_ctx;
         query_ctx->addr_header_len = addr_header_len;
         query_ctx->src_addr = src_addr;
@@ -713,7 +710,8 @@ static void server_recv_cb (EV_P_ ev_io *w, int revents)
     else
     {
 
-        int s = sendto(remote_ctx->fd, buf, buf_len, 0, &remote_ctx->dst_addr, sizeof(remote_ctx->dst_addr));
+        int s = sendto(remote_ctx->fd, buf + addr_header_len,
+                buf_len - addr_header_len, 0, &remote_ctx->dst_addr, sizeof(remote_ctx->dst_addr));
 
         if (s == -1)
         {