cleaned up main_loop

1 files changed, 93 insertions, 78 deletions

diff --git a/src/uanytun.c b/src/uanytun.c
index 609a873..b857afd 100644
--- a/src/uanytun.c
+++ b/src/uanytun.c
@@ -93,11 +93,11 @@ int init_libgcrypt()
 #endif
 #endif
 
-#ifndef NO_CRYPT
-int init_main_loop(options_t* opt, cipher_t* c, auth_algo_t* aa, key_derivation_t* kd_in, key_derivation_t* kd_out, seq_win_t* seq_win)
-#else
-int init_main_loop(options_t* opt, cipher_t* c, key_derivation_t* kd_in, key_derivation_t* kd_out, seq_win_t* seq_win)
+#ifdef NO_CRYPT
+typedef u_int8_t auth_algo_t;
 #endif
+
+int init_main_loop(options_t* opt, cipher_t* c, auth_algo_t* aa, key_derivation_t* kd_in, key_derivation_t* kd_out, seq_win_t* seq_win)
 {
   int ret = cipher_init(c, opt->cipher_);
   if(ret) {
@@ -145,6 +145,91 @@ int init_main_loop(options_t* opt, cipher_t* c, key_derivation_t* kd_in, key_der
   return 0;
 }
 
+int process_tun_data(tun_device_t* dev, udp_socket_t* sock, options_t* opt, plain_packet_t* plain_packet, encrypted_packet_t* encrypted_packet,
+                     cipher_t* c, auth_algo_t* aa, key_derivation_t* kd_out, seq_nr_t seq_nr)
+{
+  int len = tun_read(dev, plain_packet_get_payload(plain_packet), plain_packet_get_payload_length(plain_packet));
+  if(len == -1) {
+    log_printf(ERR, "error on reading from device: %m");
+    return 0;
+  }
+  
+  plain_packet_set_payload_length(plain_packet, len);
+  
+  if(dev->type_ = TYPE_TUN)
+    plain_packet_set_type(plain_packet, PAYLOAD_TYPE_TUN);
+  else if(dev->type_ = TYPE_TAP)
+    plain_packet_set_type(plain_packet, PAYLOAD_TYPE_TAP);    
+  else
+    plain_packet_set_type(plain_packet, PAYLOAD_TYPE_UNKNOWN);
+  
+  cipher_encrypt(c, kd_out, plain_packet, encrypted_packet, seq_nr, opt->sender_id_, opt->mux_); 
+  
+#ifndef NO_CRYPT
+  auth_algo_generate(aa, kd_out, encrypted_packet);
+#endif
+  
+  len = udp_write(sock, encrypted_packet_get_packet(encrypted_packet), encrypted_packet_get_length(encrypted_packet));
+  if(len == -1)
+    log_printf(ERR, "error on sending udp packet: %m");
+
+  return 0;
+}
+
+int process_sock_data(tun_device_t* dev, udp_socket_t* sock, options_t* opt, plain_packet_t* plain_packet, encrypted_packet_t* encrypted_packet,
+                      cipher_t* c, auth_algo_t* aa, key_derivation_t* kd_in, seq_win_t* seq_win)
+{
+  udp_endpoint_t remote;
+  memset(&remote, 0, sizeof(udp_endpoint_t));
+  int len = udp_read(sock, encrypted_packet_get_packet(encrypted_packet), encrypted_packet_get_length(encrypted_packet), &remote);
+  if(len == -1) {
+    log_printf(ERR, "error on receiving udp packet: %m");
+    return 0;
+  }
+  
+  encrypted_packet_set_length(encrypted_packet, len);
+  
+#ifndef NO_CRYPT
+  if(!auth_algo_check_tag(aa, kd_in, encrypted_packet)) {
+    log_printf(WARNING, "wrong authentication tag, discarding packet");
+    return 0;
+  }
+#endif
+  
+  if(encrypted_packet_get_mux(encrypted_packet) != opt->mux_) {
+    log_printf(WARNING, "wrong mux value, discarding packet");
+    return 0;
+  }
+  
+  int result = seq_win_check_and_add(seq_win, encrypted_packet_get_sender_id(encrypted_packet), encrypted_packet_get_seq_nr(encrypted_packet));
+  if(result > 0) {
+    log_printf(WARNING, "detected replay attack, discarding packet");
+    return 0;
+  }
+  else if(result < 0) {
+    log_printf(ERR, "memory error at sequence window");
+    return -2;
+  }
+   
+  if(memcmp(&remote, &(sock->remote_end_), sizeof(remote))) {
+    memcpy(&(sock->remote_end_), &remote, sizeof(remote));
+    char* addrstring = udp_endpoint_to_string(remote);
+    log_printf(NOTICE, "autodetected remote host changed %s", addrstring);
+    free(addrstring);
+  }
+  
+  int ret = cipher_decrypt(c, kd_in, encrypted_packet, plain_packet); 
+  if(ret) 
+    return ret;
+ 
+  len = tun_write(dev, plain_packet_get_payload(plain_packet), plain_packet_get_payload_length(plain_packet));
+  if(len == -1)
+    log_printf(ERR, "error on writing to device: %m");
+  
+  return 0;
+}
+
+
 int main_loop(tun_device_t* dev, udp_socket_t* sock, options_t* opt)
 {
   log_printf(INFO, "entering main loop");
@@ -153,23 +238,15 @@ int main_loop(tun_device_t* dev, udp_socket_t* sock, options_t* opt)
   plain_packet_init(&plain_packet);
   encrypted_packet_t encrypted_packet;
   encrypted_packet_init(&encrypted_packet);
-  int len = 0;
-  udp_endpoint_t remote;
   seq_nr_t seq_nr = 0;
   fd_set readfds;
 
   cipher_t c;
-#ifndef NO_CRYPT
   auth_algo_t aa;
-#endif
   key_derivation_t kd_in, kd_out;
   seq_win_t seq_win;
 
-#ifndef NO_CRYPT
   int ret = init_main_loop(opt, &c, &aa, &kd_in, &kd_out, &seq_win);
-#else
-  int ret = init_main_loop(opt, &c, &kd_in, &kd_out, &seq_win);
-#endif
   if(ret)
     return ret;
 
@@ -198,76 +275,14 @@ int main_loop(tun_device_t* dev, udp_socket_t* sock, options_t* opt)
     }
 
     if(FD_ISSET(dev->fd_, &readfds)) {
-      len = tun_read(dev, plain_packet_get_payload(&plain_packet), plain_packet_get_payload_length(&plain_packet));
-      if(len == -1) {
-        log_printf(ERR, "error on reading from device: %m");
-        continue;
-      }
-
-      plain_packet_set_payload_length(&plain_packet, len);
-      
-      if(dev->type_ = TYPE_TUN)
-        plain_packet_set_type(&plain_packet, PAYLOAD_TYPE_TUN);
-      else if(dev->type_ = TYPE_TAP)
-        plain_packet_set_type(&plain_packet, PAYLOAD_TYPE_TAP);    
-      else
-        plain_packet_set_type(&plain_packet, PAYLOAD_TYPE_UNKNOWN);
-      
-      cipher_encrypt(&c, &kd_out, &plain_packet, &encrypted_packet, seq_nr, opt->sender_id_, opt->mux_); 
+      return_value = process_tun_data(dev, sock, opt, &plain_packet, &encrypted_packet, &c, &aa, &kd_out, seq_nr);
       seq_nr++;
-      
-#ifndef NO_CRYPT
-      auth_algo_generate(&aa, &kd_out, &encrypted_packet);
-#endif
-      
-      len = udp_write(sock, encrypted_packet_get_packet(&encrypted_packet), encrypted_packet_get_length(&encrypted_packet));
-      if(len == -1)
-        log_printf(ERR, "error on sending udp packet: %m");
+      continue;
     }
 
     if(FD_ISSET(sock->fd_, &readfds)) {
-      len = udp_read(sock, encrypted_packet_get_packet(&encrypted_packet), encrypted_packet_get_length(&encrypted_packet), &remote);
-      if(len == -1) {
-        log_printf(ERR, "error on receiving udp packet: %m");
-        continue;
-      }
-
-      encrypted_packet_set_length(&encrypted_packet, len);
-
-#ifndef NO_CRYPT
-      if(!auth_algo_check_tag(&aa, &kd_out, &encrypted_packet)) {
-        log_printf(WARNING, "wrong authentication tag, discarding packet");
-        continue;
-      }
-#endif
-      
-      if(encrypted_packet_get_mux(&encrypted_packet) != opt->mux_)
-        continue;
-      
-      int result = seq_win_check_and_add(&seq_win, encrypted_packet_get_sender_id(&encrypted_packet), encrypted_packet_get_seq_nr(&encrypted_packet));
-      if(result > 0) {
-        log_printf(WARNING, "detected replay attack, discarding packet");
-        continue;
-      }
-      else if(result < 0) {
-        log_printf(ERR, "memory error at sequence window");
-        return_value -1;
-        break;
-      }
-      
-
-      if(memcmp(&remote, &(sock->remote_end_), sizeof(remote))) {
-        memcpy(&(sock->remote_end_), &remote, sizeof(remote));
-        char* addrstring = udp_endpoint_to_string(remote);
-        log_printf(NOTICE, "autodetected remote host changed %s", addrstring);
-        free(addrstring);
-      }
-      
-      cipher_decrypt(&c, &kd_in, &encrypted_packet, &plain_packet); 
-      
-      len = tun_write(dev, plain_packet_get_payload(&plain_packet), plain_packet_get_payload_length(&plain_packet));
-      if(len == -1)
-        log_printf(ERR, "error on writing to device: %m");
+      return_value = process_sock_data(dev, sock, opt, &plain_packet, &encrypted_packet, &c, &aa, &kd_in, &seq_win); 
+      continue;
     }
   }