[patch] Patch to fix bug that occurs in atftp 0.7-r1 when block number wraps

atftp-0.7-blocknumwrap.patch (text/plain), 5.55 KB, created by Grant Edwards on 2010-05-27 18:20:24 UTC

--- atftp-0.7/tftp_file.c~	2010-05-27 13:05:12.000000000 -0500
+++ atftp-0.7/tftp_file.c	2010-05-27 12:50:05.000000000 -0500
@@ -133,19 +133,21 @@
      int mcast_sockfd = 0;
      struct sockaddr_in sa_mcast;
      struct ip_mreq mreq;
      struct hostent *host;
      int master_client = 0;
      unsigned int file_bitmap[NB_BLOCK];
      int prev_bitmap_hole = -1; /* the previous hole found in the bitmap */
      char string[MAXLEN];
+     int rx_block_number;
 
      int prev_block_number = 0; /* needed to support netascii convertion */
      int temp = 0;
+     size_t ignore;
 
      data->file_size = 0;
      tftp_cancel = 0;
      from.sin_addr.s_addr = 0;
 
      memset(&sa_mcast, 0, sizeof(struct sockaddr_in));
      memset(&file_bitmap, 0, sizeof(file_bitmap));
 
@@ -300,17 +302,17 @@
                     {
                          connect(sockfd, (struct sockaddr *)&sa, sizeof(sa));
                          connected = 1;
                     }
                     state = S_OACK_RECEIVED;
                     break;
                case GET_ERROR:
                     fprintf(stderr, "tftp: error received from server <");
-                    fwrite(tftphdr->th_msg, 1, data_size - 4 - 1, stderr);
+                    ignore = fwrite(tftphdr->th_msg, 1, data_size - 4 - 1, stderr);
                     fprintf(stderr, ">\n");
                     state = S_ABORT;
                     break;
                case GET_DATA:
                     number_of_timeout = 0;
                     /* if the socket if not connected, connect it */
                     if (!connected)
                     {
@@ -513,21 +515,24 @@
                     state = S_WAIT_PACKET;
                break;
           case S_DATA_RECEIVED:
                if ((multicast && master_client) || (!multicast))
                     timeout_state = S_SEND_ACK;
                else
                     timeout_state = S_WAIT_PACKET;
 
-               block_number = ntohs(tftphdr->th_block);
+               rx_block_number = ntohs(tftphdr->th_block);
                if (data->trace)
                     fprintf(stderr, "received DATA <block: %d, size: %d>\n",
                             ntohs(tftphdr->th_block), data_size - 4);
 
+               if ((uint16_t)rx_block_number == (uint16_t)(block_number+1))
+                    ++block_number;
+
                if (tftp_file_write(fp, tftphdr->th_data, data->data_buffer_size - 4, block_number,
                                    data_size - 4, convert, &prev_block_number, &temp)
                    != data_size - 4)
                {
                     
                     fprintf(stderr, "tftp: error writing to file %s\n",
                             data->local_file);
                     tftp_send_error(sockfd, &sa, ENOSPACE, data->data_buffer,
@@ -613,19 +618,21 @@
      int connected;             /* 1 when sockfd is connected */
      struct tftphdr *tftphdr = (struct tftphdr *)data->data_buffer;
      FILE *fp;                  /* the local file pointer */
      int number_of_timeout = 0;
      struct stat file_stat;
      int convert = 0;           /* if true, do netascii convertion */
      char string[MAXLEN];
 
+     int ack_block_number;
      int prev_block_number = 0; /* needed to support netascii convertion */
      int prev_file_pos = 0;
      int temp = 0;
+     size_t ignore;
 
      data->file_size = 0;
      tftp_cancel = 0;
      from.sin_addr.s_addr = 0;
 
      /* make sure the socket is not connected */
      sa.sin_family = AF_UNSPEC;
      connect(sockfd, (struct sockaddr *)&sa, sizeof(sa));
@@ -759,20 +766,23 @@
                case GET_ACK:
                     number_of_timeout = 0;
                     /* if the socket if not connected, connect it */
                     if (!connected)
                     {
                          //connect(sockfd, (struct sockaddr *)&sa, sizeof(sa));
                          connected = 1;
                     }
-                    block_number = ntohs(tftphdr->th_block);
+                    ack_block_number = ntohs(tftphdr->th_block);
+                    if ((uint16_t)(block_number+1) == ack_block_number)
+                         ++block_number;
                     if (data->trace)
                          fprintf(stderr, "received ACK <block: %d>\n",
-                                 block_number);
+                                 ack_block_number);
+                    
                     if ((last_block != -1) && (block_number > last_block))
                     {
                          state = S_END;
                          break;
                     }
                     state = S_SEND_DATA;
                     break;
                case GET_OACK:
@@ -782,17 +792,17 @@
                     {
                          //connect(sockfd, (struct sockaddr *)&sa, sizeof(sa));
                          connected = 1;
                     }
                     state = S_OACK_RECEIVED;
                     break;
                case GET_ERROR:
                     fprintf(stderr, "tftp: error received from server <");
-                    fwrite(tftphdr->th_msg, 1, data_size - 4 - 1, stderr);
+                    ignore = fwrite(tftphdr->th_msg, 1, data_size - 4 - 1, stderr);
                     fprintf(stderr, ">\n");
                     state = S_ABORT;
                     break;
                case GET_DISCARD:
                     /* consider discarded packet as timeout to make sure when don't lock up
                        if routing is broken */
                     number_of_timeout++;
                     fprintf(stderr, "tftp: packet discard <%s:%d>.\n",