inetutils-1.3.2 tftp file limit 16MB

[Denis Laplante]

GNU tftp and/or tftpd has a 16 Mega Byte limit on file transfers, as 
demonstrated by a transfer with the following options

> tftp HOSTNAME
> bin
> verbose
> trace
> get BIGFILE
[...]
received DATA <block=32767, 512 bytes>
sent ACK <block=32767>
received DATA <block=-32768, 512 bytes>
sent ACK <block=32767>
received DATA <block=-32768, 512 bytes>
received DATA <block=-32768, 512 bytes>
sent ACK <block=32767>
sent ACK <block=32767>
sent ACK <block=32767>
Transfer timed out.

tftp> 

I believe that changing the data type for tu_block to unsigned short would 
raise the limit to 32M

[inetutils-1.3.2/include/arpa/tftp.h]
struct  tftphdr {
        short   th_opcode;              /* packet type */
        union {
                short   tu_block;       /* block # */
                short   tu_code;        /* error code */
                char    tu_stuff[1];    /* request packet stuff */
        } th_u;
        char    th_data[1];             /* data or error string */
};

#define th_block        th_u.tu_block
#define th_code         th_u.tu_code
#define th_stuff        th_u.tu_stuff
#define th_msg          th_data

, and changing variable 'block' in tftpd.c/tftp.c functions sendfile/recvfile 
to unsigned short would result in unlimited file size, because both sides of 
comparison would overflow into -32768 at the same time.


-- Denis Laplante <address@hidden> -- Network Analyst   --
-- ITServices Network Engineering         -- TEL: 604/822-9914 --