[syslinux] pxelinux tries to load ldlinux.c32 from DHCP server, instead of next-server

[Gene Cumm]

On Sat, Sep 12, 2015 at 6:37 PM, Gene Cumm <gene.cumm at gmail.com> wrote:
> On Sat, Sep 12, 2015 at 10:23 AM, Geert Stappers <stappers at stappers.nl> wrote:

>> Euh, could this be reviewed:
>>
>> diff --git a/core/fs/pxe/dhcp_option.c b/core/fs/pxe/dhcp_option.c
>> index 8d93a6a..b82e944 100644
>> --- a/core/fs/pxe/dhcp_option.c
>> +++ b/core/fs/pxe/dhcp_option.c
>> @@ -143,8 +143,8 @@ static const struct dhcp_options dhcp_opts[] = {
>>      {15,  local_domain},
>>      {43,  vendor_encaps},
>>      {52,  option_overload},
>> -    {54,  server},
>>      {61,  client_identifier},
>> +    {66,  tftpserver_name},
>>      {67,  bootfile_name},
>>      {97,  uuid_client_identifier},
>>      {209, pxelinux_configfile},
>> @@ -215,7 +215,7 @@ void parse_dhcp_options(const void *option, int size, uint8_t opt_filter)
>>   * information is present:
>>   *
>>   * MyIP                - client IP address
>> - * server_ip   - boot server IP address
>> + * server_ip   - boot server IP address,  REVIEW ME   FIXME
>>   * net_mask    - network mask
>>   * gate_way    - default gateway router IP
>>   * boot_file   - boot file name
>> @@ -252,4 +252,6 @@ void parse_dhcp(const void *pkt, size_t pkt_len, int pkt_type)
>>
>>      if (over_load & 2)
>>          parse_dhcp_options(dhcp->sname, 64, 0);
>> +
>> +    /* What about option 66, tftserver_name ?   FIXME */
>>  }
>
> Something like this would be preferable except it's not quite so
> simple.  We'd need to not store BOOTP siaddr before parsing.  Store a
> pointer to the string during parsing if serverip is unset.  After all
> parsing, if the pointer is set, attempt to resolve then set serverip.
> Last, if serverip is not set, copy siaddr to serverip.

Perhaps a more important question is if ANY PXE implementation uses
DHCP option 66 over BOOTP field siaddr.

-- 
-Gene