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/* ----------------------------------------------------------------------- *
*
* Copyright 2010 Intel Corporation; author: H. Peter Anvin
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ----------------------------------------------------------------------- */
/*
* pxe_dns.c
*
* Resolve a hostname via DNS
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <com32.h>
#include <syslinux/pxe.h>
/* Returns the status code from PXE (0 on success),
or -1 on invocation failure */
uint32_t pxe_dns(const char *hostname)
{
com32sys_t regs;
union {
unsigned char b[4];
uint32_t ip;
} q;
char *lm_hostname;
/* Is this a dot-quad? */
if (sscanf(hostname, "%hhu.%hhu.%hhu.%hhu",
&q.b[0], &q.b[1], &q.b[2], &q.b[3]) == 4)
return q.ip;
lm_hostname = lstrdup(hostname);
if (!lm_hostname)
return 0;
memset(®s, 0, sizeof regs);
regs.eax.w[0] = 0x0010;
regs.es = SEG(lm_hostname);
/* regs.ebx.w[0] = OFFS(lm_hostname); */
__intcall(0x22, ®s, ®s);
lfree(lm_hostname);
if (regs.eflags.l & EFLAGS_CF)
return 0;
return regs.eax.l;
}
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