1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 2010 Intel Corporation; author: H. Peter Anvin
4 *
5 * Permission is hereby granted, free of charge, to any person
6 * obtaining a copy of this software and associated documentation
7 * files (the "Software"), to deal in the Software without
8 * restriction, including without limitation the rights to use,
9 * copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom
11 * the Software is furnished to do so, subject to the following
12 * conditions:
13 *
14 * The above copyright notice and this permission notice shall
15 * be included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
19 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
21 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
22 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24 * OTHER DEALINGS IN THE SOFTWARE.
25 *
26 * ----------------------------------------------------------------------- */
27
28 /*
29 * pxe_dns.c
30 *
31 * Resolve a hostname via DNS
32 */
33
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <stdint.h>
37 #include <string.h>
38 #include <com32.h>
39
40 #include <syslinux/pxe.h>
41
42 /* Returns the status code from PXE (0 on success),
43 or -1 on invocation failure */
pxe_dns(const char * hostname)44 uint32_t pxe_dns(const char *hostname)
45 {
46 union {
47 unsigned char b[4];
48 uint32_t ip;
49 } q;
50 char *lm_hostname;
51 uint32_t status;
52
53 /* Is this a dot-quad? */
54 if (sscanf(hostname, "%hhu.%hhu.%hhu.%hhu",
55 &q.b[0], &q.b[1], &q.b[2], &q.b[3]) == 4)
56 return q.ip;
57
58 lm_hostname = lstrdup(hostname);
59 if (!lm_hostname)
60 return 0;
61
62 status = dns_resolv(lm_hostname);
63
64 lfree(lm_hostname);
65
66 return status;
67 }
68