1 /*
2 * COPYRIGHT: See COPYING in the top level directory
3 * PROJECT: ReactOS DNS Shared Library
4 * FILE: lib/dnslib/hostent.c
5 * PURPOSE: Functions for dealing with Host Entry structures
6 */
7
8 /* INCLUDES ******************************************************************/
9 #include "precomp.h"
10
11 /* DATA **********************************************************************/
12
13 /* FUNCTIONS *****************************************************************/
14
15 PHOSTENT
16 WINAPI
Hostent_Init(IN PVOID * Buffer,IN WORD AddressFamily,IN ULONG AddressSize,IN ULONG AddressCount,IN ULONG AliasCount)17 Hostent_Init(IN PVOID *Buffer,
18 IN WORD AddressFamily,
19 IN ULONG AddressSize,
20 IN ULONG AddressCount,
21 IN ULONG AliasCount)
22 {
23 PHOSTENT Hostent;
24 ULONG_PTR BufferPosition = (ULONG_PTR)*Buffer;
25
26 /* Align the hostent on the buffer's 4 byte boundary */
27 BufferPosition += 3 & ~3;
28
29 /* Set up the basic data */
30 Hostent = (PHOSTENT)BufferPosition;
31 Hostent->h_length = (WORD)AddressSize;
32 Hostent->h_addrtype = AddressFamily;
33
34 /* Put aliases after Hostent */
35 Hostent->h_aliases = (PCHAR*)((ULONG_PTR)(Hostent + 1) & ~3);
36
37 /* Zero it out */
38 RtlZeroMemory(Hostent->h_aliases, AliasCount * sizeof(PCHAR));
39
40 /* Put addresses after aliases */
41 Hostent->h_addr_list = (PCHAR*)
42 ((ULONG_PTR)Hostent->h_aliases +
43 (AliasCount * sizeof(PCHAR)) + sizeof(PCHAR));
44
45 /* Update the location */
46 BufferPosition = (ULONG_PTR)Hostent->h_addr_list +
47 ((AddressCount * sizeof(PCHAR)) + sizeof(PCHAR));
48
49 /* Send it back */
50 *Buffer = (PVOID)BufferPosition;
51
52 /* Return the hostent */
53 return Hostent;
54 }
55
56 VOID
57 WINAPI
Dns_PtrArrayToOffsetArray(PCHAR * List,ULONG_PTR Base)58 Dns_PtrArrayToOffsetArray(PCHAR *List,
59 ULONG_PTR Base)
60 {
61 /* Loop every pointer in the list */
62 do
63 {
64 /* Update the pointer */
65 *List = (PCHAR)((ULONG_PTR)*List - Base);
66 } while(*List++);
67 }
68
69 VOID
70 WINAPI
Hostent_ConvertToOffsets(IN PHOSTENT Hostent)71 Hostent_ConvertToOffsets(IN PHOSTENT Hostent)
72 {
73 /* Do we have a name? */
74 if (Hostent->h_name)
75 {
76 /* Update it */
77 Hostent->h_name -= (ULONG_PTR)Hostent;
78 }
79
80 /* Do we have aliases? */
81 if (Hostent->h_aliases)
82 {
83 /* Update the pointer */
84 Hostent->h_aliases -= (ULONG_PTR)Hostent;
85
86 /* Fix them up */
87 Dns_PtrArrayToOffsetArray(Hostent->h_aliases, (ULONG_PTR)Hostent);
88 }
89
90 /* Do we have addresses? */
91 if (Hostent->h_addr_list)
92 {
93 /* Fix them up */
94 Dns_PtrArrayToOffsetArray(Hostent->h_addr_list, (ULONG_PTR)Hostent);
95 }
96 }
97
98