1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
#include "pthread.h"
#include <netdb.h>
#include <string.h>
#ifdef __sparc__
#define NEED_ALIGNED_ACCESS
#endif
static pthread_mutex_t gethostby_mutex = PTHREAD_MUTEX_INITIALIZER;
static int
convert (struct hostent *host, struct hostent *result,
char *buf, int buflen, int *h_errnop)
{
int len, i;
if (!buf || !h_errnop) return -1;
*h_errnop = h_errno;
*result = *host;
result->h_name = (char *) buf;
/* This is the size. */
len = strlen (host->h_name) + 1;
if (len > buflen) return -1;
buflen -= len;
buf += len;
strcpy ((char *) result->h_name, host->h_name);
/* How many aliases and how big the buffer should be? There
is always a NULL pointer. */
for (len = sizeof (char *), i = 0; host->h_aliases [i]; i++)
{
/* It should be size of (char *) and the length of string
plus 1. */
len += strlen (host->h_aliases [i]) + 1 + sizeof (char *);
}
if (len > buflen) return -1;
buflen -= len;
/* This is an array of char * for h_aliases. */
#ifdef NEED_ALIGNED_ACCESS
{
int extra;
extra = 4 - (((unsigned long) buf) & 3);
if (extra != 4) {
if (buflen < extra)
return -1;
buf = (char *) buf + extra;
}
}
#endif
result->h_aliases = (char **) buf;
buf += (i + 1) * sizeof (char *);
/* We copy the aliases now. */
for (i = 0; host->h_aliases [i]; i++)
{
result->h_aliases [i] = (char *) buf;
strcpy (result->h_aliases [i], host->h_aliases [i]);
buf += strlen (host->h_aliases [i]) + 1;
}
/* This is the last one */
result->h_aliases [i] = NULL;
#if BSD >= 43 || defined(h_addr)
for (len = sizeof (char *), i = 0; host->h_addr_list [i]; i++)
{
/* It should be size of (char *) and the length of string
plus 1. */
len += host->h_length + sizeof (char *);
}
if (len > buflen) return -1;
/* This is an array of char * for h_addr_list. */
#ifdef NEED_ALIGNED_ACCESS
{
int extra;
extra = 4 - (((unsigned long) buf) & 0x3);
if (extra != 4) {
if (buflen < extra)
return -1;
buf = ((char *) buf) + extra;
}
}
#endif
result->h_addr_list = (char **) buf;
buf += (i + 1) * sizeof (char *);
/* We copy the h_addr_list now. */
for (i = 0; host->h_addr_list [i]; i++)
{
result->h_addr_list [i] = (char *) buf;
memcpy (result->h_addr_list [i], host->h_addr_list [i], host->h_length);
buf += host->h_length;
}
/* This is the last one */
result->h_addr_list [i] = NULL;
#else
len = strlen (host->h_addr) + 1 + sizeof (char *);
if (len > buflen) return -1;
result->h_addr = (char *) buf;
strcpy (result->h_addr, host->h_addr);
#endif
return 0;
}
struct hostent *
gethostbyaddr_r (const char *addr, int length, int type,
struct hostent *result, char *buffer, int buflen,
int *h_errnop)
{
struct hostent *host;
pthread_mutex_lock (&gethostby_mutex);
host = gethostbyaddr (addr, length, type);
if (!host ||
convert (host, result, buffer, buflen, h_errnop) != 0)
{
result = NULL;
}
pthread_mutex_unlock (&gethostby_mutex);
return result;
}
struct hostent *
gethostbyname_r (const char *name,
struct hostent *result, char *buffer, int buflen,
int *h_errnop)
{
struct hostent *host;
pthread_mutex_lock (&gethostby_mutex);
host = gethostbyname (name);
if (!host ||
convert (host, result, buffer, buflen, h_errnop) != 0)
{
result = NULL;
}
pthread_mutex_unlock (&gethostby_mutex);
return result;
}
struct hostent *
gethostent_r (struct hostent *result, char *buffer, int buflen,
int *h_errnop)
{
struct hostent *host;
pthread_mutex_lock (&gethostby_mutex);
host = gethostent ();
if (!host ||
convert (host, result, buffer, buflen, h_errnop) != 0)
{
result = NULL;
}
pthread_mutex_unlock (&gethostby_mutex);
return result;
}
|
