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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
#include <netdb.h>
#include <limits.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <ctype.h>
#include <resolv.h>
#include "lookup.h"
#include "stdio_impl.h"
#define PTR_MAX (64 + sizeof ".in-addr.arpa")
#define RR_PTR 12
static char *itoa(char *p, unsigned x) {
p += 3*sizeof(int);
*--p = 0;
do {
*--p = '0' + x % 10;
x /= 10;
} while (x);
return p;
}
static void mkptr4(char *s, const unsigned char *ip)
{
sprintf(s, "%d.%d.%d.%d.in-addr.arpa",
ip[3], ip[2], ip[1], ip[0]);
}
static void mkptr6(char *s, const unsigned char *ip)
{
static const char xdigits[] = "0123456789abcdef";
int i;
for (i=15; i>=0; i--) {
*s++ = xdigits[ip[i]&15]; *s++ = '.';
*s++ = xdigits[ip[i]>>4]; *s++ = '.';
}
strcpy(s, "ip6.arpa");
}
static void reverse_hosts(char *buf, const unsigned char *a, unsigned scopeid, int family)
{
char line[512], *p, *z;
unsigned char _buf[1032], atmp[16];
struct address iplit;
FILE _f, *f = __fopen_rb_ca("/etc/hosts", &_f, _buf, sizeof _buf);
if (!f) return;
if (family == AF_INET) {
memcpy(atmp+12, a, 4);
memcpy(atmp, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
a = atmp;
}
while (fgets(line, sizeof line, f)) {
if ((p=strchr(line, '#'))) *p++='\n', *p=0;
for (p=line; *p && !isspace(*p); p++);
*p++ = 0;
if (__lookup_ipliteral(&iplit, line, AF_UNSPEC)<=0)
continue;
if (iplit.family == AF_INET) {
memcpy(iplit.addr+12, iplit.addr, 4);
memcpy(iplit.addr, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
iplit.scopeid = 0;
}
if (memcmp(a, iplit.addr, 16) || iplit.scopeid != scopeid)
continue;
for (; *p && isspace(*p); p++);
for (z=p; *z && !isspace(*z); z++);
*z = 0;
if (z-p < 256) {
memcpy(buf, p, z-p+1);
break;
}
}
__fclose_ca(f);
}
static void reverse_services(char *buf, int port, int dgram)
{
unsigned long svport;
char line[128], *p, *z;
unsigned char _buf[1032];
FILE _f, *f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf);
if (!f) return;
while (fgets(line, sizeof line, f)) {
if ((p=strchr(line, '#'))) *p++='\n', *p=0;
for (p=line; *p && !isspace(*p); p++);
if (!*p) continue;
*p++ = 0;
svport = strtoul(p, &z, 10);
if (svport != port || z==p) continue;
if (dgram && strncmp(z, "/udp", 4)) continue;
if (!dgram && strncmp(z, "/tcp", 4)) continue;
if (p-line > 32) continue;
memcpy(buf, line, p-line);
break;
}
__fclose_ca(f);
}
static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet)
{
if (rr != RR_PTR) return 0;
if (__dn_expand(packet, (const unsigned char *)packet + 512,
data, c, 256) <= 0)
*(char *)c = 0;
return 0;
}
int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl,
char *restrict node, socklen_t nodelen,
char *restrict serv, socklen_t servlen,
int flags)
{
char ptr[PTR_MAX];
char buf[256], num[3*sizeof(int)+1];
int af = sa->sa_family;
unsigned char *a;
unsigned scopeid;
switch (af) {
case AF_INET:
a = (void *)&((struct sockaddr_in *)sa)->sin_addr;
if (sl < sizeof(struct sockaddr_in)) return EAI_FAMILY;
mkptr4(ptr, a);
scopeid = 0;
break;
case AF_INET6:
a = (void *)&((struct sockaddr_in6 *)sa)->sin6_addr;
if (sl < sizeof(struct sockaddr_in6)) return EAI_FAMILY;
if (memcmp(a, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12))
mkptr6(ptr, a);
else
mkptr4(ptr, a+12);
scopeid = ((struct sockaddr_in6 *)sa)->sin6_scope_id;
break;
default:
return EAI_FAMILY;
}
if (node && nodelen) {
buf[0] = 0;
if (!(flags & NI_NUMERICHOST)) {
reverse_hosts(buf, a, scopeid, af);
}
if (!*buf && !(flags & NI_NUMERICHOST)) {
unsigned char query[18+PTR_MAX], reply[512];
int qlen = __res_mkquery(0, ptr, 1, RR_PTR,
0, 0, 0, query, sizeof query);
query[3] = 0; /* don't need AD flag */
int rlen = __res_send(query, qlen, reply, sizeof reply);
buf[0] = 0;
if (rlen > 0)
__dns_parse(reply, rlen, dns_parse_callback, buf);
}
if (!*buf) {
if (flags & NI_NAMEREQD) return EAI_NONAME;
inet_ntop(af, a, buf, sizeof buf);
if (scopeid) {
char *p = 0, tmp[IF_NAMESIZE+1];
if (!(flags & NI_NUMERICSCOPE) &&
(IN6_IS_ADDR_LINKLOCAL(a) ||
IN6_IS_ADDR_MC_LINKLOCAL(a)))
p = if_indextoname(scopeid, tmp+1);
if (!p)
p = itoa(num, scopeid);
*--p = '%';
strcat(buf, p);
}
}
if (strlen(buf) >= nodelen) return EAI_OVERFLOW;
strcpy(node, buf);
}
if (serv && servlen) {
char *p = buf;
int port = ntohs(((struct sockaddr_in *)sa)->sin_port);
buf[0] = 0;
if (!(flags & NI_NUMERICSERV))
reverse_services(buf, port, flags & NI_DGRAM);
if (!*p)
p = itoa(num, port);
if (strlen(p) >= servlen)
return EAI_OVERFLOW;
strcpy(serv, p);
}
return 0;
}
|
