source: azure_iot_hub/trunk/musl-1.1.18/src/network/getnameinfo.c@ 388

Last change on this file since 388 was 388, checked in by coas-nagasima, 5 years ago

Azure IoT Hub Device C SDK を使ったサンプルの追加
  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
  • Property svn:mime-type set to text/x-csrc
File size: 5.0 KB
Line 
1#include <netdb.h>
2#include <limits.h>
3#include <string.h>
4#include <stdio.h>
5#include <sys/socket.h>
6#include <netinet/in.h>
7#include <arpa/inet.h>
8#include <net/if.h>
9#include <ctype.h>
10#include "lookup.h"
11#include "stdio_impl.h"
12
13int __dns_parse(const unsigned char *, int, int (*)(void *, int, const void *, int, const void *), void *);
14int __dn_expand(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
15int __res_mkquery(int, const char *, int, int, const unsigned char *, int, const unsigned char*, unsigned char *, int);
16int __res_send(const unsigned char *, int, unsigned char *, int);
17
18#define PTR_MAX (64 + sizeof ".in-addr.arpa")
19#define RR_PTR 12
20
21static char *itoa(char *p, unsigned x) {
22 p += 3*sizeof(int);
23 *--p = 0;
24 do {
25 *--p = '0' + x % 10;
26 x /= 10;
27 } while (x);
28 return p;
29}
30
31static void mkptr4(char *s, const unsigned char *ip)
32{
33 sprintf(s, "%d.%d.%d.%d.in-addr.arpa",
34 ip[3], ip[2], ip[1], ip[0]);
35}
36
37static void mkptr6(char *s, const unsigned char *ip)
38{
39 static const char xdigits[] = "0123456789abcdef";
40 int i;
41 for (i=15; i>=0; i--) {
42 *s++ = xdigits[ip[i]&15]; *s++ = '.';
43 *s++ = xdigits[ip[i]>>4]; *s++ = '.';
44 }
45 strcpy(s, "ip6.arpa");
46}
47
48static void reverse_hosts(char *buf, const unsigned char *a, unsigned scopeid, int family)
49{
50 char line[512], *p, *z;
51 unsigned char _buf[1032], atmp[16];
52 struct address iplit;
53 FILE _f, *f = __fopen_rb_ca("/etc/hosts", &_f, _buf, sizeof _buf);
54 if (!f) return;
55 if (family == AF_INET) {
56 memcpy(atmp+12, a, 4);
57 memcpy(atmp, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
58 a = atmp;
59 }
60 while (fgets(line, sizeof line, f)) {
61 if ((p=strchr(line, '#'))) *p++='\n', *p=0;
62
63 for (p=line; *p && !isspace(*p); p++);
64 *p++ = 0;
65 if (__lookup_ipliteral(&iplit, line, AF_UNSPEC)<=0)
66 continue;
67
68 if (iplit.family == AF_INET) {
69 memcpy(iplit.addr+12, iplit.addr, 4);
70 memcpy(iplit.addr, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
71 iplit.scopeid = 0;
72 }
73
74 if (memcmp(a, iplit.addr, 16) || iplit.scopeid != scopeid)
75 continue;
76
77 for (; *p && isspace(*p); p++);
78 for (z=p; *z && !isspace(*z); z++);
79 *z = 0;
80 if (z-p < 256) {
81 memcpy(buf, p, z-p+1);
82 break;
83 }
84 }
85 __fclose_ca(f);
86}
87
88static void reverse_services(char *buf, int port, int dgram)
89{
90 unsigned long svport;
91 char line[128], *p, *z;
92 unsigned char _buf[1032];
93 FILE _f, *f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf);
94 if (!f) return;
95 while (fgets(line, sizeof line, f)) {
96 if ((p=strchr(line, '#'))) *p++='\n', *p=0;
97
98 for (p=line; *p && !isspace(*p); p++);
99 if (!*p) continue;
100 *p++ = 0;
101 svport = strtoul(p, &z, 10);
102
103 if (svport != port || z==p) continue;
104 if (dgram && strncmp(z, "/udp", 4)) continue;
105 if (!dgram && strncmp(z, "/tcp", 4)) continue;
106 if (p-line > 32) continue;
107
108 memcpy(buf, line, p-line);
109 break;
110 }
111 __fclose_ca(f);
112}
113
114static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet)
115{
116 if (rr != RR_PTR) return 0;
117 if (__dn_expand(packet, (const unsigned char *)packet + 512,
118 data, c, 256) <= 0)
119 *(char *)c = 0;
120 return 0;
121
122}
123
124int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl,
125 char *restrict node, socklen_t nodelen,
126 char *restrict serv, socklen_t servlen,
127 int flags)
128{
129 char ptr[PTR_MAX];
130 char buf[256], num[3*sizeof(int)+1];
131 int af = sa->sa_family;
132 unsigned char *a;
133 unsigned scopeid;
134
135 switch (af) {
136 case AF_INET:
137 a = (void *)&((struct sockaddr_in *)sa)->sin_addr;
138 if (sl < sizeof(struct sockaddr_in)) return EAI_FAMILY;
139 mkptr4(ptr, a);
140 scopeid = 0;
141 break;
142 case AF_INET6:
143 a = (void *)&((struct sockaddr_in6 *)sa)->sin6_addr;
144 if (sl < sizeof(struct sockaddr_in6)) return EAI_FAMILY;
145 if (memcmp(a, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12))
146 mkptr6(ptr, a);
147 else
148 mkptr4(ptr, a+12);
149 scopeid = ((struct sockaddr_in6 *)sa)->sin6_scope_id;
150 break;
151 default:
152 return EAI_FAMILY;
153 }
154
155 if (node && nodelen) {
156 buf[0] = 0;
157 if (!(flags & NI_NUMERICHOST)) {
158 reverse_hosts(buf, a, scopeid, af);
159 }
160 if (!*buf && !(flags & NI_NUMERICHOST)) {
161 unsigned char query[18+PTR_MAX], reply[512];
162 int qlen = __res_mkquery(0, ptr, 1, RR_PTR,
163 0, 0, 0, query, sizeof query);
164 int rlen = __res_send(query, qlen, reply, sizeof reply);
165 buf[0] = 0;
166 if (rlen > 0)
167 __dns_parse(reply, rlen, dns_parse_callback, buf);
168 }
169 if (!*buf) {
170 if (flags & NI_NAMEREQD) return EAI_NONAME;
171 inet_ntop(af, a, buf, sizeof buf);
172 if (scopeid) {
173 char *p = 0, tmp[IF_NAMESIZE+1];
174 if (!(flags & NI_NUMERICSCOPE) &&
175 (IN6_IS_ADDR_LINKLOCAL(a) ||
176 IN6_IS_ADDR_MC_LINKLOCAL(a)))
177 p = if_indextoname(scopeid, tmp+1);
178 if (!p)
179 p = itoa(num, scopeid);
180 *--p = '%';
181 strcat(buf, p);
182 }
183 }
184 if (strlen(buf) >= nodelen) return EAI_OVERFLOW;
185 strcpy(node, buf);
186 }
187
188 if (serv && servlen) {
189 char *p = buf;
190 int port = ntohs(((struct sockaddr_in *)sa)->sin_port);
191 buf[0] = 0;
192 if (!(flags & NI_NUMERICSERV))
193 reverse_services(buf, port, flags & NI_DGRAM);
194 if (!*p)
195 p = itoa(num, port);
196 if (strlen(p) >= servlen)
197 return EAI_OVERFLOW;
198 strcpy(serv, p);
199 }
200
201 return 0;
202}
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