• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 #include <stdlib.h>
2 #include <sys/socket.h>
3 #include <netinet/in.h>
4 #include <netdb.h>
5 #include <string.h>
6 #include <pthread.h>
7 #include <unistd.h>
8 #include <endian.h>
9 #include <errno.h>
10 #include "lookup.h"
11 
getaddrinfo(const char * restrict host,const char * restrict serv,const struct addrinfo * restrict hint,struct addrinfo ** restrict res)12 int getaddrinfo(const char *restrict host, const char *restrict serv, const struct addrinfo *restrict hint, struct addrinfo **restrict res)
13 {
14 #if OHOS_DNS_PROXY_BY_NETSYS
15 	if (dns_get_addr_info_from_netsys_cache(host, serv, hint, res) == 0) {
16 		DNS_CONFIG_PRINT("get from netsys cache OK\n");
17 		return 0;
18 	}
19 #endif
20 
21 	struct service ports[MAXSERVS];
22 	struct address addrs[MAXADDRS];
23 	char canon[256], *outcanon;
24 	int nservs, naddrs, nais, canon_len, i, j, k;
25 	int family = AF_UNSPEC, flags = 0, proto = 0, socktype = 0;
26 	struct aibuf *out;
27 
28 	if (!host && !serv) return EAI_NONAME;
29 
30 	if (hint) {
31 		family = hint->ai_family;
32 		flags = hint->ai_flags;
33 		proto = hint->ai_protocol;
34 		socktype = hint->ai_socktype;
35 
36 		const int mask = AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST |
37 			AI_V4MAPPED | AI_ALL | AI_ADDRCONFIG | AI_NUMERICSERV;
38 		if ((flags & mask) != flags)
39 			return EAI_BADFLAGS;
40 
41 		switch (family) {
42 		case AF_INET:
43 		case AF_INET6:
44 		case AF_UNSPEC:
45 			break;
46 		default:
47 			return EAI_FAMILY;
48 		}
49 	}
50 
51 	if (flags & AI_ADDRCONFIG) {
52 		/* Define the "an address is configured" condition for address
53 		 * families via ability to create a socket for the family plus
54 		 * routability of the loopback address for the family. */
55 		static const struct sockaddr_in lo4 = {
56 			.sin_family = AF_INET, .sin_port = 65535,
57 			.sin_addr.s_addr = __BYTE_ORDER == __BIG_ENDIAN
58 				? 0x7f000001 : 0x0100007f
59 		};
60 		static const struct sockaddr_in6 lo6 = {
61 			.sin6_family = AF_INET6, .sin6_port = 65535,
62 			.sin6_addr = IN6ADDR_LOOPBACK_INIT
63 		};
64 		int tf[2] = { AF_INET, AF_INET6 };
65 		const void *ta[2] = { &lo4, &lo6 };
66 		socklen_t tl[2] = { sizeof lo4, sizeof lo6 };
67 		for (i=0; i<2; i++) {
68 			if (family==tf[1-i]) continue;
69 			int s = socket(tf[i], SOCK_CLOEXEC|SOCK_DGRAM,
70 				IPPROTO_UDP);
71 			if (s>=0) {
72 				int cs;
73 				pthread_setcancelstate(
74 					PTHREAD_CANCEL_DISABLE, &cs);
75 				int r = connect(s, ta[i], tl[i]);
76 				pthread_setcancelstate(cs, 0);
77 				close(s);
78 				if (!r) continue;
79 			}
80 			switch (errno) {
81 			case EADDRNOTAVAIL:
82 			case EAFNOSUPPORT:
83 			case EHOSTUNREACH:
84 			case ENETDOWN:
85 			case ENETUNREACH:
86 				break;
87 			default:
88 				return EAI_SYSTEM;
89 			}
90 			if (family == tf[i]) return EAI_NONAME;
91 			family = tf[1-i];
92 		}
93 	}
94 
95 	nservs = __lookup_serv(ports, serv, proto, socktype, flags);
96 	if (nservs < 0) return nservs;
97 
98 	naddrs = __lookup_name(addrs, canon, host, family, flags);
99 	if (naddrs < 0) return naddrs;
100 
101 	nais = nservs * naddrs;
102 	canon_len = strlen(canon);
103 	out = calloc(1, nais * sizeof(*out) + canon_len + 1);
104 	if (!out) return EAI_MEMORY;
105 
106 	if (canon_len) {
107 		outcanon = (void *)&out[nais];
108 		memcpy(outcanon, canon, canon_len+1);
109 	} else {
110 		outcanon = 0;
111 	}
112 
113 	for (k=i=0; i<naddrs; i++) for (j=0; j<nservs; j++, k++) {
114 		out[k].slot = k;
115 		out[k].ai = (struct addrinfo){
116 			.ai_family = addrs[i].family,
117 			.ai_socktype = ports[j].socktype,
118 			.ai_protocol = ports[j].proto,
119 			.ai_addrlen = addrs[i].family == AF_INET
120 				? sizeof(struct sockaddr_in)
121 				: sizeof(struct sockaddr_in6),
122 			.ai_addr = (void *)&out[k].sa,
123 			.ai_canonname = outcanon };
124 		if (k) out[k-1].ai.ai_next = &out[k].ai;
125 		switch (addrs[i].family) {
126 		case AF_INET:
127 			out[k].sa.sin.sin_family = AF_INET;
128 			out[k].sa.sin.sin_port = htons(ports[j].port);
129 			memcpy(&out[k].sa.sin.sin_addr, &addrs[i].addr, 4);
130 			break;
131 		case AF_INET6:
132 			out[k].sa.sin6.sin6_family = AF_INET6;
133 			out[k].sa.sin6.sin6_port = htons(ports[j].port);
134 			out[k].sa.sin6.sin6_scope_id = addrs[i].scopeid;
135 			memcpy(&out[k].sa.sin6.sin6_addr, &addrs[i].addr, 16);
136 			break;
137 		}
138 	}
139 	out[0].ref = nais;
140 	*res = &out->ai;
141 #if OHOS_DNS_PROXY_BY_NETSYS
142 	dns_set_addr_info_to_netsys_cache(host, serv, hint, *res);
143 #endif
144 	return 0;
145 }
146