summaryrefslogtreecommitdiff
path: root/src/network/getaddrinfo.c
blob: efaab306828e847deecbb26751dc7cb8a4c90e2e (plain) (blame)
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
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
#include <endian.h>
#include <errno.h>
#include "lookup.h"

int getaddrinfo(const char *restrict host, const char *restrict serv, const struct addrinfo *restrict hint, struct addrinfo **restrict res)
{
	struct service ports[MAXSERVS];
	struct address addrs[MAXADDRS];
	char canon[256], *outcanon;
	int nservs, naddrs, nais, canon_len, i, j, k;
	int family = AF_UNSPEC, flags = 0, proto = 0, socktype = 0;
	struct aibuf *out;

	if (!host && !serv) return EAI_NONAME;

	if (hint) {
		family = hint->ai_family;
		flags = hint->ai_flags;
		proto = hint->ai_protocol;
		socktype = hint->ai_socktype;

		const int mask = AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST |
			AI_V4MAPPED | AI_ALL | AI_ADDRCONFIG | AI_NUMERICSERV;
		if ((flags & mask) != flags)
			return EAI_BADFLAGS;

		switch (family) {
		case AF_INET:
		case AF_INET6:
		case AF_UNSPEC:
			break;
		default:
			return EAI_FAMILY;
		}
	}

	if (flags & AI_ADDRCONFIG) {
		/* Define the "an address is configured" condition for address
		 * families via ability to create a socket for the family plus
		 * routability of the loopback address for the family. */
		static const struct sockaddr_in lo4 = {
			.sin_family = AF_INET, .sin_port = 65535,
			.sin_addr.s_addr = __BYTE_ORDER == __BIG_ENDIAN
				? 0x7f000001 : 0x0100007f
		};
		static const struct sockaddr_in6 lo6 = {
			.sin6_family = AF_INET6, .sin6_port = 65535,
			.sin6_addr = IN6ADDR_LOOPBACK_INIT
		};
		int tf[2] = { AF_INET, AF_INET6 };
		const void *ta[2] = { &lo4, &lo6 };
		socklen_t tl[2] = { sizeof lo4, sizeof lo6 };
		for (i=0; i<2; i++) {
			if (family==tf[1-i]) continue;
			int s = socket(tf[i], SOCK_CLOEXEC|SOCK_DGRAM,
				IPPROTO_UDP);
			if (s>=0) {
				int cs;
				pthread_setcancelstate(
					PTHREAD_CANCEL_DISABLE, &cs);
				int r = connect(s, ta[i], tl[i]);
				pthread_setcancelstate(cs, 0);
				close(s);
				if (!r) continue;
			}
			switch (errno) {
			case EADDRNOTAVAIL:
			case EAFNOSUPPORT:
			case EHOSTUNREACH:
			case ENETDOWN:
			case ENETUNREACH:
				break;
			default:
				return EAI_SYSTEM;
			}
			if (family == tf[i]) return EAI_NONAME;
			family = tf[1-i];
		}
	}

	nservs = __lookup_serv(ports, serv, proto, socktype, flags);
	if (nservs < 0) return nservs;

	naddrs = __lookup_name(addrs, canon, host, family, flags);
	if (naddrs < 0) return naddrs;

	nais = nservs * naddrs;
	canon_len = strlen(canon);
	out = calloc(1, nais * sizeof(*out) + canon_len + 1);
	if (!out) return EAI_MEMORY;

	if (canon_len) {
		outcanon = (void *)&out[nais];
		memcpy(outcanon, canon, canon_len+1);
	} else {
		outcanon = 0;
	}

	for (k=i=0; i<naddrs; i++) for (j=0; j<nservs; j++, k++) {
		out[k].slot = k;
		out[k].ai = (struct addrinfo){
			.ai_family = addrs[i].family,
			.ai_socktype = ports[j].socktype,
			.ai_protocol = ports[j].proto,
			.ai_addrlen = addrs[i].family == AF_INET
				? sizeof(struct sockaddr_in)
				: sizeof(struct sockaddr_in6),
			.ai_addr = (void *)&out[k].sa,
			.ai_canonname = outcanon };
		if (k) out[k-1].ai.ai_next = &out[k].ai;
		switch (addrs[i].family) {
		case AF_INET:
			out[k].sa.sin.sin_family = AF_INET;
			out[k].sa.sin.sin_port = htons(ports[j].port);
			memcpy(&out[k].sa.sin.sin_addr, &addrs[i].addr, 4);
			break;
		case AF_INET6:
			out[k].sa.sin6.sin6_family = AF_INET6;
			out[k].sa.sin6.sin6_port = htons(ports[j].port);
			out[k].sa.sin6.sin6_scope_id = addrs[i].scopeid;
			memcpy(&out[k].sa.sin6.sin6_addr, &addrs[i].addr, 16);
			break;			
		}
	}
	out[0].ref = nais;
	*res = &out->ai;
	return 0;
}