aboutsummaryrefslogtreecommitdiffstats
path: root/src/system/Resolver.cxx
blob: 656de1349335908c9a9b49ad1b0b306dc1cd864d (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
136
137
138
139
140
141
142
143
144
145
146
/*
 * Copyright (C) 2003-2013 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "Resolver.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"

#include <glib.h>

#ifndef WIN32
#include <sys/socket.h>
#include <netdb.h>
#else
#include <ws2tcpip.h>
#include <winsock.h>
#endif

#include <string.h>
#include <stdio.h>

const Domain resolver_domain("resolver");

char *
sockaddr_to_string(const struct sockaddr *sa, size_t length, Error &error)
{
#if defined(HAVE_IPV6) && defined(IN6_IS_ADDR_V4MAPPED)
	const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *)sa;
	struct sockaddr_in a4;
#endif
	int ret;
	char host[NI_MAXHOST], serv[NI_MAXSERV];

#if defined(HAVE_IPV6) && defined(IN6_IS_ADDR_V4MAPPED)
	if (sa->sa_family == AF_INET6 &&
	    IN6_IS_ADDR_V4MAPPED(&a6->sin6_addr)) {
		/* convert "::ffff:127.0.0.1" to "127.0.0.1" */

		memset(&a4, 0, sizeof(a4));
		a4.sin_family = AF_INET;
		memcpy(&a4.sin_addr, ((const char *)&a6->sin6_addr) + 12,
		       sizeof(a4.sin_addr));
		a4.sin_port = a6->sin6_port;

		sa = (const struct sockaddr *)&a4;
		length = sizeof(a4);
	}
#endif

	ret = getnameinfo(sa, length, host, sizeof(host), serv, sizeof(serv),
			  NI_NUMERICHOST|NI_NUMERICSERV);
	if (ret != 0) {
		error.Set(resolver_domain, ret, gai_strerror(ret));
		return NULL;
	}

#ifdef HAVE_UN
	if (sa->sa_family == AF_UNIX)
		/* "serv" contains corrupt information with unix
		   sockets */
		return g_strdup(host);
#endif

#ifdef HAVE_IPV6
	if (strchr(host, ':') != NULL)
		return g_strconcat("[", host, "]:", serv, NULL);
#endif

	return g_strconcat(host, ":", serv, NULL);
}

struct addrinfo *
resolve_host_port(const char *host_port, unsigned default_port,
		  int flags, int socktype,
		  Error &error)
{
	char *p = g_strdup(host_port);
	const char *host = p, *port = NULL;

	if (host_port[0] == '[') {
		/* IPv6 needs enclosing square braces, to
		   differentiate between IP colons and the port
		   separator */

		char *q = strchr(p + 1, ']');
		if (q != NULL && q[1] == ':' && q[2] != 0) {
			*q = 0;
			++host;
			port = q + 2;
		}
	}

	if (port == NULL) {
		/* port is after the colon, but only if it's the only
		   colon (don't split IPv6 addresses) */

		char *q = strchr(p, ':');
		if (q != NULL && q[1] != 0 && strchr(q + 1, ':') == NULL) {
			*q = 0;
			port = q + 1;
		}
	}

	char buffer[32];
	if (port == NULL && default_port != 0) {
		snprintf(buffer, sizeof(buffer), "%u", default_port);
		port = buffer;
	}

	if ((flags & AI_PASSIVE) != 0 && strcmp(host, "*") == 0)
		host = NULL;

	addrinfo hints;
	memset(&hints, 0, sizeof(hints));
	hints.ai_flags = flags;
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = socktype;

	struct addrinfo *ai;
	int ret = getaddrinfo(host, port, &hints, &ai);
	g_free(p);
	if (ret != 0) {
		error.Format(resolver_domain, ret,
			     "Failed to look up '%s': %s",
			     host_port, gai_strerror(ret));
		return NULL;
	}

	return ai;
}