Attempt to fix the IPv4/IPv6 problems once and for all

[deb_shairplay.git] / src / lib / netutils.c

/**
 *  Copyright (C) 2011-2012  Juho Vähä-Herttua
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 */

#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "compat.h"

int
netutils_init()
{
#ifdef WIN32
	WORD wVersionRequested;
	WSADATA wsaData;
	int ret;

	wVersionRequested = MAKEWORD(2, 2);
	ret = WSAStartup(wVersionRequested, &wsaData);
	if (ret) {
		return -1;
	}

	if (LOBYTE(wsaData.wVersion) != 2 ||
	    HIBYTE(wsaData.wVersion) != 2) {
		/* Version mismatch, requested version not found */
		return -1;
	}
#endif
	return 0;
}

void
netutils_cleanup()
{
#ifdef WIN32
	WSACleanup();
#endif
}

int
netutils_init_socket(unsigned short *port, int use_ipv6, int use_udp)
{
	int family = use_ipv6 ? AF_INET6 : AF_INET;
	int type = use_udp ? SOCK_DGRAM : SOCK_STREAM;
	int proto = use_udp ? IPPROTO_UDP : IPPROTO_TCP;

	struct sockaddr_storage saddr;
	socklen_t socklen;
	int server_fd;
	int ret;

	assert(port);

	server_fd = socket(family, type, proto);
	if (server_fd == -1) {
		goto cleanup;
	}

	memset(&saddr, 0, sizeof(saddr));
	if (use_ipv6) {
		struct sockaddr_in6 *sin6ptr = (struct sockaddr_in6 *)&saddr;
		int v6only = 1;

		/* Initialize sockaddr for bind */
		sin6ptr->sin6_family = family;
		sin6ptr->sin6_addr = in6addr_any;
		sin6ptr->sin6_port = htons(*port);

		/* Make sure we only listen to IPv6 addresses */
		setsockopt(server_fd, IPPROTO_IPV6, IPV6_V6ONLY,
		           (char *) &v6only, sizeof(v6only));

		socklen = sizeof(*sin6ptr);
		ret = bind(server_fd, (struct sockaddr *)sin6ptr, socklen);
		if (ret == -1) {
			goto cleanup;
		}

		ret = getsockname(server_fd, (struct sockaddr *)sin6ptr, &socklen);
		if (ret == -1) {
			goto cleanup;
		}
		*port = ntohs(sin6ptr->sin6_port);
	} else {
		struct sockaddr_in *sinptr = (struct sockaddr_in *)&saddr;

		/* Initialize sockaddr for bind */
		sinptr->sin_family = family;
		sinptr->sin_addr.s_addr = INADDR_ANY;
		sinptr->sin_port = htons(*port);

		socklen = sizeof(*sinptr);
		ret = bind(server_fd, (struct sockaddr *)sinptr, socklen);
		if (ret == -1) {
			goto cleanup;
		}

		ret = getsockname(server_fd, (struct sockaddr *)sinptr, &socklen);
		if (ret == -1) {
			goto cleanup;
		}
		*port = ntohs(sinptr->sin_port);
	}
	return server_fd;

cleanup:
	ret = SOCKET_GET_ERROR();
	if (server_fd != -1) {
		closesocket(server_fd);
	}
	SOCKET_SET_ERROR(ret);
	return -1;
}

unsigned char *
netutils_get_address(void *sockaddr, int *length)
{
	unsigned char ipv4_prefix[] = { 0,0,0,0,0,0,0,0,0,0,255,255 };
	struct sockaddr *address = sockaddr;

	assert(address);
	assert(length);

	if (address->sa_family == AF_INET) {
		struct sockaddr_in *sin;

		sin = (struct sockaddr_in *)address;
		*length = sizeof(sin->sin_addr.s_addr);
		return (unsigned char *)&sin->sin_addr.s_addr;
	} else if (address->sa_family == AF_INET6) {
		struct sockaddr_in6 *sin6;

		sin6 = (struct sockaddr_in6 *)address;
		if (!memcmp(sin6->sin6_addr.s6_addr, ipv4_prefix, 12)) {
			/* Actually an embedded IPv4 address */
			*length = sizeof(sin6->sin6_addr.s6_addr)-12;
			return (sin6->sin6_addr.s6_addr+12);
		}
		*length = sizeof(sin6->sin6_addr.s6_addr);
		return sin6->sin6_addr.s6_addr;
	}

	*length = 0;
	return NULL;
}

int
netutils_parse_address(int family, const char *src, void *dst, int dstlen)
{
	struct addrinfo *result;
	struct addrinfo *ptr;
	struct addrinfo hints;
	int length;
	int ret;

	if (family != AF_INET && family != AF_INET6) {
		return -1;
	}
	if (!src || !dst) {
		return -1;
	}

	memset(&hints, 0, sizeof(hints));
	hints.ai_family = family;
	hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;

	ret = getaddrinfo(src, NULL, &hints, &result);
	if (ret != 0) {
		return -1;
	}

	length = -1;
	for (ptr=result; ptr!=NULL; ptr=ptr->ai_next) {
		if (family == ptr->ai_family && (unsigned int)dstlen >= ptr->ai_addrlen) {
			memcpy(dst, ptr->ai_addr, ptr->ai_addrlen);
			length = ptr->ai_addrlen;
			break;
		}
	}
	freeaddrinfo(result);
	return length;
}