/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2010, Digium, Inc.
 *
 * Viagénie <asteriskv6@viagenie.ca>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Network socket handling
 *
 * \author Viagénie <asteriskv6@viagenie.ca>
 */

/*** MODULEINFO
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/config.h"
#include "asterisk/netsock2.h"
#include "asterisk/utils.h"
#include "asterisk/threadstorage.h"

int ast_sockaddr_ipv4_mapped(const struct ast_sockaddr *addr, struct ast_sockaddr *ast_mapped)
{
	const struct sockaddr_in6 *sin6;
	struct sockaddr_in sin4;

	if (!ast_sockaddr_is_ipv6(addr)) {
		return 0;
	}

	if (!ast_sockaddr_is_ipv4_mapped(addr)) {
		return 0;
	}

	sin6 = (const struct sockaddr_in6*)&addr->ss;

	memset(&sin4, 0, sizeof(sin4));
	sin4.sin_family = AF_INET;
	sin4.sin_port = sin6->sin6_port;
	sin4.sin_addr.s_addr = ((uint32_t *)&sin6->sin6_addr)[3];

	ast_sockaddr_from_sin(ast_mapped, &sin4);

	return 1;
}


AST_THREADSTORAGE(ast_sockaddr_stringify_buf);

char *ast_sockaddr_stringify_fmt(const struct ast_sockaddr *sa, int format)
{
	struct ast_sockaddr sa_ipv4;
	const struct ast_sockaddr *sa_tmp;
	char host[NI_MAXHOST];
	char port[NI_MAXSERV];
	struct ast_str *str;
	int e;
	static const size_t size = sizeof(host) - 1 + sizeof(port) - 1 + 4;


	if (ast_sockaddr_isnull(sa)) {
		return "(null)";
	}

	if (!(str = ast_str_thread_get(&ast_sockaddr_stringify_buf, size))) {
		return "";
	}

	if (ast_sockaddr_ipv4_mapped(sa, &sa_ipv4)) {
		sa_tmp = &sa_ipv4;
	} else {
		sa_tmp = sa;
	}

	if ((e = getnameinfo((struct sockaddr *)&sa_tmp->ss, sa_tmp->len,
			     format & AST_SOCKADDR_STR_ADDR ? host : NULL,
			     format & AST_SOCKADDR_STR_ADDR ? sizeof(host) : 0,
			     format & AST_SOCKADDR_STR_PORT ? port : 0,
			     format & AST_SOCKADDR_STR_PORT ? sizeof(port): 0,
			     NI_NUMERICHOST | NI_NUMERICSERV))) {
		ast_log(LOG_ERROR, "getnameinfo(): %s\n", gai_strerror(e));
		return "";
	}

	if ((format & AST_SOCKADDR_STR_REMOTE) == AST_SOCKADDR_STR_REMOTE) {
		char *p;
		if (ast_sockaddr_is_ipv6_link_local(sa) && (p = strchr(host, '%'))) {
			*p = '\0';
		}
	}

	switch ((format & AST_SOCKADDR_STR_FORMAT_MASK))  {
	case AST_SOCKADDR_STR_DEFAULT:
		ast_str_set(&str, 0, sa_tmp->ss.ss_family == AF_INET6 ?
				"[%s]:%s" : "%s:%s", host, port);
		break;
	case AST_SOCKADDR_STR_ADDR:
		ast_str_set(&str, 0, "%s", host);
		break;
	case AST_SOCKADDR_STR_HOST:
		ast_str_set(&str, 0,
			    sa_tmp->ss.ss_family == AF_INET6 ? "[%s]" : "%s", host);
		break;
	case AST_SOCKADDR_STR_PORT:
		ast_str_set(&str, 0, "%s", port);
		break;
	default:
		ast_log(LOG_ERROR, "Invalid format\n");
		return "";
	}

	return ast_str_buffer(str);
}

int ast_sockaddr_cidr_bits(const struct ast_sockaddr *sa)
{
	struct ast_sockaddr sa_ipv4;
	const struct ast_sockaddr *sa_tmp;
	int bits = 0;
	int bytes;
	int i;
	int j;
	char *addr;

	if (ast_sockaddr_isnull(sa)) {
		return 0;
	}

	if (ast_sockaddr_ipv4_mapped(sa, &sa_ipv4)) {
		sa_tmp = &sa_ipv4;
	} else {
		sa_tmp = sa;
	}

	bytes = sa_tmp->len;
	addr = ((struct sockaddr *)&sa_tmp->ss)->sa_data;

	for (i = 0; i < bytes ; ++i) {
		for (j = 0; j < 8; ++j) {
			if ((addr[i] >> j) & 1) {
				bits++;
			}
		}
	}

	return bits;
}

int ast_sockaddr_split_hostport(char *str, char **host, char **port, int flags)
{
	char *s = str;
	char *orig_str = str;/* Original string in case the port presence is incorrect. */
	char *host_end = NULL;/* Delay terminating the host in case the port presence is incorrect. */

	ast_debug(5, "Splitting '%s' into...\n", str);
	*host = NULL;
	*port = NULL;
	if (*s == '[') {
		*host = ++s;
		for (; *s && *s != ']'; ++s) {
		}
		if (*s == ']') {
			host_end = s;
			++s;
		}
		if (*s == ':') {
			*port = s + 1;
		}
	} else {
		*host = s;
		for (; *s; ++s) {
			if (*s == ':') {
				if (*port) {
					*port = NULL;
					break;
				} else {
					*port = s;
				}
			}
		}
		if (*port) {
			host_end = *port;
			++*port;
		}
	}

	switch (flags & PARSE_PORT_MASK) {
	case PARSE_PORT_IGNORE:
		*port = NULL;
		break;
	case PARSE_PORT_REQUIRE:
		if (*port == NULL) {
			ast_log(LOG_WARNING, "Port missing in %s\n", orig_str);
			return 0;
		}
		break;
	case PARSE_PORT_FORBID:
		if (*port != NULL) {
			ast_log(LOG_WARNING, "Port disallowed in %s\n", orig_str);
			return 0;
		}
		break;
	}

	/* Can terminate the host string now if needed. */
	if (host_end) {
		*host_end = '\0';
	}
	ast_debug(5, "...host '%s' and port '%s'.\n", *host, *port ? *port : "");
	return 1;
}



int ast_sockaddr_parse(struct ast_sockaddr *addr, const char *str, int flags)
{
	struct addrinfo hints;
	struct addrinfo	*res;
	char *s;
	char *host;
	char *port;
	int	e;

	s = ast_strdupa(str);
	if (!ast_sockaddr_split_hostport(s, &host, &port, flags)) {
		return 0;
	}

	memset(&hints, 0, sizeof(hints));
	/* Hint to get only one entry from getaddrinfo */
	hints.ai_socktype = SOCK_DGRAM;

#ifdef AI_NUMERICSERV
	hints.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV;
#else
	hints.ai_flags = AI_NUMERICHOST;
#endif
	if ((e = getaddrinfo(host, port, &hints, &res))) {
		if (e != EAI_NONAME) { /* if this was just a host name rather than a ip address, don't print error */
			ast_log(LOG_ERROR, "getaddrinfo(\"%s\", \"%s\", ...): %s\n",
				host, S_OR(port, "(null)"), gai_strerror(e));
		}
		return 0;
	}

	/*
	 * I don't see how this could be possible since we're not resolving host
	 * names. But let's be careful...
	 */
	if (res->ai_next != NULL) {
		ast_log(LOG_WARNING, "getaddrinfo() returned multiple "
			"addresses. Ignoring all but the first.\n");
	}

	if (addr) {
		addr->len = res->ai_addrlen;
		memcpy(&addr->ss, res->ai_addr, addr->len);
	}

	freeaddrinfo(res);

	return 1;
}

int ast_sockaddr_resolve(struct ast_sockaddr **addrs, const char *str,
			 int flags, int family)
{
	struct addrinfo hints, *res, *ai;
	char *s, *host, *port;
	int	e, i, res_cnt;

	if (!str) {
		*addrs = NULL;
		return 0;
	}

	s = ast_strdupa(str);
	if (!ast_sockaddr_split_hostport(s, &host, &port, flags)) {
		*addrs = NULL;
		return 0;
	}

	memset(&hints, 0, sizeof(hints));
	hints.ai_family = family;
	hints.ai_socktype = SOCK_DGRAM;

	if ((e = getaddrinfo(host, port, &hints, &res))) {
		ast_log(LOG_ERROR, "getaddrinfo(\"%s\", \"%s\", ...): %s\n",
			host, S_OR(port, "(null)"), gai_strerror(e));
		*addrs = NULL;
		return 0;
	}

	res_cnt = 0;
	for (ai = res; ai; ai = ai->ai_next) {
		res_cnt++;
	}

	if (res_cnt == 0) {
		*addrs = NULL;
		goto cleanup;
	}

	if ((*addrs = ast_malloc(res_cnt * sizeof(struct ast_sockaddr))) == NULL) {
		res_cnt = 0;
		goto cleanup;
	}

	i = 0;
	for (ai = res; ai; ai = ai->ai_next) {
		(*addrs)[i].len = ai->ai_addrlen;
		memcpy(&(*addrs)[i].ss, ai->ai_addr, ai->ai_addrlen);
		++i;
	}

cleanup:
	freeaddrinfo(res);
	return res_cnt;
}

int ast_sockaddr_apply_netmask(const struct ast_sockaddr *addr, const struct ast_sockaddr *netmask,
		struct ast_sockaddr *result)
{
	int res = 0;

	if (ast_sockaddr_is_ipv4(addr)) {
		struct sockaddr_in result4 = { 0, };
		struct sockaddr_in *addr4 = (struct sockaddr_in *) &addr->ss;
		struct sockaddr_in *mask4 = (struct sockaddr_in *) &netmask->ss;
		result4.sin_family = AF_INET;
		result4.sin_addr.s_addr = addr4->sin_addr.s_addr & mask4->sin_addr.s_addr;
		ast_sockaddr_from_sin(result, &result4);
	} else if (ast_sockaddr_is_ipv6(addr)) {
		struct sockaddr_in6 result6 = { 0, };
		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) &addr->ss;
		struct sockaddr_in6 *mask6 = (struct sockaddr_in6 *) &netmask->ss;
		int i;
		result6.sin6_family = AF_INET6;
		for (i = 0; i < 4; ++i) {
			V6_WORD(&result6, i) = V6_WORD(addr6, i) & V6_WORD(mask6, i);
		}
		memcpy(&result->ss, &result6, sizeof(result6));
		result->len = sizeof(result6);
	} else {
		/* Unsupported address scheme */
		res = -1;
	}

	return res;
}

int ast_sockaddr_cmp(const struct ast_sockaddr *a, const struct ast_sockaddr *b)
{
	const struct ast_sockaddr *a_tmp, *b_tmp;
	struct ast_sockaddr ipv4_mapped;

	a_tmp = a;
	b_tmp = b;

	if (a_tmp->len != b_tmp->len) {
		if (ast_sockaddr_ipv4_mapped(a, &ipv4_mapped)) {
			a_tmp = &ipv4_mapped;
		} else if (ast_sockaddr_ipv4_mapped(b, &ipv4_mapped)) {
			b_tmp = &ipv4_mapped;
		}
	}

	if (a_tmp->len < b_tmp->len) {
		return -1;
	} else if (a_tmp->len > b_tmp->len) {
		return 1;
	}

	return memcmp(&a_tmp->ss, &b_tmp->ss, a_tmp->len);
}

int ast_sockaddr_cmp_addr(const struct ast_sockaddr *a, const struct ast_sockaddr *b)
{
	const struct ast_sockaddr *a_tmp, *b_tmp;
	struct ast_sockaddr ipv4_mapped;
	const struct in_addr *ip4a, *ip4b;
	const struct in6_addr *ip6a, *ip6b;
	int ret = -1;

	a_tmp = a;
	b_tmp = b;

	if (a_tmp->len != b_tmp->len) {
		if (ast_sockaddr_ipv4_mapped(a, &ipv4_mapped)) {
			a_tmp = &ipv4_mapped;
		} else if (ast_sockaddr_ipv4_mapped(b, &ipv4_mapped)) {
			b_tmp = &ipv4_mapped;
		}
	}

	if (a->len < b->len) {
		ret = -1;
	} else if (a->len > b->len) {
		ret = 1;
	}

	switch (a_tmp->ss.ss_family) {
	case AF_INET:
		ip4a = &((const struct sockaddr_in*)&a_tmp->ss)->sin_addr;
		ip4b = &((const struct sockaddr_in*)&b_tmp->ss)->sin_addr;
		ret = memcmp(ip4a, ip4b, sizeof(*ip4a));
		break;
	case AF_INET6:
		ip6a = &((const struct sockaddr_in6*)&a_tmp->ss)->sin6_addr;
		ip6b = &((const struct sockaddr_in6*)&b_tmp->ss)->sin6_addr;
		ret = memcmp(ip6a, ip6b, sizeof(*ip6a));
		break;
	}
	return ret;
}

uint16_t _ast_sockaddr_port(const struct ast_sockaddr *addr, const char *file, int line, const char *func)
{
	/*
	 * Test addr->len first to be tolerant of an ast_sockaddr_setnull()
	 * addr.  In that case addr->len might be the only value initialized.
	 */
	if (addr->len == sizeof(struct sockaddr_in)
		&& addr->ss.ss_family == AF_INET) {
		return ntohs(((struct sockaddr_in *)&addr->ss)->sin_port);
	}
	if (addr->len == sizeof(struct sockaddr_in6)
		&& addr->ss.ss_family == AF_INET6) {
		return ntohs(((struct sockaddr_in6 *)&addr->ss)->sin6_port);
	}
	if (DEBUG_ATLEAST(1)) {
		ast_log(__LOG_DEBUG, file, line, func, "Not an IPv4 nor IPv6 address, cannot get port.\n");
	}
	return 0;
}

void _ast_sockaddr_set_port(struct ast_sockaddr *addr, uint16_t port, const char *file, int line, const char *func)
{
	/*
	 * Test addr->len first to be tolerant of an ast_sockaddr_setnull()
	 * addr.  In that case addr->len might be the only value initialized.
	 */
	if (addr->len == sizeof(struct sockaddr_in)
		&& addr->ss.ss_family == AF_INET) {
		((struct sockaddr_in *)&addr->ss)->sin_port = htons(port);
	} else if (addr->len == sizeof(struct sockaddr_in6)
		&& addr->ss.ss_family == AF_INET6) {
		((struct sockaddr_in6 *)&addr->ss)->sin6_port = htons(port);
	} else if (DEBUG_ATLEAST(1)) {
		ast_log(__LOG_DEBUG, file, line, func,
			"Not an IPv4 nor IPv6 address, cannot set port.\n");
	}
}

uint32_t ast_sockaddr_ipv4(const struct ast_sockaddr *addr)
{
	const struct sockaddr_in *sin = (struct sockaddr_in *)&addr->ss;
	return ntohl(sin->sin_addr.s_addr);
}

int ast_sockaddr_is_ipv4(const struct ast_sockaddr *addr)
{
	/*
	 * Test addr->len first to be tolerant of an ast_sockaddr_setnull()
	 * addr.  In that case addr->len might be the only value initialized.
	 */
	return addr->len == sizeof(struct sockaddr_in)
		&& addr->ss.ss_family == AF_INET;
}

int ast_sockaddr_is_ipv4_mapped(const struct ast_sockaddr *addr)
{
	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&addr->ss;
	return addr->len && IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr);
}

int ast_sockaddr_is_ipv4_multicast(const struct ast_sockaddr *addr)
{
	return ((ast_sockaddr_ipv4(addr) & 0xf0000000) == 0xe0000000);
}

int ast_sockaddr_is_ipv6_link_local(const struct ast_sockaddr *addr)
{
	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&addr->ss;
	return ast_sockaddr_is_ipv6(addr) && IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr);
}

int ast_sockaddr_is_ipv6(const struct ast_sockaddr *addr)
{
	/*
	 * Test addr->len first to be tolerant of an ast_sockaddr_setnull()
	 * addr.  In that case addr->len might be the only value initialized.
	 */
	return addr->len == sizeof(struct sockaddr_in6)
		&& addr->ss.ss_family == AF_INET6;
}

int ast_sockaddr_is_any(const struct ast_sockaddr *addr)
{
	union {
		struct sockaddr_storage ss;
		struct sockaddr_in sin;
		struct sockaddr_in6 sin6;
	} tmp_addr = {
		.ss = addr->ss,
	};

	return (ast_sockaddr_is_ipv4(addr) && (tmp_addr.sin.sin_addr.s_addr == INADDR_ANY)) ||
	    (ast_sockaddr_is_ipv6(addr) && IN6_IS_ADDR_UNSPECIFIED(&tmp_addr.sin6.sin6_addr));
}

int ast_sockaddr_hash(const struct ast_sockaddr *addr)
{
	/*
	 * For IPv4, return the IP address as-is. For IPv6, return the last 32
	 * bits.
	 */
	switch (addr->ss.ss_family) {
	case AF_INET:
		return ((const struct sockaddr_in *)&addr->ss)->sin_addr.s_addr;
	case AF_INET6:
		return ((uint32_t *)&((const struct sockaddr_in6 *)&addr->ss)->sin6_addr)[3];
	default:
		ast_log(LOG_ERROR, "Unknown address family '%d'.\n",
			addr->ss.ss_family);
		return 0;
	}
}

const char *ast_transport2str(enum ast_transport transport)
{
	switch (transport) {
	case AST_TRANSPORT_TLS:
		return "TLS";
	case AST_TRANSPORT_UDP:
		return "UDP";
	case AST_TRANSPORT_TCP:
		return "TCP";
	case AST_TRANSPORT_WS:
		return "WS";
	case AST_TRANSPORT_WSS:
		return "WSS";
	}

	return "Undefined";
}

int ast_accept(int sockfd, struct ast_sockaddr *addr)
{
	addr->len = sizeof(addr->ss);
	return accept(sockfd, (struct sockaddr *)&addr->ss, &addr->len);
}

int ast_bind(int sockfd, const struct ast_sockaddr *addr)
{
	return bind(sockfd, (const struct sockaddr *)&addr->ss, addr->len);
}

int ast_connect(int sockfd, const struct ast_sockaddr *addr)
{
	return connect(sockfd, (const struct sockaddr *)&addr->ss, addr->len);
}

int ast_getsockname(int sockfd, struct ast_sockaddr *addr)
{
	addr->len = sizeof(addr->ss);
	return getsockname(sockfd, (struct sockaddr *)&addr->ss, &addr->len);
}

ssize_t ast_recvfrom(int sockfd, void *buf, size_t len, int flags,
		     struct ast_sockaddr *src_addr)
{
	src_addr->len = sizeof(src_addr->ss);
	return recvfrom(sockfd, buf, len, flags,
			(struct sockaddr *)&src_addr->ss, &src_addr->len);
}

ssize_t ast_sendto(int sockfd, const void *buf, size_t len, int flags,
		   const struct ast_sockaddr *dest_addr)
{
	return sendto(sockfd, buf, len, flags,
		      (const struct sockaddr *)&dest_addr->ss, dest_addr->len);
}

int ast_set_qos(int sockfd, int tos, int cos, const char *desc)
{
	int res = 0;
	int set_tos;
	int set_tclass;
	struct ast_sockaddr addr;

	/* If the sock address is IPv6, the TCLASS field must be set. */
	set_tclass = !ast_getsockname(sockfd, &addr) && ast_sockaddr_is_ipv6(&addr) ? 1 : 0;

	/* If the sock address is IPv4 or (IPv6 set to any address [::]) set TOS bits */
	set_tos = (!set_tclass || (set_tclass && ast_sockaddr_is_any(&addr))) ? 1 : 0;

	if (set_tos) {
		if ((res = setsockopt(sockfd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)))) {
			ast_log(LOG_WARNING, "Unable to set %s DSCP TOS value to %d (may be you have no "
				"root privileges): %s\n", desc, tos, strerror(errno));
		} else if (tos) {
			ast_verb(2, "Using %s TOS bits %d\n", desc, tos);
		}
	}

#if defined(IPV6_TCLASS) && defined(IPPROTO_IPV6)
	if (set_tclass) {
		if (!ast_getsockname(sockfd, &addr) && ast_sockaddr_is_ipv6(&addr)) {
			if ((res = setsockopt(sockfd, IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)))) {
				ast_log(LOG_WARNING, "Unable to set %s DSCP TCLASS field to %d (may be you have no "
					"root privileges): %s\n", desc, tos, strerror(errno));
			} else if (tos) {
				ast_verb(2, "Using %s TOS bits %d in TCLASS field.\n", desc, tos);
			}
		}
	}
#endif

#ifdef linux
	if (setsockopt(sockfd, SOL_SOCKET, SO_PRIORITY, &cos, sizeof(cos))) {
		ast_log(LOG_WARNING, "Unable to set %s CoS to %d: %s\n", desc, cos,
			strerror(errno));
	} else if (cos) {
		ast_verb(2, "Using %s CoS mark %d\n", desc, cos);
	}
#endif

	return res;
}

int _ast_sockaddr_to_sin(const struct ast_sockaddr *addr,
			struct sockaddr_in *sin, const char *file, int line, const char *func)
{
	if (ast_sockaddr_isnull(addr)) {
		memset(sin, 0, sizeof(*sin));
		return 1;
	}

	if (addr->len != sizeof(*sin)) {
		ast_log(__LOG_ERROR, file, line, func, "Bad address cast to IPv4\n");
		return 0;
	}

	if (addr->ss.ss_family != AF_INET && DEBUG_ATLEAST(1)) {
		ast_log(__LOG_DEBUG, file, line, func, "Address family is not AF_INET\n");
	}

	*sin = *(struct sockaddr_in *)&addr->ss;
	return 1;
}

void _ast_sockaddr_from_sin(struct ast_sockaddr *addr, const struct sockaddr_in *sin,
		const char *file, int line, const char *func)
{
	memcpy(&addr->ss, sin, sizeof(*sin));

	if (addr->ss.ss_family != AF_INET && DEBUG_ATLEAST(1)) {
		ast_log(__LOG_DEBUG, file, line, func, "Address family is not AF_INET\n");
	}

	addr->len = sizeof(*sin);
}