bind9/lib/isc/sockaddr.c

/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <netdb.h>
#include <stdbool.h>
#include <stdio.h>

#include <isc/buffer.h>
#include <isc/hash.h>
#include <isc/net.h>
#include <isc/netaddr.h>
#include <isc/netscope.h>
#include <isc/region.h>
#include <isc/sockaddr.h>
#include <isc/string.h>
#include <isc/types.h>
#include <isc/util.h>

bool
isc_sockaddr_equal(const isc_sockaddr_t *a, const isc_sockaddr_t *b) {
	return (isc_sockaddr_compare(a, b,
				     ISC_SOCKADDR_CMPADDR |
					     ISC_SOCKADDR_CMPPORT |
					     ISC_SOCKADDR_CMPSCOPE));
}

bool
isc_sockaddr_eqaddr(const isc_sockaddr_t *a, const isc_sockaddr_t *b) {
	return (isc_sockaddr_compare(
		a, b, ISC_SOCKADDR_CMPADDR | ISC_SOCKADDR_CMPSCOPE));
}

bool
isc_sockaddr_compare(const isc_sockaddr_t *a, const isc_sockaddr_t *b,
		     unsigned int flags) {
	REQUIRE(a != NULL && b != NULL);

	if (a->length != b->length) {
		return (false);
	}

	/*
	 * We don't just memcmp because the sin_zero field isn't always
	 * zero.
	 */

	if (a->type.sa.sa_family != b->type.sa.sa_family) {
		return (false);
	}
	switch (a->type.sa.sa_family) {
	case AF_INET:
		if ((flags & ISC_SOCKADDR_CMPADDR) != 0 &&
		    memcmp(&a->type.sin.sin_addr, &b->type.sin.sin_addr,
			   sizeof(a->type.sin.sin_addr)) != 0)
		{
			return (false);
		}
		if ((flags & ISC_SOCKADDR_CMPPORT) != 0 &&
		    a->type.sin.sin_port != b->type.sin.sin_port)
		{
			return (false);
		}
		break;
	case AF_INET6:
		if ((flags & ISC_SOCKADDR_CMPADDR) != 0 &&
		    memcmp(&a->type.sin6.sin6_addr, &b->type.sin6.sin6_addr,
			   sizeof(a->type.sin6.sin6_addr)) != 0)
		{
			return (false);
		}
		/*
		 * If ISC_SOCKADDR_CMPSCOPEZERO is set then don't return
		 * false if one of the scopes in zero.
		 */
		if ((flags & ISC_SOCKADDR_CMPSCOPE) != 0 &&
		    a->type.sin6.sin6_scope_id != b->type.sin6.sin6_scope_id &&
		    ((flags & ISC_SOCKADDR_CMPSCOPEZERO) == 0 ||
		     (a->type.sin6.sin6_scope_id != 0 &&
		      b->type.sin6.sin6_scope_id != 0)))
		{
			return (false);
		}
		if ((flags & ISC_SOCKADDR_CMPPORT) != 0 &&
		    a->type.sin6.sin6_port != b->type.sin6.sin6_port)
		{
			return (false);
		}
		break;
	default:
		if (memcmp(&a->type, &b->type, a->length) != 0) {
			return (false);
		}
	}
	return (true);
}

bool
isc_sockaddr_eqaddrprefix(const isc_sockaddr_t *a, const isc_sockaddr_t *b,
			  unsigned int prefixlen) {
	isc_netaddr_t na, nb;
	isc_netaddr_fromsockaddr(&na, a);
	isc_netaddr_fromsockaddr(&nb, b);
	return (isc_netaddr_eqprefix(&na, &nb, prefixlen));
}

isc_result_t
isc_sockaddr_totext(const isc_sockaddr_t *sockaddr, isc_buffer_t *target) {
	isc_result_t result;
	isc_netaddr_t netaddr;
	char pbuf[sizeof("65000")];
	unsigned int plen;
	isc_region_t avail;

	REQUIRE(sockaddr != NULL);

	/*
	 * Do the port first, giving us the opportunity to check for
	 * unsupported address families before calling
	 * isc_netaddr_fromsockaddr().
	 */
	switch (sockaddr->type.sa.sa_family) {
	case AF_INET:
		snprintf(pbuf, sizeof(pbuf), "%u",
			 ntohs(sockaddr->type.sin.sin_port));
		break;
	case AF_INET6:
		snprintf(pbuf, sizeof(pbuf), "%u",
			 ntohs(sockaddr->type.sin6.sin6_port));
		break;
	case AF_UNIX:
		plen = strlen(sockaddr->type.sunix.sun_path);
		if (plen >= isc_buffer_availablelength(target)) {
			return (ISC_R_NOSPACE);
		}

		isc_buffer_putmem(
			target,
			(const unsigned char *)sockaddr->type.sunix.sun_path,
			plen);

		/*
		 * Null terminate after used region.
		 */
		isc_buffer_availableregion(target, &avail);
		INSIST(avail.length >= 1);
		avail.base[0] = '\0';

		return (ISC_R_SUCCESS);
	default:
		return (ISC_R_FAILURE);
	}

	plen = strlen(pbuf);
	INSIST(plen < sizeof(pbuf));

	isc_netaddr_fromsockaddr(&netaddr, sockaddr);
	result = isc_netaddr_totext(&netaddr, target);
	if (result != ISC_R_SUCCESS) {
		return (result);
	}

	if (1 + plen + 1 > isc_buffer_availablelength(target)) {
		return (ISC_R_NOSPACE);
	}

	isc_buffer_putmem(target, (const unsigned char *)"#", 1);
	isc_buffer_putmem(target, (const unsigned char *)pbuf, plen);

	/*
	 * Null terminate after used region.
	 */
	isc_buffer_availableregion(target, &avail);
	INSIST(avail.length >= 1);
	avail.base[0] = '\0';

	return (ISC_R_SUCCESS);
}

void
isc_sockaddr_format(const isc_sockaddr_t *sa, char *array, unsigned int size) {
	isc_result_t result;
	isc_buffer_t buf;

	if (size == 0U) {
		return;
	}

	isc_buffer_init(&buf, array, size);
	result = isc_sockaddr_totext(sa, &buf);
	if (result != ISC_R_SUCCESS) {
		/*
		 * The message is the same as in netaddr.c.
		 */
		snprintf(array, size, "<unknown address, family %u>",
			 sa->type.sa.sa_family);
		array[size - 1] = '\0';
	}
}

unsigned int
isc_sockaddr_hash(const isc_sockaddr_t *sockaddr, bool address_only) {
	unsigned int length = 0;
	const unsigned char *s = NULL;
	unsigned int h = 0;
	unsigned int p = 0;
	const struct in6_addr *in6;

	REQUIRE(sockaddr != NULL);

	switch (sockaddr->type.sa.sa_family) {
	case AF_INET:
		s = (const unsigned char *)&sockaddr->type.sin.sin_addr;
		p = ntohs(sockaddr->type.sin.sin_port);
		length = sizeof(sockaddr->type.sin.sin_addr.s_addr);
		break;
	case AF_INET6:
		in6 = &sockaddr->type.sin6.sin6_addr;
		s = (const unsigned char *)in6;
		if (IN6_IS_ADDR_V4MAPPED(in6)) {
			s += 12;
			length = sizeof(sockaddr->type.sin.sin_addr.s_addr);
		} else {
			length = sizeof(sockaddr->type.sin6.sin6_addr);
		}
		p = ntohs(sockaddr->type.sin6.sin6_port);
		break;
	default:
		UNEXPECTED_ERROR("unknown address family: %d",
				 (int)sockaddr->type.sa.sa_family);
		s = (const unsigned char *)&sockaddr->type;
		length = sockaddr->length;
		p = 0;
	}

	uint8_t buf[sizeof(struct sockaddr_storage) + sizeof(p)];
	memmove(buf, s, length);
	if (!address_only) {
		memmove(buf + length, &p, sizeof(p));
		h = isc_hash_function(buf, length + sizeof(p), true);
	} else {
		h = isc_hash_function(buf, length, true);
	}

	return (h);
}

void
isc_sockaddr_any(isc_sockaddr_t *sockaddr) {
	memset(sockaddr, 0, sizeof(*sockaddr));
	sockaddr->type.sin.sin_family = AF_INET;
	sockaddr->type.sin.sin_addr.s_addr = INADDR_ANY;
	sockaddr->type.sin.sin_port = 0;
	sockaddr->length = sizeof(sockaddr->type.sin);
	ISC_LINK_INIT(sockaddr, link);
}

void
isc_sockaddr_any6(isc_sockaddr_t *sockaddr) {
	memset(sockaddr, 0, sizeof(*sockaddr));
	sockaddr->type.sin6.sin6_family = AF_INET6;
	sockaddr->type.sin6.sin6_addr = in6addr_any;
	sockaddr->type.sin6.sin6_port = 0;
	sockaddr->length = sizeof(sockaddr->type.sin6);
	ISC_LINK_INIT(sockaddr, link);
}

void
isc_sockaddr_fromin(isc_sockaddr_t *sockaddr, const struct in_addr *ina,
		    in_port_t port) {
	memset(sockaddr, 0, sizeof(*sockaddr));
	sockaddr->type.sin.sin_family = AF_INET;
	sockaddr->type.sin.sin_addr = *ina;
	sockaddr->type.sin.sin_port = htons(port);
	sockaddr->length = sizeof(sockaddr->type.sin);
	ISC_LINK_INIT(sockaddr, link);
}

void
isc_sockaddr_anyofpf(isc_sockaddr_t *sockaddr, int pf) {
	switch (pf) {
	case AF_INET:
		isc_sockaddr_any(sockaddr);
		break;
	case AF_INET6:
		isc_sockaddr_any6(sockaddr);
		break;
	default:
		UNREACHABLE();
	}
}

void
isc_sockaddr_fromin6(isc_sockaddr_t *sockaddr, const struct in6_addr *ina6,
		     in_port_t port) {
	memset(sockaddr, 0, sizeof(*sockaddr));
	sockaddr->type.sin6.sin6_family = AF_INET6;
	sockaddr->type.sin6.sin6_addr = *ina6;
	sockaddr->type.sin6.sin6_port = htons(port);
	sockaddr->length = sizeof(sockaddr->type.sin6);
	ISC_LINK_INIT(sockaddr, link);
}

void
isc_sockaddr_v6fromin(isc_sockaddr_t *sockaddr, const struct in_addr *ina,
		      in_port_t port) {
	memset(sockaddr, 0, sizeof(*sockaddr));
	sockaddr->type.sin6.sin6_family = AF_INET6;
	sockaddr->type.sin6.sin6_addr.s6_addr[10] = 0xff;
	sockaddr->type.sin6.sin6_addr.s6_addr[11] = 0xff;
	memmove(&sockaddr->type.sin6.sin6_addr.s6_addr[12], ina, 4);
	sockaddr->type.sin6.sin6_port = htons(port);
	sockaddr->length = sizeof(sockaddr->type.sin6);
	ISC_LINK_INIT(sockaddr, link);
}

int
isc_sockaddr_pf(const isc_sockaddr_t *sockaddr) {
	/*
	 * Get the protocol family of 'sockaddr'.
	 */

#if (AF_INET == PF_INET && AF_INET6 == PF_INET6)
	/*
	 * Assume that PF_xxx == AF_xxx for all AF and PF.
	 */
	return (sockaddr->type.sa.sa_family);
#else  /* if (AF_INET == PF_INET && AF_INET6 == PF_INET6) */
	switch (sockaddr->type.sa.sa_family) {
	case AF_INET:
		return (PF_INET);
	case AF_INET6:
		return (PF_INET6);
	default:
		FATAL_ERROR("unknown address family: %d",
			    (int)sockaddr->type.sa.sa_family);
	}
#endif /* if (AF_INET == PF_INET && AF_INET6 == PF_INET6) */
}

void
isc_sockaddr_fromnetaddr(isc_sockaddr_t *sockaddr, const isc_netaddr_t *na,
			 in_port_t port) {
	memset(sockaddr, 0, sizeof(*sockaddr));
	sockaddr->type.sin.sin_family = na->family;
	switch (na->family) {
	case AF_INET:
		sockaddr->length = sizeof(sockaddr->type.sin);
		sockaddr->type.sin.sin_addr = na->type.in;
		sockaddr->type.sin.sin_port = htons(port);
		break;
	case AF_INET6:
		sockaddr->length = sizeof(sockaddr->type.sin6);
		memmove(&sockaddr->type.sin6.sin6_addr, &na->type.in6, 16);
		sockaddr->type.sin6.sin6_scope_id = isc_netaddr_getzone(na);
		sockaddr->type.sin6.sin6_port = htons(port);
		break;
	default:
		UNREACHABLE();
	}
	ISC_LINK_INIT(sockaddr, link);
}

void
isc_sockaddr_setport(isc_sockaddr_t *sockaddr, in_port_t port) {
	switch (sockaddr->type.sa.sa_family) {
	case AF_INET:
		sockaddr->type.sin.sin_port = htons(port);
		break;
	case AF_INET6:
		sockaddr->type.sin6.sin6_port = htons(port);
		break;
	default:
		FATAL_ERROR("unknown address family: %d",
			    (int)sockaddr->type.sa.sa_family);
	}
}

in_port_t
isc_sockaddr_getport(const isc_sockaddr_t *sockaddr) {
	in_port_t port = 0;

	switch (sockaddr->type.sa.sa_family) {
	case AF_INET:
		port = ntohs(sockaddr->type.sin.sin_port);
		break;
	case AF_INET6:
		port = ntohs(sockaddr->type.sin6.sin6_port);
		break;
	default:
		FATAL_ERROR("unknown address family: %d",
			    (int)sockaddr->type.sa.sa_family);
	}

	return (port);
}

bool
isc_sockaddr_ismulticast(const isc_sockaddr_t *sockaddr) {
	isc_netaddr_t netaddr;

	if (sockaddr->type.sa.sa_family == AF_INET ||
	    sockaddr->type.sa.sa_family == AF_INET6)
	{
		isc_netaddr_fromsockaddr(&netaddr, sockaddr);
		return (isc_netaddr_ismulticast(&netaddr));
	}
	return (false);
}

bool
isc_sockaddr_isexperimental(const isc_sockaddr_t *sockaddr) {
	isc_netaddr_t netaddr;

	if (sockaddr->type.sa.sa_family == AF_INET) {
		isc_netaddr_fromsockaddr(&netaddr, sockaddr);
		return (isc_netaddr_isexperimental(&netaddr));
	}
	return (false);
}

bool
isc_sockaddr_issitelocal(const isc_sockaddr_t *sockaddr) {
	isc_netaddr_t netaddr;

	if (sockaddr->type.sa.sa_family == AF_INET6) {
		isc_netaddr_fromsockaddr(&netaddr, sockaddr);
		return (isc_netaddr_issitelocal(&netaddr));
	}
	return (false);
}

bool
isc_sockaddr_islinklocal(const isc_sockaddr_t *sockaddr) {
	isc_netaddr_t netaddr;

	if (sockaddr->type.sa.sa_family == AF_INET6) {
		isc_netaddr_fromsockaddr(&netaddr, sockaddr);
		return (isc_netaddr_islinklocal(&netaddr));
	}
	return (false);
}

bool
isc_sockaddr_isnetzero(const isc_sockaddr_t *sockaddr) {
	isc_netaddr_t netaddr;

	if (sockaddr->type.sa.sa_family == AF_INET) {
		isc_netaddr_fromsockaddr(&netaddr, sockaddr);
		return (isc_netaddr_isnetzero(&netaddr));
	}
	return (false);
}

isc_result_t
isc_sockaddr_frompath(isc_sockaddr_t *sockaddr, const char *path) {
	if (strlen(path) >= sizeof(sockaddr->type.sunix.sun_path)) {
		return (ISC_R_NOSPACE);
	}
	memset(sockaddr, 0, sizeof(*sockaddr));
	sockaddr->length = sizeof(sockaddr->type.sunix);
	sockaddr->type.sunix.sun_family = AF_UNIX;
	strlcpy(sockaddr->type.sunix.sun_path, path,
		sizeof(sockaddr->type.sunix.sun_path));
	return (ISC_R_SUCCESS);
}

isc_result_t
isc_sockaddr_fromsockaddr(isc_sockaddr_t *isa, const struct sockaddr *sa) {
	unsigned int length = 0;

	switch (sa->sa_family) {
	case AF_INET:
		length = sizeof(isa->type.sin);
		break;
	case AF_INET6:
		length = sizeof(isa->type.sin6);
		break;
	case AF_UNIX:
		length = sizeof(isa->type.sunix);
		break;
	default:
		return (ISC_R_NOTIMPLEMENTED);
	}

	memset(isa, 0, sizeof(isc_sockaddr_t));
	memmove(isa, sa, length);
	isa->length = length;

	return (ISC_R_SUCCESS);
}

isc_result_t
isc_sockaddr_fromtext(const char *hostname, in_port_t port,
		      isc_sockaddr_t *addrs, int addrsize, int *addrcount) {
	struct in_addr in4;
	struct in6_addr in6;
	bool have_ipv4, have_ipv6;
	int i;

	struct addrinfo *ai = NULL, *tmpai, hints;
	int result;

	REQUIRE(hostname != NULL);
	REQUIRE(addrs != NULL);
	REQUIRE(addrcount != NULL);
	REQUIRE(addrsize > 0);

	have_ipv4 = (isc_net_probeipv4() == ISC_R_SUCCESS);
	have_ipv6 = (isc_net_probeipv6() == ISC_R_SUCCESS);

	/*
	 * Try IPv4, then IPv6.  In order to handle the extended format
	 * for IPv6 scoped addresses (address%scope_ID), we'll use a local
	 * working buffer of 128 bytes.  The length is an ad-hoc value, but
	 * should be enough for this purpose; the buffer can contain a string
	 * of at least 80 bytes for scope_ID in addition to any IPv6 numeric
	 * addresses (up to 46 bytes), the delimiter character and the
	 * terminating NULL character.
	 */
	if (inet_pton(AF_INET, hostname, &in4) == 1) {
		if (have_ipv4) {
			isc_sockaddr_fromin(&addrs[0], &in4, port);
		} else {
			isc_sockaddr_v6fromin(&addrs[0], &in4, port);
		}
		*addrcount = 1;
		return (ISC_R_SUCCESS);
	} else if (strlen(hostname) <= 127U) {
		char tmpbuf[128], *d;
		uint32_t zone = 0;

		strlcpy(tmpbuf, hostname, sizeof(tmpbuf));
		d = strchr(tmpbuf, '%');
		if (d != NULL) {
			*d = '\0';
		}

		if (inet_pton(AF_INET6, tmpbuf, &in6) == 1) {
			isc_netaddr_t na;

			if (!have_ipv6) {
				return (ISC_R_FAMILYNOSUPPORT);
			}

			if (d != NULL) {
				isc_result_t iresult;

				iresult = isc_netscope_pton(AF_INET6, d + 1,
							    &in6, &zone);

				if (iresult != ISC_R_SUCCESS) {
					return (iresult);
				}
			}

			isc_netaddr_fromin6(&na, &in6);
			isc_netaddr_setzone(&na, zone);
			isc_sockaddr_fromnetaddr(
				&addrs[0], (const isc_netaddr_t *)&na, port);

			*addrcount = 1;
			return (ISC_R_SUCCESS);
		}
	}
	memset(&hints, 0, sizeof(hints));
	if (!have_ipv6) {
		hints.ai_family = PF_INET;
	} else if (!have_ipv4) {
		hints.ai_family = PF_INET6;
	} else {
		hints.ai_family = PF_UNSPEC;
#ifdef AI_ADDRCONFIG
		hints.ai_flags = AI_ADDRCONFIG;
#endif /* ifdef AI_ADDRCONFIG */
	}
	hints.ai_socktype = SOCK_STREAM;
#ifdef AI_ADDRCONFIG
again:
#endif /* ifdef AI_ADDRCONFIG */
	result = getaddrinfo(hostname, NULL, &hints, &ai);
	switch (result) {
	case 0:
		break;
	case EAI_NONAME:
#if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME)
	case EAI_NODATA:
#endif /* if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME) */
		return (ISC_R_NOTFOUND);
#ifdef AI_ADDRCONFIG
	case EAI_BADFLAGS:
		if ((hints.ai_flags & AI_ADDRCONFIG) != 0) {
			hints.ai_flags &= ~AI_ADDRCONFIG;
			goto again;
		}
#endif /* ifdef AI_ADDRCONFIG */
		FALLTHROUGH;
	default:
		return (ISC_R_FAILURE);
	}
	for (tmpai = ai, i = 0; tmpai != NULL && i < addrsize;
	     tmpai = tmpai->ai_next)
	{
		if (tmpai->ai_family != AF_INET && tmpai->ai_family != AF_INET6)
		{
			continue;
		}
		if (tmpai->ai_family == AF_INET) {
			struct sockaddr_in *sin;
			sin = (struct sockaddr_in *)tmpai->ai_addr;
			isc_sockaddr_fromin(&addrs[i], &sin->sin_addr, port);
		} else {
			struct sockaddr_in6 *sin6;
			sin6 = (struct sockaddr_in6 *)tmpai->ai_addr;
			isc_sockaddr_fromin6(&addrs[i], &sin6->sin6_addr, port);
		}
		i++;
	}
	freeaddrinfo(ai);
	*addrcount = i;
	if (*addrcount == 0) {
		return (ISC_R_NOTFOUND);
	} else {
		return (ISC_R_SUCCESS);
	}
}