xref: /dports/net/samba412/samba-4.12.15/source3/lib/util_sock.c

/*
   Unix SMB/CIFS implementation.
   Samba utility functions
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Tim Potter      2000-2001
   Copyright (C) Jeremy Allison  1992-2007

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "system/filesys.h"
#include "../lib/util/memcache.h"
#include "../lib/async_req/async_sock.h"
#include "../lib/util/select.h"
#include "lib/socket/interfaces.h"
#include "../lib/util/tevent_unix.h"
#include "../lib/util/tevent_ntstatus.h"
#include "../lib/tsocket/tsocket.h"
#include "lib/util/sys_rw.h"
#include "lib/util/sys_rw_data.h"

const char *client_addr(int fd, char *addr, size_t addrlen)
{
	return get_peer_addr(fd,addr,addrlen);
}

#if 0
/* Not currently used. JRA. */
int client_socket_port(int fd)
{
	return get_socket_port(fd);
}
#endif

/****************************************************************************
 Determine if a file descriptor is in fact a socket.
****************************************************************************/

bool is_a_socket(int fd)
{
	int v;
	socklen_t l;
	l = sizeof(int);
	return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
}

/****************************************************************************
 Read from a socket.
****************************************************************************/

ssize_t read_udp_v4_socket(int fd,
			char *buf,
			size_t len,
			struct sockaddr_storage *psa)
{
	ssize_t ret;
	socklen_t socklen = sizeof(*psa);
	struct sockaddr_in *si = (struct sockaddr_in *)psa;

	memset((char *)psa,'\0',socklen);

	ret = (ssize_t)sys_recvfrom(fd,buf,len,0,
			(struct sockaddr *)psa,&socklen);
	if (ret <= 0) {
		/* Don't print a low debug error for a non-blocking socket. */
		if (errno == EAGAIN) {
			DEBUG(10,("read_udp_v4_socket: returned EAGAIN\n"));
		} else {
			DEBUG(2,("read_udp_v4_socket: failed. errno=%s\n",
				strerror(errno)));
		}
		return 0;
	}

	if (psa->ss_family != AF_INET) {
		DEBUG(2,("read_udp_v4_socket: invalid address family %d "
			"(not IPv4)\n", (int)psa->ss_family));
		return 0;
	}

	DEBUG(10,("read_udp_v4_socket: ip %s port %d read: %lu\n",
			inet_ntoa(si->sin_addr),
			si->sin_port,
			(unsigned long)ret));

	return ret;
}

/****************************************************************************
 Read data from a file descriptor with a timout in msec.
 mincount = if timeout, minimum to read before returning
 maxcount = number to be read.
 time_out = timeout in milliseconds
 NB. This can be called with a non-socket fd, don't change
 sys_read() to sys_recv() or other socket call.
****************************************************************************/

NTSTATUS read_fd_with_timeout(int fd, char *buf,
				  size_t mincnt, size_t maxcnt,
				  unsigned int time_out,
				  size_t *size_ret)
{
	int pollrtn;
	ssize_t readret;
	size_t nread = 0;

	/* just checking .... */
	if (maxcnt <= 0)
		return NT_STATUS_OK;

	/* Blocking read */
	if (time_out == 0) {
		if (mincnt == 0) {
			mincnt = maxcnt;
		}

		while (nread < mincnt) {
			readret = sys_read(fd, buf + nread, maxcnt - nread);

			if (readret == 0) {
				DEBUG(5,("read_fd_with_timeout: "
					"blocking read. EOF from client.\n"));
				return NT_STATUS_END_OF_FILE;
			}

			if (readret == -1) {
				return map_nt_error_from_unix(errno);
			}
			nread += readret;
		}
		goto done;
	}

	/* Most difficult - timeout read */
	/* If this is ever called on a disk file and
	   mincnt is greater then the filesize then
	   system performance will suffer severely as
	   select always returns true on disk files */

	for (nread=0; nread < mincnt; ) {
		int revents;

		pollrtn = poll_intr_one_fd(fd, POLLIN|POLLHUP, time_out,
					   &revents);

		/* Check if error */
		if (pollrtn == -1) {
			return map_nt_error_from_unix(errno);
		}

		/* Did we timeout ? */
		if ((pollrtn == 0) ||
		    ((revents & (POLLIN|POLLHUP|POLLERR)) == 0)) {
			DEBUG(10,("read_fd_with_timeout: timeout read. "
				"select timed out.\n"));
			return NT_STATUS_IO_TIMEOUT;
		}

		readret = sys_read(fd, buf+nread, maxcnt-nread);

		if (readret == 0) {
			/* we got EOF on the file descriptor */
			DEBUG(5,("read_fd_with_timeout: timeout read. "
				"EOF from client.\n"));
			return NT_STATUS_END_OF_FILE;
		}

		if (readret == -1) {
			return map_nt_error_from_unix(errno);
		}

		nread += readret;
	}

 done:
	/* Return the number we got */
	if (size_ret) {
		*size_ret = nread;
	}
	return NT_STATUS_OK;
}

/****************************************************************************
 Read data from an fd, reading exactly N bytes.
 NB. This can be called with a non-socket fd, don't add dependencies
 on socket calls.
****************************************************************************/

NTSTATUS read_data_ntstatus(int fd, char *buffer, size_t N)
{
	return read_fd_with_timeout(fd, buffer, N, N, 0, NULL);
}

/****************************************************************************
 Send a keepalive packet (rfc1002).
****************************************************************************/

bool send_keepalive(int client)
{
	unsigned char buf[4];

	buf[0] = NBSSkeepalive;
	buf[1] = buf[2] = buf[3] = 0;

	return(write_data(client,(char *)buf,4) == 4);
}

/****************************************************************************
 Read 4 bytes of a smb packet and return the smb length of the packet.
 Store the result in the buffer.
 This version of the function will return a length of zero on receiving
 a keepalive packet.
 Timeout is in milliseconds.
****************************************************************************/

NTSTATUS read_smb_length_return_keepalive(int fd, char *inbuf,
					  unsigned int timeout,
					  size_t *len)
{
	int msg_type;
	NTSTATUS status;

	status = read_fd_with_timeout(fd, inbuf, 4, 4, timeout, NULL);

	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	*len = smb_len(inbuf);
	msg_type = CVAL(inbuf,0);

	if (msg_type == NBSSkeepalive) {
		DEBUG(5,("Got keepalive packet\n"));
	}

	DEBUG(10,("got smb length of %lu\n",(unsigned long)(*len)));

	return NT_STATUS_OK;
}

/****************************************************************************
 Read an smb from a fd.
 The timeout is in milliseconds.
 This function will return on receipt of a session keepalive packet.
 maxlen is the max number of bytes to return, not including the 4 byte
 length. If zero it means buflen limit.
 Doesn't check the MAC on signed packets.
****************************************************************************/

NTSTATUS receive_smb_raw(int fd, char *buffer, size_t buflen, unsigned int timeout,
			 size_t maxlen, size_t *p_len)
{
	size_t len;
	NTSTATUS status;

	status = read_smb_length_return_keepalive(fd,buffer,timeout,&len);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("read_fd_with_timeout failed, read "
			  "error = %s.\n", nt_errstr(status)));
		return status;
	}

	if (len > buflen) {
		DEBUG(0,("Invalid packet length! (%lu bytes).\n",
					(unsigned long)len));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if(len > 0) {
		if (maxlen) {
			len = MIN(len,maxlen);
		}

		status = read_fd_with_timeout(
			fd, buffer+4, len, len, timeout, &len);

		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(0, ("read_fd_with_timeout failed, read error = "
				  "%s.\n", nt_errstr(status)));
			return status;
		}

		/* not all of samba3 properly checks for packet-termination
		 * of strings. This ensures that we don't run off into
		 * empty space. */
		SSVAL(buffer+4,len, 0);
	}

	*p_len = len;
	return NT_STATUS_OK;
}

/****************************************************************************
 Open a socket of the specified type, port, and address for incoming data.
****************************************************************************/

int open_socket_in(int type,
		uint16_t port,
		int dlevel,
		const struct sockaddr_storage *psock,
		bool rebind)
{
	struct sockaddr_storage sock;
	int res;
	socklen_t slen = sizeof(struct sockaddr_in);

	sock = *psock;

#if defined(HAVE_IPV6)
	if (sock.ss_family == AF_INET6) {
		((struct sockaddr_in6 *)&sock)->sin6_port = htons(port);
		slen = sizeof(struct sockaddr_in6);
	}
#endif
	if (sock.ss_family == AF_INET) {
		((struct sockaddr_in *)&sock)->sin_port = htons(port);
	}

	res = socket(sock.ss_family, type, 0 );
	if( res == -1 ) {
		if( DEBUGLVL(0) ) {
			dbgtext( "open_socket_in(): socket() call failed: " );
			dbgtext( "%s\n", strerror( errno ) );
		}
		return -1;
	}

	/* This block sets/clears the SO_REUSEADDR and possibly SO_REUSEPORT. */
	{
		int val = rebind ? 1 : 0;
		if( setsockopt(res,SOL_SOCKET,SO_REUSEADDR,
					(char *)&val,sizeof(val)) == -1 ) {
			if( DEBUGLVL( dlevel ) ) {
				dbgtext( "open_socket_in(): setsockopt: " );
				dbgtext( "SO_REUSEADDR = %s ",
						val?"true":"false" );
				dbgtext( "on port %d failed ", port );
				dbgtext( "with error = %s\n", strerror(errno) );
			}
		}
#ifdef SO_REUSEPORT
		if( setsockopt(res,SOL_SOCKET,SO_REUSEPORT,
					(char *)&val,sizeof(val)) == -1 ) {
			if( DEBUGLVL( dlevel ) ) {
				dbgtext( "open_socket_in(): setsockopt: ");
				dbgtext( "SO_REUSEPORT = %s ",
						val?"true":"false");
				dbgtext( "on port %d failed ", port);
				dbgtext( "with error = %s\n", strerror(errno));
			}
		}
#endif /* SO_REUSEPORT */
	}

#ifdef HAVE_IPV6
	/*
	 * As IPV6_V6ONLY is the default on some systems,
	 * we better try to be consistent and always use it.
	 *
	 * This also avoids using IPv4 via AF_INET6 sockets
	 * and makes sure %I never resolves to a '::ffff:192.168.0.1'
	 * string.
	 */
	if (sock.ss_family == AF_INET6) {
		int val = 1;
		int ret;

		ret = setsockopt(res, IPPROTO_IPV6, IPV6_V6ONLY,
				 (const void *)&val, sizeof(val));
		if (ret == -1) {
			if(DEBUGLVL(0)) {
				dbgtext("open_socket_in(): IPV6_ONLY failed: ");
				dbgtext("%s\n", strerror(errno));
			}
			close(res);
			return -1;
		}
	}
#endif

	/* now we've got a socket - we need to bind it */
	if (bind(res, (struct sockaddr *)&sock, slen) == -1 ) {
		if( DEBUGLVL(dlevel) && (port == NMB_PORT ||
					 port == NBT_SMB_PORT ||
					 port == TCP_SMB_PORT) ) {
			char addr[INET6_ADDRSTRLEN];
			print_sockaddr(addr, sizeof(addr),
					&sock);
			dbgtext( "bind failed on port %d ", port);
			dbgtext( "socket_addr = %s.\n", addr);
			dbgtext( "Error = %s\n", strerror(errno));
		}
		close(res);
		return -1;
	}

	DEBUG( 10, ( "bind succeeded on port %d\n", port ) );
	return( res );
 }

struct open_socket_out_state {
	int fd;
	struct tevent_context *ev;
	struct sockaddr_storage ss;
	socklen_t salen;
	uint16_t port;
	int wait_usec;
	struct tevent_req *connect_subreq;
};

static void open_socket_out_connected(struct tevent_req *subreq);

static void open_socket_out_cleanup(struct tevent_req *req,
				    enum tevent_req_state req_state)
{
	struct open_socket_out_state *state =
		tevent_req_data(req, struct open_socket_out_state);

	/*
	 * Make sure that the async_connect_send subreq has a chance to reset
	 * fcntl before the socket goes away.
	 */
	TALLOC_FREE(state->connect_subreq);

	if (req_state == TEVENT_REQ_DONE) {
		/*
		 * we keep the socket open for the caller to use
		 */
		return;
	}

	if (state->fd != -1) {
		close(state->fd);
		state->fd = -1;
	}
}

/****************************************************************************
 Create an outgoing socket. timeout is in milliseconds.
**************************************************************************/

struct tevent_req *open_socket_out_send(TALLOC_CTX *mem_ctx,
					struct tevent_context *ev,
					const struct sockaddr_storage *pss,
					uint16_t port,
					int timeout)
{
	char addr[INET6_ADDRSTRLEN];
	struct tevent_req *result;
	struct open_socket_out_state *state;
	NTSTATUS status;

	result = tevent_req_create(mem_ctx, &state,
				   struct open_socket_out_state);
	if (result == NULL) {
		return NULL;
	}
	state->ev = ev;
	state->ss = *pss;
	state->port = port;
	state->wait_usec = 10000;
	state->salen = -1;

	state->fd = socket(state->ss.ss_family, SOCK_STREAM, 0);
	if (state->fd == -1) {
		status = map_nt_error_from_unix(errno);
		goto post_status;
	}

	tevent_req_set_cleanup_fn(result, open_socket_out_cleanup);

	if (!tevent_req_set_endtime(
		    result, ev, timeval_current_ofs_msec(timeout))) {
		goto fail;
	}

#if defined(HAVE_IPV6)
	if (pss->ss_family == AF_INET6) {
		struct sockaddr_in6 *psa6;
		psa6 = (struct sockaddr_in6 *)&state->ss;
		psa6->sin6_port = htons(port);
		if (psa6->sin6_scope_id == 0
		    && IN6_IS_ADDR_LINKLOCAL(&psa6->sin6_addr)) {
			setup_linklocal_scope_id(
				(struct sockaddr *)&(state->ss));
		}
		state->salen = sizeof(struct sockaddr_in6);
	}
#endif
	if (pss->ss_family == AF_INET) {
		struct sockaddr_in *psa;
		psa = (struct sockaddr_in *)&state->ss;
		psa->sin_port = htons(port);
		state->salen = sizeof(struct sockaddr_in);
	}

	if (pss->ss_family == AF_UNIX) {
		state->salen = sizeof(struct sockaddr_un);
	}

	print_sockaddr(addr, sizeof(addr), &state->ss);
	DEBUG(3,("Connecting to %s at port %u\n", addr,	(unsigned int)port));

	state->connect_subreq = async_connect_send(
		state, state->ev, state->fd, (struct sockaddr *)&state->ss,
		state->salen, NULL, NULL, NULL);
	if ((state->connect_subreq == NULL)
	    || !tevent_req_set_endtime(
		    state->connect_subreq, state->ev,
		    timeval_current_ofs(0, state->wait_usec))) {
		goto fail;
	}
	tevent_req_set_callback(state->connect_subreq,
				open_socket_out_connected, result);
	return result;

 post_status:
	tevent_req_nterror(result, status);
	return tevent_req_post(result, ev);
 fail:
	TALLOC_FREE(result);
	return NULL;
}

static void open_socket_out_connected(struct tevent_req *subreq)
{
	struct tevent_req *req =
		tevent_req_callback_data(subreq, struct tevent_req);
	struct open_socket_out_state *state =
		tevent_req_data(req, struct open_socket_out_state);
	int ret;
	int sys_errno;

	ret = async_connect_recv(subreq, &sys_errno);
	TALLOC_FREE(subreq);
	state->connect_subreq = NULL;
	if (ret == 0) {
		tevent_req_done(req);
		return;
	}

	if (
#ifdef ETIMEDOUT
		(sys_errno == ETIMEDOUT) ||
#endif
		(sys_errno == EINPROGRESS) ||
		(sys_errno == EALREADY) ||
		(sys_errno == EAGAIN)) {

		/*
		 * retry
		 */

		if (state->wait_usec < 250000) {
			state->wait_usec *= 1.5;
		}

		subreq = async_connect_send(state, state->ev, state->fd,
					    (struct sockaddr *)&state->ss,
					    state->salen, NULL, NULL, NULL);
		if (tevent_req_nomem(subreq, req)) {
			return;
		}
		if (!tevent_req_set_endtime(
			    subreq, state->ev,
			    timeval_current_ofs_usec(state->wait_usec))) {
			return;
		}
		state->connect_subreq = subreq;
		tevent_req_set_callback(subreq, open_socket_out_connected, req);
		return;
	}

#ifdef EISCONN
	if (sys_errno == EISCONN) {
		tevent_req_done(req);
		return;
	}
#endif

	/* real error */
	tevent_req_nterror(req, map_nt_error_from_unix(sys_errno));
}

NTSTATUS open_socket_out_recv(struct tevent_req *req, int *pfd)
{
	struct open_socket_out_state *state =
		tevent_req_data(req, struct open_socket_out_state);
	NTSTATUS status;

	if (tevent_req_is_nterror(req, &status)) {
		tevent_req_received(req);
		return status;
	}
	*pfd = state->fd;
	state->fd = -1;
	tevent_req_received(req);
	return NT_STATUS_OK;
}

/**
* @brief open a socket
*
* @param pss a struct sockaddr_storage defining the address to connect to
* @param port to connect to
* @param timeout in MILLISECONDS
* @param pfd file descriptor returned
*
* @return NTSTATUS code
*/
NTSTATUS open_socket_out(const struct sockaddr_storage *pss, uint16_t port,
			 int timeout, int *pfd)
{
	TALLOC_CTX *frame = talloc_stackframe();
	struct tevent_context *ev;
	struct tevent_req *req;
	NTSTATUS status = NT_STATUS_NO_MEMORY;

	ev = samba_tevent_context_init(frame);
	if (ev == NULL) {
		goto fail;
	}

	req = open_socket_out_send(frame, ev, pss, port, timeout);
	if (req == NULL) {
		goto fail;
	}
	if (!tevent_req_poll(req, ev)) {
		status = NT_STATUS_INTERNAL_ERROR;
		goto fail;
	}
	status = open_socket_out_recv(req, pfd);
 fail:
	TALLOC_FREE(frame);
	return status;
}

struct open_socket_out_defer_state {
	struct tevent_context *ev;
	struct sockaddr_storage ss;
	uint16_t port;
	int timeout;
	int fd;
};

static void open_socket_out_defer_waited(struct tevent_req *subreq);
static void open_socket_out_defer_connected(struct tevent_req *subreq);

struct tevent_req *open_socket_out_defer_send(TALLOC_CTX *mem_ctx,
					      struct tevent_context *ev,
					      struct timeval wait_time,
					      const struct sockaddr_storage *pss,
					      uint16_t port,
					      int timeout)
{
	struct tevent_req *req, *subreq;
	struct open_socket_out_defer_state *state;

	req = tevent_req_create(mem_ctx, &state,
				struct open_socket_out_defer_state);
	if (req == NULL) {
		return NULL;
	}
	state->ev = ev;
	state->ss = *pss;
	state->port = port;
	state->timeout = timeout;

	subreq = tevent_wakeup_send(
		state, ev,
		timeval_current_ofs(wait_time.tv_sec, wait_time.tv_usec));
	if (subreq == NULL) {
		goto fail;
	}
	tevent_req_set_callback(subreq, open_socket_out_defer_waited, req);
	return req;
 fail:
	TALLOC_FREE(req);
	return NULL;
}

static void open_socket_out_defer_waited(struct tevent_req *subreq)
{
	struct tevent_req *req = tevent_req_callback_data(
		subreq, struct tevent_req);
	struct open_socket_out_defer_state *state = tevent_req_data(
		req, struct open_socket_out_defer_state);
	bool ret;

	ret = tevent_wakeup_recv(subreq);
	TALLOC_FREE(subreq);
	if (!ret) {
		tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
		return;
	}

	subreq = open_socket_out_send(state, state->ev, &state->ss,
				      state->port, state->timeout);
	if (tevent_req_nomem(subreq, req)) {
		return;
	}
	tevent_req_set_callback(subreq, open_socket_out_defer_connected, req);
}

static void open_socket_out_defer_connected(struct tevent_req *subreq)
{
	struct tevent_req *req = tevent_req_callback_data(
		subreq, struct tevent_req);
	struct open_socket_out_defer_state *state = tevent_req_data(
		req, struct open_socket_out_defer_state);
	NTSTATUS status;

	status = open_socket_out_recv(subreq, &state->fd);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		tevent_req_nterror(req, status);
		return;
	}
	tevent_req_done(req);
}

NTSTATUS open_socket_out_defer_recv(struct tevent_req *req, int *pfd)
{
	struct open_socket_out_defer_state *state = tevent_req_data(
		req, struct open_socket_out_defer_state);
	NTSTATUS status;

	if (tevent_req_is_nterror(req, &status)) {
		return status;
	}
	*pfd = state->fd;
	state->fd = -1;
	return NT_STATUS_OK;
}

/****************************************************************************
 Open a connected UDP socket to host on port
**************************************************************************/

int open_udp_socket(const char *host, int port)
{
	struct sockaddr_storage ss;
	int res;
	socklen_t salen;

	if (!interpret_string_addr(&ss, host, 0)) {
		DEBUG(10,("open_udp_socket: can't resolve name %s\n",
			host));
		return -1;
	}

	res = socket(ss.ss_family, SOCK_DGRAM, 0);
	if (res == -1) {
		return -1;
	}

#if defined(HAVE_IPV6)
	if (ss.ss_family == AF_INET6) {
		struct sockaddr_in6 *psa6;
		psa6 = (struct sockaddr_in6 *)&ss;
		psa6->sin6_port = htons(port);
		if (psa6->sin6_scope_id == 0
				&& IN6_IS_ADDR_LINKLOCAL(&psa6->sin6_addr)) {
			setup_linklocal_scope_id(
				(struct sockaddr *)&ss);
		}
		salen = sizeof(struct sockaddr_in6);
	} else
#endif
	if (ss.ss_family == AF_INET) {
		struct sockaddr_in *psa;
		psa = (struct sockaddr_in *)&ss;
		psa->sin_port = htons(port);
	    salen = sizeof(struct sockaddr_in);
	} else {
		DEBUG(1, ("unknown socket family %d", ss.ss_family));
		close(res);
		return -1;
	}

	if (connect(res, (struct sockaddr *)&ss, salen)) {
		close(res);
		return -1;
	}

	return res;
}

/*******************************************************************
 Return the IP addr of the remote end of a socket as a string.
 Optionally return the struct sockaddr_storage.
 ******************************************************************/

static const char *get_peer_addr_internal(int fd,
				char *addr_buf,
				size_t addr_buf_len,
				struct sockaddr *pss,
				socklen_t *plength)
{
	struct sockaddr_storage ss;
	socklen_t length = sizeof(ss);

	strlcpy(addr_buf,"0.0.0.0",addr_buf_len);

	if (fd == -1) {
		return addr_buf;
	}

	if (pss == NULL) {
		pss = (struct sockaddr *)&ss;
		plength = &length;
	}

	if (getpeername(fd, (struct sockaddr *)pss, plength) < 0) {
		int level = (errno == ENOTCONN) ? 2 : 0;
		DEBUG(level, ("getpeername failed. Error was %s\n",
			       strerror(errno)));
		return addr_buf;
	}

	print_sockaddr_len(addr_buf,
			addr_buf_len,
			pss,
			*plength);
	return addr_buf;
}

/*******************************************************************
 Matchname - determine if host name matches IP address. Used to
 confirm a hostname lookup to prevent spoof attacks.
******************************************************************/

static bool matchname(const char *remotehost,
		const struct sockaddr *pss,
		socklen_t len)
{
	struct addrinfo *res = NULL;
	struct addrinfo *ailist = NULL;
	char addr_buf[INET6_ADDRSTRLEN];
	bool ret = interpret_string_addr_internal(&ailist,
			remotehost,
			AI_ADDRCONFIG|AI_CANONNAME);

	if (!ret || ailist == NULL) {
		DEBUG(3,("matchname: getaddrinfo failed for "
			"name %s [%s]\n",
			remotehost,
			gai_strerror(ret) ));
		return false;
	}

	/*
	 * Make sure that getaddrinfo() returns the "correct" host name.
	 */

	if (ailist->ai_canonname == NULL ||
		(!strequal(remotehost, ailist->ai_canonname) &&
		 !strequal(remotehost, "localhost"))) {
		DEBUG(0,("matchname: host name/name mismatch: %s != %s\n",
			 remotehost,
			 ailist->ai_canonname ?
				 ailist->ai_canonname : "(NULL)"));
		freeaddrinfo(ailist);
		return false;
	}

	/* Look up the host address in the address list we just got. */
	for (res = ailist; res; res = res->ai_next) {
		if (!res->ai_addr) {
			continue;
		}
		if (sockaddr_equal((const struct sockaddr *)res->ai_addr,
					(const struct sockaddr *)pss)) {
			freeaddrinfo(ailist);
			return true;
		}
	}

	/*
	 * The host name does not map to the original host address. Perhaps
	 * someone has compromised a name server. More likely someone botched
	 * it, but that could be dangerous, too.
	 */

	DEBUG(0,("matchname: host name/address mismatch: %s != %s\n",
		print_sockaddr_len(addr_buf,
			sizeof(addr_buf),
			pss,
			len),
		 ailist->ai_canonname ? ailist->ai_canonname : "(NULL)"));

	if (ailist) {
		freeaddrinfo(ailist);
	}
	return false;
}

/*******************************************************************
 Deal with the singleton cache.
******************************************************************/

struct name_addr_pair {
	struct sockaddr_storage ss;
	const char *name;
};

/*******************************************************************
 Lookup a name/addr pair. Returns memory allocated from memcache.
******************************************************************/

static bool lookup_nc(struct name_addr_pair *nc)
{
	DATA_BLOB tmp;

	ZERO_STRUCTP(nc);

	if (!memcache_lookup(
			NULL, SINGLETON_CACHE,
			data_blob_string_const_null("get_peer_name"),
			&tmp)) {
		return false;
	}

	memcpy(&nc->ss, tmp.data, sizeof(nc->ss));
	nc->name = (const char *)tmp.data + sizeof(nc->ss);
	return true;
}

/*******************************************************************
 Save a name/addr pair.
******************************************************************/

static void store_nc(const struct name_addr_pair *nc)
{
	DATA_BLOB tmp;
	size_t namelen = strlen(nc->name);

	tmp = data_blob(NULL, sizeof(nc->ss) + namelen + 1);
	if (!tmp.data) {
		return;
	}
	memcpy(tmp.data, &nc->ss, sizeof(nc->ss));
	memcpy(tmp.data+sizeof(nc->ss), nc->name, namelen+1);

	memcache_add(NULL, SINGLETON_CACHE,
			data_blob_string_const_null("get_peer_name"),
			tmp);
	data_blob_free(&tmp);
}

/*******************************************************************
 Return the IP addr of the remote end of a socket as a string.
 ******************************************************************/

const char *get_peer_addr(int fd, char *addr, size_t addr_len)
{
	return get_peer_addr_internal(fd, addr, addr_len, NULL, NULL);
}

int get_remote_hostname(const struct tsocket_address *remote_address,
			char **name,
			TALLOC_CTX *mem_ctx)
{
	char name_buf[MAX_DNS_NAME_LENGTH];
	char tmp_name[MAX_DNS_NAME_LENGTH];
	struct name_addr_pair nc;
	struct sockaddr_storage ss;
	ssize_t len;
	int rc;

	if (!lp_hostname_lookups()) {
		nc.name = tsocket_address_inet_addr_string(remote_address,
							   mem_ctx);
		if (nc.name == NULL) {
			return -1;
		}

		len = tsocket_address_bsd_sockaddr(remote_address,
						   (struct sockaddr *) &nc.ss,
						   sizeof(struct sockaddr_storage));
		if (len < 0) {
			return -1;
		}

		store_nc(&nc);
		lookup_nc(&nc);

		if (nc.name == NULL) {
			*name = talloc_strdup(mem_ctx, "UNKNOWN");
		} else {
			*name = talloc_strdup(mem_ctx, nc.name);
		}
		return 0;
	}

	lookup_nc(&nc);

	ZERO_STRUCT(ss);

	len = tsocket_address_bsd_sockaddr(remote_address,
					   (struct sockaddr *) &ss,
					   sizeof(struct sockaddr_storage));
	if (len < 0) {
		return -1;
	}

	/* it might be the same as the last one - save some DNS work */
	if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&nc.ss)) {
		if (nc.name == NULL) {
			*name = talloc_strdup(mem_ctx, "UNKNOWN");
		} else {
			*name = talloc_strdup(mem_ctx, nc.name);
		}
		return 0;
	}

	/* Look up the remote host name. */
	rc = sys_getnameinfo((struct sockaddr *) &ss,
			     len,
			     name_buf,
			     sizeof(name_buf),
			     NULL,
			     0,
			     0);
	if (rc < 0) {
		char *p;

		p = tsocket_address_inet_addr_string(remote_address, mem_ctx);
		if (p == NULL) {
			return -1;
		}

		DEBUG(1,("getnameinfo failed for %s with error %s\n",
			 p,
			 gai_strerror(rc)));
		strlcpy(name_buf, p, sizeof(name_buf));

		TALLOC_FREE(p);
	} else {
		if (!matchname(name_buf, (struct sockaddr *)&ss, len)) {
			DEBUG(0,("matchname failed on %s\n", name_buf));
			strlcpy(name_buf, "UNKNOWN", sizeof(name_buf));
		}
	}

	strlcpy(tmp_name, name_buf, sizeof(tmp_name));
	alpha_strcpy(name_buf, tmp_name, "_-.", sizeof(name_buf));
	if (strstr(name_buf,"..")) {
		strlcpy(name_buf, "UNKNOWN", sizeof(name_buf));
	}

	nc.name = name_buf;
	nc.ss = ss;

	store_nc(&nc);
	lookup_nc(&nc);

	if (nc.name == NULL) {
		*name = talloc_strdup(mem_ctx, "UNKNOWN");
	} else {
		*name = talloc_strdup(mem_ctx, nc.name);
	}

	return 0;
}

/*******************************************************************
 Create protected unix domain socket.

 Some unixes cannot set permissions on a ux-dom-sock, so we
 have to make sure that the directory contains the protection
 permissions instead.
 ******************************************************************/

int create_pipe_sock(const char *socket_dir,
		     const char *socket_name,
		     mode_t dir_perms)
{
#ifdef HAVE_UNIXSOCKET
	struct sockaddr_un sunaddr;
	bool ok;
	int sock = -1;
	mode_t old_umask;
	char *path = NULL;
	size_t path_len;

	old_umask = umask(0);

	ok = directory_create_or_exist_strict(socket_dir,
					      sec_initial_uid(),
					      dir_perms);
	if (!ok) {
		goto out_close;
	}

	/* Create the socket file */
	sock = socket(AF_UNIX, SOCK_STREAM, 0);

	if (sock == -1) {
		DEBUG(0, ("create_pipe_sock: socket error %s\n",
			strerror(errno) ));
                goto out_close;
	}

	if (asprintf(&path, "%s/%s", socket_dir, socket_name) == -1) {
                goto out_close;
	}

	unlink(path);
	memset(&sunaddr, 0, sizeof(sunaddr));
	sunaddr.sun_family = AF_UNIX;

	path_len = strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path));
	if (path_len > sizeof(sunaddr.sun_path)) {
		DBG_ERR("Refusing to attempt to create pipe socket "
			"%s.  Path is longer than permitted for a "
			"unix domain socket.  It would truncate to "
			"%s\n",
			path,
			sunaddr.sun_path);
		goto out_close;
	}

	if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) {
		DEBUG(0, ("bind failed on pipe socket %s: %s\n", path,
			strerror(errno)));
		goto out_close;
	}

	SAFE_FREE(path);

	umask(old_umask);
	return sock;

out_close:
	SAFE_FREE(path);
	if (sock != -1)
		close(sock);

	umask(old_umask);
	return -1;

#else
        DEBUG(0, ("create_pipe_sock: No Unix sockets on this system\n"));
        return -1;
#endif /* HAVE_UNIXSOCKET */
}

/****************************************************************************
 Get my own canonical name, including domain.
****************************************************************************/

const char *get_mydnsfullname(void)
{
	struct addrinfo *res = NULL;
	char my_hostname[HOST_NAME_MAX];
	bool ret;
	DATA_BLOB tmp;

	if (memcache_lookup(NULL, SINGLETON_CACHE,
			data_blob_string_const_null("get_mydnsfullname"),
			&tmp)) {
		SMB_ASSERT(tmp.length > 0);
		return (const char *)tmp.data;
	}

	/* get my host name */
	if (gethostname(my_hostname, sizeof(my_hostname)) == -1) {
		DEBUG(0,("get_mydnsfullname: gethostname failed\n"));
		return NULL;
	}

	/* Ensure null termination. */
	my_hostname[sizeof(my_hostname)-1] = '\0';

	ret = interpret_string_addr_internal(&res,
				my_hostname,
				AI_ADDRCONFIG|AI_CANONNAME);

	if (!ret || res == NULL) {
		DEBUG(3,("get_mydnsfullname: getaddrinfo failed for "
			"name %s [%s]\n",
			my_hostname,
			gai_strerror(ret) ));
		return NULL;
	}

	/*
	 * Make sure that getaddrinfo() returns the "correct" host name.
	 */

	if (res->ai_canonname == NULL) {
		DEBUG(3,("get_mydnsfullname: failed to get "
			"canonical name for %s\n",
			my_hostname));
		freeaddrinfo(res);
		return NULL;
	}

	/* This copies the data, so we must do a lookup
	 * afterwards to find the value to return.
	 */

	memcache_add(NULL, SINGLETON_CACHE,
			data_blob_string_const_null("get_mydnsfullname"),
			data_blob_string_const_null(res->ai_canonname));

	if (!memcache_lookup(NULL, SINGLETON_CACHE,
			data_blob_string_const_null("get_mydnsfullname"),
			&tmp)) {
		tmp = data_blob_talloc(talloc_tos(), res->ai_canonname,
				strlen(res->ai_canonname) + 1);
	}

	freeaddrinfo(res);

	return (const char *)tmp.data;
}

/************************************************************
 Is this my ip address ?
************************************************************/

static bool is_my_ipaddr(const char *ipaddr_str)
{
	struct sockaddr_storage ss;
	struct iface_struct *nics;
	int i, n;

	if (!interpret_string_addr(&ss, ipaddr_str, AI_NUMERICHOST)) {
		return false;
	}

	if (is_zero_addr(&ss)) {
		return false;
	}

	if (ismyaddr((struct sockaddr *)&ss) ||
			is_loopback_addr((struct sockaddr *)&ss)) {
		return true;
	}

	n = get_interfaces(talloc_tos(), &nics);
	for (i=0; i<n; i++) {
		if (sockaddr_equal((struct sockaddr *)&nics[i].ip, (struct sockaddr *)&ss)) {
			TALLOC_FREE(nics);
			return true;
		}
	}
	TALLOC_FREE(nics);
	return false;
}

/************************************************************
 Is this my name ?
************************************************************/

bool is_myname_or_ipaddr(const char *s)
{
	TALLOC_CTX *ctx = talloc_tos();
	char *name = NULL;
	const char *dnsname;
	char *servername = NULL;

	if (!s) {
		return false;
	}

	/* Santize the string from '\\name' */
	name = talloc_strdup(ctx, s);
	if (!name) {
		return false;
	}

	servername = strrchr_m(name, '\\' );
	if (!servername) {
		servername = name;
	} else {
		servername++;
	}

	/* Optimize for the common case */
	if (strequal(servername, lp_netbios_name())) {
		return true;
	}

	/* Check for an alias */
	if (is_myname(servername)) {
		return true;
	}

	/* Check for loopback */
	if (strequal(servername, "127.0.0.1") ||
			strequal(servername, "::1")) {
		return true;
	}

	if (strequal(servername, "localhost")) {
		return true;
	}

	/* Maybe it's my dns name */
	dnsname = get_mydnsfullname();
	if (dnsname && strequal(servername, dnsname)) {
		return true;
	}

	/* Maybe its an IP address? */
	if (is_ipaddress(servername)) {
		return is_my_ipaddr(servername);
	}

	/* Handle possible CNAME records - convert to an IP addr. list. */
	{
		/* Use DNS to resolve the name, check all addresses. */
		struct addrinfo *p = NULL;
		struct addrinfo *res = NULL;

		if (!interpret_string_addr_internal(&res,
				servername,
				AI_ADDRCONFIG)) {
			return false;
		}

		for (p = res; p; p = p->ai_next) {
			char addr[INET6_ADDRSTRLEN];
			struct sockaddr_storage ss;

			ZERO_STRUCT(ss);
			memcpy(&ss, p->ai_addr, p->ai_addrlen);
			print_sockaddr(addr,
					sizeof(addr),
					&ss);
			if (is_my_ipaddr(addr)) {
				freeaddrinfo(res);
				return true;
			}
		}
		freeaddrinfo(res);
	}

	/* No match */
	return false;
}

int poll_one_fd(int fd, int events, int timeout, int *revents)
{
	struct pollfd pfd;
	int ret;

	pfd.fd = fd;
	pfd.events = events;

	ret = poll(&pfd, 1, timeout);

	/*
	 * Assign whatever poll did, even in the ret<=0 case.
	 */
	*revents = pfd.revents;

	return ret;
}

int poll_intr_one_fd(int fd, int events, int timeout, int *revents)
{
	struct pollfd pfd;
	int ret;

	pfd.fd = fd;
	pfd.events = events;

	ret = sys_poll_intr(&pfd, 1, timeout);
	if (ret <= 0) {
		*revents = 0;
		return ret;
	}
	*revents = pfd.revents;
	return 1;
}