iscsi/iscsitgtd/util_ifname.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <libdlpi.h>
#include <ctype.h>
#include <sys/sysmacros.h>
#include <net/if_types.h>
#include <net/if.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <net/if_dl.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <unistd.h>
#include <strings.h>
#include <stropts.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <iscsitgt_impl.h>
#include "target.h"
#include "queue.h"
#include "utility.h"

#define	LOCAL_LOOPBACK	"lo0"

/*
 * This entire file is all about getting these two variables. To create a
 * unique iSCSI IQN string we need information that is unique. What Sun has
 * decided is to use a MAC address along with a timestamp. No other machine
 * at this given time will have the same MAC address and as time moves along
 * well, time will change.
 */
uchar_t 	mac_addr[DLPI_PHYSADDR_MAX];
size_t		mac_len;

static struct lifreq *if_setup(int *n);
static void dump_addr_to_ascii(struct sockaddr *addr, char *buf,
    size_t len);
static Boolean_t grab_address(char *ifname, uchar_t *addrp, size_t *addrlenp);

/*
 * []----
 * | if_find_mac -- Finds a valid MAC address to use for GUID & IQN creation
 * |
 * | To create both the GUID and the IQN string we need to make them unique
 * | and do so without requiring the user to have to register each target
 * | creation with Sun. Each machine that's using iSCSI will have a network
 * | interface from which we can obtain the MAC address. That guarantees
 * | uniqueness within the network, but doesn't guarantee uniqueness with
 * | the machine. So when creating the GUID/IQN we also use a timestamp.
 * []----
 */
Boolean_t
if_find_mac(target_queue_t *mgmt)
{
	struct lifreq	*lifrp, *first;
	int		n;
	char		*str;

	mac_len = DLPI_PHYSADDR_MAX;

	first = if_setup(&n);
	for (lifrp = first; n > 0; n--, lifrp++) {
		if (grab_address(lifrp->lifr_name, mac_addr,
		    &mac_len) == True) {
			str = _link_ntoa(mac_addr, NULL, mac_len, IFT_OTHER);
			if ((str != NULL) && (mgmt != NULL)) {
				queue_prt(mgmt, Q_GEN_DETAILS,
				    "MAIN  %s: %s \n", lifrp->lifr_name, str);
				free(str);
			}
			/* ---- grab the first valid MAC address ---- */
			break;
		}
	}
	if (first)
		free(first);
	return (mac_len == 0 ? False : True);
}

/*
 * []----
 * | if_target_address -- setup IP address for SendTargets
 * |
 * | This routine is called when the iSCSI target is returning SendTargets
 * | data during a discovery phase. The target name is returned along
 * | with all of the IP address that can access that target. There's one
 * | catch, the first address in the list will be the address used by
 * | the initiator if it doesn't support multiple connections per session.
 * | Therefore, whatever connection the initiator used is the first one
 * | that should be in our list. The ramificiations of not doing this are
 * | possible performance issues. Take for example a setup where both the
 * | initiator and target have 10GbE and 1GbE interfaces. The initiator wants
 * | to use the 10GbE interface because of it's speed. If the target returns
 * | a list of addresses with the 1GbE listed first, that's the one which
 * | the initiator would use. Not good.
 * []----
 */
void
if_target_address(char **text, int *text_length, struct sockaddr *sp)
{
	struct lifreq		*lp, *first;
	int			n, i, s;
	struct sockaddr_in	*sin4_cur, *sin4_pos;
	struct sockaddr_in6	*sin6_cur, *sin6_pos;
	char			ta[80], ip_buf[INET6_ADDRSTRLEN];
	int			fromlen;

	if (sp->sa_family == AF_INET) {
		fromlen = sizeof (struct sockaddr_in);

		if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
			return;

		/*LINTED*/
		sin4_cur = (struct sockaddr_in *)sp;

		/*
		 * Ugh. Would you believe that even though this array
		 * is defined as zero, we get back non-zero data from
		 * getsockname().
		 */
		bzero(&sin4_cur->sin_zero[0], sizeof (sin4_cur->sin_zero));

	} else if (sp->sa_family == AF_INET6) {
		fromlen = sizeof (struct sockaddr_in6);

		if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)
			return;

		/*LINTED*/
		sin6_cur = (struct sockaddr_in6 *)sp;
	} else
		return;

	first = if_setup(&n);
	for (lp = first, i = 0; i < n; i++, lp++) {

		if (sp->sa_family != lp->lifr_addr.ss_family)
			continue;

		/*
		 * Change the possible incoming addresses port number,
		 * which would be zero, to that of the current incoming
		 * port number. Otherwise the comparison will not match.
		 */
		if (sp->sa_family == AF_INET) {
			sin4_pos = (struct sockaddr_in *)&lp->lifr_addr;
			sin4_pos->sin_port = sin4_cur->sin_port;
		} else if (sp->sa_family == AF_INET6) {
			sin6_pos = (struct sockaddr_in6 *)&lp->lifr_addr;
			sin6_pos->sin6_port = sin6_cur->sin6_port;
		} else
			goto clean_up;
	}

	for (lp = first, i = 0; i < n; i++, lp++) {

		if (bcmp(sp, &lp->lifr_addr, fromlen) == 0) {
			dump_addr_to_ascii((struct sockaddr *)&lp->lifr_addr,
			    ip_buf, sizeof (ip_buf));

			if (sp->sa_family == AF_INET) {
				(void) snprintf(ta, sizeof (ta), "%s,1",
				    ip_buf);
			} else if (sp->sa_family == AF_INET6) {
				(void) snprintf(ta, sizeof (ta), "[%s],1",
				    ip_buf);
			} else
				goto clean_up;

			(void) add_text(text, text_length, "TargetAddress", ta);

			/*
			 * There is possiblity that both IPv4 & IPv6 enabled on
			 * certain interface, then we will see that interface
			 * twice identically in the list.
			 * Of course we need only one of them, not both.
			 */
			break;
		}
	}

	for (lp = first, i = 0; i < n; i++, lp++) {
		/*
		 * We allow for the loopback address to match the discovery
		 * address above since it's entirely possible to create
		 * a target on the same machine that you're running the
		 * initiator. Now, when we provide the list of other
		 * possible interfaces to use we don't want to include
		 * the loopback because that's obviously not a valid I/F
		 * for a remote node.
		 */
		if (strcmp(lp->lifr_name, LOCAL_LOOPBACK) == 0)
			continue;

		if (bcmp(sp, &lp->lifr_addr, fromlen) != 0) {
			struct sockaddr *sp2;
			sp2 = (struct sockaddr *)&lp->lifr_addr;
			dump_addr_to_ascii(sp2, ip_buf, sizeof (ip_buf));

			if (sp2->sa_family == AF_INET) {
				(void) snprintf(ta, sizeof (ta), "%s,1",
				    ip_buf);
			} else if (sp2->sa_family == AF_INET6) {
				(void) snprintf(ta, sizeof (ta), "[%s],1",
				    ip_buf);
			} else
				goto clean_up;
			(void) add_text(text, text_length, "TargetAddress", ta);
		}
	}

clean_up:
	(void) close(s);
	if (first)
		free(first);
}

/*
 * []----
 * | dump_addr_to_ascii -- Use appropriate translation routine
 * []----
 */
static void
dump_addr_to_ascii(struct sockaddr *addr, char *buf, size_t len)
{
	struct sockaddr_in	*sin4;
	struct sockaddr_in6	*sin6;

	if (addr->sa_family == AF_INET) {
		/*LINTED*/
		sin4 = (struct sockaddr_in *)addr;
		(void) inet_ntop(AF_INET, &sin4->sin_addr, buf, len);
	} else if (addr->sa_family == AF_INET6) {
		/*LINTED*/
		sin6 = (struct sockaddr_in6 *)addr;
		(void) inet_ntop(AF_INET6, &sin6->sin6_addr, buf, len);
	}
}

/*
 * []----
 * | if_setup -- Load up the interface names
 * |
 * | If this routine returns NULL, argument 'n' is also guaranteed to
 * | be set to 0.
 * []----
 */
static struct lifreq *
if_setup(int *n)
{
	struct lifnum	lifn;
	struct lifconf	lifc;
	int		numifs;
	unsigned	bufsize;
	char		*buf;
	int		s;

	*n = 0;
	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1) {
		/*
		 * If we failed to open an IPv6 socket
		 * try IPv4 socket instead
		 */
		if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
			return (NULL);
	}

	lifn.lifn_family = AF_UNSPEC;
	lifn.lifn_flags = LIFC_ALLZONES | LIFC_EXTERNAL_SOURCE;
	if (ioctl(s, SIOCGLIFNUM, (char *)&lifn) < 0)
		return (NULL);

	numifs = lifn.lifn_count;

	bufsize = numifs * sizeof (struct lifreq);
	if ((buf = malloc(bufsize)) == NULL) {
		/*
		 * This call is made so early on that if we're out of memory
		 * here, just say goodbye.
		 */
		return (NULL);
	}

	lifc.lifc_family = AF_UNSPEC;
	lifc.lifc_flags = LIFC_ALLZONES | LIFC_EXTERNAL_SOURCE;
	lifc.lifc_len = bufsize;
	lifc.lifc_buf = buf;

	if (ioctl(s, SIOCGLIFCONF, (char *)&lifc) < 0) {
		free(buf);
		return (NULL);
	}

	(void) close(s);
	*n = lifc.lifc_len / sizeof (struct lifreq);
	return (lifc.lifc_req);
}

static Boolean_t
grab_address(char *ifname, uchar_t *addrp, size_t *addrlenp)
{
	int		retval;
	dlpi_handle_t	dh;

	if (dlpi_open(ifname, &dh, 0) != DLPI_SUCCESS)
		return (False);

	retval = dlpi_get_physaddr(dh, DL_CURR_PHYS_ADDR, addrp, addrlenp);

	dlpi_close(dh);

	return (retval == DLPI_SUCCESS);
}