drivers/staging/lustre/lnet/lnet/config.c

/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_LNET
#include "../../include/linux/lnet/lib-lnet.h"

struct lnet_text_buf_t {	    /* tmp struct for parsing routes */
	struct list_head	 ltb_list;	/* stash on lists */
	int		ltb_size;	/* allocated size */
	char	       ltb_text[0];     /* text buffer */
};

static int lnet_tbnob;			/* track text buf allocation */
#define LNET_MAX_TEXTBUF_NOB     (64<<10)	/* bound allocation */
#define LNET_SINGLE_TEXTBUF_NOB  (4<<10)

static void
lnet_syntax(char *name, char *str, int offset, int width)
{
	static char dots[LNET_SINGLE_TEXTBUF_NOB];
	static char dashes[LNET_SINGLE_TEXTBUF_NOB];

	memset(dots, '.', sizeof(dots));
	dots[sizeof(dots)-1] = 0;
	memset(dashes, '-', sizeof(dashes));
	dashes[sizeof(dashes)-1] = 0;

	LCONSOLE_ERROR_MSG(0x10f, "Error parsing '%s=\"%s\"'\n", name, str);
	LCONSOLE_ERROR_MSG(0x110, "here...........%.*s..%.*s|%.*s|\n",
			   (int)strlen(name), dots, offset, dots,
			    (width < 1) ? 0 : width - 1, dashes);
}

static int
lnet_issep(char c)
{
	switch (c) {
	case '\n':
	case '\r':
	case ';':
		return 1;
	default:
		return 0;
	}
}

static int
lnet_net_unique(__u32 net, struct list_head *nilist)
{
	struct list_head       *tmp;
	lnet_ni_t	*ni;

	list_for_each(tmp, nilist) {
		ni = list_entry(tmp, lnet_ni_t, ni_list);

		if (LNET_NIDNET(ni->ni_nid) == net)
			return 0;
	}

	return 1;
}

void
lnet_ni_free(struct lnet_ni *ni)
{
	if (ni->ni_refs != NULL)
		cfs_percpt_free(ni->ni_refs);

	if (ni->ni_tx_queues != NULL)
		cfs_percpt_free(ni->ni_tx_queues);

	if (ni->ni_cpts != NULL)
		cfs_expr_list_values_free(ni->ni_cpts, ni->ni_ncpts);

	LIBCFS_FREE(ni, sizeof(*ni));
}

static lnet_ni_t *
lnet_ni_alloc(__u32 net, struct cfs_expr_list *el, struct list_head *nilist)
{
	struct lnet_tx_queue	*tq;
	struct lnet_ni		*ni;
	int			rc;
	int			i;

	if (!lnet_net_unique(net, nilist)) {
		LCONSOLE_ERROR_MSG(0x111, "Duplicate network specified: %s\n",
				   libcfs_net2str(net));
		return NULL;
	}

	LIBCFS_ALLOC(ni, sizeof(*ni));
	if (ni == NULL) {
		CERROR("Out of memory creating network %s\n",
		       libcfs_net2str(net));
		return NULL;
	}

	spin_lock_init(&ni->ni_lock);
	INIT_LIST_HEAD(&ni->ni_cptlist);
	ni->ni_refs = cfs_percpt_alloc(lnet_cpt_table(),
				       sizeof(*ni->ni_refs[0]));
	if (ni->ni_refs == NULL)
		goto failed;

	ni->ni_tx_queues = cfs_percpt_alloc(lnet_cpt_table(),
					    sizeof(*ni->ni_tx_queues[0]));
	if (ni->ni_tx_queues == NULL)
		goto failed;

	cfs_percpt_for_each(tq, i, ni->ni_tx_queues)
		INIT_LIST_HEAD(&tq->tq_delayed);

	if (el == NULL) {
		ni->ni_cpts  = NULL;
		ni->ni_ncpts = LNET_CPT_NUMBER;
	} else {
		rc = cfs_expr_list_values(el, LNET_CPT_NUMBER, &ni->ni_cpts);
		if (rc <= 0) {
			CERROR("Failed to set CPTs for NI %s: %d\n",
			       libcfs_net2str(net), rc);
			goto failed;
		}

		LASSERT(rc <= LNET_CPT_NUMBER);
		if (rc == LNET_CPT_NUMBER) {
			LIBCFS_FREE(ni->ni_cpts, rc * sizeof(ni->ni_cpts[0]));
			ni->ni_cpts = NULL;
		}

		ni->ni_ncpts = rc;
	}

	/* LND will fill in the address part of the NID */
	ni->ni_nid = LNET_MKNID(net, 0);
	ni->ni_last_alive = get_seconds();
	list_add_tail(&ni->ni_list, nilist);
	return ni;
 failed:
	lnet_ni_free(ni);
	return NULL;
}

int
lnet_parse_networks(struct list_head *nilist, char *networks)
{
	struct cfs_expr_list *el = NULL;
	int		tokensize = strlen(networks) + 1;
	char		*tokens;
	char		*str;
	char		*tmp;
	struct lnet_ni	*ni;
	__u32		net;
	int		nnets = 0;

	if (strlen(networks) > LNET_SINGLE_TEXTBUF_NOB) {
		/* _WAY_ conservative */
		LCONSOLE_ERROR_MSG(0x112,
				   "Can't parse networks: string too long\n");
		return -EINVAL;
	}

	LIBCFS_ALLOC(tokens, tokensize);
	if (tokens == NULL) {
		CERROR("Can't allocate net tokens\n");
		return -ENOMEM;
	}

	the_lnet.ln_network_tokens = tokens;
	the_lnet.ln_network_tokens_nob = tokensize;
	memcpy(tokens, networks, tokensize);
	str = tmp = tokens;

	/* Add in the loopback network */
	ni = lnet_ni_alloc(LNET_MKNET(LOLND, 0), NULL, nilist);
	if (ni == NULL)
		goto failed;

	while (str != NULL && *str != 0) {
		char	*comma = strchr(str, ',');
		char	*bracket = strchr(str, '(');
		char	*square = strchr(str, '[');
		char	*iface;
		int	niface;
		int	rc;

		/* NB we don't check interface conflicts here; it's the LNDs
		 * responsibility (if it cares at all) */

		if (square != NULL && (comma == NULL || square < comma)) {
			/* i.e: o2ib0(ib0)[1,2], number between square
			 * brackets are CPTs this NI needs to be bond */
			if (bracket != NULL && bracket > square) {
				tmp = square;
				goto failed_syntax;
			}

			tmp = strchr(square, ']');
			if (tmp == NULL) {
				tmp = square;
				goto failed_syntax;
			}

			rc = cfs_expr_list_parse(square, tmp - square + 1,
						 0, LNET_CPT_NUMBER - 1, &el);
			if (rc != 0) {
				tmp = square;
				goto failed_syntax;
			}

			while (square <= tmp)
				*square++ = ' ';
		}

		if (bracket == NULL ||
		    (comma != NULL && comma < bracket)) {

			/* no interface list specified */

			if (comma != NULL)
				*comma++ = 0;
			net = libcfs_str2net(cfs_trimwhite(str));

			if (net == LNET_NIDNET(LNET_NID_ANY)) {
				LCONSOLE_ERROR_MSG(0x113,
						   "Unrecognised network type\n");
				tmp = str;
				goto failed_syntax;
			}

			if (LNET_NETTYP(net) != LOLND && /* LO is implicit */
			    lnet_ni_alloc(net, el, nilist) == NULL)
				goto failed;

			if (el != NULL) {
				cfs_expr_list_free(el);
				el = NULL;
			}

			str = comma;
			continue;
		}

		*bracket = 0;
		net = libcfs_str2net(cfs_trimwhite(str));
		if (net == LNET_NIDNET(LNET_NID_ANY)) {
			tmp = str;
			goto failed_syntax;
		}

		nnets++;
		ni = lnet_ni_alloc(net, el, nilist);
		if (ni == NULL)
			goto failed;

		if (el != NULL) {
			cfs_expr_list_free(el);
			el = NULL;
		}

		niface = 0;
		iface = bracket + 1;

		bracket = strchr(iface, ')');
		if (bracket == NULL) {
			tmp = iface;
			goto failed_syntax;
		}

		*bracket = 0;
		do {
			comma = strchr(iface, ',');
			if (comma != NULL)
				*comma++ = 0;

			iface = cfs_trimwhite(iface);
			if (*iface == 0) {
				tmp = iface;
				goto failed_syntax;
			}

			if (niface == LNET_MAX_INTERFACES) {
				LCONSOLE_ERROR_MSG(0x115,
						   "Too many interfaces for net %s\n",
						   libcfs_net2str(net));
				goto failed;
			}

			ni->ni_interfaces[niface++] = iface;
			iface = comma;
		} while (iface != NULL);

		str = bracket + 1;
		comma = strchr(bracket + 1, ',');
		if (comma != NULL) {
			*comma = 0;
			str = cfs_trimwhite(str);
			if (*str != 0) {
				tmp = str;
				goto failed_syntax;
			}
			str = comma + 1;
			continue;
		}

		str = cfs_trimwhite(str);
		if (*str != 0) {
			tmp = str;
			goto failed_syntax;
		}
	}

	LASSERT(!list_empty(nilist));
	return 0;

 failed_syntax:
	lnet_syntax("networks", networks, (int)(tmp - tokens), strlen(tmp));
 failed:
	while (!list_empty(nilist)) {
		ni = list_entry(nilist->next, lnet_ni_t, ni_list);

		list_del(&ni->ni_list);
		lnet_ni_free(ni);
	}

	if (el != NULL)
		cfs_expr_list_free(el);

	LIBCFS_FREE(tokens, tokensize);
	the_lnet.ln_network_tokens = NULL;

	return -EINVAL;
}

static struct lnet_text_buf_t *
lnet_new_text_buf(int str_len)
{
	struct lnet_text_buf_t *ltb;
	int	      nob;

	/* NB allocate space for the terminating 0 */
	nob = offsetof(struct lnet_text_buf_t, ltb_text[str_len + 1]);
	if (nob > LNET_SINGLE_TEXTBUF_NOB) {
		/* _way_ conservative for "route net gateway..." */
		CERROR("text buffer too big\n");
		return NULL;
	}

	if (lnet_tbnob + nob > LNET_MAX_TEXTBUF_NOB) {
		CERROR("Too many text buffers\n");
		return NULL;
	}

	LIBCFS_ALLOC(ltb, nob);
	if (ltb == NULL)
		return NULL;

	ltb->ltb_size = nob;
	ltb->ltb_text[0] = 0;
	lnet_tbnob += nob;
	return ltb;
}

static void
lnet_free_text_buf(struct lnet_text_buf_t *ltb)
{
	lnet_tbnob -= ltb->ltb_size;
	LIBCFS_FREE(ltb, ltb->ltb_size);
}

static void
lnet_free_text_bufs(struct list_head *tbs)
{
	struct lnet_text_buf_t  *ltb;

	while (!list_empty(tbs)) {
		ltb = list_entry(tbs->next, struct lnet_text_buf_t, ltb_list);

		list_del(&ltb->ltb_list);
		lnet_free_text_buf(ltb);
	}
}

static int
lnet_str2tbs_sep(struct list_head *tbs, char *str)
{
	struct list_head	pending;
	char	     *sep;
	int	       nob;
	int	       i;
	struct lnet_text_buf_t  *ltb;

	INIT_LIST_HEAD(&pending);

	/* Split 'str' into separate commands */
	for (;;) {
		/* skip leading whitespace */
		while (isspace(*str))
			str++;

		/* scan for separator or comment */
		for (sep = str; *sep != 0; sep++)
			if (lnet_issep(*sep) || *sep == '#')
				break;

		nob = (int)(sep - str);
		if (nob > 0) {
			ltb = lnet_new_text_buf(nob);
			if (ltb == NULL) {
				lnet_free_text_bufs(&pending);
				return -1;
			}

			for (i = 0; i < nob; i++)
				if (isspace(str[i]))
					ltb->ltb_text[i] = ' ';
				else
					ltb->ltb_text[i] = str[i];

			ltb->ltb_text[nob] = 0;

			list_add_tail(&ltb->ltb_list, &pending);
		}

		if (*sep == '#') {
			/* scan for separator */
			do {
				sep++;
			} while (*sep != 0 && !lnet_issep(*sep));
		}

		if (*sep == 0)
			break;

		str = sep + 1;
	}

	list_splice(&pending, tbs->prev);
	return 0;
}

static int
lnet_expand1tb(struct list_head *list,
	       char *str, char *sep1, char *sep2,
	       char *item, int itemlen)
{
	int	      len1 = (int)(sep1 - str);
	int	      len2 = strlen(sep2 + 1);
	struct lnet_text_buf_t *ltb;

	LASSERT(*sep1 == '[');
	LASSERT(*sep2 == ']');

	ltb = lnet_new_text_buf(len1 + itemlen + len2);
	if (ltb == NULL)
		return -ENOMEM;

	memcpy(ltb->ltb_text, str, len1);
	memcpy(&ltb->ltb_text[len1], item, itemlen);
	memcpy(&ltb->ltb_text[len1+itemlen], sep2 + 1, len2);
	ltb->ltb_text[len1 + itemlen + len2] = 0;

	list_add_tail(&ltb->ltb_list, list);
	return 0;
}

static int
lnet_str2tbs_expand(struct list_head *tbs, char *str)
{
	char	      num[16];
	struct list_head	pending;
	char	     *sep;
	char	     *sep2;
	char	     *parsed;
	char	     *enditem;
	int	       lo;
	int	       hi;
	int	       stride;
	int	       i;
	int	       nob;
	int	       scanned;

	INIT_LIST_HEAD(&pending);

	sep = strchr(str, '[');
	if (sep == NULL)			/* nothing to expand */
		return 0;

	sep2 = strchr(sep, ']');
	if (sep2 == NULL)
		goto failed;

	for (parsed = sep; parsed < sep2; parsed = enditem) {

		enditem = ++parsed;
		while (enditem < sep2 && *enditem != ',')
			enditem++;

		if (enditem == parsed)		/* no empty items */
			goto failed;

		if (sscanf(parsed, "%d-%d/%d%n", &lo, &hi,
			   &stride, &scanned) < 3) {

			if (sscanf(parsed, "%d-%d%n", &lo, &hi, &scanned) < 2) {

				/* simple string enumeration */
				if (lnet_expand1tb(
				     &pending, str, sep, sep2,
				     parsed,
				     (int)(enditem - parsed)) != 0) {
					goto failed;
				}

				continue;
			}

			stride = 1;
		}

		/* range expansion */

		if (enditem != parsed + scanned) /* no trailing junk */
			goto failed;

		if (hi < 0 || lo < 0 || stride < 0 || hi < lo ||
		    (hi - lo) % stride != 0)
			goto failed;

		for (i = lo; i <= hi; i += stride) {

			snprintf(num, sizeof(num), "%d", i);
			nob = strlen(num);
			if (nob + 1 == sizeof(num))
				goto failed;

			if (lnet_expand1tb(&pending, str, sep, sep2,
					   num, nob) != 0)
				goto failed;
		}
	}

	list_splice(&pending, tbs->prev);
	return 1;

 failed:
	lnet_free_text_bufs(&pending);
	return -1;
}

static int
lnet_parse_hops(char *str, unsigned int *hops)
{
	int     len = strlen(str);
	int     nob = len;

	return (sscanf(str, "%u%n", hops, &nob) >= 1 &&
		nob == len &&
		*hops > 0 && *hops < 256);
}

#define LNET_PRIORITY_SEPARATOR (':')

static int
lnet_parse_priority(char *str, unsigned int *priority, char **token)
{
	int   nob;
	char *sep;
	int   len;

	sep = strchr(str, LNET_PRIORITY_SEPARATOR);
	if (sep == NULL) {
		*priority = 0;
		return 0;
	}
	len = strlen(sep + 1);

	if ((sscanf((sep+1), "%u%n", priority, &nob) < 1) || (len != nob)) {
		/* Update the caller's token pointer so it treats the found
		   priority as the token to report in the error message. */
		*token += sep - str + 1;
		return -1;
	}

	CDEBUG(D_NET, "gateway %s, priority %d, nob %d\n", str, *priority, nob);

	/*
	 * Change priority separator to \0 to be able to parse NID
	 */
	*sep = '\0';
	return 0;
}

static int
lnet_parse_route(char *str, int *im_a_router)
{
	/* static scratch buffer OK (single threaded) */
	static char       cmd[LNET_SINGLE_TEXTBUF_NOB];

	struct list_head	nets;
	struct list_head	gateways;
	struct list_head       *tmp1;
	struct list_head       *tmp2;
	__u32	     net;
	lnet_nid_t	nid;
	struct lnet_text_buf_t  *ltb;
	int	       rc;
	char	     *sep;
	char	     *token = str;
	int	       ntokens = 0;
	int	       myrc = -1;
	unsigned int      hops;
	int	       got_hops = 0;
	unsigned int	  priority = 0;

	INIT_LIST_HEAD(&gateways);
	INIT_LIST_HEAD(&nets);

	/* save a copy of the string for error messages */
	strncpy(cmd, str, sizeof(cmd) - 1);
	cmd[sizeof(cmd) - 1] = 0;

	sep = str;
	for (;;) {
		/* scan for token start */
		while (isspace(*sep))
			sep++;
		if (*sep == 0) {
			if (ntokens < (got_hops ? 3 : 2))
				goto token_error;
			break;
		}

		ntokens++;
		token = sep++;

		/* scan for token end */
		while (*sep != 0 && !isspace(*sep))
			sep++;
		if (*sep != 0)
			*sep++ = 0;

		if (ntokens == 1) {
			tmp2 = &nets;		/* expanding nets */
		} else if (ntokens == 2 &&
			   lnet_parse_hops(token, &hops)) {
			got_hops = 1;	   /* got a hop count */
			continue;
		} else {
			tmp2 = &gateways;	/* expanding gateways */
		}

		ltb = lnet_new_text_buf(strlen(token));
		if (ltb == NULL)
			goto out;

		strcpy(ltb->ltb_text, token);
		tmp1 = &ltb->ltb_list;
		list_add_tail(tmp1, tmp2);

		while (tmp1 != tmp2) {
			ltb = list_entry(tmp1, struct lnet_text_buf_t,
					 ltb_list);

			rc = lnet_str2tbs_expand(tmp1->next, ltb->ltb_text);
			if (rc < 0)
				goto token_error;

			tmp1 = tmp1->next;

			if (rc > 0) {		/* expanded! */
				list_del(&ltb->ltb_list);
				lnet_free_text_buf(ltb);
				continue;
			}

			if (ntokens == 1) {
				net = libcfs_str2net(ltb->ltb_text);
				if (net == LNET_NIDNET(LNET_NID_ANY) ||
				    LNET_NETTYP(net) == LOLND)
					goto token_error;
			} else {
				rc = lnet_parse_priority(ltb->ltb_text,
							 &priority, &token);
				if (rc < 0)
					goto token_error;

				nid = libcfs_str2nid(ltb->ltb_text);
				if (nid == LNET_NID_ANY ||
				    LNET_NETTYP(LNET_NIDNET(nid)) == LOLND)
					goto token_error;
			}
		}
	}

	if (!got_hops)
		hops = 1;

	LASSERT(!list_empty(&nets));
	LASSERT(!list_empty(&gateways));

	list_for_each(tmp1, &nets) {
		ltb = list_entry(tmp1, struct lnet_text_buf_t, ltb_list);
		net = libcfs_str2net(ltb->ltb_text);
		LASSERT(net != LNET_NIDNET(LNET_NID_ANY));

		list_for_each(tmp2, &gateways) {
			ltb = list_entry(tmp2, struct lnet_text_buf_t,
					 ltb_list);
			nid = libcfs_str2nid(ltb->ltb_text);
			LASSERT(nid != LNET_NID_ANY);

			if (lnet_islocalnid(nid)) {
				*im_a_router = 1;
				continue;
			}

			rc = lnet_add_route(net, hops, nid, priority);
			if (rc != 0) {
				CERROR("Can't create route to %s via %s\n",
				       libcfs_net2str(net),
				       libcfs_nid2str(nid));
				goto out;
			}
		}
	}

	myrc = 0;
	goto out;

 token_error:
	lnet_syntax("routes", cmd, (int)(token - str), strlen(token));
 out:
	lnet_free_text_bufs(&nets);
	lnet_free_text_bufs(&gateways);
	return myrc;
}

static int
lnet_parse_route_tbs(struct list_head *tbs, int *im_a_router)
{
	struct lnet_text_buf_t   *ltb;

	while (!list_empty(tbs)) {
		ltb = list_entry(tbs->next, struct lnet_text_buf_t, ltb_list);

		if (lnet_parse_route(ltb->ltb_text, im_a_router) < 0) {
			lnet_free_text_bufs(tbs);
			return -EINVAL;
		}

		list_del(&ltb->ltb_list);
		lnet_free_text_buf(ltb);
	}

	return 0;
}

int
lnet_parse_routes(char *routes, int *im_a_router)
{
	struct list_head	tbs;
	int	       rc = 0;

	*im_a_router = 0;

	INIT_LIST_HEAD(&tbs);

	if (lnet_str2tbs_sep(&tbs, routes) < 0) {
		CERROR("Error parsing routes\n");
		rc = -EINVAL;
	} else {
		rc = lnet_parse_route_tbs(&tbs, im_a_router);
	}

	LASSERT(lnet_tbnob == 0);
	return rc;
}

static int
lnet_match_network_token(char *token, int len, __u32 *ipaddrs, int nip)
{
	LIST_HEAD(list);
	int		rc;
	int		i;

	rc = cfs_ip_addr_parse(token, len, &list);
	if (rc != 0)
		return rc;

	for (rc = i = 0; !rc && i < nip; i++)
		rc = cfs_ip_addr_match(ipaddrs[i], &list);

	cfs_ip_addr_free(&list);

	return rc;
}

static int
lnet_match_network_tokens(char *net_entry, __u32 *ipaddrs, int nip)
{
	static char tokens[LNET_SINGLE_TEXTBUF_NOB];

	int   matched = 0;
	int   ntokens = 0;
	int   len;
	char *net = NULL;
	char *sep;
	char *token;
	int   rc;

	LASSERT(strlen(net_entry) < sizeof(tokens));

	/* work on a copy of the string */
	strcpy(tokens, net_entry);
	sep = tokens;
	for (;;) {
		/* scan for token start */
		while (isspace(*sep))
			sep++;
		if (*sep == 0)
			break;

		token = sep++;

		/* scan for token end */
		while (*sep != 0 && !isspace(*sep))
			sep++;
		if (*sep != 0)
			*sep++ = 0;

		if (ntokens++ == 0) {
			net = token;
			continue;
		}

		len = strlen(token);

		rc = lnet_match_network_token(token, len, ipaddrs, nip);
		if (rc < 0) {
			lnet_syntax("ip2nets", net_entry,
				    (int)(token - tokens), len);
			return rc;
		}

		matched |= (rc != 0);
	}

	if (!matched)
		return 0;

	strcpy(net_entry, net);		 /* replace with matched net */
	return 1;
}

static __u32
lnet_netspec2net(char *netspec)
{
	char   *bracket = strchr(netspec, '(');
	__u32   net;

	if (bracket != NULL)
		*bracket = 0;

	net = libcfs_str2net(netspec);

	if (bracket != NULL)
		*bracket = '(';

	return net;
}

static int
lnet_splitnets(char *source, struct list_head *nets)
{
	int	       offset = 0;
	int	       offset2;
	int	       len;
	struct lnet_text_buf_t  *tb;
	struct lnet_text_buf_t  *tb2;
	struct list_head       *t;
	char	     *sep;
	char	     *bracket;
	__u32	     net;

	LASSERT(!list_empty(nets));
	LASSERT(nets->next == nets->prev);     /* single entry */

	tb = list_entry(nets->next, struct lnet_text_buf_t, ltb_list);

	for (;;) {
		sep = strchr(tb->ltb_text, ',');
		bracket = strchr(tb->ltb_text, '(');

		if (sep != NULL &&
		    bracket != NULL &&
		    bracket < sep) {
			/* netspec lists interfaces... */

			offset2 = offset + (int)(bracket - tb->ltb_text);
			len = strlen(bracket);

			bracket = strchr(bracket + 1, ')');

			if (bracket == NULL ||
			    !(bracket[1] == ',' || bracket[1] == 0)) {
				lnet_syntax("ip2nets", source, offset2, len);
				return -EINVAL;
			}

			sep = (bracket[1] == 0) ? NULL : bracket + 1;
		}

		if (sep != NULL)
			*sep++ = 0;

		net = lnet_netspec2net(tb->ltb_text);
		if (net == LNET_NIDNET(LNET_NID_ANY)) {
			lnet_syntax("ip2nets", source, offset,
				    strlen(tb->ltb_text));
			return -EINVAL;
		}

		list_for_each(t, nets) {
			tb2 = list_entry(t, struct lnet_text_buf_t, ltb_list);

			if (tb2 == tb)
				continue;

			if (net == lnet_netspec2net(tb2->ltb_text)) {
				/* duplicate network */
				lnet_syntax("ip2nets", source, offset,
					    strlen(tb->ltb_text));
				return -EINVAL;
			}
		}

		if (sep == NULL)
			return 0;

		offset += (int)(sep - tb->ltb_text);
		tb2 = lnet_new_text_buf(strlen(sep));
		if (tb2 == NULL)
			return -ENOMEM;

		strcpy(tb2->ltb_text, sep);
		list_add_tail(&tb2->ltb_list, nets);

		tb = tb2;
	}
}

static int
lnet_match_networks(char **networksp, char *ip2nets, __u32 *ipaddrs, int nip)
{
	static char	networks[LNET_SINGLE_TEXTBUF_NOB];
	static char	source[LNET_SINGLE_TEXTBUF_NOB];

	struct list_head	  raw_entries;
	struct list_head	  matched_nets;
	struct list_head	  current_nets;
	struct list_head	 *t;
	struct list_head	 *t2;
	struct lnet_text_buf_t    *tb;
	struct lnet_text_buf_t    *tb2;
	__u32	       net1;
	__u32	       net2;
	int		 len;
	int		 count;
	int		 dup;
	int		 rc;

	INIT_LIST_HEAD(&raw_entries);
	if (lnet_str2tbs_sep(&raw_entries, ip2nets) < 0) {
		CERROR("Error parsing ip2nets\n");
		LASSERT(lnet_tbnob == 0);
		return -EINVAL;
	}

	INIT_LIST_HEAD(&matched_nets);
	INIT_LIST_HEAD(&current_nets);
	networks[0] = 0;
	count = 0;
	len = 0;
	rc = 0;

	while (!list_empty(&raw_entries)) {
		tb = list_entry(raw_entries.next, struct lnet_text_buf_t,
				    ltb_list);

		strncpy(source, tb->ltb_text, sizeof(source)-1);
		source[sizeof(source)-1] = 0;

		/* replace ltb_text with the network(s) add on match */
		rc = lnet_match_network_tokens(tb->ltb_text, ipaddrs, nip);
		if (rc < 0)
			break;

		list_del(&tb->ltb_list);

		if (rc == 0) {		  /* no match */
			lnet_free_text_buf(tb);
			continue;
		}

		/* split into separate networks */
		INIT_LIST_HEAD(&current_nets);
		list_add(&tb->ltb_list, &current_nets);
		rc = lnet_splitnets(source, &current_nets);
		if (rc < 0)
			break;

		dup = 0;
		list_for_each(t, &current_nets) {
			tb = list_entry(t, struct lnet_text_buf_t, ltb_list);
			net1 = lnet_netspec2net(tb->ltb_text);
			LASSERT(net1 != LNET_NIDNET(LNET_NID_ANY));

			list_for_each(t2, &matched_nets) {
				tb2 = list_entry(t2, struct lnet_text_buf_t,
						     ltb_list);
				net2 = lnet_netspec2net(tb2->ltb_text);
				LASSERT(net2 != LNET_NIDNET(LNET_NID_ANY));

				if (net1 == net2) {
					dup = 1;
					break;
				}
			}

			if (dup)
				break;
		}

		if (dup) {
			lnet_free_text_bufs(&current_nets);
			continue;
		}

		list_for_each_safe(t, t2, &current_nets) {
			tb = list_entry(t, struct lnet_text_buf_t, ltb_list);

			list_del(&tb->ltb_list);
			list_add_tail(&tb->ltb_list, &matched_nets);

			len += snprintf(networks + len, sizeof(networks) - len,
					"%s%s", (len == 0) ? "" : ",",
					tb->ltb_text);

			if (len >= sizeof(networks)) {
				CERROR("Too many matched networks\n");
				rc = -E2BIG;
				goto out;
			}
		}

		count++;
	}

 out:
	lnet_free_text_bufs(&raw_entries);
	lnet_free_text_bufs(&matched_nets);
	lnet_free_text_bufs(&current_nets);
	LASSERT(lnet_tbnob == 0);

	if (rc < 0)
		return rc;

	*networksp = networks;
	return count;
}

static void
lnet_ipaddr_free_enumeration(__u32 *ipaddrs, int nip)
{
	LIBCFS_FREE(ipaddrs, nip * sizeof(*ipaddrs));
}

static int
lnet_ipaddr_enumerate(__u32 **ipaddrsp)
{
	int	up;
	__u32      netmask;
	__u32     *ipaddrs;
	__u32     *ipaddrs2;
	int	nip;
	char     **ifnames;
	int	nif = libcfs_ipif_enumerate(&ifnames);
	int	i;
	int	rc;

	if (nif <= 0)
		return nif;

	LIBCFS_ALLOC(ipaddrs, nif * sizeof(*ipaddrs));
	if (ipaddrs == NULL) {
		CERROR("Can't allocate ipaddrs[%d]\n", nif);
		libcfs_ipif_free_enumeration(ifnames, nif);
		return -ENOMEM;
	}

	for (i = nip = 0; i < nif; i++) {
		if (!strcmp(ifnames[i], "lo"))
			continue;

		rc = libcfs_ipif_query(ifnames[i], &up,
				       &ipaddrs[nip], &netmask);
		if (rc != 0) {
			CWARN("Can't query interface %s: %d\n",
			      ifnames[i], rc);
			continue;
		}

		if (!up) {
			CWARN("Ignoring interface %s: it's down\n",
			      ifnames[i]);
			continue;
		}

		nip++;
	}

	libcfs_ipif_free_enumeration(ifnames, nif);

	if (nip == nif) {
		*ipaddrsp = ipaddrs;
	} else {
		if (nip > 0) {
			LIBCFS_ALLOC(ipaddrs2, nip * sizeof(*ipaddrs2));
			if (ipaddrs2 == NULL) {
				CERROR("Can't allocate ipaddrs[%d]\n", nip);
				nip = -ENOMEM;
			} else {
				memcpy(ipaddrs2, ipaddrs,
				       nip * sizeof(*ipaddrs));
				*ipaddrsp = ipaddrs2;
				rc = nip;
			}
		}
		lnet_ipaddr_free_enumeration(ipaddrs, nif);
	}
	return nip;
}

int
lnet_parse_ip2nets(char **networksp, char *ip2nets)
{
	__u32     *ipaddrs = NULL;
	int	nip = lnet_ipaddr_enumerate(&ipaddrs);
	int	rc;

	if (nip < 0) {
		LCONSOLE_ERROR_MSG(0x117,
				   "Error %d enumerating local IP interfaces for ip2nets to match\n",
				   nip);
		return nip;
	}

	if (nip == 0) {
		LCONSOLE_ERROR_MSG(0x118,
				   "No local IP interfaces for ip2nets to match\n");
		return -ENOENT;
	}

	rc = lnet_match_networks(networksp, ip2nets, ipaddrs, nip);
	lnet_ipaddr_free_enumeration(ipaddrs, nip);

	if (rc < 0) {
		LCONSOLE_ERROR_MSG(0x119, "Error %d parsing ip2nets\n", rc);
		return rc;
	}

	if (rc == 0) {
		LCONSOLE_ERROR_MSG(0x11a,
				   "ip2nets does not match any local IP interfaces\n");
		return -ENOENT;
	}

	return 0;
}

int
lnet_set_ip_niaddr(lnet_ni_t *ni)
{
	__u32  net = LNET_NIDNET(ni->ni_nid);
	char **names;
	int    n;
	__u32  ip;
	__u32  netmask;
	int    up;
	int    i;
	int    rc;

	/* Convenience for LNDs that use the IP address of a local interface as
	 * the local address part of their NID */

	if (ni->ni_interfaces[0] != NULL) {

		CLASSERT(LNET_MAX_INTERFACES > 1);

		if (ni->ni_interfaces[1] != NULL) {
			CERROR("Net %s doesn't support multiple interfaces\n",
			       libcfs_net2str(net));
			return -EPERM;
		}

		rc = libcfs_ipif_query(ni->ni_interfaces[0],
				       &up, &ip, &netmask);
		if (rc != 0) {
			CERROR("Net %s can't query interface %s: %d\n",
			       libcfs_net2str(net), ni->ni_interfaces[0], rc);
			return -EPERM;
		}

		if (!up) {
			CERROR("Net %s can't use interface %s: it's down\n",
			       libcfs_net2str(net), ni->ni_interfaces[0]);
			return -ENETDOWN;
		}

		ni->ni_nid = LNET_MKNID(net, ip);
		return 0;
	}

	n = libcfs_ipif_enumerate(&names);
	if (n <= 0) {
		CERROR("Net %s can't enumerate interfaces: %d\n",
		       libcfs_net2str(net), n);
		return 0;
	}

	for (i = 0; i < n; i++) {
		if (!strcmp(names[i], "lo")) /* skip the loopback IF */
			continue;

		rc = libcfs_ipif_query(names[i], &up, &ip, &netmask);

		if (rc != 0) {
			CWARN("Net %s can't query interface %s: %d\n",
			      libcfs_net2str(net), names[i], rc);
			continue;
		}

		if (!up) {
			CWARN("Net %s ignoring interface %s (down)\n",
			      libcfs_net2str(net), names[i]);
			continue;
		}

		libcfs_ipif_free_enumeration(names, n);
		ni->ni_nid = LNET_MKNID(net, ip);
		return 0;
	}

	CERROR("Net %s can't find any interfaces\n", libcfs_net2str(net));
	libcfs_ipif_free_enumeration(names, n);
	return -ENOENT;
}
EXPORT_SYMBOL(lnet_set_ip_niaddr);