// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, Intel Corporation.
 */

/* This file is part of Lustre, http://www.lustre.org/
 *
 * Author: Phil Schwan <phil@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_LNET

#include <linux/sunrpc/addr.h>
#include <libcfs/libcfs.h>
#include <uapi/linux/lnet/nidstr.h>
#include <lnet/lib-types.h>

/* max value for numeric network address */
#define MAX_NUMERIC_VALUE 0xffffffff

#define IPSTRING_LENGTH 16

/* CAVEAT VENDITOR! Keep the canonical string representation of nets/nids
 * consistent in all conversion functions.  Some code fragments are copied
 * around for the sake of clarity...
 */

/* CAVEAT EMPTOR! Racey temporary buffer allocation!
 * Choose the number of nidstrings to support the MAXIMUM expected number of
 * concurrent users.  If there are more, the returned string will be volatile.
 * NB this number must allow for a process to be descheduled for a timeslice
 * between getting its string and using it.
 */

static char	 libcfs_nidstrings[LNET_NIDSTR_COUNT][LNET_NIDSTR_SIZE];
static int	 libcfs_nidstring_idx;

static DEFINE_SPINLOCK(libcfs_nidstring_lock);

static struct netstrfns *libcfs_namenum2netstrfns(const char *name);

char *
libcfs_next_nidstring(void)
{
	char	      *str;
	unsigned long  flags;

	spin_lock_irqsave(&libcfs_nidstring_lock, flags);

	str = libcfs_nidstrings[libcfs_nidstring_idx++];
	if (libcfs_nidstring_idx == ARRAY_SIZE(libcfs_nidstrings))
		libcfs_nidstring_idx = 0;

	spin_unlock_irqrestore(&libcfs_nidstring_lock, flags);
	return str;
}
EXPORT_SYMBOL(libcfs_next_nidstring);

/**
 * Nid range list syntax.
 * \verbatim
 *
 * <nidlist>	     :== <nidrange> [ ' ' <nidrange> ]
 * <nidrange>	     :== <addrrange> '@' <net>
 * <addrrange>	     :== '*' |
 *			 <ipaddr_range> |
 *			 <cfs_expr_list>
 * <ipaddr_range>    :== <cfs_expr_list>.<cfs_expr_list>.<cfs_expr_list>.
 *			 <cfs_expr_list>
 * <cfs_expr_list>   :== <number> |
 *			 <expr_list>
 * <expr_list>	     :== '[' <range_expr> [ ',' <range_expr>] ']'
 * <range_expr>      :== <number> |
 *			 <number> '-' <number> |
 *			 <number> '-' <number> '/' <number>
 * <net>	     :== <netname> | <netname><number>
 * <netname>	     :== "lo" | "tcp" | "o2ib" | "cib" | "openib" | "iib" |
 *			 "vib" | "ra" | "elan" | "mx" | "ptl"
 * \endverbatim
 */

/**
 * Structure to represent \<nidrange\> token of the syntax.
 *
 * One of this is created for each \<net\> parsed.
 */
struct nidrange {
	/**
	 * Link to list of this structures which is built on nid range
	 * list parsing.
	 */
	struct list_head nr_link;
	/**
	 * List head for addrrange::ar_link.
	 */
	struct list_head nr_addrranges;
	/**
	 * Flag indicating that *@<net> is found.
	 */
	int nr_all;
	/**
	 * Pointer to corresponding element of libcfs_netstrfns.
	 */
	struct netstrfns *nr_netstrfns;
	/**
	 * Number of network. E.g. 5 if \<net\> is "elan5".
	 */
	int nr_netnum;
};

/**
 * Structure to represent \<addrrange\> token of the syntax.
 */
struct addrrange {
	/**
	 * Link to nidrange::nr_addrranges.
	 */
	struct list_head ar_link;
	/**
	 * List head for cfs_expr_list::el_list.
	 */
	struct list_head ar_numaddr_ranges;
};

/**
 * Parses \<range_expr\> token of the syntax. If \a bracketed is false,
 * \a src should only have a single token which can be \<number\> or  \*
 *
 * \retval pointer to allocated range_expr and initialized
 * range_expr::re_lo, range_expr::re_hi and range_expr:re_stride if \a
 `* src parses to
 * \<number\> |
 * \<number\> '-' \<number\> |
 * \<number\> '-' \<number\> '/' \<number\>
 * \retval 0 will be returned if it can be parsed, otherwise -EINVAL or
 * -ENOMEM will be returned.
 */
static int
cfs_range_expr_parse(char *src, unsigned int min, unsigned int max,
		     int bracketed, struct cfs_range_expr **expr)
{
	struct cfs_range_expr *re;
	char *tok;
	unsigned int num;

	LIBCFS_ALLOC(re, sizeof(*re));
	if (!re)
		return -ENOMEM;

	src = strim(src);
	if (strcmp(src, "*") == 0) {
		re->re_lo = min;
		re->re_hi = max;
		re->re_stride = 1;
		goto out;
	}

	if (kstrtouint(src, 0, &num) == 0) {
		if (num < min || num > max)
			goto failed;
		/* <number> is parsed */
		re->re_lo = num;
		re->re_hi = re->re_lo;
		re->re_stride = 1;
		goto out;
	}

	if (!bracketed)
		goto failed;
	tok = strim(strsep(&src, "-"));
	if (!src)
		goto failed;
	if (kstrtouint(tok, 0, &num) != 0 ||
	    num < min || num > max)
		goto failed;
	re->re_lo = num;

	/* <number> - */
	if (kstrtouint(strim(src), 0, &num) == 0) {
		if (num < min || num > max)
			goto failed;
		re->re_hi = num;
		/* <number> - <number> is parsed */
		re->re_stride = 1;
		goto out;
	}

	/* go to check <number> '-' <number> '/' <number> */
	tok = strim(strsep(&src, "/"));
	if (!src)
		goto failed;
	if (kstrtouint(tok, 0, &num) != 0 ||
	    num < min || num > max)
		goto failed;
	re->re_hi = num;
	if (kstrtouint(strim(src), 0, &num) != 0 ||
	    num < min || num > max)
		goto failed;
	re->re_stride = num;

out:
	*expr = re;
	return 0;

failed:
	LIBCFS_FREE(re, sizeof(*re));
	return -EINVAL;
}

/**
 * Matches value (\a value) against ranges expression list \a expr_list.
 *
 * \retval 1 if \a value matches
 * \retval 0 otherwise
 */
int
cfs_expr_list_match(u32 value, struct cfs_expr_list *expr_list)
{
	struct cfs_range_expr *expr;

	list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
		if (value >= expr->re_lo && value <= expr->re_hi &&
		    ((value - expr->re_lo) % expr->re_stride) == 0)
			return 1;
	}

	return 0;
}

/**
 * Convert express list (\a expr_list) to an array of all matched values
 *
 * \retval N N is total number of all matched values
 * \retval 0 if expression list is empty
 * \retval < 0 for failure
 */
int
cfs_expr_list_values(struct cfs_expr_list *expr_list, int max, u32 **valpp)
{
	struct cfs_range_expr *expr;
	int count = 0;
	u32 *val;
	int i;

	list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
		for (i = expr->re_lo; i <= expr->re_hi; i++) {
			if (((i - expr->re_lo) % expr->re_stride) == 0)
				count++;
		}
	}

	if (count == 0) /* empty expression list */
		return 0;

	if (count > max) {
		CERROR("Number of values %d exceeds max allowed %d\n",
		       max, count);
		return -EINVAL;
	}

	CFS_ALLOC_PTR_ARRAY(val, count);
	if (!val)
		return -ENOMEM;

	count = 0;
	list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
		for (i = expr->re_lo; i <= expr->re_hi; i++) {
			if (((i - expr->re_lo) % expr->re_stride) == 0)
				val[count++] = i;
		}
	}

	*valpp = val;
	return count;
}
EXPORT_SYMBOL(cfs_expr_list_values);

/**
 * Frees cfs_range_expr structures of \a expr_list.
 *
 * \retval none
 */
void
cfs_expr_list_free(struct cfs_expr_list *expr_list)
{
	while (!list_empty(&expr_list->el_exprs)) {
		struct cfs_range_expr *expr;

		expr = list_entry(expr_list->el_exprs.next,
				      struct cfs_range_expr, re_link);
		list_del(&expr->re_link);
		LIBCFS_FREE(expr, sizeof(*expr));
	}

	LIBCFS_FREE(expr_list, sizeof(*expr_list));
}
EXPORT_SYMBOL(cfs_expr_list_free);

/**
 * Parses \<cfs_expr_list\> token of the syntax.
 *
 * \retval 0 if \a str parses to \<number\> | \<expr_list\>
 * \retval -errno otherwise
 */
int
cfs_expr_list_parse(char *str, int len, unsigned int min, unsigned int max,
		    struct cfs_expr_list **elpp)
{
	struct cfs_expr_list *expr_list;
	struct cfs_range_expr *expr;
	char *src;
	int rc;

	CFS_ALLOC_PTR(expr_list);
	if (!expr_list)
		return -ENOMEM;

	str = kstrndup(str, len, GFP_KERNEL);
	if (!str) {
		CFS_FREE_PTR(expr_list);
		return -ENOMEM;
	}

	src = str;

	INIT_LIST_HEAD(&expr_list->el_exprs);

	if (src[0] == '[' &&
	    src[strlen(src) - 1] == ']') {
		src++;
		src[strlen(src)-1] = '\0';

		rc = -EINVAL;
		while (src) {
			char *tok = strsep(&src, ",");

			if (!*tok) {
				rc = -EINVAL;
				break;
			}
			tok = strim(tok);

			rc = cfs_range_expr_parse(tok, min, max, 1, &expr);
			if (rc != 0)
				break;

			list_add_tail(&expr->re_link, &expr_list->el_exprs);
		}
	} else {
		rc = cfs_range_expr_parse(src, min, max, 0, &expr);
		if (rc == 0)
			list_add_tail(&expr->re_link, &expr_list->el_exprs);
	}
	kfree(str);

	if (rc != 0)
		cfs_expr_list_free(expr_list);
	else
		*elpp = expr_list;

	return rc;
}
EXPORT_SYMBOL(cfs_expr_list_parse);

/**
 * Frees cfs_expr_list structures of \a list.
 *
 * For each struct cfs_expr_list structure found on \a list it frees
 * range_expr list attached to it and frees the cfs_expr_list itself.
 *
 * \retval none
 */
void
cfs_expr_list_free_list(struct list_head *list)
{
	struct cfs_expr_list *el;

	while (!list_empty(list)) {
		el = list_first_entry(list,
				      struct cfs_expr_list, el_link);
		list_del(&el->el_link);
		cfs_expr_list_free(el);
	}
}

/**
 * Parses \<addrrange\> token on the syntax.
 *
 * Allocates struct addrrange and links to \a nidrange via
 * (nidrange::nr_addrranges)
 *
 * \retval 0 if \a src parses to '*' | \<ipaddr_range\> | \<cfs_expr_list\>
 * \retval -errno otherwise
 */
static int
parse_addrange(char *str, struct nidrange *nidrange)
{
	struct addrrange *addrrange;

	if (strcmp(str, "*") == 0) {
		nidrange->nr_all = 1;
		return 0;
	}

	CFS_ALLOC_PTR(addrrange);
	if (addrrange == NULL)
		return -ENOMEM;
	list_add_tail(&addrrange->ar_link, &nidrange->nr_addrranges);
	INIT_LIST_HEAD(&addrrange->ar_numaddr_ranges);

	return nidrange->nr_netstrfns->nf_parse_addrlist(str, strlen(str),
						&addrrange->ar_numaddr_ranges);
}

/**
 * Finds or creates struct nidrange.
 *
 * Checks if \a src is a valid network name, looks for corresponding
 * nidrange on the ist of nidranges (\a nidlist), creates new struct
 * nidrange if it is not found.
 *
 * \retval pointer to struct nidrange matching network specified via \a src
 * \retval NULL if \a src does not match any network
 */
static struct nidrange *
add_nidrange(char *str, struct list_head *nidlist)
{
	struct netstrfns *nf;
	struct nidrange *nr;
	char *end;
	unsigned int netnum;

	nf = libcfs_namenum2netstrfns(str);
	if (nf == NULL)
		return NULL;
	end = str + strlen(nf->nf_name);
	if (!*end) {
		/* network name only, e.g. "elan" or "tcp" */
		netnum = 0;
	} else {
		/* e.g. "elan25" or "tcp23", refuse to parse if
		 * network name is not appended with decimal or
		 * hexadecimal number
		 */
		if (kstrtouint(end, 0, &netnum) != 0)
			return NULL;
	}

	list_for_each_entry(nr, nidlist, nr_link) {
		if (nr->nr_netstrfns != nf)
			continue;
		if (nr->nr_netnum != netnum)
			continue;
		return nr;
	}

	CFS_ALLOC_PTR(nr);
	if (nr == NULL)
		return NULL;
	list_add_tail(&nr->nr_link, nidlist);
	INIT_LIST_HEAD(&nr->nr_addrranges);
	nr->nr_netstrfns = nf;
	nr->nr_all = 0;
	nr->nr_netnum = netnum;

	return nr;
}

/**
 * Parses \<nidrange\> token of the syntax.
 *
 * \retval 0 if \a src parses to \<addrrange\> '@' \<net\>
 * \retval -EINVAL otherwise
 */
static int
parse_nidrange(char *str, struct list_head *nidlist)
{
	char *addrrange;
	char *net;
	struct nidrange *nr;

	addrrange = strim(strsep(&str, "@"));
	if (!str)
		goto failed;

	net = strim(str);
	if (strchr(net, '@') != NULL || !*net)
		goto failed;

	nr = add_nidrange(net, nidlist);
	if (nr == NULL)
		goto failed;

	if (parse_addrange(addrrange, nr) != 0)
		goto failed;

	return 0;
failed:
	return -EINVAL;
}

/**
 * Frees addrrange structures of \a list.
 *
 * For each struct addrrange structure found on \a list it frees
 * cfs_expr_list list attached to it and frees the addrrange itself.
 *
 * \retval none
 */
static void
free_addrranges(struct list_head *list)
{
	struct addrrange *ar;

	while ((ar = list_first_entry_or_null(list,
					      struct addrrange,
					      ar_link)) != NULL) {
		cfs_expr_list_free_list(&ar->ar_numaddr_ranges);
		list_del(&ar->ar_link);
		CFS_FREE_PTR(ar);
	}
}

/**
 * Frees nidrange strutures of \a list.
 *
 * For each struct nidrange structure found on \a list it frees
 * addrrange list attached to it and frees the nidrange itself.
 *
 * \retval none
 */
void
cfs_free_nidlist(struct list_head *list)
{
	struct list_head *pos, *next;
	struct nidrange *nr;

	list_for_each_safe(pos, next, list) {
		nr = list_entry(pos, struct nidrange, nr_link);
		free_addrranges(&nr->nr_addrranges);
		list_del(pos);
		CFS_FREE_PTR(nr);
	}
}
EXPORT_SYMBOL(cfs_free_nidlist);

/**
 * Parses nid range list.
 *
 * Parses with rigorous syntax and overflow checking \a str into
 * \<nidrange\> [ ' ' \<nidrange\> ], compiles \a str into set of
 * structures and links that structure to \a nidlist. The resulting
 * list can be used to match a NID againts set of NIDS defined by \a
 * str.
 * \see cfs_match_nid
 *
 * \retval 0 on success
 * \retval -errno otherwise (-ENOMEM or -EINVAL)
 */
int
cfs_parse_nidlist(char *orig, struct list_head *nidlist)
{
	int rc = 0;
	char *str;

	orig = kstrdup(orig, GFP_KERNEL);
	if (!orig)
		return -ENOMEM;

	INIT_LIST_HEAD(nidlist);
	str = orig;
	while (rc == 0 && str) {
		char *tok = strsep(&str, " ");

		if (*tok)
			rc = parse_nidrange(tok, nidlist);
	}
	kfree(orig);
	if (rc)
		cfs_free_nidlist(nidlist);
	else if (list_empty(nidlist))
		rc = -EINVAL;
	return rc;
}
EXPORT_SYMBOL(cfs_parse_nidlist);

/**
 * Matches a nid (\a nid) against the compiled list of nidranges (\a nidlist).
 *
 * \see cfs_parse_nidlist()
 *
 * \retval 1 on match
 * \retval 0  otherwises
 */
int cfs_match_nid(struct lnet_nid *nid, struct list_head *nidlist)
{
	struct nidrange *nr;
	struct addrrange *ar;

	if (!nid_is_nid4(nid))
		return 0;
	list_for_each_entry(nr, nidlist, nr_link) {
		if (nr->nr_netstrfns->nf_type != nid->nid_type)
			continue;
		if (nr->nr_netnum != be16_to_cpu(nid->nid_num))
			continue;
		if (nr->nr_all)
			return 1;
		list_for_each_entry(ar, &nr->nr_addrranges, ar_link)
			if (nr->nr_netstrfns->nf_match_addr(
				    be32_to_cpu(nid->nid_addr[0]),
				    &ar->ar_numaddr_ranges))
				return 1;
	}
	return 0;
}
EXPORT_SYMBOL(cfs_match_nid);

/**
 * Print the network part of the nidrange \a nr into the specified \a buffer.
 *
 * \retval number of characters written
 */
static int
cfs_print_network(char *buffer, int count, struct nidrange *nr)
{
	struct netstrfns *nf = nr->nr_netstrfns;

	if (nr->nr_netnum == 0)
		return scnprintf(buffer, count, "@%s", nf->nf_name);
	else
		return scnprintf(buffer, count, "@%s%u",
				    nf->nf_name, nr->nr_netnum);
}

/**
 * Print a list of addrrange (\a addrranges) into the specified \a buffer.
 * At max \a count characters can be printed into \a buffer.
 *
 * \retval number of characters written
 */
static int
cfs_print_addrranges(char *buffer, int count, struct list_head *addrranges,
		     struct nidrange *nr)
{
	int i = 0;
	struct addrrange *ar;
	struct netstrfns *nf = nr->nr_netstrfns;

	list_for_each_entry(ar, addrranges, ar_link) {
		if (i != 0)
			i += scnprintf(buffer + i, count - i, " ");
		i += nf->nf_print_addrlist(buffer + i, count - i,
					   &ar->ar_numaddr_ranges);
		i += cfs_print_network(buffer + i, count - i, nr);
	}
	return i;
}

/**
 * Print a list of nidranges (\a nidlist) into the specified \a buffer.
 * At max \a count characters can be printed into \a buffer.
 * Nidranges are separated by a space character.
 *
 * \retval number of characters written
 */
int cfs_print_nidlist(char *buffer, int count, struct list_head *nidlist)
{
	int i = 0;
	struct nidrange *nr;

	if (count <= 0)
		return 0;

	list_for_each_entry(nr, nidlist, nr_link) {
		if (i != 0)
			i += scnprintf(buffer + i, count - i, " ");

		if (nr->nr_all != 0) {
			LASSERT(list_empty(&nr->nr_addrranges));
			i += scnprintf(buffer + i, count - i, "*");
			i += cfs_print_network(buffer + i, count - i, nr);
		} else {
			i += cfs_print_addrranges(buffer + i, count - i,
						  &nr->nr_addrranges, nr);
		}
	}
	return i;
}
EXPORT_SYMBOL(cfs_print_nidlist);

static int
libcfs_lo_str2addr(const char *str, int nob, __u32 *addr)
{
	*addr = 0;
	return 1;
}

static void
libcfs_ip_addr2str(__u32 addr, char *str, size_t size)
{
	snprintf(str, size, "%u.%u.%u.%u",
		 (addr >> 24) & 0xff, (addr >> 16) & 0xff,
		 (addr >> 8) & 0xff, addr & 0xff);
}

static void
libcfs_ip_addr2str_size(const __be32 *addr, size_t asize,
			char *str, size_t size)
{
	struct sockaddr_storage sa = {};

	switch (asize) {
	case 4:
		sa.ss_family = AF_INET;
		memcpy(&((struct sockaddr_in *)(&sa))->sin_addr.s_addr,
		       addr, asize);
		break;
	case 16:
		sa.ss_family = AF_INET6;
		memcpy(&((struct sockaddr_in6 *)(&sa))->sin6_addr.s6_addr,
		       addr, asize);
		break;
	default:
		return;
	}

	rpc_ntop((struct sockaddr *)&sa, str, size);
}

/* CAVEAT EMPTOR XscanfX
 * I use "%n" at the end of a sscanf format to detect trailing junk.  However
 * sscanf may return immediately if it sees the terminating '0' in a string, so
 * I initialise the %n variable to the expected length.  If sscanf sets it;
 * fine, if it doesn't, then the scan ended at the end of the string, which is
 * fine too :) */
static int
libcfs_ip_str2addr(const char *str, int nob, __u32 *addr)
{
	unsigned int	a;
	unsigned int	b;
	unsigned int	c;
	unsigned int	d;
	int		n = nob; /* XscanfX */

	/* numeric IP? */
	if (sscanf(str, "%u.%u.%u.%u%n", &a, &b, &c, &d, &n) >= 4 &&
	    n == nob &&
	    (a & ~0xff) == 0 && (b & ~0xff) == 0 &&
	    (c & ~0xff) == 0 && (d & ~0xff) == 0) {
		*addr = ((a<<24)|(b<<16)|(c<<8)|d);
		return 1;
	}
	return 0;
}

static int
libcfs_ip_str2addr_size(const char *str, int nob,
			__be32 *addr, size_t *alen)
{
	struct sockaddr_storage sa;

	/* Note: 'net' arg to rpc_pton is only needed for link-local
	 * addresses.  Such addresses would not work with LNet routing,
	 * so we can assume they aren't used.  So it doesn't matter
	 * which net namespace is passed.
	 */
	if (rpc_pton(&init_net, str, nob,
		     (struct sockaddr *)&sa, sizeof(sa)) == 0)
		return 0;
	if (sa.ss_family == AF_INET6) {
		memcpy(addr,
		       &((struct sockaddr_in6 *)(&sa))->sin6_addr.s6_addr,
		       16);
		*alen = 16;
		return 1;
	}
	if (sa.ss_family == AF_INET) {
		memcpy(addr,
		       &((struct sockaddr_in *)(&sa))->sin_addr.s_addr,
		       4);
		*alen = 4;
		return 1;
	}
	return 0;
}


/* Used by lnet/config.c so it can't be static */
int
cfs_ip_addr_parse(char *str, int len_ignored, struct list_head *list)
{
	struct cfs_expr_list *el;
	int rc = 0;
	int i = 0;

	str = strim(str);
	while (rc == 0 && str) {
		char *res;

		res = strsep(&str, ".");
		res = strim(res);
		if (!*res) {
			rc = -EINVAL;
		} else if ((rc = cfs_expr_list_parse(res, strlen(res),
						   0, 255, &el)) == 0) {
			list_add_tail(&el->el_link, list);
			i++;
		}
	}

	if (rc == 0 && i == 4)
		return 0;
	cfs_expr_list_free_list(list);

	return rc ?: -EINVAL;
}

/**
 * Print the range expression \a re into specified \a buffer.
 * If \a bracketed is true, expression does not need additional
 * brackets.
 *
 * \retval number of characters written
 */
static int
cfs_range_expr_print(char *buffer, int count, struct cfs_range_expr *expr,
		     bool bracketed)
{
	int i;
	char s[] = "[";
	char e[] = "]";

	if (bracketed)
		s[0] = e[0] = '\0';

	if (expr->re_lo == expr->re_hi)
		i = scnprintf(buffer, count, "%u", expr->re_lo);
	else if (expr->re_stride == 1)
		i = scnprintf(buffer, count, "%s%u-%u%s",
			      s, expr->re_lo, expr->re_hi, e);
	else
		i = scnprintf(buffer, count, "%s%u-%u/%u%s",
			      s, expr->re_lo, expr->re_hi,
			      expr->re_stride, e);
	return i;
}

/**
 * Print a list of range expressions (\a expr_list) into specified \a buffer.
 * If the list contains several expressions, separate them with comma
 * and surround the list with brackets.
 *
 * \retval number of characters written
 */
static int
cfs_expr_list_print(char *buffer, int count, struct cfs_expr_list *expr_list)
{
	struct cfs_range_expr *expr;
	int i = 0, j = 0;
	int numexprs = 0;

	if (count <= 0)
		return 0;

	list_for_each_entry(expr, &expr_list->el_exprs, re_link)
		numexprs++;

	if (numexprs > 1)
		i += scnprintf(buffer + i, count - i, "[");

	list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
		if (j++ != 0)
			i += scnprintf(buffer + i, count - i, ",");
		i += cfs_range_expr_print(buffer + i, count - i, expr,
					  numexprs > 1);
	}

	if (numexprs > 1)
		i += scnprintf(buffer + i, count - i, "]");

	return i;
}

static int
libcfs_ip_addr_range_print(char *buffer, int count, struct list_head *list)
{
	int i = 0, j = 0;
	struct cfs_expr_list *el;

	list_for_each_entry(el, list, el_link) {
		LASSERT(j++ < 4);
		if (i != 0)
			i += scnprintf(buffer + i, count - i, ".");
		i += cfs_expr_list_print(buffer + i, count - i, el);
	}
	return i;
}

/**
 * Matches address (\a addr) against address set encoded in \a list.
 *
 * \retval 1 if \a addr matches
 * \retval 0 otherwise
 */
int
cfs_ip_addr_match(__u32 addr, struct list_head *list)
{
	struct cfs_expr_list *el;
	int i = 0;

	list_for_each_entry_reverse(el, list, el_link) {
		if (!cfs_expr_list_match(addr & 0xff, el))
			return 0;
		addr >>= 8;
		i++;
	}

	return i == 4;
}

/**
 * Print the network part of the nidrange \a nr into the specified \a buffer.
 *
 * \retval number of characters written
 */
static void
libcfs_decnum_addr2str(__u32 addr, char *str, size_t size)
{
	snprintf(str, size, "%u", addr);
}

static int
libcfs_num_str2addr(const char *str, int nob, __u32 *addr)
{
	int	n;

	n = nob;
	if (sscanf(str, "0x%x%n", addr, &n) >= 1 && n == nob)
		return 1;

	n = nob;
	if (sscanf(str, "0X%x%n", addr, &n) >= 1 && n == nob)
		return 1;

	n = nob;
	if (sscanf(str, "%u%n", addr, &n) >= 1 && n == nob)
		return 1;

	return 0;
}

/**
 * Nf_parse_addrlist method for networks using numeric addresses.
 *
 * Examples of such networks are gm and elan.
 *
 * \retval 0 if \a str parsed to numeric address
 * \retval errno otherwise
 */
int
libcfs_num_parse(char *str, int len, struct list_head *list)
{
	struct cfs_expr_list *el;
	int	rc;

	rc = cfs_expr_list_parse(str, len, 0, MAX_NUMERIC_VALUE, &el);
	if (rc == 0)
		list_add_tail(&el->el_link, list);

	return rc;
}

static int
libcfs_num_addr_range_print(char *buffer, int count, struct list_head *list)
{
	int i = 0, j = 0;
	struct cfs_expr_list *el;

	list_for_each_entry(el, list, el_link) {
		LASSERT(j++ < 1);
		i += cfs_expr_list_print(buffer + i, count - i, el);
	}
	return i;
}

/*
 * Nf_match_addr method for networks using numeric addresses
 *
 * \retval 1 on match
 * \retval 0 otherwise
 */
static int
libcfs_num_match(__u32 addr, struct list_head *numaddr)
{
	struct cfs_expr_list *el;

	LASSERT(!list_empty(numaddr));
	el = list_first_entry(numaddr, struct cfs_expr_list, el_link);

	return cfs_expr_list_match(addr, el);
}

static struct netstrfns libcfs_netstrfns[] = {
	{ .nf_type		= LOLND,
	  .nf_name		= "lo",
	  .nf_modname		= "klolnd",
	  .nf_addr2str		= libcfs_decnum_addr2str,
	  .nf_str2addr		= libcfs_lo_str2addr,
	  .nf_parse_addrlist	= libcfs_num_parse,
	  .nf_print_addrlist	= libcfs_num_addr_range_print,
	  .nf_match_addr	= libcfs_num_match
	},
	{ .nf_type		= SOCKLND,
	  .nf_name		= "tcp",
	  .nf_modname		= "ksocklnd",
	  .nf_addr2str		= libcfs_ip_addr2str,
	  .nf_addr2str_size	= libcfs_ip_addr2str_size,
	  .nf_str2addr		= libcfs_ip_str2addr,
	  .nf_str2addr_size	= libcfs_ip_str2addr_size,
	  .nf_parse_addrlist	= cfs_ip_addr_parse,
	  .nf_print_addrlist	= libcfs_ip_addr_range_print,
	  .nf_match_addr	= cfs_ip_addr_match
	},
	{ .nf_type		= O2IBLND,
	  .nf_name		= "o2ib",
	  .nf_modname		= "ko2iblnd",
	  .nf_addr2str		= libcfs_ip_addr2str,
	  .nf_str2addr		= libcfs_ip_str2addr,
	  .nf_parse_addrlist	= cfs_ip_addr_parse,
	  .nf_print_addrlist	= libcfs_ip_addr_range_print,
	  .nf_match_addr	= cfs_ip_addr_match
	},
	{ .nf_type		= GNILND,
	  .nf_name		= "gni",
	  .nf_modname		= "kgnilnd",
	  .nf_addr2str		= libcfs_decnum_addr2str,
	  .nf_str2addr		= libcfs_num_str2addr,
	  .nf_parse_addrlist	= libcfs_num_parse,
	  .nf_print_addrlist	= libcfs_num_addr_range_print,
	  .nf_match_addr	= libcfs_num_match
	},
	{ .nf_type		= GNIIPLND,
	  .nf_name		= "gip",
	  .nf_modname		= "kgnilnd",
	  .nf_addr2str		= libcfs_ip_addr2str,
	  .nf_str2addr		= libcfs_ip_str2addr,
	  .nf_parse_addrlist	= cfs_ip_addr_parse,
	  .nf_print_addrlist	= libcfs_ip_addr_range_print,
	  .nf_match_addr	= cfs_ip_addr_match
	},
	{ .nf_type		= PTL4LND,
	  .nf_name		= "ptlf",
	  .nf_modname		= "kptl4lnd",
	  .nf_addr2str		= libcfs_decnum_addr2str,
	  .nf_str2addr		= libcfs_num_str2addr,
	  .nf_parse_addrlist	= libcfs_num_parse,
	  .nf_print_addrlist	= libcfs_num_addr_range_print,
	  .nf_match_addr	= libcfs_num_match
	},
	{
	  .nf_type		= KFILND,
	  .nf_name		= "kfi",
	  .nf_modname		= "kkfilnd",
	  .nf_addr2str		= libcfs_decnum_addr2str,
	  .nf_str2addr		= libcfs_num_str2addr,
	  .nf_parse_addrlist	= libcfs_num_parse,
	  .nf_print_addrlist	= libcfs_num_addr_range_print,
	  .nf_match_addr	= libcfs_num_match
	},
};

static const size_t libcfs_nnetstrfns = ARRAY_SIZE(libcfs_netstrfns);

static struct netstrfns *
type2net_info(__u32 net_type)
{
	int i;

	for (i = 0; i < libcfs_nnetstrfns; i++) {
		if (libcfs_netstrfns[i].nf_type == net_type)
			return &libcfs_netstrfns[i];
	}

	return NULL;
}

int
cfs_match_net(__u32 net_id, __u32 net_type, struct list_head *net_num_list)
{
	__u32 net_num;

	if (!net_num_list)
		return 0;

	if (net_type != LNET_NETTYP(net_id))
		return 0;

	net_num = LNET_NETNUM(net_id);

	/* if there is a net number but the list passed in is empty, then
	 * there is no match.
	 */
	if (!net_num && list_empty(net_num_list))
		return 1;
	else if (list_empty(net_num_list))
		return 0;

	if (!libcfs_num_match(net_num, net_num_list))
		return 0;

	return 1;
}

int
cfs_match_nid_net(struct lnet_nid *nid, __u32 net_type,
		   struct list_head *net_num_list,
		   struct list_head *addr)
{
	__u32 address;
	struct netstrfns *nf;

	if (!addr || list_empty(addr) || !net_num_list)
		return 0;

	nf = type2net_info(LNET_NETTYP(LNET_NID_NET(nid)));
	if (!nf)
		return 0;

	/* FIXME handle long-addr nid */
	address = LNET_NIDADDR(lnet_nid_to_nid4(nid));

	/* if either the address or net number don't match then no match */
	if (!nf->nf_match_addr(address, addr) ||
	    !cfs_match_net(LNET_NID_NET(nid), net_type, net_num_list))
		return 0;

	return 1;
}
EXPORT_SYMBOL(cfs_match_nid_net);

static struct netstrfns *
libcfs_lnd2netstrfns(__u32 lnd)
{
	int	i;

	for (i = 0; i < libcfs_nnetstrfns; i++)
		if (lnd == libcfs_netstrfns[i].nf_type)
			return &libcfs_netstrfns[i];

	return NULL;
}

static struct netstrfns *
libcfs_namenum2netstrfns(const char *name)
{
	struct netstrfns *nf;
	int		  i;

	for (i = 0; i < libcfs_nnetstrfns; i++) {
		nf = &libcfs_netstrfns[i];
		if (!strncmp(name, nf->nf_name, strlen(nf->nf_name)))
			return nf;
	}
	return NULL;
}

static struct netstrfns *
libcfs_name2netstrfns(const char *name)
{
	int    i;

	for (i = 0; i < libcfs_nnetstrfns; i++)
		if (!strcmp(libcfs_netstrfns[i].nf_name, name))
			return &libcfs_netstrfns[i];

	return NULL;
}

int
libcfs_isknown_lnd(__u32 lnd)
{
	return libcfs_lnd2netstrfns(lnd) != NULL;
}
EXPORT_SYMBOL(libcfs_isknown_lnd);

char *
libcfs_lnd2modname(__u32 lnd)
{
	struct netstrfns *nf = libcfs_lnd2netstrfns(lnd);

	return (nf == NULL) ? NULL : nf->nf_modname;
}
EXPORT_SYMBOL(libcfs_lnd2modname);

int
libcfs_str2lnd(const char *str)
{
	struct netstrfns *nf = libcfs_name2netstrfns(str);

	if (nf != NULL)
		return nf->nf_type;

	return -ENXIO;
}
EXPORT_SYMBOL(libcfs_str2lnd);

char *
libcfs_lnd2str_r(__u32 lnd, char *buf, size_t buf_size)
{
	struct netstrfns *nf;

	nf = libcfs_lnd2netstrfns(lnd);
	if (nf == NULL)
		snprintf(buf, buf_size, "?%u?", lnd);
	else
		snprintf(buf, buf_size, "%s", nf->nf_name);

	return buf;
}
EXPORT_SYMBOL(libcfs_lnd2str_r);

char *
libcfs_net2str_r(__u32 net, char *buf, size_t buf_size)
{
	__u32		  nnum = LNET_NETNUM(net);
	__u32		  lnd  = LNET_NETTYP(net);
	struct netstrfns *nf;

	nf = libcfs_lnd2netstrfns(lnd);
	if (nf == NULL)
		snprintf(buf, buf_size, "<%u:%u>", lnd, nnum);
	else if (nnum == 0)
		snprintf(buf, buf_size, "%s", nf->nf_name);
	else
		snprintf(buf, buf_size, "%s%u", nf->nf_name, nnum);

	return buf;
}
EXPORT_SYMBOL(libcfs_net2str_r);

char *
libcfs_nid2str_r(lnet_nid_t nid, char *buf, size_t buf_size)
{
	__u32		  addr = LNET_NIDADDR(nid);
	__u32		  net  = LNET_NIDNET(nid);
	__u32		  nnum = LNET_NETNUM(net);
	__u32		  lnd  = LNET_NETTYP(net);
	struct netstrfns *nf;

	if (nid == LNET_NID_ANY) {
		strncpy(buf, "<?>", buf_size);
		buf[buf_size - 1] = '\0';
		return buf;
	}

	nf = libcfs_lnd2netstrfns(lnd);
	if (nf == NULL) {
		snprintf(buf, buf_size, "%x@<%u:%u>", addr, lnd, nnum);
	} else {
		size_t addr_len;

		nf->nf_addr2str(addr, buf, buf_size);
		addr_len = strlen(buf);
		if (nnum == 0)
			snprintf(buf + addr_len, buf_size - addr_len, "@%s",
				 nf->nf_name);
		else
			snprintf(buf + addr_len, buf_size - addr_len, "@%s%u",
				 nf->nf_name, nnum);
	}

	return buf;
}
EXPORT_SYMBOL(libcfs_nid2str_r);

char *
libcfs_nidstr_r(const struct lnet_nid *nid, char *buf, size_t buf_size)
{
	__u32 nnum;
	__u32 lnd;
	struct netstrfns *nf;

	if (LNET_NID_IS_ANY(nid)) {
		strncpy(buf, "<?>", buf_size);
		buf[buf_size - 1] = '\0';
		return buf;
	}

	nnum = be16_to_cpu(nid->nid_num);
	lnd = nid->nid_type;
	nf = libcfs_lnd2netstrfns(lnd);
	if (nf) {
		size_t addr_len;

		if (nf->nf_addr2str_size)
			nf->nf_addr2str_size(nid->nid_addr, NID_ADDR_BYTES(nid),
					     buf, buf_size);
		else
			nf->nf_addr2str(ntohl(nid->nid_addr[0]), buf, buf_size);
		addr_len = strlen(buf);
		if (nnum == 0)
			snprintf(buf + addr_len, buf_size - addr_len, "@%s",
				 nf->nf_name);
		else
			snprintf(buf + addr_len, buf_size - addr_len, "@%s%u",
				 nf->nf_name, nnum);
	} else {
		int l = 0;
		int words = DIV_ROUND_UP(NID_ADDR_BYTES(nid), 4);
		int i;

		for (i = 0; i < words && i < 4; i++)
			l = snprintf(buf+l, buf_size-l, "%s%x",
				     i ? ":" : "", ntohl(nid->nid_addr[i]));
		snprintf(buf+l, buf_size-l, "@<%u:%u>", lnd, nnum);
	}

	return buf;
}
EXPORT_SYMBOL(libcfs_nidstr_r);

static struct netstrfns *
libcfs_str2net_internal(const char *str, __u32 *net)
{
	struct netstrfns *nf = NULL;
	int		  nob;
	unsigned int	  netnum;
	int		  i;

	for (i = 0; i < libcfs_nnetstrfns; i++) {
		nf = &libcfs_netstrfns[i];
		if (!strncmp(str, nf->nf_name, strlen(nf->nf_name)))
			break;
	}

	if (i == libcfs_nnetstrfns)
		return NULL;

	nob = strlen(nf->nf_name);

	if (strlen(str) == (unsigned int)nob) {
		netnum = 0;
	} else {
		if (nf->nf_type == LOLND) /* net number not allowed */
			return NULL;

		str += nob;
		i = strlen(str);
		if (sscanf(str, "%u%n", &netnum, &i) < 1 ||
		    i != (int)strlen(str))
			return NULL;
	}

	*net = LNET_MKNET(nf->nf_type, netnum);
	return nf;
}

__u32
libcfs_str2net(const char *str)
{
	__u32  net;

	if (libcfs_str2net_internal(str, &net) != NULL)
		return net;

	return LNET_NET_ANY;
}
EXPORT_SYMBOL(libcfs_str2net);

lnet_nid_t
libcfs_str2nid(const char *str)
{
	const char	 *sep = strchr(str, '@');
	struct netstrfns *nf;
	__u32		  net;
	__u32		  addr;

	if (sep != NULL) {
		nf = libcfs_str2net_internal(sep + 1, &net);
		if (nf == NULL)
			return LNET_NID_ANY;
	} else {
		sep = str + strlen(str);
		net = LNET_MKNET(SOCKLND, 0);
		nf = libcfs_lnd2netstrfns(SOCKLND);
		LASSERT(nf != NULL);
	}

	if (!nf->nf_str2addr(str, (int)(sep - str), &addr))
		return LNET_NID_ANY;

	return LNET_MKNID(net, addr);
}
EXPORT_SYMBOL(libcfs_str2nid);

int
libcfs_strnid(struct lnet_nid *nid, const char *str)
{
	const char	 *sep = strchr(str, '@');
	struct netstrfns *nf;
	__u32		  net;

	if (sep != NULL) {
		nf = libcfs_str2net_internal(sep + 1, &net);
		if (nf == NULL)
			return -EINVAL;
	} else {
		if (strcmp(str, "<?>") == 0) {
			memcpy(nid, &LNET_ANY_NID, sizeof(*nid));
			return 0;
		}
		sep = str + strlen(str);
		net = LNET_MKNET(SOCKLND, 0);
		nf = libcfs_lnd2netstrfns(SOCKLND);
		LASSERT(nf != NULL);
	}

	memset(nid, 0, sizeof(*nid));
	nid->nid_type = LNET_NETTYP(net);
	nid->nid_num = htons(LNET_NETNUM(net));
	if (nf->nf_str2addr_size) {
		size_t asize = 0;

		if (!nf->nf_str2addr_size(str, (int)(sep - str),
					  nid->nid_addr, &asize))
			return -EINVAL;
		nid->nid_size = asize - 4;
	} else {
		__u32 addr;

		if (!nf->nf_str2addr(str, (int)(sep - str), &addr))
			return -EINVAL;
		nid->nid_addr[0] = htonl(addr);
		nid->nid_size = 0;
	}
	return 0;
}
EXPORT_SYMBOL(libcfs_strnid);

char *
libcfs_id2str(struct lnet_process_id id)
{
	char *str = libcfs_next_nidstring();

	if (id.pid == LNET_PID_ANY) {
		snprintf(str, LNET_NIDSTR_SIZE,
			 "LNET_PID_ANY-%s", libcfs_nid2str(id.nid));
		return str;
	}

	snprintf(str, LNET_NIDSTR_SIZE, "%s%u-%s",
		 ((id.pid & LNET_PID_USERFLAG) != 0) ? "U" : "",
		 (id.pid & ~LNET_PID_USERFLAG), libcfs_nid2str(id.nid));
	return str;
}
EXPORT_SYMBOL(libcfs_id2str);

char *
libcfs_idstr(struct lnet_processid *id)
{
	char *str = libcfs_next_nidstring();

	if (id->pid == LNET_PID_ANY) {
		snprintf(str, LNET_NIDSTR_SIZE,
			 "LNET_PID_ANY-%s", libcfs_nidstr(&id->nid));
		return str;
	}

	snprintf(str, LNET_NIDSTR_SIZE, "%s%u-%s",
		 ((id->pid & LNET_PID_USERFLAG) != 0) ? "U" : "",
		 (id->pid & ~LNET_PID_USERFLAG), libcfs_nidstr(&id->nid));
	return str;
}
EXPORT_SYMBOL(libcfs_idstr);

int
libcfs_strid(struct lnet_processid *id, const char *str)
{
	char *tmp = strchr(str, '-');

	id->pid = LNET_PID_LUSTRE;
	if (tmp &&
	    strncmp("LNET_PID_ANY-", str, tmp - str) != 0) {
		char pid[LNET_NIDSTR_SIZE];
		int rc;

		strscpy(pid, str, tmp - str);
		rc = kstrtou32(pid, 10, &id->pid);
		if (rc < 0)
			return rc;
		tmp++;
	} else {
		tmp = (char *)str;
	}

	return libcfs_strnid(&id->nid, tmp);
}
EXPORT_SYMBOL(libcfs_strid);

int
libcfs_str2anynid(lnet_nid_t *nidp, const char *str)
{
	if (!strcmp(str, "*")) {
		*nidp = LNET_NID_ANY;
		return 1;
	}

	*nidp = libcfs_str2nid(str);
	return *nidp != LNET_NID_ANY;
}
EXPORT_SYMBOL(libcfs_str2anynid);