/*
 * 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) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * libcfs/libcfs/nidstrings.c
 *
 * Author: Phil Schwan <phil@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_LNET

#include <libcfs/libcfs.h>
#include <lnet/lnet.h>
#ifndef __KERNEL__
#ifdef HAVE_GETHOSTBYNAME
# include <netdb.h>
#endif
#endif

#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 = 0;

#ifdef __KERNEL__
static spinlock_t libcfs_nidstring_lock;

void libcfs_init_nidstrings (void)
{
	spin_lock_init(&libcfs_nidstring_lock);
}

# define NIDSTR_LOCK(f)   spin_lock_irqsave(&libcfs_nidstring_lock, f)
# define NIDSTR_UNLOCK(f) spin_unlock_irqrestore(&libcfs_nidstring_lock, f)
#else
# define NIDSTR_LOCK(f)   (f=sizeof(f))  /* avoid set-but-unused warnings */
# define NIDSTR_UNLOCK(f) (f=sizeof(f))
#endif

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

        NIDSTR_LOCK(flags);

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

        NIDSTR_UNLOCK(flags);
        return str;
}

static int  libcfs_lo_str2addr(const char *str, int nob, __u32 *addr);
static void libcfs_ip_addr2str(__u32 addr, char *str);
static int  libcfs_ip_str2addr(const char *str, int nob, __u32 *addr);
static bool cfs_ip_is_contiguous(struct list_head *nidlist);
static void cfs_ip_min_max(struct list_head *nidlist, __u32 *min, __u32 *max);
static void libcfs_decnum_addr2str(__u32 addr, char *str);
static void libcfs_hexnum_addr2str(__u32 addr, char *str);
static int  libcfs_num_str2addr(const char *str, int nob, __u32 *addr);
static int  libcfs_num_parse(char *str, int len, struct list_head *list);
static int  libcfs_num_match(__u32 addr, struct list_head *list);
static int  libcfs_num_addr_range_print(char *buffer, int count,
					struct list_head *list);
static int  libcfs_ip_addr_range_print(char *buffer, int count,
				       struct list_head *list);
static bool cfs_num_is_contiguous(struct list_head *nidlist);
static void cfs_num_min_max(struct list_head *nidlist, __u32 *min, __u32 *max);

struct netstrfns {
	int	 nf_type;
	char	*nf_name;
	char	*nf_modname;
	void	(*nf_addr2str)(__u32 addr, char *str);
	int	(*nf_str2addr)(const char *str, int nob, __u32 *addr);
	int	(*nf_parse_addrlist)(char *str, int len,
					struct list_head *list);
	int	(*nf_print_addrlist)(char *buffer, int count,
				     struct list_head *list);
	int	(*nf_match_addr)(__u32 addr, struct list_head *list);
	bool	(*nf_is_contiguous)(struct list_head *nidlist);
	void	(*nf_min_max)(struct list_head *nidlist, __u32 *min_nid,
				__u32 *max_nid);
};

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_addr*/  libcfs_num_parse,
	 /* .nf_print_addrlist*/  libcfs_num_addr_range_print,
	 /* .nf_match_addr*/	  libcfs_num_match,
	 /* .nf_is_contiguous */  cfs_num_is_contiguous,
	 /* .nf_min_max   */	  cfs_num_min_max},
	{/* .nf_type      */  SOCKLND,
	 /* .nf_name      */  "tcp",
	 /* .nf_modname   */  "ksocklnd",
	 /* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .nf_type      */  CIBLND,
	 /* .nf_name      */  "cib",
	 /* .nf_modname   */  "kciblnd",
	 /* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .nf_type      */  OPENIBLND,
	 /* .nf_name      */  "openib",
	 /* .nf_modname   */  "kopeniblnd",
	 /* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .nf_type      */  IIBLND,
	 /* .nf_name      */  "iib",
	 /* .nf_modname   */  "kiiblnd",
	 /* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .nf_type      */  VIBLND,
	 /* .nf_name      */  "vib",
	 /* .nf_modname   */  "kviblnd",
	 /* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .nf_type      */  RALND,
	 /* .nf_name      */  "ra",
	 /* .nf_modname   */  "kralnd",
	 /* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .nf_type      */	  QSWLND,
	 /* .nf_name      */	  "elan",
	 /* .nf_modname   */	  "kqswlnd",
	 /* .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_is_contiguous */  cfs_num_is_contiguous,
	 /* .nf_min_max   */	  cfs_num_min_max},
	{/* .nf_type      */	  GMLND,
	 /* .nf_name      */	  "gm",
	 /* .nf_modname   */	  "kgmlnd",
	 /* .nf_addr2str  */	  libcfs_hexnum_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_is_contiguous */  cfs_num_is_contiguous,
	 /* .nf_min_max   */	  cfs_num_min_max},
	{/* .nf_type      */	  MXLND,
	 /* .nf_name      */	  "mx",
	 /* .nf_modname   */	  "kmxlnd",
	 /* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	{/* .nf_type      */	  PTLLND,
	 /* .nf_name      */	  "ptl",
	 /* .nf_modname   */	  "kptllnd",
	 /* .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_is_contiguous */  cfs_num_is_contiguous,
	 /* .nf_min_max   */	  cfs_num_min_max},
	{/* .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_is_contiguous */  cfs_num_is_contiguous,
	 /* .nf_min_max   */	  cfs_num_min_max},
	{/* .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_is_contiguous */  cfs_ip_is_contiguous,
	 /* .nf_min_max   */	  cfs_ip_min_max},
	 /* placeholder for net0 alias.  It MUST BE THE LAST ENTRY */
	{/* .nf_type      */  -1},
};

const int libcfs_nnetstrfns = sizeof(libcfs_netstrfns)/sizeof(libcfs_netstrfns[0]);

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

void
libcfs_ip_addr2str(__u32 addr, char *str)
{
#if 0   /* never lookup */
#if !defined(__KERNEL__) && defined HAVE_GETHOSTBYNAME
        __u32           netip = htonl(addr);
        struct hostent *he = gethostbyaddr(&netip, sizeof(netip), AF_INET);

        if (he != NULL) {
                snprintf(str, LNET_NIDSTR_SIZE, "%s", he->h_name);
                return;
        }
#endif
#endif
        snprintf(str, LNET_NIDSTR_SIZE, "%u.%u.%u.%u",
                 (addr >> 24) & 0xff, (addr >> 16) & 0xff,
                 (addr >> 8) & 0xff, addr & 0xff);
}

/* 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 :) */

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;
        }

#if !defined(__KERNEL__) && defined HAVE_GETHOSTBYNAME
        /* known hostname? */
        if (('a' <= str[0] && str[0] <= 'z') ||
            ('A' <= str[0] && str[0] <= 'Z')) {
                char *tmp;

                LIBCFS_ALLOC(tmp, nob + 1);
                if (tmp != NULL) {
                        struct hostent *he;

                        memcpy(tmp, str, nob);
                        tmp[nob] = 0;

                        he = gethostbyname(tmp);

                        LIBCFS_FREE(tmp, nob);

                        if (he != NULL) {
                                __u32 ip = *(__u32 *)he->h_addr;

                                *addr = ntohl(ip);
                                return 1;
                        }
                }
        }
#endif
        return 0;
}

void
libcfs_decnum_addr2str(__u32 addr, char *str)
{
        snprintf(str, LNET_NIDSTR_SIZE, "%u", addr);
}

void
libcfs_hexnum_addr2str(__u32 addr, char *str)
{
        snprintf(str, LNET_NIDSTR_SIZE, "0x%x", addr);
}

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;
}

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

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

        return NULL;
}

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

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

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

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

        return NULL;
}

int
libcfs_isknown_lnd(int type)
{
        return libcfs_lnd2netstrfns(type) != NULL;
}

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

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

char *
libcfs_lnd2str(int lnd)
{
        char           *str;
        struct netstrfns *nf = libcfs_lnd2netstrfns(lnd);

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

        str = libcfs_next_nidstring();
        snprintf(str, LNET_NIDSTR_SIZE, "?%u?", lnd);
        return str;
}

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

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

        return -1;
}

char *
libcfs_net2str(__u32 net)
{
        int               lnd = LNET_NETTYP(net);
        int               num = LNET_NETNUM(net);
        struct netstrfns *nf  = libcfs_lnd2netstrfns(lnd);
        char             *str = libcfs_next_nidstring();

        if (nf == NULL)
                snprintf(str, LNET_NIDSTR_SIZE, "<%u:%u>", lnd, num);
        else if (num == 0)
                snprintf(str, LNET_NIDSTR_SIZE, "%s", nf->nf_name);
        else
                snprintf(str, LNET_NIDSTR_SIZE, "%s%u", nf->nf_name, num);

        return str;
}

char *
libcfs_nid2str(lnet_nid_t nid)
{
        __u32             addr = LNET_NIDADDR(nid);
        __u32             net = LNET_NIDNET(nid);
        int               lnd = LNET_NETTYP(net);
        int               nnum = LNET_NETNUM(net);
        struct netstrfns *nf;
        char             *str;
        int               nob;

        if (nid == LNET_NID_ANY)
                return "<?>";

        nf = libcfs_lnd2netstrfns(lnd);
        str = libcfs_next_nidstring();

        if (nf == NULL)
                snprintf(str, LNET_NIDSTR_SIZE, "%x@<%u:%u>", addr, lnd, nnum);
        else {
                nf->nf_addr2str(addr, str);
                nob = strlen(str);
                if (nnum == 0)
                        snprintf(str + nob, LNET_NIDSTR_SIZE - nob, "@%s",
                                 nf->nf_name);
                else
                        snprintf(str + nob, LNET_NIDSTR_SIZE - nob, "@%s%u",
                                 nf->nf_name, nnum);
        }

        return str;
}

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 (nf->nf_type >= 0 &&
                    !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_NIDNET(LNET_NID_ANY);
}

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);
}

char *
libcfs_id2str(lnet_process_id_t 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;
}

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;
}

/**
 * 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;
};

/**
 * 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
 */
static 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;
}

/**
 * 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(const struct cfs_lstr *src, struct nidrange *nidrange)
{
	struct addrrange *addrrange;

	if (src->ls_len == 1 && src->ls_str[0] == '*') {
		nidrange->nr_all = 1;
		return 0;
	}

	LIBCFS_ALLOC(addrrange, sizeof(struct 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(src->ls_str,
						src->ls_len,
						&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(const struct cfs_lstr *src,
	     struct list_head *nidlist)
{
        struct netstrfns *nf;
        struct nidrange *nr;
        int endlen;
        unsigned netnum;

        if (src->ls_len >= LNET_NIDSTR_SIZE)
                return NULL;

        nf = libcfs_namenum2netstrfns(src->ls_str);
        if (nf == NULL)
                return NULL;
        endlen = src->ls_len - strlen(nf->nf_name);
        if (endlen == 0)
                /* 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 (!cfs_str2num_check(src->ls_str + strlen(nf->nf_name),
				       endlen, &netnum, 0, MAX_NUMERIC_VALUE))
                        return NULL;
        }

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

	LIBCFS_ALLOC(nr, sizeof(struct nidrange));
	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 1 if \a src parses to \<addrrange\> '@' \<net\>
 * \retval 0 otherwise
 */
static int
parse_nidrange(struct cfs_lstr *src, struct list_head *nidlist)
{
	struct cfs_lstr addrrange;
	struct cfs_lstr net;
	struct cfs_lstr tmp;
        struct nidrange *nr;

        tmp = *src;
	if (cfs_gettok(src, '@', &addrrange) == 0)
                goto failed;

	if (cfs_gettok(src, '@', &net) == 0 || src->ls_str != NULL)
                goto failed;

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

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

        return 1;
 failed:
        CWARN("can't parse nidrange: \"%.*s\"\n", tmp.ls_len, tmp.ls_str);
        return 0;
}

/**
 * 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)
{
	while (!list_empty(list)) {
		struct addrrange *ar;

		ar = list_entry(list->next, struct addrrange, ar_link);

		cfs_expr_list_free_list(&ar->ar_numaddr_ranges);
		list_del(&ar->ar_link);
		LIBCFS_FREE(ar, sizeof(struct addrrange));
	}
}

/**
 * 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);
		LIBCFS_FREE(nr, sizeof(struct nidrange));
	}
}

/**
 * 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 1 on success
 * \retval 0 otherwise
 */
int
cfs_parse_nidlist(char *str, int len, struct list_head *nidlist)
{
	struct cfs_lstr src;
	struct cfs_lstr res;
	int rc;
	ENTRY;

	src.ls_str = str;
	src.ls_len = len;
	INIT_LIST_HEAD(nidlist);
	while (src.ls_str) {
		rc = cfs_gettok(&src, ' ', &res);
		if (rc == 0) {
			cfs_free_nidlist(nidlist);
			RETURN(0);
		}
		rc = parse_nidrange(&res, nidlist);
		if (rc == 0) {
			cfs_free_nidlist(nidlist);
			RETURN(0);
		}
	}
	RETURN(1);
}

/*
 * 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_entry(numaddr->next, struct cfs_expr_list, el_link);

	return cfs_expr_list_match(addr, el);
}

/**
 * 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(lnet_nid_t nid, struct list_head *nidlist)
{
	struct nidrange *nr;
	struct addrrange *ar;
	ENTRY;

	list_for_each_entry(nr, nidlist, nr_link) {
		if (nr->nr_netstrfns->nf_type != LNET_NETTYP(LNET_NIDNET(nid)))
			continue;
		if (nr->nr_netnum != LNET_NETNUM(LNET_NIDNET(nid)))
			continue;
		if (nr->nr_all)
			RETURN(1);
		list_for_each_entry(ar, &nr->nr_addrranges, ar_link)
			if (nr->nr_netstrfns->nf_match_addr(LNET_NIDADDR(nid),
							&ar->ar_numaddr_ranges))
				RETURN(1);
	}
	RETURN(0);
}

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;
}

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 += cfs_snprintf(buffer + i, count - i, ".");
		i += cfs_expr_list_print(buffer + i, count - i, el);
	}
	return i;
}


/**
 * 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 cfs_snprintf(buffer, count, "@%s", nf->nf_name);
	else
		return cfs_snprintf(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 += cfs_snprintf(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;
	ENTRY;

	if (count <= 0)
		RETURN(0);

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

		if (nr->nr_all != 0) {
			LASSERT(list_empty(&nr->nr_addrranges));
			i += cfs_snprintf(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);
}

/**
 * Determines minimum and maximum addresses for a single
 * numeric address range
 *
 * \param	ar
 * \param	min_nid
 * \param	max_nid
 */
static void cfs_ip_ar_min_max(struct addrrange *ar, __u32 *min_nid,
			      __u32 *max_nid)
{
	struct cfs_expr_list	*el;
	struct cfs_range_expr	*re;
	__u32			tmp_ip_addr = 0;
	unsigned int		min_ip[4] = {0};
	unsigned int		max_ip[4] = {0};
	int			re_count = 0;

	list_for_each_entry(el, &ar->ar_numaddr_ranges, el_link) {
		list_for_each_entry(re, &el->el_exprs, re_link) {
			min_ip[re_count] = re->re_lo;
			max_ip[re_count] = re->re_hi;
			re_count++;
		}
	}

	tmp_ip_addr = ((min_ip[0] << 24) | (min_ip[1] << 16) |
		       (min_ip[2] << 8) | min_ip[3]);

	if (min_nid != NULL)
		*min_nid = tmp_ip_addr;

	tmp_ip_addr = ((max_ip[0] << 24) | (max_ip[1] << 16) |
		       (max_ip[2] << 8) | max_ip[3]);

	if (max_nid != NULL)
		*max_nid = tmp_ip_addr;
}

/**
 * Determines minimum and maximum addresses for a single
 * numeric address range
 *
 * \param	ar
 * \param	min_nid
 * \param	max_nid
 */
static void cfs_num_ar_min_max(struct addrrange *ar, __u32 *min_nid,
			       __u32 *max_nid)
{
	struct cfs_expr_list	*el;
	struct cfs_range_expr	*re;
	unsigned int		min_addr = 0;
	unsigned int		max_addr = 0;

	list_for_each_entry(el, &ar->ar_numaddr_ranges, el_link) {
		list_for_each_entry(re, &el->el_exprs, re_link) {
			if (re->re_lo < min_addr || min_addr == 0)
				min_addr = re->re_lo;
			if (re->re_hi > max_addr)
				max_addr = re->re_hi;
		}
	}

	if (min_nid != NULL)
		*min_nid = min_addr;
	if (max_nid != NULL)
		*max_nid = max_addr;
}

/**
 * Determines whether an expression list in an nidrange contains exactly
 * one contiguous address range. Calls the correct netstrfns for the LND
 *
 * \param	*nidlist
 *
 * \retval	true if contiguous
 * \retval	false if not contiguous
 */
bool cfs_nidrange_is_contiguous(struct list_head *nidlist)
{
	struct nidrange		*nr;
	struct netstrfns	*nf = NULL;
	char			*lndname = NULL;
	int			netnum = -1;

	list_for_each_entry(nr, nidlist, nr_link) {
		nf = nr->nr_netstrfns;
		if (lndname == NULL)
			lndname = nf->nf_name;
		if (netnum == -1)
			netnum = nr->nr_netnum;

		if (strcmp(lndname, nf->nf_name) != 0 ||
		    netnum != nr->nr_netnum)
			return false;
	}

	if (nf == NULL)
		return false;

	if (!nf->nf_is_contiguous(nidlist))
		return false;

	return true;
}
EXPORT_SYMBOL(cfs_nidrange_is_contiguous);

/**
 * Determines whether an expression list in an num nidrange contains exactly
 * one contiguous address range.
 *
 * \param	*nidlist
 *
 * \retval	true if contiguous
 * \retval	false if not contiguous
 */
static bool cfs_num_is_contiguous(struct list_head *nidlist)
{
	struct nidrange		*nr;
	struct addrrange	*ar;
	struct cfs_expr_list	*el;
	struct cfs_range_expr	*re;
	int			last_hi = 0;
	__u32			last_end_nid = 0;
	__u32			current_start_nid = 0;
	__u32			current_end_nid = 0;

	list_for_each_entry(nr, nidlist, nr_link) {
		list_for_each_entry(ar, &nr->nr_addrranges, ar_link) {
			cfs_num_ar_min_max(ar, &current_start_nid,
					   &current_end_nid);
			if (last_end_nid != 0 &&
			    (current_start_nid - last_end_nid != 1))
					return false;
			last_end_nid = current_end_nid;
			list_for_each_entry(el, &ar->ar_numaddr_ranges,
					    el_link) {
				list_for_each_entry(re, &el->el_exprs,
						    re_link) {
					if (re->re_stride > 1)
						return false;
					else if (last_hi != 0 &&
						 re->re_hi - last_hi != 1)
						return false;
					last_hi = re->re_hi;
				}
			}
		}
	}

	return true;
}

/**
 * Determines whether an expression list in an ip nidrange contains exactly
 * one contiguous address range.
 *
 * \param	*nidlist
 *
 * \retval	true if contiguous
 * \retval	false if not contiguous
 */
static bool cfs_ip_is_contiguous(struct list_head *nidlist)
{
	struct nidrange		*nr;
	struct addrrange	*ar;
	struct cfs_expr_list	*el;
	struct cfs_range_expr	*re;
	int			expr_count;
	int			last_hi = 255;
	int			last_diff = 0;
	__u32			last_end_nid = 0;
	__u32			current_start_nid = 0;
	__u32			current_end_nid = 0;

	list_for_each_entry(nr, nidlist, nr_link) {
		list_for_each_entry(ar, &nr->nr_addrranges, ar_link) {
			last_hi = 255;
			last_diff = 0;
			cfs_ip_ar_min_max(ar, &current_start_nid,
					  &current_end_nid);
			if (last_end_nid != 0 &&
			    (current_start_nid - last_end_nid != 1))
					return false;
			last_end_nid = current_end_nid;
			list_for_each_entry(el,
					    &ar->ar_numaddr_ranges,
					    el_link) {
				expr_count = 0;
				list_for_each_entry(re, &el->el_exprs,
						    re_link) {
					expr_count++;
					if (re->re_stride > 1 ||
					    (last_diff > 0 && last_hi != 255) ||
					    (last_diff > 0 && last_hi == 255 &&
					     re->re_lo > 0))
						return false;
					last_hi = re->re_hi;
					last_diff = re->re_hi - re->re_lo;
				}
			}
		}
	}

	return true;
}

/**
 * Takes a linked list of nidrange expressions, determines the minimum
 * and maximum nid and creates appropriate nid structures
 *
 * \param	*nidlist
 * \param	*min_nid
 * \param	*max_nid
 */
void cfs_nidrange_find_min_max(struct list_head *nidlist, char *min_nid,
			       char *max_nid, int nidstr_length)
{
	struct nidrange		*nr;
	struct netstrfns	*nf = NULL;
	int			netnum = -1;
	__u32			min_addr;
	__u32			max_addr;
	char			*lndname = NULL;
	char			min_addr_str[IPSTRING_LENGTH];
	char			max_addr_str[IPSTRING_LENGTH];

	list_for_each_entry(nr, nidlist, nr_link) {
		nf = nr->nr_netstrfns;
		lndname = nf->nf_name;
		if (netnum == -1)
			netnum = nr->nr_netnum;

		nf->nf_min_max(nidlist, &min_addr, &max_addr);
	}
	nf->nf_addr2str(min_addr, min_addr_str);
	nf->nf_addr2str(max_addr, max_addr_str);

	snprintf(min_nid, nidstr_length, "%s@%s%d", min_addr_str, lndname,
		 netnum);
	snprintf(max_nid, nidstr_length, "%s@%s%d", max_addr_str, lndname,
		 netnum);
}
EXPORT_SYMBOL(cfs_nidrange_find_min_max);

/**
 * Determines the min and max NID values for num LNDs
 *
 * \param	*nidlist
 * \param	*min_nid
 * \param	*max_nid
 */
static void cfs_num_min_max(struct list_head *nidlist, __u32 *min_nid,
			    __u32 *max_nid)
{
	struct nidrange		*nr;
	struct addrrange	*ar;
	unsigned int		tmp_min_addr = 0;
	unsigned int		tmp_max_addr = 0;
	unsigned int		min_addr = 0;
	unsigned int		max_addr = 0;

	list_for_each_entry(nr, nidlist, nr_link) {
		list_for_each_entry(ar, &nr->nr_addrranges, ar_link) {
			cfs_num_ar_min_max(ar, &tmp_min_addr,
					   &tmp_max_addr);
			if (tmp_min_addr < min_addr || min_addr == 0)
				min_addr = tmp_min_addr;
			if (tmp_max_addr > max_addr)
				max_addr = tmp_min_addr;
		}
	}
	*max_nid = max_addr;
	*min_nid = min_addr;
}

/**
 * Takes an nidlist and determines the minimum and maximum
 * ip addresses.
 *
 * \param	*nidlist
 * \param	*min_nid
 * \param	*max_nid
 */
static void cfs_ip_min_max(struct list_head *nidlist, __u32 *min_nid,
			   __u32 *max_nid)
{
	struct nidrange		*nr;
	struct addrrange	*ar;
	__u32			tmp_min_ip_addr = 0;
	__u32			tmp_max_ip_addr = 0;
	__u32			min_ip_addr = 0;
	__u32			max_ip_addr = 0;

	list_for_each_entry(nr, nidlist, nr_link) {
		list_for_each_entry(ar, &nr->nr_addrranges, ar_link) {
			cfs_ip_ar_min_max(ar, &tmp_min_ip_addr,
					  &tmp_max_ip_addr);
			if (tmp_min_ip_addr < min_ip_addr || min_ip_addr == 0)
				min_ip_addr = tmp_min_ip_addr;
			if (tmp_max_ip_addr > max_ip_addr)
				max_ip_addr = tmp_max_ip_addr;
		}
	}

	if (min_nid != NULL)
		*min_nid = min_ip_addr;
	if (max_nid != NULL)
		*max_nid = max_ip_addr;
}

#ifdef __KERNEL__

EXPORT_SYMBOL(libcfs_isknown_lnd);
EXPORT_SYMBOL(libcfs_lnd2modname);
EXPORT_SYMBOL(libcfs_lnd2str);
EXPORT_SYMBOL(libcfs_str2lnd);
EXPORT_SYMBOL(libcfs_net2str);
EXPORT_SYMBOL(libcfs_nid2str);
EXPORT_SYMBOL(libcfs_str2net);
EXPORT_SYMBOL(libcfs_str2nid);
EXPORT_SYMBOL(libcfs_id2str);
EXPORT_SYMBOL(libcfs_str2anynid);
EXPORT_SYMBOL(cfs_free_nidlist);
EXPORT_SYMBOL(cfs_parse_nidlist);
EXPORT_SYMBOL(cfs_print_nidlist);
EXPORT_SYMBOL(cfs_match_nid);

#endif