/*
 * 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.gnu.org/licenses/gpl-2.0.html
 *
 * 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.
 *
 * lnet/lnet/nidstrings.c
 *
 * Author: Phil Schwan <phil@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_LNET

#include "../../include/linux/libcfs/libcfs.h"
#include "../../include/linux/lnet/lnet.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 \<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)
                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)
                return NULL;
        endlen = src->ls_len - strlen(nf->nf_name);
        if (!endlen)
                /* 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)
                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))
                goto failed;

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

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

        if (parse_addrange(&addrrange, nr))
                goto failed;

        return 1;
failed:
        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));
        }
}
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 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;

        src.ls_str = str;
        src.ls_len = len;
        INIT_LIST_HEAD(nidlist);
        while (src.ls_str) {
                rc = cfs_gettok(&src, ' ', &res);
                if (!rc) {
                        cfs_free_nidlist(nidlist);
                        return 0;
                }
                rc = parse_nidrange(&res, nidlist);
                if (!rc) {
                        cfs_free_nidlist(nidlist);
                        return 0;
                }
        }
        return 1;
}
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(lnet_nid_t nid, struct list_head *nidlist)
{
        struct nidrange *nr;
        struct addrrange *ar;

        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;
}
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)
                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)
                        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)
                        i += scnprintf(buffer + i, count - i, " ");

                if (nr->nr_all) {
                        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);

/**
 * 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)
                *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)
                *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)
                                min_addr = re->re_lo;
                        if (re->re_hi > max_addr)
                                max_addr = re->re_hi;
                }
        }

        if (min_nid)
                *min_nid = min_addr;
        if (max_nid)
                *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)
                        lndname = nf->nf_name;
                if (netnum == -1)
                        netnum = nr->nr_netnum;

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

        if (!nf)
                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 &&
                            (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 &&
                                                 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 &&
                            (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, size_t 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, sizeof(min_addr_str));
        nf->nf_addr2str(max_addr, max_addr_str, sizeof(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)
                                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)
                                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)
                *min_nid = min_ip_addr;
        if (max_nid)
                *max_nid = max_ip_addr;
}

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);
}

/*
 * 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) && !(b & ~0xff) &&
            !(c & ~0xff) && !(d & ~0xff)) {
                *addr = ((a << 24) | (b << 16) | (c << 8) | d);
                return 1;
        }

        return 0;
}

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

        src.ls_str = str;
        src.ls_len = len;
        i = 0;

        while (src.ls_str) {
                struct cfs_lstr res;

                if (!cfs_gettok(&src, '.', &res)) {
                        rc = -EINVAL;
                        goto out;
                }

                rc = cfs_expr_list_parse(res.ls_str, res.ls_len, 0, 255, &el);
                if (rc)
                        goto out;

                list_add_tail(&el->el_link, list);
                i++;
        }

        if (i == 4)
                return 0;

        rc = -EINVAL;
out:
        cfs_expr_list_free_list(list);

        return rc;
}

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)
                        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;
}

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
 */
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)
                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_entry(numaddr->next, 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_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              = 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 },
};

static const size_t libcfs_nnetstrfns = ARRAY_SIZE(libcfs_netstrfns);

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);
}
EXPORT_SYMBOL(libcfs_isknown_lnd);

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

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

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

        if (nf)
                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)
                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)
                snprintf(buf, buf_size, "<%u:%u>", lnd, nnum);
        else if (!nnum)
                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) {
                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)
                        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);

static struct netstrfns *
libcfs_str2net_internal(const char *str, __u32 *net)
{
        struct netstrfns *uninitialized_var(nf);
        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))
                return net;

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

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

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

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 ? "U" : "",
                 id.pid & ~LNET_PID_USERFLAG, libcfs_nid2str(id.nid));
        return str;
}
EXPORT_SYMBOL(libcfs_id2str);

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);