nidstrings.c

lustre 1.6.5 source code

/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 * Copyright (C) 2002 Cluster File Systems, Inc.
 *   Author: Phil Schwan <[e-mail]>
 *
 *   This file is part of Lustre, http://www.lustre.org.
 *
 *   Lustre is free software; you can redistribute it and/or
 *   modify it under the terms of version 2 of the GNU General Public
 *   License as published by the Free Software Foundation.
 *
 *   Lustre 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 for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with Lustre; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef EXPORT_SYMTAB
# define EXPORT_SYMTAB
#endif

#define DEBUG_SUBSYSTEM S_LNET

#include <lnet/lnet.h>
#include <libcfs/kp30.h>
#ifndef __KERNEL__
#ifdef HAVE_GETHOSTBYNAME
# include <netdb.h>
#endif
#endif

/* 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.
 */

#define LNET_NIDSTR_COUNT  128     /* # of nidstrings */
#define LNET_NIDSTR_SIZE   32      /* size of each one (see below for usage) */

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=0)                 /* avoid unused var warnings */
# define NIDSTR_UNLOCK(f) (f=0)
#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 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);

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);
};

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_type      */  SOCKLND,
         /* .nf_name      */  "tcp",
         /* .nf_modname   */  "ksocklnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  O2IBLND,
         /* .nf_name      */  "o2ib",
         /* .nf_modname   */  "ko2iblnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  CIBLND,
         /* .nf_name      */  "cib",
         /* .nf_modname   */  "kciblnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  OPENIBLND,
         /* .nf_name      */  "openib",
         /* .nf_modname   */  "kopeniblnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  IIBLND,
         /* .nf_name      */  "iib",
         /* .nf_modname   */  "kiiblnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  VIBLND,
         /* .nf_name      */  "vib",
         /* .nf_modname   */  "kviblnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  RALND,
         /* .nf_name      */  "ra",
         /* .nf_modname   */  "kralnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  QSWLND,
         /* .nf_name      */  "elan",
         /* .nf_modname   */  "kqswlnd",
         /* .nf_addr2str  */  libcfs_decnum_addr2str,
         /* .nf_str2addr  */  libcfs_num_str2addr},
        {/* .nf_type      */  GMLND,
         /* .nf_name      */  "gm",
         /* .nf_modname   */  "kgmlnd",
         /* .nf_addr2str  */  libcfs_hexnum_addr2str,
         /* .nf_str2addr  */  libcfs_num_str2addr},
        {/* .nf_type      */  MXLND,
         /* .nf_name      */  "mx",
         /* .nf_modname   */  "kmxlnd",
         /* .nf_addr2str  */  libcfs_ip_addr2str,
         /* .nf_str2addr  */  libcfs_ip_str2addr},
        {/* .nf_type      */  PTLLND,
         /* .nf_name      */  "ptl",
         /* .nf_modname   */  "kptllnd",
         /* .nf_addr2str  */  libcfs_decnum_addr2str,
         /* .nf_str2addr  */  libcfs_num_str2addr},
        /* 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)
{
        int   a;
        int   b;
        int   c;
        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)