githubmirror/lsof

lib/lkud.c
193 строки5 KB
Chen
Expose functionality as a re-usable library - Part 2 (#284)
12 апр 2023, 09:01
12 апр 2023, 09:016dca348
/*
 * lkud.c -- device lookup functions for lsof library
 */

/*
 * Copyright 1997 Purdue Research Foundation, West Lafayette, Indiana
 * 47907.  All rights reserved.
 *
 * Written by Victor A. Abell
 *
 * This software is not subject to any license of the American Telephone
 * and Telegraph Company or the Regents of the University of California.
 *
 * Permission is granted to anyone to use this software for any purpose on
 * any computer system, and to alter it and redistribute it freely, subject
 * to the following restrictions:
 *
 * 1. Neither the authors nor Purdue University are responsible for any
 *    consequences of the use of this software.
 *
 * 2. The origin of this software must not be misrepresented, either by
 *    explicit claim or by omission.  Credit to the authors and Purdue
 *    University must appear in documentation and sources.
 *
 * 3. Altered versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 *
 * 4. This notice may not be removed or altered.
 */

/*
 * lkud.c -- lookup device
 *
 * The caller may define:
 *
 *	HASBLKDEV	to activate block device lookup
 */

#include "common.h"
#include "machine.h"

#if defined(HASBLKDEV) || defined(USE_LIB_LKUPDEV)

#else  /* !defined(HASBLKDEV) && !defined(USE_LIB_LKUPDEV) */
char lkud_d1[] = "d";
char *lkud_d2 = lkud_d1;
#endif /* defined(HASBLKDEV) || defined(USE_LIB_LKUPDEV) */

#if defined(HASBLKDEV)
/*
 * lkupbdev() - look up a block device
 */

struct l_dev *lkupbdev(struct lsof_context *ctx,
                       dev_t *dev,  /* pointer to device number */
                       dev_t *rdev, /* pointer to raw device number */
                       int i,       /* inode match status */
                       int r)       /* if 1, rebuild the device cache with
                                     * rereaddev() when no match is found
                                     * and HASDCACHE is defined and
                                     * DCunsafe is one */
{
    INODETYPE inode = (INODETYPE)0;
    int low, hi, mid;
    struct l_dev *dp;
    int ty = 0;

    if (*dev != DevDev)
        return ((struct l_dev *)NULL);
    readdev(ctx, 0);
    if (i) {
        inode = Lf->inode;
        ty = Lf->inp_ty;
    }
    /*
     * Search block device table for match.
     */

#    if defined(HASDCACHE)

lkupbdev_again:

#    endif /* defined(HASDCACHE) */

    low = mid = 0;
    hi = BNdev - 1;
    while (low <= hi) {
        mid = (low + hi) / 2;
        dp = BSdev[mid];
        if (*rdev < dp->rdev)
            hi = mid - 1;
        else if (*rdev > dp->rdev)
            low = mid + 1;
        else {
            if ((i == 0) || (ty != 1) || (inode == dp->inode)) {

#    if defined(HASDCACHE)
                if (DCunsafe && !dp->v && !vfy_dev(ctx, dp))
                    goto lkupbdev_again;
#    endif /* defined(HASDCACHE) */

                return (dp);
            }
            if (inode < dp->inode)
                hi = mid - 1;
            else
                low = mid + 1;
        }
    }

#    if defined(HASDCACHE)
    if (DCunsafe && r) {
        (void)rereaddev(ctx);
        goto lkupbdev_again;
    }
#    endif /* defined(HASDCACHE) */

    return ((struct l_dev *)NULL);
}
#endif /* defined(HASBLKDEV) */

#if defined(USE_LIB_LKUPDEV)
/*
 * lkupdev() - look up a character device
 */

struct l_dev *lkupdev(struct lsof_context *ctx,
                      dev_t *dev,  /* pointer to device number */
                      dev_t *rdev, /* pointer to raw device number */
                      int i,       /* inode match status */
                      int r)       /* if 1, rebuild the device cache with
                                    * rereaddev() when no match is found
                                    * and HASDCACHE is defined and
                                    * DCunsafe is one */
{
    INODETYPE inode = (INODETYPE)0;
    int low, hi, mid;
    struct l_dev *dp;
    int ty = 0;

    if (*dev != DevDev)
        return ((struct l_dev *)NULL);
    readdev(ctx, 0);
    if (i) {
        inode = Lf->inode;
        ty = Lf->inp_ty;
    }
    /*
     * Search device table for match.
     */

#    if defined(HASDCACHE)

lkupdev_again:

#    endif /* defined(HASDCACHE) */

    low = mid = 0;
    hi = Ndev - 1;
    while (low <= hi) {
        mid = (low + hi) / 2;
        dp = Sdev[mid];
        if (*rdev < dp->rdev)
            hi = mid - 1;
        else if (*rdev > dp->rdev)
            low = mid + 1;
        else {
            if ((i == 0) || (ty != 1) || (inode == dp->inode)) {

#    if defined(HASDCACHE)
                if (DCunsafe && !dp->v && !vfy_dev(ctx, dp))
                    goto lkupdev_again;
#    endif /* defined(HASDCACHE) */

                return (dp);
            }
            if (inode < dp->inode)
                hi = mid - 1;
            else
                low = mid + 1;
        }
    }

#    if defined(HASDCACHE)
    if (DCunsafe && r) {
        (void)rereaddev(ctx);
        goto lkupdev_again;
    }
#    endif /* defined(HASDCACHE) */

    return ((struct l_dev *)NULL);
}
#endif /* defined(USE_LIB_LKUPDEV) */