githubmirror/lsof

lib/isfn.c
357 строк12 KB
Jiajie Chen
Move hashSfile static state to lsof_context
31 мар 2026, 13:14
31 мар 2026, 13:14dd692bd
/*
 * isfn.c -- is_file_named() function 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.
 */

/*
 * To use this source file:
 *
 * 1. Define USE_LIB_IS_FILE_NAMED.
 *
 * 2. If clone support is required:
 *
 *    a.  Define HAVECLONEMAJ to be the name of the variable that
 *	  contains the status of the clone major device -- e.g.,
 *
 *		#define HAVECLONEMAJ HaveCloneMaj
 *
 *    b.  Define CLONEMAJ to be the name of the constant or
 *	  variable that defines the clone major device -- e.g.,
 *
 *		#define CLONEMAJ CloneMaj
 *
 *    c.  Make sure that clone devices are identified by an lfile
 *	  element is_stream value of 1.
 *
 *    d.  Accept clone searching by device number only.
 */

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

#if defined(USE_LIB_IS_FILE_NAMED)

/*
 * Local structures
 */

/*
 * Local static variables
 */

/*
 * Local definitions
 */

#    if defined(HAVECLONEMAJ)
#        define SFCDHASH                                                       \
            1024 /* Sfile hash by clone device (power                          \
                  * of 2!) */
#    endif       /* defined(HAVECLONEMAJ) */

#    define SFDIHASH                                                           \
        4094 /* Sfile hash by (device,inode) number                            \
              * pair bucket count (power of 2!) */
#    define SFFSHASH                                                           \
        1024 /* Sfile hash by file system device                               \
              * number bucket count (power of 2!) */
#    define SFHASHDEVINO(maj, min, ino, mod)                                   \
        ((int)(((int)((((int)(maj + 1)) * ((int)((min + 1)))) + ino) *         \
                31415) &                                                       \
               (mod - 1)))
/* hash for Sfile by major device,
 * minor device, and inode, modulo mod
 * (mod must be a power of 2) */
#    define SFRDHASH                                                           \
        1024 /* Sfile hash by raw device number                                \
              * bucket count (power of 2!) */
#    define SFHASHRDEVI(maj, min, rmaj, rmin, ino, mod)                        \
        ((int)(((int)((((int)(maj + 1)) * ((int)((min + 1)))) +                \
                      ((int)(rmaj + 1) * (int)(rmin + 1)) + ino) *             \
                31415) &                                                       \
               (mod - 1)))
/* hash for Sfile by major device,
 * minor device, major raw device,
 * minor raw device, and inode, modulo
 * mod (mod must be a power of 2) */
#    define SFNMHASH                                                           \
        4096 /* Sfile hash by name bucket count                                \
              * (must be a power of 2!) */

/*
 * hashSfile() - hash Sfile entries for use in is_file_named() searches
 */

void hashSfile(struct lsof_context *ctx) {
    int i;
    int sfplm = 3;
    struct sfile *s;
    struct hsfile *sh, *sn;
    /*
     * Do nothing if there are no file search arguments cached or if the
     * hashes have already been constructed.
     */
    if (!Sfile || Hs)
        return;
    /*
     * Allocate hash buckets by (device,inode), file system device, and file
     * name.
     */

#    if defined(HAVECLONEMAJ)
    if (HAVECLONEMAJ) {
        if (!(HbyCd = (struct hsfile *)calloc((MALLOC_S)SFCDHASH,
                                              sizeof(struct hsfile)))) {
            (void)fprintf(
                stderr, "%s: can't allocate space for %d clone hash buckets\n",
                Pn, SFCDHASH);
            Error(ctx);
        }
        sfplm++;
    }
#    endif /* defined(HAVECLONEMAJ) */

    if (!(HbyFdi = (struct hsfile *)calloc((MALLOC_S)SFDIHASH,
                                           sizeof(struct hsfile)))) {
        (void)fprintf(
            stderr, "%s: can't allocate space for %d (dev,ino) hash buckets\n",
            Pn, SFDIHASH);
        Error(ctx);
    }
    if (!(HbyFrd = (struct hsfile *)calloc((MALLOC_S)SFRDHASH,
                                           sizeof(struct hsfile)))) {
        (void)fprintf(stderr,
                      "%s: can't allocate space for %d rdev hash buckets\n", Pn,
                      SFRDHASH);
        Error(ctx);
    }
    if (!(HbyFsd = (struct hsfile *)calloc((MALLOC_S)SFFSHASH,
                                           sizeof(struct hsfile)))) {
        (void)fprintf(stderr,
                      "%s: can't allocate space for %d file sys hash buckets\n",
                      Pn, SFFSHASH);
        Error(ctx);
    }
    if (!(HbyNm = (struct hsfile *)calloc((MALLOC_S)SFNMHASH,
                                          sizeof(struct hsfile)))) {
        (void)fprintf(stderr,
                      "%s: can't allocate space for %d name hash buckets\n", Pn,
                      SFNMHASH);
        Error(ctx);
    }
    Hs++;
    /*
     * Scan the Sfile chain, building file, file system, raw device, and file
     * name hash bucket chains.
     */
    for (s = Sfile; s; s = s->next) {
        for (i = 0; i < sfplm; i++) {
            if (i == 0) {
                if (!s->aname)
                    continue;
                sh = &HbyNm[hashbyname(s->aname, SFNMHASH)];
                HbyNmCt++;
            } else if (i == 1) {
                if (s->type) {
                    sh = &HbyFdi[SFHASHDEVINO(GET_MAJ_DEV(s->dev),
                                              GET_MIN_DEV(s->dev), s->i,
                                              SFDIHASH)];
                    HbyFdiCt++;
                } else {
                    sh = &HbyFsd[SFHASHDEVINO(
                        GET_MAJ_DEV(s->dev), GET_MIN_DEV(s->dev), 0, SFFSHASH)];
                    HbyFsdCt++;
                }
            } else if (i == 2) {
                if ((s->mode == S_IFCHR) || (s->mode == S_IFBLK)) {
                    sh = &HbyFrd[SFHASHRDEVI(
                        GET_MAJ_DEV(s->dev), GET_MIN_DEV(s->dev),
                        GET_MAJ_DEV(s->rdev), GET_MIN_DEV(s->rdev), s->i,
                        SFRDHASH)];
                    HbyFrdCt++;
                } else
                    continue;
            }

#    if defined(HAVECLONEMAJ)
            else {
                if (!HAVECLONEMAJ || (GET_MAJ_DEV(s->rdev) != CLONEMAJ))
                    continue;
                sh = &HbyCd[SFHASHDEVINO(0, GET_MIN_DEV(s->rdev), 0, SFCDHASH)];
                HbyCdCt++;
            }
#    else  /* ! defined(HAVECLONEMAJ) */
            else
                continue;
#    endif /* defined(HAVECLONEMAJ) */

            if (!sh->s) {
                sh->s = s;
                sh->next = (struct hsfile *)NULL;
                continue;
            } else {
                if (!(sn = (struct hsfile *)malloc(
                          (MALLOC_S)sizeof(struct hsfile)))) {
                    (void)fprintf(stderr,
                                  "%s: can't allocate hsfile bucket for: %s\n",
                                  Pn, s->aname);
                    Error(ctx);
                }
                sn->s = s;
                sn->next = sh->next;
                sh->next = sn;
            }
        }
    }
}

/*
 * is_file_named() - is this file named?
 */

int is_file_named(struct lsof_context *ctx,
                  char *p, /* path name; NULL = search by device
                            * and inode (from *Lf) */
                  int cd)  /* character or block type file --
                            * VCHR or VBLK vnode, or S_IFCHR
                            * or S_IFBLK inode */
{
    char *ep;
    int f = 0;
    struct sfile *s = (struct sfile *)NULL;
    struct hsfile *sh;
    size_t sz;
    /*
     * Check for a path name match, as requested.
     */
    if (p && HbyNmCt) {
        for (sh = &HbyNm[hashbyname(p, SFNMHASH)]; sh; sh = sh->next) {
            if ((s = sh->s) && strcmp(p, s->aname) == 0) {
                f = 2;
                break;
            }
        }
    }

#    if defined(HAVECLONEMAJ)
    /*
     * If this is a stream, check for a clone device match.
     */
    if (!f && HbyCdCt && Lf->is_stream && Lf->dev_def && Lf->rdev_def &&
        (Lf->dev == DevDev)) {
        for (sh = &HbyCd[SFHASHDEVINO(0, GET_MAJ_DEV(Lf->rdev), 0, SFCDHASH)];
             sh; sh = sh->next) {
            if ((s = sh->s) &&
                (GET_MAJ_DEV(Lf->rdev) == GET_MIN_DEV(s->rdev))) {
                f = 3;
                break;
            }
        }
    }
#    endif /* defined(HAVECLONEMAJ) */

    /*
     * Check for a regular file.
     */
    if (!f && HbyFdiCt && Lf->dev_def && (Lf->inp_ty == 1 || Lf->inp_ty == 3)) {
        for (sh = &HbyFdi[SFHASHDEVINO(GET_MAJ_DEV(Lf->dev),
                                       GET_MIN_DEV(Lf->dev), Lf->inode,
                                       SFDIHASH)];
             sh; sh = sh->next) {
            if ((s = sh->s) && (Lf->dev == s->dev) && (Lf->inode == s->i)) {
                f = 1;
                break;
            }
        }
    }
    /*
     * Check for a file system match.
     */
    if (!f && HbyFsdCt && Lf->dev_def) {
        for (sh = &HbyFsd[SFHASHDEVINO(GET_MAJ_DEV(Lf->dev),
                                       GET_MIN_DEV(Lf->dev), 0, SFFSHASH)];
             sh; sh = sh->next) {
            if ((s = sh->s) && (s->dev == Lf->dev)) {
                f = 1;
                break;
            }
        }
    }
    /*
     * Check for a character or block device match.
     */
    if (!f && HbyFrdCt && cd && Lf->dev_def && (Lf->dev == DevDev) &&
        Lf->rdev_def && (Lf->inp_ty == 1 || Lf->inp_ty == 3)) {
        for (sh = &HbyFrd[SFHASHRDEVI(
                 GET_MAJ_DEV(Lf->dev), GET_MIN_DEV(Lf->dev),
                 GET_MAJ_DEV(Lf->rdev), GET_MIN_DEV(Lf->rdev), Lf->inode,
                 SFRDHASH)];
             sh; sh = sh->next) {
            if ((s = sh->s) && (s->dev == Lf->dev) && (s->rdev == Lf->rdev) &&
                (s->i == Lf->inode)) {
                f = 1;
                break;
            }
        }
    }
    /*
     * Convert the name if a match occurred.
     */
    switch (f) {
    case 0:
        return (0);
    case 1:
        if (s->type) {

            /*
             * If the search argument isn't a file system, propagate it
             * to Namech[]; otherwise, let printname() compose the name.
             */
            (void)snpf(Namech, Namechl, "%s", s->name);
            if (s->devnm) {
                ep = endnm(ctx, &sz);
                (void)snpf(ep, sz, " (%s)", s->devnm);
            }
        }
        break;
    case 2:
        (void)snpf(Namech, Namechl, "%s", p);
        break;

#    if defined(HAVECLONEMAJ)
        /* case 3:		do nothing for stream clone matches */
#    endif /* defined(HAVECLONEMAJ) */
    }
    if (s)
        s->f = 1;
    return (1);
}
#else  /* !defined(USE_LIB_IS_FILE_NAMED) */
char isfn_d1[] = "d";
char *isfn_d2 = isfn_d1;
#endif /* defined(USE_LIB_IS_FILE_NAMED) */