/*      $OpenBSD: ldconfig.c,v 1.40 2026/02/18 08:54:46 deraadt Exp $   */

/*
 * Copyright (c) 1993,1995 Paul Kranenburg
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Paul Kranenburg.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <ar.h>
#include <ranlib.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

#include "ld.h"

#undef major
#undef minor

extern char                     *__progname;

int                             verbose;
static int                      nostd;
static int                      justread;
int                             merge;
static int                      rescan;
static int                      unconfig;

struct shlib_list {
        /* Internal list of shared libraries found */
        char                    *name;
        char                    *path;
        int                     dewey[MAXDEWEY];
        int                     ndewey;
#define major dewey[0]
#define minor dewey[1]
        struct shlib_list       *next;
};

static struct shlib_list        *shlib_head = NULL, **shlib_tail = &shlib_head;
static char                     *dir_list;

static void     enter(char *, char *, char *, int *, int);
static int      dodir(char *, int);
static int      buildhints(void);
static int      readhints(void);
static void     listhints(void);

static void
usage(void)
{
        fprintf(stderr,
            "usage: %s [-mRrsUv] [path ...]\n", __progname);
        exit(1);
}

int
main(int argc, char *argv[])
{
        int i, c;
        int rval = 0;

        if (pledge("stdio rpath wpath cpath fattr", NULL) == -1)
                err(1, "pledge");

        while ((c = getopt(argc, argv, "DmPrRsSUv")) != -1) {
                switch (c) {
                case 'R':
                        rescan = 1;
                        break;
                case 'U':
                        rescan = unconfig = 1;
                        break;
                case 'm':
                        merge = 1;
                        break;
                case 'r':
                        justread = 1;
                        break;
                case 's':
                        nostd = 1;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                default:
                        usage();
                        break;
                }
        }

        if (unconfig && merge)
                errx(1, "cannot use -U with -m");

        dir_list = xmalloc(1);
        *dir_list = '\0';

        if (justread || merge || rescan) {
                if ((rval = readhints()) != 0)
                        return rval;
                if (justread) {
                        listhints();
                        return 0;
                }
                add_search_path(dir_list);
                dir_list = xrealloc(dir_list, 1);
                *dir_list = '\0';
        } else if (!nostd)
                std_search_path();

        if (unconfig) {
                if (optind < argc)
                        for (i = optind; i < argc; i++)
                                remove_search_dir(argv[i]);
                else {
                        i = 0;
                        while (i < n_search_dirs) {
                                if (access(search_dirs[i], R_OK) < 0)
                                        remove_search_dir(search_dirs[i]);
                                else
                                        i++;
                        }
                }
        } else
                for (i = optind; i < argc; i++)
                        add_search_dir(argv[i]);

        for (i = 0; i < n_search_dirs; i++) {
                char *cp = concat(dir_list, *dir_list?":":"", search_dirs[i]);

                free(dir_list);
                dir_list = cp;
                rval |= dodir(search_dirs[i], 0);
        }

        rval |= buildhints();

        return rval;
}

int
dodir(char *dir, int silent)
{
        DIR             *dd;
        struct dirent   *dp;
        char            name[PATH_MAX];
        int             dewey[MAXDEWEY], ndewey;

        if ((dd = opendir(dir)) == NULL) {
                if (!silent || errno != ENOENT)
                        warn("%s", dir);
                return -1;
        }

        while ((dp = readdir(dd)) != NULL) {
                size_t n;
                char *cp;

                /* Check for `lib' prefix */
                if (dp->d_name[0] != 'l' ||
                    dp->d_name[1] != 'i' ||
                    dp->d_name[2] != 'b')
                        continue;

                /* Copy the entry minus prefix */
                (void)strlcpy(name, dp->d_name + 3, sizeof name);
                n = strlen(name);
                if (n < 4)
                        continue;

                /* Find ".so." in name */
                for (cp = name + n - 4; cp > name; --cp) {
                        if (cp[0] == '.' &&
                            cp[1] == 's' &&
                            cp[2] == 'o' &&
                            cp[3] == '.')
                                break;
                }
                if (cp <= name)
                        continue;

                *cp = '\0';

                bzero((caddr_t)dewey, sizeof(dewey));
                ndewey = getdewey(dewey, cp + 3);
                if (ndewey > 0)
                        enter(dir, dp->d_name, name, dewey, ndewey);
        }
        closedir(dd);
        return 0;
}

static void
enter(char *dir, char *file, char *name, int dewey[], int ndewey)
{
        struct shlib_list       *shp;

        for (shp = shlib_head; shp; shp = shp->next) {
                if (strcmp(name, shp->name) != 0 || major != shp->major)
                        continue;

                /* Name matches existing entry */
                if (cmpndewey(dewey, ndewey, shp->dewey, shp->ndewey) > 0) {

                        /* Update this entry with higher versioned lib */
                        if (verbose)
                                printf("Updating lib%s.%d.%d to %s/%s\n",
                                    shp->name, shp->major, shp->minor,
                                    dir, file);

                        free(shp->name);
                        shp->name = xstrdup(name);
                        free(shp->path);
                        shp->path = concat(dir, "/", file);
                        bcopy(dewey, shp->dewey, sizeof(shp->dewey));
                        shp->ndewey = ndewey;
                }
                break;
        }

        if (shp)
                /* Name exists: older version or just updated */
                return;

        /* Allocate new list element */
        if (verbose)
                printf("Adding %s/%s\n", dir, file);

        shp = (struct shlib_list *)xmalloc(sizeof *shp);
        shp->name = xstrdup(name);
        shp->path = concat(dir, "/", file);
        bcopy(dewey, shp->dewey, sizeof(shp->dewey));
        shp->ndewey = ndewey;
        shp->next = NULL;

        *shlib_tail = shp;
        shlib_tail = &shp->next;
}


#if DEBUG
/* test */
#undef _PATH_LD_HINTS
#define _PATH_LD_HINTS          "./ld.so.hints"
#endif

static int
hinthash(char *cp, int vmajor, int vminor)
{
        int     k = 0;

        while (*cp)
                k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;

        k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff;
#if 0
        k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff;
#endif

        return k;
}

int
buildhints(void)
{
        int strtab_sz = 0, nhints = 0, fd = -1, i, ret = -1, str_index = 0;
        struct hints_bucket *blist;
        struct hints_header hdr;
        struct shlib_list *shp;
        char *strtab, *tmpfilenam;
        size_t n;

        for (shp = shlib_head; shp; shp = shp->next) {
                strtab_sz += 1 + strlen(shp->name);
                strtab_sz += 1 + strlen(shp->path);
                nhints++;
        }

        /* Fill hints file header */
        hdr.hh_magic = HH_MAGIC;
        hdr.hh_version = LD_HINTS_VERSION_2;
        hdr.hh_nbucket = 1 * nhints;
        n = hdr.hh_nbucket * sizeof(struct hints_bucket);
        hdr.hh_hashtab = sizeof(struct hints_header);
        hdr.hh_strtab = hdr.hh_hashtab + n;
        hdr.hh_dirlist = strtab_sz;
        strtab_sz += 1 + strlen(dir_list);
        hdr.hh_strtab_sz = strtab_sz;
        hdr.hh_ehints = hdr.hh_strtab + hdr.hh_strtab_sz;

        if (verbose)
                printf("Totals: entries %d, buckets %ld, string size %d\n",
                    nhints, hdr.hh_nbucket, strtab_sz);

        /* Allocate buckets and string table */
        blist = (struct hints_bucket *)xmalloc(n);
        bzero(blist, n);
        for (i = 0; i < hdr.hh_nbucket; i++)
                /* Empty all buckets */
                blist[i].hi_next = -1;

        strtab = xmalloc(strtab_sz);

        /* Enter all */
        for (shp = shlib_head; shp; shp = shp->next) {
                struct hints_bucket     *bp;

                bp = blist + (hinthash(shp->name, shp->major, shp->minor) %
                    hdr.hh_nbucket);

                if (bp->hi_pathx) {
                        int     j;

                        for (j = 0; j < hdr.hh_nbucket; j++) {
                                if (blist[j].hi_pathx == 0)
                                        break;
                        }
                        if (j == hdr.hh_nbucket) {
                                warnx("Bummer!");
                                goto out;
                        }
                        while (bp->hi_next != -1)
                                bp = &blist[bp->hi_next];
                        bp->hi_next = j;
                        bp = blist + j;
                }

                /* Insert strings in string table */
                bp->hi_namex = str_index;
                strlcpy(strtab + str_index, shp->name, strtab_sz - str_index);
                str_index += 1 + strlen(shp->name);

                bp->hi_pathx = str_index;
                strlcpy(strtab + str_index, shp->path, strtab_sz - str_index);
                str_index += 1 + strlen(shp->path);

                /* Copy versions */
                bcopy(shp->dewey, bp->hi_dewey, sizeof(bp->hi_dewey));
                bp->hi_ndewey = shp->ndewey;
        }

        /* Copy search directories */
        strlcpy(strtab + str_index, dir_list, strtab_sz - str_index);
        str_index += 1 + strlen(dir_list);

        /* Sanity check */
        if (str_index != strtab_sz)
                errx(1, "str_index(%d) != strtab_sz(%d)", str_index, strtab_sz);

        tmpfilenam = concat(_PATH_LD_HINTS, ".XXXXXXXXXX", "");
        if ((fd = mkstemp(tmpfilenam)) == -1) {
                warn("%s", tmpfilenam);
                goto out;
        }
        if (fchmod(fd, 0444) == -1) {
                warn("%s: failed to change mode", tmpfilenam);
                goto out;
        }

        if (write(fd, &hdr, sizeof(struct hints_header)) !=
            sizeof(struct hints_header)) {
                warn("%s", _PATH_LD_HINTS);
                goto out;
        }
        if (write(fd, blist, hdr.hh_nbucket * sizeof(struct hints_bucket)) !=
            hdr.hh_nbucket * sizeof(struct hints_bucket)) {
                warn("%s", _PATH_LD_HINTS);
                goto out;
        }
        if (write(fd, strtab, strtab_sz) != strtab_sz) {
                warn("%s", _PATH_LD_HINTS);
                goto out;
        }

        if (rename(tmpfilenam, _PATH_LD_HINTS) != 0) {
                warn("%s", _PATH_LD_HINTS);
                goto out;
        }

        ret = 0;
out:
        if (fd != -1)
                close(fd);
        free(blist);
        free(strtab);
        return (ret);
}

static int
readhints(void)
{
        struct stat sb;
        struct hints_bucket *blist;
        struct hints_header *hdr;
        struct shlib_list *shp;
        caddr_t addr;
        char *strtab;
        long msize;
        int fd, i;

        if ((fd = open(_PATH_LD_HINTS, O_RDONLY)) == -1) {
                warn("%s", _PATH_LD_HINTS);
                return -1;
        }
        if (fstat(fd, &sb) != 0 || !S_ISREG(sb.st_mode) ||
            sb.st_size < sizeof(struct hints_header) || sb.st_size > LONG_MAX) {
                warn("%s", _PATH_LD_HINTS);
                return -1;
        }

        msize = (long)sb.st_size;
        addr = mmap(0, msize, PROT_READ, MAP_PRIVATE, fd, 0);

        if (addr == MAP_FAILED) {
                warn("%s", _PATH_LD_HINTS);
                return -1;
        }

        hdr = (struct hints_header *)addr;
        if (HH_BADMAG(*hdr)) {
                warnx("%s: Bad magic: %lo",
                    _PATH_LD_HINTS, hdr->hh_magic);
                return -1;
        }

        if (hdr->hh_ehints > msize) {
                warnx("%s: hintsize greater than filesize: 0x%lx > 0x%lx ",
                    _PATH_LD_HINTS, hdr->hh_ehints, msize);
                    return -1;
        }

        if (hdr->hh_version != LD_HINTS_VERSION_2) {
                warnx("Unsupported version: %ld", hdr->hh_version);
                return -1;
        }

        close(fd);

        blist = (struct hints_bucket *)(addr + hdr->hh_hashtab);
        strtab = (char *)(addr + hdr->hh_strtab);

        dir_list = xstrdup(strtab + hdr->hh_dirlist);

        if (rescan)
                return (0);

        for (i = 0; i < hdr->hh_nbucket; i++) {
                struct hints_bucket     *bp = &blist[i];

                /* Sanity check */
                if (bp->hi_namex >= hdr->hh_strtab_sz) {
                        warnx("Bad name index: %#x", bp->hi_namex);
                        return -1;
                }
                if (bp->hi_pathx >= hdr->hh_strtab_sz) {
                        warnx("Bad path index: %#x", bp->hi_pathx);
                        return -1;
                }

                /* Allocate new list element */
                shp = (struct shlib_list *)xmalloc(sizeof *shp);
                shp->name = xstrdup(strtab + bp->hi_namex);
                shp->path = xstrdup(strtab + bp->hi_pathx);
                bcopy(bp->hi_dewey, shp->dewey, sizeof(shp->dewey));
                shp->ndewey = bp->hi_ndewey;
                shp->next = NULL;

                *shlib_tail = shp;
                shlib_tail = &shp->next;
        }
        return 0;
}

static void
listhints(void)
{
        struct shlib_list *shp;
        int i;

        printf("%s:\n", _PATH_LD_HINTS);
        printf("\tsearch directories: %s\n", dir_list);

        for (i = 0, shp = shlib_head; shp; i++, shp = shp->next)
                printf("\t%d:-l%s.%d.%d => %s\n",
                    i, shp->name, shp->major, shp->minor, shp->path);
}