FreeBSD-5.3/sbin/ldconfig/elfhints.c
/*-
* Copyright (c) 1998 John D. Polstra
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*
* $FreeBSD: src/sbin/ldconfig/elfhints.c,v 1.8 2001/05/02 23:56:18 obrien Exp $
*/
#include <sys/param.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <ctype.h>
#include <dirent.h>
#include <elf-hints.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "ldconfig.h"
#define MAXDIRS 1024 /* Maximum directories in path */
#define MAXFILESIZE (16*1024) /* Maximum hints file size */
static void add_dir(const char *, const char *, int);
static void read_dirs_from_file(const char *, const char *);
static void read_elf_hints(const char *, int);
static void write_elf_hints(const char *);
static const char *dirs[MAXDIRS];
static int ndirs;
int insecure;
static void
add_dir(const char *hintsfile, const char *name, int trusted)
{
struct stat stbuf;
int i;
/* Do some security checks */
if (!trusted && !insecure) {
if (stat(name, &stbuf) == -1) {
warn("%s", name);
return;
}
if (stbuf.st_uid != 0) {
warnx("%s: ignoring directory not owned by root", name);
return;
}
if ((stbuf.st_mode & S_IWOTH) != 0) {
warnx("%s: ignoring world-writable directory", name);
return;
}
if ((stbuf.st_mode & S_IWGRP) != 0) {
warnx("%s: ignoring group-writable directory", name);
return;
}
}
for (i = 0; i < ndirs; i++)
if (strcmp(dirs[i], name) == 0)
return;
if (ndirs >= MAXDIRS)
errx(1, "\"%s\": Too many directories in path", hintsfile);
dirs[ndirs++] = name;
}
void
list_elf_hints(const char *hintsfile)
{
int i;
int nlibs;
read_elf_hints(hintsfile, 1);
printf("%s:\n", hintsfile);
printf("\tsearch directories:");
for (i = 0; i < ndirs; i++)
printf("%c%s", i == 0 ? ' ' : ':', dirs[i]);
printf("\n");
nlibs = 0;
for (i = 0; i < ndirs; i++) {
DIR *dirp;
struct dirent *dp;
if ((dirp = opendir(dirs[i])) == NULL)
continue;
while ((dp = readdir(dirp)) != NULL) {
int len;
int namelen;
const char *name;
const char *vers;
/* Name can't be shorter than "libx.so.0" */
if ((len = strlen(dp->d_name)) < 9 ||
strncmp(dp->d_name, "lib", 3) != 0)
continue;
name = dp->d_name + 3;
vers = dp->d_name + len;
while (vers > dp->d_name && isdigit(*(vers-1)))
vers--;
if (vers == dp->d_name + len)
continue;
if (vers < dp->d_name + 4 ||
strncmp(vers - 4, ".so.", 4) != 0)
continue;
/* We have a valid shared library name. */
namelen = (vers - 4) - name;
printf("\t%d:-l%.*s.%s => %s/%s\n", nlibs,
namelen, name, vers, dirs[i], dp->d_name);
nlibs++;
}
closedir(dirp);
}
}
static void
read_dirs_from_file(const char *hintsfile, const char *listfile)
{
FILE *fp;
char buf[MAXPATHLEN];
int linenum;
if ((fp = fopen(listfile, "r")) == NULL)
err(1, "%s", listfile);
linenum = 0;
while (fgets(buf, sizeof buf, fp) != NULL) {
char *cp, *sp;
linenum++;
cp = buf;
/* Skip leading white space. */
while (isspace(*cp))
cp++;
if (*cp == '#' || *cp == '\0')
continue;
sp = cp;
/* Advance over the directory name. */
while (!isspace(*cp) && *cp != '\0')
cp++;
/* Terminate the string and skip trailing white space. */
if (*cp != '\0') {
*cp++ = '\0';
while (isspace(*cp))
cp++;
}
/* Now we had better be at the end of the line. */
if (*cp != '\0')
warnx("%s:%d: trailing characters ignored",
listfile, linenum);
if ((sp = strdup(sp)) == NULL)
errx(1, "Out of memory");
add_dir(hintsfile, sp, 0);
}
fclose(fp);
}
static void
read_elf_hints(const char *hintsfile, int must_exist)
{
int fd;
struct stat s;
void *mapbase;
struct elfhints_hdr *hdr;
char *strtab;
char *dirlist;
char *p;
if ((fd = open(hintsfile, O_RDONLY)) == -1) {
if (errno == ENOENT && !must_exist)
return;
err(1, "Cannot open \"%s\"", hintsfile);
}
if (fstat(fd, &s) == -1)
err(1, "Cannot stat \"%s\"", hintsfile);
if (s.st_size > MAXFILESIZE)
errx(1, "\"%s\" is unreasonably large", hintsfile);
/*
* We use a read-write, private mapping so that we can null-terminate
* some strings in it without affecting the underlying file.
*/
mapbase = mmap(NULL, s.st_size, PROT_READ|PROT_WRITE,
MAP_PRIVATE, fd, 0);
if (mapbase == MAP_FAILED)
err(1, "Cannot mmap \"%s\"", hintsfile);
close(fd);
hdr = (struct elfhints_hdr *)mapbase;
if (hdr->magic != ELFHINTS_MAGIC)
errx(1, "\"%s\": invalid file format", hintsfile);
if (hdr->version != 1)
errx(1, "\"%s\": unrecognized file version (%d)", hintsfile,
hdr->version);
strtab = (char *)mapbase + hdr->strtab;
dirlist = strtab + hdr->dirlist;
if (*dirlist != '\0')
while ((p = strsep(&dirlist, ":")) != NULL)
add_dir(hintsfile, p, 1);
}
void
update_elf_hints(const char *hintsfile, int argc, char **argv, int merge)
{
int i;
if (merge)
read_elf_hints(hintsfile, 0);
for (i = 0; i < argc; i++) {
struct stat s;
if (stat(argv[i], &s) == -1)
warn("warning: %s", argv[i]);
else if (S_ISREG(s.st_mode))
read_dirs_from_file(hintsfile, argv[i]);
else
add_dir(hintsfile, argv[i], 0);
}
write_elf_hints(hintsfile);
}
static void
write_elf_hints(const char *hintsfile)
{
struct elfhints_hdr hdr;
char *tempname;
int fd;
FILE *fp;
int i;
if (asprintf(&tempname, "%s.XXXXXX", hintsfile) == -1)
errx(1, "Out of memory");
if ((fd = mkstemp(tempname)) == -1)
err(1, "mkstemp(%s)", tempname);
if (fchmod(fd, 0444) == -1)
err(1, "fchmod(%s)", tempname);
if ((fp = fdopen(fd, "wb")) == NULL)
err(1, "fdopen(%s)", tempname);
hdr.magic = ELFHINTS_MAGIC;
hdr.version = 1;
hdr.strtab = sizeof hdr;
hdr.strsize = 0;
hdr.dirlist = 0;
memset(hdr.spare, 0, sizeof hdr.spare);
/* Count up the size of the string table. */
if (ndirs > 0) {
hdr.strsize += strlen(dirs[0]);
for (i = 1; i < ndirs; i++)
hdr.strsize += 1 + strlen(dirs[i]);
}
hdr.dirlistlen = hdr.strsize;
hdr.strsize++; /* For the null terminator */
/* Write the header. */
if (fwrite(&hdr, 1, sizeof hdr, fp) != sizeof hdr)
err(1, "%s: write error", tempname);
/* Write the strings. */
if (ndirs > 0) {
if (fputs(dirs[0], fp) == EOF)
err(1, "%s: write error", tempname);
for (i = 1; i < ndirs; i++)
if (fprintf(fp, ":%s", dirs[i]) < 0)
err(1, "%s: write error", tempname);
}
if (putc('\0', fp) == EOF || fclose(fp) == EOF)
err(1, "%s: write error", tempname);
if (rename(tempname, hintsfile) == -1)
err(1, "rename %s to %s", tempname, hintsfile);
free(tempname);
}