freebsd-dev/libexec/rtld-aout/shlib.c
John Polstra a3bd401942 Don't recognize a file as an a.out shared library unless it has at
least 2 version numbers.  This fixes the bug where the dynamic
linker would try to load an ELF shared library if it found one.

Note, this change also fixes the same thing in "ld", because the
code is shared.

For "ld" there is still a problem with ".a" libraries, which cannot
be distinguished by name.  I haven't decided what, if anything, to
do about that.
1998-09-05 20:28:48 +00:00

341 lines
8.0 KiB
C

/*
* Copyright (c) 1993 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.
*
* $Id: shlib.c,v 1.20 1998/06/07 03:53:08 brian Exp $
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <a.out.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <link.h>
#include "shlib.h"
#include "support.h"
/*
* Standard directories to search for files specified by -l.
*/
#ifndef STANDARD_SEARCH_DIRS
#define STANDARD_SEARCH_DIRS "/usr/lib/aout"
#endif
/*
* Actual vector of library search directories,
* including `-L'ed and LD_LIBRARY_PATH spec'd ones.
*/
char **search_dirs;
int n_search_dirs;
char *standard_search_dirs[] = {
STANDARD_SEARCH_DIRS
};
void
add_search_dir(name)
char *name;
{
int n;
for (n = 0; n < n_search_dirs; n++)
if (strcmp(search_dirs[n], name) == 0)
return;
n_search_dirs++;
search_dirs = (char **)
xrealloc(search_dirs, n_search_dirs * sizeof search_dirs[0]);
search_dirs[n_search_dirs - 1] = strdup(name);
}
void
add_search_path(path)
char *path;
{
register char *cp, *dup;
if (path == NULL)
return;
/* Add search directories from `path' */
path = dup = strdup(path);
while ((cp = strsep(&path, ":")) != NULL)
add_search_dir(cp);
free(dup);
}
void
std_search_path()
{
int i, n;
/* Append standard search directories */
n = sizeof standard_search_dirs / sizeof standard_search_dirs[0];
for (i = 0; i < n; i++)
add_search_dir(standard_search_dirs[i]);
}
/*
* Return true if CP points to a valid dewey number.
* Decode and leave the result in the array DEWEY.
* Return the number of decoded entries in DEWEY.
*/
int
getdewey(dewey, cp)
int dewey[];
char *cp;
{
int i, n;
for (n = 0, i = 0; i < MAXDEWEY; i++) {
if (*cp == '\0')
break;
if (*cp == '.') cp++;
if (!isdigit(*cp))
return 0;
dewey[n++] = strtol(cp, &cp, 10);
}
return n;
}
/*
* Compare two dewey arrays.
* Return -1 if `d1' represents a smaller value than `d2'.
* Return 1 if `d1' represents a greater value than `d2'.
* Return 0 if equal.
*/
int
cmpndewey(d1, n1, d2, n2)
int d1[], d2[];
int n1, n2;
{
register int i;
for (i = 0; i < n1 && i < n2; i++) {
if (d1[i] < d2[i])
return -1;
if (d1[i] > d2[i])
return 1;
}
if (n1 == n2)
return 0;
if (i == n1)
return -1;
if (i == n2)
return 1;
errx(1, "cmpndewey: cant happen");
return 0;
}
/*
* Search directories for a shared library matching the given
* major and minor version numbers. See search_lib_dir() below for
* the detailed matching rules.
*
* As soon as a directory with an acceptable match is found, the search
* terminates. Subsequent directories are not searched for a better
* match. This is in conformance with the SunOS searching rules. Also,
* it avoids a lot of directory searches that are virtually guaranteed to
* be fruitless.
*
* The return value is a full pathname to the matching library. The
* string is dynamically allocated. If no matching library is found, the
* function returns NULL.
*/
char *
findshlib(name, majorp, minorp, do_dot_a)
char *name;
int *majorp, *minorp;
int do_dot_a;
{
int i;
for (i = 0; i < n_search_dirs; i++) {
char *path;
path = search_lib_dir(search_dirs[i], name, majorp, minorp,
do_dot_a);
if(path != NULL)
return path;
}
return NULL;
}
/*
* Search library directories for a file with the given name. The
* return value is a full pathname to the matching file. The string
* is dynamically allocated. If no matching file is found, the function
* returns NULL.
*/
char *
find_lib_file(name)
const char *name;
{
int i;
for (i = 0; i < n_search_dirs; i++) {
char *path = concat(search_dirs[i], "/", name);
struct stat sb;
if (lstat(path, &sb) != -1) /* We found it */
return path;
free(path);
}
return NULL;
}
/*
* Search a given directory for a library (preferably shared) satisfying
* the given criteria.
*
* The matching rules are as follows:
*
* if(*majorp == -1)
* find the library with the highest major version;
* else
* insist on a major version identical to *majorp;
*
* Always find the library with the highest minor version;
* if(*minorp != -1)
* insist on a minor version >= *minorp;
*
* It is invalid to specify a specific minor number while wildcarding
* the major number.
*
* The actual major and minor numbers found are returned via the pointer
* arguments.
*
* A suitable shared library is always preferred over a static (.a) library.
* If do_dot_a is false, then a static library will not be accepted in
* any case.
*
* The return value is a full pathname to the matching library. The
* string is dynamically allocated. If no matching library is found, the
* function returns NULL.
*/
char *
search_lib_dir(dir, name, majorp, minorp, do_dot_a)
char *dir;
char *name;
int *majorp;
int *minorp;
int do_dot_a;
{
int namelen;
DIR *dd;
struct dirent *dp;
int best_dewey[MAXDEWEY];
int best_ndewey;
char dot_a_name[MAXNAMLEN+1];
char dot_so_name[MAXNAMLEN+1];
if((dd = opendir(dir)) == NULL)
return NULL;
namelen = strlen(name);
best_ndewey = 0;
dot_a_name[0] = '\0';
dot_so_name[0] = '\0';
while((dp = readdir(dd)) != NULL) {
char *extension;
if(strlen(dp->d_name) < 3 + namelen + 2 || /* lib+xxx+.a */
strncmp(dp->d_name, "lib", 3) != 0 ||
strncmp(dp->d_name + 3, name, namelen) != 0 ||
dp->d_name[3+namelen] != '.')
continue;
extension = dp->d_name + 3 + namelen + 1; /* a or so.* */
if(strncmp(extension, "so.", 3) == 0) {
int cur_dewey[MAXDEWEY];
int cur_ndewey;
cur_ndewey = getdewey(cur_dewey, extension+3);
if(cur_ndewey < 2) /* Too few version numbers */
continue;
if(*majorp != -1) { /* Need exact match on major */
if(cur_dewey[0] != *majorp)
continue;
if(*minorp != -1) { /* Need minor >= minimum */
if(cur_dewey[1] < *minorp)
continue;
}
}
if(cmpndewey(cur_dewey, cur_ndewey, best_dewey,
best_ndewey) <= 0) /* No better than prior match */
continue;
/* We found a better match */
strcpy(dot_so_name, dp->d_name);
bcopy(cur_dewey, best_dewey,
cur_ndewey * sizeof best_dewey[0]);
best_ndewey = cur_ndewey;
} else if(do_dot_a && strcmp(extension, "a") == 0)
strcpy(dot_a_name, dp->d_name);
}
closedir(dd);
if(dot_so_name[0] != '\0') {
*majorp = best_dewey[0];
*minorp = best_dewey[1];
return concat(dir, "/", dot_so_name);
}
if(dot_a_name[0] != '\0')
return concat(dir, "/", dot_a_name);
return NULL;
}