libdll/common/dllnext.c

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/***********************************************************************
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                                                                      *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*               This software is part of the ast package               *
3e14f97f673e8a630f076077de35afdd43dc1587Roger A. Faulkner*          Copyright (c) 1997-2010 AT&T Intellectual Property          *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                      and is licensed under the                       *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                  Common Public License, Version 1.0                  *
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin*                    by AT&T Intellectual Property                     *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                                                                      *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                A copy of the License is available at                 *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*            http://www.opensource.org/licenses/cpl1.0.txt             *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                                                                      *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*              Information and Software Systems Research               *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                            AT&T Research                             *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                           Florham Park NJ                            *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                                                                      *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                 Glenn Fowler <gsf@research.att.com>                  *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin*                                                                      *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin***********************************************************************/
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#pragma prototyped
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Glenn Fowler
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * AT&T Research
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifndef _GNU_SOURCE
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define _GNU_SOURCE 1
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifndef __EXTENSIONS__
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define __EXTENSIONS__  1
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <ast.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <dlldefs.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if _hdr_rld_interface
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <rld_interface.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * return a handle for the next layer down,
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * i.e., the next layer that has symbols covered
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * by the main prog and dll's loaded so far
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * intentionally light on external lib calls
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * so this routine can be used early in process
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * startup
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifdef  _DLL_RLD_SYM
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define DEBUG       1
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chintypedef ssize_t (*Write_f)(int, const void*, size_t);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#undef  dllnext
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinvoid*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin_dll_next(int flags, _DLL_RLD_SYM_TYPE* here)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register char*  vp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register void*  lp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register int    found = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    char*       s;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    char*       b;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    char*       e;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    char        dummy[256];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    Write_f     wr = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    Write_f     xr;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    char        buf[1024];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if (getenv("DLL_DEBUG") && (vp = (char*)_rld_new_interface(_RLD_FIRST_PATHNAME)))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        do
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {
34f9b3eef6fdadbda0a846aa4d68691ac40eace5Roland Mainz            if (strcmp(vp, "MAIN") && (lp = dllopen(vp, flags)))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if (xr = (Write_f)dlsym(lp, "write"))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    wr = xr;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        } while (vp = (char*)_rld_new_interface(_RLD_NEXT_PATHNAME));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if (vp = (char*)_rld_new_interface(_RLD_FIRST_PATHNAME))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        do
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {
34f9b3eef6fdadbda0a846aa4d68691ac40eace5Roland Mainz            if (lp = dllopen(strcmp(vp, "MAIN") ? vp : (char*)0, flags))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if (found)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    b = e = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    s = vp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    for (;;)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        switch (*s++)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        case 0:
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        case '/':
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            b = s;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            e = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            continue;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        case '.':
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            if (!e)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                                e = s - 1;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            continue;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        default:
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            continue;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if (b && e)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        s = dummy;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        *s++ = '_';
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        *s++ = '_';
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        while (b < e)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            *s++ = *b++;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        b = "_dummy";
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        while (*s++ = *b++);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        if (dlsym(lp, dummy))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            dlclose(lp);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            lp = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if (lp)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        if (wr)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                            (*wr)(2, buf, sfsprintf(buf, sizeof(buf), "dll: next %s\n", vp));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        return lp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    else if (wr)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        (*wr)(2, buf, sfsprintf(buf, sizeof(buf), "dll: skip %s\n", vp));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                else if ((_DLL_RLD_SYM_TYPE*)dlsym(lp, _DLL_RLD_SYM_STR) == here)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    if (wr)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                        (*wr)(2, buf, sfsprintf(buf, sizeof(buf), "dll: this %s\n", vp));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    found = 1;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        } while (vp = (char*)_rld_new_interface(_RLD_NEXT_PATHNAME));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    return dllnext(flags);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifndef RTLD_NEXT
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if _dll_DYNAMIC
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <link.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinextern struct link_dynamic  _DYNAMIC;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinvoid*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chindllnext(int flags)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register void*          dll;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifndef RTLD_NEXT
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if _dll_DYNAMIC
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register struct link_map*   map;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register char*          s;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register char*          b;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    register char*          ver;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    char*               path;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    static char         next[] = { _DLL_NEXT_PATH };
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifdef RTLD_NEXT
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    dll = RTLD_NEXT;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    path = next;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if _dll_DYNAMIC
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    for (map = _DYNAMIC.ld_un.ld_1->ld_loaded; map; map = map->lm_next)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        b = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        s = map->lm_name;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        while (*s)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if (*s++ == '/')
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                b = s;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if (b && b[0] == 'l' && b[1] == 'i' && b[2] == 'b' && b[3] == 'c' && b[4] == '.')
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            path = map->lm_name;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    ver = path + strlen(path);
34f9b3eef6fdadbda0a846aa4d68691ac40eace5Roland Mainz    while (!(dll = dllopen(path, flags)))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        do
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if (ver <= path)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                return 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        } while (*--ver != '.');
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if (*(ver + 1) <= '0' || *(ver + 1) >= '9')
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            return 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        *ver = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    return dll;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}