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/* vi: set sw=4 ts=4: */
/*
 * A small little ldd implementation for uClibc
 *
 * Copyright (C) 2000 by Lineo, inc and Erik Andersen
 * Copyright (C) 2000-2002 Erik Andersen <andersee@debian.org>
 *
 * Several functions in this file (specifically, elf_find_section_type(),
 * elf_find_phdr_type(), and elf_find_dynamic(), were stolen from elflib.c from
 * elfvector (http://www.BitWagon.com/elfvector.html) by John F. Reiser
 * <jreiser@BitWagon.com>, which is copyright 2000 BitWagon Software LLC
 * (GPL2).
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
 
 
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/types.h>
#include <sys/wait.h>
 
#include "bswap.h"
#if defined (sun)
#include "link.h"
#else
#include "elf.h"
#endif
 
#ifdef DMALLOC
#include <dmalloc.h>
#endif
 
#if defined(__arm__)
#define MATCH_MACHINE(x) (x == EM_ARM)
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined(__s390__)
#define MATCH_MACHINE(x) (x == EM_S390)
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined(__i386__)
#ifndef EM_486
#define MATCH_MACHINE(x) (x == EM_386)
#else
#define MATCH_MACHINE(x) (x == EM_386 || x == EM_486)
#endif
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined(__mc68000__) 
#define MATCH_MACHINE(x) (x == EM_68K)
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined(__mips__)
#define MATCH_MACHINE(x) (x == EM_MIPS || x == EM_MIPS_RS3_LE)
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined(__powerpc__)
#define MATCH_MACHINE(x) (x == EM_PPC)
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined(__sh__)
#define MATCH_MACHINE(x) (x == EM_SH)
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined (__v850e__)
#define MATCH_MACHINE(x) ((x) == EM_V850 || (x) == EM_CYGNUS_V850)
#define ELFCLASSM       ELFCLASS32
#endif
 
#if defined (__sparc__)
#define MATCH_MACHINE(x) ((x) == EM_SPARC || (x) == EM_SPARC32PLUS)
#define ELFCLASSM    ELFCLASS32
#endif
 
#if defined(__cris__)
#define MATCH_MACHINE(x) (x == EM_CRIS)
#define ELFCLASSM       ELFCLASS32
#endif
 
#ifndef MATCH_MACHINE
#warning "You really should add a MATCH_MACHINE() macro for your architecture"
#endif
 
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define ELFDATAM        ELFDATA2LSB
#elif __BYTE_ORDER == __BIG_ENDIAN
#define ELFDATAM        ELFDATA2MSB
#endif
 
struct library {
        char *name;
        int resolved;
        char *path;
        struct library *next;
};
struct library *lib_list = NULL;
char not_found[] = "not found";
char *interp = NULL;
char *interp_dir = NULL;
int byteswap;
static int interpreter_already_found=0;
 
inline uint32_t byteswap32_to_host(uint32_t value)
{
        if (byteswap==1) {
                return(bswap_32(value));
        } else {
                return(value);
        }
}
 
 
 
Elf32_Shdr * elf_find_section_type( int key, Elf32_Ehdr *ehdr)
{
        int j;
        Elf32_Shdr *shdr;
        shdr = (Elf32_Shdr *)(ehdr->e_shoff + (char *)ehdr);
        for (j = ehdr->e_shnum; --j>=0; ++shdr) {
                if (key==(int)byteswap32_to_host(shdr->sh_type)) {
                        return shdr;
                }
        }
        return NULL;
}
 
Elf32_Phdr * elf_find_phdr_type( int type, Elf32_Ehdr *ehdr)
{
        int j;
        Elf32_Phdr *phdr = (Elf32_Phdr *)(ehdr->e_phoff + (char *)ehdr);
        for (j = ehdr->e_phnum; --j>=0; ++phdr) {
                if (type==(int)byteswap32_to_host(phdr->p_type)) {
                        return phdr;
                }
        }
        return NULL;
}
 
/* Returns value if return_val==1, ptr otherwise */
void * elf_find_dynamic(int const key, Elf32_Dyn *dynp,
        Elf32_Ehdr *ehdr, int return_val)
{
        Elf32_Phdr *pt_text = elf_find_phdr_type(PT_LOAD, ehdr);
        unsigned tx_reloc = byteswap32_to_host(pt_text->p_vaddr) - byteswap32_to_host(pt_text->p_offset);
        for (; DT_NULL!=byteswap32_to_host(dynp->d_tag); ++dynp) {
                if (key == (int)byteswap32_to_host(dynp->d_tag)) {
                        if (return_val == 1)
                                return (void *)(intptr_t)byteswap32_to_host(dynp->d_un.d_val);
                        else
                                return (void *)(byteswap32_to_host(dynp->d_un.d_val) - tx_reloc + (char *)ehdr );
                }
        }
        return NULL;
}
 
int check_elf_header(Elf32_Ehdr *const ehdr)
{
        if (! ehdr || strncmp((void *)ehdr, ELFMAG, SELFMAG) != 0 ||
                        ehdr->e_ident[EI_CLASS] != ELFCLASS32 ||
                        ehdr->e_ident[EI_VERSION] != EV_CURRENT)
        {
                return 1;
        }
 
        /* Check if the target endianness matches the host's endianness */
        byteswap = 0;
#if __BYTE_ORDER == __LITTLE_ENDIAN
        if (ehdr->e_ident[5] == ELFDATA2MSB) {
                /* Ick -- we will have to byte-swap everything */
                byteswap = 1;
        }
#elif __BYTE_ORDER == __BIG_ENDIAN
        if (ehdr->e_ident[5] == ELFDATA2LSB) {
                /* Ick -- we will have to byte-swap everything */
                byteswap = 1;
        }
#else
#error Unknown host byte order!
#endif
 
        /* Be vary lazy, and only byteswap the stuff we use */
        if (byteswap==1) {
                ehdr->e_type=bswap_16(ehdr->e_type);
                ehdr->e_phoff=bswap_32(ehdr->e_phoff);
                ehdr->e_shoff=bswap_32(ehdr->e_shoff);
                ehdr->e_phnum=bswap_16(ehdr->e_phnum);
                ehdr->e_shnum=bswap_16(ehdr->e_shnum);
        }
 
        return 0;
}
 
/* This function's behavior must exactly match that
 * in uClibc/ldso/ldso/readelflib1.c */
static void search_for_named_library(char *name, char *result, const char *path_list)
{
        int i, count = 1;
        char *path, *path_n;
        struct stat filestat;
 
        /* We need a writable copy of this string */
        path = strdup(path_list);
        if (!path) {
                fprintf(stderr, "Out of memory!\n");
                exit(EXIT_FAILURE);
        }
        /* Eliminate all double //s */
        path_n=path;
        while((path_n=strstr(path_n, "//"))) {
                i = strlen(path_n);
                memmove(path_n, path_n+1, i-1);
                *(path_n + i - 1)='\0';
        }
 
        /* Replace colons with zeros in path_list and count them */
        for(i=strlen(path); i > 0; i--) {
                if (path[i]==':') {
                        path[i]=0;
                        count++;
                }
        }
        path_n = path;
        for (i = 0; i < count; i++) {
                strcpy(result, path_n);
                strcat(result, "/");
                strcat(result, name);
                if (stat (result, &filestat) == 0 && filestat.st_mode & S_IRUSR) {
                        free(path);
                        return;
                }
                path_n += (strlen(path_n) + 1);
        }
        free(path);
        *result = '\0';
}
 
void locate_library_file(Elf32_Ehdr* ehdr, Elf32_Dyn* dynamic, int is_suid, struct library *lib)
{
        char *buf;
        char *path;
        struct stat filestat;
 
        /* If this is a fully resolved name, our job is easy */
        if (stat (lib->name, &filestat) == 0) {
                lib->path = lib->name;
                return;
        }
 
        /* We need some elbow room here.  Make some room...*/
        buf = malloc(1024);
        if (!buf) {
                fprintf(stderr, "Out of memory!\n");
                exit(EXIT_FAILURE);
        }
 
        /* This function must match the behavior of _dl_load_shared_library
         * in readelflib1.c or things won't work out as expected... */
 
        /* The ABI specifies that RPATH is searched first, so do that now.  */
        path = (char *)elf_find_dynamic(DT_RPATH, dynamic, ehdr, 0);
        if (path) {
                search_for_named_library(lib->name, buf, path);
                if (*buf != '\0') {
                        lib->path = buf;
                        return;
                }
        }
 
        /* Next check LD_{ELF_}LIBRARY_PATH if specified and allowed.
         * Since this app doesn't actually run an executable I will skip
         * the suid check, and just use LD_{ELF_}LIBRARY_PATH if set */
        if (is_suid==1)
                path = NULL;
        else
                path = getenv("LD_LIBRARY_PATH");
        if (path) {
                search_for_named_library(lib->name, buf, path);
                if (*buf != '\0') {
                        lib->path = buf;
                        return;
                }
        }
 
#ifdef USE_CACHE
        /* FIXME -- add code to check the Cache here */
#endif
 
 
        /* Next look for libraries wherever the shared library
         * loader was installed -- this is usually where we
         * should find things... */
        if (interp_dir) {
                search_for_named_library(lib->name, buf, interp_dir);
                if (*buf != '\0') {
                        lib->path = buf;
                        return;
                }
        }
 
        /* Lastly, search the standard list of paths for the library.
           This list must exactly match the list in uClibc/ldso/ldso/readelflib1.c */
        path =  UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib:"
                        UCLIBC_RUNTIME_PREFIX "usr/lib:"
                        UCLIBC_RUNTIME_PREFIX "lib:"
                        "/usr/lib:"
                        "/lib";
        search_for_named_library(lib->name, buf, path);
        if (*buf != '\0') {
                lib->path = buf;
        } else {
                free(buf);
                lib->path = not_found;
        }
}
 
static int add_library(Elf32_Ehdr* ehdr, Elf32_Dyn* dynamic, int is_setuid, char *s)
{
        char *tmp, *tmp1, *tmp2;
        struct library *cur, *newlib=lib_list;
 
        if (!s || !strlen(s))
                return 1;
 
        tmp = s;
        while (*tmp) {
                if (*tmp == '/')
                        s = tmp + 1;
                tmp++;
        }
 
        /* We add libc.so.0 elsewhere */
        if (interpreter_already_found && (tmp=strrchr(interp, '/')) != NULL)
        {
                int len = strlen(interp_dir);
                if (strcmp(s, interp+1+len)==0)
                        return 1;
        }
 
        for (cur = lib_list; cur; cur=cur->next) {
                /* Check if this library is already in the list */
                tmp1 = tmp2 = cur->name;
                while (*tmp1) {
                        if (*tmp1 == '/')
                                tmp2 = tmp1 + 1;
                        tmp1++;
                }
                if(strcmp(tmp2, s)==0) {
                        //printf("find_elf_interpreter is skipping '%s' (already in list)\n", cur->name);
                        return 0;
                }
        }
 
        /* Ok, this lib needs to be added to the list */
        newlib = malloc(sizeof(struct library));
        if (!newlib)
                return 1;
        newlib->name = malloc(strlen(s)+1);
        strcpy(newlib->name, s);
        newlib->resolved = 0;
        newlib->path = NULL;
        newlib->next = NULL;
 
        /* Now try and locate where this library might be living... */
        locate_library_file(ehdr, dynamic, is_setuid, newlib);
 
        //printf("add_library is adding '%s' to '%s'\n", newlib->name, newlib->path);
        if (!lib_list) {
                lib_list = newlib;
        } else {
                for (cur = lib_list;  cur->next; cur=cur->next); /* nothing */
                cur->next = newlib;
        }
        return 0;
}
 
 
static void find_needed_libraries(Elf32_Ehdr* ehdr, Elf32_Dyn* dynamic, char *strtab, int is_setuid)
{
        Elf32_Dyn  *dyns;
 
        for (dyns=dynamic; byteswap32_to_host(dyns->d_tag)!=DT_NULL; ++dyns) {
                if (DT_NEEDED == byteswap32_to_host(dyns->d_tag)) {
                        add_library(ehdr, dynamic, is_setuid,
                                        (char*)strtab + byteswap32_to_host(dyns->d_un.d_val));
                }
        }
}
 
static struct library * find_elf_interpreter(Elf32_Ehdr* ehdr)
{
        Elf32_Phdr *phdr;
 
        if (interpreter_already_found==1)
                return NULL;
        phdr = elf_find_phdr_type(PT_INTERP, ehdr);
        if (phdr) {
                struct library *cur, *newlib=NULL;
                char *s = (char*)ehdr + byteswap32_to_host(phdr->p_offset);
 
                char *tmp, *tmp1;
                interp = strdup(s);
                interp_dir = strdup(s);
                tmp = strrchr(interp_dir, '/');
                if (*tmp)
                        *tmp = '\0';
                else {
                        free(interp_dir);
                        interp_dir = interp;
                }
                tmp1 = tmp = s;
                while (*tmp) {
                        if (*tmp == '/')
                                tmp1 = tmp + 1;
                        tmp++;
                }
                for (cur = lib_list; cur; cur=cur->next) {
                        /* Check if this library is already in the list */
                        if(strcmp(cur->name, tmp1)==0) {
                                //printf("find_elf_interpreter is replacing '%s' (already in list)\n", cur->name);
                                newlib = cur;
                                free(newlib->name);
                                free(newlib->path);
                                return NULL;
                        }
                }
                if (newlib == NULL)
                        newlib = malloc(sizeof(struct library));
                if (!newlib)
                        return NULL;
                newlib->name = malloc(strlen(s)+1);
                strcpy(newlib->name, s);
                newlib->path = newlib->name;
                newlib->resolved = 1;
                newlib->next = NULL;
 
#if 0
                //printf("find_elf_interpreter is adding '%s' to '%s'\n", newlib->name, newlib->path);
                if (!lib_list) {
                        lib_list = newlib;
                } else {
                        for (cur = lib_list;  cur->next; cur=cur->next); /* nothing */
                        cur->next = newlib;
                }
#endif
                interpreter_already_found=1;
                return newlib;
        }
        return NULL;
}
 
/* map the .so, and locate interesting pieces */
int find_dependancies(char* filename)
{
        int is_suid = 0;
        FILE *thefile;
        struct stat statbuf;
        char *dynstr=NULL;
        Elf32_Ehdr *ehdr = NULL;
        Elf32_Shdr *dynsec = NULL;
        Elf32_Dyn *dynamic = NULL;
        struct library *interp;
 
        if (filename == not_found)
                return 0;
 
        if (!filename) {
                fprintf(stderr, "No filename specified.\n");
                return -1;
        }
        if (!(thefile = fopen(filename, "r"))) {
                perror(filename);
                return -1;
        }
        if (fstat(fileno(thefile), &statbuf) < 0) {
                perror(filename);
                return -1;
        }
 
        if ((size_t)statbuf.st_size < sizeof(Elf32_Ehdr))
                goto foo;
 
        if (!S_ISREG(statbuf.st_mode))
                goto foo;
 
        /* mmap the file to make reading stuff from it effortless */
        ehdr = (Elf32_Ehdr *)mmap(0, statbuf.st_size,
                        PROT_READ|PROT_WRITE, MAP_PRIVATE, fileno(thefile), 0);
 
foo:
        /* Check if this looks like a legit ELF file */
        if (check_elf_header(ehdr)) {
                fprintf(stderr, "%s: not an ELF file.\n", filename);
                return -1;
        }
        /* Check if this is the right kind of ELF file */
        if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
                fprintf(stderr, "%s: not a dynamic executable\n", filename);
                return -1;
        }
        if (ehdr->e_type == ET_EXEC) {
                if (statbuf.st_mode & S_ISUID)
                        is_suid = 1;
                if ((statbuf.st_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
                        is_suid = 1;
                /* FIXME */
                if (is_suid)
                        fprintf(stderr, "%s: is setuid\n", filename);
        }
 
        interpreter_already_found=0;
        interp = find_elf_interpreter(ehdr);
 
#ifdef __LDSO_LDD_SUPPORT
        if (interp && ehdr->e_type == ET_EXEC && ehdr->e_ident[EI_CLASS] == ELFCLASSM &&
                        ehdr->e_ident[EI_DATA] == ELFDATAM
                && ehdr->e_ident[EI_VERSION] == EV_CURRENT && MATCH_MACHINE(ehdr->e_machine))
        {
                struct stat statbuf;
                if (stat(interp->path, &statbuf) == 0 && S_ISREG(statbuf.st_mode)) {
                        pid_t pid;
                        int status;
                        static const char * const environment[] = {
                                "PATH=/usr/bin:/bin:/usr/sbin:/sbin",
                                "SHELL=/bin/sh",
                                "LD_TRACE_LOADED_OBJECTS=1",
                                NULL
                        };
 
                        if ((pid = fork()) == 0) {
                                /* Cool, it looks like we should be able to actually
                                 * run this puppy.  Do so now... */
                                execle(filename, filename, NULL, environment);
                                _exit(0xdead);
                        }
 
                        /* Wait till it returns */
                        waitpid(pid, &status, 0);
                        if (WIFEXITED(status) && WEXITSTATUS(status)==0) {
                                return 1;
                        }
 
                        /* If the exec failed, we fall through to trying to find
                         * all the needed libraries ourselves by rummaging about
                         * in the ELF headers... */
                }
        }
#endif
 
        dynsec = elf_find_section_type(SHT_DYNAMIC, ehdr);
        if (dynsec) {
                dynamic = (Elf32_Dyn*)(byteswap32_to_host(dynsec->sh_offset) + (intptr_t)ehdr);
                dynstr = (char *)elf_find_dynamic(DT_STRTAB, dynamic, ehdr, 0);
                find_needed_libraries(ehdr, dynamic, dynstr, is_suid);
        }
 
        return 0;
}
 
 
 
int main( int argc, char** argv)
{
        int multi=0;
        int got_em_all=1;
        char *filename = NULL;
        struct library *cur;
 
        if (argc < 2) {
                fprintf(stderr, "ldd: missing file arguments\n");
                fprintf(stderr, "Try `ldd --help' for more information.\n");
                exit(EXIT_FAILURE);
        }
        if (argc > 2) {
                multi++;
        }
 
        while (--argc > 0) {
                ++argv;
 
                if(strcmp(*argv, "--")==0) {
                        /* Ignore "--" */
                        continue;
                }
 
                if(strcmp(*argv, "--help")==0) {
                        fprintf(stderr, "Usage: ldd [OPTION]... FILE...\n");
                        fprintf(stderr, "\t--help\t\tprint this help and exit\n");
                        exit(EXIT_FAILURE);
                }
 
                filename=*argv;
                if (!filename) {
                        fprintf(stderr, "No filename specified.\n");
                        exit(EXIT_FAILURE);
                }
 
                if (multi) {
                        printf("%s:\n", *argv);
                }
 
                if (find_dependancies(filename)!=0)
                        continue;
 
                while(got_em_all) {
                        got_em_all=0;
                        /* Keep walking the list till everybody is resolved */
                        for (cur = lib_list; cur; cur=cur->next) {
                                if (cur->resolved == 0 && cur->path) {
                                        got_em_all=1;
                                        //printf("checking sub-depends for '%s\n", cur->path);
                                        find_dependancies(cur->path);
                                        cur->resolved = 1;
                                }
                        }
                }
 
 
                /* Print the list */
                got_em_all=0;
                for (cur = lib_list; cur; cur=cur->next) {
                        got_em_all=1;
                        printf("\t%s => %s (0x00000000)\n", cur->name, cur->path);
                }
                if (interp_dir && got_em_all==1)
                        printf("\t%s => %s (0x00000000)\n", interp, interp);
                if (got_em_all==0)
                        printf("\tnot a dynamic executable\n");
 
                for (cur = lib_list; cur; cur=cur->next) {
                        free(cur->name);
                        cur->name=NULL;
                        if (cur->path && cur->path != not_found)
                                free(cur->path);
                        cur->path=NULL;
                }
                lib_list=NULL;
        }
 
        return 0;
}
 

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[/] [or1k/] [trunk/] [linux/] [uClibc/] [utils/] [ldd.c] - Blame information for rev 1325

Line No.	Rev	Author	Line
1	1325	phoenix	`/* vi: set sw=4 ts=4: */`
2			`/*`
3			`* A small little ldd implementation for uClibc`
4			`*`
5			`* Copyright (C) 2000 by Lineo, inc and Erik Andersen`
6			`* Copyright (C) 2000-2002 Erik Andersen <andersee@debian.org>`
7			`*`
8			`* Several functions in this file (specifically, elf_find_section_type(),`
9			`* elf_find_phdr_type(), and elf_find_dynamic(), were stolen from elflib.c from`
10			`* elfvector (http://www.BitWagon.com/elfvector.html) by John F. Reiser`
11			`* <jreiser@BitWagon.com>, which is copyright 2000 BitWagon Software LLC`
12			`* (GPL2).`
13			`*`
14			`* This program is free software; you can redistribute it and/or modify`
15			`* it under the terms of the GNU General Public License as published by`
16			`* the Free Software Foundation; either version 2 of the License, or`
17			`* (at your option) any later version.`
18			`*`
19			`* This program is distributed in the hope that it will be useful,`
20			`* but WITHOUT ANY WARRANTY; without even the implied warranty of`
21			`* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU`
22			`* General Public License for more details.`
23			`*`
24			`* You should have received a copy of the GNU General Public License`
25			`* along with this program; if not, write to the Free Software`
26			`* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA`
27			`*`
28			`*/`
29
30
31			`#define _GNU_SOURCE`
32			`#include <stdlib.h>`
33			`#include <stdio.h>`
34			`#include <fcntl.h>`
35			`#include <string.h>`
36			`#include <unistd.h>`
37			`#include <sys/mman.h>`
38			`#include <sys/stat.h>`
39			`#include <sys/types.h>`
40			`#include <sys/types.h>`
41			`#include <sys/wait.h>`
42
43			`#include "bswap.h"`
44			`#if defined (sun)`
45			`#include "link.h"`
46			`#else`
47			`#include "elf.h"`
48			`#endif`
49
50			`#ifdef DMALLOC`
51			`#include <dmalloc.h>`
52			`#endif`
53
54			`#if defined(__arm__)`
55			`#define MATCH_MACHINE(x) (x == EM_ARM)`
56			`#define ELFCLASSM ELFCLASS32`
57			`#endif`
58
59			`#if defined(__s390__)`
60			`#define MATCH_MACHINE(x) (x == EM_S390)`
61			`#define ELFCLASSM ELFCLASS32`
62			`#endif`
63
64			`#if defined(__i386__)`
65			`#ifndef EM_486`
66			`#define MATCH_MACHINE(x) (x == EM_386)`
67			`#else`
68			`#define MATCH_MACHINE(x) (x == EM_386 \|\| x == EM_486)`
69			`#endif`
70			`#define ELFCLASSM ELFCLASS32`
71			`#endif`
72
73			`#if defined(__mc68000__)`
74			`#define MATCH_MACHINE(x) (x == EM_68K)`
75			`#define ELFCLASSM ELFCLASS32`
76			`#endif`
77
78			`#if defined(__mips__)`
79			`#define MATCH_MACHINE(x) (x == EM_MIPS \|\| x == EM_MIPS_RS3_LE)`
80			`#define ELFCLASSM ELFCLASS32`
81			`#endif`
82
83			`#if defined(__powerpc__)`
84			`#define MATCH_MACHINE(x) (x == EM_PPC)`
85			`#define ELFCLASSM ELFCLASS32`
86			`#endif`
87
88			`#if defined(__sh__)`
89			`#define MATCH_MACHINE(x) (x == EM_SH)`
90			`#define ELFCLASSM ELFCLASS32`
91			`#endif`
92
93			`#if defined (__v850e__)`
94			`#define MATCH_MACHINE(x) ((x) == EM_V850 \|\| (x) == EM_CYGNUS_V850)`
95			`#define ELFCLASSM ELFCLASS32`
96			`#endif`
97
98			`#if defined (__sparc__)`
99			`#define MATCH_MACHINE(x) ((x) == EM_SPARC \|\| (x) == EM_SPARC32PLUS)`
100			`#define ELFCLASSM ELFCLASS32`
101			`#endif`
102
103			`#if defined(__cris__)`
104			`#define MATCH_MACHINE(x) (x == EM_CRIS)`
105			`#define ELFCLASSM ELFCLASS32`
106			`#endif`
107
108			`#ifndef MATCH_MACHINE`
109			`#warning "You really should add a MATCH_MACHINE() macro for your architecture"`
110			`#endif`
111
112			`#if __BYTE_ORDER == __LITTLE_ENDIAN`
113			`#define ELFDATAM ELFDATA2LSB`
114			`#elif __BYTE_ORDER == __BIG_ENDIAN`
115			`#define ELFDATAM ELFDATA2MSB`
116			`#endif`
117
118			`struct library {`
119			`char *name;`
120			`int resolved;`
121			`char *path;`
122			`struct library *next;`
123			`};`
124			`struct library *lib_list = NULL;`
125			`char not_found[] = "not found";`
126			`char *interp = NULL;`
127			`char *interp_dir = NULL;`
128			`int byteswap;`
129			`static int interpreter_already_found=0;`
130
131			`inline uint32_t byteswap32_to_host(uint32_t value)`
132			`{`
133			`if (byteswap==1) {`
134			`return(bswap_32(value));`
135			`} else {`
136			`return(value);`
137			`}`
138			`}`
139
140
141
142			`Elf32_Shdr * elf_find_section_type( int key, Elf32_Ehdr *ehdr)`
143			`{`
144			`int j;`
145			`Elf32_Shdr *shdr;`
146			`shdr = (Elf32_Shdr )(ehdr->e_shoff + (char )ehdr);`
147			`for (j = ehdr->e_shnum; --j>=0; ++shdr) {`
148			`if (key==(int)byteswap32_to_host(shdr->sh_type)) {`
149			`return shdr;`
150			`}`
151			`}`
152			`return NULL;`
153			`}`
154
155			`Elf32_Phdr * elf_find_phdr_type( int type, Elf32_Ehdr *ehdr)`
156			`{`
157			`int j;`
158			`Elf32_Phdr phdr = (Elf32_Phdr )(ehdr->e_phoff + (char *)ehdr);`
159			`for (j = ehdr->e_phnum; --j>=0; ++phdr) {`
160			`if (type==(int)byteswap32_to_host(phdr->p_type)) {`
161			`return phdr;`
162			`}`
163			`}`
164			`return NULL;`
165			`}`
166
167			`/* Returns value if return_val==1, ptr otherwise */`
168			`void * elf_find_dynamic(int const key, Elf32_Dyn *dynp,`
169			`Elf32_Ehdr *ehdr, int return_val)`
170			`{`
171			`Elf32_Phdr *pt_text = elf_find_phdr_type(PT_LOAD, ehdr);`
172			`unsigned tx_reloc = byteswap32_to_host(pt_text->p_vaddr) - byteswap32_to_host(pt_text->p_offset);`
173			`for (; DT_NULL!=byteswap32_to_host(dynp->d_tag); ++dynp) {`
174			`if (key == (int)byteswap32_to_host(dynp->d_tag)) {`
175			`if (return_val == 1)`
176			`return (void *)(intptr_t)byteswap32_to_host(dynp->d_un.d_val);`
177			`else`
178			`return (void )(byteswap32_to_host(dynp->d_un.d_val) - tx_reloc + (char )ehdr );`
179			`}`
180			`}`
181			`return NULL;`
182			`}`
183
184			`int check_elf_header(Elf32_Ehdr *const ehdr)`
185			`{`
186			`if (! ehdr \|\| strncmp((void *)ehdr, ELFMAG, SELFMAG) != 0 \|\|`
187			`ehdr->e_ident[EI_CLASS] != ELFCLASS32 \|\|`
188			`ehdr->e_ident[EI_VERSION] != EV_CURRENT)`
189			`{`
190			`return 1;`
191			`}`
192
193			`/* Check if the target endianness matches the host's endianness */`
194			`byteswap = 0;`
195			`#if __BYTE_ORDER == __LITTLE_ENDIAN`
196			`if (ehdr->e_ident[5] == ELFDATA2MSB) {`
197			`/* Ick -- we will have to byte-swap everything */`
198			`byteswap = 1;`
199			`}`
200			`#elif __BYTE_ORDER == __BIG_ENDIAN`
201			`if (ehdr->e_ident[5] == ELFDATA2LSB) {`
202			`/* Ick -- we will have to byte-swap everything */`
203			`byteswap = 1;`
204			`}`
205			`#else`
206			`#error Unknown host byte order!`
207			`#endif`
208
209			`/* Be vary lazy, and only byteswap the stuff we use */`
210			`if (byteswap==1) {`
211			`ehdr->e_type=bswap_16(ehdr->e_type);`
212			`ehdr->e_phoff=bswap_32(ehdr->e_phoff);`
213			`ehdr->e_shoff=bswap_32(ehdr->e_shoff);`
214			`ehdr->e_phnum=bswap_16(ehdr->e_phnum);`
215			`ehdr->e_shnum=bswap_16(ehdr->e_shnum);`
216			`}`
217
218			`return 0;`
219			`}`
220
221			`/* This function's behavior must exactly match that`
222			`* in uClibc/ldso/ldso/readelflib1.c */`
223			`static void search_for_named_library(char name, char result, const char *path_list)`
224			`{`
225			`int i, count = 1;`
226			`char path, path_n;`
227			`struct stat filestat;`
228
229			`/* We need a writable copy of this string */`
230			`path = strdup(path_list);`
231			`if (!path) {`
232			`fprintf(stderr, "Out of memory!\n");`
233			`exit(EXIT_FAILURE);`
234			`}`
235			`/* Eliminate all double //s */`
236			`path_n=path;`
237			`while((path_n=strstr(path_n, "//"))) {`
238			`i = strlen(path_n);`
239			`memmove(path_n, path_n+1, i-1);`
240			`*(path_n + i - 1)='\0';`
241			`}`
242
243			`/* Replace colons with zeros in path_list and count them */`
244			`for(i=strlen(path); i > 0; i--) {`
245			`if (path[i]==':') {`
246			`path[i]=0;`
247			`count++;`
248			`}`
249			`}`
250			`path_n = path;`
251			`for (i = 0; i < count; i++) {`
252			`strcpy(result, path_n);`
253			`strcat(result, "/");`
254			`strcat(result, name);`
255			`if (stat (result, &filestat) == 0 && filestat.st_mode & S_IRUSR) {`
256			`free(path);`
257			`return;`
258			`}`
259			`path_n += (strlen(path_n) + 1);`
260			`}`
261			`free(path);`
262			`*result = '\0';`
263			`}`
264
265			`void locate_library_file(Elf32_Ehdr* ehdr, Elf32_Dyn* dynamic, int is_suid, struct library *lib)`
266			`{`
267			`char *buf;`
268			`char *path;`
269			`struct stat filestat;`
270
271			`/* If this is a fully resolved name, our job is easy */`
272			`if (stat (lib->name, &filestat) == 0) {`
273			`lib->path = lib->name;`
274			`return;`
275			`}`
276
277			`/* We need some elbow room here. Make some room...*/`
278			`buf = malloc(1024);`
279			`if (!buf) {`
280			`fprintf(stderr, "Out of memory!\n");`
281			`exit(EXIT_FAILURE);`
282			`}`
283
284			`/* This function must match the behavior of _dl_load_shared_library`
285			`* in readelflib1.c or things won't work out as expected... */`
286
287			`/* The ABI specifies that RPATH is searched first, so do that now. */`
288			`path = (char *)elf_find_dynamic(DT_RPATH, dynamic, ehdr, 0);`
289			`if (path) {`
290			`search_for_named_library(lib->name, buf, path);`
291			`if (*buf != '\0') {`
292			`lib->path = buf;`
293			`return;`
294			`}`
295			`}`
296
297			`/* Next check LD_{ELF_}LIBRARY_PATH if specified and allowed.`
298			`* Since this app doesn't actually run an executable I will skip`
299			`* the suid check, and just use LD_{ELF_}LIBRARY_PATH if set */`
300			`if (is_suid==1)`
301			`path = NULL;`
302			`else`
303			`path = getenv("LD_LIBRARY_PATH");`
304			`if (path) {`
305			`search_for_named_library(lib->name, buf, path);`
306			`if (*buf != '\0') {`
307			`lib->path = buf;`
308			`return;`
309			`}`
310			`}`
311
312			`#ifdef USE_CACHE`
313			`/* FIXME -- add code to check the Cache here */`
314			`#endif`
315
316
317			`/* Next look for libraries wherever the shared library`
318			`* loader was installed -- this is usually where we`
319			`* should find things... */`
320			`if (interp_dir) {`
321			`search_for_named_library(lib->name, buf, interp_dir);`
322			`if (*buf != '\0') {`
323			`lib->path = buf;`
324			`return;`
325			`}`
326			`}`
327
328			`/* Lastly, search the standard list of paths for the library.`
329			`This list must exactly match the list in uClibc/ldso/ldso/readelflib1.c */`
330			`path = UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib:"`
331			`UCLIBC_RUNTIME_PREFIX "usr/lib:"`
332			`UCLIBC_RUNTIME_PREFIX "lib:"`
333			`"/usr/lib:"`
334			`"/lib";`
335			`search_for_named_library(lib->name, buf, path);`
336			`if (*buf != '\0') {`
337			`lib->path = buf;`
338			`} else {`
339			`free(buf);`
340			`lib->path = not_found;`
341			`}`
342			`}`
343
344			`static int add_library(Elf32_Ehdr* ehdr, Elf32_Dyn* dynamic, int is_setuid, char *s)`
345			`{`
346			`char tmp, tmp1, *tmp2;`
347			`struct library cur, newlib=lib_list;`
348
349			`if (!s \|\| !strlen(s))`
350			`return 1;`
351
352			`tmp = s;`
353			`while (*tmp) {`
354			`if (*tmp == '/')`
355			`s = tmp + 1;`
356			`tmp++;`
357			`}`
358
359			`/* We add libc.so.0 elsewhere */`
360			`if (interpreter_already_found && (tmp=strrchr(interp, '/')) != NULL)`
361			`{`
362			`int len = strlen(interp_dir);`
363			`if (strcmp(s, interp+1+len)==0)`
364			`return 1;`
365			`}`
366
367			`for (cur = lib_list; cur; cur=cur->next) {`
368			`/* Check if this library is already in the list */`
369			`tmp1 = tmp2 = cur->name;`
370			`while (*tmp1) {`
371			`if (*tmp1 == '/')`
372			`tmp2 = tmp1 + 1;`
373			`tmp1++;`
374			`}`
375			`if(strcmp(tmp2, s)==0) {`
376			`//printf("find_elf_interpreter is skipping '%s' (already in list)\n", cur->name);`
377			`return 0;`
378			`}`
379			`}`
380
381			`/* Ok, this lib needs to be added to the list */`
382			`newlib = malloc(sizeof(struct library));`
383			`if (!newlib)`
384			`return 1;`
385			`newlib->name = malloc(strlen(s)+1);`
386			`strcpy(newlib->name, s);`
387			`newlib->resolved = 0;`
388			`newlib->path = NULL;`
389			`newlib->next = NULL;`
390
391			`/* Now try and locate where this library might be living... */`
392			`locate_library_file(ehdr, dynamic, is_setuid, newlib);`
393
394			`//printf("add_library is adding '%s' to '%s'\n", newlib->name, newlib->path);`
395			`if (!lib_list) {`
396			`lib_list = newlib;`
397			`} else {`
398			`for (cur = lib_list; cur->next; cur=cur->next); /* nothing */`
399			`cur->next = newlib;`
400			`}`
401			`return 0;`
402			`}`
403
404
405			`static void find_needed_libraries(Elf32_Ehdr* ehdr, Elf32_Dyn* dynamic, char *strtab, int is_setuid)`
406			`{`
407			`Elf32_Dyn *dyns;`
408
409			`for (dyns=dynamic; byteswap32_to_host(dyns->d_tag)!=DT_NULL; ++dyns) {`
410			`if (DT_NEEDED == byteswap32_to_host(dyns->d_tag)) {`
411			`add_library(ehdr, dynamic, is_setuid,`
412			`(char*)strtab + byteswap32_to_host(dyns->d_un.d_val));`
413			`}`
414			`}`
415			`}`
416
417			`static struct library * find_elf_interpreter(Elf32_Ehdr* ehdr)`
418			`{`
419			`Elf32_Phdr *phdr;`
420
421			`if (interpreter_already_found==1)`
422			`return NULL;`
423			`phdr = elf_find_phdr_type(PT_INTERP, ehdr);`
424			`if (phdr) {`
425			`struct library cur, newlib=NULL;`
426			`char s = (char)ehdr + byteswap32_to_host(phdr->p_offset);`
427
428			`char tmp, tmp1;`
429			`interp = strdup(s);`
430			`interp_dir = strdup(s);`
431			`tmp = strrchr(interp_dir, '/');`
432			`if (*tmp)`
433			`*tmp = '\0';`
434			`else {`
435			`free(interp_dir);`
436			`interp_dir = interp;`
437			`}`
438			`tmp1 = tmp = s;`
439			`while (*tmp) {`
440			`if (*tmp == '/')`
441			`tmp1 = tmp + 1;`
442			`tmp++;`
443			`}`
444			`for (cur = lib_list; cur; cur=cur->next) {`
445			`/* Check if this library is already in the list */`
446			`if(strcmp(cur->name, tmp1)==0) {`
447			`//printf("find_elf_interpreter is replacing '%s' (already in list)\n", cur->name);`
448			`newlib = cur;`
449			`free(newlib->name);`
450			`free(newlib->path);`
451			`return NULL;`
452			`}`
453			`}`
454			`if (newlib == NULL)`
455			`newlib = malloc(sizeof(struct library));`
456			`if (!newlib)`
457			`return NULL;`
458			`newlib->name = malloc(strlen(s)+1);`
459			`strcpy(newlib->name, s);`
460			`newlib->path = newlib->name;`
461			`newlib->resolved = 1;`
462			`newlib->next = NULL;`
463
464			`#if 0`
465			`//printf("find_elf_interpreter is adding '%s' to '%s'\n", newlib->name, newlib->path);`
466			`if (!lib_list) {`
467			`lib_list = newlib;`
468			`} else {`
469			`for (cur = lib_list; cur->next; cur=cur->next); /* nothing */`
470			`cur->next = newlib;`
471			`}`
472			`#endif`
473			`interpreter_already_found=1;`
474			`return newlib;`
475			`}`
476			`return NULL;`
477			`}`
478
479			`/* map the .so, and locate interesting pieces */`
480			`int find_dependancies(char* filename)`
481			`{`
482			`int is_suid = 0;`
483			`FILE *thefile;`
484			`struct stat statbuf;`
485			`char *dynstr=NULL;`
486			`Elf32_Ehdr *ehdr = NULL;`
487			`Elf32_Shdr *dynsec = NULL;`
488			`Elf32_Dyn *dynamic = NULL;`
489			`struct library *interp;`
490
491			`if (filename == not_found)`
492			`return 0;`
493
494			`if (!filename) {`
495			`fprintf(stderr, "No filename specified.\n");`
496			`return -1;`
497			`}`
498			`if (!(thefile = fopen(filename, "r"))) {`
499			`perror(filename);`
500			`return -1;`
501			`}`
502			`if (fstat(fileno(thefile), &statbuf) < 0) {`
503			`perror(filename);`
504			`return -1;`
505			`}`
506
507			`if ((size_t)statbuf.st_size < sizeof(Elf32_Ehdr))`
508			`goto foo;`
509
510			`if (!S_ISREG(statbuf.st_mode))`
511			`goto foo;`
512
513			`/* mmap the file to make reading stuff from it effortless */`
514			`ehdr = (Elf32_Ehdr *)mmap(0, statbuf.st_size,`
515			`PROT_READ\|PROT_WRITE, MAP_PRIVATE, fileno(thefile), 0);`
516
517			`foo:`
518			`/* Check if this looks like a legit ELF file */`
519			`if (check_elf_header(ehdr)) {`
520			`fprintf(stderr, "%s: not an ELF file.\n", filename);`
521			`return -1;`
522			`}`
523			`/* Check if this is the right kind of ELF file */`
524			`if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {`
525			`fprintf(stderr, "%s: not a dynamic executable\n", filename);`
526			`return -1;`
527			`}`
528			`if (ehdr->e_type == ET_EXEC) {`
529			`if (statbuf.st_mode & S_ISUID)`
530			`is_suid = 1;`
531			`if ((statbuf.st_mode & (S_ISGID \| S_IXGRP)) == (S_ISGID \| S_IXGRP))`
532			`is_suid = 1;`
533			`/* FIXME */`
534			`if (is_suid)`
535			`fprintf(stderr, "%s: is setuid\n", filename);`
536			`}`
537
538			`interpreter_already_found=0;`
539			`interp = find_elf_interpreter(ehdr);`
540
541			`#ifdef __LDSO_LDD_SUPPORT`
542			`if (interp && ehdr->e_type == ET_EXEC && ehdr->e_ident[EI_CLASS] == ELFCLASSM &&`
543			`ehdr->e_ident[EI_DATA] == ELFDATAM`
544			`&& ehdr->e_ident[EI_VERSION] == EV_CURRENT && MATCH_MACHINE(ehdr->e_machine))`
545			`{`
546			`struct stat statbuf;`
547			`if (stat(interp->path, &statbuf) == 0 && S_ISREG(statbuf.st_mode)) {`
548			`pid_t pid;`
549			`int status;`
550			`static const char * const environment[] = {`
551			`"PATH=/usr/bin:/bin:/usr/sbin:/sbin",`
552			`"SHELL=/bin/sh",`
553			`"LD_TRACE_LOADED_OBJECTS=1",`
554			`NULL`
555			`};`
556
557			`if ((pid = fork()) == 0) {`
558			`/* Cool, it looks like we should be able to actually`
559			`* run this puppy. Do so now... */`
560			`execle(filename, filename, NULL, environment);`
561			`_exit(0xdead);`
562			`}`
563
564			`/* Wait till it returns */`
565			`waitpid(pid, &status, 0);`
566			`if (WIFEXITED(status) && WEXITSTATUS(status)==0) {`
567			`return 1;`
568			`}`
569
570			`/* If the exec failed, we fall through to trying to find`
571			`* all the needed libraries ourselves by rummaging about`
572			`* in the ELF headers... */`
573			`}`
574			`}`
575			`#endif`
576
577			`dynsec = elf_find_section_type(SHT_DYNAMIC, ehdr);`
578			`if (dynsec) {`
579			`dynamic = (Elf32_Dyn*)(byteswap32_to_host(dynsec->sh_offset) + (intptr_t)ehdr);`
580			`dynstr = (char *)elf_find_dynamic(DT_STRTAB, dynamic, ehdr, 0);`
581			`find_needed_libraries(ehdr, dynamic, dynstr, is_suid);`
582			`}`
583
584			`return 0;`
585			`}`
586
587
588
589			`int main( int argc, char** argv)`
590			`{`
591			`int multi=0;`
592			`int got_em_all=1;`
593			`char *filename = NULL;`
594			`struct library *cur;`
595
596			`if (argc < 2) {`
597			`fprintf(stderr, "ldd: missing file arguments\n");`
598			fprintf(stderr, "Try `ldd --help' for more information.\n");
599			`exit(EXIT_FAILURE);`
600			`}`
601			`if (argc > 2) {`
602			`multi++;`
603			`}`
604
605			`while (--argc > 0) {`
606			`++argv;`
607
608			`if(strcmp(*argv, "--")==0) {`
609			`/* Ignore "--" */`
610			`continue;`
611			`}`
612
613			`if(strcmp(*argv, "--help")==0) {`
614			`fprintf(stderr, "Usage: ldd [OPTION]... FILE...\n");`
615			`fprintf(stderr, "\t--help\t\tprint this help and exit\n");`
616			`exit(EXIT_FAILURE);`
617			`}`
618
619			`filename=*argv;`
620			`if (!filename) {`
621			`fprintf(stderr, "No filename specified.\n");`
622			`exit(EXIT_FAILURE);`
623			`}`
624
625			`if (multi) {`
626			`printf("%s:\n", *argv);`
627			`}`
628
629			`if (find_dependancies(filename)!=0)`
630			`continue;`
631
632			`while(got_em_all) {`
633			`got_em_all=0;`
634			`/* Keep walking the list till everybody is resolved */`
635			`for (cur = lib_list; cur; cur=cur->next) {`
636			`if (cur->resolved == 0 && cur->path) {`
637			`got_em_all=1;`
638			`//printf("checking sub-depends for '%s\n", cur->path);`
639			`find_dependancies(cur->path);`
640			`cur->resolved = 1;`
641			`}`
642			`}`
643			`}`
644
645
646			`/* Print the list */`
647			`got_em_all=0;`
648			`for (cur = lib_list; cur; cur=cur->next) {`
649			`got_em_all=1;`
650			`printf("\t%s => %s (0x00000000)\n", cur->name, cur->path);`
651			`}`
652			`if (interp_dir && got_em_all==1)`
653			`printf("\t%s => %s (0x00000000)\n", interp, interp);`
654			`if (got_em_all==0)`
655			`printf("\tnot a dynamic executable\n");`
656
657			`for (cur = lib_list; cur; cur=cur->next) {`
658			`free(cur->name);`
659			`cur->name=NULL;`
660			`if (cur->path && cur->path != not_found)`
661			`free(cur->path);`
662			`cur->path=NULL;`
663			`}`
664			`lib_list=NULL;`
665			`}`
666
667			`return 0;`
668			`}`
669