summaryrefslogtreecommitdiff
path: root/utils/ldd.c
diff options
context:
space:
mode:
authorEric Andersen <andersen@codepoet.org>2003-11-06 22:38:49 +0000
committerEric Andersen <andersen@codepoet.org>2003-11-06 22:38:49 +0000
commite556691e4f2411bddc228266e9fcb8dbbf122ac6 (patch)
treebe332f3b5cab0519e4f813f7a0f739e9e4bc8f12 /utils/ldd.c
parent7e617ab5308b2dadf231dbe77739ccfceec8c205 (diff)
Begin converting the client utils
Diffstat (limited to 'utils/ldd.c')
-rw-r--r--utils/ldd.c664
1 files changed, 664 insertions, 0 deletions
diff --git a/utils/ldd.c b/utils/ldd.c
new file mode 100644
index 000000000..3ea41b424
--- /dev/null
+++ b/utils/ldd.c
@@ -0,0 +1,664 @@
+/* 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
+
+
+#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;
+ free(cur->path);
+ cur->path=NULL;
+ }
+ lib_list=NULL;
+ }
+
+ return 0;
+}
+