164 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			164 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*-
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|  * Copyright (c) 2006,2008 Joseph Koshy
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #include <sys/cdefs.h>
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| 
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| #include <sys/types.h>
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| #include <sys/errno.h>
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| #if 0
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| #include <sys/mman.h>
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| #endif
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| #include <sys/stat.h>
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| 
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| #include <ar.h>
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| #include <ctype.h>
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| #include <errno.h>
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| #include <libelf.h>
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| #include <unistd.h>
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| 
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| #include "_libelf.h"
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| 
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| LIBELF_VCSID("$Id$");
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| 
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| static Elf *
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| _libelf_open_object(int fd, Elf_Cmd c)
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| {
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| 	Elf *e;
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| 	void *m;
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| 	struct stat sb;
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| 
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| 	/*
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| 	 * 'Raw' files are always mapped with 'PROT_READ'.  At
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| 	 * elf_update(3) time for files opened with ELF_C_RDWR the
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| 	 * mapping is unmapped, file data is written to using write(2)
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| 	 * and then the raw data is immediately mapped back in.
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| 	 */
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| 	if (fstat(fd, &sb) < 0) {
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| 		LIBELF_SET_ERROR(IO, errno);
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| 		return (NULL);
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| 	}
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| 
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| 	m = NULL;
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| 	if ((m = mmap(NULL, (size_t) sb.st_size, PROT_READ, MAP_PRIVATE, fd,
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| 	    (off_t) 0)) == MAP_FAILED) {
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| 		LIBELF_SET_ERROR(IO, errno);
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| 		return (NULL);
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| 	}
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| 
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| 	if ((e = elf_memory(m, (size_t) sb.st_size)) == NULL) {
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| 		(void) munmap(m, (size_t) sb.st_size);
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| 		return (NULL);
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| 	}
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| 
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| 	e->e_flags |= LIBELF_F_MMAP;
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| 	e->e_fd = fd;
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| 	e->e_cmd = c;
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| 
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| 	if (c == ELF_C_RDWR && e->e_kind == ELF_K_AR) {
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| 		(void) elf_end(e);
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| 		LIBELF_SET_ERROR(ARGUMENT, 0);
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| 		return (NULL);
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| 	}
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| 
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| 	return (e);
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| }
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| 
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| Elf *
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| elf_begin(int fd, Elf_Cmd c, Elf *a)
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| {
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| 	Elf *e;
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| 
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| 	e = NULL;
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| 
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| 	if (LIBELF_PRIVATE(version) == EV_NONE) {
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| 		LIBELF_SET_ERROR(SEQUENCE, 0);
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| 		return (NULL);
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| 	}
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| 
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| 	switch (c) {
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| 	case ELF_C_NULL:
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| 		return (NULL);
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| 
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| 	case ELF_C_WRITE:
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| 
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| 		if (a != NULL) { /* not allowed for ar(1) archives. */
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| 			LIBELF_SET_ERROR(ARGUMENT, 0);
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| 			return (NULL);
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| 		}
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| 
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| 		/*
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| 		 * Check writeability of `fd' immediately and fail if
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| 		 * not writeable.
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| 		 */
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| 		if (ftruncate(fd, (off_t) 0) < 0) {
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| 			LIBELF_SET_ERROR(IO, errno);
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| 			return (NULL);
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| 		}
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| 
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| 		if ((e = _libelf_allocate_elf()) != NULL) {
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| 			_libelf_init_elf(e, ELF_K_ELF);
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| 			e->e_byteorder = LIBELF_PRIVATE(byteorder);
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| 			e->e_fd = fd;
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| 			e->e_cmd = c;
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| 		}
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| 		return (e);
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| 
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| 	case ELF_C_RDWR:
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| 		if (a != NULL) { /* not allowed for ar(1) archives. */
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| 			LIBELF_SET_ERROR(ARGUMENT, 0);
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| 			return (NULL);
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| 		}
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| 		/*FALLTHROUGH*/
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| 	case ELF_C_READ:
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| 		/*
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| 		 * Descriptor `a' could be for a regular ELF file, or
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| 		 * for an ar(1) archive.  If descriptor `a' was opened
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| 		 * using a valid file descriptor, we need to check if
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| 		 * the passed in `fd' value matches the original one.
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| 		 */
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| 		if (a &&
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| 		    ((a->e_fd != -1 && a->e_fd != fd) || c != a->e_cmd)) {
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| 			LIBELF_SET_ERROR(ARGUMENT, 0);
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| 			return (NULL);
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| 		}
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| 		break;
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| 
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| 	default:
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| 		LIBELF_SET_ERROR(ARGUMENT, 0);
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| 		return (NULL);
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| 
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| 	}
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| 
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| 	if (a == NULL)
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| 		e = _libelf_open_object(fd, c);
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| 	else if (a->e_kind == ELF_K_AR)
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| 		e = _libelf_ar_open_member(a->e_fd, c, a);
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| 	else
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| 		(e = a)->e_activations++;
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| 
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| 	return (e);
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| }
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