/*
 * Copyright (c) 1995, 1994, 1993, 1992, 1991, 1990  
 * Open Software Foundation, Inc. 
 *  
 * Permission to use, copy, modify, and distribute this software and 
 * its documentation for any purpose and without fee is hereby granted, 
 * provided that the above copyright notice appears in all copies and 
 * that both the copyright notice and this permission notice appear in 
 * supporting documentation, and that the name of ("OSF") or Open Software 
 * Foundation not be used in advertising or publicity pertaining to 
 * distribution of the software without specific, written prior permission. 
 *  
 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL OSF BE LIABLE FOR ANY 
 * SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
 * ACTION OF CONTRACT, NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING 
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE 
 */
/*
 * OSF Research Institute MK6.1 (unencumbered) 1/31/1995
 */

#include <alloca.h>
#include <mach/machine/vm_types.h>
#include <mach/exec/elf.h>
#include <mach/exec/exec.h>

int exec_load(exec_read_func_t *read, exec_read_exec_func_t *read_exec,
		  void *handle, exec_info_t *out_info)
{
	vm_size_t actual;
	Elf32_Ehdr x;
	Elf32_Phdr *phdr, *ph;
	vm_size_t phsize;
	int i;
	int result;
	vm_offset_t loadbase = 0;

	/* Read the ELF header.  */
	if ((result = (*read)(handle, 0, &x, sizeof(x), &actual)) != 0)
		return result;
	if (actual < sizeof(x))
		return EX_NOT_EXECUTABLE;

	if ((x.e_ident[EI_MAG0] != ELFMAG0) ||
	    (x.e_ident[EI_MAG1] != ELFMAG1) ||
	    (x.e_ident[EI_MAG2] != ELFMAG2) ||
	    (x.e_ident[EI_MAG3] != ELFMAG3))
		return EX_NOT_EXECUTABLE;

	/* Make sure the file is of the right architecture.  */
	if ((x.e_ident[EI_CLASS] != ELFCLASS32) ||
	    (x.e_ident[EI_DATA] != MY_EI_DATA) ||
	    (x.e_machine != MY_E_MACHINE))
		return EX_WRONG_ARCH;

	/* Leave room for mmaps etc. before PIE binaries.
	 * Could add address randomization here.  */
	if (x.e_type == ET_DYN || x.e_type == ET_REL)
		loadbase = 128 << 20;

	/* XXX others */
	out_info->entry = (vm_offset_t) x.e_entry + loadbase;

	phsize = x.e_phnum * x.e_phentsize;
	phdr = (Elf32_Phdr *)alloca(phsize);

	result = (*read)(handle, x.e_phoff, phdr, phsize, &actual);
	if (result)
		return result;
	if (actual < phsize)
		return EX_CORRUPT;

	for (i = 0; i < x.e_phnum; i++)
	{
		ph = (Elf32_Phdr *)((vm_offset_t)phdr + i * x.e_phentsize);
		if (ph->p_type == PT_LOAD)
		{
			exec_sectype_t type = EXEC_SECTYPE_ALLOC |
					      EXEC_SECTYPE_LOAD;
			if (ph->p_flags & PF_R) type |= EXEC_SECTYPE_READ;
			if (ph->p_flags & PF_W) type |= EXEC_SECTYPE_WRITE;
			if (ph->p_flags & PF_X) type |= EXEC_SECTYPE_EXECUTE;

			result = (*read_exec)(handle,
					      ph->p_offset, ph->p_filesz,
					      ph->p_vaddr + loadbase, ph->p_memsz, type);
			if (result)
				return result;
		}
	}

	return 0;
}