/* $NetBSD: lookup_elf32.c,v 1.3 2010/02/11 21:28:16 martin Exp $ */

/*-
* Copyright (c) 2010 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Martin Husemann.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/* If not included by lookup_elf64.c, ELFSIZE won't be defined. */
#ifndef ELFSIZE
#define ELFSIZE 32
#endif

#include <lib/libkern/libkern.h>
#include <sys/param.h>
#include <sys/exec_elf.h>

#if ((ELFSIZE == 32) && defined(BOOT_ELF32)) || \
   ((ELFSIZE == 64) && defined(BOOT_ELF64))

void * ELFNAMEEND(lookup_symbol)(const char *, void *, void *);

void *
ELFNAMEEND(lookup_symbol)(const char *symname, void *sstab, void *estab)
{
       Elf_Ehdr *elf;
       Elf_Shdr *shp;
       Elf_Sym *symtab_start, *symtab_end, *sp;
       char *strtab_start, *strtab_end;
       int i, j;

       elf = sstab;
       if (elf->e_shoff == 0)
               return NULL;

       switch (elf->e_machine) {
       ELFDEFNNAME(MACHDEP_ID_CASES)
       default:
               return NULL;
       }

       symtab_start = symtab_end = NULL;
       strtab_start = strtab_end = NULL;

       shp = (Elf_Shdr *)((char *)sstab + elf->e_shoff);
       for (i = 0; i < elf->e_shnum; i++) {
               if (shp[i].sh_type != SHT_SYMTAB)
                       continue;
               if (shp[i].sh_offset == 0)
                       continue;
               symtab_start = (Elf_Sym*)((char*)sstab + shp[i].sh_offset);
               symtab_end = (Elf_Sym*)((char*)sstab + shp[i].sh_offset
                       + shp[i].sh_size);
               j = shp[i].sh_link;
               if (shp[j].sh_offset == 0)
                       continue;
               strtab_start = (char*)sstab + shp[j].sh_offset;
               strtab_end = (char*)sstab + shp[j].sh_offset + shp[j].sh_size;
               break;
       }

       if (!symtab_start || !strtab_start)
               return NULL;

       for (sp = symtab_start; sp < symtab_end; sp++)
               if (sp->st_name != 0 &&
                   strcmp(strtab_start + sp->st_name, symname) == 0)
                       return (void*)(uintptr_t)sp->st_value;

       return NULL;
}

#endif /* (ELFSIZE == 32 && BOOT_ELF32) || (ELFSIZE == 64 && BOOT_ELF64) */