ext/libelf/libelf_extended.c

   1 /*-
   2  * Copyright (c) 2006 Joseph Koshy
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <assert.h>
  28 #include "libelf.h"
  29
  30 #include "_libelf.h"
  31
  32 /*
  33  * Retrieve section #0, allocating a new section if needed.
  34  */
  35 static Elf_Scn *
  36 _libelf_getscn0(Elf *e)
  37 {
  38         Elf_Scn *s;
  39
  40         if ((s = STAILQ_FIRST(&e->e_u.e_elf.e_scn)) != NULL)
  41                 return (s);
  42
  43         return (_libelf_allocate_scn(e, (size_t) SHN_UNDEF));
  44 }
  45
  46 int
  47 _libelf_setshnum(Elf *e, void *eh, int ec, size_t shnum)
  48 {
  49         Elf_Scn *scn;
  50
  51         if (shnum >= SHN_LORESERVE) {
  52                 if ((scn = _libelf_getscn0(e)) == NULL)
  53                         return (0);
  54
  55                 assert(scn->s_ndx == SHN_UNDEF);
  56
  57                 if (ec == ELFCLASS32)
  58                         scn->s_shdr.s_shdr32.sh_size = shnum;
  59                 else
  60                         scn->s_shdr.s_shdr64.sh_size = shnum;
  61
  62                 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
  63
  64                 shnum = 0;
  65         }
  66
  67         if (ec == ELFCLASS32)
  68                 ((Elf32_Ehdr *) eh)->e_shnum = shnum;
  69         else
  70                 ((Elf64_Ehdr *) eh)->e_shnum = shnum;
  71
  72
  73         return (1);
  74 }
  75
  76 int
  77 _libelf_setshstrndx(Elf *e, void *eh, int ec, size_t shstrndx)
  78 {
  79         Elf_Scn *scn;
  80
  81         if (shstrndx >= SHN_LORESERVE) {
  82                 if ((scn = _libelf_getscn0(e)) == NULL)
  83                         return (0);
  84
  85                 assert(scn->s_ndx == SHN_UNDEF);
  86
  87                 if (ec == ELFCLASS32)
  88                         scn->s_shdr.s_shdr32.sh_link = shstrndx;
  89                 else
  90                         scn->s_shdr.s_shdr64.sh_link = shstrndx;
  91
  92                 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
  93
  94                 shstrndx = SHN_XINDEX;
  95         }
  96
  97         if (ec == ELFCLASS32)
  98                 ((Elf32_Ehdr *) eh)->e_shstrndx = shstrndx;
  99         else
 100                 ((Elf64_Ehdr *) eh)->e_shstrndx = shstrndx;
 101
 102         return (1);
 103 }
 104
 105 int
 106 _libelf_setphnum(Elf *e, void *eh, int ec, size_t phnum)
 107 {
 108         Elf_Scn *scn;
 109
 110         if (phnum >= PN_XNUM) {
 111                 if ((scn = _libelf_getscn0(e)) == NULL)
 112                         return (0);
 113
 114                 assert(scn->s_ndx == SHN_UNDEF);
 115
 116                 if (ec == ELFCLASS32)
 117                         scn->s_shdr.s_shdr32.sh_info = phnum;
 118                 else
 119                         scn->s_shdr.s_shdr64.sh_info = phnum;
 120
 121                 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
 122
 123                 phnum = PN_XNUM;
 124         }
 125
 126         if (ec == ELFCLASS32)
 127                 ((Elf32_Ehdr *) eh)->e_phnum = phnum;
 128         else
 129                 ((Elf64_Ehdr *) eh)->e_phnum = phnum;
 130
 131         return (1);
 132 }
 133