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section.c
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section.c
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/*
* =====================================================================================
*
* Filename: section.c
*
* Description:
*
* Version: 1.0
* Created: 03/02/2014 02:40:57 PM
* Revision: none
* Compiler: gcc
*
* Author: YOUR NAME (),
* Organization:
*
* =====================================================================================
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <elf.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <math.h>
#include "section.h"
#include "sectionGD.h"
static void FillInterpSection(Section *, char *);
static void FillDynstrSection(Section *, Symbol *, char *);
static void FillDynsymSection(Section *, Symbol *);
static void FillGVSection(Section *, Symbol *);
static void FillHashSection(Section *, Symbol *);
static void FillGNRSection(Section *, Symbol *, Section *, char *);
static void AddDynstrEntryFromName(Section *, Symbol *);
static void AddDynstrEntryFromVersion(Section *, Symbol *);
static void AddShstrEntry(Section *, Section *);
static void AddDynsymEntry(Section *, Symbol *);
static void AddGVEntry(Section *, Symbol *);
static void AddGNREntry(Section *, Symbol *, Section *, int);
static void AddGOTPLTTop(Section *);
static void AddPLTTop(Section *);
static void AddPLTEntry(Section *, int);
static void AddGOTorGOTPLTEntry(Section *);
static void AddRelPLTEntry(Section *, Symbol *, int);
static void AddRelGOTEntry(Section *, Symbol *, int);
static UINT32 CalculateHash(const UINT8 *);
static int FindOffset(Section *, char *);
static void DeleteSection(Section *);
static Section *MergeTwoSections(Section *, Section *);
static int SkipXSection(UINT8 *name);
static Section *CopySection(Section *);
Section *GetSections(Elf32_File *elf_file)
{
Section *cur_section, *last_section, *first_section;
Elf32_Shdr *section_table;
UINT8 *section_strn_table, *file_data;
int i, numberOfSections;
section_table = elf_file->elf_section_table;
section_strn_table = elf_file->elf_section_strn_table;
file_data = elf_file->elf_file_data;
numberOfSections = elf_file->elf_file_header->e_shnum;
cur_section = last_section = first_section = NULL;
for (i = 0; i < numberOfSections; i++) {
Elf32_Shdr *cur_sec_dr;
cur_sec_dr = section_table + i;
cur_section = (Section *)malloc(sizeof(Section));
cur_section->sec_number = i;
cur_section->sec_data = (UINT8 *)malloc(cur_sec_dr->sh_size);
memcpy(cur_section->sec_data, file_data + cur_sec_dr->sh_offset, cur_sec_dr->sh_size);
cur_section->sec_datasize = cur_section->sec_newdatasize = cur_sec_dr->sh_size;
cur_section->sec_address = cur_sec_dr->sh_addr;
cur_section->sec_type = cur_sec_dr->sh_type;
cur_section->sec_flags = cur_sec_dr->sh_flags;
cur_section->sec_link = cur_sec_dr->sh_link;
cur_section->sec_info = cur_sec_dr->sh_info;
cur_section->sec_align = cur_sec_dr->sh_addralign;
cur_section->sec_entsize = cur_sec_dr->sh_entsize;
cur_section->sec_name_offset = cur_sec_dr->sh_name;
cur_section->sec_file_offset = cur_sec_dr->sh_offset;
cur_section->sec_misc = i;
int name_length = strlen(section_strn_table + cur_section->sec_name_offset);
cur_section->sec_name = (UINT8 *)malloc(name_length + 1);
strcpy(cur_section->sec_name, section_strn_table + cur_section->sec_name_offset);
if (first_section == NULL) {
first_section = cur_section;
last_section = cur_section;
}
else {
InsertSectionAfterSection(cur_section, last_section);
last_section = cur_section;
}
}
return first_section;
}
// new_section is inserted after section
void InsertSectionAfterSection(Section *new_section, Section *section)
{
new_section->sec_prev = section;
new_section->sec_next = section->sec_next;
section->sec_next = new_section;
if (new_section->sec_next != NULL) {
new_section->sec_next->sec_prev = new_section;
}
}
Section *GetSectionByIndex(Section *sec_list, UINT16 sec_id)
{
Section *cur_sec;
cur_sec = sec_list;
while (cur_sec) {
if (cur_sec->sec_number == sec_id)
return cur_sec;
cur_sec = cur_sec->sec_next;
}
/*printf("error in finding the %dth section\n", sec_id);*/
return NULL;
/*exit(EXIT_FAILURE);*/
}
Section *GetSectionByName(Section *sec_list, UINT8 *sec_name)
{
Section *cur_section;
cur_section = sec_list;
while (cur_section) {
if (strcmp(cur_section->sec_name, sec_name) == 0)
return cur_section;
cur_section = cur_section->sec_next;
}
printf("error the %s section doesn't exits\n", sec_name);
exit(EXIT_FAILURE);
}
void CreateSections(Section *sec_list)
{
Section *tail_sec;
tail_sec = sec_list;
while (tail_sec->sec_next != NULL)
tail_sec = tail_sec->sec_next;
int i;
for (i = 0; i < ADDEDSECTIONNUMBER; i++) {
Section *new_section;
new_section = (Section *)malloc(sizeof(Section));
new_section->sec_type = AddedSectionsInfo[i].sh_type;
new_section->sec_flags = AddedSectionsInfo[i].sh_flags;
new_section->sec_address = AddedSectionsInfo[i].sh_addr;
new_section->sec_file_offset = AddedSectionsInfo[i].sh_offset;
new_section->sec_datasize = AddedSectionsInfo[i].sh_size;
new_section->sec_link = AddedSectionsInfo[i].sh_link;
new_section->sec_info = AddedSectionsInfo[i].sh_info;
new_section->sec_align = AddedSectionsInfo[i].sh_addralign;
new_section->sec_entsize = AddedSectionsInfo[i].sh_entsize;
new_section->sec_name = (UINT8 *)malloc(strlen(AddedSectionsName[i]) + 1);
strcpy(new_section->sec_name, AddedSectionsName[i]);
new_section->sec_number = tail_sec->sec_number + 1;
new_section->sec_misc = 0;
new_section->sec_data = NULL;
InsertSectionAfterSection(new_section, tail_sec);
tail_sec = new_section;
}
}
void UpdateInterpSection(Section *sec_list, char *ld_path)
{
Section *interp_sec;
interp_sec = GetSectionByName(sec_list, INTERP_SECTION_NAME);
FillInterpSection(interp_sec, ld_path);
}
static void FillInterpSection(Section *interp_sec, char *ld_path)
{
int length;
length = strlen(ld_path);
interp_sec->sec_data = (UINT8 *)malloc(length + 1);
interp_sec->sec_datasize = interp_sec->sec_newdatasize = length + 1;
strcpy(interp_sec->sec_data, ld_path);
}
void UpdateShstrSection(Section *sec_list)
{
Section *shstrtab, *cur_sec;
shstrtab = GetSectionByName(sec_list, SHSTRTAB_SECTION_NAME);
free(shstrtab->sec_data);
shstrtab->sec_data = NULL;
shstrtab->sec_datasize = 0;
cur_sec = sec_list;
while (cur_sec) {
AddShstrEntry(shstrtab, cur_sec);
cur_sec = cur_sec->sec_next;
}
}
static void AddShstrEntry(Section *shstrtab, Section *section)
{
int datasize, newdatasize, length;
datasize = shstrtab->sec_datasize;
length = strlen(section->sec_name) + 1;
newdatasize = datasize + length;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
memcpy(buffer, shstrtab->sec_data, datasize);
strcpy(buffer + datasize, section->sec_name);
if (shstrtab != NULL)
free(shstrtab->sec_data);
shstrtab->sec_data = buffer;
shstrtab->sec_datasize = newdatasize;
section->sec_name_offset = datasize;
}
void UpdateDynstrSection(Section *sec_list, Symbol *dynsym_list, char *so_filename)
{
Section *dynstr_sec;
dynstr_sec = GetSectionByName(sec_list, DYNSTR_SECTION_NAME);
FillDynstrSection(dynstr_sec, dynsym_list, so_filename);
}
static void FillDynstrSection(Section *dynstr_sec, Symbol *dynsym_list, char *so_filename)
{
Symbol *cur_sym, *first_sym;
UINT8 *sec_data;
int datasize;
/*printf("%d\n", strlen(so_filename));*/
sec_data = (UINT8 *)malloc(strlen(so_filename) + 2);
memset(sec_data, 0x0, strlen(so_filename) + 2);
datasize = strlen(so_filename) + 2;
strcpy(sec_data + 1, so_filename);
dynstr_sec->sec_data = sec_data;
dynstr_sec->sec_datasize = datasize;
first_sym = cur_sym = dynsym_list;
/* skip the first NULL symbol */
cur_sym = cur_sym->sym_next;
while (cur_sym) {
AddDynstrEntryFromName(dynstr_sec, cur_sym);
cur_sym = cur_sym->sym_next;
}
cur_sym = first_sym;
// UNFIXED: How to tell a version has ever occured
// number 0, 1 do not have a version name
int flags[100] = {1, 1, 0};
while (cur_sym) {
int version;
version = cur_sym->sym_version;
if (!flags[version] && version != 0) {
flags[version] = 1;
AddDynstrEntryFromVersion(dynstr_sec, cur_sym);
}
cur_sym = cur_sym->sym_next;
}
}
static void AddDynstrEntryFromName(Section *dynstr_sec, Symbol *sym)
{
int datasize, newdatasize;
datasize = dynstr_sec->sec_datasize;
int length;
length = strlen(sym->sym_name) + 1;
newdatasize = datasize + length;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
printf("%d\n", datasize);
memcpy(buffer, dynstr_sec->sec_data, datasize);
strcpy(buffer + datasize, sym->sym_name);
free(dynstr_sec->sec_data);
dynstr_sec->sec_data = buffer;
dynstr_sec->sec_datasize = newdatasize;
sym->sym_content->st_name = datasize;
}
static void AddDynstrEntryFromVersion(Section *dynstr_sec, Symbol *sym)
{
int datasize, newdatasize;
datasize = dynstr_sec->sec_datasize;
int length;
length = strlen(sym->sym_version_name) + 1;
newdatasize = datasize + length;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
memset(buffer, 0, newdatasize);
memcpy(buffer, dynstr_sec->sec_data, datasize);
strcpy(buffer + datasize, sym->sym_version_name);
free(dynstr_sec->sec_data);
dynstr_sec->sec_data = buffer;
dynstr_sec->sec_datasize = newdatasize;
}
void UpdateDynsymSection(Section *sec_list, Symbol *sym_list)
{
Section *dynsym;
dynsym = GetSectionByName(sec_list, DYNSYM_SECTION_NAME);
FillDynsymSection(dynsym, sym_list);
}
// UNFIXED: dynsym.sh_link
// wait until all the layout settled
static void FillDynsymSection(Section *dynsym, Symbol *sym_list)
{
Symbol *cur_sym;
cur_sym = sym_list;
while (cur_sym) {
AddDynsymEntry(dynsym, cur_sym);
cur_sym = cur_sym->sym_next;
}
}
static void AddDynsymEntry(Section *dynsym, Symbol *sym)
{
int datasize, newdatasize;
datasize = dynsym->sec_datasize;
int addition;
addition = dynsym->sec_entsize;
newdatasize = datasize + addition;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
memset(buffer, 0, newdatasize);
memcpy(buffer, dynsym->sec_data, datasize);
memcpy(buffer + datasize, sym->sym_content, addition);
free(dynsym->sec_data);
dynsym->sec_data = buffer;
dynsym->sec_datasize = newdatasize;
}
/* TODO: Can't understand the algorithm here now' */
void UpdateHashSectionNew(Section *sec_list, Symbol *sym_list)
{
Section *hash;
hash = GetSectionByName(sec_list, HASH_SECTION_NAME);
int number = 0;
Symbol *cur_sym;
cur_sym = sym_list;
printf("test\n");
while (cur_sym->sym_next != NULL) {
number++;
cur_sym = cur_sym->sym_next;
}
number++;
printf("number is %d\n", number);
int nbuckets, nchains;
nchains = number;
nbuckets = (int)log2(number) + 1;
int datasize = (1 + 1 + nbuckets + nchains) * 4;
UINT8 *buffer;
buffer = (UINT8 *)malloc(datasize);
memset(buffer, 0x0, datasize);
memcpy(buffer, &nbuckets, sizeof(int));
memcpy(buffer + 4, &nchains, sizeof(int));
/*int i;*/
/*for (i = 0; i < nbuckets; i++) {*/
/*int num = number - i;*/
/*memcpy(buffer + 8 + 4 * i, &num, sizeof(int));*/
/*}*/
/*cur_sym = cur_sym->sym_prev;*/
while (cur_sym->sym_prev != NULL) {
int hashvalue = CalculateHash(cur_sym->sym_name);
int order, index;
order = hashvalue % nbuckets;
index = *(int *)((buffer + 8 + order * 4));
if (index == 0)
memcpy(buffer + 8 + order * 4, &cur_sym->sym_id, sizeof(int));
else {
order = index;
index = *(int *)((buffer + 8 + nbuckets * 4 + order * 4));
while (index) {
order = index;
index = *(int *)((buffer + 8 + nbuckets * 4 + order * 4));
}
memcpy(buffer + 8 + nbuckets * 4 + order * 4, &cur_sym->sym_id, 4);
}
cur_sym = cur_sym->sym_prev;
}
hash->sec_data = buffer;
hash->sec_datasize = datasize;
}
void UpdateHashSection(Section *sec_list, Symbol *sym_list, Section *hash)
{
Section *hash_sec;
hash_sec = GetSectionByName(sec_list, HASH_SECTION_NAME);
/*FillHashSection(hash_sec, sym_list);*/
int datasize = hash->sec_datasize;
hash_sec->sec_data = (UINT8 *)malloc(datasize);
memset(hash_sec->sec_data, 0x0, datasize);
memcpy(hash_sec->sec_data, hash->sec_data, datasize);
hash_sec->sec_datasize = datasize;
}
/* TODO: Replace the content using a file temporaly */
static void FillHashSection(Section *hash_sec, Symbol *sym_list)
{
Symbol *cur_sym;
cur_sym = sym_list;
while (cur_sym) {
printf("%d\n", CalculateHash(cur_sym->sym_name));
cur_sym = cur_sym->sym_next;
}
/*FILE *file;*/
/*file = fopen("hash", "rb");*/
/*if (file == NULL) {*/
/*printf("error opening hash file\n");*/
/*exit(EXIT_FAILURE);*/
/*}*/
/*struct stat fs;*/
/*if (stat("hash", &fs) == -1) {*/
/*printf("error reading hash file meta data\n");*/
/*exit(EXIT_FAILURE);*/
/*}*/
/*UINT32 datasize;*/
/*datasize = fs.st_size;*/
/*hash_sec->sec_data = (UINT8 *)malloc(datasize);*/
/*hash_sec->sec_datasize = datasize;*/
/*if (fread(hash_sec->sec_data, datasize, 1, file) != datasize) {*/
/*printf("error in reading hash file data\n");*/
/*exit(EXIT_FAILURE);*/
/*}*/
/*fclose(file);*/
}
static UINT32 CalculateHash(const UINT8 *name)
{
UINT32 h = 0, g;
while (*name) {
h = (h << 4) + *name++;
if (g = h & 0xf0000000)
h ^= g >> 24;
h &= ~g;
}
return h;
}
void UpdateGVSection(Section *sec_list, Symbol *sym_list)
{
Section *gv_sec;
gv_sec = GetSectionByName(sec_list, GV_SECTION_NAME);
FillGVSection(gv_sec, sym_list);
}
static void FillGVSection(Section *gv_sec, Symbol *sym_list)
{
Symbol *cur_sym;
cur_sym = sym_list;
while (cur_sym) {
AddGVEntry(gv_sec, cur_sym);
cur_sym = cur_sym->sym_next;
}
}
static void AddGVEntry(Section *gv_sec, Symbol *sym)
{
int datasize, newdatasize;
datasize = gv_sec->sec_datasize;
UINT16 addition;
addition = gv_sec->sec_entsize;
newdatasize = datasize + addition;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
memset(buffer, 0, newdatasize);
memcpy(buffer, gv_sec->sec_data, datasize);
buffer[datasize] = sym->sym_version;
free(gv_sec->sec_data);
gv_sec->sec_data = buffer;
gv_sec->sec_datasize = newdatasize;
}
void UpdateGNRSection(Section *sec_list, Symbol *sym_list, char *so_filename)
{
Section *gnr_sec, *dynstr;
gnr_sec = GetSectionByName(sec_list, GNR_SECTION_NAME);
dynstr = GetSectionByName(sec_list, DYNSTR_SECTION_NAME);
/*int offset;*/
/*offset = FindOffset(dynstr, so_filename);*/
/*printf("\n%d\n", offset);*/
/*printf("\n%d\n", FindOffset(dynstr, "printf"));*/
FillGNRSection(gnr_sec, sym_list, dynstr, so_filename);
}
/* TODO: UNFIXED: more than two .so files have to be taken cared */
static void FillGNRSection(Section *gnr_sec, Symbol *sym_list, Section *dynstr, char *so_filename)
{
Symbol *cur_sym;
cur_sym = sym_list;
Elf32_Verneed verneed;
int i, version_number, last, datasize;
int flags[100] = {1, 1, 0};
version_number = 0;
while (cur_sym) {
if (flags[cur_sym->sym_version] == 0) {
version_number++;
flags[cur_sym->sym_version] = 1;
}
cur_sym = cur_sym->sym_next;
}
verneed.vn_version = 1;
verneed.vn_cnt = version_number;
verneed.vn_file = FindOffset(dynstr, so_filename);
verneed.vn_aux = 0x10;
verneed.vn_next = 0;
datasize = sizeof(Elf32_Verneed);
gnr_sec->sec_data = malloc(datasize);
memset(gnr_sec->sec_data, 0, datasize);
memcpy(gnr_sec->sec_data, &verneed, datasize);
gnr_sec->sec_datasize = datasize;
for (i = 2; i < 100; i++)
flags[i] = 0;
cur_sym = sym_list;
last = 0;
while (cur_sym) {
if (flags[cur_sym->sym_version] == 0) {
flags[cur_sym->sym_version] = 1;
last++;
if (last == verneed.vn_cnt)
AddGNREntry(gnr_sec, cur_sym, dynstr, 1);
else
AddGNREntry(gnr_sec, cur_sym, dynstr, 0);
}
cur_sym = cur_sym->sym_next;
}
}
static void AddGNREntry(Section *gnr_sec, Symbol *sym, Section *dynstr, int flag)
{
Elf32_Vernaux vernaux;
UINT8 *version_name;
UINT16 version;
version_name = sym->sym_version_name;
version = sym->sym_version;
vernaux.vna_hash = CalculateHash(version_name);
vernaux.vna_flags = 0;
vernaux.vna_other = version;
vernaux.vna_name = FindOffset(dynstr, version_name);
if (flag)
vernaux.vna_next = 0;
else
vernaux.vna_next = 0x10;
UINT8 *buffer;
buffer = (UINT8 *)malloc(gnr_sec->sec_datasize + sizeof(Elf32_Vernaux));
memcpy(buffer, gnr_sec->sec_data, gnr_sec->sec_datasize);
memcpy(buffer + gnr_sec->sec_datasize, &vernaux, sizeof(Elf32_Vernaux));
free(gnr_sec->sec_data);
gnr_sec->sec_data = buffer;
gnr_sec->sec_datasize = gnr_sec->sec_datasize + sizeof(Elf32_Vernaux);
}
static int FindOffset(Section *dynstr, char *str)
{
UINT8 *data;
data = dynstr->sec_data;
int offset = 0;
while (strcmp(str, data) != 0){
data++;
offset++;
}
return offset;
}
static void AddGOTPLTTop(Section *gotplt)
{
int datasize, addition;
UINT8 *buffer;
addition = 0xc;
buffer = (UINT8 *)malloc(addition);
memset(buffer, 0x0, addition);
datasize = addition;
gotplt->sec_data = buffer;
gotplt->sec_datasize = datasize;
}
void UpdatePLTRelatedSections(Section *sec_list, Symbol *sym_list)
{
Section *plt, *gotplt, *relplt;
plt = GetSectionByName(sec_list, PLT_SECTION_NAME);
gotplt = GetSectionByName(sec_list, GOT_PLT_SECTION_NAME);
relplt = GetSectionByName(sec_list, REL_PLT_SECTION_NAME);
AddPLTTop(plt);
AddGOTPLTTop(gotplt);
Symbol *cur_sym;
cur_sym = sym_list;
int plt_number = 0;
while (cur_sym) {
if (cur_sym->sym_sd_type & SYM_PLT) {
AddPLTEntry(plt, plt_number);
AddRelPLTEntry(relplt, cur_sym, plt_number);
AddGOTorGOTPLTEntry(gotplt);
plt_number += 1;
}
cur_sym = cur_sym->sym_next;
}
}
void UpdateGOTRelatedSections(Section *sec_list, Symbol *sym_list)
{
Section *got, *reldyn;
got = GetSectionByName(sec_list, GOT_SECTION_NAME);
reldyn = GetSectionByName(sec_list, REL_DYN_SECTION_NAME);
Symbol *cur_sym;
cur_sym = sym_list;
int got_number = 0;
while (cur_sym) {
if (cur_sym->sym_sd_type & SYM_GOT) {
AddGOTorGOTPLTEntry(got);
AddRelGOTEntry(reldyn, cur_sym, got_number);
got_number += 1;
}
cur_sym = cur_sym->sym_next;
}
}
static void AddPLTTop(Section *plt)
{
Instr instr[2];
int i, offset;
UINT8 *buffer;
buffer = (UINT8 *)malloc(0x10);
memset(buffer, 0x0, 0x10);
instr[0].opcode = 0x35ff;
instr[0].oprand = 0x0;
instr[1].opcode = 0x25ff;
instr[1].oprand = 0x0;
offset = 0;
for (i = 0; i < 2; i++) {
memcpy(buffer + offset, &(instr[i].opcode), 0x2);
offset += 2;
memcpy(buffer + offset, &(instr[i].oprand), 0x4);
offset += 4;
}
plt->sec_data = buffer;
plt->sec_datasize = 0x10;
}
static void AddPLTEntry(Section *plt, int n)
{
Instr instr[3];
instr[0].opcode = 0x25ff;
instr[0].oprand = 0x0;
instr[1].opcode = 0x68;
instr[1].oprand = n * 0x8;
instr[2].opcode = 0xe9;
instr[2].oprand = 0x0;
int i, offset, datasize, newdatasize;
datasize = plt->sec_datasize;
newdatasize = datasize + 0x10;
i = offset = 0;
UINT8 *buffer, *bufferOff;
buffer = (UINT8 *)malloc(newdatasize);
memset(buffer, 0x0, 0x10);
memcpy(buffer, plt->sec_data, datasize);
bufferOff = buffer + datasize;
memcpy(bufferOff + offset, &(instr[0].opcode), 2);
offset += 2;
memcpy(bufferOff + offset, &(instr[0].oprand), 4);
offset += 4;
/* Trick: write one byte for opcode */
for (i = 1; i < 3; i++) {
memcpy(bufferOff + offset, &(instr[i].opcode), 1);
offset += 1;
memcpy(bufferOff + offset, &(instr[i].oprand), 4);
offset += 4;
}
free(plt->sec_data);
plt->sec_data = buffer;
plt->sec_datasize = newdatasize;
}
static void AddGOTorGOTPLTEntry(Section *sec)
{
int datasize, addition, newdatasize;
addition = 0x4;
datasize = sec->sec_datasize;
newdatasize = datasize + addition;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
memset(buffer, 0x0, newdatasize);
memcpy(buffer, sec->sec_data, datasize);
free(sec->sec_data);
sec->sec_data = buffer;
sec->sec_datasize = newdatasize;
}
static void AddRelPLTEntry(Section *relplt, Symbol *sym, int n)
{
Elf32_Rel cur_rel;
int datasize, addition, newdatasize;
datasize = relplt->sec_datasize;
addition = sizeof(Elf32_Rel);
newdatasize = datasize + addition;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
memset(buffer, 0x0, newdatasize);
memcpy(buffer, relplt->sec_data, datasize);
cur_rel.r_offset = 0xc + 4 * n;
cur_rel.r_info = (sym->sym_id << 8) + R_386_JMP_SLOT;
memcpy(buffer + datasize, &cur_rel, addition);
free(relplt->sec_data);
relplt->sec_data = buffer;
relplt->sec_datasize = newdatasize;
}
static void AddRelGOTEntry(Section *relgot, Symbol *sym, int n)
{
Elf32_Rel cur_rel;
int datasize, addition, newdatasize;
datasize = relgot->sec_datasize;
addition = sizeof(Elf32_Rel);
newdatasize = datasize + addition;
UINT8 *buffer;
buffer = (UINT8 *)malloc(newdatasize);
memset(buffer, 0x0, newdatasize);
memcpy(buffer, relgot->sec_data, datasize);
cur_rel.r_offset = 4 * n;
cur_rel.r_info = (sym->sym_id << 8) + R_386_GLOB_DAT;
memcpy(buffer + datasize, &cur_rel, addition);
free(relgot->sec_data);
relgot->sec_data = buffer;
relgot->sec_datasize = newdatasize;
}
void UpdateDynamicSection(Section *sec_list, int number)
{
Section *dynamic;
dynamic = GetSectionByName(sec_list, DYNAMIC_SECTION_NAME);
UINT8 *buffer;
int datasize;
datasize = DYNAMIC_ENTSIZE * (DYNAMIC_NUMBER + number);
buffer = (UINT8 *)malloc(datasize);
memset(buffer, 0x0, datasize);
dynamic->sec_data = buffer;
dynamic->sec_datasize = datasize;
}
Section *MergeSection(Section *sec_list)
{
Section *cur_sec, *last_sec, *text, *next_sec, *rm_sec, *merge_list;
merge_list = NULL;
cur_sec = sec_list;
text = GetSectionByName(sec_list, TEXT_SECTION_NAME);
int flag = 0;
while (cur_sec) {
/*printf("%d %s %s\n", cur_sec->sec_number, cur_sec->sec_name, cur_sec->sec_next->sec_name);*/
if (cur_sec->sec_flags & SHF_MERGE) {
/* TODO: modify the comment content */
if (!strcmp(cur_sec->sec_name,".comment")) {
/*MergeCommentSection(cur_sec);*/
}
else {
next_sec = cur_sec->sec_next;
rm_sec = MergeTwoSections(last_sec, cur_sec);
flag = 1;
if (merge_list == NULL)
merge_list = rm_sec;
else
InsertSectionAfterSection(rm_sec, merge_list);
}
}
if ((cur_sec->sec_flags & SHF_EXECINSTR) && !SkipXSection(cur_sec->sec_name)) {
next_sec = cur_sec->sec_next;
rm_sec = MergeTwoSections(text, cur_sec);
flag = 1;
if (merge_list == NULL)
merge_list = rm_sec;
else
InsertSectionAfterSection(rm_sec, merge_list);
}
if (!flag) {
last_sec = cur_sec;
cur_sec = cur_sec->sec_next;
}
else {
cur_sec = next_sec;
}
flag = 0;
}
return merge_list;
}
static int SkipXSection(UINT8 *name)
{
UINT8 *sec_name[] = {
TEXT_SECTION_NAME,
INIT_SECTION_NAME,
FINI_SECTION_NAME
};
int i;
for (i = 0; i < 3; i++) {
if (!strcmp(sec_name[i], name))
return 1;
}
return 0;
}
static Section *MergeTwoSections(Section *target, Section *source)
{
UINT8 *buffer;
int addition, num, i, target_datasize, source_datasize, target_newdatasize;
target_datasize = target->sec_datasize;
source_datasize = source->sec_datasize;
UINT32 source_align;
source_align = 1;
/*source_align <<= source->sec_align;*/
source_align = source->sec_align;
addition = 0;
while ((target_datasize + addition) % source_align != 0) {
addition++;
}
target_newdatasize = target_datasize + source_datasize + addition;
buffer = (UINT8 *)malloc(target_newdatasize);
memset(buffer, 0x0, target_newdatasize);
memcpy(buffer, target->sec_data, target_datasize);
memcpy(buffer + target_datasize + addition, source->sec_data, source_datasize);
free(target->sec_data);
target->sec_data = buffer;
target->sec_datasize = target_newdatasize;
source->sec_mergeto = target;
source->sec_delta = target_datasize + addition;
Section *res;
res = CopySection(source);
DeleteSection(source);
return res;
}
static void DeleteSection(Section *useless)
{
Section *head, *tail;
head = useless->sec_prev;
tail = useless->sec_next;
head->sec_next = tail;
tail->sec_prev = head;
free(useless->sec_data);
free(useless->sec_name);
free(useless);
}
static Section *CopySection(Section *sec)
{
Section *sec_shadow;
sec_shadow = malloc(sizeof(Section));
sec_shadow->sec_number = sec->sec_number;
sec_shadow->sec_prev = sec_shadow->sec_next = NULL;
sec_shadow->sec_mergeto = sec->sec_mergeto;
sec_shadow->sec_datasize = sec->sec_datasize;
sec_shadow->sec_data = malloc(sec->sec_datasize);
memcpy(sec_shadow->sec_data, sec->sec_data, sec->sec_datasize);
sec_shadow->sec_delta = sec->sec_delta;
sec_shadow->sec_address = sec->sec_address;
sec_shadow->sec_name = malloc(strlen(sec->sec_name) + 1);
strcpy(sec_shadow->sec_name, sec->sec_name);
sec_shadow->sec_type = sec->sec_type;
sec_shadow->sec_flags = sec->sec_flags;
sec_shadow->sec_link = sec->sec_link;
sec_shadow->sec_info = sec->sec_info;
sec_shadow->sec_align = sec->sec_align;
sec_shadow->sec_entsize = sec->sec_entsize;
sec_shadow->sec_name_offset = sec->sec_name_offset;
sec_shadow->sec_file_offset = sec->sec_file_offset;
sec_shadow->sec_misc = sec->sec_misc;
return sec_shadow;
}
void DropSection(Section *sec)
{
Section *head, *tail;
tail = NULL;
head = sec->sec_prev;
if (sec->sec_next)
tail = sec->sec_next;
head->sec_next = tail;
if (tail)
tail->sec_prev = head;
free(sec->sec_data);
free(sec->sec_name);
free(sec);
}
void RenewRelGOTSection(Section *sec_list)
{
Section *relgot, *got;
relgot = GetSectionByName(sec_list, REL_DYN_SECTION_NAME);
got = GetSectionByName(sec_list, GOT_SECTION_NAME);
UINT32 got_sec_address;