/**
* Called from elfsh_fixup_symtab
* When trying to inject part of the libc, some bss symbols have a wrong sctndx
* @param symtab
* @return
*/
elfshsect_t *elfsh_fixup_sctndx(elfshsect_t *symtab)
{
int index;
elfsh_Sym *sym;
elfsh_SAddr offset;
elfsh_Shdr *shdr;
elfshsect_t *sct;
PROFILER_IN(__FILE__, __FUNCTION__, __LINE__);
//return (symtab); // XXX
sym = symtab->data;
shdr = symtab->parent->sht + symtab->index;
for (index = 0; index < shdr->sh_size / sizeof(elfsh_Sym); index++)
{
if (elfsh_get_symbol_link(sym + index) != SHN_COMMON)
{
if (elfsh_get_symbol_type(sym + index) == STT_SECTION)
continue;
sct = elfsh_get_parent_section(symtab->parent,
elfsh_get_symbol_value(sym + index),
&offset);
if (sct == NULL)
{
sct = elfsh_get_section_by_index(symtab->parent,
elfsh_get_symbol_link(sym + index),
NULL,
NULL);
if (sct && elfsh_get_section_type(sct->shdr) == SHT_NOBITS)
{
#if __DEBUG_MAP__
printf(" [*] Symbol [%s] sctndx changed from %u to SHN_COMMON\n",
elfsh_get_symbol_name(symtab->parent, sym + index),
elfsh_get_symbol_link(sym + index));
#endif
elfsh_set_symbol_link(sym + index, SHN_COMMON);
continue;
}
}
if (sct && elfsh_get_section_type(sct->shdr) == SHT_NOBITS)
{
elfsh_set_symbol_link(sym + index, SHN_COMMON);
#if __DEBUG_MAP__
printf(" [*] Symbol [%s] sctndx changed to SHN_COMMON\n",
elfsh_get_symbol_name(symtab->parent, sym + index));
#endif
}
}
}
PROFILER_ROUT(__FILE__, __FUNCTION__, __LINE__, symtab);
}
/**
* Relocate the just injected section
* @param enew
* @param reltab
* @param stage
* @return
*/
static int elfsh_relocate_etrel_section(elfshsect_t *enew,
elfshsect_t *reltab,
u_char stage)
{
elfsh_Rel *cur;
volatile u_int index;
elfsh_Sym *sym;
volatile u_int size;
eresi_Addr *dword;
eresi_Addr addr;
char *name;
char tmpname[BUFSIZ];
elfshsect_t *sect;
u_int entsz;
elfshsect_t *plt;
void *data;
elfsh_Half symtype;
PROFILER_IN(__FILE__, __FUNCTION__, __LINE__);
/* ET_REL object is not mapped we use unconditionaly
the ondisk relocation tables for such operation */
data = reltab->data;
#if __DEBUG_RELADD__
fprintf(stderr, "[DEBUG_RELADD] Using reloc table from %s [%s] data at %p \n",
reltab->parent->name, reltab->name, data);
#endif
/* Loop on the relocation table entries */
size = (reltab->shdr->sh_type == SHT_RELA ?
sizeof(elfsh_Rela) : sizeof(elfsh_Rel));
size = reltab->shdr->sh_size / size;
plt = elfsh_get_plt(enew->parent, NULL);
if (NULL == plt && elfsh_dynamic_file(enew->parent))
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Unable to get plt", -1);
entsz = elfsh_get_pltentsz(enew->parent);
if (entsz < 0)
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Unable to get pltentsz", -1);
for (index = 0; index < size; index++)
{
#if __DEBUG_RELADD__
fprintf(stderr, "[DEBUG_RELADD] relocation loop stage %u for section %s index %u \n",
stage, enew->name, index);
#endif
/* We try a enew relocation now that the ET_REL dependence is mapped */
retry:
/* Get symbol value in ET_REL */
cur = (reltab->shdr->sh_type == SHT_RELA ?
(void *) (((elfsh_Rela *) data) + index) :
(void *) (((elfsh_Rel *) data) + index));
sym = elfsh_get_symbol_from_reloc(reltab->parent, cur);
name = elfsh_get_symname_from_reloc(reltab->parent, cur);
if (sym == NULL || name == NULL)
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Unable to find symbol in ET_REL", -1);
/* Grab a pointer on the dword that need to be relocated */
dword = (eresi_Addr *) ((char *) elfsh_readmem(enew) + cur->r_offset);
/*
** If symbol type is NOTYPE, we use ET_EXEC symtab, else if
** symbol link is COMMON, we use ET_REL symbol inserted in ET_EXEC
** during BSS sizescan in bss.c:elfsh_find_bsslen()
*/
symtype = elfsh_get_symbol_type(sym);
if (elfsh_get_symbol_bind(sym) != STB_LOCAL && /* patch BEOS */
(symtype == STT_NOTYPE || elfsh_get_symbol_link(sym) == SHN_COMMON))
{
if (stage == ELFSH_RELOC_STAGE2 && !strstr(name, "old_"))
continue;
/* If the symbol is not found and we are still in
the first stage relocation, just pass it */
sym = elfsh_get_metasym_by_name(enew->parent, name);
if (!sym)
{
switch (elfsh_find_relocsym(enew, reltab, &sym, name, stage, symtype))
{
case 2:
#if __DEBUG_STATIC__
fprintf(stderr, "[DEBUG_STATIC] RETRY\n");
#endif
goto retry;
break;
case 0:
continue;
case 1:
break;
case -1:
default:
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Unable to satisfy symbol in ET_REL", -1);
}
}
addr = sym->st_value;
#if __DEBUG_RELADD__
fprintf(stderr, "[DEBUG_RELADD] Relocate using existing symbol %-20s " AFMT "]\n",
name, (eresi_Addr) addr);
#endif
}
/* Compute addr giving the injected section's vaddr in ET_EXEC */
else
{
/* All the following relocs are computed in stage 1 */
if (stage == ELFSH_RELOC_STAGE2)
continue;
/* Find target section in ET_REL */
sect = elfsh_get_section_by_index(reltab->parent, sym->st_shndx,
NULL, NULL);
if (sect == NULL)
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Cant find extracted section in ET_REL", -1);
#if __DEBUG_RELADD__
fprintf(stderr, "[DEBUG_RELADD] Found -%s- section (idx = %u), now looking at "
"injected base address\n", sect->name, sect->index);
#endif
/* Find corresponding inserted section in ET_EXEC */
snprintf(tmpname, sizeof(tmpname), "%s%s", reltab->parent->name, sect->name);
sect = elfsh_get_section_by_name(enew->parent, tmpname, NULL, NULL, NULL);
if (sect == NULL)
{
#if __DEBUG_RELADD__
elfsh_print_sectlist(reltab->parent, "HEH");
fprintf(stderr, "[DEBUG_RELADD] Did not found %s section (sym = %s) \n",
tmpname, name);
#endif
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Cant find inserted section in ET_EXEC", -1);
}
/* Compute pointer value */
addr = sect->shdr->sh_addr;
addr += ((elfsh_get_symbol_type(sym) == STT_SECTION &&
!FILE_IS_SPARC(sect->parent) &&
!FILE_IS_ALPHA64(sect->parent) &&
!FILE_IS_MIPS(sect->parent)) ?
*dword : sym->st_value);
#if __DEBUG_RELADD__
fprintf(stderr, "[DEBUG_RELADD] Relocate using section %-20s base [-> " AFMT "] \n",
sect->name, (eresi_Addr) addr);
#endif
}
/* Perform relocation */
if (elfsh_relocate_entry(enew, cur, dword, addr, reltab) < 0)
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Unable to relocate entry", -1);
}
PROFILER_ROUT(__FILE__, __FUNCTION__, __LINE__, 0);
}
/**
* Print the chosen symbol table
* @param file
* @param sect
* @param tab
* @param num
* @param regx
* @param get_symname
* @return
*/
int ds(elfshobj_t *file,
elfshsect_t *sect,
u_int num,
regex_t *regx,
char *(*get_symname)(elfshobj_t *f, elfsh_Sym *s))
{
elfsh_Sym *table;
char *name;
char *type;
char *bind;
u_int typenum;
u_int bindnum;
u_int foff;
u_int index;
char *sect_name;
char buff[512];
char off[50];
char type_unk[ERESI_MEANING + 1];
char bind_unk[ERESI_MEANING + 1];
PROFILER_IN(__FILE__, __FUNCTION__, __LINE__);
/* Sort the table if necessary */
if (world.state.sort != NULL)
switch (*world.state.sort)
{
case ELFSH_SORT_BY_ADDR:
table = sect->altdata;
break;
case ELFSH_SORT_BY_SIZE:
table = sect->terdata;
break;
default:
PROFILER_ERR(__FILE__, __FUNCTION__, __LINE__,
"Unknown sort mode", -1);
}
/* Avoid reading inexistant memory in the process for .symtab */
else
table = (elfsh_Sym *) (sect->shdr->sh_addr ? elfsh_readmem(sect) : sect->data);
/* Browse symtab */
for (index = 0; index < num; index++)
{
/* Retreive names */
typenum = elfsh_get_symbol_type(table + index);
bindnum = elfsh_get_symbol_bind(table + index);
type = (char *) (typenum > ELFSH_SYMTYPE_MAX ?
revm_build_unknown(type_unk, "type", typenum) :
elfsh_sym_type[typenum].desc);
bind = (char *) (bindnum >= ELFSH_SYMBIND_MAX ?
revm_build_unknown(bind_unk, "type", bindnum) :
elfsh_sym_bind[bindnum].desc);
name = get_symname(world.curjob->curfile, table + index);
sect_name = NULL;
sect = elfsh_get_parent_section(world.curjob->curfile,
table[index].st_value,
NULL);
if (sect == NULL && table[index].st_shndx)
sect = elfsh_get_section_by_index(world.curjob->curfile,
table[index].st_shndx,
NULL, NULL);
if (sect != NULL)
sect_name = elfsh_get_section_name(world.curjob->curfile, sect);
/* Fixup names */
if (name == NULL || *name == 0)
name = ELFSH_NULL_STRING;
if (type == NULL || *type == 0)
type = ELFSH_NULL_STRING;
if (bind == NULL || *bind == 0)
bind = ELFSH_NULL_STRING;
if (sect_name == NULL)
sect_name = ELFSH_NULL_STRING;
foff = (!table[index].st_value ? 0 :
elfsh_get_foffset_from_vaddr(world.curjob->curfile,
table[index].st_value));
if (sect && sect->shdr->sh_addr != table[index].st_value)
snprintf(off, sizeof(off), " + %s",
revm_colornumber("%u", (u_int) (table[index].st_value - sect->shdr->sh_addr)));
else
*off = '\0';
/* Different output depending on the quiet flag */
if (!world.state.revm_quiet)
{
snprintf(buff, sizeof(buff),
" %s %s %s %s %s%s "
"%s%s %s%s %s%s => %s%s\n",
revm_colornumber("[%03u]", index),
revm_coloraddress(XFMT, (eresi_Addr) elfsh_get_symbol_value(table + index) + file->rhdr.base),
revm_colortypestr_fmt("%-8s", type),
revm_colorstr_fmt("%-40s", name),
revm_colorfieldstr("size:"),
revm_colornumber("%010u", elfsh_get_symbol_size(table + index)),
revm_colorfieldstr("foffset:"),
revm_colornumber("%06u", foff),
revm_colorfieldstr("scope:"),
revm_colortypestr_fmt("%-6s", bind),
revm_colorfieldstr("sctndx:"),
revm_colornumber("%02u", elfsh_get_symbol_link(table + index)),
revm_colorstr(sect_name), off);
}
else
{
snprintf(buff, sizeof(buff),
" %s %s %s %s %s%s %s%s %s%-6s\n",
revm_colornumber("[%03u]", index),
revm_coloraddress(XFMT, (eresi_Addr) elfsh_get_symbol_value(table + index) + file->rhdr.base),
revm_colortypestr_fmt("%-8s", type), revm_colorstr_fmt("%-15s", name),
revm_colorfieldstr("sz:"),
revm_colornumber("%06u", elfsh_get_symbol_size(table + index)),
revm_colorfieldstr("foff:"),
revm_colornumber("%06u", foff),
revm_colorfieldstr("scop:"),
revm_colortypestr_fmt("%-6s", bind));
}
if (regx == NULL ||
(regx != NULL && regexec(regx, buff, 0, 0, 0) == 0))
{
/* If the user ask quit, we just break */
if (revm_output(buff) == -1)
break;
}
revm_endline();
}
revm_endline();
revm_output("\n");
PROFILER_ROUT(__FILE__, __FUNCTION__, __LINE__, 0);
}
