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/*****************************************************************************/
/* pemagination: a (virtual) tour into portable bits and executable bytes */
/* Copyright (C) 2013,2014,2015 Z. Gilboa */
/* Released under GPLv2 and GPLv3; see COPYING.PEMAGINE. */
/*****************************************************************************/
#include <psxtypes/psxtypes.h>
#include <pemagine/pe_consts.h>
#include <pemagine/pe_structs.h>
#include <pemagine/pemagine.h>
#include "pe_impl.h"
static __inline__ int pe_addr_within_bounds(void * addr, void * bottom, void * top)
{
return (((uintptr_t)addr >= (uintptr_t)bottom) && ((uintptr_t)addr < (uintptr_t)top));
}
pe_api
int pe_get_export_symbol_info(
const void * base,
const char * name,
struct pe_export_sym * sym)
{
struct pe_export_hdr * exp_hdr;
ssize_t len;
uint32_t * rva_offset;
uintptr_t * addr_offset;
uint32_t sec_size;
void * sec_addr_cap;
uint32_t * fn_addr;
uint32_t * fn_names;
uint16_t * fn_ordinals;
uint32_t * addr_entries;
uint32_t * name_entries;
char * exp_name;
const char * src;
const char * dst;
size_t match;
uint32_t lower;
uint32_t upper;
uint32_t idx;
/* initialize pe_exp_item */
sym->ordinal_base = (uint32_t *)0;
sym->ordinal = (uint16_t *)0;
sym->addr = (void *)0;
sym->forwarder_rva = (void *)0;
sym->name = (char *)0;
sym->status = 0;
if (!(exp_hdr = pe_get_image_export_hdr_addr(base,&sec_size)))
return -1;
sec_addr_cap = pe_va_from_rva(exp_hdr,sec_size);
rva_offset = (uint32_t *)(exp_hdr->export_addr_tbl_rva);
fn_addr = (uint32_t *)pe_va_from_rva(base,*rva_offset);
rva_offset = (uint32_t *)(exp_hdr->name_ptr_rva);
fn_names = (uint32_t *)pe_va_from_rva(base,*rva_offset);
rva_offset = (uint32_t *)(exp_hdr->ordinal_tbl_rva);
fn_ordinals = (uint16_t *)pe_va_from_rva(base,*rva_offset);
addr_entries = (uint32_t *)exp_hdr->addr_tbl_entries;
name_entries = (uint32_t *)exp_hdr->num_of_name_ptrs;
/* by ordinal? */
if ((intptr_t)name < 0x10000) {
sym->ordinal_base = (uint32_t *)exp_hdr->ordinal_base;
/* the array is zero-based, but ordinals are normally one-based... */
if (((intptr_t)name - *sym->ordinal_base + 1) > *addr_entries)
return -1;
rva_offset = (uint32_t *)pe_va_from_rva(fn_addr,((uintptr_t)name-*sym->ordinal_base)*sizeof(uint32_t));
addr_offset = (uintptr_t *)pe_va_from_rva(base,*rva_offset);
if (pe_addr_within_bounds(addr_offset,exp_hdr,sec_addr_cap)) {
sym->forwarder_rva = 0;
sym->addr = addr_offset;
} else
/* todo: resolve forwarder address */
sym->addr = addr_offset;
return 0;
}
if ((len = pe_impl_strlen_ansi(name)) < 0)
return -1;
len++;
lower = 0;
upper = *name_entries;
while (lower < upper) {
idx = (lower + upper) / 2;
rva_offset = (uint32_t *)pe_va_from_rva(fn_names,idx*sizeof(uint32_t));
exp_name = (char *)pe_va_from_rva(base,*rva_offset);
src = name;
dst = exp_name;
for (match=0; (match<len) && (*src==*dst); match++) {
src++;
dst++;
}
if (match == len) {
sym->ordinal_base = (uint32_t *)exp_hdr->ordinal_base;
sym->ordinal = (uint16_t *)pe_va_from_rva(fn_ordinals,idx*sizeof(uint16_t));
rva_offset = (uint32_t *)pe_va_from_rva(fn_addr,(*sym->ordinal)*sizeof(uint32_t));
addr_offset = (uintptr_t *)pe_va_from_rva(base,*rva_offset);
if (pe_addr_within_bounds(addr_offset,exp_hdr,sec_addr_cap)) {
/* todo: resolve forwarder address */
sym->forwarder_rva = 0;
sym->addr = 0;
} else {
sym->forwarder_rva = 0;
sym->addr = addr_offset;
}
return 0;
}
else {
if (*src > *dst)
lower = idx + 1;
else
upper = idx;
}
}
/* export name not found */
return -1;
}
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