initial commit.

1 files changed, 142 insertions, 0 deletions

diff --git a/src/exports/pe_get_export_symbol_info.c b/src/exports/pe_get_export_symbol_info.c
new file mode 100644
index 0000000..9f00634
--- /dev/null
+++ b/src/exports/pe_get_export_symbol_info.c
@@ -0,0 +1,142 @@
+/*****************************************************************************/
+/*  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;
+
+	size_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;
+}