object generation: added mdso_objgen_symentry().

1 files changed, 257 insertions, 0 deletions

diff --git a/src/object/mdso_objgen_symentry.c b/src/object/mdso_objgen_symentry.c
new file mode 100644
index 0000000..9dd22be
--- /dev/null
+++ b/src/object/mdso_objgen_symentry.c
@@ -0,0 +1,257 @@
+/****************************************************************/
+/*  mdso: midipix dso scavenger                                 */
+/*  Copyright (C) 2015--2017  Z. Gilboa                         */
+/*  Released under GPLv2 and GPLv3; see COPYING.MDSO.           */
+/****************************************************************/
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <mdso/mdso.h>
+#include "mdso_object_impl.h"
+#include "mdso_errinfo_impl.h"
+#include "perk_consts.h"
+#include "perk_structs.h"
+
+struct mdso_symfn_references {
+	unsigned char 	refs[16];
+};
+
+struct mdso_symentry_object {
+	struct pe_raw_coff_object_hdr	hdr;
+	struct pe_raw_sec_hdr		sec[2];
+	struct mdso_symfn_references	ref[1];
+	struct pe_raw_coff_reloc	rel[2];
+	struct pe_raw_coff_symbol	sym[9];
+	struct pe_raw_coff_strtbl	cst;
+};
+
+int mdso_objgen_symentry(
+	const struct mdso_driver_ctx *	dctx,
+	const char *			sym,
+	FILE *				fout,
+	struct mdso_object *		vobj)
+{
+	struct mdso_symentry_object *	syment;
+	struct pe_raw_coff_symbol *	symrec;
+	unsigned char *			mark;
+	struct pe_aux_rec_section *	aux;
+	size_t				buflen;
+	size_t				liblen;
+	uint32_t			symlen;
+	uint32_t			cstlen;
+	uint32_t			objlen;
+	uint32_t			aattr;
+	uint32_t			sattr;
+	uint32_t			rattr;
+	uint16_t			oattr;
+	uint16_t			machine;
+	uint16_t			reltype;
+	uint32_t			relrva;
+	uint32_t			refoff;
+	uint32_t			reloff;
+	uint32_t			symoff;
+	uint32_t			cstoff;
+	uint32_t			datoff;
+	uint32_t			stroff;
+
+	if ((buflen = strlen(sym)) > 1024*1024)
+		return MDSO_CUSTOM_ERROR(dctx,MDSO_ERR_INVALID_DATA);
+
+	if ((liblen = strlen(dctx->cctx->libname)) > 1024*1024)
+		return MDSO_CUSTOM_ERROR(dctx,MDSO_ERR_INVALID_DATA);
+
+	symlen = (uint32_t)buflen;
+	cstlen = (uint32_t)liblen + (3 * symlen) + 64;
+	objlen = sizeof(*syment) + cstlen;
+
+	if (vobj && vobj->addr && (vobj->size < objlen))
+		return MDSO_BUFFER_ERROR(dctx);
+
+	if (vobj && !vobj->addr) {
+		vobj->size = objlen;
+		return 0;
+	}
+
+	if (vobj)
+		syment = (struct mdso_symentry_object *)vobj->addr;
+
+	else if (!(syment = calloc(1,objlen)))
+		return MDSO_SYSTEM_ERROR(dctx);
+
+	if (dctx->cctx->drvflags & MDSO_DRIVER_QUAD_PTR) {
+		aattr   = PE_IMAGE_SCN_ALIGN_16BYTES;
+		machine = PE_IMAGE_FILE_MACHINE_AMD64;
+		reltype = PE_IMAGE_REL_AMD64_ADDR64;
+		relrva  = 8;
+	} else {
+		aattr   = PE_IMAGE_SCN_ALIGN_4BYTES;
+		machine = PE_IMAGE_FILE_MACHINE_I386;
+		reltype = PE_IMAGE_REL_I386_DIR32;
+		relrva  = 4;
+	}
+
+	sattr  = PE_IMAGE_SCN_ALIGN_1BYTES;
+	sattr |= PE_IMAGE_SCN_MEM_READ;
+	sattr |= PE_IMAGE_SCN_CNT_INITIALIZED_DATA;
+
+	rattr  = aattr;
+	rattr |= PE_IMAGE_SCN_MEM_READ;
+	rattr |= PE_IMAGE_SCN_CNT_INITIALIZED_DATA;
+
+	oattr  = PE_IMAGE_FILE_LINE_NUMS_STRIPPED;
+	refoff = offsetof(struct mdso_symentry_object,ref);
+	reloff = offsetof(struct mdso_symentry_object,rel);
+	symoff = offsetof(struct mdso_symentry_object,sym);
+	cstoff = offsetof(struct pe_raw_coff_strtbl,cst_data);
+	datoff = 0;
+
+	stroff  = objlen - symlen - 16;
+	stroff += 0xf;
+	stroff |= 0xf;
+	stroff ^= 0xf;
+
+	/* coff object header */
+	mdso_obj_write_short(syment->hdr.cfh_machine,machine);
+	mdso_obj_write_short(syment->hdr.cfh_num_of_sections,2);
+	mdso_obj_write_long(syment->hdr.cfh_ptr_to_sym_tbl,symoff);
+	mdso_obj_write_long(syment->hdr.cfh_num_of_syms,9);
+	mdso_obj_write_short(syment->hdr.cfh_characteristics,oattr);
+
+	/* .dsostrs section header */
+	memcpy(syment->sec[0].sh_name,".dsostrs",8);
+	mdso_obj_write_long(syment->sec[0].sh_size_of_raw_data,symlen+1);
+	mdso_obj_write_long(syment->sec[0].sh_ptr_to_raw_data,stroff);
+	mdso_obj_write_long(syment->sec[0].sh_characteristics,sattr);
+
+	/* .dsosyms section header */
+	memcpy(syment->sec[1].sh_name,".dsosyms",8);
+	mdso_obj_write_long(syment->sec[1].sh_size_of_raw_data,2*relrva);
+	mdso_obj_write_long(syment->sec[1].sh_ptr_to_raw_data,refoff);
+	mdso_obj_write_long(syment->sec[1].sh_ptr_to_relocs,reloff);
+	mdso_obj_write_short(syment->sec[1].sh_num_of_relocs,2);
+	mdso_obj_write_long(syment->sec[1].sh_characteristics,rattr);
+
+	/* .dsosyms relocation record: .symstr */
+	mdso_obj_write_long(syment->rel[0].rel_sym,6);
+	mdso_obj_write_long(syment->rel[0].rel_rva,0);
+	mdso_obj_write_short(syment->rel[0].rel_type,reltype);
+
+	/* .dsosyms relocation record: .dsometa_libname */
+	mdso_obj_write_long(syment->rel[1].rel_sym,8);
+	mdso_obj_write_long(syment->rel[1].rel_rva,relrva);
+	mdso_obj_write_short(syment->rel[1].rel_type,reltype);
+
+	/* coff string table */
+	mdso_obj_write_long(syment->cst.cst_size,cstlen);
+
+	/* coff symbol table */
+	symrec = syment->sym;
+	mark   = syment->cst.cst_data;
+
+	/* coff symbol: .file */
+	symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_FILE;
+	symrec[0].cs_num_of_aux_symbols[0] = 1;
+
+	mdso_obj_write_short(&symrec[0].cs_section_number[0],PE_IMAGE_SYM_DEBUG);
+	mdso_obj_write_long(&symrec[1].cs_name[4],cstoff+datoff);
+
+	memcpy(symrec[0].cs_name,".file",5);
+	memcpy(&mark[0],"__",2);
+	memcpy(&mark[2],sym,symlen);
+	memcpy(&mark[2+symlen],"_sym_entry.s",12);
+
+	datoff += 15 + symlen;
+	mark   += 15 + symlen;
+	symrec += 2;
+
+	/* coff symbol: .dsostrs */
+	symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_STATIC;
+	symrec[0].cs_num_of_aux_symbols[0] = 1;
+
+	mdso_obj_write_short(symrec[0].cs_section_number,1);
+	memcpy(symrec[0].cs_name,".dsostrs",8);
+
+	aux = (struct pe_aux_rec_section *)&symrec[1];
+	mdso_obj_write_long(aux->aux_size,symlen+1);
+	mdso_obj_write_short(aux->aux_num_of_relocs,0);
+
+	datoff += 0;
+	mark   += 0;
+	symrec += 2;
+
+	/* coff symbol: .dsosyms */
+	symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_STATIC;
+	symrec[0].cs_num_of_aux_symbols[0] = 1;
+
+	mdso_obj_write_short(symrec[0].cs_section_number,2);
+	memcpy(symrec[0].cs_name,".dsosyms",8);
+
+	aux = (struct pe_aux_rec_section *)&symrec[1];
+	mdso_obj_write_long(aux->aux_size,2*relrva);
+	mdso_obj_write_short(aux->aux_num_of_relocs,2);
+
+	datoff += 0;
+	mark   += 0;
+	symrec += 2;
+
+	/* coff symbol: .symstr */
+	symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_STATIC;
+	symrec[0].cs_num_of_aux_symbols[0] = 0;
+
+	mdso_obj_write_short(symrec[0].cs_section_number,1);
+	memcpy(symrec[0].cs_name,".symstr",7);
+
+	datoff += 0;
+	mark   += 0;
+	symrec += 1;
+
+	/* coff symbol: __imp_sym */
+	symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_EXTERNAL;
+	symrec[0].cs_num_of_aux_symbols[0] = 0;
+
+	mdso_obj_write_short(symrec[0].cs_section_number,2);
+	mdso_obj_write_long(&symrec[0].cs_name[4],cstoff+datoff);
+
+	if (dctx->cctx->drvflags & MDSO_DRIVER_QUAD_PTR) {
+		memcpy(&mark[0],"__imp_",6);
+		memcpy(&mark[6],sym,symlen);
+	} else {
+		memcpy(&mark[0],"__imp_",6);
+		memcpy(&mark[7],sym,symlen);
+		mark[6] = '_';
+		datoff++;
+		mark++;
+	}
+
+	datoff += 7 + symlen;
+	mark   += 7 + symlen;
+	symrec += 1;
+
+	/* coff symbol: .dsometa_libname */
+	symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_EXTERNAL;
+	symrec[0].cs_num_of_aux_symbols[0] = 0;
+
+	mdso_obj_write_short(symrec[0].cs_section_number,0);
+	mdso_obj_write_long(&symrec[0].cs_name[4],cstoff+datoff);
+
+	memcpy(&mark[0],".dsometa_",9);
+	memcpy(&mark[9],dctx->cctx->libname,liblen);
+
+	/* .symstr */
+	mark = syment->hdr.cfh_machine;
+	memcpy(&mark[stroff],sym,symlen);
+
+	/* tada */
+	if (fout)
+		if (fwrite(syment,objlen,1,fout) == 0)
+			return MDSO_FILE_ERROR(dctx);
+
+	if (!vobj)
+		free(syment);
+
+	return 0;
+}