/*
* Load, and verify ClamAV bytecode.
*
* Copyright (C) 2009-2010 Sourcefire, Inc.
*
* Authors: Török Edvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <assert.h>
#include "dconf.h"
#include "clamav.h"
#include "others.h"
#include "pe.h"
#include "bytecode.h"
#include "bytecode_priv.h"
#include "readdb.h"
#include "scanners.h"
#include <string.h>
/* TODO: we should make sure lsigcnt is never NULL, and has at least as many
* elements as the bytecode needs */
static const uint32_t nomatch[64];
struct cli_bc_ctx *cli_bytecode_context_alloc(void)
{
struct cli_bc_ctx *ctx = cli_malloc(sizeof(*ctx));
ctx->bc = NULL;
ctx->func = NULL;
ctx->values = NULL;
ctx->operands = NULL;
ctx->opsizes = NULL;
ctx->fmap = NULL;
ctx->off = 0;
ctx->ctx = NULL;
ctx->hooks.match_counts = nomatch;
/* TODO: init all hooks with safe values */
ctx->virname = NULL;
ctx->outfd = -1;
ctx->tempfile = NULL;
ctx->written = 0;
ctx->trace_level = trace_none;
ctx->trace = NULL;
ctx->trace_op = NULL;
ctx->trace_val = NULL;
ctx->trace_ptr = NULL;
ctx->scope = NULL;
ctx->scopeid = 0;
ctx->file = "??";
ctx->directory = "";
ctx->line = 0;
ctx->col = 0;
ctx->mpool = NULL;
ctx->numGlobals = 0;
ctx->globals = NULL;
return ctx;
}
void cli_bytecode_context_destroy(struct cli_bc_ctx *ctx)
{
cli_bytecode_context_clear(ctx);
free(ctx);
}
int cli_bytecode_context_getresult_file(struct cli_bc_ctx *ctx, char **tempfilename)
{
int fd;
*tempfilename = ctx->tempfile;
fd = ctx->outfd;
ctx->tempfile = NULL;
ctx->outfd = -1;
return fd;
}
/* resets bytecode state, so you can run another bytecode with same ctx */
static int cli_bytecode_context_reset(struct cli_bc_ctx *ctx)
{
free(ctx->opsizes);
free(ctx->values);
free(ctx->operands);
ctx->operands = NULL;
ctx->values = NULL;
ctx->opsizes = NULL;
ctx->written = 0;
if (ctx->outfd != -1) {
cli_dbgmsg("Bytecode: nobody cared about FD %d, %s\n", ctx->outfd,
ctx->tempfile);
if (ftruncate(ctx->outfd, 0) == -1)
cli_dbgmsg("ftruncate failed\n");
close(ctx->outfd);
cli_unlink(ctx->tempfile);
free(ctx->tempfile);
ctx->tempfile = NULL;
ctx->outfd = -1;
}
#if USE_MPOOL
if (ctx->mpool) {
mpool_destroy(ctx->mpool);
ctx->mpool = NULL;
}
#else
/*TODO: implement for no-mmap case too*/
#endif
return CL_SUCCESS;
}
int cli_bytecode_context_clear(struct cli_bc_ctx *ctx)
{
cli_bytecode_context_reset(ctx);
memset(ctx, 0, sizeof(*ctx));
return CL_SUCCESS;
}
static unsigned typesize(const struct cli_bc *bc, uint16_t type)
{
type &= 0x7fff;
if (!type)
return 0;
if (type <= 8)
return 1;
if (type <= 16)
return 2;
if (type <= 32)
return 4;
if (type <= 64)
return 8;
return bc->types[type-65].size;
}
static unsigned typealign(const struct cli_bc *bc, uint16_t type)
{
type &= 0x7fff;
if (type <= 64) {
unsigned size = typesize(bc, type);
return size ? size : 1;
}
return bc->types[type-65].align;
}
int cli_bytecode_context_setfuncid(struct cli_bc_ctx *ctx, const struct cli_bc *bc, unsigned funcid)
{
unsigned i, s=0;
const struct cli_bc_func *func;
if (funcid >= bc->num_func) {
cli_errmsg("bytecode: function ID doesn't exist: %u\n", funcid);
return CL_EARG;
}
func = ctx->func = &bc->funcs[funcid];
ctx->bc = bc;
ctx->numParams = func->numArgs;
ctx->funcid = funcid;
if (func->numArgs) {
ctx->operands = cli_malloc(sizeof(*ctx->operands)*func->numArgs);
if (!ctx->operands) {
cli_errmsg("bytecode: error allocating memory for parameters\n");
return CL_EMEM;
}
ctx->opsizes = cli_malloc(sizeof(*ctx->opsizes)*func->numArgs);
for (i=0;i<func->numArgs;i++) {
unsigned al = typealign(bc, func->types[i]);
s = (s+al-1)&~(al-1);
ctx->operands[i] = s;
s += ctx->opsizes[i] = typesize(bc, func->types[i]);
}
}
s += 8;/* return value */
ctx->bytes = s;
ctx->values = cli_malloc(s);
if (!ctx->values) {
cli_errmsg("bytecode: error allocating memory for parameters\n");
return CL_EMEM;
}
return CL_SUCCESS;
}
static inline int type_isint(uint16_t type)
{
return type > 0 && type <= 64;
}
int cli_bytecode_context_setparam_int(struct cli_bc_ctx *ctx, unsigned i, uint64_t c)
{
if (i >= ctx->numParams) {
cli_errmsg("bytecode: param index out of bounds: %u\n", i);
return CL_EARG;
}
if (!type_isint(ctx->func->types[i])) {
cli_errmsg("bytecode: parameter type mismatch\n");
return CL_EARG;
}
switch (ctx->opsizes[i]) {
case 1:
ctx->values[ctx->operands[i]] = c;
break;
case 2:
*(uint16_t*)&ctx->values[ctx->operands[i]] = c;
break;
case 4:
*(uint32_t*)&ctx->values[ctx->operands[i]] = c;
break;
case 8:
*(uint64_t*)&ctx->values[ctx->operands[i]] = c;
break;
}
return CL_SUCCESS;
}
int cli_bytecode_context_setparam_ptr(struct cli_bc_ctx *ctx, unsigned i, void *data, unsigned datalen)
{
cli_errmsg("Pointer parameters are not implemented yet!\n");
return CL_EARG;
}
static inline uint64_t readNumber(const unsigned char *p, unsigned *off, unsigned len, char *ok)
{
uint64_t n=0;
unsigned i, newoff, lim, p0 = p[*off], shift=0;
lim = p0 - 0x60;
if (lim > 0x10) {
cli_errmsg("Invalid number type: %c\n", p0);
*ok = 0;
return 0;
}
newoff = *off +lim+1;
if (newoff > len) {
cli_errmsg("End of line encountered while reading number\n");
*ok = 0;
return 0;
}
if (p0 == 0x60) {
*off = newoff;
return 0;
}
for (i=*off+1;i < newoff; i++) {
uint64_t v = p[i];
if (UNLIKELY((v&0xf0) != 0x60)) {
cli_errmsg("Invalid number part: %c\n", (char)v);
*ok = 0;
return 0;
}
v &= 0xf;
v <<= shift;
n |= v;
shift += 4;
}
*off = newoff;
return n;
}
static inline funcid_t readFuncID(struct cli_bc *bc, unsigned char *p,
unsigned *off, unsigned len, char *ok)
{
funcid_t id = readNumber(p, off, len, ok)-1;
if (*ok && id >= bc->num_func) {
cli_errmsg("Called function out of range: %u >= %u\n", id, bc->num_func);
*ok = 0;
return ~0;
}
return id;
}
static inline funcid_t readAPIFuncID(struct cli_bc *bc, unsigned char *p,
unsigned *off, unsigned len, char *ok)
{
funcid_t id = readNumber(p, off, len, ok)-1;
if (*ok && !cli_bitset_test(bc->uses_apis, id)) {
cli_errmsg("Called undeclared API function: %u\n", id);
*ok = 0;
return ~0;
}
return id;
}
static inline unsigned readFixedNumber(const unsigned char *p, unsigned *off,
unsigned len, char *ok, unsigned width)
{
unsigned i, n=0, shift=0;
unsigned newoff = *off + width;
if (newoff > len) {
cli_errmsg("Newline encountered while reading number\n");
*ok = 0;
return 0;
}
for (i=*off;i<newoff;i++) {
unsigned v = p[i];
if (UNLIKELY((v&0xf0) != 0x60)) {
cli_errmsg("Invalid number part: %c\n", v);
*ok = 0;
return 0;
}
v &= 0xf;
v <<= shift;
n |= v;
shift += 4;
}
*off = newoff;
return n;
}
static inline operand_t readOperand(struct cli_bc_func *func, unsigned char *p,
unsigned *off, unsigned len, char *ok)
{
uint64_t v;
if ((p[*off]&0xf0) == 0x40 || p[*off] == 0x50) {
uint64_t *dest;
uint16_t ty;
p[*off] |= 0x20;
/* TODO: unique constants */
func->constants = cli_realloc2(func->constants, (func->numConstants+1)*sizeof(*func->constants));
if (!func->constants) {
*ok = 0;
return MAX_OP;
}
v = readNumber(p, off, len, ok);
dest = &func->constants[func->numConstants];
/* Write the constant to the correct place according to its type.
* This is needed on big-endian machines, because constants are always
* read as u64, but accesed as one of these types: u8, u16, u32, u64 */
*dest= 0;
ty = 8*readFixedNumber(p, off, len, ok, 1);
if (!ty) {
/* This is a global variable */
return 0x80000000 | v;
}
if (ty <= 8)
*(uint8_t*)dest = v;
else if (ty <= 16)
*(uint16_t*)dest = v;
else if (ty <= 32)
*(uint32_t*)dest = v;
else
*dest = v;
return func->numValues + func->numConstants++;
}
v = readNumber(p, off, len, ok);
if (!*ok)
return MAX_OP;
if (v >= func->numValues) {
cli_errmsg("Operand index exceeds bounds: %u >= %u!\n", (unsigned)v, (unsigned)func->numValues);
*ok = 0;
return MAX_OP;
}
return v;
}
static inline unsigned char *readData(const unsigned char *p, unsigned *off, unsigned len, char *ok, unsigned *datalen)
{
unsigned char *dat, *q;
unsigned l, newoff, i;
if (p[*off] != '|') {
cli_errmsg("Data start marker missing: %c\n", p[*off]);
*ok = 0;
return NULL;
}
(*off)++;
l = readNumber(p, off, len, ok);
if (!l || !ok) {
*datalen = l;
return NULL;
}
newoff = *off + 2*l;
if (newoff > len) {
cli_errmsg("Line ended while reading data\n");
*ok = 0;
return 0;
}
dat = cli_malloc(l);
if (!dat) {
cli_errmsg("Cannot allocate memory for data\n");
*ok = 0;
return NULL;
}
q = dat;
for (i=*off;i<newoff;i += 2) {
const unsigned char v0 = p[i];
const unsigned char v1 = p[i+1];
if (UNLIKELY((v0&0xf0) != 0x60 || (v1&0xf0) != 0x60)) {
cli_errmsg("Invalid data part: %c%c\n", v0, v1);
*ok = 0;
return 0;
}
*q++ = (v0&0xf) | ((v1&0xf) << 4);
}
*off = newoff;
*datalen = l;
return dat;
}
static inline char *readString(const unsigned char *p, unsigned *off, unsigned len, char *ok)
{
unsigned stringlen;
char *str = (char*)readData(p, off, len, ok, &stringlen);
if (*ok && stringlen && str[stringlen-1] != '\0') {
str[stringlen-1] = '\0';
cli_errmsg("bytecode: string missing \\0 terminator: %s\n", str);
free(str);
*ok = 0;
return NULL;
}
return str;
}
static int parseHeader(struct cli_bc *bc, unsigned char *buffer, unsigned *linelength)
{
uint64_t magic1;
unsigned magic2;
char ok = 1;
unsigned offset, len, flevel;
char *pos;
if (strncmp((const char*)buffer, BC_HEADER, sizeof(BC_HEADER)-1)) {
cli_errmsg("Missing file magic in bytecode");
return CL_EMALFDB;
}
offset = sizeof(BC_HEADER)-1;
len = strlen((const char*)buffer);
flevel = readNumber(buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Unable to parse functionality level in bytecode header\n");
return CL_EMALFDB;
}
if (flevel != BC_FUNC_LEVEL) {
cli_dbgmsg("Skipping bytecode with functionality level: %u (current %u)\n", flevel, BC_FUNC_LEVEL);
return CL_BREAK;
}
/* Optimistic parsing, check for error only at the end.*/
bc->metadata.timestamp = readNumber(buffer, &offset, len, &ok);
bc->metadata.sigmaker = readString(buffer, &offset, len, &ok);
bc->metadata.targetExclude = readNumber(buffer, &offset, len, &ok);
bc->kind = readNumber(buffer, &offset, len, &ok);
bc->metadata.maxStack = readNumber(buffer, &offset, len, &ok);
bc->metadata.maxMem = readNumber(buffer, &offset, len, &ok);
bc->metadata.maxTime = readNumber(buffer, &offset, len, &ok);
bc->metadata.compiler = readString(buffer, &offset, len, &ok);
bc->num_types = readNumber(buffer, &offset, len, &ok);
bc->num_func = readNumber(buffer, &offset, len, &ok);
bc->state = bc_loaded;
bc->uses_apis = NULL;
bc->dbgnodes = NULL;
bc->dbgnode_cnt = 0;
if (!ok) {
cli_errmsg("Invalid bytecode header at %u\n", offset);
return CL_EMALFDB;
}
magic1 = readNumber(buffer, &offset, len, &ok);
magic2 = readFixedNumber(buffer, &offset, len, &ok, 2);
if (!ok || magic1 != 0x53e5493e9f3d1c30ull || magic2 != 42) {
unsigned long m0 = magic1 >> 32;
unsigned long m1 = magic1;
cli_errmsg("Magic numbers don't match: %lx%lx, %u\n", m0, m1, magic2);
return CL_EMALFDB;
}
if (buffer[offset] != ':') {
cli_errmsg("Expected : but found: %c\n", buffer[offset]);
return CL_EMALFDB;
}
offset++;
*linelength = strtol(buffer+offset, &pos, 10);
if (*pos != '\0') {
cli_errmsg("Invalid number: %s\n", buffer+offset);
return CL_EMALFDB;
}
bc->funcs = cli_calloc(bc->num_func, sizeof(*bc->funcs));
if (!bc->funcs) {
cli_errmsg("Out of memory allocating %u functions\n", bc->num_func);
return CL_EMEM;
}
bc->types = cli_calloc(bc->num_types, sizeof(*bc->types));
if (!bc->types) {
cli_errmsg("Out of memory allocating %u types\n", bc->num_types);
return CL_EMEM;
}
return CL_SUCCESS;
}
static int parseLSig(struct cli_bc *bc, unsigned char *buffer)
{
const char *prefix;
char *vnames, *vend = strchr(buffer, ';');
if (vend) {
bc->lsig = cli_strdup(buffer);
*vend++ = '\0';
prefix = buffer;
vnames = strchr(vend, '{');
} else {
/* Not a logical signature, but we still have a virusname */
bc->lsig = NULL;
}
return CL_SUCCESS;
}
static uint16_t readTypeID(struct cli_bc *bc, unsigned char *buffer,
unsigned *offset, unsigned len, char *ok)
{
uint64_t t = readNumber(buffer, offset, len, ok);
if (!ok)
return ~0;
if (t >= bc->num_types + bc->start_tid) {
cli_errmsg("Invalid type id: %llu\n", (unsigned long long)t);
*ok = 0;
return ~0;
}
return t;
}
static void parseType(struct cli_bc *bc, struct cli_bc_type *ty,
unsigned char *buffer, unsigned *off, unsigned len,
char *ok)
{
unsigned j;
ty->numElements = readNumber(buffer, off, len, ok);
if (!ok) {
cli_errmsg("Error parsing type\n");
*ok = 0;
return;
}
ty->containedTypes = cli_malloc(sizeof(*ty->containedTypes)*ty->numElements);
if (!ty->containedTypes) {
cli_errmsg("Out of memory allocating %u types\n", ty->numElements);
*ok = 0;
return;
}
for (j=0;j<ty->numElements;j++) {
ty->containedTypes[j] = readTypeID(bc, buffer, off, len, ok);
}
}
static uint16_t containedTy[] = {8,16,32,64};
#define NUM_STATIC_TYPES 4
static void add_static_types(struct cli_bc *bc)
{
unsigned i;
for (i=0;i<NUM_STATIC_TYPES;i++) {
bc->types[i].kind = DPointerType;
bc->types[i].numElements = 1;
bc->types[i].containedTypes = &containedTy[i];
bc->types[i].size = bc->types[i].align = sizeof(void*);
}
}
static int parseTypes(struct cli_bc *bc, unsigned char *buffer)
{
unsigned i, offset = 1, len = strlen((const char*)buffer);
char ok=1;
if (buffer[0] != 'T') {
cli_errmsg("Invalid function types header: %c\n", buffer[0]);
return CL_EMALFDB;
}
bc->start_tid = readFixedNumber(buffer, &offset, len, &ok, 2);
if (bc->start_tid != BC_START_TID) {
cli_warnmsg("Type start id mismatch: %u != %u\n", bc->start_tid,
BC_START_TID);
return CL_BREAK;
}
add_static_types(bc);
for (i=(BC_START_TID - 65);i<bc->num_types-1;i++) {
struct cli_bc_type *ty = &bc->types[i];
uint8_t t = readFixedNumber(buffer, &offset, len, &ok, 1);
if (!ok) {
cli_errmsg("Error reading type kind\n");
return CL_EMALFDB;
}
switch (t) {
case 1:
ty->kind = DFunctionType;
ty->size = ty->align = sizeof(void*);
parseType(bc, ty, buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Error parsing type %u\n", i);
return CL_EMALFDB;
}
if (!ty->numElements) {
cli_errmsg("Function with no return type? %u\n", i);
return CL_EMALFDB;
}
break;
case 2:
case 3:
ty->kind = (t == 2) ? DPackedStructType : DStructType;
ty->size = ty->align = 0;/* TODO:calculate size/align of structs */
ty->align = 8;
parseType(bc, ty, buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Error parsing type %u\n", i);
return CL_EMALFDB;
}
break;
case 4:
ty->kind = DArrayType;
/* number of elements of array, not subtypes! */
ty->numElements = readNumber(buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Error parsing type %u\n", i);
return CL_EMALFDB;
}
/* fall-through */
case 5:
if (t == 5) {
ty->kind = DPointerType;
ty->numElements = 1;
}
ty->containedTypes = cli_malloc(sizeof(*ty->containedTypes));
if (!ty->containedTypes) {
cli_errmsg("Out of memory allocating containedType\n");
return CL_EMALFDB;
}
ty->containedTypes[0] = readTypeID(bc, buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Error parsing type %u\n", i);
return CL_EMALFDB;
}
if (t == 5) {
ty->size = ty->align = sizeof(void*);
} else {
ty->size = ty->numElements*typesize(bc, ty->containedTypes[0]);
ty->align = typealign(bc, ty->containedTypes[0]);
}
break;
default:
cli_errmsg("Invalid type kind: %u\n", t);
return CL_EMALFDB;
}
}
return CL_SUCCESS;
}
/* checks whether the type described by tid is the same as the one described by
* expectty. */
static int types_equal(const struct cli_bc *bc, uint16_t *apity2ty, uint16_t tid, uint16_t apitid)
{
unsigned i;
const struct cli_bc_type *ty = &bc->types[tid - 65];
const struct cli_bc_type *apity = &cli_apicall_types[apitid];
/* If we've already verified type equality, return.
* Since we need to check equality of recursive types, we assume types are
* equal while checking equality of contained types, unless proven
* otherwise. */
if (apity2ty[apitid] == tid + 1)
return 1;
apity2ty[apitid] = tid+1;
if (ty->kind != apity->kind) {
cli_dbgmsg("bytecode: type kind mismatch: %u != %u\n", ty->kind, apity->kind);
return 0;
}
if (ty->numElements != apity->numElements) {
cli_dbgmsg("bytecode: type numElements mismatch: %u != %u\n", ty->numElements, apity->numElements);
return 0;
}
for (i=0;i<ty->numElements;i++) {
if (apity->containedTypes[i] < BC_START_TID) {
if (ty->containedTypes[i] != apity->containedTypes[i]) {
cli_dbgmsg("bytecode: contained type mismatch: %u != %u\n",
ty->containedTypes[i], apity->containedTypes[i]);
return 0;
}
} else if (!types_equal(bc, apity2ty, ty->containedTypes[i], apity->containedTypes[i] - BC_START_TID))
return 0;
if (ty->kind == DArrayType)
break;/* validated the contained type already */
}
return 1;
}
static int parseApis(struct cli_bc *bc, unsigned char *buffer)
{
unsigned i, offset = 1, len = strlen((const char*)buffer), maxapi, calls;
char ok =1;
uint16_t *apity2ty;/*map of api type to current bytecode type ID */
if (buffer[0] != 'E') {
cli_errmsg("bytecode: Invalid api header: %c\n", buffer[0]);
return CL_EMALFDB;
}
maxapi = readNumber(buffer, &offset, len, &ok);
if (!ok)
return CL_EMALFDB;
if (maxapi > cli_apicall_maxapi) {
cli_dbgmsg("bytecode using API %u, but highest API known to libclamav is %u, skipping\n", maxapi, cli_apicall_maxapi);
return CL_BREAK;
}
calls = readNumber(buffer, &offset, len, &ok);
if (!ok)
return CL_EMALFDB;
if (calls > maxapi) {
cli_errmsg("bytecode: attempting to describe more APIs than max: %u > %u\n", calls, maxapi);
return CL_EMALFDB;
}
bc->uses_apis = cli_bitset_init();
if (!bc->uses_apis) {
cli_errmsg("Out of memory allocating apis bitset\n");
return CL_EMEM;
}
apity2ty = cli_calloc(cli_apicall_maxtypes, sizeof(*cli_apicall_types));
if (!apity2ty) {
cli_errmsg("Out of memory allocating apity2ty\n");
return CL_EMEM;
}
for (i=0;i < calls; i++) {
unsigned id = readNumber(buffer, &offset, len, &ok);
uint16_t tid = readTypeID(bc, buffer, &offset, len, &ok);
char *name = readString(buffer, &offset, len, &ok);
/* validate APIcall prototype */
if (id > maxapi) {
cli_errmsg("bytecode: API id %u out of range, max %u\n", id, maxapi);
ok = 0;
}
/* API ids start from 1 */
id--;
if (ok && name && strcmp(cli_apicalls[id].name, name)) {
cli_errmsg("bytecode: API %u name mismatch: %s expected %s\n", id, name, cli_apicalls[id].name);
ok = 0;
}
if (ok && !types_equal(bc, apity2ty, tid, cli_apicalls[id].type)) {
cli_errmsg("bytecode: API %u prototype doesn't match\n", id);
ok = 0;
}
/* don't need the name anymore */
free(name);
if (!ok)
return CL_EMALFDB;
/* APIcall is valid */
cli_bitset_set(bc->uses_apis, id);
}
free(apity2ty); /* free temporary map */
cli_dbgmsg("bytecode: Parsed %u APIcalls, maxapi %u\n", calls, maxapi);
return CL_SUCCESS;
}
static uint16_t type_components(struct cli_bc *bc, uint16_t id, char *ok)
{
unsigned i, sum=0;
const struct cli_bc_type *ty;
if (id <= 64)
return 1;
ty = &bc->types[id-65];
/* TODO: protect against recursive types */
switch (ty->kind) {
case DFunctionType:
cli_errmsg("bytecode: function type not accepted for constant: %u\n", id);
/* don't accept functions as constant initializers */
*ok = 0;
return 0;
case DPointerType:
return 2;
case DStructType:
case DPackedStructType:
for (i=0;i<ty->numElements;i++) {
sum += type_components(bc, ty->containedTypes[i], ok);
}
return sum;
case DArrayType:
return type_components(bc, ty->containedTypes[0], ok)*ty->numElements;
default:
*ok = 0;
return 0;
}
}
static void readConstant(struct cli_bc *bc, unsigned i, unsigned comp,
unsigned char *buffer, unsigned *offset,
unsigned len, char *ok)
{
unsigned j=0;
while (*ok && buffer[*offset] != 0x60) {
if (j >= comp) {
cli_errmsg("bytecode: constant has too many subcomponents, expected %u\n", comp);
*ok = 0;
return;
}
buffer[*offset] |= 0x20;
bc->globals[i][j++] = readNumber(buffer, offset, len, ok);
}
if (*ok && j != comp) {
cli_errmsg("bytecode: constant has too few subcomponents: %u < %u\n", j, comp);
}
(*offset)++;
}
/* parse constant globals with constant initializers */
static int parseGlobals(struct cli_bc *bc, unsigned char *buffer)
{
unsigned i, offset = 1, len = strlen((const char*)buffer), numglobals;
unsigned maxglobal;
char ok=1;
if (buffer[0] != 'G') {
cli_errmsg("bytecode: Invalid globals header: %c\n", buffer[0]);
return CL_EMALFDB;
}
maxglobal = readNumber(buffer, &offset, len, &ok);
if (maxglobal > cli_apicall_maxglobal) {
cli_dbgmsg("bytecode using global %u, but highest global known to libclamav is %u, skipping\n", maxglobal, cli_apicall_maxglobal);
return CL_BREAK;
}
numglobals = readNumber(buffer, &offset, len, &ok);
bc->globals = cli_calloc(numglobals, sizeof(*bc->globals));
if (!bc->globals) {
cli_errmsg("bytecode: OOM allocating memory for %u globals\n", numglobals);
return CL_EMEM;
}
bc->globaltys = cli_calloc(numglobals, sizeof(*bc->globaltys));
if (!bc->globaltys) {
cli_errmsg("bytecode: OOM allocating memory for %u global types\n", numglobals);
return CL_EMEM;
}
bc->num_globals = numglobals;
if (!ok)
return CL_EMALFDB;
for (i=0;i<numglobals;i++) {
unsigned comp;
bc->globaltys[i] = readTypeID(bc, buffer, &offset, len, &ok);
comp = type_components(bc, bc->globaltys[i], &ok);
if (!ok)
return CL_EMALFDB;
bc->globals[i] = cli_malloc(sizeof(*bc->globals[0])*comp);
if (!bc->globals[i])
return CL_EMEM;
readConstant(bc, i, comp, buffer, &offset, len, &ok);
}
if (!ok)
return CL_EMALFDB;
if (offset != len) {
cli_errmsg("Trailing garbage in globals: %d extra bytes\n",
len-offset);
return CL_EMALFDB;
}
return CL_SUCCESS;
}
static int parseMD(struct cli_bc *bc, unsigned char *buffer)
{
unsigned offset = 1, len = strlen(buffer);
unsigned numMD, i, b;
char ok = 1;
if (buffer[0] != 'D')
return CL_EMALFDB;
numMD = readNumber(buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Unable to parse number of MD nodes\n");
return CL_EMALFDB;
}
b = bc->dbgnode_cnt;
bc->dbgnode_cnt += numMD;
bc->dbgnodes = cli_realloc(bc->dbgnodes, bc->dbgnode_cnt * sizeof(*bc->dbgnodes));
if (!bc->dbgnodes)
return CL_EMEM;
for (i=0;i<numMD;i++) {
unsigned j;
struct cli_bc_dbgnode_element* elts;
unsigned el = readNumber(buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Unable to parse number of elements\n");
return CL_EMALFDB;
}
bc->dbgnodes[b+i].numelements = el;
bc->dbgnodes[b+i].elements = elts = cli_calloc(el, sizeof(*elts));
if (!elts)
return CL_EMEM;
for (j=0;j<el;j++) {
if (buffer[offset] == '|') {
elts[j].string = readData(buffer, &offset, len, &ok, &elts[j].len);
if (!ok)
return CL_EMALFDB;
} else {
elts[j].len = readNumber(buffer, &offset, len, &ok);
if (!ok)
return CL_EMALFDB;
if (elts[j].len) {
elts[j].constant = readNumber(buffer, &offset, len, &ok);
}
else
elts[j].nodeid = readNumber(buffer, &offset, len, &ok);
if (!ok)
return CL_EMALFDB;
}
}
}
cli_dbgmsg("bytecode: Parsed %u nodes total\n", bc->dbgnode_cnt);
return CL_SUCCESS;
}
static int parseFunctionHeader(struct cli_bc *bc, unsigned fn, unsigned char *buffer)
{
char ok=1;
unsigned offset, len, all_locals=0, i;
struct cli_bc_func *func;
if (fn >= bc->num_func) {
cli_errmsg("Found more functions than declared: %u >= %u\n", fn,
bc->num_func);
return CL_EMALFDB;
}
func = &bc->funcs[fn];
len = strlen((const char*)buffer);
if (buffer[0] != 'A') {
cli_errmsg("Invalid function arguments header: %c\n", buffer[0]);
return CL_EMALFDB;
}
offset = 1;
func->numArgs = readFixedNumber(buffer, &offset, len, &ok, 1);
func->returnType = readTypeID(bc, buffer, &offset, len, &ok);
if (buffer[offset] != 'L') {
cli_errmsg("Invalid function locals header: %c\n", buffer[offset]);
return CL_EMALFDB;
}
offset++;
func->numLocals = readNumber(buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Invalid number of arguments/locals\n");
return CL_EMALFDB;
}
all_locals = func->numArgs + func->numLocals;
func->types = cli_calloc(all_locals, sizeof(*func->types));
if (!func->types) {
cli_errmsg("Out of memory allocating function arguments\n");
return CL_EMEM;
}
for (i=0;i<all_locals;i++) {
func->types[i] = readNumber(buffer, &offset, len, &ok);
if (readFixedNumber(buffer, &offset, len, &ok, 1))
func->types[i] |= 0x8000;
}
if (!ok) {
cli_errmsg("Invalid local types\n");
return CL_EMALFDB;
}
if (buffer[offset] != 'F') {
cli_errmsg("Invalid function body header: %c\n", buffer[offset]);
return CL_EMALFDB;
}
offset++;
func->numInsts = readNumber(buffer, &offset, len, &ok);
if (!ok ){
cli_errmsg("Invalid instructions count\n");
return CL_EMALFDB;
}
func->numValues = func->numArgs + func->numLocals;
func->insn_idx = 0;
func->numConstants=0;
func->allinsts = cli_calloc(func->numInsts, sizeof(*func->allinsts));
if (!func->allinsts) {
cli_errmsg("Out of memory allocating instructions\n");
return CL_EMEM;
}
func->numBB = readNumber(buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Invalid basic block count\n");
return CL_EMALFDB;
}
func->BB = cli_calloc(func->numBB, sizeof(*func->BB));
if (!func->BB) {
cli_errmsg("Out of memory allocating basic blocks\n");
return CL_EMEM;
}
return CL_SUCCESS;
}
static bbid_t readBBID(struct cli_bc_func *func, const unsigned char *buffer, unsigned *off, unsigned len, char *ok) {
unsigned id = readNumber(buffer, off, len, ok);
if (!id || id >= func->numBB) {
cli_errmsg("Basic block ID out of range: %u\n", id);
*ok = 0;
}
if (!*ok)
return ~0;
return id;
}
/*
static uint16_t get_type(struct cli_bc_func *func, operand_t op)
{
if (op >= func->numValues)
return 64;
return func->types[op];
}*/
static int parseBB(struct cli_bc *bc, unsigned func, unsigned bb, unsigned char *buffer)
{
char ok=1;
unsigned offset, len, i, last = 0;
struct cli_bc_bb *BB;
struct cli_bc_func *bcfunc = &bc->funcs[func];
struct cli_bc_inst inst;
if (bb >= bcfunc->numBB) {
cli_errmsg("Found too many basic blocks\n");
return CL_EMALFDB;
}
BB = &bcfunc->BB[bb];
len = strlen((const char*) buffer);
if (buffer[0] != 'B') {
cli_errmsg("Invalid basic block header: %c\n", buffer[0]);
return CL_EMALFDB;
}
offset = 1;
BB->numInsts = 0;
BB->insts = &bcfunc->allinsts[bcfunc->insn_idx];
while (!last) {
unsigned numOp;
if (buffer[offset] == 'T') {
last = 1;
offset++;
/* terminators are void */
inst.type = 0;
inst.dest = 0;
} else {
inst.type = readNumber(buffer, &offset, len, &ok);
inst.dest = readNumber(buffer, &offset, len, &ok);
}
inst.opcode = readFixedNumber(buffer, &offset, len, &ok, 2);
if (!ok) {
cli_errmsg("Invalid type or operand\n");
return CL_EMALFDB;
}
if (inst.opcode >= OP_BC_INVALID) {
cli_errmsg("Invalid opcode: %u\n", inst.opcode);
return CL_EMALFDB;
}
switch (inst.opcode) {
case OP_BC_JMP:
inst.u.jump = readBBID(bcfunc, buffer, &offset, len, &ok);
break;
case OP_BC_RET:
inst.type = readNumber(buffer, &offset, len, &ok);
inst.u.unaryop = readOperand(bcfunc, buffer, &offset, len, &ok);
break;
case OP_BC_BRANCH:
inst.u.branch.condition = readOperand(bcfunc, buffer, &offset, len, &ok);
inst.u.branch.br_true = readBBID(bcfunc, buffer, &offset, len, &ok);
inst.u.branch.br_false = readBBID(bcfunc, buffer, &offset, len, &ok);
break;
case OP_BC_CALL_API:/* fall-through */
case OP_BC_CALL_DIRECT:
numOp = readFixedNumber(buffer, &offset, len, &ok, 1);
if (ok) {
inst.u.ops.numOps = numOp;
inst.u.ops.opsizes=NULL;
inst.u.ops.ops = cli_calloc(numOp, sizeof(*inst.u.ops.ops));
if (!inst.u.ops.ops) {
cli_errmsg("Out of memory allocating operands\n");
return CL_EMEM;
}
if (inst.opcode == OP_BC_CALL_DIRECT)
inst.u.ops.funcid = readFuncID(bc, buffer, &offset, len, &ok);
else
inst.u.ops.funcid = readAPIFuncID(bc, buffer, &offset, len, &ok);
for (i=0;i<numOp;i++) {
inst.u.ops.ops[i] = readOperand(bcfunc, buffer, &offset, len, &ok);
}
}
break;
case OP_BC_ZEXT:
case OP_BC_SEXT:
case OP_BC_TRUNC:
inst.u.cast.source = readOperand(bcfunc, buffer, &offset, len, &ok);
inst.u.cast.mask = bcfunc->types[inst.u.cast.source];
if (inst.u.cast.mask == 1)
inst.u.cast.size = 0;
else if (inst.u.cast.mask <= 8)
inst.u.cast.size = 1;
else if (inst.u.cast.mask <= 16)
inst.u.cast.size = 2;
else if (inst.u.cast.mask <= 32)
inst.u.cast.size = 3;
else if (inst.u.cast.mask <= 64)
inst.u.cast.size = 4;
/* calculate mask */
if (inst.opcode != OP_BC_SEXT)
inst.u.cast.mask = inst.u.cast.mask != 64 ?
(1ull<<inst.u.cast.mask)-1 :
~0ull;
break;
case OP_BC_GEP1:
case OP_BC_GEPZ:
inst.u.three[0] = readNumber(buffer, &offset, len, &ok);
inst.u.three[1] = readOperand(bcfunc, buffer, &offset, len, &ok);
inst.u.three[2] = readOperand(bcfunc, buffer, &offset, len, &ok);
break;
case OP_BC_GEPN:
numOp = readFixedNumber(buffer, &offset, len, &ok, 1);
if (ok) {
inst.u.ops.numOps = numOp+2;
inst.u.ops.opsizes = NULL;
inst.u.ops.ops = cli_calloc(numOp+2, sizeof(*inst.u.ops.ops));
if (!inst.u.ops.ops) {
cli_errmsg("Out of memory allocating operands\n");
return CL_EMEM;
}
inst.u.ops.ops[0] = readNumber(buffer, &offset, len, &ok);
for (i=1;i<numOp+2;i++)
inst.u.ops.ops[i] = readOperand(bcfunc, buffer, &offset, len, &ok);
}
break;
case OP_BC_ICMP_EQ:
case OP_BC_ICMP_NE:
case OP_BC_ICMP_UGT:
case OP_BC_ICMP_UGE:
case OP_BC_ICMP_ULT:
case OP_BC_ICMP_ULE:
case OP_BC_ICMP_SGT:
case OP_BC_ICMP_SGE:
case OP_BC_ICMP_SLE:
case OP_BC_ICMP_SLT:
/* instruction type must be correct before readOperand! */
inst.type = readNumber(buffer, &offset, len, &ok);
/* fall-through */
default:
numOp = operand_counts[inst.opcode];
switch (numOp) {
case 0:
break;
case 1:
inst.u.unaryop = readOperand(bcfunc, buffer, &offset, len, &ok);
break;
case 2:
inst.u.binop[0] = readOperand(bcfunc, buffer, &offset, len, &ok);
inst.u.binop[1] = readOperand(bcfunc, buffer, &offset, len, &ok);
break;
case 3:
inst.u.three[0] = readOperand(bcfunc, buffer, &offset, len, &ok);
inst.u.three[1] = readOperand(bcfunc, buffer, &offset, len, &ok);
inst.u.three[2] = readOperand(bcfunc, buffer, &offset, len, &ok);
break;
default:
cli_errmsg("Opcode %u with too many operands: %u?\n", inst.opcode, numOp);
ok = 0;
break;
}
}
if (!ok) {
cli_errmsg("Invalid instructions or operands\n");
return CL_EMALFDB;
}
if (bcfunc->insn_idx + BB->numInsts >= bcfunc->numInsts) {
cli_errmsg("More instructions than declared in total: %u > %u!\n",
bcfunc->insn_idx+BB->numInsts, bcfunc->numInsts);
return CL_EMALFDB;
}
inst.interp_op = inst.opcode*5;
if (inst.type > 1) {
if (inst.type <= 8)
inst.interp_op += 1;
else if (inst.type <= 16)
inst.interp_op += 2;
else if (inst.type <= 32)
inst.interp_op += 3;
else if (inst.type <= 64)
inst.interp_op += 4;
}
BB->insts[BB->numInsts++] = inst;
}
if (bb+1 == bc->funcs[func].numBB) {
if (buffer[offset] != 'E') {
cli_errmsg("Missing basicblock terminator, got: %c\n", buffer[offset]);
return CL_EMALFDB;
}
offset++;
}
if (buffer[offset] == 'D') {
unsigned num;
offset += 3;
if (offset >= len)
return CL_EMALFDB;
num = readNumber(buffer, &offset, len, &ok);
if (!ok)
return CL_EMALFDB;
if (num != bcfunc->numInsts) {
cli_errmsg("invalid number of dbg nodes, expected: %u, got: %u\n", bcfunc->numInsts, num);
return CL_EMALFDB;
}
bcfunc->dbgnodes = cli_malloc(num*sizeof(*bcfunc->dbgnodes));
if (!bcfunc->dbgnodes)
return CL_EMEM;
for (i=0;i<num;i++) {
bcfunc->dbgnodes[i] = readNumber(buffer, &offset, len, &ok);
if (!ok)
return CL_EMALFDB;
}
}
if (offset != len) {
cli_errmsg("Trailing garbage in basicblock: %d extra bytes\n",
len-offset);
return CL_EMALFDB;
}
bcfunc->numBytes = 0;
bcfunc->insn_idx += BB->numInsts;
return CL_SUCCESS;
}
enum parse_state {
PARSE_BC_TYPES=0,
PARSE_BC_APIS,
PARSE_BC_GLOBALS,
PARSE_BC_LSIG,
PARSE_MD_OPT_HEADER,
PARSE_FUNC_HEADER,
PARSE_BB
};
int cli_bytecode_load(struct cli_bc *bc, FILE *f, struct cli_dbio *dbio, int trust)
{
unsigned row = 0, current_func = 0, bb=0;
char *buffer;
unsigned linelength=0;
char firstbuf[FILEBUFF];
enum parse_state state;
int rc, end=0;
memset(bc, 0, sizeof(*bc));
bc->trusted = trust;
if (!f && !dbio) {
cli_errmsg("Unable to load bytecode (null file)\n");
return CL_ENULLARG;
}
if (!cli_dbgets(firstbuf, FILEBUFF, f, dbio)) {
cli_errmsg("Unable to load bytecode (empty file)\n");
return CL_EMALFDB;
}
cli_chomp(firstbuf);
rc = parseHeader(bc, (unsigned char*)firstbuf, &linelength);
if (rc == CL_BREAK) {
bc->state = bc_skip;
return CL_SUCCESS;
}
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
return rc;
}
buffer = cli_malloc(linelength);
if (!buffer) {
cli_errmsg("Out of memory allocating line of length %u\n", linelength);
return CL_EMEM;
}
state = PARSE_BC_LSIG;
while (cli_dbgets(buffer, linelength, f, dbio) && !end) {
cli_chomp(buffer);
row++;
switch (state) {
case PARSE_BC_LSIG:
rc = parseLSig(bc, (unsigned char*)buffer);
if (rc == CL_BREAK) /* skip */ {
bc->state = bc_skip;
free(buffer);
return CL_SUCCESS;
}
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
free(buffer);
return rc;
}
state = PARSE_BC_TYPES;
break;
case PARSE_BC_TYPES:
rc = parseTypes(bc, (unsigned char*)buffer);
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
free(buffer);
return rc;
}
state = PARSE_BC_APIS;
break;
case PARSE_BC_APIS:
rc = parseApis(bc, (unsigned char*)buffer);
if (rc == CL_BREAK) /* skip */ {
bc->state = bc_skip;
free(buffer);
return CL_SUCCESS;
}
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
free(buffer);
return rc;
}
state = PARSE_BC_GLOBALS;
break;
case PARSE_BC_GLOBALS:
rc = parseGlobals(bc, (unsigned char*)buffer);
if (rc == CL_BREAK) /* skip */ {
bc->state = bc_skip;
free(buffer);
return CL_SUCCESS;
}
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
free(buffer);
return rc;
}
state = PARSE_MD_OPT_HEADER;
break;
case PARSE_MD_OPT_HEADER:
if (buffer[0] == 'D') {
rc = parseMD(bc, (unsigned char*)buffer);
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
free(buffer);
return rc;
}
break;
}
/* fall-through */
case PARSE_FUNC_HEADER:
if (*buffer == 'S') {
end = 1;
break;
}
rc = parseFunctionHeader(bc, current_func, (unsigned char*)buffer);
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
free(buffer);
return rc;
}
bb = 0;
state = PARSE_BB;
break;
case PARSE_BB:
rc = parseBB(bc, current_func, bb++, (unsigned char*)buffer);
if (rc != CL_SUCCESS) {
cli_errmsg("Error at bytecode line %u\n", row);
free(buffer);
return rc;
}
if (bb >= bc->funcs[current_func].numBB) {
if (bc->funcs[current_func].insn_idx != bc->funcs[current_func].numInsts) {
cli_errmsg("Parsed different number of instructions than declared: %u != %u\n",
bc->funcs[current_func].insn_idx, bc->funcs[current_func].numInsts);
free(buffer);
return CL_EMALFDB;
}
cli_dbgmsg("Parsed %u BBs, %u instructions\n",
bb, bc->funcs[current_func].numInsts);
state = PARSE_FUNC_HEADER;
current_func++;
}
break;
}
}
free(buffer);
cli_dbgmsg("Parsed %d functions\n", current_func);
if (current_func != bc->num_func) {
cli_errmsg("Loaded less functions than declared: %u vs. %u\n",
current_func, bc->num_func);
return CL_EMALFDB;
}
return CL_SUCCESS;
}
int cli_bytecode_run(const struct cli_all_bc *bcs, const struct cli_bc *bc, struct cli_bc_ctx *ctx)
{
struct cli_bc_inst inst;
struct cli_bc_func func;
if (!ctx || !ctx->bc || !ctx->func)
return CL_ENULLARG;
if (ctx->numParams && (!ctx->values || !ctx->operands))
return CL_ENULLARG;
if (bc->state == bc_loaded) {
cli_errmsg("bytecode has to be prepared either for interpreter or JIT!\n");
return CL_EARG;
}
if (bc->state == bc_interp) {
memset(&func, 0, sizeof(func));
func.numInsts = 1;
func.numValues = 1;
func.numConstants = 0;
func.numBytes = ctx->bytes;
memset(ctx->values+ctx->bytes-8, 0, 8);
inst.opcode = OP_BC_CALL_DIRECT;
inst.interp_op = OP_BC_CALL_DIRECT*5;
inst.dest = func.numArgs;
inst.type = 0;
inst.u.ops.numOps = ctx->numParams;
inst.u.ops.funcid = ctx->funcid;
inst.u.ops.ops = ctx->operands;
inst.u.ops.opsizes = ctx->opsizes;
return cli_vm_execute(ctx->bc, ctx, &func, &inst);
}
return cli_vm_execute_jit(bcs, ctx, &bc->funcs[ctx->funcid]);
}
uint64_t cli_bytecode_context_getresult_int(struct cli_bc_ctx *ctx)
{
return *(uint32_t*)ctx->values;/*XXX*/
}
void cli_bytecode_destroy(struct cli_bc *bc)
{
unsigned i, j, k;
free(bc->metadata.compiler);
free(bc->metadata.sigmaker);
if (bc->funcs) {
for (i=0;i<bc->num_func;i++) {
struct cli_bc_func *f = &bc->funcs[i];
if (!f)
continue;
free(f->types);
for (j=0;j<f->numBB;j++) {
struct cli_bc_bb *BB = &f->BB[j];
for(k=0;k<BB->numInsts;k++) {
struct cli_bc_inst *ii = &BB->insts[k];
if (operand_counts[ii->opcode] > 3 ||
ii->opcode == OP_BC_CALL_DIRECT || ii->opcode == OP_BC_CALL_API) {
free(ii->u.ops.ops);
free(ii->u.ops.opsizes);
}
}
}
free(f->BB);
free(f->allinsts);
free(f->constants);
}
free(bc->funcs);
}
if (bc->types) {
for (i=NUM_STATIC_TYPES;i<bc->num_types;i++) {
if (bc->types[i].containedTypes)
free(bc->types[i].containedTypes);
}
free(bc->types);
}
if (bc->globals) {
for (i=0;i<bc->num_globals;i++) {
free(bc->globals[i]);
}
free(bc->globals);
}
if (bc->dbgnodes) {
for (i=0;i<bc->dbgnode_cnt;i++) {
for (j=0;j<bc->dbgnodes[i].numelements;j++) {
struct cli_bc_dbgnode_element *el = &bc->dbgnodes[i].elements[j];
if (el && el->string)
free(el->string);
}
}
free(bc->dbgnodes);
}
free(bc->globaltys);
if (bc->uses_apis)
cli_bitset_free(bc->uses_apis);
free(bc->lsig);
}
#define MAP(val) do { operand_t o = val; \
if (o & 0x80000000) {\
o &= 0x7fffffff;\
if (o > bc->num_globals) {\
cli_errmsg("bytecode: global out of range: %u > %u, for instruction %u in function %u\n",\
o, bc->num_globals, j, i);\
return CL_EBYTECODE;\
}\
val = 0x80000000 | gmap[o];\
break;\
}\
if (o > totValues) {\
cli_errmsg("bytecode: operand out of range: %u > %u, for instruction %u in function %u\n", o, totValues, j, i);\
return CL_EBYTECODE;\
}\
val = map[o]; } while (0)
static int cli_bytecode_prepare_interpreter(struct cli_bc *bc)
{
unsigned i, j, k;
unsigned *gmap;
bc->numGlobalBytes = 0;
gmap = cli_malloc(bc->num_globals*sizeof(*gmap));
if (!gmap)
return CL_EMEM;
for (j=0;j<bc->num_globals;j++) {
uint16_t ty = bc->globaltys[j];
unsigned align = typealign(bc, ty);
assert(align);
bc->numGlobalBytes = (bc->numGlobalBytes + align-1)&(~(align-1));
gmap[j] = bc->numGlobalBytes;
bc->numGlobalBytes += typesize(bc, ty);
}
for (i=0;i<bc->num_func;i++) {
struct cli_bc_func *bcfunc = &bc->funcs[i];
unsigned totValues = bcfunc->numValues + bcfunc->numConstants + bc->num_globals;
unsigned *map = cli_malloc(sizeof(*map)*totValues);
if (!map)
return CL_EMEM;
bcfunc->numBytes = 0;
for (j=0;j<bcfunc->numValues;j++) {
uint16_t ty = bcfunc->types[j];
unsigned align;
align = typealign(bc, ty);
assert(align);
bcfunc->numBytes = (bcfunc->numBytes + align-1)&(~(align-1));
map[j] = bcfunc->numBytes;
bcfunc->numBytes += typesize(bc, ty);
}
bcfunc->numBytes = (bcfunc->numBytes + 7)&~7;
for (j=0;j<bcfunc->numConstants;j++) {
map[bcfunc->numValues+j] = bcfunc->numBytes;
bcfunc->numBytes += 8;
}
for (j=0;j<bcfunc->numInsts;j++) {
struct cli_bc_inst *inst = &bcfunc->allinsts[j];
inst->dest = map[inst->dest];
switch (inst->opcode) {
case OP_BC_ADD:
case OP_BC_SUB:
case OP_BC_MUL:
case OP_BC_UDIV:
case OP_BC_SDIV:
case OP_BC_UREM:
case OP_BC_SREM:
case OP_BC_SHL:
case OP_BC_LSHR:
case OP_BC_ASHR:
case OP_BC_AND:
case OP_BC_OR:
case OP_BC_XOR:
case OP_BC_ICMP_EQ:
case OP_BC_ICMP_NE:
case OP_BC_ICMP_UGT:
case OP_BC_ICMP_UGE:
case OP_BC_ICMP_ULT:
case OP_BC_ICMP_ULE:
case OP_BC_ICMP_SGT:
case OP_BC_ICMP_SGE:
case OP_BC_ICMP_SLT:
case OP_BC_ICMP_SLE:
case OP_BC_COPY:
case OP_BC_STORE:
MAP(inst->u.binop[0]);
MAP(inst->u.binop[1]);
break;
case OP_BC_SEXT:
case OP_BC_ZEXT:
case OP_BC_TRUNC:
MAP(inst->u.cast.source);
break;
case OP_BC_BRANCH:
MAP(inst->u.branch.condition);
break;
case OP_BC_JMP:
break;
case OP_BC_RET:
MAP(inst->u.unaryop);
break;
case OP_BC_SELECT:
MAP(inst->u.three[0]);
MAP(inst->u.three[1]);
MAP(inst->u.three[2]);
break;
case OP_BC_CALL_API:/* fall-through */
case OP_BC_CALL_DIRECT:
{
struct cli_bc_func *target = NULL;
if (inst->opcode == OP_BC_CALL_DIRECT) {
target = &bc->funcs[inst->u.ops.funcid];
if (inst->u.ops.funcid > bc->num_func) {
cli_errmsg("bytecode: called function out of range: %u > %u\n", inst->u.ops.funcid, bc->num_func);
return CL_EBYTECODE;
}
if (inst->u.ops.numOps != target->numArgs) {
cli_errmsg("bytecode: call operands don't match function prototype\n");
return CL_EBYTECODE;
}
} else {
/* APIs have at most 2 parameters always */
if (inst->u.ops.numOps > 2) {
cli_errmsg("bytecode: call operands don't match function prototype\n");
return CL_EBYTECODE;
}
}
if (inst->u.ops.numOps) {
inst->u.ops.opsizes = cli_malloc(sizeof(*inst->u.ops.opsizes)*inst->u.ops.numOps);
if (!inst->u.ops.opsizes) {
cli_errmsg("Out of memory when allocating operand sizes\n");
return CL_EMEM;
}
} else
inst->u.ops.opsizes = NULL;
for (k=0;k<inst->u.ops.numOps;k++) {
MAP(inst->u.ops.ops[k]);
if (inst->opcode == OP_BC_CALL_DIRECT)
inst->u.ops.opsizes[k] = typesize(bc, target->types[k]);
else
inst->u.ops.opsizes[k] = 32; /*XXX*/
}
break;
}
case OP_BC_LOAD:
MAP(inst->u.unaryop);
break;
case OP_BC_GEP1:
case OP_BC_GEPZ:
/*three[0] is the type*/
MAP(inst->u.three[1]);
MAP(inst->u.three[2]);
break;
case OP_BC_GEPN:
/*TODO */
break;
case OP_BC_MEMSET:
case OP_BC_MEMCPY:
case OP_BC_MEMMOVE:
case OP_BC_MEMCMP:
/*TODO*/
break;
case OP_BC_ISBIGENDIAN:
/*TODO */
break;
case OP_BC_ABORT:
/* TODO */
break;
case OP_BC_BSWAP16:
/*TODO */
break;
case OP_BC_BSWAP32:
/*TODO */
break;
case OP_BC_BSWAP64:
/*TODO */
break;
case OP_BC_PTRDIFF32:
/*TODO */
break;
default:
cli_dbgmsg("Unhandled opcode: %d\n", inst->opcode);
return CL_EBYTECODE;
}
}
free(map);
}
free(gmap);
bc->state = bc_interp;
return CL_SUCCESS;
}
int cli_bytecode_prepare(struct cli_all_bc *bcs, unsigned dconfmask)
{
unsigned i;
int rc;
if (cli_bytecode_prepare_jit(bcs) == CL_SUCCESS)
return CL_SUCCESS;
for (i=0;i<bcs->count;i++) {
struct cli_bc *bc = &bcs->all_bcs[i];
if (bc->state == bc_interp || bc->state == bc_jit)
continue;
if (!(dconfmask & BYTECODE_INTERPRETER)) {
cli_warnmsg("Bytecode needs interpreter, but interpreter is disabled\n");
continue;
}
rc = cli_bytecode_prepare_interpreter(bc);
if (rc != CL_SUCCESS)
return rc;
}
return CL_SUCCESS;
}
int cli_bytecode_init(struct cli_all_bc *allbc, unsigned dconfmask)
{
memset(allbc, 0, sizeof(*allbc));
return cli_bytecode_init_jit(allbc, dconfmask);
}
int cli_bytecode_done(struct cli_all_bc *allbc)
{
return cli_bytecode_done_jit(allbc);
}
int cli_bytecode_context_setfile(struct cli_bc_ctx *ctx, fmap_t *map)
{
ctx->fmap = map;
ctx->file_size = map->len + map->offset;
ctx->hooks.filesize = &ctx->file_size;
return 0;
}
int cli_bytecode_runlsig(cli_ctx *cctx, const struct cli_all_bc *bcs, unsigned bc_idx, const char **virname, const uint32_t* lsigcnt, const uint32_t *lsigsuboff, fmap_t *map)
{
int ret;
struct cli_bc_ctx ctx;
const struct cli_bc *bc = &bcs->all_bcs[bc_idx-1];
if (bc->hook_lsig_id) {
cli_dbgmsg("hook lsig id %d matched (bc %d)\n", bc->hook_lsig_id, bc->id);
/* this is a bytecode for a hook, defer running it until hook is
* executed, so that it has all the info for the hook */
if (cctx->hook_lsig_matches)
cli_bitset_set(cctx->hook_lsig_matches, bc->hook_lsig_id-1);
return CL_SUCCESS;
}
memset(&ctx, 0, sizeof(ctx));
cli_bytecode_context_setfuncid(&ctx, bc, 0);
ctx.hooks.match_counts = lsigcnt;
cli_bytecode_context_setfile(&ctx, map);
cli_dbgmsg("Running bytecode for logical signature match\n");
ret = cli_bytecode_run(bcs, bc, &ctx);
if (ret != CL_SUCCESS) {
cli_warnmsg("Bytcode failed to run: %s\n", cl_strerror(ret));
return CL_SUCCESS;
}
if (ctx.virname) {
cli_dbgmsg("Bytecode found virus: %s\n", ctx.virname);
if (virname)
*virname = ctx.virname;
cli_bytecode_context_clear(&ctx);
return CL_VIRUS;
}
ret = cli_bytecode_context_getresult_int(&ctx);
cli_dbgmsg("Bytecode %u returned code: %u\n", bc->id, ret);
cli_bytecode_context_clear(&ctx);
return CL_SUCCESS;
}
int cli_bytecode_runhook(cli_ctx *cctx, const struct cl_engine *engine, struct cli_bc_ctx *ctx,
unsigned id, fmap_t *map, const char **virname)
{
const unsigned *hooks = engine->hooks[id - _BC_START_HOOKS];
unsigned i, hooks_cnt = engine->hooks_cnt[id - _BC_START_HOOKS];
int ret;
cli_bytecode_context_setfile(ctx, map);
cli_dbgmsg("Bytecode executing hook id %u (%u hooks)\n", id, hooks_cnt);
for (i=0;i < hooks_cnt;i++) {
const struct cli_bc *bc = &engine->bcs.all_bcs[hooks[i]];
if (bc->lsig) {
if (!cctx->hook_lsig_matches ||
!cli_bitset_test(cctx->hook_lsig_matches, bc->hook_lsig_id-1))
continue;
cli_dbgmsg("Bytecode: executing bytecode %u (lsig matched)\n" , bc->id);
}
cli_bytecode_context_setfuncid(ctx, bc, 0);
ret = cli_bytecode_run(&engine->bcs, bc, ctx);
if (ret != CL_SUCCESS) {
cli_warnmsg("Bytecode failed to run: %s\n", cl_strerror(ret));
return CL_SUCCESS;
}
if (ctx->virname) {
cli_dbgmsg("Bytecode found virus: %s\n", ctx->virname);
if (virname)
*virname = ctx->virname;
cli_bytecode_context_clear(ctx);
return CL_VIRUS;
}
ret = cli_bytecode_context_getresult_int(ctx);
/* TODO: use prefix here */
cli_dbgmsg("Bytecode %u returned %u\n", bc->id, ret);
if (!ret) {
char *tempfile;
int fd = cli_bytecode_context_getresult_file(ctx, &tempfile);
if (fd != -1) {
if (cctx && cctx->engine->keeptmp)
cli_dbgmsg("Bytecode %u unpacked file saved in %s\n",
bc->id, tempfile);
else
cli_dbgmsg("Bytecode %u unpacked file\n", bc->id);
lseek(fd, 0, SEEK_SET);
cli_dbgmsg("***** Scanning unpacked file ******\n");
ret = cli_magic_scandesc(fd, cctx);
if (!cctx || !cctx->engine->keeptmp)
if (ftruncate(fd, 0) == -1)
cli_dbgmsg("ftruncate failed\n");
close(fd);
if (!cctx || !cctx->engine->keeptmp) {
if (cli_unlink(tempfile))
ret = CL_EUNLINK;
}
free(tempfile);
if (ret != CL_CLEAN) {
if (ret == CL_VIRUS)
cli_dbgmsg("Scanning unpacked file by bytecode %u found a virus\n", bc->id);
cli_bytecode_context_clear(ctx);
return ret;
}
cli_bytecode_context_reset(ctx);
continue;
}
}
cli_bytecode_context_reset(ctx);
}
return CL_CLEAN;
}
int cli_bytecode_context_setpe(struct cli_bc_ctx *ctx, const struct cli_pe_hook_data *data, const struct cli_exe_section *sections)
{
ctx->sections = sections;
ctx->hooks.pedata = data;
return 0;
}
void cli_bytecode_context_setctx(struct cli_bc_ctx *ctx, void *cctx)
{
ctx->ctx = cctx;
}
void cli_bytecode_describe(const struct cli_bc *bc)
{
char buf[128];
int cols;
unsigned i;
time_t stamp;
int had;
if (!bc) {
printf("(null bytecode)\n");
return;
}
stamp = bc->metadata.timestamp;
printf("Bytecode format functionality level: %u\n", BC_FUNC_LEVEL);
printf("Bytecode metadata:\n\tcompiler version: %s\n",
bc->metadata.compiler ? bc->metadata.compiler : "N/A");
printf("\tcompiled on: %s",
cli_ctime(&stamp, buf, sizeof(buf)));
printf("\tcompiled by: %s\n", bc->metadata.sigmaker ? bc->metadata.sigmaker : "N/A");
/*TODO: parse and display arch name, also take it into account when
JITing*/
printf("\ttarget exclude: %d\n", bc->metadata.targetExclude);
printf("\tbytecode type: ");
switch (bc->kind) {
case BC_GENERIC:
puts("generic, not loadable by clamscan/clamd");
break;
case BC_LOGICAL:
puts("logical only");
break;
case BC_PE_UNPACKER:
puts("PE hook");
break;
default:
printf("Unknown (type %u)", bc->kind);
break;
}
printf("\tbytecode logical signature: %s\n",
bc->lsig ? bc->lsig : "<none>");
printf("\tvirusname prefix: %s\n",
bc->vnameprefix);
printf("\tvirusnames: %u\n", bc->vnames_cnt);
printf("\tbytecode triggered on: ");
switch (bc->kind) {
case BC_GENERIC:
puts("N/A (loaded in clambc only)");
break;
case BC_LOGICAL:
puts("files matching logical signature");
break;
case BC_PE_UNPACKER:
if (bc->lsig)
puts("PE files matching logical signature");
else
puts("all PE files!");
break;
default:
puts("N/A (unknown type)\n");
break;
}
printf("\tnumber of functions: %u\n\tnumber of types: %u\n",
bc->num_func, bc->num_types);
printf("\tnumber of global constants: %u\n", (unsigned)bc->num_globals);
printf("\tnumber of debug nodes: %u\n", bc->dbgnode_cnt);
printf("\tbytecode APIs used:");
cols = 0; /* remaining */
had = 0;
for (i=0;i<cli_apicall_maxapi;i++) {
if (cli_bitset_test(bc->uses_apis, i)) {
unsigned len = strlen(cli_apicalls[i].name);
if (had)
printf(",");
if (len > cols) {
printf("\n\t");
cols = 72;
}
printf(" %s", cli_apicalls[i].name);
had = 1;
cols -= len;
}
}
printf("\n");
}