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imports.cpp
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imports.cpp
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/*
Copyright (c) 2015 Piotr Stolarz
dumpext: PE files fix, dump & analysis WinDbg extension
Distributed under the GNU General Public License (the License)
see accompanying file LICENSE for details.
This software is distributed WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the License for more information.
*/
#include "common.h"
#include "config.h"
#include "imports.h"
#include <imagehlp.h>
#include <errno.h>
/* max number of symbols in a dll with an identical addr */
#define MAX_SYNONS 20U
/* max number of forwarders' modules taken into account
during resolving an owning module of its IAT table */
#define MAX_FRWRDS 32U
#define IDTSPEC_NO_PADD_NAMES 0x01U
#define IDTSPEC_NO_ILTS 0x02U
typedef struct _imp_proc_desc_t
{
/* ordinal of a proc (index in the export addr table;
"base-ordinal" based); required to be set if proc has no name */
DWORD ord;
/* hint of a proc (index in name/hint table; 0-based); if a proc
has no name (only an ordinal) hint is set to (DWORD)-1 */
DWORD hint;
/* number of duplicates of the proc (set only
for the 1st dup in the module's list of procs) */
DWORD dups;
/* next proc in the chain */
_imp_proc_desc_t *next;
/* proc name (NULL term; rounded to even bytes by padding zero);
if a proc has no name (only ordinal) this string is set to "" */
char name[1];
} imp_proc_desc_t;
typedef struct _imp_mod_desc_t
{
/* imported module's base (may be NULL for imports read
form the conf file and not able to be resolved) */
ULONG64 mod_base;
/* module's IAT table address */
ULONG64 iat_addr;
/* num of proc descs in the list */
DWORD n_procs;
/* 1st imported proc desc of the list */
imp_proc_desc_t *proc;
/* number of duplicates of the module (set only
for the 1st dup in the list of importing mods) */
DWORD dups;
/* size of module's Hint/Name Table (in bytes) */
DWORD hnt_sz;
/* size of module's Hint/Name Table (in bytes) w/o even rounded proc names */
DWORD hnt_nrnd_sz;
/* next module in the chain */
_imp_mod_desc_t *next;
/* module name (NULL term; rounded to even bytes by padding zero) */
char name[1];
} imp_mod_desc_t;
/* selected module's export directory's fields */
typedef struct _mod_exp_dir_t
{
/* module's base addr */
ULONG64 mod_base;
/* exp dir data addr & size */
ULONG64 exp_dd_addr;
DWORD exp_dd_sz;
/* exp dir data content */
DWORD ord_base; /* ordinal's base */
DWORD n_faddrs; /* number of functions in EAT */
DWORD n_fnames; /* number of exported names */
ULONG64 mod_name_addr; /* module's name address */
ULONG64 faddrs_addr; /* address of EAT */
ULONG64 fnames_addr; /* address of names table */
ULONG64 fords_addr; /* address of ordinals table */
} mod_exp_dir_t;
/* struct of internal handle for imports scan */
typedef struct _scan_imps_hndl_t
{
/* module's base */
ULONG64 mod_base;
/* module's headers */
IMAGE_DOS_HEADER dos_hdr;
image_nt_headers_t nt_hdrs;
/* sections table */
DWORD n_sects;
IMAGE_SECTION_HEADER sectab[MAX_SECTIONS];
/* TRUE if 32bit target emulated on Wow64 platform */
BOOL wow64_emul;
/* flag indicating end of current module's
imports and a need to create a new one */
BOOL crt_new_list;
DWORD n_mods; /* number of modules in the imp_mods list */
imp_mod_desc_t *p_imp_mods; /* pointer to the head of mod desc's struct */
imp_mod_desc_t *p_last_mod; /* lastly added mod desc */
imp_proc_desc_t *p_last_proc; /* lastly added proc desc */
mod_exp_dir_t ed_reslv; /* cache of exp dir - proc resolving */
mod_exp_dir_t ed_frwrd; /* cache of exp dir - forwards resolving */
} scan_imps_hndl_t;
/* delay load description struct */
typedef struct _img_delay_descr_t
{
DWORD attrs; /* attributes */
DWORD rvaDLLName; /* RVA to dll name */
DWORD rvaHmod; /* RVA of module handle */
DWORD rvaIAT; /* RVA of the IAT */
DWORD rvaILT; /* RVA of the ILT */
DWORD rvaBoundIAT; /* RVA of the optional bound IAT */
DWORD rvaUnloadIAT; /* RVA of optional copy of original IAT */
DWORD dwTimeStamp; /* 0 if not bound, otherwise
date/time stamp of DLL bound to (Old BIND) */
} img_delay_descr_t;
/* Delay Load Attributes */
enum delay_imp_attr
{
/* RVAs are used instead of pointers */
dlattr_rva = 0x1
};
/* Read the export directory and write the data into the structure pointed by
'p_ed'. The func requires p_ed->mod_base to be set to the base of the module
whose export dir need to be read. If 'b_logs' is TRUE print error info.
Returns TRUE for success, FALSE otherwise
*/
static BOOL get_mod_exp_dir(mod_exp_dir_t *p_ed, BOOL b_logs)
{
BOOL ret=FALSE;
IMAGE_DOS_HEADER dos_hdr;
image_nt_headers_t nt_hdrs;
/* read PE header and the export directory */
if (!read_pe_headers(p_ed->mod_base, &dos_hdr, &nt_hdrs, NULL, b_logs))
goto finish;
IMAGE_DATA_DIRECTORY *p_dd_exp;
if (!get_data_dir(&nt_hdrs, IMAGE_DIRECTORY_ENTRY_EXPORT, &p_dd_exp, b_logs))
goto finish;
DWORD exp_dd_rva = get_32uint_le(&p_dd_exp->VirtualAddress);
p_ed->exp_dd_addr = RVA2ADDR(exp_dd_rva, p_ed->mod_base);
p_ed->exp_dd_sz = get_32uint_le(&p_dd_exp->Size);
if (!exp_dd_rva || !p_ed->exp_dd_sz) {
if (b_logs)
err_dbgprintf(
"No export directory for a module with the base addr: 0x%p\n",
p_ed->mod_base);
goto finish;
}
ULONG cb;
IMAGE_EXPORT_DIRECTORY exp_dir;
/* retrieve export table info */
if (!(read_memory(p_ed->exp_dd_addr,
&exp_dir, sizeof(exp_dir), &cb) && cb==sizeof(exp_dir))) goto finish;
p_ed->ord_base = get_32uint_le(&exp_dir.Base);
p_ed->n_faddrs = get_32uint_le(&exp_dir.NumberOfFunctions);
p_ed->n_fnames = get_32uint_le(&exp_dir.NumberOfNames);
p_ed->mod_name_addr =
RVA2ADDR(get_32uint_le(&exp_dir.Name), p_ed->mod_base);
p_ed->faddrs_addr =
RVA2ADDR(get_32uint_le(&exp_dir.AddressOfFunctions), p_ed->mod_base);
p_ed->fnames_addr =
RVA2ADDR(get_32uint_le(&exp_dir.AddressOfNames), p_ed->mod_base);
p_ed->fords_addr =
RVA2ADDR(get_32uint_le(&exp_dir.AddressOfNameOrdinals), p_ed->mod_base);
ret=TRUE;
finish:
return ret;
}
/* Search for the proc name pointed by 'pc_proc_name' in the exported table of
names. Optimized method basing on a lexical order of names in the exporting
table. If the name is found the func returns TRUE and proc's hint & ordinal
(zero-based) are returned under 'p_hint' and 'p_ord'.
*/
static BOOL get_name_hint_ord(const mod_exp_dir_t *p_ed,
const char *pc_proc_name, DWORD *p_hint, DWORD *p_ord)
{
ULONG cb;
BOOL ret=FALSE, found=FALSE;
BOOL loop_finish=FALSE;
if (!p_ed->n_fnames) goto finish;
for (DWORD h_min=0, h_max=p_ed->n_fnames-1, h_mid; !loop_finish;)
{
if (h_min==h_max) loop_finish=TRUE;
/* read proc name address in the middle of the searching range */
h_mid = (h_min+h_max)/2;
DWORD proc_name_rva;
if (!(read_memory(p_ed->fnames_addr + h_mid*sizeof(proc_name_rva),
&proc_name_rva, sizeof(proc_name_rva), &cb) &&
cb==sizeof(proc_name_rva))) goto finish;
ULONG64 proc_name_addr =
RVA2ADDR(get_32uint_le(&proc_name_rva), p_ed->mod_base);
int cmp_res = string_cmp_lt(pc_proc_name, proc_name_addr);
if (!cmp_res) {
*p_hint = h_mid;
found = TRUE;
break;
} else
if (cmp_res>0) {
h_min = (h_min!=h_mid ? h_mid : h_max);
} else {
if (h_min!=h_mid) h_max=h_mid;
else break;
}
}
if (found) {
WORD ord;
if (!(read_memory(p_ed->fords_addr + *p_hint*sizeof(ord),
&ord, sizeof(ord), &cb) && cb==sizeof(ord))) goto finish;
*p_ord = get_16uint_le(&ord);
}
ret=TRUE;
finish:
return ret;
}
/* Count how many modules from 'p_mods' list ('n_mods' long, less or equal to
MAX_FRWRDS) are referenced as forwarders from the EAT table of the import
module with 'mod_base'. Name of the module is additionally returned under
'pc_mod_name' (min MAX_PATH+1 long).
The func returns TRUE on success and the count number under 'p_cnt'.
*/
static BOOL count_forwards(
IDebugSymbols *DebugSymbols, ULONG64 mod_base, ULONG64 *p_mods,
UINT n_mods, UINT *p_cnt, char *pc_mod_name, BOOL b_logs=FALSE)
{
BOOL ret=FALSE;
*p_cnt=0;
mod_exp_dir_t ed;
ed.mod_base = mod_base;
if (!get_mod_exp_dir(&ed, b_logs)) goto finish;
if (!string_cpy_lt(pc_mod_name, ed.mod_name_addr, MAX_PATH+1)) goto finish;
DWORD ord;
ULONG64 faddrs_addr;
/* flags table of already found modules */
BOOL found_mods[MAX_FRWRDS];
memset(found_mods, 0, sizeof(found_mods));
ret=TRUE;
/* go through EAT looking for forwards */
DWORD exp_proc_rva;
for (ord=0, faddrs_addr=ed.faddrs_addr;
ord < ed.n_faddrs;
faddrs_addr+=sizeof(exp_proc_rva), ord++)
{
ULONG cb;
if (!(read_memory(faddrs_addr, &exp_proc_rva, sizeof(exp_proc_rva), &cb)
&& cb==sizeof(exp_proc_rva))) goto finish;
ULONG64 exp_proc_addr = RVA2ADDR(get_32uint_le(&exp_proc_rva), mod_base);
if ((ed.exp_dd_addr <= exp_proc_addr) &&
(exp_proc_addr < ed.exp_dd_addr+ed.exp_dd_sz))
{
/* forward is found, get its mod name & base */
char frwrd_name[MAX_PATH+1];
ULONG64 frwrd_base;
if (!string_cpy_lt(
frwrd_name, exp_proc_addr, sizeof(frwrd_name), '.')) continue;
if (DebugSymbols->GetModuleByModuleName(
frwrd_name, 0, NULL, &frwrd_base)!=S_OK) continue;
for (UINT i=0; i<n_mods; i++)
if (p_mods[i]==frwrd_base && !found_mods[i])
{
(*p_cnt)++;
found_mods[i]=TRUE;
break;
}
}
}
finish:
return ret;
}
/* Get import module desc from index 'i' (0-based) */
static imp_mod_desc_t *get_imp_mod(const imp_mod_desc_t *p_imp_mods, UINT i)
{
UINT j;
const imp_mod_desc_t *p_mod = p_imp_mods;
for (j=0; j!=i && p_mod; j++, p_mod=p_mod->next);
if (j!=i) p_mod=NULL;
return (imp_mod_desc_t*)p_mod;
}
/* Free all memory allocated by the imp_mods's structs */
static void free_imp_mods(imp_mod_desc_t *p_imp_mods)
{
void *to_free;
for (imp_mod_desc_t *mod=p_imp_mods; mod;) {
for (imp_proc_desc_t *proc=mod->proc; proc; ) {
to_free=proc;
proc=proc->next;
free(to_free);
}
to_free=mod;
mod=mod->next;
free(to_free);
}
}
/* Free imports stored in scan imports handle */
static void free_imps_in_scan_imps_hndl(scan_imps_hndl_t *p_hndl)
{
if (p_hndl->p_imp_mods) {
free_imp_mods(p_hndl->p_imp_mods);
p_hndl->p_imp_mods=NULL;
}
p_hndl->p_last_mod=NULL;
p_hndl->p_last_proc=NULL;
p_hndl->n_mods=0;
p_hndl->crt_new_list=FALSE;
}
/* Free scan imports handle */
static void free_scan_imps_hndl(scan_imps_hndl_t *p_hndl)
{
free_imps_in_scan_imps_hndl(p_hndl);
}
/* Initialize scan imports handle; returns TRUE on success */
static BOOL init_scan_imps_hndl(
scan_imps_hndl_t *p_hndl, ULONG64 mod_base, BOOL b_wow_chk)
{
BOOL ret=FALSE;
IDebugSymbols *DebugSymbols=NULL;
memset(p_hndl, 0, sizeof(*p_hndl));
if ((get_client()->QueryInterface(
__uuidof(IDebugSymbols), (void **)&DebugSymbols)) != S_OK) goto finish;
p_hndl->mod_base = mod_base;
ULONG64 sectab_addr;
if (!read_pe_headers(mod_base,
&p_hndl->dos_hdr, &p_hndl->nt_hdrs, §ab_addr, TRUE)) goto finish;
p_hndl->n_sects =
read_sectab(&p_hndl->nt_hdrs, sectab_addr, p_hndl->sectab, TRUE, TRUE);
if (!p_hndl->n_sects) goto finish;
ULONG64 mb;
if (b_wow_chk &&
DebugSymbols->GetModuleByModuleName("wow64", 0, NULL, &mb)==S_OK &&
DebugSymbols->GetModuleByModuleName("ntdll", 0, NULL, &mb)==S_OK &&
DebugSymbols->GetModuleByModuleName("ntdll32", 0, NULL, &mb)==S_OK &&
p_hndl->nt_hdrs.pe_tpy==pe_32bit)
{
p_hndl->wow64_emul = TRUE;
}
ret=TRUE;
finish:
if (DebugSymbols) DebugSymbols->Release();
if (!ret) free_scan_imps_hndl(p_hndl);
return ret;
}
static void init_scan_imps_hndl(
scan_imps_hndl_t *p_hndl, const dump_pe_hndl_t *p_dpe_hndl)
{
memset(p_hndl, 0, sizeof(*p_hndl));
p_hndl->mod_base = p_dpe_hndl->mod_base;
p_hndl->dos_hdr = p_dpe_hndl->dos_hdr;
p_hndl->nt_hdrs = p_dpe_hndl->nt_hdrs;
memcpy(p_hndl->sectab,
p_dpe_hndl->sectab, p_dpe_hndl->n_sects*sizeof(p_dpe_hndl->sectab[0]));
p_hndl->n_sects = p_dpe_hndl->n_sects;
/* wow64_emul is set to FALSE */
}
/* Resolve forwarder redirection string pointed by 'frwrd_name_addr' (the string
in the format "module.proc_name" or "module.#ordinal") to the forwarder proc
address. The function tries to resolve forwards to forwards until the final
code reference. Returns TRUE on success.
*/
static BOOL get_frwrd_proc_addr(scan_imps_hndl_t *p_hndl,
ULONG64 frwrd_name_addr, ULONG64 *p_reslv_addr, BOOL b_logs=FALSE)
{
BOOL ret=FALSE;
IDebugSymbols *DebugSymbols=NULL;
if ((get_client()->QueryInterface(
__uuidof(IDebugSymbols), (void **)&DebugSymbols)) != S_OK) goto finish;
char mod_name[MAX_PATH+1];
char proc_name[MAX_SYM_NAME+1];
{
/* read module and proc name from forwarder string */
char rd_buf[sizeof(mod_name)+sizeof(proc_name)+4];
if (!string_cpy_lt(rd_buf, frwrd_name_addr, sizeof(rd_buf))) goto finish;
/* mod name separated from proc name by '.' */
char *pc_dot = strchr(rd_buf, '.');
if (!pc_dot) {
if (b_logs) err_dbgprintf("Invalid forwarder name: %s\n", rd_buf);
goto finish;
}
*pc_dot++ = 0;
strncpy(proc_name, pc_dot, sizeof(proc_name));
proc_name[sizeof(proc_name)-1] = 0;
if (p_hndl->wow64_emul && !strcmpi(rd_buf, "ntdll")) {
/* on emulated subsystem ntdll is substituted by the ntdll32 lib by
the Wow64 emulator; we need to search in the 32-bit version of
the library */
strcpy(mod_name, "ntdll32");
} else {
strncpy(mod_name, rd_buf, sizeof(mod_name));
mod_name[sizeof(mod_name)-1] = 0;
}
}
ULONG64 mod_base;
if (DebugSymbols->GetModuleByModuleName(mod_name, 0, NULL, &mod_base)!=S_OK)
{
if (b_logs)
err_dbgprintf("Unable to find the forwarder's module: %s\n", mod_name);
goto finish;
}
/* check if the cache may be used */
mod_exp_dir_t *p_ed = &p_hndl->ed_frwrd;
if (p_ed->mod_base != mod_base) {
p_ed->mod_base = mod_base;
if (!get_mod_exp_dir(p_ed, b_logs)) goto finish;
}
ULONG cb;
DWORD ord; /* index in EAT */
const char *pc_ord = strchr(proc_name, '#');
if (pc_ord)
{
/* proc given by an ordinal number */
pc_ord++;
errno = 0;
ord = strtoul(pc_ord, NULL, 10);
if (errno) {
if (b_logs)
err_dbgprintf("Forwarder's ordinal number conversion "
"problem: %s\n", &proc_name[0]);
goto finish;
}
if (ord < p_ed->ord_base) {
if (b_logs)
err_dbgprintf("Forwarder's ordinal number [0x%04X] larger than "
"the ordinal base [0x%04X]\n", ord, p_ed->ord_base);
goto finish;
}
ord = ord-p_ed->ord_base;
} else
{
/* proc given by name */
DWORD hint;
if (!get_name_hint_ord(p_ed, proc_name, &hint, &ord)) {
if (b_logs)
err_dbgprintf("Can't find forwarder's proc with the name: %s\n",
proc_name);
goto finish;
}
}
/* get forwarder proc addr basing on the EAT index */
DWORD proc_rva;
if (!(read_memory(p_ed->faddrs_addr + ord*sizeof(proc_rva),
&proc_rva, sizeof(proc_rva), &cb) && cb==sizeof(proc_rva))) goto finish;
ULONG64 proc_addr = RVA2ADDR(get_32uint_le(&proc_rva), p_ed->mod_base);
if ((p_ed->exp_dd_addr <= proc_addr) &&
(proc_addr < p_ed->exp_dd_addr+p_ed->exp_dd_sz))
{
/* if the resolved proc is forwarder we need to recursively resolve it */
ret = get_frwrd_proc_addr(p_hndl, proc_addr, p_reslv_addr, b_logs);
} else {
*p_reslv_addr = proc_addr;
ret=TRUE;
}
finish:
if (DebugSymbols) DebugSymbols->Release();
return ret;
}
/* Get the export information from a dll module about a proc pointed by the
'proc_addr'. 'ords', 'hints' and 'proc_names' are populated with the info
from the dll's export tab. These tabs have the same number of output elements
stored on response under the addr of 'p_n_synons'. If an elem in the
'proc_names' is NULL, then the corresponding item has no name (only an
ordinal). The pointers of 'proc_names' point to addresses in the
'pc_names_buf' with the length 'names_buf_sz'. If 'p_proc_mod_base' points to
value other than NULL, the value indicates the module base address used for
resolving the proc_addr. If the value is NULL the owning module of the
proc_addr will be used. 'p_proc_mod_base' will be set to the owning module
base. 'pc_mod_name' points to value other than NULL, it will get the owner's
module name. Min size of this buf is MAX_PATH+1. If 'b_logs' is TRUE print
error info. Returns TRUE for success, FALSE - error or 'proc_addr' not found.
*/
static BOOL get_exp_proc_info(scan_imps_hndl_t *p_hndl, ULONG64 *p_proc_mod_base,
ULONG64 proc_addr, DWORD ords[MAX_SYNONS], DWORD hints[MAX_SYNONS],
char* (proc_names)[MAX_SYNONS], char *pc_names_buf, size_t names_buf_sz,
DWORD *p_n_synons, char *pc_mod_name, BOOL b_logs)
{
BOOL ret=FALSE;
IDebugSymbols *DebugSymbols=NULL;
/* requested module base to search */
ULONG64 srch_mod_base = *p_proc_mod_base;
/* owning proc module base */
ULONG64 own_mod_base = NULL;
*p_n_synons=0;
if ((get_client()->QueryInterface(
__uuidof(IDebugSymbols), (void **)&DebugSymbols)) != S_OK) goto err;
if (DebugSymbols->GetModuleByOffset(proc_addr, 0, NULL, &own_mod_base)!=S_OK)
{
if (b_logs)
err_dbgprintf("Unable to find a module owning the proc addr: 0x%p\n",
proc_addr);
goto err;
}
*p_proc_mod_base = own_mod_base;
if (srch_mod_base==NULL) srch_mod_base=own_mod_base;
/* check if the cache may be used */
mod_exp_dir_t *p_ed = &p_hndl->ed_reslv;
if (p_ed->mod_base != srch_mod_base) {
p_ed->mod_base = srch_mod_base;
if (!get_mod_exp_dir(p_ed, b_logs)) goto err;
}
ULONG cb;
BOOL forwd_resv;
for (UINT pass=0; *p_n_synons==0 && pass<2; pass++)
{
if (pass==0) {
/* at the 1st resolving pass, forwards are resolved only for
proc located in external module to the currently searched */
forwd_resv = (srch_mod_base!=own_mod_base);
} else {
/* at the 2nd pass additionally resolve
forwards to the owning module */
if (forwd_resv) break;
else
if ((p_ed->exp_dd_addr <= proc_addr) &&
(proc_addr < p_ed->exp_dd_addr+p_ed->exp_dd_sz)) break;
else
forwd_resv=TRUE;
}
DWORD ord;
ULONG64 faddrs_addr;
/* go through Export Address Table looking for the proc_addr */
DWORD exp_proc_rva;
for (ord=0, faddrs_addr=p_ed->faddrs_addr;
ord < p_ed->n_faddrs;
faddrs_addr+=sizeof(exp_proc_rva), ord++)
{
if (!(read_memory(
faddrs_addr, &exp_proc_rva, sizeof(exp_proc_rva), &cb) &&
cb==sizeof(exp_proc_rva))) goto err;
ULONG64 exp_proc_addr =
RVA2ADDR(get_32uint_le(&exp_proc_rva), srch_mod_base);
if (forwd_resv && (p_ed->exp_dd_addr <= exp_proc_addr) &&
(exp_proc_addr < p_ed->exp_dd_addr+p_ed->exp_dd_sz))
{
/* the exported address is a forward reference; we need to
convert this address to the actual address inside the
referenced module */
if (!get_frwrd_proc_addr(p_hndl, exp_proc_addr, &exp_proc_addr))
continue;
}
if (exp_proc_addr==proc_addr) {
if (*p_n_synons < MAX_SYNONS) {
ords[(*p_n_synons)++] = p_ed->ord_base+ord;
/* don't brake and search for more entries with the same addr */
} else {
if (b_logs) {
warn_dbgprintf(
"Too much symbols with the same addr [0x%p] in the "
"module (base: 0x%p); break searching for more "
"symbol duplicates for this addr\n",
proc_addr, srch_mod_base);
}
break;
}
}
}
}
if (*p_n_synons==0) {
if (b_logs)
err_dbgprintf("Unable to find the proc for the addr: 0x%p\n",
proc_addr);
goto err;
}
/* look for the names for the found ordinals */
size_t alloc_bts=0;
for (DWORD i=0; i<*p_n_synons; i++)
{
ULONG64 fords_addr = p_ed->fords_addr;
proc_names[i] = NULL;
hints[i] = 0;
WORD ot_ord; /* ord read from the ordinals table */
for (DWORD hint=0;
hint < p_ed->n_fnames;
fords_addr+=sizeof(ot_ord), hint++)
{
if (!(read_memory(fords_addr,
&ot_ord, sizeof(ot_ord), &cb) && cb==sizeof(ot_ord))) goto err;
ot_ord = get_16uint_le(&ot_ord);
if (ords[i]==p_ed->ord_base+(DWORD)ot_ord)
{
DWORD proc_name_rva;
char buf[MAX_SYM_NAME+1];
/* read proc name address */
if (!(read_memory(p_ed->fnames_addr + hint*sizeof(proc_name_rva),
&proc_name_rva, sizeof(proc_name_rva), &cb) &&
cb==sizeof(proc_name_rva))) goto err;
/* ... and store the proc name */
ULONG64 proc_name_addr =
RVA2ADDR(get_32uint_le(&proc_name_rva), srch_mod_base);
if (!string_cpy_lt(buf, proc_name_addr, sizeof(buf))) goto err;
size_t name_len = strlen(buf);
/* ... in the names_buf */
if (alloc_bts+name_len+1 <= names_buf_sz) {
proc_names[i] = pc_names_buf+alloc_bts;
alloc_bts += name_len+1;
strcpy(proc_names[i], buf);
hints[i] = hint;
} else {
if (b_logs)
warn_dbgprintf(
"Buffer too small to store proc name %s [0x%p] from "
"module (base: 0x%p)", buf, proc_addr, srch_mod_base);
}
break;
}
}
}
/* store mod name */
if (pc_mod_name)
if (!string_cpy_lt(pc_mod_name, p_ed->mod_name_addr, MAX_PATH+1))
goto err;
no_err:
ret=TRUE;
err:
if (DebugSymbols) DebugSymbols->Release();
return ret;
}
/* Resolve proc name, its ord, hint and write them under 'p_out_ord', 'p_out_hint'
and 'pc_out_proc_name' (min MAX_PATH+1 long). Number of entries with the same
'proc_addr' is returned under 'p_n_synons'. Returns TRUE if the resolution
finishes with success, FALSE otherwise.
*/
static BOOL resv_proc_name_mod(scan_imps_hndl_t *p_hndl, ULONG64 mod_base,
ULONG64 proc_addr, DWORD *p_out_ord, DWORD *p_out_hint, char *pc_out_proc_name,
DWORD *p_n_synons, BOOL b_logs)
{
BOOL ret=FALSE;
DWORD n_synons;
DWORD ords[MAX_SYNONS];
DWORD hints[MAX_SYNONS];
char* (proc_names)[MAX_SYNONS];
char name_buf[0x1000];
char mod_name[MAX_PATH+1];
ULONG64 proc_mod_base = mod_base;
if (!get_exp_proc_info(p_hndl, &proc_mod_base, proc_addr, ords, hints,
proc_names, name_buf, sizeof(name_buf), &n_synons, mod_name, b_logs))
goto finish;
DWORD i;
*p_n_synons = n_synons;
/* The resolved proc is:
- the 1st matching proc with a name
- the 1st ord if the proc doesn't have any name */
for (i=0; i<n_synons; i++) {
if (proc_names[i]) {
*p_out_ord = ords[i];
*p_out_hint = hints[i];
strncpy(pc_out_proc_name, proc_names[i], MAX_PATH+1);
pc_out_proc_name[MAX_PATH]=0;
break;
}
}
if (i>=n_synons) {
*p_out_ord = ords[0];
*p_out_hint = 0;
*pc_out_proc_name = 0;
}
if (n_synons>1)
{
/* printed regardless of b_logs flag - the func finished with
success but there is a need to inform about the duplicates */
warn_dbgprintf(
"Proc with many aliases has been found [0x%p]: ", proc_addr);
for (i=0; i<n_synons; i++) {
dbgprintf("%s#0x%04X%s", (proc_names[i] ? proc_names[i] : ""),
ords[i], (i+1<n_synons ? ", " : ""));
}
dbgprintf("\n Resolved to: %s!%s#0x%04X\n",
mod_name, pc_out_proc_name, *p_out_ord);
}
ret=TRUE;
finish:
return ret;
}
/* Info about proc duplicates in the lastly resolved module's list of imports */
static void print_info_proc_dups(const scan_imps_hndl_t *p_hndl)
{
BOOL hdr_printed=FALSE;
const char *sep = " ";
/* are there any modules loaded? */
if (!p_hndl->p_imp_mods) goto finish;
for (const imp_proc_desc_t *p_proc = p_hndl->p_last_mod->proc;
p_proc != p_hndl->p_last_proc;
p_proc=p_proc->next)
{
if (p_proc->dups>0)
{
const char *pc_mod_name = (*(p_hndl->p_last_mod->name) ?
p_hndl->p_last_mod->name : "<unspec>");
if (!hdr_printed)
warn_dbgprintf("Found duplicates in a module %s:", pc_mod_name);
hdr_printed = TRUE;
dbgprintf("%s%s#0x%04X [%d]",
sep, p_proc->name, p_proc->ord, p_proc->dups+1);
sep = ", ";
}
}
if (hdr_printed) dbgprintf("\n");
finish:
return;
}
/* Info about module duplicates in the resolved list of imports */
static void print_info_mod_dups(const scan_imps_hndl_t *p_hndl)
{
BOOL hdr_printed=FALSE;
const char *sep = " ";
for (const imp_mod_desc_t *p_mod = p_hndl->p_imp_mods;
p_mod != p_hndl->p_last_mod;
p_mod = p_mod->next)
{
if (p_mod->dups>0 && *(p_mod->name))
{
if (!hdr_printed) info_dbgprintf("Duplicated modules found:");
hdr_printed = TRUE;
dbgprintf("%s%s [%d]", sep, p_mod->name, p_mod->dups+1);
sep = ", ";
}
}
if (hdr_printed) dbgprintf("\n");
}
/* Mark end of a module's imports list */
static void mark_end_mod_imp_list(scan_imps_hndl_t *p_hndl)
{
p_hndl->crt_new_list = TRUE;
if (p_hndl->p_imp_mods)
{
if (*(p_hndl->p_last_mod->name))
{
if (p_hndl->wow64_emul &&
!strcmpi(p_hndl->p_last_mod->name, "ntdll32.dll"))
{
/* for 32-bit target emulated on Wow64 platform the ntdll32 is
an alias to ntdll, whereas ntdll itself is a 64-bit version
of the library; therefore we need to rename the ntdll32 to
ntdll keeping all ordinals, hints and proc names untouched */
/* even num of bytes, enough name space */
strcpy(p_hndl->p_last_mod->name, "ntdll.dll");
}
/* calculate dups of the added module */
for (imp_mod_desc_t *p_mod = p_hndl->p_imp_mods;
p_mod != p_hndl->p_last_mod;
p_mod = p_mod->next)
{
if (!strcmpi(p_mod->name, p_hndl->p_last_mod->name)) {
p_mod->dups++;
break;
}
}
}
print_info_proc_dups(p_hndl);
}
finish:
return;
}
/* Compare 2 proc; returns TRUE if the same */
inline static BOOL cmp_procs(const char *pc_proc1_name,
DWORD proc1_ord, const char *pc_proc2_name, DWORD proc2_ord)
{
BOOL ret=FALSE;
if (*pc_proc1_name && *pc_proc2_name)
ret = !strcmp(pc_proc1_name, pc_proc2_name);
else
ret = (proc1_ord==proc2_ord);
return ret;
}
/* Add importing module to the scan imports handle's list */
static BOOL add_imp_mod(scan_imps_hndl_t *p_hndl,
ULONG64 mod_iat_addr, ULONG64 mod_base, const char *pc_proc_mod_name)
{
BOOL ret=FALSE;
size_t proc_mod_name_len = strlen(pc_proc_mod_name);
imp_mod_desc_t *p_new_mod_desc;
size_t to_alloc = sizeof(*p_new_mod_desc)+proc_mod_name_len+4;
p_new_mod_desc = (imp_mod_desc_t*)malloc(to_alloc);
if (!p_new_mod_desc) goto finish;
p_new_mod_desc->mod_base = mod_base;
p_new_mod_desc->iat_addr = mod_iat_addr;
p_new_mod_desc->n_procs = 0;
p_new_mod_desc->proc = NULL;
p_new_mod_desc->dups = 0;
p_new_mod_desc->hnt_sz = 0;
p_new_mod_desc->hnt_nrnd_sz = 0;
p_new_mod_desc->next = NULL;
strcpy(p_new_mod_desc->name, pc_proc_mod_name);
/* even padd byte */
if (!(proc_mod_name_len&1)) p_new_mod_desc->name[proc_mod_name_len+1]=0;
if (p_hndl->p_imp_mods)
p_hndl->p_last_mod->next = p_new_mod_desc;
else
p_hndl->p_imp_mods = p_new_mod_desc;
p_hndl->p_last_mod = p_new_mod_desc;
p_hndl->p_last_proc = NULL;
p_hndl->crt_new_list = FALSE;
p_hndl->n_mods++;
ret=TRUE;
finish:
return ret;
}
/* Add to the scan imports handle's list of procs of an importing module. If
required the importing module itself may also be added. The input params
as returned by the resv_proc_name_mod(). TRUE returned on success. FALSE: no
memory error.
*/
static BOOL add_imp_mod_proc(scan_imps_hndl_t *p_hndl, DWORD ord, DWORD hint,
const char *pc_proc_name, ULONG64 mod_iat_addr, ULONG64 mod_base,
const char *pc_proc_mod_name, BOOL b_check_proc_dups)
{
BOOL ret=FALSE;
/* create new mod's list if required */
if (!p_hndl->p_imp_mods || p_hndl->crt_new_list) {
if (!add_imp_mod(p_hndl, mod_iat_addr, mod_base, pc_proc_mod_name))
goto finish;
}
/* add proc name to the current module's list */
size_t proc_name_len = strlen(pc_proc_name);
imp_proc_desc_t *p_new_proc_desc;
size_t to_alloc = sizeof(*p_new_proc_desc)+proc_name_len+4;
p_new_proc_desc = (imp_proc_desc_t*)malloc(to_alloc);
if (!p_new_proc_desc) goto finish;
p_new_proc_desc->ord = ord;
p_new_proc_desc->hint = (proc_name_len>0 ? hint : (DWORD)-1);
p_new_proc_desc->dups = 0;
p_new_proc_desc->next = NULL;
strcpy(p_new_proc_desc->name, pc_proc_name);
/* even padd byte */
if (!(proc_name_len&1)) p_new_proc_desc->name[proc_name_len+1]=0;
if (p_hndl->p_last_proc)
p_hndl->p_last_proc->next = p_new_proc_desc;
else
p_hndl->p_last_mod->proc = p_new_proc_desc;
p_hndl->p_last_proc = p_new_proc_desc;
p_hndl->p_last_mod->n_procs++;
if (proc_name_len>0) {
p_hndl->p_last_mod->hnt_sz += 2+RNDUP_W(proc_name_len+1);
p_hndl->p_last_mod->hnt_nrnd_sz += 2+proc_name_len+1;
}