/* restable.c - Decoding PE and NE resource tables
 *
 * Copyright (C) 1998 Oskar Liljeblad
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <inttypes.h>		/* ? */
#include "gettext.h"		/* Gnulib */
#define _(s) gettext(s)
#define N_(s) gettext_noop(s)
#include "common/intutil.h"
#include "xalloc.h"		/* Gnulib */
#include "xvasprintf.h"	/* Gnulib */
#include "minmax.h"		/* Gnulib */
#include "common/error.h"
#include "wrestool.h"
#include "win32.h"
#include "fileread.h"

static bool decode_pe_resource_id (WinLibrary *, WinResource *, uint32_t);
static bool decode_ne_resource_id (WinLibrary *, WinResource *, uint16_t);
static WinResource *list_ne_type_resources (WinLibrary *, int *);
static WinResource *list_ne_name_resources (WinLibrary *, WinResource *, int *);
static WinResource *list_pe_resources (WinLibrary *, Win32ImageResourceDirectory *, int, int *);
static int calc_vma_size (WinLibrary *);
static void do_resources_recurs (WinLibrary *, WinResource *, WinResource *, WinResource *, WinResource *, const char *, const char *, const char *, DoResourceCallback);
static char *get_resource_id_quoted (WinResource *);
static WinResource *find_with_resource_array(WinLibrary *, WinResource *, const char *);
static WinResource *list_resources (WinLibrary *fi, WinResource *res, int *count);
static bool compare_resource_id (WinResource *wr, const char *id);

/* Check whether access to a PE_SECTIONS is allowed */
#define RETURN_IF_BAD_PE_SECTIONS(ret, module)                                              \
    do {                                                                                    \
        void* pe_sec_;                                                                      \
        RETURN_IF_BAD_POINTER(ret, PE_HEADER(module)->optional_header);                     \
        RETURN_IF_BAD_POINTER(ret, PE_HEADER(module)->file_header.number_of_sections);      \
        pe_sec_ = PE_SECTIONS(module);                                                      \
        RETURN_IF_BAD_OFFSET(ret, pe_sec_, sizeof(Win32ImageSectionHeader)                  \
            * PE_HEADER(module)->file_header.number_of_sections);                           \
    } while(0)

/* do_resources:
 *   Do something for each resource matching type, name and lang.
 */

void
do_resources (WinLibrary *fi, const char *type, const char *name, const char *lang, DoResourceCallback cb)
{
    WinResource *type_wr;
    WinResource *name_wr;
    WinResource *lang_wr;

    type_wr = malloc(sizeof(WinResource)*3);
    name_wr = type_wr + 1;
    lang_wr = type_wr + 2;
    memset(type_wr, 0, sizeof(WinResource)*3);

    do_resources_recurs(fi, NULL, type_wr, name_wr, lang_wr, type, name, lang, cb);

    free(type_wr);
}

/* what is each entry in this directory level for? type, name or language? */
#define WINRESOURCE_BY_LEVEL(x) ((x)==0 ? type_wr : ((x)==1 ? name_wr : lang_wr))

/* does the id of this entry match the specified id? */
#define LEVEL_MATCHES(x) (x == NULL || x ## _wr->id[0] == '\0' || compare_resource_id(x ## _wr, x))

static void
do_resources_recurs (WinLibrary *fi, WinResource *base, WinResource *type_wr,
                     WinResource *name_wr, WinResource *lang_wr,
                     const char *type, const char *name, const char *lang, DoResourceCallback cb)
{
    int c, rescnt;
    WinResource *wr;

    /* get a list of all resources at this level */
    wr = list_resources (fi, base, &rescnt);
    if (wr == NULL)
        return;

    /* process each resource listed */
    for (c = 0 ; c < rescnt ; c++) {
        /* (over)write the corresponding WinResource holder with the current */
        memcpy(WINRESOURCE_BY_LEVEL(wr[c].level), wr+c, sizeof(WinResource));
        if ((base && (wr[c].level <= base->level))
            || (wr[c].level >= 3))
        {
            warn(_("%s: resource structure malformed"), fi->name);
            return;
        }

        /* go deeper unless there is something that does NOT match */
        if (LEVEL_MATCHES(type) && LEVEL_MATCHES(name) && LEVEL_MATCHES(lang)) {
            if (wr->is_directory)
                do_resources_recurs (fi, wr+c, type_wr, name_wr, lang_wr, type, name, lang, cb);
            else
                cb(fi, wr+c, type_wr, name_wr, lang_wr);
        }
    }

    /* since we're moving back one level after this, unset the
     * WinResource holder used on this level */
    memset(WINRESOURCE_BY_LEVEL(wr[0].level), 0, sizeof(WinResource));
}

void
print_resources_callback (WinLibrary *fi, WinResource *wr,
                          WinResource *type_wr, WinResource *name_wr,
                          WinResource *lang_wr)
{
    const char *type, *offset;
    int32_t id;
    size_t size;
    char *type_quoted, *name_quoted, *lang_quoted;

    /* get named resource type if possible */
    type = NULL;
    if (parse_int32(type_wr->id, &id))
        type = res_type_id_to_string(id);

    /* get offset and size info on resource */
    offset = get_resource_entry(fi, wr, &size);
    if (offset == NULL)
        return;

    type_quoted = get_resource_id_quoted(type_wr);
    name_quoted = get_resource_id_quoted(name_wr);
    lang_quoted = get_resource_id_quoted(lang_wr);
    printf(_("--type=%s --name=%s%s%s [%s%s%soffset=0x%x size=%zu]\n"),
      type_quoted,
      name_quoted,
      (lang_wr->id[0] != '\0' ? _(" --language=") : ""),
      lang_quoted,
      (type != NULL ? "type=" : ""),
      (type != NULL ? type : ""),
      (type != NULL ? " " : ""),
      (uint32_t) (offset - fi->memory), size);
    free(type_quoted);
    free(name_quoted);
    free(lang_quoted);
}

/* return the resource id quoted if it's a string, otherwise just return it */
static char *
get_resource_id_quoted (WinResource *wr)
{
    if (wr->numeric_id || wr->id[0] == '\0')
        return xstrdup(wr->id);

    return xasprintf("'%s'", wr->id);
}

static bool
compare_resource_id (WinResource *wr, const char *id)
{
    if (wr->numeric_id) {
        int32_t cmp1, cmp2;
        if (id[0] == '+')
            return false;
        if (id[0] == '-')
            id++;
        if (!parse_int32(wr->id, &cmp1) || !parse_int32(id, &cmp2) || cmp1 != cmp2)
            return false;
    } else {
        if (id[0] == '-')
            return false;
        if (id[0] == '+')
            id++;
        if (strcmp(wr->id, id))
            return false;
    }

    return true;
}

static bool
decode_pe_resource_id (WinLibrary *fi, WinResource *wr, uint32_t value)
{
    if (value & IMAGE_RESOURCE_NAME_IS_STRING) {	/* numeric id */
        int c, len;
        uint16_t *mem = (uint16_t *)
          (fi->first_resource + (value & ~IMAGE_RESOURCE_NAME_IS_STRING));

        /* copy each char of the string, and terminate it */
        RETURN_IF_BAD_POINTER(false, *mem);
        len = mem[0];
        RETURN_IF_BAD_OFFSET(false, &mem[1], sizeof(uint16_t) * len);

        len = MIN(mem[0], WINRES_ID_MAXLEN);
        for (c = 0 ; c < len ; c++)
            wr->id[c] = mem[c+1] & 0x00FF;
        wr->id[len] = '\0';
    } else {					/* Unicode string id */
        /* translate id into a string */
        snprintf(wr->id, WINRES_ID_MAXLEN, "%" PRIu32, value);
    }

    wr->numeric_id = (value & IMAGE_RESOURCE_NAME_IS_STRING ? false:true);
    return true;
}
 
void *
get_resource_entry (WinLibrary *fi, WinResource *wr, size_t *size)
{
    if (fi->is_PE_binary) {
        Win32ImageResourceDataEntry *dataent;

        dataent = (Win32ImageResourceDataEntry *) wr->children;
        RETURN_IF_BAD_POINTER(NULL, *dataent);
        *size = dataent->size;
        RETURN_IF_BAD_OFFSET(NULL, fi->memory + dataent->offset_to_data, *size);

        return fi->memory + dataent->offset_to_data;
    } else {
        Win16NENameInfo *nameinfo;
        int sizeshift;

        nameinfo = (Win16NENameInfo *) wr->children;
        sizeshift = *((uint16_t *) fi->first_resource - 1);
        *size = nameinfo->length << sizeshift;
        RETURN_IF_BAD_OFFSET(NULL, fi->memory + (nameinfo->offset << sizeshift), *size);

        return fi->memory + (nameinfo->offset << sizeshift);
    }
}

static bool
decode_ne_resource_id (WinLibrary *fi, WinResource *wr, uint16_t value)
{
    if (value & NE_RESOURCE_NAME_IS_NUMERIC) {		/* numeric id */
        /* translate id into a string */
        snprintf(wr->id, WINRES_ID_MAXLEN, "%d", value & ~NE_RESOURCE_NAME_IS_NUMERIC);
    } else {					/* ASCII string id */
        unsigned char len;
        char *mem = (char *) NE_HEADER(fi->memory)
                             + NE_HEADER(fi->memory)->rsrctab
                             + value;

        /* copy each char of the string, and terminate it */
        RETURN_IF_BAD_POINTER(false, *mem);
        len = mem[0];
        RETURN_IF_BAD_OFFSET(false, &mem[1], sizeof(char) * len);
        memcpy(wr->id, &mem[1], len);
        wr->id[len] = '\0';
    }

    wr->numeric_id = (value & NE_RESOURCE_NAME_IS_NUMERIC ? true:false);
    return true;
}

static WinResource *
list_pe_resources (WinLibrary *fi, Win32ImageResourceDirectory *pe_res, int level, int *count)
{
    WinResource *wr;
    unsigned int out_c;
    int dirent_c, rescnt;
    Win32ImageResourceDirectoryEntry *dirent
      = (Win32ImageResourceDirectoryEntry *) (pe_res + 1);

    /* count number of `type' resources */
    RETURN_IF_BAD_POINTER(NULL, *dirent);
    rescnt = pe_res->number_of_named_entries + pe_res->number_of_id_entries;
    *count = 0;
    if (rescnt == 0) return NULL;

    /* allocate WinResource's */
    wr = xmalloc(sizeof(WinResource) * rescnt);

    /* fill in the WinResource's */
    out_c = 0;
    for (dirent_c = 0 ; dirent_c < rescnt ; dirent_c++) {
        RETURN_IF_BAD_POINTER(NULL, dirent[dirent_c]);
        wr[out_c].this = pe_res;
        wr[out_c].level = level;
        wr[out_c].is_directory = (dirent[dirent_c].u2.s.data_is_directory);
        /* Require data to point somewhere after the directory */
        if (dirent[dirent_c].u2.s.offset_to_directory < sizeof(Win32ImageResourceDirectory))
            continue;
        wr[out_c].children = fi->first_resource + dirent[dirent_c].u2.s.offset_to_directory;

        /* fill in wr->id, wr->numeric_id */
        if (!decode_pe_resource_id (fi, wr + out_c, dirent[dirent_c].u1.name))
            continue;

        ++out_c;
        ++(*count);
    }
    if (out_c == 0) {
        free(wr);
        return NULL;
    }

    return wr;
}

static WinResource *
list_ne_name_resources (WinLibrary *fi, WinResource *typeres, int *count)
{
    int c, rescnt;
    WinResource *wr;
    Win16NETypeInfo *typeinfo = (Win16NETypeInfo *) typeres->this;
    Win16NENameInfo *nameinfo = (Win16NENameInfo *) typeres->children;

    /* count number of `type' resources */
    RETURN_IF_BAD_POINTER(NULL, typeinfo->count);
    *count = rescnt = typeinfo->count;
    if (rescnt == 0) return NULL;

    /* allocate WinResource's */
    wr = xmalloc(sizeof(WinResource) * rescnt);

    /* fill in the WinResource's */
    for (c = 0 ; c < rescnt ; c++) {
        RETURN_IF_BAD_POINTER(NULL, nameinfo[c]);
        wr[c].this = nameinfo+c;
        wr[c].is_directory = false;
        wr[c].children = nameinfo+c;
        wr[c].level = 1;

        /* fill in wr->id, wr->numeric_id */
        if (!decode_ne_resource_id (fi, wr + c, (nameinfo+c)->id)) {
            free(wr);
            return NULL;
        }
    }

    return wr;
}

static WinResource *
list_ne_type_resources (WinLibrary *fi, int *count)
{
    size_t c, rescnt;
    WinResource *wr;
    Win16NETypeInfo *typeinfo;

    /* count number of `type' resources */
    typeinfo = (Win16NETypeInfo *) fi->first_resource;
    RETURN_IF_BAD_POINTER(NULL, *typeinfo);
    for (rescnt = 0 ; typeinfo->type_id != 0 ; rescnt++) {
        if (((char *) NE_TYPEINFO_NEXT(typeinfo))+sizeof(uint16_t) > fi->memory + fi->total_size) {
            warn(_("%s: resource table invalid, ignoring remaining entries"), fi->name);
            break;
        }
        typeinfo = NE_TYPEINFO_NEXT(typeinfo);
        RETURN_IF_BAD_POINTER(NULL, *typeinfo);
    }
    *count = rescnt;
    if (rescnt == 0) return NULL;

    /* allocate WinResource's */
    wr = xmalloc(sizeof(WinResource) * rescnt);

    /* fill in the WinResource's */
    typeinfo = (Win16NETypeInfo *) fi->first_resource;
    for (c = 0 ; c < rescnt ; c++) {
        wr[c].this = typeinfo;
        wr[c].is_directory = (typeinfo->count != 0);
        wr[c].children = typeinfo+1;
        wr[c].level = 0;

        /* fill in wr->id, wr->numeric_id */
        if (!decode_ne_resource_id (fi, wr + c, typeinfo->type_id)) {
            free(wr);
            return NULL;
        }

        typeinfo = NE_TYPEINFO_NEXT(typeinfo);
    }

    return wr;
}

/* list_resources:
 *   Return an array of WinResource's in the current
 *   resource level specified by res.
 */
static WinResource *
list_resources (WinLibrary *fi, WinResource *res, int *count)
{
    if (res != NULL && !res->is_directory)
        return NULL;

    if (fi->is_PE_binary) {
        return list_pe_resources(fi, (Win32ImageResourceDirectory *)
                 (res == NULL ? fi->first_resource : res->children),
                 (res == NULL ? 0 : res->level+1),
                 count);
    } else {
        return (res == NULL
                ? list_ne_type_resources(fi, count)
                : list_ne_name_resources(fi, res, count));
    }
}

static Win32ImageDataDirectory *
get_data_directory_entry (WinLibrary *fi, unsigned int entry)
{
    Win32ImageNTHeaders *pe_header;
    pe_header = PE_HEADER(fi->memory);
    RETURN_IF_BAD_POINTER(NULL, pe_header->optional_header.magic);

    if (pe_header->optional_header.magic == OPTIONAL_MAGIC_PE32) {
        Win32ImageOptionalHeader *optional_header = &(pe_header->optional_header);
        RETURN_IF_BAD_POINTER(false, optional_header->data_directory[entry]);
        return optional_header->data_directory + entry;
    } else if (pe_header->optional_header.magic == OPTIONAL_MAGIC_PE32_64) {
        Win32ImageOptionalHeader64 *optional_header =
            (Win32ImageOptionalHeader64*)&(pe_header->optional_header);
        RETURN_IF_BAD_POINTER(false, optional_header->data_directory[entry]);
        return optional_header->data_directory + entry;
    } else {
        return NULL;
    }
}

/* read_library:
 *
 * Read header and get resource directory offset in a Windows library
 * (AKA module).
 */
bool
read_library (WinLibrary *fi)
{
    /* check for DOS header signature `MZ' */
    RETURN_IF_BAD_POINTER(false, MZ_HEADER(fi->memory)->magic);
    if (MZ_HEADER(fi->memory)->magic == IMAGE_DOS_SIGNATURE) {
        DOSImageHeader *mz_header = MZ_HEADER(fi->memory);

        RETURN_IF_BAD_POINTER(false, mz_header->lfanew);
        if (mz_header->lfanew < sizeof (DOSImageHeader)) {
            warn(_("%s: not a PE or NE library"), fi->name);
            return false;
        }

        /* falls through */
    }

    RETURN_IF_BAD_OFFSET(false, MZ_HEADER(fi->memory), sizeof(Win32ImageNTHeaders));
    /* check for OS2 (Win16) header signature `NE' */
    RETURN_IF_BAD_POINTER(false, NE_HEADER(fi->memory)->magic);
    if (NE_HEADER(fi->memory)->magic == IMAGE_OS2_SIGNATURE) {
        OS2ImageHeader *header = NE_HEADER(fi->memory);
        uint16_t *alignshift;

        RETURN_IF_BAD_POINTER(false, header->rsrctab);
        RETURN_IF_BAD_POINTER(false, header->restab);
        if (header->rsrctab >= header->restab) {
            warn(_("%s: no resource directory found"), fi->name);
            return false;
        }

        fi->is_PE_binary = false;
        alignshift = (uint16_t *) ((uint8_t *) NE_HEADER(fi->memory) + header->rsrctab);
        fi->first_resource = ((uint8_t *) alignshift) + sizeof(uint16_t);
        RETURN_IF_BAD_POINTER(false, *(Win16NETypeInfo *) fi->first_resource);

        return true;
    }

    /* check for NT header signature `PE' */
    RETURN_IF_BAD_POINTER(false, PE_HEADER(fi->memory)->signature);
    if (PE_HEADER(fi->memory)->signature == IMAGE_NT_SIGNATURE) {
        Win32ImageSectionHeader *pe_sections;
        Win32ImageDataDirectory *dir;
        Win32ImageNTHeaders *pe_header;
        int d;

        /* allocate new memory */
        fi->total_size = calc_vma_size(fi);
        if (fi->total_size <= 0) {
            /* calc_vma_size has reported error */
            return false;
        }
        fi->memory = xrealloc(fi->memory, fi->total_size);

        /* relocate memory, start from last section */
        pe_header = PE_HEADER(fi->memory);
        RETURN_IF_BAD_PE_SECTIONS(false, fi->memory);
        pe_sections = PE_SECTIONS(fi->memory);

        /* we don't need to do OFFSET checking for the sections.
         * calc_vma_size has already done that */
        for (d = pe_header->file_header.number_of_sections - 1; d >= 0 ; d--) {
            Win32ImageSectionHeader *pe_sec = pe_sections + d;

            if (pe_sec->characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA)
                continue;

            //if (pe_sec->virtual_address + pe_sec->size_of_raw_data > fi->total_size)

            /* Protect against memory moves overwriting the section table */
            if ((uint8_t*)(fi->memory + pe_sec->virtual_address)
                < (uint8_t*)(pe_sections + pe_header->file_header.number_of_sections)) {
                warn(_("%s: invalid sections layout"), fi->name);
                return false;
            }

            RETURN_IF_BAD_OFFSET(0, fi->memory + pe_sec->virtual_address, pe_sec->size_of_raw_data);
            RETURN_IF_BAD_OFFSET(0, fi->memory + pe_sec->pointer_to_raw_data, pe_sec->size_of_raw_data);
            if (pe_sec->virtual_address != pe_sec->pointer_to_raw_data) {
                memmove(fi->memory + pe_sec->virtual_address,
                    fi->memory + pe_sec->pointer_to_raw_data,
                    pe_sec->size_of_raw_data);
            }
        }

        /* find resource directory */
        dir = get_data_directory_entry (fi, IMAGE_DIRECTORY_ENTRY_RESOURCE);
        if (dir == NULL) return false;
        if (dir->size == 0) {
            warn(_("%s: file contains no resources"), fi->name);
            return false;
        }

        fi->first_resource = ((uint8_t *) fi->memory) + dir->virtual_address;
        fi->is_PE_binary = true;
        return true;
    }

    /* other (unknown) header signature was found */
    warn(_("%s: not a PE or NE library"), fi->name);
    return false;
}

/* calc_vma_size:
 *   Calculate the total amount of memory needed for a 32-bit Windows
 *   module. Returns -1 if file was too small.
 */
static int
calc_vma_size (WinLibrary *fi)
{
    Win32ImageSectionHeader *seg;
    size_t c, segcount, size;

    size = 0;
    RETURN_IF_BAD_POINTER(-1, PE_HEADER(fi->memory)->file_header.number_of_sections);
    segcount = PE_HEADER(fi->memory)->file_header.number_of_sections;

    /* If there are no segments, just process file like it is.
     * This is (probably) not the right thing to do, but problems
     * will be delt with later anyway.
     */
    if (segcount == 0)
        return fi->total_size;

    RETURN_IF_BAD_PE_SECTIONS(-1, fi->memory);
    seg = PE_SECTIONS(fi->memory);
    RETURN_IF_BAD_POINTER(-1, *seg);
    
    for (c = 0 ; c < segcount ; c++) {
        RETURN_IF_BAD_POINTER(0, *seg);

        size = MAX(size, seg->virtual_address + seg->size_of_raw_data);
        /* I have no idea what misc.virtual_size is for... */
        size = MAX(size, seg->virtual_address + seg->misc.virtual_size);
        seg++;
    }

    return size;
}

static WinResource *
find_with_resource_array(WinLibrary *fi, WinResource *wr, const char *id)
{
    int c, rescnt;
    WinResource *return_wr;

    wr = list_resources(fi, wr, &rescnt);
    if (wr == NULL)
        return NULL;

    for (c = 0 ; c < rescnt ; c++) {
        if (compare_resource_id (&wr[c], id)) {
            /* duplicate WinResource and return it */
            return_wr = xmalloc(sizeof(WinResource));
            memcpy(return_wr, &wr[c], sizeof(WinResource));

            /* free old WinResource */
            free(wr);
            return return_wr;
        }
    }

    return NULL;
}

WinResource *
find_resource (WinLibrary *fi, const char *type, const char *name, const char *language, int *level)
{
    WinResource *wr;

    *level = 0;
    if (type == NULL)
        return NULL;
    wr = find_with_resource_array(fi, NULL, type);
    if (wr == NULL || !wr->is_directory)
        return wr;

    *level = 1;
    if (name == NULL)
        return wr;
    wr = find_with_resource_array(fi, wr, name);
    if (wr == NULL || !wr->is_directory)
        return wr;

    *level = 2;
    if (language == NULL)
        return wr;
    wr = find_with_resource_array(fi, wr, language);
    return wr;
}