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#include "mupdf/fitz.h"
#include "fitz-imp.h"
#include <string.h>
typedef struct tar_entry_s tar_entry;
typedef struct fz_tar_archive_s fz_tar_archive;
struct tar_entry_s
{
char *name;
int offset, size;
};
struct fz_tar_archive_s
{
fz_archive super;
int count;
tar_entry *entries;
};
static inline int isoctdigit(char c)
{
return c >= '0' && c <= '7';
}
static inline int otoi(const char *s)
{
int value = 0;
while (*s && isoctdigit(*s))
{
value *= 8;
value += (*s) - '0';
s++;
}
return value;
}
static void drop_tar_archive(fz_context *ctx, fz_archive *arch)
{
fz_tar_archive *tar = (fz_tar_archive *) arch;
int i;
for (i = 0; i < tar->count; ++i)
fz_free(ctx, tar->entries[i].name);
fz_free(ctx, tar->entries);
}
static void ensure_tar_entries(fz_context *ctx, fz_tar_archive *tar)
{
fz_stream *file = tar->super.file;
char name[100];
char octsize[12];
char typeflag;
int offset, blocks, size;
size_t n;
tar->count = 0;
fz_seek(ctx, file, 0, SEEK_SET);
while (1)
{
offset = fz_tell(ctx, file);
n = fz_read(ctx, file, (unsigned char *) name, nelem(name));
if (n < nelem(name))
fz_throw(ctx, FZ_ERROR_GENERIC, "premature end of data in tar entry name");
name[nelem(name) - 1] = '\0';
if (strlen(name) == 0)
break;
fz_seek(ctx, file, 24, 1);
n = fz_read(ctx, file, (unsigned char *) octsize, nelem(octsize));
if (n < nelem(octsize))
fz_throw(ctx, FZ_ERROR_GENERIC, "premature end of data in tar entry size");
size = otoi(octsize);
fz_seek(ctx, file, 20, 1);
typeflag = fz_read_byte(ctx, file);
fz_seek(ctx, file, 355, 1);
blocks = (size + 511) / 512;
fz_seek(ctx, file, blocks * 512, 1);
if (typeflag != '0')
continue;
tar->entries = fz_resize_array(ctx, tar->entries, tar->count + 1, sizeof *tar->entries);
tar->entries[tar->count].name = fz_strdup(ctx, name);
tar->entries[tar->count].offset = offset;
tar->entries[tar->count].size = size;
tar->count++;
}
}
static tar_entry *lookup_tar_entry(fz_context *ctx, fz_tar_archive *tar, const char *name)
{
int i;
for (i = 0; i < tar->count; i++)
if (!fz_strcasecmp(name, tar->entries[i].name))
return &tar->entries[i];
return NULL;
}
static fz_stream *open_tar_entry(fz_context *ctx, fz_archive *arch, const char *name)
{
fz_tar_archive *tar = (fz_tar_archive *) arch;
fz_stream *file = tar->super.file;
tar_entry *ent;
ent = lookup_tar_entry(ctx, tar, name);
if (!ent)
fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find named tar archive entry");
fz_seek(ctx, file, ent->offset + 512, 0);
return fz_open_null_filter(ctx, file, ent->size, fz_tell(ctx, file));
}
static fz_buffer *read_tar_entry(fz_context *ctx, fz_archive *arch, const char *name)
{
fz_tar_archive *tar = (fz_tar_archive *) arch;
fz_stream *file = tar->super.file;
fz_buffer *ubuf;
tar_entry *ent;
ent = lookup_tar_entry(ctx, tar, name);
if (!ent)
fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find named tar archive entry");
ubuf = fz_new_buffer(ctx, ent->size);
fz_try(ctx)
{
fz_seek(ctx, file, ent->offset + 512, 0);
ubuf->len = fz_read(ctx, file, ubuf->data, ent->size);
if (ubuf->len != ent->size)
fz_throw(ctx, FZ_ERROR_GENERIC, "cannot read entire archive entry");
}
fz_catch(ctx)
{
fz_drop_buffer(ctx, ubuf);
fz_rethrow(ctx);
}
return ubuf;
}
static int has_tar_entry(fz_context *ctx, fz_archive *arch, const char *name)
{
fz_tar_archive *tar = (fz_tar_archive *) arch;
tar_entry *ent = lookup_tar_entry(ctx, tar, name);
return ent != NULL;
}
static const char *list_tar_entry(fz_context *ctx, fz_archive *arch, int idx)
{
fz_tar_archive *tar = (fz_tar_archive *) arch;
if (idx < 0 || idx >= tar->count)
return NULL;
return tar->entries[idx].name;
}
static int count_tar_entries(fz_context *ctx, fz_archive *arch)
{
fz_tar_archive *tar = (fz_tar_archive *) arch;
return tar->count;
}
int
fz_is_tar_archive(fz_context *ctx, fz_stream *file)
{
const unsigned char signature[6] = { 'u', 's', 't', 'a', 'r', ' ' };
unsigned char data[6];
size_t n;
fz_seek(ctx, file, 257, 0);
n = fz_read(ctx, file, data, nelem(data));
if (n != nelem(signature))
return 0;
if (memcmp(data, signature, nelem(signature)))
return 0;
return 1;
}
fz_archive *
fz_open_tar_archive_with_stream(fz_context *ctx, fz_stream *file)
{
fz_tar_archive *tar;
if (!fz_is_tar_archive(ctx, file))
fz_throw(ctx, FZ_ERROR_GENERIC, "cannot recognize tar archive");
tar = fz_new_derived_archive(ctx, file, fz_tar_archive);
tar->super.format = "tar";
tar->super.count_entries = count_tar_entries;
tar->super.list_entry = list_tar_entry;
tar->super.has_entry = has_tar_entry;
tar->super.read_entry = read_tar_entry;
tar->super.open_entry = open_tar_entry;
tar->super.drop_archive = drop_tar_archive;
fz_try(ctx)
{
ensure_tar_entries(ctx, tar);
}
fz_catch(ctx)
{
fz_drop_archive(ctx, &tar->super);
fz_rethrow(ctx);
}
return &tar->super;
}
fz_archive *
fz_open_tar_archive(fz_context *ctx, const char *filename)
{
fz_archive *tar = NULL;
fz_stream *file;
file = fz_open_file(ctx, filename);
fz_try(ctx)
tar = fz_open_tar_archive_with_stream(ctx, file);
fz_always(ctx)
fz_drop_stream(ctx, file);
fz_catch(ctx)
fz_rethrow(ctx);
return tar;
}
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