zip_source_zip_new.c [plain text]
#include <stdlib.h>
#include "zipint.h"
struct zip_source *
_zip_source_zip_new(struct zip *za, struct zip *srcza, zip_uint64_t srcidx, zip_flags_t flags,
zip_uint64_t start, zip_uint64_t len, const char *password)
{
zip_compression_implementation comp_impl;
zip_encryption_implementation enc_impl;
struct zip_source *src, *s2;
zip_uint64_t offset;
struct zip_stat st;
if (za == NULL)
return NULL;
if (srcza == NULL || srcidx >= srcza->nentry) {
_zip_error_set(&za->error, ZIP_ER_INVAL, 0);
return NULL;
}
if ((flags & ZIP_FL_UNCHANGED) == 0
&& (ZIP_ENTRY_DATA_CHANGED(srcza->entry+srcidx) || srcza->entry[srcidx].deleted)) {
_zip_error_set(&za->error, ZIP_ER_CHANGED, 0);
return NULL;
}
if (zip_stat_index(srcza, srcidx, flags|ZIP_FL_UNCHANGED, &st) < 0) {
_zip_error_set(&za->error, ZIP_ER_INTERNAL, 0);
return NULL;
}
if (flags & ZIP_FL_ENCRYPTED)
flags |= ZIP_FL_COMPRESSED;
if ((start > 0 || len > 0) && (flags & ZIP_FL_COMPRESSED)) {
_zip_error_set(&za->error, ZIP_ER_INVAL, 0);
return NULL;
}
if ((start > 0 || len > 0) && (start+len < start || start+len > st.size)) {
_zip_error_set(&za->error, ZIP_ER_INVAL, 0);
return NULL;
}
enc_impl = NULL;
if (((flags & ZIP_FL_ENCRYPTED) == 0) && (st.encryption_method != ZIP_EM_NONE)) {
if (password == NULL) {
_zip_error_set(&za->error, ZIP_ER_NOPASSWD, 0);
return NULL;
}
if ((enc_impl=_zip_get_encryption_implementation(st.encryption_method)) == NULL) {
_zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0);
return NULL;
}
}
comp_impl = NULL;
if ((flags & ZIP_FL_COMPRESSED) == 0) {
if (st.comp_method != ZIP_CM_STORE) {
if ((comp_impl=_zip_get_compression_implementation(st.comp_method)) == NULL) {
_zip_error_set(&za->error, ZIP_ER_COMPNOTSUPP, 0);
return NULL;
}
}
}
if ((offset=_zip_file_get_offset(srcza, srcidx, &za->error)) == 0)
return NULL;
if (st.comp_size == 0) {
if ((src=zip_source_buffer(za, NULL, 0, 0)) == NULL)
return NULL;
}
else {
if (start+len > 0 && enc_impl == NULL && comp_impl == NULL) {
struct zip_stat st2;
st2.size = len ? len : st.size-start;
st2.comp_size = st2.size;
st2.comp_method = ZIP_CM_STORE;
st2.mtime = st.mtime;
st2.valid = ZIP_STAT_SIZE|ZIP_STAT_COMP_SIZE|ZIP_STAT_COMP_METHOD|ZIP_STAT_MTIME;
if ((src=_zip_source_file_or_p(za, NULL, srcza->zp, offset+start, (zip_int64_t)st2.size, 0, &st2)) == NULL)
return NULL;
}
else {
if ((src=_zip_source_file_or_p(za, NULL, srcza->zp, offset, (zip_int64_t)st.comp_size, 0, &st)) == NULL)
return NULL;
}
if (enc_impl) {
if ((s2=enc_impl(za, src, st.encryption_method, 0, password)) == NULL) {
zip_source_free(src);
return NULL;
}
src = s2;
}
if (comp_impl) {
if ((s2=comp_impl(za, src, st.comp_method, 0)) == NULL) {
zip_source_free(src);
return NULL;
}
src = s2;
}
if (((flags & ZIP_FL_COMPRESSED) == 0 || st.comp_method == ZIP_CM_STORE)
&& (len == 0 || len == st.comp_size)) {
if ((s2=zip_source_crc(za, src, 1)) == NULL) {
zip_source_free(src);
return NULL;
}
src = s2;
}
if (start+len > 0 && (comp_impl || enc_impl)) {
if ((s2=zip_source_window(za, src, start, len ? len : st.size-start)) == NULL) {
zip_source_free(src);
return NULL;
}
src = s2;
}
}
return src;
}