Reduce number of string duplications in phar (php#17814)

We don't need to duplicate these strings from the resource, we can just
use them with an offset.
To prove this was safe, I had to make the arguments const and then
propagate that everywhere, so this patch also introduces some more
constness.

Author: ndossche

ext/phar/phar_internal.h

@@ -420,8 +420,8 @@ char *phar_decompress_filter(phar_entry_info * entry, int return_unknown);
 char *phar_compress_filter(phar_entry_info * entry, int return_unknown);
 
 /* void phar_remove_virtual_dirs(phar_archive_data *phar, char *filename, size_t filename_len); */
-void phar_add_virtual_dirs(phar_archive_data *phar, char *filename, size_t filename_len);
-zend_result phar_mount_entry(phar_archive_data *phar, char *filename, size_t filename_len, char *path, size_t path_len);
+void phar_add_virtual_dirs(phar_archive_data *phar, const char *filename, size_t filename_len);
+zend_result phar_mount_entry(phar_archive_data *phar, char *filename, size_t filename_len, const char *path, size_t path_len);
 zend_string *phar_find_in_include_path(zend_string *file, phar_archive_data **pphar);
 char *phar_fix_filepath(char *path, size_t *new_len, int use_cwd);
 phar_entry_info * phar_open_jit(phar_archive_data *phar, phar_entry_info *entry, char **error);
@@ -463,10 +463,10 @@ extern HashTable cached_alias;
 bool phar_archive_delref(phar_archive_data *phar);
 void phar_entry_delref(phar_entry_data *idata);
 
-phar_entry_info *phar_get_entry_info(phar_archive_data *phar, char *path, size_t path_len, char **error, int security);
-phar_entry_info *phar_get_entry_info_dir(phar_archive_data *phar, char *path, size_t path_len, char dir, char **error, int security);
-phar_entry_data *phar_get_or_create_entry_data(char *fname, size_t fname_len, char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security);
-zend_result phar_get_entry_data(phar_entry_data **ret, char *fname, size_t fname_len, char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security);
+phar_entry_info *phar_get_entry_info(phar_archive_data *phar, const char *path, size_t path_len, char **error, int security);
+phar_entry_info *phar_get_entry_info_dir(phar_archive_data *phar, const char *path, size_t path_len, char dir, char **error, int security);
+phar_entry_data *phar_get_or_create_entry_data(char *fname, size_t fname_len, const char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security);
+zend_result phar_get_entry_data(phar_entry_data **ret, char *fname, size_t fname_len, const char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security);
 void phar_flush_ex(phar_archive_data *archive, zend_string *user_stub, bool is_default_stub, char **error);
 void phar_flush(phar_archive_data *archive, char **error);
 zend_result phar_detect_phar_fname_ext(const char *filename, size_t filename_len, const char **ext_str, size_t *ext_len, int executable, int for_create, int is_complete);
@@ -484,6 +484,6 @@ typedef enum {
 	pcr_err_empty_entry
 } phar_path_check_result;
 
-phar_path_check_result phar_path_check(char **p, size_t *len, const char **error);
+phar_path_check_result phar_path_check(const char **p, size_t *len, const char **error);
 
 END_EXTERN_C()

ext/phar/phar_object.c

@@ -1976,7 +1976,7 @@ static zend_result phar_copy_file_contents(phar_entry_info *entry, php_stream *f
 }
 /* }}} */
 
-static zend_object *phar_rename_archive(phar_archive_data **sphar, char *ext) /* {{{ */
+static zend_object *phar_rename_archive(phar_archive_data **sphar, const char *ext) /* {{{ */
 {
 	const char *oldname = NULL;
 	phar_archive_data *phar = *sphar;
@@ -3484,7 +3484,7 @@ PHP_METHOD(Phar, copy)
 	}
 
 	size_t tmp_len = ZSTR_LEN(new_file);
-	char *tmp_new_file = ZSTR_VAL(new_file);
+	const char *tmp_new_file = ZSTR_VAL(new_file);
 	if (phar_path_check(&tmp_new_file, &tmp_len, &pcr_error) > pcr_is_ok) {
 		zend_throw_exception_ex(spl_ce_UnexpectedValueException, 0,
 				"file \"%s\" contains invalid characters %s, cannot be copied from \"%s\" in phar %s", ZSTR_VAL(new_file), pcr_error, ZSTR_VAL(old_file), phar_obj->archive->fname);

ext/phar/phar_path_check.re

@@ -18,7 +18,7 @@
 
 #include "phar_internal.h"
 
-phar_path_check_result phar_path_check(char **s, size_t *len, const char **error)
+phar_path_check_result phar_path_check(const char **s, size_t *len, const char **error)
 {
 	const unsigned char *p = (const unsigned char*)*s;
 	const unsigned char *m;

ext/phar/stream.c

@@ -162,7 +162,7 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 {
 	phar_archive_data *phar;
 	phar_entry_data *idata;
-	char *internal_file;
+	const char *internal_file;
 	char *error;
 	HashTable *pharcontext;
 	php_url *resource = NULL;
@@ -189,7 +189,7 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 	phar_request_initialize();
 
 	/* strip leading "/" */
-	internal_file = estrndup(ZSTR_VAL(resource->path) + 1, ZSTR_LEN(resource->path) - 1);
+	internal_file = ZSTR_VAL(resource->path) + 1;
 	if (mode[0] == 'w' || (mode[0] == 'r' && mode[1] == '+')) {
 		if (NULL == (idata = phar_get_or_create_entry_data(ZSTR_VAL(resource->host), ZSTR_LEN(resource->host), internal_file, strlen(internal_file), mode, 0, &error, 1))) {
 			if (error) {
@@ -198,7 +198,6 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 			} else {
 				php_stream_wrapper_log_error(wrapper, options, "phar error: file \"%s\" could not be created in phar \"%s\"", internal_file, ZSTR_VAL(resource->host));
 			}
-			efree(internal_file);
 			php_url_free(resource);
 			return NULL;
 		}
@@ -207,7 +206,6 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 		}
 		fpf = php_stream_alloc(&phar_ops, idata, NULL, mode);
 		php_url_free(resource);
-		efree(internal_file);
 
 		if (context && Z_TYPE(context->options) != IS_UNDEF && (pzoption = zend_hash_str_find(HASH_OF(&context->options), "phar", sizeof("phar")-1)) != NULL) {
 			pharcontext = HASH_OF(pzoption);
@@ -237,15 +235,13 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 			/* retrieve the stub */
 			if (FAILURE == phar_get_archive(&phar, ZSTR_VAL(resource->host), ZSTR_LEN(resource->host), NULL, 0, NULL)) {
 				php_stream_wrapper_log_error(wrapper, options, "file %s is not a valid phar archive", ZSTR_VAL(resource->host));
-				efree(internal_file);
 				php_url_free(resource);
 				return NULL;
 			}
 			if (phar->is_tar || phar->is_zip) {
 				if ((FAILURE == phar_get_entry_data(&idata, ZSTR_VAL(resource->host), ZSTR_LEN(resource->host), ".phar/stub.php", sizeof(".phar/stub.php")-1, "r", 0, &error, 0)) || !idata) {
 					goto idata_error;
 				}
-				efree(internal_file);
 				if (opened_path) {
 					*opened_path = strpprintf(MAXPATHLEN, "%s", phar->fname);
 				}
@@ -256,7 +252,6 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 				if (stream == NULL) {
 					if (UNEXPECTED(FAILURE == phar_open_archive_fp(phar))) {
 						php_stream_wrapper_log_error(wrapper, options, "phar error: could not reopen phar \"%s\"", ZSTR_VAL(resource->host));
-						efree(internal_file);
 						php_url_free(resource);
 						return NULL;
 					}
@@ -285,7 +280,6 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 				if (opened_path) {
 					*opened_path = strpprintf(MAXPATHLEN, "%s", phar->fname);
 				}
-				efree(internal_file);
 				goto phar_stub;
 			}
 		}
@@ -298,7 +292,6 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 			} else {
 				php_stream_wrapper_log_error(wrapper, options, "phar error: \"%s\" is not a file in phar \"%s\"", internal_file, ZSTR_VAL(resource->host));
 			}
-			efree(internal_file);
 			php_url_free(resource);
 			return NULL;
 		}
@@ -317,7 +310,6 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 		php_stream_wrapper_log_error(wrapper, options, "%s", error);
 		efree(error);
 		phar_entry_delref(idata);
-		efree(internal_file);
 		return NULL;
 	}
 
@@ -340,7 +332,6 @@ static php_stream * phar_wrapper_open_url(php_stream_wrapper *wrapper, const cha
 	if (opened_path) {
 		*opened_path = zend_strpprintf_unchecked(MAXPATHLEN, "phar://%s/%S", idata->phar->fname, idata->internal_file->filename);
 	}
-	efree(internal_file);
 phar_stub:
 	fpf = php_stream_alloc(&phar_ops, idata, NULL, mode);
 	return fpf;
@@ -662,7 +653,8 @@ static int phar_wrapper_stat(php_stream_wrapper *wrapper, const char *url, int f
 static int phar_wrapper_unlink(php_stream_wrapper *wrapper, const char *url, int options, php_stream_context *context) /* {{{ */
 {
 	php_url *resource;
-	char *internal_file, *error;
+	const char *internal_file;
+	char *error;
 	int internal_file_len;
 	phar_entry_data *idata;
 	phar_archive_data *pphar;
@@ -695,7 +687,7 @@ static int phar_wrapper_unlink(php_stream_wrapper *wrapper, const char *url, int
 	}
 
 	/* need to copy to strip leading "/", will get touched again */
-	internal_file = estrndup(ZSTR_VAL(resource->path) + 1, ZSTR_LEN(resource->path) - 1);
+	internal_file = ZSTR_VAL(resource->path) + 1;
 	internal_file_len = ZSTR_LEN(resource->path) - 1;
 	if (FAILURE == phar_get_entry_data(&idata, ZSTR_VAL(resource->host), ZSTR_LEN(resource->host), internal_file, internal_file_len, "r", 0, &error, 1)) {
 		/* constraints of fp refcount were not met */
@@ -705,7 +697,6 @@ static int phar_wrapper_unlink(php_stream_wrapper *wrapper, const char *url, int
 		} else {
 			php_stream_wrapper_log_error(wrapper, options, "unlink of \"%s\" failed, file does not exist", url);
 		}
-		efree(internal_file);
 		php_url_free(resource);
 		return 0;
 	}
@@ -715,13 +706,11 @@ static int phar_wrapper_unlink(php_stream_wrapper *wrapper, const char *url, int
 	if (idata->internal_file->fp_refcount > 1) {
 		/* more than just our fp resource is open for this file */
 		php_stream_wrapper_log_error(wrapper, options, "phar error: \"%s\" in phar \"%s\", has open file pointers, cannot unlink", internal_file, ZSTR_VAL(resource->host));
-		efree(internal_file);
 		php_url_free(resource);
 		phar_entry_delref(idata);
 		return 0;
 	}
 	php_url_free(resource);
-	efree(internal_file);
 	phar_entry_remove(idata, &error);
 	if (error) {
 		php_stream_wrapper_log_error(wrapper, options, "%s", error);

ext/phar/util.c

@@ -189,7 +189,7 @@ int phar_seek_efp(phar_entry_info *entry, zend_off_t offset, int whence, zend_of
 /* }}} */
 
 /* mount an absolute path or uri to a path internal to the phar archive */
-zend_result phar_mount_entry(phar_archive_data *phar, char *filename, size_t filename_len, char *path, size_t path_len) /* {{{ */
+zend_result phar_mount_entry(phar_archive_data *phar, char *filename, size_t filename_len, const char *path, size_t path_len) /* {{{ */
 {
 	phar_entry_info entry = {0};
 	php_stream_statbuf ssb;
@@ -472,7 +472,7 @@ static zend_result phar_separate_entry_fp(phar_entry_info *entry, char **error)
  * appended, truncated, or read.  For read, if the entry is marked unmodified, it is
  * assumed that the file pointer, if present, is opened for reading
  */
-zend_result phar_get_entry_data(phar_entry_data **ret, char *fname, size_t fname_len, char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security) /* {{{ */
+zend_result phar_get_entry_data(phar_entry_data **ret, char *fname, size_t fname_len, const char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security) /* {{{ */
 {
 	phar_archive_data *phar;
 	phar_entry_info *entry;
@@ -632,7 +632,7 @@ zend_result phar_get_entry_data(phar_entry_data **ret, char *fname, size_t fname
 /**
  * Create a new dummy file slot within a writeable phar for a newly created file
  */
-phar_entry_data *phar_get_or_create_entry_data(char *fname, size_t fname_len, char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security) /* {{{ */
+phar_entry_data *phar_get_or_create_entry_data(char *fname, size_t fname_len, const char *path, size_t path_len, const char *mode, char allow_dir, char **error, int security) /* {{{ */
 {
 	phar_archive_data *phar;
 	phar_entry_info *entry, etemp;
@@ -1234,7 +1234,7 @@ char * phar_decompress_filter(phar_entry_info * entry, int return_unknown) /* {{
 /**
  * retrieve information on a file contained within a phar, or null if it ain't there
  */
-phar_entry_info *phar_get_entry_info(phar_archive_data *phar, char *path, size_t path_len, char **error, int security) /* {{{ */
+phar_entry_info *phar_get_entry_info(phar_archive_data *phar, const char *path, size_t path_len, char **error, int security) /* {{{ */
 {
 	return phar_get_entry_info_dir(phar, path, path_len, 0, error, security);
 }
@@ -1245,7 +1245,7 @@ phar_entry_info *phar_get_entry_info(phar_archive_data *phar, char *path, size_t
  * valid pre-existing empty directory entries
  */
 // TODO: convert this to use zend_string too
-phar_entry_info *phar_get_entry_info_dir(phar_archive_data *phar, char *path, size_t path_len, char dir, char **error, int security) /* {{{ */
+phar_entry_info *phar_get_entry_info_dir(phar_archive_data *phar, const char *path, size_t path_len, char dir, char **error, int security) /* {{{ */
 {
 	const char *pcr_error;
 	phar_entry_info *entry;
@@ -2006,7 +2006,7 @@ zend_result phar_create_signature(phar_archive_data *phar, php_stream *fp, char
 /* }}} */
 
 // TODO: convert this to zend_string too
-void phar_add_virtual_dirs(phar_archive_data *phar, char *filename, size_t filename_len) /* {{{ */
+void phar_add_virtual_dirs(phar_archive_data *phar, const char *filename, size_t filename_len) /* {{{ */
 {
 	const char *s;
 	zend_string *str;