From: Michael Tremer <michael.tremer@ipfire.org>
Date: Wed, 12 Apr 2023 13:55:35 +0000 (+0000)
Subject: archive: Remove any nested functions from reading files
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=94e71d7a7120900100e91fc54ec2d5c763ab2da3;p=people%2Fstevee%2Fpakfire.git

archive: Remove any nested functions from reading files

Nested functions require an executable stack which we want to avoid.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/archive.c b/src/libpakfire/archive.c
index 019438f6..880c2170 100644
--- a/src/libpakfire/archive.c
+++ b/src/libpakfire/archive.c
@@ -577,11 +577,17 @@ struct pakfire_archive_read_cookie {
 	// A reference to the archive
 	struct pakfire_archive* archive;
 
+	// The path we are reading
+	char path[PATH_MAX];
+
 	// A copy of the underlying file descriptor
 	FILE* f;
 
 	// The opened archive
 	struct archive* a;
+
+	// File handle opened by the cookie
+	FILE* __f;
 };
 
 static ssize_t __pakfire_archive_cookie_read(void* c, char* buffer, size_t size) {
@@ -612,9 +618,41 @@ static cookie_io_functions_t pakfire_archive_read_functions = {
 	.close = __pakfire_archive_cookie_close,
 };
 
+// Tries to find a matching file in the archive
+static int __pakfire_archive_read_filter(struct pakfire* pakfire, struct archive* a,
+		struct archive_entry* e, void* data) {
+	struct pakfire_archive_read_cookie* cookie = (struct pakfire_archive_read_cookie*)data;
+
+	// Fetch path
+	const char* p = archive_entry_pathname(e);
+	if (!p)
+		return PAKFIRE_WALK_ERROR;
+
+	// We found a match
+	if (strcmp(cookie->path, p) == 0)
+		return PAKFIRE_WALK_DONE;
+
+	// Otherwise we skip the file
+	return PAKFIRE_WALK_SKIP;
+}
+
+// Reads a matching file into memory
+static int __pakfire_archive_read(struct pakfire* pakfire, struct archive* a,
+		struct archive_entry* e, void* data) {
+	struct pakfire_archive_read_cookie* cookie = (struct pakfire_archive_read_cookie*)data;
+
+	// Create a file descriptor
+	cookie->__f = fopencookie(cookie, "r", pakfire_archive_read_functions);
+	if (!cookie->__f) {
+		ERROR(pakfire, "Could not open /%s: %m\n", cookie->path);
+		return PAKFIRE_WALK_ERROR;
+	}
+
+	return PAKFIRE_WALK_DONE;
+}
+
 PAKFIRE_EXPORT FILE* pakfire_archive_read(struct pakfire_archive* archive, const char* path) {
 	struct pakfire_archive_read_cookie* cookie = NULL;
-	FILE* f = NULL;
 	int r;
 
 	// Check if path is absolute
@@ -638,6 +676,13 @@ PAKFIRE_EXPORT FILE* pakfire_archive_read(struct pakfire_archive* archive, const
 	// Store a reference to the archive
 	cookie->archive = pakfire_archive_ref(archive);
 
+	// Store the path
+	r = pakfire_string_set(cookie->path, path);
+	if (r) {
+		ERROR(archive->pakfire, "Could not set path: %m\n");
+		goto ERROR;
+	}
+
 	// Clone the archive file descriptor to read the file independently
 	cookie->f = pakfire_archive_clone_file(archive);
 	if (!cookie->f) {
@@ -651,47 +696,14 @@ PAKFIRE_EXPORT FILE* pakfire_archive_read(struct pakfire_archive* archive, const
 	if (!cookie->a)
 		goto ERROR;
 
-	// Tries to find a matching file in the archive
-	int __pakfire_archive_read_filter(struct pakfire* pakfire, struct archive* a,
-			struct archive_entry* e, void* data) {
-		// Stop reading the archive after we have found our file
-		if (f)
-			return PAKFIRE_WALK_END;
-
-		// Fetch path
-		const char* p = archive_entry_pathname(e);
-		if (!p)
-			return PAKFIRE_WALK_ERROR;
-
-		// We found a match
-		if (strcmp(path, p) == 0)
-			return PAKFIRE_WALK_OK;
-
-		// Otherwise we skip the file
-		return PAKFIRE_WALK_SKIP;
-	}
-
-	// Reads a matching file into memory
-	int __pakfire_archive_read(struct pakfire* pakfire, struct archive* a,
-			struct archive_entry* e, void* data) {
-		// Create a file descriptor
-		f = fopencookie(cookie, "r", pakfire_archive_read_functions);
-		if (!f) {
-			ERROR(pakfire, "Could not open /%s: %m\n", path);
-			return PAKFIRE_WALK_ERROR;
-		}
-
-		return PAKFIRE_WALK_DONE;
-	}
-
 	// Walk through the archive
 	r = pakfire_walk(archive->pakfire, cookie->a,
-		__pakfire_archive_read, __pakfire_archive_read_filter, NULL);
+		__pakfire_archive_read, __pakfire_archive_read_filter, cookie);
 	if (r)
 		goto ERROR;
 
 	// Nothing found
-	if (!f) {
+	if (!cookie->__f) {
 		ERROR(archive->pakfire, "Could not find /%s\n", path);
 
 		// No such file or directory
@@ -699,7 +711,7 @@ PAKFIRE_EXPORT FILE* pakfire_archive_read(struct pakfire_archive* archive, const
 		goto ERROR;
 	}
 
-	return f;
+	return cookie->__f;
 
 ERROR:
 	if (cookie)