From: Michael Tremer <michael.tremer@ipfire.org>
Date: Tue, 31 Dec 2024 13:56:54 +0000 (+0000)
Subject: util: Implement rewind() that returns any errors
X-Git-Tag: 0.9.30~629
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3260871b08b544f6e8f6071ec807fcb8e2c0ecae;p=pakfire.git

util: Implement rewind() that returns any errors

The Clang Static Analyzer complains that we don't check errno after
using rewind(). This patch adds a new version of this function which
returns an error.

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

diff --git a/src/libpakfire/archive.c b/src/libpakfire/archive.c
index 2421e1c1b..28c2a92d0 100644
--- a/src/libpakfire/archive.c
+++ b/src/libpakfire/archive.c
@@ -160,6 +160,7 @@ static int archive_file_close(struct archive* a, void* data) {
 static int archive_read_file_open(struct archive* a, FILE* f) {
 	struct pakfire_archive_file* file = NULL;
 	int fd = -EBADF;
+	int r;
 
 	// Fetch the underlying file descriptor
 	fd = fileno(f);
@@ -184,7 +185,9 @@ static int archive_read_file_open(struct archive* a, FILE* f) {
 	fd = -EBADF;
 
 	// Start reading at the beginning
-	rewind(f);
+	r = pakfire_rewind(f);
+	if (r < 0)
+		goto ERROR;
 
 	// Allocate an object
 	file = calloc(1, sizeof(*file));
@@ -265,7 +268,11 @@ static int pakfire_archive_compute_digests(struct pakfire_archive* archive) {
 	int r;
 
 	// Start reading at the beginning
-	rewind(archive->f);
+	r = pakfire_rewind(archive->f);
+	if (r < 0) {
+		ERROR(archive->ctx, "Could not rewind %s: %m\n", archive->path);
+		return -errno;
+	}
 
 	// Calculate digest
 	r = pakfire_digests_compute_from_file(archive->ctx, &archive->digests,
@@ -992,6 +999,9 @@ ERROR:
 }
 
 int pakfire_archive_copy(struct pakfire_archive* archive, const char* path) {
+	FILE* f = NULL;
+	int r;
+
 	if (!path)
 		return -EINVAL;
 
@@ -1003,23 +1013,29 @@ int pakfire_archive_copy(struct pakfire_archive* archive, const char* path) {
 	DEBUG(archive->ctx, "Copying %s to %s...\n", archive->path, path);
 
 	// Ensure we copy from the very beginning
-	rewind(archive->f);
+	r = pakfire_rewind(archive->f);
+	if (r < 0) {
+		ERROR(archive->ctx, "Could not rewind %s: %m\n", archive->path);
+		r = -errno;
+		goto ERROR;
+	}
 
 	// Ensure the parent directory exists
 	pakfire_mkparentdir(path, 0755);
 
 	// Open destination file
-	FILE* f = fopen(path, "w");
-	if (!f)
-		return -errno;
-
-	int r = 1;
+	f = fopen(path, "w");
+	if (!f) {
+		r = -errno;
+		goto ERROR;
+	}
 
 	// Copy everything
 	ssize_t bytes_written = sendfile(fileno(f), fileno(archive->f), NULL, size);
 	if (bytes_written < size) {
-		ERROR(archive->ctx, "Could not copy archive (%zd byte(s) written): %m\n",
-			bytes_written);
+		ERROR(archive->ctx,
+			"Could not copy archive (%zd byte(s) written): %m\n", bytes_written);
+		r = -errno;
 		goto ERROR;
 	}
 
@@ -1027,7 +1043,8 @@ int pakfire_archive_copy(struct pakfire_archive* archive, const char* path) {
 	r = 0;
 
 ERROR:
-	fclose(f);
+	if (f)
+		fclose(f);
 
 	// Delete the file on error
 	if (r)
diff --git a/src/libpakfire/compress.c b/src/libpakfire/compress.c
index 17a174fca..6d5d11e96 100644
--- a/src/libpakfire/compress.c
+++ b/src/libpakfire/compress.c
@@ -552,12 +552,17 @@ struct pakfire_compress {
 static int pakfire_copy_data_from_file(struct pakfire_ctx* ctx,
 		struct archive* archive, FILE* f) {
 	char buffer[BUFFER_SIZE];
+	int r;
 
 	ssize_t bytes_read = 0;
 	ssize_t bytes_written = 0;
 
 	// Read file from the very beginning - also allows calling this multiple times
-	rewind(f);
+	r = pakfire_rewind(f);
+	if (r < 0) {
+		ERROR(ctx, "Could not rewind file for copying: %m\n");
+		return -errno;
+	}
 
 	// Loop through the entire length of the file
 	while (!feof(f)) {
diff --git a/src/libpakfire/digest.c b/src/libpakfire/digest.c
index c42632844..8663680d5 100644
--- a/src/libpakfire/digest.c
+++ b/src/libpakfire/digest.c
@@ -467,7 +467,11 @@ ERROR:
 		EVP_MD_CTX_free(sha2_256_ctx);
 
 	// Reset file offset to the beginning
-	rewind(f);
+	r = pakfire_rewind(f);
+	if (r < 0) {
+		ERROR(ctx, "Could not rewind: %m\n");
+		return -errno;
+	}
 
 	return r;
 }
diff --git a/src/libpakfire/include/pakfire/util.h b/src/libpakfire/include/pakfire/util.h
index 9aee571aa..dba9f347a 100644
--- a/src/libpakfire/include/pakfire/util.h
+++ b/src/libpakfire/include/pakfire/util.h
@@ -50,6 +50,10 @@ const char* pakfire_path_relpath(const char* root, const char* path);
 
 // File stuff
 
+static inline int pakfire_rewind(FILE* f) {
+	return fseek(f, 0, SEEK_SET);
+}
+
 int pakfire_file_write(struct pakfire* pakfire, const char* path,
 	uid_t owner, gid_t group, mode_t mode, const char* format, ...)
 	__attribute__((format(printf, 6, 7)));
diff --git a/src/libpakfire/key.c b/src/libpakfire/key.c
index b5423681e..3bd6625ff 100644
--- a/src/libpakfire/key.c
+++ b/src/libpakfire/key.c
@@ -773,7 +773,12 @@ PAKFIRE_EXPORT char* pakfire_key_dump(struct pakfire_key* key) {
 	size_t length = ftell(f);
 
 	// Go back to the beginning of the file
-	rewind(f);
+	r = pakfire_rewind(f);
+	if (r < 0) {
+		ERROR(key->ctx, "Could not rewind buffer: %m\n");
+		r = -errno;
+		goto ERROR;
+	}
 
 	// Allocate a buffer
 	buffer = calloc(1, length + 1);
diff --git a/src/libpakfire/xfer.c b/src/libpakfire/xfer.c
index 0514f8220..d5d014b5b 100644
--- a/src/libpakfire/xfer.c
+++ b/src/libpakfire/xfer.c
@@ -872,7 +872,11 @@ static int pakfire_xfer_fail(struct pakfire_xfer* xfer, int code) {
 		}
 
 		// Rewind
-		rewind(xfer->fin);
+		r = pakfire_rewind(xfer->fin);
+		if (r < 0) {
+			ERROR(xfer->ctx, "Could not rewind output file: %m\n");
+			return -errno;
+		}
 	}
 
 	// Did we use a mirror?