From: Michael Tremer <michael.tremer@ipfire.org>
Date: Thu, 24 Oct 2024 16:52:02 +0000 (+0000)
Subject: linter: Read the payload into memory
X-Git-Tag: 0.9.30~909
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bae3d503f387239f6358d3d0c8f14b098546b688;p=pakfire.git

linter: Read the payload into memory

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

diff --git a/src/libpakfire/file.c b/src/libpakfire/file.c
index c162fa3b9..05c84181f 100644
--- a/src/libpakfire/file.c
+++ b/src/libpakfire/file.c
@@ -993,6 +993,20 @@ PAKFIRE_EXPORT void pakfire_file_set_mtime(struct pakfire_file* file, time_t tim
 	archive_entry_set_mtime(file->entry, time, 0);
 }
 
+int pakfire_file_has_payload(struct pakfire_file* file) {
+	// File must be a regular file
+	switch (pakfire_file_get_type(file)) {
+		case S_IFREG:
+			break;
+
+		default:
+			return 0;
+	}
+
+	// File must be larger than zero
+	return pakfire_file_get_size(file) > 0;
+}
+
 PAKFIRE_EXPORT const unsigned char* pakfire_file_get_digest(
 		struct pakfire_file* file, const enum pakfire_digest_types type, size_t* length) {
 
diff --git a/src/libpakfire/include/pakfire/file.h b/src/libpakfire/include/pakfire/file.h
index a175c91ff..468fb8657 100644
--- a/src/libpakfire/include/pakfire/file.h
+++ b/src/libpakfire/include/pakfire/file.h
@@ -132,6 +132,7 @@ enum pakfire_file_classes {
 	PAKFIRE_FILE_RUNTIME_LINKER  = (1 << 14),
 };
 
+int pakfire_file_has_payload(struct pakfire_file* file);
 
 int pakfire_file_read(struct pakfire_file* file, struct archive* reader, const char* path);
 
diff --git a/src/libpakfire/linter.c b/src/libpakfire/linter.c
index 99119b4ef..3f033ae15 100644
--- a/src/libpakfire/linter.c
+++ b/src/libpakfire/linter.c
@@ -20,6 +20,7 @@
 
 #include <errno.h>
 #include <stdlib.h>
+#include <sys/mman.h>
 #include <sys/queue.h>
 
 // libarchive
@@ -218,6 +219,107 @@ void pakfire_linter_set_result_callback(struct pakfire_linter* linter,
 	linter->result_data     = data;
 }
 
+static int pakfire_linter_read_file(
+		struct pakfire_linter* linter, struct pakfire_file* file, struct archive* a) {
+	int fd = -EBADF;
+	int r;
+
+	// Fetch path
+	const char* path = pakfire_file_get_path(file);
+
+	// Allocate a new buffer
+	fd = memfd_create(path, MFD_CLOEXEC);
+	if (fd < 0) {
+		CTX_ERROR(linter->ctx, "memfd_create() failed: %m\n");
+		r = -errno;
+		goto ERROR;
+	}
+
+	// Fetch file size
+	size_t size = pakfire_file_get_size(file);
+
+	// Tell the kernel how large the file would be
+	r = ftruncate(fd, size);
+	if (r < 0) {
+		CTX_ERROR(linter->ctx, "fallocate() failed: %m\n");
+		r = -errno;
+		goto ERROR;
+	}
+
+	// Read the payload into the file descriptor
+	r = archive_read_data_into_fd(a, fd);
+	if (r) {
+		CTX_ERROR(linter->ctx, "Could not read %s: %s\n", path, archive_error_string(a));
+		r = -errno;
+		goto ERROR;
+	}
+
+	// Check how much data we have read
+	off_t offset = lseek(fd, 0, SEEK_CUR);
+	if (offset < 0) {
+		CTX_ERROR(linter->ctx, "lseek() failed: %m\n");
+		r = -errno;
+		goto ERROR;
+	}
+
+	CTX_DEBUG(linter->ctx, "Read %jd byte(s)\n", offset);
+
+	// Check if we didn't read too little data
+	if ((size_t)offset < size) {
+		r = pakfire_linter_error(linter, "%s is actually smaller than %zu byte(s)", path, size);
+		if (r < 0)
+			goto ERROR;
+
+	// Check if we have not read more data
+	} else if ((size_t)offset > size) {
+		r = pakfire_linter_error(linter, "/%s is actually larger than %zu byte(s)", path, size);
+		if (r < 0)
+			goto ERROR;
+	}
+
+	// Rewind
+	offset = lseek(fd, 0, SEEK_SET);
+	if (offset) {
+		CTX_ERROR(linter->ctx, "Could not rewind: %m\n");
+		r = -errno;
+		goto ERROR;
+	}
+
+	return fd;
+
+ERROR:
+	if (fd >= 0)
+		close(fd);
+
+	return r;
+}
+
+static int pakfire_linter_payload(
+		struct pakfire_linter* linter, struct pakfire_file* file, struct archive* a) {
+	int fd = -EBADF;
+	int r;
+
+	// Fetch path
+	const char* path = pakfire_file_get_path(file);
+
+	CTX_DEBUG(linter->ctx, "Checking payload of %s\n", path);
+
+	// Read the file
+	fd = pakfire_linter_read_file(linter, file, a);
+	if (fd < 0) {
+		r = fd;
+		goto ERROR;
+	}
+
+	r = 0;
+
+ERROR:
+	if (fd >= 0)
+		close(fd);
+
+	return r;
+}
+
 static int pakfire_linter_name(struct pakfire_linter* linter) {
 	int r;
 
@@ -289,7 +391,7 @@ static int pakfire_linter_lint_fhs(
 	return 0;
 }
 
-static int pakfire_linter_payload(struct pakfire_archive* archive,
+static int pakfire_linter_file(struct pakfire_archive* archive,
 		struct archive* a, struct archive_entry* e, void* data) {
 	struct pakfire_linter* linter = data;
 	struct pakfire_file* file = NULL;
@@ -309,6 +411,13 @@ static int pakfire_linter_payload(struct pakfire_archive* archive,
 			 goto ERROR;
 	}
 
+	// Lint the payload for regular files
+	if (pakfire_file_has_payload(file)) {
+		r = pakfire_linter_payload(linter, file, a);
+		if (r < 0)
+			goto ERROR;
+	}
+
 ERROR:
 	if (file)
 		pakfire_file_unref(file);
@@ -325,7 +434,7 @@ int pakfire_linter_lint(struct pakfire_linter* linter) {
 		return r;
 
 	// Lint the payload
-	r = pakfire_archive_walk_payload(linter->archive, pakfire_linter_payload, linter);
+	r = pakfire_archive_walk_payload(linter->archive, pakfire_linter_file, linter);
 	if (r < 0)
 		return r;