From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sun, 5 Mar 2023 15:41:13 +0000 (+0000)
Subject: file: Check if files are in ELF format
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=df71dc601fd6c7e75e859bb51176350ed9025df5;p=people%2Fstevee%2Fpakfire.git

file: Check if files are in ELF format

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

diff --git a/Makefile.am b/Makefile.am
index b7396e3d..6d2a0b7b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -301,6 +301,7 @@ libpakfire_la_CFLAGS = \
 	-fvisibility=hidden \
 	$(CAP_LIBS) \
 	$(CURL_CFLAGS) \
+	$(ELF_CFLAGS) \
 	$(JSON_C_CFLAGS) \
 	$(MAGIC_CFLAGS) \
 	$(MOUNT_CFLAGS) \
@@ -329,6 +330,7 @@ libpakfire_la_LIBADD = \
 	$(ARCHIVE_LIBS) \
 	$(CAP_LIBS) \
 	$(CURL_LIBS) \
+	$(ELF_LIBS) \
 	$(GPGME_LIBS) \
 	$(JSON_C_LIBS) \
 	$(LZMA_LIBS) \
diff --git a/configure.ac b/configure.ac
index cf84c5e3..91029206 100644
--- a/configure.ac
+++ b/configure.ac
@@ -255,6 +255,7 @@ AX_PYTHON_MODULE([tornado], [fatal])
 PKG_CHECK_MODULES([ARCHIVE], [libarchive >= 3.4.0])
 PKG_CHECK_MODULES([CAP], [libcap])
 PKG_CHECK_MODULES([CURL], [libcurl])
+PKG_CHECK_MODULES([ELF], [libelf])
 PKG_CHECK_MODULES([GPGME], [gpgme >= 1.6.0])
 PKG_CHECK_MODULES([PYTHON_DEVEL], [python-${PYTHON_VERSION}-embed],
 	[], [PKG_CHECK_MODULES([PYTHON_DEVEL], [python-${PYTHON_VERSION}])])
diff --git a/src/libpakfire/file.c b/src/libpakfire/file.c
index 1ea29042..d1cedb90 100644
--- a/src/libpakfire/file.c
+++ b/src/libpakfire/file.c
@@ -31,6 +31,8 @@
 
 #include <archive_entry.h>
 
+#include <gelf.h>
+
 #include <pakfire/constants.h>
 #include <pakfire/digest.h>
 #include <pakfire/file.h>
@@ -934,6 +936,17 @@ int pakfire_file_symlink_target_exists(struct pakfire_file* file) {
 	Classification
 */
 
+static int setup_libelf(struct pakfire* pakfire) {
+	// Initialize libelf
+	if (elf_version(EV_CURRENT) == EV_NONE) {
+		ERROR(pakfire, "Could not initialize libelf: %s\n", elf_errmsg(-1));
+
+		return 1;
+	}
+
+	return 0;
+}
+
 static int pakfire_file_classify_mode(struct pakfire_file* file) {
 	// Check for regular files
 	if (S_ISREG(file->st.st_mode))
@@ -1026,6 +1039,54 @@ static int pakfire_file_classify_magic(struct pakfire_file* file) {
 	return 0;
 }
 
+static int pakfire_file_classify_elf(struct pakfire_file* file) {
+	FILE* f = NULL;
+	Elf* elf = NULL;
+	int r;
+
+	// Don't run this if we already know that file is an ELF file
+	if (file->class & PAKFIRE_FILE_ELF)
+		return 0;
+
+	// Setup libelf
+	r = setup_libelf(file->pakfire);
+	if (r)
+		return r;
+
+	// Open the file
+	f = fopen(file->abspath, "r");
+	if (!f) {
+		ERROR(file->pakfire, "Could not open %s: %m\n", file->path);
+		return 1;
+	}
+
+	// Try to open the ELF file
+	elf = elf_begin(fileno(f), ELF_C_READ, NULL);
+	if (!elf) {
+		// We fail silently here, because this file might be in a different format
+		goto ERROR;
+	}
+
+	switch (elf_kind(elf)) {
+		// Mark this file as an ELF file
+		case ELF_K_ELF:
+			file->class |= PAKFIRE_FILE_ELF;
+			break;
+
+		// Ignore everything else
+		default:
+			break;
+	}
+
+ERROR:
+	if (elf)
+		elf_end(elf);
+	if (f)
+		fclose(f);
+
+	return 0;
+}
+
 int pakfire_file_classify(struct pakfire_file* file) {
 	int r;
 
@@ -1046,6 +1107,11 @@ int pakfire_file_classify(struct pakfire_file* file) {
 			r = pakfire_file_classify_magic(file);
 			if (r)
 				goto ERROR;
+
+			// Check if the file is an ELF file
+			r = pakfire_file_classify_elf(file);
+			if (r)
+				goto ERROR;
 		}
 	}
 
diff --git a/src/libpakfire/include/pakfire/file.h b/src/libpakfire/include/pakfire/file.h
index 18366180..dc26fa84 100644
--- a/src/libpakfire/include/pakfire/file.h
+++ b/src/libpakfire/include/pakfire/file.h
@@ -104,11 +104,12 @@ enum pakfire_file_classes {
 	PAKFIRE_FILE_SOCKET          = (1 << 6),
 
 	// The rest
-	PAKFIRE_FILE_EXECUTABLE      = (1 << 7),
-	PAKFIRE_FILE_PKGCONFIG       = (1 << 8),
-	PAKFIRE_FILE_PERL            = (1 << 9),
-	PAKFIRE_FILE_STATIC_LIBRARY  = (1 << 10),
-	PAKFIRE_FILE_LIBTOOL_ARCHIVE = (1 << 11),
+	PAKFIRE_FILE_ELF             = (1 << 7),
+	PAKFIRE_FILE_EXECUTABLE      = (1 << 8),
+	PAKFIRE_FILE_PKGCONFIG       = (1 << 9),
+	PAKFIRE_FILE_PERL            = (1 << 10),
+	PAKFIRE_FILE_STATIC_LIBRARY  = (1 << 11),
+	PAKFIRE_FILE_LIBTOOL_ARCHIVE = (1 << 12),
 };
 
 int pakfire_file_create_from_path(struct pakfire_file** file,