Move modalias parsing code to generic code

1 files changed, 87 insertions, 0 deletions

diff --git a/modalias.c b/modalias.c
new file mode 100644
index 0000000..6df02f0
--- /dev/null
+++ b/modalias.c
@@ -0,0 +1,87 @@
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/utsname.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <modprobe.h>
+#include <dirent.h>
+#include "common.h"
+
+static char *aliasdefault = NULL;
+
+static void set_default_alias_file(void) {
+	struct utsname rel_buf;
+	if (!aliasdefault) {
+		char *dirname;
+		char *fallback_aliases = table_name_to_file("fallback-modules.alias");
+		char *aliasfilename;
+		struct stat st_alias, st_fallback;
+
+		uname(&rel_buf);
+		asprintf(&dirname, "%s/%s", MODULE_DIR, rel_buf.release);
+		asprintf(&aliasfilename, "%s/modules.alias", dirname);
+		free(dirname);
+
+		/* fallback on ldetect-lst's modules.alias and prefer it if more recent */
+		if (stat(aliasfilename, &st_alias) ||
+		    (!stat(fallback_aliases, &st_fallback) && st_fallback.st_mtime > st_alias.st_mtime)) {
+			free(aliasfilename);
+			aliasdefault = fallback_aliases;
+		} else {
+			aliasdefault = aliasfilename;
+		}
+	}
+}
+
+char *modalias_resolve_module(const char *modalias) {
+	struct module_command *commands = NULL;
+	struct module_options *modoptions = NULL;
+	struct module_alias *aliases = NULL;
+	struct module_blacklist *blacklist = NULL;
+	const char *config = NULL;
+
+	if (!aliasdefault)
+		set_default_alias_file();
+
+	/* Returns the resolved alias, options */
+	read_toplevel_config(config, modalias, 0,
+			     0, &modoptions, &commands, &aliases, &blacklist);
+
+	if (!aliases) {
+		/* We only use canned aliases as last resort. */
+		char *dkms_file = table_name_to_file("dkms-modules.alias");
+		char *alias_filelist[] = {
+			"/lib/module-init-tools/ldetect-lst-modules.alias",
+			aliasdefault,
+			dkms_file,
+			NULL,
+		};
+		char **alias_file = alias_filelist;
+		while (!aliases && *alias_file) {
+			read_config(*alias_file, modalias, 0,
+				    0, &modoptions, &commands,
+				    &aliases, &blacklist);
+			aliases = apply_blacklist(aliases, blacklist);
+			alias_file++;
+		}
+		free(dkms_file);
+	}
+	if (aliases) {
+		// take the last one because we find eg: generic/ata_generic/sata_sil
+		while (aliases->next)
+			aliases = aliases->next;
+
+		return strdup(aliases->module);
+	}
+
+	return NULL;
+}
+
+void modalias_cleanup(void) {
+    ifree(aliasdefault);
+}