From: Karel Zak <kzak@redhat.com>
Date: Thu, 8 Nov 2012 10:52:23 +0000 (+0100)
Subject: libmount: add private mnt_get_kernel_cmdline_option()
X-Git-Tag: v2.23-rc1~557
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f308ec19a71327b5601915ce6f8064eefe6ee0d5;p=thirdparty%2Futil-linux.git

libmount: add private mnt_get_kernel_cmdline_option()

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/include/pathnames.h b/include/pathnames.h
index 58bba519a3..a7f33fed59 100644
--- a/include/pathnames.h
+++ b/include/pathnames.h
@@ -152,5 +152,8 @@
 /* wdctl path */
 #define _PATH_WATCHDOG_DEV	"/dev/watchdog"
 
+/* kernel command line */
+#define _PATH_PROC_CMDLINE	"/proc/cmdline"
+
 #endif /* PATHNAMES_H */
 
diff --git a/libmount/src/mountP.h b/libmount/src/mountP.h
index bbaa2c6c4d..f28935d0d0 100644
--- a/libmount/src/mountP.h
+++ b/libmount/src/mountP.h
@@ -147,6 +147,8 @@ extern const char *mnt_get_utab_path(void);
 extern int mnt_get_filesystems(char ***filesystems, const char *pattern);
 extern void mnt_free_filesystems(char **filesystems);
 
+extern char *mnt_get_kernel_cmdline_option(const char *name);
+
 /* tab.c */
 extern int mnt_table_set_parser_fltrcb(	struct libmnt_table *tb,
 					int (*cb)(struct libmnt_fs *, void *),
diff --git a/libmount/src/utils.c b/libmount/src/utils.c
index 0cfefb3474..624633dd85 100644
--- a/libmount/src/utils.c
+++ b/libmount/src/utils.c
@@ -881,6 +881,78 @@ char *mnt_get_fs_root(const char *path, const char *mnt)
 	return res;
 }
 
+/*
+ * Search for @name kernel command parametr.
+ *
+ * Returns newly allocated string with parameter argument if the @name is
+ * specified as "name=" or returns pointer to @name or returns NULL if not
+ * found.
+ *
+ * For example cmdline: "aaa bbb=BBB ccc"
+ *
+ *	@name is "aaa"	--returns--> "aaa" (pointer to @name)
+ *	@name is "bbb=" --returns--> "BBB" (allocated)
+ *	@name is "foo"  --returns--> NULL
+ */
+char *mnt_get_kernel_cmdline_option(const char *name)
+{
+	FILE *f;
+	size_t len;
+	int val = 0;
+	char *p, *res = NULL;
+	char buf[BUFSIZ];	/* see kernel include/asm-generic/setup.h: COMMAND_LINE_SIZE */
+	const char *path = _PATH_PROC_CMDLINE;
+
+	assert(name);
+	assert(*name);
+
+#ifdef TEST_PROGRAM
+	path = safe_getenv("LIBMOUNT_KERNEL_CMDLINE");
+	if (!path)
+		path = _PATH_PROC_CMDLINE;
+#endif
+	f = fopen(path, "r");
+	if (!f)
+		return NULL;
+
+	p = fgets(buf, sizeof(buf), f);
+	fclose(f);
+
+	if (!p || !*p || *p == '\n')
+		return NULL;
+
+	len = strlen(buf);
+	*(buf + len - 1) = '\0';	/* remove last '\n' */
+
+	len = strlen(name);
+	if (len && *(name + len - 1) == '=')
+		val = 1;
+
+	while (p && *p) {
+		if (p != buf)
+			p++;
+		if (!(p = strstr(p, name)))
+			break;			/* not found the option */
+		if (p != buf && !isblank(*(p - 1)))
+			continue;		/* no space before the option */
+		if (!val && *(p + len) != '\0' && !isblank(*(p + len)))
+			continue;		/* no space behind the option */
+		if (val) {
+			char *v = p + len;
+
+			while (*p && !isblank(*p))	/* jump to the end of the argument */
+				p++;
+			*p = '\0';
+			res = strdup(v);
+			break;
+		} else
+			res = (char *) name;	/* option without '=' */
+		break;
+	}
+
+	return res;
+}
+
 #ifdef TEST_PROGRAM
 int test_match_fstype(struct libmnt_test *ts, int argc, char *argv[])
 {
@@ -974,6 +1046,24 @@ int test_chdir(struct libmnt_test *ts, int argc, char *argv[])
 	return rc;
 }
 
+int test_kernel_cmdline(struct libmnt_test *ts, int argc, char *argv[])
+{
+	char *name = argv[1];
+	char *res;
+
+	res = mnt_get_kernel_cmdline_option(name);
+	if (!res)
+		printf("'%s' not found\n", name);
+	else if (res == name)
+		printf("'%s' found\n", name);
+	else {
+		printf("'%s' found, argument: '%s'\n", name, res);
+		free(res);
+	}
+
+	return 0;
+}
+
 
 int main(int argc, char *argv[])
 {
@@ -986,6 +1076,7 @@ int main(int argc, char *argv[])
 	{ "--mountpoint",    test_mountpoint,      "<path>" },
 	{ "--fs-root",       test_fsroot,          "<path>" },
 	{ "--cd-parent",     test_chdir,           "<path>" },
+	{ "--kernel-cmdline",test_kernel_cmdline,  "<option> | <option>=" },
 	{ NULL }
 	};
 
diff --git a/tests/expected/libmount/utils-kernel-cmdline b/tests/expected/libmount/utils-kernel-cmdline
new file mode 100644
index 0000000000..2a6316583a
--- /dev/null
+++ b/tests/expected/libmount/utils-kernel-cmdline
@@ -0,0 +1,5 @@
+'selinux=' found, argument: '0'
+'selinux' not found
+'ro' found
+'ro=' not found
+'root=' found, argument: 'UUID=33230ae2-1093-4353-824c-f7ca09a2a882'
diff --git a/tests/ts/libmount/files/kernel_cmdline b/tests/ts/libmount/files/kernel_cmdline
new file mode 100644
index 0000000000..37a0c89e97
--- /dev/null
+++ b/tests/ts/libmount/files/kernel_cmdline
@@ -0,0 +1 @@
+rd.md=0 rd.lvm=0 rd.dm=0  KEYTABLE=us root=UUID=33230ae2-1093-4353-824c-f7ca09a2a882 rd.luks=0 SYSFONT=latarcyrheb-sun16 ro LANG=en_US.UTF-8 selinux=0
diff --git a/tests/ts/libmount/utils b/tests/ts/libmount/utils
index d425400adf..6facaad103 100755
--- a/tests/ts/libmount/utils
+++ b/tests/ts/libmount/utils
@@ -76,4 +76,13 @@ ts_init_subtest "fs-root-subdir2"
 ts_valgrind $TESTPROG --fs-root /etc &> $TS_OUTPUT
 ts_finalize_subtest
 
+ts_init_subtest "kernel-cmdline"
+export LIBMOUNT_KERNEL_CMDLINE="$TS_SELF/files/kernel_cmdline"
+ts_valgrind $TESTPROG --kernel-cmdline selinux= &>> $TS_OUTPUT
+ts_valgrind $TESTPROG --kernel-cmdline selinux &>> $TS_OUTPUT
+ts_valgrind $TESTPROG --kernel-cmdline ro &>> $TS_OUTPUT
+ts_valgrind $TESTPROG --kernel-cmdline ro= &>> $TS_OUTPUT
+ts_valgrind $TESTPROG --kernel-cmdline root= &>> $TS_OUTPUT
+ts_finalize_subtest
+
 ts_finalize