next portion of selinux updates: chcon, runcon. From

Yuichi Nakamura <himainu-ynakam@miomio.jp>  
KaiGai Kohei <busybox@kaigai.gr.jp>

selinux/runcon.c

@@ -0,0 +1,137 @@
+/*
+ * runcon [ context |
+ *         ( [ -c ] [ -r role ] [-t type] [ -u user ] [ -l levelrange ] )
+ *         command [arg1 [arg2 ...] ]
+ *
+ * attempt to run the specified command with the specified context.
+ *
+ * -r role  : use the current context with the specified role
+ * -t type  : use the current context with the specified type
+ * -u user  : use the current context with the specified user
+ * -l level : use the current context with the specified level range
+ * -c       : compute process transition context before modifying
+ *
+ * Contexts are interpreted as follows:
+ *
+ * Number of       MLS
+ * components    system?
+ *
+ *     1            -         type
+ *     2            -         role:type
+ *     3            Y         role:type:range
+ *     3            N         user:role:type
+ *     4            Y         user:role:type:range
+ *     4            N         error
+ *
+ * Port to busybox: KaiGai Kohei <kaigai@kaigai.gr.jp>
+ *                  - based on coreutils-5.97 (in Fedora Core 6)
+ */
+#include "busybox.h"
+#include <getopt.h>
+#include <selinux/context.h>
+#include <selinux/flask.h>
+
+static context_t runcon_compute_new_context(char *user, char *role, char *type, char *range,
+					    char *command, int compute_trans)
+{
+	context_t con;
+	security_context_t cur_context;
+
+	if (getcon(&cur_context))
+		bb_error_msg_and_die("cannot get current context");
+
+	if (compute_trans) {
+		security_context_t file_context, new_context;
+
+		if (getfilecon(command, &file_context) < 0)
+			bb_error_msg_and_die("cannot retrieve attributes of '%s'",
+					     command);
+		if (security_compute_create(cur_context, file_context,
+					    SECCLASS_PROCESS, &new_context))
+			bb_error_msg_and_die("unable to compute a new context");
+		cur_context = new_context;
+	}
+
+	con = context_new(cur_context);
+	if (!con)
+		bb_error_msg_and_die("'%s' is not a valid context", cur_context);
+	if (user && context_user_set(con, user))
+		bb_error_msg_and_die("failed to set new user '%s'", user);
+	if (type && context_type_set(con, type))
+		bb_error_msg_and_die("failed to set new type '%s'", type);
+	if (range && context_range_set(con, range))
+		bb_error_msg_and_die("failed to set new range '%s'", range);
+	if (role && context_role_set(con, role))
+		bb_error_msg_and_die("failed to set new role '%s'", role);
+
+	return con;
+}
+
+#if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
+static const struct option runcon_options[] = {
+	{ "user",       1, NULL, 'u' },
+	{ "role",       1, NULL, 'r' },
+	{ "type",       1, NULL, 't' },
+	{ "range",      1, NULL, 'l' },
+	{ "compute",    0, NULL, 'c' },
+	{ "help",       0, NULL, 'h' },
+	{ NULL,         0, NULL, 0 },
+};
+#endif
+
+#define OPTS_ROLE	(1<<0)	/* r */
+#define OPTS_TYPE	(1<<1)	/* t */
+#define OPTS_USER	(1<<2)	/* u */
+#define OPTS_RANGE	(1<<3)	/* l */
+#define OPTS_COMPUTE	(1<<4)	/* c */
+#define OPTS_HELP	(1<<5)	/* h */
+#define OPTS_CONTEXT_COMPONENT		(OPTS_ROLE | OPTS_TYPE | OPTS_USER | OPTS_RANGE)
+
+int runcon_main(int argc, char *argv[]);
+int runcon_main(int argc, char *argv[])
+{
+	char *role = NULL;
+	char *range = NULL;
+	char *user = NULL;
+	char *type = NULL;
+	char *context = NULL;
+	unsigned opts;
+	context_t con;
+
+	selinux_or_die();
+
+#if ENABLE_FEATURE_RUNCON_LONG_OPTIONS
+	applet_long_options = runcon_options;
+#endif
+	opt_complementary = "-1";
+	opts = getopt32(argc, argv, "r:t:u:l:ch", &role, &type, &user, &range);
+	argv += optind;
+
+	if (!(opts & OPTS_CONTEXT_COMPONENT)) {
+		context = *argv++;
+		if (!argv[0])
+			bb_error_msg_and_die("no command found");
+	}
+
+	if (context) {
+		con = context_new(context);
+		if (!con)
+			bb_error_msg_and_die("'%s' is not a valid context", context);
+	} else {
+		con = runcon_compute_new_context(user, role, type, range,
+				argv[0], opts & OPTS_COMPUTE);
+	}
+
+	if (security_check_context(context_str(con)))
+		bb_error_msg_and_die("'%s' is not a valid context",
+				     context_str(con));
+
+	if (setexeccon(context_str(con)))
+		bb_error_msg_and_die("cannot set up security context '%s'",
+				     context_str(con));
+
+	execvp(argv[0], argv);
+
+	bb_perror_msg_and_die("cannot execute '%s'", command);
+	return 1;
+}