binutils: Add the --namespace option to C based aa-exec

Switch to the policy in the namespace specified by the --namespace
option.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>

binutils/aa_exec.c

@@ -19,6 +19,7 @@
 #include <errno.h>
 #include <getopt.h>
 #include <libintl.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
@@ -28,6 +29,7 @@
 #define _(s) gettext(s)
 
 static const char *opt_profile = NULL;
+static const char *opt_namespace = NULL;
 static bool opt_debug = false;
 static bool opt_immediate = false;
 static bool opt_verbose = false;
@@ -49,6 +51,7 @@ static void usage(const char *name, bool error)
 		"\n"
 		"OPTIONS:\n"
 		"  -p PROFILE, --profile=PROFILE		PROFILE to confine <prog> with\n"
+		"  -n NAMESPACE, --namespace=NAMESPACE	NAMESPACE to confine <prog> in\n"
 		"  -d, --debug				show messages with debugging information\n"
 		"  -i, --immediate			change profile immediately instead of at exec\n"
 		"  -v, --verbose				show messages with stats\n"
@@ -112,11 +115,12 @@ static char **parse_args(int argc, char **argv)
 		{"debug", no_argument, 0, 'd'},
 		{"help", no_argument, 0, 'h'},
 		{"profile", required_argument, 0, 'p'},
+		{"namespace", required_argument, 0, 'n'},
 		{"immediate", no_argument, 0, 'i'},
 		{"verbose", no_argument, 0, 'v'},
 	};
 
-	while ((opt = getopt_long(argc, argv, "+dhp:iv", long_opts, NULL)) != -1) {
+	while ((opt = getopt_long(argc, argv, "+dhp:n:iv", long_opts, NULL)) != -1) {
 		switch (opt) {
 		case 'd':
 			opt_debug = true;
@@ -127,6 +131,9 @@ static char **parse_args(int argc, char **argv)
 		case 'p':
 			opt_profile = optarg;
 			break;
+		case 'n':
+			opt_namespace = optarg;
+			break;
 		case 'i':
 			opt_immediate = true;
 			break;
@@ -145,28 +152,58 @@ static char **parse_args(int argc, char **argv)
 	return argv + optind;
 }
 
+static void build_name(char *name, size_t name_len,
+		       const char *namespace, const char *profile)
+{
+	size_t required_len = 1; /* reserve 1 byte for NUL-terminator */
+
+	if (namespace)
+		required_len += 1 + strlen(namespace) + 3; /* :<NAMESPACE>:// */
+
+	if (profile)
+		required_len += strlen(profile);
+
+	if (required_len > name_len)
+		error("name too long (%zu > %zu)", required_len, name_len);
+
+	name[0] = '\0';
+
+	if (namespace) {
+		strcat(name, ":");
+		strcat(name, namespace);
+		strcat(name, "://");
+	}
+
+	if (profile)
+		strcat(name, profile);
+}
+
 int main(int argc, char **argv)
 {
+	char name[PATH_MAX];
 	int rc = 0;
 
 	argv = parse_args(argc, argv);
 
-	if (!opt_profile)
+	if (opt_namespace || opt_profile)
+		build_name(name, sizeof(name), opt_namespace, opt_profile);
+	else
 		goto exec;
 
 	if (opt_immediate) {
-		verbose("aa_change_profile(\"%s\")", opt_profile);
+		verbose("aa_change_profile(\"%s\")", name);
-		rc = aa_change_profile(opt_profile);
+		rc = aa_change_profile(name);
-		debug("%d = aa_change_profile(\"%s\")", rc, opt_profile);
+		debug("%d = aa_change_profile(\"%s\")", rc, name);
 	} else {
-		verbose("aa_change_onexec(\"%s\")", opt_profile);
+		verbose("aa_change_onexec(\"%s\")", name);
-		rc = aa_change_onexec(opt_profile);
+		rc = aa_change_onexec(name);
-		debug("%d = aa_change_onexec(\"%s\")", rc, opt_profile);
+		debug("%d = aa_change_onexec(\"%s\")", rc, name);
 	}
 
 	if (rc) {
 		if (errno == ENOENT || errno == EACCES) {
-			error("profile '%s' does not exist", opt_profile);
+			error("%s '%s' does not exist\n",
+			      opt_profile ? "profile" : "namespace", name);
 		} else if (errno == EINVAL) {
 			error("AppArmor interface not available");
 		} else {