Merge pull request #2453 from 2xsec/bugfix

src/lxc/namespace.c

@@ -193,6 +193,40 @@ int lxc_namespace_2_ns_idx(const char *namespace)
 	return -EINVAL;
 }
 
+extern int lxc_namespace_2_std_identifiers(char *namespaces)
+{
+	char **it;
+	char *del;
+
+	/* The identifiers for namespaces used with lxc-attach and lxc-unshare
+	 * as given on the manpage do not align with the standard identifiers.
+	 * This affects network, mount, and uts namespaces. The standard identifiers
+	 * are: "mnt", "uts", and "net" whereas lxc-attach and lxc-unshare uses
+	 * "MOUNT", "UTSNAME", and "NETWORK". So let's use some cheap memmove()s
+	 * to replace them by their standard identifiers.
+	 * Let's illustrate this with an example:
+	 * Assume the string:
+	 *
+	 *	"IPC|MOUNT|PID"
+	 *
+	 * then we memmove()
+	 *
+	 *	dest: del + 1 == OUNT|PID
+	 *	src:  del + 3 == NT|PID
+	 */
+	if (!namespaces)
+		return -1;
+
+	while ((del = strstr(namespaces, "MOUNT")))
+		memmove(del + 1, del + 3, strlen(del) - 2);
+
+	for (it = (char *[]){"NETWORK", "UTSNAME", NULL}; it && *it; it++)
+		while ((del = strstr(namespaces, *it)))
+			memmove(del + 3, del + 7, strlen(del) - 6);
+
+	return 0;
+}
+
 int lxc_fill_namespace_flags(char *flaglist, int *flags)
 {
 	char *token, *saveptr = NULL;

src/lxc/namespace.h

@@ -181,6 +181,7 @@ extern pid_t lxc_raw_clone_cb(int (*fn)(void *), void *args,
 
 extern int lxc_namespace_2_cloneflag(const char *namespace);
 extern int lxc_namespace_2_ns_idx(const char *namespace);
+extern int lxc_namespace_2_std_identifiers(char *namespaces);
 extern int lxc_fill_namespace_flags(char *flaglist, int *flags);
 
 /**

src/lxc/tools/lxc_attach.c

@@ -100,8 +100,6 @@ static int add_to_simple_array(char ***array, ssize_t *capacity, char *value)
 
 static int my_parser(struct lxc_arguments *args, int c, char *arg)
 {
-	char **it;
-	char *del;
 	int ret;
 
 	switch (c) {
@@ -121,32 +119,13 @@ static int my_parser(struct lxc_arguments *args, int c, char *arg)
 	case 's':
 		namespace_flags = 0;
 
-		/* The identifiers for namespaces used with lxc-attach as given
-		 * on the manpage do not align with the standard identifiers.
-		 * This affects network, mount, and uts namespaces. The standard
-		 * identifiers are: "mnt", "uts", and "net" whereas lxc-attach
-		 * uses "MOUNT", "UTSNAME", and "NETWORK". So let's use some
-		 * cheap memmove()s to replace them by their standard
-		 * identifiers. Let's illustrate this with an example:
-		 * Assume the string:
-		 *
-		 *	"IPC|MOUNT|PID"
-		 *
-		 * then we memmove()
-		 *
-		 *	dest: del + 1 == OUNT|PID
-		 *	src:  del + 3 == NT|PID
-		 */
-		while ((del = strstr(arg, "MOUNT")))
-			memmove(del + 1, del + 3, strlen(del) - 2);
-
-		for (it = (char *[]){"NETWORK", "UTSNAME", NULL}; it && *it; it++)
-			while ((del = strstr(arg, *it)))
-				memmove(del + 3, del + 7, strlen(del) - 6);
+		if (lxc_namespace_2_std_identifiers(arg) < 0)
+			return -1;
 
 		ret = lxc_fill_namespace_flags(arg, &namespace_flags);
 		if (ret)
 			return -1;
+
 		/* -s implies -e */
 		lxc_fill_elevated_privileges(NULL, &elevated_privileges);
 		break;

src/lxc/tools/lxc_unshare.c

@@ -244,8 +244,7 @@ static int write_id_mapping(pid_t pid, const char *buf, size_t buf_size)
 
 int main(int argc, char *argv[])
 {
-	char *del;
-	char **it, **args;
+	char **args;
 	int opt;
 	int ret;
 	char *namespaces = NULL;
@@ -308,31 +307,9 @@ int main(int argc, char *argv[])
 	if (ret)
 		exit(EXIT_FAILURE);
 
-	/* The identifiers for namespaces used with lxc-unshare as given on the
-	 * manpage do not align with the standard identifiers. This affects
-	 * network, mount, and uts namespaces. The standard identifiers are:
-	 * "mnt", "uts", and "net" whereas lxc-unshare uses "MOUNT", "UTSNAME",
-	 * and "NETWORK". So let's use some cheap memmove()s to replace them by
-	 * their standard identifiers. Let's illustrate this with an example:
-	 * Assume the string:
-	 *
-	 *	"IPC|MOUNT|PID"
-	 *
-	 * then we memmove()
-	 *
-	 *	dest: del + 1 == OUNT|PID
-	 *	src:  del + 3 == NT|PID
-	 */
-	if (!namespaces)
+	if (lxc_namespace_2_std_identifiers(namespaces) < 0)
 		usage(argv[0]);
 
-	while ((del = strstr(namespaces, "MOUNT")))
-		memmove(del + 1, del + 3, strlen(del) - 2);
-
-	for (it = (char *[]){"NETWORK", "UTSNAME", NULL}; it && *it; it++)
-		while ((del = strstr(namespaces, *it)))
-			memmove(del + 3, del + 7, strlen(del) - 6);
-
 	ret = lxc_fill_namespace_flags(namespaces, &flags);
 	if (ret)
 		usage(argv[0]);