ramfs: fix rename when new name is not longer

strlcpy() expects buffer length not string length.

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>

bootfs.manifest

@@ -59,6 +59,7 @@
 /&/tests/tst-dns-resolver.so: ./&
 /&/tests/tst-fs-link.so: ./&
 /&/tests/tst-kill.so: ./&
+/&/tests/tst-rename.so: ./&
 /&/tests/bench/bench.jar: ./&
 /testrunner.so: ./tests/testrunner.so
 /java/Hello.class: ./tests/hello/Hello.class

build.mk

@@ -157,6 +157,7 @@ tests += tests/tst-loadbalance.so
 tests += tests/tst-dns-resolver.so
 tests += tests/tst-fs-link.so
 tests += tests/tst-kill.so
+tests += tests/tst-rename.so
 
 tests/hello/Hello.class: javabase=tests/hello
 

fs/ramfs/ramfs_vnops.c

@@ -143,7 +143,7 @@ ramfs_rename_node(struct ramfs_node *np, char *name)
 	len = strlen(name);
 	if (len <= np->rn_namelen) {
 		/* Reuse current name buffer */
-		strlcpy(np->rn_name, name, np->rn_namelen);
+		strlcpy(np->rn_name, name, np->rn_namelen + 1);
 	} else {
 		/* Expand name buffer */
 		tmp = malloc(len + 1);

tests/tst-rename.c

+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+
+static const char *SECRET = "Hello, world";
+
+static bool has_secret(const char *name) {
+	FILE * file = fopen(name, "r");
+	if (!file) {
+		perror("Failed to open");
+		return 1;
+	}
+
+	char buf[strlen(SECRET) + 1];
+	fgets(buf, sizeof(buf), file);
+
+	if (strcmp(SECRET, buf)) {
+		fprintf(stderr, "File content does not match, "
+			"expected %s but found %s, file=%s\n", SECRET, buf, file);
+		fclose(file);
+		return false;
+	}
+
+	fclose(file);
+	return true;
+}
+
+static int do_rename(const char *src, const char *dst)
+{
+	printf("Renaming %s to %s\n", src, dst);
+
+	if (rename(src, dst)) {
+		perror("Failed to rename.");
+		return 1;
+	}
+
+	if (!has_secret(dst)) {
+		return 1;
+	}
+
+	return 0;
+}
+
+static int write_secret(const char *file_name) {
+	printf("Writing secret to: %s\n", file_name);
+
+	FILE * file = fopen(file_name, "w");
+	if (!file) {
+		perror("Failed to open");
+		return 1;
+	}
+
+	fputs(SECRET, file);
+	fclose(file);
+	return 0;
+}
+
+int main(int argc, char const *argv[])
+{
+	const char * src_name = strdup(tmpnam(NULL));
+	if (write_secret(src_name))
+		return 1;
+
+	const char * dst_name = strdup(tmpnam(NULL));
+	if (do_rename(src_name, dst_name))
+		return 1;
+
+	const char *short_name = "a";
+	if (do_rename(dst_name, short_name))
+		return 1;
+
+	if (do_rename(short_name, src_name))
+		return 1;
+
+	printf("OK.\n");
+	return 0;
+}