1 files changed, 104 insertions, 0 deletions
diff --git a/lib/util/rcstr.c b/lib/util/rcstr.c
new file mode 100644
index 0000000..08b00bc
--- /dev/null
+++ b/lib/util/rcstr.c
@@ -0,0 +1,104 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2016-2018 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sudo_compat.h"
+#include "sudo_debug.h"
+#include "sudo_util.h"
+
+/* Trivial reference-counted strings. */
+struct rcstr {
+    int refcnt;
+    char str[1];	/* actually bigger */
+};
+
+/*
+ * Allocate a reference-counted string and copy src to it.
+ * Returns the newly-created string with a refcnt of 1.
+ */
+char *
+sudo_rcstr_dup(const char *src)
+{
+    size_t len = strlen(src);
+    char *dst;
+    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);
+
+    dst = sudo_rcstr_alloc(len);
+    if (dst != NULL) {
+        memcpy(dst, src, len);
+        dst[len] = '\0';
+    }
+    debug_return_ptr(dst);
+}
+
+char *
+sudo_rcstr_alloc(size_t len)
+{
+    struct rcstr *rcs;
+    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);
+
+    /* Note: sizeof(struct rcstr) includes space for the NUL */
+    rcs = malloc(sizeof(struct rcstr) + len);
+    if (rcs == NULL)
+	return NULL;
+
+    rcs->refcnt = 1;
+    rcs->str[0] = '\0';
+    /* cppcheck-suppress memleak */
+    debug_return_ptr(rcs->str); // -V773
+}
+
+char *
+sudo_rcstr_addref(const char *s)
+{
+    struct rcstr *rcs;
+    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);
+
+    if (s == NULL)
+	debug_return_ptr(NULL);
+
+    rcs = __containerof((const void *)s, struct rcstr, str);
+    rcs->refcnt++;
+    debug_return_ptr(rcs->str);
+}
+
+void
+sudo_rcstr_delref(const char *s)
+{
+    struct rcstr *rcs;
+    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);
+
+    if (s != NULL) {
+	rcs = __containerof((const void *)s, struct rcstr, str);
+	if (--rcs->refcnt == 0) {
+	    rcs->str[0] = '\0';
+	    free(rcs);
+	}
+    }
+    debug_return;
+}