Add pw_dup(3), a function to copy 'struct passwd'. It is allocated as

a single chunk with the strings pointing elsewhere in the buffer so
a simple free() of the struct passwd * is all that is needed to decallocate.

1 files changed, 111 insertions, 0 deletions

diff --git a/lib/libc/gen/pw_dup.c b/lib/libc/gen/pw_dup.c
new file mode 100644
index 00000000000..fcde9b90093
--- /dev/null
+++ b/lib/libc/gen/pw_dup.c
@@ -0,0 +1,111 @@
+/*	$OpenBSD: pw_dup.c,v 1.1 2000/11/21 00:49:58 millert Exp $	*/
+
+/*
+ * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] = "$OpenBSD: pw_dup.c,v 1.1 2000/11/21 00:49:58 millert Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <pwd.h>
+
+struct passwd *
+pw_dup(pw)
+	const struct passwd *pw;
+{
+	struct passwd *newpw;
+	char *cp;
+	size_t siz;
+
+	/* Allocate in one big chunk for easy freeing */
+	siz = sizeof(struct passwd);
+	if (pw->pw_name)
+		siz += strlen(pw->pw_name) + 1;
+	if (pw->pw_passwd)
+		siz += strlen(pw->pw_passwd) + 1;
+	if (pw->pw_class)
+		siz += strlen(pw->pw_class) + 1;
+	if (pw->pw_gecos)
+		siz += strlen(pw->pw_gecos) + 1;
+	if (pw->pw_dir)
+		siz += strlen(pw->pw_dir) + 1;
+	if (pw->pw_shell)
+		siz += strlen(pw->pw_shell) + 1;
+	if ((cp = malloc(siz)) == NULL)
+		return(NULL);
+	newpw = (struct passwd *)cp;
+
+	/*
+	 * Copy in passwd contents and make strings relative to space
+	 * at the end of the buffer.
+	 */
+	memcpy(newpw, pw, sizeof(struct passwd));
+	cp += sizeof(struct passwd);
+	if (pw->pw_name) {
+		siz = strlen(pw->pw_name) + 1;
+		memcpy(cp, pw->pw_name, siz);
+		newpw->pw_name = cp;
+		cp += siz;
+	}
+	if (pw->pw_passwd) {
+		siz = strlen(pw->pw_passwd) + 1;
+		memcpy(cp, pw->pw_passwd, siz);
+		newpw->pw_passwd = cp;
+		cp += siz;
+	}
+	if (pw->pw_class) {
+		siz = strlen(pw->pw_class) + 1;
+		memcpy(cp, pw->pw_class, siz);
+		newpw->pw_class = cp;
+		cp += siz;
+	}
+	if (pw->pw_gecos) {
+		siz = strlen(pw->pw_gecos) + 1;
+		memcpy(cp, pw->pw_gecos, siz);
+		newpw->pw_gecos = cp;
+		cp += siz;
+	}
+	if (pw->pw_dir) {
+		siz = strlen(pw->pw_dir) + 1;
+		memcpy(cp, pw->pw_dir, siz);
+		newpw->pw_dir = cp;
+		cp += siz;
+	}
+	if (pw->pw_shell) {
+		siz = strlen(pw->pw_shell) + 1;
+		memcpy(cp, pw->pw_shell, siz);
+		newpw->pw_shell = cp;
+		cp += siz;
+	}
+
+	return(newpw);
+}