Add OpenBSD strlcat() and strlcpy() safe string manipulation APIs

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

configure.ac

@@ -32,6 +32,11 @@ AC_HEADER_STDC
 # Check for required packages
 PKG_PROG_PKG_CONFIG
 
+# Check for usually missing API's, which we can replace
+AC_REPLACE_FUNCS([strlcpy strlcat])
+AC_CONFIG_LIBOBJ_DIR([lib])
+
+# Command line options
 AC_ARG_WITH(suspend-time,
         AS_HELP_STRING([--with-suspend-time=SEC], [Retry timeout for remote syslogd servers, default: 180]),
 	[suspend_time=$withval], [suspend_time='no'])

lib/.gitignore

@@ -0,0 +1,2 @@
+*.o
+.dirstamp

lib/strlcat.c

@@ -0,0 +1,55 @@
+/*	$OpenBSD: strlcat.c,v 1.15 2015/03/02 21:41:08 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Appends src to string dst of size dsize (unlike strncat, dsize is the
+ * full size of dst, not space left).  At most dsize-1 characters
+ * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
+ * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
+ * If retval >= dsize, truncation occurred.
+ */
+size_t
+strlcat(char *dst, const char *src, size_t dsize)
+{
+	const char *odst = dst;
+	const char *osrc = src;
+	size_t n = dsize;
+	size_t dlen;
+
+	/* Find the end of dst and adjust bytes left but don't go past end. */
+	while (n-- != 0 && *dst != '\0')
+		dst++;
+	dlen = dst - odst;
+	n = dsize - dlen;
+
+	if (n-- == 0)
+		return(dlen + strlen(src));
+	while (*src != '\0') {
+		if (n != 0) {
+			*dst++ = *src;
+			n--;
+		}
+		src++;
+	}
+	*dst = '\0';
+
+	return(dlen + (src - osrc));	/* count does not include NUL */
+}

lib/strlcpy.c

@@ -0,0 +1,50 @@
+/*	$OpenBSD: strlcpy.c,v 1.12 2015/01/15 03:54:12 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t dsize)
+{
+	const char *osrc = src;
+	size_t nleft = dsize;
+
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
+				break;
+		}
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
+			;
+	}
+
+	return(src - osrc - 1);	/* count does not include NUL */
+}

src/Makefile.am

@@ -15,6 +15,7 @@
 #   You should have received a copy of the GNU General Public License
 #   along with this program; if not, write to the Free Software
 #   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+AUTOMAKE_OPTIONS = subdir-objects
 
 bin_PROGRAMS     = logger
 sbin_PROGRAMS    = syslogd klogd
@@ -26,16 +27,21 @@ AM_CFLAGS       += -fno-strict-aliasing -fno-strength-reduce
 
 syslogd_SOURCES  = syslogd.c pidfile.c pidfile.h
 syslogd_CPPFLAGS = -D_BSD_SOURCE -D_DEFAULT_SOURCE
+syslogd_LDADD    = $(LIBS) $(LIBOBJS)
 
 klogd_SOURCES    = klogd.c klogd.h syslog.c pidfile.c pidfile.h \
 		   ksym.c ksyms.h ksym_mod.c module.h
 klogd_CPPFLAGS   = -DALLOW_KERNEL_LOGGING -D_BSD_SOURCE -D_DEFAULT_SOURCE
+klogd_LDADD      = $(LIBS) $(LIBOBJS)
 
 logger_SOURCES   = logger.c syslog.c
 logger_CPPFLAGS  = -D_XOPEN_SOURCE=600 -D_BSD_SOURCE -D_GNU_SOURCE -D_DEFAULT_SOURCE
+logger_LDADD     = $(LIBS) $(LIBOBJS)
 
 tsyslogd_SOURCES  = $(syslogd_SOURCES)
 tsyslogd_CPPFLAGS = $(syslogd_CPPFLAGS) -DTESTING
+tsyslogd_LDADD    = $(LIBS) $(LIBOBJS)
 
 syslog_tst_SOURCES  = syslog_tst.c syslog.c
 syslog_tst_CPPFLAGS = -D_BSD_SOURCE -D_DEFAULT_SOURCE -DTESTING
+syslog_tst_LDADD    = $(LIBS) $(LIBOBJS)