compat: Add support for getprogname(3)

compat/getprogname.c

@@ -0,0 +1,57 @@
+/*
+ * getprogname: compat
+ * SPDX-License-Identifier: BSD-2-Clause
+ * Copyright (c) 2006-2025 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+
+#include <errno.h>
+#include <stddef.h>
+
+#include "config.h"
+#include "defs.h"
+#include "getprogname.h"
+
+static const char *progname;
+
+const char *
+getprogname(void)
+{
+#if defined(HAVE_PROGRAM_INVOCATION_SHORT_NAME)
+	if (progname == NULL)
+		progname = program_invocation_short_name;
+	return progname;
+#else
+#warning "no OS support for getprogname(3)"
+	if (progname == NULL)
+		progname = PACKAGE;
+	return progname;
+#endif
+}
+
+void
+setprogname(const char *name)
+{
+	progname = name;
+}

compat/getprogname.h

@@ -0,0 +1,35 @@
+/*
+ * getprogname: compat
+ * SPDX-License-Identifier: BSD-2-Clause
+ * Copyright (c) 2006-2025 Roy Marples <roy@marples.name>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+
+#ifndef GETPROGNAME_H
+#define GETPROGNAME_H
+
+const char *getprogname(void);
+void setprogname(const char *);
+
+#endif

compat/setproctitle.c

@@ -165,7 +165,7 @@ spt_copyargs(int argc, char *argv[])
 void
 setproctitle_init(int argc, char *argv[], char *envp[])
 {
-	char *base, *end, *nul, *tmp;
+	char *base, *end, *nul;
 	int i, envc, error;
 
 	/* Try to make sure we got called with main() arguments. */
@@ -200,13 +200,6 @@ setproctitle_init(int argc, char *argv[], char *envp[])
 		return;
 	}
 
-	tmp = strdup(getprogname());
-	if (tmp == NULL) {
-		SPT.error = errno;
-		return;
-	}
-	setprogname(tmp);
-
 	error = spt_copyenv(envc, envp);
 	if (error) {
 		SPT.error = error;

compat/setproctitle.h

@@ -34,20 +34,6 @@
 #endif
 #endif /* !__printflike */
 
-/* WEXITSTATUS is defined in stdlib.h which defines free() */
-#ifdef WEXITSTATUS
-static inline const char *
-getprogname(void)
-{
-	return "dhcpcd";
-}
-static inline void
-setprogname(char *name)
-{
-	free(name);
-}
-#endif
-
 void setproctitle_init(int, char *[], char *[]);
 __printflike(1, 2) void setproctitle(const char *, ...);
 void setproctitle_fini(void);

configure

@@ -1075,6 +1075,43 @@ else
 	fi
 fi
 
+if [ -z "$GETPROGNAME" ]; then
+	printf "Testing for getprogname ... "
+	cat << EOF >_getprogname.c
+#include <stdlib.h>
+int main(void) {
+	return getprogname() ? 0 : 1;
+}
+EOF
+	if $XCC _getprogname.c -o _getprogname 2>&3; then
+		GETPROGNAME=yes
+	else
+		GETPROGNAME=no
+	fi
+	echo "$GETPROGNAME"
+	rm -rf _getprogname.* _getprogname
+fi
+if [ "$GETPROGNAME" = no ]; then
+	echo "COMPAT_SRCS+=	compat/getprogname.c" >>$CONFIG_MK
+	echo "#include			\"compat/getprogname.h\"" >>$CONFIG_H
+
+	printf "Testing for program_invocation_short_name ... "
+	cat << EOF >_getprognameshort.c
+#include <errno.h>
+int main(void) {
+	return program_invocation_short_name ? 0 : 1;
+}
+EOF
+	if $XCC _getprognameshort.c -o _getprognameshort 2>&3; then
+		GETPROGNAMESHORT=yes
+		echo "#define	HAVE_PROGRAM_INVOCATION_SHORT_NAME" >>$CONFIG_H
+	else
+		GETPROGNAMESHORT=no
+	fi
+	echo "$GETPROGNAMESHORT"
+	rm -rf _getprognameshort.* _getprognameshort
+fi
+
 if [ -z "$SETPROCTITLE" ]; then
 	printf "Testing for setproctitle ... "
 	cat << EOF >_setproctitle.c

src/logerr.c

@@ -39,6 +39,7 @@
 #include <time.h>
 #include <unistd.h>
 
+#include "config.h"
 #include "logerr.h"
 
 #ifndef LOGERR_SYSLOG_FACILITY
@@ -74,35 +75,6 @@ static struct logctx _logctx = {
 	.log_pid = 0,
 };
 
-#if defined(__linux__)
-/* Poor man's getprogname(3). */
-static char *_logprog;
-static const char *
-getprogname(void)
-{
-	const char *p;
-
-	/* Use PATH_MAX + 1 to avoid truncation. */
-	if (_logprog == NULL) {
-		/* readlink(2) does not append a NULL byte,
-		 * so zero the buffer. */
-		if ((_logprog = calloc(1, PATH_MAX + 1)) == NULL)
-			return NULL;
-		if (readlink("/proc/self/exe", _logprog, PATH_MAX + 1) == -1) {
-			free(_logprog);
-			_logprog = NULL;
-			return NULL;
-		}
-	}
-	if (_logprog[0] == '[')
-		return NULL;
-	p = strrchr(_logprog, '/');
-	if (p == NULL)
-		return _logprog;
-	return p + 1;
-}
-#endif
-
 #ifndef SMALL
 /* Write the time, syslog style. month day time - */
 static int
@@ -518,10 +490,6 @@ logclose(void)
 #endif
 
 	closelog();
-#if defined(__linux__)
-	free(_logprog);
-	_logprog = NULL;
-#endif
 #ifndef SMALL
 	if (ctx->log_file == NULL)
 		return;