Add socket helper functions from SMCRoute, licesened as 3-clause BSD

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

src/Makefile.am

@@ -26,7 +26,7 @@ AM_CFLAGS            += -Wno-unused-result -Wno-unused-parameter -fno-strict-ali
 AM_CPPFLAGS           = -DSYSCONFDIR=\"@sysconfdir@\" -DLOCALSTATEDIR=\"@localstatedir@\"
 AM_CPPFLAGS          += -D_BSD_SOURCE -D_DEFAULT_SOURCE
 
-syslogd_SOURCES       = syslogd.c syslogd.h syslog.h queue.h compat.h
+syslogd_SOURCES       = syslogd.c syslogd.h socket.c socket.h syslog.h queue.h compat.h
 syslogd_CPPFLAGS      = $(AM_CPPFLAGS) -D_XOPEN_SOURCE=600
 syslogd_LDADD         = $(LIBS) $(LIBOBJS)
 

src/socket.c

@@ -0,0 +1,168 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (C) 2017-2019  Joachim Nilsson <troglobit@gmail.com>
+ *
+ * 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. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 "config.h"
+
+#include <errno.h>
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#include "log.h"
+#include "queue.h"
+
+struct sock {
+	LIST_ENTRY(sock) link;
+
+	int sd;
+
+	void (*cb)(int, void *arg);
+	void *arg;
+};
+
+static int max_fdnum = -1;
+LIST_HEAD(, sock) sl = LIST_HEAD_INITIALIZER();
+
+
+int nfds(void)
+{
+	return max_fdnum + 1;
+}
+
+/*
+ * register socket/fd/pipe created elsewhere, optional callback
+ */
+int socket_register(int sd, void (*cb)(int, void *), void *arg)
+{
+	struct sock *entry;
+
+	entry = malloc(sizeof(*entry));
+	if (!entry)
+		return -1;
+
+	entry->sd  = sd;
+	entry->cb  = cb;
+	entry->arg = arg;
+	LIST_INSERT_HEAD(&sl, entry, link);
+
+#if !defined(HAVE_SOCK_CLOEXEC) && defined(HAVE_FCNTL_H)
+	fcntl(sd, F_SETFD, fcntl(sd, F_GETFD) | FD_CLOEXEC);
+#endif
+
+	/* Keep track for select() */
+	if (sd > max_fdnum)
+		max_fdnum = sd;
+
+	return sd;
+}
+
+/*
+ * create socket, with optional callback for reading inbound data
+ */
+int socket_create(int domain, int type, int proto, void (*cb)(int, void *), void *arg)
+{
+	int sd;
+
+#ifdef HAVE_SOCK_CLOEXEC
+	type |= SOCK_CLOEXEC;
+#endif
+	sd = socket(domain, type, proto);
+	if (sd < 0)
+		return -1;
+
+	if (socket_register(sd, cb, arg) < 0) {
+		close(sd);
+		return -1;
+	}
+
+	return sd;
+}
+
+int socket_close(int sd)
+{
+	struct sock *entry, *tmp;
+
+	LIST_FOREACH_SAFE(entry, &sl, link, tmp) {
+		if (entry->sd == sd) {
+			LIST_REMOVE(entry, link);
+			close(entry->sd);
+			free(entry);
+
+			return 0;
+		}
+	}
+
+	errno = ENOENT;
+	return -1;
+}
+
+int socket_poll(struct timeval *timeout)
+{
+	int num;
+	fd_set fds;
+	struct sock *entry;
+
+	FD_ZERO(&fds);
+	LIST_FOREACH(entry, &sl, link)
+		FD_SET(entry->sd, &fds);
+
+	num = select(nfds(), &fds, NULL, NULL, timeout);
+	if (num <= 0) {
+		/* Log all errors, except when signalled, ignore failures. */
+		if (num < 0 && EINTR != errno)
+			smclog(LOG_WARNING, "Failed select(): %s", strerror(errno));
+
+		return num;
+	}
+
+	LIST_FOREACH(entry, &sl, link) {
+		if (!FD_ISSET(entry->sd, &fds))
+			continue;
+
+		if (entry->cb)
+			entry->cb(entry->sd, entry->arg);
+	}
+
+	return num;
+}
+
+/**
+ * Local Variables:
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */

src/socket.h

@@ -0,0 +1,43 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (C) 2017-2019  Joachim Nilsson <troglobit@gmail.com>
+ *
+ * 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. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 SYSKLOGD_SOCKET_H_
+#define SYSKLOGD_SOCKET_H_
+
+#include <stdarg.h>
+#include <string.h>
+#include <sys/time.h>
+
+int socket_register(int sd, void (*cb)(int, void *), void *arg);
+int socket_create  (int domain, int type, int proto, void (*cb)(int, void *), void *arg);
+int socket_close   (int sd);
+int socket_poll    (struct timeval *timeout);
+
+#endif /* SYSKLOGD_SOCKET_H_ */

src/syslogd.c

@@ -90,6 +90,7 @@ static char sccsid[] __attribute__((unused)) =
 
 #define SYSLOG_NAMES
 #include "syslogd.h"
+#include "socket.h"
 #include "compat.h"
 
 char *ConfFile = _PATH_LOGCONF;