Introduce transport over UNIX domain sockets.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

makefile

@@ -24,7 +24,7 @@ CFLAGS	= -Wall $(INC) $(DEBUG) $(EXTRA_CFLAGS)
 LDLIBS	= -lm -lrt $(EXTRA_LDFLAGS)
 PRG	= ptp4l pmc phc2sys hwstamp_ctl
 OBJ	= bmc.o clock.o config.o fsm.o ptp4l.o mave.o msg.o phc.o pi.o port.o \
- print.o raw.o servo.o sk.o tlv.o tmtab.o transport.o udp.o udp6.o util.o
+ print.o raw.o servo.o sk.o tlv.o tmtab.o transport.o udp.o udp6.o uds.o util.o
 
 OBJECTS	= $(OBJ) pmc.o phc2sys.o hwstamp_ctl.o
 SRC	= $(OBJECTS:.o=.c)
@@ -36,7 +36,7 @@ all: $(PRG)
 
 ptp4l: $(OBJ)
 
-pmc: pmc.o msg.o print.o raw.o sk.o tlv.o transport.o udp.o udp6.o util.o
+pmc: pmc.o msg.o print.o raw.o sk.o tlv.o transport.o udp.o udp6.o uds.o util.o
 
 phc2sys: phc2sys.o
 

transport.c

@@ -22,6 +22,7 @@
 #include "raw.h"
 #include "udp.h"
 #include "udp6.h"
+#include "uds.h"
 
 int transport_close(struct transport *t, struct fdarray *fda)
 {
@@ -65,6 +66,8 @@ struct transport *transport_create(enum transport_type type)
 	case TRANS_CONTROLNET:
 	case TRANS_PROFINET:
 		break;
+	case TRANS_UDS:
+		return uds_transport_create();
 	}
 	return NULL;
 }

transport.h

@@ -31,6 +31,7 @@ enum transport_type {
 	TRANS_DEVICENET,
 	TRANS_CONTROLNET,
 	TRANS_PROFINET,
+	TRANS_UDS,
 };
 
 enum timestamp_type {

uds.c

@@ -0,0 +1,129 @@
+/**
+ * @file uds.c
+ * @note Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "contain.h"
+#include "print.h"
+#include "transport_private.h"
+#include "uds.h"
+
+#define UDS_FILEMODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) /*0660*/
+
+struct uds {
+	struct transport t;
+	struct sockaddr_un sa;
+	socklen_t len;
+};
+
+static int uds_close(struct transport *t, struct fdarray *fda)
+{
+	close(fda->fd[FD_GENERAL]);
+	return 0;
+}
+
+static int uds_open(struct transport *t, char *name, struct fdarray *fda,
+		    enum timestamp_type tt)
+{
+	int fd, err;
+	struct sockaddr_un sa;
+	struct uds *uds = container_of(t, struct uds, t);
+
+	fd = socket(AF_LOCAL, SOCK_DGRAM, 0);
+	if (fd < 0) {
+		pr_err("uds: failed to create socket: %m");
+		return -1;
+	}
+	memset(&sa, 0, sizeof(sa));
+	sa.sun_family = AF_LOCAL;
+	strcpy(sa.sun_path, name);
+
+	unlink(name);
+
+	err = bind(fd, (struct sockaddr *) &sa, sizeof(sa));
+	if (err < 0) {
+		pr_err("uds: bind failed: %m");
+		close(fd);
+		return -1;
+	}
+
+	/* For client use, pre load the server path. */
+	memset(&sa, 0, sizeof(sa));
+	sa.sun_family = AF_LOCAL;
+	strcpy(sa.sun_path, UDS_PATH);
+	uds->sa = sa;
+	uds->len = sizeof(sa);
+
+	chmod(name, UDS_FILEMODE);
+	fda->fd[FD_GENERAL] = fd;
+	return 0;
+}
+
+static int uds_recv(struct transport *t, int fd, void *buf, int buflen,
+		    struct hw_timestamp *hwts)
+{
+	int cnt;
+	struct uds *uds = container_of(t, struct uds, t);
+	socklen_t *len = &uds->len;
+	uds->len = sizeof(uds->sa);
+	cnt = recvfrom(fd, buf, buflen, 0, (struct sockaddr *) &uds->sa, len);
+	if (cnt <= 0) {
+		pr_err("uds: recvfrom failed: %m");
+	}
+	return cnt;
+}
+
+static int uds_send(struct transport *t, struct fdarray *fda, int event,
+		    int peer, void *buf, int buflen, struct hw_timestamp *hwts)
+{
+	int cnt, fd = fda->fd[FD_GENERAL];
+	struct uds *uds = container_of(t, struct uds, t);
+	cnt = sendto(fd, buf, buflen, 0, (struct sockaddr *) &uds->sa, uds->len);
+	if (cnt <= 0) {
+		pr_err("uds: sendto failed: %m");
+	}
+	return cnt;
+}
+
+static void uds_release(struct transport *t)
+{
+	struct uds *uds = container_of(t, struct uds, t);
+	free(uds);
+}
+
+struct transport *uds_transport_create(void)
+{
+	struct uds *uds;
+	uds = calloc(1, sizeof(*uds));
+	if (!uds)
+		return NULL;
+	uds->t.close   = uds_close;
+	uds->t.open    = uds_open;
+	uds->t.recv    = uds_recv;
+	uds->t.send    = uds_send;
+	uds->t.release = uds_release;
+	return &uds->t;
+}
+

uds.h

@@ -0,0 +1,37 @@
+/**
+ * @file uds.h
+ * @brief Implements a management interface via UNIX domain sockets.
+ * @note Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef HAVE_UDS_H
+#define HAVE_UDS_H
+
+#include "fd.h"
+#include "transport.h"
+
+/**
+ * Address of the server.
+ */
+#define UDS_PATH "/tmp/ptp4l"
+
+/**
+ * Allocate an instance of a UDS transport.
+ * @return Pointer to a new transport instance on success, NULL otherwise.
+ */
+struct transport *uds_transport_create(void);
+
+#endif