Implement ISOBUS File Server (FS) Interface as a Personal Project

Introduce the ISOBUS File Server (FS) interface, compatible with ISO 11783-13. The implementation utilizes the kernel's existing CAN J1939 socket support. For testing following setup can be used: ip link add type vcan ip l s dev vcan0 up j1939acd -r 64-95 -c /tmp/1122334455667788.jacd 1122334455667788 vcan0 & j1939acd -r 96-127 -c /tmp/1122334455667789.jacd 1122334455667789 vcan0 & sleep 1 isobusfs-srv -i vcan0 -n 1122334455667788 -v vol1:/path/to/export/ isobusfs-cli -i vcan0 -n 0x1122334455667789 -m 0x1122334455667788 -I Interactive mode currently support following commands: exit - exit interactive mode quit - exit interactive mode help - show this help dmesg - show log buffer selftest - run selftest ls - list directory ll - list directory with long listing format cd - change directory pwd - print name of current/working directory get - get file Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
2026-09-23 08:31:09 +02:00 · 2024-02-02 13:44:07 +01:00
parent 6004c64f06
commit 42edaeaf52
30 changed files with 9750 additions and 0 deletions
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2023 Oleksij Rempel <linux@rempel-privat.de>
+/*
+ * This file implements Annex C.1.2 File Server Status according to
+ * ISO 11783-13:2021.
+ */
+
+#include <err.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "isobusfs_srv.h"
+
+/*
+ * isobusfs_srv_fss_init - Initialize the file server status structure
+ * @priv: Pointer to the private data structure of the ISOBUS file server
+ *
+ * This function initializes the file server status structure, which
+ * represents the status of the file server according to Annex C.1.2
+ * of ISO 11783-13:2021.
+ */
+void isobusfs_srv_fss_init(struct isobusfs_srv_priv *priv)
+{
+	struct isobusfs_cm_fss *st = &priv->st;
+
+	st->fs_function =
+		isobusfs_cg_function_to_buf(ISOBUSFS_CG_CONNECTION_MANAGMENT,
+					    ISOBUSFS_CM_F_FS_STATUS);
+	st->status = 0;
+	st->num_open_files = 0;
+	memset(st->reserved, 0xFF, sizeof(st->reserved));
+}
+
+/*
+ * isobusfs_srv_fss_get_rate - Get the rate of File Server Status transmission
+ * @priv: Pointer to the private data structure of the ISOBUS file server
+ *
+ * Returns: the transmission rate of the File Server Status messages depending
+ * on the current state of the file server.
+ */
+static unsigned int isobusfs_srv_fss_get_rate(struct isobusfs_srv_priv *priv)
+{
+	switch (priv->st_state) {
+	case ISOBUSFS_SRV_STATE_IDLE:
+		return ISOBUSFS_CM_F_FS_STATUS_IDLE_RATE;
+	/*
+	 * On every change of Byte 2 "File Server Status" send max 5 status
+	 * messages per second.
+	 */
+	case ISOBUSFS_SRV_STATE_STAT_CHANGE_1: /* fall through */
+	case ISOBUSFS_SRV_STATE_STAT_CHANGE_2: /* fall through */
+	case ISOBUSFS_SRV_STATE_STAT_CHANGE_3: /* fall through */
+	case ISOBUSFS_SRV_STATE_STAT_CHANGE_4: /* fall through */
+	case ISOBUSFS_SRV_STATE_STAT_CHANGE_5:
+		priv->st_state--;
+		return ISOBUSFS_CM_F_FS_STATUS_BUSY_RATE;
+	case ISOBUSFS_SRV_STATE_BUSY:
+		return ISOBUSFS_CM_F_FS_STATUS_BUSY_RATE;
+	default:
+		pr_warn("%s:%i: unknown state %d", __func__, __LINE__,
+			priv->st_state);
+	}
+
+	/*
+	 * In case something is wrong, fall back to idle rate to not spam the
+	 * bus.
+	 */
+	return ISOBUSFS_CM_F_FS_STATUS_IDLE_RATE;
+}
+
+/**
+ * isobusfs_srv_fss_send - Send periodic File Server Status messages
+ * @priv: Pointer to the private data structure of the ISOBUS file server
+ *
+ * Returns: 0 if the message was sent successfully, a negative error code
+ * otherwise.
+ */
+int isobusfs_srv_fss_send(struct isobusfs_srv_priv *priv)
+{
+	unsigned int next_msg_rate;
+	int64_t time_diff;
+	int ret;
+
+	/* Test if it is proper time to send next status message. */
+	time_diff = timespec_diff_ms(&priv->cmn.next_send_time,
+				     &priv->cmn.last_time);
+	if (time_diff > ISOBUSFS_CM_F_FS_STATUS_RATE_JITTER) {
+		/* too early to send next message */
+		return 0;
+	}
+
+	if (time_diff < -ISOBUSFS_CM_F_FS_STATUS_RATE_JITTER) {
+		pr_warn("too late to send next fs status message: %ld ms",
+			time_diff);
+	}
+
+	/* Make sure we send the message with the latest stats */
+	if (priv->st_msg_stats.tskey_sch != priv->st_msg_stats.tskey_ack)
+		pr_warn("previous message was not acked");
+
+	/* send periodic file servers status messages. */
+	ret = send(priv->sock_fss, &priv->st, sizeof(priv->st), MSG_DONTWAIT);
+	if (ret < 0) {
+		ret = -errno;
+		pr_warn("Failed to send FS status message, error code: %d (%s)",
+			ret, strerror(ret));
+		return ret;
+	}
+
+	pr_debug("> tx FS status: 0x%02x, opened files: %d",
+		 priv->st.status, priv->st.num_open_files);
+
+	/* Calculate time for the next status message */
+	next_msg_rate = isobusfs_srv_fss_get_rate(priv);
+	priv->cmn.next_send_time = priv->cmn.last_time;
+	timespec_add_ms(&priv->cmn.next_send_time, next_msg_rate);
+
+	return 0;
+}