[CAN]: Add PF_CAN core module

This patch adds the CAN core functionality but no protocols or drivers.
No protocol implementations are included here.  They come as separate
patches.  Protocol numbers are already in include/linux/can.h.

Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 533 insertions, 0 deletions

diff --git a/net/can/proc.c b/net/can/proc.c
new file mode 100644
index 000000000000..520fef5e5398
--- /dev/null
+++ b/net/can/proc.c
@@ -0,0 +1,533 @@
+/*
+ * proc.c - procfs support for Protocol family CAN core module
+ *
+ * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
+ * 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.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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.
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/can/core.h>
+
+#include "af_can.h"
+
+/*
+ * proc filenames for the PF_CAN core
+ */
+
+#define CAN_PROC_VERSION     "version"
+#define CAN_PROC_STATS       "stats"
+#define CAN_PROC_RESET_STATS "reset_stats"
+#define CAN_PROC_RCVLIST_ALL "rcvlist_all"
+#define CAN_PROC_RCVLIST_FIL "rcvlist_fil"
+#define CAN_PROC_RCVLIST_INV "rcvlist_inv"
+#define CAN_PROC_RCVLIST_SFF "rcvlist_sff"
+#define CAN_PROC_RCVLIST_EFF "rcvlist_eff"
+#define CAN_PROC_RCVLIST_ERR "rcvlist_err"
+
+static struct proc_dir_entry *can_dir;
+static struct proc_dir_entry *pde_version;
+static struct proc_dir_entry *pde_stats;
+static struct proc_dir_entry *pde_reset_stats;
+static struct proc_dir_entry *pde_rcvlist_all;
+static struct proc_dir_entry *pde_rcvlist_fil;
+static struct proc_dir_entry *pde_rcvlist_inv;
+static struct proc_dir_entry *pde_rcvlist_sff;
+static struct proc_dir_entry *pde_rcvlist_eff;
+static struct proc_dir_entry *pde_rcvlist_err;
+
+static int user_reset;
+
+static const char rx_list_name[][8] = {
+        [RX_ERR] = "rx_err",
+        [RX_ALL] = "rx_all",
+        [RX_FIL] = "rx_fil",
+        [RX_INV] = "rx_inv",
+        [RX_EFF] = "rx_eff",
+};
+
+/*
+ * af_can statistics stuff
+ */
+
+static void can_init_stats(void)
+{
+        /*
+         * This memset function is called from a timer context (when
+         * can_stattimer is active which is the default) OR in a process
+         * context (reading the proc_fs when can_stattimer is disabled).
+         */
+        memset(&can_stats, 0, sizeof(can_stats));
+        can_stats.jiffies_init = jiffies;
+
+        can_pstats.stats_reset++;
+
+        if (user_reset) {
+                user_reset = 0;
+                can_pstats.user_reset++;
+        }
+}
+
+static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
+                               unsigned long count)
+{
+        unsigned long rate;
+
+        if (oldjif == newjif)
+                return 0;
+
+        /* see can_stat_update() - this should NEVER happen! */
+        if (count > (ULONG_MAX / HZ)) {
+                printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
+                       count);
+                return 99999999;
+        }
+
+        rate = (count * HZ) / (newjif - oldjif);
+
+        return rate;
+}
+
+void can_stat_update(unsigned long data)
+{
+        unsigned long j = jiffies; /* snapshot */
+
+        /* restart counting in timer context on user request */
+        if (user_reset)
+                can_init_stats();
+
+        /* restart counting on jiffies overflow */
+        if (j < can_stats.jiffies_init)
+                can_init_stats();
+
+        /* prevent overflow in calc_rate() */
+        if (can_stats.rx_frames > (ULONG_MAX / HZ))
+                can_init_stats();
+
+        /* prevent overflow in calc_rate() */
+        if (can_stats.tx_frames > (ULONG_MAX / HZ))
+                can_init_stats();
+
+        /* matches overflow - very improbable */
+        if (can_stats.matches > (ULONG_MAX / 100))
+                can_init_stats();
+
+        /* calc total values */
+        if (can_stats.rx_frames)
+                can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
+                        can_stats.rx_frames;
+
+        can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
+                                            can_stats.tx_frames);
+        can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
+                                            can_stats.rx_frames);
+
+        /* calc current values */
+        if (can_stats.rx_frames_delta)
+                can_stats.current_rx_match_ratio =
+                        (can_stats.matches_delta * 100) /
+                        can_stats.rx_frames_delta;
+
+        can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
+        can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
+
+        /* check / update maximum values */
+        if (can_stats.max_tx_rate < can_stats.current_tx_rate)
+                can_stats.max_tx_rate = can_stats.current_tx_rate;
+
+        if (can_stats.max_rx_rate < can_stats.current_rx_rate)
+                can_stats.max_rx_rate = can_stats.current_rx_rate;
+
+        if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
+                can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
+
+        /* clear values for 'current rate' calculation */
+        can_stats.tx_frames_delta = 0;
+        can_stats.rx_frames_delta = 0;
+        can_stats.matches_delta   = 0;
+
+        /* restart timer (one second) */
+        mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
+}
+
+/*
+ * proc read functions
+ *
+ * From known use-cases we expect about 10 entries in a receive list to be
+ * printed in the proc_fs. So PAGE_SIZE is definitely enough space here.
+ *
+ */
+
+static int can_print_rcvlist(char *page, int len, struct hlist_head *rx_list,
+                             struct net_device *dev)
+{
+        struct receiver *r;
+        struct hlist_node *n;
+
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(r, n, rx_list, list) {
+                char *fmt = (r->can_id & CAN_EFF_FLAG)?
+                        "   %-5s  %08X  %08x  %08x  %08x  %8ld  %s\n" :
+                        "   %-5s     %03X    %08x  %08lx  %08lx  %8ld  %s\n";
+
+                len += snprintf(page + len, PAGE_SIZE - len, fmt,
+                                DNAME(dev), r->can_id, r->mask,
+                                (unsigned long)r->func, (unsigned long)r->data,
+                                r->matches, r->ident);
+
+                /* does a typical line fit into the current buffer? */
+
+                /* 100 Bytes before end of buffer */
+                if (len > PAGE_SIZE - 100) {
+                        /* mark output cut off */
+                        len += snprintf(page + len, PAGE_SIZE - len,
+                                        "   (..)\n");
+                        break;
+                }
+        }
+        rcu_read_unlock();
+
+        return len;
+}
+
+static int can_print_recv_banner(char *page, int len)
+{
+        /*
+         *                  can1.  00000000  00000000  00000000
+         *                 .......          0  tp20
+         */
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        "  device   can_id   can_mask  function"
+                        "  userdata   matches  ident\n");
+
+        return len;
+}
+
+static int can_proc_read_stats(char *page, char **start, off_t off,
+                               int count, int *eof, void *data)
+{
+        int len = 0;
+
+        len += snprintf(page + len, PAGE_SIZE - len, "\n");
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        " %8ld transmitted frames (TXF)\n",
+                        can_stats.tx_frames);
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        " %8ld received frames (RXF)\n", can_stats.rx_frames);
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        " %8ld matched frames (RXMF)\n", can_stats.matches);
+
+        len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+        if (can_stattimer.function == can_stat_update) {
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld %% total match ratio (RXMR)\n",
+                                can_stats.total_rx_match_ratio);
+
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld frames/s total tx rate (TXR)\n",
+                                can_stats.total_tx_rate);
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld frames/s total rx rate (RXR)\n",
+                                can_stats.total_rx_rate);
+
+                len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld %% current match ratio (CRXMR)\n",
+                                can_stats.current_rx_match_ratio);
+
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld frames/s current tx rate (CTXR)\n",
+                                can_stats.current_tx_rate);
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld frames/s current rx rate (CRXR)\n",
+                                can_stats.current_rx_rate);
+
+                len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld %% max match ratio (MRXMR)\n",
+                                can_stats.max_rx_match_ratio);
+
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld frames/s max tx rate (MTXR)\n",
+                                can_stats.max_tx_rate);
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld frames/s max rx rate (MRXR)\n",
+                                can_stats.max_rx_rate);
+
+                len += snprintf(page + len, PAGE_SIZE - len, "\n");
+        }
+
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        " %8ld current receive list entries (CRCV)\n",
+                        can_pstats.rcv_entries);
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        " %8ld maximum receive list entries (MRCV)\n",
+                        can_pstats.rcv_entries_max);
+
+        if (can_pstats.stats_reset)
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                "\n %8ld statistic resets (STR)\n",
+                                can_pstats.stats_reset);
+
+        if (can_pstats.user_reset)
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                " %8ld user statistic resets (USTR)\n",
+                                can_pstats.user_reset);
+
+        len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+        *eof = 1;
+        return len;
+}
+
+static int can_proc_read_reset_stats(char *page, char **start, off_t off,
+                                     int count, int *eof, void *data)
+{
+        int len = 0;
+
+        user_reset = 1;
+
+        if (can_stattimer.function == can_stat_update) {
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                "Scheduled statistic reset #%ld.\n",
+                                can_pstats.stats_reset + 1);
+
+        } else {
+                if (can_stats.jiffies_init != jiffies)
+                        can_init_stats();
+
+                len += snprintf(page + len, PAGE_SIZE - len,
+                                "Performed statistic reset #%ld.\n",
+                                can_pstats.stats_reset);
+        }
+
+        *eof = 1;
+        return len;
+}
+
+static int can_proc_read_version(char *page, char **start, off_t off,
+                                 int count, int *eof, void *data)
+{
+        int len = 0;
+
+        len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
+                        CAN_VERSION_STRING);
+        *eof = 1;
+        return len;
+}
+
+static int can_proc_read_rcvlist(char *page, char **start, off_t off,
+                                 int count, int *eof, void *data)
+{
+        /* double cast to prevent GCC warning */
+        int idx = (int)(long)data;
+        int len = 0;
+        struct dev_rcv_lists *d;
+        struct hlist_node *n;
+
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        "\nreceive list '%s':\n", rx_list_name[idx]);
+
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
+
+                if (!hlist_empty(&d->rx[idx])) {
+                        len = can_print_recv_banner(page, len);
+                        len = can_print_rcvlist(page, len, &d->rx[idx], d->dev);
+                } else
+                        len += snprintf(page + len, PAGE_SIZE - len,
+                                        "  (%s: no entry)\n", DNAME(d->dev));
+
+                /* exit on end of buffer? */
+                if (len > PAGE_SIZE - 100)
+                        break;
+        }
+        rcu_read_unlock();
+
+        len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+        *eof = 1;
+        return len;
+}
+
+static int can_proc_read_rcvlist_sff(char *page, char **start, off_t off,
+                                     int count, int *eof, void *data)
+{
+        int len = 0;
+        struct dev_rcv_lists *d;
+        struct hlist_node *n;
+
+        /* RX_SFF */
+        len += snprintf(page + len, PAGE_SIZE - len,
+                        "\nreceive list 'rx_sff':\n");
+
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
+                int i, all_empty = 1;
+                /* check wether at least one list is non-empty */
+                for (i = 0; i < 0x800; i++)
+                        if (!hlist_empty(&d->rx_sff[i])) {
+                                all_empty = 0;
+                                break;
+                        }
+
+                if (!all_empty) {
+                        len = can_print_recv_banner(page, len);
+                        for (i = 0; i < 0x800; i++) {
+                                if (!hlist_empty(&d->rx_sff[i]) &&
+                                    len < PAGE_SIZE - 100)
+                                        len = can_print_rcvlist(page, len,
+                                                                &d->rx_sff[i],
+                                                                d->dev);
+                        }
+                } else
+                        len += snprintf(page + len, PAGE_SIZE - len,
+                                        "  (%s: no entry)\n", DNAME(d->dev));
+
+                /* exit on end of buffer? */
+                if (len > PAGE_SIZE - 100)
+                        break;
+        }
+        rcu_read_unlock();
+
+        len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+        *eof = 1;
+        return len;
+}
+
+/*
+ * proc utility functions
+ */
+
+static struct proc_dir_entry *can_create_proc_readentry(const char *name,
+                                                        mode_t mode,
+                                                        read_proc_t *read_proc,
+                                                        void *data)
+{
+        if (can_dir)
+                return create_proc_read_entry(name, mode, can_dir, read_proc,
+                                              data);
+        else
+                return NULL;
+}
+
+static void can_remove_proc_readentry(const char *name)
+{
+        if (can_dir)
+                remove_proc_entry(name, can_dir);
+}
+
+/*
+ * can_init_proc - create main CAN proc directory and procfs entries
+ */
+void can_init_proc(void)
+{
+        /* create /proc/net/can directory */
+        can_dir = proc_mkdir("can", init_net.proc_net);
+
+        if (!can_dir) {
+                printk(KERN_INFO "can: failed to create /proc/net/can . "
+                       "CONFIG_PROC_FS missing?\n");
+                return;
+        }
+
+        can_dir->owner = THIS_MODULE;
+
+        /* own procfs entries from the AF_CAN core */
+        pde_version     = can_create_proc_readentry(CAN_PROC_VERSION, 0644,
+                                        can_proc_read_version, NULL);
+        pde_stats       = can_create_proc_readentry(CAN_PROC_STATS, 0644,
+                                        can_proc_read_stats, NULL);
+        pde_reset_stats = can_create_proc_readentry(CAN_PROC_RESET_STATS, 0644,
+                                        can_proc_read_reset_stats, NULL);
+        pde_rcvlist_err = can_create_proc_readentry(CAN_PROC_RCVLIST_ERR, 0644,
+                                        can_proc_read_rcvlist, (void *)RX_ERR);
+        pde_rcvlist_all = can_create_proc_readentry(CAN_PROC_RCVLIST_ALL, 0644,
+                                        can_proc_read_rcvlist, (void *)RX_ALL);
+        pde_rcvlist_fil = can_create_proc_readentry(CAN_PROC_RCVLIST_FIL, 0644,
+                                        can_proc_read_rcvlist, (void *)RX_FIL);
+        pde_rcvlist_inv = can_create_proc_readentry(CAN_PROC_RCVLIST_INV, 0644,
+                                        can_proc_read_rcvlist, (void *)RX_INV);
+        pde_rcvlist_eff = can_create_proc_readentry(CAN_PROC_RCVLIST_EFF, 0644,
+                                        can_proc_read_rcvlist, (void *)RX_EFF);
+        pde_rcvlist_sff = can_create_proc_readentry(CAN_PROC_RCVLIST_SFF, 0644,
+                                        can_proc_read_rcvlist_sff, NULL);
+}
+
+/*
+ * can_remove_proc - remove procfs entries and main CAN proc directory
+ */
+void can_remove_proc(void)
+{
+        if (pde_version)
+                can_remove_proc_readentry(CAN_PROC_VERSION);
+
+        if (pde_stats)
+                can_remove_proc_readentry(CAN_PROC_STATS);
+
+        if (pde_reset_stats)
+                can_remove_proc_readentry(CAN_PROC_RESET_STATS);
+
+        if (pde_rcvlist_err)
+                can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
+
+        if (pde_rcvlist_all)
+                can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
+
+        if (pde_rcvlist_fil)
+                can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
+
+        if (pde_rcvlist_inv)
+                can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
+
+        if (pde_rcvlist_eff)
+                can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
+
+        if (pde_rcvlist_sff)
+                can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
+
+        if (can_dir)
+                proc_net_remove(&init_net, "can");
+}