debugfs.c

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/* Copyright (C) 2010-2012 B.A.T.M.A.N. contributors:
 *
 * Marek Lindner
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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 "main.h"

#include <linux/debugfs.h>

#include "debugfs.h"
#include "translation-table.h"
#include "originator.h"
#include "hard-interface.h"
#include "gateway_common.h"
#include "gateway_client.h"
#include "soft-interface.h"
#include "vis.h"
#include "icmp_socket.h"
#include "bridge_loop_avoidance.h"

static struct dentry *batadv_debugfs;

#ifdef CONFIG_BATMAN_ADV_DEBUG
#define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)

static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;

static char *batadv_log_char_addr(struct batadv_debug_log *debug_log,
                  size_t idx)
{
    return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
}

static void batadv_emit_log_char(struct batadv_debug_log *debug_log, char c)
{
    char *char_addr;

    char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
    *char_addr = c;
    debug_log->log_end++;

    if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
        debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
}

__printf(2, 3)
static int batadv_fdebug_log(struct batadv_debug_log *debug_log,
                 const char *fmt, ...)
{
    va_list args;
    static char debug_log_buf[256];
    char *p;

    if (!debug_log)
        return 0;

    spin_lock_bh(&debug_log->lock);
    va_start(args, fmt);
    vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
    va_end(args);

    for (p = debug_log_buf; *p != 0; p++)
        batadv_emit_log_char(debug_log, *p);

    spin_unlock_bh(&debug_log->lock);

    wake_up(&debug_log->queue_wait);

    return 0;
}

int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
{
    va_list args;
    char tmp_log_buf[256];

    va_start(args, fmt);
    vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args);
    batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s",
              jiffies_to_msecs(jiffies), tmp_log_buf);
    va_end(args);

    return 0;
}

static int batadv_log_open(struct inode *inode, struct file *file)
{
    nonseekable_open(inode, file);
    file->private_data = inode->i_private;
    batadv_inc_module_count();
    return 0;
}

static int batadv_log_release(struct inode *inode, struct file *file)
{
    batadv_dec_module_count();
    return 0;
}

static int batadv_log_empty(struct batadv_debug_log *debug_log)
{
    return !(debug_log->log_start - debug_log->log_end);
}

static ssize_t batadv_log_read(struct file *file, char __user *buf,
                   size_t count, loff_t *ppos)
{
    struct batadv_priv *bat_priv = file->private_data;
    struct batadv_debug_log *debug_log = bat_priv->debug_log;
    int error, i = 0;
    char *char_addr;
    char c;

    if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
        return -EAGAIN;

    if (!buf)
        return -EINVAL;

    if (count == 0)
        return 0;

    if (!access_ok(VERIFY_WRITE, buf, count))
        return -EFAULT;

    error = wait_event_interruptible(debug_log->queue_wait,
                     (!batadv_log_empty(debug_log)));

    if (error)
        return error;

    spin_lock_bh(&debug_log->lock);

    while ((!error) && (i < count) &&
           (debug_log->log_start != debug_log->log_end)) {
        char_addr = batadv_log_char_addr(debug_log,
                         debug_log->log_start);
        c = *char_addr;

        debug_log->log_start++;

        spin_unlock_bh(&debug_log->lock);

        error = __put_user(c, buf);

        spin_lock_bh(&debug_log->lock);

        buf++;
        i++;

    }

    spin_unlock_bh(&debug_log->lock);

    if (!error)
        return i;

    return error;
}

static unsigned int batadv_log_poll(struct file *file, poll_table *wait)
{
    struct batadv_priv *bat_priv = file->private_data;
    struct batadv_debug_log *debug_log = bat_priv->debug_log;

    poll_wait(file, &debug_log->queue_wait, wait);

    if (!batadv_log_empty(debug_log))
        return POLLIN | POLLRDNORM;

    return 0;
}

static const struct file_operations batadv_log_fops = {
    .open           = batadv_log_open,
    .release        = batadv_log_release,
    .read           = batadv_log_read,
    .poll           = batadv_log_poll,
    .llseek         = no_llseek,
};

static int batadv_debug_log_setup(struct batadv_priv *bat_priv)
{
    struct dentry *d;

    if (!bat_priv->debug_dir)
        goto err;

    bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
    if (!bat_priv->debug_log)
        goto err;

    spin_lock_init(&bat_priv->debug_log->lock);
    init_waitqueue_head(&bat_priv->debug_log->queue_wait);

    d = debugfs_create_file("log", S_IFREG | S_IRUSR,
                bat_priv->debug_dir, bat_priv,
                &batadv_log_fops);
    if (!d)
        goto err;

    return 0;

err:
    return -ENOMEM;
}

static void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
{
    kfree(bat_priv->debug_log);
    bat_priv->debug_log = NULL;
}
#else /* CONFIG_BATMAN_ADV_DEBUG */
static int batadv_debug_log_setup(struct batadv_priv *bat_priv)
{
    bat_priv->debug_log = NULL;
    return 0;
}

static void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
{
    return;
}
#endif

static int batadv_algorithms_open(struct inode *inode, struct file *file)
{
    return single_open(file, batadv_algo_seq_print_text, NULL);
}

static int batadv_originators_open(struct inode *inode, struct file *file)
{
    struct net_device *net_dev = (struct net_device *)inode->i_private;
    return single_open(file, batadv_orig_seq_print_text, net_dev);
}

static int batadv_gateways_open(struct inode *inode, struct file *file)
{
    struct net_device *net_dev = (struct net_device *)inode->i_private;
    return single_open(file, batadv_gw_client_seq_print_text, net_dev);
}

static int batadv_transtable_global_open(struct inode *inode, struct file *file)
{
    struct net_device *net_dev = (struct net_device *)inode->i_private;
    return single_open(file, batadv_tt_global_seq_print_text, net_dev);
}

#ifdef CONFIG_BATMAN_ADV_BLA
static int batadv_bla_claim_table_open(struct inode *inode, struct file *file)
{
    struct net_device *net_dev = (struct net_device *)inode->i_private;
    return single_open(file, batadv_bla_claim_table_seq_print_text,
               net_dev);
}

static int batadv_bla_backbone_table_open(struct inode *inode,
                      struct file *file)
{
    struct net_device *net_dev = (struct net_device *)inode->i_private;
    return single_open(file, batadv_bla_backbone_table_seq_print_text,
               net_dev);
}

#endif

static int batadv_transtable_local_open(struct inode *inode, struct file *file)
{
    struct net_device *net_dev = (struct net_device *)inode->i_private;
    return single_open(file, batadv_tt_local_seq_print_text, net_dev);
}

static int batadv_vis_data_open(struct inode *inode, struct file *file)
{
    struct net_device *net_dev = (struct net_device *)inode->i_private;
    return single_open(file, batadv_vis_seq_print_text, net_dev);
}

struct batadv_debuginfo {
    struct attribute attr;
    const struct file_operations fops;
};

#define BATADV_DEBUGINFO(_name, _mode, _open)       \
struct batadv_debuginfo batadv_debuginfo_##_name = {    \
    .attr = { .name = __stringify(_name),       \
          .mode = _mode, },         \
    .fops = { .owner = THIS_MODULE,         \
          .open = _open,            \
          .read = seq_read,         \
          .llseek = seq_lseek,          \
          .release = single_release,        \
        }                   \
};

static BATADV_DEBUGINFO(routing_algos, S_IRUGO, batadv_algorithms_open);
static BATADV_DEBUGINFO(originators, S_IRUGO, batadv_originators_open);
static BATADV_DEBUGINFO(gateways, S_IRUGO, batadv_gateways_open);
static BATADV_DEBUGINFO(transtable_global, S_IRUGO,
            batadv_transtable_global_open);
#ifdef CONFIG_BATMAN_ADV_BLA
static BATADV_DEBUGINFO(bla_claim_table, S_IRUGO, batadv_bla_claim_table_open);
static BATADV_DEBUGINFO(bla_backbone_table, S_IRUGO,
            batadv_bla_backbone_table_open);
#endif
static BATADV_DEBUGINFO(transtable_local, S_IRUGO,
            batadv_transtable_local_open);
static BATADV_DEBUGINFO(vis_data, S_IRUGO, batadv_vis_data_open);

static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
    &batadv_debuginfo_originators,
    &batadv_debuginfo_gateways,
    &batadv_debuginfo_transtable_global,
#ifdef CONFIG_BATMAN_ADV_BLA
    &batadv_debuginfo_bla_claim_table,
    &batadv_debuginfo_bla_backbone_table,
#endif
    &batadv_debuginfo_transtable_local,
    &batadv_debuginfo_vis_data,
    NULL,
};

void batadv_debugfs_init(void)
{
    struct batadv_debuginfo *bat_debug;
    struct dentry *file;

    batadv_debugfs = debugfs_create_dir(BATADV_DEBUGFS_SUBDIR, NULL);
    if (batadv_debugfs == ERR_PTR(-ENODEV))
        batadv_debugfs = NULL;

    if (!batadv_debugfs)
        goto out;

    bat_debug = &batadv_debuginfo_routing_algos;
    file = debugfs_create_file(bat_debug->attr.name,
                   S_IFREG | bat_debug->attr.mode,
                   batadv_debugfs, NULL, &bat_debug->fops);
    if (!file)
        pr_err("Can't add debugfs file: %s\n", bat_debug->attr.name);

out:
    return;
}

void batadv_debugfs_destroy(void)
{
    if (batadv_debugfs) {
        debugfs_remove_recursive(batadv_debugfs);
        batadv_debugfs = NULL;
    }
}

int batadv_debugfs_add_meshif(struct net_device *dev)
{
    struct batadv_priv *bat_priv = netdev_priv(dev);
    struct batadv_debuginfo **bat_debug;
    struct dentry *file;

    if (!batadv_debugfs)
        goto out;

    bat_priv->debug_dir = debugfs_create_dir(dev->name, batadv_debugfs);
    if (!bat_priv->debug_dir)
        goto out;

    if (batadv_socket_setup(bat_priv) < 0)
        goto rem_attr;

    if (batadv_debug_log_setup(bat_priv) < 0)
        goto rem_attr;

    for (bat_debug = batadv_mesh_debuginfos; *bat_debug; ++bat_debug) {
        file = debugfs_create_file(((*bat_debug)->attr).name,
                       S_IFREG | ((*bat_debug)->attr).mode,
                       bat_priv->debug_dir,
                       dev, &(*bat_debug)->fops);
        if (!file) {
            batadv_err(dev, "Can't add debugfs file: %s/%s\n",
                   dev->name, ((*bat_debug)->attr).name);
            goto rem_attr;
        }
    }

    return 0;
rem_attr:
    debugfs_remove_recursive(bat_priv->debug_dir);
    bat_priv->debug_dir = NULL;
out:
#ifdef CONFIG_DEBUG_FS
    return -ENOMEM;
#else
    return 0;
#endif /* CONFIG_DEBUG_FS */
}

void batadv_debugfs_del_meshif(struct net_device *dev)
{
    struct batadv_priv *bat_priv = netdev_priv(dev);

    batadv_debug_log_cleanup(bat_priv);

    if (batadv_debugfs) {
        debugfs_remove_recursive(bat_priv->debug_dir);
        bat_priv->debug_dir = NULL;
    }
}