sysctl.c

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/*
 * linux/net/sunrpc/sysctl.c
 *
 * Sysctl interface to sunrpc module.
 *
 * I would prefer to register the sunrpc table below sys/net, but that's
 * impossible at the moment.
 */

#include <linux/types.h>
#include <linux/linkage.h>
#include <linux/ctype.h>
#include <linux/fs.h>
#include <linux/sysctl.h>
#include <linux/module.h>

#include <asm/uaccess.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svc_xprt.h>

#include "netns.h"

/*
 * Declare the debug flags here
 */
unsigned int    rpc_debug;
EXPORT_SYMBOL_GPL(rpc_debug);

unsigned int    nfs_debug;
EXPORT_SYMBOL_GPL(nfs_debug);

unsigned int    nfsd_debug;
EXPORT_SYMBOL_GPL(nfsd_debug);

unsigned int    nlm_debug;
EXPORT_SYMBOL_GPL(nlm_debug);

#ifdef RPC_DEBUG

static struct ctl_table_header *sunrpc_table_header;
static ctl_table        sunrpc_table[];

void
rpc_register_sysctl(void)
{
    if (!sunrpc_table_header)
        sunrpc_table_header = register_sysctl_table(sunrpc_table);
}

void
rpc_unregister_sysctl(void)
{
    if (sunrpc_table_header) {
        unregister_sysctl_table(sunrpc_table_header);
        sunrpc_table_header = NULL;
    }
}

static int proc_do_xprt(ctl_table *table, int write,
            void __user *buffer, size_t *lenp, loff_t *ppos)
{
    char tmpbuf[256];
    size_t len;

    if ((*ppos && !write) || !*lenp) {
        *lenp = 0;
        return 0;
    }
    len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
    return simple_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
}

static int
proc_dodebug(ctl_table *table, int write,
                void __user *buffer, size_t *lenp, loff_t *ppos)
{
    char        tmpbuf[20], c, *s;
    char __user *p;
    unsigned int    value;
    size_t      left, len;

    if ((*ppos && !write) || !*lenp) {
        *lenp = 0;
        return 0;
    }

    left = *lenp;

    if (write) {
        if (!access_ok(VERIFY_READ, buffer, left))
            return -EFAULT;
        p = buffer;
        while (left && __get_user(c, p) >= 0 && isspace(c))
            left--, p++;
        if (!left)
            goto done;

        if (left > sizeof(tmpbuf) - 1)
            return -EINVAL;
        if (copy_from_user(tmpbuf, p, left))
            return -EFAULT;
        tmpbuf[left] = '\0';

        for (s = tmpbuf, value = 0; '0' <= *s && *s <= '9'; s++, left--)
            value = 10 * value + (*s - '0');
        if (*s && !isspace(*s))
            return -EINVAL;
        while (left && isspace(*s))
            left--, s++;
        *(unsigned int *) table->data = value;
        /* Display the RPC tasks on writing to rpc_debug */
        if (strcmp(table->procname, "rpc_debug") == 0)
            rpc_show_tasks(&init_net);
    } else {
        if (!access_ok(VERIFY_WRITE, buffer, left))
            return -EFAULT;
        len = sprintf(tmpbuf, "%d", *(unsigned int *) table->data);
        if (len > left)
            len = left;
        if (__copy_to_user(buffer, tmpbuf, len))
            return -EFAULT;
        if ((left -= len) > 0) {
            if (put_user('\n', (char __user *)buffer + len))
                return -EFAULT;
            left--;
        }
    }

done:
    *lenp -= left;
    *ppos += *lenp;
    return 0;
}


static ctl_table debug_table[] = {
    {
        .procname   = "rpc_debug",
        .data       = &rpc_debug,
        .maxlen     = sizeof(int),
        .mode       = 0644,
        .proc_handler   = proc_dodebug
    },
    {
        .procname   = "nfs_debug",
        .data       = &nfs_debug,
        .maxlen     = sizeof(int),
        .mode       = 0644,
        .proc_handler   = proc_dodebug
    },
    {
        .procname   = "nfsd_debug",
        .data       = &nfsd_debug,
        .maxlen     = sizeof(int),
        .mode       = 0644,
        .proc_handler   = proc_dodebug
    },
    {
        .procname   = "nlm_debug",
        .data       = &nlm_debug,
        .maxlen     = sizeof(int),
        .mode       = 0644,
        .proc_handler   = proc_dodebug
    },
    {
        .procname   = "transports",
        .maxlen     = 256,
        .mode       = 0444,
        .proc_handler   = proc_do_xprt,
    },
    { }
};

static ctl_table sunrpc_table[] = {
    {
        .procname   = "sunrpc",
        .mode       = 0555,
        .child      = debug_table
    },
    { }
};

#endif