sysctl_net_decnet.c

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/*
 * DECnet       An implementation of the DECnet protocol suite for the LINUX
 *              operating system.  DECnet is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              DECnet sysctl support functions
 *
 * Author:      Steve Whitehouse <[email protected]>
 *
 *
 * Changes:
 * Steve Whitehouse - C99 changes and default device handling
 * Steve Whitehouse - Memory buffer settings, like the tcp ones
 *
 */
#include <linux/mm.h>
#include <linux/sysctl.h>
#include <linux/fs.h>
#include <linux/netdevice.h>
#include <linux/string.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>

#include <asm/uaccess.h>

#include <net/dn.h>
#include <net/dn_dev.h>
#include <net/dn_route.h>


int decnet_debug_level;
int decnet_time_wait = 30;
int decnet_dn_count = 1;
int decnet_di_count = 3;
int decnet_dr_count = 3;
int decnet_log_martians = 1;
int decnet_no_fc_max_cwnd = NSP_MIN_WINDOW;

/* Reasonable defaults, I hope, based on tcp's defaults */
long sysctl_decnet_mem[3] = { 768 << 3, 1024 << 3, 1536 << 3 };
int sysctl_decnet_wmem[3] = { 4 * 1024, 16 * 1024, 128 * 1024 };
int sysctl_decnet_rmem[3] = { 4 * 1024, 87380, 87380 * 2 };

#ifdef CONFIG_SYSCTL
extern int decnet_dst_gc_interval;
static int min_decnet_time_wait[] = { 5 };
static int max_decnet_time_wait[] = { 600 };
static int min_state_count[] = { 1 };
static int max_state_count[] = { NSP_MAXRXTSHIFT };
static int min_decnet_dst_gc_interval[] = { 1 };
static int max_decnet_dst_gc_interval[] = { 60 };
static int min_decnet_no_fc_max_cwnd[] = { NSP_MIN_WINDOW };
static int max_decnet_no_fc_max_cwnd[] = { NSP_MAX_WINDOW };
static char node_name[7] = "???";

static struct ctl_table_header *dn_table_header = NULL;

/*
 * ctype.h :-)
 */
#define ISNUM(x) (((x) >= '0') && ((x) <= '9'))
#define ISLOWER(x) (((x) >= 'a') && ((x) <= 'z'))
#define ISUPPER(x) (((x) >= 'A') && ((x) <= 'Z'))
#define ISALPHA(x) (ISLOWER(x) || ISUPPER(x))
#define INVALID_END_CHAR(x) (ISNUM(x) || ISALPHA(x))

static void strip_it(char *str)
{
    for(;;) {
        switch (*str) {
        case ' ':
        case '\n':
        case '\r':
        case ':':
            *str = 0;
            /* Fallthrough */
        case 0:
            return;
        }
        str++;
    }
}

/*
 * Simple routine to parse an ascii DECnet address
 * into a network order address.
 */
static int parse_addr(__le16 *addr, char *str)
{
    __u16 area, node;

    while(*str && !ISNUM(*str)) str++;

    if (*str == 0)
        return -1;

    area = (*str++ - '0');
    if (ISNUM(*str)) {
        area *= 10;
        area += (*str++ - '0');
    }

    if (*str++ != '.')
        return -1;

    if (!ISNUM(*str))
        return -1;

    node = *str++ - '0';
    if (ISNUM(*str)) {
        node *= 10;
        node += (*str++ - '0');
    }
    if (ISNUM(*str)) {
        node *= 10;
        node += (*str++ - '0');
    }
    if (ISNUM(*str)) {
        node *= 10;
        node += (*str++ - '0');
    }

    if ((node > 1023) || (area > 63))
        return -1;

    if (INVALID_END_CHAR(*str))
        return -1;

    *addr = cpu_to_le16((area << 10) | node);

    return 0;
}

static int dn_node_address_handler(ctl_table *table, int write,
                void __user *buffer,
                size_t *lenp, loff_t *ppos)
{
    char addr[DN_ASCBUF_LEN];
    size_t len;
    __le16 dnaddr;

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

    if (write) {
        len = (*lenp < DN_ASCBUF_LEN) ? *lenp : (DN_ASCBUF_LEN-1);

        if (copy_from_user(addr, buffer, len))
            return -EFAULT;

        addr[len] = 0;
        strip_it(addr);

        if (parse_addr(&dnaddr, addr))
            return -EINVAL;

        dn_dev_devices_off();

        decnet_address = dnaddr;

        dn_dev_devices_on();

        *ppos += len;

        return 0;
    }

    dn_addr2asc(le16_to_cpu(decnet_address), addr);
    len = strlen(addr);
    addr[len++] = '\n';

    if (len > *lenp) len = *lenp;

    if (copy_to_user(buffer, addr, len))
        return -EFAULT;

    *lenp = len;
    *ppos += len;

    return 0;
}

static int dn_def_dev_handler(ctl_table *table, int write,
                void __user *buffer,
                size_t *lenp, loff_t *ppos)
{
    size_t len;
    struct net_device *dev;
    char devname[17];

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

    if (write) {
        if (*lenp > 16)
            return -E2BIG;

        if (copy_from_user(devname, buffer, *lenp))
            return -EFAULT;

        devname[*lenp] = 0;
        strip_it(devname);

        dev = dev_get_by_name(&init_net, devname);
        if (dev == NULL)
            return -ENODEV;

        if (dev->dn_ptr == NULL) {
            dev_put(dev);
            return -ENODEV;
        }

        if (dn_dev_set_default(dev, 1)) {
            dev_put(dev);
            return -ENODEV;
        }
        *ppos += *lenp;

        return 0;
    }

    dev = dn_dev_get_default();
    if (dev == NULL) {
        *lenp = 0;
        return 0;
    }

    strcpy(devname, dev->name);
    dev_put(dev);
    len = strlen(devname);
    devname[len++] = '\n';

    if (len > *lenp) len = *lenp;

    if (copy_to_user(buffer, devname, len))
        return -EFAULT;

    *lenp = len;
    *ppos += len;

    return 0;
}

static ctl_table dn_table[] = {
    {
        .procname = "node_address",
        .maxlen = 7,
        .mode = 0644,
        .proc_handler = dn_node_address_handler,
    },
    {
        .procname = "node_name",
        .data = node_name,
        .maxlen = 7,
        .mode = 0644,
        .proc_handler = proc_dostring,
    },
    {
        .procname = "default_device",
        .maxlen = 16,
        .mode = 0644,
        .proc_handler = dn_def_dev_handler,
    },
    {
        .procname = "time_wait",
        .data = &decnet_time_wait,
        .maxlen = sizeof(int),
        .mode = 0644,
        .proc_handler = proc_dointvec_minmax,
        .extra1 = &min_decnet_time_wait,
        .extra2 = &max_decnet_time_wait
    },
    {
        .procname = "dn_count",
        .data = &decnet_dn_count,
        .maxlen = sizeof(int),
        .mode = 0644,
        .proc_handler = proc_dointvec_minmax,
        .extra1 = &min_state_count,
        .extra2 = &max_state_count
    },
    {
        .procname = "di_count",
        .data = &decnet_di_count,
        .maxlen = sizeof(int),
        .mode = 0644,
        .proc_handler = proc_dointvec_minmax,
        .extra1 = &min_state_count,
        .extra2 = &max_state_count
    },
    {
        .procname = "dr_count",
        .data = &decnet_dr_count,
        .maxlen = sizeof(int),
        .mode = 0644,
        .proc_handler = proc_dointvec_minmax,
        .extra1 = &min_state_count,
        .extra2 = &max_state_count
    },
    {
        .procname = "dst_gc_interval",
        .data = &decnet_dst_gc_interval,
        .maxlen = sizeof(int),
        .mode = 0644,
        .proc_handler = proc_dointvec_minmax,
        .extra1 = &min_decnet_dst_gc_interval,
        .extra2 = &max_decnet_dst_gc_interval
    },
    {
        .procname = "no_fc_max_cwnd",
        .data = &decnet_no_fc_max_cwnd,
        .maxlen = sizeof(int),
        .mode = 0644,
        .proc_handler = proc_dointvec_minmax,
        .extra1 = &min_decnet_no_fc_max_cwnd,
        .extra2 = &max_decnet_no_fc_max_cwnd
    },
       {
        .procname = "decnet_mem",
        .data = &sysctl_decnet_mem,
        .maxlen = sizeof(sysctl_decnet_mem),
        .mode = 0644,
        .proc_handler = proc_doulongvec_minmax
    },
    {
        .procname = "decnet_rmem",
        .data = &sysctl_decnet_rmem,
        .maxlen = sizeof(sysctl_decnet_rmem),
        .mode = 0644,
        .proc_handler = proc_dointvec,
    },
    {
        .procname = "decnet_wmem",
        .data = &sysctl_decnet_wmem,
        .maxlen = sizeof(sysctl_decnet_wmem),
        .mode = 0644,
        .proc_handler = proc_dointvec,
    },
    {
        .procname = "debug",
        .data = &decnet_debug_level,
        .maxlen = sizeof(int),
        .mode = 0644,
        .proc_handler = proc_dointvec,
    },
    { }
};

void dn_register_sysctl(void)
{
    dn_table_header = register_net_sysctl(&init_net, "net/decnet", dn_table);
}

void dn_unregister_sysctl(void)
{
    unregister_net_sysctl_table(dn_table_header);
}

#else  /* CONFIG_SYSCTL */
void dn_unregister_sysctl(void)
{
}
void dn_register_sysctl(void)
{
}

#endif