mpoa_proc.c

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#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#ifdef CONFIG_PROC_FS
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/time.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/atmmpc.h>
#include <linux/atm.h>
#include <linux/gfp.h>
#include "mpc.h"
#include "mpoa_caches.h"

/*
 * mpoa_proc.c: Implementation MPOA client's proc
 * file system statistics
 */

#if 1
#define dprintk(format, args...)                    \
    printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
#else
#define dprintk(format, args...)                    \
    do { if (0)                         \
        printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
    } while (0)
#endif

#if 0
#define ddprintk(format, args...)                   \
    printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
#else
#define ddprintk(format, args...)                   \
    do { if (0)                         \
        printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
    } while (0)
#endif

#define STAT_FILE_NAME "mpc"     /* Our statistic file's name */

extern struct mpoa_client *mpcs;
extern struct proc_dir_entry *atm_proc_root;  /* from proc.c. */

static int proc_mpc_open(struct inode *inode, struct file *file);
static ssize_t proc_mpc_write(struct file *file, const char __user *buff,
                  size_t nbytes, loff_t *ppos);

static int parse_qos(const char *buff);

/*
 *   Define allowed FILE OPERATIONS
 */
static const struct file_operations mpc_file_operations = {
    .owner =    THIS_MODULE,
    .open =     proc_mpc_open,
    .read =     seq_read,
    .llseek =   seq_lseek,
    .write =    proc_mpc_write,
    .release =  seq_release,
};

/*
 * Returns the state of an ingress cache entry as a string
 */
static const char *ingress_state_string(int state)
{
    switch (state) {
    case INGRESS_RESOLVING:
        return "resolving  ";
    case INGRESS_RESOLVED:
        return "resolved   ";
    case INGRESS_INVALID:
        return "invalid    ";
    case INGRESS_REFRESHING:
        return "refreshing ";
    }

    return "";
}

/*
 * Returns the state of an egress cache entry as a string
 */
static const char *egress_state_string(int state)
{
    switch (state) {
    case EGRESS_RESOLVED:
        return "resolved   ";
    case EGRESS_PURGE:
        return "purge      ";
    case EGRESS_INVALID:
        return "invalid    ";
    }

    return "";
}

/*
 * FIXME: mpcs (and per-mpc lists) have no locking whatsoever.
 */

static void *mpc_start(struct seq_file *m, loff_t *pos)
{
    loff_t l = *pos;
    struct mpoa_client *mpc;

    if (!l--)
        return SEQ_START_TOKEN;
    for (mpc = mpcs; mpc; mpc = mpc->next)
        if (!l--)
            return mpc;
    return NULL;
}

static void *mpc_next(struct seq_file *m, void *v, loff_t *pos)
{
    struct mpoa_client *p = v;
    (*pos)++;
    return v == SEQ_START_TOKEN ? mpcs : p->next;
}

static void mpc_stop(struct seq_file *m, void *v)
{
}

/*
 * READING function - called when the /proc/atm/mpoa file is read from.
 */
static int mpc_show(struct seq_file *m, void *v)
{
    struct mpoa_client *mpc = v;
    int i;
    in_cache_entry *in_entry;
    eg_cache_entry *eg_entry;
    struct timeval now;
    unsigned char ip_string[16];

    if (v == SEQ_START_TOKEN) {
        atm_mpoa_disp_qos(m);
        return 0;
    }

    seq_printf(m, "\nInterface %d:\n\n", mpc->dev_num);
    seq_printf(m, "Ingress Entries:\nIP address      State      Holding time  Packets fwded  VPI  VCI\n");
    do_gettimeofday(&now);

    for (in_entry = mpc->in_cache; in_entry; in_entry = in_entry->next) {
        sprintf(ip_string, "%pI4", &in_entry->ctrl_info.in_dst_ip);
        seq_printf(m, "%-16s%s%-14lu%-12u",
               ip_string,
               ingress_state_string(in_entry->entry_state),
               in_entry->ctrl_info.holding_time -
               (now.tv_sec-in_entry->tv.tv_sec),
               in_entry->packets_fwded);
        if (in_entry->shortcut)
            seq_printf(m, "   %-3d  %-3d",
                   in_entry->shortcut->vpi,
                   in_entry->shortcut->vci);
        seq_printf(m, "\n");
    }

    seq_printf(m, "\n");
    seq_printf(m, "Egress Entries:\nIngress MPC ATM addr\nCache-id        State      Holding time  Packets recvd  Latest IP addr   VPI VCI\n");
    for (eg_entry = mpc->eg_cache; eg_entry; eg_entry = eg_entry->next) {
        unsigned char *p = eg_entry->ctrl_info.in_MPC_data_ATM_addr;
        for (i = 0; i < ATM_ESA_LEN; i++)
            seq_printf(m, "%02x", p[i]);
        seq_printf(m, "\n%-16lu%s%-14lu%-15u",
               (unsigned long)ntohl(eg_entry->ctrl_info.cache_id),
               egress_state_string(eg_entry->entry_state),
               (eg_entry->ctrl_info.holding_time -
                (now.tv_sec-eg_entry->tv.tv_sec)),
               eg_entry->packets_rcvd);

        /* latest IP address */
        sprintf(ip_string, "%pI4", &eg_entry->latest_ip_addr);
        seq_printf(m, "%-16s", ip_string);

        if (eg_entry->shortcut)
            seq_printf(m, " %-3d %-3d",
                   eg_entry->shortcut->vpi,
                   eg_entry->shortcut->vci);
        seq_printf(m, "\n");
    }
    seq_printf(m, "\n");
    return 0;
}

static const struct seq_operations mpc_op = {
    .start =    mpc_start,
    .next =     mpc_next,
    .stop =     mpc_stop,
    .show =     mpc_show
};

static int proc_mpc_open(struct inode *inode, struct file *file)
{
    return seq_open(file, &mpc_op);
}

static ssize_t proc_mpc_write(struct file *file, const char __user *buff,
                  size_t nbytes, loff_t *ppos)
{
    char *page, *p;
    unsigned int len;

    if (nbytes == 0)
        return 0;

    if (nbytes >= PAGE_SIZE)
        nbytes = PAGE_SIZE-1;

    page = (char *)__get_free_page(GFP_KERNEL);
    if (!page)
        return -ENOMEM;

    for (p = page, len = 0; len < nbytes; p++, len++) {
        if (get_user(*p, buff++)) {
            free_page((unsigned long)page);
            return -EFAULT;
        }
        if (*p == '\0' || *p == '\n')
            break;
    }

    *p = '\0';

    if (!parse_qos(page))
        printk("mpoa: proc_mpc_write: could not parse '%s'\n", page);

    free_page((unsigned long)page);

    return len;
}

static int parse_qos(const char *buff)
{
    /* possible lines look like this
     * add 130.230.54.142 tx=max_pcr,max_sdu rx=max_pcr,max_sdu
     */
    unsigned char ip[4];
    int tx_pcr, tx_sdu, rx_pcr, rx_sdu;
    __be32 ipaddr;
    struct atm_qos qos;

    memset(&qos, 0, sizeof(struct atm_qos));

    if (sscanf(buff, "del %hhu.%hhu.%hhu.%hhu",
            ip, ip+1, ip+2, ip+3) == 4) {
        ipaddr = *(__be32 *)ip;
        return atm_mpoa_delete_qos(atm_mpoa_search_qos(ipaddr));
    }

    if (sscanf(buff, "add %hhu.%hhu.%hhu.%hhu tx=%d,%d rx=tx",
            ip, ip+1, ip+2, ip+3, &tx_pcr, &tx_sdu) == 6) {
        rx_pcr = tx_pcr;
        rx_sdu = tx_sdu;
    } else if (sscanf(buff, "add %hhu.%hhu.%hhu.%hhu tx=%d,%d rx=%d,%d",
        ip, ip+1, ip+2, ip+3, &tx_pcr, &tx_sdu, &rx_pcr, &rx_sdu) != 8)
        return 0;

    ipaddr = *(__be32 *)ip;
    qos.txtp.traffic_class = ATM_CBR;
    qos.txtp.max_pcr = tx_pcr;
    qos.txtp.max_sdu = tx_sdu;
    qos.rxtp.traffic_class = ATM_CBR;
    qos.rxtp.max_pcr = rx_pcr;
    qos.rxtp.max_sdu = rx_sdu;
    qos.aal = ATM_AAL5;
    dprintk("parse_qos(): setting qos paramameters to tx=%d,%d rx=%d,%d\n",
        qos.txtp.max_pcr, qos.txtp.max_sdu,
        qos.rxtp.max_pcr, qos.rxtp.max_sdu);

    atm_mpoa_add_qos(ipaddr, &qos);
    return 1;
}

/*
 * INITIALIZATION function - called when module is initialized/loaded.
 */
int mpc_proc_init(void)
{
    struct proc_dir_entry *p;

    p = proc_create(STAT_FILE_NAME, 0, atm_proc_root, &mpc_file_operations);
    if (!p) {
        pr_err("Unable to initialize /proc/atm/%s\n", STAT_FILE_NAME);
        return -ENOMEM;
    }
    return 0;
}

/*
 * DELETING function - called when module is removed.
 */
void mpc_proc_clean(void)
{
    remove_proc_entry(STAT_FILE_NAME, atm_proc_root);
}

#endif /* CONFIG_PROC_FS */