android_kernel_motorola_sm6225/net/atm/mpoa_proc.c
Alexey Dobriyan 99b7623380 proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-03-31 01:14:44 +04:00

302 lines
6.9 KiB
C

#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 <asm/uaccess.h>
#include <linux/atmmpc.h>
#include <linux/atm.h>
#include "mpc.h"
#include "mpoa_caches.h"
/*
* mpoa_proc.c: Implementation MPOA client's proc
* file system statistics
*/
#if 1
#define dprintk printk /* debug */
#else
#define dprintk(format,args...)
#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 ";
break;
case INGRESS_RESOLVED:
return "resolved ";
break;
case INGRESS_INVALID:
return "invalid ";
break;
case INGRESS_REFRESHING:
return "refreshing ";
break;
default:
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 ";
break;
case EGRESS_PURGE:
return "purge ";
break;
case EGRESS_INVALID:
return "invalid ";
break;
default:
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;
unsigned char *temp;
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) {
temp = (unsigned char *)&in_entry->ctrl_info.in_dst_ip;
sprintf(ip_string,"%d.%d.%d.%d", temp[0], temp[1], temp[2], temp[3]);
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 */
temp = (unsigned char *)&eg_entry->latest_ip_addr;
sprintf(ip_string, "%d.%d.%d.%d", temp[0], temp[1], temp[2], temp[3]);
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 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("mpoa: mpoa_proc.c: 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) {
printk(KERN_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 */