mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
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bcfff0b471
This fixes various crashes on 64-bit when using this module. Based upon a patch by Juergen Kreileder <jk@blackdown.de>. Signed-off-by: David S. Miller <davem@davemloft.net> ACKed-by: Patrick McHardy <kaber@trash.net>
1002 lines
33 KiB
C
1002 lines
33 KiB
C
/* Kernel module to check if the source address has been seen recently. */
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/* Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org */
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/* Author: Stephen Frost <sfrost@snowman.net> */
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/* Project Page: http://snowman.net/projects/ipt_recent/ */
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/* This software is distributed under the terms of the GPL, Version 2 */
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/* This copyright does not cover user programs that use kernel services
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* by normal system calls. */
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/proc_fs.h>
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#include <linux/spinlock.h>
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#include <linux/interrupt.h>
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#include <asm/uaccess.h>
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#include <linux/ctype.h>
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#include <linux/ip.h>
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#include <linux/vmalloc.h>
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#include <linux/moduleparam.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv4/ipt_recent.h>
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#undef DEBUG
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#define HASH_LOG 9
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/* Defaults, these can be overridden on the module command-line. */
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static int ip_list_tot = 100;
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static int ip_pkt_list_tot = 20;
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static int ip_list_hash_size = 0;
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static int ip_list_perms = 0644;
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#ifdef DEBUG
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static int debug = 1;
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#endif
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static char version[] =
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KERN_INFO RECENT_NAME " " RECENT_VER ": Stephen Frost <sfrost@snowman.net>. http://snowman.net/projects/ipt_recent/\n";
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MODULE_AUTHOR("Stephen Frost <sfrost@snowman.net>");
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MODULE_DESCRIPTION("IP tables recently seen matching module " RECENT_VER);
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MODULE_LICENSE("GPL");
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module_param(ip_list_tot, int, 0400);
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module_param(ip_pkt_list_tot, int, 0400);
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module_param(ip_list_hash_size, int, 0400);
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module_param(ip_list_perms, int, 0400);
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#ifdef DEBUG
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module_param(debug, int, 0600);
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MODULE_PARM_DESC(debug,"debugging level, defaults to 1");
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#endif
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MODULE_PARM_DESC(ip_list_tot,"number of IPs to remember per list");
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MODULE_PARM_DESC(ip_pkt_list_tot,"number of packets per IP to remember");
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MODULE_PARM_DESC(ip_list_hash_size,"size of hash table used to look up IPs");
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MODULE_PARM_DESC(ip_list_perms,"permissions on /proc/net/ipt_recent/* files");
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/* Structure of our list of recently seen addresses. */
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struct recent_ip_list {
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u_int32_t addr;
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u_int8_t ttl;
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unsigned long last_seen;
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unsigned long *last_pkts;
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u_int32_t oldest_pkt;
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u_int32_t hash_entry;
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u_int32_t time_pos;
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};
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struct time_info_list {
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u_int32_t position;
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u_int32_t time;
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};
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/* Structure of our linked list of tables of recent lists. */
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struct recent_ip_tables {
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char name[IPT_RECENT_NAME_LEN];
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int count;
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int time_pos;
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struct recent_ip_list *table;
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struct recent_ip_tables *next;
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spinlock_t list_lock;
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int *hash_table;
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struct time_info_list *time_info;
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#ifdef CONFIG_PROC_FS
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struct proc_dir_entry *status_proc;
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#endif /* CONFIG_PROC_FS */
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};
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/* Our current list of addresses we have recently seen.
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* Only added to on a --set, and only updated on --set || --update
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*/
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static struct recent_ip_tables *r_tables = NULL;
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/* We protect r_list with this spinlock so two processors are not modifying
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* the list at the same time.
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*/
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static DEFINE_SPINLOCK(recent_lock);
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#ifdef CONFIG_PROC_FS
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/* Our /proc/net/ipt_recent entry */
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static struct proc_dir_entry *proc_net_ipt_recent = NULL;
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#endif
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/* Function declaration for later. */
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static int
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match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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int *hotdrop);
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/* Function to hash a given address into the hash table of table_size size */
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static int hash_func(unsigned int addr, int table_size)
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{
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int result = 0;
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unsigned int value = addr;
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do { result ^= value; } while((value >>= HASH_LOG));
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": %d = hash_func(%u,%d)\n",
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result & (table_size - 1),
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addr,
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table_size);
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#endif
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return(result & (table_size - 1));
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}
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#ifdef CONFIG_PROC_FS
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/* This is the function which produces the output for our /proc output
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* interface which lists each IP address, the last seen time and the
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* other recent times the address was seen.
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*/
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static int ip_recent_get_info(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
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{
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int len = 0, count, last_len = 0, pkt_count;
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off_t pos = 0;
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off_t begin = 0;
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struct recent_ip_tables *curr_table;
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curr_table = (struct recent_ip_tables*) data;
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spin_lock_bh(&curr_table->list_lock);
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for(count = 0; count < ip_list_tot; count++) {
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if(!curr_table->table[count].addr) continue;
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last_len = len;
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len += sprintf(buffer+len,"src=%u.%u.%u.%u ",NIPQUAD(curr_table->table[count].addr));
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len += sprintf(buffer+len,"ttl: %u ",curr_table->table[count].ttl);
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len += sprintf(buffer+len,"last_seen: %lu ",curr_table->table[count].last_seen);
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len += sprintf(buffer+len,"oldest_pkt: %u ",curr_table->table[count].oldest_pkt);
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len += sprintf(buffer+len,"last_pkts: %lu",curr_table->table[count].last_pkts[0]);
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for(pkt_count = 1; pkt_count < ip_pkt_list_tot; pkt_count++) {
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if(!curr_table->table[count].last_pkts[pkt_count]) break;
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len += sprintf(buffer+len,", %lu",curr_table->table[count].last_pkts[pkt_count]);
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}
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len += sprintf(buffer+len,"\n");
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pos = begin + len;
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if(pos < offset) { len = 0; begin = pos; }
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if(pos > offset + length) { len = last_len; break; }
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}
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*start = buffer + (offset - begin);
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len -= (offset - begin);
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if(len > length) len = length;
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spin_unlock_bh(&curr_table->list_lock);
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return len;
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}
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/* ip_recent_ctrl provides an interface for users to modify the table
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* directly. This allows adding entries, removing entries, and
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* flushing the entire table.
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* This is done by opening up the appropriate table for writing and
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* sending one of:
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* xx.xx.xx.xx -- Add entry to table with current time
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* +xx.xx.xx.xx -- Add entry to table with current time
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* -xx.xx.xx.xx -- Remove entry from table
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* clear -- Flush table, remove all entries
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*/
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static int ip_recent_ctrl(struct file *file, const char __user *input, unsigned long size, void *data)
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{
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static const u_int32_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
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u_int32_t val;
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int base, used = 0;
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char c, *cp;
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union iaddr {
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uint8_t bytes[4];
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uint32_t word;
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} res;
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uint8_t *pp = res.bytes;
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int digit;
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char buffer[20];
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int len, check_set = 0, count;
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u_int32_t addr = 0;
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struct sk_buff *skb;
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struct ipt_recent_info *info;
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struct recent_ip_tables *curr_table;
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curr_table = (struct recent_ip_tables*) data;
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if(size > 20) len = 20; else len = size;
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if(copy_from_user(buffer,input,len)) return -EFAULT;
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if(len < 20) buffer[len] = '\0';
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl len: %d, input: `%.20s'\n",len,buffer);
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#endif
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cp = buffer;
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while(isspace(*cp)) { cp++; used++; if(used >= len-5) return used; }
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/* Check if we are asked to flush the entire table */
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if(!memcmp(cp,"clear",5)) {
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used += 5;
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spin_lock_bh(&curr_table->list_lock);
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curr_table->time_pos = 0;
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for(count = 0; count < ip_list_hash_size; count++) {
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curr_table->hash_table[count] = -1;
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}
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for(count = 0; count < ip_list_tot; count++) {
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curr_table->table[count].last_seen = 0;
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curr_table->table[count].addr = 0;
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curr_table->table[count].ttl = 0;
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memset(curr_table->table[count].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
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curr_table->table[count].oldest_pkt = 0;
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curr_table->table[count].time_pos = 0;
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curr_table->time_info[count].position = count;
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curr_table->time_info[count].time = 0;
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}
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spin_unlock_bh(&curr_table->list_lock);
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return used;
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}
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check_set = IPT_RECENT_SET;
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switch(*cp) {
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case '+': check_set = IPT_RECENT_SET; cp++; used++; break;
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case '-': check_set = IPT_RECENT_REMOVE; cp++; used++; break;
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default: if(!isdigit(*cp)) return (used+1); break;
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}
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl cp: `%c', check_set: %d\n",*cp,check_set);
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#endif
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/* Get addr (effectively inet_aton()) */
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/* Shamelessly stolen from libc, a function in the kernel for doing
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* this would, of course, be greatly preferred, but our options appear
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* to be rather limited, so we will just do it ourselves here.
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*/
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res.word = 0;
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c = *cp;
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for(;;) {
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if(!isdigit(c)) return used;
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val = 0; base = 10; digit = 0;
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if(c == '0') {
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c = *++cp;
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if(c == 'x' || c == 'X') base = 16, c = *++cp;
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else { base = 8; digit = 1; }
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}
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for(;;) {
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if(isascii(c) && isdigit(c)) {
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if(base == 8 && (c == '8' || c == '0')) return used;
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val = (val * base) + (c - '0');
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c = *++cp;
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digit = 1;
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} else if(base == 16 && isascii(c) && isxdigit(c)) {
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val = (val << 4) | (c + 10 - (islower(c) ? 'a' : 'A'));
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c = *++cp;
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digit = 1;
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} else break;
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}
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if(c == '.') {
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if(pp > res.bytes + 2 || val > 0xff) return used;
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*pp++ = val;
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c = *++cp;
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} else break;
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}
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used = cp - buffer;
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if(c != '\0' && (!isascii(c) || !isspace(c))) return used;
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if(c == '\n') used++;
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if(!digit) return used;
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if(val > max[pp - res.bytes]) return used;
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addr = res.word | htonl(val);
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if(!addr && check_set == IPT_RECENT_SET) return used;
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": ip_recent_ctrl c: %c, addr: %u used: %d\n",c,addr,used);
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#endif
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/* Set up and just call match */
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info = kmalloc(sizeof(struct ipt_recent_info),GFP_KERNEL);
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if(!info) { return -ENOMEM; }
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info->seconds = 0;
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info->hit_count = 0;
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info->check_set = check_set;
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info->invert = 0;
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info->side = IPT_RECENT_SOURCE;
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strncpy(info->name,curr_table->name,IPT_RECENT_NAME_LEN);
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info->name[IPT_RECENT_NAME_LEN-1] = '\0';
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skb = kmalloc(sizeof(struct sk_buff),GFP_KERNEL);
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if (!skb) {
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used = -ENOMEM;
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goto out_free_info;
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}
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skb->nh.iph = kmalloc(sizeof(struct iphdr),GFP_KERNEL);
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if (!skb->nh.iph) {
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used = -ENOMEM;
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goto out_free_skb;
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}
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skb->nh.iph->saddr = addr;
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skb->nh.iph->daddr = 0;
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/* Clear ttl since we have no way of knowing it */
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skb->nh.iph->ttl = 0;
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match(skb,NULL,NULL,info,0,NULL);
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kfree(skb->nh.iph);
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out_free_skb:
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kfree(skb);
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out_free_info:
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kfree(info);
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": Leaving ip_recent_ctrl addr: %u used: %d\n",addr,used);
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#endif
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return used;
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}
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#endif /* CONFIG_PROC_FS */
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/* 'match' is our primary function, called by the kernel whenever a rule is
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* hit with our module as an option to it.
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* What this function does depends on what was specifically asked of it by
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* the user:
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* --set -- Add or update last seen time of the source address of the packet
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* -- matchinfo->check_set == IPT_RECENT_SET
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* --rcheck -- Just check if the source address is in the list
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* -- matchinfo->check_set == IPT_RECENT_CHECK
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* --update -- If the source address is in the list, update last_seen
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* -- matchinfo->check_set == IPT_RECENT_UPDATE
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* --remove -- If the source address is in the list, remove it
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* -- matchinfo->check_set == IPT_RECENT_REMOVE
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* --seconds -- Option to --rcheck/--update, only match if last_seen within seconds
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* -- matchinfo->seconds
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* --hitcount -- Option to --rcheck/--update, only match if seen hitcount times
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* -- matchinfo->hit_count
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* --seconds and --hitcount can be combined
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*/
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static int
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match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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int *hotdrop)
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{
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int pkt_count, hits_found, ans;
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unsigned long now;
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const struct ipt_recent_info *info = matchinfo;
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u_int32_t addr = 0, time_temp;
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u_int8_t ttl = skb->nh.iph->ttl;
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int *hash_table;
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int orig_hash_result, hash_result, temp, location = 0, time_loc, end_collision_chain = -1;
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struct time_info_list *time_info;
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struct recent_ip_tables *curr_table;
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struct recent_ip_tables *last_table;
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struct recent_ip_list *r_list;
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": match() called\n");
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#endif
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/* Default is false ^ info->invert */
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ans = info->invert;
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": match(): name = '%s'\n",info->name);
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#endif
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/* if out != NULL then routing has been done and TTL changed.
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* We change it back here internally for match what came in before routing. */
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if(out) ttl++;
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/* Find the right table */
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spin_lock_bh(&recent_lock);
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curr_table = r_tables;
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while( (last_table = curr_table) && strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (curr_table = curr_table->next) );
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": match(): table found('%s')\n",info->name);
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#endif
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spin_unlock_bh(&recent_lock);
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/* Table with this name not found, match impossible */
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if(!curr_table) { return ans; }
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/* Make sure no one is changing the list while we work with it */
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spin_lock_bh(&curr_table->list_lock);
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r_list = curr_table->table;
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if(info->side == IPT_RECENT_DEST) addr = skb->nh.iph->daddr; else addr = skb->nh.iph->saddr;
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if(!addr) {
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": match() address (%u) invalid, leaving.\n",addr);
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#endif
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spin_unlock_bh(&curr_table->list_lock);
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return ans;
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}
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#ifdef DEBUG
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if(debug) printk(KERN_INFO RECENT_NAME ": match(): checking table, addr: %u, ttl: %u, orig_ttl: %u\n",addr,ttl,skb->nh.iph->ttl);
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#endif
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/* Get jiffies now in case they changed while we were waiting for a lock */
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now = jiffies;
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hash_table = curr_table->hash_table;
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time_info = curr_table->time_info;
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orig_hash_result = hash_result = hash_func(addr,ip_list_hash_size);
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/* Hash entry at this result used */
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/* Check for TTL match if requested. If TTL is zero then a match would never
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* happen, so match regardless of existing TTL in that case. Zero means the
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* entry was added via the /proc interface anyway, so we will just use the
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* first TTL we get for that IP address. */
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if(info->check_set & IPT_RECENT_TTL) {
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while(hash_table[hash_result] != -1 && !(r_list[hash_table[hash_result]].addr == addr &&
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(!r_list[hash_table[hash_result]].ttl || r_list[hash_table[hash_result]].ttl == ttl))) {
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/* Collision in hash table */
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hash_result = (hash_result + 1) % ip_list_hash_size;
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}
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} else {
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while(hash_table[hash_result] != -1 && r_list[hash_table[hash_result]].addr != addr) {
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/* Collision in hash table */
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hash_result = (hash_result + 1) % ip_list_hash_size;
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}
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}
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if(hash_table[hash_result] == -1 && !(info->check_set & IPT_RECENT_SET)) {
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/* IP not in list and not asked to SET */
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spin_unlock_bh(&curr_table->list_lock);
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return ans;
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}
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/* Check if we need to handle the collision, do not need to on REMOVE */
|
|
if(orig_hash_result != hash_result && !(info->check_set & IPT_RECENT_REMOVE)) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision in hash table. (or: %d,hr: %d,oa: %u,ha: %u)\n",
|
|
orig_hash_result,
|
|
hash_result,
|
|
r_list[hash_table[orig_hash_result]].addr,
|
|
addr);
|
|
#endif
|
|
|
|
/* We had a collision.
|
|
* orig_hash_result is where we started, hash_result is where we ended up.
|
|
* So, swap them because we are likely to see the same guy again sooner */
|
|
#ifdef DEBUG
|
|
if(debug) {
|
|
printk(KERN_INFO RECENT_NAME ": match(): Collision; hash_table[orig_hash_result] = %d\n",hash_table[orig_hash_result]);
|
|
printk(KERN_INFO RECENT_NAME ": match(): Collision; r_list[hash_table[orig_hash_result]].hash_entry = %d\n",
|
|
r_list[hash_table[orig_hash_result]].hash_entry);
|
|
}
|
|
#endif
|
|
|
|
r_list[hash_table[orig_hash_result]].hash_entry = hash_result;
|
|
|
|
|
|
temp = hash_table[orig_hash_result];
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision; hash_table[hash_result] = %d\n",hash_table[hash_result]);
|
|
#endif
|
|
hash_table[orig_hash_result] = hash_table[hash_result];
|
|
hash_table[hash_result] = temp;
|
|
temp = hash_result;
|
|
hash_result = orig_hash_result;
|
|
orig_hash_result = temp;
|
|
time_info[r_list[hash_table[orig_hash_result]].time_pos].position = hash_table[orig_hash_result];
|
|
if(hash_table[hash_result] != -1) {
|
|
r_list[hash_table[hash_result]].hash_entry = hash_result;
|
|
time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): Collision handled.\n");
|
|
#endif
|
|
}
|
|
|
|
if(hash_table[hash_result] == -1) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): New table entry. (hr: %d,ha: %u)\n",
|
|
hash_result, addr);
|
|
#endif
|
|
|
|
/* New item found and IPT_RECENT_SET, so we need to add it */
|
|
location = time_info[curr_table->time_pos].position;
|
|
hash_table[r_list[location].hash_entry] = -1;
|
|
hash_table[hash_result] = location;
|
|
memset(r_list[location].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
|
|
r_list[location].time_pos = curr_table->time_pos;
|
|
r_list[location].addr = addr;
|
|
r_list[location].ttl = ttl;
|
|
r_list[location].last_seen = now;
|
|
r_list[location].oldest_pkt = 1;
|
|
r_list[location].last_pkts[0] = now;
|
|
r_list[location].hash_entry = hash_result;
|
|
time_info[curr_table->time_pos].time = r_list[location].last_seen;
|
|
curr_table->time_pos = (curr_table->time_pos + 1) % ip_list_tot;
|
|
|
|
ans = !info->invert;
|
|
} else {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): Existing table entry. (hr: %d,ha: %u)\n",
|
|
hash_result,
|
|
addr);
|
|
#endif
|
|
|
|
/* Existing item found */
|
|
location = hash_table[hash_result];
|
|
/* We have a match on address, now to make sure it meets all requirements for a
|
|
* full match. */
|
|
if(info->check_set & IPT_RECENT_CHECK || info->check_set & IPT_RECENT_UPDATE) {
|
|
if(!info->seconds && !info->hit_count) ans = !info->invert; else ans = info->invert;
|
|
if(info->seconds && !info->hit_count) {
|
|
if(time_before_eq(now,r_list[location].last_seen+info->seconds*HZ)) ans = !info->invert; else ans = info->invert;
|
|
}
|
|
if(info->seconds && info->hit_count) {
|
|
for(pkt_count = 0, hits_found = 0; pkt_count < ip_pkt_list_tot; pkt_count++) {
|
|
if(time_before_eq(now,r_list[location].last_pkts[pkt_count]+info->seconds*HZ)) hits_found++;
|
|
}
|
|
if(hits_found >= info->hit_count) ans = !info->invert; else ans = info->invert;
|
|
}
|
|
if(info->hit_count && !info->seconds) {
|
|
for(pkt_count = 0, hits_found = 0; pkt_count < ip_pkt_list_tot; pkt_count++) {
|
|
if(r_list[location].last_pkts[pkt_count] == 0) break;
|
|
hits_found++;
|
|
}
|
|
if(hits_found >= info->hit_count) ans = !info->invert; else ans = info->invert;
|
|
}
|
|
}
|
|
#ifdef DEBUG
|
|
if(debug) {
|
|
if(ans)
|
|
printk(KERN_INFO RECENT_NAME ": match(): match addr: %u\n",addr);
|
|
else
|
|
printk(KERN_INFO RECENT_NAME ": match(): no match addr: %u\n",addr);
|
|
}
|
|
#endif
|
|
|
|
/* If and only if we have been asked to SET, or to UPDATE (on match) do we add the
|
|
* current timestamp to the last_seen. */
|
|
if((info->check_set & IPT_RECENT_SET && (ans = !info->invert)) || (info->check_set & IPT_RECENT_UPDATE && ans)) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): SET or UPDATE; updating time info.\n");
|
|
#endif
|
|
/* Have to update our time info */
|
|
time_loc = r_list[location].time_pos;
|
|
time_info[time_loc].time = now;
|
|
time_info[time_loc].position = location;
|
|
while((time_info[(time_loc+1) % ip_list_tot].time < time_info[time_loc].time) && ((time_loc+1) % ip_list_tot) != curr_table->time_pos) {
|
|
time_temp = time_info[time_loc].time;
|
|
time_info[time_loc].time = time_info[(time_loc+1)%ip_list_tot].time;
|
|
time_info[(time_loc+1)%ip_list_tot].time = time_temp;
|
|
time_temp = time_info[time_loc].position;
|
|
time_info[time_loc].position = time_info[(time_loc+1)%ip_list_tot].position;
|
|
time_info[(time_loc+1)%ip_list_tot].position = time_temp;
|
|
r_list[time_info[time_loc].position].time_pos = time_loc;
|
|
r_list[time_info[(time_loc+1)%ip_list_tot].position].time_pos = (time_loc+1)%ip_list_tot;
|
|
time_loc = (time_loc+1) % ip_list_tot;
|
|
}
|
|
r_list[location].time_pos = time_loc;
|
|
r_list[location].ttl = ttl;
|
|
r_list[location].last_pkts[r_list[location].oldest_pkt] = now;
|
|
r_list[location].oldest_pkt = ++r_list[location].oldest_pkt % ip_pkt_list_tot;
|
|
r_list[location].last_seen = now;
|
|
}
|
|
/* If we have been asked to remove the entry from the list, just set it to 0 */
|
|
if(info->check_set & IPT_RECENT_REMOVE) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; clearing entry (or: %d, hr: %d).\n",orig_hash_result,hash_result);
|
|
#endif
|
|
/* Check if this is part of a collision chain */
|
|
while(hash_table[(orig_hash_result+1) % ip_list_hash_size] != -1) {
|
|
orig_hash_result++;
|
|
if(hash_func(r_list[hash_table[orig_hash_result]].addr,ip_list_hash_size) == hash_result) {
|
|
/* Found collision chain, how deep does this rabbit hole go? */
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; found collision chain.\n");
|
|
#endif
|
|
end_collision_chain = orig_hash_result;
|
|
}
|
|
}
|
|
if(end_collision_chain != -1) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match(): REMOVE; part of collision chain, moving to end.\n");
|
|
#endif
|
|
/* Part of a collision chain, swap it with the end of the chain
|
|
* before removing. */
|
|
r_list[hash_table[end_collision_chain]].hash_entry = hash_result;
|
|
temp = hash_table[end_collision_chain];
|
|
hash_table[end_collision_chain] = hash_table[hash_result];
|
|
hash_table[hash_result] = temp;
|
|
time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
|
|
hash_result = end_collision_chain;
|
|
r_list[hash_table[hash_result]].hash_entry = hash_result;
|
|
time_info[r_list[hash_table[hash_result]].time_pos].position = hash_table[hash_result];
|
|
}
|
|
location = hash_table[hash_result];
|
|
hash_table[r_list[location].hash_entry] = -1;
|
|
time_loc = r_list[location].time_pos;
|
|
time_info[time_loc].time = 0;
|
|
time_info[time_loc].position = location;
|
|
while((time_info[(time_loc+1) % ip_list_tot].time < time_info[time_loc].time) && ((time_loc+1) % ip_list_tot) != curr_table->time_pos) {
|
|
time_temp = time_info[time_loc].time;
|
|
time_info[time_loc].time = time_info[(time_loc+1)%ip_list_tot].time;
|
|
time_info[(time_loc+1)%ip_list_tot].time = time_temp;
|
|
time_temp = time_info[time_loc].position;
|
|
time_info[time_loc].position = time_info[(time_loc+1)%ip_list_tot].position;
|
|
time_info[(time_loc+1)%ip_list_tot].position = time_temp;
|
|
r_list[time_info[time_loc].position].time_pos = time_loc;
|
|
r_list[time_info[(time_loc+1)%ip_list_tot].position].time_pos = (time_loc+1)%ip_list_tot;
|
|
time_loc = (time_loc+1) % ip_list_tot;
|
|
}
|
|
r_list[location].time_pos = time_loc;
|
|
r_list[location].last_seen = 0;
|
|
r_list[location].addr = 0;
|
|
r_list[location].ttl = 0;
|
|
memset(r_list[location].last_pkts,0,ip_pkt_list_tot*sizeof(unsigned long));
|
|
r_list[location].oldest_pkt = 0;
|
|
ans = !info->invert;
|
|
}
|
|
spin_unlock_bh(&curr_table->list_lock);
|
|
return ans;
|
|
}
|
|
|
|
spin_unlock_bh(&curr_table->list_lock);
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": match() left.\n");
|
|
#endif
|
|
return ans;
|
|
}
|
|
|
|
/* This function is to verify that the rule given during the userspace iptables
|
|
* command is correct.
|
|
* If the command is valid then we check if the table name referred to by the
|
|
* rule exists, if not it is created.
|
|
*/
|
|
static int
|
|
checkentry(const char *tablename,
|
|
const struct ipt_ip *ip,
|
|
void *matchinfo,
|
|
unsigned int matchsize,
|
|
unsigned int hook_mask)
|
|
{
|
|
int flag = 0, c;
|
|
unsigned long *hold;
|
|
const struct ipt_recent_info *info = matchinfo;
|
|
struct recent_ip_tables *curr_table, *find_table, *last_table;
|
|
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() entered.\n");
|
|
#endif
|
|
|
|
if (matchsize != IPT_ALIGN(sizeof(struct ipt_recent_info))) return 0;
|
|
|
|
/* seconds and hit_count only valid for CHECK/UPDATE */
|
|
if(info->check_set & IPT_RECENT_SET) { flag++; if(info->seconds || info->hit_count) return 0; }
|
|
if(info->check_set & IPT_RECENT_REMOVE) { flag++; if(info->seconds || info->hit_count) return 0; }
|
|
if(info->check_set & IPT_RECENT_CHECK) flag++;
|
|
if(info->check_set & IPT_RECENT_UPDATE) flag++;
|
|
|
|
/* One and only one of these should ever be set */
|
|
if(flag != 1) return 0;
|
|
|
|
/* Name must be set to something */
|
|
if(!info->name || !info->name[0]) return 0;
|
|
|
|
/* Things look good, create a list for this if it does not exist */
|
|
/* Lock the linked list while we play with it */
|
|
spin_lock_bh(&recent_lock);
|
|
|
|
/* Look for an entry with this name already created */
|
|
/* Finds the end of the list and the entry before the end if current name does not exist */
|
|
find_table = r_tables;
|
|
while( (last_table = find_table) && strncmp(info->name,find_table->name,IPT_RECENT_NAME_LEN) && (find_table = find_table->next) );
|
|
|
|
/* If a table already exists just increment the count on that table and return */
|
|
if(find_table) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: table found (%s), incrementing count.\n",info->name);
|
|
#endif
|
|
find_table->count++;
|
|
spin_unlock_bh(&recent_lock);
|
|
return 1;
|
|
}
|
|
|
|
spin_unlock_bh(&recent_lock);
|
|
|
|
/* Table with this name not found */
|
|
/* Allocate memory for new linked list item */
|
|
|
|
#ifdef DEBUG
|
|
if(debug) {
|
|
printk(KERN_INFO RECENT_NAME ": checkentry: no table found (%s)\n",info->name);
|
|
printk(KERN_INFO RECENT_NAME ": checkentry: Allocationg %d for link-list entry.\n",sizeof(struct recent_ip_tables));
|
|
}
|
|
#endif
|
|
|
|
curr_table = vmalloc(sizeof(struct recent_ip_tables));
|
|
if(curr_table == NULL) return 0;
|
|
|
|
spin_lock_init(&curr_table->list_lock);
|
|
curr_table->next = NULL;
|
|
curr_table->count = 1;
|
|
curr_table->time_pos = 0;
|
|
strncpy(curr_table->name,info->name,IPT_RECENT_NAME_LEN);
|
|
curr_table->name[IPT_RECENT_NAME_LEN-1] = '\0';
|
|
|
|
/* Allocate memory for this table and the list of packets in each entry. */
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for table (%s).\n",
|
|
sizeof(struct recent_ip_list)*ip_list_tot,
|
|
info->name);
|
|
#endif
|
|
|
|
curr_table->table = vmalloc(sizeof(struct recent_ip_list)*ip_list_tot);
|
|
if(curr_table->table == NULL) { vfree(curr_table); return 0; }
|
|
memset(curr_table->table,0,sizeof(struct recent_ip_list)*ip_list_tot);
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for pkt_list.\n",
|
|
sizeof(unsigned long)*ip_pkt_list_tot*ip_list_tot);
|
|
#endif
|
|
|
|
hold = vmalloc(sizeof(unsigned long)*ip_pkt_list_tot*ip_list_tot);
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: After pkt_list allocation.\n");
|
|
#endif
|
|
if(hold == NULL) {
|
|
printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for pkt_list.\n");
|
|
vfree(curr_table->table);
|
|
vfree(curr_table);
|
|
return 0;
|
|
}
|
|
for(c = 0; c < ip_list_tot; c++) {
|
|
curr_table->table[c].last_pkts = hold + c*ip_pkt_list_tot;
|
|
}
|
|
|
|
/* Allocate memory for the hash table */
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for hash_table.\n",
|
|
sizeof(int)*ip_list_hash_size);
|
|
#endif
|
|
|
|
curr_table->hash_table = vmalloc(sizeof(int)*ip_list_hash_size);
|
|
if(!curr_table->hash_table) {
|
|
printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for hash_table.\n");
|
|
vfree(hold);
|
|
vfree(curr_table->table);
|
|
vfree(curr_table);
|
|
return 0;
|
|
}
|
|
|
|
for(c = 0; c < ip_list_hash_size; c++) {
|
|
curr_table->hash_table[c] = -1;
|
|
}
|
|
|
|
/* Allocate memory for the time info */
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: Allocating %d for time_info.\n",
|
|
sizeof(struct time_info_list)*ip_list_tot);
|
|
#endif
|
|
|
|
curr_table->time_info = vmalloc(sizeof(struct time_info_list)*ip_list_tot);
|
|
if(!curr_table->time_info) {
|
|
printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for time_info.\n");
|
|
vfree(curr_table->hash_table);
|
|
vfree(hold);
|
|
vfree(curr_table->table);
|
|
vfree(curr_table);
|
|
return 0;
|
|
}
|
|
for(c = 0; c < ip_list_tot; c++) {
|
|
curr_table->time_info[c].position = c;
|
|
curr_table->time_info[c].time = 0;
|
|
}
|
|
|
|
/* Put the new table in place */
|
|
spin_lock_bh(&recent_lock);
|
|
find_table = r_tables;
|
|
while( (last_table = find_table) && strncmp(info->name,find_table->name,IPT_RECENT_NAME_LEN) && (find_table = find_table->next) );
|
|
|
|
/* If a table already exists just increment the count on that table and return */
|
|
if(find_table) {
|
|
find_table->count++;
|
|
spin_unlock_bh(&recent_lock);
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry: table found (%s), created by other process.\n",info->name);
|
|
#endif
|
|
vfree(curr_table->time_info);
|
|
vfree(curr_table->hash_table);
|
|
vfree(hold);
|
|
vfree(curr_table->table);
|
|
vfree(curr_table);
|
|
return 1;
|
|
}
|
|
if(!last_table) r_tables = curr_table; else last_table->next = curr_table;
|
|
|
|
spin_unlock_bh(&recent_lock);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
/* Create our proc 'status' entry. */
|
|
curr_table->status_proc = create_proc_entry(curr_table->name, ip_list_perms, proc_net_ipt_recent);
|
|
if (!curr_table->status_proc) {
|
|
printk(KERN_INFO RECENT_NAME ": checkentry: unable to allocate for /proc entry.\n");
|
|
/* Destroy the created table */
|
|
spin_lock_bh(&recent_lock);
|
|
last_table = NULL;
|
|
curr_table = r_tables;
|
|
if(!curr_table) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() create_proc failed, no tables.\n");
|
|
#endif
|
|
spin_unlock_bh(&recent_lock);
|
|
return 0;
|
|
}
|
|
while( strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (last_table = curr_table) && (curr_table = curr_table->next) );
|
|
if(!curr_table) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() create_proc failed, table already destroyed.\n");
|
|
#endif
|
|
spin_unlock_bh(&recent_lock);
|
|
return 0;
|
|
}
|
|
if(last_table) last_table->next = curr_table->next; else r_tables = curr_table->next;
|
|
spin_unlock_bh(&recent_lock);
|
|
vfree(curr_table->time_info);
|
|
vfree(curr_table->hash_table);
|
|
vfree(hold);
|
|
vfree(curr_table->table);
|
|
vfree(curr_table);
|
|
return 0;
|
|
}
|
|
|
|
curr_table->status_proc->owner = THIS_MODULE;
|
|
curr_table->status_proc->data = curr_table;
|
|
wmb();
|
|
curr_table->status_proc->read_proc = ip_recent_get_info;
|
|
curr_table->status_proc->write_proc = ip_recent_ctrl;
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": checkentry() left.\n");
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* This function is called in the event that a rule matching this module is
|
|
* removed.
|
|
* When this happens we need to check if there are no other rules matching
|
|
* the table given. If that is the case then we remove the table and clean
|
|
* up its memory.
|
|
*/
|
|
static void
|
|
destroy(void *matchinfo, unsigned int matchsize)
|
|
{
|
|
const struct ipt_recent_info *info = matchinfo;
|
|
struct recent_ip_tables *curr_table, *last_table;
|
|
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": destroy() entered.\n");
|
|
#endif
|
|
|
|
if(matchsize != IPT_ALIGN(sizeof(struct ipt_recent_info))) return;
|
|
|
|
/* Lock the linked list while we play with it */
|
|
spin_lock_bh(&recent_lock);
|
|
|
|
/* Look for an entry with this name already created */
|
|
/* Finds the end of the list and the entry before the end if current name does not exist */
|
|
last_table = NULL;
|
|
curr_table = r_tables;
|
|
if(!curr_table) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": destroy() No tables found, leaving.\n");
|
|
#endif
|
|
spin_unlock_bh(&recent_lock);
|
|
return;
|
|
}
|
|
while( strncmp(info->name,curr_table->name,IPT_RECENT_NAME_LEN) && (last_table = curr_table) && (curr_table = curr_table->next) );
|
|
|
|
/* If a table does not exist then do nothing and return */
|
|
if(!curr_table) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table not found, leaving.\n");
|
|
#endif
|
|
spin_unlock_bh(&recent_lock);
|
|
return;
|
|
}
|
|
|
|
curr_table->count--;
|
|
|
|
/* If count is still non-zero then there are still rules referenceing it so we do nothing */
|
|
if(curr_table->count) {
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table found, non-zero count, leaving.\n");
|
|
#endif
|
|
spin_unlock_bh(&recent_lock);
|
|
return;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": destroy() table found, zero count, removing.\n");
|
|
#endif
|
|
|
|
/* Count must be zero so we remove this table from the list */
|
|
if(last_table) last_table->next = curr_table->next; else r_tables = curr_table->next;
|
|
|
|
spin_unlock_bh(&recent_lock);
|
|
|
|
/* lock to make sure any late-runners still using this after we removed it from
|
|
* the list finish up then remove everything */
|
|
spin_lock_bh(&curr_table->list_lock);
|
|
spin_unlock_bh(&curr_table->list_lock);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
if(curr_table->status_proc) remove_proc_entry(curr_table->name,proc_net_ipt_recent);
|
|
#endif /* CONFIG_PROC_FS */
|
|
vfree(curr_table->table[0].last_pkts);
|
|
vfree(curr_table->table);
|
|
vfree(curr_table->hash_table);
|
|
vfree(curr_table->time_info);
|
|
vfree(curr_table);
|
|
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": destroy() left.\n");
|
|
#endif
|
|
|
|
return;
|
|
}
|
|
|
|
/* This is the structure we pass to ipt_register to register our
|
|
* module with iptables.
|
|
*/
|
|
static struct ipt_match recent_match = {
|
|
.name = "recent",
|
|
.match = &match,
|
|
.checkentry = &checkentry,
|
|
.destroy = &destroy,
|
|
.me = THIS_MODULE
|
|
};
|
|
|
|
/* Kernel module initialization. */
|
|
static int __init init(void)
|
|
{
|
|
int err, count;
|
|
|
|
printk(version);
|
|
#ifdef CONFIG_PROC_FS
|
|
proc_net_ipt_recent = proc_mkdir("ipt_recent",proc_net);
|
|
if(!proc_net_ipt_recent) return -ENOMEM;
|
|
#endif
|
|
|
|
if(ip_list_hash_size && ip_list_hash_size <= ip_list_tot) {
|
|
printk(KERN_WARNING RECENT_NAME ": ip_list_hash_size too small, resetting to default.\n");
|
|
ip_list_hash_size = 0;
|
|
}
|
|
|
|
if(!ip_list_hash_size) {
|
|
ip_list_hash_size = ip_list_tot*3;
|
|
count = 2*2;
|
|
while(ip_list_hash_size > count) count = count*2;
|
|
ip_list_hash_size = count;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
if(debug) printk(KERN_INFO RECENT_NAME ": ip_list_hash_size: %d\n",ip_list_hash_size);
|
|
#endif
|
|
|
|
err = ipt_register_match(&recent_match);
|
|
if (err)
|
|
remove_proc_entry("ipt_recent", proc_net);
|
|
return err;
|
|
}
|
|
|
|
/* Kernel module destruction. */
|
|
static void __exit fini(void)
|
|
{
|
|
ipt_unregister_match(&recent_match);
|
|
|
|
remove_proc_entry("ipt_recent",proc_net);
|
|
}
|
|
|
|
/* Register our module with the kernel. */
|
|
module_init(init);
|
|
module_exit(fini);
|