release/src-rt-6.x.4708/linux/linux-2.6.36/net/ipv4/netfilter/lfp.c

   1 /*
   2  * Packet matching code.
   3  *
   4  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   5  * Copyright (C) 2009-2002 Netfilter core team <coreteam@netfilter.org>
   6  *
   7  * 19 Jan 2002 Harald Welte <laforge@gnumonks.org>
   8  *      - increase module usage count as soon as we have rules inside
   9  *        a table
  10  */
  11 #include <linux/cache.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/kmod.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/module.h>
  17 #include <linux/ip.h>
  18 #include <linux/tcp.h>
  19 #include <net/route.h>
  20 #include <net/ip.h>
  21 #include <linux/netfilter.h>
  22 #include <linux/netfilter_ipv4.h>
  23 #include <net/netfilter/nf_nat_core.h>
  24 #include <net/netfilter/nf_conntrack.h>
  25 #include <net/netfilter/nf_conntrack_core.h>
  26 #include <linux/netfilter/nf_conntrack_common.h>
  27 #include <linux/netfilter_ipv4/ip_tables.h>
  28 #include <linux/proc_fs.h>
  29
  30 #define LFP_DEBUG 0
  31
  32 #if LFP_DEBUG
  33 #define DEBUGP(format, args...) printk(KERN_DEBUG format, ##args)
  34 #else
  35 #define DEBUGP(format, args...)
  36 #endif
  37
  38 unsigned int  lfp_ip=0;
  39
  40 struct lfp_port_s {
  41         unsigned int port;
  42 };
  43
  44 #define NR_STATIC_LFP_PORTS     2
  45 #define NR_DYNAMIC_LFP_PORTS    5
  46 #define NR_ALL_LFP_PORTS        (NR_STATIC_LFP_PORTS + NR_DYNAMIC_LFP_PORTS)
  47 static struct lfp_port_s lfp_ports[NR_ALL_LFP_PORTS] = {
  48         [0] = { 445 },
  49         [1] = {  20 },
  50 };
  51 static int next_slot = NR_STATIC_LFP_PORTS;
  52
  53 #define NFC_LFP_ENABLE (1<<29)
  54
  55 typedef int (*lfpHitHook)(int pf, unsigned int hook, struct sk_buff *skb);
  56 lfpHitHook lfp_hit_hook = NULL;
  57
  58 static inline int lfp_hit_hook_func(lfpHitHook hook_func)
  59 {
  60         lfp_hit_hook = hook_func;
  61         return 0;
  62 }
  63
  64 static inline int lfp_func(int pf, unsigned int hook, struct sk_buff *skb)
  65 {
  66         int i, ret = 0;
  67         struct iphdr *iph;
  68         struct tcphdr *tcph;
  69         struct lfp_port_s *p;
  70         __u32 ipaddr=0, r_ipaddr=0;
  71         __u16 port=0;
  72
  73         if(lfp_ip == 0 || pf != AF_INET) return 0;
  74         if(skb->nfcache & NFC_LFP_ENABLE) return 1;
  75
  76         iph = ip_hdr(skb);
  77         if (unlikely(iph->protocol != IPPROTO_TCP))
  78                 return 0;
  79
  80         if (hook == NF_INET_PRE_ROUTING || hook == NF_INET_LOCAL_IN) {
  81                 tcph = (struct tcphdr *)(skb->data+(iph->ihl<<2));
  82
  83                 ipaddr = iph->daddr;
  84                 r_ipaddr = iph->saddr;
  85                 port = ntohs(tcph->dest);
  86         } else if (hook == NF_INET_LOCAL_OUT || hook == NF_INET_POST_ROUTING) {
  87                 tcph = (struct tcphdr *)(skb->data+(iph->ihl<<2));
  88
  89                 ipaddr = iph->saddr;
  90                 r_ipaddr = iph->daddr;
  91                 port = ntohs(tcph->source);
  92         }
  93
  94         if (likely(ipaddr != lfp_ip || !ipaddr))
  95                 return 0;
  96
  97         DEBUGP("ip match: %x %x %x %x\n", hook, ipaddr, r_ipaddr, lfp_ip);
  98         for (i = 0, p = &lfp_ports[0]; i < NR_ALL_LFP_PORTS; ++i, ++p) {
  99                 if (!p->port)
 100                         continue;
 101
 102                 if (port == p->port) {
 103                         skb->nfcache |= NFC_LFP_ENABLE;
 104                         ret = 1;
 105                         break;
 106                 }
 107         }
 108
 109         return ret;
 110 }
 111
 112 #ifdef CONFIG_PROC_FS
 113 static int lfp_ctrl(struct file *file, const char *buffer, unsigned long length, void *data)
 114 {
 115         char s[10];
 116
 117         if ((length > 0) && (length < 10)) {
 118                 memcpy(s, buffer, length);
 119                 s[length] = 0;
 120                 lfp_ip = simple_strtoul(s, NULL, 16);
 121         }
 122         else lfp_ip=0;
 123
 124         if(lfp_ip==0) lfp_hit_hook_func (NULL);
 125         else lfp_hit_hook_func(lfp_func);
 126
 127         return length;
 128 }
 129
 130 static int lfp_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
 131 {
 132         sprintf(page, "%x,%p,%d\n", lfp_ip, lfp_hit_hook, LFP_DEBUG);
 133         *eof = 1;
 134         return strlen(page);
 135 }
 136
 137 /* Add port to LFP ports list
 138  * @return:
 139  *  0:          Add port to empty slot success.
 140  *  1:          Override port to an exist port.
 141  *  2:          Same port exist
 142  *  -1:         Invalid port number.
 143  */
 144 int lfp_add_port(unsigned int port)
 145 {
 146         int i, ret = 0;
 147         struct lfp_port_s *p;
 148
 149         if (!port || port > 65535)
 150                 return -1;
 151
 152         for (i = 0, p = &lfp_ports[0]; i < NR_ALL_LFP_PORTS; ++i, ++p) {
 153                 if (!p->port || p->port != port)
 154                         continue;
 155
 156                 return 2;
 157         }
 158
 159         /* find empty slot */
 160         for (i = 0, p = &lfp_ports[NR_STATIC_LFP_PORTS]; i < NR_DYNAMIC_LFP_PORTS; ++i, ++p) {
 161                 if (p->port)
 162                         continue;
 163
 164                 p->port = port;
 165                 DEBUGP("Add port %d to LFP port list\n", port);
 166                 return 0;
 167         }
 168
 169         if (next_slot < NR_STATIC_LFP_PORTS || next_slot >= NR_ALL_LFP_PORTS)
 170                 next_slot = NR_STATIC_LFP_PORTS;
 171
 172         p = &lfp_ports[next_slot];
 173         if (p->port) {
 174                 DEBUGP("Override port %d with %d\n", p->port, port);
 175                 ret = 1;
 176         }
 177         p->port = port;
 178         next_slot++;
 179
 180         return ret;
 181 }
 182
 183 /* Remove port from dynamic LFP ports list.
 184  * @return:
 185  *  0:          Remove port success.
 186  *  1:          Port not found.
 187  *  -1:         Invalid port number.
 188  */
 189 int lfp_del_port(unsigned int port)
 190 {
 191         int i;
 192         struct lfp_port_s *p;
 193
 194         if (!port || port > 65535)
 195                 return -1;
 196
 197         for (i = 0, p = &lfp_ports[NR_STATIC_LFP_PORTS]; i < NR_DYNAMIC_LFP_PORTS; ++i, ++p) {
 198                 if (!p->port || p->port != port)
 199                         continue;
 200
 201                 p->port = 0;
 202                 DEBUGP("Remove port %d from LFP port list\n", port);
 203                 return 0;
 204         }
 205
 206         return 1;
 207 }
 208
 209 /* Query port in LFP ports list
 210  * @return:
 211  *  0:          Not found
 212  *  1:          found
 213  *  -1:         Invalid port number.
 214  */
 215 int lfp_query_port(unsigned int port)
 216 {
 217         int i;
 218         struct lfp_port_s *p;
 219
 220         if (!port || port > 65535)
 221                 return -1;
 222
 223         for (i = 0, p = &lfp_ports[NR_STATIC_LFP_PORTS]; i < NR_DYNAMIC_LFP_PORTS; ++i, ++p) {
 224                 if (port != p->port)
 225                         continue;
 226
 227                 DEBUGP("Port %d found in LFP port list\n", port);
 228                 return 1;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int lfp_port_write_proc(struct file *file, const char *buffer, unsigned long length, void *data)
 235 {
 236         unsigned int port = 0;
 237
 238         port = simple_strtoul(buffer, NULL, 10);
 239         lfp_add_port(port);
 240
 241         return length;
 242 }
 243
 244 static int lfp_port_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
 245 {
 246         int i, len = 0, c = 0;
 247         struct lfp_port_s *p;
 248
 249         if (next_slot < NR_STATIC_LFP_PORTS || next_slot >= NR_ALL_LFP_PORTS)
 250                 next_slot = NR_STATIC_LFP_PORTS;
 251
 252         for (i = 0, p = &lfp_ports[NR_STATIC_LFP_PORTS]; !c && i < NR_DYNAMIC_LFP_PORTS; ++i, ++p) {
 253                 if (!p->port)
 254                         c++;
 255         }
 256
 257         for (i = NR_STATIC_LFP_PORTS, p = &lfp_ports[NR_STATIC_LFP_PORTS]; i < NR_ALL_LFP_PORTS; ++i, ++p) {
 258                 if (!p->port)
 259                         continue;
 260
 261                 len += sprintf(page + len, "%d%c\n", p->port, (c || i != next_slot)?' ':'*');
 262         }
 263
 264         *eof = 1;
 265         return len;
 266 }
 267 #endif  /* CONFIG_PROC_FS */
 268
 269 static int __init init(void)
 270 {
 271 #ifdef CONFIG_PROC_FS
 272         struct proc_dir_entry *p;
 273
 274         p = create_proc_entry("lfpctrl", 0600, init_net.proc_net);
 275
 276         if (p) {
 277                 p->read_proc = lfp_read_proc;
 278                 p->write_proc = lfp_ctrl;
 279         }
 280
 281         p = create_proc_entry("lfp_ports_ctrl", 0600, init_net.proc_net);
 282         if (p) {
 283                 p->read_proc = lfp_port_read_proc;
 284                 p->write_proc = lfp_port_write_proc;
 285         }
 286 #endif
 287         // it will be enabled later
 288         lfp_hit_hook_func (NULL);
 289         return 0;
 290 }
 291
 292 static void __exit fini(void)
 293 {
 294         lfp_hit_hook_func (NULL);
 295
 296 #ifdef CONFIG_PROC_FS
 297         remove_proc_entry("lfp_ports_ctrl", init_net.proc_net);
 298         remove_proc_entry("lfpctrl", init_net.proc_net);
 299 #endif
 300 }
 301
 302 module_init(init);
 303 module_exit(fini);
 304 MODULE_LICENSE("Proprietary");