| 1 | /* |
| 2 | * This is a module which is used for counting packets. |
| 3 | */ |
| 4 | #include <linux/module.h> |
| 5 | #include <linux/skbuff.h> |
| 6 | #include <linux/ip.h> |
| 7 | #include <linux/spinlock.h> |
| 8 | #include <net/icmp.h> |
| 9 | #include <net/udp.h> |
| 10 | #include <net/tcp.h> |
| 11 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 12 | |
| 13 | struct in_device; |
| 14 | #include <net/route.h> |
| 15 | #include <linux/netfilter_ipv4/ipt_ACCOUNT.h> |
| 16 | |
| 17 | //#if 0 |
| 18 | #define DEBUGP printk |
| 19 | //#else |
| 20 | //#define DEBUGP(format, args...) |
| 21 | //#endif |
| 22 | |
| 23 | struct ipt_account_table *ipt_account_tables = NULL; |
| 24 | struct ipt_account_handle *ipt_account_handles = NULL; |
| 25 | |
| 26 | static spinlock_t ipt_account_lock = SPIN_LOCK_UNLOCKED; |
| 27 | |
| 28 | static unsigned int |
| 29 | ipt_account_target(struct sk_buff **pskb, |
| 30 | unsigned int hooknum, |
| 31 | const struct net_device *in, |
| 32 | const struct net_device *out, |
| 33 | const void *targinfo, |
| 34 | void *userinfo) |
| 35 | { |
| 36 | spin_lock_bh(&ipt_account_lock); |
| 37 | spin_unlock_bh(&ipt_account_lock); |
| 38 | |
| 39 | return IPT_CONTINUE; |
| 40 | } |
| 41 | |
| 42 | /* Recursive free of all data structures */ |
| 43 | void ipt_account_data_free(void *data, unsigned char depth) |
| 44 | { |
| 45 | // Empty data set |
| 46 | if (!data) |
| 47 | return; |
| 48 | |
| 49 | // Free for 8 bit network |
| 50 | if (depth == 0) |
| 51 | { |
| 52 | free_page((unsigned long)data); |
| 53 | data = NULL; |
| 54 | return; |
| 55 | } |
| 56 | |
| 57 | // Free for 16 bit network |
| 58 | if (depth == 1) |
| 59 | { |
| 60 | struct ipt_account_mask_16 *mask_16 = (struct ipt_account_mask_16 *)data; |
| 61 | unsigned char b; |
| 62 | for (b=0; b < 255; b++) |
| 63 | { |
| 64 | if (mask_16->mask_24[b] != 0) |
| 65 | { |
| 66 | free_page((unsigned long)mask_16->mask_24[b]); |
| 67 | mask_16->mask_24[b] = NULL; |
| 68 | } |
| 69 | } |
| 70 | free_page((unsigned long)data); |
| 71 | data = NULL; |
| 72 | return; |
| 73 | } |
| 74 | |
| 75 | // Free for 24 bit network |
| 76 | if (depth == 3) |
| 77 | { |
| 78 | unsigned char a, b; |
| 79 | for (a=0; a < 255; a++) |
| 80 | { |
| 81 | if (((struct ipt_account_mask_8 *)data)->mask_16[a]) |
| 82 | { |
| 83 | struct ipt_account_mask_16 *mask_16 = (struct ipt_account_mask_16*)((struct ipt_account_mask_8 *)data)->mask_16[a]; |
| 84 | for (b=0; b < 255; b++) |
| 85 | { |
| 86 | if (mask_16->mask_24[b]) { |
| 87 | free_page((unsigned long)mask_16->mask_24[b]); |
| 88 | mask_16->mask_24[b] = NULL; |
| 89 | } |
| 90 | } |
| 91 | free_page((unsigned long)mask_16); |
| 92 | mask_16 = NULL; |
| 93 | } |
| 94 | } |
| 95 | free_page((unsigned long)data); |
| 96 | data = NULL; |
| 97 | return; |
| 98 | } |
| 99 | |
| 100 | printk("ACCOUNT: ipt_account_data_free called with unknown depth: %d\n", depth); |
| 101 | return; |
| 102 | } |
| 103 | |
| 104 | /* Look for existing table / insert new one. Return internal ID or -1 on error */ |
| 105 | int ipt_account_table_insert(char *name, unsigned int ip, unsigned int netmask) |
| 106 | { |
| 107 | unsigned int i; |
| 108 | |
| 109 | DEBUGP("ACCOUNT: ipt_account_table_insert: %s, %u.%u.%u.%u/%u.%u.%u.%u\n", name, NIPQUAD(ip), NIPQUAD(netmask)); |
| 110 | |
| 111 | // Look for existing table |
| 112 | for (i = 0; i < ACCOUNT_MAX_TABLES; i++) |
| 113 | { |
| 114 | if (strcmp(ipt_account_tables[i].name, name) == 0) |
| 115 | { |
| 116 | DEBUGP("ACCOUNT: Found existing slot: %d - %u.%u.%u.%u/%u.%u.%u.%u\n", i, |
| 117 | NIPQUAD(ipt_account_tables[i].ip), NIPQUAD(ipt_account_tables[i].netmask)); |
| 118 | |
| 119 | if (ipt_account_tables[i].ip != ip || ipt_account_tables[i].netmask != netmask) |
| 120 | { |
| 121 | printk("ACCOUNT: Table %s found, but IP/netmask mismatch. IP/netmask found: %u.%u.%u.%u/%u.%u.%u.%u\n", |
| 122 | name, NIPQUAD(ipt_account_tables[i].ip), NIPQUAD(ipt_account_tables[i].netmask)); |
| 123 | return -1; |
| 124 | } |
| 125 | |
| 126 | ipt_account_tables[i].refcount++; |
| 127 | DEBUGP("ACCOUNT: Refcount: %d\n", ipt_account_tables[i].refcount); |
| 128 | return i; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | // Insert new table |
| 133 | for (i = 0; i < ACCOUNT_MAX_TABLES; i++) |
| 134 | { |
| 135 | // Found free slot |
| 136 | if (ipt_account_tables[i].name[0] == 0) |
| 137 | { |
| 138 | DEBUGP("ACCOUNT: Found free slot: %d\n", i); |
| 139 | |
| 140 | strncpy (ipt_account_tables[i].name, name, ACCOUNT_TABLE_NAME_LEN-1); |
| 141 | |
| 142 | ipt_account_tables[i].ip = ip; |
| 143 | ipt_account_tables[i].netmask = netmask; |
| 144 | |
| 145 | // Calculate netsize |
| 146 | unsigned int j, calc_mask, netsize=0; |
| 147 | calc_mask = htonl(netmask); |
| 148 | for (j = 31; j > 0; j--) |
| 149 | { |
| 150 | if (calc_mask&(1<<j)) |
| 151 | netsize++; |
| 152 | else |
| 153 | break; |
| 154 | } |
| 155 | |
| 156 | // Calculate depth from netsize |
| 157 | if (netsize >= 24) |
| 158 | ipt_account_tables[i].depth = 0; |
| 159 | else if (netsize >= 16) |
| 160 | ipt_account_tables[i].depth = 1; |
| 161 | else if(netsize >= 8) |
| 162 | ipt_account_tables[i].depth = 2; |
| 163 | |
| 164 | printk("ACCOUNT: calculated netsize: %u -> ipt_account_table depth %u\n", netsize, ipt_account_tables[i].depth); |
| 165 | |
| 166 | ipt_account_tables[i].refcount++; |
| 167 | if (!(ipt_account_tables[i].data = (void *)get_zeroed_page(GFP_KERNEL))) |
| 168 | { |
| 169 | printk("ACCOUNT: out of memory for data of table: %s\n", name); |
| 170 | memset(&ipt_account_tables[i], 0, sizeof(struct ipt_account_table)); |
| 171 | return -1; |
| 172 | } |
| 173 | |
| 174 | return i; |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | // No free slot found |
| 179 | printk("ACCOUNT: No free table slot found (max: %d). Please increase ACCOUNT_MAX_TABLES.\n", ACCOUNT_MAX_TABLES); |
| 180 | return -1; |
| 181 | } |
| 182 | |
| 183 | static int ipt_account_checkentry(const char *tablename, |
| 184 | const struct ipt_entry *e, |
| 185 | void *targinfo, |
| 186 | unsigned int targinfosize, |
| 187 | unsigned int hook_mask) |
| 188 | { |
| 189 | struct ipt_account_info *info = targinfo; |
| 190 | |
| 191 | if (targinfosize != IPT_ALIGN(sizeof(struct ipt_account_info))) { |
| 192 | DEBUGP("ACCOUNT: targinfosize %u != %u\n", |
| 193 | targinfosize, IPT_ALIGN(sizeof(struct ipt_account_info))); |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | spin_lock_bh(&ipt_account_lock); |
| 198 | int table_nr = ipt_account_table_insert(info->table_name, info->net_ip, info->net_mask); |
| 199 | if (table_nr == -1) |
| 200 | { |
| 201 | printk("ACCOUNT: Table insert problem. Aborting\n"); |
| 202 | spin_unlock_bh(&ipt_account_lock); |
| 203 | return 0; |
| 204 | } |
| 205 | // Table nr caching so we don't have to do an extra string compare for every packet |
| 206 | info->table_nr = table_nr; |
| 207 | |
| 208 | spin_unlock_bh(&ipt_account_lock); |
| 209 | |
| 210 | return 1; |
| 211 | } |
| 212 | |
| 213 | void ipt_account_deleteentry(void *targinfo, unsigned int targinfosize) |
| 214 | { |
| 215 | unsigned int i; |
| 216 | struct ipt_account_info *info = targinfo; |
| 217 | |
| 218 | if (targinfosize != IPT_ALIGN(sizeof(struct ipt_account_info))) { |
| 219 | DEBUGP("ACCOUNT: targinfosize %u != %u\n", |
| 220 | targinfosize, IPT_ALIGN(sizeof(struct ipt_account_info))); |
| 221 | } |
| 222 | |
| 223 | spin_lock_bh(&ipt_account_lock); |
| 224 | |
| 225 | DEBUGP("ACCOUNT: ipt_account_deleteentry called for table: %s (#%d)\n", info->table_name, info->table_nr); |
| 226 | |
| 227 | info->table_nr = -1; // Set back to original state |
| 228 | |
| 229 | // Look for table |
| 230 | for (i = 0; i < ACCOUNT_MAX_TABLES; i++) |
| 231 | { |
| 232 | if (strcmp(ipt_account_tables[i].name, info->table_name) == 0) |
| 233 | { |
| 234 | DEBUGP("ACCOUNT: Found table at slot: %d\n", i); |
| 235 | |
| 236 | ipt_account_tables[i].refcount--; |
| 237 | DEBUGP("ACCOUNT: Refcount left: %d\n", ipt_account_tables[i].refcount); |
| 238 | |
| 239 | // Table not needed anymore? |
| 240 | if (ipt_account_tables[i].refcount == 0) |
| 241 | { |
| 242 | DEBUGP("ACCOUNT: Destroying table at slot: %d\n", i); |
| 243 | ipt_account_data_free(ipt_account_tables[i].data, ipt_account_tables[i].depth); |
| 244 | memset(&ipt_account_tables[i], 0, sizeof(struct ipt_account_table)); |
| 245 | } |
| 246 | |
| 247 | spin_unlock_bh(&ipt_account_lock); |
| 248 | return; |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | // Table not found |
| 253 | printk("ACCOUNT: Table %s not found for destroy\n", info->table_name); |
| 254 | spin_unlock_bh(&ipt_account_lock); |
| 255 | } |
| 256 | |
| 257 | static struct ipt_target ipt_account_reg |
| 258 | = { { NULL, NULL }, "ACCOUNT", ipt_account_target, ipt_account_checkentry, ipt_account_deleteentry, |
| 259 | THIS_MODULE }; |
| 260 | |
| 261 | static int __init init(void) |
| 262 | { |
| 263 | if (!(ipt_account_tables = kmalloc(ACCOUNT_MAX_TABLES*sizeof(struct ipt_account_table), GFP_KERNEL))) |
| 264 | { |
| 265 | printk("ACCOUNT: Out of memory allocating account_tables structure"); |
| 266 | return -EINVAL; |
| 267 | } |
| 268 | memset(ipt_account_tables, 0, ACCOUNT_MAX_TABLES*sizeof(struct ipt_account_table)); |
| 269 | |
| 270 | if (!(ipt_account_handles = kmalloc(ACCOUNT_MAX_HANDLES*sizeof(struct ipt_account_handle), GFP_KERNEL))) |
| 271 | { |
| 272 | printk("ACCOUNT: Out of memory allocating account_handles structure"); |
| 273 | kfree (ipt_account_tables); |
| 274 | ipt_account_tables = NULL; |
| 275 | return -EINVAL; |
| 276 | } |
| 277 | memset(ipt_account_handles, 0, ACCOUNT_MAX_HANDLES*sizeof(struct ipt_account_handle)); |
| 278 | |
| 279 | if (ipt_register_target(&ipt_account_reg)) |
| 280 | return -EINVAL; |
| 281 | |
| 282 | return 0; |
| 283 | } |
| 284 | |
| 285 | static void __exit fini(void) |
| 286 | { |
| 287 | ipt_unregister_target(&ipt_account_reg); |
| 288 | |
| 289 | kfree(ipt_account_tables); |
| 290 | ipt_account_tables = NULL; |
| 291 | |
| 292 | kfree(ipt_account_handles); |
| 293 | ipt_account_handles = NULL; |
| 294 | } |
| 295 | |
| 296 | module_init(init); |
| 297 | module_exit(fini); |
| 298 | MODULE_LICENSE("GPL"); |