1 /* 2 * Generic address resultion entity 3 * 4 * Authors: 5 * net_random Alan Cox 6 * net_ratelimit Andi Kleen 7 * in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project 8 * 9 * Created by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 */ 16 17 #include <linux/module.h> 18 #include <linux/jiffies.h> 19 #include <linux/kernel.h> 20 #include <linux/inet.h> 21 #include <linux/mm.h> 22 #include <linux/net.h> 23 #include <linux/string.h> 24 #include <linux/types.h> 25 #include <linux/percpu.h> 26 #include <linux/init.h> 27 #include <linux/ratelimit.h> 28 29 #include <net/sock.h> 30 #include <net/net_ratelimit.h> 31 32 #include <asm/byteorder.h> 33 #include <asm/uaccess.h> 34 35 int net_msg_warn __read_mostly = 1; 36 EXPORT_SYMBOL(net_msg_warn); 37 38 DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10); 39 /* 40 * All net warning printk()s should be guarded by this function. 41 */ 42 int net_ratelimit(void) 43 { 44 return __ratelimit(&net_ratelimit_state); 45 } 46 EXPORT_SYMBOL(net_ratelimit); 47 48 /* 49 * Convert an ASCII string to binary IP. 50 * This is outside of net/ipv4/ because various code that uses IP addresses 51 * is otherwise not dependent on the TCP/IP stack. 52 */ 53 54 __be32 in_aton(const char *str) 55 { 56 unsigned long l; 57 unsigned int val; 58 int i; 59 60 l = 0; 61 for (i = 0; i < 4; i++) { 62 l <<= 8; 63 if (*str != '\0') { 64 val = 0; 65 while (*str != '\0' && *str != '.' && *str != '\n') { 66 val *= 10; 67 val += *str - '0'; 68 str++; 69 } 70 l |= val; 71 if (*str != '\0') 72 str++; 73 } 74 } 75 return htonl(l); 76 } 77 EXPORT_SYMBOL(in_aton); 78 79 #define IN6PTON_XDIGIT 0x00010000 80 #define IN6PTON_DIGIT 0x00020000 81 #define IN6PTON_COLON_MASK 0x00700000 82 #define IN6PTON_COLON_1 0x00100000 /* single : requested */ 83 #define IN6PTON_COLON_2 0x00200000 /* second : requested */ 84 #define IN6PTON_COLON_1_2 0x00400000 /* :: requested */ 85 #define IN6PTON_DOT 0x00800000 /* . */ 86 #define IN6PTON_DELIM 0x10000000 87 #define IN6PTON_NULL 0x20000000 /* first/tail */ 88 #define IN6PTON_UNKNOWN 0x40000000 89 90 static inline int xdigit2bin(char c, int delim) 91 { 92 int val; 93 94 if (c == delim || c == '\0') 95 return IN6PTON_DELIM; 96 if (c == ':') 97 return IN6PTON_COLON_MASK; 98 if (c == '.') 99 return IN6PTON_DOT; 100 101 val = hex_to_bin(c); 102 if (val >= 0) 103 return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0); 104 105 if (delim == -1) 106 return IN6PTON_DELIM; 107 return IN6PTON_UNKNOWN; 108 } 109 110 /** 111 * in4_pton - convert an IPv4 address from literal to binary representation 112 * @src: the start of the IPv4 address string 113 * @srclen: the length of the string, -1 means strlen(src) 114 * @dst: the binary (u8[4] array) representation of the IPv4 address 115 * @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter 116 * @end: A pointer to the end of the parsed string will be placed here 117 * 118 * Return one on success, return zero when any error occurs 119 * and @end will point to the end of the parsed string. 120 * 121 */ 122 int in4_pton(const char *src, int srclen, 123 u8 *dst, 124 int delim, const char **end) 125 { 126 const char *s; 127 u8 *d; 128 u8 dbuf[4]; 129 int ret = 0; 130 int i; 131 int w = 0; 132 133 if (srclen < 0) 134 srclen = strlen(src); 135 s = src; 136 d = dbuf; 137 i = 0; 138 while(1) { 139 int c; 140 c = xdigit2bin(srclen > 0 ? *s : '\0', delim); 141 if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) { 142 goto out; 143 } 144 if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) { 145 if (w == 0) 146 goto out; 147 *d++ = w & 0xff; 148 w = 0; 149 i++; 150 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) { 151 if (i != 4) 152 goto out; 153 break; 154 } 155 goto cont; 156 } 157 w = (w * 10) + c; 158 if ((w & 0xffff) > 255) { 159 goto out; 160 } 161 cont: 162 if (i >= 4) 163 goto out; 164 s++; 165 srclen--; 166 } 167 ret = 1; 168 memcpy(dst, dbuf, sizeof(dbuf)); 169 out: 170 if (end) 171 *end = s; 172 return ret; 173 } 174 EXPORT_SYMBOL(in4_pton); 175 176 /** 177 * in6_pton - convert an IPv6 address from literal to binary representation 178 * @src: the start of the IPv6 address string 179 * @srclen: the length of the string, -1 means strlen(src) 180 * @dst: the binary (u8[16] array) representation of the IPv6 address 181 * @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter 182 * @end: A pointer to the end of the parsed string will be placed here 183 * 184 * Return one on success, return zero when any error occurs 185 * and @end will point to the end of the parsed string. 186 * 187 */ 188 int in6_pton(const char *src, int srclen, 189 u8 *dst, 190 int delim, const char **end) 191 { 192 const char *s, *tok = NULL; 193 u8 *d, *dc = NULL; 194 u8 dbuf[16]; 195 int ret = 0; 196 int i; 197 int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL; 198 int w = 0; 199 200 memset(dbuf, 0, sizeof(dbuf)); 201 202 s = src; 203 d = dbuf; 204 if (srclen < 0) 205 srclen = strlen(src); 206 207 while (1) { 208 int c; 209 210 c = xdigit2bin(srclen > 0 ? *s : '\0', delim); 211 if (!(c & state)) 212 goto out; 213 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) { 214 /* process one 16-bit word */ 215 if (!(state & IN6PTON_NULL)) { 216 *d++ = (w >> 8) & 0xff; 217 *d++ = w & 0xff; 218 } 219 w = 0; 220 if (c & IN6PTON_DELIM) { 221 /* We've processed last word */ 222 break; 223 } 224 /* 225 * COLON_1 => XDIGIT 226 * COLON_2 => XDIGIT|DELIM 227 * COLON_1_2 => COLON_2 228 */ 229 switch (state & IN6PTON_COLON_MASK) { 230 case IN6PTON_COLON_2: 231 dc = d; 232 state = IN6PTON_XDIGIT | IN6PTON_DELIM; 233 if (dc - dbuf >= sizeof(dbuf)) 234 state |= IN6PTON_NULL; 235 break; 236 case IN6PTON_COLON_1|IN6PTON_COLON_1_2: 237 state = IN6PTON_XDIGIT | IN6PTON_COLON_2; 238 break; 239 case IN6PTON_COLON_1: 240 state = IN6PTON_XDIGIT; 241 break; 242 case IN6PTON_COLON_1_2: 243 state = IN6PTON_COLON_2; 244 break; 245 default: 246 state = 0; 247 } 248 tok = s + 1; 249 goto cont; 250 } 251 252 if (c & IN6PTON_DOT) { 253 ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s); 254 if (ret > 0) { 255 d += 4; 256 break; 257 } 258 goto out; 259 } 260 261 w = (w << 4) | (0xff & c); 262 state = IN6PTON_COLON_1 | IN6PTON_DELIM; 263 if (!(w & 0xf000)) { 264 state |= IN6PTON_XDIGIT; 265 } 266 if (!dc && d + 2 < dbuf + sizeof(dbuf)) { 267 state |= IN6PTON_COLON_1_2; 268 state &= ~IN6PTON_DELIM; 269 } 270 if (d + 2 >= dbuf + sizeof(dbuf)) { 271 state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2); 272 } 273 cont: 274 if ((dc && d + 4 < dbuf + sizeof(dbuf)) || 275 d + 4 == dbuf + sizeof(dbuf)) { 276 state |= IN6PTON_DOT; 277 } 278 if (d >= dbuf + sizeof(dbuf)) { 279 state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK); 280 } 281 s++; 282 srclen--; 283 } 284 285 i = 15; d--; 286 287 if (dc) { 288 while(d >= dc) 289 dst[i--] = *d--; 290 while(i >= dc - dbuf) 291 dst[i--] = 0; 292 while(i >= 0) 293 dst[i--] = *d--; 294 } else 295 memcpy(dst, dbuf, sizeof(dbuf)); 296 297 ret = 1; 298 out: 299 if (end) 300 *end = s; 301 return ret; 302 } 303 EXPORT_SYMBOL(in6_pton); 304 305 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, 306 __be32 from, __be32 to, int pseudohdr) 307 { 308 __be32 diff[] = { ~from, to }; 309 if (skb->ip_summed != CHECKSUM_PARTIAL) { 310 *sum = csum_fold(csum_partial(diff, sizeof(diff), 311 ~csum_unfold(*sum))); 312 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr) 313 skb->csum = ~csum_partial(diff, sizeof(diff), 314 ~skb->csum); 315 } else if (pseudohdr) 316 *sum = ~csum_fold(csum_partial(diff, sizeof(diff), 317 csum_unfold(*sum))); 318 } 319 EXPORT_SYMBOL(inet_proto_csum_replace4); 320 321 void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, 322 const __be32 *from, const __be32 *to, 323 int pseudohdr) 324 { 325 __be32 diff[] = { 326 ~from[0], ~from[1], ~from[2], ~from[3], 327 to[0], to[1], to[2], to[3], 328 }; 329 if (skb->ip_summed != CHECKSUM_PARTIAL) { 330 *sum = csum_fold(csum_partial(diff, sizeof(diff), 331 ~csum_unfold(*sum))); 332 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr) 333 skb->csum = ~csum_partial(diff, sizeof(diff), 334 ~skb->csum); 335 } else if (pseudohdr) 336 *sum = ~csum_fold(csum_partial(diff, sizeof(diff), 337 csum_unfold(*sum))); 338 } 339 EXPORT_SYMBOL(inet_proto_csum_replace16); 340 341 int mac_pton(const char *s, u8 *mac) 342 { 343 int i; 344 345 /* XX:XX:XX:XX:XX:XX */ 346 if (strlen(s) < 3 * ETH_ALEN - 1) 347 return 0; 348 349 /* Don't dirty result unless string is valid MAC. */ 350 for (i = 0; i < ETH_ALEN; i++) { 351 if (!strchr("0123456789abcdefABCDEF", s[i * 3])) 352 return 0; 353 if (!strchr("0123456789abcdefABCDEF", s[i * 3 + 1])) 354 return 0; 355 if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':') 356 return 0; 357 } 358 for (i = 0; i < ETH_ALEN; i++) { 359 mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]); 360 } 361 return 1; 362 } 363 EXPORT_SYMBOL(mac_pton); 364