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/random.h> 26 #include <linux/percpu.h> 27 #include <linux/init.h> 28 #include <net/sock.h> 29 30 #include <asm/byteorder.h> 31 #include <asm/system.h> 32 #include <asm/uaccess.h> 33 34 int net_msg_warn __read_mostly = 1; 35 EXPORT_SYMBOL(net_msg_warn); 36 37 DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10); 38 /* 39 * All net warning printk()s should be guarded by this function. 40 */ 41 int net_ratelimit(void) 42 { 43 return __ratelimit(&net_ratelimit_state); 44 } 45 EXPORT_SYMBOL(net_ratelimit); 46 47 /* 48 * Convert an ASCII string to binary IP. 49 * This is outside of net/ipv4/ because various code that uses IP addresses 50 * is otherwise not dependent on the TCP/IP stack. 51 */ 52 53 __be32 in_aton(const char *str) 54 { 55 unsigned long l; 56 unsigned int val; 57 int i; 58 59 l = 0; 60 for (i = 0; i < 4; i++) 61 { 62 l <<= 8; 63 if (*str != '\0') 64 { 65 val = 0; 66 while (*str != '\0' && *str != '.' && *str != '\n') 67 { 68 val *= 10; 69 val += *str - '0'; 70 str++; 71 } 72 l |= val; 73 if (*str != '\0') 74 str++; 75 } 76 } 77 return(htonl(l)); 78 } 79 80 EXPORT_SYMBOL(in_aton); 81 82 #define IN6PTON_XDIGIT 0x00010000 83 #define IN6PTON_DIGIT 0x00020000 84 #define IN6PTON_COLON_MASK 0x00700000 85 #define IN6PTON_COLON_1 0x00100000 /* single : requested */ 86 #define IN6PTON_COLON_2 0x00200000 /* second : requested */ 87 #define IN6PTON_COLON_1_2 0x00400000 /* :: requested */ 88 #define IN6PTON_DOT 0x00800000 /* . */ 89 #define IN6PTON_DELIM 0x10000000 90 #define IN6PTON_NULL 0x20000000 /* first/tail */ 91 #define IN6PTON_UNKNOWN 0x40000000 92 93 static inline int xdigit2bin(char c, int delim) 94 { 95 if (c == delim || c == '\0') 96 return IN6PTON_DELIM; 97 if (c == ':') 98 return IN6PTON_COLON_MASK; 99 if (c == '.') 100 return IN6PTON_DOT; 101 if (c >= '0' && c <= '9') 102 return (IN6PTON_XDIGIT | IN6PTON_DIGIT| (c - '0')); 103 if (c >= 'a' && c <= 'f') 104 return (IN6PTON_XDIGIT | (c - 'a' + 10)); 105 if (c >= 'A' && c <= 'F') 106 return (IN6PTON_XDIGIT | (c - 'A' + 10)); 107 if (delim == -1) 108 return IN6PTON_DELIM; 109 return IN6PTON_UNKNOWN; 110 } 111 112 int in4_pton(const char *src, int srclen, 113 u8 *dst, 114 int delim, const char **end) 115 { 116 const char *s; 117 u8 *d; 118 u8 dbuf[4]; 119 int ret = 0; 120 int i; 121 int w = 0; 122 123 if (srclen < 0) 124 srclen = strlen(src); 125 s = src; 126 d = dbuf; 127 i = 0; 128 while(1) { 129 int c; 130 c = xdigit2bin(srclen > 0 ? *s : '\0', delim); 131 if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) { 132 goto out; 133 } 134 if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) { 135 if (w == 0) 136 goto out; 137 *d++ = w & 0xff; 138 w = 0; 139 i++; 140 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) { 141 if (i != 4) 142 goto out; 143 break; 144 } 145 goto cont; 146 } 147 w = (w * 10) + c; 148 if ((w & 0xffff) > 255) { 149 goto out; 150 } 151 cont: 152 if (i >= 4) 153 goto out; 154 s++; 155 srclen--; 156 } 157 ret = 1; 158 memcpy(dst, dbuf, sizeof(dbuf)); 159 out: 160 if (end) 161 *end = s; 162 return ret; 163 } 164 165 EXPORT_SYMBOL(in4_pton); 166 167 int in6_pton(const char *src, int srclen, 168 u8 *dst, 169 int delim, const char **end) 170 { 171 const char *s, *tok = NULL; 172 u8 *d, *dc = NULL; 173 u8 dbuf[16]; 174 int ret = 0; 175 int i; 176 int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL; 177 int w = 0; 178 179 memset(dbuf, 0, sizeof(dbuf)); 180 181 s = src; 182 d = dbuf; 183 if (srclen < 0) 184 srclen = strlen(src); 185 186 while (1) { 187 int c; 188 189 c = xdigit2bin(srclen > 0 ? *s : '\0', delim); 190 if (!(c & state)) 191 goto out; 192 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) { 193 /* process one 16-bit word */ 194 if (!(state & IN6PTON_NULL)) { 195 *d++ = (w >> 8) & 0xff; 196 *d++ = w & 0xff; 197 } 198 w = 0; 199 if (c & IN6PTON_DELIM) { 200 /* We've processed last word */ 201 break; 202 } 203 /* 204 * COLON_1 => XDIGIT 205 * COLON_2 => XDIGIT|DELIM 206 * COLON_1_2 => COLON_2 207 */ 208 switch (state & IN6PTON_COLON_MASK) { 209 case IN6PTON_COLON_2: 210 dc = d; 211 state = IN6PTON_XDIGIT | IN6PTON_DELIM; 212 if (dc - dbuf >= sizeof(dbuf)) 213 state |= IN6PTON_NULL; 214 break; 215 case IN6PTON_COLON_1|IN6PTON_COLON_1_2: 216 state = IN6PTON_XDIGIT | IN6PTON_COLON_2; 217 break; 218 case IN6PTON_COLON_1: 219 state = IN6PTON_XDIGIT; 220 break; 221 case IN6PTON_COLON_1_2: 222 state = IN6PTON_COLON_2; 223 break; 224 default: 225 state = 0; 226 } 227 tok = s + 1; 228 goto cont; 229 } 230 231 if (c & IN6PTON_DOT) { 232 ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s); 233 if (ret > 0) { 234 d += 4; 235 break; 236 } 237 goto out; 238 } 239 240 w = (w << 4) | (0xff & c); 241 state = IN6PTON_COLON_1 | IN6PTON_DELIM; 242 if (!(w & 0xf000)) { 243 state |= IN6PTON_XDIGIT; 244 } 245 if (!dc && d + 2 < dbuf + sizeof(dbuf)) { 246 state |= IN6PTON_COLON_1_2; 247 state &= ~IN6PTON_DELIM; 248 } 249 if (d + 2 >= dbuf + sizeof(dbuf)) { 250 state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2); 251 } 252 cont: 253 if ((dc && d + 4 < dbuf + sizeof(dbuf)) || 254 d + 4 == dbuf + sizeof(dbuf)) { 255 state |= IN6PTON_DOT; 256 } 257 if (d >= dbuf + sizeof(dbuf)) { 258 state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK); 259 } 260 s++; 261 srclen--; 262 } 263 264 i = 15; d--; 265 266 if (dc) { 267 while(d >= dc) 268 dst[i--] = *d--; 269 while(i >= dc - dbuf) 270 dst[i--] = 0; 271 while(i >= 0) 272 dst[i--] = *d--; 273 } else 274 memcpy(dst, dbuf, sizeof(dbuf)); 275 276 ret = 1; 277 out: 278 if (end) 279 *end = s; 280 return ret; 281 } 282 283 EXPORT_SYMBOL(in6_pton); 284 285 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, 286 __be32 from, __be32 to, int pseudohdr) 287 { 288 __be32 diff[] = { ~from, to }; 289 if (skb->ip_summed != CHECKSUM_PARTIAL) { 290 *sum = csum_fold(csum_partial(diff, sizeof(diff), 291 ~csum_unfold(*sum))); 292 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr) 293 skb->csum = ~csum_partial(diff, sizeof(diff), 294 ~skb->csum); 295 } else if (pseudohdr) 296 *sum = ~csum_fold(csum_partial(diff, sizeof(diff), 297 csum_unfold(*sum))); 298 } 299 EXPORT_SYMBOL(inet_proto_csum_replace4); 300