DDE - The L4 Device Driver Environment: utils.c Source File

00001 /*
00002  *      Generic address resultion entity
00003  *
00004  *      Authors:
00005  *      net_random Alan Cox
00006  *      net_ratelimit Andi Kleen
00007  *      in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
00008  *
00009  *      Created by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
00010  *
00011  *      This program is free software; you can redistribute it and/or
00012  *      modify it under the terms of the GNU General Public License
00013  *      as published by the Free Software Foundation; either version
00014  *      2 of the License, or (at your option) any later version.
00015  */
00016 
00017 #include <linux/module.h>
00018 #include <linux/jiffies.h>
00019 #include <linux/kernel.h>
00020 #include <linux/inet.h>
00021 #include <linux/mm.h>
00022 #include <linux/net.h>
00023 #include <linux/string.h>
00024 #include <linux/types.h>
00025 #include <linux/random.h>
00026 #include <linux/percpu.h>
00027 #include <linux/init.h>
00028 #include <net/sock.h>
00029 
00030 #include <asm/byteorder.h>
00031 #include <asm/system.h>
00032 #include <asm/uaccess.h>
00033 
00034 #ifndef DDE_LINUX
00035 int net_msg_cost __read_mostly = 5*HZ;
00036 DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
00037 #else
00038 int net_msg_cost = 500;
00039 #endif /* DDE_LINUX */
00040 int net_msg_burst __read_mostly = 10;
00041 int net_msg_warn __read_mostly = 1;
00042 EXPORT_SYMBOL(net_msg_warn);
00043 
00044 /*
00045  * All net warning printk()s should be guarded by this function.
00046  */
00047 int net_ratelimit(void)
00048 {
00049 #ifndef DDE_LINUX
00050         return __ratelimit(&net_ratelimit_state);
00051 #else
00052         return 0;
00053 #endif
00054 }
00055 EXPORT_SYMBOL(net_ratelimit);
00056 
00057 /*
00058  * Convert an ASCII string to binary IP.
00059  * This is outside of net/ipv4/ because various code that uses IP addresses
00060  * is otherwise not dependent on the TCP/IP stack.
00061  */
00062 
00063 __be32 in_aton(const char *str)
00064 {
00065         unsigned long l;
00066         unsigned int val;
00067         int i;
00068 
00069         l = 0;
00070         for (i = 0; i < 4; i++)
00071         {
00072                 l <<= 8;
00073                 if (*str != '\0')
00074                 {
00075                         val = 0;
00076                         while (*str != '\0' && *str != '.' && *str != '\n')
00077                         {
00078                                 val *= 10;
00079                                 val += *str - '0';
00080                                 str++;
00081                         }
00082                         l |= val;
00083                         if (*str != '\0')
00084                                 str++;
00085                 }
00086         }
00087         return(htonl(l));
00088 }
00089 
00090 EXPORT_SYMBOL(in_aton);
00091 
00092 #define IN6PTON_XDIGIT          0x00010000
00093 #define IN6PTON_DIGIT           0x00020000
00094 #define IN6PTON_COLON_MASK      0x00700000
00095 #define IN6PTON_COLON_1         0x00100000      /* single : requested */
00096 #define IN6PTON_COLON_2         0x00200000      /* second : requested */
00097 #define IN6PTON_COLON_1_2       0x00400000      /* :: requested */
00098 #define IN6PTON_DOT             0x00800000      /* . */
00099 #define IN6PTON_DELIM           0x10000000
00100 #define IN6PTON_NULL            0x20000000      /* first/tail */
00101 #define IN6PTON_UNKNOWN         0x40000000
00102 
00103 static inline int xdigit2bin(char c, int delim)
00104 {
00105         if (c == delim || c == '\0')
00106                 return IN6PTON_DELIM;
00107         if (c == ':')
00108                 return IN6PTON_COLON_MASK;
00109         if (c == '.')
00110                 return IN6PTON_DOT;
00111         if (c >= '0' && c <= '9')
00112                 return (IN6PTON_XDIGIT | IN6PTON_DIGIT| (c - '0'));
00113         if (c >= 'a' && c <= 'f')
00114                 return (IN6PTON_XDIGIT | (c - 'a' + 10));
00115         if (c >= 'A' && c <= 'F')
00116                 return (IN6PTON_XDIGIT | (c - 'A' + 10));
00117         if (delim == -1)
00118                 return IN6PTON_DELIM;
00119         return IN6PTON_UNKNOWN;
00120 }
00121 
00122 int in4_pton(const char *src, int srclen,
00123              u8 *dst,
00124              int delim, const char **end)
00125 {
00126         const char *s;
00127         u8 *d;
00128         u8 dbuf[4];
00129         int ret = 0;
00130         int i;
00131         int w = 0;
00132 
00133         if (srclen < 0)
00134                 srclen = strlen(src);
00135         s = src;
00136         d = dbuf;
00137         i = 0;
00138         while(1) {
00139                 int c;
00140                 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
00141                 if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
00142                         goto out;
00143                 }
00144                 if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
00145                         if (w == 0)
00146                                 goto out;
00147                         *d++ = w & 0xff;
00148                         w = 0;
00149                         i++;
00150                         if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
00151                                 if (i != 4)
00152                                         goto out;
00153                                 break;
00154                         }
00155                         goto cont;
00156                 }
00157                 w = (w * 10) + c;
00158                 if ((w & 0xffff) > 255) {
00159                         goto out;
00160                 }
00161 cont:
00162                 if (i >= 4)
00163                         goto out;
00164                 s++;
00165                 srclen--;
00166         }
00167         ret = 1;
00168         memcpy(dst, dbuf, sizeof(dbuf));
00169 out:
00170         if (end)
00171                 *end = s;
00172         return ret;
00173 }
00174 
00175 EXPORT_SYMBOL(in4_pton);
00176 
00177 int in6_pton(const char *src, int srclen,
00178              u8 *dst,
00179              int delim, const char **end)
00180 {
00181         const char *s, *tok = NULL;
00182         u8 *d, *dc = NULL;
00183         u8 dbuf[16];
00184         int ret = 0;
00185         int i;
00186         int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
00187         int w = 0;
00188 
00189         memset(dbuf, 0, sizeof(dbuf));
00190 
00191         s = src;
00192         d = dbuf;
00193         if (srclen < 0)
00194                 srclen = strlen(src);
00195 
00196         while (1) {
00197                 int c;
00198 
00199                 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
00200                 if (!(c & state))
00201                         goto out;
00202                 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
00203                         /* process one 16-bit word */
00204                         if (!(state & IN6PTON_NULL)) {
00205                                 *d++ = (w >> 8) & 0xff;
00206                                 *d++ = w & 0xff;
00207                         }
00208                         w = 0;
00209                         if (c & IN6PTON_DELIM) {
00210                                 /* We've processed last word */
00211                                 break;
00212                         }
00213                         /*
00214                          * COLON_1 => XDIGIT
00215                          * COLON_2 => XDIGIT|DELIM
00216                          * COLON_1_2 => COLON_2
00217                          */
00218                         switch (state & IN6PTON_COLON_MASK) {
00219                         case IN6PTON_COLON_2:
00220                                 dc = d;
00221                                 state = IN6PTON_XDIGIT | IN6PTON_DELIM;
00222                                 if (dc - dbuf >= sizeof(dbuf))
00223                                         state |= IN6PTON_NULL;
00224                                 break;
00225                         case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
00226                                 state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
00227                                 break;
00228                         case IN6PTON_COLON_1:
00229                                 state = IN6PTON_XDIGIT;
00230                                 break;
00231                         case IN6PTON_COLON_1_2:
00232                                 state = IN6PTON_COLON_2;
00233                                 break;
00234                         default:
00235                                 state = 0;
00236                         }
00237                         tok = s + 1;
00238                         goto cont;
00239                 }
00240 
00241                 if (c & IN6PTON_DOT) {
00242                         ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
00243                         if (ret > 0) {
00244                                 d += 4;
00245                                 break;
00246                         }
00247                         goto out;
00248                 }
00249 
00250                 w = (w << 4) | (0xff & c);
00251                 state = IN6PTON_COLON_1 | IN6PTON_DELIM;
00252                 if (!(w & 0xf000)) {
00253                         state |= IN6PTON_XDIGIT;
00254                 }
00255                 if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
00256                         state |= IN6PTON_COLON_1_2;
00257                         state &= ~IN6PTON_DELIM;
00258                 }
00259                 if (d + 2 >= dbuf + sizeof(dbuf)) {
00260                         state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
00261                 }
00262 cont:
00263                 if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
00264                     d + 4 == dbuf + sizeof(dbuf)) {
00265                         state |= IN6PTON_DOT;
00266                 }
00267                 if (d >= dbuf + sizeof(dbuf)) {
00268                         state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
00269                 }
00270                 s++;
00271                 srclen--;
00272         }
00273 
00274         i = 15; d--;
00275 
00276         if (dc) {
00277                 while(d >= dc)
00278                         dst[i--] = *d--;
00279                 while(i >= dc - dbuf)
00280                         dst[i--] = 0;
00281                 while(i >= 0)
00282                         dst[i--] = *d--;
00283         } else
00284                 memcpy(dst, dbuf, sizeof(dbuf));
00285 
00286         ret = 1;
00287 out:
00288         if (end)
00289                 *end = s;
00290         return ret;
00291 }
00292 
00293 EXPORT_SYMBOL(in6_pton);
00294 
00295 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
00296                               __be32 from, __be32 to, int pseudohdr)
00297 {
00298         __be32 diff[] = { ~from, to };
00299         if (skb->ip_summed != CHECKSUM_PARTIAL) {
00300                 *sum = csum_fold(csum_partial(diff, sizeof(diff),
00301                                 ~csum_unfold(*sum)));
00302                 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
00303                         skb->csum = ~csum_partial(diff, sizeof(diff),
00304                                                 ~skb->csum);
00305         } else if (pseudohdr)
00306                 *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
00307                                 csum_unfold(*sum)));
00308 }
00309 EXPORT_SYMBOL(inet_proto_csum_replace4);