src/libloc/private.h

   1 /*
   2         libloc - A library to determine the location of someone on the Internet
   3
   4         Copyright (C) 2017 IPFire Development Team <info@ipfire.org>
   5
   6         This library is free software; you can redistribute it and/or
   7         modify it under the terms of the GNU Lesser General Public
   8         License as published by the Free Software Foundation; either
   9         version 2.1 of the License, or (at your option) any later version.
  10
  11         This library is distributed in the hope that it will be useful,
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14         Lesser General Public License for more details.
  15 */
  16
  17 #ifndef LIBLOC_PRIVATE_H
  18 #define LIBLOC_PRIVATE_H
  19
  20 #ifdef LIBLOC_PRIVATE
  21
  22 #include <netinet/in.h>
  23 #include <stdbool.h>
  24 #include <stdio.h>
  25 #include <syslog.h>
  26
  27 #include <libloc/libloc.h>
  28
  29 static inline void __attribute__((always_inline, format(printf, 2, 3)))
  30 loc_log_null(struct loc_ctx *ctx, const char *format, ...) {}
  31
  32 #define loc_log_cond(ctx, prio, arg...) \
  33         do { \
  34                 if (loc_get_log_priority(ctx) >= prio) \
  35                         loc_log(ctx, prio, __FILE__, __LINE__, __FUNCTION__, ## arg); \
  36         } while (0)
  37
  38 #ifdef ENABLE_DEBUG
  39 #  define DEBUG(ctx, arg...) loc_log_cond(ctx, LOG_DEBUG, ## arg)
  40 #else
  41 #  define DEBUG(ctx, arg...) loc_log_null(ctx, ## arg)
  42 #endif
  43
  44 #define INFO(ctx, arg...) loc_log_cond(ctx, LOG_INFO, ## arg)
  45 #define ERROR(ctx, arg...) loc_log_cond(ctx, LOG_ERR, ## arg)
  46
  47 #ifndef HAVE_SECURE_GETENV
  48 #  ifdef HAVE___SECURE_GETENV
  49 #    define secure_getenv __secure_getenv
  50 #  else
  51 #    define secure_getenv getenv
  52 #  endif
  53 #endif
  54
  55 #define LOC_EXPORT __attribute__ ((visibility("default")))
  56
  57 void loc_log(struct loc_ctx *ctx,
  58         int priority, const char *file, int line, const char *fn,
  59         const char *format, ...) __attribute__((format(printf, 6, 7)));
  60
  61 static inline int in6_addr_cmp(const struct in6_addr* a1, const struct in6_addr* a2) {
  62         for (unsigned int i = 0; i < 16; i++) {
  63                 if (a1->s6_addr[i] > a2->s6_addr[i])
  64                         return 1;
  65
  66                 else if (a1->s6_addr[i] < a2->s6_addr[i])
  67                         return -1;
  68         }
  69
  70         return 0;
  71 }
  72
  73 static inline int in6_addr_get_bit(const struct in6_addr* address, unsigned int i) {
  74         return ((address->s6_addr[i / 8] >> (7 - (i % 8))) & 1);
  75 }
  76
  77 static inline void in6_addr_set_bit(struct in6_addr* address, unsigned int i, unsigned int val) {
  78         address->s6_addr[i / 8] ^= (-val ^ address->s6_addr[i / 8]) & (1 << (7 - (i % 8)));
  79 }
  80
  81 static inline struct in6_addr loc_prefix_to_bitmask(const unsigned int prefix) {
  82         struct in6_addr bitmask;
  83
  84         for (unsigned int i = 0; i < 16; i++)
  85                 bitmask.s6_addr[i] = 0;
  86
  87         for (int i = prefix, j = 0; i > 0; i -= 8, j++) {
  88                 if (i >= 8)
  89                         bitmask.s6_addr[j] = 0xff;
  90                 else
  91                         bitmask.s6_addr[j] = 0xff << (8 - i);
  92         }
  93
  94         return bitmask;
  95 }
  96
  97 static inline unsigned int loc_address_bit_length(const struct in6_addr* address) {
  98         unsigned int length = 128;
  99
 100         for (int octet = 0; octet <= 15; octet++) {
 101                 if (address->s6_addr[octet]) {
 102                         length -= __builtin_clz(address->s6_addr[octet]) - 24;
 103                         break;
 104                 } else
 105                         length -= 8;
 106         }
 107
 108         return length;
 109 }
 110
 111 static inline struct in6_addr loc_address_and(
 112                 const struct in6_addr* address, const struct in6_addr* bitmask) {
 113         struct in6_addr a;
 114
 115         // Perform bitwise AND
 116         for (unsigned int i = 0; i < 4; i++)
 117                 a.s6_addr32[i] = address->s6_addr32[i] & bitmask->s6_addr32[i];
 118
 119         return a;
 120 }
 121
 122 static inline struct in6_addr loc_address_or(
 123                 const struct in6_addr* address, const struct in6_addr* bitmask) {
 124         struct in6_addr a;
 125
 126         // Perform bitwise OR
 127         for (unsigned int i = 0; i < 4; i++)
 128                 a.s6_addr32[i] = address->s6_addr32[i] | ~bitmask->s6_addr32[i];
 129
 130         return a;
 131 }
 132
 133 static inline struct in6_addr loc_address_sub(
 134                 const struct in6_addr* address1, const struct in6_addr* address2) {
 135         struct in6_addr a;
 136
 137         int remainder = 0;
 138
 139         for (int octet = 15; octet >= 0; octet--) {
 140                 int x = address1->s6_addr[octet] - address2->s6_addr[octet] + remainder;
 141
 142                 // Store remainder for the next iteration
 143                 remainder = (x >> 8);
 144
 145                 a.s6_addr[octet] = x & 0xff;
 146         }
 147
 148         return a;
 149 }
 150
 151 static inline void hexdump(struct loc_ctx* ctx, const void* addr, size_t len) {
 152         char buffer_hex[16 * 3 + 6];
 153         char buffer_ascii[17];
 154
 155         unsigned int i = 0;
 156         unsigned char* p = (unsigned char*)addr;
 157
 158         DEBUG(ctx, "Dumping %zu byte(s)\n", len);
 159
 160         // Process every byte in the data
 161         for (i = 0; i < len; i++) {
 162                 // Multiple of 16 means new line (with line offset)
 163                 if ((i % 16) == 0) {
 164                         // Just don't print ASCII for the zeroth line
 165                         if (i != 0)
 166                                 DEBUG(ctx, "  %s %s\n", buffer_hex, buffer_ascii);
 167
 168                         // Output the offset.
 169                         sprintf(buffer_hex, "%04x ", i);
 170                 }
 171
 172                 // Now the hex code for the specific character
 173                 sprintf(buffer_hex + 5 + ((i % 16) * 3), " %02x", p[i]);
 174
 175                 // And store a printable ASCII character for later
 176                 if ((p[i] < 0x20) || (p[i] > 0x7e))
 177                         buffer_ascii[i % 16] = '.';
 178                 else
 179                         buffer_ascii[i % 16] = p[i];
 180
 181                 // Terminate string
 182                 buffer_ascii[(i % 16) + 1] = '\0';
 183         }
 184
 185         // Pad out last line if not exactly 16 characters
 186         while ((i % 16) != 0) {
 187                 sprintf(buffer_hex + 5 + ((i % 16) * 3), "   ");
 188                 i++;
 189         }
 190
 191         // And print the final bit
 192         DEBUG(ctx, "  %s %s\n", buffer_hex, buffer_ascii);
 193 }
 194
 195 #endif
 196 #endif