gdb/common/rsp-low.c

   1 /* Low-level RSP routines for GDB, the GNU debugger.
   2
   3    Copyright (C) 1988-2014 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifdef GDBSERVER
  21 #include "server.h"
  22 #else
  23 #include "defs.h"
  24 #endif
  25
  26 #include <string.h>
  27
  28 #include "rsp-low.h"
  29
  30 /* Convert hex digit A to a number.  */
  31
  32 int
  33 fromhex (int a)
  34 {
  35   if (a >= '0' && a <= '9')
  36     return a - '0';
  37   else if (a >= 'a' && a <= 'f')
  38     return a - 'a' + 10;
  39   else if (a >= 'A' && a <= 'F')
  40     return a - 'A' + 10;
  41   else
  42     error (_("Reply contains invalid hex digit %d"), a);
  43 }
  44
  45 int
  46 tohex (int nib)
  47 {
  48   if (nib < 10)
  49     return '0' + nib;
  50   else
  51     return 'a' + nib - 10;
  52 }
  53
  54 /* Encode 64 bits in 16 chars of hex.  */
  55
  56 static const char hexchars[] = "0123456789abcdef";
  57
  58 static int
  59 ishex (int ch, int *val)
  60 {
  61   if ((ch >= 'a') && (ch <= 'f'))
  62     {
  63       *val = ch - 'a' + 10;
  64       return 1;
  65     }
  66   if ((ch >= 'A') && (ch <= 'F'))
  67     {
  68       *val = ch - 'A' + 10;
  69       return 1;
  70     }
  71   if ((ch >= '0') && (ch <= '9'))
  72     {
  73       *val = ch - '0';
  74       return 1;
  75     }
  76   return 0;
  77 }
  78
  79 char *
  80 pack_nibble (char *buf, int nibble)
  81 {
  82   *buf++ = hexchars[(nibble & 0x0f)];
  83   return buf;
  84 }
  85
  86 char *
  87 pack_hex_byte (char *pkt, int byte)
  88 {
  89   *pkt++ = hexchars[(byte >> 4) & 0xf];
  90   *pkt++ = hexchars[(byte & 0xf)];
  91   return pkt;
  92 }
  93
  94 char *
  95 unpack_varlen_hex (char *buff,  /* packet to parse */
  96                    ULONGEST *result)
  97 {
  98   int nibble;
  99   ULONGEST retval = 0;
 100
 101   while (ishex (*buff, &nibble))
 102     {
 103       buff++;
 104       retval = retval << 4;
 105       retval |= nibble & 0x0f;
 106     }
 107   *result = retval;
 108   return buff;
 109 }
 110
 111 int
 112 hex2bin (const char *hex, gdb_byte *bin, int count)
 113 {
 114   int i;
 115
 116   for (i = 0; i < count; i++)
 117     {
 118       if (hex[0] == 0 || hex[1] == 0)
 119         {
 120           /* Hex string is short, or of uneven length.
 121              Return the count that has been converted so far.  */
 122           return i;
 123         }
 124       *bin++ = fromhex (hex[0]) * 16 + fromhex (hex[1]);
 125       hex += 2;
 126     }
 127   return i;
 128 }
 129
 130 int
 131 unhexify (char *bin, const char *hex, int count)
 132 {
 133   int i;
 134
 135   for (i = 0; i < count; i++)
 136     {
 137       if (hex[0] == 0 || hex[1] == 0)
 138         {
 139           /* Hex string is short, or of uneven length.
 140              Return the count that has been converted so far. */
 141           return i;
 142         }
 143       *bin++ = fromhex (hex[0]) * 16 + fromhex (hex[1]);
 144       hex += 2;
 145     }
 146   return i;
 147 }
 148
 149 void
 150 convert_ascii_to_int (const char *from, unsigned char *to, int n)
 151 {
 152   int nib1, nib2;
 153   while (n--)
 154     {
 155       nib1 = fromhex (*from++);
 156       nib2 = fromhex (*from++);
 157       *to++ = (((nib1 & 0x0f) << 4) & 0xf0) | (nib2 & 0x0f);
 158     }
 159 }
 160
 161 int
 162 bin2hex (const gdb_byte *bin, char *hex, int count)
 163 {
 164   int i;
 165
 166   for (i = 0; i < count; i++)
 167     {
 168       *hex++ = tohex ((*bin >> 4) & 0xf);
 169       *hex++ = tohex (*bin++ & 0xf);
 170     }
 171   *hex = 0;
 172   return i;
 173 }
 174
 175 int
 176 remote_escape_output (const gdb_byte *buffer, int len,
 177                       gdb_byte *out_buf, int *out_len,
 178                       int out_maxlen)
 179 {
 180   int input_index, output_index;
 181
 182   output_index = 0;
 183   for (input_index = 0; input_index < len; input_index++)
 184     {
 185       gdb_byte b = buffer[input_index];
 186
 187       if (b == '$' || b == '#' || b == '}' || b == '*')
 188         {
 189           /* These must be escaped.  */
 190           if (output_index + 2 > out_maxlen)
 191             break;
 192           out_buf[output_index++] = '}';
 193           out_buf[output_index++] = b ^ 0x20;
 194         }
 195       else
 196         {
 197           if (output_index + 1 > out_maxlen)
 198             break;
 199           out_buf[output_index++] = b;
 200         }
 201     }
 202
 203   *out_len = input_index;
 204   return output_index;
 205 }
 206
 207 int
 208 remote_unescape_input (const gdb_byte *buffer, int len,
 209                        gdb_byte *out_buf, int out_maxlen)
 210 {
 211   int input_index, output_index;
 212   int escaped;
 213
 214   output_index = 0;
 215   escaped = 0;
 216   for (input_index = 0; input_index < len; input_index++)
 217     {
 218       gdb_byte b = buffer[input_index];
 219
 220       if (output_index + 1 > out_maxlen)
 221         error (_("Received too much data from the target."));
 222
 223       if (escaped)
 224         {
 225           out_buf[output_index++] = b ^ 0x20;
 226           escaped = 0;
 227         }
 228       else if (b == '}')
 229         escaped = 1;
 230       else
 231         out_buf[output_index++] = b;
 232     }
 233
 234   if (escaped)
 235     error (_("Unmatched escape character in target response."));
 236
 237   return output_index;
 238 }
 239