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 "rsp-low.h"
  27
  28 /* See rsp-low.h.  */
  29
  30 int
  31 fromhex (int a)
  32 {
  33   if (a >= '0' && a <= '9')
  34     return a - '0';
  35   else if (a >= 'a' && a <= 'f')
  36     return a - 'a' + 10;
  37   else if (a >= 'A' && a <= 'F')
  38     return a - 'A' + 10;
  39   else
  40     error (_("Reply contains invalid hex digit %d"), a);
  41 }
  42
  43 /* See rsp-low.h.  */
  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 /* See rsp-low.h.  */
  80
  81 char *
  82 pack_nibble (char *buf, int nibble)
  83 {
  84   *buf++ = hexchars[(nibble & 0x0f)];
  85   return buf;
  86 }
  87
  88 /* See rsp-low.h.  */
  89
  90 char *
  91 pack_hex_byte (char *pkt, int byte)
  92 {
  93   *pkt++ = hexchars[(byte >> 4) & 0xf];
  94   *pkt++ = hexchars[(byte & 0xf)];
  95   return pkt;
  96 }
  97
  98 /* See rsp-low.h.  */
  99
 100 char *
 101 unpack_varlen_hex (char *buff,  /* packet to parse */
 102                    ULONGEST *result)
 103 {
 104   int nibble;
 105   ULONGEST retval = 0;
 106
 107   while (ishex (*buff, &nibble))
 108     {
 109       buff++;
 110       retval = retval << 4;
 111       retval |= nibble & 0x0f;
 112     }
 113   *result = retval;
 114   return buff;
 115 }
 116
 117 /* See rsp-low.h.  */
 118
 119 int
 120 hex2bin (const char *hex, gdb_byte *bin, int count)
 121 {
 122   int i;
 123
 124   for (i = 0; i < count; i++)
 125     {
 126       if (hex[0] == 0 || hex[1] == 0)
 127         {
 128           /* Hex string is short, or of uneven length.
 129              Return the count that has been converted so far.  */
 130           return i;
 131         }
 132       *bin++ = fromhex (hex[0]) * 16 + fromhex (hex[1]);
 133       hex += 2;
 134     }
 135   return i;
 136 }
 137
 138 /* See rsp-low.h.  */
 139
 140 int
 141 bin2hex (const gdb_byte *bin, char *hex, int count)
 142 {
 143   int i;
 144
 145   for (i = 0; i < count; i++)
 146     {
 147       *hex++ = tohex ((*bin >> 4) & 0xf);
 148       *hex++ = tohex (*bin++ & 0xf);
 149     }
 150   *hex = 0;
 151   return i;
 152 }
 153
 154 /* See rsp-low.h.  */
 155
 156 int
 157 remote_escape_output (const gdb_byte *buffer, int len,
 158                       gdb_byte *out_buf, int *out_len,
 159                       int out_maxlen)
 160 {
 161   int input_index, output_index;
 162
 163   output_index = 0;
 164   for (input_index = 0; input_index < len; input_index++)
 165     {
 166       gdb_byte b = buffer[input_index];
 167
 168       if (b == '$' || b == '#' || b == '}' || b == '*')
 169         {
 170           /* These must be escaped.  */
 171           if (output_index + 2 > out_maxlen)
 172             break;
 173           out_buf[output_index++] = '}';
 174           out_buf[output_index++] = b ^ 0x20;
 175         }
 176       else
 177         {
 178           if (output_index + 1 > out_maxlen)
 179             break;
 180           out_buf[output_index++] = b;
 181         }
 182     }
 183
 184   *out_len = input_index;
 185   return output_index;
 186 }
 187
 188 /* See rsp-low.h.  */
 189
 190 int
 191 remote_unescape_input (const gdb_byte *buffer, int len,
 192                        gdb_byte *out_buf, int out_maxlen)
 193 {
 194   int input_index, output_index;
 195   int escaped;
 196
 197   output_index = 0;
 198   escaped = 0;
 199   for (input_index = 0; input_index < len; input_index++)
 200     {
 201       gdb_byte b = buffer[input_index];
 202
 203       if (output_index + 1 > out_maxlen)
 204         error (_("Received too much data from the target."));
 205
 206       if (escaped)
 207         {
 208           out_buf[output_index++] = b ^ 0x20;
 209           escaped = 0;
 210         }
 211       else if (b == '}')
 212         escaped = 1;
 213       else
 214         out_buf[output_index++] = b;
 215     }
 216
 217   if (escaped)
 218     error (_("Unmatched escape character in target response."));
 219
 220   return output_index;
 221 }
 222