gdb/gdbserver/hostio.c

   1 /* Host file transfer support for gdbserver.
   2    Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   3
   4    Contributed by CodeSourcery.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "server.h"
  22 #include "gdb/fileio.h"
  23
  24 #include <fcntl.h>
  25 #include <limits.h>
  26 #include <unistd.h>
  27
  28 extern int remote_debug;
  29
  30 struct fd_list
  31 {
  32   int fd;
  33   struct fd_list *next;
  34 };
  35
  36 static struct fd_list *open_fds;
  37
  38 static int
  39 safe_fromhex (char a, int *nibble)
  40 {
  41   if (a >= '0' && a <= '9')
  42     *nibble = a - '0';
  43   else if (a >= 'a' && a <= 'f')
  44     *nibble = a - 'a' + 10;
  45   else if (a >= 'A' && a <= 'F')
  46     *nibble = a - 'A' + 10;
  47   else
  48     return -1;
  49
  50   return 0;
  51 }
  52
  53 static int
  54 require_filename (char **pp, char *filename)
  55 {
  56   int count;
  57   char *p;
  58
  59   p = *pp;
  60   count = 0;
  61
  62   while (*p && *p != ',')
  63     {
  64       int nib1, nib2;
  65
  66       /* Don't allow overflow.  */
  67       if (count >= PATH_MAX - 1)
  68         return -1;
  69
  70       if (safe_fromhex (p[0], &nib1)
  71           || safe_fromhex (p[1], &nib2))
  72         return -1;
  73
  74       filename[count++] = nib1 * 16 + nib2;
  75       p += 2;
  76     }
  77
  78   filename[count] = '\0';
  79   *pp = p;
  80   return 0;
  81 }
  82
  83 static int
  84 require_int (char **pp, int *value)
  85 {
  86   char *p;
  87   int count;
  88
  89   p = *pp;
  90   *value = 0;
  91   count = 0;
  92
  93   while (*p && *p != ',')
  94     {
  95       int nib;
  96
  97       /* Don't allow overflow.  */
  98       if (count >= 7)
  99         return -1;
 100
 101       if (safe_fromhex (p[0], &nib))
 102         return -1;
 103       *value = *value * 16 + nib;
 104       p++;
 105       count++;
 106     }
 107
 108   *pp = p;
 109   return 0;
 110 }
 111
 112 static int
 113 require_data (char *p, int p_len, char **data, int *data_len)
 114 {
 115   int input_index, output_index, escaped;
 116
 117   *data = xmalloc (p_len);
 118
 119   output_index = 0;
 120   escaped = 0;
 121   for (input_index = 0; input_index < p_len; input_index++)
 122     {
 123       char b = p[input_index];
 124
 125       if (escaped)
 126         {
 127           (*data)[output_index++] = b ^ 0x20;
 128           escaped = 0;
 129         }
 130       else if (b == '}')
 131         escaped = 1;
 132       else
 133         (*data)[output_index++] = b;
 134     }
 135
 136   if (escaped)
 137     return -1;
 138
 139   *data_len = output_index;
 140   return 0;
 141 }
 142
 143 static int
 144 require_comma (char **pp)
 145 {
 146   if (**pp == ',')
 147     {
 148       (*pp)++;
 149       return 0;
 150     }
 151   else
 152     return -1;
 153 }
 154
 155 static int
 156 require_end (char *p)
 157 {
 158   if (*p == '\0')
 159     return 0;
 160   else
 161     return -1;
 162 }
 163
 164 static int
 165 require_valid_fd (int fd)
 166 {
 167   struct fd_list *fd_ptr;
 168
 169   for (fd_ptr = open_fds; fd_ptr != NULL; fd_ptr = fd_ptr->next)
 170     if (fd_ptr->fd == fd)
 171       return 0;
 172
 173   return -1;
 174 }
 175
 176 /* Fill in own_buf with the last hostio error packet, however it
 177    suitable for the target.  */
 178 static void
 179 hostio_error (char *own_buf)
 180 {
 181   the_target->hostio_last_error (own_buf);
 182 }
 183
 184 static void
 185 hostio_packet_error (char *own_buf)
 186 {
 187   sprintf (own_buf, "F-1,%x", FILEIO_EINVAL);
 188 }
 189
 190 static void
 191 hostio_reply (char *own_buf, int result)
 192 {
 193   sprintf (own_buf, "F%x", result);
 194 }
 195
 196 static int
 197 hostio_reply_with_data (char *own_buf, char *buffer, int len,
 198                         int *new_packet_len)
 199 {
 200   int input_index, output_index, out_maxlen;
 201
 202   sprintf (own_buf, "F%x;", len);
 203   output_index = strlen (own_buf);
 204
 205   out_maxlen = PBUFSIZ;
 206
 207   for (input_index = 0; input_index < len; input_index++)
 208     {
 209       char b = buffer[input_index];
 210
 211       if (b == '$' || b == '#' || b == '}' || b == '*')
 212         {
 213           /* These must be escaped.  */
 214           if (output_index + 2 > out_maxlen)
 215             break;
 216           own_buf[output_index++] = '}';
 217           own_buf[output_index++] = b ^ 0x20;
 218         }
 219       else
 220         {
 221           if (output_index + 1 > out_maxlen)
 222             break;
 223           own_buf[output_index++] = b;
 224         }
 225     }
 226
 227   *new_packet_len = output_index;
 228   return input_index;
 229 }
 230
 231 static int
 232 fileio_open_flags_to_host (int fileio_open_flags, int *open_flags_p)
 233 {
 234   int open_flags = 0;
 235
 236   if (fileio_open_flags & ~FILEIO_O_SUPPORTED)
 237     return -1;
 238
 239   if (fileio_open_flags & FILEIO_O_CREAT)
 240     open_flags |= O_CREAT;
 241   if (fileio_open_flags & FILEIO_O_EXCL)
 242     open_flags |= O_EXCL;
 243   if (fileio_open_flags & FILEIO_O_TRUNC)
 244     open_flags |= O_TRUNC;
 245   if (fileio_open_flags & FILEIO_O_APPEND)
 246     open_flags |= O_APPEND;
 247   if (fileio_open_flags & FILEIO_O_RDONLY)
 248     open_flags |= O_RDONLY;
 249   if (fileio_open_flags & FILEIO_O_WRONLY)
 250     open_flags |= O_WRONLY;
 251   if (fileio_open_flags & FILEIO_O_RDWR)
 252     open_flags |= O_RDWR;
 253 /* On systems supporting binary and text mode, always open files in
 254    binary mode. */
 255 #ifdef O_BINARY
 256   open_flags |= O_BINARY;
 257 #endif
 258
 259   *open_flags_p = open_flags;
 260   return 0;
 261 }
 262
 263 static void
 264 handle_open (char *own_buf)
 265 {
 266   char filename[PATH_MAX];
 267   char *p;
 268   int fileio_flags, mode, flags, fd;
 269   struct fd_list *new_fd;
 270
 271   p = own_buf + strlen ("vFile:open:");
 272
 273   if (require_filename (&p, filename)
 274       || require_comma (&p)
 275       || require_int (&p, &fileio_flags)
 276       || require_comma (&p)
 277       || require_int (&p, &mode)
 278       || require_end (p)
 279       || fileio_open_flags_to_host (fileio_flags, &flags))
 280     {
 281       hostio_packet_error (own_buf);
 282       return;
 283     }
 284
 285   /* We do not need to convert MODE, since the fileio protocol
 286      uses the standard values.  */
 287   fd = open (filename, flags, mode);
 288
 289   if (fd == -1)
 290     {
 291       hostio_error (own_buf);
 292       return;
 293     }
 294
 295   /* Record the new file descriptor.  */
 296   new_fd = xmalloc (sizeof (struct fd_list));
 297   new_fd->fd = fd;
 298   new_fd->next = open_fds;
 299   open_fds = new_fd;
 300
 301   hostio_reply (own_buf, fd);
 302 }
 303
 304 static void
 305 handle_pread (char *own_buf, int *new_packet_len)
 306 {
 307   int fd, ret, len, offset, bytes_sent;
 308   char *p, *data;
 309
 310   p = own_buf + strlen ("vFile:pread:");
 311
 312   if (require_int (&p, &fd)
 313       || require_comma (&p)
 314       || require_valid_fd (fd)
 315       || require_int (&p, &len)
 316       || require_comma (&p)
 317       || require_int (&p, &offset)
 318       || require_end (p))
 319     {
 320       hostio_packet_error (own_buf);
 321       return;
 322     }
 323
 324   data = xmalloc (len);
 325 #ifdef HAVE_PREAD
 326   ret = pread (fd, data, len, offset);
 327 #else
 328   ret = lseek (fd, offset, SEEK_SET);
 329   if (ret != -1)
 330     ret = read (fd, data, len);
 331 #endif
 332
 333   if (ret == -1)
 334     {
 335       hostio_error (own_buf);
 336       free (data);
 337       return;
 338     }
 339
 340   bytes_sent = hostio_reply_with_data (own_buf, data, ret, new_packet_len);
 341
 342   /* If we were using read, and the data did not all fit in the reply,
 343      we would have to back up using lseek here.  With pread it does
 344      not matter.  But we still have a problem; the return value in the
 345      packet might be wrong, so we must fix it.  This time it will
 346      definitely fit.  */
 347   if (bytes_sent < ret)
 348     bytes_sent = hostio_reply_with_data (own_buf, data, bytes_sent,
 349                                          new_packet_len);
 350
 351   free (data);
 352 }
 353
 354 static void
 355 handle_pwrite (char *own_buf, int packet_len)
 356 {
 357   int fd, ret, len, offset;
 358   char *p, *data;
 359
 360   p = own_buf + strlen ("vFile:pwrite:");
 361
 362   if (require_int (&p, &fd)
 363       || require_comma (&p)
 364       || require_valid_fd (fd)
 365       || require_int (&p, &offset)
 366       || require_comma (&p)
 367       || require_data (p, packet_len - (p - own_buf), &data, &len))
 368     {
 369       hostio_packet_error (own_buf);
 370       return;
 371     }
 372
 373 #ifdef HAVE_PWRITE
 374   ret = pwrite (fd, data, len, offset);
 375 #else
 376   ret = lseek (fd, offset, SEEK_SET);
 377   if (ret != -1)
 378     ret = write (fd, data, len);
 379 #endif
 380
 381   if (ret == -1)
 382     {
 383       hostio_error (own_buf);
 384       free (data);
 385       return;
 386     }
 387
 388   hostio_reply (own_buf, ret);
 389   free (data);
 390 }
 391
 392 static void
 393 handle_close (char *own_buf)
 394 {
 395   int fd, ret;
 396   char *p;
 397   struct fd_list **open_fd_p, *old_fd;
 398
 399   p = own_buf + strlen ("vFile:close:");
 400
 401   if (require_int (&p, &fd)
 402       || require_valid_fd (fd)
 403       || require_end (p))
 404     {
 405       hostio_packet_error (own_buf);
 406       return;
 407     }
 408
 409   ret = close (fd);
 410
 411   if (ret == -1)
 412     {
 413       hostio_error (own_buf);
 414       return;
 415     }
 416
 417   open_fd_p = &open_fds;
 418   while (*open_fd_p && (*open_fd_p)->fd != fd)
 419     open_fd_p = &(*open_fd_p)->next;
 420
 421   old_fd = *open_fd_p;
 422   *open_fd_p = (*open_fd_p)->next;
 423   free (old_fd);
 424
 425   hostio_reply (own_buf, ret);
 426 }
 427
 428 static void
 429 handle_unlink (char *own_buf)
 430 {
 431   char filename[PATH_MAX];
 432   char *p;
 433   int ret;
 434
 435   p = own_buf + strlen ("vFile:unlink:");
 436
 437   if (require_filename (&p, filename)
 438       || require_end (p))
 439     {
 440       hostio_packet_error (own_buf);
 441       return;
 442     }
 443
 444   ret = unlink (filename);
 445
 446   if (ret == -1)
 447     {
 448       hostio_error (own_buf);
 449       return;
 450     }
 451
 452   hostio_reply (own_buf, ret);
 453 }
 454
 455 /* Handle all the 'F' file transfer packets.  */
 456
 457 int
 458 handle_vFile (char *own_buf, int packet_len, int *new_packet_len)
 459 {
 460   if (strncmp (own_buf, "vFile:open:", 11) == 0)
 461     handle_open (own_buf);
 462   else if (strncmp (own_buf, "vFile:pread:", 11) == 0)
 463     handle_pread (own_buf, new_packet_len);
 464   else if (strncmp (own_buf, "vFile:pwrite:", 12) == 0)
 465     handle_pwrite (own_buf, packet_len);
 466   else if (strncmp (own_buf, "vFile:close:", 12) == 0)
 467     handle_close (own_buf);
 468   else if (strncmp (own_buf, "vFile:unlink:", 13) == 0)
 469     handle_unlink (own_buf);
 470   else
 471     return 0;
 472
 473   return 1;
 474 }