src/helper/command.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Dominic Rath                                    *
   3  *   Dominic.Rath@gmx.de                                                   *
   4  *                                                                         *
   5  *   part of this file is taken from libcli (libcli.sourceforge.net)       *
   6  *   Copyright (C) David Parrish (david@dparrish.com)                      *
   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 2 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, write to the                         *
  20  *   Free Software Foundation, Inc.,                                       *
  21  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  22  ***************************************************************************/
  23 #ifdef HAVE_CONFIG_H
  24 #include "config.h"
  25 #endif
  26
  27 #include "replacements.h"
  28
  29 #include "command.h"
  30
  31 #include "log.h"
  32
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <ctype.h>
  36 #include <stdarg.h>
  37 #include <stdio.h>
  38 #include <unistd.h>
  39
  40 int handle_sleep_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  41
  42 int build_unique_lengths(command_context_t *context, command_t *commands)
  43 {
  44         command_t *c, *p;
  45
  46         /* iterate through all commands */
  47         for (c = commands; c; c = c->next)
  48         {
  49                 /* find out how many characters are required to uniquely identify a command */
  50                 for (c->unique_len = 1; c->unique_len <= strlen(c->name); c->unique_len++)
  51                 {
  52                         int foundmatch = 0;
  53
  54                         /* for every command, see if the current length is enough */
  55                         for (p = commands; p; p = p->next)
  56                         {
  57                                 /* ignore the command itself */
  58                                 if (c == p)
  59                                         continue;
  60
  61                                 /* compare commands up to the current length */
  62                                 if (strncmp(p->name, c->name, c->unique_len) == 0)
  63                                         foundmatch++;
  64                         }
  65
  66                         /* when none of the commands matched, we've found the minimum length required */
  67                         if (!foundmatch)
  68                                 break;
  69                 }
  70
  71                 /* if the current command has children, build the unique lengths for them */
  72                 if (c->children)
  73                         build_unique_lengths(context, c->children);
  74         }
  75
  76         return ERROR_OK;
  77 }
  78
  79 /* Avoid evaluating this each time we add a command. Reduces overhead from O(n^2) to O(n).
  80  * Makes a difference on ARM7 types machines and is not observable on GHz machines.
  81  */
  82 static int unique_length_dirty = 1;
  83
  84 command_t* register_command(command_context_t *context, command_t *parent, char *name, int (*handler)(struct command_context_s *context, char* name, char** args, int argc), enum command_mode mode, char *help)
  85 {
  86         command_t *c, *p;
  87         unique_length_dirty = 1;
  88
  89         if (!context || !name)
  90                 return NULL;
  91
  92         c = malloc(sizeof(command_t));
  93
  94         c->name = strdup(name);
  95         c->parent = parent;
  96         c->children = NULL;
  97         c->handler = handler;
  98         c->mode = mode;
  99         if (help)
 100                 c->help = strdup(help);
 101         else
 102                 c->help = NULL;
 103         c->unique_len = 0;
 104         c->next = NULL;
 105
 106         /* place command in tree */
 107         if (parent)
 108         {
 109                 if (parent->children)
 110                 {
 111                         /* find last child */
 112                         for (p = parent->children; p && p->next; p = p->next);
 113                         if (p)
 114                                 p->next = c;
 115                 }
 116                 else
 117                 {
 118                         parent->children = c;
 119                 }
 120         }
 121         else
 122         {
 123                 if (context->commands)
 124                 {
 125                         /* find last command */
 126                         for (p = context->commands; p && p->next; p = p->next);
 127                         if (p)
 128                                 p->next = c;
 129                 }
 130                 else
 131                 {
 132                         context->commands = c;
 133                 }
 134         }
 135
 136         return c;
 137 }
 138
 139 int unregister_command(command_context_t *context, char *name)
 140 {
 141         unique_length_dirty = 1;
 142
 143         command_t *c, *p = NULL, *c2;
 144
 145         if ((!context) || (!name))
 146                 return ERROR_INVALID_ARGUMENTS;
 147
 148         /* find command */
 149         for (c = context->commands; c; c = c->next)
 150         {
 151                 if (strcmp(name, c->name) == 0)
 152                 {
 153                         /* unlink command */
 154                         if (p)
 155                         {
 156                                 p->next = c->next;
 157                         }
 158                         else
 159                         {
 160                                 context->commands = c->next;
 161                         }
 162
 163                         /* unregister children */
 164                         if (c->children)
 165                         {
 166                                 for (c2 = c->children; c2; c2 = c2->next)
 167                                 {
 168                                         free(c2->name);
 169                                         if (c2->help)
 170                                                 free(c2->help);
 171                                         free(c2);
 172                                 }
 173                         }
 174
 175                         /* delete command */
 176                         free(c->name);
 177                         if (c->help)
 178                                 free(c->help);
 179                         free(c);
 180                 }
 181
 182                 /* remember the last command for unlinking */
 183                 p = c;
 184         }
 185
 186         return ERROR_OK;
 187 }
 188
 189 int parse_line(char *line, char *words[], int max_words)
 190 {
 191         int nwords = 0;
 192         char *p = line;
 193         char *word_start = line;
 194         int inquote = 0;
 195
 196         while (nwords < max_words - 1)
 197         {
 198                 /* check if we reached
 199                  * a terminating NUL
 200                  * a matching closing quote character " or '
 201                  * we're inside a word but not a quote, and the current character is whitespace
 202                  */
 203                 if (!*p || *p == inquote || (word_start && !inquote && isspace(*p)))
 204                 {
 205                         /* we're inside a word or quote, and reached its end*/
 206                         if (word_start)
 207                         {
 208                                 int len;
 209                                 char *word_end=p;
 210
 211                                 /* This will handle extra whitespace within quotes */
 212                                 while (isspace(*word_start)&&(word_start<word_end))
 213                                         word_start++;
 214                                 while (isspace(*(word_end-1))&&(word_start<word_end))
 215                                         word_end--;
 216                                 len = word_end - word_start;
 217
 218                                 if (len>0)
 219                                 {
 220                                         /* copy the word */
 221                                         memcpy(words[nwords] = malloc(len + 1), word_start, len);
 222                                         /* add terminating NUL */
 223                                         words[nwords++][len] = 0;
 224                                 }
 225                         }
 226                         /* we're done parsing the line */
 227                         if (!*p)
 228                                 break;
 229
 230                         /* skip over trailing quote or whitespace*/
 231                         if (inquote || isspace(*p))
 232                                 p++;
 233                         while (isspace(*p))
 234                                 p++;
 235
 236                         inquote = 0;
 237                         word_start = 0;
 238                 }
 239                 else if (*p == '"' || *p == '\'')
 240                 {
 241                         /* we've reached the beginning of a quote */
 242                         inquote = *p++;
 243                         word_start = p;
 244                 }
 245                 else
 246                 {
 247                         /* we've reached the beginning of a new word */
 248                         if (!word_start)
 249                                 word_start = p;
 250
 251                         /* normal character, skip */
 252                         p++;
 253                 }
 254         }
 255
 256         return nwords;
 257 }
 258
 259 void command_print(command_context_t *context, char *format, ...)
 260 {
 261         char *buffer = NULL;
 262         int n, size = 0;
 263         char *p;
 264
 265         /* process format string */
 266         for (;;)
 267         {
 268                 va_list ap;
 269                 va_start(ap, format);
 270                 if (!buffer || (n = vsnprintf(buffer, size, format, ap)) >= size)
 271                 {
 272                         /* increase buffer until it fits the whole string */
 273                         if (!(p = realloc(buffer, size += 4096)))
 274                         {
 275                                 /* gotta free up */
 276                                 if (buffer)
 277                                         free(buffer);
 278                                 return;
 279                         }
 280
 281                         buffer = p;
 282
 283                         va_end(ap);
 284                         continue;
 285                 }
 286                 va_end(ap);
 287                 break;
 288         }
 289
 290         /* vsnprintf failed */
 291         if (n < 0)
 292         {
 293                 if (buffer)
 294                         free(buffer);
 295                 return;
 296         }
 297
 298         p = buffer;
 299
 300         /* process lines in buffer */
 301         do {
 302                 char *next = strchr(p, '\n');
 303
 304                 if (next)
 305                         *next++ = 0;
 306
 307                 if (context->output_handler)
 308                         context->output_handler(context, p);
 309
 310                 p = next;
 311         } while (p);
 312
 313         if (buffer)
 314                 free(buffer);
 315 }
 316
 317 int find_and_run_command(command_context_t *context, command_t *commands, char *words[], int num_words, int start_word)
 318 {
 319         command_t *c;
 320
 321         if (unique_length_dirty)
 322         {
 323                 unique_length_dirty = 0;
 324                 /* update unique lengths */
 325                 build_unique_lengths(context, context->commands);
 326         }
 327
 328         for (c = commands; c; c = c->next)
 329         {
 330                 if (strncasecmp(c->name, words[start_word], c->unique_len))
 331                         continue;
 332
 333                 if (strncasecmp(c->name, words[start_word], strlen(words[start_word])))
 334                         continue;
 335
 336                 if ((context->mode == COMMAND_CONFIG) || (c->mode == COMMAND_ANY) || (c->mode == context->mode) )
 337                 {
 338                         if (!c->children)
 339                         {
 340                                 if (!c->handler)
 341                                 {
 342                                         command_print(context, "No handler for command");
 343                                         break;
 344                                 }
 345                                 else
 346                                 {
 347                                         return c->handler(context, c->name, words + start_word + 1, num_words - start_word - 1);
 348                                 }
 349                         }
 350                         else
 351                         {
 352                                 if (start_word == num_words - 1)
 353                                 {
 354                                         command_print(context, "Incomplete command");
 355                                         break;
 356                                 }
 357                                 return find_and_run_command(context, c->children, words, num_words, start_word + 1);
 358                         }
 359                 }
 360         }
 361
 362         command_print(context, "Command %s not found", words[start_word]);
 363         return ERROR_OK;
 364 }
 365
 366 static int command_run_line_inner(command_context_t *context, char *line)
 367 {
 368         int nwords;
 369         char *words[128] = {0};
 370         int retval;
 371         int i;
 372
 373         if ((!context) || (!line))
 374                 return ERROR_INVALID_ARGUMENTS;
 375
 376         /* skip preceding whitespace */
 377         while (isspace(*line))
 378                 line++;
 379
 380         /* empty line, ignore */
 381         if (!*line)
 382                 return ERROR_OK;
 383
 384         /* ignore comments */
 385         if (*line && (line[0] == '#'))
 386                 return ERROR_OK;
 387
 388         if (context->echo)
 389         {
 390                 command_print(context, "%s", line);
 391         }
 392
 393         nwords = parse_line(line, words, sizeof(words) / sizeof(words[0]));
 394
 395         if (nwords > 0)
 396                 retval = find_and_run_command(context, context->commands, words, nwords, 0);
 397         else
 398                 return ERROR_INVALID_ARGUMENTS;
 399
 400         for (i = 0; i < nwords; i++)
 401                 free(words[i]);
 402
 403         return retval;
 404 }
 405
 406 int command_run_line(command_context_t *context, char *line)
 407 {
 408         int retval=command_run_line_inner(context, line);
 409         // we don't want any dangling callbacks!
 410         //
 411         // Capturing output from logging is *very* loosly modeled on C/C++ exceptions.
 412         // the capture must be set up at function entry and
 413         // stops when the function call returns
 414         log_setCallback(NULL, NULL);
 415         return retval;
 416 }
 417 int command_run_file(command_context_t *context, FILE *file, enum command_mode mode)
 418 {
 419         int retval = ERROR_OK;
 420         int old_command_mode;
 421         char *buffer=malloc(4096);
 422         if (buffer==NULL)
 423         {
 424                 return ERROR_INVALID_ARGUMENTS;
 425         }
 426
 427         old_command_mode = context->mode;
 428         context->mode = mode;
 429
 430         while (fgets(buffer, 4096, file))
 431         {
 432                 char *p;
 433                 char *cmd, *end;
 434
 435                 /* stop processing line after a comment (#, !) or a LF, CR were encountered */
 436                 if ((p = strpbrk(buffer, "#!\r\n")))
 437                         *p = 0;
 438
 439                 /* skip over leading whitespace */
 440                 cmd = buffer;
 441                 while (isspace(*cmd))
 442                         cmd++;
 443
 444                 /* empty (all whitespace) line? */
 445                 if (!*cmd)
 446                         continue;
 447
 448                 /* search the end of the current line, ignore trailing whitespace */
 449                 for (p = end = cmd; *p; p++)
 450                         if (!isspace(*p))
 451                                 end = p;
 452
 453                 /* terminate end */
 454                 *++end = 0;
 455                 if (strcasecmp(cmd, "quit") == 0)
 456                         break;
 457
 458                 /* run line */
 459                 if ((retval = command_run_line_inner(context, cmd)) == ERROR_COMMAND_CLOSE_CONNECTION)
 460                         break;
 461         }
 462
 463         context->mode = old_command_mode;
 464
 465
 466         free(buffer);
 467
 468         return retval;
 469 }
 470
 471 void command_print_help_line(command_context_t* context, struct command_s *command, int indent)
 472 {
 473         command_t *c;
 474         char indents[32] = {0};
 475         char *help = "no help available";
 476         char name_buf[64];
 477         int i;
 478
 479         for (i = 0; i < indent; i+=2)
 480         {
 481                 indents[i*2] = ' ';
 482                 indents[i*2+1] = '-';
 483         }
 484         indents[i*2] = 0;
 485
 486         if (command->help)
 487                 help = command->help;
 488
 489         snprintf(name_buf, 64, command->name);
 490         strncat(name_buf, indents, 64);
 491         command_print(context, "%20s\t%s", name_buf, help);
 492
 493         if (command->children)
 494         {
 495                 for (c = command->children; c; c = c->next)
 496                 {
 497                         command_print_help_line(context, c, indent + 1);
 498                 }
 499         }
 500 }
 501
 502 int command_print_help(command_context_t* context, char* name, char** args, int argc)
 503 {
 504         command_t *c;
 505
 506         for (c = context->commands; c; c = c->next)
 507         {
 508                 if (argc == 1)
 509                 {
 510                          if (strncasecmp(c->name, args[0], c->unique_len))
 511                                  continue;
 512
 513                          if (strncasecmp(c->name, args[0], strlen(args[0])))
 514                                  continue;
 515                 }
 516
 517                 command_print_help_line(context, c, 0);
 518         }
 519
 520         return ERROR_OK;
 521 }
 522
 523 void command_set_output_handler(command_context_t* context, int (*output_handler)(struct command_context_s *context, char* line), void *priv)
 524 {
 525         context->output_handler = output_handler;
 526         context->output_handler_priv = priv;
 527 }
 528
 529 command_context_t* copy_command_context(command_context_t* context)
 530 {
 531         command_context_t* copy_context = malloc(sizeof(command_context_t));
 532
 533         *copy_context = *context;
 534
 535         return copy_context;
 536 }
 537
 538 int command_done(command_context_t *context)
 539 {
 540         free(context);
 541         context = NULL;
 542
 543         return ERROR_OK;
 544 }
 545
 546 command_context_t* command_init()
 547 {
 548         command_context_t* context = malloc(sizeof(command_context_t));
 549
 550         context->mode = COMMAND_EXEC;
 551         context->commands = NULL;
 552         context->current_target = 0;
 553         context->echo = 0;
 554         context->output_handler = NULL;
 555         context->output_handler_priv = NULL;
 556
 557         register_command(context, NULL, "help", command_print_help,
 558                                          COMMAND_EXEC, "display this help");
 559
 560         register_command(context, NULL, "sleep", handle_sleep_command,
 561                                          COMMAND_ANY, "sleep for <n> milliseconds");
 562
 563         return context;
 564 }
 565
 566 /* sleep command sleeps for <n> miliseconds
 567  * this is useful in target startup scripts
 568  */
 569 int handle_sleep_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 570 {
 571         unsigned long duration = 0;
 572
 573         if (argc == 1)
 574         {
 575                 duration = strtoul(args[0], NULL, 0);
 576                 usleep(duration * 1000);
 577         }
 578
 579         return ERROR_OK;
 580 }