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 void command_print_help_line(command_context_t* context, struct command_s *command, int indent);
  41
  42 int handle_sleep_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  43
  44 int build_unique_lengths(command_context_t *context, command_t *commands)
  45 {
  46         command_t *c, *p;
  47
  48         /* iterate through all commands */
  49         for (c = commands; c; c = c->next)
  50         {
  51                 /* find out how many characters are required to uniquely identify a command */
  52                 for (c->unique_len = 1; c->unique_len <= strlen(c->name); c->unique_len++)
  53                 {
  54                         int foundmatch = 0;
  55
  56                         /* for every command, see if the current length is enough */
  57                         for (p = commands; p; p = p->next)
  58                         {
  59                                 /* ignore the command itself */
  60                                 if (c == p)
  61                                         continue;
  62
  63                                 /* compare commands up to the current length */
  64                                 if (strncmp(p->name, c->name, c->unique_len) == 0)
  65                                         foundmatch++;
  66                         }
  67
  68                         /* when none of the commands matched, we've found the minimum length required */
  69                         if (!foundmatch)
  70                                 break;
  71                 }
  72
  73                 /* if the current command has children, build the unique lengths for them */
  74                 if (c->children)
  75                         build_unique_lengths(context, c->children);
  76         }
  77
  78         return ERROR_OK;
  79 }
  80
  81 /* Avoid evaluating this each time we add a command. Reduces overhead from O(n^2) to O(n).
  82  * Makes a difference on ARM7 types machines and is not observable on GHz machines.
  83  */
  84 static int unique_length_dirty = 1;
  85
  86 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)
  87 {
  88         command_t *c, *p;
  89         unique_length_dirty = 1;
  90
  91         if (!context || !name)
  92                 return NULL;
  93
  94         c = malloc(sizeof(command_t));
  95
  96         c->name = strdup(name);
  97         c->parent = parent;
  98         c->children = NULL;
  99         c->handler = handler;
 100         c->mode = mode;
 101         if (help)
 102                 c->help = strdup(help);
 103         else
 104                 c->help = NULL;
 105         c->unique_len = 0;
 106         c->next = NULL;
 107
 108         /* place command in tree */
 109         if (parent)
 110         {
 111                 if (parent->children)
 112                 {
 113                         /* find last child */
 114                         for (p = parent->children; p && p->next; p = p->next);
 115                         if (p)
 116                                 p->next = c;
 117                 }
 118                 else
 119                 {
 120                         parent->children = c;
 121                 }
 122         }
 123         else
 124         {
 125                 if (context->commands)
 126                 {
 127                         /* find last command */
 128                         for (p = context->commands; p && p->next; p = p->next);
 129                         if (p)
 130                                 p->next = c;
 131                 }
 132                 else
 133                 {
 134                         context->commands = c;
 135                 }
 136         }
 137
 138         return c;
 139 }
 140
 141 int unregister_command(command_context_t *context, char *name)
 142 {
 143         unique_length_dirty = 1;
 144
 145         command_t *c, *p = NULL, *c2;
 146
 147         if ((!context) || (!name))
 148                 return ERROR_INVALID_ARGUMENTS;
 149
 150         /* find command */
 151         for (c = context->commands; c; c = c->next)
 152         {
 153                 if (strcmp(name, c->name) == 0)
 154                 {
 155                         /* unlink command */
 156                         if (p)
 157                         {
 158                                 p->next = c->next;
 159                         }
 160                         else
 161                         {
 162                                 context->commands = c->next;
 163                         }
 164
 165                         /* unregister children */
 166                         if (c->children)
 167                         {
 168                                 for (c2 = c->children; c2; c2 = c2->next)
 169                                 {
 170                                         free(c2->name);
 171                                         if (c2->help)
 172                                                 free(c2->help);
 173                                         free(c2);
 174                                 }
 175                         }
 176
 177                         /* delete command */
 178                         free(c->name);
 179                         if (c->help)
 180                                 free(c->help);
 181                         free(c);
 182                 }
 183
 184                 /* remember the last command for unlinking */
 185                 p = c;
 186         }
 187
 188         return ERROR_OK;
 189 }
 190
 191 int parse_line(char *line, char *words[], int max_words)
 192 {
 193         int nwords = 0;
 194         char *p = line;
 195         char *word_start = line;
 196         int inquote = 0;
 197
 198         while (nwords < max_words - 1)
 199         {
 200                 /* check if we reached
 201                  * a terminating NUL
 202                  * a matching closing quote character " or '
 203                  * we're inside a word but not a quote, and the current character is whitespace
 204                  */
 205                 if (!*p || *p == inquote || (word_start && !inquote && isspace(*p)))
 206                 {
 207                         /* we're inside a word or quote, and reached its end*/
 208                         if (word_start)
 209                         {
 210                                 int len;
 211                                 char *word_end=p;
 212
 213                                 /* This will handle extra whitespace within quotes */
 214                                 while (isspace(*word_start)&&(word_start<word_end))
 215                                         word_start++;
 216                                 while (isspace(*(word_end-1))&&(word_start<word_end))
 217                                         word_end--;
 218                                 len = word_end - word_start;
 219
 220                                 if (len>0)
 221                                 {
 222                                         /* copy the word */
 223                                         memcpy(words[nwords] = malloc(len + 1), word_start, len);
 224                                         /* add terminating NUL */
 225                                         words[nwords++][len] = 0;
 226                                 }
 227                         }
 228                         /* we're done parsing the line */
 229                         if (!*p)
 230                                 break;
 231
 232                         /* skip over trailing quote or whitespace*/
 233                         if (inquote || isspace(*p))
 234                                 p++;
 235                         while (isspace(*p))
 236                                 p++;
 237
 238                         inquote = 0;
 239                         word_start = 0;
 240                 }
 241                 else if (*p == '"' || *p == '\'')
 242                 {
 243                         /* we've reached the beginning of a quote */
 244                         inquote = *p++;
 245                         word_start = p;
 246                 }
 247                 else
 248                 {
 249                         /* we've reached the beginning of a new word */
 250                         if (!word_start)
 251                                 word_start = p;
 252
 253                         /* normal character, skip */
 254                         p++;
 255                 }
 256         }
 257
 258         return nwords;
 259 }
 260
 261 void command_print(command_context_t *context, char *format, ...)
 262 {
 263         char *buffer = NULL;
 264         int n, size = 0;
 265         char *p;
 266
 267         /* process format string */
 268         for (;;)
 269         {
 270                 va_list ap;
 271                 va_start(ap, format);
 272                 if (!buffer || (n = vsnprintf(buffer, size, format, ap)) >= size)
 273                 {
 274                         /* increase buffer until it fits the whole string */
 275                         if (!(p = realloc(buffer, size += 4096)))
 276                         {
 277                                 /* gotta free up */
 278                                 if (buffer)
 279                                         free(buffer);
 280                                 va_end(ap);
 281                                 return;
 282                         }
 283
 284                         buffer = p;
 285
 286                         va_end(ap);
 287                         continue;
 288                 }
 289                 va_end(ap);
 290                 break;
 291         }
 292
 293         /* vsnprintf failed */
 294         if (n < 0)
 295         {
 296                 if (buffer)
 297                         free(buffer);
 298                 return;
 299         }
 300
 301         p = buffer;
 302
 303         /* process lines in buffer */
 304         do {
 305                 char *next = strchr(p, '\n');
 306
 307                 if (next)
 308                         *next++ = 0;
 309
 310                 if (context->output_handler)
 311                         context->output_handler(context, p);
 312
 313                 p = next;
 314         } while (p);
 315
 316         if (buffer)
 317                 free(buffer);
 318 }
 319
 320 int find_and_run_command(command_context_t *context, command_t *commands, char *words[], int num_words, int start_word)
 321 {
 322         command_t *c;
 323
 324         if (unique_length_dirty)
 325         {
 326                 unique_length_dirty = 0;
 327                 /* update unique lengths */
 328                 build_unique_lengths(context, context->commands);
 329         }
 330
 331         for (c = commands; c; c = c->next)
 332         {
 333                 if (strncasecmp(c->name, words[start_word], c->unique_len))
 334                         continue;
 335
 336                 if (strncasecmp(c->name, words[start_word], strlen(words[start_word])))
 337                         continue;
 338
 339                 if ((context->mode == COMMAND_CONFIG) || (c->mode == COMMAND_ANY) || (c->mode == context->mode) )
 340                 {
 341                         if (!c->children)
 342                         {
 343                                 if (!c->handler)
 344                                 {
 345                                         command_print(context, "No handler for command");
 346                                         break;
 347                                 }
 348                                 else
 349                                 {
 350                                         int retval = c->handler(context, c->name, words + start_word + 1, num_words - start_word - 1);
 351                                         if (retval == ERROR_COMMAND_SYNTAX_ERROR)
 352                                         {
 353                                                 command_print(context, "Syntax error:");
 354                                                 command_print_help_line(context, c, 0);
 355                                         }
 356                                         return retval;
 357                                 }
 358                         }
 359                         else
 360                         {
 361                                 if (start_word == num_words - 1)
 362                                 {
 363                                         command_print(context, "Incomplete command");
 364                                         break;
 365                                 }
 366                                 return find_and_run_command(context, c->children, words, num_words, start_word + 1);
 367                         }
 368                 }
 369         }
 370
 371         command_print(context, "Command %s not found", words[start_word]);
 372         return ERROR_OK;
 373 }
 374
 375 static int command_run_line_inner(command_context_t *context, char *line)
 376 {
 377         int nwords;
 378         char *words[128] = {0};
 379         int retval;
 380         int i;
 381
 382         if ((!context) || (!line))
 383                 return ERROR_INVALID_ARGUMENTS;
 384
 385         /* skip preceding whitespace */
 386         while (isspace(*line))
 387                 line++;
 388
 389         /* empty line, ignore */
 390         if (!*line)
 391                 return ERROR_OK;
 392
 393         /* ignore comments */
 394         if (*line && (line[0] == '#'))
 395                 return ERROR_OK;
 396
 397         if (context->echo)
 398         {
 399                 command_print(context, "%s", line);
 400         }
 401
 402         nwords = parse_line(line, words, sizeof(words) / sizeof(words[0]));
 403
 404         if (nwords > 0)
 405                 retval = find_and_run_command(context, context->commands, words, nwords, 0);
 406         else
 407                 return ERROR_INVALID_ARGUMENTS;
 408
 409         for (i = 0; i < nwords; i++)
 410                 free(words[i]);
 411
 412         return retval;
 413 }
 414
 415 int command_run_line(command_context_t *context, char *line)
 416 {
 417         int retval=command_run_line_inner(context, line);
 418         // we don't want any dangling callbacks!
 419         //
 420         // Capturing output from logging is *very* loosly modeled on C/C++ exceptions.
 421         // the capture must be set up at function entry and
 422         // stops when the function call returns
 423         log_setCallback(NULL, NULL);
 424         return retval;
 425 }
 426 int command_run_file(command_context_t *context, FILE *file, enum command_mode mode)
 427 {
 428         int retval = ERROR_OK;
 429         int old_command_mode;
 430         char *buffer=malloc(4096);
 431         if (buffer==NULL)
 432         {
 433                 return ERROR_INVALID_ARGUMENTS;
 434         }
 435
 436         old_command_mode = context->mode;
 437         context->mode = mode;
 438
 439         while (fgets(buffer, 4096, file))
 440         {
 441                 char *p;
 442                 char *cmd, *end;
 443
 444                 /* stop processing line after a comment (#, !) or a LF, CR were encountered */
 445                 if ((p = strpbrk(buffer, "#!\r\n")))
 446                         *p = 0;
 447
 448                 /* skip over leading whitespace */
 449                 cmd = buffer;
 450                 while (isspace(*cmd))
 451                         cmd++;
 452
 453                 /* empty (all whitespace) line? */
 454                 if (!*cmd)
 455                         continue;
 456
 457                 /* search the end of the current line, ignore trailing whitespace */
 458                 for (p = end = cmd; *p; p++)
 459                         if (!isspace(*p))
 460                                 end = p;
 461
 462                 /* terminate end */
 463                 *++end = 0;
 464                 if (strcasecmp(cmd, "quit") == 0)
 465                         break;
 466
 467                 /* run line */
 468                 if ((retval = command_run_line_inner(context, cmd)) == ERROR_COMMAND_CLOSE_CONNECTION)
 469                         break;
 470         }
 471
 472         context->mode = old_command_mode;
 473
 474
 475         free(buffer);
 476
 477         return retval;
 478 }
 479
 480 void command_print_help_line(command_context_t* context, struct command_s *command, int indent)
 481 {
 482         command_t *c;
 483         char indents[32] = {0};
 484         char *help = "no help available";
 485         char name_buf[64];
 486         int i;
 487
 488         for (i = 0; i < indent; i+=2)
 489         {
 490                 indents[i*2] = ' ';
 491                 indents[i*2+1] = '-';
 492         }
 493         indents[i*2] = 0;
 494
 495         if (command->help)
 496                 help = command->help;
 497
 498         snprintf(name_buf, 64, command->name);
 499         strncat(name_buf, indents, 64);
 500         command_print(context, "%20s\t%s", name_buf, help);
 501
 502         if (command->children)
 503         {
 504                 for (c = command->children; c; c = c->next)
 505                 {
 506                         command_print_help_line(context, c, indent + 1);
 507                 }
 508         }
 509 }
 510
 511 int command_print_help(command_context_t* context, char* name, char** args, int argc)
 512 {
 513         command_t *c;
 514
 515         for (c = context->commands; c; c = c->next)
 516         {
 517                 if (argc == 1)
 518                 {
 519                          if (strncasecmp(c->name, args[0], c->unique_len))
 520                                  continue;
 521
 522                          if (strncasecmp(c->name, args[0], strlen(args[0])))
 523                                  continue;
 524                 }
 525
 526                 command_print_help_line(context, c, 0);
 527         }
 528
 529         return ERROR_OK;
 530 }
 531
 532 void command_set_output_handler(command_context_t* context, int (*output_handler)(struct command_context_s *context, char* line), void *priv)
 533 {
 534         context->output_handler = output_handler;
 535         context->output_handler_priv = priv;
 536 }
 537
 538 command_context_t* copy_command_context(command_context_t* context)
 539 {
 540         command_context_t* copy_context = malloc(sizeof(command_context_t));
 541
 542         *copy_context = *context;
 543
 544         return copy_context;
 545 }
 546
 547 int command_done(command_context_t *context)
 548 {
 549         free(context);
 550         context = NULL;
 551
 552         return ERROR_OK;
 553 }
 554
 555 command_context_t* command_init()
 556 {
 557         command_context_t* context = malloc(sizeof(command_context_t));
 558
 559         context->mode = COMMAND_EXEC;
 560         context->commands = NULL;
 561         context->current_target = 0;
 562         context->echo = 0;
 563         context->output_handler = NULL;
 564         context->output_handler_priv = NULL;
 565
 566         register_command(context, NULL, "help", command_print_help,
 567                                          COMMAND_EXEC, "display this help");
 568
 569         register_command(context, NULL, "sleep", handle_sleep_command,
 570                                          COMMAND_ANY, "sleep for <n> milliseconds");
 571
 572         return context;
 573 }
 574
 575 /* sleep command sleeps for <n> miliseconds
 576  * this is useful in target startup scripts
 577  */
 578 int handle_sleep_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 579 {
 580         unsigned long duration = 0;
 581
 582         if (argc == 1)
 583         {
 584                 duration = strtoul(args[0], NULL, 0);
 585                 usleep(duration * 1000);
 586         }
 587
 588         return ERROR_OK;
 589 }