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         va_list ap;
 262         char *buffer = NULL;
 263         int n, size = 0;
 264         char *p;
 265
 266         va_start(ap, format);
 267
 268         /* process format string */
 269         /* TODO: possible bug. va_list is undefined after the first call to vsnprintf */
 270         while (!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
 284         /* vsnprintf failed */
 285         if (n < 0)
 286         {
 287                 if (buffer)
 288                         free(buffer);
 289                 return;
 290         }
 291
 292         p = buffer;
 293
 294         /* process lines in buffer */
 295         do {
 296                 char *next = strchr(p, '\n');
 297
 298                 if (next)
 299                         *next++ = 0;
 300
 301                 if (context->output_handler)
 302                         context->output_handler(context, p);
 303
 304                 p = next;
 305         } while (p);
 306
 307         if (buffer)
 308                 free(buffer);
 309
 310         va_end(ap);
 311 }
 312
 313 int find_and_run_command(command_context_t *context, command_t *commands, char *words[], int num_words, int start_word)
 314 {
 315         command_t *c;
 316
 317         if (unique_length_dirty)
 318         {
 319                 unique_length_dirty=0;
 320                 /* update unique lengths */
 321                 build_unique_lengths(context, context->commands);
 322         }
 323
 324         for (c = commands; c; c = c->next)
 325         {
 326                 if (strncasecmp(c->name, words[start_word], c->unique_len))
 327                         continue;
 328
 329                 if (strncasecmp(c->name, words[start_word], strlen(words[start_word])))
 330                         continue;
 331
 332                 if ((c->mode == context->mode) || (c->mode == COMMAND_ANY))
 333                 {
 334                         if (!c->children)
 335                         {
 336                                 if (!c->handler)
 337                                 {
 338                                         command_print(context, "No handler for command");
 339                                         break;
 340                                 }
 341                                 else
 342                                 {
 343                                         return c->handler(context, c->name, words + start_word + 1, num_words - start_word - 1);
 344                                 }
 345                         }
 346                         else
 347                         {
 348                                 if (start_word == num_words - 1)
 349                                 {
 350                                         command_print(context, "Incomplete command");
 351                                         break;
 352                                 }
 353                                 return find_and_run_command(context, c->children, words, num_words, start_word + 1);
 354                         }
 355                 }
 356         }
 357
 358         command_print(context, "Command %s not found", words[start_word]);
 359         return ERROR_OK;
 360 }
 361
 362 int command_run_line(command_context_t *context, char *line)
 363 {
 364         int nwords;
 365         char *words[128] = {0};
 366         int retval;
 367         int i;
 368
 369         if ((!context) || (!line))
 370                 return ERROR_INVALID_ARGUMENTS;
 371
 372         /* skip preceding whitespace */
 373         while (isspace(*line))
 374                 line++;
 375
 376         /* empty line, ignore */
 377         if (!*line)
 378                 return ERROR_OK;
 379
 380         /* ignore comments */
 381         if (*line && (line[0] == '#'))
 382                 return ERROR_OK;
 383
 384         if (context->echo)
 385         {
 386                 command_print(context, "%s", line);
 387         }
 388
 389         nwords = parse_line(line, words, sizeof(words) / sizeof(words[0]));
 390
 391         if (nwords > 0)
 392                 retval = find_and_run_command(context, context->commands, words, nwords, 0);
 393         else
 394                 return ERROR_INVALID_ARGUMENTS;
 395
 396         for (i = 0; i < nwords; i++)
 397                 free(words[i]);
 398
 399         return retval;
 400 }
 401
 402 int command_run_file(command_context_t *context, FILE *file, enum command_mode mode)
 403 {
 404         int retval = ERROR_OK;
 405         int old_command_mode;
 406         char *buffer=malloc(4096);
 407         if (buffer==NULL)
 408         {
 409                 return ERROR_INVALID_ARGUMENTS;
 410         }
 411
 412         old_command_mode = context->mode;
 413         context->mode = mode;
 414
 415         while (fgets(buffer, 4096, file))
 416         {
 417                 char *p;
 418                 char *cmd, *end;
 419
 420                 /* stop processing line after a comment (#, !) or a LF, CR were encountered */
 421                 if ((p = strpbrk(buffer, "#!\r\n")))
 422                         *p = 0;
 423
 424                 /* skip over leading whitespace */
 425                 cmd = buffer;
 426                 while (isspace(*cmd))
 427                         cmd++;
 428
 429                 /* empty (all whitespace) line? */
 430                 if (!*cmd)
 431                         continue;
 432
 433                 /* search the end of the current line, ignore trailing whitespace */
 434                 for (p = end = cmd; *p; p++)
 435                         if (!isspace(*p))
 436                                 end = p;
 437
 438                 /* terminate end */
 439                 *++end = 0;
 440                 if (strcasecmp(cmd, "quit") == 0)
 441                         break;
 442
 443                 /* run line */
 444                 if ((retval = command_run_line(context, cmd)) == ERROR_COMMAND_CLOSE_CONNECTION)
 445                         break;
 446         }
 447
 448         context->mode = old_command_mode;
 449
 450
 451         free(buffer);
 452
 453         return retval;
 454 }
 455
 456 void command_print_help_line(command_context_t* context, struct command_s *command, int indent)
 457 {
 458         command_t *c;
 459         char indents[32] = {0};
 460         char *help = "no help available";
 461         char name_buf[64];
 462         int i;
 463
 464         for (i = 0; i < indent; i+=2)
 465         {
 466                 indents[i*2] = ' ';
 467                 indents[i*2+1] = '-';
 468         }
 469         indents[i*2] = 0;
 470
 471         if ((command->mode == COMMAND_EXEC) || (command->mode == COMMAND_ANY))
 472         {
 473                 if (command->help)
 474                         help = command->help;
 475
 476                 snprintf(name_buf, 64, command->name);
 477                 strncat(name_buf, indents, 64);
 478                 command_print(context, "%20s\t%s", name_buf, help);
 479         }
 480
 481         if (command->children)
 482         {
 483                 for (c = command->children; c; c = c->next)
 484                 {
 485                         command_print_help_line(context, c, indent + 1);
 486                 }
 487         }
 488 }
 489
 490 int command_print_help(command_context_t* context, char* name, char** args, int argc)
 491 {
 492         command_t *c;
 493
 494         for (c = context->commands; c; c = c->next)
 495         {
 496                 if (argc == 1)
 497                 {
 498                          if (strncasecmp(c->name, args[0], c->unique_len))
 499                                  continue;
 500
 501                          if (strncasecmp(c->name, args[0], strlen(args[0])))
 502                                  continue;
 503                 }
 504
 505                 command_print_help_line(context, c, 0);
 506         }
 507
 508         return ERROR_OK;
 509 }
 510
 511 void command_set_output_handler(command_context_t* context, int (*output_handler)(struct command_context_s *context, char* line), void *priv)
 512 {
 513         context->output_handler = output_handler;
 514         context->output_handler_priv = priv;
 515 }
 516
 517 command_context_t* copy_command_context(command_context_t* context)
 518 {
 519         command_context_t* copy_context = malloc(sizeof(command_context_t));
 520
 521         *copy_context = *context;
 522
 523         return copy_context;
 524 }
 525
 526 int command_done(command_context_t *context)
 527 {
 528         free(context);
 529         context = NULL;
 530
 531         return ERROR_OK;
 532 }
 533
 534 command_context_t* command_init()
 535 {
 536         command_context_t* context = malloc(sizeof(command_context_t));
 537
 538         context->mode = COMMAND_EXEC;
 539         context->commands = NULL;
 540         context->current_target = 0;
 541         context->echo = 0;
 542         context->output_handler = NULL;
 543         context->output_handler_priv = NULL;
 544
 545         register_command(context, NULL, "help", command_print_help,
 546                                          COMMAND_EXEC, "display this help");
 547
 548         register_command(context, NULL, "sleep", handle_sleep_command,
 549                                          COMMAND_ANY, "sleep for <n> milliseconds");
 550
 551         return context;
 552 }
 553
 554 /* sleep command sleeps for <n> miliseconds
 555  * this is useful in target startup scripts
 556  */
 557 int handle_sleep_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 558 {
 559         unsigned long duration = 0;
 560
 561         if (argc == 1)
 562         {
 563                 duration = strtoul(args[0], NULL, 0);
 564                 usleep(duration * 1000);
 565         }
 566
 567         return ERROR_OK;
 568 }