misc/tools-source/cmd_wrapper.c

   1 /*
   2  * --- T2-COPYRIGHT-NOTE-BEGIN ---
   3  * This copyright note is auto-generated by scripts/Create-CopyPatch.
   4  *
   5  * T2 SDE: misc/tools-source/cmd_wrapper.c
   6  * Copyright (C) 2004 - 2021 The T2 SDE Project
   7  * Copyright (C) 1998 - 2003 ROCK Linux Project
   8  * Copyright (C) 2006 - 2010 Rene Rebe <rene@exactcode.de>
   9  *
  10  * More information can be found in the files COPYING and README.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; version 2 of the License. A copy of the
  15  * GNU General Public License can be found in the file COPYING.
  16  * --- T2-COPYRIGHT-NOTE-END ---
  17  *
  18  *  Generic command wrapper.
  19  *
  20  *  Recognised Variables:
  21  *
  22  *      prefix_WRAPPER_MYPATH           "/path/to/binary"
  23  *      prefix_WRAPPER_LOGFILE          ".cmd_wrapper_log"
  24  *
  25  *      prefix_WRAPPER_DEBUG            0
  26  *      prefix_WRAPPER_BYPASS           0
  27  *
  28  *      prefix_WRAPPER_OTHERS           "other_cmd"
  29  *
  30  *      prefix_WRAPPER_INSERT           "-1st-opt -2nd-opt"
  31  *      prefix_WRAPPER_REMOVE           "-del-this-opt -this-also [!-]*"
  32  *      prefix_WRAPPER_APPEND           "-last-opt"
  33  *
  34  *      prefix_WRAPPER_FILTER           "sed '...' | awk '...' | foobar"
  35  *
  36  *      prefix_WRAPPER_NOLOOP           Internal use only.
  37  *      prefix_WRAPPER_OTHERS_DONE      Internal use only.
  38  *
  39  */
  40
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <stdio.h>
  44 #include <unistd.h>
  45 #include <ctype.h>
  46 #include <sys/wait.h>
  47 #include <libgen.h>
  48 #include <fnmatch.h>
  49 #include <errno.h>
  50
  51 #ifndef ENVPREFIX
  52 #    error You must use -DENVPREFIX=".." when compiling this tool.
  53 #endif
  54
  55 #ifndef MYNAME
  56 #    error You must use -DMYNAME=".." when compiling this tool.
  57 #endif
  58
  59 #define VERBOSE_DEBUG 1
  60 int debug=1;
  61
  62 /*
  63  *  Clean config vars before using them
  64  */
  65 void cleanenv(const char * name, const char ch) {
  66         int pos1=0, pos2=0, delim=1;
  67         char *tmp1, *tmp2;
  68
  69         setenv(name, "", 0); /* no overwrite - make sure it is defined */
  70         tmp1 = getenv(name);
  71         tmp2 = malloc(strlen(tmp1)+1);
  72
  73         while ( tmp1[pos1] ) {
  74                 if ( tmp1[pos1]  == ch ) {
  75                         if ( ! delim ) {
  76                                 tmp2[pos2++] = ch;
  77                                 delim = 1;
  78                         }
  79                 } else {
  80                         tmp2[pos2++] = tmp1[pos1];
  81                         delim = 0;
  82                 }
  83                 pos1++;
  84         }
  85         if (pos2 > 0 && tmp2[pos2-1] == ch) pos2--;
  86         tmp2[pos2] = 0; setenv(name, tmp2, 1);
  87 }
  88
  89 /*
  90  * Evaluate conditional argument in the form:
  91  * "condition?matched-value:unmatched-value"
  92  */
  93 char* eval_cond_arg (char * arg, int argc, char ** argv) {
  94         char * c = arg;
  95         char * lhs = NULL, * rhs = NULL;
  96
  97         /* look for '?' */
  98         while (*c && *c != '?') c++;
  99
 100         if (*c != '?') {
 101                 return arg;
 102         }
 103 #if VERBOSE_DEBUG
 104         if (debug) fprintf(stderr, "Conditonal arg: '%s'\n", arg);
 105 #endif
 106
 107         /* split conditional (arg), left hand and right hand statement */
 108         *c++ = 0;
 109         lhs = c;
 110
 111         /* look for ':' */
 112         while (*c && *c != ':') c++;
 113         if (*c == ':')
 114                 *c++ = 0;
 115         rhs = c;
 116
 117         if (debug) fprintf(stderr, "Conditonal: '%s', lhs: '%s', rhs: '%s'\n", arg, lhs, rhs);
 118
 119         /* match arguments against conditional */
 120         while (argc--)
 121         {
 122                 if (!fnmatch(arg, *argv, 0)) {
 123 #if VERBOSE_DEBUG
 124                         if (debug) fprintf(stderr, "Conditonal: '%s', matched: '%s'\n", arg, *argv);
 125 #endif
 126                         return lhs;
 127                 }
 128                 argv++;
 129         }
 130
 131         return rhs;
 132 }
 133
 134 /* newargv memory management, realloc if newargv is filled */
 135 static inline char** realloc_if_needed(int c1, int* newargc, char** newargv) {
 136         if (c1 + 1 >= *newargc) { /* +1 for NULL-sentinel */
 137                 *newargc *= 2;
 138                 newargv = realloc (newargv, sizeof(char*) * *newargc);
 139         }
 140         return newargv;
 141 }
 142
 143 /*
 144  *  Main function.
 145  */
 146 int main(int argc, char ** argv) {
 147         int newargc = 64; /* initial newargv size, anyhting >3 (name, other, NULL) */
 148         char **newargv;
 149         char *other, *other_done;
 150         int c1,c2,c3;
 151         char *delim, *optbuf, *wrdir;
 152         FILE *logfile = NULL;
 153
 154         /* Calling the wrapper with an absolute path results in an
 155            endless-loop. Use basename only to force a $PATH lookup. */
 156         argv[0] = basename(argv[0]);
 157         if ( !strcmp(argv[0], MYNAME) ) {
 158                 if ( argc > 1 ) {
 159                         argv++; argc--;
 160                         argv[0] = basename(argv[0]);
 161                 } else {
 162                         exit(250);
 163                 }
 164         }
 165
 166         /* Open logfile (if any) */
 167         delim = getenv(ENVPREFIX "_WRAPPER_LOGFILE");
 168         if (delim && delim[0]) {
 169                 logfile = fopen(delim, "a");
 170         }
 171         if (logfile) {
 172                 delim = malloc(FILENAME_MAX);
 173                 if ( getcwd(delim, FILENAME_MAX) == NULL ) delim[0]=0;
 174                 fprintf(logfile, "\n%s:\n-", delim);
 175                 for (c3=0; c3<argc; c3++) fprintf(logfile, " %s", argv[c3]);
 176                 fprintf(logfile, "\n");
 177                 free(delim);
 178         }
 179
 180         /*
 181          *  Read prefix_WRAPPER_DEBUG and prefix_WRAPPER_BYPASS
 182          */
 183
 184         if ( (delim=getenv(ENVPREFIX "_WRAPPER_DEBUG")) != NULL &&
 185                                         delim[0] ) debug = atoi(delim);
 186
 187         if ( (delim=getenv(ENVPREFIX "_WRAPPER_BYPASS")) != NULL &&
 188                                         delim[0] && atoi(delim)) {
 189 #if VERBOSE_DEBUG
 190                 if (debug) fprintf(stderr, "Bypassing cmd_wrapper by "
 191                                            "clearing all config variables.\n");
 192 #endif
 193                 setenv(ENVPREFIX "_WRAPPER_OTHERS", "", 1);
 194                 setenv(ENVPREFIX "_WRAPPER_INSERT", "", 1);
 195                 setenv(ENVPREFIX "_WRAPPER_REMOVE", "", 1);
 196                 setenv(ENVPREFIX "_WRAPPER_APPEND", "", 1);
 197                 setenv(ENVPREFIX "_WRAPPER_FILTER", "", 1);
 198         }
 199
 200         cleanenv(ENVPREFIX "_WRAPPER_OTHERS", ':');
 201         cleanenv(ENVPREFIX "_WRAPPER_INSERT", ' ');
 202         cleanenv(ENVPREFIX "_WRAPPER_REMOVE", ' ');
 203         cleanenv(ENVPREFIX "_WRAPPER_APPEND", ' ');
 204         cleanenv(ENVPREFIX "_WRAPPER_FILTER", '|');
 205
 206 #if VERBOSE_DEBUG
 207         if (debug) {
 208                 fprintf(stderr, "Old Command:");
 209                 for (c3=0; c3<argc; c3++) fprintf(stderr, " %s", argv[c3]);
 210                 fprintf(stderr, "\n");
 211                 fprintf(stderr, "ENVPREFIX = '%s'\n", ENVPREFIX);
 212                 fprintf(stderr, "OTHERS = '%s'\n",
 213                                 getenv(ENVPREFIX "_WRAPPER_OTHERS"));
 214                 if (getenv(ENVPREFIX "_WRAPPER_OTHERS_DONE"))
 215                 fprintf(stderr, "OTHERS DONE = '%s'\n",
 216                                 getenv(ENVPREFIX "_WRAPPER_OTHERS_DONE"));
 217                 fprintf(stderr, "INSERT = '%s'\n",
 218                                 getenv(ENVPREFIX "_WRAPPER_INSERT"));
 219                 fprintf(stderr, "REMOVE = '%s'\n",
 220                                 getenv(ENVPREFIX "_WRAPPER_REMOVE"));
 221                 fprintf(stderr, "APPEND = '%s'\n",
 222                                 getenv(ENVPREFIX "_WRAPPER_APPEND"));
 223                 fprintf(stderr, "FILTER = '%s'\n",
 224                                 getenv(ENVPREFIX "_WRAPPER_FILTER"));
 225         }
 226 #endif
 227
 228         /* extract the next other wrapper */
 229         other = getenv(ENVPREFIX "_WRAPPER_OTHERS");
 230         other_done = getenv(ENVPREFIX "_WRAPPER_OTHERS_DONE");
 231
 232         if (other && strlen(other) > 0) {
 233                 other = strdup(other);
 234                 char *newother_done;
 235
 236                 if (other_done) {
 237                         char *str = strstr(other, other_done);
 238                         if (str != other) {
 239                                 fprintf(stderr, "OTHERS_DONE set but does not match.\n");
 240                                 return 249;
 241                         }
 242
 243                         other += strlen(other_done);
 244                         if (*other == 0) {
 245                           other = 0;
 246                         }
 247                         else {
 248                           if (*other == ':')
 249                             other++;
 250
 251                           newother_done = (char *) malloc(strlen(getenv(ENVPREFIX "_WRAPPER_OTHERS")));
 252                           strcpy(newother_done, other_done);
 253                           strcat(newother_done, ":");
 254                           strcat(newother_done, other);
 255
 256                           setenv(ENVPREFIX "_WRAPPER_OTHERS_DONE", newother_done, 1);
 257                         }
 258                 }
 259                 else {
 260                         other = strtok(other, ":");
 261                         setenv(ENVPREFIX "_WRAPPER_OTHERS_DONE", other, 1);
 262                 }
 263         }
 264
 265         /*
 266          *  Main work.
 267          */
 268
 269         newargv = malloc( sizeof(char*) * newargc );
 270
 271         /* init newargv[], c1 and c2 */
 272         c1 = c2 = 0;
 273         if (other && strlen(other) > 0)
 274                 newargv[c1++] = other;
 275         newargv[c1++] = argv[c2++];
 276
 277         /*
 278          *  Copy options from prefix_WRAPPER_INSERT to newargv[]
 279          */
 280
 281         if ( (delim=getenv(ENVPREFIX  "_WRAPPER_INSERT")) != NULL ) {
 282                 optbuf = malloc( strlen(delim) + 1 );
 283                 strcpy(optbuf, delim);
 284
 285                 delim = strtok(optbuf, " ");
 286                 while (delim != NULL) {
 287                         delim = eval_cond_arg (delim, argc, argv);
 288
 289                         if (delim[0]) {
 290 #if VERBOSE_DEBUG
 291                             if (debug) fprintf(stderr, "Insert: %s\n", delim);
 292 #endif
 293                             newargv = realloc_if_needed(c1, &newargc, newargv);
 294                             newargv[c1++] = delim;
 295                         }
 296                         delim = strtok(NULL, " ");
 297                 }
 298         }
 299
 300
 301         /*
 302          *  Copy options from argv[] to newargv[] if they are not listed
 303          *  in prefix_WRAPPER_REMOVE
 304          */
 305
 306         for (; c2<argc; c2++) {
 307                 if ( (delim=getenv(ENVPREFIX  "_WRAPPER_REMOVE")) != NULL ) {
 308                         optbuf = malloc( strlen(delim) + 1 );
 309                         strcpy(optbuf, delim);
 310
 311                         delim = strtok(optbuf, " ");
 312                         while (delim != NULL) {
 313                                 delim = eval_cond_arg (delim, argc, argv);
 314                                 if ( delim[0] &&
 315                                      !fnmatch(delim, argv[c2], 0) ) break;
 316                                 delim = strtok(NULL, " ");
 317                         }
 318                         free(optbuf);
 319                 }
 320                 if (delim == NULL) {
 321 #if VERBOSE_DEBUG
 322                     if (debug) fprintf(stderr, "Copy:   %s\n", argv[c2]);
 323 #endif
 324
 325                     newargv = realloc_if_needed(c1, &newargc, newargv);
 326                     newargv[c1++] = argv[c2];
 327 #if VERBOSE_DEBUG
 328                 } else {
 329                     if (debug) fprintf(stderr, "Remove: %s\n", argv[c2]);
 330 #endif
 331                 }
 332         }
 333
 334
 335         /*
 336          *  Copy options from prefix_WRAPPER_APPEND to newargv[]
 337          */
 338
 339         if ( (delim=getenv(ENVPREFIX  "_WRAPPER_APPEND")) != NULL ) {
 340                 optbuf = malloc( strlen(delim) + 1 );
 341                 strcpy(optbuf, delim);
 342
 343                 delim = strtok(optbuf, " ");
 344                 while (delim != NULL) {
 345                         delim = eval_cond_arg (delim, argc, argv);
 346                         if (delim[0]) {
 347 #if VERBOSE_DEBUG
 348                             if (debug) fprintf(stderr, "Append: %s\n", delim);
 349 #endif
 350
 351                             newargv = realloc_if_needed(c1, &newargc, newargv);
 352                             newargv[c1++] = delim;
 353                         }
 354                         delim = strtok(NULL, " ");
 355                 }
 356         }
 357
 358
 359         /*
 360          *  Use prefix_WRAPPER_FILTER if set and not ""
 361          *
 362          *  (Maybe we make a nice re-write of this code-block later.)
 363          */
 364
 365         if ( (delim=getenv(ENVPREFIX "_WRAPPER_FILTER")) != NULL && delim[0] ) {
 366
 367                 /* Open temp files. */
 368                 char outfn[] = "/tmp/gccfilter_out.XXXXXX";
 369                 char infn[] = "/tmp/gccfilter_in.XXXXXX";
 370                 int outfd = mkstemp(outfn);
 371                 int infd = mkstemp(infn);
 372                 int pid, status;
 373
 374                 /* Create content of input file */
 375                 for (c3=0; c3<c1; c3++) {
 376                         write(infd, newargv[c3], strlen(newargv[c3]));
 377                         write(infd, "\n", 1);
 378                 }
 379                 lseek(infd, 0, SEEK_SET);
 380
 381                 /* Run filter command with shell (sh -c xxx) */
 382 #if VERBOSE_DEBUG
 383                 if (debug) fprintf(stderr, "Run Filter: %s\n", delim);
 384 #endif
 385                 pid = fork();
 386                 if (!pid) {
 387                         dup2(infd,  0);  close(infd);
 388                         dup2(outfd, 1);  close(outfd);
 389                         execlp("sh", "sh", "-c", delim, NULL);
 390                         return 1;
 391                 } else if (pid == -1) {
 392                         fprintf(stderr, "Fork failed: %d: %s\n", errno, strerror(errno));
 393                 } else {
 394                         /* We don't expect any signals and have no other child processes. */
 395                         wait(&status);
 396                         if (WEXITSTATUS(status) != 0) {
 397                                 fprintf(stderr, "Filter failed: %d\n", WEXITSTATUS(status));
 398                         }
 399                 }
 400
 401                 /* Re-read parameter list. */
 402                 {
 403                   size_t argvsize = lseek(outfd, 0, SEEK_END);
 404                   char* argvmem = malloc (argvsize + 1); /* might not have trailing \n */
 405                   lseek(outfd, 0, SEEK_SET);
 406                   read(outfd, argvmem, argvsize);
 407
 408                   if (argvsize == 0) {
 409                           fprintf(stderr, "Filter produced no output!\n");
 410                           return 248;
 411                   }
 412
 413                   for (c1 = c2 = 0; c2 < argvsize; ++c2) {
 414                         newargv = realloc_if_needed(c1, &newargc, newargv);
 415                         newargv[c1++] = argvmem + c2;
 416
 417                         /* scan for newlines, terminate, next */
 418                         while (c2 < argvsize && argvmem[c2] != '\n')
 419                                 ++c2;
 420                         argvmem[c2] = 0;
 421                   }
 422                 }
 423
 424                 /* Close and remove temp files */
 425                 close(outfd); unlink(outfn);
 426                 close(infd);  unlink(infn);
 427         }
 428
 429         /*
 430          * Run other wrappers first. They will re-start us.
 431          */
 432
 433         if (other && strlen(other) > 0) {
 434
 435 #if VERBOSE_DEBUG
 436                 if (debug) {
 437                   fprintf(stderr, "Running external wrapper: %s\n", newargv[0]);
 438                   for (c3=0; c3<c1; c3++)
 439                     fprintf(stderr, " %s", newargv[c3]);
 440                   fprintf(stderr, "\n");
 441                 }
 442 #endif
 443
 444                 if (logfile) {
 445                         fprintf(logfile, "+");
 446                         for (c3=0; c3<c1; c3++)
 447                                         fprintf(logfile, " %s", newargv[c3]);
 448                         fprintf(logfile, "\n");
 449                         fclose(logfile);
 450                 }
 451
 452                 newargv[c1] = NULL;
 453                 execvp(newargv[0], newargv);
 454                 fprintf(stderr, "cmd_wrapper: execvp(%s,...) - %s\n",
 455                         newargv[0], strerror(errno));
 456
 457                 return 253;
 458         }
 459
 460         /*
 461          *  Remove the wrapper dir from PATH
 462          */
 463
 464         if ( (delim=getenv("PATH")) != NULL && delim[0] &&
 465              (wrdir=getenv(ENVPREFIX "_WRAPPER_MYPATH")) != NULL &&
 466                                                                 wrdir[0] ) {
 467                 optbuf = malloc( strlen(delim) + 1 );
 468                 optbuf[0] = 0;
 469
 470 #if VERBOSE_DEBUG
 471                 if (debug)
 472                         fprintf(stderr, "Old PATH: %s\n", delim);
 473 #endif
 474
 475                 delim = strtok(delim, ":");
 476                 while ( delim != NULL ) {
 477                         if (strcmp(delim, wrdir)) {
 478                                 if (optbuf[0]) strcat(optbuf, ":");
 479                                 strcat(optbuf, delim);
 480                         }
 481                         delim = strtok(NULL, ":");
 482                 }
 483                 setenv("PATH", optbuf, 1);
 484
 485 #if VERBOSE_DEBUG
 486                 if (debug) fprintf(stderr, "New PATH: %s\n", optbuf);
 487 #endif
 488         } else {
 489                 return 252;
 490         }
 491
 492         /*
 493          *  Detect loops
 494          */
 495
 496         if ( (delim=getenv(ENVPREFIX "_WRAPPER_NOLOOP")) != NULL &&
 497                                         delim[0] && delim[0] != '0') {
 498                 return 251;
 499         }
 500         setenv(ENVPREFIX "_WRAPPER_NOLOOP", "1", 1);
 501
 502         /*
 503          *  Run the new command
 504          */
 505
 506 #if VERBOSE_DEBUG
 507         if (debug) {
 508                 fprintf(stderr, "New Command:");
 509                 for (c3=0; c3<c1; c3++) fprintf(stderr, " %s", newargv[c3]);
 510                 fprintf(stderr, "\n");
 511         }
 512 #endif
 513
 514         if (logfile) {
 515                 fprintf(logfile, "+");
 516                 for (c3=0; c3<c1; c3++) fprintf(logfile, " %s", newargv[c3]);
 517                 fprintf(logfile, "\n");
 518                 fclose(logfile);
 519         }
 520
 521         newargv[c1]=NULL;
 522         execvp(newargv[0], newargv);
 523         fprintf(stderr, "cmd_wrapper: execvp(%s,...) - %s\n",
 524                 newargv[0], strerror(errno));
 525
 526         return 254;
 527 }