epan/disabled_protos.c

   1 /* disabled_protos.c
   2  * Code for reading and writing the disabled protocols file.
   3  *
   4  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  */
  24
  25 #include "config.h"
  26
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30 #include <errno.h>
  31
  32 #ifdef HAVE_UNISTD_H
  33 #include <unistd.h>
  34 #endif
  35
  36 #include <glib.h>
  37
  38 #include <epan/filesystem.h>
  39 #include <epan/proto.h>
  40
  41 #include "disabled_protos.h"
  42 #include <wsutil/file_util.h>
  43
  44 #define GLOBAL_PROTOCOLS_FILE_NAME      "disabled_protos"
  45 #define PROTOCOLS_FILE_NAME             "disabled_protos"
  46
  47 /*
  48  * List of disabled protocols
  49  */
  50 static GList *global_disabled_protos = NULL;
  51 static GList *disabled_protos = NULL;
  52
  53 #define INIT_BUF_SIZE   128
  54
  55 static void
  56 discard_existing_list (GList **flp)
  57 {
  58   GList      *fl_ent;
  59   protocol_def *prot;
  60
  61   if (*flp != NULL) {
  62     fl_ent = g_list_first(*flp);
  63     while (fl_ent != NULL) {
  64       prot = (protocol_def *) fl_ent->data;
  65       g_free(prot->name);
  66       g_free(prot);
  67       fl_ent = fl_ent->next;
  68     }
  69     g_list_free(*flp);
  70     *flp = NULL;
  71   }
  72 }
  73
  74 /*
  75  * Read in a list of disabled protocols.
  76  *
  77  * On success, "*pref_path_return" is set to NULL.
  78  * On error, "*pref_path_return" is set to point to the pathname of
  79  * the file we tried to read - it should be freed by our caller -
  80  * and "*open_errno_return" is set to the error if an open failed
  81  * or "*read_errno_return" is set to the error if a read failed.
  82  */
  83
  84 static int read_disabled_protos_list_file(const char *ff_path, FILE *ff,
  85                                           GList **flp);
  86
  87 void
  88 read_disabled_protos_list(char **gpath_return, int *gopen_errno_return,
  89                           int *gread_errno_return,
  90                           char **path_return, int *open_errno_return,
  91                           int *read_errno_return)
  92 {
  93   int         err;
  94   char       *gff_path, *ff_path;
  95   FILE       *ff;
  96
  97   /* Construct the pathname of the global disabled protocols file. */
  98   gff_path = get_datafile_path(GLOBAL_PROTOCOLS_FILE_NAME);
  99
 100   /* If we already have a list of protocols, discard it. */
 101   discard_existing_list (&global_disabled_protos);
 102
 103   /* Read the global disabled protocols file, if it exists. */
 104   *gpath_return = NULL;
 105   if ((ff = ws_fopen(gff_path, "r")) != NULL) {
 106     /* We succeeded in opening it; read it. */
 107     err = read_disabled_protos_list_file(gff_path, ff,
 108                                          &global_disabled_protos);
 109     if (err != 0) {
 110       /* We had an error reading the file; return the errno and the
 111          pathname, so our caller can report the error. */
 112       *gopen_errno_return = 0;
 113       *gread_errno_return = err;
 114       *gpath_return = gff_path;
 115     } else
 116       g_free(gff_path);
 117     fclose(ff);
 118   } else {
 119     /* We failed to open it.  If we failed for some reason other than
 120        "it doesn't exist", return the errno and the pathname, so our
 121        caller can report the error. */
 122     if (errno != ENOENT) {
 123       *gopen_errno_return = errno;
 124       *gread_errno_return = 0;
 125       *gpath_return = gff_path;
 126     } else
 127       g_free(gff_path);
 128   }
 129
 130   /* Construct the pathname of the user's disabled protocols file. */
 131   ff_path = get_persconffile_path(PROTOCOLS_FILE_NAME, TRUE);
 132
 133   /* If we already have a list of protocols, discard it. */
 134   discard_existing_list (&disabled_protos);
 135
 136   /* Read the user's disabled protocols file, if it exists. */
 137   *path_return = NULL;
 138   if ((ff = ws_fopen(ff_path, "r")) != NULL) {
 139     /* We succeeded in opening it; read it. */
 140     err = read_disabled_protos_list_file(ff_path, ff, &disabled_protos);
 141     if (err != 0) {
 142       /* We had an error reading the file; return the errno and the
 143          pathname, so our caller can report the error. */
 144       *open_errno_return = 0;
 145       *read_errno_return = err;
 146       *path_return = ff_path;
 147     } else
 148       g_free(ff_path);
 149     fclose(ff);
 150   } else {
 151     /* We failed to open it.  If we failed for some reason other than
 152        "it doesn't exist", return the errno and the pathname, so our
 153        caller can report the error. */
 154     if (errno != ENOENT) {
 155       *open_errno_return = errno;
 156       *read_errno_return = 0;
 157       *path_return = ff_path;
 158     } else
 159       g_free(ff_path);
 160   }
 161 }
 162
 163 static int
 164 read_disabled_protos_list_file(const char *ff_path, FILE *ff,
 165                                GList **flp)
 166 {
 167   protocol_def *prot;
 168   int         c;
 169   char       *prot_name;
 170   int         prot_name_len;
 171   int         prot_name_index;
 172   int         line = 1;
 173
 174
 175   /* Allocate the protocol name buffer. */
 176   prot_name_len = INIT_BUF_SIZE;
 177   prot_name = (char *)g_malloc(prot_name_len + 1);
 178
 179   for (line = 1; ; line++) {
 180     /* Lines in a disabled protocol file contain the "filter name" of
 181        a protocol to be disabled. */
 182
 183     /* Skip over leading white space, if any. */
 184     while ((c = getc(ff)) != EOF && isspace(c)) {
 185       if (c == '\n') {
 186         /* Blank line. */
 187         continue;
 188       }
 189     }
 190
 191     if (c == EOF) {
 192       if (ferror(ff))
 193         goto error;     /* I/O error */
 194       else
 195         break;  /* Nothing more to read */
 196     }
 197     ungetc(c, ff);      /* Unread the non-white-space character. */
 198
 199     /* Get the name of the protocol. */
 200     prot_name_index = 0;
 201     for (;;) {
 202       c = getc(ff);
 203       if (c == EOF)
 204         break;  /* End of file, or I/O error */
 205       if (isspace(c))
 206         break;  /* Trailing white space, or end of line. */
 207       if (c == '#')
 208         break;  /* Start of comment, running to end of line. */
 209       /* Add this character to the protocol name string. */
 210       if (prot_name_index >= prot_name_len) {
 211         /* protocol name buffer isn't long enough; double its length. */
 212         prot_name_len *= 2;
 213         prot_name = (char *)g_realloc(prot_name, prot_name_len + 1);
 214       }
 215       prot_name[prot_name_index] = c;
 216       prot_name_index++;
 217     }
 218
 219     if (isspace(c) && c != '\n') {
 220       /* Skip over trailing white space. */
 221       while ((c = getc(ff)) != EOF && c != '\n' && isspace(c))
 222         ;
 223       if (c != EOF && c != '\n' && c != '#') {
 224         /* Non-white-space after the protocol name; warn about it,
 225            in case we come up with a reason to use it. */
 226         g_warning("'%s' line %d has extra stuff after the protocol name.",
 227                   ff_path, line);
 228       }
 229     }
 230     if (c != EOF && c != '\n') {
 231       /* Skip to end of line. */
 232       while ((c = getc(ff)) != EOF && c != '\n')
 233         ;
 234     }
 235
 236     if (c == EOF) {
 237       if (ferror(ff))
 238         goto error;     /* I/O error */
 239       else {
 240         /* EOF, not error; no newline seen before EOF */
 241         g_warning("'%s' line %d doesn't have a newline.", ff_path,
 242                   line);
 243       }
 244       break;    /* nothing more to read */
 245     }
 246
 247     /* Null-terminate the protocol name. */
 248     if (prot_name_index >= prot_name_len) {
 249       /* protocol name buffer isn't long enough; double its length. */
 250       prot_name_len *= 2;
 251       prot_name = (char *)g_realloc(prot_name, prot_name_len + 1);
 252     }
 253     prot_name[prot_name_index] = '\0';
 254
 255     /* Add the new protocol to the list of disabled protocols */
 256     prot         = (protocol_def *) g_malloc(sizeof(protocol_def));
 257     prot->name   = g_strdup(prot_name);
 258     *flp = g_list_append(*flp, prot);
 259   }
 260   g_free(prot_name);
 261   return 0;
 262
 263 error:
 264   return errno;
 265 }
 266
 267 /*
 268  * Disable protocols as per the stored configuration
 269  */
 270 void
 271 set_disabled_protos_list(void)
 272 {
 273   gint i;
 274   GList *fl_ent;
 275   protocol_def *prot;
 276
 277   /*
 278    * assume all protocols are enabled by default
 279    */
 280   if (disabled_protos == NULL)
 281     goto skip;
 282
 283   fl_ent = g_list_first(disabled_protos);
 284
 285   while (fl_ent != NULL) {
 286     prot = (protocol_def *) fl_ent->data;
 287     i = proto_get_id_by_filter_name(prot->name);
 288     if (i == -1) {
 289       /* XXX - complain here? */
 290     } else {
 291       if (proto_can_toggle_protocol(i))
 292         proto_set_decoding(i, FALSE);
 293     }
 294
 295     fl_ent = fl_ent->next;
 296   }
 297
 298 skip:
 299   if (global_disabled_protos == NULL)
 300     return;
 301
 302   fl_ent = g_list_first(global_disabled_protos);
 303
 304   while (fl_ent != NULL) {
 305     prot = (protocol_def *) fl_ent->data;
 306     i = proto_get_id_by_filter_name(prot->name);
 307     if (i == -1) {
 308       /* XXX - complain here? */
 309     } else {
 310       if (proto_can_toggle_protocol(i)) {
 311         proto_set_decoding(i, FALSE);
 312         proto_set_cant_toggle(i);
 313       }
 314     }
 315
 316     fl_ent = fl_ent->next;
 317   }
 318 }
 319
 320 /*
 321  * Write out a list of disabled protocols.
 322  *
 323  * On success, "*pref_path_return" is set to NULL.
 324  * On error, "*pref_path_return" is set to point to the pathname of
 325  * the file we tried to read - it should be freed by our caller -
 326  * and "*errno_return" is set to the error.
 327  */
 328 void
 329 save_disabled_protos_list(char **pref_path_return, int *errno_return)
 330 {
 331   gchar       *ff_path, *ff_path_new;
 332   FILE        *ff;
 333   gint         i;
 334   protocol_t  *protocol;
 335   void        *cookie;
 336
 337   *pref_path_return = NULL;     /* assume no error */
 338
 339   ff_path = get_persconffile_path(PROTOCOLS_FILE_NAME, TRUE);
 340
 341   /* Write to "XXX.new", and rename if that succeeds.
 342      That means we don't trash the file if we fail to write it out
 343      completely. */
 344   ff_path_new = g_strdup_printf("%s.new", ff_path);
 345
 346   if ((ff = ws_fopen(ff_path_new, "w")) == NULL) {
 347     *pref_path_return = ff_path;
 348     *errno_return = errno;
 349     g_free(ff_path_new);
 350     return;
 351   }
 352
 353   /* Iterate over all the protocols */
 354
 355   for (i = proto_get_first_protocol(&cookie); i != -1;
 356        i = proto_get_next_protocol(&cookie)) {
 357
 358     if (!proto_can_toggle_protocol(i)) {
 359       continue;
 360     }
 361
 362     protocol = find_protocol_by_id(i);
 363     if (proto_is_protocol_enabled(protocol)) {
 364       continue;
 365     }
 366
 367     /* Write out the protocol name. */
 368     fprintf(ff, "%s\n", proto_get_protocol_filter_name(i));
 369   }
 370
 371   if (fclose(ff) == EOF) {
 372     *pref_path_return = ff_path;
 373     *errno_return = errno;
 374     ws_unlink(ff_path_new);
 375     g_free(ff_path_new);
 376     return;
 377   }
 378
 379 #ifdef _WIN32
 380   /* ANSI C doesn't say whether "rename()" removes the target if it
 381      exists; the Win32 call to rename files doesn't do so, which I
 382      infer is the reason why the MSVC++ "rename()" doesn't do so.
 383      We must therefore remove the target file first, on Windows.
 384
 385      XXX - ws_rename() should be ws_stdio_rename() on Windows,
 386      and ws_stdio_rename() uses MoveFileEx() with MOVEFILE_REPLACE_EXISTING,
 387      so it should remove the target if it exists, so this stuff
 388      shouldn't be necessary.  Perhaps it dates back to when we were
 389      calling rename(), with that being a wrapper around Microsoft's
 390      _rename(), which didn't remove the target. */
 391   if (ws_remove(ff_path) < 0 && errno != ENOENT) {
 392     /* It failed for some reason other than "it's not there"; if
 393        it's not there, we don't need to remove it, so we just
 394        drive on. */
 395     *pref_path_return = ff_path;
 396     *errno_return = errno;
 397     ws_unlink(ff_path_new);
 398     g_free(ff_path_new);
 399     return;
 400   }
 401 #endif
 402
 403   if (ws_rename(ff_path_new, ff_path) < 0) {
 404     *pref_path_return = ff_path;
 405     *errno_return = errno;
 406     ws_unlink(ff_path_new);
 407     g_free(ff_path_new);
 408     return;
 409   }
 410   g_free(ff_path_new);
 411   g_free(ff_path);
 412 }