2 * Routines for packet capture windows
4 * Wireshark - Network traffic analyzer
5 * By Gerald Combs <gerald@wireshark.org>
6 * Copyright 1998 Gerald Combs
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
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.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 * <laurent.deniel@free.fr>
26 * Almost completely rewritten in order to:
28 * - be able to use a unlimited number of ringbuffer files
29 * - close the current file and open (truncating) the next file at switch
30 * - set the final file name once open (or reopen)
31 * - avoid the deletion of files that could not be truncated (can't arise now)
32 * and do not erase empty files
34 * The idea behind that is to remove the limitation of the maximum # of
35 * ringbuffer files being less than the maximum # of open fd per process
36 * and to be able to reduce the amount of virtual memory usage (having only
37 * one file open at most) or the amount of file system usage (by truncating
38 * the files at switch and not the capture stop, and by closing them which
39 * makes possible their move or deletion after a switch).
64 #include "ringbuffer.h"
65 #include <wsutil/file_util.h>
68 /* Ringbuffer file structure */
69 typedef struct _rb_file {
73 /* Ringbuffer data structure */
74 typedef struct _ringbuf_data {
76 guint num_files; /* Number of ringbuffer files (1 to ...) */
77 guint curr_file_num; /* Number of the current file (ever increasing) */
78 gchar *fprefix; /* Filename prefix */
79 gchar *fsuffix; /* Filename suffix */
80 gboolean unlimited; /* TRUE if unlimited number of files */
82 int fd; /* Current ringbuffer file descriptor */
84 gboolean group_read_access; /* TRUE if files need to be opened with group read access */
87 static ringbuf_data rb_data;
91 * create the next filename and open a new binary file with that name
93 static int ringbuf_open_file(rb_file *rfile, int *err)
99 if (rfile->name != NULL) {
100 if (rb_data.unlimited == FALSE) {
101 /* remove old file (if any, so ignore error) */
102 ws_unlink(rfile->name);
110 current_time = time(NULL);
112 g_snprintf(filenum, sizeof(filenum), "%05u", (rb_data.curr_file_num + 1) % RINGBUFFER_MAX_NUM_FILES);
113 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(¤t_time));
114 rfile->name = g_strconcat(rb_data.fprefix, "_", filenum, "_", timestr,
115 rb_data.fsuffix, NULL);
117 if (rfile->name == NULL) {
123 rb_data.fd = ws_open(rfile->name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT,
124 rb_data.group_read_access ? 0640 : 0600);
126 if (rb_data.fd == -1 && err != NULL) {
134 * Initialize the ringbuffer data structures
137 ringbuf_init(const char *capfile_name, guint num_files, gboolean group_read_access)
140 char *pfx, *last_pathsep;
143 rb_data.files = NULL;
144 rb_data.curr_file_num = 0;
145 rb_data.fprefix = NULL;
146 rb_data.fsuffix = NULL;
147 rb_data.unlimited = FALSE;
150 rb_data.group_read_access = group_read_access;
152 /* just to be sure ... */
153 if (num_files <= RINGBUFFER_MAX_NUM_FILES) {
154 rb_data.num_files = num_files;
156 rb_data.num_files = RINGBUFFER_MAX_NUM_FILES;
159 /* Check file name */
160 if (capfile_name == NULL) {
161 /* ringbuffer does not work with temporary files! */
165 /* set file name prefix/suffix */
167 save_file = g_strdup(capfile_name);
168 last_pathsep = strrchr(save_file, G_DIR_SEPARATOR);
169 pfx = strrchr(save_file,'.');
170 if (pfx != NULL && (last_pathsep == NULL || pfx > last_pathsep)) {
171 /* The pathname has a "." in it, and it's in the last component
172 of the pathname (because there is either only one component,
173 i.e. last_pathsep is null as there are no path separators,
174 or the "." is after the path separator before the last
177 Treat it as a separator between the rest of the file name and
178 the file name suffix, and arrange that the names given to the
179 ring buffer files have the specified suffix, i.e. put the
180 changing part of the name *before* the suffix. */
182 rb_data.fprefix = g_strdup(save_file);
183 pfx[0] = '.'; /* restore capfile_name */
184 rb_data.fsuffix = g_strdup(pfx);
186 /* Either there's no "." in the pathname, or it's in a directory
187 component, so the last component has no suffix. */
188 rb_data.fprefix = g_strdup(save_file);
189 rb_data.fsuffix = NULL;
194 /* allocate rb_file structures (only one if unlimited since there is no
195 need to save all file names in that case) */
197 if (num_files == RINGBUFFER_UNLIMITED_FILES) {
198 rb_data.unlimited = TRUE;
199 rb_data.num_files = 1;
202 rb_data.files = (rb_file *)g_malloc(rb_data.num_files * sizeof(rb_file));
203 if (rb_data.files == NULL) {
207 for (i=0; i < rb_data.num_files; i++) {
208 rb_data.files[i].name = NULL;
211 /* create the first file */
212 if (ringbuf_open_file(&rb_data.files[0], NULL) == -1) {
213 ringbuf_error_cleanup();
221 const gchar *ringbuf_current_filename(void)
223 return rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
227 * Calls ws_fdopen() for the current ringbuffer file
230 ringbuf_init_libpcap_fdopen(int *err)
232 rb_data.pdh = ws_fdopen(rb_data.fd, "wb");
233 if (rb_data.pdh == NULL) {
242 * Switches to the next ringbuffer file
245 ringbuf_switch_file(FILE **pdh, gchar **save_file, int *save_file_fd, int *err)
248 rb_file *next_rfile = NULL;
250 /* close current file */
252 if (fclose(rb_data.pdh) == EOF) {
256 ws_close(rb_data.fd); /* XXX - the above should have closed this already */
257 rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */
265 /* get the next file number and open it */
267 rb_data.curr_file_num++ /* = next_file_num*/;
268 next_file_index = (rb_data.curr_file_num) % rb_data.num_files;
269 next_rfile = &rb_data.files[next_file_index];
271 if (ringbuf_open_file(next_rfile, err) == -1) {
275 if (ringbuf_init_libpcap_fdopen(err) == NULL) {
279 /* switch to the new file */
280 *save_file = next_rfile->name;
281 *save_file_fd = rb_data.fd;
282 (*pdh) = rb_data.pdh;
288 * Calls fclose() for the current ringbuffer file
291 ringbuf_libpcap_dump_close(gchar **save_file, int *err)
293 gboolean ret_val = TRUE;
295 /* close current file, if it's open */
296 if (rb_data.pdh != NULL) {
297 if (fclose(rb_data.pdh) == EOF) {
301 ws_close(rb_data.fd);
308 /* set the save file name to the current file */
309 *save_file = rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
314 * Frees all memory allocated by the ringbuffer
321 if (rb_data.files != NULL) {
322 for (i=0; i < rb_data.num_files; i++) {
323 if (rb_data.files[i].name != NULL) {
324 g_free(rb_data.files[i].name);
325 rb_data.files[i].name = NULL;
328 g_free(rb_data.files);
329 rb_data.files = NULL;
331 if (rb_data.fprefix != NULL) {
332 g_free(rb_data.fprefix);
333 rb_data.fprefix = NULL;
335 if (rb_data.fsuffix != NULL) {
336 g_free(rb_data.fsuffix);
337 rb_data.fsuffix = NULL;
342 * Frees all memory allocated by the ringbuffer
345 ringbuf_error_cleanup(void)
349 /* try to close via wtap */
350 if (rb_data.pdh != NULL) {
351 if (fclose(rb_data.pdh) == 0) {
357 /* close directly if still open */
358 if (rb_data.fd != -1) {
359 ws_close(rb_data.fd);
363 if (rb_data.files != NULL) {
364 for (i=0; i < rb_data.num_files; i++) {
365 if (rb_data.files[i].name != NULL) {
366 ws_unlink(rb_data.files[i].name);
370 /* free the memory */
374 #endif /* HAVE_LIBPCAP */