2 * Routines for packet capture windows
6 * Wireshark - Network traffic analyzer
7 * By Gerald Combs <gerald@wireshark.org>
8 * Copyright 1998 Gerald Combs
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.
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.
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26 * <laurent.deniel@free.fr>
28 * Almost completely rewritten in order to:
30 * - be able to use a unlimited number of ringbuffer files
31 * - close the current file and open (truncating) the next file at switch
32 * - set the final file name once open (or reopen)
33 * - avoid the deletion of files that could not be truncated (can't arise now)
34 * and do not erase empty files
36 * The idea behind that is to remove the limitation of the maximum # of
37 * ringbuffer files being less than the maximum # of open fd per process
38 * and to be able to reduce the amount of virtual memory usage (having only
39 * one file open at most) or the amount of file system usage (by truncating
40 * the files at switch and not the capture stop, and by closing them which
41 * makes possible their move or deletion after a switch).
69 #include "ringbuffer.h"
70 #include <wsutil/file_util.h>
73 /* Ringbuffer file structure */
74 typedef struct _rb_file {
78 /* Ringbuffer data structure */
79 typedef struct _ringbuf_data {
81 guint num_files; /* Number of ringbuffer files (1 to ...) */
82 guint curr_file_num; /* Number of the current file (ever increasing) */
83 gchar *fprefix; /* Filename prefix */
84 gchar *fsuffix; /* Filename suffix */
85 gboolean unlimited; /* TRUE if unlimited number of files */
87 int fd; /* Current ringbuffer file descriptor */
91 static ringbuf_data rb_data;
95 * create the next filename and open a new binary file with that name
97 static int ringbuf_open_file(rb_file *rfile, int *err)
103 if (rfile->name != NULL) {
104 if (rb_data.unlimited == FALSE) {
105 /* remove old file (if any, so ignore error) */
106 ws_unlink(rfile->name);
114 current_time = time(NULL);
116 g_snprintf(filenum, sizeof(filenum), "%05u", (rb_data.curr_file_num + 1) % 100000);
117 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(¤t_time));
118 rfile->name = g_strconcat(rb_data.fprefix, "_", filenum, "_", timestr,
119 rb_data.fsuffix, NULL);
121 if (rfile->name == NULL) {
126 rb_data.fd = ws_open(rfile->name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT, 0600);
128 if (rb_data.fd == -1 && err != NULL) {
136 * Initialize the ringbuffer data structures
139 ringbuf_init(const char *capfile_name, guint num_files)
142 char *pfx, *last_pathsep;
145 rb_data.files = NULL;
146 rb_data.curr_file_num = 0;
147 rb_data.fprefix = NULL;
148 rb_data.fsuffix = NULL;
149 rb_data.unlimited = FALSE;
153 /* just to be sure ... */
154 if (num_files <= RINGBUFFER_MAX_NUM_FILES) {
155 rb_data.num_files = num_files;
157 rb_data.num_files = RINGBUFFER_MAX_NUM_FILES;
160 /* Check file name */
161 if (capfile_name == NULL) {
162 /* ringbuffer does not work with temporary files! */
166 /* set file name prefix/suffix */
168 save_file = g_strdup(capfile_name);
169 last_pathsep = strrchr(save_file, G_DIR_SEPARATOR);
170 pfx = strrchr(save_file,'.');
171 if (pfx != NULL && (last_pathsep == NULL || pfx > last_pathsep)) {
172 /* The pathname has a "." in it, and it's in the last component
173 of the pathname (because there is either only one component,
174 i.e. last_pathsep is null as there are no path separators,
175 or the "." is after the path separator before the last
178 Treat it as a separator between the rest of the file name and
179 the file name suffix, and arrange that the names given to the
180 ring buffer files have the specified suffix, i.e. put the
181 changing part of the name *before* the suffix. */
183 rb_data.fprefix = g_strdup(save_file);
184 pfx[0] = '.'; /* restore capfile_name */
185 rb_data.fsuffix = g_strdup(pfx);
187 /* Either there's no "." in the pathname, or it's in a directory
188 component, so the last component has no suffix. */
189 rb_data.fprefix = g_strdup(save_file);
190 rb_data.fsuffix = NULL;
195 /* allocate rb_file structures (only one if unlimited since there is no
196 need to save all file names in that case) */
198 if (num_files == RINGBUFFER_UNLIMITED_FILES) {
199 rb_data.unlimited = TRUE;
200 rb_data.num_files = 1;
203 rb_data.files = (rb_file *)g_malloc(rb_data.num_files * sizeof(rb_file));
204 if (rb_data.files == NULL) {
208 for (i=0; i < rb_data.num_files; i++) {
209 rb_data.files[i].name = NULL;
212 /* create the first file */
213 if (ringbuf_open_file(&rb_data.files[0], NULL) == -1) {
214 ringbuf_error_cleanup();
222 const gchar *ringbuf_current_filename(void)
224 return rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
228 * Calls libpcap_fdopen() for the current ringbuffer file
231 ringbuf_init_libpcap_fdopen(int *err)
233 rb_data.pdh = libpcap_fdopen(rb_data.fd, err);
238 * Switches to the next ringbuffer file
241 ringbuf_switch_file(FILE **pdh, gchar **save_file, int *save_file_fd, int *err)
244 rb_file *next_rfile = NULL;
246 /* close current file */
248 if (!libpcap_dump_close(rb_data.pdh, err)) {
249 ws_close(rb_data.fd); /* XXX - the above should have closed this already */
250 rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */
258 /* get the next file number and open it */
260 rb_data.curr_file_num++ /* = next_file_num*/;
261 next_file_index = (rb_data.curr_file_num) % rb_data.num_files;
262 next_rfile = &rb_data.files[next_file_index];
264 if (ringbuf_open_file(next_rfile, err) == -1) {
268 if (ringbuf_init_libpcap_fdopen(err) == NULL) {
272 /* switch to the new file */
273 *save_file = next_rfile->name;
274 *save_file_fd = rb_data.fd;
275 (*pdh) = rb_data.pdh;
281 * Calls libpcap_dump_close() for the current ringbuffer file
284 ringbuf_libpcap_dump_close(gchar **save_file, int *err)
286 gboolean ret_val = TRUE;
288 /* close current file, if it's open */
289 if (rb_data.pdh != NULL) {
290 if (!libpcap_dump_close(rb_data.pdh, err)) {
291 ws_close(rb_data.fd);
299 /* set the save file name to the current file */
300 *save_file = rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
305 * Frees all memory allocated by the ringbuffer
312 if (rb_data.files != NULL) {
313 for (i=0; i < rb_data.num_files; i++) {
314 if (rb_data.files[i].name != NULL) {
315 g_free(rb_data.files[i].name);
316 rb_data.files[i].name = NULL;
319 g_free(rb_data.files);
320 rb_data.files = NULL;
322 if (rb_data.fprefix != NULL) {
323 g_free(rb_data.fprefix);
324 rb_data.fprefix = NULL;
326 if (rb_data.fsuffix != NULL) {
327 g_free(rb_data.fsuffix);
328 rb_data.fsuffix = NULL;
333 * Frees all memory allocated by the ringbuffer
336 ringbuf_error_cleanup(void)
340 /* try to close via wtap */
341 if (rb_data.pdh != NULL) {
342 if (libpcap_dump_close(rb_data.pdh, NULL)) {
348 /* close directly if still open */
349 /* XXX - it shouldn't still be open; "libpcap_dump_close()" should leave the
350 file closed even if it fails */
351 if (rb_data.fd != -1) {
352 ws_close(rb_data.fd);
356 if (rb_data.files != NULL) {
357 for (i=0; i < rb_data.num_files; i++) {
358 if (rb_data.files[i].name != NULL) {
359 ws_unlink(rb_data.files[i].name);
363 /* free the memory */
367 #endif /* HAVE_LIBPCAP */