2 * Routines for packet capture windows
6 * Ethereal - Network traffic analyzer
7 * By Gerald Combs <gerald@ethereal.com>
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).
59 #ifdef HAVE_SYS_STAT_H
72 #include "wiretap/wtap.h"
73 #include "ringbuffer.h"
75 /* Win32 needs the O_BINARY flag for open() */
80 /* Ringbuffer file structure */
81 typedef struct _rb_file {
85 /* Ringbuffer data structure */
86 typedef struct _ringbuf_data {
88 guint num_files; /* Number of ringbuffer files */
89 guint curr_file_num; /* Number of the current file */
90 gchar *fprefix; /* Filename prefix */
91 gchar *fsuffix; /* Filename suffix */
92 gboolean unlimited; /* TRUE if unlimited number of files */
97 int fd; /* Current ringbuffer file descriptor */
101 static ringbuf_data rb_data;
105 * create the next filename and open a new binary file with that name
107 static int ringbuf_open_file(rb_file *rfile, int *err)
113 if (rfile->name != NULL) {
114 if (rb_data.unlimited == FALSE) {
115 /* remove old file (if any, so ignore error) */
124 current_time = time(NULL);
126 g_snprintf(filenum, sizeof(filenum), "%05d", rb_data.curr_file_num + 1 /*.number*/);
127 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(¤t_time));
128 rfile->name = g_strconcat(rb_data.fprefix, "_", filenum, "_", timestr,
129 rb_data.fsuffix, NULL);
131 if (rfile->name == NULL) {
136 rb_data.fd = open(rfile->name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT, 0600);
138 if (rb_data.fd == -1 && err != NULL) {
146 * Initialize the ringbuffer data structures
149 ringbuf_init(const char *capfile_name, guint num_files)
152 char *pfx, *last_pathsep;
155 rb_data.files = NULL;
156 rb_data.curr_file_num = 0;
157 rb_data.fprefix = NULL;
158 rb_data.fsuffix = NULL;
159 rb_data.unlimited = FALSE;
163 /* just to be sure ... */
164 if (num_files <= RINGBUFFER_MAX_NUM_FILES) {
165 rb_data.num_files = num_files;
167 rb_data.num_files = RINGBUFFER_MAX_NUM_FILES;
170 /* Check file name */
171 if (capfile_name == NULL) {
172 /* ringbuffer does not work with temporary files! */
176 /* set file name prefix/suffix */
178 save_file = g_strdup(capfile_name);
179 last_pathsep = strrchr(save_file, G_DIR_SEPARATOR);
180 pfx = strrchr(save_file,'.');
181 if (pfx != NULL && (last_pathsep == NULL || pfx > last_pathsep)) {
182 /* The pathname has a "." in it, and it's in the last component
183 of the pathname (because there is either only one component,
184 i.e. last_pathsep is null as there are no path separators,
185 or the "." is after the path separator before the last
188 Treat it as a separator between the rest of the file name and
189 the file name suffix, and arrange that the names given to the
190 ring buffer files have the specified suffix, i.e. put the
191 changing part of the name *before* the suffix. */
193 rb_data.fprefix = g_strdup(save_file);
194 pfx[0] = '.'; /* restore capfile_name */
195 rb_data.fsuffix = g_strdup(pfx);
197 /* Either there's no "." in the pathname, or it's in a directory
198 component, so the last component has no suffix. */
199 rb_data.fprefix = g_strdup(save_file);
200 rb_data.fsuffix = NULL;
205 /* allocate rb_file structures (only one if unlimited since there is no
206 need to save all file names in that case) */
208 if (num_files == RINGBUFFER_UNLIMITED_FILES) {
209 rb_data.unlimited = TRUE;
210 rb_data.num_files = 1;
213 rb_data.files = g_malloc(rb_data.num_files * sizeof(rb_file));
214 if (rb_data.files == NULL) {
218 for (i=0; i < rb_data.num_files; i++) {
219 rb_data.files[i].name = NULL;
222 /* create the first file */
223 if (ringbuf_open_file(&rb_data.files[0], NULL) == -1) {
224 ringbuf_error_cleanup();
232 const gchar *ringbuf_current_filename(void)
234 return rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
238 * Calls wtap_dump_fdopen() for the current ringbuffer file
241 ringbuf_init_wtap_dump_fdopen(int filetype, int linktype, int snaplen, int *err)
244 rb_data.filetype = filetype;
245 rb_data.linktype = linktype;
246 rb_data.snaplen = snaplen;
248 rb_data.pdh = wtap_dump_fdopen(rb_data.fd, filetype, linktype, snaplen, err);
254 * Switches to the next ringbuffer file
257 ringbuf_switch_file(wtap_dumper **pdh, gchar **save_file, int *save_file_fd, int *err)
260 rb_file *next_rfile = NULL;
262 /* close current file */
264 if (!wtap_dump_close(rb_data.pdh, err)) {
265 close(rb_data.fd); /* XXX - the above should have closed this already */
266 rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */
274 /* get the next file number and open it */
276 next_file_num = (rb_data.curr_file_num + 1) % rb_data.num_files;
277 next_rfile = &rb_data.files[next_file_num];
279 if (ringbuf_open_file(next_rfile, err) == -1) {
283 if (ringbuf_init_wtap_dump_fdopen(rb_data.filetype, rb_data.linktype,
284 rb_data.snaplen, err) == NULL) {
288 /* switch to the new file */
289 rb_data.curr_file_num = next_file_num;
290 *save_file = next_rfile->name;
291 *save_file_fd = rb_data.fd;
292 (*pdh) = rb_data.pdh;
298 * Calls wtap_dump_close() for the current ringbuffer file
301 ringbuf_wtap_dump_close(gchar **save_file, int *err)
303 gboolean ret_val = TRUE;
305 /* close current file, if it's open */
306 if (rb_data.pdh != NULL) {
307 if (!wtap_dump_close(rb_data.pdh, err)) {
316 /* set the save file name to the current file */
317 *save_file = rb_data.files[rb_data.curr_file_num].name;
322 * Frees all memory allocated by the ringbuffer
329 if (rb_data.files != NULL) {
330 for (i=0; i < rb_data.num_files; i++) {
331 if (rb_data.files[i].name != NULL) {
332 g_free(rb_data.files[i].name);
333 rb_data.files[i].name = NULL;
336 g_free(rb_data.files);
337 rb_data.files = NULL;
339 if (rb_data.fprefix != NULL) {
340 g_free(rb_data.fprefix);
341 rb_data.fprefix = NULL;
343 if (rb_data.fsuffix != NULL) {
344 g_free(rb_data.fsuffix);
345 rb_data.fsuffix = NULL;
350 * Frees all memory allocated by the ringbuffer
353 ringbuf_error_cleanup(void)
357 /* try to close via wtap */
358 if (rb_data.pdh != NULL) {
359 if (wtap_dump_close(rb_data.pdh, NULL)) {
365 /* close directly if still open */
366 /* XXX - it shouldn't still be open; "wtap_dump_close()" should leave the
367 file closed even if it fails */
368 if (rb_data.fd != -1) {
373 if (rb_data.files != NULL) {
374 for (i=0; i < rb_data.num_files; i++) {
375 if (rb_data.files[i].name != NULL) {
376 unlink(rb_data.files[i].name);
380 /* free the memory */
384 #endif /* HAVE_LIBPCAP */