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 #ifdef NEED_SNPRINTF_H
76 #include "wiretap/wtap.h"
77 #include "ringbuffer.h"
79 /* Win32 needs the O_BINARY flag for open() */
84 /* Ringbuffer file structure */
85 typedef struct _rb_file {
89 /* Ringbuffer data structure */
90 typedef struct _ringbuf_data {
92 guint num_files; /* Number of ringbuffer files */
93 guint curr_file_num; /* Number of the current file */
94 gchar *fprefix; /* Filename prefix */
95 gchar *fsuffix; /* Filename suffix */
96 gboolean unlimited; /* TRUE if unlimited number of files */
101 int fd; /* Current ringbuffer file descriptor */
105 static ringbuf_data rb_data;
109 * create the next filename and open a new binary file with that name
111 static int ringbuf_open_file(rb_file *rfile, int *err)
117 if (rfile->name != NULL) {
118 if (rb_data.unlimited == FALSE) {
119 /* remove old file (if any, so ignore error) */
128 current_time = time(NULL);
130 snprintf(filenum, sizeof(filenum), "%05d", rb_data.curr_file_num + 1 /*.number*/);
131 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(¤t_time));
132 rfile->name = g_strconcat(rb_data.fprefix, "_", filenum, "_", timestr,
133 rb_data.fsuffix, NULL);
135 if (rfile->name == NULL) {
140 rb_data.fd = open(rfile->name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT, 0600);
142 if (rb_data.fd == -1 && err != NULL) {
150 * Initialize the ringbuffer data structures
153 ringbuf_init(const char *capfile_name, guint num_files)
156 char *pfx, *last_pathsep;
159 rb_data.files = NULL;
160 rb_data.curr_file_num = 0;
161 rb_data.fprefix = NULL;
162 rb_data.fsuffix = NULL;
163 rb_data.unlimited = FALSE;
167 /* just to be sure ... */
168 if (num_files <= RINGBUFFER_MAX_NUM_FILES) {
169 rb_data.num_files = num_files;
171 rb_data.num_files = RINGBUFFER_MAX_NUM_FILES;
174 /* Check file name */
175 if (capfile_name == NULL) {
176 /* ringbuffer does not work with temporary files! */
180 /* set file name prefix/suffix */
182 save_file = g_strdup(capfile_name);
183 last_pathsep = strrchr(save_file, G_DIR_SEPARATOR);
184 pfx = strrchr(save_file,'.');
185 if (pfx != NULL && (last_pathsep == NULL || pfx > last_pathsep)) {
186 /* The pathname has a "." in it, and it's in the last component
187 of the pathname (because there is either only one component,
188 i.e. last_pathsep is null as there are no path separators,
189 or the "." is after the path separator before the last
192 Treat it as a separator between the rest of the file name and
193 the file name suffix, and arrange that the names given to the
194 ring buffer files have the specified suffix, i.e. put the
195 changing part of the name *before* the suffix. */
197 rb_data.fprefix = g_strdup(save_file);
198 pfx[0] = '.'; /* restore capfile_name */
199 rb_data.fsuffix = g_strdup(pfx);
201 /* Either there's no "." in the pathname, or it's in a directory
202 component, so the last component has no suffix. */
203 rb_data.fprefix = g_strdup(save_file);
204 rb_data.fsuffix = NULL;
209 /* allocate rb_file structures (only one if unlimited since there is no
210 need to save all file names in that case) */
212 if (num_files == RINGBUFFER_UNLIMITED_FILES) {
213 rb_data.unlimited = TRUE;
214 rb_data.num_files = 1;
217 rb_data.files = g_malloc(rb_data.num_files * sizeof(rb_file));
218 if (rb_data.files == NULL) {
222 for (i=0; i < rb_data.num_files; i++) {
223 rb_data.files[i].name = NULL;
226 /* create the first file */
227 if (ringbuf_open_file(&rb_data.files[0], NULL) == -1) {
228 ringbuf_error_cleanup();
236 * Calls wtap_dump_fdopen() for the current ringbuffer file
239 ringbuf_init_wtap_dump_fdopen(int filetype, int linktype, int snaplen, int *err)
242 rb_data.filetype = filetype;
243 rb_data.linktype = linktype;
244 rb_data.snaplen = snaplen;
246 rb_data.pdh = wtap_dump_fdopen(rb_data.fd, filetype, linktype, snaplen, err);
252 * Switches to the next ringbuffer file
255 ringbuf_switch_file(wtap_dumper **pdh, gchar **save_file, int *save_file_fd, int *err)
258 rb_file *next_rfile = NULL;
260 /* close current file */
262 if (!wtap_dump_close(rb_data.pdh, err)) {
263 close(rb_data.fd); /* XXX - the above should have closed this already */
264 rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */
272 /* get the next file number and open it */
274 next_file_num = (rb_data.curr_file_num + 1) % rb_data.num_files;
275 next_rfile = &rb_data.files[next_file_num];
277 if (ringbuf_open_file(next_rfile, err) == -1) {
281 if (ringbuf_init_wtap_dump_fdopen(rb_data.filetype, rb_data.linktype,
282 rb_data.snaplen, err) == NULL) {
286 /* switch to the new file */
287 rb_data.curr_file_num = next_file_num;
288 *save_file = next_rfile->name;
289 *save_file_fd = rb_data.fd;
290 (*pdh) = rb_data.pdh;
296 * Calls wtap_dump_close() for the current ringbuffer file
299 ringbuf_wtap_dump_close(gchar **save_file, int *err)
301 gboolean ret_val = TRUE;
303 /* close current file, if it's open */
304 if (rb_data.pdh != NULL) {
305 if (!wtap_dump_close(rb_data.pdh, err)) {
314 /* set the save file name to the current file */
315 *save_file = rb_data.files[rb_data.curr_file_num].name;
320 * Frees all memory allocated by the ringbuffer
327 if (rb_data.files != NULL) {
328 for (i=0; i < rb_data.num_files; i++) {
329 if (rb_data.files[i].name != NULL) {
330 g_free(rb_data.files[i].name);
331 rb_data.files[i].name = NULL;
334 g_free(rb_data.files);
335 rb_data.files = NULL;
337 if (rb_data.fprefix != NULL) {
338 g_free(rb_data.fprefix);
339 rb_data.fprefix = NULL;
341 if (rb_data.fsuffix != NULL) {
342 g_free(rb_data.fsuffix);
343 rb_data.fsuffix = NULL;
348 * Frees all memory allocated by the ringbuffer
351 ringbuf_error_cleanup(void)
355 /* try to close via wtap */
356 if (rb_data.pdh != NULL) {
357 if (wtap_dump_close(rb_data.pdh, NULL)) {
363 /* close directly if still open */
364 /* XXX - it shouldn't still be open; "wtap_dump_close()" should leave the
365 file closed even if it fails */
366 if (rb_data.fd != -1) {
371 if (rb_data.files != NULL) {
372 for (i=0; i < rb_data.num_files; i++) {
373 if (rb_data.files[i].name != NULL) {
374 unlink(rb_data.files[i].name);
378 /* free the memory */
382 #endif /* HAVE_LIBPCAP */