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;
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);
128 snprintf(filenum, sizeof(filenum), "%05d", rb_data.number);
129 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(¤t_time));
130 rfile->name = g_strconcat(rb_data.fprefix, "_", filenum, "_", timestr,
131 rb_data.fsuffix, NULL);
133 if (rfile->name == NULL) {
138 rb_data.fd = open(rfile->name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT, 0600);
140 if (rb_data.fd == -1 && err != NULL) {
148 * Initialize the ringbuffer data structures
151 ringbuf_init(const char *capfile_name, guint num_files)
154 char *pfx, *last_pathsep;
157 rb_data.files = NULL;
158 rb_data.curr_file_num = 0;
159 rb_data.fprefix = NULL;
160 rb_data.fsuffix = NULL;
161 rb_data.unlimited = FALSE;
166 /* just to be sure ... */
167 if (num_files <= RINGBUFFER_MAX_NUM_FILES) {
168 rb_data.num_files = num_files;
170 rb_data.num_files = RINGBUFFER_MAX_NUM_FILES;
173 /* Check file name */
174 if (capfile_name == NULL) {
175 /* ringbuffer does not work with temporary files! */
179 /* set file name prefix/suffix */
181 save_file = g_strdup(capfile_name);
182 last_pathsep = strrchr(save_file, G_DIR_SEPARATOR);
183 pfx = strrchr(save_file,'.');
184 if (pfx != NULL && (last_pathsep == NULL || pfx > last_pathsep)) {
185 /* The pathname has a "." in it, and it's in the last component
186 of the pathname (because there is either only one component,
187 i.e. last_pathsep is null as there are no path separators,
188 or the "." is after the path separator before the last
191 Treat it as a separator between the rest of the file name and
192 the file name suffix, and arrange that the names given to the
193 ring buffer files have the specified suffix, i.e. put the
194 changing part of the name *before* the suffix. */
196 rb_data.fprefix = g_strdup(save_file);
197 pfx[0] = '.'; /* restore capfile_name */
198 rb_data.fsuffix = g_strdup(pfx);
200 /* Either there's no "." in the pathname, or it's in a directory
201 component, so the last component has no suffix. */
202 rb_data.fprefix = g_strdup(save_file);
203 rb_data.fsuffix = NULL;
208 /* allocate rb_file structures (only one if unlimited since there is no
209 need to save all file names in that case) */
211 if (num_files == RINGBUFFER_UNLIMITED_FILES) {
212 rb_data.unlimited = TRUE;
213 rb_data.num_files = 1;
216 rb_data.files = g_malloc(rb_data.num_files * sizeof(rb_file));
217 if (rb_data.files == NULL) {
221 for (i=0; i < rb_data.num_files; i++) {
222 rb_data.files[i].name = NULL;
225 /* create the first file */
226 if (ringbuf_open_file(&rb_data.files[0], NULL) == -1) {
227 ringbuf_error_cleanup();
235 * Calls wtap_dump_fdopen() for the current ringbuffer file
238 ringbuf_init_wtap_dump_fdopen(int filetype, int linktype, int snaplen, int *err)
241 rb_data.filetype = filetype;
242 rb_data.linktype = linktype;
243 rb_data.snaplen = snaplen;
245 rb_data.pdh = wtap_dump_fdopen(rb_data.fd, filetype, linktype, snaplen, err);
251 * Switches to the next ringbuffer file
254 ringbuf_switch_file(capture_file *cf, wtap_dumper **pdh, int *err)
257 rb_file *next_rfile = NULL;
259 /* close current file */
261 if (!wtap_dump_close(rb_data.pdh, err)) {
262 close(rb_data.fd); /* XXX - the above should have closed this already */
263 rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */
271 /* get the next file number and open it */
273 next_file_num = (rb_data.curr_file_num + 1) % rb_data.num_files;
274 next_rfile = &rb_data.files[next_file_num];
276 if (ringbuf_open_file(next_rfile, err) == -1) {
280 if (ringbuf_init_wtap_dump_fdopen(rb_data.filetype, rb_data.linktype,
281 rb_data.snaplen, err) == NULL) {
285 /* switch to the new file */
286 rb_data.curr_file_num = next_file_num;
287 cf->save_file = next_rfile->name;
288 cf->save_file_fd = rb_data.fd;
289 (*pdh) = rb_data.pdh;
295 * Calls wtap_dump_close() for the current ringbuffer file
298 ringbuf_wtap_dump_close(capture_file *cf, int *err)
300 gboolean ret_val = TRUE;
302 /* close current file, if it's open */
303 if (rb_data.pdh != NULL) {
304 if (!wtap_dump_close(rb_data.pdh, err)) {
313 /* set the save file name to the current file */
314 cf->save_file = rb_data.files[rb_data.curr_file_num].name;
319 * Frees all memory allocated by the ringbuffer
326 if (rb_data.files != NULL) {
327 for (i=0; i < rb_data.num_files; i++) {
328 if (rb_data.files[i].name != NULL) {
329 g_free(rb_data.files[i].name);
330 rb_data.files[i].name = NULL;
333 g_free(rb_data.files);
334 rb_data.files = NULL;
336 if (rb_data.fprefix != NULL) {
337 g_free(rb_data.fprefix);
338 rb_data.fprefix = NULL;
340 if (rb_data.fsuffix != NULL) {
341 g_free(rb_data.fsuffix);
342 rb_data.fsuffix = NULL;
347 * Frees all memory allocated by the ringbuffer
350 ringbuf_error_cleanup(void)
354 /* try to close via wtap */
355 if (rb_data.pdh != NULL) {
356 if (wtap_dump_close(rb_data.pdh, NULL)) {
362 /* close directly if still open */
363 /* XXX - it shouldn't still be open; "wtap_dump_close()" should leave the
364 file closed even if it fails */
365 if (rb_data.fd != -1) {
370 if (rb_data.files != NULL) {
371 for (i=0; i < rb_data.num_files; i++) {
372 if (rb_data.files[i].name != NULL) {
373 unlink(rb_data.files[i].name);
377 /* free the memory */
381 #endif /* HAVE_LIBPCAP */