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).
68 #include <wiretap/wtap.h>
69 #include "ringbuffer.h"
71 /* Win32 needs the O_BINARY flag for open() */
76 /* Ringbuffer file structure */
77 typedef struct _rb_file {
81 /* Ringbuffer data structure */
82 typedef struct _ringbuf_data {
84 guint num_files; /* Number of ringbuffer files */
85 guint curr_file_num; /* Number of the current file */
86 gchar *fprefix; /* Filename prefix */
87 gchar *fsuffix; /* Filename suffix */
88 gboolean unlimited; /* TRUE if unlimited number of files */
93 int fd; /* Current ringbuffer file descriptor */
97 static ringbuf_data rb_data;
101 * create the next filename and open a new binary file with that name
103 static int ringbuf_open_file(rb_file *rfile, int *err)
109 if (rfile->name != NULL) {
110 if (rb_data.unlimited == FALSE) {
111 /* remove old file (if any, so ignore error) */
120 current_time = time(NULL);
122 g_snprintf(filenum, sizeof(filenum), "%05d", rb_data.curr_file_num + 1 /*.number*/);
123 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(¤t_time));
124 rfile->name = g_strconcat(rb_data.fprefix, "_", filenum, "_", timestr,
125 rb_data.fsuffix, NULL);
127 if (rfile->name == NULL) {
132 rb_data.fd = open(rfile->name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT, 0600);
134 if (rb_data.fd == -1 && err != NULL) {
142 * Initialize the ringbuffer data structures
145 ringbuf_init(const char *capfile_name, guint num_files)
148 char *pfx, *last_pathsep;
151 rb_data.files = NULL;
152 rb_data.curr_file_num = 0;
153 rb_data.fprefix = NULL;
154 rb_data.fsuffix = NULL;
155 rb_data.unlimited = FALSE;
159 /* just to be sure ... */
160 if (num_files <= RINGBUFFER_MAX_NUM_FILES) {
161 rb_data.num_files = num_files;
163 rb_data.num_files = RINGBUFFER_MAX_NUM_FILES;
166 /* Check file name */
167 if (capfile_name == NULL) {
168 /* ringbuffer does not work with temporary files! */
172 /* set file name prefix/suffix */
174 save_file = g_strdup(capfile_name);
175 last_pathsep = strrchr(save_file, G_DIR_SEPARATOR);
176 pfx = strrchr(save_file,'.');
177 if (pfx != NULL && (last_pathsep == NULL || pfx > last_pathsep)) {
178 /* The pathname has a "." in it, and it's in the last component
179 of the pathname (because there is either only one component,
180 i.e. last_pathsep is null as there are no path separators,
181 or the "." is after the path separator before the last
184 Treat it as a separator between the rest of the file name and
185 the file name suffix, and arrange that the names given to the
186 ring buffer files have the specified suffix, i.e. put the
187 changing part of the name *before* the suffix. */
189 rb_data.fprefix = g_strdup(save_file);
190 pfx[0] = '.'; /* restore capfile_name */
191 rb_data.fsuffix = g_strdup(pfx);
193 /* Either there's no "." in the pathname, or it's in a directory
194 component, so the last component has no suffix. */
195 rb_data.fprefix = g_strdup(save_file);
196 rb_data.fsuffix = NULL;
201 /* allocate rb_file structures (only one if unlimited since there is no
202 need to save all file names in that case) */
204 if (num_files == RINGBUFFER_UNLIMITED_FILES) {
205 rb_data.unlimited = TRUE;
206 rb_data.num_files = 1;
209 rb_data.files = g_malloc(rb_data.num_files * sizeof(rb_file));
210 if (rb_data.files == NULL) {
214 for (i=0; i < rb_data.num_files; i++) {
215 rb_data.files[i].name = NULL;
218 /* create the first file */
219 if (ringbuf_open_file(&rb_data.files[0], NULL) == -1) {
220 ringbuf_error_cleanup();
228 const gchar *ringbuf_current_filename(void)
230 return rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
234 * Calls wtap_dump_fdopen() for the current ringbuffer file
237 ringbuf_init_wtap_dump_fdopen(int filetype, int linktype, int snaplen, int *err)
240 rb_data.filetype = filetype;
241 rb_data.linktype = linktype;
242 rb_data.snaplen = snaplen;
244 rb_data.pdh = wtap_dump_fdopen(rb_data.fd, filetype, linktype, snaplen, err);
250 * Switches to the next ringbuffer file
253 ringbuf_switch_file(wtap_dumper **pdh, gchar **save_file, int *save_file_fd, int *err)
256 rb_file *next_rfile = NULL;
258 /* close current file */
260 if (!wtap_dump_close(rb_data.pdh, err)) {
261 close(rb_data.fd); /* XXX - the above should have closed this already */
262 rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */
270 /* get the next file number and open it */
272 next_file_num = (rb_data.curr_file_num + 1) % rb_data.num_files;
273 next_rfile = &rb_data.files[next_file_num];
275 if (ringbuf_open_file(next_rfile, err) == -1) {
279 if (ringbuf_init_wtap_dump_fdopen(rb_data.filetype, rb_data.linktype,
280 rb_data.snaplen, err) == NULL) {
284 /* switch to the new file */
285 rb_data.curr_file_num = next_file_num;
286 *save_file = next_rfile->name;
287 *save_file_fd = rb_data.fd;
288 (*pdh) = rb_data.pdh;
294 * Calls wtap_dump_close() for the current ringbuffer file
297 ringbuf_wtap_dump_close(gchar **save_file, int *err)
299 gboolean ret_val = TRUE;
301 /* close current file, if it's open */
302 if (rb_data.pdh != NULL) {
303 if (!wtap_dump_close(rb_data.pdh, err)) {
312 /* set the save file name to the current file */
313 *save_file = rb_data.files[rb_data.curr_file_num].name;
318 * Frees all memory allocated by the ringbuffer
325 if (rb_data.files != NULL) {
326 for (i=0; i < rb_data.num_files; i++) {
327 if (rb_data.files[i].name != NULL) {
328 g_free(rb_data.files[i].name);
329 rb_data.files[i].name = NULL;
332 g_free(rb_data.files);
333 rb_data.files = NULL;
335 if (rb_data.fprefix != NULL) {
336 g_free(rb_data.fprefix);
337 rb_data.fprefix = NULL;
339 if (rb_data.fsuffix != NULL) {
340 g_free(rb_data.fsuffix);
341 rb_data.fsuffix = NULL;
346 * Frees all memory allocated by the ringbuffer
349 ringbuf_error_cleanup(void)
353 /* try to close via wtap */
354 if (rb_data.pdh != NULL) {
355 if (wtap_dump_close(rb_data.pdh, NULL)) {
361 /* close directly if still open */
362 /* XXX - it shouldn't still be open; "wtap_dump_close()" should leave the
363 file closed even if it fails */
364 if (rb_data.fd != -1) {
369 if (rb_data.files != NULL) {
370 for (i=0; i < rb_data.num_files; i++) {
371 if (rb_data.files[i].name != NULL) {
372 unlink(rb_data.files[i].name);
376 /* free the memory */
380 #endif /* HAVE_LIBPCAP */