2 * Routines for packet capture windows
4 * Wireshark - Network traffic analyzer
5 * By Gerald Combs <gerald@wireshark.org>
6 * Copyright 1998 Gerald Combs
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 * <laurent.deniel@free.fr>
26 * Almost completely rewritten in order to:
28 * - be able to use a unlimited number of ringbuffer files
29 * - close the current file and open (truncating) the next file at switch
30 * - set the final file name once open (or reopen)
31 * - avoid the deletion of files that could not be truncated (can't arise now)
32 * and do not erase empty files
34 * The idea behind that is to remove the limitation of the maximum # of
35 * ringbuffer files being less than the maximum # of open fd per process
36 * and to be able to reduce the amount of virtual memory usage (having only
37 * one file open at most) or the amount of file system usage (by truncating
38 * the files at switch and not the capture stop, and by closing them which
39 * makes possible their move or deletion after a switch).
56 #include "ringbuffer.h"
57 #include <wsutil/file_util.h>
60 /* Ringbuffer file structure */
61 typedef struct _rb_file {
65 /* Ringbuffer data structure */
66 typedef struct _ringbuf_data {
68 guint num_files; /* Number of ringbuffer files (1 to ...) */
69 guint curr_file_num; /* Number of the current file (ever increasing) */
70 gchar *fprefix; /* Filename prefix */
71 gchar *fsuffix; /* Filename suffix */
72 gboolean unlimited; /* TRUE if unlimited number of files */
74 int fd; /* Current ringbuffer file descriptor */
76 gboolean group_read_access; /* TRUE if files need to be opened with group read access */
79 static ringbuf_data rb_data;
83 * create the next filename and open a new binary file with that name
85 static int ringbuf_open_file(rb_file *rfile, int *err)
91 if (rfile->name != NULL) {
92 if (rb_data.unlimited == FALSE) {
93 /* remove old file (if any, so ignore error) */
94 ws_unlink(rfile->name);
102 current_time = time(NULL);
104 g_snprintf(filenum, sizeof(filenum), "%05u", (rb_data.curr_file_num + 1) % RINGBUFFER_MAX_NUM_FILES);
105 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(¤t_time));
106 rfile->name = g_strconcat(rb_data.fprefix, "_", filenum, "_", timestr,
107 rb_data.fsuffix, NULL);
109 if (rfile->name == NULL) {
115 rb_data.fd = ws_open(rfile->name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT,
116 rb_data.group_read_access ? 0640 : 0600);
118 if (rb_data.fd == -1 && err != NULL) {
126 * Initialize the ringbuffer data structures
129 ringbuf_init(const char *capfile_name, guint num_files, gboolean group_read_access)
132 char *pfx, *last_pathsep;
135 rb_data.files = NULL;
136 rb_data.curr_file_num = 0;
137 rb_data.fprefix = NULL;
138 rb_data.fsuffix = NULL;
139 rb_data.unlimited = FALSE;
142 rb_data.group_read_access = group_read_access;
144 /* just to be sure ... */
145 if (num_files <= RINGBUFFER_MAX_NUM_FILES) {
146 rb_data.num_files = num_files;
148 rb_data.num_files = RINGBUFFER_MAX_NUM_FILES;
151 /* Check file name */
152 if (capfile_name == NULL) {
153 /* ringbuffer does not work with temporary files! */
157 /* set file name prefix/suffix */
159 save_file = g_strdup(capfile_name);
160 last_pathsep = strrchr(save_file, G_DIR_SEPARATOR);
161 pfx = strrchr(save_file,'.');
162 if (pfx != NULL && (last_pathsep == NULL || pfx > last_pathsep)) {
163 /* The pathname has a "." in it, and it's in the last component
164 of the pathname (because there is either only one component,
165 i.e. last_pathsep is null as there are no path separators,
166 or the "." is after the path separator before the last
169 Treat it as a separator between the rest of the file name and
170 the file name suffix, and arrange that the names given to the
171 ring buffer files have the specified suffix, i.e. put the
172 changing part of the name *before* the suffix. */
174 rb_data.fprefix = g_strdup(save_file);
175 pfx[0] = '.'; /* restore capfile_name */
176 rb_data.fsuffix = g_strdup(pfx);
178 /* Either there's no "." in the pathname, or it's in a directory
179 component, so the last component has no suffix. */
180 rb_data.fprefix = g_strdup(save_file);
181 rb_data.fsuffix = NULL;
186 /* allocate rb_file structures (only one if unlimited since there is no
187 need to save all file names in that case) */
189 if (num_files == RINGBUFFER_UNLIMITED_FILES) {
190 rb_data.unlimited = TRUE;
191 rb_data.num_files = 1;
194 rb_data.files = (rb_file *)g_malloc(rb_data.num_files * sizeof(rb_file));
195 if (rb_data.files == NULL) {
199 for (i=0; i < rb_data.num_files; i++) {
200 rb_data.files[i].name = NULL;
203 /* create the first file */
204 if (ringbuf_open_file(&rb_data.files[0], NULL) == -1) {
205 ringbuf_error_cleanup();
213 const gchar *ringbuf_current_filename(void)
215 return rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
219 * Calls ws_fdopen() for the current ringbuffer file
222 ringbuf_init_libpcap_fdopen(int *err)
224 rb_data.pdh = ws_fdopen(rb_data.fd, "wb");
225 if (rb_data.pdh == NULL) {
234 * Switches to the next ringbuffer file
237 ringbuf_switch_file(FILE **pdh, gchar **save_file, int *save_file_fd, int *err)
240 rb_file *next_rfile = NULL;
242 /* close current file */
244 if (fclose(rb_data.pdh) == EOF) {
248 ws_close(rb_data.fd); /* XXX - the above should have closed this already */
249 rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */
257 /* get the next file number and open it */
259 rb_data.curr_file_num++ /* = next_file_num*/;
260 next_file_index = (rb_data.curr_file_num) % rb_data.num_files;
261 next_rfile = &rb_data.files[next_file_index];
263 if (ringbuf_open_file(next_rfile, err) == -1) {
267 if (ringbuf_init_libpcap_fdopen(err) == NULL) {
271 /* switch to the new file */
272 *save_file = next_rfile->name;
273 *save_file_fd = rb_data.fd;
274 (*pdh) = rb_data.pdh;
280 * Calls fclose() for the current ringbuffer file
283 ringbuf_libpcap_dump_close(gchar **save_file, int *err)
285 gboolean ret_val = TRUE;
287 /* close current file, if it's open */
288 if (rb_data.pdh != NULL) {
289 if (fclose(rb_data.pdh) == EOF) {
293 ws_close(rb_data.fd);
300 /* set the save file name to the current file */
301 *save_file = rb_data.files[rb_data.curr_file_num % rb_data.num_files].name;
306 * Frees all memory allocated by the ringbuffer
313 if (rb_data.files != NULL) {
314 for (i=0; i < rb_data.num_files; i++) {
315 if (rb_data.files[i].name != NULL) {
316 g_free(rb_data.files[i].name);
317 rb_data.files[i].name = NULL;
320 g_free(rb_data.files);
321 rb_data.files = NULL;
323 if (rb_data.fprefix != NULL) {
324 g_free(rb_data.fprefix);
325 rb_data.fprefix = NULL;
327 if (rb_data.fsuffix != NULL) {
328 g_free(rb_data.fsuffix);
329 rb_data.fsuffix = NULL;
334 * Frees all memory allocated by the ringbuffer
337 ringbuf_error_cleanup(void)
341 /* try to close via wtap */
342 if (rb_data.pdh != NULL) {
343 if (fclose(rb_data.pdh) == 0) {
349 /* close directly if still open */
350 if (rb_data.fd != -1) {
351 ws_close(rb_data.fd);
355 if (rb_data.files != NULL) {
356 for (i=0; i < rb_data.num_files; i++) {
357 if (rb_data.files[i].name != NULL) {
358 ws_unlink(rb_data.files[i].name);
362 /* free the memory */
366 #endif /* HAVE_LIBPCAP */
369 * Editor modelines - http://www.wireshark.org/tools/modelines.html
374 * indent-tabs-mode: nil
377 * ex: set shiftwidth=2 tabstop=8 expandtab:
378 * :indentSize=2:tabSize=8:noTabs=true: