4 * Ethereal - Network traffic analyzer
5 * By Gerald Combs <gerald@ethereal.com>
6 * Copyright 2001 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
30 #ifdef NEED_SNPRINTF_H
34 #include "dfilter-int.h"
35 #include "syntax-tree.h"
39 #include <epan/epan_dissect.h>
41 #define DFILTER_TOKEN_ID_OFFSET 1
43 /* Global error message space for dfilter_compile errors */
44 static gchar dfilter_error_msg_buf[1024];
45 gchar *dfilter_error_msg; /* NULL when no error resulted */
48 void df_scanner_text(const char *text);
49 void df_scanner_cleanup(void);
52 /* Holds the singular instance of our Lemon parser object */
53 static void* ParserObj = NULL;
56 dfilter_fail(const char *format, ...)
60 /* If we've already reported one error, don't overwite it */
61 if (dfilter_error_msg != NULL)
64 va_start(args, format);
66 vsnprintf(dfilter_error_msg_buf, sizeof(dfilter_error_msg_buf),
68 dfilter_error_msg = dfilter_error_msg_buf;
73 /* Initialize the dfilter module */
78 g_message("I expected ParserObj to be NULL\n");
79 /* Free the Lemon Parser object */
80 DfilterFree(ParserObj, g_free);
82 /* Allocate an instance of our Lemon-based parser */
83 ParserObj = DfilterAlloc(g_malloc);
85 /* Enable parser tracing by defining AM_CFLAGS
86 * so that it contains "-DDFTRACE".
90 DfilterTrace(stdout, "lemon> ");
93 /* Initialize the syntax-tree sub-sub-system */
97 /* Clean-up the dfilter module */
101 /* Free the Lemon Parser object */
103 DfilterFree(ParserObj, g_free);
106 /* Clean up the syntax-tree sub-sub-system */
115 df = g_new(dfilter_t, 1);
121 /* Given a GPtrArray of instructions (dfvm_insn_t),
124 free_insns(GPtrArray *insns)
129 for (i = 0; i < insns->len; i++) {
130 insn = g_ptr_array_index(insns, i);
131 dfvm_insn_free(insn);
136 dfilter_free(dfilter_t *df)
139 free_insns(df->insns);
142 if (df->interesting_fields) {
143 g_free(df->interesting_fields);
146 g_free(df->registers);
147 g_free(df->attempted_load);
157 dfw = g_new(dfwork_t, 1);
160 dfw->syntax_error = FALSE;
162 dfw->loaded_fields = NULL;
163 dfw->interesting_fields = NULL;
164 dfw->next_insn_id = 0;
165 dfw->next_register = 0;
171 dfwork_free(dfwork_t *dfw)
174 stnode_free(dfw->st_root);
177 if (dfw->loaded_fields) {
178 g_hash_table_destroy(dfw->loaded_fields);
181 if (dfw->interesting_fields) {
182 g_hash_table_destroy(dfw->interesting_fields);
186 free_insns(dfw->insns);
195 dfilter_compile(const gchar *text, dfilter_t **dfp)
200 gboolean failure = FALSE;
202 dfilter_error_msg = NULL;
206 df_scanner_text(text);
209 df_lval = stnode_new(STTYPE_UNINITIALIZED, NULL);
212 /* Check for scanner failure */
213 if (token == SCAN_FAILED) {
218 /* Check for end-of-input */
223 /* Give the token to the parser */
224 Dfilter(ParserObj, token, df_lval, dfw);
225 /* We've used the stnode_t, so we don't want to free it */
228 if (dfw->syntax_error) {
234 /* If we created an stnode_t but didn't use it, free it; the
235 * parser doesn't know about it and won't free it for us. */
237 stnode_free(df_lval);
241 /* Tell the parser that we have reached the end of input; that
242 * way, it'll reset its state for the next compile. (We want
243 * to do that even if we got a syntax error, to make sure the
244 * parser state is cleaned up; we don't create a new parser
245 * object when we start a new parse, and don't destroy it when
246 * the parse finishes.) */
247 Dfilter(ParserObj, 0, NULL, dfw);
249 /* One last check for syntax error (after EOF) */
250 if (dfw->syntax_error)
254 df_scanner_cleanup();
259 /* Success, but was it an empty filter? If so, discard
260 * it and set *dfp to NULL */
261 if (dfw->st_root == NULL) {
266 /* Check semantics and do necessary type conversion*/
267 if (!dfw_semcheck(dfw)) {
271 /* Create bytecode */
274 /* Tuck away the bytecode in the dfilter_t */
275 dfilter = dfilter_new();
276 dfilter->insns = dfw->insns;
278 dfilter->interesting_fields = dfw_interesting_fields(dfw,
279 &dfilter->num_interesting_fields);
281 /* Initialize run-time space */
282 dfilter->num_registers = dfw->next_register;
283 dfilter->registers = g_new0(GList*, dfilter->num_registers);
284 dfilter->attempted_load = g_new0(gboolean, dfilter->num_registers);
286 /* And give it to the user. */
297 dfilter_fail("Unable to parse filter string \"%s\".", text);
305 dfilter_apply(dfilter_t *df, proto_tree *tree)
307 return dfvm_apply(df, tree);
311 dfilter_apply_edt(dfilter_t *df, epan_dissect_t* edt)
313 return dfvm_apply(df, edt->tree);
318 dfilter_prime_proto_tree(const dfilter_t *df, proto_tree *tree)
322 for (i = 0; i < df->num_interesting_fields; i++) {
323 proto_tree_prime_hfid(tree, df->interesting_fields[i]);
329 dfilter_dump(dfilter_t *df)
331 dfvm_dump(stdout, df->insns);