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- /*
- * Filtering functions
- * Copyright (C) 2012 Unix Solutions Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License (COPYING file) for more details.
- *
- */
- #include <ctype.h>
- #include <string.h>
-
- #include "data.h"
- #include "filter.h"
-
- int filter_parse(char *filter_def, struct filter *filter) {
- int i, j, k, ret = 0;
- char *str1, *saveptr1;
- char *f = strdup(filter_def);
- memset(filter, 0, sizeof(struct filter));
- snprintf(filter->name, sizeof(filter->name), "NONAME");
- for (j = 1, str1 = f; ; j++, str1 = NULL) {
- char *token = strtok_r(str1, "/", &saveptr1);
- if (token == NULL)
- break;
- if (j == 1) { // First token, the command
- if (strstr(token, "accept_all") == token || strstr(token, "acceptall") == token) {
- filter->action = FILTER_ACCEPT_ALL;
- ret = 1;
- goto OUT; // Other tokens are not needed
- } else if (strstr(token, "reject_all") == token || strstr(token, "rejectall") == token) {
- filter->action = FILTER_REJECT_ALL;
- ret = 1;
- goto OUT; // Other tokens are not needed
- } else if (strstr(token, "accept") == token) {
- filter->action = FILTER_ACCEPT;
- continue; // Continue looking for other tokes
- } else if (strstr(token, "reject") == token) {
- filter->action = FILTER_REJECT;
- continue; // Continue looking for other tokes
- } else {
- fprintf(stderr, "ERROR: Unknown filter command: %s\n", token);
- ret = 0;
- goto OUT; // Other tokens are not needed
- }
- }
- if (j == 2) { // Second token, the settings
- char *str2, *saveptr2;
- for (k = 1, str2 = token; ; k++, str2 = NULL) {
- char *token2 = strtok_r(str2, ",", &saveptr2);
- if (token2 == NULL)
- break;
- char *eq = strrchr(token2, '=');
- if (eq) {
- if (strstr(token2, "ofs") == token2 || strstr(token2, "offset") == token2) {
- filter->offset = strtoul(eq + 1, NULL, 0);
- } else if (strstr(token2, "name") == token2) {
- snprintf(filter->name, sizeof(filter->name), "%s", eq + 1);
- } else if (strstr(token2, "data") == token2) {
- char *data = eq + 1;
- int len = strlen(data), consumed = 0;
- for (i = 0; i < len; i++) { // Parse data (01 02 03 04 ...)
- char ch = toupper(data[i]);
- // Skip 0x prefixes
- if (i + 1 < len && ch == '0' && toupper(data[i + 1]) == 'X')
- continue;
- if (!isxdigit(ch))
- continue;
- ch -= ch > 64 ? 55 : 48; // hex2dec
- if (consumed % 2 == 0) {
- filter->data[filter->data_len ] += ch << 4;
- } else {
- filter->data[filter->data_len++] += ch;
- if (filter->data_len + 1 >= MAX_FILTER_LEN) {
- fprintf(stderr, "WARN : Too much filter data (max %d bytes), ignoring last bytes: %s\n",
- MAX_FILTER_LEN, data + i + 2);
- break;
- }
- }
- consumed++;
- }
- ret = filter->data_len;
- } else {
- fprintf(stderr, "WARN : Unknown filter setting: %s\n", token2);
- }
- }
- }
- }
- }
- OUT:
- FREE(f);
- return ret;
- }
-
- void filter_dump(struct filter *filter, char *buffer, unsigned int buf_len) {
- unsigned int pos = 0;
- memset(buffer, 0, buf_len);
- pos += snprintf(buffer + pos, buf_len - pos, "Action: %s",
- filter->action == FILTER_ACCEPT_ALL ? "ACCEPT_ALL (default)" :
- filter->action == FILTER_REJECT_ALL ? "REJECT_ALL (default)" :
- filter->action == FILTER_ACCEPT ? "ACCEPT" :
- filter->action == FILTER_REJECT ? "REJECT" : "???");
- if (filter->action == FILTER_ACCEPT || filter->action == FILTER_REJECT)
- pos += snprintf(buffer + pos, buf_len - pos, " Name: %-20s", filter->name);
- if (filter->action == FILTER_ACCEPT || filter->action == FILTER_REJECT) {
- char tmp[MAX_FILTER_LEN * 6];
- ts_hex_dump_buf(tmp, sizeof(tmp), filter->data, filter->data_len, 0);
- pos += snprintf(buffer + pos, buf_len - pos, " Offset: %2d Data: %s", filter->offset, tmp);
- }
- }
-
- static enum filter_action filter_match(uint8_t *data, unsigned int data_len, struct filter *filter) {
- if (filter->action == FILTER_ACCEPT_ALL || filter->action == FILTER_REJECT_ALL)
- return filter->action;
- if (filter->action == FILTER_ACCEPT || filter->action == FILTER_REJECT) {
- if (filter->data_len + filter->offset > data_len)
- return FILTER_NO_MATCH;
- if (memcmp(data + filter->offset, filter->data, filter->data_len) == 0)
- return filter->action;
- }
- return FILTER_NO_MATCH;
- }
-
- int filter_match_emm(struct ts *ts, uint8_t *data, unsigned int data_len) {
- int i, ret = 1;
- for (i = 0; i < ts->emm_filters_num; i++) {
- enum filter_action result = filter_match(data, data_len, &ts->emm_filters[i]);
- switch (result) {
- case FILTER_NO_MATCH : continue;
- case FILTER_ACCEPT_ALL: ret = 1; continue;
- case FILTER_ACCEPT : ret = 1; break;
- case FILTER_REJECT_ALL: ret = 0; continue;
- case FILTER_REJECT : ret = 0; break;
- }
- }
- return ret;
- }
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