1 files changed, 105 insertions, 0 deletions
diff --git a/filter.c b/filter.c
new file mode 100644
index 0000000..2a7d564
--- /dev/null
+++ b/filter.c
@@ -0,0 +1,105 @@
+/* Copyright (C) 2020  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * Additional permission under GNU GPL version 3 section 7:
+ *
+ * If you modify this Program, or any covered work, by linking or
+ * combining it with OpenSSL (or a modified version of that library),
+ * containing parts covered by the terms of the OpenSSL License and the
+ * original SSLeay license, the licensors of this Program grant you
+ * additional permission to convey the resulting work. Corresponding
+ * Source for a non-source form of such a combination shall include the
+ * source code for the parts of OpenSSL used as well as that of the
+ * covered work.
+ */
+
+#include <err.h>
+#include <fnmatch.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+
+#include "chat.h"
+
+struct Filter filters[FilterCap];
+static size_t len;
+
+struct Filter filterParse(enum Heat heat, char *pattern) {
+	struct Filter filter = { .heat = heat };
+	filter.mask = strsep(&pattern, " ");
+	filter.cmd  = strsep(&pattern, " ");
+	filter.chan = strsep(&pattern, " ");
+	filter.mesg = pattern;
+	return filter;
+}
+
+struct Filter filterAdd(enum Heat heat, const char *pattern) {
+	if (len == FilterCap) errx(EX_CONFIG, "filter limit exceeded");
+	char *own;
+	if (!strchr(pattern, '!') && !strchr(pattern, ' ')) {
+		int n = asprintf(&own, "%s!*@*", pattern);
+		if (n < 0) err(EX_OSERR, "asprintf");
+	} else {
+		own = strdup(pattern);
+		if (!own) err(EX_OSERR, "strdup");
+	}
+	struct Filter filter = filterParse(heat, own);
+	filters[len++] = filter;
+	return filter;
+}
+
+bool filterRemove(struct Filter filter) {
+	bool found = false;
+	for (size_t i = len - 1; i < len; --i) {
+		if (filters[i].heat != filter.heat) continue;
+		if (!filters[i].cmd != !filter.cmd) continue;
+		if (!filters[i].chan != !filter.chan) continue;
+		if (!filters[i].mesg != !filter.mesg) continue;
+		if (strcasecmp(filters[i].mask, filter.mask)) continue;
+		if (filter.cmd && strcasecmp(filters[i].cmd, filter.cmd)) continue;
+		if (filter.chan && strcasecmp(filters[i].chan, filter.chan)) continue;
+		if (filter.mesg && strcasecmp(filters[i].mesg, filter.mesg)) continue;
+		free(filters[i].mask);
+		filters[i] = filters[--len];
+		filters[len] = (struct Filter) {0};
+		found = true;
+	}
+	return found;
+}
+
+static bool filterTest(
+	struct Filter filter, const char *mask, uint id, const struct Message *msg
+) {
+	if (fnmatch(filter.mask, mask, FNM_CASEFOLD)) return false;
+	if (!filter.cmd) return true;
+	if (fnmatch(filter.cmd, msg->cmd, FNM_CASEFOLD)) return false;
+	if (!filter.chan) return true;
+	if (fnmatch(filter.chan, idNames[id], FNM_CASEFOLD)) return false;
+	if (!filter.mesg) return true;
+	if (!msg->params[1]) return false;
+	return !fnmatch(filter.mesg, msg->params[1], FNM_CASEFOLD);
+}
+
+enum Heat filterCheck(enum Heat heat, uint id, const struct Message *msg) {
+	if (!len) return heat;
+	char mask[512];
+	snprintf(mask, sizeof(mask), "%s!%s@%s", msg->nick, msg->user, msg->host);
+	for (size_t i = 0; i < len; ++i) {
+		if (filterTest(filters[i], mask, id, msg)) return filters[i].heat;
+	}
+	return heat;
+}