From 4b883177dc025db24473e62469f97631a12ad536 Mon Sep 17 00:00:00 2001
From: "C. McEnroe" <june@causal.agency>
Date: Fri, 1 Jan 2021 20:09:10 -0500
Subject: Split ignore fields to avoid over-eager * matching

Split ignore fields and match each separately to avoid an early *
eagerly matching across several fields. For example, "* JOIN * *" should
not match messages which happen to contain the word "JOIN" followed by
two other words.

Ignore capacity is reduced to 64 to keep the size of the array the same.
I don't think it's an issue.
---
 ignore.c | 89 +++++++++++++++++++++++++++++++++++++---------------------------
 1 file changed, 52 insertions(+), 37 deletions(-)

(limited to 'ignore.c')

diff --git a/ignore.c b/ignore.c
index f8e4d59..5a9d296 100644
--- a/ignore.c
+++ b/ignore.c
@@ -35,55 +35,70 @@
 
 #include "chat.h"
 
-struct Ignore ignore;
+struct Ignore ignores[IgnoreCap];
+static size_t len;
 
-const char *ignoreAdd(const char *pattern) {
-	if (ignore.len == IgnoreCap) errx(EX_CONFIG, "ignore limit exceeded");
-	uint ex = 0, sp = 0;
-	for (const char *ch = pattern; *ch; ++ch) {
-		if (*ch == '!') ex++;
-		if (*ch == ' ') sp++;
-	}
-	char **dest = &ignore.patterns[ignore.len++];
-	int n = 0;
-	if (!ex && !sp) {
-		n = asprintf(dest, "%s!*@* * * *", pattern);
-	} else if (sp < 1) {
-		n = asprintf(dest, "%s * * *", pattern);
-	} else if (sp < 2) {
-		n = asprintf(dest, "%s * *", pattern);
-	} else if (sp < 3) {
-		n = asprintf(dest, "%s *", pattern);
+struct Ignore ignoreParse(char *pattern) {
+	struct Ignore ignore = {0};
+	ignore.mask = strsep(&pattern, " ");
+	ignore.cmd  = strsep(&pattern, " ");
+	ignore.chan = strsep(&pattern, " ");
+	ignore.mesg = pattern;
+	return ignore;
+}
+
+struct Ignore ignoreAdd(const char *pattern) {
+	if (len == IgnoreCap) errx(EX_CONFIG, "ignore limit exceeded");
+	char *own;
+	if (!strchr(pattern, '!') && !strchr(pattern, ' ')) {
+		int n = asprintf(&own, "%s!*@*", pattern);
+		if (n < 0) err(EX_OSERR, "asprintf");
 	} else {
-		*dest = strdup(pattern);
+		own = strdup(pattern);
+		if (!own) err(EX_OSERR, "strdup");
 	}
-	if (n < 0) err(EX_OSERR, "asprintf");
-	if (!*dest) err(EX_OSERR, "strdup");
-	return *dest;
+	struct Ignore ignore = ignoreParse(own);
+	ignores[len++] = ignore;
+	return ignore;
 }
 
-bool ignoreRemove(const char *pattern) {
+bool ignoreRemove(struct Ignore ignore) {
 	bool found = false;
-	for (size_t i = 0; i < ignore.len; ++i) {
-		if (strcasecmp(ignore.patterns[i], pattern)) continue;
-		free(ignore.patterns[i]);
-		ignore.patterns[i] = ignore.patterns[--ignore.len];
+	for (size_t i = len - 1; i < len; --i) {
+		if (!ignores[i].cmd != !ignore.cmd) continue;
+		if (!ignores[i].chan != !ignore.chan) continue;
+		if (!ignores[i].mesg != !ignore.mesg) continue;
+		if (strcasecmp(ignores[i].mask, ignore.mask)) continue;
+		if (ignore.cmd && strcasecmp(ignores[i].cmd, ignore.cmd)) continue;
+		if (ignore.chan && strcasecmp(ignores[i].chan, ignore.chan)) continue;
+		if (ignore.mesg && strcasecmp(ignores[i].mesg, ignore.mesg)) continue;
+		free(ignores[i].mask);
+		ignores[i] = ignores[--len];
+		ignores[len] = (struct Ignore) {0};
 		found = true;
 	}
 	return found;
 }
 
+static bool ignoreTest(
+	struct Ignore ignore, const char *mask, uint id, const struct Message *msg
+) {
+	if (fnmatch(ignore.mask, mask, FNM_CASEFOLD)) return false;
+	if (!ignore.cmd) return true;
+	if (fnmatch(ignore.cmd, msg->cmd, FNM_CASEFOLD)) return false;
+	if (!ignore.chan) return true;
+	if (fnmatch(ignore.chan, idNames[id], FNM_CASEFOLD)) return false;
+	if (!ignore.mesg) return true;
+	if (!msg->params[1]) return false;
+	return !fnmatch(ignore.mesg, msg->params[1], FNM_CASEFOLD);
+}
+
 enum Heat ignoreCheck(enum Heat heat, uint id, const struct Message *msg) {
-	if (!ignore.len) return heat;
-	char match[512];
-	snprintf(
-		match, sizeof(match), "%s!%s@%s %s %s %s",
-		msg->nick, msg->user, msg->host,
-		msg->cmd, idNames[id], (msg->params[1] ?: "")
-	);
-	for (size_t i = 0; i < ignore.len; ++i) {
-		if (fnmatch(ignore.patterns[i], match, FNM_CASEFOLD)) continue;
-		return Ice;
+	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 (ignoreTest(ignores[i], mask, id, msg)) return Ice;
 	}
 	return heat;
 }
-- 
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