From e4d05300767df1526f0885e6b2f909fd8cdc94ed Mon Sep 17 00:00:00 2001
From: Egor <egor@patchysicp.xyz>
Date: Fri, 27 May 2022 11:51:45 +0300
Subject: [PATCH] don't use str{,n}{cpy,cat}

---
 irc.c    | 20 ++++++++++++--------
 ircfmt.c |  2 +-
 main.c   |  8 ++++----
 util.h   |  6 ++++++
 4 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/irc.c b/irc.c
index 5176a98..821d97d 100644
--- a/irc.c
+++ b/irc.c
@@ -228,12 +228,13 @@ int processPacket(struct client_data *client, char *source, char *command, int a
 		if (is_registered(client))
 			return err_alreadyregistered(client), sendbuf(client), 0;
 		free(client->username);
-		client->username = malloc(strlen(args[0])+2);
+		size_t ulen = strlen(args[0]);
+		client->username = malloc(ulen+2);
 		if (!client->username)
 			abort();
 		client->umode &= ~UMODE_REGISTERED;
 		client->username[0] = '~';
-		strcpy(client->username + 1, args[0]);
+		memcpy(client->username + 1, args[0], ulen+1);
 		// set realname
 		free(client->realname); // ditto
 		client->realname = mystrdup(args[3]);
@@ -1018,7 +1019,8 @@ void sendMOTD(struct client_data *client) {
 void setNick(struct client_data *client, char* nickname) {
 	// TODO: perform basic sanitization
 
-	if (strlen(nickname) >= MAX_NICKLEN || nickname[0] == '\0') {
+	size_t nicklen = strlen(nickname);
+	if (nicklen >= MAX_NICKLEN || nickname[0] == '\0') {
 		err_erroneusnickname(client, nickname), sendbuf(client);
 		return;
 	}
@@ -1030,7 +1032,7 @@ void setNick(struct client_data *client, char* nickname) {
 		}
 
 	char key[MAX_NICKLEN];
-	strcpy(key, nickname);
+	memcpy(key, nickname, nicklen+1);
 	stringlower(key);
 
 	if (trie_get(&client_map, key)) {
@@ -1112,10 +1114,11 @@ void channel_join(struct client_data *client, const char *channel, const char *c
 		return; // FIXME: error
 	if (strchr(channel, '\7') || strchr(channel, ' ') || strchr(channel, ','))
 		return; // FIXME: error
-	if (strlen(channel) > 32)
+	size_t chanlen = strlen(channel);
+	if (chanlen > 32)
 		return; // FIXME: error
 	char key[33];
-	strcpy(key, channel);
+	memcpy(key, channel, chanlen+1);
 	stringlower(key);
 	struct channel *chan = trie_get(&channel_map, key);
 	int newchan = !chan;
@@ -1227,10 +1230,11 @@ struct client_data *findClient(const char *nickname)
 }
 struct channel *findChannel(const char *channel)
 {
-	if (strlen(channel) > 32)
+	size_t chanlen = strlen(channel);
+	if (chanlen > 32)
 		return NULL;
 	char key[33];
-	strcpy(key, channel);
+	memcpy(key, channel, chanlen+1);
 	stringlower(key);
 	return trie_get(&channel_map, key);
 }
diff --git a/ircfmt.c b/ircfmt.c
index 9918ec0..61a6790 100644
--- a/ircfmt.c
+++ b/ircfmt.c
@@ -445,7 +445,7 @@ void rpl_time(struct client_data *client, time_t ts) // 391
 {
 	// FIXME: 64-bit time_t support
 	char buf[26];
-	strcpy(buf, ctime(&ts));
+	memcpy(buf, ctime(&ts), 26);
 	buf[24] = '\0';
 	copy_strf(&databuf, ":%s 391 %s %s :%s\r\n", hostname, client->nick, ts, buf);
 }
diff --git a/main.c b/main.c
index 8318d7a..5d3838b 100644
--- a/main.c
+++ b/main.c
@@ -149,7 +149,7 @@ void accept_from_sock(struct listener *listener)
 			inet_ntop(AF_INET6, &((struct sockaddr_in6*)&addr)->sin6_addr, client_addr, sizeof(client_addr));
 			port = ntohs(((struct sockaddr_in6*)&addr)->sin6_port);
 		} else {
-			strcpy(client_addr, "?");
+			strcpy_lit(client_addr, "?");
 			port = 0;
 		}
 		fprintf(stderr, "Connection accepted from Socket: %"PRISocket", IP: %s PORT: %d\n", newSocket,
@@ -258,10 +258,10 @@ int main(int argc, char *argv[])
 	if (f) {
 		struct client_data *fake = allocClient();
 		fake->umode |= UMODE_OPER | UMODE_SECURE;
-		strcpy(fake->buf, "NICK :root\r\n");
+		strcpy_lit(fake->buf, "NICK :root\r\n");
 		fake->bufLen = strlen(fake->buf);
 		parsePacket(fake);
-		strcpy(fake->buf, "USER root 0 * :Patchouli Knowledge\r\n");
+		strcpy_lit(fake->buf, "USER root 0 * :Patchouli Knowledge\r\n");
 		fake->bufLen = strlen(fake->buf);
 		parsePacket(fake);
 		while (fgets(fake->buf, sizeof(fake->buf), f)) {
@@ -296,7 +296,7 @@ int main(int argc, char *argv[])
 			fake->bufLen = len;
 			parsePacket(fake);
 		}
-		strcpy(fake->buf, "QUIT :bye\r\n");
+		strcpy_lit(fake->buf, "QUIT :bye\r\n");
 		fake->bufLen = strlen(fake->buf);
 		parsePacket(fake);
 		set_time(0);
diff --git a/util.h b/util.h
index edc75cd..26ee14d 100644
--- a/util.h
+++ b/util.h
@@ -15,7 +15,13 @@ void stringupper(char *s);
 void stringlower(char *s);
 #ifndef _MSC_VER
 #pragma GCC poison strdup
+
+#pragma GCC poison strcpy
+#pragma GCC poison strncpy
+#pragma GCC poison strcat
+#pragma GCC poison strncat
 #endif
+#define strcpy_lit(a, b) memcpy((a), (b), sizeof(b))
 char *mystrdup(const char *s);
 time_t get_time();
 void set_time(time_t t);
-- 
2.56.0