From f3a4f9e544e93eccd353a2af1813b77b1dbd6ca7 Mon Sep 17 00:00:00 2001
From: claudio <claudio@openbsd.org>
Date: Tue, 20 Apr 2021 07:35:42 +0000
Subject: [PATCH] Use LIST instead of SLIST for requests. The way SLIST_REMOVE
 was used did a double traverse of the list which now is replaced with no
 traversal at all. Also stop double wrapping requests just for the list. OK
 millert@

---
 usr.sbin/slowcgi/slowcgi.c | 41 ++++++++------------------------------
 1 file changed, 8 insertions(+), 33 deletions(-)

diff --git a/usr.sbin/slowcgi/slowcgi.c b/usr.sbin/slowcgi/slowcgi.c
index 48de4e61b1c..56d29d1618d 100644
--- a/usr.sbin/slowcgi/slowcgi.c
+++ b/usr.sbin/slowcgi/slowcgi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: slowcgi.c,v 1.59 2021/04/20 07:32:19 claudio Exp $ */
+/*	$OpenBSD: slowcgi.c,v 1.60 2021/04/20 07:35:42 claudio Exp $ */
 /*
  * Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
  * Copyright (c) 2013 Florian Obser <florian@openbsd.org>
@@ -113,6 +113,7 @@ struct fcgi_stdin {
 TAILQ_HEAD(fcgi_stdin_head, fcgi_stdin);
 
 struct request {
+	LIST_ENTRY(request)		entry;
 	struct event			ev;
 	struct event			resp_ev;
 	struct event			tmo;
@@ -139,11 +140,7 @@ struct request {
 	int				inflight_fds_accounted;
 };
 
-struct requests {
-	SLIST_ENTRY(requests)	 entry;
-	struct request		*request;
-};
-SLIST_HEAD(requests_head, requests);
+LIST_HEAD(requests_head, request);
 
 struct slowcgi_proc {
 	struct requests_head	requests;
@@ -360,7 +357,7 @@ main(int argc, char *argv[])
 	if (pledge("stdio rpath unix proc exec", NULL) == -1)
 		lerr(1, "pledge");
 
-	SLIST_INIT(&slowcgi_proc.requests);
+	LIST_INIT(&slowcgi_proc.requests);
 	event_init();
 
 	l = calloc(1, sizeof(*l));
@@ -453,7 +450,6 @@ slowcgi_accept(int fd, short events, void *arg)
 	struct sockaddr_storage	 ss;
 	struct timeval		 backoff;
 	struct request		*c;
-	struct requests		*requests;
 	socklen_t		 len;
 	int			 s;
 
@@ -487,14 +483,6 @@ slowcgi_accept(int fd, short events, void *arg)
 		cgi_inflight--;
 		return;
 	}
-	requests = calloc(1, sizeof(*requests));
-	if (requests == NULL) {
-		lwarn("cannot calloc requests");
-		close(s);
-		cgi_inflight--;
-		free(c);
-		return;
-	}
 	c->fd = s;
 	c->buf_pos = 0;
 	c->buf_len = 0;
@@ -509,8 +497,7 @@ slowcgi_accept(int fd, short events, void *arg)
 	event_set(&c->resp_ev, s, EV_WRITE | EV_PERSIST, slowcgi_response, c);
 	evtimer_set(&c->tmo, slowcgi_timeout, c);
 	evtimer_add(&c->tmo, &timeout);
-	requests->request = c;
-	SLIST_INSERT_HEAD(&slowcgi_proc.requests, requests, entry);
+	LIST_INSERT_HEAD(&slowcgi_proc.requests, c, entry);
 }
 
 void
@@ -523,7 +510,6 @@ void
 slowcgi_sig_handler(int sig, short event, void *arg)
 {
 	struct request		*c;
-	struct requests		*ncs;
 	struct slowcgi_proc	*p;
 	pid_t			 pid;
 	int			 status;
@@ -533,12 +519,9 @@ slowcgi_sig_handler(int sig, short event, void *arg)
 	switch (sig) {
 	case SIGCHLD:
 		while ((pid = waitpid(WAIT_ANY, &status, WNOHANG)) > 0) {
-			c = NULL;
-			SLIST_FOREACH(ncs, &p->requests, entry)
-				if (ncs->request->script_pid == pid) {
-					c = ncs->request;
+			LIST_FOREACH(c, &p->requests, entry)
+				if (c->script_pid == pid)
 					break;
-				}
 			if (c == NULL) {
 				lwarnx("caught exit of unknown child %i", pid);
 				continue;
@@ -1129,7 +1112,6 @@ cleanup_request(struct request *c)
 	struct fcgi_response	*resp;
 	struct fcgi_stdin	*stdin_node;
 	struct env_val		*env_entry;
-	struct requests		*ncs, *tcs;
 
 	evtimer_del(&c->tmo);
 	if (event_initialized(&c->ev))
@@ -1167,14 +1149,7 @@ cleanup_request(struct request *c)
 		TAILQ_REMOVE(&c->stdin_head, stdin_node, entry);
 		free(stdin_node);
 	}
-	SLIST_FOREACH_SAFE(ncs, &slowcgi_proc.requests, entry, tcs) {
-		if (ncs->request == c) {
-			SLIST_REMOVE(&slowcgi_proc.requests, ncs, requests,
-			    entry);
-			free(ncs);
-			break;
-		}
-	}
+	LIST_REMOVE(c, entry);
 	if (! c->inflight_fds_accounted)
 		cgi_inflight--;
 	free(c);
-- 
2.20.1