quark

commit f1892c4dffa7df6995cd8c9ebd47e0ce7f0e457e
parent 3729e7222aafc4c4ca30351748a89e05f78e2230
Author: Laslo Hunhold <dev@frign.de>
Date:   Sun, 31 Jan 2021 00:39:11 +0100

Fix handling of unexpected hangups

During slowloris-stress-testing I noticed that closing the tool would
pretty reliably trigger a case where quark was continuously getting
edge-triggered on EPOLLIN and notified that there was something to read
on the now definitely closed client-sockets.

This was wrong and due to the fact that I mishandled the case when
read() returns 0 in http_recv_header(). The condition read()==0 and
EPOLL or EWOULDBLOCK does not indicate that you should try again. It's
an EOF-condition and should be handled as such.

Given the request is incomplete at this point, this is handled as a
bad request (HTTP status 400) mostly for the logs at this point, as
being able to transmit the error page itself is highly unlikely.

Signed-off-by: Laslo Hunhold <dev@frign.de>

Diffstat:
M
http.c
 | 
10
+++++++++-

1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/http.c b/http.c
@@ -154,7 +154,7 @@ http_recv_header(int fd, struct buffer *buf, int *done)
 
 	while (1) {
 		if ((r = read(fd, buf->data + buf->len,
-		              sizeof(buf->data) - buf->len)) <= 0) {
+		              sizeof(buf->data) - buf->len)) < 0) {
 			if (errno == EAGAIN || errno == EWOULDBLOCK) {
 				/*
 				 * socket is drained, return normally,
@@ -166,6 +166,14 @@ http_recv_header(int fd, struct buffer *buf, int *done)
 				s = S_REQUEST_TIMEOUT;
 				goto err;
 			}
+		} else if (r == 0) {
+			/*
+			 * unexpected EOF because the client probably
+			 * hung up. This is technically a bad request,
+			 * because it's incomplete
+			 */
+			s = S_BAD_REQUEST;
+			goto err;
 		}
 		buf->len += r;