Fix handling of unexpected hangups - quark - quark web server
(HTM) git clone git://git.suckless.org/quark
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---
(DIR) commit f1892c4dffa7df6995cd8c9ebd47e0ce7f0e457e
(DIR) parent 3729e7222aafc4c4ca30351748a89e05f78e2230
(HTM) 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(-)
---
(DIR) 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;