Mercurial > hg > nginx-quic
annotate src/os/unix/ngx_udp_recv.c @ 8867:5119c8150478
Fixed runtime handling of systems without EPOLLRDHUP support.
In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the
ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP
support in the kernel (but with EPOLLRDHUP in headers) was broken.
Before the change, rev->available was never set to 0 unless
ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP
introduced in 6536:f7849bfb6d21 succeeded). After the change,
rev->available might reach 0 on systems without runtime EPOLLRDHUP
support, stopping further reading in ngx_readv_chain() and ngx_unix_recv().
And, if EOF happened to be already reported along with the last event,
it is not reported again by epoll_wait(), leading to connection hangs
and timeouts on such systems.
This affects Linux kernels before 2.6.17 if nginx was compiled
with newer headers, and, more importantly, emulation layers, such as
DigitalOcean's App Platform's / gVisor's epoll emulation layer.
Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding
rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author | Marcus Ball <marcus.ball@live.com> |
---|---|
date | Mon, 30 May 2022 02:38:07 +0300 |
parents | 5ad379eab6fa |
children |
rev | line source |
---|---|
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
375
diff
changeset
|
1 |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
375
diff
changeset
|
2 /* |
444
42d11f017717
nginx-0.1.0-2004-09-29-20:00:49 import; remove years from copyright
Igor Sysoev <igor@sysoev.ru>
parents:
441
diff
changeset
|
3 * Copyright (C) Igor Sysoev |
4412 | 4 * Copyright (C) Nginx, Inc. |
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
375
diff
changeset
|
5 */ |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
375
diff
changeset
|
6 |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
7 |
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
8 #include <ngx_config.h> |
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
9 #include <ngx_core.h> |
103
6dfda4cf5200
nginx-0.0.1-2003-06-11-19:28:34 import
Igor Sysoev <igor@sysoev.ru>
parents:
96
diff
changeset
|
10 #include <ngx_event.h> |
96
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
11 |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
12 |
1680 | 13 ssize_t |
1689 | 14 ngx_udp_unix_recv(ngx_connection_t *c, u_char *buf, size_t size) |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
15 { |
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
16 ssize_t n; |
253
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
17 ngx_err_t err; |
96
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
18 ngx_event_t *rev; |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
19 |
96
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
20 rev = c->read; |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
21 |
96
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
22 do { |
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
23 n = recv(c->fd, buf, size, 0); |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
24 |
253
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
25 ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, |
6480 | 26 "recv: fd:%d %z of %uz", c->fd, n, size); |
93
738fe44c70d5
nginx-0.0.1-2003-05-21-17:28:21 import
Igor Sysoev <igor@sysoev.ru>
parents:
91
diff
changeset
|
27 |
96
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
28 if (n >= 0) { |
6505
5ad379eab6fa
Merged implementations of ngx_udp_unix_recv().
Valentin Bartenev <vbart@nginx.com>
parents:
6480
diff
changeset
|
29 |
5ad379eab6fa
Merged implementations of ngx_udp_unix_recv().
Valentin Bartenev <vbart@nginx.com>
parents:
6480
diff
changeset
|
30 #if (NGX_HAVE_KQUEUE) |
5ad379eab6fa
Merged implementations of ngx_udp_unix_recv().
Valentin Bartenev <vbart@nginx.com>
parents:
6480
diff
changeset
|
31 |
455 | 32 if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { |
96
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
33 rev->available -= n; |
163
fb61ba77beba
nginx-0.0.1-2003-10-28-18:45:41 import
Igor Sysoev <igor@sysoev.ru>
parents:
148
diff
changeset
|
34 |
fb61ba77beba
nginx-0.0.1-2003-10-28-18:45:41 import
Igor Sysoev <igor@sysoev.ru>
parents:
148
diff
changeset
|
35 /* |
583 | 36 * rev->available may be negative here because some additional |
587 | 37 * bytes may be received between kevent() and recv() |
163
fb61ba77beba
nginx-0.0.1-2003-10-28-18:45:41 import
Igor Sysoev <igor@sysoev.ru>
parents:
148
diff
changeset
|
38 */ |
fb61ba77beba
nginx-0.0.1-2003-10-28-18:45:41 import
Igor Sysoev <igor@sysoev.ru>
parents:
148
diff
changeset
|
39 |
144
ef8c87afcfc5
nginx-0.0.1-2003-10-12-20:49:16 import
Igor Sysoev <igor@sysoev.ru>
parents:
103
diff
changeset
|
40 if (rev->available <= 0) { |
1689 | 41 rev->ready = 0; |
605 | 42 rev->available = 0; |
43 } | |
163
fb61ba77beba
nginx-0.0.1-2003-10-28-18:45:41 import
Igor Sysoev <igor@sysoev.ru>
parents:
148
diff
changeset
|
44 } |
fb61ba77beba
nginx-0.0.1-2003-10-28-18:45:41 import
Igor Sysoev <igor@sysoev.ru>
parents:
148
diff
changeset
|
45 |
6505
5ad379eab6fa
Merged implementations of ngx_udp_unix_recv().
Valentin Bartenev <vbart@nginx.com>
parents:
6480
diff
changeset
|
46 #endif |
5ad379eab6fa
Merged implementations of ngx_udp_unix_recv().
Valentin Bartenev <vbart@nginx.com>
parents:
6480
diff
changeset
|
47 |
96
a23d010f356d
nginx-0.0.1-2003-05-27-16:18:54 import
Igor Sysoev <igor@sysoev.ru>
parents:
93
diff
changeset
|
48 return n; |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
49 } |
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
50 |
253
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
51 err = ngx_socket_errno; |
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
52 |
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
53 if (err == NGX_EAGAIN || err == NGX_EINTR) { |
257
70e1c7d2b83d
nginx-0.0.2-2004-02-11-20:08:49 import
Igor Sysoev <igor@sysoev.ru>
parents:
256
diff
changeset
|
54 ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, |
253
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
55 "recv() not ready"); |
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
56 n = NGX_AGAIN; |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
57 |
253
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
58 } else { |
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
59 n = ngx_connection_error(c, err, "recv() failed"); |
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
60 break; |
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
61 } |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
62 |
253
b6793bc5034b
nginx-0.0.2-2004-02-09-10:46:43 import
Igor Sysoev <igor@sysoev.ru>
parents:
218
diff
changeset
|
63 } while (err == NGX_EINTR); |
188
0061d1f0908d
nginx-0.0.1-2003-11-18-11:04:34 import
Igor Sysoev <igor@sysoev.ru>
parents:
184
diff
changeset
|
64 |
0061d1f0908d
nginx-0.0.1-2003-11-18-11:04:34 import
Igor Sysoev <igor@sysoev.ru>
parents:
184
diff
changeset
|
65 rev->ready = 0; |
0061d1f0908d
nginx-0.0.1-2003-11-18-11:04:34 import
Igor Sysoev <igor@sysoev.ru>
parents:
184
diff
changeset
|
66 |
3642 | 67 if (n == NGX_ERROR) { |
184
1bf718ce0dde
nginx-0.0.1-2003-11-14-10:20:34 import
Igor Sysoev <igor@sysoev.ru>
parents:
163
diff
changeset
|
68 rev->error = 1; |
1bf718ce0dde
nginx-0.0.1-2003-11-14-10:20:34 import
Igor Sysoev <igor@sysoev.ru>
parents:
163
diff
changeset
|
69 } |
1bf718ce0dde
nginx-0.0.1-2003-11-14-10:20:34 import
Igor Sysoev <igor@sysoev.ru>
parents:
163
diff
changeset
|
70 |
91
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
71 return n; |
637625a2acdb
nginx-0.0.1-2003-05-19-20:39:14 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
72 } |