1. The isc__nm_tcp_send() and isc__nm_tcp_read() was not checking
whether the socket was still alive and scheduling reads/sends on
closed socket.
2. The isc_nm_read(), isc_nm_send() and isc_nm_resumeread() have been
changed to always return the error conditions via the callbacks, so
they always succeed. This applies to all protocols (UDP, TCP and
TCPDNS).
(cherry picked from commit f7c82e406e)
There were two problems how udp_send_direct() was used:
1. The udp_send_direct() can return ISC_R_CANCELED (or translated error
from uv_udp_send()), but the isc__nm_async_udpsend() wasn't checking
the error code and not releasing the uvreq in case of an error.
2. In isc__nm_udp_send(), when the UDP send is already in the right
netthread, it uses udp_send_direct() to send the UDP packet right
away. When that happened the uvreq was not freed, and the error code
was returned to the caller. We need to return ISC_R_SUCCESS and
rather use the callback to report an error in such case.
(cherry picked from commit afca2e3b21)
If we clone the csock (children socket) in TCP accept_connection()
instead of passing the ssock (server socket) to the call back and
cloning it there we unbreak the assumption that every socket is handled
inside it's own worker thread and therefore we can get rid of (at least)
callback locking.
(cherry picked from commit e8b56acb49)
The SO_REUSEADDR, SO_REUSEPORT and SO_REUSEPORT_LB has different meaning
on different platform. In this commit, we split the function to set the
reuse of address/port and setting the load-balancing into separate
functions.
The libuv library already have multiplatform support for setting
SO_REUSEADDR and SO_REUSEPORT that allows binding to the same address
and port, but unfortunately, when used after the load-balancing socket
options have been already set, it overrides the previous setting, so we
need our own helper function to enable the SO_REUSEADDR/SO_REUSEPORT
first and then enable the load-balancing socket option.
(cherry picked from commit fd975a551d)
The isc__nm_socket_freebind() has been refactored to match other
isc__nm_socket_...() helper functions and take uv_os_fd_t and
sa_family_t as function arguments.
(cherry picked from commit 9dc01a636b)
Attaching and detaching handle pointers will make it easier to
determine where and why reference counting errors have occurred.
A handle needs to be referenced more than once when multiple
asynchronous operations are in flight, so callers must now maintain
multiple handle pointers for each pending operation. For example,
ns_client objects now contain:
- reqhandle: held while waiting for a request callback (query,
notify, update)
- sendhandle: held while waiting for a send callback
- fetchhandle: held while waiting for a recursive fetch to
complete
- updatehandle: held while waiting for an update-forwarding
task to complete
(cherry picked from commit 57b4dde974)
- rename isc_nmsocket_t->tcphandle to statichandle
- cancelread functions now take handles instead of sockets
- add a 'client' flag in socket objects, currently unused, to
indicate whether it is to be used as a client or server socket
(cherry picked from commit 7eb4564895)
Each worker has a receive buffer with space for 20 DNS messages of up
to 2^16 bytes each, and the allocator function passed to uv_read_start()
or uv_udp_recv_start() will reserve a portion of it for use by sockets.
UDP can use recvmmsg() and so it needs that entire space, but TCP reads
one message at a time.
This commit introduces separate allocator functions for TCP and UDP
setting different buffer size limits, so that libuv will provide the
correct buffer sizes to each of them.
(cherry picked from commit 38264b6a4d)
When a new IPv6 interface/address appears it's first in a tentative
state - in which we cannot bind to it, yet it's already being reported
by the route socket. Because of that BIND9 is unable to listen on any
newly detected IPv6 addresses. Fix it by setting IP_FREEBIND option (or
equivalent option on other OSes) and then retrying bind() call.
(cherry picked from commit a0f7d28967)
We need to mark the socket as inactive early (and synchronously)
in the stoplistening process; otherwise we might destroy the
callback argument before we actually stop listening, and call
the callback on bad memory.
(cherry picked from commit 1cf65cd882)
this will allow recv event handlers to distinguish between cases
in which the region is NULL because of error, shutdown, or cancelation.
(cherry picked from commit 75c985c07f)
- isc__nmhandle_get() now attaches to the sock in the nmhandle object.
the caller is responsible for dereferencing the original socket
pointer when necessary.
- tcpdns listener sockets attach sock->outer to the outer tcp listener
socket. tcpdns connected sockets attach sock->outerhandle to the handle
for the tcp connected socket.
- only listener sockets need to be attached/detached directly. connected
sockets should only be accessed and reference-counted via their
associated handles.
(cherry picked from commit 5ea26ee1f1)
there is no need for a caller to reference-count socket objects.
they need tto be able tto close listener sockets (i.e., those
returned by isc_nm_listen{udp,tcp,tcpdns}), and an isc_nmsocket_close()
function has been added for that. other sockets are only accessed via
handles.
(cherry picked from commit 9e740cad21)
The following reverted changes will be picked again as part of the
netmgr sync with main branch.
Revert "Merge branch '1996-confidential-issue-v9_16' into 'security-v9_16'"
This reverts commit e160b1509f, reversing
changes made to c01e643715.
Revert "Merge branch '2038-use-freebind-when-bind-fails-v9_16' into 'v9_16'"
This reverts commit 5f8ecfb918, reversing
changes made to 23021385d5.
Revert "Merge branch '1936-blackhole-fix-v9_16' into 'v9_16'"
This reverts commit f20bc90a72, reversing
changes made to 490016ebf1.
Revert "Merge branch '1938-fix-udp-race' into 'v9_16'"
This reverts commit 0a6c7ab2a9, reversing
changes made to 4ea84740e6.
Revert "Merge branch '1947-fix-tcpdns-race' into 'v9_16'"
This reverts commit 4ea84740e6, reversing
changes made to d761cd576b.
Each worker has a receive buffer with space for 20 DNS messages of up
to 2^16 bytes each, and the allocator function passed to uv_read_start()
or uv_udp_recv_start() will reserve a portion of it for use by sockets.
UDP can use recvmmsg() and so it needs that entire space, but TCP reads
one message at a time.
This commit introduces separate allocator functions for TCP and UDP
setting different buffer size limits, so that libuv will provide the
correct buffer sizes to each of them.
When a new IPv6 interface/address appears it's first in a tentative
state - in which we cannot bind to it, yet it's already being reported
by the route socket. Because of that BIND9 is unable to listen on any
newly detected IPv6 addresses. Fix it by setting IP_FREEBIND option (or
equivalent option on other OSes) and then retrying bind() call.
(cherry picked from commit a0f7d28967)
We need to mark the socket as inactive early (and synchronously)
in the stoplistening process - otherwise we might destroy the
callback argument before actually stopping listening, and call
the callback on a bad memory.
The SO_INCOMING_CPU is available since Linux 3.19 for getting the value,
but only since Linux 4.4 for setting the value (see below for a full
description). BIND 9 should not fail when setting the option on the
socket fails, as this is only an optimization and not hard requirement
to run BIND 9.
SO_INCOMING_CPU (gettable since Linux 3.19, settable since Linux 4.4)
Sets or gets the CPU affinity of a socket. Expects an integer flag.
int cpu = 1;
setsockopt(fd, SOL_SOCKET, SO_INCOMING_CPU, &cpu, sizeof(cpu));
Because all of the packets for a single stream (i.e., all
packets for the same 4-tuple) arrive on the single RX queue that
is associated with a particular CPU, the typical use case is to
employ one listening process per RX queue, with the incoming
flow being handled by a listener on the same CPU that is
handling the RX queue. This provides optimal NUMA behavior and
keeps CPU caches hot.
(cherry picked from commit 4ec357da0a)
The SO_REUSEPORT socket option on Linux means something else on BSD
based systems. On FreeBSD there's 1:1 option SO_REUSEPORT_LB, so we can
use that.
(cherry picked from commit 09ba47b067)
tcpdns used transport-specific functions to operate on the outer socket.
Use generic ones instead, and select the proper call in netmgr.c.
Make the missing functions (e.g. isc_nm_read) generic and add type-specific
calls (isc__nm_tcp_read). This is the preparation for netmgr TLS layer.
(cherry picked from commit 5fedd21e16)
Start enforcing the clang-format rules on changed files
Closes#46
See merge request isc-projects/bind9!3063
(cherry picked from commit a04cdde45d)
d2b5853b Start enforcing the clang-format rules on changed files
618947c6 Switch AlwaysBreakAfterReturnType from TopLevelDefinitions to All
654927c8 Add separate .clang-format files for headers
5777c44a Reformat using the new rules
60d29f69 Don't enforce copyrights on .clang-format
adjust clang-format options to get closer to ISC style
See merge request isc-projects/bind9!3061
(cherry picked from commit d3b49b6675)
0255a974 revise .clang-format and add a C formatting script in util
e851ed0b apply the modified style
Add curly braces using uncrustify and then reformat with clang-format back
Closes#46
See merge request isc-projects/bind9!3057
(cherry picked from commit 67b68e06ad)
36c6105e Use coccinelle to add braces to nested single line statement
d14bb713 Add copy of run-clang-tidy that can fixup the filepaths
056e133c Use clang-tidy to add curly braces around one-line statements
Reformat source code with clang-format
Closes#46
See merge request isc-projects/bind9!2156
(cherry picked from commit 7099e79a9b)
4c3b063e Import Linux kernel .clang-format with small modifications
f50b1e06 Use clang-format to reformat the source files
11341c76 Update the definition files for Windows
df6c1f76 Remove tkey_test (which is no-op anyway)
We weren't consistent about who should unreference the handle in
case of network error. Make it consistent so that it's always the
client code responsibility to unreference the handle - either
in the callback or right away if send function failed and the callback
will never be called.
In tcp and udp stoplistening code we accessed libuv structures
from a different thread, which caused a shutdown crash when named
was under load. Also added additional DbC checks making sure we're
in a proper thread when accessing uv_ functions.
We had a race in which n UDP socket could have been already closing
by libuv but we still sent data to it. Mark socket as not-active
when stopping listening and verify that socket is not active when
trying to send data to it.
- the socket stat counters have been moved from socket.h to stats.h.
- isc_nm_t now attaches to the same stats counter group as
isc_socketmgr_t, so that both managers can increment the same
set of statistics
- isc__nmsocket_init() now takes an interface as a paramter so that
the address family can be determined when initializing the socket.
- based on the address family and socket type, a group of statistics
counters will be associated with the socket - for example, UDP4Active
with IPv4 UDP sockets and TCP6Active with IPv6 TCP sockets. note
that no counters are currently associated with TCPDNS sockets; those
stats will be handled by the underlying TCP socket.
- the counters are not actually used by netmgr sockets yet; counter
increment and decrement calls will be added in a later commit.
- use UV_{TC,UD}P_IPV6ONLY for IPv6 sockets, keeping the pre-netmgr
behaviour.
- add a new listening_error bool flag which is set if the child
listener fails to start listening. This fixes a bug where named would
hang if, e.g., we failed to bind to a TCP socket.
When listening for TCP connections we create a socket, bind it
and then pass it over IPC to all threads - which then listen on
in and accept connections. This sounds broken, but it's the
official way of dealing with multithreaded TCP listeners in libuv,
and works on all platforms supported by libuv.
This is a replacement for the existing isc_socket and isc_socketmgr
implementation. It uses libuv for asynchronous network communication;
"networker" objects will be distributed across worker threads reading
incoming packets and sending them for processing.
UDP listener sockets automatically create an array of "child" sockets
so each worker can listen separately.
TCP sockets are shared amongst worker threads.
A TCPDNS socket is a wrapper around a TCP socket, which handles the
the two-byte length field at the beginning of DNS messages over TCP.
(Other wrapper socket types can be implemented in the future to handle
DNS over TLS, DNS over HTTPS, etc.)
