Commit Graph

32548 Commits

Author SHA1 Message Date
Matthijs Mekking
cf0439cd5f Treat dnssec-policy "none" as a builtin zone
Configure "none" as a builtin policy. Change the 'cfg_kasp_fromconfig'
api so that the 'name' will determine what policy needs to be
configured.

When transitioning a zone from secure to insecure, there will be
cases when a zone with no DNSSEC policy (dnssec-policy none) should
be using KASP. When there are key state files available, this is an
indication that the zone once was DNSSEC signed but is reconfigured
to become insecure.

If we would not run the keymgr, named would abruptly remove the
DNSSEC records from the zone, making the zone bogus. Therefore,
change the code such that a zone will use kasp if there is a valid
dnssec-policy configured, or if there are state files available.

(cherry picked from commit cf420b2af0)
2020-12-23 11:56:33 +01:00
Matthijs Mekking
6ff69ee8ba Add function to see if dst key uses kasp
For purposes of zones transitioning back to insecure mode, it is
practical to see if related keys have a state file associated.

(cherry picked from commit 8f2c5e45da)
2020-12-23 11:56:25 +01:00
Matthijs Mekking
63b72ad5e9 Small adjustments to kasp rndc_checkds function
Slightly better test output, and only call 'load keys' if the
'rndc checkds' call succeeded.

(cherry picked from commit 756674f6d1)
2020-12-23 11:56:16 +01:00
Matthijs Mekking
c3d2843915 Add tests for going from secure to insecure
Add two test zones that will be reconfigured to go insecure, by
setting the 'dnssec-policy' option to 'none'.

One zone was using inline-signing (implicitly through dnssec-policy),
the other is a dynamic zone.

Two tweaks to the kasp system test are required: we need to set
when to except the CDS/CDS Delete Records, and we need to know
when we are dealing with a dynamic zone (because the logs to look for
are slightly different, inline-signing prints "(signed)" after the
zone name, dynamic zones do not).

(cherry picked from commit fa2e4e66b0)
2020-12-23 11:56:07 +01:00
Mark Andrews
b5db21f80b Merge branch '2245-bind-9-16-8-does-not-honor-cpu-affinity-v9_16' into 'v9_16'
Resolve "bind 9.16.8 does not honor CPU affinity"

See merge request isc-projects/bind9!4510
2020-12-22 23:13:49 +00:00
Mark Andrews
b8c44c8e1f Add CHANGES and release notes for [GL #2245]
(cherry picked from commit fc4af548e7)
2020-12-23 09:26:50 +11:00
Matthijs Mekking
ba75744331 Add test for cpu affinity
Add a test to check BIND 9 honors CPU affinity mask. This requires
some changes to the start script, to construct the named command.

(cherry picked from commit f1a097964c)
2020-12-23 09:25:48 +11:00
Mark Andrews
4d003dd0f8 Only pick CPUs that are part of the existing CPU affinity set when
assigning a thread to a CPU.

(cherry picked from commit 698d9285d4)
2020-12-23 09:21:29 +11:00
Mark Andrews
107ca22258 Merge branch '2348-bin-tools-mdig-compile-link-failure-because-of-missing-isccfg-dependency' into 'v9_16'
Resolve "bin/tools/mdig: compile/link failure because of missing isccfg dependency"

See merge request isc-projects/bind9!4493
2020-12-20 21:54:45 +00:00
Mark Andrews
b278d91680 Handle shared library platforms that don't support inter library dependancies 2020-12-20 21:36:09 +00:00
Mark Andrews
afbc6f41d9 Fixup library link lists 2020-12-20 21:36:09 +00:00
Michał Kępień
2dfe130936 Merge branch 'v9_16_10-release' into 'v9_16'
Merge 9.16.10 release branch

See merge request isc-projects/bind9!4501
2020-12-16 21:29:31 +00:00
Michał Kępień
797974c7c3 Set up release notes for BIND 9.16.11 2020-12-16 22:21:19 +01:00
Michał Kępień
bfdce48781 Bump BIND_BASELINE_VERSION for ABI checks 2020-12-16 22:21:19 +01:00
Michal Nowak
05dfd2a90a Merge branch 'mnowak/fix-program-name-in-dnssec-keymgr-8' into 'v9_16'
[v9_16] Man page fixes (named.rst & dnssec-keymgr.rst)

See merge request isc-projects/bind9!4479
2020-12-14 12:21:06 +00:00
Michal Nowak
5f0e9c8645 Fix program name reference in dnssec-keymgr(8) 2020-12-14 13:17:27 +01:00
Michal Nowak
c77c96133d Fix a reference to rndc(8) in named(8) manual page
(cherry picked from commit befcbcac28)
2020-12-14 13:17:27 +01:00
Ondřej Surý
df315cd8fc Merge branch '2058-print-warning-when-fallback-to-soaserial-increment-v9_16' into 'v9_16'
Resolve "`dnssec-signzone -N unixtime` behaves like `increment`"

See merge request isc-projects/bind9!4492
2020-12-12 07:37:24 +00:00
Ondřej Surý
66bb0a1e80 Add CHANGES and release notes for GL #2058
(cherry picked from commit ba887a688c)
2020-12-12 08:08:49 +01:00
Mark Andrews
151500b522 Update dnssec-signzone -N soa-serial-format description
document the autoincrement when the serial would go backwards.

(cherry picked from commit eb1b29b19e)
2020-12-12 08:07:51 +01:00
Ondřej Surý
04f9f45c54 Print warning when falling back to increment soa serial method
When using the `unixtime` or `date` method to update the SOA serial,
`named` and `dnssec-signzone` would silently fallback to `increment`
method to prevent the new serial number to be smaller than the old
serial number (using the serial number arithmetics).  Add a warning
message when such fallback happens.

(cherry picked from commit ef685bab5c)
2020-12-12 07:55:29 +01:00
Ondřej Surý
5e27492302 Merge branch '2321-netmgr-v2-v9_16' into 'v9_16'
Synchronize netmgr sub-library with main branch

See merge request isc-projects/bind9!4455
2020-12-09 16:04:21 +00:00
Ondřej Surý
645701afb0 Merge branch 'ondrej/release-notes-doesnt-need-copyright-v9_16' into 'v9_16'
Remove the requirement for the release notes to have copyright

See merge request isc-projects/bind9!4484
2020-12-09 09:51:20 +00:00
Ondřej Surý
fcfb3e77bb Remove the requirement for the release notes to have copyright
The release notes doesn't have to have copyright header, it doesn't add
any value there as the release notes are useless outside the project.

(cherry picked from commit cb30d9892d)
2020-12-09 10:50:15 +01:00
Ondřej Surý
099fc1fdf8 Add CHANGES and release notes 2020-12-09 10:46:16 +01:00
Ondřej Surý
2c04299eb1 Fix HAVE_SO_REUSEPORT_LB macro name definition
A typo in macro definition caused the load-balanced sockets to be
disabled even on platforms with existing support for load-balanced
sockets.

(cherry picked from commit 5caf33feda)
2020-12-09 10:46:16 +01:00
Ondřej Surý
90979a79e2 Sync the func() -> func(void) in netmgr 2020-12-09 10:46:16 +01:00
Ondřej Surý
bb9b55dfba Use sock->nchildren instead of mgr->nworkers when initializing NM
On Windows, we were limiting the number of listening children to just 1,
but we were then iterating on mgr->nworkers.  That lead to scheduling
more async_*listen() than actually allocated and out-of-bound read-write
operation on the heap.

(cherry picked from commit 87c5867202)
2020-12-09 10:46:16 +01:00
Ondřej Surý
857704b879 Explicitly link the netmgr tests with -luv 2020-12-09 10:46:16 +01:00
Ondřej Surý
7ec4ec3a81 Fix datarace when UDP/TCP connect fails and we are in nmthread
When we were in nmthread, the isc__nm_async_<proto>connect() function
executes in the same thread as the isc__nm_<proto>connect() and on a
failure, it would block indefinitely because the failure branch was
setting sock->active to false before the condition around the wait had a
chance to skip the WAIT().

This also fixes the zero system test being stuck on FreeBSD 11, so we
re-enable the test in the commit.
2020-12-09 10:46:16 +01:00
Ondřej Surý
90a9b0611a Add FreeBSD connection timeout socket option
On FreeBSD, the option to configure connection timeout is called
TCP_KEEPINIT, use it to configure the connection timeout there.

This also fixes the dangling socket problems in the unit test, so
re-enable them.
2020-12-09 10:46:16 +01:00
Ondřej Surý
0ee8672692 Distribute queries among threads even on platforms without lb sockets
On platforms without load-balancing socket all the queries would be
handle by a single thread.  Currently, the support for load-balanced
sockets is present in Linux with SO_REUSEPORT and FreeBSD 12 with
SO_REUSEPORT_LB.

This commit adds workaround for such platforms that:

1. setups single shared listening socket for all listening nmthreads for
   UDP, TCP and TCPDNS netmgr transports

2. Calls uv_udp_bind/uv_tcp_bind on the underlying socket just once and
   for rest of the nmthreads only copy the internal libuv flags (should
   be just UV_HANDLE_BOUND and optionally UV_HANDLE_IPV6).

3. start reading on UDP socket or listening on TCP socket

The load distribution among the nmthreads is uneven, but it's still
better than utilizing just one thread for processing all the incoming
queries
2020-12-09 10:46:16 +01:00
Ondřej Surý
4c70100ce0 Don't use stack allocated buffer for uv_write()
On FreeBSD, the stack is destroyed more aggressively than on Linux and
that revealed a bug where we were allocating the 16-bit len for the
TCPDNS message on the stack and the buffer got garbled before the
uv_write() sendback was executed.  Now, the len is part of the uvreq, so
we can safely pass it to the uv_write() as the req gets destroyed after
the sendcb is executed.

(cherry picked from commit 94afea9325)
2020-12-09 10:46:16 +01:00
Michał Kępień
12fa8a7aed Make netmgr initialize and cleanup Winsock itself
On Windows, WSAStartup() needs to be called to initialize Winsock before
any sockets are created or else socket() calls will return error code
10093 (WSANOTINITIALISED).  Since BIND's Network Manager is intended to
work as a reusable networking library, it should take care of calling
WSAStartup() - and its cleanup counterpart, WSACleanup() - itself rather
than relying on external code to do it.  Add the necessary WSAStartup()
and WSACleanup() calls to isc_nm_start() and isc_nm_destroy(),
respectively.

(cherry picked from commit 88f96faba8)
2020-12-09 10:46:16 +01:00
Michał Kępień
216fc34490 Extend log message for unexpected socket() errors
Make sure the error code is included in the message logged for
unexpected socket creation errors in order to facilitate troubleshooting
on Windows.

(cherry picked from commit dc2e1dea86)
2020-12-09 10:46:16 +01:00
Ondřej Surý
e8e8ed7fb9 Adjust the nstests for isc_nmhandle_{attach,detach} name change
Due to the added attach/detach tracing in the netmgr-v2 code, the
libns tests needs to be adjusted as the real function names have
changed from isc_nmhandle_* to isc__nmhandle_*.
2020-12-09 10:46:16 +01:00
Ondřej Surý
9b2184893d The cmocka.h header MUST be included before isc/util.h gets included
The isc/util.h header redefine the DbC checks (REQUIRE, INSIST, ...)  to
be cmocka "fake" assertions.  However that means that cmocka.h needs to
be included after UNIT_TESTING is defined but before isc/util.h is
included.  Because isc/util.h is included in most of the project headers
this means that the sequence MUST be:

    #define UNIT_TESTING
    #include <cmocka.h>

    #include <isc/_anything_.h>

See !2204 for other header requirements for including cmocka.h.

(cherry picked from commit 0ba697fe8c)
2020-12-09 10:46:16 +01:00
Witold Kręcicki
012946eadc autoconf: link with libssl
This is prerequisite to adding DoT and DoH support to BIND 9.
2020-12-09 10:46:16 +01:00
Ondřej Surý
7fc62f829d Add libssl libraries to Windows build
This commit extends the perl Configure script to also check for libssl
in addition to libcrypto and change the vcxproj source files to link
with both libcrypto and libssl.
2020-12-09 10:46:16 +01:00
Ondřej Surý
48759bd047 Fix the data race in accessing the isc_nm_t timers
The following TSAN report about accessing the mgr timers (mgr->init,
mgr->idle, mgr->keepalive and mgr->advertised) has been fixed in this
commit:

    ==================
    WARNING: ThreadSanitizer: data race (pid=2746)
    Read of size 4 at 0x7b440008a948 by thread T18:
    #0 isc__nm_tcpdns_read /home/ondrej/Projects/bind9/lib/isc/netmgr/tcpdns.c:849:25 (libisc.so.1706+0x2ba0f)
    #1 isc_nm_read /home/ondrej/Projects/bind9/lib/isc/netmgr/netmgr.c:1679:3 (libisc.so.1706+0x22258)
    #2 tcpdns_connect_connect_cb /home/ondrej/Projects/bind9/lib/isc/tests/tcpdns_test.c:363:2 (tcpdns_test+0x4bc5fb)
    #3 isc__nm_async_connectcb /home/ondrej/Projects/bind9/lib/isc/netmgr/netmgr.c:1816:2 (libisc.so.1706+0x228c9)
    #4 isc__nm_connectcb /home/ondrej/Projects/bind9/lib/isc/netmgr/netmgr.c:1791:3 (libisc.so.1706+0x22713)
    #5 tcpdns_connect_cb /home/ondrej/Projects/bind9/lib/isc/netmgr/tcpdns.c:343:2 (libisc.so.1706+0x2d89d)
    #6 uv__stream_connect /home/ondrej/Projects/tsan/libuv/src/unix/stream.c:1381:5 (libuv.so.1+0x27c18)
    #7 uv__stream_io /home/ondrej/Projects/tsan/libuv/src/unix/stream.c:1298:5 (libuv.so.1+0x25977)
    #8 uv__io_poll /home/ondrej/Projects/tsan/libuv/src/unix/linux-core.c:462:11 (libuv.so.1+0x2e795)
    #9 uv_run /home/ondrej/Projects/tsan/libuv/src/unix/core.c:385:5 (libuv.so.1+0x158ec)
    #10 nm_thread /home/ondrej/Projects/bind9/lib/isc/netmgr/netmgr.c:530:11 (libisc.so.1706+0x1c94a)

    Previous write of size 4 at 0x7b440008a948 by main thread:
    #0 isc_nm_settimeouts /home/ondrej/Projects/bind9/lib/isc/netmgr/netmgr.c:490:12 (libisc.so.1706+0x1dda5)
    #1 tcpdns_recv_two /home/ondrej/Projects/bind9/lib/isc/tests/tcpdns_test.c:601:2 (tcpdns_test+0x4bad0e)
    #2 cmocka_run_one_test_or_fixture <null> (libcmocka.so.0+0x70be)
    #3 __libc_start_main /build/glibc-vjB4T1/glibc-2.28/csu/../csu/libc-start.c:308:16 (libc.so.6+0x2409a)

    Location is heap block of size 281 at 0x7b440008a840 allocated by main thread:
    #0 malloc <null> (tcpdns_test+0x42864b)
    #1 default_memalloc /home/ondrej/Projects/bind9/lib/isc/mem.c:713:8 (libisc.so.1706+0x6d261)
    #2 mem_get /home/ondrej/Projects/bind9/lib/isc/mem.c:622:8 (libisc.so.1706+0x69b9c)
    #3 isc___mem_get /home/ondrej/Projects/bind9/lib/isc/mem.c:1044:9 (libisc.so.1706+0x6d379)
    #4 isc__mem_get /home/ondrej/Projects/bind9/lib/isc/mem.c:2432:10 (libisc.so.1706+0x6889e)
    #5 isc_nm_start /home/ondrej/Projects/bind9/lib/isc/netmgr/netmgr.c:203:8 (libisc.so.1706+0x1c219)
    #6 nm_setup /home/ondrej/Projects/bind9/lib/isc/tests/tcpdns_test.c:244:11 (tcpdns_test+0x4baaa4)
    #7 cmocka_run_one_test_or_fixture <null> (libcmocka.so.0+0x70fd)
    #8 __libc_start_main /build/glibc-vjB4T1/glibc-2.28/csu/../csu/libc-start.c:308:16 (libc.so.6+0x2409a)

    Thread T18 'isc-net-0000' (tid=3513, running) created by main thread at:
    #0 pthread_create <null> (tcpdns_test+0x429e7b)
    #1 isc_thread_create /home/ondrej/Projects/bind9/lib/isc/pthreads/thread.c:73:8 (libisc.so.1706+0x8476a)
    #2 isc_nm_start /home/ondrej/Projects/bind9/lib/isc/netmgr/netmgr.c:271:3 (libisc.so.1706+0x1c66a)
    #3 nm_setup /home/ondrej/Projects/bind9/lib/isc/tests/tcpdns_test.c:244:11 (tcpdns_test+0x4baaa4)
    #4 cmocka_run_one_test_or_fixture <null> (libcmocka.so.0+0x70fd)
    #5 __libc_start_main /build/glibc-vjB4T1/glibc-2.28/csu/../csu/libc-start.c:308:16 (libc.so.6+0x2409a)

    SUMMARY: ThreadSanitizer: data race /home/ondrej/Projects/bind9/lib/isc/netmgr/tcpdns.c:849:25 in isc__nm_tcpdns_read
    ==================
    ThreadSanitizer: reported 1 warnings

(cherry picked from commit 2e1dd56d0b)
2020-12-09 10:46:16 +01:00
Ondřej Surý
a61b7294c2 Avoid netievent allocations when the callbacks can be called directly
After turning the users callbacks to be asynchronous, there was a
visible performance drop.  This commit prevents the unnecessary
allocations while keeping the code paths same for both asynchronous and
synchronous calls.

The same change was done to the isc__nm_udp_{read,send} as those two
functions are in the hot path.

(cherry picked from commit d6d2fbe0e9)
2020-12-09 10:46:16 +01:00
Ondřej Surý
7b9c8b9781 Refactor netmgr and add more unit tests
This is a part of the works that intends to make the netmgr stable,
testable, maintainable and tested.  It contains a numerous changes to
the netmgr code and unfortunately, it was not possible to split this
into smaller chunks as the work here needs to be committed as a complete
works.

NOTE: There's a quite a lot of duplicated code between udp.c, tcp.c and
tcpdns.c and it should be a subject to refactoring in the future.

The changes that are included in this commit are listed here
(extensively, but not exclusively):

* The netmgr_test unit test was split into individual tests (udp_test,
  tcp_test, tcpdns_test and newly added tcp_quota_test)

* The udp_test and tcp_test has been extended to allow programatic
  failures from the libuv API.  Unfortunately, we can't use cmocka
  mock() and will_return(), so we emulate the behaviour with #define and
  including the netmgr/{udp,tcp}.c source file directly.

* The netievents that we put on the nm queue have variable number of
  members, out of these the isc_nmsocket_t and isc_nmhandle_t always
  needs to be attached before enqueueing the netievent_<foo> and
  detached after we have called the isc_nm_async_<foo> to ensure that
  the socket (handle) doesn't disappear between scheduling the event and
  actually executing the event.

* Cancelling the in-flight TCP connection using libuv requires to call
  uv_close() on the original uv_tcp_t handle which just breaks too many
  assumptions we have in the netmgr code.  Instead of using uv_timer for
  TCP connection timeouts, we use platform specific socket option.

* Fix the synchronization between {nm,async}_{listentcp,tcpconnect}

  When isc_nm_listentcp() or isc_nm_tcpconnect() is called it was
  waiting for socket to either end up with error (that path was fine) or
  to be listening or connected using condition variable and mutex.

  Several things could happen:

    0. everything is ok

    1. the waiting thread would miss the SIGNAL() - because the enqueued
       event would be processed faster than we could start WAIT()ing.
       In case the operation would end up with error, it would be ok, as
       the error variable would be unchanged.

    2. the waiting thread miss the sock->{connected,listening} = `true`
       would be set to `false` in the tcp_{listen,connect}close_cb() as
       the connection would be so short lived that the socket would be
       closed before we could even start WAIT()ing

* The tcpdns has been converted to using libuv directly.  Previously,
  the tcpdns protocol used tcp protocol from netmgr, this proved to be
  very complicated to understand, fix and make changes to.  The new
  tcpdns protocol is modeled in a similar way how tcp netmgr protocol.
  Closes: #2194, #2283, #2318, #2266, #2034, #1920

* The tcp and tcpdns is now not using isc_uv_import/isc_uv_export to
  pass accepted TCP sockets between netthreads, but instead (similar to
  UDP) uses per netthread uv_loop listener.  This greatly reduces the
  complexity as the socket is always run in the associated nm and uv
  loops, and we are also not touching the libuv internals.

  There's an unfortunate side effect though, the new code requires
  support for load-balanced sockets from the operating system for both
  UDP and TCP (see #2137).  If the operating system doesn't support the
  load balanced sockets (either SO_REUSEPORT on Linux or SO_REUSEPORT_LB
  on FreeBSD 12+), the number of netthreads is limited to 1.

* The netmgr has now two debugging #ifdefs:

  1. Already existing NETMGR_TRACE prints any dangling nmsockets and
     nmhandles before triggering assertion failure.  This options would
     reduce performance when enabled, but in theory, it could be enabled
     on low-performance systems.

  2. New NETMGR_TRACE_VERBOSE option has been added that enables
     extensive netmgr logging that allows the software engineer to
     precisely track any attach/detach operations on the nmsockets and
     nmhandles.  This is not suitable for any kind of production
     machine, only for debugging.

* The tlsdns netmgr protocol has been split from the tcpdns and it still
  uses the old method of stacking the netmgr boxes on top of each other.
  We will have to refactor the tlsdns netmgr protocol to use the same
  approach - build the stack using only libuv and openssl.

* Limit but not assert the tcp buffer size in tcp_alloc_cb
  Closes: #2061

(cherry picked from commit 634bdfb16d)
2020-12-09 10:46:16 +01:00
Ondřej Surý
fa9ca83862 Turn all the callback to be always asynchronous
When calling the high level netmgr functions, the callback would be
sometimes called synchronously if we catch the failure directly, or
asynchronously if it happens later.  The synchronous call to the
callback could create deadlocks as the caller would not expect the
failed callback to be executed directly.

(cherry picked from commit a49d88568f)
2020-12-09 10:46:16 +01:00
Ondřej Surý
bcc9ad98ea netmgr: Add additional safeguards to netmgr/tls.c
This commit adds couple of additional safeguards against running
sends/reads on inactive sockets.  The changes was modeled after the
changes we made to netmgr/tcpdns.c

(cherry picked from commit fa424225af)
2020-12-09 10:46:16 +01:00
Witold Kręcicki
b83dff0585 isc_nm_tls_create_server_ctx can create ephemeral certs
In-memory ephemeral certs creation for easy DoT/DoH deployment.

(cherry picked from commit 3c00fb71db)
2020-12-09 10:46:16 +01:00
Witold Kręcicki
d7fa046a69 Add DoT support to bind
Parse the configuration of tls objects into SSL_CTX* objects.  Listen on
DoT if 'tls' option is setup in listen-on directive.  Use DoT/DoH ports
for DoT/DoH.

(cherry picked from commit 38b78f59a0)
2020-12-09 10:46:16 +01:00
Evan Hunt
0f5fff5c1e report peer address in TLS mode, and specify protocol
- peer address was not being reported correctly by "dig +tls"
- the protocol used is now reported in the dig output: UDP, TCP, or TLS.

(cherry picked from commit 8886569e9d)
2020-12-09 10:46:16 +01:00
Witold Kręcicki
4a854da141 netmgr: server-side TLS support
Add server-side TLS support to netmgr - that includes moving some of the
isc_nm_ functions from tcp.c to a wrapper in netmgr.c calling a proper
tcp or tls function, and a new isc_nm_listentls() function.

Add DoT support to tcpdns - isc_nm_listentlsdns().

(cherry picked from commit b2ee0e9dc3)
2020-12-09 10:46:16 +01:00
Evan Hunt
6f6f0e26ab address some possible shutdown races in xfrin
there were two failures during observed in testing, both occurring
when 'rndc halt' was run rather than 'rndc stop' - the latter dumps
zone contents to disk and presumably introduced enough delay to
prevent the races:

- a failure when the zone was shut down and called dns_xfrin_detach()
  before the xfrin had finished connecting; the connect timeout
  terminated without detaching its handle
- a failure when the tcpdns socket timer fired after the outerhandle
  had already been cleared.

this commit incidentally addresses a failure observed in mutexatomic
due to a variable having been initialized incorrectly.
2020-12-09 10:46:16 +01:00
Ondřej Surý
c4dcedd2dc netmgr: Don't crash if socket() returns an error in udpconnect
socket() call can return an error - e.g. EMFILE, so we need to handle
this nicely and not crash.

Additionally wrap the socket() call inside a platform independent helper
function as the Socket data type on Windows is unsigned integer:

> This means, for example, that checking for errors when the socket and
> accept functions return should not be done by comparing the return
> value with –1, or seeing if the value is negative (both common and
> legal approaches in UNIX). Instead, an application should use the
> manifest constant INVALID_SOCKET as defined in the Winsock2.h header
> file.

(cherry picked from commit 8af7f81d6c)
2020-12-09 10:46:16 +01:00