Before 4a8c9139e579, ngx_resolver_create() didn't use configuration
pool, and allocations were done using malloc().
In 016352c19049, when resolver gained support of several servers,
new allocations were done from the pool.
Previously, only one client packet could be processed in a udp stream session
even though multiple response packets were supported. Now multiple packets
coming from the same client address and port are delivered to the same stream
session.
If it's required to maintain a single stream of data, nginx should be
configured in a way that all packets from a client are delivered to the same
worker. On Linux and DragonFly BSD the "reuseport" parameter should be
specified for this. Other systems do not currently provide appropriate
mechanisms. For these systems a single stream of udp packets is only
guaranteed in single-worker configurations.
The proxy_response directive now specifies how many packets are expected in
response to a single client packet.
FreeBSD returns EINVAL when getsockopt(TCP_FASTOPEN) is called on a unix
domain socket, resulting in "getsockopt(TCP_FASTOPEN) ... failed" messages
during binary upgrade when unix domain listen sockets are present in
the configuration. Added EINVAL to the list of ignored error codes.
Previously, only unix domain sockets were reopened to tolerate cases when
local syslog server was restarted. It makes sense to treat other cases
(for example, local IP address changes) similarly.
- use normal prefixes for types and macros
- removed some macros and types
- revised debug messages
- removed useless check of ngx_sock_ntop() returning 0
- removed special processing of AF_UNSPEC
The protocol used on inbound connection is auto-detected and corresponding
parser is used to extract passed addresses. TLV parameters are ignored.
The maximum supported size of PROXY protocol header is 107 bytes
(similar to version 1).
When clock_gettime(CLOCK_MONOTONIC) (or faster variants, _FAST on FreeBSD,
and _COARSE on Linux) is available, we now use it for ngx_current_msec.
This should improve handling of timers if system time changes (ticket #189).
Specifically, it is now allowed to start with a variable expression with braces:
${name}. The opening curly bracket in such a token was previously considered
the start of a new block. Variables located anywhere else in a token worked
fine: foo${name}.
The capability is retained automatically in unprivileged worker processes after
changing UID if transparent proxying is enabled at least once in nginx
configuration.
The feature is only available in Linux.
On some systems, it's possible that reaper of orphaned processes is
set to something other than "init" process. On such systems, the
changing binary procedure did not work.
The fix is to check if PPID has changed, instead of assuming it's
always 1 for orphaned processes.
This is what usually happens for zones no longer used in the new
configuration, but zones where size or tag were changed were freed
when creating new memory zones. If reconfiguration failed (for
example, due to a conflicting listening socket), this resulted in a
segmentation fault in the master process.
Reported by Zhihua Cao,
http://mailman.nginx.org/pipermail/nginx-devel/2017-October/010536.html.
At least FreeBSD, macOS, NetBSD, and OpenBSD can return unix sockets
with non-null-terminated sun_path. Additionally, the address may become
non-null-terminated if it does not fit into the buffer provided and was
truncated (may happen on macOS, NetBSD, and Solaris, which allow unix socket
addresess larger than struct sockaddr_un). As such, ngx_sock_ntop() might
overread the sockaddr provided, as it used "%s" format and thus assumed
null-terminated string.
To fix this, the ngx_strnlen() function was introduced, and it is now used
to calculate correct length of sun_path.
Some OSes (notably macOS, NetBSD, and Solaris) allow unix socket addresses
larger than struct sockaddr_un. Moreover, some of them (macOS, Solaris)
return socklen of the socket address before it was truncated to fit the
buffer provided. As such, on these systems socklen must not be used without
additional check that it is within the buffer provided.
Appropriate checks added to ngx_event_accept() (after accept()),
ngx_event_recvmsg() (after recvmsg()), and ngx_set_inherited_sockets()
(after getsockname()).
We also obtain socket addresses via getsockname() in
ngx_connection_local_sockaddr(), but it does not need any checks as
it is only used for INET and INET6 sockets (as there can be no
wildcard unix sockets).
Various buffers are allocated in an assumption that there would be
no more than 4 year digits. This might not be true on platforms
with 64-bit time_t, as 64-bit time_t is able to represent more than that.
Such dates with more than 4 year digits hardly make sense though, as
various date formats in use do not allow them anyway.
As such, all dates are now truncated by ngx_gmtime() to December 31, 9999.
This should have no effect on valid dates, though will prevent potential
buffer overflows on invalid ones.
In ngx_gmtime(), instead of casting to ngx_uint_t we now work with
time_t directly. This allows using dates after 2038 on 32-bit platforms
which use 64-bit time_t, notably NetBSD and OpenBSD.
As the code is not able to work with negative time_t values, argument
is now set to 0 for negative values. As a positive side effect, this
results in Epoch being used for such values instead of a date in distant
future.
On Windows, a worker process does not call ngx_slab_init() from
ngx_init_zone_pool(), so ngx_slab_max_size, ngx_slab_exact_size,
and ngx_slab_exact_shift were left uninitialized.
When closing a socket with SO_REUSEPORT, Linux drops all connections waiting
in this socket's listen queue. Previously, it was believed to only result
in connection resets when reconfiguring nginx to use smaller number of worker
processes. It also results in connection resets during configuration
testing though.
Workaround is to avoid using SO_REUSEPORT when testing configuration. It
should prevent listening sockets from being created if a conflicting socket
already exists, while still preserving detection of other possible errors.
It should also cover UDP sockets.
The only downside of this approach seems to be that a configuration testing
won't be able to properly report the case when nginx was compiled with
SO_REUSEPORT, but the kernel is not able to set it. Such errors will be
reported on a real start instead.
It is safe because re-sending still works during graceful shutdown as
long as resolving takes place (and resolve tasks set their own timeouts
that are not cancelable).
Also, the new ctx->cancelable flag can be set to make resolve task's
timeout event cancelable.
Notably, on ppc64 with 64k pagesize, slab 0 (of size 8) requires
128 64-bit elements for bitmasks. The code bogusly assumed that
one uintptr_t is enough for bitmasks plus at least one free slot.
Resolving an SRV record includes resolving its host names in subrequests.
Previously, if memory allocation failed while reporting a subrequest result
after receiving a response from a DNS server, the SRV resolve handler was
called immediately with the NGX_ERROR state. However, if the SRV record
included another copy of the resolved name, it was reported once again.
This could trigger the use-after-free memory access after SRV resolve
handler freed the resolve context by calling ngx_resolve_name_done().
Now the SRV resolve handler is called only when all its subrequests are
completed.
The directive configures a timeout to be used when gracefully shutting down
worker processes. When the timer expires, nginx will try to close all
the connections currently open to facilitate shutdown.
The ngx_chain_coalesce_file() function may produce more bytes to send then
requested in the limit passed, as it aligns the last file position
to send to memory page boundary. As a result, (limit - send) may become
negative. This resulted in big positive number when converted to size_t
while calling ngx_output_chain_to_iovec().
Another part of the problem is in ngx_chain_coalesce_file(): it changes cl
to the next chain link even if the current buffer is only partially sent
due to limit.
Therefore, if a file buffer was not expected to be fully sent due to limit,
and was followed by a memory buffer, nginx called sendfile() with a part
of the file buffer, and the memory buffer in trailer. If there were enough
room in the socket buffer, this resulted in a part of the file buffer being
skipped, and corresponding part of the memory buffer sent instead.
The bug was introduced in 8e903522c17a (1.7.8). Configurations affected
are ones using limits, that is, limit_rate and/or sendfile_max_chunk, and
memory buffers after file ones (may happen when using subrequests or
with proxying with disk buffering).
Fix is to explicitly check if (send < limit) before constructing trailer
with ngx_output_chain_to_iovec(). Additionally, ngx_chain_coalesce_file()
was modified to preserve unfinished file buffers in cl.
Closing up to 32 connections might be too aggressive if worker_connections
is set to a comparable number (and/or there are only a small number of
reusable connections). If an occasional connection shorage happens in
such a configuration, it leads to closing all reusable connections instead
of gradually reducing keepalive timeout to a smaller value. To improve
granularity in such configurations we now close no more than 1/8 of all
reusable connections at once.
Suggested by Joel Cunningham.
There are lots of C4244 warnings (conversion from 'type1' to 'type2',
possible loss of data), so they were disabled.
The same applies to C4267 warnings (conversion from 'size_t' to 'type',
possible loss of data), most notably - conversion from ngx_str_t.len to
ngx_variable_value_t.len (which is unsigned:28). Additionally, there
is at least one case when it is not possible to fix the warning properly
without introducing win32-specific code: recv() on win32 uses "int len",
while POSIX defines "size_t len".
The ssize_t type now properly defined for 64-bit compilation with MSVC.
Caught by warning C4305 (truncation from '__int64' to 'ssize_t'), on
"cutoff = NGX_MAX_SIZE_T_VALUE / 10" in ngx_atosz()).
Several C4334 warnings (result of 32-bit shift implicitly converted to 64 bits)
were fixed by adding explicit conversions.
Several C4214 warnings (nonstandard extension used: bit field types other
than int) in ngx_http_script.h fixed by changing bit field types from
uintptr_t to unsigned.
Most notably, warning W8012 (comparing signed and unsigned values) reported
in multiple places where an unsigned value of small type (e.g., u_short) is
promoted to an int and compared to an unsigned value.
Warning W8072 (suspicious pointer arithmetic) disabled, it is reported
when we increment base pointer in ngx_shm_alloc().
The resolver handles SRV requests in two stages. In the first
stage it gets all SRV RRs, and in the second stage it resolves
the names from SRV RRs into addresses.
Previously, if a response to an SRV request was cached, the
queries to resolve names were not limited by a timeout. If a
response to any of these queries was not received, the SRV
request could never complete.
If a response to an SRV request was not cached, and some of the
queries to resolve names timed out, NGX_RESOLVE_TIMEDOUT was
returned instead of successfully resolved addresses.
To fix both issues, resolving of names is now always limited by
a timeout.
Removed code that would cause an endless loop, and removed condition
check that is always false. The first page in the slot list is
guaranteed to satisfy an allocation.
On exit environment allocated from a pool is no longer available, leading
to a segmentation fault if, for example, a library tries to use it from
an atexit() handler.
Fix is to allocate environment via ngx_alloc() instead, and explicitly
free it using a pool cleanup handler if it's no longer used (e.g., on
configuration reload).
In Perl 5.8.6 the default was switched to use putenv() when used as
embedded library unless "PL_use_safe_putenv = 0" is explicitly used
in the code. Therefore, for modern versions of Perl it is no longer
necessary to restore previous environment when calling perl_destruct().
