With these debug options we still get these warnings:
include/common/memory.h:501:23: warning: null pointer dereference [-Wnull-dereference]
*(volatile int *)0 = 0;
~~~~~~~~~~~~~~~~~~~^~~
include/common/memory.h:460:22: warning: null pointer dereference [-Wnull-dereference]
*(volatile int *)0 = 0;
~~~~~~~~~~~~~~~~~~~^~~
These are purposely there to crash the process at specific locations.
But the annoying warnings do not help with debugging and they are not
even reliable as the compiler may decide to optimize them away. Let's
pass the pointer through DISGUISE() to avoid this.
It's more generic and versatile than the previous shut_your_big_mouth_gcc()
that was used to silence annoying warnings as it's not limited to ignoring
syscalls returns only. This allows us to get rid of the aforementioned
function and the shut_your_big_mouth_gcc_int variable, that started to
look ugly in multi-threaded environments.
Tim reported that BUG_ON() issues warnings on his distro, as the libc marks
some syscalls with __attribute__((warn_unused_result)). Let's pass the
write() result through DISGUISE() to hide it.
This does exactly the same as ALREADY_CHECKED() but does it inline,
returning an identical copy of the scalar variable without letting
the compiler know how it might have been transformed. This can
forcefully disable certain null-pointer checks or result checks when
known undesirable. Typically forcing a crash with *(DISGUISE(NULL))=0
will not cause a null-deref warning.
These are mostly comments in the code. A few error messages were fixed
and are of low enough importance not to deserve a backport. Some regtests
were also fixed.
This patch adds the `unique-id` option to `proxy-v2-options`. If this
option is set a unique ID will be generated based on the `unique-id-format`
while sending the proxy protocol v2 header and stored as the unique id for
the first stream of the connection.
This feature is meant to be used in `tcp` mode. It works on HTTP mode, but
might result in inconsistent unique IDs for the first request on a keep-alive
connection, because the unique ID for the first stream is generated earlier
than the others.
Now that we can send unique IDs in `tcp` mode the `%ID` log variable is made
available in TCP mode.
Remove the list of private connections from server, it has been largely
unused, we only inserted connections in it, but we would never actually
use it.
Implement mt_list_to_list() and list_to_mt_list(), to be able to convert
from a struct list to a struct mt_list, and vice versa.
This is normally of no use, except for struct connection's list field, that
can go in either a struct list or a struct mt_list.
The stream-int code doesn't need to load server.h as it doesn't use
servers at all. However removing this one reveals that proxy.h was
lacking types/checks.h that used to be silently inherited from
types/server.h loaded before in stream_interface.h.
Ryan O'Hara reported that haproxy breaks on fedora-32 using gcc-10
(pre-release). It turns out that constructs such as:
while (item != head) {
item = LIST_ELEM(item.n);
}
loop forever, never matching <item> to <head> despite a printf there
showing them equal. In practice the problem is that the LIST_ELEM()
macro is wrong, it assigns the subtract of two pointers (an integer)
to another pointer through a cast to its pointer type. And GCC 10 now
considers that this cannot match a pointer and silently optimizes the
comparison away. A tested workaround for this is to build with
-fno-tree-pta. Note that older gcc versions even with -ftree-pta do
not exhibit this rather surprizing behavior.
This patch changes the test to instead cast the null-based address to
an int to get the offset and subtract it from the pointer, and this
time it works. There were just a few places to adjust. Ideally
offsetof() should be used but the LIST_ELEM() API doesn't make this
trivial as it's commonly called with a typeof(ptr) and not typeof(ptr*)
thus it would require to completely change the whole API, which is not
something workable in the short term, especially for a backport.
With this change, the emitted code is subtly different even on older
versions. A code size reduction of ~600 bytes and a total executable
size reduction of ~1kB are expected to be observed and should not be
taken as an anomaly. Typically this loop in dequeue_proxy_listeners() :
while ((listener = MT_LIST_POP(...)))
used to produce this code where the comparison is performed on RAX
while the new offset is assigned to RDI even though both are always
identical:
53ded8: 48 8d 78 c0 lea -0x40(%rax),%rdi
53dedc: 48 83 f8 40 cmp $0x40,%rax
53dee0: 74 39 je 53df1b <dequeue_proxy_listeners+0xab>
and now produces this one which is slightly more efficient as the
same register is used for both purposes:
53dd08: 48 83 ef 40 sub $0x40,%rdi
53dd0c: 74 2d je 53dd3b <dequeue_proxy_listeners+0x9b>
Similarly, retrieving the channel from a stream_interface using si_ic()
and si_oc() used to cause this (stream-int in rdi):
1cb7: c7 47 1c 00 02 00 00 movl $0x200,0x1c(%rdi)
1cbe: f6 47 04 10 testb $0x10,0x4(%rdi)
1cc2: 74 1c je 1ce0 <si_report_error+0x30>
1cc4: 48 81 ef 00 03 00 00 sub $0x300,%rdi
1ccb: 81 4f 10 00 08 00 00 orl $0x800,0x10(%rdi)
and now causes this:
1cb7: c7 47 1c 00 02 00 00 movl $0x200,0x1c(%rdi)
1cbe: f6 47 04 10 testb $0x10,0x4(%rdi)
1cc2: 74 1c je 1ce0 <si_report_error+0x30>
1cc4: 81 8f 10 fd ff ff 00 orl $0x800,-0x2f0(%rdi)
There is extremely little chance that this fix wakes up a dormant bug as
the emitted code effectively does what the source code intends.
This must be backported to all supported branches (dropping MT_LIST_ELEM
and the spoa_example parts as needed), since the bug is subtle and may
not always be visible even when compiling with gcc-10.
In MT_LIST_DEL_SAFE(), when the code was changed to use a temporary variable
instead of using the provided pointer directly, we shouldn't have changed
the code that set the pointer to NULL, as we really want the pointer
provided to be nullified, otherwise other parts of the code won't know
we just deleted an element, and bad things will happen.
This should be backported to 2.1.
The splice() syscall has been supported in glibc since version 2.5 issued
in 2006 and is present on supported systems so there's no need for having
our own arch-specific syscall definitions anymore.
This was made to support epoll on patched 2.4 kernels, and on early 2.6
using alternative libcs thanks to the arch-specific syscall definitions.
All the features we support have been around since 2.6.2 and present in
glibc since 2.3.2, neither of which are found in field anymore. Let's
simply drop this and use epoll normally.
The accept4() syscall has been present for a while now, there is no more
reason for maintaining our own arch-specific syscall implementation for
systems lacking it in libc but having it in the kernel.
This was introduced 10 years ago to squeeze a few CPU cycles per syscall
on 32-bit x86 machines and was already quite old by then, requiring to
explicitly enable support for this in the kernel. We don't even know if
it still builds, let alone if it works at all on recent kernels! Let's
completely drop this now.
Since commit 244b070 ("MINOR: ssl/cli: support crt-list filters"),
HAProxy generates a list of filters based on the sni_ctx in memory.
However it's not always relevant, sometimes no filters were configured
and the CN/SAN in the new certificate are not the same.
This patch fixes the issue by using a flag filters in the ckch_inst, so
we are able to know if there were filters or not. In the late case it
uses the CN/SAN of the new certificate to generate the sni_ctx.
note: filters are still only used in the crt-list atm.
We currently have two UUID generation functions, one for the sample
fetch and the other one in the SPOE filter. Both were a bit complicated
since they were made to support random() implementations returning an
arbitrary number of bits, and were throwing away 33 bits every 64. Now
we don't need this anymore, so let's have a generic function consuming
64 bits at once and use it as appropriate.
This is the replacement of failed attempt to add thread safety and
per-process sequences of random numbers initally tried with commit
1c306aa84d ("BUG/MEDIUM: random: implement per-thread and per-process
random sequences").
This new version takes a completely different approach and doesn't try
to work around the horrible OS-specific and non-portable random API
anymore. Instead it implements "xoroshiro128**", a reputedly high
quality random number generator, which is one of the many variants of
xorshift, which passes all quality tests and which is described here:
http://prng.di.unimi.it/
While not cryptographically secure, it is fast and features a 2^128-1
period. It supports fast jumps allowing to cut the period into smaller
non-overlapping sequences, which we use here to support up to 2^32
processes each having their own, non-overlapping sequence of 2^96
numbers (~7*10^28). This is enough to provide 1 billion randoms per
second and per process for 2200 billion years.
The implementation was made thread-safe either by using a double 64-bit
CAS on platforms supporting it (x86_64, aarch64) or by using a local
lock for the time needed to perform the shift operations. This ensures
that all threads pick numbers from the same pool so that it is not
needed to assign per-thread ranges. For processes we use the fast jump
method to advance the sequence by 2^96 for each process.
Before this patch, the following config:
global
nbproc 8
frontend f
bind :4445
mode http
log stdout format raw daemon
log-format "%[uuid] %pid"
redirect location /
Would produce this output:
a4d0ad64-2645-4b74-b894-48acce0669af 12987
a4d0ad64-2645-4b74-b894-48acce0669af 12992
a4d0ad64-2645-4b74-b894-48acce0669af 12986
a4d0ad64-2645-4b74-b894-48acce0669af 12988
a4d0ad64-2645-4b74-b894-48acce0669af 12991
a4d0ad64-2645-4b74-b894-48acce0669af 12989
a4d0ad64-2645-4b74-b894-48acce0669af 12990
82d5f6cd-f6c1-4f85-a89c-36ae85d26fb9 12987
82d5f6cd-f6c1-4f85-a89c-36ae85d26fb9 12992
82d5f6cd-f6c1-4f85-a89c-36ae85d26fb9 12986
(...)
And now produces:
f94b29b3-da74-4e03-a0c5-a532c635bad9 13011
47470c02-4862-4c33-80e7-a952899570e5 13014
86332123-539a-47bf-853f-8c8ea8b2a2b5 13013
8f9efa99-3143-47b2-83cf-d618c8dea711 13012
3cc0f5c7-d790-496b-8d39-bec77647af5b 13015
3ec64915-8f95-4374-9e66-e777dc8791e0 13009
0f9bf894-dcde-408c-b094-6e0bb3255452 13011
49c7bfde-3ffb-40e9-9a8d-8084d650ed8f 13014
e23f6f2e-35c5-4433-a294-b790ab902653 13012
There are multiple benefits to using this method. First, it doesn't
depend anymore on a non-portable API. Second it's thread safe. Third it
is fast and more proven than any hack we could attempt to try to work
around the deficiencies of the various implementations around.
This commit depends on previous patches "MINOR: tools: add 64-bit rotate
operators" and "BUG/MEDIUM: random: initialize the random pool a bit
better", all of which will need to be backported at least as far as
version 2.0. It doesn't require to backport the build fixes for circular
include files dependecy anymore.
This reverts commit 1c306aa84d.
It breaks the build on all non-glibc platforms. I got confused by the
man page (which possibly is the most confusing man page I've ever read
about a standard libc function) and mistakenly understood that random_r
was portable, especially since it appears in latest freebsd source as
well but not in released versions, and with a slightly different API :-/
We need to find a different solution with a fallback. Among the
possibilities, we may reintroduce this one with a fallback relying on
locking around the standard functions, keeping fingers crossed for no
other library function to call them in parallel, or we may also provide
our own PRNG, which is not necessarily more difficult than working
around the totally broken up design of the portable API.
As mentioned in previous patch, the random number generator was never
made thread-safe, which used not to be a problem for health checks
spreading, until the uuid sample fetch function appeared. Currently
it is possible for two threads or processes to produce exactly the
same UUID. In fact it's extremely likely that this will happen for
processes, as can be seen with this config:
global
nbproc 8
frontend f
bind :4445
mode http
log stdout daemon format raw
log-format "%[uuid] %pid"
redirect location /
It typically produces this log:
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30645
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30641
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30644
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30639
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30646
07764439-c24d-4e6f-a5a6-0138be59e7a8 30645
07764439-c24d-4e6f-a5a6-0138be59e7a8 30639
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30643
07764439-c24d-4e6f-a5a6-0138be59e7a8 30646
b6773fdd-678f-4d04-96f2-4fb11ad15d6b 30646
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30642
07764439-c24d-4e6f-a5a6-0138be59e7a8 30642
What this patch does is to use a distinct per-thread and per-process
seed to make sure the same sequences will not appear, and will then
extend these seeds by "burning" a number of randoms that depends on
the global random seed, the thread ID and the process ID. This adds
roughly 20 extra bits of randomness, resulting in 52 bits total per
thread and per process.
It only takes a few milliseconds to burn these randoms and given
that threads start with a different seed, we know they will not
catch each other. So these random extra bits are essentially added
to ensure randomness between boots and cluster instances.
This replaces all uses of random() with ha_random() which uses the
thread-local state.
This must be backported as far as 2.0 or any version having the
UUID sample-fetch function since it's the main victim here.
It's important to note that this patch, in addition to depending on
the previous one "BUG/MEDIUM: init: initialize the random pool a bit
better", also depends on the preceeding build fixes to address a
circular dependency issue in the include files that prevented it
from building. Part or all of these patches may need to be backported
or adapted as well.
Since the UUID sample fetch was created, some people noticed that in
certain virtualized environments they manage to get exact same UUIDs
on different instances started exactly at the same moment. It turns
out that the randoms were only initialized to spread the health checks
originally, not to provide "clean" randoms.
This patch changes this and collects more randomness from various
sources, including existing randoms, /dev/urandom when available,
RAND_bytes() when OpenSSL is available, as well as the timing for such
operations, then applies a SHA1 on all this to keep a 160 bits random
seed available, 32 of which are passed to srandom().
It's worth mentioning that there's no clean way to pass more than 32
bits to srandom() as even initstate() provides an opaque state that
must absolutely not be tampered with since known implementations
contain state information.
At least this allows to have up to 4 billion different sequences
from the boot, which is not that bad.
Note that the thread safety was still not addressed, which is another
issue for another patch.
This must be backported to all versions containing the UUID sample
fetch function, i.e. as far as 2.0.
buffer.h relies on proto/activity because it contains some code and not
just type definitions. It must not be included from types files. It
should probably also be split in two if it starts to include a proto.
This causes some circular dependencies at other places.
This flag was used in some internal functions to be sure the current stream is
able to handle HTTP content. It was introduced when the legacy HTTP code was
still there. Now, It is possible to rely on stream's flags to be sure we have an
HTX stream.
So the flag HLUA_TXN_HTTP_RDY can be removed. Everywhere it was tested, it is
replaced by a call to the IS_HTX_STRM() macro.
This patch is mandatory to allow the support of the filters written in lua.
The htx_find_offset() function may be used to look for a block at a specific
offset in an HTX message, starting from the message head. A compound result is
returned, an htx_ret structure, with the found block and the position of the
offset in the block. If the offset is ouside of the HTX message, the returned
block is NULL.
The b_insert_blk() function may now be used to insert a string, given a pointer
and the string length, at an absolute offset in a buffer, moving data between
this offset and the buffer's tail just after the end of the inserted string. The
buffer's length is automatically updated. This function supports wrapping. All
the string is copied or nothing. So it returns 0 if there are not enough space
to perform the copy. Otherwise, the number of bytes copied is returned.
pattern_finalize_config() uses an inefficient algorithm which is a
problem with very large configuration files. This affects startup, and
therefore reload time. When haproxy is deployed as a router in a
Kubernetes cluster the generated configuration file may be large and
reloads are frequently occuring, which makes this a significant issue.
The old algorithm is O(n^2)
* allocate missing uids - O(n^2)
* sort linked list - O(n^2)
The new algorithm is O(n log n):
* find the user allocated uids - O(n)
* store them for efficient lookup - O(n log n)
* allocate missing uids - n times O(log n)
* sort all uids - O(n log n)
* convert back to linked list - O(n)
Performance examples, startup time in seconds:
pat_refs old new
1000 0.02 0.01
10000 2.1 0.04
20000 12.3 0.07
30000 27.9 0.10
40000 52.5 0.14
50000 77.5 0.17
Please backport to 1.8, 2.0 and 2.1.
`istalloc` allocates memory and returns an `ist` with the size `0` that points
to this allocation.
`istfree` frees the pointed memory and clears the pointer.
It was only possible to go down from the ckch_store to the sni_ctx but
not to go up from the sni_ctx to the ckch_store.
To allow that, 2 pointers were added:
- a ckch_inst pointer in the struct sni_ctx
- a ckckh_store pointer in the struct ckch_inst
Generate a list of the previous filters when updating a certificate
which use filters in crt-list. Then pass this list to the function
generating the sni_ctx during the commit.
This feature allows the update of the crt-list certificates which uses
the filters with "set ssl cert".
This function could be probably replaced by creating a new
ckch_inst_new_load_store() function which take the previous sni_ctx list as
an argument instead of the char **sni_filter, avoiding the
allocation/copy during runtime for each filter. But since are still
handling the multi-cert bundles, it's better this way to avoid code
duplication.
A test on FreeBSD with clang 4 to 8 produces this on a call to a
spinning loop on the CLI:
call trace(5):
| 0x53e2bc [eb 16 48 63 c3 48 c1 e0]: wdt_handler+0x10c
| 0x800e02cfe [e8 5d 83 00 00 8b 18 8b]: libthr:pthread_sigmask+0x53e
with our own function it correctly produces this:
call trace(20):
| 0x53e2dc [eb 16 48 63 c3 48 c1 e0]: wdt_handler+0x10c
| 0x800e02cfe [e8 5d 83 00 00 8b 18 8b]: libthr:pthread_sigmask+0x53e
| 0x800e022bf [48 83 c4 38 5b 41 5c 41]: libthr:pthread_getspecific+0xdef
| 0x7ffffffff003 [48 8d 7c 24 10 6a 00 48]: main+0x7fffffb416f3
| 0x801373809 [85 c0 0f 84 6f ff ff ff]: libc:__sys_gettimeofday+0x199
| 0x801373709 [89 c3 85 c0 75 a6 48 8b]: libc:__sys_gettimeofday+0x99
| 0x801371c62 [83 f8 4e 75 0f 48 89 df]: libc:gettimeofday+0x12
| 0x51fa0a [48 89 df 4c 89 f6 e8 6b]: ha_thread_dump_all_to_trash+0x49a
| 0x4b723b [85 c0 75 09 49 8b 04 24]: mworker_cli_sockpair_new+0xd9b
| 0x4b6c68 [85 c0 75 08 4c 89 ef e8]: mworker_cli_sockpair_new+0x7c8
| 0x532f81 [4c 89 e7 48 83 ef 80 41]: task_run_applet+0xe1
So let's add clang+x86_64 to the list of platforms that will use our
simplified version. As a bonus it will not require to link with
-lexecinfo on FreeBSD and will work out of the box when passing
USE_BACKTRACE=1.
It happens that on aarch64 backtrace() only returns one entry (tested
with gcc 4.7.4, 5.5.0 and 7.4.1). Probably that it refrains from unwinding
the stack due to the risk of hitting a bad pointer. Here we can use
may_access() to know when it's safe, so we can actually unwind the stack
without taking risks. It happens that the faulting function (the one
just after the signal handler) is not listed here, very likely because
the signal handler uses a special stack and did not create a new frame.
So this patch creates a new my_backtrace() function in standard.h that
either calls backtrace() or does its own unrolling. The choice depends
on HA_HAVE_WORKING_BACKTRACE which is set in compat.h based on the build
target.
It's only available for bind line. "ca-verify-file" allows to separate
CA certificates from "ca-file". CA names sent in server hello message is
only compute from "ca-file". Typically, "ca-file" must be defined with
intermediate certificates and "ca-verify-file" with certificates to
ending the chain, like root CA.
Fix issue #404.
