Released version 2.9-dev9 with the following main changes :
- DOC: internal: filters: fix reference to entities.pdf
- BUG/MINOR: ssl: load correctly @system-ca when ca-base is define
- MINOR: lua: Add flags to configure logging behaviour
- MINOR: lua: change tune.lua.log.stderr default from 'on' to 'auto'
- BUG/MINOR: backend: fix wrong BUG_ON for avail conn
- BUG/MAJOR: backend: fix idle conn crash under low FD
- MINOR: backend: refactor insertion in avail conns tree
- DEBUG: mux-h2/flags: fix list of h2c flags used by the flags decoder
- BUG/MEDIUM: server/log: "mode log" after server keyword causes crash
- MINOR: connection: add conn_pr_mode_to_proto_mode() helper func
- BUG/MEDIUM: server: "proto" not working for dynamic servers
- MINOR: server: add helper function to detach server from proxy list
- DEBUG: add a tainted flag when ha_panic() is called
- DEBUG: lua: add tainted flags for stuck Lua contexts
- DEBUG: pools: detect that malloc_trim() is in progress
- BUG/MINOR: quic: do not consider idle timeout on CLOSING state
- MINOR: frontend: implement a dedicated actconn increment function
- BUG/MINOR: ssl: use a thread-safe sslconns increment
- MEDIUM: quic: count quic_conn instance for maxconn
- MEDIUM: quic: count quic_conn for global sslconns
- BUG/MINOR: ssl: suboptimal certificate selection with TLSv1.3 and dual ECDSA/RSA
- REGTESTS: ssl: update the filters test for TLSv1.3 and sigalgs
- BUG/MINOR: mux-quic: fix early close if unset client timeout
- BUG/MEDIUM: ssl: segfault when cipher is NULL
- BUG/MINOR: tcpcheck: Report hexstring instead of binary one on check failure
- MEDIUM: systemd: be more verbose about the reload
- MINOR: sample: Add fetcher for getting all cookie names
- BUG/MINOR: proto_reverse_connect: support SNI on active connect
- MINOR: proxy/stktable: add resolve_stick_rule helper function
- BUG/MINOR: stktable: missing free in parse_stick_table()
- BUG/MINOR: cfgparse/stktable: fix error message on stktable_init() failure
- MINOR: stktable: stktable_init() sets err_msg on error
- MINOR: stktable: check if a type should be used as-is
- MEDIUM: stktable/peers: "write-to" local table on peer updates
- CI: github: update wolfSSL to 5.6.4
- DOC: install: update the wolfSSL required version
- MINOR: server: Add parser support for set-proxy-v2-tlv-fmt
- MINOR: connection: Send out generic, user-defined server TLVs
- BUG/MEDIUM: pattern: don't trim pools under lock in pat_ref_purge_range()
- MINOR: mux-h2: always use h2_send() in h2_done_ff(), not h2_process()
- OPTIM: mux-h2: call h2_send() directly from h2_snd_buf()
- BUG/MINOR: server: remove some incorrect free() calls on null elements
This reverts commit c618ed5ff4.
The list iterator is broken. As found by Fred, running QUIC single-
threaded shows that only the first connection is accepted because the
accepter relies on the element being initialized once detached (which
is expected and matches what MT_LIST_DELETE_SAFE() used to do before).
However while doing this in the quic_sock code seems to work, doing it
inside the macro show total breakage and the unit test doesn't work
anymore (random crashes). Thus it looks like the fix is not trivial,
let's roll this back for the time it will take to fix the loop.
The new mt_list code supports exponential back-off on conflict, which
is important for use cases where there is contention on a large number
of threads. The API evolved a little bit and required some updates:
- mt_list_for_each_entry_safe() is now in upper case to explicitly
show that it is a macro, and only uses the back element, doesn't
require a secondary pointer for deletes anymore.
- MT_LIST_DELETE_SAFE() doesn't exist anymore, instead one just has
to set the list iterator to NULL so that it is not re-inserted
into the list and the list is spliced there. One must be careful
because it was usually performed before freeing the element. Now
instead the element must be nulled before the continue/break.
- MT_LIST_LOCK_ELT() and MT_LIST_UNLOCK_ELT() have always been
unclear. They were replaced by mt_list_cut_around() and
mt_list_connect_elem() which more explicitly detach the element
and reconnect it into the list.
- MT_LIST_APPEND_LOCKED() was only in haproxy so it was left as-is
in list.h. It may however possibly benefit from being upstreamed.
This required tiny adaptations to event_hdl.c and quic_sock.c. The
test case was updated and the API doc added. Note that in order to
keep include files small, the struct mt_list definition remains in
list-t.h (par of the internal API) and was ifdef'd out in mt_list.h.
A test on QUIC with both quictls 1.1.1 and wolfssl 5.6.3 on ARM64 with
80 threads shows a drastic reduction of CPU usage thanks to this and
the refined memory barriers. Please note that the CPU usage on OpenSSL
3.0.9 is significantly higher due to the excessive use of atomic ops
by openssl, but 3.1 is only slightly above 1.1.1 though:
- before: 35 Gbps, 3.5 Mpps, 7800% CPU
- after: 41 Gbps, 4.2 Mpps, 2900% CPU
More and more utility functions rely on the trash while most of the init
code doesn't have access to it because it's initialized very late (in
PRE_CHECK for the initial one). It's a pool, and it purposely supports
being reallocated, so let's initialize it in STG_POOL so that early
STG_INIT code can at least use it.
These were docs for very old design thoughts or internal subsystems
which are now totally irrelevant and even misleading. Those with some
outdated ideas mixed with useful stuff were kept though.
The conditions where ERR, EOS and EOI are found are not always
crystal clear, and the fact that there's still a good bunch of
original ones dating from the early days and that seem to test for
non-existing cases doesn't help either.
After auditing the code base and projecting the 3 main muxes' stream
termination conditions, with Christopher and Amaury we could establish
the current flags matrix which indicates both what each combination
means for each mux and when it is set by each of them (or not set and
for what reason).
It should be sufficient to void doubts when adding code or when chasing
a bug.
It *must not* be backported because it is highly specific to the latest
2.8-dev.
Released version 2.8-dev7 with the following main changes :
- BUG/MINOR: stats: Don't replace sc_shutr() by SE_FL_EOS flag yet
- BUG/MEDIUM: mux-h2: Be able to detect connection error during handshake
- BUG/MINOR: quic: Missing padding in very short probe packets
- MINOR: proxy/pool: prevent unnecessary calls to pool_gc()
- CLEANUP: proxy: remove stop_time related dead code
- DOC/MINOR: reformat configuration.txt's "quoting and escaping" table
- MINOR: http_fetch: Add support for empty delim in url_param
- MINOR: http_fetch: add case insensitive support for smp_fetch_url_param
- MINOR: http_fetch: Add case-insensitive argument for url_param/urlp_val
- REGTESTS : Add test support for case insentitive for url_param
- BUG/MEDIUM: proxy/sktable: prevent watchdog trigger on soft-stop
- BUG/MINOR: backend: make be_usable_srv() consistent when stopping
- BUG/MINOR: ssl: Remove dead code in cli_parse_update_ocsp_response
- BUG/MINOR: ssl: Fix potential leak in cli_parse_update_ocsp_response
- BUG/MINOR: ssl: ssl-(min|max)-ver parameter not duplicated for bundles in crt-list
- BUG/MINOR: quic: Wrong use of now_ms timestamps (cubic algo)
- MINOR: quic: Add recovery related information to "show quic"
- BUG/MINOR: quic: Wrong use of now_ms timestamps (newreno algo)
- BUG/MINOR: quic: Missing max_idle_timeout initialization for the connection
- MINOR: quic: Implement cubic state trace callback
- MINOR: quic: Adjustments for generic control congestion traces
- MINOR: quic: Traces adjustments at proto level.
- MEDIUM: quic: Ack delay implementation
- BUG/MINOR: quic: Wrong rtt variance computing
- MINOR: cli: support filtering on FD types in "show fd"
- MINOR: quic: Add a fake congestion control algorithm named "nocc"
- CI: run smoke tests on config syntax to check memory related issues
- CLEANUP: assorted typo fixes in the code and comments
- CI: exclude doc/{design-thoughts,internals} from spell check
- BUG/MINOR: quic: Remaining useless statements in cubic slow start callback
- BUG/MINOR: quic: Cubic congestion control window may wrap
- MINOR: quic: Add missing traces in cubic algorithm implementation
- BUG/MAJOR: quic: Congestion algorithms states shared between the connection
- BUG/MINOR: ssl: Undefined reference when building with OPENSSL_NO_DEPRECATED
- BUG/MINOR: quic: Remove useless BUG_ON() in newreno and cubic algo implementation
- MINOR: http-act: emit a warning when a header field name contains forbidden chars
- DOC: config: strict-sni allows to start without certificate
- MINOR: quic: Add trace to debug idle timer task issues
- BUG/MINOR: quic: Unexpected connection closures upon idle timer task execution
- BUG/MINOR: quic: Wrong idle timer expiration (during 20s)
- BUILD: quic: 32bits compilation issue in cli_io_handler_dump_quic()
- BUG/MINOR: quic: Possible wrong PTO computing
- BUG/MINOR: tcpcheck: Be able to expect an empty response
- BUG/MEDIUM: stconn: Add a missing return statement in sc_app_shutr()
- BUG/MINOR: stream: Fix test on channels flags to set clientfin/serverfin touts
- MINOR: applet: Uninline appctx_free()
- MEDIUM: applet/trace: Register a new trace source with its events
- CLEANUP: stconn: Remove remaining debug messages
- BUG/MEDIUM: channel: Improve reports for shut in co_getblk()
- BUG/MEDIUM: dns: Properly handle error when a response consumed
- MINOR: stconn: Remove unecessary test on SE_FL_EOS before receiving data
- MINOR: stconn/channel: Move CF_READ_DONTWAIT into the SC and rename it
- MINOR: stconn/channel: Move CF_SEND_DONTWAIT into the SC and rename it
- MINOR: stconn/channel: Move CF_NEVER_WAIT into the SC and rename it
- MINOR: stconn/channel: Move CF_EXPECT_MORE into the SC and rename it
- MINOR: mux-pt: Report end-of-input with the end-of-stream after a read
- BUG/MINOR: mux-h1: Properly report EOI/ERROR on read0 in h1_rcv_pipe()
- CLEANUP: mux-h1/mux-pt: Remove useless test on SE_FL_SHR/SE_FL_SHW flags
- MINOR: mux-h1: Report an error to the SE descriptor on truncated message
- MINOR: stconn: Always ack EOS at the end of sc_conn_recv()
- MINOR: stconn/applet: Handle EOI in the applet .wake callback function
- MINOR: applet: No longer set EOI on the SC
- MINOR: stconn/applet: Handle EOS in the applet .wake callback function
- MEDIUM: cache: Use the sedesc to report and detect end of processing
- MEDIUM: cli: Use the sedesc to report and detect end of processing
- MINOR: dns: Remove the test on the opposite SC state to send requests
- MEDIUM: dns: Use the sedesc to report and detect end of processing
- MEDIUM: spoe: Use the sedesc to report and detect end of processing
- MEDIUM: hlua/applet: Use the sedesc to report and detect end of processing
- MEDIUM: log: Use the sedesc to report and detect end of processing
- MEDIUM: peers: Use the sedesc to report and detect end of processing
- MINOR: sink: Remove the tests on the opposite SC state to process messages
- MEDIUM: sink: Use the sedesc to report and detect end of processing
- MEDIUM: stats: Use the sedesc to report and detect end of processing
- MEDIUM: promex: Use the sedesc to report and detect end of processing
- MEDIUM: http_client: Use the sedesc to report and detect end of processing
- MINOR: stconn/channel: Move CF_EOI into the SC and rename it
- MEDIUM: tree-wide: Move flags about shut from the channel to the SC
- MINOR: tree-wide: Simplifiy some tests on SHUT flags by accessing SCs directly
- MINOR: stconn/applet: Add BUG_ON_HOT() to be sure SE_FL_EOS is never set alone
- MINOR: server: add SRV_F_DELETED flag
- BUG/MINOR: server/del: fix srv->next pointer consistency
- BUG/MINOR: stats: properly handle server stats dumping resumption
- BUG/MINOR: sink: free forward_px on deinit()
- BUG/MINOR: log: free log forward proxies on deinit()
- MINOR: server: always call ssl->destroy_srv when available
- MINOR: server: correctly free servers on deinit()
- BUG/MINOR: hlua: hook yield does not behave as expected
- MINOR: hlua: properly handle hlua_process_task HLUA_E_ETMOUT
- BUG/MINOR: hlua: enforce proper running context for register_x functions
- MINOR: hlua: Fix two functions that return nothing useful
- MEDIUM: hlua: Dynamic list of frontend/backend in Lua
- MINOR: hlua_fcn: alternative to old proxy and server attributes
- MEDIUM: hlua_fcn: dynamic server iteration and indexing
- MEDIUM: hlua_fcn/api: remove some old server and proxy attributes
- CLEANUP: hlua: fix conflicting comment in hlua_ctx_destroy()
- MINOR: hlua: add simple hlua reference handling API
- MINOR: hlua: fix return type for hlua_checkfunction() and hlua_checktable()
- BUG/MINOR: hlua: fix reference leak in core.register_task()
- BUG/MINOR: hlua: fix reference leak in hlua_post_init_state()
- BUG/MINOR: hlua: prevent function and table reference leaks on errors
- CLEANUP: hlua: use hlua_ref() instead of luaL_ref()
- CLEANUP: hlua: use hlua_pushref() instead of lua_rawgeti()
- CLEANUP: hlua: use hlua_unref() instead of luaL_unref()
- MINOR: hlua: simplify lua locking
- BUG/MEDIUM: hlua: prevent deadlocks with main lua lock
- MINOR: hlua_fcn: add server->get_rid() method
- MINOR: hlua: support for optional arguments to core.register_task()
- DOC: lua: silence "literal block ends without a blank line" Sphinx warnings
- DOC: lua: silence "Unexpected indentation" Sphinx warnings
- BUG/MINOR: event_hdl: fix rid storage type
- BUG/MINOR: event_hdl: make event_hdl_subscribe thread-safe
- MINOR: event_hdl: global sublist management clarification
- BUG/MEDIUM: event_hdl: clean soft-stop handling
- BUG/MEDIUM: event_hdl: fix async data refcount issue
- MINOR: event_hdl: normal tasks support for advanced async mode
- MINOR: event_hdl: add event_hdl_async_equeue_isempty() function
- MINOR: event_hdl: add event_hdl_async_equeue_size() function
- MINOR: event_hdl: pause/resume for subscriptions
- MINOR: proxy: add findserver_unique_id() and findserver_unique_name()
- MEDIUM: hlua/event_hdl: initial support for event handlers
- MINOR: hlua/event_hdl: per-server event subscription
- EXAMPLES: add basic event_hdl lua example script
- MINOR: http-ana: Add a HTTP_MSGF flag to state the Expect header was checked
- BUG/MINOR: http-ana: Don't switch message to DATA when waiting for payload
- BUG/MINOR: quic: Possible crashes in qc_idle_timer_task()
- MINOR: quic: derive first DCID from client ODCID
- MINOR: quic: remove ODCID dedicated tree
- MINOR: quic: remove address concatenation to ODCID
- BUG/MINOR: mworker: unset more internal variables from program section
- BUG/MINOR: errors: invalid use of memprintf in startup_logs_init()
- MINOR: applet: Use unsafe version to get stream from SC in the trace function
- BUG/MUNOR: http-ana: Use an unsigned integer for http_msg flags
- MINOR: compression: Make compression offload a flag
- MINOR: compression: Prepare compression code for request compression
- MINOR: compression: Store algo and type for both request and response
- MINOR: compression: Count separately request and response compression
- MEDIUM: compression: Make it so we can compress requests as well.
- BUG/MINOR: lua: remove incorrect usage of strncat()
- CLEANUP: tcpcheck: remove the only occurrence of sprintf() in the code
- CLEANUP: ocsp: do no use strpcy() to copy a path!
- CLEANUP: tree-wide: remove strpcy() from constant strings
- CLEANUP: opentracing: remove the last two occurrences of strncat()
- BUILD: compiler: fix __equals_1() on older compilers
- MINOR: compiler: define a __attribute__warning() macro
- BUILD: bug.h: add a warning in the base API when unsafe functions are used
- BUG/MEDIUM: listeners: Use the right parameters for strlcpy2().
advanced async mode (EVENT_HDL_ASYNC_TASK) provided full support for
custom tasklets registration.
Due to the similarities between tasks and tasklets, it may be useful
to use the advanced mode with an existing task (not a tasklet).
While the API did not explicitly disallow this usage, things would
get bad if we try to wakeup a task using tasklet_wakeup() for notifying
the task about new events.
To make the API support both custom tasks and tasklets, we use the
TASK_IS_TASKLET() macro to call the proper waking function depending
on the task's type:
- For tasklets: we use tasklet_wakeup()
- For tasks: we use task_wakeup()
If 68e692da0 ("MINOR: event_hdl: add event handler base api")
is being backported, then this commit should be backported with it.
The same change was already performed for the cli. The stats applet and the
prometheus exporter are also concerned. Both use the stats API and rely on
pool functions to get total pool usage in bytes. pool_total_allocated() and
pool_total_used() must return 64 bits unsigned integer to avoid any wrapping
around 4G.
This may be backported to all versions.
Till now it was only possible to change the thread local hot cache size
at build time using CONFIG_HAP_POOL_CACHE_SIZE. But along benchmarks it
was sometimes noticed a huge contention in the lower level memory
allocators indicating that larger caches could be beneficial, especially
on machines with large L2 CPUs.
Given that the checks against this value was no longer on a hot path
anymore, there was no reason for continuing to force it to be tuned at
build time. So this patch allows to set it by tune.memory-hot-size.
It's worth noting that during the boot phase the value remains zero so
that it's possible to know if the value was set or not, which opens the
possibility that we try to automatically adjust it based on the per-cpu
L2 cache size or the use of certain protocols (none of this is done yet).
Since the massive pools cleanup that happened in 2.6, the pools
architecture was made quite more hierarchical and many alternate code
blocks could be moved to runtime flags set by -dM. One of them had not
been converted by then, DEBUG_UAF. It's not much more difficult actually,
since it only acts on a pair of functions indirection on the slow path
(OS-level allocator) and a default setting for the cache activation.
This patch adds the "uaf" setting to the options permitted in -dM so
that it now becomes possible to set or unset UAF at boot time without
recompiling. This is particularly convenient, because every 3 months on
average, developers ask a user to recompile haproxy with DEBUG_UAF to
understand a bug. Now it will not be needed anymore, instead the user
will only have to disable pools and enable uaf using -dMuaf. Note that
-dMuaf only disables previously enabled pools, but it remains possible
to re-enable caching by specifying the cache after, like -dMuaf,cache.
A few tests with this mode show that it can be an interesting combination
which catches significantly less UAF but will do so with much less
overhead, so it might be compatible with some high-traffic deployments.
The change is very small and isolated. It could be helpful to backport
this at least to 2.7 once confirmed not to cause build issues on exotic
systems, and even to 2.6 a bit later as this has proven to be useful
over time, and could be even more if it did not require a rebuild. If
a backport is desired, the following patches are needed as well:
CLEANUP: pools: move the write before free to the uaf-only function
CLEANUP: pool: only include pool-os from pool.c not pool.h
REORG: pool: move all the OS specific code to pool-os.h
CLEANUP: pools: get rid of CONFIG_HAP_POOLS
DEBUG: pool: show a few examples in -dMhelp
This is an initial work for the dedicated
event handler API internal documentation.
The file is located at doc/internals/api/event_hdl.txt
event_hdl feature has been introduced with:
MINOR: event_hdl: add event handler base api
Let's keep these notes as references for later use. Polling on connect()
can sometimes return a few unexpected state combinations that such tests
illustrate. They can serve as reminders for special error handling.
The "sequence" and "entities" diagrams have become so much outdated that
they are at best confusing, but more generally wrong. Let's simply remove
them.
The "layers" mini-doc shows how streams, stconn, sedesc, conns, applets
and muxes interact, with field names, pointers and invariants. It should
be completed but already provides a quick overview about what can be
guaranteed at any step and at different layers.
The stream connector replaced the conn_stream and the sc_conn_io_cb()
function appeared. There's no place there to mention the endpoint
descriptor, but a separate diagram showing the relation between stream
and endpoint via the connector would be nice.
This adds a call to function <fct> to the list of functions to be called at
the step just before the configuration validity checks. This is useful when you
need to create things like it would have been done during the configuration
parsing and where the initialization should continue in the configuration
check.
It could be used for example to generate a proxy with multiple servers using
the configuration parser itself. At this step the trash buffers are allocated.
Threads are not yet started so no protection is required. The function is
expected to return non-zero on success, or zero on failure. A failure will make
the process emit a succinct error message and immediately exit.
The STG_REGISTER init level is used to register known keywords and
protocol stacks. It must be called earlier because some of the init
code already relies on it to be known. For example, "haproxy -vv"
for now is constrained to start very late only because of this.
This patch moves it between STG_LOCK and STG_ALLOC, which is fine as
it's used for static registration.
The poisonning performed on pool_free() used to help a little bit with
use-after-free detection, but usually did more harm than good in that
it was never possible to perform post-mortem analysis on released
objects once poisonning was enabled on allocation. Now that there is
a dedicated DEBUG_POOL_INTEGRITY, let's get rid of this annoyance
which is not even documented in the management manual.
This new option, when set, will cause the callers of pool_alloc() and
pool_free() to be recorded into an extra area in the pool that is expected
to be helpful for later inspection (e.g. in core dumps). For example it
may help figure that an object was released to a pool with some sub-fields
not yet released or that a use-after-free happened after releasing it,
with an immediate indication about the exact line of code that released
it (possibly an error path).
This only works with the per-thread cache, and even objects refilled from
the shared pool directly into the thread-local cache will have a NULL
there. That's not an issue since these objects have not yet been freed.
It's worth noting that pool_alloc_nocache() continues not to set any
caller pointer (e.g. when the cache is empty) because that would require
a possibly undesirable API change.
The extra cost is minimal (one pointer per object) and this completes
well with DEBUG_POOL_INTEGRITY.
When enabled, objects picked from the cache are checked for corruption
by comparing their contents against a pattern that was placed when they
were inserted into the cache. Objects are also allocated in the reverse
order, from the oldest one to the most recent, so as to maximize the
ability to detect such a corruption. The goal is to detect writes after
free (or possibly hardware memory corruptions). Contrary to DEBUG_UAF
this cannot detect reads after free, but may possibly detect later
corruptions and will not consume extra memory. The CPU usage will
increase a bit due to the cost of filling/checking the area and for the
preference for cold cache instead of hot cache, though not as much as
with DEBUG_UAF. This option is meant to be usable in production.
The purpose here is to explain how memory pools work, what their
architecture is depending on the build options (4 possible combinations),
and how the various build options affect their behavior.
Two pool-specific macros that were previously documented in initcalls
were moved to pools.txt.
Another non-trivial part that is often needed. Exported functions
and flags available to applications were documented as well as some
restrictions and falltraps.
This one was missing. It should be easier to use now. It is obvious that
some functions are missing, and it looks like ist2str() and istpad() are
exactly the same.
Released version 2.5-dev13 with the following main changes :
- SCRIPTS: git-show-backports: re-enable file-based filtering
- MINOR: jwt: Make invalid static JWT algorithms an error in `jwt_verify` converter
- MINOR: mux-h2: add trace on extended connect usage
- BUG/MEDIUM: mux-h2: reject upgrade if no RFC8441 support
- MINOR: stream/mux: implement websocket stream flag
- MINOR: connection: implement function to update ALPN
- MINOR: connection: add alternative mux_ops param for conn_install_mux_be
- MEDIUM: server/backend: implement websocket protocol selection
- MINOR: server: add ws keyword
- BUG/MINOR: resolvers: fix sent messages were counted twice
- BUG/MINOR: resolvers: throw log message if trash not large enough for query
- MINOR: resolvers/dns: split dns and resolver counters in dns_counter struct
- MEDIUM: resolvers: rename dns extra counters to resolvers extra counters
- BUG/MINOR: jwt: Fix jwt_parse_alg incorrectly returning JWS_ALG_NONE
- DOC: add QUIC instruction in INSTALL
- CLEANUP: halog: Remove dead stores
- DEV: coccinelle: Add ha_free.cocci
- CLEANUP: Apply ha_free.cocci
- DEV: coccinelle: Add rule to use `istnext()` where possible
- CLEANUP: Apply ist.cocci
- REGTESTS: Use `feature cmd` for 2.5+ tests (2)
- DOC: internals: move some API definitions to an "api" subdirectory
- MINOR: quic: Allocate listener RX buffers
- CLEANUP: quic: Remove useless code
- MINOR: quic: Enhance the listener RX buffering part
- MINOR: quic: Remove a useless lock for CRYPTO frames
- MINOR: quic: Use QUIC_LOCK QUIC specific lock label.
- MINOR: backend: Get client dst address to set the server's one only if needful
- MINOR: compression: Warn for 'compression offload' in defaults sections
- MEDIUM: connection: rename fc_conn_err and bc_conn_err to fc_err and bc_err
- DOC: configuration: move the default log formats to their own section
- MINOR: ssl: make the ssl_fc_sni() sample-fetch function always available
- MEDIUM: log: add the client's SNI to the default HTTPS log format
- DOC: config: add an example of reasonably complete error-log-format
- DOC: config: move error-log-format before custom log format
It's not always easy to figure that there are some docs on internal API
stuff, let's move them to their own directory. There's a diagram for
lists that could be placed there but instead would deserve a greppable
description for quick lookups, so it was not moved there.
Right now we're using a DWCAS to atomically set the running_mask while
being constrained by the thread_mask. This DWCAS is annoying because we
may seriously need it later when adding support for thread groups, for
checking that the running_mask applies to the correct group.
It turns out that the DWCAS is not strictly necessary because we never
need it to set the thread_mask based on the running_mask, only the other
way around. And in fact, the running_mask is always cleared alone, and
the thread_mask is changed alone as well. The running_mask is only
relevant to indicate a takeover when the thread_mask matches it. Any
bit set in running and not present in thread_mask indicates a transition
in progress.
As such, it is possible to re-arrange this by using a regular CAS around a
consistency check between running_mask and thread_mask in fd_update_events
and by making a CAS on running_mask then an atomic store on the thread_mask
in fd_takeover(). The only other case is fd_delete() but that one already
sets the running_mask before clearing the thread_mask, which is compatible
with the consistency check above.
This change has happily survived 10 billion takeovers on a 16-thread
machine at 800k requests/s.
The fd-migration doc was updated to reflect this change.
This explains the traps to avoid and the sequence that leads to
consistent use of an FD known by multiple threads at once. This
was co-authored with Olivier.
Released version 2.4-dev19 with the following main changes :
- BUG/MINOR: hlua: Don't rely on top of the stack when using Lua buffers
- BUG/MEDIUM: cli: prevent memory leak on write errors
- BUG/MINOR: ssl/cli: fix a lock leak when no memory available
- MINOR: debug: add a new "debug dev sym" command in expert mode
- MINOR: pools/debug: slightly relax DEBUG_DONT_SHARE_POOLS
- CI: Github Actions: switch to LibreSSL-3.3.3
- MINOR: srv: close all idle connections on shutdown
- MINOR: connection: move session_list member in a union
- MEDIUM: mux_h1: release idling frontend conns on soft-stop
- MEDIUM: connection: close front idling connection on soft-stop
- MINOR: tools: add functions to retrieve the address of a symbol
- CLEANUP: activity: mark the profiling and task_profiling_mask __read_mostly
- MINOR: activity: add a "memory" entry to "profiling"
- MINOR: activity: declare the storage for memory usage statistics
- MEDIUM: activity: collect memory allocator statistics with USE_MEMORY_PROFILING
- MINOR: activity: clean up the show profiling io_handler a little bit
- MINOR: activity: make "show profiling" support a few arguments
- MINOR: activity: make "show profiling" also dump the memoery usage
- MINOR: activity: add the profiling.memory global setting
- BUILD: makefile: add new option USE_MEMORY_PROFILING
- MINOR: channel: Rely on HTX version if appropriate in channel_may_recv()
- BUG/MINOR: stream-int: Don't block reads in si_update_rx() if chn may receive
- MINOR: conn-stream: Force mux to wait for read events if abortonclose is set
- MEDIUM: mux-h1: Don't block reads when waiting for the other side
- BUG/MEDIUM: mux-h1: Properly report client close if abortonclose option is set
- REGTESTS: Add script to test abortonclose option
- MINOR: mux-h1: clean up conditions to enabled and disabled splicing
- MINOR: mux-h1: Subscribe for sends if output buffer is not empty in h1_snd_pipe
- MINOR: mux-h1: Always subscribe for reads when splicing is disabled
- MEDIUM: mux-h1: Wake H1 stream when both sides a synchronized
- CLEANUP: mux-h1: rename WAIT_INPUT/WAIT_OUTPUT flags
- MINOR: mux-h1: Manage processing blocking flags on the H1 stream
- BUG/MINOR: stream: Decrement server current session counter on L7 retry
- BUG/MINOR: config: fix uninitialized initial state in ".if" block evaluator
- BUG/MINOR: config: add a missing "ELIF_TAKE" test for ".elif" condition evaluator
- BUG/MINOR: config: .if/.elif should also accept negative integers
- MINOR: config: centralize the ".if"/".elif" condition parser and evaluator
- MINOR: config: keep up-to-date current file/line/section in the global struct
- MINOR: config: support some pseudo-variables for file/line/section
- BUILD: activity: do not include malloc.h
- MINOR: arg: improve the error message on missing closing parenthesis
- MINOR: global: export the build features string list
- MINOR: global: add version comparison functions
- MINOR: config: improve .if condition error reporting
- MINOR: config: make cfg_eval_condition() support predicates with arguments
- MINOR: config: add predicate "defined()" to conditional expression blocks
- MINOR: config: add predicates "streq()" and "strneq()" to conditional expressions
- MINOR: config: add predicate "feature" to detect certain built-in features
- MINOR: config: add predicates "version_atleast" and "version_before" to cond blocks
- BUG/MINOR: activity: use the new pointer to calculate the new size in realloc()
- BUG/MINOR: stream: properly clear the previous error mask on L7 retries
- MEDIUM: log: slightly refine the output format of alerts/warnings/etc
- MINOR: config: add a new message directive: .diag
- CLEANUP: cli/tree-wide: properly re-align the CLI commands' help messages
- BUG/MINOR: stream: Reset stream final state and si error type on L7 retry
- BUG/MINOR: checks: Handle synchronous connect when a tcpcheck is started
- BUG/MINOR: checks: Reschedule check on observe mode only if fastinter is set
- MINOR: global: define tainted flag
- MINOR: cfgparse: add a new field flags in cfg_keyword
- MINOR: cfgparse: implement experimental config keywords
- MINOR: action: replace match_pfx by a keyword flags field
- MINOR: action: implement experimental actions
- MINOR: cli: set tainted when using CLI expert/experimental mode
- MINOR: stats: report tainted on show info
- MINOR: http_act: mark normalize-uri as experimental
- BUILD: fix usage of ha_alert without format string
- MINOR: proxy: define PR_CAP_LB
- BUG/MINOR: server: do not report diag for peer servers with null weight
- DOC: ssl: Extra files loading now works for backends too
- ADDONS: make addons/ discoverable by git via .gitignore
- DOC: ssl: Add information about crl-file option
- MINOR: sample: improve error reporting on missing arg to strcmp() converter
- DOC: management: mention that some fields may be emitted as floats
- MINOR: tools: implement trimming of floating point numbers
- MINOR: tools: add a float-to-ascii conversion function
- MINOR: freq_ctr: add new functions to report float measurements
- MINOR: stats: avoid excessive padding of float values with trailing zeroes
- MINOR: stats: add the HTML conversion for float types
- MINOR: stats: pass the appctx flags to stats_fill_info()
- MINOR: stats: support an optional "float" option to "show info"
- MINOR: stats: use tv_remain() to precisely compute the uptime
- MINOR: stats: report uptime and start time as floats with subsecond resolution
- MINOR: stats: make "show info" able to report rates as floats when asked
- MINOR: config: mark tune.fd.edge-triggered as experimental
- REORG: vars: move the "proc" scope variables out of the global struct
- REORG: threads: move all_thread_mask() to thread.h
- BUILD: wdt: include signal-t.h
- BUILD: auth: include missing list.h
- REORG: mworker: move proc_self from global to mworker
- BUILD: ssl: ssl_utils requires chunk.h
- BUILD: config: cfgparse-ssl.c needs tools.h
- BUILD: wurfl: wurfl.c needs tools.h
- BUILD: spoe: flt_spoe.c needs tools.h
- BUILD: promex: service-prometheus.c needs tools.h
- BUILD: resolvers: include tools.h
- BUILD: config: include tools.h in cfgparse-listen.c
- BUILD: htx: include tools.h in http_htx.c
- BUILD: proxy: include tools.h in proxy.c
- BUILD: session: include tools.h in session.c
- BUILD: cache: include tools.h in cache.c
- BUILD: sink: include tools.h in sink.c
- BUILD: connection: include tools.h in connection.c
- BUILD: server-state: include tools.h from server_state.c
- BUILD: dns: include tools.h in dns.c
- BUILD: payload: include tools.h in payload.c
- BUILD: vars: include tools.h in vars.c
- BUILD: compression: include tools.h in compression.c
- BUILD: mworker: include tools.h from mworker.c
- BUILD: queue: include tools.h from queue.c
- BUILD: udp: include tools.h from proto_udp.c
- BUILD: stick-table: include freq_ctr.h from stick_table.h
- BUILD: server: include tools.h from server.c
- BUILD: server: include missing proxy.h in server.c
- BUILD: sink: include proxy.h in sink.c
- BUILD: mworker: include proxy.h in mworker.c
- BUILD: filters: include proxy.h in filters.c
- BUILD: fcgi-app: include proxy.h in fcgi-app.c
- BUILD: connection: move list_mux_proto() to connection.c
- REORG: stick-table: uninline stktable_alloc_data_type()
- REORG: stick-table: move composite address functions to stick_table.h
- REORG: config: uninline warnifnotcap() and failifnotcap()
- BUILD: task: remove unused includes from task.c
- MINOR: task: stop including stream.h from task.c
- BUILD: connection: stop including listener-t.h
- BUILD: hlua: include proxy.h from hlua.c
- BUILD: mux-h1: include proxy.h from mux-h1.c
- BUILD: mux-fcgi: include proxy.h from mux-fcgi.c
- BUILD: listener: include proxy.h from listener.c
- BUILD: http-rules: include proxy.h from http_rules.c
- BUILD: thread: include log.h from thread.c
- BUILD: comp: include proxy.h from flt_http_comp.c
- BUILD: fd: include log.h from fd.c
- BUILD: config: do not include proxy.h nor errors.h anymore in cfgparse.h
- BUILD: makefile: reorder object files by build time
- DOC: Fix a few grammar/spelling issues and casing of HAProxy
- REGTESTS: run-regtests: match both "HAProxy" and "HA-Proxy" in the version
- MINOR: version: report "HAProxy" not "HA-Proxy" in the version output
- DOC: remove last occurrences of "HA-Proxy" syntax
- DOC: peers: fix the protocol tag name in the doc
- ADMIN: netsnmp: report "HAProxy" and not "Haproxy" in output descriptions
- MEDIUM: mailers: use "HAProxy" nor "HAproxy" in the subject of messages
- DOC: fix a few remainig cases of "Haproxy" and "HAproxy" in doc and comments
- MINOR: tools/rnd: compute the result outside of the CAS loop
- BUILD: http_fetch: address a few aliasing warnings with older compilers
- BUILD: ssl: define HAVE_CRYPTO_memcmp() based on the library version
- BUILD: errors: include stdarg in errors.h
- REGTESTS: disable inter-thread idle connection sharing on sensitive tests
- MINOR: cli: make "help" support a command in argument
- MINOR: cli: sort the output of the "help" keywords
- CLEANUP: cli/mworker: properly align the help messages
- BUILD: memprof: make the old caller pointer a const in get_prof_bin()
- BUILD: compat: include malloc_np.h for USE_MEMORY_PROFILING on FreeBSD
- CI: Github Actions: enable USE_QUIC=1 for BoringSSL builds
- BUG/MEDIUM: quic: fix null deref on error path in qc_conn_init()
- BUILD: cli: appease a null-deref warning in cli_gen_usage_msg()
Some of the Lua doc and a few places still used "Haproxy" or "HAproxy".
There was even one "HA proxy". A few of them were in an example of VTest
output, indicating that VTest ought to be fixed as well. No big deal but
better address all the remaining ones so that these inconsistencies stop
spreading around.
There were only a few more used as output examples and comments in a few
docs, it was the right moment to get rid of them. The file intro.txt
which explains how to parse the version also got a hint about the possible
presence of a hyphen in the name in older versions.
Released version 2.4-dev17 with the following main changes :
- MINOIR: mux-pt/trace: Register a new trace source with its events
- BUG/MINOR: mux-pt: Fix a possible UAF because of traces in mux_pt_io_cb
- CI: travis: Drastically clean up .travis.yml
- CLEANUP: pattern: make all pattern tables read-only
- MINOR: trace: replace the trace() inline function with an equivalent macro
- MINOR: initcall: uniformize the section names between MacOS and other unixes
- CLEANUP: initcall: rename HA_SECTION to HA_INIT_SECTION
- MINOR: compiler: add macros to declare section names
- CLEANUP: initcall: rely on HA_SECTION_* instead of defining its own
- MINOR: global: declare a read_mostly section
- MINOR: fd: move a few read-mostly variables to their own section
- MINOR: epoll: move epoll_fd to read_mostly
- MINOR: kqueue: move kqueue_fd to read_mostly
- MINOR: pool: move pool declarations to read_mostly
- MINOR: threads: mark all_threads_mask as read_mostly
- MINOR: server: move idle_conn_task to read_mostly
- MINOR: protocol: move __protocol_by_family to read_mostly
- MINOR: pattern: make the pat_lru_seed read_mostly
- MINOR: trace: make trace sources read_mostly
- MINOR: freq_ctr: add a generic function to report the total value
- MEDIUM: freq_ctr: make read_freq_ctr_period() use freq_ctr_total()
- MEDIUM: freq_ctr: reimplement freq_ctr_remain_period() from freq_ctr_total()
- MINOR: freq_ctr: add the missing next_event_delay_period()
- MINOR: freq_ctr: unify freq_ctr and freq_ctr_period into freq_ctr
- MEDIUM: freq_ctr: replace the per-second counters with the generic ones
- MINOR: freq_ctr: add cpu_relax in the rotation loop of update_freq_ctr_period()
- MINOR: freq_ctr: simplify and improve the update function
- CLEANUP: time: remove the now unused ms_left_scaled
- MINOR: time: move the time initialization out of tv_update_date()
- MINOR: time: remove useless variable copies in tv_update_date()
- MINOR: time: change the global timeval and the the global tick at once
- MEDIUM: time: make the clock offset global and no per-thread
- MINOR: atomic: reimplement the relaxed version of x86 BTS/BTR
- MINOR: trace: Add the checks as a possible trace source
- MINOIR: checks/trace: Register a new trace source with its events
- MINOR: hlua: Add function to release a lua function
- BUG/MINOR: hlua: Fix memory leaks on error path when registering a task
- BUG/MINOR: hlua: Fix memory leaks on error path when registering a converter
- BUG/MINOR: hlua: Fix memory leaks on error path when registering a fetch
- BUG/MINOR: hlua: Fix memory leaks on error path when parsing a lua action
- BUG/MINOR: hlua: Fix memory leaks on error path when registering an action
- BUG/MINOR: hlua: Fix memory leaks on error path when registering a service
- BUG/MINOR: hlua: Fix memory leaks on error path when registering a cli keyword
- BUG/MINOR: cfgparse/proxy: Fix some leaks during proxy section parsing
- BUG/MINOR: listener: Handle allocation error when allocating a new bind_conf
- BUG/MINOR: cfgparse/proxy: Hande allocation errors during proxy section parsing
- MINOR: cfgparse/proxy: Group alloc error handling during proxy section parsing
- DOC: internals: update the SSL architecture schema
- BUG/MEDIUM: sample: Fix adjusting size in field converter
- MINOR: sample: add ub64dec and ub64enc converters
- CLEANUP: sample: align samples list in sample.c
- MINOR: ist: Add `istclear(struct ist*)`
- CI: cirrus: install "pcre" package
- MINOR: opentracing: correct calculation of the number of arguments in the args[]
- MINOR: opentracing: transfer of context names without prefix
- MINOR: sample: converter: Add mjson library.
- MINOR: sample: converter: Add json_query converter
- CI: travis-ci: enable weekly graviton2 builds
- DOC: ssl: Certificate hot update only works on fronted certificates
- DOC: ssl: Certificate hot update works on server certificates
- BUG/MEDIUM: threads: Ignore current thread to end its harmless period
- MINOR: threads: Only consider running threads to end a thread harmeless period
- BUG/MINOR: checks: Set missing id to the dummy checks frontend
- MINOR: logs: Add support of checks as session origin to format lf strings
- BUG/MINOR: connection: Fix fc_http_major and bc_http_major for TCP connections
- MINOR: connection: Make bc_http_major compatible with tcp-checks
- BUG/MINOR: ssl-samples: Fix ssl_bc_* samples when called from a health-check
- BUG/MINOR: http-fetch: Make method smp safe if headers were already forwarded
- MINOR: tcp_samples: Add samples to get src/dst info of the backend connection
- MINOR: tcp_samples: Be able to call bc_src/bc_dst from the health-checks
- BUG/MINOR: http_htx: Remove BUG_ON() from http_get_stline() function
- BUG/MINOR: logs: Report the true number of retries if there was no connection
- BUILD: makefile: Redirect stderr to /dev/null when probing options
- MINOR: uri_normalizer: Add uri_normalizer module
- MINOR: uri_normalizer: Add `enum uri_normalizer_err`
- MINOR: uri_normalizer: Add `http-request normalize-uri`
- MINOR: uri_normalizer: Add a `merge-slashes` normalizer to http-request normalize-uri
- MINOR: uri_normalizer: Add a `dotdot` normalizer to http-request normalize-uri
- MINOR: uri_normalizer: Add support for supressing leading `../` for dotdot normalizer
- MINOR: uri_normalizer: Add a `sort-query` normalizer
- MINOR: uri_normalizer: Add a `percent-upper` normalizer
- MEDIUM: http_act: Rename uri-normalizers
- DOC: Add introduction to http-request normalize-uri
- DOC: Note that URI normalization is experimental
- BUG/MINOR: pools: maintain consistent ->allocated count on alloc failures
- BUG/MINOR: pools/buffers: make sure to always reserve the required buffers
- MINOR: pools: drop the unused static history of artificially failed allocs
- CLEANUP: pools: remove unused arguments to pool_evict_from_cache()
- MEDIUM: pools: move the cache into the pool header
- MINOR: pool: remove the size field from pool_cache_head
- MINOR: pools: rename CONFIG_HAP_LOCAL_POOLS to CONFIG_HAP_POOLS
- MINOR: pools: enable the fault injector in all allocation modes
- MINOR: pools: make the basic pool_refill_alloc()/pool_free() update needed_avg
- MEDIUM: pools: unify pool_refill_alloc() across all models
- CLEANUP: pools: re-merge pool_refill_alloc() and __pool_refill_alloc()
- MINOR: pools: call pool_alloc_nocache() out of the pool's lock
- CLEANUP: pools: move the lock to the only __pool_get_first() that needs it
- CLEANUP: pools: rename __pool_get_first() to pool_get_from_shared_cache()
- CLEANUP: pools: rename pool_*_{from,to}_cache() to *_local_cache()
- CLEANUP: pools: rename __pool_free() to pool_put_to_shared_cache()
- MINOR: tools: add statistical_prng_range() to get a random number over a range
- MINOR: pools: use cheaper randoms for fault injections
- MINOR: pools: move the fault injector to __pool_alloc()
- MINOR: pools: split the OS-based allocator in two
- MINOR: pools: always use atomic ops to maintain counters
- MINOR: pools: move pool_free_area() out of the lock in the locked version
- MINOR: pools: factor the release code into pool_put_to_os()
- MEDIUM: pools: make CONFIG_HAP_POOLS control both local and shared pools
- MINOR: pools: create unified pool_{get_from,put_to}_cache()
- MINOR: pools: evict excess objects using pool_evict_from_local_cache()
- MEDIUM: pools: make pool_put_to_cache() always call pool_put_to_local_cache()
- CLEANUP: pools: make the local cache allocator fall back to the shared cache
- CLEANUP: pools: merge pool_{get_from,put_to}_local_caches with generic ones
- CLEANUP: pools: uninline pool_put_to_cache()
- CLEANUP: pools: declare dummy pool functions to remove some ifdefs
- BUILD: pools: fix build with DEBUG_FAIL_ALLOC
- BUG/MINOR: server: make srv_alloc_lb() allocate lb_nodes for consistent hash
- CONTRIB: mod_defender: import the minimal number of includes
- CONTRIB: mod_defender: make the code build with the embedded includes
- CONTRIB: modsecurity: import the minimal number of includes
- CONTRIB: modsecurity: make the code build with the embedded includes
- CLEANUP: sample: Improve local variables in sample_conv_json_query
- CLEANUP: sample: Explicitly handle all possible enum values from mjson
- CLEANUP: sample: Use explicit return for successful `json_query`s
- CLEANUP: lists/tree-wide: rename some list operations to avoid some confusion
- CONTRIB: move spoa_example out of the tree
- BUG/MINOR: server: free srv.lb_nodes in free_server
- BUG/MINOR: logs: free logsrv.conf.file on exit
- BUG/MEDIUM: server: ensure thread-safety of server runtime creation
- MINOR: server: add log on dynamic server creation
- MINOR: server: implement delete server cli command
- CONTRIB: move spoa_server out of the tree
- CONTRIB: move modsecurity out of the tree
- BUG/MINOR: server: fix potential null gcc error in delete server
- BUG/MAJOR: mux-h2: Properly detect too large frames when decoding headers
- BUG/MEDIUM: mux-h2: Fix dfl calculation when merging CONTINUATION frames
- BUG/MINOR: uri_normalizer: Use delim parameter when building the sorted query in uri_normalizer_query_sort
- CLEANUP: uri_normalizer: Remove trailing whitespace
- MINOR: uri_normalizer: Add a `strip-dot` normalizer
- CONTRIB: move mod_defender out of the tree
- CLEANUP: contrib: remove the last references to the now dead contrib/ directory
- BUG/MEDIUM: config: fix cpu-map notation with both process and threads
- MINOR: config: add a diag for invalid cpu-map statement
- BUG/MINOR: mworker/init: don't reset nb_oldpids in non-mworker cases
- BUG/MINOR: mworker: don't use oldpids[] anymore for reload
- BUILD: makefile: fix the "make clean" target on strict bourne shells
- IMPORT: slz: import slz into the tree
- BUILD: compression: switch SLZ from out-of-tree to in-tree
- CI: github: do not build libslz any more
- CLEANUP: compression: remove calls to SLZ init functions
- BUG/MEDIUM: mux-h2: Properly handle shutdowns when received with data
- MINOR: cpuset: define a platform-independent cpuset type
- MINOR: cfgparse: use hap_cpuset for parse_cpu_set
- MEDIUM: config: use platform independent type hap_cpuset for cpu-map
- MINOR: thread: implement the detection of forced cpu affinity
- MINOR: cfgparse: support the comma separator on parse_cpu_set
- MEDIUM: cfgparse: detect numa and set affinity if needed
- MINOR: global: add option to disable numa detection
- BUG/MINOR: haproxy: fix compilation on macOS
- BUG/MINOR: cpuset: fix compilation on platform without cpu affinity
- MINOR: time: avoid unneeded updates to now_offset
- MINOR: time: avoid overwriting the same values of global_now
- CLEANUP: time: use __tv_to_ms() in tv_update_date() instead of open-coding
- MINOR: time: avoid u64 needlessly expensive computations for the 32-bit now_ms
- BUG/MINOR: peers: remove useless table check if initial resync is finished
- BUG/MEDIUM: peers: re-work connection to new process during reload.
- BUG/MEDIUM: peers: re-work refcnt on table to protect against flush
- BUG/MEDIUM: config: fix missing initialization in numa_detect_topology()
The current "ADD" vs "ADDQ" is confusing because when thinking in terms
of appending at the end of a list, "ADD" naturally comes to mind, but
here it does the opposite, it inserts. Several times already it's been
incorrectly used where ADDQ was expected, the latest of which was a
fortunate accident explained in 6fa922562 ("CLEANUP: stream: explain
why we queue the stream at the head of the server list").
Let's use more explicit (but slightly longer) names now:
LIST_ADD -> LIST_INSERT
LIST_ADDQ -> LIST_APPEND
LIST_ADDED -> LIST_INLIST
LIST_DEL -> LIST_DELETE
The same is true for MT_LISTs, including their "TRY" variant.
LIST_DEL_INIT keeps its short name to encourage to use it instead of the
lazier LIST_DELETE which is often less safe.
The change is large (~674 non-comment entries) but is mechanical enough
to remain safe. No permutation was performed, so any out-of-tree code
can easily map older names to new ones.
The list doc was updated.
This commit adds the new fields added to the ckch_inst structure in
order to manage the backend certificate hot update (GitHub #427) and the
bug of the default certificate update (GitHub #1143).
It is never used anymore since 1.7 where it was used by b_alloc_margin()
then replaced by direct calls to the pools function, and it maintains a
dependency on the exposed pools functions. It's time to get rid of it,
as it's not even certain it still works.
Right now there is a discrepancy beteween b_alloc() and b_allow_margin():
the former forcefully overwrites the target pointer while the latter tests
it and returns it as-is if already allocated.
As a matter of fact, all callers of b_alloc() either preliminary test the
buffer, or assume it's already null.
Let's remove this pain and make the function test the buffer's allocation
before doing it again, and match call places' expectations.
