Commit graph

4095 commits

Author SHA1 Message Date
Christopher Faulet
33f05df650 MEDIUM: checks: Implement redis check using tcp-check rules
A share tcp-check ruleset is now created to support redis checks. This way no
extra memory is used if several backends use a redis check.

The following sequence is used :

  tcp-check send "*1\r\n$4\r\nPING\r\n"

  tcp-check expect string "+PONG\r\n" error-status "L7STS" \
      on-error "%[check.payload(),cut_crlf]" on-success "Redis server is ok"
2020-04-27 09:39:38 +02:00
Christopher Faulet
9e6ed1598e MINOR: checks: Support custom functions to eval a tcp-check expect rules
It is now possible to set a custom function to evaluate a tcp-check expect
rule. It is an internal and not documentd option because the right pointer of
function must be set and it is not possible to express it in the
configuration. It will be used to convert some protocol healthchecks to
tcp-checks.

Custom functions must have the following signature:

  enum tcpcheck_eval_ret (*custom)(struct check *, struct tcpcheck_rule *, int);
2020-04-27 09:39:38 +02:00
Christopher Faulet
6f87adcf20 MINOR: checks: Export the tcpcheck_eval_ret enum
This enum will be used to define custom function for tcp-check expect rules.
2020-04-27 09:39:38 +02:00
Christopher Faulet
7a1e2e1823 MEDIUM: checks: Add a list of vars to set before executing a tpc-check ruleset
A list of variables is now associated to each tcp-check ruleset. It is more a
less a list of set-var expressions. This list may be filled during the
configuration parsing. The listed variables will then be set during each
execution of the tcp-check healthcheck, at the begining, before execution of the
the first tcp-check rule.

This patch is mandatory to convert all protocol checks to tcp-checks. It is a
way to customize shared tcp-check rulesets.
2020-04-27 09:39:37 +02:00
Christopher Faulet
bb591a1a11 MINOR: checks: Relax the default option for tcp-check connect rules
Now this option may be mixed with other options. This way, options on the server
line are used but may be overridden by tcp-check connect options.
2020-04-27 09:39:37 +02:00
Christopher Faulet
98cc57cf5c MEDIUM: checks: Add status-code sample expression on tcp-check expect rules
This option defines a sample expression, evaluated as an integer, to set the
status code (check->code) if a tcp-check healthcheck ends on the corresponding
expect rule.
2020-04-27 09:39:37 +02:00
Christopher Faulet
be52b4de66 MEDIUM: checks: Add on-error/on-success option on tcp-check expect rules
These options define log-format strings used to produce the info message if a
tcp-check expect rule fails (on-error option) or succeeds (on-success
option). For this last option, it must be the ending rule, otherwise the
parameter is ignored.
2020-04-27 09:39:37 +02:00
Christopher Faulet
cf80f2f263 MINOR: checks: Add option to tcp-check expect rules to customize error status
It is now possible to specified the healthcheck status to use on error or on
timeout for tcp-check expect rules. First, to define the error status, the
option "error-status" must be used followed by "L4CON", "L6RSP", "L7RSP" or
"L7STS". Then, to define the timeout status, the option "tout-status" must be
used followed by "L4TOUT", "L6TOUT" or "L7TOUT".

These options will be used to convert specific protocol healthchecks (redis,
pgsql...) to tcp-check ones.
x
2020-04-27 09:39:37 +02:00
Christopher Faulet
1032059bd0 MINOR: checks: Use a name for the healthcheck status enum
The enum defining all healthcheck status (HCHK_STATUS_*) is now named.
2020-04-27 09:39:37 +02:00
Christopher Faulet
5d503fcf5b MEDIUM: checks: Add a shared list of tcp-check rules
A global list to tcp-check ruleset can now be used to share common rulesets with
all backends without any duplication. It is mandatory to convert all specific
protocol checks (redis, pgsql...) to tcp-check healthchecks.

To do so, a flag is now attached to each tcp-check ruleset to know if it is a
shared ruleset or not. tcp-check rules defined in a backend are still directly
attached to the proxy and not shared. In addition a second flag is used to know
if the ruleset is inherited from the defaults section.
2020-04-27 09:39:37 +02:00
Christopher Faulet
f50f4e956f MEDIUM: checks: Support log-format strings for tcp-check send rules
An extra parameter for tcp-check send rules can be specified to handle the
string or the hexa string as a log-format one. Using "log-format" option,
instead of considering the data to send as raw data, it is parsed as a
log-format string. Thus it is possible to call sample fetches to customize data
sent to a server. Of course, because we have no stream attached to healthchecks,
not all sample fetches are available. So be careful.

    tcp-check set-var(check.port) int(8000)
    tcp-check set-var(check.uri) str(/status)
    tcp-check connect port var(check.port)
    tcp-check send "GET %[check.uri] HTTP/1.0\r\n" log-format
    tcp-check send "Host: %[srv_name]\r\n" log-format
    tcp-check send "\r\n"
2020-04-27 09:39:37 +02:00
Christopher Faulet
b7d30098f3 MEDIUM: checks: Support expression to set the port
Since we have a session attached to tcp-check healthchecks, It is possible use
sample expression and variables. In addition, it is possible to add tcp-check
set-var rules to define custom variables. So, now, a sample expression can be
used to define the port to use to establish a connection for a tcp-check connect
rule. For instance:

    tcp-check set-var(check.port) int(8888)
    tcp-check connect port var(check.port)
2020-04-27 09:39:37 +02:00
Christopher Faulet
5c28874a69 MINOR: checks: Add the addr option for tcp-check connect rule
With this option, it is now possible to use a specific address to open the
connection for a tcp-check connect rule. If the port option is also specified,
it is used in priority.
2020-04-27 09:39:37 +02:00
Christopher Faulet
d75f57e94c MINOR: ssl: Export a generic function to parse an alpn string
Parsing of an alpn string has been moved in a dedicated function and exposed to
be used from outside the ssl_sock module.
2020-04-27 09:39:37 +02:00
Christopher Faulet
085426aea9 MINOR: checks: Add the via-socks4 option for tcp-check connect rules
With this option, it is possible to establish the connection opened by a
tcp-check connect rule using upstream socks4 proxy. Info from the socks4
parameter on the server are used.
2020-04-27 09:39:37 +02:00
Christopher Faulet
79b31d4ee5 MINOR: checks: Add the sni option for tcp-check connect rules
With this option, it is possible to specify the SNI to be used for SSL
conncection opened by a tcp-check connect rule.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
707b52f17e MEDIUM: checks: Parse custom action rules in tcp-checks
Register the custom action rules "set-var" and "unset-var", that will
call the parse_store() command upon parsing.

These rules are thus built and integrated to the tcp-check ruleset, but
have no further effect for the moment.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
13a5043a9e MINOR: checks/vars: Add a check scope for variables
Add a dedicated vars scope for checks. This scope is considered as part of the
session scope for accounting purposes.

The scope can be addressed by a valid session, even embryonic. The stream is not
necessary.

The scope is initialized after the check session is created. All variables are
then pruned before the session is destroyed.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
05d692dc09 MEDIUM: checks: Associate a session to each tcp-check healthcheck
Create a session for each healthcheck relying on a tcp-check ruleset. When such
check is started, a session is allocated, which will be freed when the check
finishes. A dummy static frontend is used to create these sessions. This will be
useful to support variables and sample expression. This will also be used,
later, by HTTP healthchecks to rely on HTTP muxes.
2020-04-27 09:39:37 +02:00
Christopher Faulet
b2c2e0fcca MAJOR: checks: Refactor and simplify the tcp-check loop
The loop in tcpcheck_main() function is quite hard to understand. Depending
where we are in the loop, The current_step is the currentely executed rule or
the one to execute on the next call to tcpcheck_main(). When the check result is
reported, we rely on the rule pointed by last_started_step or the one pointed by
current_step. In addition, the loop does not use the common list_for_each_entry
macro and it is thus quite confusing.

So the loop has been totally rewritten and splitted to several functions to
simplify its reading and its understanding. Tcp-check rules are evaluated in
dedicated functions. And a common for_each loop is used and only one rule is
referenced, the current one.
2020-04-27 09:39:37 +02:00
Christopher Faulet
a202d1d4c1 MEDIUM: checks: Add implicit tcp-check connect rule
After the configuration parsing, when its validity check, an implicit tcp-check
connect rule is added in front of the tcp-check ruleset if the first non-comment
rule is not a connect one. This implicit rule is flagged to use the default
check parameter.

This means now, all tcp-check rulesets begin with a connect and are never
empty. When tcp-check healthchecks are used, all connections are thus handled by
tcpcheck_main() function.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
06d963aeca MINOR: checks: define a tcp-check connect type
The check rule itself is not changed, only its representation.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
48219dc50e MINOR: checks: define tcp-check send type
The check rule itself is not changed, only its representation.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
5301b01f99 MINOR: checks: Set the tcp-check rule index during parsing
Now the position of a tcp-check rule in a chain is set during the parsing. This
simplify significantly the function retrieving the current step id.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
04578dbf37 MINOR: checks: Don't use a static tcp rule list head
To allow reusing these blocks without consuming more memory, their list
should be static and share-able accross uses. The head of the list will
be shared as well.

It is thus necessary to extract the head of the rule list from the proxy
itself. Transform it into a pointer instead, that can be easily set to
an external dynamically allocated head.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
9dcb09fc98 MEDIUM: checks: capture groups in expect regexes
Parse back-references in comments of tcp-check expect rules.  If references are
made, capture groups in the match and replace references to it within the
comment when logging the error. Both text and binary regex can caputre groups
and reference them in the expect rule comment.

[Cf: I slightly updated the patch. exp_replace() function is used instead of a
custom one. And if the trash buffer is too small to contain the comment during
the substitution, the comment is ignored.]
2020-04-27 09:39:37 +02:00
Gaetan Rivet
efab6c61d9 MINOR: checks: add rbinary expect match type
The rbinary match works similarly to the rstring match type, however the
received data is rewritten as hex-string before the match operation is
done.

This allows using regexes on binary content even with the POSIX regex
engine.

[Cf: I slightly updated the patch. mem2hex function was removed and dump_binary
is used instead.]
2020-04-27 09:39:37 +02:00
Gaetan Rivet
b616add793 MINOR: checks: define a tcp expect type
Extract the expect definition from its tcpcheck ; create a standalone type.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
f8ba6773e5 MINOR: checks: add linger option to tcp connect
Allow declaring tcpcheck connect commands with a new parameter,
"linger". This option will configure the connection to avoid using an
RST segment to close, instead following the four-way termination
handshake. Some servers would otherwise log each healthcheck as
an error.
2020-04-27 09:39:37 +02:00
Gaetan Rivet
1afd826ae4 MINOR: checks: add min-recv tcp-check expect option
Some expect rules cannot be satisfied due to inherent ambiguity towards
the received data: in the absence of match, the current behavior is to
be forced to wait either the end of the connection or a buffer full,
whichever comes first. Only then does the matching diagnostic is
considered  conclusive. For instance :

    tcp-check connect
    tcp-check expect !rstring "^error"
    tcp-check expect string "valid"

This check will only succeed if the connection is closed by the server before
the check timeout. Otherwise the first expect rule will wait for more data until
"^error" regex matches or the check expires.

Allow the user to explicitly define an amount of data that will be
considered enough to determine the value of the check.

This allows succeeding on negative rstring rules, as previously
in valid condition no match happened, and the matching was repeated
until the end of the connection. This could timeout the check
while no error was happening.

[Cf: I slighly updated the patch. The parameter was renamed and the value is a
signed integer to support -1 as default value to ignore the parameter.]
2020-04-27 09:39:37 +02:00
Gaetan Rivet
4038b94706 MEDIUM: checks: rewind to the first inverse expect rule of a chain on new data
When receiving additional data while chaining multiple tcp-check expects,
previous inverse expects might have a different result with the new data. They
need to be evaluated again against the new data.

Add a pointer to the first inverse expect rule of the current expect chain
(possibly of length one) to each expect rule. When receiving new data, the
currently evaluated tcp-check rule is set back to this pointed rule.

Fonctionnaly speaking, it is a bug and it exists since the introduction of the
feature. But there is no way for now to hit it because when an expect rule does
not match, we wait for more data, independently on the inverse flag. The only
way to move to the following rule is to be sure no more data will be received.

This patch depends on the commit "MINOR: mini-clist: Add functions to iterate
backward on a list".

[Cf: I slightly updated the patch. First, it only concerns inverse expect
rule. Normal expect rules are not concerned. Then, I removed the BUG tag
because, for now, it is not possible to move to the following rule when the
current one does not match while more data can be received.]
2020-04-27 09:39:37 +02:00
Gaetan Rivet
dd66732ffe MINOR: checks: Use an enum to describe the tcp-check rule type
Replace the generic integer with an enumerated list. This allows light
type check and helps debugging (seeing action = 2 in the struct is not
helpful).
2020-04-27 09:39:37 +02:00
Christopher Faulet
31c30fdf1e CLEANUP: checks: Don't export anymore init_check and srv_check_healthcheck_port
These functions are no longer called outside the checks.
2020-04-27 09:39:37 +02:00
Christopher Faulet
f61f33a1b2 BUG/MINOR: checks: Respect the no-check-ssl option
This options is used to force a non-SSL connection to check a SSL server or to
invert a check-ssl option inherited from the default section. The use_ssl field
in the check structure is used to know if a SSL connection must be used
(use_ssl=1) or not (use_ssl=0). The server configuration is used by default.

The problem is that we cannot distinguish the default case (no specific SSL
check option) and the case of an explicit non-SSL check. In both, use_ssl is set
to 0. So the server configuration is always used. For a SSL server, when
no-check-ssl option is set, the check is still performed using a SSL
configuration.

To fix the bug, instead of a boolean value (0=TCP, 1=SSL), we use a ternary value :

  * 0  = use server config
  * 1  = force SSL
  * -1 = force non-SSL

The same is done for the server parameter. It is not really necessary for
now. But it is a good way to know is the server no-ssl option is set.

In addition, the PR_O_TCPCHK_SSL proxy option is no longer used to set use_ssl
to 1 for a check. Instead the flag is directly tested to prepare or destroy the
server SSL context.

This patch should be backported as far as 1.8.
2020-04-27 09:39:37 +02:00
Christopher Faulet
8acb1284bc MINOR: checks: Add a way to send custom headers and payload during http chekcs
The 'http-check send' directive have been added to add headers and optionnaly a
payload to the request sent during HTTP healthchecks. The request line may be
customized by the "option httpchk" directive but there was not official way to
add extra headers. An old trick consisted to hide these headers at the end of
the version string, on the "option httpchk" line. And it was impossible to add
an extra payload with an "http-check expect" directive because of the
"Connection: close" header appended to the request (See issue #16 for details).

So to make things official and fully support payload additions, the "http-check
send" directive have been added :

    option httpchk POST /status HTTP/1.1

    http-check send hdr Content-Type "application/json;charset=UTF-8" \
        hdr X-test-1 value1 hdr X-test-2 value2 \
        body "{id: 1, field: \"value\"}"

When a payload is defined, the Content-Length header is automatically added. So
chunk-encoded requests are not supported yet. For now, there is no special
validity checks on the extra headers.

This patch is inspired by Kiran Gavali's work. It should fix the issue #16 and
as far as possible, it may be backported, at least as far as 1.8.
2020-04-27 09:39:37 +02:00
Christopher Faulet
bc1f54b0fc MINOR: mini-clist: Add functions to iterate backward on a list
list_for_each_entry_rev() and list_for_each_entry_from_rev() and corresponding
safe versions have been added to iterate on a list in the reverse order. All
these functions work the same way than the forward versions, except they use the
.p field to move for an element to another.
2020-04-27 09:39:37 +02:00
Christopher Faulet
aaae9a0e99 BUG/MINOR: check: Update server address and port to execute an external check
Server address and port may change at runtime. So the address and port passed as
arguments and as environment variables when an external check is executed must
be updated. The current number of connections on the server was already updated
before executing the command. So the same mechanism is used for the server
address and port. But in addition, command arguments are also updated.

This patch must be backported to all stable versions. It should fix the
issue #577.
2020-04-27 09:39:13 +02:00
Willy Tarreau
62ba9ba6ca BUG/MINOR: http: make url_decode() optionally convert '+' to SP
The url_decode() function used by the url_dec converter and a few other
call points is ambiguous on its processing of the '+' character which
itself isn't stable in the spec. This one belongs to the reserved
characters for the query string but not for the path nor the scheme,
in which it must be left as-is. It's only in argument strings that
follow the application/x-www-form-urlencoded encoding that it must be
turned into a space, that is, in query strings and POST arguments.

The problem is that the function is used to process full URLs and
paths in various configs, and to process query strings from the stats
page for example.

This patch updates the function to differentiate the situation where
it's parsing a path and a query string. A new argument indicates if a
query string should be assumed, otherwise it's only assumed after seeing
a question mark.

The various locations in the code making use of this function were
updated to take care of this (most call places were using it to decode
POST arguments).

The url_dec converter is usually called on path or url samples, so it
needs to remain compatible with this and will default to parsing a path
and turning the '+' to a space only after a question mark. However in
situations where it would explicitly be extracted from a POST or a
query string, it now becomes possible to enforce the decoding by passing
a non-null value in argument.

It seems to be what was reported in issue #585. This fix may be
backported to older stable releases.
2020-04-23 20:03:27 +02:00
Willy Tarreau
09568fd54d BUG/MINOR: tools: fix the i386 version of the div64_32 function
As reported in issue #596, the edx register isn't marked as clobbered
in div64_32(), which could technically allow gcc to try to reuse it
if it needed a copy of the 32 highest bits of the o1 register after
the operation.

Two attempts were tried, one using a dummy 32-bit local variable to
store the intermediary edx and another one switching to "=A" and making
result a long long. It turns out the former makes the resulting object
code significantly dirtier while the latter makes it better and was
kept. This is due to gcc's difficulties at working with register pairs
mixing 32- and 64- bit values on i386. It was verified that no code
change happened at all on x86_64, armv7, aarch64 nor mips32.

In practice it's only used by the frequency counters so this bug
cannot even be triggered but better fix it.

This may be backported to stable branches though it will not fix any
issue.
2020-04-23 17:21:37 +02:00
Ilya Shipitsin
856aabcda5 CLEANUP: assorted typo fixes in the code and comments
This is 8th iteration of typo fixes
2020-04-17 09:37:36 +02:00
Willy Tarreau
bb86986253 MINOR: init: report the haproxy version and executable path once on errors
If haproxy fails to start and emits an alert, then it can be useful
to have it also emit the version and the path used to load it. Some
users may be mistakenly launching the wrong binary due to a misconfigured
PATH variable and this will save them some troubleshooting time when it
reports that some keywords are not understood.

What we do here is that we *try* to extract the binary name from the
AUX vector on glibc, and we report this as a NOTICE tag before the
very first alert is emitted.
2020-04-16 10:52:41 +02:00
Ilya Shipitsin
d425950c68 CLEANUP: assorted typo fixes in the code and comments
This is 7th iteration of typo fixes
2020-04-16 10:04:36 +02:00
Willy Tarreau
3eb10b8e98 MINOR: init: add -dW and "zero-warning" to reject configs with warnings
Since some systems switched to service managers which hide all warnings
by default, some users are not aware of some possibly important warnings
and get caught too late with errors that could have been detected earlier.

This patch adds a new global keyword, "zero-warning" and an equivalent
command-line option "-dW" to refuse to start in case any warning is
detected. It is recommended to use these with configurations that are
managed by humans in order to catch mistakes very early.
2020-04-15 16:42:39 +02:00
Willy Tarreau
bebd212064 MINOR: init: report in "haproxy -c" whether there were warnings or not
This helps quickly checking if the config produces any warning. For
this we reuse the "warned" bit field to add a new WARN_ANY bit that is
set by ha_warning(). The rest of the bit field was also cleaned from
unused bits.
2020-04-15 16:42:00 +02:00
Frdric Lcaille
8ba10fea69 BUG/MINOR: peers: Incomplete peers sections should be validated.
Before supporting "server" line in "peers" section, such sections without
any local peer were removed from the configuration to get it validated.

This patch fixes the issue where a "server" line without address and port which
is a remote peer without address and port makes the configuration parsing fail.
When encoutering such cases we now ignore such lines remove them from the
configuration.

Thank you to Jrme Magnin for having reported this bug.

Must be backported to 2.1 and 2.0.
2020-04-15 10:47:39 +02:00
William Lallemand
b7296c42bd CLEANUP: ssl: remove a commentary in struct ckch_inst
The struct ckch_inst now handles the ssl_bind_conf so this commentary is
obsolete
2020-04-09 16:13:42 +02:00
William Lallemand
caa161982f CLEANUP: ssl/cli: use the list of filters in the crtlist_entry
In 'commit ssl cert', instead of trying to regenerate a list of filters
from the SNIs, use the list provided by the crtlist_entry used to
generate the ckch_inst.

This list of filters doesn't need to be free'd anymore since they are
always reused from the crtlist_entry.
2020-04-08 16:52:51 +02:00
William Lallemand
02e19a5c7b CLEANUP: ssl: use the refcount for the SSL_CTX'
Use the refcount of the SSL_CTX' to free them instead of freeing them on
certains conditions. That way we can free the SSL_CTX everywhere its
pointer is used.
2020-04-08 16:52:51 +02:00
William Lallemand
c69f02d0f0 MINOR: ssl/cli: replace dump/show ssl crt-list by '-n' option
The dump and show ssl crt-list commands does the same thing, they dump
the content of a crt-list, but the 'show' displays an ID in the first
column. Delete the 'dump' command so it is replaced by the 'show' one.
The old 'show' command is replaced by an '-n' option to dump the ID.
And the ID which was a pointer is replaced by a line number and placed
after colons in the filename.

Example:
  $ echo "show ssl crt-list -n kikyo.crt-list" | socat /tmp/sock1 -
  # kikyo.crt-list
  kikyo.pem.rsa:1 secure.domain.tld
  kikyo.pem.ecdsa:2 secure.domain.tld
2020-04-06 19:33:33 +02:00
Frdric Lcaille
876ed55d9b BUG/MINOR: protocol_buffer: Wrong maximum shifting.
This patch fixes a bad stop condition when decoding a protocol buffer variable integer
whose maximum lenghts are 10, shifting a uint64_t value by more than 63.

Thank you to Ilya for having reported this issue.

Must be backported to 2.1 and 2.0.
2020-04-02 15:09:46 +02:00
Olivier Houchard
4a0e7fe4f7 MINOR: connections: Don't mark conn flags 0x00000001 and 0x00000002 as unused.
Remove the comments saying 0x00000001 and 0x00000002 are unused, they are
now used by CO_FL_SAFE_LIST and CO_FL_IDLE_LIST.
2020-03-31 23:04:20 +02:00
William Lallemand
fa8cf0c476 MINOR: ssl: store a ptr to crtlist in crtlist_entry
Store a pointer to crtlist in crtlist_entry so we can re-insert a
crtlist_entry in its crtlist ebpt after updating its key.
2020-03-31 12:32:17 +02:00
William Lallemand
23d61c00b9 MINOR: ssl: add a list of crtlist_entry in ckch_store
When updating a ckch_store we may want to update its pointer in the
crtlist_entry which use it. To do this, we need the list of the entries
using the store.
2020-03-31 12:32:17 +02:00
William Lallemand
493983128b BUG/MINOR: ssl: ckch_inst wrongly inserted in crtlist_entry
The instances were wrongly inserted in the crtlist entries, all
instances of a crt-list were inserted in the last crt-list entry.
Which was kind of handy to free all instances upon error.

Now that it's done correctly, the error path was changed, it must
iterate on the entries and find the ckch_insts which were generated for
this bind_conf. To avoid wasting time, it stops the iteration once it
found the first unsuccessful generation.
2020-03-31 12:32:17 +02:00
William Lallemand
ad3c37b760 REORG: ssl: move SETCERT enum to ssl_sock.h
Move the SETCERT enum at the right place to cleanup ssl_sock.c.
2020-03-31 12:32:17 +02:00
William Lallemand
79d31ec0d4 MINOR: ssl: add a list of bind_conf in struct crtlist
In order to be able to add new certificate in a crt-list, we need the
list of bind_conf that uses this crt-list so we can create a ckch_inst
for each of them.
2020-03-31 12:32:17 +02:00
William Lallemand
638f6ad033 MINOR: cli: add a general purpose pointer in the CLI struct
This patch adds a p2 generic pointer which is inialized to zero before
calling the parser.
2020-03-31 12:32:17 +02:00
Olivier Houchard
cf612a0457 MINOR: servers: Add a counter for the number of currently used connections.
Add a counter to know the current number of used connections, as well as the
max, this will be used later to refine the algorithm used to kill idle
connections, based on current usage.
2020-03-30 00:30:01 +02:00
Jerome Magnin
824186bb08 MEDIUM: stream: support use-server rules with dynamic names
With server-template was introduced the possibility to scale the
number of servers in a backend without needing a configuration change
and associated reload. On the other hand it became impractical to
write use-server rules for these servers as they would only accept
existing server labels as argument. This patch allows the use of
log-format notation to describe targets of a use-server rules, such
as in the example below:

  listen test
    bind *:1234
    use-server %[hdr(srv)] if { hdr(srv) -m found }
    use-server s1 if { path / }
    server s1 127.0.0.1:18080
    server s2 127.0.0.1:18081

If a use-server rule is applied because it was conditionned by an
ACL returning true, but the target of the use-server rule cannot be
resolved, no other use-server rule is evaluated and we fall back to
load balancing.

This feature was requested on the ML, and bumped with issue #563.
2020-03-29 09:55:10 +02:00
Olivier Houchard
dbda31939d BUG/MINOR: connections: Set idle_time before adding to idle list.
In srv_add_to_idle_list(), make sure we set the idle_time before we add
the connection to an idle list, not after, otherwise another thread may
grab it, set the idle_time to 0, only to have the original thread set it
back to now_ms.
This may have an impact, as in conn_free() we check idle_time to decide
if we should decrement the idle connection counters for the server.
2020-03-22 20:05:59 +01:00
Olivier Houchard
ad91124bcf BUILD/MEDIUM: fd: Declare fd_mig_lock as extern.
Declare fd_mig_lock as extern so that it isn't defined multiple times.
This should fix build for architectures without double-width CAS.
2020-03-20 11:42:11 +01:00
Olivier Houchard
566df309c6 MEDIUM: connections: Attempt to get idle connections from other threads.
In connect_server(), if we no longer have any idle connections for the
current thread, attempt to use the new "takeover" mux method to steal a
connection from another thread.
This should have no impact right now, given no mux implements it.
2020-03-19 22:07:33 +01:00
Olivier Houchard
d2489e00b0 MINOR: connections: Add a flag to know if we're in the safe or idle list.
Add flags to connections, CO_FL_SAFE_LIST and CO_FL_IDLE_LIST, to let one
know we are in the safe list, or the idle list.
2020-03-19 22:07:33 +01:00
Olivier Houchard
f0d4dff25c MINOR: connections: Make the "list" element a struct mt_list instead of list.
Make the "list" element a struct mt_list, and explicitely use
list_from_mt_list to get a struct list * where it is used as such, so that
mt_list_for_each_entry will be usable with it.
2020-03-19 22:07:33 +01:00
Olivier Houchard
00bdce24d5 MINOR: connections: Add a new mux method, "takeover".
Add a new mux method, "takeover", that will attempt to make the current thread
responsible for the connection.
It should return 0 on success, and non-zero on failure.
2020-03-19 22:07:33 +01:00
Olivier Houchard
8851664293 MINOR: fd: Implement fd_takeover().
Implement a new function, fd_takeover(), that lets you become the thread
responsible for the fd. On architectures that do not have a double-width CAS,
use a global rwlock.
fd_set_running() was also changed to be able to compete with fd_takeover(),
either using a dooble-width CAS on both running_mask and thread_mask, or
by claiming a reader on the global rwlock. This extra operation should not
have any measurable impact on modern architectures where threading is
relevant.
2020-03-19 22:07:33 +01:00
Olivier Houchard
dc2f2753e9 MEDIUM: servers: Split the connections into idle, safe, and available.
Revamp the server connection lists. We know have 3 lists :
- idle_conns, which contains idling connections
- safe_conns, which contains idling connections that are safe to use even
for the first request
- available_conns, which contains connections that are not idling, but can
still accept new streams (those are HTTP/2 or fastcgi, and are always
considered safe).
2020-03-19 22:07:33 +01:00
Olivier Houchard
2444aa5b66 MEDIUM: sessions: Don't be responsible for connections anymore.
Make it so sessions are not responsible for connection anymore, except for
connections that are private, and thus can't be shared, otherwise, as soon
as a request is done, the session will just add the connection to the
orphan connections pool.
This will break http-reuse safe, but it is expected to be fixed later.
2020-03-19 22:07:33 +01:00
Olivier Houchard
899fb8abdc MINOR: memory: Change the flush_lock to a spinlock, and don't get it in alloc.
The flush_lock was introduced, mostly to be sure that pool_gc() will never
dereference a pointer that has been free'd. __pool_get_first() was acquiring
the lock to, the fear was that otherwise that pointer could get free'd later,
and then pool_gc() would attempt to dereference it. However, that can not
happen, because the only functions that can free a pointer, when using
lockless pools, are pool_gc() and pool_flush(), and as long as those two
are mutually exclusive, nobody will be able to free the pointer while
pool_gc() attempts to access it.
So change the flush_lock to a spinlock, and don't bother acquire/release
it in __pool_get_first(), that way callers of __pool_get_first() won't have
to wait while the pool is flushed. The worst that can happen is we call
__pool_refill_alloc() while the pool is getting flushed, and memory can
get allocated just to be free'd.

This may help with github issue #552

This may be backported to 2.1, 2.0 and 1.9.
2020-03-18 15:55:35 +01:00
Olivier Houchard
de01ea9878 MINOR: wdt: Move the definitions of WDTSIG and DEBUGSIG into types/signal.h.
Move the definition of WDTSIG and DEBUGSIG from wdt.c and debug.c into
types/signal.h, so that we can access them in another file.
We need those definition to avoid blocking those signals when running
__signal_process_queue().

This should be backported to 2.1, 2.0 and 1.9.
2020-03-18 13:07:19 +01:00
Olivier Houchard
a7bf573520 MEDIUM: fd: Introduce a running mask, and use it instead of the spinlock.
In the struct fdtab, introduce a new mask, running_mask. Each thread should
add its bit before using the fd.
Use the running_mask instead of a lock, in fd_insert/fd_delete, we'll just
spin as long as the mask is non-zero, to be sure we access the data
exclusively.
fd_set_running_excl() spins until the mask is 0, fd_set_running() just
adds the thread bit, and fd_clr_running() removes it.
2020-03-17 15:30:07 +01:00
William Lallemand
2954c478eb MEDIUM: ssl: allow crt-list caching
The crtlist structure defines a crt-list in the HAProxy configuration.
It contains crtlist_entry structures which are the lines in a crt-list
file.

crt-list are now loaded in memory using crtlist and crtlist_entry
structures. The file is read only once. The generation algorithm changed
a little bit, new ckch instances are generated from the crtlist
structures, instead of being generated during the file loading.

The loading function was split in two, one that loads and caches the
crt-list and certificates, and one that looks for a crt-list and creates
the ckch instances.

Filters are also stored in crtlist_entry->filters as a char ** so we can
generate the sni_ctx again if needed. I won't be needed anymore to parse
the sni_ctx to do that.

A crtlist_entry stores the list of all ckch_inst that were generated
from this entry.
2020-03-16 16:18:49 +01:00
Willy Tarreau
e4d42551bd BUILD: pools: silence build warnings with DEBUG_MEMORY_POOLS and DEBUG_UAF
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.
2020-03-14 11:10:21 +01:00
Willy Tarreau
2e8ab6b560 MINOR: use DISGUISE() everywhere we deliberately want to ignore a result
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.
2020-03-14 11:04:49 +01:00
Willy Tarreau
15ed69fd3f MINOR: debug: consume the write() result in BUG_ON() to silence a warning
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.
2020-03-14 10:58:35 +01:00
Willy Tarreau
f401668306 MINOR: debug: add a new DISGUISE() macro to pass a value as identity
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.
2020-03-14 10:52:46 +01:00
Ilya Shipitsin
77e3b4a2c4 CLEANUP: assorted typo fixes in the code and comments
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.
2020-03-14 09:42:07 +01:00
Tim Duesterhus
cf6e0c8a83 MEDIUM: proxy_protocol: Support sending unique IDs using PPv2
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.
2020-03-13 17:26:43 +01:00
Tim Duesterhus
d1b15b6e9b MINOR: proxy_protocol: Ingest PP2_TYPE_UNIQUE_ID on incoming connections
This patch reads a proxy protocol v2 provided unique ID and makes it
available using the `fc_pp_unique_id` fetch.
2020-03-13 17:25:23 +01:00
Tim Duesterhus
b435f77620 DOC: proxy_protocol: Reserve TLV type 0x05 as PP2_TYPE_UNIQUE_ID
This reserves and defines TLV type 0x05.
2020-03-13 17:25:23 +01:00
Olivier Houchard
84fd8a77b7 MINOR: lists: fix indentation.
Fix indentation in the recently added list_to_mt_list().
2020-03-11 21:41:13 +01:00
Olivier Houchard
8676514d4e MINOR: servers: Kill priv_conns.
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.
2020-03-11 19:20:01 +01:00
Olivier Houchard
751e5e21a9 MINOR: lists: Implement function to convert list => mt_list and mt_list => list
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.
2020-03-11 17:10:40 +01:00
Olivier Houchard
49983a9fe1 MINOR: mt_lists: Appease gcc.
gcc is confused, and think p may end up being NULL in _MT_LIST_RELINK_DELETED.
It should never happen, so let gcc know that.
2020-03-11 17:10:08 +01:00
Willy Tarreau
638698da37 BUILD: stream-int: fix a few includes dependencies
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.
2020-03-11 14:15:33 +01:00
Willy Tarreau
855796bdc8 BUG/MAJOR: list: fix invalid element address calculation
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.
2020-03-11 14:12:51 +01:00
Olivier Houchard
1d117e3dcd BUG/MEDIUM: mt_lists: Make sure we set the deleted element to NULL;
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.
2020-03-10 17:45:05 +01:00
Willy Tarreau
9a0dfa5298 CLEANUP: remove the now unused common/syscall.h
It was added 9 years ago to implement USE_MY_SPLICE on some libcs where
syscall() was bogus. It's about time to get rid of this.
2020-03-10 07:28:46 +01:00
Willy Tarreau
06c63aec95 CLEANUP: remove support for USE_MY_SPLICE
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.
2020-03-10 07:23:41 +01:00
Willy Tarreau
3858b122a6 CLEANUP: remove support for USE_MY_EPOLL
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.
2020-03-10 07:08:10 +01:00
Willy Tarreau
618ac6ea52 CLEANUP: drop support for USE_MY_ACCEPT4
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.
2020-03-10 07:02:46 +01:00
Willy Tarreau
c3e926bf3b CLEANUP: remove support for Linux i686 vsyscalls
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.
2020-03-10 06:55:52 +01:00
William Lallemand
6763016866 BUG/MINOR: ssl/cli: sni_ctx' mustn't always be used as filters
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.
2020-03-09 17:32:04 +01:00
William Lallemand
0a52846603 CLEANUP: ssl: is_default is a bit in ckch_inst
The field is_default becomes a bit in the ckch_inst structure.
2020-03-09 17:32:04 +01:00
Miroslav Zagorac
d7dc67ba1d CLEANUP: remove unused code in 'my_ffsl/my_flsl' functions
Shifting the variable 'a' one bit to the right has no effect on the
result of the functions.
2020-03-09 14:47:27 +01:00
Willy Tarreau
ee3bcddef7 MINOR: tools: add a generic function to generate UUIDs
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.
2020-03-08 18:04:16 +01:00
Willy Tarreau
52bf839394 BUG/MEDIUM: random: implement a thread-safe and process-safe PRNG
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.
2020-03-08 10:09:02 +01:00
Willy Tarreau
7a40909c00 MINOR: tools: add 64-bit rotate operators
This adds rotl64/rotr64 to rotate a 64-bit word by an arbitrary number
of bits. It's mainly aimed at being used with constants.
2020-03-08 00:42:18 +01:00
Willy Tarreau
0fbf28a05b Revert "BUG/MEDIUM: random: implement per-thread and per-process random sequences"
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.
2020-03-07 11:24:39 +01:00
Willy Tarreau
1c306aa84d BUG/MEDIUM: random: implement per-thread and per-process random sequences
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.
2020-03-07 06:11:15 +01:00