It is now possible to get any variables from the cli. Concretely, only
variables in the PROC scope can be retrieved because there is neither stream
nor session defined. But, nothing forbids anyone to try to get a variable in
any scope. No value will be found, but it is allowed. Thus, we must be sure
to not rely on an undefined session or stream in that case. Especially, the
session must be tested before retrieving variables in CHECK scope.
This patch should fix the issue #1249. It must be backported to 2.4.
Variable names are stored into a unified list that helps compare them
just based on a pointer instead of duplicating their name with every
variable. This is convenient for those declared in the configuration
but this started to cause issues with Lua when random names would be
created upon each access, eating lots of memory and CPU for lookups,
hence the work in 2.2 with commit 4e172c93f ("MEDIUM: lua: Add
`ifexist` parameter to `set_var`") to address this.
But there remains a corner case with get_var(), which also allocates
a new variables. After a bit of thinking and discussion, it never
makes sense to allocate a new variable name on get_var():
- if the name exists, it will be returned ;
- if it does not exist, then the only way for it to appear will
be that some code calls set_var() on it
- a call to get_var() after a careful set_var(ifexist) ruins the
effort on set_var().
For this reason, this patch addresses this issue by making sure that
get_var() will never cause a variable to be allocated. This is done
by modifying vars_get_by_name() to always call register_name() with
alloc=0, since vars_get_by_name() is exclusively used by Lua and the
new CLI's "get/set var" which also benefit from this protection.
It probably makes sense to backport this as far as 2.2 after some
observation period and feedback from users.
For more context and discussions about the issues this was causing,
see https://www.mail-archive.com/haproxy@formilux.org/msg40451.html
and in issue #664.
The presence of this field causes a long dependency chain because almost
everyone includes global-t.h, and vars include sample_data which include
some system includes as well as HTTP parts.
There is absolutely no reason for having the process-wide variables in
the global struct, let's just move them into vars.c and vars.h. This
reduces from ~190k to ~170k the preprocessed output of version.c.
Define a new keyword flag KWF_MATCH_PREFIX. This is used to replace the
match_pfx field of action struct.
This has the benefit to have more explicit action declaration, and now
it is possible to quickly implement experimental actions.
There were 102 CLI commands whose help were zig-zagging all along the dump
making them unreadable. This patch realigns all these messages so that the
command now uses up to 40 characters before the delimiting colon. About a
third of the commands did not correctly list their arguments which were
added after the first version, so they were all updated. Some abuses of
the term "id" were fixed to use a more explanatory term. The
"set ssl ocsp-response" command was not listed because it lacked a help
message, this was fixed as well. The deprecated enable/disable commands
for agent/health/server were prominently written as deprecated. Whenever
possible, clearer explanations were provided.
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.
In issue #1200 Coverity believes we may use an uninitialized field
smp.sess here while it's not possible because the returned variable
necessarily matches SCOPE_PROC hence smp.sess is not used. But it
cannot see this and it could be confusing if the code later evolved
into something more complex. That's not a critical path so let's
first reset the sample.
set var <name> <expression>
Allows to set or overwrite the process-wide variable 'name' with the result
of expression <expression>. Only process-wide variables may be used, so the
name must begin with 'proc.' otherwise no variable will be set. The
<expression> may only involve "internal" sample fetch keywords and converters
even though the most likely useful ones will be str('something') or int().
Note that the command line parser doesn't know about quotes, so any space in
the expression must be preceeded by a backslash. This command requires levels
"operator" or "admin". This command is only supported on a CLI connection
running in experimental mode (see "experimental-mode on").
Just like for "set-var" in the global section, the command uses a temporary
dummy proxy to create a temporary "set-var(name)" rule to assign the value.
The reg test was updated to verify that an updated global variable is properly
reflected in subsequent HTTP responses.
Process-wide variables can now be displayed from the CLI using "get var"
followed by the variable name. They must all start with "proc." otherwise
they will not be found. The output is very similar to the one of the
debug converter, with a type and value being reported for the embedded
sample.
This command is limited to clients with the level "operator" or higher,
since it can possibly expose traffic-related data.
In order to process samples from the command line interface we'll need
rules as well, and these rules will have to be marked as coming from
the CLI parser. This new origin is used for this.
While we do support process-wide variables ("proc.<name>"), there was
no way to preset them from the configuration. This was particularly
limiting their usefulness since configs involving them always had to
first check if the variable was set prior to performing an operation.
This patch adds a new "set-var" directive in the global section that
supports setting the proc.<name> variables from an expression, like
other set-var actions do. The syntax however follows what is already
being done for setenv, which consists in having one argument for the
variable name and another one for the expression.
Only "constant" expressions are allowed here, such as "int", "str"
etc, combined with arithmetic or string converters, and variable
lookups. A few extra sample fetch keywords like "date", "rand" and
"uuid" are also part of the constant expressions and may make sense
to allow to create a random key or differentiate processes.
The way it was done consists in parsing a dummy rule an executing the
expression in the CFG_PARSE context, then releasing the expression.
This is safe because the sample that variables store does not hold a
back pointer to expression that created them.
In order to process samples from the config file we'll need rules as
well, and these rules will have to be marked as coming from the
config parser. This new origin is used for this.
A number of keywords are really constant and safe to use at config
time. This is the case for str(), int() etc but also env(), hostname(),
nbproc() etc. By extension a few other ones which can be useful to
preset values in a configuration were enabled as well, like data(),
rand() or uuid(). At the moment this doesn't change anything as they
are still only usable from runtime rules.
The "var()" keyword was also marked as const as it can definitely
return stable stuff at boot time.
This sample fetch doesn't require any L4 client session in practice, as
get_var() now checks for the session. This is important to remove this
dependency in order to support accessing variables in scope "proc" from
anywhere.
The error message after "http-response set-var" isn't very clear:
[ALERT] 070/115043 (30526) : parsing [/dev/stdin:2] : error detected in proxy 'f' while parsing 'http-response set-var' rule : invalid variable 'set-var'. Expects 'set-var(<var-name>)' or 'unset-var(<var-name>)'.
Let's change it to this instead:
[ALERT] 070/115608 (30799) : parsing [/dev/stdin:2] : error detected in proxy 'f' while parsing 'http-response set-var' rule : invalid or incomplete action 'set-var'. Expects 'set-var(<var-name>)' or 'unset-var(<var-name>)'.
With a wrong action name, it also works better (it's handled as a prefix
due to the opening parenthesis):
[ALERT] 070/115608 (30799) : parsing [/dev/stdin:2] : error detected in proxy 'f' while parsing 'http-response set-varxxx' rule : invalid or incomplete action 'set-varxxx'. Expects 'set-var(<var-name>)' or 'unset-var(<var-name>)'.
The default proxy was passed as a variable to all parsers instead of a
const, which is not without risk, especially when some timeout parsers used
to make some int pointers point to the default values for comparisons. We
want to be certain that none of these parsers will modify the defaults
sections by accident, so it's important to mark this proxy as const.
This patch touches all occurrences found (89).
In sample_store(), depending on the new sample types, the area pointer
was not always zeroed after being freed. Let's make sure it's always the
case to avoid the risk of dangling pointers being misused.
This patch adds a lock to functions vars_get_by_name() and
vars_get_by_desc() to protect accesses to the list of variables.
After the variable is fetched, a sample data is duplicated by using
smp_dup() because the variable may be modified by another thread.
This should be backported to all versions supporting vars along with
"BUG/MINOR: sample: secure convs that accept base64 string and var name
as args" which this patch depends on.
The OpenTracing filter uses several internal HAProxy functions to work
with variables and therefore requires two static local HAProxy functions,
var_accounting_diff() and var_clear(), to be declared global.
In fact, the var_clear() function was not originally defined as static,
but it lacked a declaration.
We cannot simply `release_sample_expr(rule->arg.vars.expr)` for a
`struct act_rule`, because `rule->arg` is a union that might not
contain valid `vars`. This leads to a crash on a configuration using
`http-request redirect` and possibly others:
frontend http
mode http
bind 127.0.0.1:80
http-request redirect scheme https
Instead a `struct act_rule` has a `release_ptr` that must be used
to properly free any additional storage allocated.
This patch fixes a regression in commit ff78fcdd7f.
It must be backported to whereever that patch is backported.
It has be verified that the configuration above no longer crashes.
It has also been verified that the configuration in ff78fcdd7f
does not leak.
This patch fixes all the leftovers from the include cleanup campaign. There
were not that many (~400 entries in ~150 files) but it was definitely worth
doing it as it revealed a few duplicates.
Most of the files dealing with error reports have to include log.h in order
to access ha_alert(), ha_warning() etc. But while these functions don't
depend on anything, log.h depends on a lot of stuff because it deals with
log-formats and samples. As a result it's impossible not to embark long
dependencies when using ha_warning() or qfprintf().
This patch moves these low-level functions to errors.h, which already
defines the error codes used at the same places. About half of the users
of log.h could be adjusted, sometimes revealing other issues such as
missing tools.h. Interestingly the total preprocessed size shrunk by
4%.
Checks.c remains one of the largest file of the project and it contains
too many things. The tcpchecks code represents half of this file, and
both parts are relatively isolated, so let's move it away into its own
file. We now have tcpcheck.c, tcpcheck{,-t}.h.
Doing so required to export quite a number of functions because check.c
has almost everything made static, which really doesn't help to split!
There's no point splitting the file in two since only cfgparse uses the
types defined there. A few call places were updated and cleaned up. All
of them were in C files which register keywords.
There is nothing left in common/ now so this directory must not be used
anymore.
This one was not easy because it was embarking many includes with it,
which other files would automatically find. At least global.h, arg.h
and tools.h were identified. 93 total locations were identified, 8
additional includes had to be added.
In the rare files where it was possible to finalize the sorting of
includes by adjusting only one or two extra lines, it was done. But
all files would need to be rechecked and cleaned up now.
It was the last set of files in types/ and proto/ and these directories
must not be reused anymore.
It was moved without any change, however many callers didn't need it at
all. This was a consequence of the split of proto_http.c into several
parts that resulted in many locations to still reference it.
All includes that were not absolutely necessary were removed because
checks.h happens to very often be part of dependency loops. A warning
was added about this in check-t.h. The fields, enums and structs were
a bit tidied because it's particularly tedious to find anything there.
It would make sense to split this in two or more files (at least
extract tcp-checks).
The file was renamed to the singular because it was one of the rare
exceptions to have an "s" appended to its name compared to the struct
name.
This one is particularly tricky to move because everyone uses it
and it depends on a lot of other types. For example it cannot include
arg-t.h and must absolutely only rely on forward declarations to avoid
dependency loops between vars -> sample_data -> arg. In order to address
this one, it would be nice to split the sample_data part out of sample.h.
So the enums and structs were placed into http-t.h and the functions
into http.h. This revealed that several files were dependeng on http.h
but not including it, as it was silently inherited via other files.
Half of the users of this include only need the type definitions and
not the manipulation macros nor the inline functions. Moves the various
types into mini-clist-t.h makes the files cleaner. The other one had all
its includes grouped at the top. A few files continued to reference it
without using it and were cleaned.
In addition it was about time that we'd rename that file, it's not
"mini" anymore and contains a bit more than just circular lists.
All files that were including one of the following include files have
been updated to only include haproxy/api.h or haproxy/api-t.h once instead:
- common/config.h
- common/compat.h
- common/compiler.h
- common/defaults.h
- common/initcall.h
- common/tools.h
The choice is simple: if the file only requires type definitions, it includes
api-t.h, otherwise it includes the full api.h.
In addition, in these files, explicit includes for inttypes.h and limits.h
were dropped since these are now covered by api.h and api-t.h.
No other change was performed, given that this patch is large and
affects 201 files. At least one (tools.h) was already freestanding and
didn't get the new one added.
With "MINOR: lua: Use vars_unset_by_name_ifexist()" the last user was
removed and as outlined in that commit there is no good reason for this
function to exist.
May be backported together with the commit mentioned above.
Before, the server was used as origin during session creation. It was only used
to get the check associated to the server when a variable is get or set in the
check scope or when a check sample fetch was called. So it seems easier to use
the check as origin of a session. It is also more logical becaues the session is
created by the health-check itself and not its server.
Evaluate the registered action_ptr associated with each CHK_ACTION_KW rules from
a ruleset. Currently only the 'set-var' and 'unset-var' are parsed by the
tcp-check parser. Thus it is now possible to set or unset variables. It is
possible to use such rules before the first connect of the ruleset.
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.
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.
The isalnum(), isalpha(), isdigit() etc functions from ctype.h are
supposed to take an int in argument which must either reflect an
unsigned char or EOF. In practice on some platforms they're implemented
as macros referencing an array, and when passed a char, they either cause
a warning "array subscript has type 'char'" when lucky, or cause random
segfaults when unlucky. It's quite unconvenient by the way since none of
them may return true for negative values. The recent introduction of
cygwin to the list of regularly tested build platforms revealed a lot
of breakage there due to the same issues again.
So this patch addresses the problem all over the code at once. It adds
unsigned char casts to every valid use case, and also drops the unneeded
double cast to int that was sometimes added on top of it.
It may be backported by dropping irrelevant changes if that helps better
support uncommon platforms. It's unlikely to fix bugs on platforms which
would already not emit any warning though.
When an end pointer is passed, instead of complaining that a comma is
missing after a keyword, sample_parse_expr() will silently return the
pointer to the current location into this return pointer so that the
caller can continue its parsing. This will be used by more complex
expressions which embed sample expressions, and may even permit to
embed sample expressions into arguments of other expressions.
This patch introduces the 'http-after-response' rules. These rules are evaluated
at the end of the response analysis, just before the data forwarding, on ALL
HTTP responses, the server ones but also all responses generated by
HAProxy. Thanks to this ruleset, it is now possible for instance to add some
headers to the responses generated by the stats applet. Following actions are
supported :
* allow
* add-header
* del-header
* replace-header
* replace-value
* set-header
* set-status
* set-var
* strict-mode
* unset-var
The old module proto_http does not exist anymore. All code dedicated to the HTTP
analysis is now grouped in the file proto_htx.c. So, to finish the polishing
after removing the legacy HTTP code, proto_htx.{c,h} files have been moved in
http_ana.{c,h} files.
In addition, all HTX analyzers and related functions prefixed with "htx_" have
been renamed to start with "http_" instead.
