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
Operations performed when internal responses (redirect/deny/auth/errors) are
returned are always the same. The http_forward_proxy_resp() function is added to
group all of them under a unique function.
The http_server_error() function now relies on http_reply_and_close(). Both do
almost the same actions. In addtion, http_server_error() sets the error flag and
the final state flag on the stream.
Now, these actions use their own dedicated function and are no longer handled
"in place" during the HTTP rules evaluation. Thus the action names
ACT_HTTP_REPLACE_HDR and ACT_HTTP_REPLACE_VAL are removed. The action type is
now set to 0 to evaluate the whole header or to 1 to evaluate every
comma-delimited values.
The function http_transform_header_str() is renamed to http_replace_hdrs() to be
more explicit and the function http_transform_header() is removed. In fact, this
last one is now more or less the new action function.
The lua code has been updated accordingly to use http_replace_hdrs().
Info used by HTTP rules manipulating the message itself are splitted in several
structures in the arg union. But it is possible to group all of them in a unique
struct. Now, <arg.http> is used by most of these rules, which contains:
* <arg.http.i> : an integer used as status code, nice/tos/mark/loglevel or
action id.
* <arg.http.str> : an IST used as header name, reason string or auth realm.
* <arg.http.fmt> : a log-format compatible expression
* <arg.http.re> : a regular expression used by replace rules
In HTTP rules, error handling during a rewrite is now handle the same way for
all rules. First, allocation errors are reported as internal errors. Then, if
soft rewrites are allowed, rewrite errors are ignored and only the
failed_rewrites counter is incremented. Otherwise, when strict rewrites are
mandatory, interanl errors are returned.
For now, only soft rewrites are supported. Note also that the warning sent to
notify a rewrite failure was removed. It will be useless once the strict
rewrites will be possible.
Since the legacy HTTP mode was removed, the stream is always released at the end
of each HTTP transaction and a new is created to handle the next request for
keep-alive connections. So the HTTP transaction is no longer reset and the
function http_reset_txn() can be removed.
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.
