CONTRIB: opentracing: add the OpenTracing filter
This commit adds the OpenTracing filter (hereinafter we will use the
abbreviated name 'the OT filter') to the contrib tree.
The OT filter adds native support for using distributed tracing in HAProxy.
This is enabled by sending an OpenTracing compliant request to one of the
supported tracers; such as Datadog, Jaeger, Lightstep and Zipkin tracers.
Please note: tracers are not listed by any preference, but alphabetically.
The OT filter is a standard HAProxy filter, so what applies to others also
applies to this one (of course, by that I mean what is described in the
documentation, more precisely in the doc/internals/filters.txt file).
The OT filter activation is done explicitly by specifying it in the HAProxy
configuration. If this is not done, the OT filter in no way participates
in the work of HAProxy.
As for the impact on HAProxy speed, this is documented with several tests
located in the test directory, and the result is found in the README-speed-*
files. In short, the speed of operation depends on the way it is used and
the complexity of the configuration, from an almost immeasurable impact to
a significant deceleration (5x and more). I think that in some normal use
the speed of HAProxy with the filter on will be quite satisfactory with a
slowdown of less than 4%.
The OT filter allows intensive use of ACLs, which can be defined anywhere in
the configuration. Thus, it is possible to use the filter only for those
connections that are of interest to us.
More detailed documentation related to the operation, configuration and use
of the filter can be found in the contrib/opentracing directory.
To make the OpenTracing filter easier to configure and compile, several
entries have been added to the Makefile. When running the make utility,
it is possible to use several new arguments:
USE_OT=1 : enable the OpenTracing filter
OT_DEBUG=1 : compile the OpenTracing filter in debug mode
OT_INC=path : force the include path to libopentracing-c-wrapper
OT_LIB=path : force the lib path to libopentracing-c-wrapper
OT_RUNPATH=1 : add libopentracing-c-wrapper RUNPATH to haproxy executable
If USE_OT is set, then an additional Makefile from the contrib/opentracing
directory is included in the compilation process.
diff --git a/contrib/opentracing/src/filter.c b/contrib/opentracing/src/filter.c
new file mode 100644
index 0000000..6699d46
--- /dev/null
+++ b/contrib/opentracing/src/filter.c
@@ -0,0 +1,1153 @@
+/***
+ * Copyright 2020 HAProxy Technologies
+ *
+ * This file is part of the HAProxy OpenTracing filter.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include "include.h"
+
+
+/*
+ * OpenTracing filter id, used to identify OpenTracing filters.
+ * The name of this variable is consistent with the other filter names
+ * declared in include/haproxy/filters.h .
+ */
+const char *ot_flt_id = "the OpenTracing filter";
+
+
+/***
+ * NAME
+ * flt_ot_is_disabled -
+ *
+ * ARGUMENTS
+ * f -
+ * event -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * -
+ */
+bool flt_ot_is_disabled(const struct filter *f FLT_OT_DBG_ARGS(, int event))
+{
+#ifdef DEBUG_OT
+ const struct flt_ot_conf *conf = FLT_OT_CONF(f);
+ const char *msg;
+#endif
+ bool retval;
+
+ retval = FLT_OT_RT_CTX(f->ctx)->flag_disabled ? 1 : 0;
+
+#ifdef DEBUG_OT
+ msg = retval ? " (disabled)" : "";
+
+ if (FLT_OT_IN_RANGE(event, 0, FLT_OT_EVENT_MAX - 1))
+ FLT_OT_DBG(2, "filter '%s', type: %s, event: '%s' %d%s", conf->id, flt_ot_type(f), flt_ot_event_data[event].name, event, msg);
+ else
+ FLT_OT_DBG(2, "filter '%s', type: %s%s", conf->id, flt_ot_type(f), msg);
+#endif
+
+ return retval;
+}
+
+
+/***
+ * NAME
+ * flt_ot_return_int -
+ *
+ * ARGUMENTS
+ * f -
+ * err -
+ * retval -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * -
+ */
+static int flt_ot_return_int(const struct filter *f, char **err, int retval)
+{
+ struct flt_ot_runtime_context *rt_ctx = f->ctx;
+
+ if ((retval == FLT_OT_RET_ERROR) || ((err != NULL) && (*err != NULL))) {
+ if (rt_ctx->flag_harderr) {
+ FLT_OT_DBG(1, "WARNING: filter hard-error (disabled)");
+
+ rt_ctx->flag_disabled = 1;
+
+ _HA_ATOMIC_ADD(FLT_OT_CONF(f)->cnt.disabled + 1, 1);
+ } else {
+ FLT_OT_DBG(1, "WARNING: filter soft-error");
+ }
+
+ retval = FLT_OT_RET_OK;
+ }
+
+ FLT_OT_ERR_FREE(*err);
+
+ return retval;
+}
+
+
+/***
+ * NAME
+ * flt_ot_return_void -
+ *
+ * ARGUMENTS
+ * f -
+ * err -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_return_void(const struct filter *f, char **err)
+{
+ struct flt_ot_runtime_context *rt_ctx = f->ctx;
+
+ if ((err != NULL) && (*err != NULL)) {
+ if (rt_ctx->flag_harderr) {
+ FLT_OT_DBG(1, "WARNING: filter hard-error (disabled)");
+
+ rt_ctx->flag_disabled = 1;
+
+ _HA_ATOMIC_ADD(FLT_OT_CONF(f)->cnt.disabled + 1, 1);
+ } else {
+ FLT_OT_DBG(1, "WARNING: filter soft-error");
+ }
+ }
+
+ FLT_OT_ERR_FREE(*err);
+}
+
+
+/***
+ * NAME
+ * flt_ot_init - Initialize the filter.
+ *
+ * ARGUMENTS
+ * p -
+ * fconf -
+ *
+ * DESCRIPTION
+ * It initializes the filter for a proxy. You may define this callback
+ * if you need to complete your filter configuration.
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, any other value otherwise.
+ */
+static int flt_ot_init(struct proxy *p, struct flt_conf *fconf)
+{
+ struct flt_ot_conf *conf = FLT_OT_DEREF(fconf, conf, NULL);
+ char *err = NULL;
+ int retval = FLT_OT_RET_ERROR;
+
+ FLT_OT_FUNC("%p, %p", p, fconf);
+
+ if (conf == NULL)
+ FLT_OT_RETURN(retval);
+
+ flt_ot_cli_init();
+
+ /*
+ * Initialize the OpenTracing library.
+ * Enable HTX streams filtering.
+ */
+ retval = ot_init(&(conf->tracer->tracer), conf->tracer->config, conf->tracer->plugin, &err);
+ if (retval != FLT_OT_RET_ERROR)
+ fconf->flags |= FLT_CFG_FL_HTX;
+ else if (err != NULL) {
+ FLT_OT_ALERT("%s", err);
+
+ FLT_OT_ERR_FREE(err);
+ }
+
+ FLT_OT_RETURN(retval);
+}
+
+
+/***
+ * NAME
+ * flt_ot_deinit - Free resources allocated by the filter.
+ *
+ * ARGUMENTS
+ * p -
+ * fconf -
+ *
+ * DESCRIPTION
+ * It cleans up what the parsing function and the init callback have done.
+ * This callback is useful to release memory allocated for the filter
+ * configuration.
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_deinit(struct proxy *p, struct flt_conf *fconf)
+{
+ struct flt_ot_conf **conf = (fconf == NULL) ? NULL : (typeof(conf))&(fconf->conf);
+#ifdef DEBUG_OT
+ int i;
+#endif
+
+ FLT_OT_FUNC("%p, %p", p, fconf);
+
+ if (conf == NULL)
+ FLT_OT_RETURN();
+
+ ot_debug();
+ ot_close(&((*conf)->tracer->tracer));
+
+#ifdef DEBUG_OT
+ FLT_OT_DBG(0, "--- used events ----------");
+ for (i = 0; i < FLT_OT_TABLESIZE((*conf)->cnt.event); i++)
+ if ((*conf)->cnt.event[i].flag_used)
+ FLT_OT_DBG(0, " %02d: %" PRIu64 " / %" PRIu64, i, (*conf)->cnt.event[i].htx[0], (*conf)->cnt.event[i].htx[1]);
+#endif
+
+ flt_ot_conf_free(conf);
+
+ FLT_OT_MEMINFO();
+
+ FLT_OT_RETURN();
+}
+
+
+/***
+ * NAME
+ * flt_ot_check - Check configuration of the filter for the specified proxy.
+ *
+ * ARGUMENTS
+ * p -
+ * fconf -
+ *
+ * DESCRIPTION
+ * Optionally, by implementing the flt_ot_check() callback, you add a
+ * step to check the internal configuration of your filter after the
+ * parsing phase, when the HAProxy configuration is fully defined.
+ *
+ * RETURN VALUE
+ * Returns the number of encountered errors.
+ */
+static int flt_ot_check(struct proxy *p, struct flt_conf *fconf)
+{
+ struct proxy *px;
+ struct flt_ot_conf *conf = FLT_OT_DEREF(fconf, conf, NULL);
+ struct flt_ot_conf_group *conf_group;
+ struct flt_ot_conf_scope *conf_scope;
+ struct flt_ot_conf_ph *ph_group, *ph_scope;
+ int retval = 0, scope_unused_cnt = 0, span_root_cnt = 0;
+
+ FLT_OT_FUNC("%p, %p", p, fconf);
+
+ if (conf == NULL)
+ FLT_OT_RETURN(++retval);
+
+ /*
+ * If only the proxy specified with the <p> parameter is checked, then
+ * no duplicate filters can be found that are not defined in the same
+ * configuration sections.
+ */
+ for (px = proxies_list; px != NULL; px = px->next) {
+ struct flt_conf *fconf_tmp;
+
+ FLT_OT_DBG(2, "proxy '%s'", px->id);
+
+ /*
+ * The names of all OT filters (filter ID) should be checked,
+ * they must be unique.
+ */
+ list_for_each_entry(fconf_tmp, &(px->filter_configs), list)
+ if ((fconf_tmp != fconf) && (fconf_tmp->id == ot_flt_id)) {
+ struct flt_ot_conf *conf_tmp = fconf_tmp->conf;
+
+ FLT_OT_DBG(2, " OT filter '%s'", conf_tmp->id);
+
+ if (strcmp(conf_tmp->id, conf->id) == 0) {
+ FLT_OT_ALERT("''%s' : duplicated filter ID'", conf_tmp->id);
+
+ retval++;
+ }
+ }
+ }
+
+ if (FLT_OT_DEREF(conf->tracer, id, NULL) == NULL) {
+ FLT_OT_ALERT("''%s' : no tracer found'", conf->id);
+
+ retval++;
+ }
+
+ /*
+ * Checking that all defined 'ot-group' sections have correctly declared
+ * 'ot-scope' sections (ie whether the declared 'ot-scope' sections have
+ * corresponding definitions).
+ */
+ list_for_each_entry(conf_group, &(conf->groups), list)
+ list_for_each_entry(ph_scope, &(conf_group->ph_scopes), list) {
+ bool flag_found = 0;
+
+ list_for_each_entry(conf_scope, &(conf->scopes), list)
+ if (strcmp(ph_scope->id, conf_scope->id) == 0) {
+ ph_scope->ptr = conf_scope;
+ conf_scope->flag_used = 1;
+ flag_found = 1;
+
+ break;
+ }
+
+ if (!flag_found) {
+ FLT_OT_ALERT("'" FLT_OT_PARSE_SECTION_GROUP_ID " '%s' : try to use undefined " FLT_OT_PARSE_SECTION_SCOPE_ID " '%s''", conf_group->id, ph_scope->id);
+
+ retval++;
+ }
+ }
+
+ if (conf->tracer != NULL) {
+ /*
+ * Checking that all declared 'groups' keywords have correctly
+ * defined 'ot-group' sections.
+ */
+ list_for_each_entry(ph_group, &(conf->tracer->ph_groups), list) {
+ bool flag_found = 0;
+
+ list_for_each_entry(conf_group, &(conf->groups), list)
+ if (strcmp(ph_group->id, conf_group->id) == 0) {
+ ph_group->ptr = conf_group;
+ conf_group->flag_used = 1;
+ flag_found = 1;
+
+ break;
+ }
+
+ if (!flag_found) {
+ FLT_OT_ALERT("'" FLT_OT_PARSE_SECTION_TRACER_ID " '%s' : try to use undefined " FLT_OT_PARSE_SECTION_GROUP_ID " '%s''", conf->tracer->id, ph_group->id);
+
+ retval++;
+ }
+ }
+
+ /*
+ * Checking that all declared 'scopes' keywords have correctly
+ * defined 'ot-scope' sections.
+ */
+ list_for_each_entry(ph_scope, &(conf->tracer->ph_scopes), list) {
+ bool flag_found = 0;
+
+ list_for_each_entry(conf_scope, &(conf->scopes), list)
+ if (strcmp(ph_scope->id, conf_scope->id) == 0) {
+ ph_scope->ptr = conf_scope;
+ conf_scope->flag_used = 1;
+ flag_found = 1;
+
+ break;
+ }
+
+ if (!flag_found) {
+ FLT_OT_ALERT("'" FLT_OT_PARSE_SECTION_TRACER_ID " '%s' : try to use undefined " FLT_OT_PARSE_SECTION_SCOPE_ID " '%s''", conf->tracer->id, ph_scope->id);
+
+ retval++;
+ }
+ }
+ }
+
+ FLT_OT_DBG(3, "--- filter '%s' configuration ----------", conf->id);
+ FLT_OT_DBG(3, "- defined spans ----------");
+
+ list_for_each_entry(conf_scope, &(conf->scopes), list) {
+ if (conf_scope->flag_used) {
+ struct flt_ot_conf_span *conf_span;
+
+ /*
+ * In principle, only one span should be labeled
+ * as a root span.
+ */
+ list_for_each_entry(conf_span, &(conf_scope->spans), list) {
+ FLT_OT_DBG_CONF_SPAN(" ", conf_span);
+
+ span_root_cnt += conf_span->flag_root ? 1 : 0;
+ }
+
+#ifdef DEBUG_OT
+ conf->cnt.event[conf_scope->event].flag_used = 1;
+#endif
+
+ /* Set the flags of the analyzers used. */
+ conf->tracer->analyzers |= flt_ot_event_data[conf_scope->event].an_bit;
+ } else {
+ FLT_OT_ALERT("''%s' : unused " FLT_OT_PARSE_SECTION_SCOPE_ID " '%s''", conf->id, conf_scope->id);
+
+ scope_unused_cnt++;
+ }
+ }
+
+ /*
+ * Unused scopes or a number of root spans other than one do not
+ * necessarily have to be errors, but it is good to print it when
+ * starting HAProxy.
+ */
+ if (scope_unused_cnt > 0)
+ FLT_OT_ALERT("''%s' : %d scope(s) not in use'", conf->id, scope_unused_cnt);
+
+ if (LIST_ISEMPTY(&(conf->scopes)))
+ /* Do nothing. */;
+ else if (span_root_cnt == 0)
+ FLT_OT_ALERT("''%s' : no span is marked as the root span'", conf->id);
+ else if (span_root_cnt > 1)
+ FLT_OT_ALERT("''%s' : multiple spans are marked as the root span'", conf->id);
+
+ FLT_OT_DBG_LIST(conf, group, "", "defined", _group,
+ FLT_OT_DBG_CONF_GROUP(" ", _group);
+ FLT_OT_DBG_LIST(_group, ph_scope, " ", "used", _scope, FLT_OT_DBG_CONF_PH(" ", _scope)));
+ FLT_OT_DBG_LIST(conf, scope, "", "defined", _scope, FLT_OT_DBG_CONF_SCOPE(" ", _scope));
+
+ if (conf->tracer != NULL) {
+ FLT_OT_DBG(3, " --- tracer '%s' configuration ----------", conf->tracer->id);
+ FLT_OT_DBG_LIST(conf->tracer, ph_group, " ", "used", _group, FLT_OT_DBG_CONF_PH(" ", _group));
+ FLT_OT_DBG_LIST(conf->tracer, ph_scope, " ", "used", _scope, FLT_OT_DBG_CONF_PH(" ", _scope));
+ }
+
+ FLT_OT_RETURN(retval);
+}
+
+
+#ifdef DEBUG_OT
+
+/***
+ * NAME
+ * flt_ot_init_per_thread -
+ *
+ * ARGUMENTS
+ * p -
+ * fconf -
+ *
+ * DESCRIPTION
+ * It initializes the filter for each thread. It works the same way than
+ * flt_ot_init() but in the context of a thread. This callback is called
+ * after the thread creation.
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, any other value otherwise.
+ */
+static int flt_ot_init_per_thread(struct proxy *p, struct flt_conf *fconf)
+{
+ int retval = FLT_OT_RET_OK;
+
+ FLT_OT_FUNC("%p, %p", p, fconf);
+
+ FLT_OT_RETURN(retval);
+}
+
+
+/***
+ * NAME
+ * flt_ot_deinit_per_thread -
+ *
+ * ARGUMENTS
+ * p -
+ * fconf -
+ *
+ * DESCRIPTION
+ * It cleans up what the init_per_thread callback have done. It is called
+ * in the context of a thread, before exiting it.
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_deinit_per_thread(struct proxy *p, struct flt_conf *fconf)
+{
+ FLT_OT_FUNC("%p, %p", p, fconf);
+
+ FLT_OT_RETURN();
+}
+
+#endif /* DEBUG_OT */
+
+
+/***
+ * NAME
+ * flt_ot_attach - Called when a filter instance is created and attach to a stream.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ *
+ * DESCRIPTION
+ * It is called after a filter instance creation, when it is attached to a
+ * stream. This happens when the stream is started for filters defined on
+ * the stream's frontend and when the backend is set for filters declared
+ * on the stream's backend. It is possible to ignore the filter, if needed,
+ * by returning 0. This could be useful to have conditional filtering.
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, 0 to ignore the filter,
+ * any other value otherwise.
+ */
+static int flt_ot_attach(struct stream *s, struct filter *f)
+{
+ const struct flt_ot_conf *conf = FLT_OT_CONF(f);
+ char *err = NULL;
+
+ FLT_OT_FUNC("%p, %p", s, f);
+
+ if (conf->tracer->flag_disabled) {
+ FLT_OT_DBG(2, "filter '%s', type: %s (disabled)", conf->id, flt_ot_type(f));
+
+ FLT_OT_RETURN(FLT_OT_RET_IGNORE);
+ }
+ else if (conf->tracer->rate_limit < FLT_OT_FLOAT_U32(FLT_OT_RATE_LIMIT_MAX, FLT_OT_RATE_LIMIT_MAX)) {
+ uint32_t rnd = ha_random32();
+
+ if (conf->tracer->rate_limit <= rnd) {
+ FLT_OT_DBG(2, "filter '%s', type: %s (ignored: %u <= %u)", conf->id, flt_ot_type(f), conf->tracer->rate_limit, rnd);
+
+ FLT_OT_RETURN(FLT_OT_RET_IGNORE);
+ }
+ }
+
+ FLT_OT_DBG(2, "filter '%s', type: %s (run)", conf->id, flt_ot_type(f));
+
+ f->ctx = flt_ot_runtime_context_init(s, f, &err);
+ FLT_OT_ERR_FREE(err);
+ if (f->ctx == NULL) {
+ FLT_OT_LOG(LOG_EMERG, "failed to create context");
+
+ FLT_OT_RETURN(FLT_OT_RET_IGNORE);
+ }
+
+ /*
+ * AN_REQ_WAIT_HTTP and AN_RES_WAIT_HTTP analyzers can only be used
+ * in the .channel_post_analyze callback function.
+ */
+ f->pre_analyzers |= conf->tracer->analyzers & ((AN_REQ_ALL & ~AN_REQ_WAIT_HTTP & ~AN_REQ_HTTP_TARPIT) | (AN_RES_ALL & ~AN_RES_WAIT_HTTP));
+ f->post_analyzers |= conf->tracer->analyzers & (AN_REQ_WAIT_HTTP | AN_RES_WAIT_HTTP);
+
+ FLT_OT_LOG(LOG_INFO, "%08x %08x", f->pre_analyzers, f->post_analyzers);
+
+ flt_ot_vars_dump(s);
+ flt_ot_http_headers_dump(&(s->req));
+
+ FLT_OT_RETURN(FLT_OT_RET_OK);
+}
+
+
+#ifdef DEBUG_OT
+
+/***
+ * NAME
+ * flt_ot_stream_start - Called when a stream is created.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ *
+ * DESCRIPTION
+ * It is called when a stream is started. This callback can fail by
+ * returning a negative value. It will be considered as a critical error
+ * by HAProxy which disabled the listener for a short time.
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, any other value otherwise.
+ */
+static int flt_ot_stream_start(struct stream *s, struct filter *f)
+{
+ char *err = NULL;
+ int retval = FLT_OT_RET_OK;
+
+ FLT_OT_FUNC("%p, %p", s, f);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN(retval);
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_stream_set_backend - Called when a backend is set for a stream.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * be -
+ *
+ * DESCRIPTION
+ * It is called when a backend is set for a stream. This callbacks will be
+ * called for all filters attached to a stream (frontend and backend). Note
+ * this callback is not called if the frontend and the backend are the same.
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, any other value otherwise.
+ */
+static int flt_ot_stream_set_backend(struct stream *s, struct filter *f, struct proxy *be)
+{
+ char *err = NULL;
+ int retval = FLT_OT_RET_OK;
+
+ FLT_OT_FUNC("%p, %p, %p", s, f, be);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN(retval);
+
+ FLT_OT_DBG(3, "backend: %s", be->id);
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_stream_stop - Called when a stream is destroyed.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ *
+ * DESCRIPTION
+ * It is called when a stream is stopped. This callback always succeed.
+ * Anyway, it is too late to return an error.
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_stream_stop(struct stream *s, struct filter *f)
+{
+ char *err = NULL;
+
+ FLT_OT_FUNC("%p, %p", s, f);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN();
+
+ flt_ot_return_void(f, &err);
+
+ FLT_OT_RETURN();
+}
+
+#endif /* DEBUG_OT */
+
+
+/***
+ * NAME
+ * flt_ot_detach - Called when a filter instance is detach from a stream, just before its destruction.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ *
+ * DESCRIPTION
+ * It is called when a filter instance is detached from a stream, before its
+ * destruction. This happens when the stream is stopped for filters defined
+ * on the stream's frontend and when the analyze ends for filters defined on
+ * the stream's backend.
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_detach(struct stream *s, struct filter *f)
+{
+ FLT_OT_FUNC("%p, %p", s, f);
+
+ FLT_OT_DBG(2, "filter '%s', type: %s", FLT_OT_CONF(f)->id, flt_ot_type(f));
+
+ flt_ot_runtime_context_free(f);
+
+ FLT_OT_RETURN();
+}
+
+
+/***
+ * NAME
+ * flt_ot_check_timeouts - Called when a stream is woken up because of an expired timer.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_check_timeouts(struct stream *s, struct filter *f)
+{
+ char *err = NULL;
+
+ FLT_OT_FUNC("%p, %p", s, f);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN();
+
+ s->pending_events |= TASK_WOKEN_MSG;
+
+ flt_ot_return_void(f, &err);
+
+ FLT_OT_RETURN();
+}
+
+
+/***
+ * NAME
+ * flt_ot_channel_start_analyze - Called when analyze starts for a given channel.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * chn -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, 0 if it needs to wait,
+ * any other value otherwise.
+ */
+static int flt_ot_channel_start_analyze(struct stream *s, struct filter *f, struct channel *chn)
+{
+ char *err = NULL;
+ int retval;
+
+ FLT_OT_FUNC("%p, %p, %p", s, f, chn);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, (chn->flags & CF_ISRESP) ? FLT_OT_EVENT_RES_SERVER_SESS_START : FLT_OT_EVENT_REQ_CLIENT_SESS_START)))
+ FLT_OT_RETURN(FLT_OT_RET_OK);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s)", flt_ot_chn_label(chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s));
+
+ if (chn->flags & CF_ISRESP) {
+ /* The response channel. */
+ chn->analysers |= f->pre_analyzers & AN_RES_ALL;
+
+ /* The event 'on-server-session-start'. */
+ retval = flt_ot_event_run(s, f, chn, FLT_OT_EVENT_RES_SERVER_SESS_START, &err);
+ if (retval == FLT_OT_RET_WAIT) {
+ channel_dont_read(chn);
+ channel_dont_close(chn);
+ }
+ } else {
+ /* The request channel. */
+ chn->analysers |= f->pre_analyzers & AN_REQ_ALL;
+
+ /* The event 'on-client-session-start'. */
+ retval = flt_ot_event_run(s, f, chn, FLT_OT_EVENT_REQ_CLIENT_SESS_START, &err);
+ }
+
+// register_data_filter(s, chn, f);
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_channel_pre_analyze - Called before a processing happens on a given channel.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * chn - the channel on which the analyzing is done
+ * an_bit - the analyzer id
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, 0 if it needs to wait,
+ * any other value otherwise.
+ */
+static int flt_ot_channel_pre_analyze(struct stream *s, struct filter *f, struct channel *chn, uint an_bit)
+{
+ char *err = NULL;
+ int i, event = -1, retval;
+
+ FLT_OT_FUNC("%p, %p, %p, 0x%08x", s, f, chn, an_bit);
+
+ for (i = 0; i < FLT_OT_TABLESIZE(flt_ot_event_data); i++)
+ if (flt_ot_event_data[i].an_bit == an_bit) {
+ event = i;
+
+ break;
+ }
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, event)))
+ FLT_OT_RETURN(FLT_OT_RET_OK);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s), analyzer: %s", flt_ot_chn_label(chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s), flt_ot_analyzer(an_bit));
+
+ retval = flt_ot_event_run(s, f, chn, event, &err);
+
+ if ((retval == FLT_OT_RET_WAIT) && (chn->flags & CF_ISRESP)) {
+ channel_dont_read(chn);
+ channel_dont_close(chn);
+ }
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_channel_post_analyze - Called after a processing happens on a given channel.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * chn -
+ * an_bit -
+ *
+ * DESCRIPTION
+ * This function, for its part, is not resumable. It is called when a
+ * filterable analyzer finishes its processing. So it called once for
+ * the same analyzer.
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, 0 if it needs to wait,
+ * any other value otherwise.
+ */
+static int flt_ot_channel_post_analyze(struct stream *s, struct filter *f, struct channel *chn, uint an_bit)
+{
+ char *err = NULL;
+ int i, event = -1, retval;
+
+ FLT_OT_FUNC("%p, %p, %p, 0x%08x", s, f, chn, an_bit);
+
+ for (i = 0; i < FLT_OT_TABLESIZE(flt_ot_event_data); i++)
+ if (flt_ot_event_data[i].an_bit == an_bit) {
+ event = i;
+
+ break;
+ }
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, event)))
+ FLT_OT_RETURN(FLT_OT_RET_OK);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s), analyzer: %s", flt_ot_chn_label(chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s), flt_ot_analyzer(an_bit));
+
+ retval = flt_ot_event_run(s, f, chn, event, &err);
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_channel_end_analyze - Called when analyze ends for a given channel.
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * chn -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, 0 if it needs to wait,
+ * any other value otherwise.
+ */
+static int flt_ot_channel_end_analyze(struct stream *s, struct filter *f, struct channel *chn)
+{
+ char *err = NULL;
+ int rc, retval;
+
+ FLT_OT_FUNC("%p, %p, %p", s, f, chn);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, (chn->flags & CF_ISRESP) ? FLT_OT_EVENT_RES_SERVER_SESS_END : FLT_OT_EVENT_REQ_CLIENT_SESS_END)))
+ FLT_OT_RETURN(FLT_OT_RET_OK);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s)", flt_ot_chn_label(chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s));
+
+ if (chn->flags & CF_ISRESP) {
+ /* The response channel, event 'on-server-session-end'. */
+ retval = flt_ot_event_run(s, f, chn, FLT_OT_EVENT_RES_SERVER_SESS_END, &err);
+ } else {
+ /* The request channel, event 'on-client-session-end'. */
+ retval = flt_ot_event_run(s, f, chn, FLT_OT_EVENT_REQ_CLIENT_SESS_END, &err);
+
+ /*
+ * In case an event using server response is defined and not
+ * executed, event 'on-server-unavailable' is called here.
+ */
+ if ((FLT_OT_CONF(f)->tracer->analyzers & AN_RES_ALL) && !(FLT_OT_RT_CTX(f->ctx)->analyzers & AN_RES_ALL)) {
+ rc = flt_ot_event_run(s, f, chn, FLT_OT_EVENT_REQ_SERVER_UNAVAILABLE, &err);
+ if ((retval == FLT_OT_RET_OK) && (rc != FLT_OT_RET_OK))
+ retval = rc;
+ }
+ }
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+#ifdef DEBUG_OT
+
+/***
+ * NAME
+ * flt_ot_http_headers -
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * msg -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, 0 if it needs to wait,
+ * any other value otherwise.
+ */
+static int flt_ot_http_headers(struct stream *s, struct filter *f, struct http_msg *msg)
+{
+ char *err = NULL;
+ struct htx *htx = htxbuf(&(msg->chn->buf));
+ struct htx_sl *sl = http_get_stline(htx);
+ int retval = FLT_OT_RET_OK;
+
+ FLT_OT_FUNC("%p, %p, %p", s, f, msg);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN(retval);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s), %.*s %.*s %.*s", flt_ot_chn_label(msg->chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s), HTX_SL_P1_LEN(sl), HTX_SL_P1_PTR(sl), HTX_SL_P2_LEN(sl), HTX_SL_P2_PTR(sl), HTX_SL_P3_LEN(sl), HTX_SL_P3_PTR(sl));
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_http_payload -
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * msg -
+ * offset -
+ * len -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, any other value otherwise.
+ */
+static int flt_ot_http_payload(struct stream *s, struct filter *f, struct http_msg *msg, uint offset, uint len)
+{
+ char *err = NULL;
+ int retval = len;
+
+ FLT_OT_FUNC("%p, %p, %p, %u, %u", s, f, msg, offset, len);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN(len);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s), offset: %u, len: %u, forward: %d", flt_ot_chn_label(msg->chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s), offset, len, retval);
+
+ if (retval != len)
+ task_wakeup(s->task, TASK_WOKEN_MSG);
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_http_end -
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * msg -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, 0 if it needs to wait,
+ * any other value otherwise.
+ */
+static int flt_ot_http_end(struct stream *s, struct filter *f, struct http_msg *msg)
+{
+ char *err = NULL;
+ int retval = FLT_OT_RET_OK;
+
+ FLT_OT_FUNC("%p, %p, %p", s, f, msg);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN(retval);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s)", flt_ot_chn_label(msg->chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s));
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+
+/***
+ * NAME
+ * flt_ot_http_reset -
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * msg -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_http_reset(struct stream *s, struct filter *f, struct http_msg *msg)
+{
+ char *err = NULL;
+
+ FLT_OT_FUNC("%p, %p, %p", s, f, msg);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN();
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s)", flt_ot_chn_label(msg->chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s));
+
+ flt_ot_return_void(f, &err);
+
+ FLT_OT_RETURN();
+}
+
+
+/***
+ * NAME
+ * flt_ot_http_reply -
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * status -
+ * msg -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * This function does not return a value.
+ */
+static void flt_ot_http_reply(struct stream *s, struct filter *f, short status, const struct buffer *msg)
+{
+ char *err = NULL;
+
+ FLT_OT_FUNC("%p, %p, %hd, %p", s, f, status, msg);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN();
+
+ FLT_OT_DBG(3, "channel: -, mode: %s (%s)", flt_ot_pr_mode(s), flt_ot_stream_pos(s));
+
+ flt_ot_return_void(f, &err);
+
+ FLT_OT_RETURN();
+}
+
+
+/***
+ * NAME
+ * flt_ot_tcp_payload -
+ *
+ * ARGUMENTS
+ * s -
+ * f -
+ * chn -
+ * offset -
+ * len -
+ *
+ * DESCRIPTION
+ * -
+ *
+ * RETURN VALUE
+ * Returns a negative value if an error occurs, any other value otherwise.
+ */
+static int flt_ot_tcp_payload(struct stream *s, struct filter *f, struct channel *chn, uint offset, uint len)
+{
+ char *err = NULL;
+ int retval = len;
+
+ FLT_OT_FUNC("%p, %p, %p, %u, %u", s, f, chn, offset, len);
+
+ if (flt_ot_is_disabled(f FLT_OT_DBG_ARGS(, -1)))
+ FLT_OT_RETURN(len);
+
+ FLT_OT_DBG(3, "channel: %s, mode: %s (%s), offset: %u, len: %u, forward: %d", flt_ot_chn_label(chn), flt_ot_pr_mode(s), flt_ot_stream_pos(s), offset, len, retval);
+
+ if (s->flags & SF_HTX) {
+ } else {
+ }
+
+ if (retval != len)
+ task_wakeup(s->task, TASK_WOKEN_MSG);
+
+ FLT_OT_RETURN(flt_ot_return_int(f, &err, retval));
+}
+
+#endif /* DEBUG_OT */
+
+
+struct flt_ops flt_ot_ops = {
+ /* Callbacks to manage the filter lifecycle. */
+ .init = flt_ot_init,
+ .deinit = flt_ot_deinit,
+ .check = flt_ot_check,
+ .init_per_thread = FLT_OT_DBG_IFDEF(flt_ot_init_per_thread, NULL),
+ .deinit_per_thread = FLT_OT_DBG_IFDEF(flt_ot_deinit_per_thread, NULL),
+
+ /* Stream callbacks. */
+ .attach = flt_ot_attach,
+ .stream_start = FLT_OT_DBG_IFDEF(flt_ot_stream_start, NULL),
+ .stream_set_backend = FLT_OT_DBG_IFDEF(flt_ot_stream_set_backend, NULL),
+ .stream_stop = FLT_OT_DBG_IFDEF(flt_ot_stream_stop, NULL),
+ .detach = flt_ot_detach,
+ .check_timeouts = flt_ot_check_timeouts,
+
+ /* Channel callbacks. */
+ .channel_start_analyze = flt_ot_channel_start_analyze,
+ .channel_pre_analyze = flt_ot_channel_pre_analyze,
+ .channel_post_analyze = flt_ot_channel_post_analyze,
+ .channel_end_analyze = flt_ot_channel_end_analyze,
+
+ /* HTTP callbacks. */
+ .http_headers = FLT_OT_DBG_IFDEF(flt_ot_http_headers, NULL),
+ .http_payload = FLT_OT_DBG_IFDEF(flt_ot_http_payload, NULL),
+ .http_end = FLT_OT_DBG_IFDEF(flt_ot_http_end, NULL),
+ .http_reset = FLT_OT_DBG_IFDEF(flt_ot_http_reset, NULL),
+ .http_reply = FLT_OT_DBG_IFDEF(flt_ot_http_reply, NULL),
+
+ /* TCP callbacks. */
+ .tcp_payload = FLT_OT_DBG_IFDEF(flt_ot_tcp_payload, NULL)
+};
+
+
+REGISTER_BUILD_OPTS("Built with OpenTracing support.");
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ *
+ * vi: noexpandtab shiftwidth=8 tabstop=8
+ */