Added support for trailing metadata

8 files changed, 182 insertions, 105 deletions

diff --git a/src/core/ext/load_reporting/load_reporting.c b/src/core/ext/load_reporting/load_reporting.c
index fb32685dc9..60082dbaaa 100644
--- a/src/core/ext/load_reporting/load_reporting.c
+++ b/src/core/ext/load_reporting/load_reporting.c
@@ -44,32 +44,32 @@
 
 struct grpc_load_reporting_config {
   grpc_load_reporting_fn fn;
-  void *data;
+  void *user_data;
 };
 
 grpc_load_reporting_config *grpc_load_reporting_config_create(
-    grpc_load_reporting_fn fn, void *data) {
+    grpc_load_reporting_fn fn, void *user_data) {
+  GPR_ASSERT(fn != NULL);
   grpc_load_reporting_config *lrc =
       gpr_malloc(sizeof(grpc_load_reporting_config));
   lrc->fn = fn;
-  lrc->data = data;
+  lrc->user_data = user_data;
   return lrc;
 }
 
 grpc_load_reporting_config *grpc_load_reporting_config_copy(
     grpc_load_reporting_config *src) {
-  return grpc_load_reporting_config_create(src->fn, src->data);
+  return grpc_load_reporting_config_create(src->fn, src->user_data);
 }
 
 void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc) {
   gpr_free(lrc);
 }
 
-void grpc_load_reporting_config_call(grpc_load_reporting_config *lrc,
-                                     const grpc_call_stats *stats) {
-  if (lrc->fn != NULL) {
-    lrc->fn(stats, lrc->data);
-  }
+void grpc_load_reporting_config_call(
+    grpc_load_reporting_config *lrc,
+    const grpc_load_reporting_call_data *call_data) {
+  lrc->fn(call_data, lrc->user_data);
 }
 
 static bool is_load_reporting_enabled(const grpc_channel_args *a) {
@@ -102,7 +102,7 @@ static void *lrd_arg_copy(void *p) {
 static int lrd_arg_cmp(void *a, void *b) {
   grpc_load_reporting_config *lhs = a;
   grpc_load_reporting_config *rhs = b;
-  return !(lhs->fn == rhs->fn && lhs->data == rhs->data);
+  return !(lhs->fn == rhs->fn && lhs->user_data == rhs->user_data);
 }
 
 static const grpc_arg_pointer_vtable lrd_ptr_vtable = {
diff --git a/src/core/ext/load_reporting/load_reporting.h b/src/core/ext/load_reporting/load_reporting.h
index 806af2bda7..316cd89bd7 100644
--- a/src/core/ext/load_reporting/load_reporting.h
+++ b/src/core/ext/load_reporting/load_reporting.h
@@ -39,24 +39,35 @@
 
 typedef struct grpc_load_reporting_config grpc_load_reporting_config;
 
+/** Call information to be passed to the provided load reporting function upon
+ * completion of the call */
+typedef struct grpc_load_reporting_call_data {
+  const grpc_call_stats *stats;   /**< Stats for the call */
+  const char *trailing_md_string; /**< LR trailing metadata info */
+} grpc_load_reporting_call_data;
+
 /** Custom function to be called by the load reporting filter. */
-typedef void (*grpc_load_reporting_fn)(const grpc_call_stats *stats,
-                                       void *data);
+typedef void (*grpc_load_reporting_fn)(
+    const grpc_load_reporting_call_data *call_data, void *user_data);
 
-/** Register \a fn as the function to be invoked by the load reporting filter,
- * passing \a data alongisde the call stats */
+/** Register \a fn as the function to be invoked by the load reporting filter.
+ * \a fn will be invoked at the beginning and at the end of the call.
+ *
+ * For the first invocation, \a fn's first argument
+ * (grpc_load_reporting_call_data*) will be NULL. \a user_data is always passed
+ * as-is. */
 grpc_load_reporting_config *grpc_load_reporting_config_create(
-    grpc_load_reporting_fn fn, void *data);
+    grpc_load_reporting_fn fn, void *user_data);
 
 grpc_load_reporting_config *grpc_load_reporting_config_copy(
     grpc_load_reporting_config *src);
 
 void grpc_load_reporting_config_destroy(grpc_load_reporting_config *lrc);
 
-/** Invoke the function registered by \a grpc_load_reporting_init, passing it \a
- * stats as one of the arguments (see \a load_reporting_fn). */
-void grpc_load_reporting_config_call(grpc_load_reporting_config *lrc,
-                                     const grpc_call_stats *stats);
+/** Invoke the function registered by \a grpc_load_reporting_init. */
+void grpc_load_reporting_config_call(
+    grpc_load_reporting_config *lrc,
+    const grpc_load_reporting_call_data *call_data);
 
 /** Return a \a grpc_arg enabling load reporting */
 grpc_arg grpc_load_reporting_config_create_arg(grpc_load_reporting_config *lrc);
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index 902c110212..f49730fac3 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -32,6 +32,7 @@
  */
 
 #include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 #include <string.h>
 
@@ -39,28 +40,40 @@
 #include "src/core/ext/load_reporting/load_reporting_filter.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/transport/static_metadata.h"
 
-typedef struct call_data { void *dummy; } call_data;
+typedef struct call_data { const char *trailing_md_string; } call_data;
 typedef struct channel_data {
   gpr_mu mu;
   grpc_load_reporting_config *lrc;
 } channel_data;
 
+static void invoke_lr_fn_locked(grpc_load_reporting_config *lrc,
+                                grpc_load_reporting_call_data *lr_call_data) {
+  GPR_TIMER_BEGIN("load_reporting_config_fn", 0);
+  grpc_load_reporting_config_call(lrc, lr_call_data);
+  GPR_TIMER_END("load_reporting_config_fn", 0);
+}
+
 /* Constructor for call_data */
 static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                           grpc_call_element_args *args) {}
+                           grpc_call_element_args *args) {
+  call_data *calld = elem->call_data;
+  memset(calld, 0, sizeof(call_data));
+}
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                               const grpc_call_stats *stats, void *ignored) {
   channel_data *chand = elem->channel_data;
-  if (chand->lrc != NULL) {
-    GPR_TIMER_BEGIN("load_reporting_filter", 0);
-    gpr_mu_lock(&chand->mu);
-    grpc_load_reporting_config_call(chand->lrc, stats);
-    gpr_mu_unlock(&chand->mu);
-    GPR_TIMER_END("load_reporting_filter", 0);
-  }
+  call_data *calld = elem->call_data;
+
+  grpc_load_reporting_call_data lr_call_data = {stats,
+                                                calld->trailing_md_string};
+
+  gpr_mu_lock(&chand->mu);
+  invoke_lr_fn_locked(chand->lrc, &lr_call_data);
+  gpr_mu_unlock(&chand->mu);
 }
 
 /* Constructor for channel_data */
@@ -84,6 +97,10 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
     }
   }
   GPR_ASSERT(chand->lrc != NULL); /* arg actually found */
+
+  gpr_mu_lock(&chand->mu);
+  invoke_lr_fn_locked(chand->lrc, NULL);
+  gpr_mu_unlock(&chand->mu);
 }
 
 /* Destructor for channel data */
@@ -94,8 +111,34 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   grpc_load_reporting_config_destroy(chand->lrc);
 }
 
+static grpc_mdelem *lr_trailing_md_filter(void *user_data, grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+
+  if (md->key == GRPC_MDSTR_LOAD_REPORTING) {
+    calld->trailing_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
+    return NULL;
+  }
+
+  return md;
+}
+
+static void lr_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
+                                         grpc_call_element *elem,
+                                         grpc_transport_stream_op *op) {
+  GPR_TIMER_BEGIN("lr_start_transport_stream_op", 0);
+
+  if (op->send_trailing_metadata) {
+    grpc_metadata_batch_filter(op->send_trailing_metadata,
+                               lr_trailing_md_filter, elem);
+  }
+  grpc_call_next_op(exec_ctx, elem, op);
+
+  GPR_TIMER_END("lr_start_transport_stream_op", 0);
+}
+
 const grpc_channel_filter grpc_load_reporting_filter = {
-    grpc_call_next_op,
+    lr_start_transport_stream_op,
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
diff --git a/src/core/lib/transport/static_metadata.c b/src/core/lib/transport/static_metadata.c
index 73b0041fd4..c5f16e530d 100644
--- a/src/core/lib/transport/static_metadata.c
+++ b/src/core/lib/transport/static_metadata.c
@@ -48,7 +48,7 @@ uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT] = {
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 4, 8, 6, 2, 4, 8, 6, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
 const uint8_t grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2] =
     {11, 35, 10, 35, 12, 35, 12, 49, 13, 35, 14, 35, 15, 35, 16, 35, 17, 35,
@@ -56,10 +56,10 @@ const uint8_t grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2] =
      30, 18, 30, 35, 31, 35, 32, 35, 36, 35, 37, 35, 38, 35, 39, 35, 42, 33,
      42, 34, 42, 48, 42, 53, 42, 54, 42, 55, 42, 56, 43, 33, 43, 48, 43, 53,
      46, 0,  46, 1,  46, 2,  50, 35, 57, 35, 58, 35, 59, 35, 60, 35, 61, 35,
-     62, 35, 63, 35, 64, 35, 65, 35, 66, 40, 66, 68, 66, 71, 67, 79, 67, 80,
-     69, 35, 70, 35, 72, 35, 73, 35, 74, 35, 75, 35, 76, 41, 76, 51, 76, 52,
-     77, 35, 78, 35, 81, 3,  81, 4,  81, 5,  81, 6,  81, 7,  81, 8,  81, 9,
-     82, 35, 83, 84, 85, 35, 86, 35, 87, 35, 88, 35, 89, 35};
+     62, 35, 63, 35, 64, 35, 65, 35, 66, 35, 67, 40, 67, 69, 67, 72, 68, 80,
+     68, 81, 70, 35, 71, 35, 73, 35, 74, 35, 75, 35, 76, 35, 77, 41, 77, 51,
+     77, 52, 78, 35, 79, 35, 82, 3,  82, 4,  82, 5,  82, 6,  82, 7,  82, 8,
+     82, 9,  83, 35, 84, 85, 86, 35, 87, 35, 88, 35, 89, 35, 90, 35};
 
 const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT] = {
     "0",
@@ -126,6 +126,7 @@ const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT] = {
     "if-unmodified-since",
     "last-modified",
     "link",
+    "load-reporting",
     "location",
     "max-forwards",
     ":method",
diff --git a/src/core/lib/transport/static_metadata.h b/src/core/lib/transport/static_metadata.h
index f9d8bcdc8f..5ff0d2f3bc 100644
--- a/src/core/lib/transport/static_metadata.h
+++ b/src/core/lib/transport/static_metadata.h
@@ -44,7 +44,7 @@
 
 #include "src/core/lib/transport/metadata.h"
 
-#define GRPC_STATIC_MDSTR_COUNT 90
+#define GRPC_STATIC_MDSTR_COUNT 91
 extern grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 /* "0" */
 #define GRPC_MDSTR_0 (&grpc_static_mdstr_table[0])
@@ -175,60 +175,62 @@ extern grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 #define GRPC_MDSTR_LAST_MODIFIED (&grpc_static_mdstr_table[62])
 /* "link" */
 #define GRPC_MDSTR_LINK (&grpc_static_mdstr_table[63])
+/* "load-reporting" */
+#define GRPC_MDSTR_LOAD_REPORTING (&grpc_static_mdstr_table[64])
 /* "location" */
-#define GRPC_MDSTR_LOCATION (&grpc_static_mdstr_table[64])
+#define GRPC_MDSTR_LOCATION (&grpc_static_mdstr_table[65])
 /* "max-forwards" */
-#define GRPC_MDSTR_MAX_FORWARDS (&grpc_static_mdstr_table[65])
+#define GRPC_MDSTR_MAX_FORWARDS (&grpc_static_mdstr_table[66])
 /* ":method" */
-#define GRPC_MDSTR_METHOD (&grpc_static_mdstr_table[66])
+#define GRPC_MDSTR_METHOD (&grpc_static_mdstr_table[67])
 /* ":path" */
-#define GRPC_MDSTR_PATH (&grpc_static_mdstr_table[67])
+#define GRPC_MDSTR_PATH (&grpc_static_mdstr_table[68])
 /* "POST" */
-#define GRPC_MDSTR_POST (&grpc_static_mdstr_table[68])
+#define GRPC_MDSTR_POST (&grpc_static_mdstr_table[69])
 /* "proxy-authenticate" */
-#define GRPC_MDSTR_PROXY_AUTHENTICATE (&grpc_static_mdstr_table[69])
+#define GRPC_MDSTR_PROXY_AUTHENTICATE (&grpc_static_mdstr_table[70])
 /* "proxy-authorization" */
-#define GRPC_MDSTR_PROXY_AUTHORIZATION (&grpc_static_mdstr_table[70])
+#define GRPC_MDSTR_PROXY_AUTHORIZATION (&grpc_static_mdstr_table[71])
 /* "PUT" */
-#define GRPC_MDSTR_PUT (&grpc_static_mdstr_table[71])
+#define GRPC_MDSTR_PUT (&grpc_static_mdstr_table[72])
 /* "range" */
-#define GRPC_MDSTR_RANGE (&grpc_static_mdstr_table[72])
+#define GRPC_MDSTR_RANGE (&grpc_static_mdstr_table[73])
 /* "referer" */
-#define GRPC_MDSTR_REFERER (&grpc_static_mdstr_table[73])
+#define GRPC_MDSTR_REFERER (&grpc_static_mdstr_table[74])
 /* "refresh" */
-#define GRPC_MDSTR_REFRESH (&grpc_static_mdstr_table[74])
+#define GRPC_MDSTR_REFRESH (&grpc_static_mdstr_table[75])
 /* "retry-after" */
-#define GRPC_MDSTR_RETRY_AFTER (&grpc_static_mdstr_table[75])
+#define GRPC_MDSTR_RETRY_AFTER (&grpc_static_mdstr_table[76])
 /* ":scheme" */
-#define GRPC_MDSTR_SCHEME (&grpc_static_mdstr_table[76])
+#define GRPC_MDSTR_SCHEME (&grpc_static_mdstr_table[77])
 /* "server" */
-#define GRPC_MDSTR_SERVER (&grpc_static_mdstr_table[77])
+#define GRPC_MDSTR_SERVER (&grpc_static_mdstr_table[78])
 /* "set-cookie" */
-#define GRPC_MDSTR_SET_COOKIE (&grpc_static_mdstr_table[78])
+#define GRPC_MDSTR_SET_COOKIE (&grpc_static_mdstr_table[79])
 /* "/" */
-#define GRPC_MDSTR_SLASH (&grpc_static_mdstr_table[79])
+#define GRPC_MDSTR_SLASH (&grpc_static_mdstr_table[80])
 /* "/index.html" */
-#define GRPC_MDSTR_SLASH_INDEX_DOT_HTML (&grpc_static_mdstr_table[80])
+#define GRPC_MDSTR_SLASH_INDEX_DOT_HTML (&grpc_static_mdstr_table[81])
 /* ":status" */
-#define GRPC_MDSTR_STATUS (&grpc_static_mdstr_table[81])
+#define GRPC_MDSTR_STATUS (&grpc_static_mdstr_table[82])
 /* "strict-transport-security" */
-#define GRPC_MDSTR_STRICT_TRANSPORT_SECURITY (&grpc_static_mdstr_table[82])
+#define GRPC_MDSTR_STRICT_TRANSPORT_SECURITY (&grpc_static_mdstr_table[83])
 /* "te" */
-#define GRPC_MDSTR_TE (&grpc_static_mdstr_table[83])
+#define GRPC_MDSTR_TE (&grpc_static_mdstr_table[84])
 /* "trailers" */
-#define GRPC_MDSTR_TRAILERS (&grpc_static_mdstr_table[84])
+#define GRPC_MDSTR_TRAILERS (&grpc_static_mdstr_table[85])
 /* "transfer-encoding" */
-#define GRPC_MDSTR_TRANSFER_ENCODING (&grpc_static_mdstr_table[85])
+#define GRPC_MDSTR_TRANSFER_ENCODING (&grpc_static_mdstr_table[86])
 /* "user-agent" */
-#define GRPC_MDSTR_USER_AGENT (&grpc_static_mdstr_table[86])
+#define GRPC_MDSTR_USER_AGENT (&grpc_static_mdstr_table[87])
 /* "vary" */
-#define GRPC_MDSTR_VARY (&grpc_static_mdstr_table[87])
+#define GRPC_MDSTR_VARY (&grpc_static_mdstr_table[88])
 /* "via" */
-#define GRPC_MDSTR_VIA (&grpc_static_mdstr_table[88])
+#define GRPC_MDSTR_VIA (&grpc_static_mdstr_table[89])
 /* "www-authenticate" */
-#define GRPC_MDSTR_WWW_AUTHENTICATE (&grpc_static_mdstr_table[89])
+#define GRPC_MDSTR_WWW_AUTHENTICATE (&grpc_static_mdstr_table[90])
 
-#define GRPC_STATIC_MDELEM_COUNT 79
+#define GRPC_STATIC_MDELEM_COUNT 80
 extern grpc_mdelem grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT];
 extern uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT];
 /* "accept-charset": "" */
@@ -333,71 +335,73 @@ extern uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT];
 #define GRPC_MDELEM_LAST_MODIFIED_EMPTY (&grpc_static_mdelem_table[45])
 /* "link": "" */
 #define GRPC_MDELEM_LINK_EMPTY (&grpc_static_mdelem_table[46])
+/* "load-reporting": "" */
+#define GRPC_MDELEM_LOAD_REPORTING_EMPTY (&grpc_static_mdelem_table[47])
 /* "location": "" */
-#define GRPC_MDELEM_LOCATION_EMPTY (&grpc_static_mdelem_table[47])
+#define GRPC_MDELEM_LOCATION_EMPTY (&grpc_static_mdelem_table[48])
 /* "max-forwards": "" */
-#define GRPC_MDELEM_MAX_FORWARDS_EMPTY (&grpc_static_mdelem_table[48])
+#define GRPC_MDELEM_MAX_FORWARDS_EMPTY (&grpc_static_mdelem_table[49])
 /* ":method": "GET" */
-#define GRPC_MDELEM_METHOD_GET (&grpc_static_mdelem_table[49])
+#define GRPC_MDELEM_METHOD_GET (&grpc_static_mdelem_table[50])
 /* ":method": "POST" */
-#define GRPC_MDELEM_METHOD_POST (&grpc_static_mdelem_table[50])
+#define GRPC_MDELEM_METHOD_POST (&grpc_static_mdelem_table[51])
 /* ":method": "PUT" */
-#define GRPC_MDELEM_METHOD_PUT (&grpc_static_mdelem_table[51])
+#define GRPC_MDELEM_METHOD_PUT (&grpc_static_mdelem_table[52])
 /* ":path": "/" */
-#define GRPC_MDELEM_PATH_SLASH (&grpc_static_mdelem_table[52])
+#define GRPC_MDELEM_PATH_SLASH (&grpc_static_mdelem_table[53])
 /* ":path": "/index.html" */
-#define GRPC_MDELEM_PATH_SLASH_INDEX_DOT_HTML (&grpc_static_mdelem_table[53])
+#define GRPC_MDELEM_PATH_SLASH_INDEX_DOT_HTML (&grpc_static_mdelem_table[54])
 /* "proxy-authenticate": "" */
-#define GRPC_MDELEM_PROXY_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[54])
+#define GRPC_MDELEM_PROXY_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[55])
 /* "proxy-authorization": "" */
-#define GRPC_MDELEM_PROXY_AUTHORIZATION_EMPTY (&grpc_static_mdelem_table[55])
+#define GRPC_MDELEM_PROXY_AUTHORIZATION_EMPTY (&grpc_static_mdelem_table[56])
 /* "range": "" */
-#define GRPC_MDELEM_RANGE_EMPTY (&grpc_static_mdelem_table[56])
+#define GRPC_MDELEM_RANGE_EMPTY (&grpc_static_mdelem_table[57])
 /* "referer": "" */
-#define GRPC_MDELEM_REFERER_EMPTY (&grpc_static_mdelem_table[57])
+#define GRPC_MDELEM_REFERER_EMPTY (&grpc_static_mdelem_table[58])
 /* "refresh": "" */
-#define GRPC_MDELEM_REFRESH_EMPTY (&grpc_static_mdelem_table[58])
+#define GRPC_MDELEM_REFRESH_EMPTY (&grpc_static_mdelem_table[59])
 /* "retry-after": "" */
-#define GRPC_MDELEM_RETRY_AFTER_EMPTY (&grpc_static_mdelem_table[59])
+#define GRPC_MDELEM_RETRY_AFTER_EMPTY (&grpc_static_mdelem_table[60])
 /* ":scheme": "grpc" */
-#define GRPC_MDELEM_SCHEME_GRPC (&grpc_static_mdelem_table[60])
+#define GRPC_MDELEM_SCHEME_GRPC (&grpc_static_mdelem_table[61])
 /* ":scheme": "http" */
-#define GRPC_MDELEM_SCHEME_HTTP (&grpc_static_mdelem_table[61])
+#define GRPC_MDELEM_SCHEME_HTTP (&grpc_static_mdelem_table[62])
 /* ":scheme": "https" */
-#define GRPC_MDELEM_SCHEME_HTTPS (&grpc_static_mdelem_table[62])
+#define GRPC_MDELEM_SCHEME_HTTPS (&grpc_static_mdelem_table[63])
 /* "server": "" */
-#define GRPC_MDELEM_SERVER_EMPTY (&grpc_static_mdelem_table[63])
+#define GRPC_MDELEM_SERVER_EMPTY (&grpc_static_mdelem_table[64])
 /* "set-cookie": "" */
-#define GRPC_MDELEM_SET_COOKIE_EMPTY (&grpc_static_mdelem_table[64])
+#define GRPC_MDELEM_SET_COOKIE_EMPTY (&grpc_static_mdelem_table[65])
 /* ":status": "200" */
-#define GRPC_MDELEM_STATUS_200 (&grpc_static_mdelem_table[65])
+#define GRPC_MDELEM_STATUS_200 (&grpc_static_mdelem_table[66])
 /* ":status": "204" */
-#define GRPC_MDELEM_STATUS_204 (&grpc_static_mdelem_table[66])
+#define GRPC_MDELEM_STATUS_204 (&grpc_static_mdelem_table[67])
 /* ":status": "206" */
-#define GRPC_MDELEM_STATUS_206 (&grpc_static_mdelem_table[67])
+#define GRPC_MDELEM_STATUS_206 (&grpc_static_mdelem_table[68])
 /* ":status": "304" */
-#define GRPC_MDELEM_STATUS_304 (&grpc_static_mdelem_table[68])
+#define GRPC_MDELEM_STATUS_304 (&grpc_static_mdelem_table[69])
 /* ":status": "400" */
-#define GRPC_MDELEM_STATUS_400 (&grpc_static_mdelem_table[69])
+#define GRPC_MDELEM_STATUS_400 (&grpc_static_mdelem_table[70])
 /* ":status": "404" */
-#define GRPC_MDELEM_STATUS_404 (&grpc_static_mdelem_table[70])
+#define GRPC_MDELEM_STATUS_404 (&grpc_static_mdelem_table[71])
 /* ":status": "500" */
-#define GRPC_MDELEM_STATUS_500 (&grpc_static_mdelem_table[71])
+#define GRPC_MDELEM_STATUS_500 (&grpc_static_mdelem_table[72])
 /* "strict-transport-security": "" */
 #define GRPC_MDELEM_STRICT_TRANSPORT_SECURITY_EMPTY \
-  (&grpc_static_mdelem_table[72])
+  (&grpc_static_mdelem_table[73])
 /* "te": "trailers" */
-#define GRPC_MDELEM_TE_TRAILERS (&grpc_static_mdelem_table[73])
+#define GRPC_MDELEM_TE_TRAILERS (&grpc_static_mdelem_table[74])
 /* "transfer-encoding": "" */
-#define GRPC_MDELEM_TRANSFER_ENCODING_EMPTY (&grpc_static_mdelem_table[74])
+#define GRPC_MDELEM_TRANSFER_ENCODING_EMPTY (&grpc_static_mdelem_table[75])
 /* "user-agent": "" */
-#define GRPC_MDELEM_USER_AGENT_EMPTY (&grpc_static_mdelem_table[75])
+#define GRPC_MDELEM_USER_AGENT_EMPTY (&grpc_static_mdelem_table[76])
 /* "vary": "" */
-#define GRPC_MDELEM_VARY_EMPTY (&grpc_static_mdelem_table[76])
+#define GRPC_MDELEM_VARY_EMPTY (&grpc_static_mdelem_table[77])
 /* "via": "" */
-#define GRPC_MDELEM_VIA_EMPTY (&grpc_static_mdelem_table[77])
+#define GRPC_MDELEM_VIA_EMPTY (&grpc_static_mdelem_table[78])
 /* "www-authenticate": "" */
-#define GRPC_MDELEM_WWW_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[78])
+#define GRPC_MDELEM_WWW_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[79])
 
 extern const uint8_t
     grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2];
diff --git a/test/core/end2end/fixtures/h2_loadreporting.c b/test/core/end2end/fixtures/h2_loadreporting.c
index 13feba29f1..4ed02f9728 100644
--- a/test/core/end2end/fixtures/h2_loadreporting.c
+++ b/test/core/end2end/fixtures/h2_loadreporting.c
@@ -76,15 +76,26 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
 
 typedef struct {
   int64_t total_bytes;
-  bool processed;
+  bool fully_processed;
+  uint32_t initial_token;
+  uint32_t final_token;
 } aggregated_bw_stats;
 
-static void sample_fn(const grpc_call_stats *stats, void *lr_data) {
-  aggregated_bw_stats *custom_stats = (aggregated_bw_stats *)lr_data;
-  custom_stats->total_bytes =
-      (int64_t)(stats->transport_stream_stats.outgoing.data_bytes +
-                stats->transport_stream_stats.incoming.data_bytes);
-  custom_stats->processed = true;
+static void sample_fn(const grpc_load_reporting_call_data *call_data,
+                      void *user_data) {
+  GPR_ASSERT(user_data != NULL);
+  aggregated_bw_stats *custom_stats = (aggregated_bw_stats *)user_data;
+  if (call_data == NULL) {
+    /* initial invocation */
+    custom_stats->initial_token = 0xDEADBEEF;
+  } else {
+    /* final invocation */
+    custom_stats->total_bytes =
+        (int64_t)(call_data->stats->transport_stream_stats.outgoing.data_bytes +
+                  call_data->stats->transport_stream_stats.incoming.data_bytes);
+    custom_stats->final_token = 0xCAFED00D;
+    custom_stats->fully_processed = true;
+  }
 }
 
 void chttp2_init_client_fullstack(grpc_end2end_test_fixture *f,
@@ -131,11 +142,11 @@ int main(int argc, char **argv) {
   aggregated_bw_stats *aggr_stats_client =
       gpr_malloc(sizeof(aggregated_bw_stats));
   aggr_stats_client->total_bytes = -1;
-  aggr_stats_client->processed = false;
+  aggr_stats_client->fully_processed = false;
   aggregated_bw_stats *aggr_stats_server =
       gpr_malloc(sizeof(aggregated_bw_stats));
   aggr_stats_server->total_bytes = -1;
-  aggr_stats_server->processed = false;
+  aggr_stats_server->fully_processed = false;
 
   g_client_lrc =
       grpc_load_reporting_config_create(sample_fn, aggr_stats_client);
@@ -155,11 +166,15 @@ int main(int argc, char **argv) {
   grpc_load_reporting_config_destroy(g_client_lrc);
   grpc_load_reporting_config_destroy(g_server_lrc);
 
-  if (aggr_stats_client->processed) {
+  if (aggr_stats_client->fully_processed) {
     GPR_ASSERT(aggr_stats_client->total_bytes >= 0);
+    GPR_ASSERT(aggr_stats_client->initial_token == 0xDEADBEEF);
+    GPR_ASSERT(aggr_stats_client->final_token == 0xCAFED00D);
   }
-  if (aggr_stats_server->processed) {
+  if (aggr_stats_server->fully_processed) {
     GPR_ASSERT(aggr_stats_server->total_bytes >= 0);
+    GPR_ASSERT(aggr_stats_server->initial_token == 0xDEADBEEF);
+    GPR_ASSERT(aggr_stats_server->final_token == 0xCAFED00D);
   }
 
   gpr_free(aggr_stats_client);
diff --git a/test/core/end2end/fuzzers/hpack.dictionary b/test/core/end2end/fuzzers/hpack.dictionary
index b081368ff6..097e9a8922 100644
--- a/test/core/end2end/fuzzers/hpack.dictionary
+++ b/test/core/end2end/fuzzers/hpack.dictionary
@@ -63,6 +63,7 @@
 "\x13if-unmodified-since"
 "\x0Dlast-modified"
 "\x04link"
+"\x0Eload-reporting"
 "\x08location"
 "\x0Cmax-forwards"
 "\x07:method"
@@ -136,6 +137,7 @@
 "\x00\x13if-unmodified-since\x00"
 "\x00\x0Dlast-modified\x00"
 "\x00\x04link\x00"
+"\x00\x0Eload-reporting\x00"
 "\x00\x08location\x00"
 "\x00\x0Cmax-forwards\x00"
 "\x00\x07:method\x03GET"
diff --git a/tools/codegen/core/gen_static_metadata.py b/tools/codegen/core/gen_static_metadata.py
index b38555e355..faa83867a6 100755
--- a/tools/codegen/core/gen_static_metadata.py
+++ b/tools/codegen/core/gen_static_metadata.py
@@ -108,6 +108,7 @@ CONFIG = [
     ('if-range', ''),
     ('if-unmodified-since', ''),
     ('last-modified', ''),
+    ('load-reporting', ''),
     ('link', ''),
     ('location', ''),
     ('max-forwards', ''),