errmap packet directly sent after hello while connecting to our proxy using config cache ro

--- include/libcouchbase/cntl.h 2021-02-19 08:17:59.930166608 +0000

+++ include/libcouchbase/cntl.h 2021-02-19 08:19:16.692446482 +0000

@@ -929,6 +929,16 @@

 #define LCB_CNTL_READ_CHUNKSIZE 0x42

/**

+ * Enable/Disable the Error Map feature. This is disabled by default.

+ * Works only on servers which support error map

+ *

+ * Use `enable_errmap` in the connection string

+ *

+ * @cntl_arg_both{int* (as boolean)}

+ */

+#define LCB_CNTL_ENABLE_ERRMAP 0x43

+

+/**

 * Enable/Disable sending the SELECT_BUCKET command after authentication.

 * This is useful to test auth, and should not be set by end-users.

 *

--- src/cntl.cc 2021-02-19 13:01:01.085968337 +0000

+++ src/cntl.cc 2021-02-19 13:01:54.803231440 +0000

@@ -222,6 +222,9 @@

 HANDLER(read_chunk_size_handler) {

 RETURN_GET_SET(lcb_U32, LCBT_SETTING(instance, read_chunk_size));

 }

+HANDLER(enable_errmap_handler) {

+ RETURN_GET_SET(int, LCBT_SETTING(instance, use_errmap));

+}

 HANDLER(select_bucket_handler) {

 RETURN_GET_SET(int, LCBT_SETTING(instance, select_bucket));

 }

@@ -758,7 +761,7 @@

 bucket_auth_handler, /* LCB_CNTL_BUCKET_CRED */

 timeout_common, /* LCB_CNTL_RETRY_NMV_DELAY */

 read_chunk_size_handler, /* LCB_CNTL_READ_CHUNKSIZE */

- NULL, /* deprecated LCB_CNTL_ENABLE_ERRMAP (0x43) */

+ enable_errmap_handler, /* deprecated LCB_CNTL_ENABLE_ERRMAP (0x43) */

 select_bucket_handler, /* LCB_CNTL_SELECT_BUCKET */

 tcp_keepalive_handler, /* LCB_CNTL_TCP_KEEPALIVE */

 config_poll_interval_handler, /* LCB_CNTL_CONFIG_POLL_INTERVAL */

@@ -968,6 +971,7 @@

 {"retry_nmv_delay", LCB_CNTL_RETRY_NMV_INTERVAL, convert_timevalue},

 {"bucket_cred", LCB_CNTL_BUCKET_CRED, NULL},

 {"read_chunk_size", LCB_CNTL_READ_CHUNKSIZE, convert_u32},

+ {"enable_errmap", LCB_CNTL_ENABLE_ERRMAP, convert_intbool},

 {"select_bucket", LCB_CNTL_SELECT_BUCKET, convert_intbool},

 {"tcp_keepalive", LCB_CNTL_TCP_KEEPALIVE, convert_intbool},

 {"config_poll_interval", LCB_CNTL_CONFIG_POLL_INTERVAL, convert_timevalue},

--- src/settings.h 2021-02-19 07:52:24.513287125 +0000

+++ src/settings.h 2021-02-19 07:56:16.901368996 +0000

@@ -183,6 +183,7 @@

 unsigned use_collections : 1;

 unsigned log_redaction : 1;

 unsigned use_tracing : 1;

+ unsigned use_errmap : 1;

 unsigned allow_static_config : 1;

 /** Do not use remap vbuckets (do not use fast forward map, or any other heuristics) */

 unsigned vb_noremap : 1;

--- src/settings.c 2021-02-19 07:52:11.453123910 +0000

+++ src/settings.c 2021-02-19 07:55:48.693839277 +0000

@@ -63,6 +63,7 @@

 settings->tcp_keepalive = LCB_DEFAULT_TCP_KEEPALIVE;

 settings->config_poll_interval = LCB_DEFAULT_CONFIG_POLL_INTERVAL;

 settings->use_collections = 1;

+ settings->use_errmap = 1;

 settings->log_redaction = 0;

 settings->use_tracing = 1;

 settings->network = NULL;

--- src/mcserver/mcserver.cc 2021-02-19 07:51:08.773505379 +0000

+++ src/mcserver/mcserver.cc 2021-02-19 07:53:23.434531569 +0000

@@ -366,7 +366,7 @@

 int Server::handle_unknown_error(const mc_PACKET *request, const MemcachedResponse &mcresp, lcb_STATUS &newerr)

 {

- if (!settings->errmap->isLoaded()) {

+ if (!settings->errmap->isLoaded() || !settings->use_errmap) {

 // If there's no error map, just return false

 return ERRMAP_HANDLE_CONTINUE;

 }

--- src/mcserver/negotiate.cc 2021-02-19 12:49:47.721190549 +0000

+++ src/mcserver/negotiate.cc 2021-02-19 12:51:27.762133953 +0000

@@ -417,7 +417,9 @@

 features[nfeatures++] = PROTOCOL_BINARY_FEATURE_XATTR;

 features[nfeatures++] = PROTOCOL_BINARY_FEATURE_JSON;

 features[nfeatures++] = PROTOCOL_BINARY_FEATURE_SELECT_BUCKET;

- features[nfeatures++] = PROTOCOL_BINARY_FEATURE_XERROR;

+ if (settings->use_errmap) {

+ features[nfeatures++] = PROTOCOL_BINARY_FEATURE_XERROR;

+ }

 if (settings->tcp_nodelay) {

 features[nfeatures++] = PROTOCOL_BINARY_FEATURE_TCPNODELAY;

 }

@@ -627,7 +629,9 @@

 break;

 }

- if (!info->has_feature(PROTOCOL_BINARY_FEATURE_XERROR)) {

+ if (info->has_feature(PROTOCOL_BINARY_FEATURE_XERROR)) {

+ request_errmap();

+ } else {

 lcb_log(LOGARGS(this, TRACE), LOGFMT "GET_ERRORMAP unsupported/disabled", LOGID(this));

 }

@@ -730,7 +734,6 @@

 }

send_hello();

- request_errmap();

 if (!settings->keypath) {

 send_list_mechs();

 }