honnor MaxRecvDataSegmentLength

iscsi-pdu.cpp

@@ -252,6 +252,7 @@ bool iscsi_pdu_login_request::set_data(std::pair<const uint8_t *, std::size_t> d
 
 	auto        kvs_in      = data_to_text_array(data.first, data.second);
 	uint32_t    max_burst   = ~0;
+	uint32_t    max_seg_len = 8192;
 	std::string target_name;
 	bool        discovery   = false;
 	for(auto & kv: kvs_in) {
@@ -265,6 +266,8 @@ bool iscsi_pdu_login_request::set_data(std::pair<const uint8_t *, std::size_t> d
 			max_burst = std::min(max_burst, uint32_t(std::stoi(parts[1])));
 		else if (parts[0] == "FirstBurstLength")
 			max_burst = std::min(max_burst, uint32_t(std::stoi(parts[1])));
+		else if (parts[0] == "MaxRecvDataSegmentLength")
+			max_seg_len = uint32_t(std::stoi(parts[1]));
 		else if (parts[0] == "InitiatorName")
 			initiator = parts[1];
 		else if (parts[0] == "TargetName")
@@ -277,6 +280,8 @@ bool iscsi_pdu_login_request::set_data(std::pair<const uint8_t *, std::size_t> d
 			ses->set_data_digest(has_CRC32C(parts[1]));
 	}
 
+	ses->set_max_seg_len(max_seg_len);
+
 	if (max_burst < uint32_t(~0)) {
 		DOLOG(logging::ll_debug, "iscsi_pdu_login_request::set_data", ses->get_endpoint_name(), "set max-burst to %u", max_burst);
 		ses->set_ack_interval(max_burst);

server.cpp

@@ -403,7 +403,7 @@ bool server::push_response(com_client *const cc, session *const ses, iscsi_pdu_b
 
 		uint64_t current_lba = stream_parameters.lba;
 		uint32_t offset      = 0;
-		uint32_t offset_end  = std::min(scsi_has, iscsi_wants);
+		uint32_t offset_end  = std::min(std::min(scsi_has, iscsi_wants), ses->get_max_seg_len());
 
 		if (offset_end == 0) {
                         auto *temp = new iscsi_pdu_scsi_response(ses) /* 0x21 */;

session.h

@@ -21,6 +21,8 @@ class session
 	uint64_t          bytes_rx      { 0       };
 	uint64_t          bytes_tx      { 0       };
 
+	uint32_t          max_seg_len   { 8192    };
+
 	bool              header_digest { false   };
 	bool              data_digest   { false   };
 
@@ -41,6 +43,9 @@ class session
 	bool     get_header_digest() const { return header_digest; }
 	bool     get_data_digest  () const { return data_digest;   }
 
+	void     set_max_seg_len(const uint32_t v) { max_seg_len = v; }
+	uint32_t get_max_seg_len() const { return max_seg_len; }
+
 	void     add_bytes_rx(const uint64_t n) { bytes_rx += n; }
 	uint64_t get_bytes_rx() const { return bytes_rx; }
 	void     reset_bytes_rx() { bytes_rx = 0; }