diff options
Diffstat (limited to 'src/server/iscsi.c')
| -rw-r--r-- | src/server/iscsi.c | 109 |
1 files changed, 52 insertions, 57 deletions
diff --git a/src/server/iscsi.c b/src/server/iscsi.c index 54cc431..04c177e 100644 --- a/src/server/iscsi.c +++ b/src/server/iscsi.c @@ -2128,19 +2128,14 @@ static int iscsi_append_key_value_pair_packet(const bool number, const char *key #define CLAMP(val, min, max) ((val) < (min) ? (min) : ((val) > (max) ? (max) : (val))) /** - * @brief Updates iSCSI connection and session values after being retrieved from the client. - * - * This function copies the key and value pairs into the - * internal connection and session structure and checks - * them for consistency.\n - * The TCP receive buffer will be adjusted to the new - * updated value but is never lower than 4KiB and never - * higher than 8KiB plus header overhead and a factor of - * 16 for receiving 16 packets at once. - * - * @param[in] conn Pointer to ISCSI connection which should - * be updated. - @param[in] pairs Set of readily parsed key-value-pairs to handle + * @brief Updates selected iSCSI connection options from negotiated key-value pairs. + * + * Copies and clamps a subset of negotiated options (MaxBurstLength, + * FirstBurstLength, MaxRecvDataSegmentLength) into the connection's + * options. + * + * @param[in] conn Pointer to ISCSI connection which should be updated. + * @param[in] pairs Set of readily parsed key-value pairs to apply. */ static void iscsi_connection_update_key_value_pairs(iscsi_connection *conn, const iscsi_negotiation_kvp *pairs) { @@ -2529,16 +2524,19 @@ static iscsi_bhs_packet *iscsi_connection_pdu_resize(iscsi_pdu *pdu, const uint /** * @brief Writes and sends a response PDU to the client. * - * This function sends a response PDU to the - * client after being processed by the server.\n - * If a header or data digest (CRC32C) needs to - * be calculated, this is done as well. + * Sends the provided response PDU over the TCP connection. On send failure, + * the connection state is set to ISCSI_CONNECT_STATE_EXITING. + * + * If a header or data segment is present, its size is rounded up to the iSCSI + * alignment before transmission, so the underlying buffer MUST include padding + * if neccesary. * * @param[in] conn Pointer to iSCSI connection to handle. Must - * NOT be NULL, so take caution. Will be freed after sending, - * so don't access afterwards. + * NOT be NULL, so take caution. * @param[in] pdu Pointer to iSCSI server response PDU to send. * Must NOT be NULL, so be careful. + * @retval true if the entire PDU was sent successfully. + * @retval false on failure (connection state will be set to EXITING). */ static bool iscsi_connection_pdu_write(iscsi_connection *conn, const iscsi_pdu *pdu) { @@ -3136,19 +3134,18 @@ static int iscsi_connection_handle_login_response(iscsi_connection *conn, iscsi_ } /** - * @brief Handles an incoming iSCSI payload data login request PDU. + * @brief Handles an incoming iSCSI login request PDU. * - * This function handles login request payload - * data sent by the client.\n - * If a response needs to be sent, this will - * be done as well. + * Parses the login request, builds a corresponding login response PDU and + * sends it. Performs basic validation (e.g., MaxRecvDataSegmentLength and + * login phase/state). On certain errors, a reject or error response is sent. * * @param[in] conn Pointer to iSCSI connection to handle. Must * NOT be NULL, so take caution. * @param[in] request_pdu Pointer to iSCSI client request PDU to handle. - * May be NULL in which case an error is returned. - * @return 0 on success. A negative value indicates - * an error. A positive value a warning. + * Must NOT be NULL. + * @return ISCSI_CONNECT_PDU_READ_OK on success; a negative + * ISCSI_CONNECT_PDU_READ_ERR_* code on error. */ static int iscsi_connection_handle_login_req(iscsi_connection *conn, iscsi_pdu *request_pdu) { @@ -3195,19 +3192,17 @@ static int iscsi_connection_handle_login_req(iscsi_connection *conn, iscsi_pdu * } /** - * @brief Handles an incoming iSCSI payload data text request PDU. + * @brief Handles an incoming iSCSI text request PDU. * - * This function handles text request payload - * data sent by the client.\n - * If a response needs to be sent, this will - * be done as well. + * Parses the key-value pairs in the text request and responds with a text + * response PDU containing the negotiated values. Multi-PDU continuation of + * text requests is not supported. * - * @param[in] conn Pointer to iSCSI connection to handle. Must - * NOT be NULL, so take caution. + * @param[in] conn Pointer to iSCSI connection to handle. Must NOT be NULL. * @param[in] request_pdu Pointer to iSCSI client request PDU to handle. - * May be NULL in which case an error is returned. - * @return 0 on success. A negative value indicates - * an error. A positive value a warning. + * Must NOT be NULL. + * @return ISCSI_CONNECT_PDU_READ_OK on success; a negative + * ISCSI_CONNECT_PDU_READ_ERR_* code on error or when a reject is sent. */ static int iscsi_connection_handle_text_req(iscsi_connection *conn, const iscsi_pdu *request_pdu) { @@ -3282,17 +3277,17 @@ static int iscsi_connection_handle_text_req(iscsi_connection *conn, const iscsi_ } /** - * @brief Handles an incoming iSCSI PDU. + * @brief Dispatches and handles a single incoming iSCSI request PDU. * - * If a response needs to be sent, this will - * be done as well. + * Parses the opcode from the request PDU and invokes the corresponding + * handler. On protocol errors, a REJECT may be sent. Fatal errors set the + * connection to exiting state via lower-level helpers. * - * @param[in] conn Pointer to iSCSI connection to handle. Must - * NOT be NULL, so take caution. + * @param[in] conn Pointer to iSCSI connection to handle. Must NOT be NULL. * @param[in] request_pdu Pointer to iSCSI client request PDU to handle. - * May be NULL in which case an error is returned. - * @return 0 on success. A negative value indicates - * an error. A positive value a warning. + * Must NOT be NULL. + * @return ISCSI_CONNECT_PDU_READ_OK on success; a negative + * ISCSI_CONNECT_PDU_READ_ERR_* code on error. */ static int iscsi_connection_pdu_handle(iscsi_connection *conn, iscsi_pdu *request_pdu) { @@ -3453,18 +3448,18 @@ static void iscsi_connection_pdu_read_loop(iscsi_connection *conn, const dnbd3_r } /** - * @brief Handles an iSCSI connection until connection is closed. - * - * This function creates an iSCSI portal group - * and iSCSI portal with connection data - * delivered from the DNBD3 client and - * request data. - * - * @param[in] client Pointer to DNBD3 client structure, - * must NOT be NULL, so be careful. - * @param[in] request Pointer to DNBD3 request packet data. - * NULL is not allowed here, take caution. - * @param[in] len Length of already read DNBD3 request data. + * @brief Handles an iSCSI connection until it is closed. + * + * Initializes a per-connection state object, processes incoming PDUs by + * delegating to the PDU read loop (which continues until an error, shutdown, + * or explicit exit state), and finally shuts down the write side of the socket + * while draining any remaining incoming data. + * + * @param[in] client Pointer to DNBD3 client structure. + * Must NOT be NULL. + * @param[in] request Pointer to the already-received initial bytes (partial + * Basic Header Segment) of the first iSCSI PDU. Must NOT be NULL. + * @param[in] len Length in bytes of the initial data in 'request'. */ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *request, const int len) { |