diff options
114 files changed, 2090 insertions, 602 deletions
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst index 6a47629ef8ed..59e86de662cd 100644 --- a/Documentation/networking/index.rst +++ b/Documentation/networking/index.rst @@ -11,19 +11,19 @@ Contents: batman-adv can can_ucan_protocol - dpaa2/index - e100 - e1000 - e1000e - fm10k - igb - igbvf - ixgb - ixgbe - ixgbevf - i40e - iavf - ice + device_drivers/freescale/dpaa2/index + device_drivers/intel/e100 + device_drivers/intel/e1000 + device_drivers/intel/e1000e + device_drivers/intel/fm10k + device_drivers/intel/igb + device_drivers/intel/igbvf + device_drivers/intel/ixgb + device_drivers/intel/ixgbe + device_drivers/intel/ixgbevf + device_drivers/intel/i40e + device_drivers/intel/iavf + device_drivers/intel/ice kapi z8530book msg_zerocopy diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt index c9d052e0cf51..2df5894353d6 100644 --- a/Documentation/networking/rxrpc.txt +++ b/Documentation/networking/rxrpc.txt @@ -1000,51 +1000,6 @@ The kernel interface functions are as follows: size should be set when the call is begun. tx_total_len may not be less than zero. - (*) Check to see the completion state of a call so that the caller can assess - whether it needs to be retried. - - enum rxrpc_call_completion { - RXRPC_CALL_SUCCEEDED, - RXRPC_CALL_REMOTELY_ABORTED, - RXRPC_CALL_LOCALLY_ABORTED, - RXRPC_CALL_LOCAL_ERROR, - RXRPC_CALL_NETWORK_ERROR, - }; - - int rxrpc_kernel_check_call(struct socket *sock, struct rxrpc_call *call, - enum rxrpc_call_completion *_compl, - u32 *_abort_code); - - On return, -EINPROGRESS will be returned if the call is still ongoing; if - it is finished, *_compl will be set to indicate the manner of completion, - *_abort_code will be set to any abort code that occurred. 0 will be - returned on a successful completion, -ECONNABORTED will be returned if the - client failed due to a remote abort and anything else will return an - appropriate error code. - - The caller should look at this information to decide if it's worth - retrying the call. - - (*) Retry a client call. - - int rxrpc_kernel_retry_call(struct socket *sock, - struct rxrpc_call *call, - struct sockaddr_rxrpc *srx, - struct key *key); - - This attempts to partially reinitialise a call and submit it again while - reusing the original call's Tx queue to avoid the need to repackage and - re-encrypt the data to be sent. call indicates the call to retry, srx the - new address to send it to and key the encryption key to use for signing or - encrypting the packets. - - For this to work, the first Tx data packet must still be in the transmit - queue, and currently this is only permitted for local and network errors - and the call must not have been aborted. Any partially constructed Tx - packet is left as is and can continue being filled afterwards. - - It returns 0 if the call was requeued and an error otherwise. - (*) Get call RTT. u64 rxrpc_kernel_get_rtt(struct socket *sock, struct rxrpc_call *call); diff --git a/Documentation/networking/snmp_counter.rst b/Documentation/networking/snmp_counter.rst index b0dfdaaca512..fe8f741193be 100644 --- a/Documentation/networking/snmp_counter.rst +++ b/Documentation/networking/snmp_counter.rst @@ -336,7 +336,26 @@ time client replies ACK, this socket will get another chance to move to the accept queue. -TCP Fast Open +* TcpEstabResets +Defined in `RFC1213 tcpEstabResets`_. + +.. _RFC1213 tcpEstabResets: https://tools.ietf.org/html/rfc1213#page-48 + +* TcpAttemptFails +Defined in `RFC1213 tcpAttemptFails`_. + +.. _RFC1213 tcpAttemptFails: https://tools.ietf.org/html/rfc1213#page-48 + +* TcpOutRsts +Defined in `RFC1213 tcpOutRsts`_. The RFC says this counter indicates +the 'segments sent containing the RST flag', but in linux kernel, this +couner indicates the segments kerenl tried to send. The sending +process might be failed due to some errors (e.g. memory alloc failed). + +.. _RFC1213 tcpOutRsts: https://tools.ietf.org/html/rfc1213#page-52 + + +TCP Fast Path ============ When kernel receives a TCP packet, it has two paths to handler the packet, one is fast path, another is slow path. The comment in kernel @@ -383,8 +402,6 @@ increase 1. TCP abort ======== - - * TcpExtTCPAbortOnData It means TCP layer has data in flight, but need to close the connection. So TCP layer sends a RST to the other side, indicate the @@ -545,7 +562,6 @@ packet yet, the sender would know packet 4 is out of order. The TCP stack of kernel will increase TcpExtTCPSACKReorder for both of the above scenarios. - DSACK ===== The DSACK is defined in `RFC2883`_. The receiver uses DSACK to report @@ -566,13 +582,63 @@ The TCP stack receives an out of order duplicate packet, so it sends a DSACK to the sender. * TcpExtTCPDSACKRecv -The TCP stack receives a DSACK, which indicate an acknowledged +The TCP stack receives a DSACK, which indicates an acknowledged duplicate packet is received. * TcpExtTCPDSACKOfoRecv The TCP stack receives a DSACK, which indicate an out of order duplicate packet is received. +invalid SACK and DSACK +==================== +When a SACK (or DSACK) block is invalid, a corresponding counter would +be updated. The validation method is base on the start/end sequence +number of the SACK block. For more details, please refer the comment +of the function tcp_is_sackblock_valid in the kernel source code. A +SACK option could have up to 4 blocks, they are checked +individually. E.g., if 3 blocks of a SACk is invalid, the +corresponding counter would be updated 3 times. The comment of the +`Add counters for discarded SACK blocks`_ patch has additional +explaination: + +.. _Add counters for discarded SACK blocks: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=18f02545a9a16c9a89778b91a162ad16d510bb32 + +* TcpExtTCPSACKDiscard +This counter indicates how many SACK blocks are invalid. If the invalid +SACK block is caused by ACK recording, the TCP stack will only ignore +it and won't update this counter. + +* TcpExtTCPDSACKIgnoredOld and TcpExtTCPDSACKIgnoredNoUndo +When a DSACK block is invalid, one of these two counters would be +updated. Which counter will be updated depends on the undo_marker flag +of the TCP socket. If the undo_marker is not set, the TCP stack isn't +likely to re-transmit any packets, and we still receive an invalid +DSACK block, the reason might be that the packet is duplicated in the +middle of the network. In such scenario, TcpExtTCPDSACKIgnoredNoUndo +will be updated. If the undo_marker is set, TcpExtTCPDSACKIgnoredOld +will be updated. As implied in its name, it might be an old packet. + +SACK shift +========= +The linux networking stack stores data in sk_buff struct (skb for +short). If a SACK block acrosses multiple skb, the TCP stack will try +to re-arrange data in these skb. E.g. if a SACK block acknowledges seq +10 to 15, skb1 has seq 10 to 13, skb2 has seq 14 to 20. The seq 14 and +15 in skb2 would be moved to skb1. This operation is 'shift'. If a +SACK block acknowledges seq 10 to 20, skb1 has seq 10 to 13, skb2 has +seq 14 to 20. All data in skb2 will be moved to skb1, and skb2 will be +discard, this operation is 'merge'. + +* TcpExtTCPSackShifted +A skb is shifted + +* TcpExtTCPSackMerged +A skb is merged + +* TcpExtTCPSackShiftFallback +A skb should be shifted or merged, but the TCP stack doesn't do it |