|  | /* SPDX-License-Identifier: GPL-2.0-or-later */ | 
|  |  | 
|  | #ifndef _LINUX_RSTREASON_H | 
|  | #define _LINUX_RSTREASON_H | 
|  | #include <net/dropreason-core.h> | 
|  | #include <uapi/linux/mptcp.h> | 
|  |  | 
|  | #define DEFINE_RST_REASON(FN, FNe)	\ | 
|  | FN(NOT_SPECIFIED)		\ | 
|  | FN(NO_SOCKET)			\ | 
|  | FN(TCP_INVALID_ACK_SEQUENCE)	\ | 
|  | FN(TCP_RFC7323_PAWS)		\ | 
|  | FN(TCP_TOO_OLD_ACK)		\ | 
|  | FN(TCP_ACK_UNSENT_DATA)		\ | 
|  | FN(TCP_FLAGS)			\ | 
|  | FN(TCP_OLD_ACK)			\ | 
|  | FN(TCP_ABORT_ON_DATA)		\ | 
|  | FN(TCP_TIMEWAIT_SOCKET)		\ | 
|  | FN(INVALID_SYN)			\ | 
|  | FN(TCP_ABORT_ON_CLOSE)		\ | 
|  | FN(TCP_ABORT_ON_LINGER)		\ | 
|  | FN(TCP_ABORT_ON_MEMORY)		\ | 
|  | FN(TCP_STATE)			\ | 
|  | FN(TCP_KEEPALIVE_TIMEOUT)	\ | 
|  | FN(TCP_DISCONNECT_WITH_DATA)	\ | 
|  | FN(MPTCP_RST_EUNSPEC)		\ | 
|  | FN(MPTCP_RST_EMPTCP)		\ | 
|  | FN(MPTCP_RST_ERESOURCE)		\ | 
|  | FN(MPTCP_RST_EPROHIBIT)		\ | 
|  | FN(MPTCP_RST_EWQ2BIG)		\ | 
|  | FN(MPTCP_RST_EBADPERF)		\ | 
|  | FN(MPTCP_RST_EMIDDLEBOX)	\ | 
|  | FN(ERROR)			\ | 
|  | FNe(MAX) | 
|  |  | 
|  | /** | 
|  | * enum sk_rst_reason - the reasons of socket reset | 
|  | * | 
|  | * The reasons of sk reset, which are used in TCP/MPTCP protocols. | 
|  | * | 
|  | * There are three parts in order: | 
|  | * 1) skb drop reasons: relying on drop reasons for such as passive reset | 
|  | * 2) independent reset reasons: such as active reset reasons | 
|  | * 3) reset reasons in MPTCP: only for MPTCP use | 
|  | */ | 
|  | enum sk_rst_reason { | 
|  | /* Refer to include/net/dropreason-core.h | 
|  | * Rely on skb drop reasons because it indicates exactly why RST | 
|  | * could happen. | 
|  | */ | 
|  | /** @SK_RST_REASON_NOT_SPECIFIED: reset reason is not specified */ | 
|  | SK_RST_REASON_NOT_SPECIFIED, | 
|  | /** @SK_RST_REASON_NO_SOCKET: no valid socket that can be used */ | 
|  | SK_RST_REASON_NO_SOCKET, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE: Not acceptable ACK SEQ | 
|  | * field because ack sequence is not in the window between snd_una | 
|  | * and snd_nxt | 
|  | */ | 
|  | SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_RFC7323_PAWS: PAWS check, corresponding to | 
|  | * LINUX_MIB_PAWSESTABREJECTED, LINUX_MIB_PAWSACTIVEREJECTED | 
|  | */ | 
|  | SK_RST_REASON_TCP_RFC7323_PAWS, | 
|  | /** @SK_RST_REASON_TCP_TOO_OLD_ACK: TCP ACK is too old */ | 
|  | SK_RST_REASON_TCP_TOO_OLD_ACK, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_ACK_UNSENT_DATA: TCP ACK for data we haven't | 
|  | * sent yet | 
|  | */ | 
|  | SK_RST_REASON_TCP_ACK_UNSENT_DATA, | 
|  | /** @SK_RST_REASON_TCP_FLAGS: TCP flags invalid */ | 
|  | SK_RST_REASON_TCP_FLAGS, | 
|  | /** @SK_RST_REASON_TCP_OLD_ACK: TCP ACK is old, but in window */ | 
|  | SK_RST_REASON_TCP_OLD_ACK, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_ABORT_ON_DATA: abort on data | 
|  | * corresponding to LINUX_MIB_TCPABORTONDATA | 
|  | */ | 
|  | SK_RST_REASON_TCP_ABORT_ON_DATA, | 
|  |  | 
|  | /* Here start with the independent reasons */ | 
|  | /** @SK_RST_REASON_TCP_TIMEWAIT_SOCKET: happen on the timewait socket */ | 
|  | SK_RST_REASON_TCP_TIMEWAIT_SOCKET, | 
|  | /** | 
|  | * @SK_RST_REASON_INVALID_SYN: receive bad syn packet | 
|  | * RFC 793 says if the state is not CLOSED/LISTEN/SYN-SENT then | 
|  | * "fourth, check the SYN bit,...If the SYN is in the window it is | 
|  | * an error, send a reset" | 
|  | */ | 
|  | SK_RST_REASON_INVALID_SYN, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_ABORT_ON_CLOSE: abort on close | 
|  | * corresponding to LINUX_MIB_TCPABORTONCLOSE | 
|  | */ | 
|  | SK_RST_REASON_TCP_ABORT_ON_CLOSE, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_ABORT_ON_LINGER: abort on linger | 
|  | * corresponding to LINUX_MIB_TCPABORTONLINGER | 
|  | */ | 
|  | SK_RST_REASON_TCP_ABORT_ON_LINGER, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_ABORT_ON_MEMORY: abort on memory | 
|  | * corresponding to LINUX_MIB_TCPABORTONMEMORY | 
|  | */ | 
|  | SK_RST_REASON_TCP_ABORT_ON_MEMORY, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_STATE: abort on tcp state | 
|  | * Please see RFC 9293 for all possible reset conditions | 
|  | */ | 
|  | SK_RST_REASON_TCP_STATE, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_KEEPALIVE_TIMEOUT: time to timeout | 
|  | * When we have already run out of all the chances, which means | 
|  | * keepalive timeout, we have to reset the connection | 
|  | */ | 
|  | SK_RST_REASON_TCP_KEEPALIVE_TIMEOUT, | 
|  | /** | 
|  | * @SK_RST_REASON_TCP_DISCONNECT_WITH_DATA: disconnect when write | 
|  | * queue is not empty | 
|  | * It means user has written data into the write queue when doing | 
|  | * disconnecting, so we have to send an RST. | 
|  | */ | 
|  | SK_RST_REASON_TCP_DISCONNECT_WITH_DATA, | 
|  |  | 
|  | /* Copy from include/uapi/linux/mptcp.h. | 
|  | * These reset fields will not be changed since they adhere to | 
|  | * RFC 8684. So do not touch them. I'm going to list each definition | 
|  | * of them respectively. | 
|  | */ | 
|  | /** | 
|  | * @SK_RST_REASON_MPTCP_RST_EUNSPEC: Unspecified error. | 
|  | * This is the default error; it implies that the subflow is no | 
|  | * longer available. The presence of this option shows that the | 
|  | * RST was generated by an MPTCP-aware device. | 
|  | */ | 
|  | SK_RST_REASON_MPTCP_RST_EUNSPEC, | 
|  | /** | 
|  | * @SK_RST_REASON_MPTCP_RST_EMPTCP: MPTCP-specific error. | 
|  | * An error has been detected in the processing of MPTCP options. | 
|  | * This is the usual reason code to return in the cases where a RST | 
|  | * is being sent to close a subflow because of an invalid response. | 
|  | */ | 
|  | SK_RST_REASON_MPTCP_RST_EMPTCP, | 
|  | /** | 
|  | * @SK_RST_REASON_MPTCP_RST_ERESOURCE: Lack of resources. | 
|  | * This code indicates that the sending host does not have enough | 
|  | * resources to support the terminated subflow. | 
|  | */ | 
|  | SK_RST_REASON_MPTCP_RST_ERESOURCE, | 
|  | /** | 
|  | * @SK_RST_REASON_MPTCP_RST_EPROHIBIT: Administratively prohibited. | 
|  | * This code indicates that the requested subflow is prohibited by | 
|  | * the policies of the sending host. | 
|  | */ | 
|  | SK_RST_REASON_MPTCP_RST_EPROHIBIT, | 
|  | /** | 
|  | * @SK_RST_REASON_MPTCP_RST_EWQ2BIG: Too much outstanding data. | 
|  | * This code indicates that there is an excessive amount of data | 
|  | * that needs to be transmitted over the terminated subflow while | 
|  | * having already been acknowledged over one or more other subflows. | 
|  | * This may occur if a path has been unavailable for a short period | 
|  | * and it is more efficient to reset and start again than it is to | 
|  | * retransmit the queued data. | 
|  | */ | 
|  | SK_RST_REASON_MPTCP_RST_EWQ2BIG, | 
|  | /** | 
|  | * @SK_RST_REASON_MPTCP_RST_EBADPERF: Unacceptable performance. | 
|  | * This code indicates that the performance of this subflow was | 
|  | * too low compared to the other subflows of this Multipath TCP | 
|  | * connection. | 
|  | */ | 
|  | SK_RST_REASON_MPTCP_RST_EBADPERF, | 
|  | /** | 
|  | * @SK_RST_REASON_MPTCP_RST_EMIDDLEBOX: Middlebox interference. | 
|  | * Middlebox interference has been detected over this subflow, | 
|  | * making MPTCP signaling invalid. For example, this may be sent | 
|  | * if the checksum does not validate. | 
|  | */ | 
|  | SK_RST_REASON_MPTCP_RST_EMIDDLEBOX, | 
|  |  | 
|  | /** @SK_RST_REASON_ERROR: unexpected error happens */ | 
|  | SK_RST_REASON_ERROR, | 
|  |  | 
|  | /** | 
|  | * @SK_RST_REASON_MAX: Maximum of socket reset reasons. | 
|  | * It shouldn't be used as a real 'reason'. | 
|  | */ | 
|  | SK_RST_REASON_MAX, | 
|  | }; | 
|  |  | 
|  | /* Convert skb drop reasons to enum sk_rst_reason type */ | 
|  | static inline enum sk_rst_reason | 
|  | sk_rst_convert_drop_reason(enum skb_drop_reason reason) | 
|  | { | 
|  | switch (reason) { | 
|  | case SKB_DROP_REASON_NOT_SPECIFIED: | 
|  | return SK_RST_REASON_NOT_SPECIFIED; | 
|  | case SKB_DROP_REASON_NO_SOCKET: | 
|  | return SK_RST_REASON_NO_SOCKET; | 
|  | case SKB_DROP_REASON_TCP_INVALID_ACK_SEQUENCE: | 
|  | return SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE; | 
|  | case SKB_DROP_REASON_TCP_RFC7323_PAWS: | 
|  | return SK_RST_REASON_TCP_RFC7323_PAWS; | 
|  | case SKB_DROP_REASON_TCP_TOO_OLD_ACK: | 
|  | return SK_RST_REASON_TCP_TOO_OLD_ACK; | 
|  | case SKB_DROP_REASON_TCP_ACK_UNSENT_DATA: | 
|  | return SK_RST_REASON_TCP_ACK_UNSENT_DATA; | 
|  | case SKB_DROP_REASON_TCP_FLAGS: | 
|  | return SK_RST_REASON_TCP_FLAGS; | 
|  | case SKB_DROP_REASON_TCP_OLD_ACK: | 
|  | return SK_RST_REASON_TCP_OLD_ACK; | 
|  | case SKB_DROP_REASON_TCP_ABORT_ON_DATA: | 
|  | return SK_RST_REASON_TCP_ABORT_ON_DATA; | 
|  | default: | 
|  | /* If we don't have our own corresponding reason */ | 
|  | return SK_RST_REASON_NOT_SPECIFIED; | 
|  | } | 
|  | } | 
|  | #endif |