1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 3 #ifndef _LINUX_RSTREASON_H 4 #define _LINUX_RSTREASON_H 5 #include <net/dropreason-core.h> 6 #include <uapi/linux/mptcp.h> 7 8 #define DEFINE_RST_REASON(FN, FNe) \ 9 FN(NOT_SPECIFIED) \ 10 FN(NO_SOCKET) \ 11 FN(TCP_INVALID_ACK_SEQUENCE) \ 12 FN(TCP_RFC7323_PAWS) \ 13 FN(TCP_TOO_OLD_ACK) \ 14 FN(TCP_ACK_UNSENT_DATA) \ 15 FN(TCP_FLAGS) \ 16 FN(TCP_OLD_ACK) \ 17 FN(TCP_ABORT_ON_DATA) \ 18 FN(TCP_TIMEWAIT_SOCKET) \ 19 FN(INVALID_SYN) \ 20 FN(MPTCP_RST_EUNSPEC) \ 21 FN(MPTCP_RST_EMPTCP) \ 22 FN(MPTCP_RST_ERESOURCE) \ 23 FN(MPTCP_RST_EPROHIBIT) \ 24 FN(MPTCP_RST_EWQ2BIG) \ 25 FN(MPTCP_RST_EBADPERF) \ 26 FN(MPTCP_RST_EMIDDLEBOX) \ 27 FN(ERROR) \ 28 FNe(MAX) 29 30 /** 31 * enum sk_rst_reason - the reasons of socket reset 32 * 33 * The reasons of sk reset, which are used in DCCP/TCP/MPTCP protocols. 34 * 35 * There are three parts in order: 36 * 1) skb drop reasons: relying on drop reasons for such as passive reset 37 * 2) independent reset reasons: such as active reset reasons 38 * 3) reset reasons in MPTCP: only for MPTCP use 39 */ 40 enum sk_rst_reason { 41 /* Refer to include/net/dropreason-core.h 42 * Rely on skb drop reasons because it indicates exactly why RST 43 * could happen. 44 */ 45 /** @SK_RST_REASON_NOT_SPECIFIED: reset reason is not specified */ 46 SK_RST_REASON_NOT_SPECIFIED, 47 /** @SK_RST_REASON_NO_SOCKET: no valid socket that can be used */ 48 SK_RST_REASON_NO_SOCKET, 49 /** 50 * @SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE: Not acceptable ACK SEQ 51 * field because ack sequence is not in the window between snd_una 52 * and snd_nxt 53 */ 54 SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE, 55 /** 56 * @SK_RST_REASON_TCP_RFC7323_PAWS: PAWS check, corresponding to 57 * LINUX_MIB_PAWSESTABREJECTED, LINUX_MIB_PAWSACTIVEREJECTED 58 */ 59 SK_RST_REASON_TCP_RFC7323_PAWS, 60 /** @SK_RST_REASON_TCP_TOO_OLD_ACK: TCP ACK is too old */ 61 SK_RST_REASON_TCP_TOO_OLD_ACK, 62 /** 63 * @SK_RST_REASON_TCP_ACK_UNSENT_DATA: TCP ACK for data we haven't 64 * sent yet 65 */ 66 SK_RST_REASON_TCP_ACK_UNSENT_DATA, 67 /** @SK_RST_REASON_TCP_FLAGS: TCP flags invalid */ 68 SK_RST_REASON_TCP_FLAGS, 69 /** @SK_RST_REASON_TCP_OLD_ACK: TCP ACK is old, but in window */ 70 SK_RST_REASON_TCP_OLD_ACK, 71 /** 72 * @SK_RST_REASON_TCP_ABORT_ON_DATA: abort on data 73 * corresponding to LINUX_MIB_TCPABORTONDATA 74 */ 75 SK_RST_REASON_TCP_ABORT_ON_DATA, 76 77 /* Here start with the independent reasons */ 78 /** @SK_RST_REASON_TCP_TIMEWAIT_SOCKET: happen on the timewait socket */ 79 SK_RST_REASON_TCP_TIMEWAIT_SOCKET, 80 /** 81 * @SK_RST_REASON_INVALID_SYN: receive bad syn packet 82 * RFC 793 says if the state is not CLOSED/LISTEN/SYN-SENT then 83 * "fourth, check the SYN bit,...If the SYN is in the window it is 84 * an error, send a reset" 85 */ 86 SK_RST_REASON_INVALID_SYN, 87 88 /* Copy from include/uapi/linux/mptcp.h. 89 * These reset fields will not be changed since they adhere to 90 * RFC 8684. So do not touch them. I'm going to list each definition 91 * of them respectively. 92 */ 93 /** 94 * @SK_RST_REASON_MPTCP_RST_EUNSPEC: Unspecified error. 95 * This is the default error; it implies that the subflow is no 96 * longer available. The presence of this option shows that the 97 * RST was generated by an MPTCP-aware device. 98 */ 99 SK_RST_REASON_MPTCP_RST_EUNSPEC, 100 /** 101 * @SK_RST_REASON_MPTCP_RST_EMPTCP: MPTCP-specific error. 102 * An error has been detected in the processing of MPTCP options. 103 * This is the usual reason code to return in the cases where a RST 104 * is being sent to close a subflow because of an invalid response. 105 */ 106 SK_RST_REASON_MPTCP_RST_EMPTCP, 107 /** 108 * @SK_RST_REASON_MPTCP_RST_ERESOURCE: Lack of resources. 109 * This code indicates that the sending host does not have enough 110 * resources to support the terminated subflow. 111 */ 112 SK_RST_REASON_MPTCP_RST_ERESOURCE, 113 /** 114 * @SK_RST_REASON_MPTCP_RST_EPROHIBIT: Administratively prohibited. 115 * This code indicates that the requested subflow is prohibited by 116 * the policies of the sending host. 117 */ 118 SK_RST_REASON_MPTCP_RST_EPROHIBIT, 119 /** 120 * @SK_RST_REASON_MPTCP_RST_EWQ2BIG: Too much outstanding data. 121 * This code indicates that there is an excessive amount of data 122 * that needs to be transmitted over the terminated subflow while 123 * having already been acknowledged over one or more other subflows. 124 * This may occur if a path has been unavailable for a short period 125 * and it is more efficient to reset and start again than it is to 126 * retransmit the queued data. 127 */ 128 SK_RST_REASON_MPTCP_RST_EWQ2BIG, 129 /** 130 * @SK_RST_REASON_MPTCP_RST_EBADPERF: Unacceptable performance. 131 * This code indicates that the performance of this subflow was 132 * too low compared to the other subflows of this Multipath TCP 133 * connection. 134 */ 135 SK_RST_REASON_MPTCP_RST_EBADPERF, 136 /** 137 * @SK_RST_REASON_MPTCP_RST_EMIDDLEBOX: Middlebox interference. 138 * Middlebox interference has been detected over this subflow, 139 * making MPTCP signaling invalid. For example, this may be sent 140 * if the checksum does not validate. 141 */ 142 SK_RST_REASON_MPTCP_RST_EMIDDLEBOX, 143 144 /** @SK_RST_REASON_ERROR: unexpected error happens */ 145 SK_RST_REASON_ERROR, 146 147 /** 148 * @SK_RST_REASON_MAX: Maximum of socket reset reasons. 149 * It shouldn't be used as a real 'reason'. 150 */ 151 SK_RST_REASON_MAX, 152 }; 153 154 /* Convert skb drop reasons to enum sk_rst_reason type */ 155 static inline enum sk_rst_reason 156 sk_rst_convert_drop_reason(enum skb_drop_reason reason) 157 { 158 switch (reason) { 159 case SKB_DROP_REASON_NOT_SPECIFIED: 160 return SK_RST_REASON_NOT_SPECIFIED; 161 case SKB_DROP_REASON_NO_SOCKET: 162 return SK_RST_REASON_NO_SOCKET; 163 case SKB_DROP_REASON_TCP_INVALID_ACK_SEQUENCE: 164 return SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE; 165 case SKB_DROP_REASON_TCP_RFC7323_PAWS: 166 return SK_RST_REASON_TCP_RFC7323_PAWS; 167 case SKB_DROP_REASON_TCP_TOO_OLD_ACK: 168 return SK_RST_REASON_TCP_TOO_OLD_ACK; 169 case SKB_DROP_REASON_TCP_ACK_UNSENT_DATA: 170 return SK_RST_REASON_TCP_ACK_UNSENT_DATA; 171 case SKB_DROP_REASON_TCP_FLAGS: 172 return SK_RST_REASON_TCP_FLAGS; 173 case SKB_DROP_REASON_TCP_OLD_ACK: 174 return SK_RST_REASON_TCP_OLD_ACK; 175 case SKB_DROP_REASON_TCP_ABORT_ON_DATA: 176 return SK_RST_REASON_TCP_ABORT_ON_DATA; 177 default: 178 /* If we don't have our own corresponding reason */ 179 return SK_RST_REASON_NOT_SPECIFIED; 180 } 181 } 182 #endif 183