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| 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 |
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