include/net/rstreason.h

   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(TCP_ABORT_ON_CLOSE)          \
  21         FN(TCP_ABORT_ON_LINGER)         \
  22         FN(TCP_ABORT_ON_MEMORY)         \
  23         FN(TCP_STATE)                   \
  24         FN(TCP_KEEPALIVE_TIMEOUT)       \
  25         FN(TCP_DISCONNECT_WITH_DATA)    \
  26         FN(MPTCP_RST_EUNSPEC)           \
  27         FN(MPTCP_RST_EMPTCP)            \
  28         FN(MPTCP_RST_ERESOURCE)         \
  29         FN(MPTCP_RST_EPROHIBIT)         \
  30         FN(MPTCP_RST_EWQ2BIG)           \
  31         FN(MPTCP_RST_EBADPERF)          \
  32         FN(MPTCP_RST_EMIDDLEBOX)        \
  33         FN(ERROR)                       \
  34         FNe(MAX)
  35
  36 /**
  37  * enum sk_rst_reason - the reasons of socket reset
  38  *
  39  * The reasons of sk reset, which are used in DCCP/TCP/MPTCP protocols.
  40  *
  41  * There are three parts in order:
  42  * 1) skb drop reasons: relying on drop reasons for such as passive reset
  43  * 2) independent reset reasons: such as active reset reasons
  44  * 3) reset reasons in MPTCP: only for MPTCP use
  45  */
  46 enum sk_rst_reason {
  47         /* Refer to include/net/dropreason-core.h
  48          * Rely on skb drop reasons because it indicates exactly why RST
  49          * could happen.
  50          */
  51         /** @SK_RST_REASON_NOT_SPECIFIED: reset reason is not specified */
  52         SK_RST_REASON_NOT_SPECIFIED,
  53         /** @SK_RST_REASON_NO_SOCKET: no valid socket that can be used */
  54         SK_RST_REASON_NO_SOCKET,
  55         /**
  56          * @SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE: Not acceptable ACK SEQ
  57          * field because ack sequence is not in the window between snd_una
  58          * and snd_nxt
  59          */
  60         SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE,
  61         /**
  62          * @SK_RST_REASON_TCP_RFC7323_PAWS: PAWS check, corresponding to
  63          * LINUX_MIB_PAWSESTABREJECTED, LINUX_MIB_PAWSACTIVEREJECTED
  64          */
  65         SK_RST_REASON_TCP_RFC7323_PAWS,
  66         /** @SK_RST_REASON_TCP_TOO_OLD_ACK: TCP ACK is too old */
  67         SK_RST_REASON_TCP_TOO_OLD_ACK,
  68         /**
  69          * @SK_RST_REASON_TCP_ACK_UNSENT_DATA: TCP ACK for data we haven't
  70          * sent yet
  71          */
  72         SK_RST_REASON_TCP_ACK_UNSENT_DATA,
  73         /** @SK_RST_REASON_TCP_FLAGS: TCP flags invalid */
  74         SK_RST_REASON_TCP_FLAGS,
  75         /** @SK_RST_REASON_TCP_OLD_ACK: TCP ACK is old, but in window */
  76         SK_RST_REASON_TCP_OLD_ACK,
  77         /**
  78          * @SK_RST_REASON_TCP_ABORT_ON_DATA: abort on data
  79          * corresponding to LINUX_MIB_TCPABORTONDATA
  80          */
  81         SK_RST_REASON_TCP_ABORT_ON_DATA,
  82
  83         /* Here start with the independent reasons */
  84         /** @SK_RST_REASON_TCP_TIMEWAIT_SOCKET: happen on the timewait socket */
  85         SK_RST_REASON_TCP_TIMEWAIT_SOCKET,
  86         /**
  87          * @SK_RST_REASON_INVALID_SYN: receive bad syn packet
  88          * RFC 793 says if the state is not CLOSED/LISTEN/SYN-SENT then
  89          * "fourth, check the SYN bit,...If the SYN is in the window it is
  90          * an error, send a reset"
  91          */
  92         SK_RST_REASON_INVALID_SYN,
  93         /**
  94          * @SK_RST_REASON_TCP_ABORT_ON_CLOSE: abort on close
  95          * corresponding to LINUX_MIB_TCPABORTONCLOSE
  96          */
  97         SK_RST_REASON_TCP_ABORT_ON_CLOSE,
  98         /**
  99          * @SK_RST_REASON_TCP_ABORT_ON_LINGER: abort on linger
 100          * corresponding to LINUX_MIB_TCPABORTONLINGER
 101          */
 102         SK_RST_REASON_TCP_ABORT_ON_LINGER,
 103         /**
 104          * @SK_RST_REASON_TCP_ABORT_ON_MEMORY: abort on memory
 105          * corresponding to LINUX_MIB_TCPABORTONMEMORY
 106          */
 107         SK_RST_REASON_TCP_ABORT_ON_MEMORY,
 108         /**
 109          * @SK_RST_REASON_TCP_STATE: abort on tcp state
 110          * Please see RFC 9293 for all possible reset conditions
 111          */
 112         SK_RST_REASON_TCP_STATE,
 113         /**
 114          * @SK_RST_REASON_TCP_KEEPALIVE_TIMEOUT: time to timeout
 115          * When we have already run out of all the chances, which means
 116          * keepalive timeout, we have to reset the connection
 117          */
 118         SK_RST_REASON_TCP_KEEPALIVE_TIMEOUT,
 119         /**
 120          * @SK_RST_REASON_TCP_DISCONNECT_WITH_DATA: disconnect when write
 121          * queue is not empty
 122          * It means user has written data into the write queue when doing
 123          * disconnecting, so we have to send an RST.
 124          */
 125         SK_RST_REASON_TCP_DISCONNECT_WITH_DATA,
 126
 127         /* Copy from include/uapi/linux/mptcp.h.
 128          * These reset fields will not be changed since they adhere to
 129          * RFC 8684. So do not touch them. I'm going to list each definition
 130          * of them respectively.
 131          */
 132         /**
 133          * @SK_RST_REASON_MPTCP_RST_EUNSPEC: Unspecified error.
 134          * This is the default error; it implies that the subflow is no
 135          * longer available. The presence of this option shows that the
 136          * RST was generated by an MPTCP-aware device.
 137          */
 138         SK_RST_REASON_MPTCP_RST_EUNSPEC,
 139         /**
 140          * @SK_RST_REASON_MPTCP_RST_EMPTCP: MPTCP-specific error.
 141          * An error has been detected in the processing of MPTCP options.
 142          * This is the usual reason code to return in the cases where a RST
 143          * is being sent to close a subflow because of an invalid response.
 144          */
 145         SK_RST_REASON_MPTCP_RST_EMPTCP,
 146         /**
 147          * @SK_RST_REASON_MPTCP_RST_ERESOURCE: Lack of resources.
 148          * This code indicates that the sending host does not have enough
 149          * resources to support the terminated subflow.
 150          */
 151         SK_RST_REASON_MPTCP_RST_ERESOURCE,
 152         /**
 153          * @SK_RST_REASON_MPTCP_RST_EPROHIBIT: Administratively prohibited.
 154          * This code indicates that the requested subflow is prohibited by
 155          * the policies of the sending host.
 156          */
 157         SK_RST_REASON_MPTCP_RST_EPROHIBIT,
 158         /**
 159          * @SK_RST_REASON_MPTCP_RST_EWQ2BIG: Too much outstanding data.
 160          * This code indicates that there is an excessive amount of data
 161          * that needs to be transmitted over the terminated subflow while
 162          * having already been acknowledged over one or more other subflows.
 163          * This may occur if a path has been unavailable for a short period
 164          * and it is more efficient to reset and start again than it is to
 165          * retransmit the queued data.
 166          */
 167         SK_RST_REASON_MPTCP_RST_EWQ2BIG,
 168         /**
 169          * @SK_RST_REASON_MPTCP_RST_EBADPERF: Unacceptable performance.
 170          * This code indicates that the performance of this subflow was
 171          * too low compared to the other subflows of this Multipath TCP
 172          * connection.
 173          */
 174         SK_RST_REASON_MPTCP_RST_EBADPERF,
 175         /**
 176          * @SK_RST_REASON_MPTCP_RST_EMIDDLEBOX: Middlebox interference.
 177          * Middlebox interference has been detected over this subflow,
 178          * making MPTCP signaling invalid. For example, this may be sent
 179          * if the checksum does not validate.
 180          */
 181         SK_RST_REASON_MPTCP_RST_EMIDDLEBOX,
 182
 183         /** @SK_RST_REASON_ERROR: unexpected error happens */
 184         SK_RST_REASON_ERROR,
 185
 186         /**
 187          * @SK_RST_REASON_MAX: Maximum of socket reset reasons.
 188          * It shouldn't be used as a real 'reason'.
 189          */
 190         SK_RST_REASON_MAX,
 191 };
 192
 193 /* Convert skb drop reasons to enum sk_rst_reason type */
 194 static inline enum sk_rst_reason
 195 sk_rst_convert_drop_reason(enum skb_drop_reason reason)
 196 {
 197         switch (reason) {
 198         case SKB_DROP_REASON_NOT_SPECIFIED:
 199                 return SK_RST_REASON_NOT_SPECIFIED;
 200         case SKB_DROP_REASON_NO_SOCKET:
 201                 return SK_RST_REASON_NO_SOCKET;
 202         case SKB_DROP_REASON_TCP_INVALID_ACK_SEQUENCE:
 203                 return SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE;
 204         case SKB_DROP_REASON_TCP_RFC7323_PAWS:
 205                 return SK_RST_REASON_TCP_RFC7323_PAWS;
 206         case SKB_DROP_REASON_TCP_TOO_OLD_ACK:
 207                 return SK_RST_REASON_TCP_TOO_OLD_ACK;
 208         case SKB_DROP_REASON_TCP_ACK_UNSENT_DATA:
 209                 return SK_RST_REASON_TCP_ACK_UNSENT_DATA;
 210         case SKB_DROP_REASON_TCP_FLAGS:
 211                 return SK_RST_REASON_TCP_FLAGS;
 212         case SKB_DROP_REASON_TCP_OLD_ACK:
 213                 return SK_RST_REASON_TCP_OLD_ACK;
 214         case SKB_DROP_REASON_TCP_ABORT_ON_DATA:
 215                 return SK_RST_REASON_TCP_ABORT_ON_DATA;
 216         default:
 217                 /* If we don't have our own corresponding reason */
 218                 return SK_RST_REASON_NOT_SPECIFIED;
 219         }
 220 }
 221 #endif