/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_DCCP_H #define _LINUX_DCCP_H #include #include #include #include #include #include #include #include #include #include #include enum dccp_state { DCCP_OPEN = TCP_ESTABLISHED, DCCP_REQUESTING = TCP_SYN_SENT, DCCP_LISTEN = TCP_LISTEN, DCCP_RESPOND = TCP_SYN_RECV, /* * States involved in closing a DCCP connection: * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq. * * 2) CLOSING can have three different meanings (RFC 4340, 8.3): * a. Client has performed active-close, has sent a Close to the server * from state OPEN or PARTOPEN, and is waiting for the final Reset * (in this case, SOCK_DONE == 1). * b. Client is asked to perform passive-close, by receiving a CloseReq * in (PART)OPEN state. It sends a Close and waits for final Reset * (in this case, SOCK_DONE == 0). * c. Server performs an active-close as in (a), keeps TIMEWAIT state. * * 3) The following intermediate states are employed to give passively * closing nodes a chance to process their unread data: * - PASSIVE_CLOSE (from OPEN => CLOSED) and * - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above). */ DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1, DCCP_PASSIVE_CLOSE = TCP_CLOSE_WAIT, /* any node receiving a Close */ DCCP_CLOSING = TCP_CLOSING, DCCP_TIME_WAIT = TCP_TIME_WAIT, DCCP_CLOSED = TCP_CLOSE, DCCP_NEW_SYN_RECV = TCP_NEW_SYN_RECV, DCCP_PARTOPEN = TCP_MAX_STATES, DCCP_PASSIVE_CLOSEREQ, /* clients receiving CloseReq */ DCCP_MAX_STATES }; enum { DCCPF_OPEN = TCPF_ESTABLISHED, DCCPF_REQUESTING = TCPF_SYN_SENT, DCCPF_LISTEN = TCPF_LISTEN, DCCPF_RESPOND = TCPF_SYN_RECV, DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1, DCCPF_CLOSING = TCPF_CLOSING, DCCPF_TIME_WAIT = TCPF_TIME_WAIT, DCCPF_CLOSED = TCPF_CLOSE, DCCPF_NEW_SYN_RECV = TCPF_NEW_SYN_RECV, DCCPF_PARTOPEN = (1 << DCCP_PARTOPEN), }; static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb) { return (struct dccp_hdr *)skb_transport_header(skb); } static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen) { skb_push(skb, headlen); skb_reset_transport_header(skb); return memset(skb_transport_header(skb), 0, headlen); } static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh) { return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh)); } static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh) { return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0); } static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb) { const struct dccp_hdr *dh = dccp_hdr(skb); return __dccp_basic_hdr_len(dh); } static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh) { __u64 seq_nr = ntohs(dh->dccph_seq); if (dh->dccph_x != 0) seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low); else seq_nr += (u32)dh->dccph_seq2 << 16; return seq_nr; } static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb) { return (struct dccp_hdr_request *)(skb_transport_header(skb) + dccp_basic_hdr_len(skb)); } static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb) { return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) + dccp_basic_hdr_len(skb)); } static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb) { const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb); return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low); } static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb) { return (struct dccp_hdr_response *)(skb_transport_header(skb) + dccp_basic_hdr_len(skb)); } static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb) { return (struct dccp_hdr_reset *)(skb_transport_header(skb) + dccp_basic_hdr_len(skb)); } static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh) { return __dccp_basic_hdr_len(dh) + dccp_packet_hdr_len(dh->dccph_type); } static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) { return __dccp_hdr_len(dccp_hdr(skb)); } /** * struct dccp_request_sock - represent DCCP-specific connection request * @dreq_inet_rsk: structure inherited from * @dreq_iss: initial sequence number, sent on the first Response (RFC 4340, 7.1) * @dreq_gss: greatest sequence number sent (for retransmitted Responses) * @dreq_isr: initial sequence number received in the first Request * @dreq_gsr: greatest sequence number received (for retransmitted Request(s)) * @dreq_service: service code present on the Request (there is just one) * @dreq_featneg: feature negotiation options for this connection * The following two fields are analogous to the ones in dccp_sock: * @dreq_timestamp_echo: last received timestamp to echo (13.1) * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo */ struct dccp_request_sock { struct inet_request_sock dreq_inet_rsk; __u64 dreq_iss; __u64 dreq_gss; __u64 dreq_isr; __u64 dreq_gsr; __be32 dreq_service; spinlock_t dreq_lock; struct list_head dreq_featneg; __u32 dreq_timestamp_echo; __u32 dreq_timestamp_time; }; static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req) { return (struct dccp_request_sock *)req; } extern struct inet_timewait_death_row dccp_death_row; extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, struct sk_buff *skb); struct dccp_options_received { u64 dccpor_ndp:48; u32 dccpor_timestamp; u32 dccpor_timestamp_echo; u32 dccpor_elapsed_time; }; struct ccid; enum dccp_role { DCCP_ROLE_UNDEFINED, DCCP_ROLE_LISTEN, DCCP_ROLE_CLIENT, DCCP_ROLE_SERVER, }; struct dccp_service_list { __u32 dccpsl_nr; __be32 dccpsl_list[0]; }; #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1) #define DCCP_SERVICE_CODE_IS_ABSENT 0 static inline bool dccp_list_has_service(const struct dccp_service_list *sl, const __be32 service) { if (likely(sl != NULL)) { u32 i = sl->dccpsl_nr; while (i--) if (sl->dccpsl_list[i] == service) return true; } return false; } struct dccp_ackvec; /** * struct dccp_sock - DCCP socket state * * @dccps_swl - sequence number window low * @dccps_swh - sequence number window high * @dccps_awl - acknowledgement number window low * @dccps_awh - acknowledgement number window high * @dccps_iss - initial sequence number sent * @dccps_isr - initial sequence number received * @dccps_osr - first OPEN sequence number received * @dccps_gss - greatest sequence number sent * @dccps_gsr - greatest valid sequence number received * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss * @dccps_service - first (passive sock) or unique (active sock) service code * @dccps_service_list - second .. last service code on passive socket * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo * @dccps_l_ack_ratio - feature-local Ack Ratio * @dccps_r_ack_ratio - feature-remote Ack Ratio * @dccps_l_seq_win - local Sequence Window (influences ack number validity) * @dccps_r_seq_win - remote Sequence Window (influences seq number validity) * @dccps_pcslen - sender partial checksum coverage (via sockopt) * @dccps_pcrlen - receiver partial checksum coverage (via sockopt) * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2) * @dccps_ndp_count - number of Non Data Packets since last data packet * @dccps_mss_cache - current value of MSS (path MTU minus header sizes) * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4) * @dccps_featneg - tracks feature-negotiation state (mostly during handshake) * @dccps_hc_rx_ackvec - rx half connection ack vector * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection) * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection) * @dccps_options_received - parsed set of retrieved options * @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy * @dccps_tx_qlen - maximum length of the TX queue * @dccps_role - role of this sock, one of %dccp_role * @dccps_hc_rx_insert_options - receiver wants to add options when acking * @dccps_hc_tx_insert_options - sender wants to add options when sending * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3) * @dccps_sync_scheduled - flag which signals "send out-of-band message soon" * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing) * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs) */ struct dccp_sock { /* inet_connection_sock has to be the first member of dccp_sock */ struct inet_connection_sock dccps_inet_connection; #define dccps_syn_rtt dccps_inet_connection.icsk_ack.lrcvtime __u64 dccps_swl; __u64 dccps_swh; __u64 dccps_awl; __u64 dccps_awh; __u64 dccps_iss; __u64 dccps_isr; __u64 dccps_osr; __u64 dccps_gss; __u64 dccps_gsr; __u64 dccps_gar; __be32 dccps_service; __u32 dccps_mss_cache; struct dccp_service_list *dccps_service_list; __u32 dccps_timestamp_echo; __u32 dccps_timestamp_time; __u16 dccps_l_ack_ratio; __u16 dccps_r_ack_ratio; __u64 dccps_l_seq_win:48; __u64 dccps_r_seq_win:48; __u8 dccps_pcslen:4; __u8 dccps_pcrlen:4; __u8 dccps_send_ndp_count:1; __u64 dccps_ndp_count:48; unsigned long dccps_rate_last; struct list_head dccps_featneg; struct dccp_ackvec *dccps_hc_rx_ackvec; struct ccid *dccps_hc_rx_ccid; struct ccid *dccps_hc_tx_ccid; struct dccp_options_received dccps_options_received; __u8 dccps_qpolicy; __u32 dccps_tx_qlen; enum dccp_role dccps_role:2; __u8 dccps_hc_rx_insert_options:1; __u8 dccps_hc_tx_insert_options:1; __u8 dccps_server_timewait:1; __u8 dccps_sync_scheduled:1; struct tasklet_struct dccps_xmitlet; struct timer_list dccps_xmit_timer; }; static inline struct dccp_sock *dccp_sk(const struct sock *sk) { return (struct dccp_sock *)sk; } static inline const char *dccp_role(const struct sock *sk) { switch (dccp_sk(sk)->dccps_role) { case DCCP_ROLE_UNDEFINED: return "undefined"; case DCCP_ROLE_LISTEN: return "listen"; case DCCP_ROLE_SERVER: return "server"; case DCCP_ROLE_CLIENT: return "client"; } return NULL; } extern void dccp_syn_ack_timeout(const struct request_sock *req); #endif /* _LINUX_DCCP_H */