1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _LINUX_DCCP_H 3#define _LINUX_DCCP_H 4 5 6#include <linux/in.h> 7#include <linux/interrupt.h> 8#include <linux/ktime.h> 9#include <linux/list.h> 10#include <linux/uio.h> 11#include <linux/workqueue.h> 12 13#include <net/inet_connection_sock.h> 14#include <net/inet_sock.h> 15#include <net/inet_timewait_sock.h> 16#include <net/tcp_states.h> 17#include <uapi/linux/dccp.h> 18 19enum dccp_state { 20 DCCP_OPEN = TCP_ESTABLISHED, 21 DCCP_REQUESTING = TCP_SYN_SENT, 22 DCCP_LISTEN = TCP_LISTEN, 23 DCCP_RESPOND = TCP_SYN_RECV, 24 /* 25 * States involved in closing a DCCP connection: 26 * 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq. 27 * 28 * 2) CLOSING can have three different meanings (RFC 4340, 8.3): 29 * a. Client has performed active-close, has sent a Close to the server 30 * from state OPEN or PARTOPEN, and is waiting for the final Reset 31 * (in this case, SOCK_DONE == 1). 32 * b. Client is asked to perform passive-close, by receiving a CloseReq 33 * in (PART)OPEN state. It sends a Close and waits for final Reset 34 * (in this case, SOCK_DONE == 0). 35 * c. Server performs an active-close as in (a), keeps TIMEWAIT state. 36 * 37 * 3) The following intermediate states are employed to give passively 38 * closing nodes a chance to process their unread data: 39 * - PASSIVE_CLOSE (from OPEN => CLOSED) and 40 * - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above). 41 */ 42 DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1, 43 DCCP_PASSIVE_CLOSE = TCP_CLOSE_WAIT, /* any node receiving a Close */ 44 DCCP_CLOSING = TCP_CLOSING, 45 DCCP_TIME_WAIT = TCP_TIME_WAIT, 46 DCCP_CLOSED = TCP_CLOSE, 47 DCCP_NEW_SYN_RECV = TCP_NEW_SYN_RECV, 48 DCCP_PARTOPEN = TCP_MAX_STATES, 49 DCCP_PASSIVE_CLOSEREQ, /* clients receiving CloseReq */ 50 DCCP_MAX_STATES 51}; 52 53enum { 54 DCCPF_OPEN = TCPF_ESTABLISHED, 55 DCCPF_REQUESTING = TCPF_SYN_SENT, 56 DCCPF_LISTEN = TCPF_LISTEN, 57 DCCPF_RESPOND = TCPF_SYN_RECV, 58 DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1, 59 DCCPF_CLOSING = TCPF_CLOSING, 60 DCCPF_TIME_WAIT = TCPF_TIME_WAIT, 61 DCCPF_CLOSED = TCPF_CLOSE, 62 DCCPF_NEW_SYN_RECV = TCPF_NEW_SYN_RECV, 63 DCCPF_PARTOPEN = (1 << DCCP_PARTOPEN), 64}; 65 66static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb) 67{ 68 return (struct dccp_hdr *)skb_transport_header(skb); 69} 70 71static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen) 72{ 73 skb_push(skb, headlen); 74 skb_reset_transport_header(skb); 75 return memset(skb_transport_header(skb), 0, headlen); 76} 77 78static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh) 79{ 80 return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh)); 81} 82 83static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh) 84{ 85 return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0); 86} 87 88static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb) 89{ 90 const struct dccp_hdr *dh = dccp_hdr(skb); 91 return __dccp_basic_hdr_len(dh); 92} 93 94static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh) 95{ 96 __u64 seq_nr = ntohs(dh->dccph_seq); 97 98 if (dh->dccph_x != 0) 99 seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low); 100 else 101 seq_nr += (u32)dh->dccph_seq2 << 16; 102 103 return seq_nr; 104} 105 106static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb) 107{ 108 return (struct dccp_hdr_request *)(skb_transport_header(skb) + 109 dccp_basic_hdr_len(skb)); 110} 111 112static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb) 113{ 114 return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) + 115 dccp_basic_hdr_len(skb)); 116} 117 118static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb) 119{ 120 const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb); 121 return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low); 122} 123 124static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb) 125{ 126 return (struct dccp_hdr_response *)(skb_transport_header(skb) + 127 dccp_basic_hdr_len(skb)); 128} 129 130static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb) 131{ 132 return (struct dccp_hdr_reset *)(skb_transport_header(skb) + 133 dccp_basic_hdr_len(skb)); 134} 135 136static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh) 137{ 138 return __dccp_basic_hdr_len(dh) + 139 dccp_packet_hdr_len(dh->dccph_type); 140} 141 142static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) 143{ 144 return __dccp_hdr_len(dccp_hdr(skb)); 145} 146 147/** 148 * struct dccp_request_sock - represent DCCP-specific connection request 149 * @dreq_inet_rsk: structure inherited from 150 * @dreq_iss: initial sequence number, sent on the first Response (RFC 4340, 7.1) 151 * @dreq_gss: greatest sequence number sent (for retransmitted Responses) 152 * @dreq_isr: initial sequence number received in the first Request 153 * @dreq_gsr: greatest sequence number received (for retransmitted Request(s)) 154 * @dreq_service: service code present on the Request (there is just one) 155 * @dreq_featneg: feature negotiation options for this connection 156 * The following two fields are analogous to the ones in dccp_sock: 157 * @dreq_timestamp_echo: last received timestamp to echo (13.1) 158 * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo 159 */ 160struct dccp_request_sock { 161 struct inet_request_sock dreq_inet_rsk; 162 __u64 dreq_iss; 163 __u64 dreq_gss; 164 __u64 dreq_isr; 165 __u64 dreq_gsr; 166 __be32 dreq_service; 167 spinlock_t dreq_lock; 168 struct list_head dreq_featneg; 169 __u32 dreq_timestamp_echo; 170 __u32 dreq_timestamp_time; 171}; 172 173static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req) 174{ 175 return (struct dccp_request_sock *)req; 176} 177 178extern struct inet_timewait_death_row dccp_death_row; 179 180extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, 181 struct sk_buff *skb); 182 183struct dccp_options_received { 184 u64 dccpor_ndp:48; 185 u32 dccpor_timestamp; 186 u32 dccpor_timestamp_echo; 187 u32 dccpor_elapsed_time; 188}; 189 190struct ccid; 191 192enum dccp_role { 193 DCCP_ROLE_UNDEFINED, 194 DCCP_ROLE_LISTEN, 195 DCCP_ROLE_CLIENT, 196 DCCP_ROLE_SERVER, 197}; 198 199struct dccp_service_list { 200 __u32 dccpsl_nr; 201 __be32 dccpsl_list[]; 202}; 203 204#define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1) 205#define DCCP_SERVICE_CODE_IS_ABSENT 0 206 207static inline bool dccp_list_has_service(const struct dccp_service_list *sl, 208 const __be32 service) 209{ 210 if (likely(sl != NULL)) { 211 u32 i = sl->dccpsl_nr; 212 while (i--) 213 if (sl->dccpsl_list[i] == service) 214 return true; 215 } 216 return false; 217} 218 219struct dccp_ackvec; 220 221/** 222 * struct dccp_sock - DCCP socket state 223 * 224 * @dccps_swl - sequence number window low 225 * @dccps_swh - sequence number window high 226 * @dccps_awl - acknowledgement number window low 227 * @dccps_awh - acknowledgement number window high 228 * @dccps_iss - initial sequence number sent 229 * @dccps_isr - initial sequence number received 230 * @dccps_osr - first OPEN sequence number received 231 * @dccps_gss - greatest sequence number sent 232 * @dccps_gsr - greatest valid sequence number received 233 * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss 234 * @dccps_service - first (passive sock) or unique (active sock) service code 235 * @dccps_service_list - second .. last service code on passive socket 236 * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option 237 * @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo 238 * @dccps_l_ack_ratio - feature-local Ack Ratio 239 * @dccps_r_ack_ratio - feature-remote Ack Ratio 240 * @dccps_l_seq_win - local Sequence Window (influences ack number validity) 241 * @dccps_r_seq_win - remote Sequence Window (influences seq number validity) 242 * @dccps_pcslen - sender partial checksum coverage (via sockopt) 243 * @dccps_pcrlen - receiver partial checksum coverage (via sockopt) 244 * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2) 245 * @dccps_ndp_count - number of Non Data Packets since last data packet 246 * @dccps_mss_cache - current value of MSS (path MTU minus header sizes) 247 * @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4) 248 * @dccps_featneg - tracks feature-negotiation state (mostly during handshake) 249 * @dccps_hc_rx_ackvec - rx half connection ack vector 250 * @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection) 251 * @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection) 252 * @dccps_options_received - parsed set of retrieved options 253 * @dccps_qpolicy - TX dequeueing policy, one of %dccp_packet_dequeueing_policy 254 * @dccps_tx_qlen - maximum length of the TX queue 255 * @dccps_role - role of this sock, one of %dccp_role 256 * @dccps_hc_rx_insert_options - receiver wants to add options when acking 257 * @dccps_hc_tx_insert_options - sender wants to add options when sending 258 * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3) 259 * @dccps_sync_scheduled - flag which signals "send out-of-band message soon" 260 * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets 261 * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing) 262 * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs) 263 */ 264struct dccp_sock { 265 /* inet_connection_sock has to be the first member of dccp_sock */ 266 struct inet_connection_sock dccps_inet_connection; 267#define dccps_syn_rtt dccps_inet_connection.icsk_ack.lrcvtime 268 __u64 dccps_swl; 269 __u64 dccps_swh; 270 __u64 dccps_awl; 271 __u64 dccps_awh; 272 __u64 dccps_iss; 273 __u64 dccps_isr; 274 __u64 dccps_osr; 275 __u64 dccps_gss; 276 __u64 dccps_gsr; 277 __u64 dccps_gar; 278 __be32 dccps_service; 279 __u32 dccps_mss_cache; 280 struct dccp_service_list *dccps_service_list; 281 __u32 dccps_timestamp_echo; 282 __u32 dccps_timestamp_time; 283 __u16 dccps_l_ack_ratio; 284 __u16 dccps_r_ack_ratio; 285 __u64 dccps_l_seq_win:48; 286 __u64 dccps_r_seq_win:48; 287 __u8 dccps_pcslen:4; 288 __u8 dccps_pcrlen:4; 289 __u8 dccps_send_ndp_count:1; 290 __u64 dccps_ndp_count:48; 291 unsigned long dccps_rate_last; 292 struct list_head dccps_featneg; 293 struct dccp_ackvec *dccps_hc_rx_ackvec; 294 struct ccid *dccps_hc_rx_ccid; 295 struct ccid *dccps_hc_tx_ccid; 296 struct dccp_options_received dccps_options_received; 297 __u8 dccps_qpolicy; 298 __u32 dccps_tx_qlen; 299 enum dccp_role dccps_role:2; 300 __u8 dccps_hc_rx_insert_options:1; 301 __u8 dccps_hc_tx_insert_options:1; 302 __u8 dccps_server_timewait:1; 303 __u8 dccps_sync_scheduled:1; 304 struct tasklet_struct dccps_xmitlet; 305 struct timer_list dccps_xmit_timer; 306}; 307 308#define dccp_sk(ptr) container_of_const(ptr, struct dccp_sock, \ 309 dccps_inet_connection.icsk_inet.sk) 310 311static inline const char *dccp_role(const struct sock *sk) 312{ 313 switch (dccp_sk(sk)->dccps_role) { 314 case DCCP_ROLE_UNDEFINED: return "undefined"; 315 case DCCP_ROLE_LISTEN: return "listen"; 316 case DCCP_ROLE_SERVER: return "server"; 317 case DCCP_ROLE_CLIENT: return "client"; 318 } 319 return NULL; 320} 321 322extern void dccp_syn_ack_timeout(const struct request_sock *req); 323 324#endif /* _LINUX_DCCP_H */ 325