Branch data     Line data    Source code

       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                 :            : 
      19                 :            : enum 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                 :            : 
      53                 :            : enum {
      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                 :            : 
      66                 :          0 : static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
      67                 :            : {
      68         [ #  # ]:          0 :         return (struct dccp_hdr *)skb_transport_header(skb);
      69                 :            : }
      70                 :            : 
      71                 :            : static 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                 :            : 
      78                 :            : static 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                 :            : 
      83                 :            : static 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                 :            : 
      88                 :            : static 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                 :            : 
      94                 :            : static 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                 :            : 
     106                 :            : static 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                 :            : 
     112                 :            : static 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                 :            : 
     118                 :            : static 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                 :            : 
     124                 :            : static 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                 :            : 
     130                 :            : static 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                 :            : 
     136                 :            : static 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                 :            : 
     142                 :            : static 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                 :            :  */
     160                 :            : struct 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                 :            : 
     173                 :            : static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
     174                 :            : {
     175                 :            :         return (struct dccp_request_sock *)req;
     176                 :            : }
     177                 :            : 
     178                 :            : extern struct inet_timewait_death_row dccp_death_row;
     179                 :            : 
     180                 :            : extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
     181                 :            :                               struct sk_buff *skb);
     182                 :            : 
     183                 :            : struct dccp_options_received {
     184                 :            :         u64     dccpor_ndp:48;
     185                 :            :         u32     dccpor_timestamp;
     186                 :            :         u32     dccpor_timestamp_echo;
     187                 :            :         u32     dccpor_elapsed_time;
     188                 :            : };
     189                 :            : 
     190                 :            : struct ccid;
     191                 :            : 
     192                 :            : enum dccp_role {
     193                 :            :         DCCP_ROLE_UNDEFINED,
     194                 :            :         DCCP_ROLE_LISTEN,
     195                 :            :         DCCP_ROLE_CLIENT,
     196                 :            :         DCCP_ROLE_SERVER,
     197                 :            : };
     198                 :            : 
     199                 :            : struct dccp_service_list {
     200                 :            :         __u32   dccpsl_nr;
     201                 :            :         __be32  dccpsl_list[0];
     202                 :            : };
     203                 :            : 
     204                 :            : #define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
     205                 :            : #define DCCP_SERVICE_CODE_IS_ABSENT             0
     206                 :            : 
     207                 :            : static 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                 :            : 
     219                 :            : struct 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                 :            :  */
     264                 :            : struct 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                 :            : static inline struct dccp_sock *dccp_sk(const struct sock *sk)
     309                 :            : {
     310                 :            :         return (struct dccp_sock *)sk;
     311                 :            : }
     312                 :            : 
     313                 :            : static inline const char *dccp_role(const struct sock *sk)
     314                 :            : {
     315                 :            :         switch (dccp_sk(sk)->dccps_role) {
     316                 :            :         case DCCP_ROLE_UNDEFINED: return "undefined";
     317                 :            :         case DCCP_ROLE_LISTEN:    return "listen";
     318                 :            :         case DCCP_ROLE_SERVER:    return "server";
     319                 :            :         case DCCP_ROLE_CLIENT:    return "client";
     320                 :            :         }
     321                 :            :         return NULL;
     322                 :            : }
     323                 :            : 
     324                 :            : extern void dccp_syn_ack_timeout(const struct request_sock *req);
     325                 :            : 
     326                 :            : #endif /* _LINUX_DCCP_H */