include/net/inet_connection_sock.h

   1 /*
   2  * NET          Generic infrastructure for INET connection oriented protocols.
   3  *
   4  *              Definitions for inet_connection_sock
   5  *
   6  * Authors:     Many people, see the TCP sources
   7  *
   8  *              From code originally in TCP
   9  *
  10  *              This program is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or (at your option) any later version.
  14  */
  15 #ifndef _INET_CONNECTION_SOCK_H
  16 #define _INET_CONNECTION_SOCK_H
  17
  18 #include <linux/compiler.h>
  19 #include <linux/string.h>
  20 #include <linux/timer.h>
  21
  22 #include <net/inet_sock.h>
  23 #include <net/request_sock.h>
  24
  25 #define INET_CSK_DEBUG 1
  26
  27 /* Cancel timers, when they are not required. */
  28 #undef INET_CSK_CLEAR_TIMERS
  29
  30 struct inet_bind_bucket;
  31 struct inet_hashinfo;
  32 struct tcp_congestion_ops;
  33
  34 /*
  35  * Pointers to address related TCP functions
  36  * (i.e. things that depend on the address family)
  37  */
  38 struct inet_connection_sock_af_ops {
  39         int         (*queue_xmit)(struct sk_buff *skb, int ipfragok);
  40         void        (*send_check)(struct sock *sk, int len,
  41                                   struct sk_buff *skb);
  42         int         (*rebuild_header)(struct sock *sk);
  43         int         (*conn_request)(struct sock *sk, struct sk_buff *skb);
  44         struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb,
  45                                       struct request_sock *req,
  46                                       struct dst_entry *dst);
  47         int         (*remember_stamp)(struct sock *sk);
  48         __u16       net_header_len;
  49         int         (*setsockopt)(struct sock *sk, int level, int optname,
  50                                   char __user *optval, int optlen);
  51         int         (*getsockopt)(struct sock *sk, int level, int optname,
  52                                   char __user *optval, int __user *optlen);
  53         void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  54         int sockaddr_len;
  55 };
  56
  57 /** inet_connection_sock - INET connection oriented sock
  58  *
  59  * @icsk_accept_queue:     FIFO of established children
  60  * @icsk_bind_hash:        Bind node
  61  * @icsk_timeout:          Timeout
  62  * @icsk_retransmit_timer: Resend (no ack)
  63  * @icsk_rto:              Retransmit timeout
  64  * @icsk_pmtu_cookie       Last pmtu seen by socket
  65  * @icsk_ca_ops            Pluggable congestion control hook
  66  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  67  * @icsk_ca_state:         Congestion control state
  68  * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  69  * @icsk_pending:          Scheduled timer event
  70  * @icsk_backoff:          Backoff
  71  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  72  * @icsk_probes_out:       unanswered 0 window probes
  73  * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  74  * @icsk_ack:              Delayed ACK control data
  75  * @icsk_mtup;             MTU probing control data
  76  */
  77 struct inet_connection_sock {
  78         /* inet_sock has to be the first member! */
  79         struct inet_sock          icsk_inet;
  80         struct request_sock_queue icsk_accept_queue;
  81         struct inet_bind_bucket   *icsk_bind_hash;
  82         unsigned long             icsk_timeout;
  83         struct timer_list         icsk_retransmit_timer;
  84         struct timer_list         icsk_delack_timer;
  85         __u32                     icsk_rto;
  86         __u32                     icsk_pmtu_cookie;
  87         const struct tcp_congestion_ops *icsk_ca_ops;
  88         const struct inet_connection_sock_af_ops *icsk_af_ops;
  89         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
  90         __u8                      icsk_ca_state;
  91         __u8                      icsk_retransmits;
  92         __u8                      icsk_pending;
  93         __u8                      icsk_backoff;
  94         __u8                      icsk_syn_retries;
  95         __u8                      icsk_probes_out;
  96         __u16                     icsk_ext_hdr_len;
  97         struct {
  98                 __u8              pending;       /* ACK is pending                         */
  99                 __u8              quick;         /* Scheduled number of quick acks         */
 100                 __u8              pingpong;      /* The session is interactive             */
 101                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 102                 __u32             ato;           /* Predicted tick of soft clock           */
 103                 unsigned long     timeout;       /* Currently scheduled timeout            */
 104                 __u32             lrcvtime;      /* timestamp of last received data packet */
 105                 __u16             last_seg_size; /* Size of last incoming segment          */
 106                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 107         } icsk_ack;
 108         struct {
 109                 int               enabled;
 110
 111                 /* Range of MTUs to search */
 112                 int               search_high;
 113                 int               search_low;
 114
 115                 /* Information on the current probe. */
 116                 int               probe_size;
 117                 __u32             probe_seq_start;
 118                 __u32             probe_seq_end;
 119         } icsk_mtup;
 120         u32                       icsk_ca_priv[16];
 121 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 122 };
 123
 124 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 125 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 126 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 127 #define ICSK_TIME_KEEPOPEN      4       /* Keepalive timer */
 128
 129 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 130 {
 131         return (struct inet_connection_sock *)sk;
 132 }
 133
 134 static inline void *inet_csk_ca(const struct sock *sk)
 135 {
 136         return (void *)inet_csk(sk)->icsk_ca_priv;
 137 }
 138
 139 extern struct sock *inet_csk_clone(struct sock *sk,
 140                                    const struct request_sock *req,
 141                                    const gfp_t priority);
 142
 143 enum inet_csk_ack_state_t {
 144         ICSK_ACK_SCHED  = 1,
 145         ICSK_ACK_TIMER  = 2,
 146         ICSK_ACK_PUSHED = 4
 147 };
 148
 149 extern void inet_csk_init_xmit_timers(struct sock *sk,
 150                                       void (*retransmit_handler)(unsigned long),
 151                                       void (*delack_handler)(unsigned long),
 152                                       void (*keepalive_handler)(unsigned long));
 153 extern void inet_csk_clear_xmit_timers(struct sock *sk);
 154
 155 static inline void inet_csk_schedule_ack(struct sock *sk)
 156 {
 157         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 158 }
 159
 160 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 161 {
 162         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 163 }
 164
 165 static inline void inet_csk_delack_init(struct sock *sk)
 166 {
 167         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 168 }
 169
 170 extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 171 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 172
 173 #ifdef INET_CSK_DEBUG
 174 extern const char inet_csk_timer_bug_msg[];
 175 #endif
 176
 177 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 178 {
 179         struct inet_connection_sock *icsk = inet_csk(sk);
 180
 181         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 182                 icsk->icsk_pending = 0;
 183 #ifdef INET_CSK_CLEAR_TIMERS
 184                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 185 #endif
 186         } else if (what == ICSK_TIME_DACK) {
 187                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 188 #ifdef INET_CSK_CLEAR_TIMERS
 189                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 190 #endif
 191         }
 192 #ifdef INET_CSK_DEBUG
 193         else {
 194                 pr_debug("%s", inet_csk_timer_bug_msg);
 195         }
 196 #endif
 197 }
 198
 199 /*
 200  *      Reset the retransmission timer
 201  */
 202 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 203                                              unsigned long when,
 204                                              const unsigned long max_when)
 205 {
 206         struct inet_connection_sock *icsk = inet_csk(sk);
 207
 208         if (when > max_when) {
 209 #ifdef INET_CSK_DEBUG
 210                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 211                          sk, what, when, current_text_addr());
 212 #endif
 213                 when = max_when;
 214         }
 215
 216         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 217                 icsk->icsk_pending = what;
 218                 icsk->icsk_timeout = jiffies + when;
 219                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 220         } else if (what == ICSK_TIME_DACK) {
 221                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 222                 icsk->icsk_ack.timeout = jiffies + when;
 223                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 224         }
 225 #ifdef INET_CSK_DEBUG
 226         else {
 227                 pr_debug("%s", inet_csk_timer_bug_msg);
 228         }
 229 #endif
 230 }
 231
 232 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 233
 234 extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 235                                                 struct request_sock ***prevp,
 236                                                 const __u16 rport,
 237                                                 const __u32 raddr,
 238                                                 const __u32 laddr);
 239 extern int inet_csk_bind_conflict(const struct sock *sk,
 240                                   const struct inet_bind_bucket *tb);
 241 extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
 242                              struct sock *sk, unsigned short snum,
 243                              int (*bind_conflict)(const struct sock *sk,
 244                                                   const struct inet_bind_bucket *tb));
 245
 246 extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 247                                             const struct request_sock *req);
 248
 249 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 250                                             struct request_sock *req,
 251                                             struct sock *child)
 252 {
 253         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 254 }
 255
 256 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 257                                           struct request_sock *req,
 258                                           unsigned long timeout);
 259
 260 static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 261                                                 struct request_sock *req)
 262 {
 263         if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 264                 inet_csk_delete_keepalive_timer(sk);
 265 }
 266
 267 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 268                                               const unsigned long timeout)
 269 {
 270         if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 271                 inet_csk_reset_keepalive_timer(sk, timeout);
 272 }
 273
 274 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 275 {
 276         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 277 }
 278
 279 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 280 {
 281         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 282 }
 283
 284 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 285 {
 286         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 287 }
 288
 289 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 290                                                struct request_sock *req,
 291                                                struct request_sock **prev)
 292 {
 293         reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 294 }
 295
 296 static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 297                                              struct request_sock *req,
 298                                              struct request_sock **prev)
 299 {
 300         inet_csk_reqsk_queue_unlink(sk, req, prev);
 301         inet_csk_reqsk_queue_removed(sk, req);
 302         reqsk_free(req);
 303 }
 304
 305 extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 306                                        const unsigned long interval,
 307                                        const unsigned long timeout,
 308                                        const unsigned long max_rto);
 309
 310 extern void inet_csk_destroy_sock(struct sock *sk);
 311
 312 /*
 313  * LISTEN is a special case for poll..
 314  */
 315 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 316 {
 317         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 318                         (POLLIN | POLLRDNORM) : 0;
 319 }
 320
 321 extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 322 extern void inet_csk_listen_stop(struct sock *sk);
 323
 324 extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 325
 326 #endif /* _INET_CONNECTION_SOCK_H */