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  */
  76 struct inet_connection_sock {
  77         /* inet_sock has to be the first member! */
  78         struct inet_sock          icsk_inet;
  79         struct request_sock_queue icsk_accept_queue;
  80         struct inet_bind_bucket   *icsk_bind_hash;
  81         unsigned long             icsk_timeout;
  82         struct timer_list         icsk_retransmit_timer;
  83         struct timer_list         icsk_delack_timer;
  84         __u32                     icsk_rto;
  85         __u32                     icsk_pmtu_cookie;
  86         const struct tcp_congestion_ops *icsk_ca_ops;
  87         const struct inet_connection_sock_af_ops *icsk_af_ops;
  88         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
  89         __u8                      icsk_ca_state;
  90         __u8                      icsk_retransmits;
  91         __u8                      icsk_pending;
  92         __u8                      icsk_backoff;
  93         __u8                      icsk_syn_retries;
  94         __u8                      icsk_probes_out;
  95         __u16                     icsk_ext_hdr_len;
  96         struct {
  97                 __u8              pending;       /* ACK is pending                         */
  98                 __u8              quick;         /* Scheduled number of quick acks         */
  99                 __u8              pingpong;      /* The session is interactive             */
 100                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 101                 __u32             ato;           /* Predicted tick of soft clock           */
 102                 unsigned long     timeout;       /* Currently scheduled timeout            */
 103                 __u32             lrcvtime;      /* timestamp of last received data packet */
 104                 __u16             last_seg_size; /* Size of last incoming segment          */
 105                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 106         } icsk_ack;
 107         u32                       icsk_ca_priv[16];
 108 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 109 };
 110
 111 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 112 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 113 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 114 #define ICSK_TIME_KEEPOPEN      4       /* Keepalive timer */
 115
 116 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 117 {
 118         return (struct inet_connection_sock *)sk;
 119 }
 120
 121 static inline void *inet_csk_ca(const struct sock *sk)
 122 {
 123         return (void *)inet_csk(sk)->icsk_ca_priv;
 124 }
 125
 126 extern struct sock *inet_csk_clone(struct sock *sk,
 127                                    const struct request_sock *req,
 128                                    const gfp_t priority);
 129
 130 enum inet_csk_ack_state_t {
 131         ICSK_ACK_SCHED  = 1,
 132         ICSK_ACK_TIMER  = 2,
 133         ICSK_ACK_PUSHED = 4
 134 };
 135
 136 extern void inet_csk_init_xmit_timers(struct sock *sk,
 137                                       void (*retransmit_handler)(unsigned long),
 138                                       void (*delack_handler)(unsigned long),
 139                                       void (*keepalive_handler)(unsigned long));
 140 extern void inet_csk_clear_xmit_timers(struct sock *sk);
 141
 142 static inline void inet_csk_schedule_ack(struct sock *sk)
 143 {
 144         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 145 }
 146
 147 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 148 {
 149         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 150 }
 151
 152 static inline void inet_csk_delack_init(struct sock *sk)
 153 {
 154         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 155 }
 156
 157 extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 158 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 159
 160 #ifdef INET_CSK_DEBUG
 161 extern const char inet_csk_timer_bug_msg[];
 162 #endif
 163
 164 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 165 {
 166         struct inet_connection_sock *icsk = inet_csk(sk);
 167
 168         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 169                 icsk->icsk_pending = 0;
 170 #ifdef INET_CSK_CLEAR_TIMERS
 171                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 172 #endif
 173         } else if (what == ICSK_TIME_DACK) {
 174                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 175 #ifdef INET_CSK_CLEAR_TIMERS
 176                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 177 #endif
 178         }
 179 #ifdef INET_CSK_DEBUG
 180         else {
 181                 pr_debug("%s", inet_csk_timer_bug_msg);
 182         }
 183 #endif
 184 }
 185
 186 /*
 187  *      Reset the retransmission timer
 188  */
 189 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 190                                              unsigned long when,
 191                                              const unsigned long max_when)
 192 {
 193         struct inet_connection_sock *icsk = inet_csk(sk);
 194
 195         if (when > max_when) {
 196 #ifdef INET_CSK_DEBUG
 197                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 198                          sk, what, when, current_text_addr());
 199 #endif
 200                 when = max_when;
 201         }
 202
 203         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 204                 icsk->icsk_pending = what;
 205                 icsk->icsk_timeout = jiffies + when;
 206                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 207         } else if (what == ICSK_TIME_DACK) {
 208                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 209                 icsk->icsk_ack.timeout = jiffies + when;
 210                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 211         }
 212 #ifdef INET_CSK_DEBUG
 213         else {
 214                 pr_debug("%s", inet_csk_timer_bug_msg);
 215         }
 216 #endif
 217 }
 218
 219 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 220
 221 extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 222                                                 struct request_sock ***prevp,
 223                                                 const __u16 rport,
 224                                                 const __u32 raddr,
 225                                                 const __u32 laddr);
 226 extern int inet_csk_bind_conflict(const struct sock *sk,
 227                                   const struct inet_bind_bucket *tb);
 228 extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
 229                              struct sock *sk, unsigned short snum,
 230                              int (*bind_conflict)(const struct sock *sk,
 231                                                   const struct inet_bind_bucket *tb));
 232
 233 extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 234                                             const struct request_sock *req);
 235
 236 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 237                                             struct request_sock *req,
 238                                             struct sock *child)
 239 {
 240         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 241 }
 242
 243 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 244                                           struct request_sock *req,
 245                                           unsigned long timeout);
 246
 247 static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 248                                                 struct request_sock *req)
 249 {
 250         if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 251                 inet_csk_delete_keepalive_timer(sk);
 252 }
 253
 254 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 255                                               const unsigned long timeout)
 256 {
 257         if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 258                 inet_csk_reset_keepalive_timer(sk, timeout);
 259 }
 260
 261 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 262 {
 263         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 264 }
 265
 266 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 267 {
 268         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 269 }
 270
 271 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 272 {
 273         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 274 }
 275
 276 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 277                                                struct request_sock *req,
 278                                                struct request_sock **prev)
 279 {
 280         reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 281 }
 282
 283 static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 284                                              struct request_sock *req,
 285                                              struct request_sock **prev)
 286 {
 287         inet_csk_reqsk_queue_unlink(sk, req, prev);
 288         inet_csk_reqsk_queue_removed(sk, req);
 289         reqsk_free(req);
 290 }
 291
 292 extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 293                                        const unsigned long interval,
 294                                        const unsigned long timeout,
 295                                        const unsigned long max_rto);
 296
 297 extern void inet_csk_destroy_sock(struct sock *sk);
 298
 299 /*
 300  * LISTEN is a special case for poll..
 301  */
 302 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 303 {
 304         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 305                         (POLLIN | POLLRDNORM) : 0;
 306 }
 307
 308 extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 309 extern void inet_csk_listen_stop(struct sock *sk);
 310
 311 extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 312
 313 #endif /* _INET_CONNECTION_SOCK_H */