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         int         (*compat_setsockopt)(struct sock *sk,
  54                                 int level, int optname,
  55                                 char __user *optval, int optlen);
  56         int         (*compat_getsockopt)(struct sock *sk,
  57                                 int level, int optname,
  58                                 char __user *optval, int __user *optlen);
  59         void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  60         int sockaddr_len;
  61 };
  62
  63 /** inet_connection_sock - INET connection oriented sock
  64  *
  65  * @icsk_accept_queue:     FIFO of established children
  66  * @icsk_bind_hash:        Bind node
  67  * @icsk_timeout:          Timeout
  68  * @icsk_retransmit_timer: Resend (no ack)
  69  * @icsk_rto:              Retransmit timeout
  70  * @icsk_pmtu_cookie       Last pmtu seen by socket
  71  * @icsk_ca_ops            Pluggable congestion control hook
  72  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  73  * @icsk_ca_state:         Congestion control state
  74  * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  75  * @icsk_pending:          Scheduled timer event
  76  * @icsk_backoff:          Backoff
  77  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  78  * @icsk_probes_out:       unanswered 0 window probes
  79  * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  80  * @icsk_ack:              Delayed ACK control data
  81  * @icsk_mtup;             MTU probing control data
  82  */
  83 struct inet_connection_sock {
  84         /* inet_sock has to be the first member! */
  85         struct inet_sock          icsk_inet;
  86         struct request_sock_queue icsk_accept_queue;
  87         struct inet_bind_bucket   *icsk_bind_hash;
  88         unsigned long             icsk_timeout;
  89         struct timer_list         icsk_retransmit_timer;
  90         struct timer_list         icsk_delack_timer;
  91         __u32                     icsk_rto;
  92         __u32                     icsk_pmtu_cookie;
  93         const struct tcp_congestion_ops *icsk_ca_ops;
  94         const struct inet_connection_sock_af_ops *icsk_af_ops;
  95         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
  96         __u8                      icsk_ca_state;
  97         __u8                      icsk_retransmits;
  98         __u8                      icsk_pending;
  99         __u8                      icsk_backoff;
 100         __u8                      icsk_syn_retries;
 101         __u8                      icsk_probes_out;
 102         __u16                     icsk_ext_hdr_len;
 103         struct {
 104                 __u8              pending;       /* ACK is pending                         */
 105                 __u8              quick;         /* Scheduled number of quick acks         */
 106                 __u8              pingpong;      /* The session is interactive             */
 107                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 108                 __u32             ato;           /* Predicted tick of soft clock           */
 109                 unsigned long     timeout;       /* Currently scheduled timeout            */
 110                 __u32             lrcvtime;      /* timestamp of last received data packet */
 111                 __u16             last_seg_size; /* Size of last incoming segment          */
 112                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 113         } icsk_ack;
 114         struct {
 115                 int               enabled;
 116
 117                 /* Range of MTUs to search */
 118                 int               search_high;
 119                 int               search_low;
 120
 121                 /* Information on the current probe. */
 122                 int               probe_size;
 123         } icsk_mtup;
 124         u32                       icsk_ca_priv[16];
 125 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 126 };
 127
 128 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 129 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 130 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 131 #define ICSK_TIME_KEEPOPEN      4       /* Keepalive timer */
 132
 133 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 134 {
 135         return (struct inet_connection_sock *)sk;
 136 }
 137
 138 static inline void *inet_csk_ca(const struct sock *sk)
 139 {
 140         return (void *)inet_csk(sk)->icsk_ca_priv;
 141 }
 142
 143 extern struct sock *inet_csk_clone(struct sock *sk,
 144                                    const struct request_sock *req,
 145                                    const gfp_t priority);
 146
 147 enum inet_csk_ack_state_t {
 148         ICSK_ACK_SCHED  = 1,
 149         ICSK_ACK_TIMER  = 2,
 150         ICSK_ACK_PUSHED = 4
 151 };
 152
 153 extern void inet_csk_init_xmit_timers(struct sock *sk,
 154                                       void (*retransmit_handler)(unsigned long),
 155                                       void (*delack_handler)(unsigned long),
 156                                       void (*keepalive_handler)(unsigned long));
 157 extern void inet_csk_clear_xmit_timers(struct sock *sk);
 158
 159 static inline void inet_csk_schedule_ack(struct sock *sk)
 160 {
 161         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 162 }
 163
 164 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 165 {
 166         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 167 }
 168
 169 static inline void inet_csk_delack_init(struct sock *sk)
 170 {
 171         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 172 }
 173
 174 extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 175 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 176
 177 #ifdef INET_CSK_DEBUG
 178 extern const char inet_csk_timer_bug_msg[];
 179 #endif
 180
 181 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 182 {
 183         struct inet_connection_sock *icsk = inet_csk(sk);
 184
 185         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 186                 icsk->icsk_pending = 0;
 187 #ifdef INET_CSK_CLEAR_TIMERS
 188                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 189 #endif
 190         } else if (what == ICSK_TIME_DACK) {
 191                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 192 #ifdef INET_CSK_CLEAR_TIMERS
 193                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 194 #endif
 195         }
 196 #ifdef INET_CSK_DEBUG
 197         else {
 198                 pr_debug("%s", inet_csk_timer_bug_msg);
 199         }
 200 #endif
 201 }
 202
 203 /*
 204  *      Reset the retransmission timer
 205  */
 206 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 207                                              unsigned long when,
 208                                              const unsigned long max_when)
 209 {
 210         struct inet_connection_sock *icsk = inet_csk(sk);
 211
 212         if (when > max_when) {
 213 #ifdef INET_CSK_DEBUG
 214                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 215                          sk, what, when, current_text_addr());
 216 #endif
 217                 when = max_when;
 218         }
 219
 220         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 221                 icsk->icsk_pending = what;
 222                 icsk->icsk_timeout = jiffies + when;
 223                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 224         } else if (what == ICSK_TIME_DACK) {
 225                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 226                 icsk->icsk_ack.timeout = jiffies + when;
 227                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 228         }
 229 #ifdef INET_CSK_DEBUG
 230         else {
 231                 pr_debug("%s", inet_csk_timer_bug_msg);
 232         }
 233 #endif
 234 }
 235
 236 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 237
 238 extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 239                                                 struct request_sock ***prevp,
 240                                                 const __u16 rport,
 241                                                 const __u32 raddr,
 242                                                 const __u32 laddr);
 243 extern int inet_csk_bind_conflict(const struct sock *sk,
 244                                   const struct inet_bind_bucket *tb);
 245 extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
 246                              struct sock *sk, unsigned short snum,
 247                              int (*bind_conflict)(const struct sock *sk,
 248                                                   const struct inet_bind_bucket *tb));
 249
 250 extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 251                                             const struct request_sock *req);
 252
 253 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 254                                             struct request_sock *req,
 255                                             struct sock *child)
 256 {
 257         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 258 }
 259
 260 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 261                                           struct request_sock *req,
 262                                           unsigned long timeout);
 263
 264 static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 265                                                 struct request_sock *req)
 266 {
 267         if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 268                 inet_csk_delete_keepalive_timer(sk);
 269 }
 270
 271 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 272                                               const unsigned long timeout)
 273 {
 274         if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 275                 inet_csk_reset_keepalive_timer(sk, timeout);
 276 }
 277
 278 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 279 {
 280         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 281 }
 282
 283 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 284 {
 285         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 286 }
 287
 288 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 289 {
 290         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 291 }
 292
 293 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 294                                                struct request_sock *req,
 295                                                struct request_sock **prev)
 296 {
 297         reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 298 }
 299
 300 static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 301                                              struct request_sock *req,
 302                                              struct request_sock **prev)
 303 {
 304         inet_csk_reqsk_queue_unlink(sk, req, prev);
 305         inet_csk_reqsk_queue_removed(sk, req);
 306         reqsk_free(req);
 307 }
 308
 309 extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 310                                        const unsigned long interval,
 311                                        const unsigned long timeout,
 312                                        const unsigned long max_rto);
 313
 314 extern void inet_csk_destroy_sock(struct sock *sk);
 315
 316 /*
 317  * LISTEN is a special case for poll..
 318  */
 319 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 320 {
 321         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 322                         (POLLIN | POLLRDNORM) : 0;
 323 }
 324
 325 extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 326 extern void inet_csk_listen_stop(struct sock *sk);
 327
 328 extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 329
 330 extern int inet_csk_ctl_sock_create(struct socket **sock,
 331                                     unsigned short family,
 332                                     unsigned short type,
 333                                     unsigned char protocol);
 334
 335 extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 336                                       char __user *optval, int __user *optlen);
 337 extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 338                                       char __user *optval, int optlen);
 339 #endif /* _INET_CONNECTION_SOCK_H */