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 #include <linux/poll.h>
  22
  23 #include <net/inet_sock.h>
  24 #include <net/request_sock.h>
  25
  26 #define INET_CSK_DEBUG 1
  27
  28 /* Cancel timers, when they are not required. */
  29 #undef INET_CSK_CLEAR_TIMERS
  30
  31 struct inet_bind_bucket;
  32 struct inet_hashinfo;
  33 struct tcp_congestion_ops;
  34
  35 /*
  36  * Pointers to address related TCP functions
  37  * (i.e. things that depend on the address family)
  38  */
  39 struct inet_connection_sock_af_ops {
  40         int         (*queue_xmit)(struct sk_buff *skb, struct sock *sk,
  41                                   int ipfragok);
  42         void        (*send_check)(struct sock *sk, int len,
  43                                   struct sk_buff *skb);
  44         int         (*rebuild_header)(struct sock *sk);
  45         int         (*conn_request)(struct sock *sk, struct sk_buff *skb);
  46         struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb,
  47                                       struct request_sock *req,
  48                                       struct dst_entry *dst);
  49         int         (*remember_stamp)(struct sock *sk);
  50         u16         net_header_len;
  51         u16         sockaddr_len;
  52         int         (*setsockopt)(struct sock *sk, int level, int optname,
  53                                   char __user *optval, int optlen);
  54         int         (*getsockopt)(struct sock *sk, int level, int optname,
  55                                   char __user *optval, int __user *optlen);
  56         int         (*compat_setsockopt)(struct sock *sk,
  57                                 int level, int optname,
  58                                 char __user *optval, int optlen);
  59         int         (*compat_getsockopt)(struct sock *sk,
  60                                 int level, int optname,
  61                                 char __user *optval, int __user *optlen);
  62         void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  63 };
  64
  65 /** inet_connection_sock - INET connection oriented sock
  66  *
  67  * @icsk_accept_queue:     FIFO of established children
  68  * @icsk_bind_hash:        Bind node
  69  * @icsk_timeout:          Timeout
  70  * @icsk_retransmit_timer: Resend (no ack)
  71  * @icsk_rto:              Retransmit timeout
  72  * @icsk_pmtu_cookie       Last pmtu seen by socket
  73  * @icsk_ca_ops            Pluggable congestion control hook
  74  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  75  * @icsk_ca_state:         Congestion control state
  76  * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  77  * @icsk_pending:          Scheduled timer event
  78  * @icsk_backoff:          Backoff
  79  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  80  * @icsk_probes_out:       unanswered 0 window probes
  81  * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  82  * @icsk_ack:              Delayed ACK control data
  83  * @icsk_mtup;             MTU probing control data
  84  */
  85 struct inet_connection_sock {
  86         /* inet_sock has to be the first member! */
  87         struct inet_sock          icsk_inet;
  88         struct request_sock_queue icsk_accept_queue;
  89         struct inet_bind_bucket   *icsk_bind_hash;
  90         unsigned long             icsk_timeout;
  91         struct timer_list         icsk_retransmit_timer;
  92         struct timer_list         icsk_delack_timer;
  93         __u32                     icsk_rto;
  94         __u32                     icsk_pmtu_cookie;
  95         const struct tcp_congestion_ops *icsk_ca_ops;
  96         const struct inet_connection_sock_af_ops *icsk_af_ops;
  97         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
  98         __u8                      icsk_ca_state;
  99         __u8                      icsk_retransmits;
 100         __u8                      icsk_pending;
 101         __u8                      icsk_backoff;
 102         __u8                      icsk_syn_retries;
 103         __u8                      icsk_probes_out;
 104         __u16                     icsk_ext_hdr_len;
 105         struct {
 106                 __u8              pending;       /* ACK is pending                         */
 107                 __u8              quick;         /* Scheduled number of quick acks         */
 108                 __u8              pingpong;      /* The session is interactive             */
 109                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 110                 __u32             ato;           /* Predicted tick of soft clock           */
 111                 unsigned long     timeout;       /* Currently scheduled timeout            */
 112                 __u32             lrcvtime;      /* timestamp of last received data packet */
 113                 __u16             last_seg_size; /* Size of last incoming segment          */
 114                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 115         } icsk_ack;
 116         struct {
 117                 int               enabled;
 118
 119                 /* Range of MTUs to search */
 120                 int               search_high;
 121                 int               search_low;
 122
 123                 /* Information on the current probe. */
 124                 int               probe_size;
 125         } icsk_mtup;
 126         u32                       icsk_ca_priv[16];
 127 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 128 };
 129
 130 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 131 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 132 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 133 #define ICSK_TIME_KEEPOPEN      4       /* Keepalive timer */
 134
 135 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 136 {
 137         return (struct inet_connection_sock *)sk;
 138 }
 139
 140 static inline void *inet_csk_ca(const struct sock *sk)
 141 {
 142         return (void *)inet_csk(sk)->icsk_ca_priv;
 143 }
 144
 145 extern struct sock *inet_csk_clone(struct sock *sk,
 146                                    const struct request_sock *req,
 147                                    const gfp_t priority);
 148
 149 enum inet_csk_ack_state_t {
 150         ICSK_ACK_SCHED  = 1,
 151         ICSK_ACK_TIMER  = 2,
 152         ICSK_ACK_PUSHED = 4,
 153         ICSK_ACK_PUSHED2 = 8
 154 };
 155
 156 extern void inet_csk_init_xmit_timers(struct sock *sk,
 157                                       void (*retransmit_handler)(unsigned long),
 158                                       void (*delack_handler)(unsigned long),
 159                                       void (*keepalive_handler)(unsigned long));
 160 extern void inet_csk_clear_xmit_timers(struct sock *sk);
 161
 162 static inline void inet_csk_schedule_ack(struct sock *sk)
 163 {
 164         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 165 }
 166
 167 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 168 {
 169         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 170 }
 171
 172 static inline void inet_csk_delack_init(struct sock *sk)
 173 {
 174         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 175 }
 176
 177 extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 178 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 179
 180 #ifdef INET_CSK_DEBUG
 181 extern const char inet_csk_timer_bug_msg[];
 182 #endif
 183
 184 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 185 {
 186         struct inet_connection_sock *icsk = inet_csk(sk);
 187
 188         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 189                 icsk->icsk_pending = 0;
 190 #ifdef INET_CSK_CLEAR_TIMERS
 191                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 192 #endif
 193         } else if (what == ICSK_TIME_DACK) {
 194                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 195 #ifdef INET_CSK_CLEAR_TIMERS
 196                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 197 #endif
 198         }
 199 #ifdef INET_CSK_DEBUG
 200         else {
 201                 pr_debug("%s", inet_csk_timer_bug_msg);
 202         }
 203 #endif
 204 }
 205
 206 /*
 207  *      Reset the retransmission timer
 208  */
 209 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 210                                              unsigned long when,
 211                                              const unsigned long max_when)
 212 {
 213         struct inet_connection_sock *icsk = inet_csk(sk);
 214
 215         if (when > max_when) {
 216 #ifdef INET_CSK_DEBUG
 217                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 218                          sk, what, when, current_text_addr());
 219 #endif
 220                 when = max_when;
 221         }
 222
 223         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 224                 icsk->icsk_pending = what;
 225                 icsk->icsk_timeout = jiffies + when;
 226                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 227         } else if (what == ICSK_TIME_DACK) {
 228                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 229                 icsk->icsk_ack.timeout = jiffies + when;
 230                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 231         }
 232 #ifdef INET_CSK_DEBUG
 233         else {
 234                 pr_debug("%s", inet_csk_timer_bug_msg);
 235         }
 236 #endif
 237 }
 238
 239 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 240
 241 extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 242                                                 struct request_sock ***prevp,
 243                                                 const __be16 rport,
 244                                                 const __be32 raddr,
 245                                                 const __be32 laddr);
 246 extern int inet_csk_bind_conflict(const struct sock *sk,
 247                                   const struct inet_bind_bucket *tb);
 248 extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
 249                              struct sock *sk, unsigned short snum,
 250                              int (*bind_conflict)(const struct sock *sk,
 251                                                   const struct inet_bind_bucket *tb));
 252
 253 extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 254                                             const struct request_sock *req);
 255
 256 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 257                                             struct request_sock *req,
 258                                             struct sock *child)
 259 {
 260         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 261 }
 262
 263 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 264                                           struct request_sock *req,
 265                                           unsigned long timeout);
 266
 267 static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 268                                                 struct request_sock *req)
 269 {
 270         if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 271                 inet_csk_delete_keepalive_timer(sk);
 272 }
 273
 274 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 275                                               const unsigned long timeout)
 276 {
 277         if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 278                 inet_csk_reset_keepalive_timer(sk, timeout);
 279 }
 280
 281 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 282 {
 283         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 284 }
 285
 286 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 287 {
 288         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 289 }
 290
 291 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 292 {
 293         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 294 }
 295
 296 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 297                                                struct request_sock *req,
 298                                                struct request_sock **prev)
 299 {
 300         reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 301 }
 302
 303 static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 304                                              struct request_sock *req,
 305                                              struct request_sock **prev)
 306 {
 307         inet_csk_reqsk_queue_unlink(sk, req, prev);
 308         inet_csk_reqsk_queue_removed(sk, req);
 309         reqsk_free(req);
 310 }
 311
 312 extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 313                                        const unsigned long interval,
 314                                        const unsigned long timeout,
 315                                        const unsigned long max_rto);
 316
 317 extern void inet_csk_destroy_sock(struct sock *sk);
 318
 319 /*
 320  * LISTEN is a special case for poll..
 321  */
 322 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 323 {
 324         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 325                         (POLLIN | POLLRDNORM) : 0;
 326 }
 327
 328 extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 329 extern void inet_csk_listen_stop(struct sock *sk);
 330
 331 extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 332
 333 extern int inet_csk_ctl_sock_create(struct socket **sock,
 334                                     unsigned short family,
 335                                     unsigned short type,
 336                                     unsigned char protocol);
 337
 338 extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 339                                       char __user *optval, int __user *optlen);
 340 extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 341                                       char __user *optval, int optlen);
 342 #endif /* _INET_CONNECTION_SOCK_H */