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