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 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 sock *sk, struct sk_buff *skb, struct flowi *fl);
  40         void        (*send_check)(struct sock *sk, struct sk_buff *skb);
  41         int         (*rebuild_header)(struct sock *sk);
  42         void        (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
  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         u16         net_header_len;
  48         u16         net_frag_header_len;
  49         u16         sockaddr_len;
  50         int         (*setsockopt)(struct sock *sk, int level, int optname,
  51                                   char __user *optval, unsigned int optlen);
  52         int         (*getsockopt)(struct sock *sk, int level, int optname,
  53                                   char __user *optval, int __user *optlen);
  54 #ifdef CONFIG_COMPAT
  55         int         (*compat_setsockopt)(struct sock *sk,
  56                                 int level, int optname,
  57                                 char __user *optval, unsigned int optlen);
  58         int         (*compat_getsockopt)(struct sock *sk,
  59                                 int level, int optname,
  60                                 char __user *optval, int __user *optlen);
  61 #endif
  62         void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  63         int         (*bind_conflict)(const struct sock *sk,
  64                                      const struct inet_bind_bucket *tb, bool relax);
  65 };
  66
  67 /** inet_connection_sock - INET connection oriented sock
  68  *
  69  * @icsk_accept_queue:     FIFO of established children
  70  * @icsk_bind_hash:        Bind node
  71  * @icsk_timeout:          Timeout
  72  * @icsk_retransmit_timer: Resend (no ack)
  73  * @icsk_rto:              Retransmit timeout
  74  * @icsk_pmtu_cookie       Last pmtu seen by socket
  75  * @icsk_ca_ops            Pluggable congestion control hook
  76  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  77  * @icsk_ca_state:         Congestion control state
  78  * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  79  * @icsk_pending:          Scheduled timer event
  80  * @icsk_backoff:          Backoff
  81  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  82  * @icsk_probes_out:       unanswered 0 window probes
  83  * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  84  * @icsk_ack:              Delayed ACK control data
  85  * @icsk_mtup;             MTU probing control data
  86  */
  87 struct inet_connection_sock {
  88         /* inet_sock has to be the first member! */
  89         struct inet_sock          icsk_inet;
  90         struct request_sock_queue icsk_accept_queue;
  91         struct inet_bind_bucket   *icsk_bind_hash;
  92         unsigned long             icsk_timeout;
  93         struct timer_list         icsk_retransmit_timer;
  94         struct timer_list         icsk_delack_timer;
  95         __u32                     icsk_rto;
  96         __u32                     icsk_pmtu_cookie;
  97         const struct tcp_congestion_ops *icsk_ca_ops;
  98         const struct inet_connection_sock_af_ops *icsk_af_ops;
  99         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 100         __u8                      icsk_ca_state;
 101         __u8                      icsk_retransmits;
 102         __u8                      icsk_pending;
 103         __u8                      icsk_backoff;
 104         __u8                      icsk_syn_retries;
 105         __u8                      icsk_probes_out;
 106         __u16                     icsk_ext_hdr_len;
 107         struct {
 108                 __u8              pending;       /* ACK is pending                         */
 109                 __u8              quick;         /* Scheduled number of quick acks         */
 110                 __u8              pingpong;      /* The session is interactive             */
 111                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 112                 __u32             ato;           /* Predicted tick of soft clock           */
 113                 unsigned long     timeout;       /* Currently scheduled timeout            */
 114                 __u32             lrcvtime;      /* timestamp of last received data packet */
 115                 __u16             last_seg_size; /* Size of last incoming segment          */
 116                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 117         } icsk_ack;
 118         struct {
 119                 int               enabled;
 120
 121                 /* Range of MTUs to search */
 122                 int               search_high;
 123                 int               search_low;
 124
 125                 /* Information on the current probe. */
 126                 int               probe_size;
 127         } icsk_mtup;
 128         u32                       icsk_ca_priv[16];
 129         u32                       icsk_user_timeout;
 130 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 131 };
 132
 133 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 134 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 135 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 136 #define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 137 #define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 138
 139 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 140 {
 141         return (struct inet_connection_sock *)sk;
 142 }
 143
 144 static inline void *inet_csk_ca(const struct sock *sk)
 145 {
 146         return (void *)inet_csk(sk)->icsk_ca_priv;
 147 }
 148
 149 struct sock *inet_csk_clone_lock(const struct sock *sk,
 150                                  const struct request_sock *req,
 151                                  const gfp_t priority);
 152
 153 enum inet_csk_ack_state_t {
 154         ICSK_ACK_SCHED  = 1,
 155         ICSK_ACK_TIMER  = 2,
 156         ICSK_ACK_PUSHED = 4,
 157         ICSK_ACK_PUSHED2 = 8
 158 };
 159
 160 void inet_csk_init_xmit_timers(struct sock *sk,
 161                                void (*retransmit_handler)(unsigned long),
 162                                void (*delack_handler)(unsigned long),
 163                                void (*keepalive_handler)(unsigned long));
 164 void inet_csk_clear_xmit_timers(struct sock *sk);
 165
 166 static inline void inet_csk_schedule_ack(struct sock *sk)
 167 {
 168         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 169 }
 170
 171 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 172 {
 173         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 174 }
 175
 176 static inline void inet_csk_delack_init(struct sock *sk)
 177 {
 178         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 179 }
 180
 181 void inet_csk_delete_keepalive_timer(struct sock *sk);
 182 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 183
 184 #ifdef INET_CSK_DEBUG
 185 extern const char inet_csk_timer_bug_msg[];
 186 #endif
 187
 188 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 189 {
 190         struct inet_connection_sock *icsk = inet_csk(sk);
 191
 192         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 193                 icsk->icsk_pending = 0;
 194 #ifdef INET_CSK_CLEAR_TIMERS
 195                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 196 #endif
 197         } else if (what == ICSK_TIME_DACK) {
 198                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 199 #ifdef INET_CSK_CLEAR_TIMERS
 200                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 201 #endif
 202         }
 203 #ifdef INET_CSK_DEBUG
 204         else {
 205                 pr_debug("%s", inet_csk_timer_bug_msg);
 206         }
 207 #endif
 208 }
 209
 210 /*
 211  *      Reset the retransmission timer
 212  */
 213 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 214                                              unsigned long when,
 215                                              const unsigned long max_when)
 216 {
 217         struct inet_connection_sock *icsk = inet_csk(sk);
 218
 219         if (when > max_when) {
 220 #ifdef INET_CSK_DEBUG
 221                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 222                          sk, what, when, current_text_addr());
 223 #endif
 224                 when = max_when;
 225         }
 226
 227         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 228             what == ICSK_TIME_EARLY_RETRANS || what ==  ICSK_TIME_LOSS_PROBE) {
 229                 icsk->icsk_pending = what;
 230                 icsk->icsk_timeout = jiffies + when;
 231                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 232         } else if (what == ICSK_TIME_DACK) {
 233                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 234                 icsk->icsk_ack.timeout = jiffies + when;
 235                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 236         }
 237 #ifdef INET_CSK_DEBUG
 238         else {
 239                 pr_debug("%s", inet_csk_timer_bug_msg);
 240         }
 241 #endif
 242 }
 243
 244 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 245
 246 struct request_sock *inet_csk_search_req(const struct sock *sk,
 247                                          struct request_sock ***prevp,
 248                                          const __be16 rport,
 249                                          const __be32 raddr,
 250                                          const __be32 laddr);
 251 int inet_csk_bind_conflict(const struct sock *sk,
 252                            const struct inet_bind_bucket *tb, bool relax);
 253 int inet_csk_get_port(struct sock *sk, unsigned short snum);
 254
 255 struct dst_entry *inet_csk_route_req(struct sock *sk, struct flowi4 *fl4,
 256                                      const struct request_sock *req);
 257 struct dst_entry *inet_csk_route_child_sock(struct sock *sk, struct sock *newsk,
 258                                             const struct request_sock *req);
 259
 260 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 261                                             struct request_sock *req,
 262                                             struct sock *child)
 263 {
 264         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 265 }
 266
 267 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 268                                    unsigned long timeout);
 269
 270 static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 271                                                 struct request_sock *req)
 272 {
 273         if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 274                 inet_csk_delete_keepalive_timer(sk);
 275 }
 276
 277 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 278                                               const unsigned long timeout)
 279 {
 280         if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 281                 inet_csk_reset_keepalive_timer(sk, timeout);
 282 }
 283
 284 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 285 {
 286         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 287 }
 288
 289 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 290 {
 291         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 292 }
 293
 294 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 295 {
 296         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 297 }
 298
 299 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 300                                                struct request_sock *req,
 301                                                struct request_sock **prev)
 302 {
 303         reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 304 }
 305
 306 static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 307                                              struct request_sock *req,
 308                                              struct request_sock **prev)
 309 {
 310         inet_csk_reqsk_queue_unlink(sk, req, prev);
 311         inet_csk_reqsk_queue_removed(sk, req);
 312         reqsk_free(req);
 313 }
 314
 315 void inet_csk_reqsk_queue_prune(struct sock *parent,
 316                                 const unsigned long interval,
 317                                 const unsigned long timeout,
 318                                 const unsigned long max_rto);
 319
 320 void inet_csk_destroy_sock(struct sock *sk);
 321 void inet_csk_prepare_forced_close(struct sock *sk);
 322
 323 /*
 324  * LISTEN is a special case for poll..
 325  */
 326 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 327 {
 328         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 329                         (POLLIN | POLLRDNORM) : 0;
 330 }
 331
 332 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 333 void inet_csk_listen_stop(struct sock *sk);
 334
 335 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 336
 337 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 338                                char __user *optval, int __user *optlen);
 339 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 340                                char __user *optval, unsigned int optlen);
 341
 342 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 343 #endif /* _INET_CONNECTION_SOCK_H */