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         void        (*mtu_reduced)(struct sock *sk);
  66 };
  67
  68 /** inet_connection_sock - INET connection oriented sock
  69  *
  70  * @icsk_accept_queue:     FIFO of established children
  71  * @icsk_bind_hash:        Bind node
  72  * @icsk_timeout:          Timeout
  73  * @icsk_retransmit_timer: Resend (no ack)
  74  * @icsk_rto:              Retransmit timeout
  75  * @icsk_pmtu_cookie       Last pmtu seen by socket
  76  * @icsk_ca_ops            Pluggable congestion control hook
  77  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  78  * @icsk_ca_state:         Congestion control state
  79  * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  80  * @icsk_pending:          Scheduled timer event
  81  * @icsk_backoff:          Backoff
  82  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  83  * @icsk_probes_out:       unanswered 0 window probes
  84  * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  85  * @icsk_ack:              Delayed ACK control data
  86  * @icsk_mtup;             MTU probing control data
  87  */
  88 struct inet_connection_sock {
  89         /* inet_sock has to be the first member! */
  90         struct inet_sock          icsk_inet;
  91         struct request_sock_queue icsk_accept_queue;
  92         struct inet_bind_bucket   *icsk_bind_hash;
  93         unsigned long             icsk_timeout;
  94         struct timer_list         icsk_retransmit_timer;
  95         struct timer_list         icsk_delack_timer;
  96         __u32                     icsk_rto;
  97         __u32                     icsk_pmtu_cookie;
  98         const struct tcp_congestion_ops *icsk_ca_ops;
  99         const struct inet_connection_sock_af_ops *icsk_af_ops;
 100         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 101         __u8                      icsk_ca_state:7,
 102                                   icsk_ca_dst_locked:1;
 103         __u8                      icsk_retransmits;
 104         __u8                      icsk_pending;
 105         __u8                      icsk_backoff;
 106         __u8                      icsk_syn_retries;
 107         __u8                      icsk_probes_out;
 108         __u16                     icsk_ext_hdr_len;
 109         struct {
 110                 __u8              pending;       /* ACK is pending                         */
 111                 __u8              quick;         /* Scheduled number of quick acks         */
 112                 __u8              pingpong;      /* The session is interactive             */
 113                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 114                 __u32             ato;           /* Predicted tick of soft clock           */
 115                 unsigned long     timeout;       /* Currently scheduled timeout            */
 116                 __u32             lrcvtime;      /* timestamp of last received data packet */
 117                 __u16             last_seg_size; /* Size of last incoming segment          */
 118                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 119         } icsk_ack;
 120         struct {
 121                 int               enabled;
 122
 123                 /* Range of MTUs to search */
 124                 int               search_high;
 125                 int               search_low;
 126
 127                 /* Information on the current probe. */
 128                 int               probe_size;
 129         } icsk_mtup;
 130         u32                       icsk_ca_priv[16];
 131         u32                       icsk_user_timeout;
 132 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 133 };
 134
 135 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 136 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 137 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 138 #define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 139 #define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 140
 141 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 142 {
 143         return (struct inet_connection_sock *)sk;
 144 }
 145
 146 static inline void *inet_csk_ca(const struct sock *sk)
 147 {
 148         return (void *)inet_csk(sk)->icsk_ca_priv;
 149 }
 150
 151 struct sock *inet_csk_clone_lock(const struct sock *sk,
 152                                  const struct request_sock *req,
 153                                  const gfp_t priority);
 154
 155 enum inet_csk_ack_state_t {
 156         ICSK_ACK_SCHED  = 1,
 157         ICSK_ACK_TIMER  = 2,
 158         ICSK_ACK_PUSHED = 4,
 159         ICSK_ACK_PUSHED2 = 8
 160 };
 161
 162 void inet_csk_init_xmit_timers(struct sock *sk,
 163                                void (*retransmit_handler)(unsigned long),
 164                                void (*delack_handler)(unsigned long),
 165                                void (*keepalive_handler)(unsigned long));
 166 void inet_csk_clear_xmit_timers(struct sock *sk);
 167
 168 static inline void inet_csk_schedule_ack(struct sock *sk)
 169 {
 170         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 171 }
 172
 173 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 174 {
 175         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 176 }
 177
 178 static inline void inet_csk_delack_init(struct sock *sk)
 179 {
 180         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 181 }
 182
 183 void inet_csk_delete_keepalive_timer(struct sock *sk);
 184 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 185
 186 #ifdef INET_CSK_DEBUG
 187 extern const char inet_csk_timer_bug_msg[];
 188 #endif
 189
 190 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 191 {
 192         struct inet_connection_sock *icsk = inet_csk(sk);
 193
 194         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 195                 icsk->icsk_pending = 0;
 196 #ifdef INET_CSK_CLEAR_TIMERS
 197                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 198 #endif
 199         } else if (what == ICSK_TIME_DACK) {
 200                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 201 #ifdef INET_CSK_CLEAR_TIMERS
 202                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 203 #endif
 204         }
 205 #ifdef INET_CSK_DEBUG
 206         else {
 207                 pr_debug("%s", inet_csk_timer_bug_msg);
 208         }
 209 #endif
 210 }
 211
 212 /*
 213  *      Reset the retransmission timer
 214  */
 215 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 216                                              unsigned long when,
 217                                              const unsigned long max_when)
 218 {
 219         struct inet_connection_sock *icsk = inet_csk(sk);
 220
 221         if (when > max_when) {
 222 #ifdef INET_CSK_DEBUG
 223                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 224                          sk, what, when, current_text_addr());
 225 #endif
 226                 when = max_when;
 227         }
 228
 229         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 230             what == ICSK_TIME_EARLY_RETRANS || what ==  ICSK_TIME_LOSS_PROBE) {
 231                 icsk->icsk_pending = what;
 232                 icsk->icsk_timeout = jiffies + when;
 233                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 234         } else if (what == ICSK_TIME_DACK) {
 235                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 236                 icsk->icsk_ack.timeout = jiffies + when;
 237                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 238         }
 239 #ifdef INET_CSK_DEBUG
 240         else {
 241                 pr_debug("%s", inet_csk_timer_bug_msg);
 242         }
 243 #endif
 244 }
 245
 246 static inline unsigned long
 247 inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
 248                      unsigned long max_when)
 249 {
 250         u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
 251
 252         return (unsigned long)min_t(u64, when, max_when);
 253 }
 254
 255 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 256
 257 struct request_sock *inet_csk_search_req(const struct sock *sk,
 258                                          struct request_sock ***prevp,
 259                                          const __be16 rport,
 260                                          const __be32 raddr,
 261                                          const __be32 laddr);
 262 int inet_csk_bind_conflict(const struct sock *sk,
 263                            const struct inet_bind_bucket *tb, bool relax);
 264 int inet_csk_get_port(struct sock *sk, unsigned short snum);
 265
 266 struct dst_entry *inet_csk_route_req(struct sock *sk, struct flowi4 *fl4,
 267                                      const struct request_sock *req);
 268 struct dst_entry *inet_csk_route_child_sock(struct sock *sk, struct sock *newsk,
 269                                             const struct request_sock *req);
 270
 271 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 272                                             struct request_sock *req,
 273                                             struct sock *child)
 274 {
 275         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 276 }
 277
 278 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 279                                    unsigned long timeout);
 280
 281 static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 282                                                 struct request_sock *req)
 283 {
 284         if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 285                 inet_csk_delete_keepalive_timer(sk);
 286 }
 287
 288 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 289                                               const unsigned long timeout)
 290 {
 291         if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 292                 inet_csk_reset_keepalive_timer(sk, timeout);
 293 }
 294
 295 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 296 {
 297         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 298 }
 299
 300 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 301 {
 302         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 303 }
 304
 305 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 306 {
 307         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 308 }
 309
 310 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 311                                                struct request_sock *req,
 312                                                struct request_sock **prev)
 313 {
 314         reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 315 }
 316
 317 static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 318                                              struct request_sock *req,
 319                                              struct request_sock **prev)
 320 {
 321         inet_csk_reqsk_queue_unlink(sk, req, prev);
 322         inet_csk_reqsk_queue_removed(sk, req);
 323         reqsk_free(req);
 324 }
 325
 326 void inet_csk_reqsk_queue_prune(struct sock *parent,
 327                                 const unsigned long interval,
 328                                 const unsigned long timeout,
 329                                 const unsigned long max_rto);
 330
 331 void inet_csk_destroy_sock(struct sock *sk);
 332 void inet_csk_prepare_forced_close(struct sock *sk);
 333
 334 /*
 335  * LISTEN is a special case for poll..
 336  */
 337 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 338 {
 339         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 340                         (POLLIN | POLLRDNORM) : 0;
 341 }
 342
 343 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 344 void inet_csk_listen_stop(struct sock *sk);
 345
 346 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 347
 348 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 349                                char __user *optval, int __user *optlen);
 350 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 351                                char __user *optval, unsigned int optlen);
 352
 353 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 354 #endif /* _INET_CONNECTION_SOCK_H */