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