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         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
 137 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 138 {
 139         return (struct inet_connection_sock *)sk;
 140 }
 141
 142 static inline void *inet_csk_ca(const struct sock *sk)
 143 {
 144         return (void *)inet_csk(sk)->icsk_ca_priv;
 145 }
 146
 147 extern struct sock *inet_csk_clone_lock(const struct sock *sk,
 148                                         const struct request_sock *req,
 149                                         const gfp_t priority);
 150
 151 enum inet_csk_ack_state_t {
 152         ICSK_ACK_SCHED  = 1,
 153         ICSK_ACK_TIMER  = 2,
 154         ICSK_ACK_PUSHED = 4,
 155         ICSK_ACK_PUSHED2 = 8
 156 };
 157
 158 extern void inet_csk_init_xmit_timers(struct sock *sk,
 159                                       void (*retransmit_handler)(unsigned long),
 160                                       void (*delack_handler)(unsigned long),
 161                                       void (*keepalive_handler)(unsigned long));
 162 extern void inet_csk_clear_xmit_timers(struct sock *sk);
 163
 164 static inline void inet_csk_schedule_ack(struct sock *sk)
 165 {
 166         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 167 }
 168
 169 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 170 {
 171         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 172 }
 173
 174 static inline void inet_csk_delack_init(struct sock *sk)
 175 {
 176         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 177 }
 178
 179 extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 180 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 181
 182 #ifdef INET_CSK_DEBUG
 183 extern const char inet_csk_timer_bug_msg[];
 184 #endif
 185
 186 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 187 {
 188         struct inet_connection_sock *icsk = inet_csk(sk);
 189
 190         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 191                 icsk->icsk_pending = 0;
 192 #ifdef INET_CSK_CLEAR_TIMERS
 193                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 194 #endif
 195         } else if (what == ICSK_TIME_DACK) {
 196                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 197 #ifdef INET_CSK_CLEAR_TIMERS
 198                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 199 #endif
 200         }
 201 #ifdef INET_CSK_DEBUG
 202         else {
 203                 pr_debug("%s", inet_csk_timer_bug_msg);
 204         }
 205 #endif
 206 }
 207
 208 /*
 209  *      Reset the retransmission timer
 210  */
 211 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 212                                              unsigned long when,
 213                                              const unsigned long max_when)
 214 {
 215         struct inet_connection_sock *icsk = inet_csk(sk);
 216
 217         if (when > max_when) {
 218 #ifdef INET_CSK_DEBUG
 219                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 220                          sk, what, when, current_text_addr());
 221 #endif
 222                 when = max_when;
 223         }
 224
 225         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 226                 icsk->icsk_pending = what;
 227                 icsk->icsk_timeout = jiffies + when;
 228                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 229         } else if (what == ICSK_TIME_DACK) {
 230                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 231                 icsk->icsk_ack.timeout = jiffies + when;
 232                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 233         }
 234 #ifdef INET_CSK_DEBUG
 235         else {
 236                 pr_debug("%s", inet_csk_timer_bug_msg);
 237         }
 238 #endif
 239 }
 240
 241 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 242
 243 extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 244                                                 struct request_sock ***prevp,
 245                                                 const __be16 rport,
 246                                                 const __be32 raddr,
 247                                                 const __be32 laddr);
 248 extern int inet_csk_bind_conflict(const struct sock *sk,
 249                                   const struct inet_bind_bucket *tb, bool relax);
 250 extern int inet_csk_get_port(struct sock *sk, unsigned short snum);
 251
 252 extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 253                                             struct flowi4 *fl4,
 254                                             const struct request_sock *req);
 255 extern struct dst_entry* inet_csk_route_child_sock(struct sock *sk,
 256                                                    struct sock *newsk,
 257                                                    const struct request_sock *req);
 258
 259 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 260                                             struct request_sock *req,
 261                                             struct sock *child)
 262 {
 263         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 264 }
 265
 266 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 267                                           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 extern 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 extern void inet_csk_destroy_sock(struct sock *sk);
 321
 322 /*
 323  * LISTEN is a special case for poll..
 324  */
 325 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 326 {
 327         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 328                         (POLLIN | POLLRDNORM) : 0;
 329 }
 330
 331 extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 332 extern void inet_csk_listen_stop(struct sock *sk);
 333
 334 extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 335
 336 extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 337                                       char __user *optval, int __user *optlen);
 338 extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 339                                       char __user *optval, unsigned int optlen);
 340
 341 extern struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 342 #endif /* _INET_CONNECTION_SOCK_H */