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