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   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
  22 #include <net/inet_sock.h>
  23 #include <net/request_sock.h>
  24
  25 #define INET_CSK_DEBUG 1
  26
  27 /* Cancel timers, when they are not required. */
  28 #undef INET_CSK_CLEAR_TIMERS
  29
  30 struct inet_bind_bucket;
  31 struct inet_hashinfo;
  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, int ipfragok);
  40         void        (*send_check)(struct sock *sk, int len,
  41                                   struct sk_buff *skb);
  42         int         (*rebuild_header)(struct sock *sk);
  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         int         (*remember_stamp)(struct sock *sk);
  48         __u16       net_header_len;
  49         int         (*setsockopt)(struct sock *sk, int level, int optname,
  50                                   char __user *optval, int optlen);
  51         int         (*getsockopt)(struct sock *sk, int level, int optname,
  52                                   char __user *optval, int __user *optlen);
  53         int         (*compat_setsockopt)(struct sock *sk,
  54                                 int level, int optname,
  55                                 char __user *optval, int optlen);
  56         int         (*compat_getsockopt)(struct sock *sk,
  57                                 int level, int optname,
  58                                 char __user *optval, int __user *optlen);
  59         void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  60         int sockaddr_len;
  61 };
  62
  63 /** inet_connection_sock - INET connection oriented sock
  64  *
  65  * @icsk_accept_queue:     FIFO of established children
  66  * @icsk_bind_hash:        Bind node
  67  * @icsk_timeout:          Timeout
  68  * @icsk_retransmit_timer: Resend (no ack)
  69  * @icsk_rto:              Retransmit timeout
  70  * @icsk_pmtu_cookie       Last pmtu seen by socket
  71  * @icsk_ca_ops            Pluggable congestion control hook
  72  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  73  * @icsk_ca_state:         Congestion control state
  74  * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  75  * @icsk_pending:          Scheduled timer event
  76  * @icsk_backoff:          Backoff
  77  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  78  * @icsk_probes_out:       unanswered 0 window probes
  79  * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  80  * @icsk_ack:              Delayed ACK control data
  81  * @icsk_mtup;             MTU probing control data
  82  */
  83 struct inet_connection_sock {
  84         /* inet_sock has to be the first member! */
  85         struct inet_sock          icsk_inet;
  86         struct request_sock_queue icsk_accept_queue;
  87         struct inet_bind_bucket   *icsk_bind_hash;
  88         unsigned long             icsk_timeout;
  89         struct timer_list         icsk_retransmit_timer;
  90         struct timer_list         icsk_delack_timer;
  91         __u32                     icsk_rto;
  92         __u32                     icsk_pmtu_cookie;
  93         const struct tcp_congestion_ops *icsk_ca_ops;
  94         const struct inet_connection_sock_af_ops *icsk_af_ops;
  95         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
  96         __u8                      icsk_ca_state;
  97         __u8                      icsk_retransmits;
  98         __u8                      icsk_pending;
  99         __u8                      icsk_backoff;
 100         __u8                      icsk_syn_retries;
 101         __u8                      icsk_probes_out;
 102         __u16                     icsk_ext_hdr_len;
 103         struct {
 104                 __u8              pending;       /* ACK is pending                         */
 105                 __u8              quick;         /* Scheduled number of quick acks         */
 106                 __u8              pingpong;      /* The session is interactive             */
 107                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 108                 __u32             ato;           /* Predicted tick of soft clock           */
 109                 unsigned long     timeout;       /* Currently scheduled timeout            */
 110                 __u32             lrcvtime;      /* timestamp of last received data packet */
 111                 __u16             last_seg_size; /* Size of last incoming segment          */
 112                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 113         } icsk_ack;
 114         struct {
 115                 int               enabled;
 116
 117                 /* Range of MTUs to search */
 118                 int               search_high;
 119                 int               search_low;
 120
 121                 /* Information on the current probe. */
 122                 int               probe_size;
 123         } icsk_mtup;
 124         u32                       icsk_ca_priv[16];
 125 #define ICSK_CA_PRIV_SIZE       (16 * sizeof(u32))
 126 };
 127
 128 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 129 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 130 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 131 #define ICSK_TIME_KEEPOPEN      4       /* Keepalive timer */
 132
 133 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 134 {
 135         return (struct inet_connection_sock *)sk;
 136 }
 137
 138 static inline void *inet_csk_ca(const struct sock *sk)
 139 {
 140         return (void *)inet_csk(sk)->icsk_ca_priv;
 141 }
 142
 143 extern struct sock *inet_csk_clone(struct sock *sk,
 144                                    const struct request_sock *req,
 145                                    const gfp_t priority);
 146
 147 enum inet_csk_ack_state_t {
 148         ICSK_ACK_SCHED  = 1,
 149         ICSK_ACK_TIMER  = 2,
 150         ICSK_ACK_PUSHED = 4,
 151         ICSK_ACK_PUSHED2 = 8
 152 };
 153
 154 extern void inet_csk_init_xmit_timers(struct sock *sk,
 155                                       void (*retransmit_handler)(unsigned long),
 156                                       void (*delack_handler)(unsigned long),
 157                                       void (*keepalive_handler)(unsigned long));
 158 extern void inet_csk_clear_xmit_timers(struct sock *sk);
 159
 160 static inline void inet_csk_schedule_ack(struct sock *sk)
 161 {
 162         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 163 }
 164
 165 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 166 {
 167         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 168 }
 169
 170 static inline void inet_csk_delack_init(struct sock *sk)
 171 {
 172         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 173 }
 174
 175 extern void inet_csk_delete_keepalive_timer(struct sock *sk);
 176 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 177
 178 #ifdef INET_CSK_DEBUG
 179 extern const char inet_csk_timer_bug_msg[];
 180 #endif
 181
 182 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 183 {
 184         struct inet_connection_sock *icsk = inet_csk(sk);
 185
 186         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 187                 icsk->icsk_pending = 0;
 188 #ifdef INET_CSK_CLEAR_TIMERS
 189                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 190 #endif
 191         } else if (what == ICSK_TIME_DACK) {
 192                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 193 #ifdef INET_CSK_CLEAR_TIMERS
 194                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 195 #endif
 196         }
 197 #ifdef INET_CSK_DEBUG
 198         else {
 199                 pr_debug("%s", inet_csk_timer_bug_msg);
 200         }
 201 #endif
 202 }
 203
 204 /*
 205  *      Reset the retransmission timer
 206  */
 207 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 208                                              unsigned long when,
 209                                              const unsigned long max_when)
 210 {
 211         struct inet_connection_sock *icsk = inet_csk(sk);
 212
 213         if (when > max_when) {
 214 #ifdef INET_CSK_DEBUG
 215                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 216                          sk, what, when, current_text_addr());
 217 #endif
 218                 when = max_when;
 219         }
 220
 221         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 222                 icsk->icsk_pending = what;
 223                 icsk->icsk_timeout = jiffies + when;
 224                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 225         } else if (what == ICSK_TIME_DACK) {
 226                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 227                 icsk->icsk_ack.timeout = jiffies + when;
 228                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 229         }
 230 #ifdef INET_CSK_DEBUG
 231         else {
 232                 pr_debug("%s", inet_csk_timer_bug_msg);
 233         }
 234 #endif
 235 }
 236
 237 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 238
 239 extern struct request_sock *inet_csk_search_req(const struct sock *sk,
 240                                                 struct request_sock ***prevp,
 241                                                 const __be16 rport,
 242                                                 const __be32 raddr,
 243                                                 const __be32 laddr);
 244 extern int inet_csk_bind_conflict(const struct sock *sk,
 245                                   const struct inet_bind_bucket *tb);
 246 extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
 247                              struct sock *sk, unsigned short snum,
 248                              int (*bind_conflict)(const struct sock *sk,
 249                                                   const struct inet_bind_bucket *tb));
 250
 251 extern struct dst_entry* inet_csk_route_req(struct sock *sk,
 252                                             const struct request_sock *req);
 253
 254 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 255                                             struct request_sock *req,
 256                                             struct sock *child)
 257 {
 258         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 259 }
 260
 261 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
 262                                           struct request_sock *req,
 263                                           unsigned long timeout);
 264
 265 static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
 266                                                 struct request_sock *req)
 267 {
 268         if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
 269                 inet_csk_delete_keepalive_timer(sk);
 270 }
 271
 272 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 273                                               const unsigned long timeout)
 274 {
 275         if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
 276                 inet_csk_reset_keepalive_timer(sk, timeout);
 277 }
 278
 279 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 280 {
 281         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 282 }
 283
 284 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 285 {
 286         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 287 }
 288
 289 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 290 {
 291         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 292 }
 293
 294 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
 295                                                struct request_sock *req,
 296                                                struct request_sock **prev)
 297 {
 298         reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
 299 }
 300
 301 static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
 302                                              struct request_sock *req,
 303                                              struct request_sock **prev)
 304 {
 305         inet_csk_reqsk_queue_unlink(sk, req, prev);
 306         inet_csk_reqsk_queue_removed(sk, req);
 307         reqsk_free(req);
 308 }
 309
 310 extern void inet_csk_reqsk_queue_prune(struct sock *parent,
 311                                        const unsigned long interval,
 312                                        const unsigned long timeout,
 313                                        const unsigned long max_rto);
 314
 315 extern void inet_csk_destroy_sock(struct sock *sk);
 316
 317 /*
 318  * LISTEN is a special case for poll..
 319  */
 320 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 321 {
 322         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 323                         (POLLIN | POLLRDNORM) : 0;
 324 }
 325
 326 extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 327 extern void inet_csk_listen_stop(struct sock *sk);
 328
 329 extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 330
 331 extern int inet_csk_ctl_sock_create(struct socket **sock,
 332                                     unsigned short family,
 333                                     unsigned short type,
 334                                     unsigned char protocol);
 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, int optlen);
 340 #endif /* _INET_CONNECTION_SOCK_H */