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)(const struct sock *sk, struct sk_buff *skb,
  45                                       struct request_sock *req,
  46                                       struct dst_entry *dst,
  47                                       struct request_sock *req_unhash,
  48                                       bool *own_req);
  49         u16         net_header_len;
  50         u16         net_frag_header_len;
  51         u16         sockaddr_len;
  52         int         (*setsockopt)(struct sock *sk, int level, int optname,
  53                                   char __user *optval, unsigned int optlen);
  54         int         (*getsockopt)(struct sock *sk, int level, int optname,
  55                                   char __user *optval, int __user *optlen);
  56 #ifdef CONFIG_COMPAT
  57         int         (*compat_setsockopt)(struct sock *sk,
  58                                 int level, int optname,
  59                                 char __user *optval, unsigned int optlen);
  60         int         (*compat_getsockopt)(struct sock *sk,
  61                                 int level, int optname,
  62                                 char __user *optval, int __user *optlen);
  63 #endif
  64         void        (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
  65         int         (*bind_conflict)(const struct sock *sk,
  66                                      const struct inet_bind_bucket *tb, bool relax);
  67         void        (*mtu_reduced)(struct sock *sk);
  68 };
  69
  70 /** inet_connection_sock - INET connection oriented sock
  71  *
  72  * @icsk_accept_queue:     FIFO of established children
  73  * @icsk_bind_hash:        Bind node
  74  * @icsk_timeout:          Timeout
  75  * @icsk_retransmit_timer: Resend (no ack)
  76  * @icsk_rto:              Retransmit timeout
  77  * @icsk_pmtu_cookie       Last pmtu seen by socket
  78  * @icsk_ca_ops            Pluggable congestion control hook
  79  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  80  * @icsk_ca_state:         Congestion control state
  81  * @icsk_retransmits:      Number of unrecovered [RTO] timeouts
  82  * @icsk_pending:          Scheduled timer event
  83  * @icsk_backoff:          Backoff
  84  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  85  * @icsk_probes_out:       unanswered 0 window probes
  86  * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  87  * @icsk_ack:              Delayed ACK control data
  88  * @icsk_mtup;             MTU probing control data
  89  */
  90 struct inet_connection_sock {
  91         /* inet_sock has to be the first member! */
  92         struct inet_sock          icsk_inet;
  93         struct request_sock_queue icsk_accept_queue;
  94         struct inet_bind_bucket   *icsk_bind_hash;
  95         unsigned long             icsk_timeout;
  96         struct timer_list         icsk_retransmit_timer;
  97         struct timer_list         icsk_delack_timer;
  98         __u32                     icsk_rto;
  99         __u32                     icsk_pmtu_cookie;
 100         const struct tcp_congestion_ops *icsk_ca_ops;
 101         const struct inet_connection_sock_af_ops *icsk_af_ops;
 102         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 103         __u8                      icsk_ca_state:6,
 104                                   icsk_ca_setsockopt:1,
 105                                   icsk_ca_dst_locked:1;
 106         __u8                      icsk_retransmits;
 107         __u8                      icsk_pending;
 108         __u8                      icsk_backoff;
 109         __u8                      icsk_syn_retries;
 110         __u8                      icsk_probes_out;
 111         __u16                     icsk_ext_hdr_len;
 112         struct {
 113                 __u8              pending;       /* ACK is pending                         */
 114                 __u8              quick;         /* Scheduled number of quick acks         */
 115                 __u8              pingpong;      /* The session is interactive             */
 116                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 117                 __u32             ato;           /* Predicted tick of soft clock           */
 118                 unsigned long     timeout;       /* Currently scheduled timeout            */
 119                 __u32             lrcvtime;      /* timestamp of last received data packet */
 120                 __u16             last_seg_size; /* Size of last incoming segment          */
 121                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 122         } icsk_ack;
 123         struct {
 124                 int               enabled;
 125
 126                 /* Range of MTUs to search */
 127                 int               search_high;
 128                 int               search_low;
 129
 130                 /* Information on the current probe. */
 131                 int               probe_size;
 132
 133                 u32               probe_timestamp;
 134         } icsk_mtup;
 135         u32                       icsk_user_timeout;
 136
 137         u64                       icsk_ca_priv[88 / sizeof(u64)];
 138 #define ICSK_CA_PRIV_SIZE      (11 * sizeof(u64))
 139 };
 140
 141 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 142 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 143 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 144 #define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 145 #define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 146
 147 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 148 {
 149         return (struct inet_connection_sock *)sk;
 150 }
 151
 152 static inline void *inet_csk_ca(const struct sock *sk)
 153 {
 154         return (void *)inet_csk(sk)->icsk_ca_priv;
 155 }
 156
 157 struct sock *inet_csk_clone_lock(const struct sock *sk,
 158                                  const struct request_sock *req,
 159                                  const gfp_t priority);
 160
 161 enum inet_csk_ack_state_t {
 162         ICSK_ACK_SCHED  = 1,
 163         ICSK_ACK_TIMER  = 2,
 164         ICSK_ACK_PUSHED = 4,
 165         ICSK_ACK_PUSHED2 = 8
 166 };
 167
 168 void inet_csk_init_xmit_timers(struct sock *sk,
 169                                void (*retransmit_handler)(unsigned long),
 170                                void (*delack_handler)(unsigned long),
 171                                void (*keepalive_handler)(unsigned long));
 172 void inet_csk_clear_xmit_timers(struct sock *sk);
 173
 174 static inline void inet_csk_schedule_ack(struct sock *sk)
 175 {
 176         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 177 }
 178
 179 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 180 {
 181         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 182 }
 183
 184 static inline void inet_csk_delack_init(struct sock *sk)
 185 {
 186         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 187 }
 188
 189 void inet_csk_delete_keepalive_timer(struct sock *sk);
 190 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 191
 192 #ifdef INET_CSK_DEBUG
 193 extern const char inet_csk_timer_bug_msg[];
 194 #endif
 195
 196 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 197 {
 198         struct inet_connection_sock *icsk = inet_csk(sk);
 199
 200         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 201                 icsk->icsk_pending = 0;
 202 #ifdef INET_CSK_CLEAR_TIMERS
 203                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 204 #endif
 205         } else if (what == ICSK_TIME_DACK) {
 206                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 207 #ifdef INET_CSK_CLEAR_TIMERS
 208                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 209 #endif
 210         }
 211 #ifdef INET_CSK_DEBUG
 212         else {
 213                 pr_debug("%s", inet_csk_timer_bug_msg);
 214         }
 215 #endif
 216 }
 217
 218 /*
 219  *      Reset the retransmission timer
 220  */
 221 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 222                                              unsigned long when,
 223                                              const unsigned long max_when)
 224 {
 225         struct inet_connection_sock *icsk = inet_csk(sk);
 226
 227         if (when > max_when) {
 228 #ifdef INET_CSK_DEBUG
 229                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 230                          sk, what, when, current_text_addr());
 231 #endif
 232                 when = max_when;
 233         }
 234
 235         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 236             what == ICSK_TIME_EARLY_RETRANS || what ==  ICSK_TIME_LOSS_PROBE) {
 237                 icsk->icsk_pending = what;
 238                 icsk->icsk_timeout = jiffies + when;
 239                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 240         } else if (what == ICSK_TIME_DACK) {
 241                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 242                 icsk->icsk_ack.timeout = jiffies + when;
 243                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 244         }
 245 #ifdef INET_CSK_DEBUG
 246         else {
 247                 pr_debug("%s", inet_csk_timer_bug_msg);
 248         }
 249 #endif
 250 }
 251
 252 static inline unsigned long
 253 inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
 254                      unsigned long max_when)
 255 {
 256         u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
 257
 258         return (unsigned long)min_t(u64, when, max_when);
 259 }
 260
 261 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 262
 263 int inet_csk_bind_conflict(const struct sock *sk,
 264                            const struct inet_bind_bucket *tb, bool relax);
 265 int inet_csk_get_port(struct sock *sk, unsigned short snum);
 266
 267 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
 268                                      const struct request_sock *req);
 269 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
 270                                             struct sock *newsk,
 271                                             const struct request_sock *req);
 272
 273 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
 274                                       struct request_sock *req,
 275                                       struct sock *child);
 276 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 277                                    unsigned long timeout);
 278 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
 279                                          struct request_sock *req,
 280                                          bool own_req);
 281
 282 static inline void inet_csk_reqsk_queue_added(struct sock *sk)
 283 {
 284         reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
 285 }
 286
 287 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 288 {
 289         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 290 }
 291
 292 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 293 {
 294         return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
 295 }
 296
 297 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
 298 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
 299
 300 void inet_csk_destroy_sock(struct sock *sk);
 301 void inet_csk_prepare_forced_close(struct sock *sk);
 302
 303 /*
 304  * LISTEN is a special case for poll..
 305  */
 306 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 307 {
 308         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 309                         (POLLIN | POLLRDNORM) : 0;
 310 }
 311
 312 int inet_csk_listen_start(struct sock *sk, int backlog);
 313 void inet_csk_listen_stop(struct sock *sk);
 314
 315 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 316
 317 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 318                                char __user *optval, int __user *optlen);
 319 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 320                                char __user *optval, unsigned int optlen);
 321
 322 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 323 #endif /* _INET_CONNECTION_SOCK_H */