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:6,
 102                                   icsk_ca_setsockopt:1,
 103                                   icsk_ca_dst_locked:1;
 104         __u8                      icsk_retransmits;
 105         __u8                      icsk_pending;
 106         __u8                      icsk_backoff;
 107         __u8                      icsk_syn_retries;
 108         __u8                      icsk_probes_out;
 109         __u16                     icsk_ext_hdr_len;
 110         struct {
 111                 __u8              pending;       /* ACK is pending                         */
 112                 __u8              quick;         /* Scheduled number of quick acks         */
 113                 __u8              pingpong;      /* The session is interactive             */
 114                 __u8              blocked;       /* Delayed ACK was blocked by socket lock */
 115                 __u32             ato;           /* Predicted tick of soft clock           */
 116                 unsigned long     timeout;       /* Currently scheduled timeout            */
 117                 __u32             lrcvtime;      /* timestamp of last received data packet */
 118                 __u16             last_seg_size; /* Size of last incoming segment          */
 119                 __u16             rcv_mss;       /* MSS used for delayed ACK decisions     */
 120         } icsk_ack;
 121         struct {
 122                 int               enabled;
 123
 124                 /* Range of MTUs to search */
 125                 int               search_high;
 126                 int               search_low;
 127
 128                 /* Information on the current probe. */
 129                 int               probe_size;
 130
 131                 u32               probe_timestamp;
 132         } icsk_mtup;
 133         u32                       icsk_user_timeout;
 134
 135         u64                       icsk_ca_priv[64 / sizeof(u64)];
 136 #define ICSK_CA_PRIV_SIZE      (8 * sizeof(u64))
 137 };
 138
 139 #define ICSK_TIME_RETRANS       1       /* Retransmit timer */
 140 #define ICSK_TIME_DACK          2       /* Delayed ack timer */
 141 #define ICSK_TIME_PROBE0        3       /* Zero window probe timer */
 142 #define ICSK_TIME_EARLY_RETRANS 4       /* Early retransmit timer */
 143 #define ICSK_TIME_LOSS_PROBE    5       /* Tail loss probe timer */
 144
 145 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 146 {
 147         return (struct inet_connection_sock *)sk;
 148 }
 149
 150 static inline void *inet_csk_ca(const struct sock *sk)
 151 {
 152         return (void *)inet_csk(sk)->icsk_ca_priv;
 153 }
 154
 155 struct sock *inet_csk_clone_lock(const struct sock *sk,
 156                                  const struct request_sock *req,
 157                                  const gfp_t priority);
 158
 159 enum inet_csk_ack_state_t {
 160         ICSK_ACK_SCHED  = 1,
 161         ICSK_ACK_TIMER  = 2,
 162         ICSK_ACK_PUSHED = 4,
 163         ICSK_ACK_PUSHED2 = 8
 164 };
 165
 166 void inet_csk_init_xmit_timers(struct sock *sk,
 167                                void (*retransmit_handler)(unsigned long),
 168                                void (*delack_handler)(unsigned long),
 169                                void (*keepalive_handler)(unsigned long));
 170 void inet_csk_clear_xmit_timers(struct sock *sk);
 171
 172 static inline void inet_csk_schedule_ack(struct sock *sk)
 173 {
 174         inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
 175 }
 176
 177 static inline int inet_csk_ack_scheduled(const struct sock *sk)
 178 {
 179         return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
 180 }
 181
 182 static inline void inet_csk_delack_init(struct sock *sk)
 183 {
 184         memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
 185 }
 186
 187 void inet_csk_delete_keepalive_timer(struct sock *sk);
 188 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 189
 190 #ifdef INET_CSK_DEBUG
 191 extern const char inet_csk_timer_bug_msg[];
 192 #endif
 193
 194 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 195 {
 196         struct inet_connection_sock *icsk = inet_csk(sk);
 197
 198         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
 199                 icsk->icsk_pending = 0;
 200 #ifdef INET_CSK_CLEAR_TIMERS
 201                 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
 202 #endif
 203         } else if (what == ICSK_TIME_DACK) {
 204                 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
 205 #ifdef INET_CSK_CLEAR_TIMERS
 206                 sk_stop_timer(sk, &icsk->icsk_delack_timer);
 207 #endif
 208         }
 209 #ifdef INET_CSK_DEBUG
 210         else {
 211                 pr_debug("%s", inet_csk_timer_bug_msg);
 212         }
 213 #endif
 214 }
 215
 216 /*
 217  *      Reset the retransmission timer
 218  */
 219 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
 220                                              unsigned long when,
 221                                              const unsigned long max_when)
 222 {
 223         struct inet_connection_sock *icsk = inet_csk(sk);
 224
 225         if (when > max_when) {
 226 #ifdef INET_CSK_DEBUG
 227                 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 228                          sk, what, when, current_text_addr());
 229 #endif
 230                 when = max_when;
 231         }
 232
 233         if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
 234             what == ICSK_TIME_EARLY_RETRANS || what ==  ICSK_TIME_LOSS_PROBE) {
 235                 icsk->icsk_pending = what;
 236                 icsk->icsk_timeout = jiffies + when;
 237                 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
 238         } else if (what == ICSK_TIME_DACK) {
 239                 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 240                 icsk->icsk_ack.timeout = jiffies + when;
 241                 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
 242         }
 243 #ifdef INET_CSK_DEBUG
 244         else {
 245                 pr_debug("%s", inet_csk_timer_bug_msg);
 246         }
 247 #endif
 248 }
 249
 250 static inline unsigned long
 251 inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
 252                      unsigned long max_when)
 253 {
 254         u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
 255
 256         return (unsigned long)min_t(u64, when, max_when);
 257 }
 258
 259 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
 260
 261 struct request_sock *inet_csk_search_req(struct sock *sk,
 262                                          const __be16 rport,
 263                                          const __be32 raddr,
 264                                          const __be32 laddr);
 265 int inet_csk_bind_conflict(const struct sock *sk,
 266                            const struct inet_bind_bucket *tb, bool relax);
 267 int inet_csk_get_port(struct sock *sk, unsigned short snum);
 268
 269 struct dst_entry *inet_csk_route_req(struct sock *sk, struct flowi4 *fl4,
 270                                      const struct request_sock *req);
 271 struct dst_entry *inet_csk_route_child_sock(struct sock *sk, struct sock *newsk,
 272                                             const struct request_sock *req);
 273
 274 static inline void inet_csk_reqsk_queue_add(struct sock *sk,
 275                                             struct request_sock *req,
 276                                             struct sock *child)
 277 {
 278         reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
 279 }
 280
 281 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
 282                                    unsigned long timeout);
 283
 284 static inline void inet_csk_reqsk_queue_added(struct sock *sk,
 285                                               const unsigned long timeout)
 286 {
 287         reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
 288 }
 289
 290 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
 291 {
 292         return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
 293 }
 294
 295 static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
 296 {
 297         return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
 298 }
 299
 300 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
 301 {
 302         return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
 303 }
 304
 305 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
 306
 307 void inet_csk_destroy_sock(struct sock *sk);
 308 void inet_csk_prepare_forced_close(struct sock *sk);
 309
 310 /*
 311  * LISTEN is a special case for poll..
 312  */
 313 static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
 314 {
 315         return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
 316                         (POLLIN | POLLRDNORM) : 0;
 317 }
 318
 319 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
 320 void inet_csk_listen_stop(struct sock *sk);
 321
 322 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 323
 324 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 325                                char __user *optval, int __user *optlen);
 326 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 327                                char __user *optval, unsigned int optlen);
 328
 329 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
 330 #endif /* _INET_CONNECTION_SOCK_H */