include/net/inet_sock.h

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Definitions for inet_sock
   7  *
   8  * Authors:     Many, reorganised here by
   9  *              Arnaldo Carvalho de Melo <acme@mandriva.com>
  10  *
  11  *              This program is free software; you can redistribute it and/or
  12  *              modify it under the terms of the GNU General Public License
  13  *              as published by the Free Software Foundation; either version
  14  *              2 of the License, or (at your option) any later version.
  15  */
  16 #ifndef _INET_SOCK_H
  17 #define _INET_SOCK_H
  18
  19 #include <linux/bitops.h>
  20 #include <linux/string.h>
  21 #include <linux/types.h>
  22 #include <linux/jhash.h>
  23 #include <linux/netdevice.h>
  24
  25 #include <net/flow.h>
  26 #include <net/sock.h>
  27 #include <net/request_sock.h>
  28 #include <net/netns/hash.h>
  29 #include <net/tcp_states.h>
  30 #include <net/l3mdev.h>
  31
  32 /** struct ip_options - IP Options
  33  *
  34  * @faddr - Saved first hop address
  35  * @nexthop - Saved nexthop address in LSRR and SSRR
  36  * @is_strictroute - Strict source route
  37  * @srr_is_hit - Packet destination addr was our one
  38  * @is_changed - IP checksum more not valid
  39  * @rr_needaddr - Need to record addr of outgoing dev
  40  * @ts_needtime - Need to record timestamp
  41  * @ts_needaddr - Need to record addr of outgoing dev
  42  */
  43 struct ip_options {
  44         __be32          faddr;
  45         __be32          nexthop;
  46         unsigned char   optlen;
  47         unsigned char   srr;
  48         unsigned char   rr;
  49         unsigned char   ts;
  50         unsigned char   is_strictroute:1,
  51                         srr_is_hit:1,
  52                         is_changed:1,
  53                         rr_needaddr:1,
  54                         ts_needtime:1,
  55                         ts_needaddr:1;
  56         unsigned char   router_alert;
  57         unsigned char   cipso;
  58         unsigned char   __pad2;
  59         unsigned char   __data[0];
  60 };
  61
  62 struct ip_options_rcu {
  63         struct rcu_head rcu;
  64         struct ip_options opt;
  65 };
  66
  67 struct ip_options_data {
  68         struct ip_options_rcu   opt;
  69         char                    data[40];
  70 };
  71
  72 struct inet_request_sock {
  73         struct request_sock     req;
  74 #define ir_loc_addr             req.__req_common.skc_rcv_saddr
  75 #define ir_rmt_addr             req.__req_common.skc_daddr
  76 #define ir_num                  req.__req_common.skc_num
  77 #define ir_rmt_port             req.__req_common.skc_dport
  78 #define ir_v6_rmt_addr          req.__req_common.skc_v6_daddr
  79 #define ir_v6_loc_addr          req.__req_common.skc_v6_rcv_saddr
  80 #define ir_iif                  req.__req_common.skc_bound_dev_if
  81 #define ir_cookie               req.__req_common.skc_cookie
  82 #define ireq_net                req.__req_common.skc_net
  83 #define ireq_state              req.__req_common.skc_state
  84 #define ireq_family             req.__req_common.skc_family
  85
  86         u16                     snd_wscale : 4,
  87                                 rcv_wscale : 4,
  88                                 tstamp_ok  : 1,
  89                                 sack_ok    : 1,
  90                                 wscale_ok  : 1,
  91                                 ecn_ok     : 1,
  92                                 acked      : 1,
  93                                 no_srccheck: 1,
  94                                 smc_ok     : 1;
  95         u32                     ir_mark;
  96         union {
  97                 struct ip_options_rcu __rcu     *ireq_opt;
  98 #if IS_ENABLED(CONFIG_IPV6)
  99                 struct {
 100                         struct ipv6_txoptions   *ipv6_opt;
 101                         struct sk_buff          *pktopts;
 102                 };
 103 #endif
 104         };
 105 };
 106
 107 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
 108 {
 109         return (struct inet_request_sock *)sk;
 110 }
 111
 112 static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
 113 {
 114         if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)
 115                 return skb->mark;
 116
 117         return sk->sk_mark;
 118 }
 119
 120 static inline int inet_request_bound_dev_if(const struct sock *sk,
 121                                             struct sk_buff *skb)
 122 {
 123 #ifdef CONFIG_NET_L3_MASTER_DEV
 124         struct net *net = sock_net(sk);
 125
 126         if (!sk->sk_bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
 127                 return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
 128 #endif
 129
 130         return sk->sk_bound_dev_if;
 131 }
 132
 133 static inline struct ip_options_rcu *ireq_opt_deref(const struct inet_request_sock *ireq)
 134 {
 135         return rcu_dereference_check(ireq->ireq_opt,
 136                                      refcount_read(&ireq->req.rsk_refcnt) > 0);
 137 }
 138
 139 struct inet_cork {
 140         unsigned int            flags;
 141         __be32                  addr;
 142         struct ip_options       *opt;
 143         unsigned int            fragsize;
 144         int                     length; /* Total length of all frames */
 145         struct dst_entry        *dst;
 146         u8                      tx_flags;
 147         __u8                    ttl;
 148         __s16                   tos;
 149         char                    priority;
 150 };
 151
 152 struct inet_cork_full {
 153         struct inet_cork        base;
 154         struct flowi            fl;
 155 };
 156
 157 struct ip_mc_socklist;
 158 struct ipv6_pinfo;
 159 struct rtable;
 160
 161 /** struct inet_sock - representation of INET sockets
 162  *
 163  * @sk - ancestor class
 164  * @pinet6 - pointer to IPv6 control block
 165  * @inet_daddr - Foreign IPv4 addr
 166  * @inet_rcv_saddr - Bound local IPv4 addr
 167  * @inet_dport - Destination port
 168  * @inet_num - Local port
 169  * @inet_saddr - Sending source
 170  * @uc_ttl - Unicast TTL
 171  * @inet_sport - Source port
 172  * @inet_id - ID counter for DF pkts
 173  * @tos - TOS
 174  * @mc_ttl - Multicasting TTL
 175  * @is_icsk - is this an inet_connection_sock?
 176  * @uc_index - Unicast outgoing device index
 177  * @mc_index - Multicast device index
 178  * @mc_list - Group array
 179  * @cork - info to build ip hdr on each ip frag while socket is corked
 180  */
 181 struct inet_sock {
 182         /* sk and pinet6 has to be the first two members of inet_sock */
 183         struct sock             sk;
 184 #if IS_ENABLED(CONFIG_IPV6)
 185         struct ipv6_pinfo       *pinet6;
 186 #endif
 187         /* Socket demultiplex comparisons on incoming packets. */
 188 #define inet_daddr              sk.__sk_common.skc_daddr
 189 #define inet_rcv_saddr          sk.__sk_common.skc_rcv_saddr
 190 #define inet_dport              sk.__sk_common.skc_dport
 191 #define inet_num                sk.__sk_common.skc_num
 192
 193         __be32                  inet_saddr;
 194         __s16                   uc_ttl;
 195         __u16                   cmsg_flags;
 196         __be16                  inet_sport;
 197         __u16                   inet_id;
 198
 199         struct ip_options_rcu __rcu     *inet_opt;
 200         int                     rx_dst_ifindex;
 201         __u8                    tos;
 202         __u8                    min_ttl;
 203         __u8                    mc_ttl;
 204         __u8                    pmtudisc;
 205         __u8                    recverr:1,
 206                                 is_icsk:1,
 207                                 freebind:1,
 208                                 hdrincl:1,
 209                                 mc_loop:1,
 210                                 transparent:1,
 211                                 mc_all:1,
 212                                 nodefrag:1;
 213         __u8                    bind_address_no_port:1,
 214                                 defer_connect:1; /* Indicates that fastopen_connect is set
 215                                                   * and cookie exists so we defer connect
 216                                                   * until first data frame is written
 217                                                   */
 218         __u8                    rcv_tos;
 219         __u8                    convert_csum;
 220         int                     uc_index;
 221         int                     mc_index;
 222         __be32                  mc_addr;
 223         struct ip_mc_socklist __rcu     *mc_list;
 224         struct inet_cork_full   cork;
 225 };
 226
 227 #define IPCORK_OPT      1       /* ip-options has been held in ipcork.opt */
 228 #define IPCORK_ALLFRAG  2       /* always fragment (for ipv6 for now) */
 229
 230 /* cmsg flags for inet */
 231 #define IP_CMSG_PKTINFO         BIT(0)
 232 #define IP_CMSG_TTL             BIT(1)
 233 #define IP_CMSG_TOS             BIT(2)
 234 #define IP_CMSG_RECVOPTS        BIT(3)
 235 #define IP_CMSG_RETOPTS         BIT(4)
 236 #define IP_CMSG_PASSSEC         BIT(5)
 237 #define IP_CMSG_ORIGDSTADDR     BIT(6)
 238 #define IP_CMSG_CHECKSUM        BIT(7)
 239 #define IP_CMSG_RECVFRAGSIZE    BIT(8)
 240
 241 /**
 242  * sk_to_full_sk - Access to a full socket
 243  * @sk: pointer to a socket
 244  *
 245  * SYNACK messages might be attached to request sockets.
 246  * Some places want to reach the listener in this case.
 247  */
 248 static inline struct sock *sk_to_full_sk(struct sock *sk)
 249 {
 250 #ifdef CONFIG_INET
 251         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 252                 sk = inet_reqsk(sk)->rsk_listener;
 253 #endif
 254         return sk;
 255 }
 256
 257 /* sk_to_full_sk() variant with a const argument */
 258 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
 259 {
 260 #ifdef CONFIG_INET
 261         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 262                 sk = ((const struct request_sock *)sk)->rsk_listener;
 263 #endif
 264         return sk;
 265 }
 266
 267 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
 268 {
 269         return sk_to_full_sk(skb->sk);
 270 }
 271
 272 static inline struct inet_sock *inet_sk(const struct sock *sk)
 273 {
 274         return (struct inet_sock *)sk;
 275 }
 276
 277 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
 278                                              const struct sock *sk_from,
 279                                              const int ancestor_size)
 280 {
 281         memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
 282                sk_from->sk_prot->obj_size - ancestor_size);
 283 }
 284 #if !(IS_ENABLED(CONFIG_IPV6))
 285 static inline void inet_sk_copy_descendant(struct sock *sk_to,
 286                                            const struct sock *sk_from)
 287 {
 288         __inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
 289 }
 290 #endif
 291
 292 int inet_sk_rebuild_header(struct sock *sk);
 293
 294 /**
 295  * inet_sk_state_load - read sk->sk_state for lockless contexts
 296  * @sk: socket pointer
 297  *
 298  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
 299  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
 300  */
 301 static inline int inet_sk_state_load(const struct sock *sk)
 302 {
 303         /* state change might impact lockless readers. */
 304         return smp_load_acquire(&sk->sk_state);
 305 }
 306
 307 /**
 308  * inet_sk_state_store - update sk->sk_state
 309  * @sk: socket pointer
 310  * @newstate: new state
 311  *
 312  * Paired with inet_sk_state_load(). Should be used in contexts where
 313  * state change might impact lockless readers.
 314  */
 315 void inet_sk_state_store(struct sock *sk, int newstate);
 316
 317 void inet_sk_set_state(struct sock *sk, int state);
 318
 319 static inline unsigned int __inet_ehashfn(const __be32 laddr,
 320                                           const __u16 lport,
 321                                           const __be32 faddr,
 322                                           const __be16 fport,
 323                                           u32 initval)
 324 {
 325         return jhash_3words((__force __u32) laddr,
 326                             (__force __u32) faddr,
 327                             ((__u32) lport) << 16 | (__force __u32)fport,
 328                             initval);
 329 }
 330
 331 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 332                                       struct sock *sk_listener,
 333                                       bool attach_listener);
 334
 335 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 336 {
 337         __u8 flags = 0;
 338
 339         if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
 340                 flags |= FLOWI_FLAG_ANYSRC;
 341         return flags;
 342 }
 343
 344 static inline void inet_inc_convert_csum(struct sock *sk)
 345 {
 346         inet_sk(sk)->convert_csum++;
 347 }
 348
 349 static inline void inet_dec_convert_csum(struct sock *sk)
 350 {
 351         if (inet_sk(sk)->convert_csum > 0)
 352                 inet_sk(sk)->convert_csum--;
 353 }
 354
 355 static inline bool inet_get_convert_csum(struct sock *sk)
 356 {
 357         return !!inet_sk(sk)->convert_csum;
 358 }
 359
 360 #endif  /* _INET_SOCK_H */