LXR linux/include/net/inet

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4 *              operating system.  INET is implemented using the  BSD Socket
   5 *              interface as the means of communication with the user level.
   6 *
   7 *              Definitions for inet_sock
   8 *
   9 * Authors:     Many, reorganised here by
  10 *              Arnaldo Carvalho de Melo <acme@mandriva.com>
  11 */
  12#ifndef _INET_SOCK_H
  13#define _INET_SOCK_H
  14
  15#include <linux/bitops.h>
  16#include <linux/string.h>
  17#include <linux/types.h>
  18#include <linux/jhash.h>
  19#include <linux/netdevice.h>
  20
  21#include <net/flow.h>
  22#include <net/sock.h>
  23#include <net/request_sock.h>
  24#include <net/netns/hash.h>
  25#include <net/tcp_states.h>
  26#include <net/l3mdev.h>
  27
  28/** struct ip_options - IP Options
  29 *
  30 * @faddr - Saved first hop address
  31 * @nexthop - Saved nexthop address in LSRR and SSRR
  32 * @is_strictroute - Strict source route
  33 * @srr_is_hit - Packet destination addr was our one
  34 * @is_changed - IP checksum more not valid
  35 * @rr_needaddr - Need to record addr of outgoing dev
  36 * @ts_needtime - Need to record timestamp
  37 * @ts_needaddr - Need to record addr of outgoing dev
  38 */
  39struct ip_options {
  40        __be32          faddr;
  41        __be32          nexthop;
  42        unsigned char   optlen;
  43        unsigned char   srr;
  44        unsigned char   rr;
  45        unsigned char   ts;
  46        unsigned char   is_strictroute:1,
  47                        srr_is_hit:1,
  48                        is_changed:1,
  49                        rr_needaddr:1,
  50                        ts_needtime:1,
  51                        ts_needaddr:1;
  52        unsigned char   router_alert;
  53        unsigned char   cipso;
  54        unsigned char   __pad2;
  55        unsigned char   __data[];
  56};
  57
  58struct ip_options_rcu {
  59        struct rcu_head rcu;
  60        struct ip_options opt;
  61};
  62
  63struct ip_options_data {
  64        struct ip_options_rcu   opt;
  65        char                    data[40];
  66};
  67
  68struct inet_request_sock {
  69        struct request_sock     req;
  70#define ir_loc_addr             req.__req_common.skc_rcv_saddr
  71#define ir_rmt_addr             req.__req_common.skc_daddr
  72#define ir_num                  req.__req_common.skc_num
  73#define ir_rmt_port             req.__req_common.skc_dport
  74#define ir_v6_rmt_addr          req.__req_common.skc_v6_daddr
  75#define ir_v6_loc_addr          req.__req_common.skc_v6_rcv_saddr
  76#define ir_iif                  req.__req_common.skc_bound_dev_if
  77#define ir_cookie               req.__req_common.skc_cookie
  78#define ireq_net                req.__req_common.skc_net
  79#define ireq_state              req.__req_common.skc_state
  80#define ireq_family             req.__req_common.skc_family
  81
  82        u16                     snd_wscale : 4,
  83                                rcv_wscale : 4,
  84                                tstamp_ok  : 1,
  85                                sack_ok    : 1,
  86                                wscale_ok  : 1,
  87                                ecn_ok     : 1,
  88                                acked      : 1,
  89                                no_srccheck: 1,
  90                                smc_ok     : 1;
  91        u32                     ir_mark;
  92        union {
  93                struct ip_options_rcu __rcu     *ireq_opt;
  94#if IS_ENABLED(CONFIG_IPV6)
  95                struct {
  96                        struct ipv6_txoptions   *ipv6_opt;
  97                        struct sk_buff          *pktopts;
  98                };
  99#endif
 100        };
 101};
 102
 103static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
 104{
 105        return (struct inet_request_sock *)sk;
 106}
 107
 108static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
 109{
 110        if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)
 111                return skb->mark;
 112
 113        return sk->sk_mark;
 114}
 115
 116static inline int inet_request_bound_dev_if(const struct sock *sk,
 117                                            struct sk_buff *skb)
 118{
 119#ifdef CONFIG_NET_L3_MASTER_DEV
 120        struct net *net = sock_net(sk);
 121
 122        if (!sk->sk_bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
 123                return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
 124#endif
 125
 126        return sk->sk_bound_dev_if;
 127}
 128
 129static inline int inet_sk_bound_l3mdev(const struct sock *sk)
 130{
 131#ifdef CONFIG_NET_L3_MASTER_DEV
 132        struct net *net = sock_net(sk);
 133
 134        if (!net->ipv4.sysctl_tcp_l3mdev_accept)
 135                return l3mdev_master_ifindex_by_index(net,
 136                                                      sk->sk_bound_dev_if);
 137#endif
 138
 139        return 0;
 140}
 141
 142static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
 143                                     int dif, int sdif)
 144{
 145        if (!bound_dev_if)
 146                return !sdif || l3mdev_accept;
 147        return bound_dev_if == dif || bound_dev_if == sdif;
 148}
 149
 150struct inet_cork {
 151        unsigned int            flags;
 152        __be32                  addr;
 153        struct ip_options       *opt;
 154        unsigned int            fragsize;
 155        int                     length; /* Total length of all frames */
 156        struct dst_entry        *dst;
 157        u8                      tx_flags;
 158        __u8                    ttl;
 159        __s16                   tos;
 160        char                    priority;
 161        __u16                   gso_size;
 162        u64                     transmit_time;
 163        u32                     mark;
 164};
 165
 166struct inet_cork_full {
 167        struct inet_cork        base;
 168        struct flowi            fl;
 169};
 170
 171struct ip_mc_socklist;
 172struct ipv6_pinfo;
 173struct rtable;
 174
 175/** struct inet_sock - representation of INET sockets
 176 *
 177 * @sk - ancestor class
 178 * @pinet6 - pointer to IPv6 control block
 179 * @inet_daddr - Foreign IPv4 addr
 180 * @inet_rcv_saddr - Bound local IPv4 addr
 181 * @inet_dport - Destination port
 182 * @inet_num - Local port
 183 * @inet_saddr - Sending source
 184 * @uc_ttl - Unicast TTL
 185 * @inet_sport - Source port
 186 * @inet_id - ID counter for DF pkts
 187 * @tos - TOS
 188 * @mc_ttl - Multicasting TTL
 189 * @is_icsk - is this an inet_connection_sock?
 190 * @uc_index - Unicast outgoing device index
 191 * @mc_index - Multicast device index
 192 * @mc_list - Group array
 193 * @cork - info to build ip hdr on each ip frag while socket is corked
 194 */
 195struct inet_sock {
 196        /* sk and pinet6 has to be the first two members of inet_sock */
 197        struct sock             sk;
 198#if IS_ENABLED(CONFIG_IPV6)
 199        struct ipv6_pinfo       *pinet6;
 200#endif
 201        /* Socket demultiplex comparisons on incoming packets. */
 202#define inet_daddr              sk.__sk_common.skc_daddr
 203#define inet_rcv_saddr          sk.__sk_common.skc_rcv_saddr
 204#define inet_dport              sk.__sk_common.skc_dport
 205#define inet_num                sk.__sk_common.skc_num
 206
 207        __be32                  inet_saddr;
 208        __s16                   uc_ttl;
 209        __u16                   cmsg_flags;
 210        __be16                  inet_sport;
 211        __u16                   inet_id;
 212
 213        struct ip_options_rcu __rcu     *inet_opt;
 214        int                     rx_dst_ifindex;
 215        __u8                    tos;
 216        __u8                    min_ttl;
 217        __u8                    mc_ttl;
 218        __u8                    pmtudisc;
 219        __u8                    recverr:1,
 220                                is_icsk:1,
 221                                freebind:1,
 222                                hdrincl:1,
 223                                mc_loop:1,
 224                                transparent:1,
 225                                mc_all:1,
 226                                nodefrag:1;
 227        __u8                    bind_address_no_port:1,
 228                                recverr_rfc4884:1,
 229                                defer_connect:1; /* Indicates that fastopen_connect is set
 230                                                  * and cookie exists so we defer connect
 231                                                  * until first data frame is written
 232                                                  */
 233        __u8                    rcv_tos;
 234        __u8                    convert_csum;
 235        int                     uc_index;
 236        int                     mc_index;
 237        __be32                  mc_addr;
 238        struct ip_mc_socklist __rcu     *mc_list;
 239        struct inet_cork_full   cork;
 240};
 241
 242#define IPCORK_OPT      1       /* ip-options has been held in ipcork.opt */
 243#define IPCORK_ALLFRAG  2       /* always fragment (for ipv6 for now) */
 244
 245/* cmsg flags for inet */
 246#define IP_CMSG_PKTINFO         BIT(0)
 247#define IP_CMSG_TTL             BIT(1)
 248#define IP_CMSG_TOS             BIT(2)
 249#define IP_CMSG_RECVOPTS        BIT(3)
 250#define IP_CMSG_RETOPTS         BIT(4)
 251#define IP_CMSG_PASSSEC         BIT(5)
 252#define IP_CMSG_ORIGDSTADDR     BIT(6)
 253#define IP_CMSG_CHECKSUM        BIT(7)
 254#define IP_CMSG_RECVFRAGSIZE    BIT(8)
 255
 256/**
 257 * sk_to_full_sk - Access to a full socket
 258 * @sk: pointer to a socket
 259 *
 260 * SYNACK messages might be attached to request sockets.
 261 * Some places want to reach the listener in this case.
 262 */
 263static inline struct sock *sk_to_full_sk(struct sock *sk)
 264{
 265#ifdef CONFIG_INET
 266        if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 267                sk = inet_reqsk(sk)->rsk_listener;
 268#endif
 269        return sk;
 270}
 271
 272/* sk_to_full_sk() variant with a const argument */
 273static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
 274{
 275#ifdef CONFIG_INET
 276        if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 277                sk = ((const struct request_sock *)sk)->rsk_listener;
 278#endif
 279        return sk;
 280}
 281
 282static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
 283{
 284        return sk_to_full_sk(skb->sk);
 285}
 286
 287static inline struct inet_sock *inet_sk(const struct sock *sk)
 288{
 289        return (struct inet_sock *)sk;
 290}
 291
 292static inline void __inet_sk_copy_descendant(struct sock *sk_to,
 293                                             const struct sock *sk_from,
 294                                             const int ancestor_size)
 295{
 296        memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
 297               sk_from->sk_prot->obj_size - ancestor_size);
 298}
 299
 300int inet_sk_rebuild_header(struct sock *sk);
 301
 302/**
 303 * inet_sk_state_load - read sk->sk_state for lockless contexts
 304 * @sk: socket pointer
 305 *
 306 * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
 307 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
 308 */
 309static inline int inet_sk_state_load(const struct sock *sk)
 310{
 311        /* state change might impact lockless readers. */
 312        return smp_load_acquire(&sk->sk_state);
 313}
 314
 315/**
 316 * inet_sk_state_store - update sk->sk_state
 317 * @sk: socket pointer
 318 * @newstate: new state
 319 *
 320 * Paired with inet_sk_state_load(). Should be used in contexts where
 321 * state change might impact lockless readers.
 322 */
 323void inet_sk_state_store(struct sock *sk, int newstate);
 324
 325void inet_sk_set_state(struct sock *sk, int state);
 326
 327static inline unsigned int __inet_ehashfn(const __be32 laddr,
 328                                          const __u16 lport,
 329                                          const __be32 faddr,
 330                                          const __be16 fport,
 331                                          u32 initval)
 332{
 333        return jhash_3words((__force __u32) laddr,
 334                            (__force __u32) faddr,
 335                            ((__u32) lport) << 16 | (__force __u32)fport,
 336                            initval);
 337}
 338
 339struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 340                                      struct sock *sk_listener,
 341                                      bool attach_listener);
 342
 343static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 344{
 345        __u8 flags = 0;
 346
 347        if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
 348                flags |= FLOWI_FLAG_ANYSRC;
 349        return flags;
 350}
 351
 352static inline void inet_inc_convert_csum(struct sock *sk)
 353{
 354        inet_sk(sk)->convert_csum++;
 355}
 356
 357static inline void inet_dec_convert_csum(struct sock *sk)
 358{
 359        if (inet_sk(sk)->convert_csum > 0)
 360                inet_sk(sk)->convert_csum--;
 361}
 362
 363static inline bool inet_get_convert_csum(struct sock *sk)
 364{
 365        return !!inet_sk(sk)->convert_csum;
 366}
 367
 368
 369static inline bool inet_can_nonlocal_bind(struct net *net,
 370                                          struct inet_sock *inet)
 371{
 372        return net->ipv4.sysctl_ip_nonlocal_bind ||
 373                inet->freebind || inet->transparent;
 374}
 375
 376#endif  /* _INET_SOCK_H */
 377