include/net/inet_sock.h

   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  */
  39 struct 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[0];
  56 };
  57
  58 struct ip_options_rcu {
  59         struct rcu_head rcu;
  60         struct ip_options opt;
  61 };
  62
  63 struct ip_options_data {
  64         struct ip_options_rcu   opt;
  65         char                    data[40];
  66 };
  67
  68 struct 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
 103 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
 104 {
 105         return (struct inet_request_sock *)sk;
 106 }
 107
 108 static 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
 116 static 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
 129 static 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
 142 static 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
 150 struct 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 };
 164
 165 struct inet_cork_full {
 166         struct inet_cork        base;
 167         struct flowi            fl;
 168 };
 169
 170 struct ip_mc_socklist;
 171 struct ipv6_pinfo;
 172 struct rtable;
 173
 174 /** struct inet_sock - representation of INET sockets
 175  *
 176  * @sk - ancestor class
 177  * @pinet6 - pointer to IPv6 control block
 178  * @inet_daddr - Foreign IPv4 addr
 179  * @inet_rcv_saddr - Bound local IPv4 addr
 180  * @inet_dport - Destination port
 181  * @inet_num - Local port
 182  * @inet_saddr - Sending source
 183  * @uc_ttl - Unicast TTL
 184  * @inet_sport - Source port
 185  * @inet_id - ID counter for DF pkts
 186  * @tos - TOS
 187  * @mc_ttl - Multicasting TTL
 188  * @is_icsk - is this an inet_connection_sock?
 189  * @uc_index - Unicast outgoing device index
 190  * @mc_index - Multicast device index
 191  * @mc_list - Group array
 192  * @cork - info to build ip hdr on each ip frag while socket is corked
 193  */
 194 struct inet_sock {
 195         /* sk and pinet6 has to be the first two members of inet_sock */
 196         struct sock             sk;
 197 #if IS_ENABLED(CONFIG_IPV6)
 198         struct ipv6_pinfo       *pinet6;
 199 #endif
 200         /* Socket demultiplex comparisons on incoming packets. */
 201 #define inet_daddr              sk.__sk_common.skc_daddr
 202 #define inet_rcv_saddr          sk.__sk_common.skc_rcv_saddr
 203 #define inet_dport              sk.__sk_common.skc_dport
 204 #define inet_num                sk.__sk_common.skc_num
 205
 206         __be32                  inet_saddr;
 207         __s16                   uc_ttl;
 208         __u16                   cmsg_flags;
 209         __be16                  inet_sport;
 210         __u16                   inet_id;
 211
 212         struct ip_options_rcu __rcu     *inet_opt;
 213         int                     rx_dst_ifindex;
 214         __u8                    tos;
 215         __u8                    min_ttl;
 216         __u8                    mc_ttl;
 217         __u8                    pmtudisc;
 218         __u8                    recverr:1,
 219                                 is_icsk:1,
 220                                 freebind:1,
 221                                 hdrincl:1,
 222                                 mc_loop:1,
 223                                 transparent:1,
 224                                 mc_all:1,
 225                                 nodefrag:1;
 226         __u8                    bind_address_no_port:1,
 227                                 defer_connect:1; /* Indicates that fastopen_connect is set
 228                                                   * and cookie exists so we defer connect
 229                                                   * until first data frame is written
 230                                                   */
 231         __u8                    rcv_tos;
 232         __u8                    convert_csum;
 233         int                     uc_index;
 234         int                     mc_index;
 235         __be32                  mc_addr;
 236         struct ip_mc_socklist __rcu     *mc_list;
 237         struct inet_cork_full   cork;
 238 };
 239
 240 #define IPCORK_OPT      1       /* ip-options has been held in ipcork.opt */
 241 #define IPCORK_ALLFRAG  2       /* always fragment (for ipv6 for now) */
 242
 243 /* cmsg flags for inet */
 244 #define IP_CMSG_PKTINFO         BIT(0)
 245 #define IP_CMSG_TTL             BIT(1)
 246 #define IP_CMSG_TOS             BIT(2)
 247 #define IP_CMSG_RECVOPTS        BIT(3)
 248 #define IP_CMSG_RETOPTS         BIT(4)
 249 #define IP_CMSG_PASSSEC         BIT(5)
 250 #define IP_CMSG_ORIGDSTADDR     BIT(6)
 251 #define IP_CMSG_CHECKSUM        BIT(7)
 252 #define IP_CMSG_RECVFRAGSIZE    BIT(8)
 253
 254 /**
 255  * sk_to_full_sk - Access to a full socket
 256  * @sk: pointer to a socket
 257  *
 258  * SYNACK messages might be attached to request sockets.
 259  * Some places want to reach the listener in this case.
 260  */
 261 static inline struct sock *sk_to_full_sk(struct sock *sk)
 262 {
 263 #ifdef CONFIG_INET
 264         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 265                 sk = inet_reqsk(sk)->rsk_listener;
 266 #endif
 267         return sk;
 268 }
 269
 270 /* sk_to_full_sk() variant with a const argument */
 271 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
 272 {
 273 #ifdef CONFIG_INET
 274         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 275                 sk = ((const struct request_sock *)sk)->rsk_listener;
 276 #endif
 277         return sk;
 278 }
 279
 280 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
 281 {
 282         return sk_to_full_sk(skb->sk);
 283 }
 284
 285 static inline struct inet_sock *inet_sk(const struct sock *sk)
 286 {
 287         return (struct inet_sock *)sk;
 288 }
 289
 290 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
 291                                              const struct sock *sk_from,
 292                                              const int ancestor_size)
 293 {
 294         memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
 295                sk_from->sk_prot->obj_size - ancestor_size);
 296 }
 297 #if !(IS_ENABLED(CONFIG_IPV6))
 298 static inline void inet_sk_copy_descendant(struct sock *sk_to,
 299                                            const struct sock *sk_from)
 300 {
 301         __inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
 302 }
 303 #endif
 304
 305 int inet_sk_rebuild_header(struct sock *sk);
 306
 307 /**
 308  * inet_sk_state_load - read sk->sk_state for lockless contexts
 309  * @sk: socket pointer
 310  *
 311  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
 312  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
 313  */
 314 static inline int inet_sk_state_load(const struct sock *sk)
 315 {
 316         /* state change might impact lockless readers. */
 317         return smp_load_acquire(&sk->sk_state);
 318 }
 319
 320 /**
 321  * inet_sk_state_store - update sk->sk_state
 322  * @sk: socket pointer
 323  * @newstate: new state
 324  *
 325  * Paired with inet_sk_state_load(). Should be used in contexts where
 326  * state change might impact lockless readers.
 327  */
 328 void inet_sk_state_store(struct sock *sk, int newstate);
 329
 330 void inet_sk_set_state(struct sock *sk, int state);
 331
 332 static inline unsigned int __inet_ehashfn(const __be32 laddr,
 333                                           const __u16 lport,
 334                                           const __be32 faddr,
 335                                           const __be16 fport,
 336                                           u32 initval)
 337 {
 338         return jhash_3words((__force __u32) laddr,
 339                             (__force __u32) faddr,
 340                             ((__u32) lport) << 16 | (__force __u32)fport,
 341                             initval);
 342 }
 343
 344 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 345                                       struct sock *sk_listener,
 346                                       bool attach_listener);
 347
 348 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 349 {
 350         __u8 flags = 0;
 351
 352         if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
 353                 flags |= FLOWI_FLAG_ANYSRC;
 354         return flags;
 355 }
 356
 357 static inline void inet_inc_convert_csum(struct sock *sk)
 358 {
 359         inet_sk(sk)->convert_csum++;
 360 }
 361
 362 static inline void inet_dec_convert_csum(struct sock *sk)
 363 {
 364         if (inet_sk(sk)->convert_csum > 0)
 365                 inet_sk(sk)->convert_csum--;
 366 }
 367
 368 static inline bool inet_get_convert_csum(struct sock *sk)
 369 {
 370         return !!inet_sk(sk)->convert_csum;
 371 }
 372
 373
 374 static inline bool inet_can_nonlocal_bind(struct net *net,
 375                                           struct inet_sock *inet)
 376 {
 377         return net->ipv4.sysctl_ip_nonlocal_bind ||
 378                 inet->freebind || inet->transparent;
 379 }
 380
 381 #endif  /* _INET_SOCK_H */