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 int inet_sk_bound_l3mdev(const struct sock *sk)
 134 {
 135 #ifdef CONFIG_NET_L3_MASTER_DEV
 136         struct net *net = sock_net(sk);
 137
 138         if (!net->ipv4.sysctl_tcp_l3mdev_accept)
 139                 return l3mdev_master_ifindex_by_index(net,
 140                                                       sk->sk_bound_dev_if);
 141 #endif
 142
 143         return 0;
 144 }
 145
 146 static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
 147                                      int dif, int sdif)
 148 {
 149         if (!bound_dev_if)
 150                 return !sdif || l3mdev_accept;
 151         return bound_dev_if == dif || bound_dev_if == sdif;
 152 }
 153
 154 struct inet_cork {
 155         unsigned int            flags;
 156         __be32                  addr;
 157         struct ip_options       *opt;
 158         unsigned int            fragsize;
 159         int                     length; /* Total length of all frames */
 160         struct dst_entry        *dst;
 161         u8                      tx_flags;
 162         __u8                    ttl;
 163         __s16                   tos;
 164         char                    priority;
 165         __u16                   gso_size;
 166         u64                     transmit_time;
 167 };
 168
 169 struct inet_cork_full {
 170         struct inet_cork        base;
 171         struct flowi            fl;
 172 };
 173
 174 struct ip_mc_socklist;
 175 struct ipv6_pinfo;
 176 struct rtable;
 177
 178 /** struct inet_sock - representation of INET sockets
 179  *
 180  * @sk - ancestor class
 181  * @pinet6 - pointer to IPv6 control block
 182  * @inet_daddr - Foreign IPv4 addr
 183  * @inet_rcv_saddr - Bound local IPv4 addr
 184  * @inet_dport - Destination port
 185  * @inet_num - Local port
 186  * @inet_saddr - Sending source
 187  * @uc_ttl - Unicast TTL
 188  * @inet_sport - Source port
 189  * @inet_id - ID counter for DF pkts
 190  * @tos - TOS
 191  * @mc_ttl - Multicasting TTL
 192  * @is_icsk - is this an inet_connection_sock?
 193  * @uc_index - Unicast outgoing device index
 194  * @mc_index - Multicast device index
 195  * @mc_list - Group array
 196  * @cork - info to build ip hdr on each ip frag while socket is corked
 197  */
 198 struct inet_sock {
 199         /* sk and pinet6 has to be the first two members of inet_sock */
 200         struct sock             sk;
 201 #if IS_ENABLED(CONFIG_IPV6)
 202         struct ipv6_pinfo       *pinet6;
 203 #endif
 204         /* Socket demultiplex comparisons on incoming packets. */
 205 #define inet_daddr              sk.__sk_common.skc_daddr
 206 #define inet_rcv_saddr          sk.__sk_common.skc_rcv_saddr
 207 #define inet_dport              sk.__sk_common.skc_dport
 208 #define inet_num                sk.__sk_common.skc_num
 209
 210         __be32                  inet_saddr;
 211         __s16                   uc_ttl;
 212         __u16                   cmsg_flags;
 213         __be16                  inet_sport;
 214         __u16                   inet_id;
 215
 216         struct ip_options_rcu __rcu     *inet_opt;
 217         int                     rx_dst_ifindex;
 218         __u8                    tos;
 219         __u8                    min_ttl;
 220         __u8                    mc_ttl;
 221         __u8                    pmtudisc;
 222         __u8                    recverr:1,
 223                                 is_icsk:1,
 224                                 freebind:1,
 225                                 hdrincl:1,
 226                                 mc_loop:1,
 227                                 transparent:1,
 228                                 mc_all:1,
 229                                 nodefrag:1;
 230         __u8                    bind_address_no_port:1,
 231                                 defer_connect:1; /* Indicates that fastopen_connect is set
 232                                                   * and cookie exists so we defer connect
 233                                                   * until first data frame is written
 234                                                   */
 235         __u8                    rcv_tos;
 236         __u8                    convert_csum;
 237         int                     uc_index;
 238         int                     mc_index;
 239         __be32                  mc_addr;
 240         struct ip_mc_socklist __rcu     *mc_list;
 241         struct inet_cork_full   cork;
 242 };
 243
 244 #define IPCORK_OPT      1       /* ip-options has been held in ipcork.opt */
 245 #define IPCORK_ALLFRAG  2       /* always fragment (for ipv6 for now) */
 246
 247 /* cmsg flags for inet */
 248 #define IP_CMSG_PKTINFO         BIT(0)
 249 #define IP_CMSG_TTL             BIT(1)
 250 #define IP_CMSG_TOS             BIT(2)
 251 #define IP_CMSG_RECVOPTS        BIT(3)
 252 #define IP_CMSG_RETOPTS         BIT(4)
 253 #define IP_CMSG_PASSSEC         BIT(5)
 254 #define IP_CMSG_ORIGDSTADDR     BIT(6)
 255 #define IP_CMSG_CHECKSUM        BIT(7)
 256 #define IP_CMSG_RECVFRAGSIZE    BIT(8)
 257
 258 /**
 259  * sk_to_full_sk - Access to a full socket
 260  * @sk: pointer to a socket
 261  *
 262  * SYNACK messages might be attached to request sockets.
 263  * Some places want to reach the listener in this case.
 264  */
 265 static inline struct sock *sk_to_full_sk(struct sock *sk)
 266 {
 267 #ifdef CONFIG_INET
 268         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 269                 sk = inet_reqsk(sk)->rsk_listener;
 270 #endif
 271         return sk;
 272 }
 273
 274 /* sk_to_full_sk() variant with a const argument */
 275 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
 276 {
 277 #ifdef CONFIG_INET
 278         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 279                 sk = ((const struct request_sock *)sk)->rsk_listener;
 280 #endif
 281         return sk;
 282 }
 283
 284 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
 285 {
 286         return sk_to_full_sk(skb->sk);
 287 }
 288
 289 static inline struct inet_sock *inet_sk(const struct sock *sk)
 290 {
 291         return (struct inet_sock *)sk;
 292 }
 293
 294 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
 295                                              const struct sock *sk_from,
 296                                              const int ancestor_size)
 297 {
 298         memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
 299                sk_from->sk_prot->obj_size - ancestor_size);
 300 }
 301 #if !(IS_ENABLED(CONFIG_IPV6))
 302 static inline void inet_sk_copy_descendant(struct sock *sk_to,
 303                                            const struct sock *sk_from)
 304 {
 305         __inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
 306 }
 307 #endif
 308
 309 int inet_sk_rebuild_header(struct sock *sk);
 310
 311 /**
 312  * inet_sk_state_load - read sk->sk_state for lockless contexts
 313  * @sk: socket pointer
 314  *
 315  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
 316  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
 317  */
 318 static inline int inet_sk_state_load(const struct sock *sk)
 319 {
 320         /* state change might impact lockless readers. */
 321         return smp_load_acquire(&sk->sk_state);
 322 }
 323
 324 /**
 325  * inet_sk_state_store - update sk->sk_state
 326  * @sk: socket pointer
 327  * @newstate: new state
 328  *
 329  * Paired with inet_sk_state_load(). Should be used in contexts where
 330  * state change might impact lockless readers.
 331  */
 332 void inet_sk_state_store(struct sock *sk, int newstate);
 333
 334 void inet_sk_set_state(struct sock *sk, int state);
 335
 336 static inline unsigned int __inet_ehashfn(const __be32 laddr,
 337                                           const __u16 lport,
 338                                           const __be32 faddr,
 339                                           const __be16 fport,
 340                                           u32 initval)
 341 {
 342         return jhash_3words((__force __u32) laddr,
 343                             (__force __u32) faddr,
 344                             ((__u32) lport) << 16 | (__force __u32)fport,
 345                             initval);
 346 }
 347
 348 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 349                                       struct sock *sk_listener,
 350                                       bool attach_listener);
 351
 352 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 353 {
 354         __u8 flags = 0;
 355
 356         if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
 357                 flags |= FLOWI_FLAG_ANYSRC;
 358         return flags;
 359 }
 360
 361 static inline void inet_inc_convert_csum(struct sock *sk)
 362 {
 363         inet_sk(sk)->convert_csum++;
 364 }
 365
 366 static inline void inet_dec_convert_csum(struct sock *sk)
 367 {
 368         if (inet_sk(sk)->convert_csum > 0)
 369                 inet_sk(sk)->convert_csum--;
 370 }
 371
 372 static inline bool inet_get_convert_csum(struct sock *sk)
 373 {
 374         return !!inet_sk(sk)->convert_csum;
 375 }
 376
 377
 378 static inline bool inet_can_nonlocal_bind(struct net *net,
 379                                           struct inet_sock *inet)
 380 {
 381         return net->ipv4.sysctl_ip_nonlocal_bind ||
 382                 inet->freebind || inet->transparent;
 383 }
 384
 385 #endif  /* _INET_SOCK_H */