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[];
  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         u32 mark = READ_ONCE(sk->sk_mark);
 111
 112         if (!mark && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
 113                 return skb->mark;
 114
 115         return mark;
 116 }
 117
 118 static inline int inet_request_bound_dev_if(const struct sock *sk,
 119                                             struct sk_buff *skb)
 120 {
 121         int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
 122 #ifdef CONFIG_NET_L3_MASTER_DEV
 123         struct net *net = sock_net(sk);
 124
 125         if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
 126                 return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
 127 #endif
 128
 129         return bound_dev_if;
 130 }
 131
 132 static inline int inet_sk_bound_l3mdev(const struct sock *sk)
 133 {
 134 #ifdef CONFIG_NET_L3_MASTER_DEV
 135         struct net *net = sock_net(sk);
 136
 137         if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
 138                 return l3mdev_master_ifindex_by_index(net,
 139                                                       sk->sk_bound_dev_if);
 140 #endif
 141
 142         return 0;
 143 }
 144
 145 static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
 146                                      int dif, int sdif)
 147 {
 148         if (!bound_dev_if)
 149                 return !sdif || l3mdev_accept;
 150         return bound_dev_if == dif || bound_dev_if == sdif;
 151 }
 152
 153 static inline bool inet_sk_bound_dev_eq(const struct net *net,
 154                                         int bound_dev_if,
 155                                         int dif, int sdif)
 156 {
 157 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
 158         return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
 159                                  bound_dev_if, dif, sdif);
 160 #else
 161         return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
 162 #endif
 163 }
 164
 165 struct inet_cork {
 166         unsigned int            flags;
 167         __be32                  addr;
 168         struct ip_options       *opt;
 169         unsigned int            fragsize;
 170         int                     length; /* Total length of all frames */
 171         struct dst_entry        *dst;
 172         u8                      tx_flags;
 173         __u8                    ttl;
 174         __s16                   tos;
 175         char                    priority;
 176         __u16                   gso_size;
 177         u32                     ts_opt_id;
 178         u64                     transmit_time;
 179         u32                     mark;
 180 };
 181
 182 struct inet_cork_full {
 183         struct inet_cork        base;
 184         struct flowi            fl;
 185 };
 186
 187 struct ip_mc_socklist;
 188 struct ipv6_pinfo;
 189 struct rtable;
 190
 191 /** struct inet_sock - representation of INET sockets
 192  *
 193  * @sk - ancestor class
 194  * @pinet6 - pointer to IPv6 control block
 195  * @inet_daddr - Foreign IPv4 addr
 196  * @inet_rcv_saddr - Bound local IPv4 addr
 197  * @inet_dport - Destination port
 198  * @inet_num - Local port
 199  * @inet_flags - various atomic flags
 200  * @inet_saddr - Sending source
 201  * @uc_ttl - Unicast TTL
 202  * @inet_sport - Source port
 203  * @inet_id - ID counter for DF pkts
 204  * @tos - TOS
 205  * @mc_ttl - Multicasting TTL
 206  * @uc_index - Unicast outgoing device index
 207  * @mc_index - Multicast device index
 208  * @mc_list - Group array
 209  * @cork - info to build ip hdr on each ip frag while socket is corked
 210  */
 211 struct inet_sock {
 212         /* sk and pinet6 has to be the first two members of inet_sock */
 213         struct sock             sk;
 214 #if IS_ENABLED(CONFIG_IPV6)
 215         struct ipv6_pinfo       *pinet6;
 216 #endif
 217         /* Socket demultiplex comparisons on incoming packets. */
 218 #define inet_daddr              sk.__sk_common.skc_daddr
 219 #define inet_rcv_saddr          sk.__sk_common.skc_rcv_saddr
 220 #define inet_dport              sk.__sk_common.skc_dport
 221 #define inet_num                sk.__sk_common.skc_num
 222
 223         unsigned long           inet_flags;
 224         __be32                  inet_saddr;
 225         __s16                   uc_ttl;
 226         __be16                  inet_sport;
 227         struct ip_options_rcu __rcu     *inet_opt;
 228         atomic_t                inet_id;
 229
 230         __u8                    tos;
 231         __u8                    min_ttl;
 232         __u8                    mc_ttl;
 233         __u8                    pmtudisc;
 234         __u8                    rcv_tos;
 235         __u8                    convert_csum;
 236         int                     uc_index;
 237         int                     mc_index;
 238         __be32                  mc_addr;
 239         u32                     local_port_range;       /* high << 16 | low */
 240
 241         struct ip_mc_socklist __rcu     *mc_list;
 242         struct inet_cork_full   cork;
 243 };
 244
 245 #define IPCORK_OPT              1       /* ip-options has been held in ipcork.opt */
 246 #define IPCORK_TS_OPT_ID        2       /* ts_opt_id field is valid, overriding sk_tskey */
 247
 248 enum {
 249         INET_FLAGS_PKTINFO      = 0,
 250         INET_FLAGS_TTL          = 1,
 251         INET_FLAGS_TOS          = 2,
 252         INET_FLAGS_RECVOPTS     = 3,
 253         INET_FLAGS_RETOPTS      = 4,
 254         INET_FLAGS_PASSSEC      = 5,
 255         INET_FLAGS_ORIGDSTADDR  = 6,
 256         INET_FLAGS_CHECKSUM     = 7,
 257         INET_FLAGS_RECVFRAGSIZE = 8,
 258
 259         INET_FLAGS_RECVERR      = 9,
 260         INET_FLAGS_RECVERR_RFC4884 = 10,
 261         INET_FLAGS_FREEBIND     = 11,
 262         INET_FLAGS_HDRINCL      = 12,
 263         INET_FLAGS_MC_LOOP      = 13,
 264         INET_FLAGS_MC_ALL       = 14,
 265         INET_FLAGS_TRANSPARENT  = 15,
 266         INET_FLAGS_IS_ICSK      = 16,
 267         INET_FLAGS_NODEFRAG     = 17,
 268         INET_FLAGS_BIND_ADDRESS_NO_PORT = 18,
 269         INET_FLAGS_DEFER_CONNECT = 19,
 270         INET_FLAGS_MC6_LOOP     = 20,
 271         INET_FLAGS_RECVERR6_RFC4884 = 21,
 272         INET_FLAGS_MC6_ALL      = 22,
 273         INET_FLAGS_AUTOFLOWLABEL_SET = 23,
 274         INET_FLAGS_AUTOFLOWLABEL = 24,
 275         INET_FLAGS_DONTFRAG     = 25,
 276         INET_FLAGS_RECVERR6     = 26,
 277         INET_FLAGS_REPFLOW      = 27,
 278         INET_FLAGS_RTALERT_ISOLATE = 28,
 279         INET_FLAGS_SNDFLOW      = 29,
 280         INET_FLAGS_RTALERT      = 30,
 281 };
 282
 283 /* cmsg flags for inet */
 284 #define IP_CMSG_PKTINFO         BIT(INET_FLAGS_PKTINFO)
 285 #define IP_CMSG_TTL             BIT(INET_FLAGS_TTL)
 286 #define IP_CMSG_TOS             BIT(INET_FLAGS_TOS)
 287 #define IP_CMSG_RECVOPTS        BIT(INET_FLAGS_RECVOPTS)
 288 #define IP_CMSG_RETOPTS         BIT(INET_FLAGS_RETOPTS)
 289 #define IP_CMSG_PASSSEC         BIT(INET_FLAGS_PASSSEC)
 290 #define IP_CMSG_ORIGDSTADDR     BIT(INET_FLAGS_ORIGDSTADDR)
 291 #define IP_CMSG_CHECKSUM        BIT(INET_FLAGS_CHECKSUM)
 292 #define IP_CMSG_RECVFRAGSIZE    BIT(INET_FLAGS_RECVFRAGSIZE)
 293
 294 #define IP_CMSG_ALL     (IP_CMSG_PKTINFO | IP_CMSG_TTL |                \
 295                          IP_CMSG_TOS | IP_CMSG_RECVOPTS |               \
 296                          IP_CMSG_RETOPTS | IP_CMSG_PASSSEC |            \
 297                          IP_CMSG_ORIGDSTADDR | IP_CMSG_CHECKSUM |       \
 298                          IP_CMSG_RECVFRAGSIZE)
 299
 300 static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet)
 301 {
 302         return READ_ONCE(inet->inet_flags) & IP_CMSG_ALL;
 303 }
 304
 305 #define inet_test_bit(nr, sk)                   \
 306         test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
 307 #define inet_set_bit(nr, sk)                    \
 308         set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
 309 #define inet_clear_bit(nr, sk)                  \
 310         clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
 311 #define inet_assign_bit(nr, sk, val)            \
 312         assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)
 313
 314 /**
 315  * sk_to_full_sk - Access to a full socket
 316  * @sk: pointer to a socket
 317  *
 318  * SYNACK messages might be attached to request sockets.
 319  * Some places want to reach the listener in this case.
 320  */
 321 static inline struct sock *sk_to_full_sk(struct sock *sk)
 322 {
 323 #ifdef CONFIG_INET
 324         if (sk && READ_ONCE(sk->sk_state) == TCP_NEW_SYN_RECV)
 325                 sk = inet_reqsk(sk)->rsk_listener;
 326         if (sk && READ_ONCE(sk->sk_state) == TCP_TIME_WAIT)
 327                 sk = NULL;
 328 #endif
 329         return sk;
 330 }
 331
 332 /* sk_to_full_sk() variant with a const argument */
 333 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
 334 {
 335 #ifdef CONFIG_INET
 336         if (sk && READ_ONCE(sk->sk_state) == TCP_NEW_SYN_RECV)
 337                 sk = ((const struct request_sock *)sk)->rsk_listener;
 338         if (sk && READ_ONCE(sk->sk_state) == TCP_TIME_WAIT)
 339                 sk = NULL;
 340 #endif
 341         return sk;
 342 }
 343
 344 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
 345 {
 346         return sk_to_full_sk(skb->sk);
 347 }
 348
 349 #define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
 350
 351 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
 352                                              const struct sock *sk_from,
 353                                              const int ancestor_size)
 354 {
 355         memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
 356                sk_from->sk_prot->obj_size - ancestor_size);
 357 }
 358
 359 int inet_sk_rebuild_header(struct sock *sk);
 360
 361 /**
 362  * inet_sk_state_load - read sk->sk_state for lockless contexts
 363  * @sk: socket pointer
 364  *
 365  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
 366  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
 367  */
 368 static inline int inet_sk_state_load(const struct sock *sk)
 369 {
 370         /* state change might impact lockless readers. */
 371         return smp_load_acquire(&sk->sk_state);
 372 }
 373
 374 /**
 375  * inet_sk_state_store - update sk->sk_state
 376  * @sk: socket pointer
 377  * @newstate: new state
 378  *
 379  * Paired with inet_sk_state_load(). Should be used in contexts where
 380  * state change might impact lockless readers.
 381  */
 382 void inet_sk_state_store(struct sock *sk, int newstate);
 383
 384 void inet_sk_set_state(struct sock *sk, int state);
 385
 386 static inline unsigned int __inet_ehashfn(const __be32 laddr,
 387                                           const __u16 lport,
 388                                           const __be32 faddr,
 389                                           const __be16 fport,
 390                                           u32 initval)
 391 {
 392         return jhash_3words((__force __u32) laddr,
 393                             (__force __u32) faddr,
 394                             ((__u32) lport) << 16 | (__force __u32)fport,
 395                             initval);
 396 }
 397
 398 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 399                                       struct sock *sk_listener,
 400                                       bool attach_listener);
 401
 402 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 403 {
 404         __u8 flags = 0;
 405
 406         if (inet_test_bit(TRANSPARENT, sk) || inet_test_bit(HDRINCL, sk))
 407                 flags |= FLOWI_FLAG_ANYSRC;
 408         return flags;
 409 }
 410
 411 static inline void inet_inc_convert_csum(struct sock *sk)
 412 {
 413         inet_sk(sk)->convert_csum++;
 414 }
 415
 416 static inline void inet_dec_convert_csum(struct sock *sk)
 417 {
 418         if (inet_sk(sk)->convert_csum > 0)
 419                 inet_sk(sk)->convert_csum--;
 420 }
 421
 422 static inline bool inet_get_convert_csum(struct sock *sk)
 423 {
 424         return !!inet_sk(sk)->convert_csum;
 425 }
 426
 427
 428 static inline bool inet_can_nonlocal_bind(struct net *net,
 429                                           struct inet_sock *inet)
 430 {
 431         return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
 432                 test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
 433                 test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
 434 }
 435
 436 static inline bool inet_addr_valid_or_nonlocal(struct net *net,
 437                                                struct inet_sock *inet,
 438                                                __be32 addr,
 439                                                int addr_type)
 440 {
 441         return inet_can_nonlocal_bind(net, inet) ||
 442                 addr == htonl(INADDR_ANY) ||
 443                 addr_type == RTN_LOCAL ||
 444                 addr_type == RTN_MULTICAST ||
 445                 addr_type == RTN_BROADCAST;
 446 }
 447
 448 #endif  /* _INET_SOCK_H */