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