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         u32                     ir_mark;
  95         union {
  96                 struct ip_options_rcu __rcu     *ireq_opt;
  97 #if IS_ENABLED(CONFIG_IPV6)
  98                 struct {
  99                         struct ipv6_txoptions   *ipv6_opt;
 100                         struct sk_buff          *pktopts;
 101                 };
 102 #endif
 103         };
 104 };
 105
 106 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
 107 {
 108         return (struct inet_request_sock *)sk;
 109 }
 110
 111 static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
 112 {
 113         if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)
 114                 return skb->mark;
 115
 116         return sk->sk_mark;
 117 }
 118
 119 static inline int inet_request_bound_dev_if(const struct sock *sk,
 120                                             struct sk_buff *skb)
 121 {
 122 #ifdef CONFIG_NET_L3_MASTER_DEV
 123         struct net *net = sock_net(sk);
 124
 125         if (!sk->sk_bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
 126                 return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
 127 #endif
 128
 129         return sk->sk_bound_dev_if;
 130 }
 131
 132 struct inet_cork {
 133         unsigned int            flags;
 134         __be32                  addr;
 135         struct ip_options       *opt;
 136         unsigned int            fragsize;
 137         int                     length; /* Total length of all frames */
 138         struct dst_entry        *dst;
 139         u8                      tx_flags;
 140         __u8                    ttl;
 141         __s16                   tos;
 142         char                    priority;
 143 };
 144
 145 struct inet_cork_full {
 146         struct inet_cork        base;
 147         struct flowi            fl;
 148 };
 149
 150 struct ip_mc_socklist;
 151 struct ipv6_pinfo;
 152 struct rtable;
 153
 154 /** struct inet_sock - representation of INET sockets
 155  *
 156  * @sk - ancestor class
 157  * @pinet6 - pointer to IPv6 control block
 158  * @inet_daddr - Foreign IPv4 addr
 159  * @inet_rcv_saddr - Bound local IPv4 addr
 160  * @inet_dport - Destination port
 161  * @inet_num - Local port
 162  * @inet_saddr - Sending source
 163  * @uc_ttl - Unicast TTL
 164  * @inet_sport - Source port
 165  * @inet_id - ID counter for DF pkts
 166  * @tos - TOS
 167  * @mc_ttl - Multicasting TTL
 168  * @is_icsk - is this an inet_connection_sock?
 169  * @uc_index - Unicast outgoing device index
 170  * @mc_index - Multicast device index
 171  * @mc_list - Group array
 172  * @cork - info to build ip hdr on each ip frag while socket is corked
 173  */
 174 struct inet_sock {
 175         /* sk and pinet6 has to be the first two members of inet_sock */
 176         struct sock             sk;
 177 #if IS_ENABLED(CONFIG_IPV6)
 178         struct ipv6_pinfo       *pinet6;
 179 #endif
 180         /* Socket demultiplex comparisons on incoming packets. */
 181 #define inet_daddr              sk.__sk_common.skc_daddr
 182 #define inet_rcv_saddr          sk.__sk_common.skc_rcv_saddr
 183 #define inet_dport              sk.__sk_common.skc_dport
 184 #define inet_num                sk.__sk_common.skc_num
 185
 186         __be32                  inet_saddr;
 187         __s16                   uc_ttl;
 188         __u16                   cmsg_flags;
 189         __be16                  inet_sport;
 190         __u16                   inet_id;
 191
 192         struct ip_options_rcu __rcu     *inet_opt;
 193         int                     rx_dst_ifindex;
 194         __u8                    tos;
 195         __u8                    min_ttl;
 196         __u8                    mc_ttl;
 197         __u8                    pmtudisc;
 198         __u8                    recverr:1,
 199                                 is_icsk:1,
 200                                 freebind:1,
 201                                 hdrincl:1,
 202                                 mc_loop:1,
 203                                 transparent:1,
 204                                 mc_all:1,
 205                                 nodefrag:1;
 206         __u8                    bind_address_no_port:1,
 207                                 defer_connect:1; /* Indicates that fastopen_connect is set
 208                                                   * and cookie exists so we defer connect
 209                                                   * until first data frame is written
 210                                                   */
 211         __u8                    rcv_tos;
 212         __u8                    convert_csum;
 213         int                     uc_index;
 214         int                     mc_index;
 215         __be32                  mc_addr;
 216         struct ip_mc_socklist __rcu     *mc_list;
 217         struct inet_cork_full   cork;
 218 };
 219
 220 #define IPCORK_OPT      1       /* ip-options has been held in ipcork.opt */
 221 #define IPCORK_ALLFRAG  2       /* always fragment (for ipv6 for now) */
 222
 223 /* cmsg flags for inet */
 224 #define IP_CMSG_PKTINFO         BIT(0)
 225 #define IP_CMSG_TTL             BIT(1)
 226 #define IP_CMSG_TOS             BIT(2)
 227 #define IP_CMSG_RECVOPTS        BIT(3)
 228 #define IP_CMSG_RETOPTS         BIT(4)
 229 #define IP_CMSG_PASSSEC         BIT(5)
 230 #define IP_CMSG_ORIGDSTADDR     BIT(6)
 231 #define IP_CMSG_CHECKSUM        BIT(7)
 232 #define IP_CMSG_RECVFRAGSIZE    BIT(8)
 233
 234 /**
 235  * sk_to_full_sk - Access to a full socket
 236  * @sk: pointer to a socket
 237  *
 238  * SYNACK messages might be attached to request sockets.
 239  * Some places want to reach the listener in this case.
 240  */
 241 static inline struct sock *sk_to_full_sk(struct sock *sk)
 242 {
 243 #ifdef CONFIG_INET
 244         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 245                 sk = inet_reqsk(sk)->rsk_listener;
 246 #endif
 247         return sk;
 248 }
 249
 250 /* sk_to_full_sk() variant with a const argument */
 251 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
 252 {
 253 #ifdef CONFIG_INET
 254         if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
 255                 sk = ((const struct request_sock *)sk)->rsk_listener;
 256 #endif
 257         return sk;
 258 }
 259
 260 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
 261 {
 262         return sk_to_full_sk(skb->sk);
 263 }
 264
 265 static inline struct inet_sock *inet_sk(const struct sock *sk)
 266 {
 267         return (struct inet_sock *)sk;
 268 }
 269
 270 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
 271                                              const struct sock *sk_from,
 272                                              const int ancestor_size)
 273 {
 274         memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
 275                sk_from->sk_prot->obj_size - ancestor_size);
 276 }
 277 #if !(IS_ENABLED(CONFIG_IPV6))
 278 static inline void inet_sk_copy_descendant(struct sock *sk_to,
 279                                            const struct sock *sk_from)
 280 {
 281         __inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
 282 }
 283 #endif
 284
 285 int inet_sk_rebuild_header(struct sock *sk);
 286
 287 static inline unsigned int __inet_ehashfn(const __be32 laddr,
 288                                           const __u16 lport,
 289                                           const __be32 faddr,
 290                                           const __be16 fport,
 291                                           u32 initval)
 292 {
 293         return jhash_3words((__force __u32) laddr,
 294                             (__force __u32) faddr,
 295                             ((__u32) lport) << 16 | (__force __u32)fport,
 296                             initval);
 297 }
 298
 299 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 300                                       struct sock *sk_listener,
 301                                       bool attach_listener);
 302
 303 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 304 {
 305         __u8 flags = 0;
 306
 307         if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
 308                 flags |= FLOWI_FLAG_ANYSRC;
 309         return flags;
 310 }
 311
 312 static inline void inet_inc_convert_csum(struct sock *sk)
 313 {
 314         inet_sk(sk)->convert_csum++;
 315 }
 316
 317 static inline void inet_dec_convert_csum(struct sock *sk)
 318 {
 319         if (inet_sk(sk)->convert_csum > 0)
 320                 inet_sk(sk)->convert_csum--;
 321 }
 322
 323 static inline bool inet_get_convert_csum(struct sock *sk)
 324 {
 325         return !!inet_sk(sk)->convert_csum;
 326 }
 327
 328 #endif  /* _INET_SOCK_H */