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