linux/include/net/ip.h
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   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 the IP module.
   7 *
   8 * Version:     @(#)ip.h        1.0.2   05/07/93
   9 *
  10 * Authors:     Ross Biro
  11 *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12 *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  13 *
  14 * Changes:
  15 *              Mike McLagan    :       Routing by source
  16 *
  17 *              This program is free software; you can redistribute it and/or
  18 *              modify it under the terms of the GNU General Public License
  19 *              as published by the Free Software Foundation; either version
  20 *              2 of the License, or (at your option) any later version.
  21 */
  22#ifndef _IP_H
  23#define _IP_H
  24
  25#include <linux/types.h>
  26#include <linux/ip.h>
  27#include <linux/in.h>
  28#include <linux/skbuff.h>
  29
  30#include <net/inet_sock.h>
  31#include <net/route.h>
  32#include <net/snmp.h>
  33#include <net/flow.h>
  34#include <net/flow_dissector.h>
  35
  36struct sock;
  37
  38struct inet_skb_parm {
  39        struct ip_options       opt;            /* Compiled IP options          */
  40        unsigned char           flags;
  41
  42#define IPSKB_FORWARDED         BIT(0)
  43#define IPSKB_XFRM_TUNNEL_SIZE  BIT(1)
  44#define IPSKB_XFRM_TRANSFORMED  BIT(2)
  45#define IPSKB_FRAG_COMPLETE     BIT(3)
  46#define IPSKB_REROUTED          BIT(4)
  47#define IPSKB_DOREDIRECT        BIT(5)
  48#define IPSKB_FRAG_PMTU         BIT(6)
  49
  50        u16                     frag_max_size;
  51};
  52
  53static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
  54{
  55        return ip_hdr(skb)->ihl * 4;
  56}
  57
  58struct ipcm_cookie {
  59        __be32                  addr;
  60        int                     oif;
  61        struct ip_options_rcu   *opt;
  62        __u8                    tx_flags;
  63        __u8                    ttl;
  64        __s16                   tos;
  65        char                    priority;
  66};
  67
  68#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
  69#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
  70
  71struct ip_ra_chain {
  72        struct ip_ra_chain __rcu *next;
  73        struct sock             *sk;
  74        union {
  75                void                    (*destructor)(struct sock *);
  76                struct sock             *saved_sk;
  77        };
  78        struct rcu_head         rcu;
  79};
  80
  81extern struct ip_ra_chain __rcu *ip_ra_chain;
  82
  83/* IP flags. */
  84#define IP_CE           0x8000          /* Flag: "Congestion"           */
  85#define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
  86#define IP_MF           0x2000          /* Flag: "More Fragments"       */
  87#define IP_OFFSET       0x1FFF          /* "Fragment Offset" part       */
  88
  89#define IP_FRAG_TIME    (30 * HZ)               /* fragment lifetime    */
  90
  91struct msghdr;
  92struct net_device;
  93struct packet_type;
  94struct rtable;
  95struct sockaddr;
  96
  97int igmp_mc_init(void);
  98
  99/*
 100 *      Functions provided by ip.c
 101 */
 102
 103int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 104                          __be32 saddr, __be32 daddr,
 105                          struct ip_options_rcu *opt);
 106int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 107           struct net_device *orig_dev);
 108int ip_local_deliver(struct sk_buff *skb);
 109int ip_mr_input(struct sk_buff *skb);
 110int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 111int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 112int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 113                   int (*output)(struct net *, struct sock *, struct sk_buff *));
 114void ip_send_check(struct iphdr *ip);
 115int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 116int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 117
 118int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
 119void ip_init(void);
 120int ip_append_data(struct sock *sk, struct flowi4 *fl4,
 121                   int getfrag(void *from, char *to, int offset, int len,
 122                               int odd, struct sk_buff *skb),
 123                   void *from, int len, int protolen,
 124                   struct ipcm_cookie *ipc,
 125                   struct rtable **rt,
 126                   unsigned int flags);
 127int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
 128                       struct sk_buff *skb);
 129ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 130                       int offset, size_t size, int flags);
 131struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 132                              struct sk_buff_head *queue,
 133                              struct inet_cork *cork);
 134int ip_send_skb(struct net *net, struct sk_buff *skb);
 135int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 136void ip_flush_pending_frames(struct sock *sk);
 137struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 138                            int getfrag(void *from, char *to, int offset,
 139                                        int len, int odd, struct sk_buff *skb),
 140                            void *from, int length, int transhdrlen,
 141                            struct ipcm_cookie *ipc, struct rtable **rtp,
 142                            unsigned int flags);
 143
 144static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 145{
 146        return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 147}
 148
 149static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
 150{
 151        return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
 152}
 153
 154static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
 155{
 156        return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
 157}
 158
 159/* datagram.c */
 160int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 161int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 162
 163void ip4_datagram_release_cb(struct sock *sk);
 164
 165struct ip_reply_arg {
 166        struct kvec iov[1];   
 167        int         flags;
 168        __wsum      csum;
 169        int         csumoffset; /* u16 offset of csum in iov[0].iov_base */
 170                                /* -1 if not needed */ 
 171        int         bound_dev_if;
 172        u8          tos;
 173}; 
 174
 175#define IP_REPLY_ARG_NOSRCCHECK 1
 176
 177static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
 178{
 179        return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
 180}
 181
 182void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 183                           const struct ip_options *sopt,
 184                           __be32 daddr, __be32 saddr,
 185                           const struct ip_reply_arg *arg,
 186                           unsigned int len);
 187
 188#define IP_INC_STATS(net, field)        SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 189#define IP_INC_STATS_BH(net, field)     SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
 190#define IP_ADD_STATS(net, field, val)   SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 191#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
 192#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 193#define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
 194#define NET_INC_STATS(net, field)       SNMP_INC_STATS((net)->mib.net_statistics, field)
 195#define NET_INC_STATS_BH(net, field)    SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
 196#define NET_INC_STATS_USER(net, field)  SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
 197#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 198#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
 199#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
 200
 201u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
 202unsigned long snmp_fold_field(void __percpu *mib, int offt);
 203#if BITS_PER_LONG==32
 204u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 205                         size_t syncp_offset);
 206u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
 207#else
 208static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 209                                        size_t syncp_offset)
 210{
 211        return snmp_get_cpu_field(mib, cpu, offct);
 212
 213}
 214
 215static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
 216{
 217        return snmp_fold_field(mib, offt);
 218}
 219#endif
 220
 221void inet_get_local_port_range(struct net *net, int *low, int *high);
 222
 223#ifdef CONFIG_SYSCTL
 224static inline int inet_is_local_reserved_port(struct net *net, int port)
 225{
 226        if (!net->ipv4.sysctl_local_reserved_ports)
 227                return 0;
 228        return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
 229}
 230
 231static inline bool sysctl_dev_name_is_allowed(const char *name)
 232{
 233        return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
 234}
 235
 236#else
 237static inline int inet_is_local_reserved_port(struct net *net, int port)
 238{
 239        return 0;
 240}
 241#endif
 242
 243__be32 inet_current_timestamp(void);
 244
 245/* From inetpeer.c */
 246extern int inet_peer_threshold;
 247extern int inet_peer_minttl;
 248extern int inet_peer_maxttl;
 249
 250void ipfrag_init(void);
 251
 252void ip_static_sysctl_init(void);
 253
 254#define IP4_REPLY_MARK(net, mark) \
 255        ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
 256
 257static inline bool ip_is_fragment(const struct iphdr *iph)
 258{
 259        return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
 260}
 261
 262#ifdef CONFIG_INET
 263#include <net/dst.h>
 264
 265/* The function in 2.2 was invalid, producing wrong result for
 266 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
 267static inline
 268int ip_decrease_ttl(struct iphdr *iph)
 269{
 270        u32 check = (__force u32)iph->check;
 271        check += (__force u32)htons(0x0100);
 272        iph->check = (__force __sum16)(check + (check>=0xFFFF));
 273        return --iph->ttl;
 274}
 275
 276static inline
 277int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 278{
 279        u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
 280
 281        return  pmtudisc == IP_PMTUDISC_DO ||
 282                (pmtudisc == IP_PMTUDISC_WANT &&
 283                 !(dst_metric_locked(dst, RTAX_MTU)));
 284}
 285
 286static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 287{
 288        return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
 289               inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
 290}
 291
 292static inline bool ip_sk_use_pmtu(const struct sock *sk)
 293{
 294        return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 295}
 296
 297static inline bool ip_sk_ignore_df(const struct sock *sk)
 298{
 299        return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
 300               inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
 301}
 302
 303static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
 304                                                    bool forwarding)
 305{
 306        struct net *net = dev_net(dst->dev);
 307
 308        if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
 309            dst_metric_locked(dst, RTAX_MTU) ||
 310            !forwarding)
 311                return dst_mtu(dst);
 312
 313        return min(dst->dev->mtu, IP_MAX_MTU);
 314}
 315
 316static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb)
 317{
 318        struct sock *sk = skb->sk;
 319
 320        if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 321                bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
 322
 323                return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
 324        }
 325
 326        return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
 327}
 328
 329u32 ip_idents_reserve(u32 hash, int segs);
 330void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 331
 332static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 333                                        struct sock *sk, int segs)
 334{
 335        struct iphdr *iph = ip_hdr(skb);
 336
 337        if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
 338                /* This is only to work around buggy Windows95/2000
 339                 * VJ compression implementations.  If the ID field
 340                 * does not change, they drop every other packet in
 341                 * a TCP stream using header compression.
 342                 */
 343                if (sk && inet_sk(sk)->inet_daddr) {
 344                        iph->id = htons(inet_sk(sk)->inet_id);
 345                        inet_sk(sk)->inet_id += segs;
 346                } else {
 347                        iph->id = 0;
 348                }
 349        } else {
 350                __ip_select_ident(net, iph, segs);
 351        }
 352}
 353
 354static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
 355                                   struct sock *sk)
 356{
 357        ip_select_ident_segs(net, skb, sk, 1);
 358}
 359
 360static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 361{
 362        return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 363                                  skb->len, proto, 0);
 364}
 365
 366/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
 367 * Equivalent to :      flow->v4addrs.src = iph->saddr;
 368 *                      flow->v4addrs.dst = iph->daddr;
 369 */
 370static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
 371                                            const struct iphdr *iph)
 372{
 373        BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
 374                     offsetof(typeof(flow->addrs), v4addrs.src) +
 375                              sizeof(flow->addrs.v4addrs.src));
 376        memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
 377        flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 378}
 379
 380static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 381{
 382        const struct iphdr *iph = skb_gro_network_header(skb);
 383
 384        return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 385                                  skb_gro_len(skb), proto, 0);
 386}
 387
 388/*
 389 *      Map a multicast IP onto multicast MAC for type ethernet.
 390 */
 391
 392static inline void ip_eth_mc_map(__be32 naddr, char *buf)
 393{
 394        __u32 addr=ntohl(naddr);
 395        buf[0]=0x01;
 396        buf[1]=0x00;
 397        buf[2]=0x5e;
 398        buf[5]=addr&0xFF;
 399        addr>>=8;
 400        buf[4]=addr&0xFF;
 401        addr>>=8;
 402        buf[3]=addr&0x7F;
 403}
 404
 405/*
 406 *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 407 *      Leave P_Key as 0 to be filled in by driver.
 408 */
 409
 410static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 411{
 412        __u32 addr;
 413        unsigned char scope = broadcast[5] & 0xF;
 414
 415        buf[0]  = 0;            /* Reserved */
 416        buf[1]  = 0xff;         /* Multicast QPN */
 417        buf[2]  = 0xff;
 418        buf[3]  = 0xff;
 419        addr    = ntohl(naddr);
 420        buf[4]  = 0xff;
 421        buf[5]  = 0x10 | scope; /* scope from broadcast address */
 422        buf[6]  = 0x40;         /* IPv4 signature */
 423        buf[7]  = 0x1b;
 424        buf[8]  = broadcast[8];         /* P_Key */
 425        buf[9]  = broadcast[9];
 426        buf[10] = 0;
 427        buf[11] = 0;
 428        buf[12] = 0;
 429        buf[13] = 0;
 430        buf[14] = 0;
 431        buf[15] = 0;
 432        buf[19] = addr & 0xff;
 433        addr  >>= 8;
 434        buf[18] = addr & 0xff;
 435        addr  >>= 8;
 436        buf[17] = addr & 0xff;
 437        addr  >>= 8;
 438        buf[16] = addr & 0x0f;
 439}
 440
 441static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 442{
 443        if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
 444                memcpy(buf, broadcast, 4);
 445        else
 446                memcpy(buf, &naddr, sizeof(naddr));
 447}
 448
 449#if IS_ENABLED(CONFIG_IPV6)
 450#include <linux/ipv6.h>
 451#endif
 452
 453static __inline__ void inet_reset_saddr(struct sock *sk)
 454{
 455        inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
 456#if IS_ENABLED(CONFIG_IPV6)
 457        if (sk->sk_family == PF_INET6) {
 458                struct ipv6_pinfo *np = inet6_sk(sk);
 459
 460                memset(&np->saddr, 0, sizeof(np->saddr));
 461                memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 462        }
 463#endif
 464}
 465
 466#endif
 467
 468static inline unsigned int ipv4_addr_hash(__be32 ip)
 469{
 470        return (__force unsigned int) ip;
 471}
 472
 473bool ip_call_ra_chain(struct sk_buff *skb);
 474
 475/*
 476 *      Functions provided by ip_fragment.c
 477 */
 478
 479enum ip_defrag_users {
 480        IP_DEFRAG_LOCAL_DELIVER,
 481        IP_DEFRAG_CALL_RA_CHAIN,
 482        IP_DEFRAG_CONNTRACK_IN,
 483        __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 484        IP_DEFRAG_CONNTRACK_OUT,
 485        __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 486        IP_DEFRAG_CONNTRACK_BRIDGE_IN,
 487        __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 488        IP_DEFRAG_VS_IN,
 489        IP_DEFRAG_VS_OUT,
 490        IP_DEFRAG_VS_FWD,
 491        IP_DEFRAG_AF_PACKET,
 492        IP_DEFRAG_MACVLAN,
 493};
 494
 495/* Return true if the value of 'user' is between 'lower_bond'
 496 * and 'upper_bond' inclusively.
 497 */
 498static inline bool ip_defrag_user_in_between(u32 user,
 499                                             enum ip_defrag_users lower_bond,
 500                                             enum ip_defrag_users upper_bond)
 501{
 502        return user >= lower_bond && user <= upper_bond;
 503}
 504
 505int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
 506#ifdef CONFIG_INET
 507struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
 508#else
 509static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 510{
 511        return skb;
 512}
 513#endif
 514int ip_frag_mem(struct net *net);
 515
 516/*
 517 *      Functions provided by ip_forward.c
 518 */
 519 
 520int ip_forward(struct sk_buff *skb);
 521 
 522/*
 523 *      Functions provided by ip_options.c
 524 */
 525 
 526void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 527                      __be32 daddr, struct rtable *rt, int is_frag);
 528
 529int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
 530                      const struct ip_options *sopt);
 531static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
 532{
 533        return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
 534}
 535
 536void ip_options_fragment(struct sk_buff *skb);
 537int ip_options_compile(struct net *net, struct ip_options *opt,
 538                       struct sk_buff *skb);
 539int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 540                   unsigned char *data, int optlen);
 541int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 542                             unsigned char __user *data, int optlen);
 543void ip_options_undo(struct ip_options *opt);
 544void ip_forward_options(struct sk_buff *skb);
 545int ip_options_rcv_srr(struct sk_buff *skb);
 546
 547/*
 548 *      Functions provided by ip_sockglue.c
 549 */
 550
 551void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 552void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int offset);
 553int ip_cmsg_send(struct net *net, struct msghdr *msg,
 554                 struct ipcm_cookie *ipc, bool allow_ipv6);
 555int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 556                  unsigned int optlen);
 557int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 558                  int __user *optlen);
 559int compat_ip_setsockopt(struct sock *sk, int level, int optname,
 560                         char __user *optval, unsigned int optlen);
 561int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 562                         char __user *optval, int __user *optlen);
 563int ip_ra_control(struct sock *sk, unsigned char on,
 564                  void (*destructor)(struct sock *));
 565
 566int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
 567void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 568                   u32 info, u8 *payload);
 569void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 570                    u32 info);
 571
 572static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 573{
 574        ip_cmsg_recv_offset(msg, skb, 0);
 575}
 576
 577bool icmp_global_allow(void);
 578extern int sysctl_icmp_msgs_per_sec;
 579extern int sysctl_icmp_msgs_burst;
 580
 581#ifdef CONFIG_PROC_FS
 582int ip_misc_proc_init(void);
 583#endif
 584
 585#endif  /* _IP_H */
 586