include/net/ip.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 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
  36 struct sock;
  37
  38 struct inet_skb_parm {
  39         int                     iif;
  40         struct ip_options       opt;            /* Compiled IP options          */
  41         unsigned char           flags;
  42
  43 #define IPSKB_FORWARDED         BIT(0)
  44 #define IPSKB_XFRM_TUNNEL_SIZE  BIT(1)
  45 #define IPSKB_XFRM_TRANSFORMED  BIT(2)
  46 #define IPSKB_FRAG_COMPLETE     BIT(3)
  47 #define IPSKB_REROUTED          BIT(4)
  48 #define IPSKB_DOREDIRECT        BIT(5)
  49 #define IPSKB_FRAG_PMTU         BIT(6)
  50
  51         u16                     frag_max_size;
  52 };
  53
  54 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
  55 {
  56         return ip_hdr(skb)->ihl * 4;
  57 }
  58
  59 struct ipcm_cookie {
  60         struct sockcm_cookie    sockc;
  61         __be32                  addr;
  62         int                     oif;
  63         struct ip_options_rcu   *opt;
  64         __u8                    tx_flags;
  65         __u8                    ttl;
  66         __s16                   tos;
  67         char                    priority;
  68 };
  69
  70 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
  71 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
  72
  73 struct ip_ra_chain {
  74         struct ip_ra_chain __rcu *next;
  75         struct sock             *sk;
  76         union {
  77                 void                    (*destructor)(struct sock *);
  78                 struct sock             *saved_sk;
  79         };
  80         struct rcu_head         rcu;
  81 };
  82
  83 extern struct ip_ra_chain __rcu *ip_ra_chain;
  84
  85 /* IP flags. */
  86 #define IP_CE           0x8000          /* Flag: "Congestion"           */
  87 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
  88 #define IP_MF           0x2000          /* Flag: "More Fragments"       */
  89 #define IP_OFFSET       0x1FFF          /* "Fragment Offset" part       */
  90
  91 #define IP_FRAG_TIME    (30 * HZ)               /* fragment lifetime    */
  92
  93 struct msghdr;
  94 struct net_device;
  95 struct packet_type;
  96 struct rtable;
  97 struct sockaddr;
  98
  99 int igmp_mc_init(void);
 100
 101 /*
 102  *      Functions provided by ip.c
 103  */
 104
 105 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 106                           __be32 saddr, __be32 daddr,
 107                           struct ip_options_rcu *opt);
 108 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 109            struct net_device *orig_dev);
 110 int ip_local_deliver(struct sk_buff *skb);
 111 int ip_mr_input(struct sk_buff *skb);
 112 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 113 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 114 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 115                    int (*output)(struct net *, struct sock *, struct sk_buff *));
 116 void ip_send_check(struct iphdr *ip);
 117 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 118 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 119
 120 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
 121 void ip_init(void);
 122 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
 123                    int getfrag(void *from, char *to, int offset, int len,
 124                                int odd, struct sk_buff *skb),
 125                    void *from, int len, int protolen,
 126                    struct ipcm_cookie *ipc,
 127                    struct rtable **rt,
 128                    unsigned int flags);
 129 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
 130                        struct sk_buff *skb);
 131 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 132                        int offset, size_t size, int flags);
 133 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 134                               struct sk_buff_head *queue,
 135                               struct inet_cork *cork);
 136 int ip_send_skb(struct net *net, struct sk_buff *skb);
 137 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 138 void ip_flush_pending_frames(struct sock *sk);
 139 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 140                             int getfrag(void *from, char *to, int offset,
 141                                         int len, int odd, struct sk_buff *skb),
 142                             void *from, int length, int transhdrlen,
 143                             struct ipcm_cookie *ipc, struct rtable **rtp,
 144                             unsigned int flags);
 145
 146 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 147 {
 148         return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 149 }
 150
 151 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
 152 {
 153         return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
 154 }
 155
 156 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
 157 {
 158         return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
 159 }
 160
 161 /* datagram.c */
 162 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 163 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 164
 165 void ip4_datagram_release_cb(struct sock *sk);
 166
 167 struct ip_reply_arg {
 168         struct kvec iov[1];
 169         int         flags;
 170         __wsum      csum;
 171         int         csumoffset; /* u16 offset of csum in iov[0].iov_base */
 172                                 /* -1 if not needed */
 173         int         bound_dev_if;
 174         u8          tos;
 175 };
 176
 177 #define IP_REPLY_ARG_NOSRCCHECK 1
 178
 179 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
 180 {
 181         return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
 182 }
 183
 184 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 185                            const struct ip_options *sopt,
 186                            __be32 daddr, __be32 saddr,
 187                            const struct ip_reply_arg *arg,
 188                            unsigned int len);
 189
 190 #define IP_INC_STATS(net, field)        SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 191 #define __IP_INC_STATS(net, field)      __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 192 #define IP_ADD_STATS(net, field, val)   SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 193 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 194 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 195 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 196 #define NET_INC_STATS(net, field)       SNMP_INC_STATS((net)->mib.net_statistics, field)
 197 #define __NET_INC_STATS(net, field)     __SNMP_INC_STATS((net)->mib.net_statistics, field)
 198 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 199 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 200
 201 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
 202 unsigned long snmp_fold_field(void __percpu *mib, int offt);
 203 #if BITS_PER_LONG==32
 204 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 205                          size_t syncp_offset);
 206 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
 207 #else
 208 static 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
 215 static 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
 221 void inet_get_local_port_range(struct net *net, int *low, int *high);
 222
 223 #ifdef CONFIG_SYSCTL
 224 static 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
 231 static 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
 237 static 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 */
 246 extern int inet_peer_threshold;
 247 extern int inet_peer_minttl;
 248 extern int inet_peer_maxttl;
 249
 250 void ipfrag_init(void);
 251
 252 void ip_static_sysctl_init(void);
 253
 254 #define IP4_REPLY_MARK(net, mark) \
 255         ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
 256
 257 static 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) */
 267 static inline
 268 int 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
 276 static inline
 277 int 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
 286 static 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
 292 static inline bool ip_sk_use_pmtu(const struct sock *sk)
 293 {
 294         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 295 }
 296
 297 static 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
 303 static 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
 316 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
 317                                           const struct sk_buff *skb)
 318 {
 319         if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 320                 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
 321
 322                 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
 323         }
 324
 325         return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
 326 }
 327
 328 u32 ip_idents_reserve(u32 hash, int segs);
 329 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 330
 331 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 332                                         struct sock *sk, int segs)
 333 {
 334         struct iphdr *iph = ip_hdr(skb);
 335
 336         if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
 337                 /* This is only to work around buggy Windows95/2000
 338                  * VJ compression implementations.  If the ID field
 339                  * does not change, they drop every other packet in
 340                  * a TCP stream using header compression.
 341                  */
 342                 if (sk && inet_sk(sk)->inet_daddr) {
 343                         iph->id = htons(inet_sk(sk)->inet_id);
 344                         inet_sk(sk)->inet_id += segs;
 345                 } else {
 346                         iph->id = 0;
 347                 }
 348         } else {
 349                 __ip_select_ident(net, iph, segs);
 350         }
 351 }
 352
 353 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
 354                                    struct sock *sk)
 355 {
 356         ip_select_ident_segs(net, skb, sk, 1);
 357 }
 358
 359 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 360 {
 361         return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 362                                   skb->len, proto, 0);
 363 }
 364
 365 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
 366  * Equivalent to :      flow->v4addrs.src = iph->saddr;
 367  *                      flow->v4addrs.dst = iph->daddr;
 368  */
 369 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
 370                                             const struct iphdr *iph)
 371 {
 372         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
 373                      offsetof(typeof(flow->addrs), v4addrs.src) +
 374                               sizeof(flow->addrs.v4addrs.src));
 375         memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
 376         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 377 }
 378
 379 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 380 {
 381         const struct iphdr *iph = skb_gro_network_header(skb);
 382
 383         return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 384                                   skb_gro_len(skb), proto, 0);
 385 }
 386
 387 /*
 388  *      Map a multicast IP onto multicast MAC for type ethernet.
 389  */
 390
 391 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
 392 {
 393         __u32 addr=ntohl(naddr);
 394         buf[0]=0x01;
 395         buf[1]=0x00;
 396         buf[2]=0x5e;
 397         buf[5]=addr&0xFF;
 398         addr>>=8;
 399         buf[4]=addr&0xFF;
 400         addr>>=8;
 401         buf[3]=addr&0x7F;
 402 }
 403
 404 /*
 405  *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 406  *      Leave P_Key as 0 to be filled in by driver.
 407  */
 408
 409 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 410 {
 411         __u32 addr;
 412         unsigned char scope = broadcast[5] & 0xF;
 413
 414         buf[0]  = 0;            /* Reserved */
 415         buf[1]  = 0xff;         /* Multicast QPN */
 416         buf[2]  = 0xff;
 417         buf[3]  = 0xff;
 418         addr    = ntohl(naddr);
 419         buf[4]  = 0xff;
 420         buf[5]  = 0x10 | scope; /* scope from broadcast address */
 421         buf[6]  = 0x40;         /* IPv4 signature */
 422         buf[7]  = 0x1b;
 423         buf[8]  = broadcast[8];         /* P_Key */
 424         buf[9]  = broadcast[9];
 425         buf[10] = 0;
 426         buf[11] = 0;
 427         buf[12] = 0;
 428         buf[13] = 0;
 429         buf[14] = 0;
 430         buf[15] = 0;
 431         buf[19] = addr & 0xff;
 432         addr  >>= 8;
 433         buf[18] = addr & 0xff;
 434         addr  >>= 8;
 435         buf[17] = addr & 0xff;
 436         addr  >>= 8;
 437         buf[16] = addr & 0x0f;
 438 }
 439
 440 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 441 {
 442         if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
 443                 memcpy(buf, broadcast, 4);
 444         else
 445                 memcpy(buf, &naddr, sizeof(naddr));
 446 }
 447
 448 #if IS_ENABLED(CONFIG_IPV6)
 449 #include <linux/ipv6.h>
 450 #endif
 451
 452 static __inline__ void inet_reset_saddr(struct sock *sk)
 453 {
 454         inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
 455 #if IS_ENABLED(CONFIG_IPV6)
 456         if (sk->sk_family == PF_INET6) {
 457                 struct ipv6_pinfo *np = inet6_sk(sk);
 458
 459                 memset(&np->saddr, 0, sizeof(np->saddr));
 460                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 461         }
 462 #endif
 463 }
 464
 465 #endif
 466
 467 static inline unsigned int ipv4_addr_hash(__be32 ip)
 468 {
 469         return (__force unsigned int) ip;
 470 }
 471
 472 bool ip_call_ra_chain(struct sk_buff *skb);
 473
 474 /*
 475  *      Functions provided by ip_fragment.c
 476  */
 477
 478 enum ip_defrag_users {
 479         IP_DEFRAG_LOCAL_DELIVER,
 480         IP_DEFRAG_CALL_RA_CHAIN,
 481         IP_DEFRAG_CONNTRACK_IN,
 482         __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 483         IP_DEFRAG_CONNTRACK_OUT,
 484         __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 485         IP_DEFRAG_CONNTRACK_BRIDGE_IN,
 486         __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 487         IP_DEFRAG_VS_IN,
 488         IP_DEFRAG_VS_OUT,
 489         IP_DEFRAG_VS_FWD,
 490         IP_DEFRAG_AF_PACKET,
 491         IP_DEFRAG_MACVLAN,
 492 };
 493
 494 /* Return true if the value of 'user' is between 'lower_bond'
 495  * and 'upper_bond' inclusively.
 496  */
 497 static inline bool ip_defrag_user_in_between(u32 user,
 498                                              enum ip_defrag_users lower_bond,
 499                                              enum ip_defrag_users upper_bond)
 500 {
 501         return user >= lower_bond && user <= upper_bond;
 502 }
 503
 504 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
 505 #ifdef CONFIG_INET
 506 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
 507 #else
 508 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 509 {
 510         return skb;
 511 }
 512 #endif
 513 int ip_frag_mem(struct net *net);
 514
 515 /*
 516  *      Functions provided by ip_forward.c
 517  */
 518
 519 int ip_forward(struct sk_buff *skb);
 520
 521 /*
 522  *      Functions provided by ip_options.c
 523  */
 524
 525 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 526                       __be32 daddr, struct rtable *rt, int is_frag);
 527
 528 int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
 529                       const struct ip_options *sopt);
 530 static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
 531 {
 532         return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
 533 }
 534
 535 void ip_options_fragment(struct sk_buff *skb);
 536 int ip_options_compile(struct net *net, struct ip_options *opt,
 537                        struct sk_buff *skb);
 538 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 539                    unsigned char *data, int optlen);
 540 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 541                              unsigned char __user *data, int optlen);
 542 void ip_options_undo(struct ip_options *opt);
 543 void ip_forward_options(struct sk_buff *skb);
 544 int ip_options_rcv_srr(struct sk_buff *skb);
 545
 546 /*
 547  *      Functions provided by ip_sockglue.c
 548  */
 549
 550 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 551 void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int offset);
 552 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
 553                  struct ipcm_cookie *ipc, bool allow_ipv6);
 554 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 555                   unsigned int optlen);
 556 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 557                   int __user *optlen);
 558 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
 559                          char __user *optval, unsigned int optlen);
 560 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 561                          char __user *optval, int __user *optlen);
 562 int ip_ra_control(struct sock *sk, unsigned char on,
 563                   void (*destructor)(struct sock *));
 564
 565 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
 566 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 567                    u32 info, u8 *payload);
 568 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 569                     u32 info);
 570
 571 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 572 {
 573         ip_cmsg_recv_offset(msg, skb, 0);
 574 }
 575
 576 bool icmp_global_allow(void);
 577 extern int sysctl_icmp_msgs_per_sec;
 578 extern int sysctl_icmp_msgs_burst;
 579
 580 #ifdef CONFIG_PROC_FS
 581 int ip_misc_proc_init(void);
 582 #endif
 583
 584 #endif  /* _IP_H */