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