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         __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
  71 struct 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
  81 extern 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
  91 struct msghdr;
  92 struct net_device;
  93 struct packet_type;
  94 struct rtable;
  95 struct sockaddr;
  96
  97 int igmp_mc_init(void);
  98
  99 /*
 100  *      Functions provided by ip.c
 101  */
 102
 103 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 104                           __be32 saddr, __be32 daddr,
 105                           struct ip_options_rcu *opt);
 106 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 107            struct net_device *orig_dev);
 108 int ip_local_deliver(struct sk_buff *skb);
 109 int ip_mr_input(struct sk_buff *skb);
 110 int ip_output(struct sock *sk, struct sk_buff *skb);
 111 int ip_mc_output(struct sock *sk, struct sk_buff *skb);
 112 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 113                    int (*output)(struct net *, struct sock *, struct sk_buff *));
 114 void ip_send_check(struct iphdr *ip);
 115 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 116 int ip_local_out(struct sock *sk, struct sk_buff *skb);
 117
 118 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
 119 void ip_init(void);
 120 int 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);
 127 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
 128                        struct sk_buff *skb);
 129 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 130                        int offset, size_t size, int flags);
 131 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 132                               struct sk_buff_head *queue,
 133                               struct inet_cork *cork);
 134 int ip_send_skb(struct net *net, struct sk_buff *skb);
 135 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 136 void ip_flush_pending_frames(struct sock *sk);
 137 struct 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
 144 static 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
 149 static 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
 154 static 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 */
 160 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 161 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 162
 163 void ip4_datagram_release_cb(struct sock *sk);
 164
 165 struct 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
 177 static 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
 182 void 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
 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 /* From inetpeer.c */
 244 extern int inet_peer_threshold;
 245 extern int inet_peer_minttl;
 246 extern int inet_peer_maxttl;
 247
 248 /* From ip_input.c */
 249 extern int sysctl_ip_early_demux;
 250
 251 /* From ip_output.c */
 252 extern int sysctl_ip_dynaddr;
 253
 254 void ipfrag_init(void);
 255
 256 void ip_static_sysctl_init(void);
 257
 258 #define IP4_REPLY_MARK(net, mark) \
 259         ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
 260
 261 static inline bool ip_is_fragment(const struct iphdr *iph)
 262 {
 263         return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
 264 }
 265
 266 #ifdef CONFIG_INET
 267 #include <net/dst.h>
 268
 269 /* The function in 2.2 was invalid, producing wrong result for
 270  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
 271 static inline
 272 int ip_decrease_ttl(struct iphdr *iph)
 273 {
 274         u32 check = (__force u32)iph->check;
 275         check += (__force u32)htons(0x0100);
 276         iph->check = (__force __sum16)(check + (check>=0xFFFF));
 277         return --iph->ttl;
 278 }
 279
 280 static inline
 281 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 282 {
 283         u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
 284
 285         return  pmtudisc == IP_PMTUDISC_DO ||
 286                 (pmtudisc == IP_PMTUDISC_WANT &&
 287                  !(dst_metric_locked(dst, RTAX_MTU)));
 288 }
 289
 290 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 291 {
 292         return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
 293                inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
 294 }
 295
 296 static inline bool ip_sk_use_pmtu(const struct sock *sk)
 297 {
 298         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 299 }
 300
 301 static inline bool ip_sk_ignore_df(const struct sock *sk)
 302 {
 303         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
 304                inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
 305 }
 306
 307 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
 308                                                     bool forwarding)
 309 {
 310         struct net *net = dev_net(dst->dev);
 311
 312         if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
 313             dst_metric_locked(dst, RTAX_MTU) ||
 314             !forwarding)
 315                 return dst_mtu(dst);
 316
 317         return min(dst->dev->mtu, IP_MAX_MTU);
 318 }
 319
 320 static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb)
 321 {
 322         struct sock *sk = skb->sk;
 323
 324         if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 325                 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
 326
 327                 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
 328         }
 329
 330         return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
 331 }
 332
 333 u32 ip_idents_reserve(u32 hash, int segs);
 334 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 335
 336 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 337                                         struct sock *sk, int segs)
 338 {
 339         struct iphdr *iph = ip_hdr(skb);
 340
 341         if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
 342                 /* This is only to work around buggy Windows95/2000
 343                  * VJ compression implementations.  If the ID field
 344                  * does not change, they drop every other packet in
 345                  * a TCP stream using header compression.
 346                  */
 347                 if (sk && inet_sk(sk)->inet_daddr) {
 348                         iph->id = htons(inet_sk(sk)->inet_id);
 349                         inet_sk(sk)->inet_id += segs;
 350                 } else {
 351                         iph->id = 0;
 352                 }
 353         } else {
 354                 __ip_select_ident(net, iph, segs);
 355         }
 356 }
 357
 358 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
 359                                    struct sock *sk)
 360 {
 361         ip_select_ident_segs(net, skb, sk, 1);
 362 }
 363
 364 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 365 {
 366         return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 367                                   skb->len, proto, 0);
 368 }
 369
 370 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
 371  * Equivalent to :      flow->v4addrs.src = iph->saddr;
 372  *                      flow->v4addrs.dst = iph->daddr;
 373  */
 374 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
 375                                             const struct iphdr *iph)
 376 {
 377         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
 378                      offsetof(typeof(flow->addrs), v4addrs.src) +
 379                               sizeof(flow->addrs.v4addrs.src));
 380         memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
 381         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 382 }
 383
 384 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 385 {
 386         const struct iphdr *iph = skb_gro_network_header(skb);
 387
 388         return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 389                                   skb_gro_len(skb), proto, 0);
 390 }
 391
 392 /*
 393  *      Map a multicast IP onto multicast MAC for type ethernet.
 394  */
 395
 396 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
 397 {
 398         __u32 addr=ntohl(naddr);
 399         buf[0]=0x01;
 400         buf[1]=0x00;
 401         buf[2]=0x5e;
 402         buf[5]=addr&0xFF;
 403         addr>>=8;
 404         buf[4]=addr&0xFF;
 405         addr>>=8;
 406         buf[3]=addr&0x7F;
 407 }
 408
 409 /*
 410  *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 411  *      Leave P_Key as 0 to be filled in by driver.
 412  */
 413
 414 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 415 {
 416         __u32 addr;
 417         unsigned char scope = broadcast[5] & 0xF;
 418
 419         buf[0]  = 0;            /* Reserved */
 420         buf[1]  = 0xff;         /* Multicast QPN */
 421         buf[2]  = 0xff;
 422         buf[3]  = 0xff;
 423         addr    = ntohl(naddr);
 424         buf[4]  = 0xff;
 425         buf[5]  = 0x10 | scope; /* scope from broadcast address */
 426         buf[6]  = 0x40;         /* IPv4 signature */
 427         buf[7]  = 0x1b;
 428         buf[8]  = broadcast[8];         /* P_Key */
 429         buf[9]  = broadcast[9];
 430         buf[10] = 0;
 431         buf[11] = 0;
 432         buf[12] = 0;
 433         buf[13] = 0;
 434         buf[14] = 0;
 435         buf[15] = 0;
 436         buf[19] = addr & 0xff;
 437         addr  >>= 8;
 438         buf[18] = addr & 0xff;
 439         addr  >>= 8;
 440         buf[17] = addr & 0xff;
 441         addr  >>= 8;
 442         buf[16] = addr & 0x0f;
 443 }
 444
 445 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 446 {
 447         if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
 448                 memcpy(buf, broadcast, 4);
 449         else
 450                 memcpy(buf, &naddr, sizeof(naddr));
 451 }
 452
 453 #if IS_ENABLED(CONFIG_IPV6)
 454 #include <linux/ipv6.h>
 455 #endif
 456
 457 static __inline__ void inet_reset_saddr(struct sock *sk)
 458 {
 459         inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
 460 #if IS_ENABLED(CONFIG_IPV6)
 461         if (sk->sk_family == PF_INET6) {
 462                 struct ipv6_pinfo *np = inet6_sk(sk);
 463
 464                 memset(&np->saddr, 0, sizeof(np->saddr));
 465                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 466         }
 467 #endif
 468 }
 469
 470 #endif
 471
 472 static inline unsigned int ipv4_addr_hash(__be32 ip)
 473 {
 474         return (__force unsigned int) ip;
 475 }
 476
 477 bool ip_call_ra_chain(struct sk_buff *skb);
 478
 479 /*
 480  *      Functions provided by ip_fragment.c
 481  */
 482
 483 enum ip_defrag_users {
 484         IP_DEFRAG_LOCAL_DELIVER,
 485         IP_DEFRAG_CALL_RA_CHAIN,
 486         IP_DEFRAG_CONNTRACK_IN,
 487         __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 488         IP_DEFRAG_CONNTRACK_OUT,
 489         __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 490         IP_DEFRAG_CONNTRACK_BRIDGE_IN,
 491         __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 492         IP_DEFRAG_VS_IN,
 493         IP_DEFRAG_VS_OUT,
 494         IP_DEFRAG_VS_FWD,
 495         IP_DEFRAG_AF_PACKET,
 496         IP_DEFRAG_MACVLAN,
 497 };
 498
 499 /* Return true if the value of 'user' is between 'lower_bond'
 500  * and 'upper_bond' inclusively.
 501  */
 502 static inline bool ip_defrag_user_in_between(u32 user,
 503                                              enum ip_defrag_users lower_bond,
 504                                              enum ip_defrag_users upper_bond)
 505 {
 506         return user >= lower_bond && user <= upper_bond;
 507 }
 508
 509 int ip_defrag(struct sk_buff *skb, u32 user);
 510 #ifdef CONFIG_INET
 511 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user);
 512 #else
 513 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
 514 {
 515         return skb;
 516 }
 517 #endif
 518 int ip_frag_mem(struct net *net);
 519
 520 /*
 521  *      Functions provided by ip_forward.c
 522  */
 523
 524 int ip_forward(struct sk_buff *skb);
 525
 526 /*
 527  *      Functions provided by ip_options.c
 528  */
 529
 530 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 531                       __be32 daddr, struct rtable *rt, int is_frag);
 532
 533 int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
 534                       const struct ip_options *sopt);
 535 static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
 536 {
 537         return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
 538 }
 539
 540 void ip_options_fragment(struct sk_buff *skb);
 541 int ip_options_compile(struct net *net, struct ip_options *opt,
 542                        struct sk_buff *skb);
 543 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 544                    unsigned char *data, int optlen);
 545 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 546                              unsigned char __user *data, int optlen);
 547 void ip_options_undo(struct ip_options *opt);
 548 void ip_forward_options(struct sk_buff *skb);
 549 int ip_options_rcv_srr(struct sk_buff *skb);
 550
 551 /*
 552  *      Functions provided by ip_sockglue.c
 553  */
 554
 555 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 556 void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int offset);
 557 int ip_cmsg_send(struct net *net, struct msghdr *msg,
 558                  struct ipcm_cookie *ipc, bool allow_ipv6);
 559 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 560                   unsigned int optlen);
 561 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 562                   int __user *optlen);
 563 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
 564                          char __user *optval, unsigned int optlen);
 565 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 566                          char __user *optval, int __user *optlen);
 567 int ip_ra_control(struct sock *sk, unsigned char on,
 568                   void (*destructor)(struct sock *));
 569
 570 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
 571 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 572                    u32 info, u8 *payload);
 573 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 574                     u32 info);
 575
 576 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 577 {
 578         ip_cmsg_recv_offset(msg, skb, 0);
 579 }
 580
 581 bool icmp_global_allow(void);
 582 extern int sysctl_icmp_msgs_per_sec;
 583 extern int sysctl_icmp_msgs_burst;
 584
 585 #ifdef CONFIG_PROC_FS
 586 int ip_misc_proc_init(void);
 587 #endif
 588
 589 #endif  /* _IP_H */