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         u16                     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 #define IPSKB_L3SLAVE           BIT(7)
  51
  52         u16                     frag_max_size;
  53 };
  54
  55 static inline bool ipv4_l3mdev_skb(u16 flags)
  56 {
  57         return !!(flags & IPSKB_L3SLAVE);
  58 }
  59
  60 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
  61 {
  62         return ip_hdr(skb)->ihl * 4;
  63 }
  64
  65 struct ipcm_cookie {
  66         struct sockcm_cookie    sockc;
  67         __be32                  addr;
  68         int                     oif;
  69         struct ip_options_rcu   *opt;
  70         __u8                    tx_flags;
  71         __u8                    ttl;
  72         __s16                   tos;
  73         char                    priority;
  74 };
  75
  76 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
  77 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
  78
  79 struct ip_ra_chain {
  80         struct ip_ra_chain __rcu *next;
  81         struct sock             *sk;
  82         union {
  83                 void                    (*destructor)(struct sock *);
  84                 struct sock             *saved_sk;
  85         };
  86         struct rcu_head         rcu;
  87 };
  88
  89 extern struct ip_ra_chain __rcu *ip_ra_chain;
  90
  91 /* IP flags. */
  92 #define IP_CE           0x8000          /* Flag: "Congestion"           */
  93 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
  94 #define IP_MF           0x2000          /* Flag: "More Fragments"       */
  95 #define IP_OFFSET       0x1FFF          /* "Fragment Offset" part       */
  96
  97 #define IP_FRAG_TIME    (30 * HZ)               /* fragment lifetime    */
  98
  99 struct msghdr;
 100 struct net_device;
 101 struct packet_type;
 102 struct rtable;
 103 struct sockaddr;
 104
 105 int igmp_mc_init(void);
 106
 107 /*
 108  *      Functions provided by ip.c
 109  */
 110
 111 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 112                           __be32 saddr, __be32 daddr,
 113                           struct ip_options_rcu *opt);
 114 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 115            struct net_device *orig_dev);
 116 int ip_local_deliver(struct sk_buff *skb);
 117 int ip_mr_input(struct sk_buff *skb);
 118 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 119 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 120 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 121                    int (*output)(struct net *, struct sock *, struct sk_buff *));
 122 void ip_send_check(struct iphdr *ip);
 123 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 124 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 125
 126 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
 127 void ip_init(void);
 128 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
 129                    int getfrag(void *from, char *to, int offset, int len,
 130                                int odd, struct sk_buff *skb),
 131                    void *from, int len, int protolen,
 132                    struct ipcm_cookie *ipc,
 133                    struct rtable **rt,
 134                    unsigned int flags);
 135 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
 136                        struct sk_buff *skb);
 137 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 138                        int offset, size_t size, int flags);
 139 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 140                               struct sk_buff_head *queue,
 141                               struct inet_cork *cork);
 142 int ip_send_skb(struct net *net, struct sk_buff *skb);
 143 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 144 void ip_flush_pending_frames(struct sock *sk);
 145 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 146                             int getfrag(void *from, char *to, int offset,
 147                                         int len, int odd, struct sk_buff *skb),
 148                             void *from, int length, int transhdrlen,
 149                             struct ipcm_cookie *ipc, struct rtable **rtp,
 150                             unsigned int flags);
 151
 152 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 153 {
 154         return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 155 }
 156
 157 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
 158 {
 159         return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
 160 }
 161
 162 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
 163 {
 164         return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
 165 }
 166
 167 /* datagram.c */
 168 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 169 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 170
 171 void ip4_datagram_release_cb(struct sock *sk);
 172
 173 struct ip_reply_arg {
 174         struct kvec iov[1];
 175         int         flags;
 176         __wsum      csum;
 177         int         csumoffset; /* u16 offset of csum in iov[0].iov_base */
 178                                 /* -1 if not needed */
 179         int         bound_dev_if;
 180         u8          tos;
 181         kuid_t      uid;
 182 };
 183
 184 #define IP_REPLY_ARG_NOSRCCHECK 1
 185
 186 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
 187 {
 188         return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
 189 }
 190
 191 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 192                            const struct ip_options *sopt,
 193                            __be32 daddr, __be32 saddr,
 194                            const struct ip_reply_arg *arg,
 195                            unsigned int len);
 196
 197 #define IP_INC_STATS(net, field)        SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 198 #define __IP_INC_STATS(net, field)      __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 199 #define IP_ADD_STATS(net, field, val)   SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 200 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 201 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 202 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 203 #define NET_INC_STATS(net, field)       SNMP_INC_STATS((net)->mib.net_statistics, field)
 204 #define __NET_INC_STATS(net, field)     __SNMP_INC_STATS((net)->mib.net_statistics, field)
 205 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 206 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 207
 208 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
 209 unsigned long snmp_fold_field(void __percpu *mib, int offt);
 210 #if BITS_PER_LONG==32
 211 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 212                          size_t syncp_offset);
 213 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
 214 #else
 215 static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 216                                         size_t syncp_offset)
 217 {
 218         return snmp_get_cpu_field(mib, cpu, offct);
 219
 220 }
 221
 222 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
 223 {
 224         return snmp_fold_field(mib, offt);
 225 }
 226 #endif
 227
 228 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
 229 { \
 230         int i, c; \
 231         for_each_possible_cpu(c) { \
 232                 for (i = 0; stats_list[i].name; i++) \
 233                         buff64[i] += snmp_get_cpu_field64( \
 234                                         mib_statistic, \
 235                                         c, stats_list[i].entry, \
 236                                         offset); \
 237         } \
 238 }
 239
 240 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
 241 { \
 242         int i, c; \
 243         for_each_possible_cpu(c) { \
 244                 for (i = 0; stats_list[i].name; i++) \
 245                         buff[i] += snmp_get_cpu_field( \
 246                                                 mib_statistic, \
 247                                                 c, stats_list[i].entry); \
 248         } \
 249 }
 250
 251 void inet_get_local_port_range(struct net *net, int *low, int *high);
 252
 253 #ifdef CONFIG_SYSCTL
 254 static inline int inet_is_local_reserved_port(struct net *net, int port)
 255 {
 256         if (!net->ipv4.sysctl_local_reserved_ports)
 257                 return 0;
 258         return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
 259 }
 260
 261 static inline bool sysctl_dev_name_is_allowed(const char *name)
 262 {
 263         return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
 264 }
 265
 266 #else
 267 static inline int inet_is_local_reserved_port(struct net *net, int port)
 268 {
 269         return 0;
 270 }
 271 #endif
 272
 273 __be32 inet_current_timestamp(void);
 274
 275 /* From inetpeer.c */
 276 extern int inet_peer_threshold;
 277 extern int inet_peer_minttl;
 278 extern int inet_peer_maxttl;
 279
 280 void ipfrag_init(void);
 281
 282 void ip_static_sysctl_init(void);
 283
 284 #define IP4_REPLY_MARK(net, mark) \
 285         ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
 286
 287 static inline bool ip_is_fragment(const struct iphdr *iph)
 288 {
 289         return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
 290 }
 291
 292 #ifdef CONFIG_INET
 293 #include <net/dst.h>
 294
 295 /* The function in 2.2 was invalid, producing wrong result for
 296  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
 297 static inline
 298 int ip_decrease_ttl(struct iphdr *iph)
 299 {
 300         u32 check = (__force u32)iph->check;
 301         check += (__force u32)htons(0x0100);
 302         iph->check = (__force __sum16)(check + (check>=0xFFFF));
 303         return --iph->ttl;
 304 }
 305
 306 static inline
 307 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 308 {
 309         u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
 310
 311         return  pmtudisc == IP_PMTUDISC_DO ||
 312                 (pmtudisc == IP_PMTUDISC_WANT &&
 313                  !(dst_metric_locked(dst, RTAX_MTU)));
 314 }
 315
 316 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 317 {
 318         return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
 319                inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
 320 }
 321
 322 static inline bool ip_sk_use_pmtu(const struct sock *sk)
 323 {
 324         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 325 }
 326
 327 static inline bool ip_sk_ignore_df(const struct sock *sk)
 328 {
 329         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
 330                inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
 331 }
 332
 333 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
 334                                                     bool forwarding)
 335 {
 336         struct net *net = dev_net(dst->dev);
 337
 338         if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
 339             dst_metric_locked(dst, RTAX_MTU) ||
 340             !forwarding)
 341                 return dst_mtu(dst);
 342
 343         return min(dst->dev->mtu, IP_MAX_MTU);
 344 }
 345
 346 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
 347                                           const struct sk_buff *skb)
 348 {
 349         if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 350                 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
 351
 352                 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
 353         }
 354
 355         return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
 356 }
 357
 358 u32 ip_idents_reserve(u32 hash, int segs);
 359 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 360
 361 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 362                                         struct sock *sk, int segs)
 363 {
 364         struct iphdr *iph = ip_hdr(skb);
 365
 366         if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
 367                 /* This is only to work around buggy Windows95/2000
 368                  * VJ compression implementations.  If the ID field
 369                  * does not change, they drop every other packet in
 370                  * a TCP stream using header compression.
 371                  */
 372                 if (sk && inet_sk(sk)->inet_daddr) {
 373                         iph->id = htons(inet_sk(sk)->inet_id);
 374                         inet_sk(sk)->inet_id += segs;
 375                 } else {
 376                         iph->id = 0;
 377                 }
 378         } else {
 379                 __ip_select_ident(net, iph, segs);
 380         }
 381 }
 382
 383 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
 384                                    struct sock *sk)
 385 {
 386         ip_select_ident_segs(net, skb, sk, 1);
 387 }
 388
 389 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 390 {
 391         return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 392                                   skb->len, proto, 0);
 393 }
 394
 395 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
 396  * Equivalent to :      flow->v4addrs.src = iph->saddr;
 397  *                      flow->v4addrs.dst = iph->daddr;
 398  */
 399 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
 400                                             const struct iphdr *iph)
 401 {
 402         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
 403                      offsetof(typeof(flow->addrs), v4addrs.src) +
 404                               sizeof(flow->addrs.v4addrs.src));
 405         memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
 406         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 407 }
 408
 409 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 410 {
 411         const struct iphdr *iph = skb_gro_network_header(skb);
 412
 413         return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 414                                   skb_gro_len(skb), proto, 0);
 415 }
 416
 417 /*
 418  *      Map a multicast IP onto multicast MAC for type ethernet.
 419  */
 420
 421 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
 422 {
 423         __u32 addr=ntohl(naddr);
 424         buf[0]=0x01;
 425         buf[1]=0x00;
 426         buf[2]=0x5e;
 427         buf[5]=addr&0xFF;
 428         addr>>=8;
 429         buf[4]=addr&0xFF;
 430         addr>>=8;
 431         buf[3]=addr&0x7F;
 432 }
 433
 434 /*
 435  *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 436  *      Leave P_Key as 0 to be filled in by driver.
 437  */
 438
 439 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 440 {
 441         __u32 addr;
 442         unsigned char scope = broadcast[5] & 0xF;
 443
 444         buf[0]  = 0;            /* Reserved */
 445         buf[1]  = 0xff;         /* Multicast QPN */
 446         buf[2]  = 0xff;
 447         buf[3]  = 0xff;
 448         addr    = ntohl(naddr);
 449         buf[4]  = 0xff;
 450         buf[5]  = 0x10 | scope; /* scope from broadcast address */
 451         buf[6]  = 0x40;         /* IPv4 signature */
 452         buf[7]  = 0x1b;
 453         buf[8]  = broadcast[8];         /* P_Key */
 454         buf[9]  = broadcast[9];
 455         buf[10] = 0;
 456         buf[11] = 0;
 457         buf[12] = 0;
 458         buf[13] = 0;
 459         buf[14] = 0;
 460         buf[15] = 0;
 461         buf[19] = addr & 0xff;
 462         addr  >>= 8;
 463         buf[18] = addr & 0xff;
 464         addr  >>= 8;
 465         buf[17] = addr & 0xff;
 466         addr  >>= 8;
 467         buf[16] = addr & 0x0f;
 468 }
 469
 470 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 471 {
 472         if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
 473                 memcpy(buf, broadcast, 4);
 474         else
 475                 memcpy(buf, &naddr, sizeof(naddr));
 476 }
 477
 478 #if IS_ENABLED(CONFIG_IPV6)
 479 #include <linux/ipv6.h>
 480 #endif
 481
 482 static __inline__ void inet_reset_saddr(struct sock *sk)
 483 {
 484         inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
 485 #if IS_ENABLED(CONFIG_IPV6)
 486         if (sk->sk_family == PF_INET6) {
 487                 struct ipv6_pinfo *np = inet6_sk(sk);
 488
 489                 memset(&np->saddr, 0, sizeof(np->saddr));
 490                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 491         }
 492 #endif
 493 }
 494
 495 #endif
 496
 497 static inline unsigned int ipv4_addr_hash(__be32 ip)
 498 {
 499         return (__force unsigned int) ip;
 500 }
 501
 502 bool ip_call_ra_chain(struct sk_buff *skb);
 503
 504 /*
 505  *      Functions provided by ip_fragment.c
 506  */
 507
 508 enum ip_defrag_users {
 509         IP_DEFRAG_LOCAL_DELIVER,
 510         IP_DEFRAG_CALL_RA_CHAIN,
 511         IP_DEFRAG_CONNTRACK_IN,
 512         __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 513         IP_DEFRAG_CONNTRACK_OUT,
 514         __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 515         IP_DEFRAG_CONNTRACK_BRIDGE_IN,
 516         __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 517         IP_DEFRAG_VS_IN,
 518         IP_DEFRAG_VS_OUT,
 519         IP_DEFRAG_VS_FWD,
 520         IP_DEFRAG_AF_PACKET,
 521         IP_DEFRAG_MACVLAN,
 522 };
 523
 524 /* Return true if the value of 'user' is between 'lower_bond'
 525  * and 'upper_bond' inclusively.
 526  */
 527 static inline bool ip_defrag_user_in_between(u32 user,
 528                                              enum ip_defrag_users lower_bond,
 529                                              enum ip_defrag_users upper_bond)
 530 {
 531         return user >= lower_bond && user <= upper_bond;
 532 }
 533
 534 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
 535 #ifdef CONFIG_INET
 536 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
 537 #else
 538 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 539 {
 540         return skb;
 541 }
 542 #endif
 543 int ip_frag_mem(struct net *net);
 544
 545 /*
 546  *      Functions provided by ip_forward.c
 547  */
 548
 549 int ip_forward(struct sk_buff *skb);
 550
 551 /*
 552  *      Functions provided by ip_options.c
 553  */
 554
 555 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 556                       __be32 daddr, struct rtable *rt, int is_frag);
 557
 558 int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
 559                       const struct ip_options *sopt);
 560 static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
 561 {
 562         return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
 563 }
 564
 565 void ip_options_fragment(struct sk_buff *skb);
 566 int ip_options_compile(struct net *net, struct ip_options *opt,
 567                        struct sk_buff *skb);
 568 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 569                    unsigned char *data, int optlen);
 570 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 571                              unsigned char __user *data, int optlen);
 572 void ip_options_undo(struct ip_options *opt);
 573 void ip_forward_options(struct sk_buff *skb);
 574 int ip_options_rcv_srr(struct sk_buff *skb);
 575
 576 /*
 577  *      Functions provided by ip_sockglue.c
 578  */
 579
 580 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 581 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
 582                          struct sk_buff *skb, int tlen, int offset);
 583 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
 584                  struct ipcm_cookie *ipc, bool allow_ipv6);
 585 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 586                   unsigned int optlen);
 587 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 588                   int __user *optlen);
 589 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
 590                          char __user *optval, unsigned int optlen);
 591 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 592                          char __user *optval, int __user *optlen);
 593 int ip_ra_control(struct sock *sk, unsigned char on,
 594                   void (*destructor)(struct sock *));
 595
 596 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
 597 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 598                    u32 info, u8 *payload);
 599 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 600                     u32 info);
 601
 602 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 603 {
 604         ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
 605 }
 606
 607 bool icmp_global_allow(void);
 608 extern int sysctl_icmp_msgs_per_sec;
 609 extern int sysctl_icmp_msgs_burst;
 610
 611 #ifdef CONFIG_PROC_FS
 612 int ip_misc_proc_init(void);
 613 #endif
 614
 615 #endif  /* _IP_H */