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