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 #define IPV4_MAX_PMTU           65535U          /* RFC 2675, Section 5.1 */
  37
  38 struct sock;
  39
  40 struct inet_skb_parm {
  41         int                     iif;
  42         struct ip_options       opt;            /* Compiled IP options          */
  43         u16                     flags;
  44
  45 #define IPSKB_FORWARDED         BIT(0)
  46 #define IPSKB_XFRM_TUNNEL_SIZE  BIT(1)
  47 #define IPSKB_XFRM_TRANSFORMED  BIT(2)
  48 #define IPSKB_FRAG_COMPLETE     BIT(3)
  49 #define IPSKB_REROUTED          BIT(4)
  50 #define IPSKB_DOREDIRECT        BIT(5)
  51 #define IPSKB_FRAG_PMTU         BIT(6)
  52 #define IPSKB_L3SLAVE           BIT(7)
  53
  54         u16                     frag_max_size;
  55 };
  56
  57 static inline bool ipv4_l3mdev_skb(u16 flags)
  58 {
  59         return !!(flags & IPSKB_L3SLAVE);
  60 }
  61
  62 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
  63 {
  64         return ip_hdr(skb)->ihl * 4;
  65 }
  66
  67 struct ipcm_cookie {
  68         struct sockcm_cookie    sockc;
  69         __be32                  addr;
  70         int                     oif;
  71         struct ip_options_rcu   *opt;
  72         __u8                    tx_flags;
  73         __u8                    ttl;
  74         __s16                   tos;
  75         char                    priority;
  76 };
  77
  78 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
  79 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
  80
  81 struct ip_ra_chain {
  82         struct ip_ra_chain __rcu *next;
  83         struct sock             *sk;
  84         union {
  85                 void                    (*destructor)(struct sock *);
  86                 struct sock             *saved_sk;
  87         };
  88         struct rcu_head         rcu;
  89 };
  90
  91 extern struct ip_ra_chain __rcu *ip_ra_chain;
  92
  93 /* IP flags. */
  94 #define IP_CE           0x8000          /* Flag: "Congestion"           */
  95 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
  96 #define IP_MF           0x2000          /* Flag: "More Fragments"       */
  97 #define IP_OFFSET       0x1FFF          /* "Fragment Offset" part       */
  98
  99 #define IP_FRAG_TIME    (30 * HZ)               /* fragment lifetime    */
 100
 101 struct msghdr;
 102 struct net_device;
 103 struct packet_type;
 104 struct rtable;
 105 struct sockaddr;
 106
 107 int igmp_mc_init(void);
 108
 109 /*
 110  *      Functions provided by ip.c
 111  */
 112
 113 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 114                           __be32 saddr, __be32 daddr,
 115                           struct ip_options_rcu *opt);
 116 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 117            struct net_device *orig_dev);
 118 int ip_local_deliver(struct sk_buff *skb);
 119 int ip_mr_input(struct sk_buff *skb);
 120 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 121 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 122 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 123                    int (*output)(struct net *, struct sock *, struct sk_buff *));
 124 void ip_send_check(struct iphdr *ip);
 125 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 126 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 127
 128 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
 129 void ip_init(void);
 130 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
 131                    int getfrag(void *from, char *to, int offset, int len,
 132                                int odd, struct sk_buff *skb),
 133                    void *from, int len, int protolen,
 134                    struct ipcm_cookie *ipc,
 135                    struct rtable **rt,
 136                    unsigned int flags);
 137 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
 138                        struct sk_buff *skb);
 139 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 140                        int offset, size_t size, int flags);
 141 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 142                               struct sk_buff_head *queue,
 143                               struct inet_cork *cork);
 144 int ip_send_skb(struct net *net, struct sk_buff *skb);
 145 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 146 void ip_flush_pending_frames(struct sock *sk);
 147 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 148                             int getfrag(void *from, char *to, int offset,
 149                                         int len, int odd, struct sk_buff *skb),
 150                             void *from, int length, int transhdrlen,
 151                             struct ipcm_cookie *ipc, struct rtable **rtp,
 152                             unsigned int flags);
 153
 154 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 155 {
 156         return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 157 }
 158
 159 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
 160 {
 161         return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
 162 }
 163
 164 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
 165 {
 166         return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
 167 }
 168
 169 /* datagram.c */
 170 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 171 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 172
 173 void ip4_datagram_release_cb(struct sock *sk);
 174
 175 struct ip_reply_arg {
 176         struct kvec iov[1];
 177         int         flags;
 178         __wsum      csum;
 179         int         csumoffset; /* u16 offset of csum in iov[0].iov_base */
 180                                 /* -1 if not needed */
 181         int         bound_dev_if;
 182         u8          tos;
 183         kuid_t      uid;
 184 };
 185
 186 #define IP_REPLY_ARG_NOSRCCHECK 1
 187
 188 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
 189 {
 190         return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
 191 }
 192
 193 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 194                            const struct ip_options *sopt,
 195                            __be32 daddr, __be32 saddr,
 196                            const struct ip_reply_arg *arg,
 197                            unsigned int len);
 198
 199 #define IP_INC_STATS(net, field)        SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 200 #define __IP_INC_STATS(net, field)      __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 201 #define IP_ADD_STATS(net, field, val)   SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 202 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_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 __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 205 #define NET_INC_STATS(net, field)       SNMP_INC_STATS((net)->mib.net_statistics, field)
 206 #define __NET_INC_STATS(net, field)     __SNMP_INC_STATS((net)->mib.net_statistics, field)
 207 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 208 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 209
 210 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
 211 unsigned long snmp_fold_field(void __percpu *mib, int offt);
 212 #if BITS_PER_LONG==32
 213 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 214                          size_t syncp_offset);
 215 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
 216 #else
 217 static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 218                                         size_t syncp_offset)
 219 {
 220         return snmp_get_cpu_field(mib, cpu, offct);
 221
 222 }
 223
 224 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
 225 {
 226         return snmp_fold_field(mib, offt);
 227 }
 228 #endif
 229
 230 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
 231 { \
 232         int i, c; \
 233         for_each_possible_cpu(c) { \
 234                 for (i = 0; stats_list[i].name; i++) \
 235                         buff64[i] += snmp_get_cpu_field64( \
 236                                         mib_statistic, \
 237                                         c, stats_list[i].entry, \
 238                                         offset); \
 239         } \
 240 }
 241
 242 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
 243 { \
 244         int i, c; \
 245         for_each_possible_cpu(c) { \
 246                 for (i = 0; stats_list[i].name; i++) \
 247                         buff[i] += snmp_get_cpu_field( \
 248                                                 mib_statistic, \
 249                                                 c, stats_list[i].entry); \
 250         } \
 251 }
 252
 253 void inet_get_local_port_range(struct net *net, int *low, int *high);
 254
 255 #ifdef CONFIG_SYSCTL
 256 static inline int inet_is_local_reserved_port(struct net *net, int port)
 257 {
 258         if (!net->ipv4.sysctl_local_reserved_ports)
 259                 return 0;
 260         return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
 261 }
 262
 263 static inline bool sysctl_dev_name_is_allowed(const char *name)
 264 {
 265         return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
 266 }
 267
 268 static inline int inet_prot_sock(struct net *net)
 269 {
 270         return net->ipv4.sysctl_ip_prot_sock;
 271 }
 272
 273 #else
 274 static inline int inet_is_local_reserved_port(struct net *net, int port)
 275 {
 276         return 0;
 277 }
 278
 279 static inline int inet_prot_sock(struct net *net)
 280 {
 281         return PROT_SOCK;
 282 }
 283 #endif
 284
 285 __be32 inet_current_timestamp(void);
 286
 287 /* From inetpeer.c */
 288 extern int inet_peer_threshold;
 289 extern int inet_peer_minttl;
 290 extern int inet_peer_maxttl;
 291
 292 void ipfrag_init(void);
 293
 294 void ip_static_sysctl_init(void);
 295
 296 #define IP4_REPLY_MARK(net, mark) \
 297         ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
 298
 299 static inline bool ip_is_fragment(const struct iphdr *iph)
 300 {
 301         return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
 302 }
 303
 304 #ifdef CONFIG_INET
 305 #include <net/dst.h>
 306
 307 /* The function in 2.2 was invalid, producing wrong result for
 308  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
 309 static inline
 310 int ip_decrease_ttl(struct iphdr *iph)
 311 {
 312         u32 check = (__force u32)iph->check;
 313         check += (__force u32)htons(0x0100);
 314         iph->check = (__force __sum16)(check + (check>=0xFFFF));
 315         return --iph->ttl;
 316 }
 317
 318 static inline
 319 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 320 {
 321         u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
 322
 323         return  pmtudisc == IP_PMTUDISC_DO ||
 324                 (pmtudisc == IP_PMTUDISC_WANT &&
 325                  !(dst_metric_locked(dst, RTAX_MTU)));
 326 }
 327
 328 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 329 {
 330         return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
 331                inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
 332 }
 333
 334 static inline bool ip_sk_use_pmtu(const struct sock *sk)
 335 {
 336         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 337 }
 338
 339 static inline bool ip_sk_ignore_df(const struct sock *sk)
 340 {
 341         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
 342                inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
 343 }
 344
 345 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
 346                                                     bool forwarding)
 347 {
 348         struct net *net = dev_net(dst->dev);
 349
 350         if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
 351             dst_metric_locked(dst, RTAX_MTU) ||
 352             !forwarding)
 353                 return dst_mtu(dst);
 354
 355         return min(dst->dev->mtu, IP_MAX_MTU);
 356 }
 357
 358 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
 359                                           const struct sk_buff *skb)
 360 {
 361         if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 362                 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
 363
 364                 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
 365         }
 366
 367         return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
 368 }
 369
 370 u32 ip_idents_reserve(u32 hash, int segs);
 371 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 372
 373 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 374                                         struct sock *sk, int segs)
 375 {
 376         struct iphdr *iph = ip_hdr(skb);
 377
 378         if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
 379                 /* This is only to work around buggy Windows95/2000
 380                  * VJ compression implementations.  If the ID field
 381                  * does not change, they drop every other packet in
 382                  * a TCP stream using header compression.
 383                  */
 384                 if (sk && inet_sk(sk)->inet_daddr) {
 385                         iph->id = htons(inet_sk(sk)->inet_id);
 386                         inet_sk(sk)->inet_id += segs;
 387                 } else {
 388                         iph->id = 0;
 389                 }
 390         } else {
 391                 __ip_select_ident(net, iph, segs);
 392         }
 393 }
 394
 395 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
 396                                    struct sock *sk)
 397 {
 398         ip_select_ident_segs(net, skb, sk, 1);
 399 }
 400
 401 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 402 {
 403         return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 404                                   skb->len, proto, 0);
 405 }
 406
 407 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
 408  * Equivalent to :      flow->v4addrs.src = iph->saddr;
 409  *                      flow->v4addrs.dst = iph->daddr;
 410  */
 411 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
 412                                             const struct iphdr *iph)
 413 {
 414         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
 415                      offsetof(typeof(flow->addrs), v4addrs.src) +
 416                               sizeof(flow->addrs.v4addrs.src));
 417         memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
 418         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 419 }
 420
 421 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 422 {
 423         const struct iphdr *iph = skb_gro_network_header(skb);
 424
 425         return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 426                                   skb_gro_len(skb), proto, 0);
 427 }
 428
 429 /*
 430  *      Map a multicast IP onto multicast MAC for type ethernet.
 431  */
 432
 433 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
 434 {
 435         __u32 addr=ntohl(naddr);
 436         buf[0]=0x01;
 437         buf[1]=0x00;
 438         buf[2]=0x5e;
 439         buf[5]=addr&0xFF;
 440         addr>>=8;
 441         buf[4]=addr&0xFF;
 442         addr>>=8;
 443         buf[3]=addr&0x7F;
 444 }
 445
 446 /*
 447  *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 448  *      Leave P_Key as 0 to be filled in by driver.
 449  */
 450
 451 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 452 {
 453         __u32 addr;
 454         unsigned char scope = broadcast[5] & 0xF;
 455
 456         buf[0]  = 0;            /* Reserved */
 457         buf[1]  = 0xff;         /* Multicast QPN */
 458         buf[2]  = 0xff;
 459         buf[3]  = 0xff;
 460         addr    = ntohl(naddr);
 461         buf[4]  = 0xff;
 462         buf[5]  = 0x10 | scope; /* scope from broadcast address */
 463         buf[6]  = 0x40;         /* IPv4 signature */
 464         buf[7]  = 0x1b;
 465         buf[8]  = broadcast[8];         /* P_Key */
 466         buf[9]  = broadcast[9];
 467         buf[10] = 0;
 468         buf[11] = 0;
 469         buf[12] = 0;
 470         buf[13] = 0;
 471         buf[14] = 0;
 472         buf[15] = 0;
 473         buf[19] = addr & 0xff;
 474         addr  >>= 8;
 475         buf[18] = addr & 0xff;
 476         addr  >>= 8;
 477         buf[17] = addr & 0xff;
 478         addr  >>= 8;
 479         buf[16] = addr & 0x0f;
 480 }
 481
 482 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 483 {
 484         if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
 485                 memcpy(buf, broadcast, 4);
 486         else
 487                 memcpy(buf, &naddr, sizeof(naddr));
 488 }
 489
 490 #if IS_ENABLED(CONFIG_IPV6)
 491 #include <linux/ipv6.h>
 492 #endif
 493
 494 static __inline__ void inet_reset_saddr(struct sock *sk)
 495 {
 496         inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
 497 #if IS_ENABLED(CONFIG_IPV6)
 498         if (sk->sk_family == PF_INET6) {
 499                 struct ipv6_pinfo *np = inet6_sk(sk);
 500
 501                 memset(&np->saddr, 0, sizeof(np->saddr));
 502                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 503         }
 504 #endif
 505 }
 506
 507 #endif
 508
 509 static inline unsigned int ipv4_addr_hash(__be32 ip)
 510 {
 511         return (__force unsigned int) ip;
 512 }
 513
 514 bool ip_call_ra_chain(struct sk_buff *skb);
 515
 516 /*
 517  *      Functions provided by ip_fragment.c
 518  */
 519
 520 enum ip_defrag_users {
 521         IP_DEFRAG_LOCAL_DELIVER,
 522         IP_DEFRAG_CALL_RA_CHAIN,
 523         IP_DEFRAG_CONNTRACK_IN,
 524         __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 525         IP_DEFRAG_CONNTRACK_OUT,
 526         __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 527         IP_DEFRAG_CONNTRACK_BRIDGE_IN,
 528         __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 529         IP_DEFRAG_VS_IN,
 530         IP_DEFRAG_VS_OUT,
 531         IP_DEFRAG_VS_FWD,
 532         IP_DEFRAG_AF_PACKET,
 533         IP_DEFRAG_MACVLAN,
 534 };
 535
 536 /* Return true if the value of 'user' is between 'lower_bond'
 537  * and 'upper_bond' inclusively.
 538  */
 539 static inline bool ip_defrag_user_in_between(u32 user,
 540                                              enum ip_defrag_users lower_bond,
 541                                              enum ip_defrag_users upper_bond)
 542 {
 543         return user >= lower_bond && user <= upper_bond;
 544 }
 545
 546 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
 547 #ifdef CONFIG_INET
 548 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
 549 #else
 550 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 551 {
 552         return skb;
 553 }
 554 #endif
 555 int ip_frag_mem(struct net *net);
 556
 557 /*
 558  *      Functions provided by ip_forward.c
 559  */
 560
 561 int ip_forward(struct sk_buff *skb);
 562
 563 /*
 564  *      Functions provided by ip_options.c
 565  */
 566
 567 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 568                       __be32 daddr, struct rtable *rt, int is_frag);
 569
 570 int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
 571                       const struct ip_options *sopt);
 572 static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
 573 {
 574         return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
 575 }
 576
 577 void ip_options_fragment(struct sk_buff *skb);
 578 int ip_options_compile(struct net *net, struct ip_options *opt,
 579                        struct sk_buff *skb);
 580 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 581                    unsigned char *data, int optlen);
 582 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 583                              unsigned char __user *data, int optlen);
 584 void ip_options_undo(struct ip_options *opt);
 585 void ip_forward_options(struct sk_buff *skb);
 586 int ip_options_rcv_srr(struct sk_buff *skb);
 587
 588 /*
 589  *      Functions provided by ip_sockglue.c
 590  */
 591
 592 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 593 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
 594                          struct sk_buff *skb, int tlen, int offset);
 595 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
 596                  struct ipcm_cookie *ipc, bool allow_ipv6);
 597 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 598                   unsigned int optlen);
 599 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 600                   int __user *optlen);
 601 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
 602                          char __user *optval, unsigned int optlen);
 603 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 604                          char __user *optval, int __user *optlen);
 605 int ip_ra_control(struct sock *sk, unsigned char on,
 606                   void (*destructor)(struct sock *));
 607
 608 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
 609 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 610                    u32 info, u8 *payload);
 611 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 612                     u32 info);
 613
 614 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 615 {
 616         ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
 617 }
 618
 619 bool icmp_global_allow(void);
 620 extern int sysctl_icmp_msgs_per_sec;
 621 extern int sysctl_icmp_msgs_burst;
 622
 623 #ifdef CONFIG_PROC_FS
 624 int ip_misc_proc_init(void);
 625 #endif
 626
 627 #endif  /* _IP_H */