linux/include/net/ip.h
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   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#include <linux/jhash.h>
  30
  31#include <net/inet_sock.h>
  32#include <net/route.h>
  33#include <net/snmp.h>
  34#include <net/flow.h>
  35#include <net/flow_dissector.h>
  36#include <net/netns/hash.h>
  37
  38#define IPV4_MAX_PMTU           65535U          /* RFC 2675, Section 5.1 */
  39#define IPV4_MIN_MTU            68                      /* RFC 791 */
  40
  41struct sock;
  42
  43struct inet_skb_parm {
  44        int                     iif;
  45        struct ip_options       opt;            /* Compiled IP options          */
  46        u16                     flags;
  47
  48#define IPSKB_FORWARDED         BIT(0)
  49#define IPSKB_XFRM_TUNNEL_SIZE  BIT(1)
  50#define IPSKB_XFRM_TRANSFORMED  BIT(2)
  51#define IPSKB_FRAG_COMPLETE     BIT(3)
  52#define IPSKB_REROUTED          BIT(4)
  53#define IPSKB_DOREDIRECT        BIT(5)
  54#define IPSKB_FRAG_PMTU         BIT(6)
  55#define IPSKB_L3SLAVE           BIT(7)
  56
  57        u16                     frag_max_size;
  58};
  59
  60static inline bool ipv4_l3mdev_skb(u16 flags)
  61{
  62        return !!(flags & IPSKB_L3SLAVE);
  63}
  64
  65static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
  66{
  67        return ip_hdr(skb)->ihl * 4;
  68}
  69
  70struct ipcm_cookie {
  71        struct sockcm_cookie    sockc;
  72        __be32                  addr;
  73        int                     oif;
  74        struct ip_options_rcu   *opt;
  75        __u8                    ttl;
  76        __s16                   tos;
  77        char                    priority;
  78        __u16                   gso_size;
  79};
  80
  81static inline void ipcm_init(struct ipcm_cookie *ipcm)
  82{
  83        *ipcm = (struct ipcm_cookie) { .tos = -1 };
  84}
  85
  86static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
  87                                const struct inet_sock *inet)
  88{
  89        ipcm_init(ipcm);
  90
  91        ipcm->sockc.tsflags = inet->sk.sk_tsflags;
  92        ipcm->oif = inet->sk.sk_bound_dev_if;
  93        ipcm->addr = inet->inet_saddr;
  94}
  95
  96#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
  97#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
  98
  99/* return enslaved device index if relevant */
 100static inline int inet_sdif(struct sk_buff *skb)
 101{
 102#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
 103        if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
 104                return IPCB(skb)->iif;
 105#endif
 106        return 0;
 107}
 108
 109/* Special input handler for packets caught by router alert option.
 110   They are selected only by protocol field, and then processed likely
 111   local ones; but only if someone wants them! Otherwise, router
 112   not running rsvpd will kill RSVP.
 113
 114   It is user level problem, what it will make with them.
 115   I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
 116   but receiver should be enough clever f.e. to forward mtrace requests,
 117   sent to multicast group to reach destination designated router.
 118 */
 119
 120struct ip_ra_chain {
 121        struct ip_ra_chain __rcu *next;
 122        struct sock             *sk;
 123        union {
 124                void                    (*destructor)(struct sock *);
 125                struct sock             *saved_sk;
 126        };
 127        struct rcu_head         rcu;
 128};
 129
 130/* IP flags. */
 131#define IP_CE           0x8000          /* Flag: "Congestion"           */
 132#define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
 133#define IP_MF           0x2000          /* Flag: "More Fragments"       */
 134#define IP_OFFSET       0x1FFF          /* "Fragment Offset" part       */
 135
 136#define IP_FRAG_TIME    (30 * HZ)               /* fragment lifetime    */
 137
 138struct msghdr;
 139struct net_device;
 140struct packet_type;
 141struct rtable;
 142struct sockaddr;
 143
 144int igmp_mc_init(void);
 145
 146/*
 147 *      Functions provided by ip.c
 148 */
 149
 150int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 151                          __be32 saddr, __be32 daddr,
 152                          struct ip_options_rcu *opt);
 153int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 154           struct net_device *orig_dev);
 155void ip_list_rcv(struct list_head *head, struct packet_type *pt,
 156                 struct net_device *orig_dev);
 157int ip_local_deliver(struct sk_buff *skb);
 158int ip_mr_input(struct sk_buff *skb);
 159int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 160int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 161int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 162                   int (*output)(struct net *, struct sock *, struct sk_buff *));
 163void ip_send_check(struct iphdr *ip);
 164int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 165int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 166
 167int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
 168                    __u8 tos);
 169void ip_init(void);
 170int ip_append_data(struct sock *sk, struct flowi4 *fl4,
 171                   int getfrag(void *from, char *to, int offset, int len,
 172                               int odd, struct sk_buff *skb),
 173                   void *from, int len, int protolen,
 174                   struct ipcm_cookie *ipc,
 175                   struct rtable **rt,
 176                   unsigned int flags);
 177int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
 178                       struct sk_buff *skb);
 179ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 180                       int offset, size_t size, int flags);
 181struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 182                              struct sk_buff_head *queue,
 183                              struct inet_cork *cork);
 184int ip_send_skb(struct net *net, struct sk_buff *skb);
 185int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 186void ip_flush_pending_frames(struct sock *sk);
 187struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 188                            int getfrag(void *from, char *to, int offset,
 189                                        int len, int odd, struct sk_buff *skb),
 190                            void *from, int length, int transhdrlen,
 191                            struct ipcm_cookie *ipc, struct rtable **rtp,
 192                            struct inet_cork *cork, unsigned int flags);
 193
 194static inline int ip_queue_xmit(struct sock *sk, struct sk_buff *skb,
 195                                struct flowi *fl)
 196{
 197        return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);
 198}
 199
 200static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 201{
 202        return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 203}
 204
 205static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
 206{
 207        return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
 208}
 209
 210static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
 211{
 212        return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
 213}
 214
 215/* datagram.c */
 216int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 217int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 218
 219void ip4_datagram_release_cb(struct sock *sk);
 220
 221struct ip_reply_arg {
 222        struct kvec iov[1];
 223        int         flags;
 224        __wsum      csum;
 225        int         csumoffset; /* u16 offset of csum in iov[0].iov_base */
 226                                /* -1 if not needed */
 227        int         bound_dev_if;
 228        u8          tos;
 229        kuid_t      uid;
 230};
 231
 232#define IP_REPLY_ARG_NOSRCCHECK 1
 233
 234static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
 235{
 236        return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
 237}
 238
 239void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 240                           const struct ip_options *sopt,
 241                           __be32 daddr, __be32 saddr,
 242                           const struct ip_reply_arg *arg,
 243                           unsigned int len);
 244
 245#define IP_INC_STATS(net, field)        SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 246#define __IP_INC_STATS(net, field)      __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 247#define IP_ADD_STATS(net, field, val)   SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 248#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 249#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 250#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 251#define NET_INC_STATS(net, field)       SNMP_INC_STATS((net)->mib.net_statistics, field)
 252#define __NET_INC_STATS(net, field)     __SNMP_INC_STATS((net)->mib.net_statistics, field)
 253#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 254#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 255
 256u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
 257unsigned long snmp_fold_field(void __percpu *mib, int offt);
 258#if BITS_PER_LONG==32
 259u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 260                         size_t syncp_offset);
 261u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
 262#else
 263static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 264                                        size_t syncp_offset)
 265{
 266        return snmp_get_cpu_field(mib, cpu, offct);
 267
 268}
 269
 270static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
 271{
 272        return snmp_fold_field(mib, offt);
 273}
 274#endif
 275
 276#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
 277{ \
 278        int i, c; \
 279        for_each_possible_cpu(c) { \
 280                for (i = 0; stats_list[i].name; i++) \
 281                        buff64[i] += snmp_get_cpu_field64( \
 282                                        mib_statistic, \
 283                                        c, stats_list[i].entry, \
 284                                        offset); \
 285        } \
 286}
 287
 288#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
 289{ \
 290        int i, c; \
 291        for_each_possible_cpu(c) { \
 292                for (i = 0; stats_list[i].name; i++) \
 293                        buff[i] += snmp_get_cpu_field( \
 294                                                mib_statistic, \
 295                                                c, stats_list[i].entry); \
 296        } \
 297}
 298
 299void inet_get_local_port_range(struct net *net, int *low, int *high);
 300
 301#ifdef CONFIG_SYSCTL
 302static inline int inet_is_local_reserved_port(struct net *net, int port)
 303{
 304        if (!net->ipv4.sysctl_local_reserved_ports)
 305                return 0;
 306        return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
 307}
 308
 309static inline bool sysctl_dev_name_is_allowed(const char *name)
 310{
 311        return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
 312}
 313
 314static inline int inet_prot_sock(struct net *net)
 315{
 316        return net->ipv4.sysctl_ip_prot_sock;
 317}
 318
 319#else
 320static inline int inet_is_local_reserved_port(struct net *net, int port)
 321{
 322        return 0;
 323}
 324
 325static inline int inet_prot_sock(struct net *net)
 326{
 327        return PROT_SOCK;
 328}
 329#endif
 330
 331__be32 inet_current_timestamp(void);
 332
 333/* From inetpeer.c */
 334extern int inet_peer_threshold;
 335extern int inet_peer_minttl;
 336extern int inet_peer_maxttl;
 337
 338void ipfrag_init(void);
 339
 340void ip_static_sysctl_init(void);
 341
 342#define IP4_REPLY_MARK(net, mark) \
 343        ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
 344
 345static inline bool ip_is_fragment(const struct iphdr *iph)
 346{
 347        return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
 348}
 349
 350#ifdef CONFIG_INET
 351#include <net/dst.h>
 352
 353/* The function in 2.2 was invalid, producing wrong result for
 354 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
 355static inline
 356int ip_decrease_ttl(struct iphdr *iph)
 357{
 358        u32 check = (__force u32)iph->check;
 359        check += (__force u32)htons(0x0100);
 360        iph->check = (__force __sum16)(check + (check>=0xFFFF));
 361        return --iph->ttl;
 362}
 363
 364static inline int ip_mtu_locked(const struct dst_entry *dst)
 365{
 366        const struct rtable *rt = (const struct rtable *)dst;
 367
 368        return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
 369}
 370
 371static inline
 372int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 373{
 374        u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
 375
 376        return  pmtudisc == IP_PMTUDISC_DO ||
 377                (pmtudisc == IP_PMTUDISC_WANT &&
 378                 !ip_mtu_locked(dst));
 379}
 380
 381static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 382{
 383        return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
 384               inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
 385}
 386
 387static inline bool ip_sk_use_pmtu(const struct sock *sk)
 388{
 389        return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 390}
 391
 392static inline bool ip_sk_ignore_df(const struct sock *sk)
 393{
 394        return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
 395               inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
 396}
 397
 398static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
 399                                                    bool forwarding)
 400{
 401        struct net *net = dev_net(dst->dev);
 402
 403        if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
 404            ip_mtu_locked(dst) ||
 405            !forwarding)
 406                return dst_mtu(dst);
 407
 408        return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
 409}
 410
 411static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
 412                                          const struct sk_buff *skb)
 413{
 414        if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 415                bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
 416
 417                return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
 418        }
 419
 420        return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
 421}
 422
 423int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len,
 424                       u32 *metrics);
 425
 426u32 ip_idents_reserve(u32 hash, int segs);
 427void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 428
 429static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 430                                        struct sock *sk, int segs)
 431{
 432        struct iphdr *iph = ip_hdr(skb);
 433
 434        if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
 435                /* This is only to work around buggy Windows95/2000
 436                 * VJ compression implementations.  If the ID field
 437                 * does not change, they drop every other packet in
 438                 * a TCP stream using header compression.
 439                 */
 440                if (sk && inet_sk(sk)->inet_daddr) {
 441                        iph->id = htons(inet_sk(sk)->inet_id);
 442                        inet_sk(sk)->inet_id += segs;
 443                } else {
 444                        iph->id = 0;
 445                }
 446        } else {
 447                __ip_select_ident(net, iph, segs);
 448        }
 449}
 450
 451static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
 452                                   struct sock *sk)
 453{
 454        ip_select_ident_segs(net, skb, sk, 1);
 455}
 456
 457static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 458{
 459        return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 460                                  skb->len, proto, 0);
 461}
 462
 463/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
 464 * Equivalent to :      flow->v4addrs.src = iph->saddr;
 465 *                      flow->v4addrs.dst = iph->daddr;
 466 */
 467static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
 468                                            const struct iphdr *iph)
 469{
 470        BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
 471                     offsetof(typeof(flow->addrs), v4addrs.src) +
 472                              sizeof(flow->addrs.v4addrs.src));
 473        memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
 474        flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 475}
 476
 477static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 478{
 479        const struct iphdr *iph = skb_gro_network_header(skb);
 480
 481        return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 482                                  skb_gro_len(skb), proto, 0);
 483}
 484
 485/*
 486 *      Map a multicast IP onto multicast MAC for type ethernet.
 487 */
 488
 489static inline void ip_eth_mc_map(__be32 naddr, char *buf)
 490{
 491        __u32 addr=ntohl(naddr);
 492        buf[0]=0x01;
 493        buf[1]=0x00;
 494        buf[2]=0x5e;
 495        buf[5]=addr&0xFF;
 496        addr>>=8;
 497        buf[4]=addr&0xFF;
 498        addr>>=8;
 499        buf[3]=addr&0x7F;
 500}
 501
 502/*
 503 *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 504 *      Leave P_Key as 0 to be filled in by driver.
 505 */
 506
 507static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 508{
 509        __u32 addr;
 510        unsigned char scope = broadcast[5] & 0xF;
 511
 512        buf[0]  = 0;            /* Reserved */
 513        buf[1]  = 0xff;         /* Multicast QPN */
 514        buf[2]  = 0xff;
 515        buf[3]  = 0xff;
 516        addr    = ntohl(naddr);
 517        buf[4]  = 0xff;
 518        buf[5]  = 0x10 | scope; /* scope from broadcast address */
 519        buf[6]  = 0x40;         /* IPv4 signature */
 520        buf[7]  = 0x1b;
 521        buf[8]  = broadcast[8];         /* P_Key */
 522        buf[9]  = broadcast[9];
 523        buf[10] = 0;
 524        buf[11] = 0;
 525        buf[12] = 0;
 526        buf[13] = 0;
 527        buf[14] = 0;
 528        buf[15] = 0;
 529        buf[19] = addr & 0xff;
 530        addr  >>= 8;
 531        buf[18] = addr & 0xff;
 532        addr  >>= 8;
 533        buf[17] = addr & 0xff;
 534        addr  >>= 8;
 535        buf[16] = addr & 0x0f;
 536}
 537
 538static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 539{
 540        if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
 541                memcpy(buf, broadcast, 4);
 542        else
 543                memcpy(buf, &naddr, sizeof(naddr));
 544}
 545
 546#if IS_ENABLED(CONFIG_IPV6)
 547#include <linux/ipv6.h>
 548#endif
 549
 550static __inline__ void inet_reset_saddr(struct sock *sk)
 551{
 552        inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
 553#if IS_ENABLED(CONFIG_IPV6)
 554        if (sk->sk_family == PF_INET6) {
 555                struct ipv6_pinfo *np = inet6_sk(sk);
 556
 557                memset(&np->saddr, 0, sizeof(np->saddr));
 558                memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 559        }
 560#endif
 561}
 562
 563#endif
 564
 565static inline unsigned int ipv4_addr_hash(__be32 ip)
 566{
 567        return (__force unsigned int) ip;
 568}
 569
 570static inline u32 ipv4_portaddr_hash(const struct net *net,
 571                                     __be32 saddr,
 572                                     unsigned int port)
 573{
 574        return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
 575}
 576
 577bool ip_call_ra_chain(struct sk_buff *skb);
 578
 579/*
 580 *      Functions provided by ip_fragment.c
 581 */
 582
 583enum ip_defrag_users {
 584        IP_DEFRAG_LOCAL_DELIVER,
 585        IP_DEFRAG_CALL_RA_CHAIN,
 586        IP_DEFRAG_CONNTRACK_IN,
 587        __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 588        IP_DEFRAG_CONNTRACK_OUT,
 589        __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 590        IP_DEFRAG_CONNTRACK_BRIDGE_IN,
 591        __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 592        IP_DEFRAG_VS_IN,
 593        IP_DEFRAG_VS_OUT,
 594        IP_DEFRAG_VS_FWD,
 595        IP_DEFRAG_AF_PACKET,
 596        IP_DEFRAG_MACVLAN,
 597};
 598
 599/* Return true if the value of 'user' is between 'lower_bond'
 600 * and 'upper_bond' inclusively.
 601 */
 602static inline bool ip_defrag_user_in_between(u32 user,
 603                                             enum ip_defrag_users lower_bond,
 604                                             enum ip_defrag_users upper_bond)
 605{
 606        return user >= lower_bond && user <= upper_bond;
 607}
 608
 609int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
 610#ifdef CONFIG_INET
 611struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
 612#else
 613static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 614{
 615        return skb;
 616}
 617#endif
 618
 619/*
 620 *      Functions provided by ip_forward.c
 621 */
 622
 623int ip_forward(struct sk_buff *skb);
 624
 625/*
 626 *      Functions provided by ip_options.c
 627 */
 628
 629void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 630                      __be32 daddr, struct rtable *rt, int is_frag);
 631
 632int __ip_options_echo(struct net *net, struct ip_options *dopt,
 633                      struct sk_buff *skb, const struct ip_options *sopt);
 634static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
 635                                  struct sk_buff *skb)
 636{
 637        return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
 638}
 639
 640void ip_options_fragment(struct sk_buff *skb);
 641int ip_options_compile(struct net *net, struct ip_options *opt,
 642                       struct sk_buff *skb);
 643int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 644                   unsigned char *data, int optlen);
 645int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 646                             unsigned char __user *data, int optlen);
 647void ip_options_undo(struct ip_options *opt);
 648void ip_forward_options(struct sk_buff *skb);
 649int ip_options_rcv_srr(struct sk_buff *skb);
 650
 651/*
 652 *      Functions provided by ip_sockglue.c
 653 */
 654
 655void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 656void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
 657                         struct sk_buff *skb, int tlen, int offset);
 658int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
 659                 struct ipcm_cookie *ipc, bool allow_ipv6);
 660int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 661                  unsigned int optlen);
 662int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 663                  int __user *optlen);
 664int compat_ip_setsockopt(struct sock *sk, int level, int optname,
 665                         char __user *optval, unsigned int optlen);
 666int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 667                         char __user *optval, int __user *optlen);
 668int ip_ra_control(struct sock *sk, unsigned char on,
 669                  void (*destructor)(struct sock *));
 670
 671int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
 672void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 673                   u32 info, u8 *payload);
 674void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 675                    u32 info);
 676
 677static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 678{
 679        ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
 680}
 681
 682bool icmp_global_allow(void);
 683extern int sysctl_icmp_msgs_per_sec;
 684extern int sysctl_icmp_msgs_burst;
 685
 686#ifdef CONFIG_PROC_FS
 687int ip_misc_proc_init(void);
 688#endif
 689
 690int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto,
 691                                struct netlink_ext_ack *extack);
 692
 693#endif  /* _IP_H */
 694