include/net/ip.h

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This source file includes following definitions.
ipv4_l3mdev_skb
ip_hdrlen
ipcm_init
ipcm_init_sk
inet_sdif
ip_fraglist_next
ip_queue_xmit
ip_finish_skb
get_rttos
get_rtconn_flags
ip_reply_arg_flowi_flags
snmp_get_cpu_field64
snmp_fold_field64
inet_is_local_reserved_port
sysctl_dev_name_is_allowed
inet_prot_sock
inet_is_local_reserved_port
inet_prot_sock
ip_is_fragment
ip_decrease_ttl
ip_mtu_locked
ip_dont_fragment
ip_sk_accept_pmtu
ip_sk_use_pmtu
ip_sk_ignore_df
ip_dst_mtu_maybe_forward
ip_skb_dst_mtu
ip_fib_metrics_put
ip_dst_init_metrics
ip_dst_metrics_put
ip_select_ident_segs
ip_select_ident
inet_compute_pseudo
iph_to_flow_copy_v4addrs
inet_gro_compute_pseudo
ip_eth_mc_map
ip_ib_mc_map
ip_ipgre_mc_map
inet_reset_saddr
ipv4_addr_hash
ipv4_portaddr_hash
ip_defrag_user_in_between
ip_check_defrag
ip_options_echo
ip_cmsg_recv
inetdev_valid_mtu
   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4  *              operating system.  INET is implemented using the  BSD Socket
   5  *              interface as the means of communication with the user level.
   6  *
   7  *              Definitions for the IP module.
   8  *
   9  * Version:     @(#)ip.h        1.0.2   05/07/93
  10  *
  11  * Authors:     Ross Biro
  12  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  13  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  14  *
  15  * Changes:
  16  *              Mike McLagan    :       Routing by source
  17  */
  18 #ifndef _IP_H
  19 #define _IP_H
  20 
  21 #include <linux/types.h>
  22 #include <linux/ip.h>
  23 #include <linux/in.h>
  24 #include <linux/skbuff.h>
  25 #include <linux/jhash.h>
  26 
  27 #include <net/inet_sock.h>
  28 #include <net/route.h>
  29 #include <net/snmp.h>
  30 #include <net/flow.h>
  31 #include <net/flow_dissector.h>
  32 #include <net/netns/hash.h>
  33 
  34 #define IPV4_MAX_PMTU           65535U          /* RFC 2675, Section 5.1 */
  35 #define IPV4_MIN_MTU            68                      /* RFC 791 */
  36 
  37 extern unsigned int sysctl_fib_sync_mem;
  38 extern unsigned int sysctl_fib_sync_mem_min;
  39 extern unsigned int sysctl_fib_sync_mem_max;
  40 
  41 struct sock;
  42 
  43 struct 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 
  60 static inline bool ipv4_l3mdev_skb(u16 flags)
  61 {
  62         return !!(flags & IPSKB_L3SLAVE);
  63 }
  64 
  65 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
  66 {
  67         return ip_hdr(skb)->ihl * 4;
  68 }
  69 
  70 struct 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 
  81 static inline void ipcm_init(struct ipcm_cookie *ipcm)
  82 {
  83         *ipcm = (struct ipcm_cookie) { .tos = -1 };
  84 }
  85 
  86 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
  87                                 const struct inet_sock *inet)
  88 {
  89         ipcm_init(ipcm);
  90 
  91         ipcm->sockc.mark = inet->sk.sk_mark;
  92         ipcm->sockc.tsflags = inet->sk.sk_tsflags;
  93         ipcm->oif = inet->sk.sk_bound_dev_if;
  94         ipcm->addr = inet->inet_saddr;
  95 }
  96 
  97 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
  98 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
  99 
 100 /* return enslaved device index if relevant */
 101 static inline int inet_sdif(struct sk_buff *skb)
 102 {
 103 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
 104         if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
 105                 return IPCB(skb)->iif;
 106 #endif
 107         return 0;
 108 }
 109 
 110 /* Special input handler for packets caught by router alert option.
 111    They are selected only by protocol field, and then processed likely
 112    local ones; but only if someone wants them! Otherwise, router
 113    not running rsvpd will kill RSVP.
 114 
 115    It is user level problem, what it will make with them.
 116    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
 117    but receiver should be enough clever f.e. to forward mtrace requests,
 118    sent to multicast group to reach destination designated router.
 119  */
 120 
 121 struct ip_ra_chain {
 122         struct ip_ra_chain __rcu *next;
 123         struct sock             *sk;
 124         union {
 125                 void                    (*destructor)(struct sock *);
 126                 struct sock             *saved_sk;
 127         };
 128         struct rcu_head         rcu;
 129 };
 130 
 131 /* IP flags. */
 132 #define IP_CE           0x8000          /* Flag: "Congestion"           */
 133 #define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
 134 #define IP_MF           0x2000          /* Flag: "More Fragments"       */
 135 #define IP_OFFSET       0x1FFF          /* "Fragment Offset" part       */
 136 
 137 #define IP_FRAG_TIME    (30 * HZ)               /* fragment lifetime    */
 138 
 139 struct msghdr;
 140 struct net_device;
 141 struct packet_type;
 142 struct rtable;
 143 struct sockaddr;
 144 
 145 int igmp_mc_init(void);
 146 
 147 /*
 148  *      Functions provided by ip.c
 149  */
 150 
 151 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 152                           __be32 saddr, __be32 daddr,
 153                           struct ip_options_rcu *opt);
 154 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 155            struct net_device *orig_dev);
 156 void ip_list_rcv(struct list_head *head, struct packet_type *pt,
 157                  struct net_device *orig_dev);
 158 int ip_local_deliver(struct sk_buff *skb);
 159 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
 160 int ip_mr_input(struct sk_buff *skb);
 161 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 162 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 163 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 164                    int (*output)(struct net *, struct sock *, struct sk_buff *));
 165 
 166 struct ip_fraglist_iter {
 167         struct sk_buff  *frag;
 168         struct iphdr    *iph;
 169         int             offset;
 170         unsigned int    hlen;
 171 };
 172 
 173 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
 174                       unsigned int hlen, struct ip_fraglist_iter *iter);
 175 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
 176 
 177 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
 178 {
 179         struct sk_buff *skb = iter->frag;
 180 
 181         iter->frag = skb->next;
 182         skb_mark_not_on_list(skb);
 183 
 184         return skb;
 185 }
 186 
 187 struct ip_frag_state {
 188         bool            DF;
 189         unsigned int    hlen;
 190         unsigned int    ll_rs;
 191         unsigned int    mtu;
 192         unsigned int    left;
 193         int             offset;
 194         int             ptr;
 195         __be16          not_last_frag;
 196 };
 197 
 198 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
 199                   unsigned int mtu, bool DF, struct ip_frag_state *state);
 200 struct sk_buff *ip_frag_next(struct sk_buff *skb,
 201                              struct ip_frag_state *state);
 202 
 203 void ip_send_check(struct iphdr *ip);
 204 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 205 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 206 
 207 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
 208                     __u8 tos);
 209 void ip_init(void);
 210 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
 211                    int getfrag(void *from, char *to, int offset, int len,
 212                                int odd, struct sk_buff *skb),
 213                    void *from, int len, int protolen,
 214                    struct ipcm_cookie *ipc,
 215                    struct rtable **rt,
 216                    unsigned int flags);
 217 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
 218                        struct sk_buff *skb);
 219 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
 220                        int offset, size_t size, int flags);
 221 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 222                               struct sk_buff_head *queue,
 223                               struct inet_cork *cork);
 224 int ip_send_skb(struct net *net, struct sk_buff *skb);
 225 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
 226 void ip_flush_pending_frames(struct sock *sk);
 227 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 228                             int getfrag(void *from, char *to, int offset,
 229                                         int len, int odd, struct sk_buff *skb),
 230                             void *from, int length, int transhdrlen,
 231                             struct ipcm_cookie *ipc, struct rtable **rtp,
 232                             struct inet_cork *cork, unsigned int flags);
 233 
 234 static inline int ip_queue_xmit(struct sock *sk, struct sk_buff *skb,
 235                                 struct flowi *fl)
 236 {
 237         return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);
 238 }
 239 
 240 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 241 {
 242         return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
 243 }
 244 
 245 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
 246 {
 247         return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
 248 }
 249 
 250 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
 251 {
 252         return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
 253 }
 254 
 255 /* datagram.c */
 256 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 257 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 258 
 259 void ip4_datagram_release_cb(struct sock *sk);
 260 
 261 struct ip_reply_arg {
 262         struct kvec iov[1];
 263         int         flags;
 264         __wsum      csum;
 265         int         csumoffset; /* u16 offset of csum in iov[0].iov_base */
 266                                 /* -1 if not needed */
 267         int         bound_dev_if;
 268         u8          tos;
 269         kuid_t      uid;
 270 };
 271 
 272 #define IP_REPLY_ARG_NOSRCCHECK 1
 273 
 274 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
 275 {
 276         return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
 277 }
 278 
 279 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 280                            const struct ip_options *sopt,
 281                            __be32 daddr, __be32 saddr,
 282                            const struct ip_reply_arg *arg,
 283                            unsigned int len, u64 transmit_time);
 284 
 285 #define IP_INC_STATS(net, field)        SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 286 #define __IP_INC_STATS(net, field)      __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 287 #define IP_ADD_STATS(net, field, val)   SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 288 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
 289 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 290 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
 291 #define NET_INC_STATS(net, field)       SNMP_INC_STATS((net)->mib.net_statistics, field)
 292 #define __NET_INC_STATS(net, field)     __SNMP_INC_STATS((net)->mib.net_statistics, field)
 293 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 294 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 295 
 296 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
 297 unsigned long snmp_fold_field(void __percpu *mib, int offt);
 298 #if BITS_PER_LONG==32
 299 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 300                          size_t syncp_offset);
 301 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
 302 #else
 303 static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
 304                                         size_t syncp_offset)
 305 {
 306         return snmp_get_cpu_field(mib, cpu, offct);
 307 
 308 }
 309 
 310 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
 311 {
 312         return snmp_fold_field(mib, offt);
 313 }
 314 #endif
 315 
 316 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
 317 { \
 318         int i, c; \
 319         for_each_possible_cpu(c) { \
 320                 for (i = 0; stats_list[i].name; i++) \
 321                         buff64[i] += snmp_get_cpu_field64( \
 322                                         mib_statistic, \
 323                                         c, stats_list[i].entry, \
 324                                         offset); \
 325         } \
 326 }
 327 
 328 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
 329 { \
 330         int i, c; \
 331         for_each_possible_cpu(c) { \
 332                 for (i = 0; stats_list[i].name; i++) \
 333                         buff[i] += snmp_get_cpu_field( \
 334                                                 mib_statistic, \
 335                                                 c, stats_list[i].entry); \
 336         } \
 337 }
 338 
 339 void inet_get_local_port_range(struct net *net, int *low, int *high);
 340 
 341 #ifdef CONFIG_SYSCTL
 342 static inline int inet_is_local_reserved_port(struct net *net, int port)
 343 {
 344         if (!net->ipv4.sysctl_local_reserved_ports)
 345                 return 0;
 346         return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
 347 }
 348 
 349 static inline bool sysctl_dev_name_is_allowed(const char *name)
 350 {
 351         return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
 352 }
 353 
 354 static inline int inet_prot_sock(struct net *net)
 355 {
 356         return net->ipv4.sysctl_ip_prot_sock;
 357 }
 358 
 359 #else
 360 static inline int inet_is_local_reserved_port(struct net *net, int port)
 361 {
 362         return 0;
 363 }
 364 
 365 static inline int inet_prot_sock(struct net *net)
 366 {
 367         return PROT_SOCK;
 368 }
 369 #endif
 370 
 371 __be32 inet_current_timestamp(void);
 372 
 373 /* From inetpeer.c */
 374 extern int inet_peer_threshold;
 375 extern int inet_peer_minttl;
 376 extern int inet_peer_maxttl;
 377 
 378 void ipfrag_init(void);
 379 
 380 void ip_static_sysctl_init(void);
 381 
 382 #define IP4_REPLY_MARK(net, mark) \
 383         ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
 384 
 385 static inline bool ip_is_fragment(const struct iphdr *iph)
 386 {
 387         return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
 388 }
 389 
 390 #ifdef CONFIG_INET
 391 #include <net/dst.h>
 392 
 393 /* The function in 2.2 was invalid, producing wrong result for
 394  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
 395 static inline
 396 int ip_decrease_ttl(struct iphdr *iph)
 397 {
 398         u32 check = (__force u32)iph->check;
 399         check += (__force u32)htons(0x0100);
 400         iph->check = (__force __sum16)(check + (check>=0xFFFF));
 401         return --iph->ttl;
 402 }
 403 
 404 static inline int ip_mtu_locked(const struct dst_entry *dst)
 405 {
 406         const struct rtable *rt = (const struct rtable *)dst;
 407 
 408         return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
 409 }
 410 
 411 static inline
 412 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 413 {
 414         u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
 415 
 416         return  pmtudisc == IP_PMTUDISC_DO ||
 417                 (pmtudisc == IP_PMTUDISC_WANT &&
 418                  !ip_mtu_locked(dst));
 419 }
 420 
 421 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 422 {
 423         return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
 424                inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
 425 }
 426 
 427 static inline bool ip_sk_use_pmtu(const struct sock *sk)
 428 {
 429         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 430 }
 431 
 432 static inline bool ip_sk_ignore_df(const struct sock *sk)
 433 {
 434         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
 435                inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
 436 }
 437 
 438 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
 439                                                     bool forwarding)
 440 {
 441         struct net *net = dev_net(dst->dev);
 442 
 443         if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
 444             ip_mtu_locked(dst) ||
 445             !forwarding)
 446                 return dst_mtu(dst);
 447 
 448         return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
 449 }
 450 
 451 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
 452                                           const struct sk_buff *skb)
 453 {
 454         if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 455                 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
 456 
 457                 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
 458         }
 459 
 460         return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
 461 }
 462 
 463 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
 464                                         int fc_mx_len,
 465                                         struct netlink_ext_ack *extack);
 466 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
 467 {
 468         if (fib_metrics != &dst_default_metrics &&
 469             refcount_dec_and_test(&fib_metrics->refcnt))
 470                 kfree(fib_metrics);
 471 }
 472 
 473 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */
 474 static inline
 475 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
 476 {
 477         dst_init_metrics(dst, fib_metrics->metrics, true);
 478 
 479         if (fib_metrics != &dst_default_metrics) {
 480                 dst->_metrics |= DST_METRICS_REFCOUNTED;
 481                 refcount_inc(&fib_metrics->refcnt);
 482         }
 483 }
 484 
 485 static inline
 486 void ip_dst_metrics_put(struct dst_entry *dst)
 487 {
 488         struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
 489 
 490         if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
 491                 kfree(p);
 492 }
 493 
 494 u32 ip_idents_reserve(u32 hash, int segs);
 495 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 496 
 497 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 498                                         struct sock *sk, int segs)
 499 {
 500         struct iphdr *iph = ip_hdr(skb);
 501 
 502         if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
 503                 /* This is only to work around buggy Windows95/2000
 504                  * VJ compression implementations.  If the ID field
 505                  * does not change, they drop every other packet in
 506                  * a TCP stream using header compression.
 507                  */
 508                 if (sk && inet_sk(sk)->inet_daddr) {
 509                         iph->id = htons(inet_sk(sk)->inet_id);
 510                         inet_sk(sk)->inet_id += segs;
 511                 } else {
 512                         iph->id = 0;
 513                 }
 514         } else {
 515                 __ip_select_ident(net, iph, segs);
 516         }
 517 }
 518 
 519 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
 520                                    struct sock *sk)
 521 {
 522         ip_select_ident_segs(net, skb, sk, 1);
 523 }
 524 
 525 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 526 {
 527         return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 528                                   skb->len, proto, 0);
 529 }
 530 
 531 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
 532  * Equivalent to :      flow->v4addrs.src = iph->saddr;
 533  *                      flow->v4addrs.dst = iph->daddr;
 534  */
 535 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
 536                                             const struct iphdr *iph)
 537 {
 538         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
 539                      offsetof(typeof(flow->addrs), v4addrs.src) +
 540                               sizeof(flow->addrs.v4addrs.src));
 541         memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
 542         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 543 }
 544 
 545 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 546 {
 547         const struct iphdr *iph = skb_gro_network_header(skb);
 548 
 549         return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 550                                   skb_gro_len(skb), proto, 0);
 551 }
 552 
 553 /*
 554  *      Map a multicast IP onto multicast MAC for type ethernet.
 555  */
 556 
 557 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
 558 {
 559         __u32 addr=ntohl(naddr);
 560         buf[0]=0x01;
 561         buf[1]=0x00;
 562         buf[2]=0x5e;
 563         buf[5]=addr&0xFF;
 564         addr>>=8;
 565         buf[4]=addr&0xFF;
 566         addr>>=8;
 567         buf[3]=addr&0x7F;
 568 }
 569 
 570 /*
 571  *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 572  *      Leave P_Key as 0 to be filled in by driver.
 573  */
 574 
 575 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 576 {
 577         __u32 addr;
 578         unsigned char scope = broadcast[5] & 0xF;
 579 
 580         buf[0]  = 0;            /* Reserved */
 581         buf[1]  = 0xff;         /* Multicast QPN */
 582         buf[2]  = 0xff;
 583         buf[3]  = 0xff;
 584         addr    = ntohl(naddr);
 585         buf[4]  = 0xff;
 586         buf[5]  = 0x10 | scope; /* scope from broadcast address */
 587         buf[6]  = 0x40;         /* IPv4 signature */
 588         buf[7]  = 0x1b;
 589         buf[8]  = broadcast[8];         /* P_Key */
 590         buf[9]  = broadcast[9];
 591         buf[10] = 0;
 592         buf[11] = 0;
 593         buf[12] = 0;
 594         buf[13] = 0;
 595         buf[14] = 0;
 596         buf[15] = 0;
 597         buf[19] = addr & 0xff;
 598         addr  >>= 8;
 599         buf[18] = addr & 0xff;
 600         addr  >>= 8;
 601         buf[17] = addr & 0xff;
 602         addr  >>= 8;
 603         buf[16] = addr & 0x0f;
 604 }
 605 
 606 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 607 {
 608         if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
 609                 memcpy(buf, broadcast, 4);
 610         else
 611                 memcpy(buf, &naddr, sizeof(naddr));
 612 }
 613 
 614 #if IS_ENABLED(CONFIG_IPV6)
 615 #include <linux/ipv6.h>
 616 #endif
 617 
 618 static __inline__ void inet_reset_saddr(struct sock *sk)
 619 {
 620         inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
 621 #if IS_ENABLED(CONFIG_IPV6)
 622         if (sk->sk_family == PF_INET6) {
 623                 struct ipv6_pinfo *np = inet6_sk(sk);
 624 
 625                 memset(&np->saddr, 0, sizeof(np->saddr));
 626                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 627         }
 628 #endif
 629 }
 630 
 631 #endif
 632 
 633 static inline unsigned int ipv4_addr_hash(__be32 ip)
 634 {
 635         return (__force unsigned int) ip;
 636 }
 637 
 638 static inline u32 ipv4_portaddr_hash(const struct net *net,
 639                                      __be32 saddr,
 640                                      unsigned int port)
 641 {
 642         return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
 643 }
 644 
 645 bool ip_call_ra_chain(struct sk_buff *skb);
 646 
 647 /*
 648  *      Functions provided by ip_fragment.c
 649  */
 650 
 651 enum ip_defrag_users {
 652         IP_DEFRAG_LOCAL_DELIVER,
 653         IP_DEFRAG_CALL_RA_CHAIN,
 654         IP_DEFRAG_CONNTRACK_IN,
 655         __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 656         IP_DEFRAG_CONNTRACK_OUT,
 657         __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 658         IP_DEFRAG_CONNTRACK_BRIDGE_IN,
 659         __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 660         IP_DEFRAG_VS_IN,
 661         IP_DEFRAG_VS_OUT,
 662         IP_DEFRAG_VS_FWD,
 663         IP_DEFRAG_AF_PACKET,
 664         IP_DEFRAG_MACVLAN,
 665 };
 666 
 667 /* Return true if the value of 'user' is between 'lower_bond'
 668  * and 'upper_bond' inclusively.
 669  */
 670 static inline bool ip_defrag_user_in_between(u32 user,
 671                                              enum ip_defrag_users lower_bond,
 672                                              enum ip_defrag_users upper_bond)
 673 {
 674         return user >= lower_bond && user <= upper_bond;
 675 }
 676 
 677 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
 678 #ifdef CONFIG_INET
 679 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
 680 #else
 681 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 682 {
 683         return skb;
 684 }
 685 #endif
 686 
 687 /*
 688  *      Functions provided by ip_forward.c
 689  */
 690 
 691 int ip_forward(struct sk_buff *skb);
 692 
 693 /*
 694  *      Functions provided by ip_options.c
 695  */
 696 
 697 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 698                       __be32 daddr, struct rtable *rt, int is_frag);
 699 
 700 int __ip_options_echo(struct net *net, struct ip_options *dopt,
 701                       struct sk_buff *skb, const struct ip_options *sopt);
 702 static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
 703                                   struct sk_buff *skb)
 704 {
 705         return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
 706 }
 707 
 708 void ip_options_fragment(struct sk_buff *skb);
 709 int __ip_options_compile(struct net *net, struct ip_options *opt,
 710                          struct sk_buff *skb, __be32 *info);
 711 int ip_options_compile(struct net *net, struct ip_options *opt,
 712                        struct sk_buff *skb);
 713 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 714                    unsigned char *data, int optlen);
 715 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 716                              unsigned char __user *data, int optlen);
 717 void ip_options_undo(struct ip_options *opt);
 718 void ip_forward_options(struct sk_buff *skb);
 719 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
 720 
 721 /*
 722  *      Functions provided by ip_sockglue.c
 723  */
 724 
 725 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 726 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
 727                          struct sk_buff *skb, int tlen, int offset);
 728 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
 729                  struct ipcm_cookie *ipc, bool allow_ipv6);
 730 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 731                   unsigned int optlen);
 732 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 733                   int __user *optlen);
 734 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
 735                          char __user *optval, unsigned int optlen);
 736 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 737                          char __user *optval, int __user *optlen);
 738 int ip_ra_control(struct sock *sk, unsigned char on,
 739                   void (*destructor)(struct sock *));
 740 
 741 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
 742 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 743                    u32 info, u8 *payload);
 744 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 745                     u32 info);
 746 
 747 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 748 {
 749         ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
 750 }
 751 
 752 bool icmp_global_allow(void);
 753 extern int sysctl_icmp_msgs_per_sec;
 754 extern int sysctl_icmp_msgs_burst;
 755 
 756 #ifdef CONFIG_PROC_FS
 757 int ip_misc_proc_init(void);
 758 #endif
 759 
 760 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
 761                                 struct netlink_ext_ack *extack);
 762 
 763 static inline bool inetdev_valid_mtu(unsigned int mtu)
 764 {
 765         return likely(mtu >= IPV4_MIN_MTU);
 766 }
 767 
 768 #endif  /* _IP_H */
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root/include/net/ip.h

INCLUDED FROM

DEFINITIONS
