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.
6 * Definitions for the IP module.
8 * Version: @(#)ip.h 1.0.2 05/07/93
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
15 * Mike McLagan : Routing by source
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.
25 #include <linux/types.h>
28 #include <linux/skbuff.h>
30 #include <net/inet_sock.h>
36 struct inet_skb_parm {
37 struct ip_options opt; /* Compiled IP options */
40 #define IPSKB_FORWARDED 1
41 #define IPSKB_XFRM_TUNNEL_SIZE 2
42 #define IPSKB_XFRM_TRANSFORMED 4
43 #define IPSKB_FRAG_COMPLETE 8
44 #define IPSKB_REROUTED 16
49 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
51 return ip_hdr(skb)->ihl * 4;
57 struct ip_options_rcu *opt;
61 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
64 struct ip_ra_chain __rcu *next;
67 void (*destructor)(struct sock *);
68 struct sock *saved_sk;
73 extern struct ip_ra_chain __rcu *ip_ra_chain;
76 #define IP_CE 0x8000 /* Flag: "Congestion" */
77 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
78 #define IP_MF 0x2000 /* Flag: "More Fragments" */
79 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
81 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
89 extern int igmp_mc_proc_init(void);
92 * Functions provided by ip.c
95 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
96 __be32 saddr, __be32 daddr,
97 struct ip_options_rcu *opt);
98 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
99 struct packet_type *pt, struct net_device *orig_dev);
100 extern int ip_local_deliver(struct sk_buff *skb);
101 extern int ip_mr_input(struct sk_buff *skb);
102 extern int ip_output(struct sk_buff *skb);
103 extern int ip_mc_output(struct sk_buff *skb);
104 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
105 extern int ip_do_nat(struct sk_buff *skb);
106 extern void ip_send_check(struct iphdr *ip);
107 extern int __ip_local_out(struct sk_buff *skb);
108 extern int ip_local_out(struct sk_buff *skb);
109 extern int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl);
110 extern void ip_init(void);
111 extern int ip_append_data(struct sock *sk, struct flowi4 *fl4,
112 int getfrag(void *from, char *to, int offset, int len,
113 int odd, struct sk_buff *skb),
114 void *from, int len, int protolen,
115 struct ipcm_cookie *ipc,
118 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
119 extern ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
120 int offset, size_t size, int flags);
121 extern struct sk_buff *__ip_make_skb(struct sock *sk,
123 struct sk_buff_head *queue,
124 struct inet_cork *cork);
125 extern int ip_send_skb(struct net *net, struct sk_buff *skb);
126 extern int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
127 extern void ip_flush_pending_frames(struct sock *sk);
128 extern struct sk_buff *ip_make_skb(struct sock *sk,
130 int getfrag(void *from, char *to, int offset, int len,
131 int odd, struct sk_buff *skb),
132 void *from, int length, int transhdrlen,
133 struct ipcm_cookie *ipc,
137 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
139 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
143 extern int ip4_datagram_connect(struct sock *sk,
144 struct sockaddr *uaddr, int addr_len);
146 extern void ip4_datagram_release_cb(struct sock *sk);
148 struct ip_reply_arg {
152 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
153 /* -1 if not needed */
159 #define IP_REPLY_ARG_NOSRCCHECK 1
161 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
163 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
166 void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
167 __be32 saddr, const struct ip_reply_arg *arg,
175 extern struct ipv4_config ipv4_config;
176 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
177 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
178 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
179 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
180 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
181 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
182 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
183 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
184 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
185 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
186 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
188 extern unsigned long snmp_fold_field(void __percpu *mib[], int offt);
189 #if BITS_PER_LONG==32
190 extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
192 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off)
194 return snmp_fold_field(mib, offt);
197 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align);
198 extern void snmp_mib_free(void __percpu *ptr[2]);
200 extern struct local_ports {
203 } sysctl_local_ports;
204 extern void inet_get_local_port_range(int *low, int *high);
206 extern unsigned long *sysctl_local_reserved_ports;
207 static inline int inet_is_reserved_local_port(int port)
209 return test_bit(port, sysctl_local_reserved_ports);
212 extern int sysctl_ip_nonlocal_bind;
214 /* From inetpeer.c */
215 extern int inet_peer_threshold;
216 extern int inet_peer_minttl;
217 extern int inet_peer_maxttl;
219 /* From ip_input.c */
220 extern int sysctl_ip_early_demux;
222 /* From ip_output.c */
223 extern int sysctl_ip_dynaddr;
225 extern void ipfrag_init(void);
227 extern void ip_static_sysctl_init(void);
229 #define IP4_REPLY_MARK(net, mark) \
230 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
232 static inline bool ip_is_fragment(const struct iphdr *iph)
234 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
240 /* The function in 2.2 was invalid, producing wrong result for
241 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
243 int ip_decrease_ttl(struct iphdr *iph)
245 u32 check = (__force u32)iph->check;
246 check += (__force u32)htons(0x0100);
247 iph->check = (__force __sum16)(check + (check>=0xFFFF));
252 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
254 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
255 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
256 !(dst_metric_locked(dst, RTAX_MTU)));
259 u32 ip_idents_reserve(u32 hash, int segs);
260 void __ip_select_ident(struct iphdr *iph, int segs);
262 static inline void ip_select_ident_segs(struct sk_buff *skb, struct sock *sk, int segs)
264 struct iphdr *iph = ip_hdr(skb);
266 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
267 /* This is only to work around buggy Windows95/2000
268 * VJ compression implementations. If the ID field
269 * does not change, they drop every other packet in
270 * a TCP stream using header compression.
272 if (sk && inet_sk(sk)->inet_daddr) {
273 iph->id = htons(inet_sk(sk)->inet_id);
274 inet_sk(sk)->inet_id += segs;
279 __ip_select_ident(iph, segs);
283 static inline void ip_select_ident(struct sk_buff *skb, struct sock *sk)
285 ip_select_ident_segs(skb, sk, 1);
289 * Map a multicast IP onto multicast MAC for type ethernet.
292 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
294 __u32 addr=ntohl(naddr);
306 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
307 * Leave P_Key as 0 to be filled in by driver.
310 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
313 unsigned char scope = broadcast[5] & 0xF;
315 buf[0] = 0; /* Reserved */
316 buf[1] = 0xff; /* Multicast QPN */
321 buf[5] = 0x10 | scope; /* scope from broadcast address */
322 buf[6] = 0x40; /* IPv4 signature */
324 buf[8] = broadcast[8]; /* P_Key */
325 buf[9] = broadcast[9];
332 buf[19] = addr & 0xff;
334 buf[18] = addr & 0xff;
336 buf[17] = addr & 0xff;
338 buf[16] = addr & 0x0f;
341 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
343 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
344 memcpy(buf, broadcast, 4);
346 memcpy(buf, &naddr, sizeof(naddr));
349 #if IS_ENABLED(CONFIG_IPV6)
350 #include <linux/ipv6.h>
353 static __inline__ void inet_reset_saddr(struct sock *sk)
355 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
356 #if IS_ENABLED(CONFIG_IPV6)
357 if (sk->sk_family == PF_INET6) {
358 struct ipv6_pinfo *np = inet6_sk(sk);
360 memset(&np->saddr, 0, sizeof(np->saddr));
361 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
368 static inline int sk_mc_loop(struct sock *sk)
372 switch (sk->sk_family) {
374 return inet_sk(sk)->mc_loop;
375 #if IS_ENABLED(CONFIG_IPV6)
377 return inet6_sk(sk)->mc_loop;
384 extern bool ip_call_ra_chain(struct sk_buff *skb);
387 * Functions provided by ip_fragment.c
390 enum ip_defrag_users {
391 IP_DEFRAG_LOCAL_DELIVER,
392 IP_DEFRAG_CALL_RA_CHAIN,
393 IP_DEFRAG_CONNTRACK_IN,
394 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
395 IP_DEFRAG_CONNTRACK_OUT,
396 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
397 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
398 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
406 int ip_defrag(struct sk_buff *skb, u32 user);
408 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user);
410 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
415 int ip_frag_mem(struct net *net);
416 int ip_frag_nqueues(struct net *net);
419 * Functions provided by ip_forward.c
422 extern int ip_forward(struct sk_buff *skb);
425 * Functions provided by ip_options.c
428 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
429 __be32 daddr, struct rtable *rt, int is_frag);
430 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
431 extern void ip_options_fragment(struct sk_buff *skb);
432 extern int ip_options_compile(struct net *net,
433 struct ip_options *opt, struct sk_buff *skb);
434 extern int ip_options_get(struct net *net, struct ip_options_rcu **optp,
435 unsigned char *data, int optlen);
436 extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
437 unsigned char __user *data, int optlen);
438 extern void ip_options_undo(struct ip_options * opt);
439 extern void ip_forward_options(struct sk_buff *skb);
440 extern int ip_options_rcv_srr(struct sk_buff *skb);
443 * Functions provided by ip_sockglue.c
446 extern void ipv4_pktinfo_prepare(struct sk_buff *skb);
447 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
448 extern int ip_cmsg_send(struct net *net,
449 struct msghdr *msg, struct ipcm_cookie *ipc);
450 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen);
451 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
452 extern int compat_ip_setsockopt(struct sock *sk, int level,
453 int optname, char __user *optval, unsigned int optlen);
454 extern int compat_ip_getsockopt(struct sock *sk, int level,
455 int optname, char __user *optval, int __user *optlen);
456 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
458 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
459 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
460 __be16 port, u32 info, u8 *payload);
461 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
464 #ifdef CONFIG_PROC_FS
465 extern int ip_misc_proc_init(void);