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 inet_sock
8 *
9 * Authors:	Many, reorganised here by
10 * 		Arnaldo Carvalho de Melo <acme@mandriva.com>
11 */
12#ifndef _INET_SOCK_H
13#define _INET_SOCK_H
14
15#include <linux/bitops.h>
16#include <linux/string.h>
17#include <linux/types.h>
18#include <linux/jhash.h>
19#include <linux/netdevice.h>
20
21#include <net/flow.h>
22#include <net/sock.h>
23#include <net/request_sock.h>
24#include <net/netns/hash.h>
25#include <net/tcp_states.h>
26#include <net/l3mdev.h>
27
28/** struct ip_options - IP Options
29 *
30 * @faddr - Saved first hop address
31 * @nexthop - Saved nexthop address in LSRR and SSRR
32 * @is_strictroute - Strict source route
33 * @srr_is_hit - Packet destination addr was our one
34 * @is_changed - IP checksum more not valid
35 * @rr_needaddr - Need to record addr of outgoing dev
36 * @ts_needtime - Need to record timestamp
37 * @ts_needaddr - Need to record addr of outgoing dev
38 */
39struct ip_options {
40	__be32		faddr;
41	__be32		nexthop;
42	unsigned char	optlen;
43	unsigned char	srr;
44	unsigned char	rr;
45	unsigned char	ts;
46	unsigned char	is_strictroute:1,
47			srr_is_hit:1,
48			is_changed:1,
49			rr_needaddr:1,
50			ts_needtime:1,
51			ts_needaddr:1;
52	unsigned char	router_alert;
53	unsigned char	cipso;
54	unsigned char	__pad2;
55	unsigned char	__data[];
56};
57
58struct ip_options_rcu {
59	struct rcu_head rcu;
60	struct ip_options opt;
61};
62
63struct ip_options_data {
64	struct ip_options_rcu	opt;
65	char			data[40];
66};
67
68struct inet_request_sock {
69	struct request_sock	req;
70#define ir_loc_addr		req.__req_common.skc_rcv_saddr
71#define ir_rmt_addr		req.__req_common.skc_daddr
72#define ir_num			req.__req_common.skc_num
73#define ir_rmt_port		req.__req_common.skc_dport
74#define ir_v6_rmt_addr		req.__req_common.skc_v6_daddr
75#define ir_v6_loc_addr		req.__req_common.skc_v6_rcv_saddr
76#define ir_iif			req.__req_common.skc_bound_dev_if
77#define ir_cookie		req.__req_common.skc_cookie
78#define ireq_net		req.__req_common.skc_net
79#define ireq_state		req.__req_common.skc_state
80#define ireq_family		req.__req_common.skc_family
81
82	u16			snd_wscale : 4,
83				rcv_wscale : 4,
84				tstamp_ok  : 1,
85				sack_ok	   : 1,
86				wscale_ok  : 1,
87				ecn_ok	   : 1,
88				acked	   : 1,
89				no_srccheck: 1,
90				smc_ok	   : 1;
91	u32                     ir_mark;
92	union {
93		struct ip_options_rcu __rcu	*ireq_opt;
94#if IS_ENABLED(CONFIG_IPV6)
95		struct {
96			struct ipv6_txoptions	*ipv6_opt;
97			struct sk_buff		*pktopts;
98		};
99#endif
100	};
101};
102
103static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
104{
105	return (struct inet_request_sock *)sk;
106}
107
108static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
109{
110	if (!sk->sk_mark &&
111	    READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
112		return skb->mark;
113
114	return sk->sk_mark;
115}
116
117static inline int inet_request_bound_dev_if(const struct sock *sk,
118					    struct sk_buff *skb)
119{
120	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
121#ifdef CONFIG_NET_L3_MASTER_DEV
122	struct net *net = sock_net(sk);
123
124	if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
125		return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
126#endif
127
128	return bound_dev_if;
129}
130
131static inline int inet_sk_bound_l3mdev(const struct sock *sk)
132{
133#ifdef CONFIG_NET_L3_MASTER_DEV
134	struct net *net = sock_net(sk);
135
136	if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
137		return l3mdev_master_ifindex_by_index(net,
138						      sk->sk_bound_dev_if);
139#endif
140
141	return 0;
142}
143
144static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
145				     int dif, int sdif)
146{
147	if (!bound_dev_if)
148		return !sdif || l3mdev_accept;
149	return bound_dev_if == dif || bound_dev_if == sdif;
150}
151
152static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,
153					int dif, int sdif)
154{
155#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
156	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
157				 bound_dev_if, dif, sdif);
158#else
159	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
160#endif
161}
162
163struct inet_cork {
164	unsigned int		flags;
165	__be32			addr;
166	struct ip_options	*opt;
167	unsigned int		fragsize;
168	int			length; /* Total length of all frames */
169	struct dst_entry	*dst;
170	u8			tx_flags;
171	__u8			ttl;
172	__s16			tos;
173	char			priority;
174	__u16			gso_size;
175	u64			transmit_time;
176	u32			mark;
177};
178
179struct inet_cork_full {
180	struct inet_cork	base;
181	struct flowi		fl;
182};
183
184struct ip_mc_socklist;
185struct ipv6_pinfo;
186struct rtable;
187
188/** struct inet_sock - representation of INET sockets
189 *
190 * @sk - ancestor class
191 * @pinet6 - pointer to IPv6 control block
192 * @inet_daddr - Foreign IPv4 addr
193 * @inet_rcv_saddr - Bound local IPv4 addr
194 * @inet_dport - Destination port
195 * @inet_num - Local port
196 * @inet_saddr - Sending source
197 * @uc_ttl - Unicast TTL
198 * @inet_sport - Source port
199 * @inet_id - ID counter for DF pkts
200 * @tos - TOS
201 * @mc_ttl - Multicasting TTL
202 * @is_icsk - is this an inet_connection_sock?
203 * @uc_index - Unicast outgoing device index
204 * @mc_index - Multicast device index
205 * @mc_list - Group array
206 * @cork - info to build ip hdr on each ip frag while socket is corked
207 */
208struct inet_sock {
209	/* sk and pinet6 has to be the first two members of inet_sock */
210	struct sock		sk;
211#if IS_ENABLED(CONFIG_IPV6)
212	struct ipv6_pinfo	*pinet6;
213#endif
214	/* Socket demultiplex comparisons on incoming packets. */
215#define inet_daddr		sk.__sk_common.skc_daddr
216#define inet_rcv_saddr		sk.__sk_common.skc_rcv_saddr
217#define inet_dport		sk.__sk_common.skc_dport
218#define inet_num		sk.__sk_common.skc_num
219
220	__be32			inet_saddr;
221	__s16			uc_ttl;
222	__u16			cmsg_flags;
223	__be16			inet_sport;
224	__u16			inet_id;
225
226	struct ip_options_rcu __rcu	*inet_opt;
227	int			rx_dst_ifindex;
228	__u8			tos;
229	__u8			min_ttl;
230	__u8			mc_ttl;
231	__u8			pmtudisc;
232	__u8			recverr:1,
233				is_icsk:1,
234				freebind:1,
235				hdrincl:1,
236				mc_loop:1,
237				transparent:1,
238				mc_all:1,
239				nodefrag:1;
240	__u8			bind_address_no_port:1,
241				recverr_rfc4884:1,
242				defer_connect:1; /* Indicates that fastopen_connect is set
243						  * and cookie exists so we defer connect
244						  * until first data frame is written
245						  */
246	__u8			rcv_tos;
247	__u8			convert_csum;
248	int			uc_index;
249	int			mc_index;
250	__be32			mc_addr;
251	struct ip_mc_socklist __rcu	*mc_list;
252	struct inet_cork_full	cork;
253};
254
255#define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
256#define IPCORK_ALLFRAG	2	/* always fragment (for ipv6 for now) */
257
258/* cmsg flags for inet */
259#define IP_CMSG_PKTINFO		BIT(0)
260#define IP_CMSG_TTL		BIT(1)
261#define IP_CMSG_TOS		BIT(2)
262#define IP_CMSG_RECVOPTS	BIT(3)
263#define IP_CMSG_RETOPTS		BIT(4)
264#define IP_CMSG_PASSSEC		BIT(5)
265#define IP_CMSG_ORIGDSTADDR	BIT(6)
266#define IP_CMSG_CHECKSUM	BIT(7)
267#define IP_CMSG_RECVFRAGSIZE	BIT(8)
268
269/**
270 * sk_to_full_sk - Access to a full socket
271 * @sk: pointer to a socket
272 *
273 * SYNACK messages might be attached to request sockets.
274 * Some places want to reach the listener in this case.
275 */
276static inline struct sock *sk_to_full_sk(struct sock *sk)
277{
278#ifdef CONFIG_INET
279	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
280		sk = inet_reqsk(sk)->rsk_listener;
281#endif
282	return sk;
283}
284
285/* sk_to_full_sk() variant with a const argument */
286static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
287{
288#ifdef CONFIG_INET
289	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
290		sk = ((const struct request_sock *)sk)->rsk_listener;
291#endif
292	return sk;
293}
294
295static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
296{
297	return sk_to_full_sk(skb->sk);
298}
299
300static inline struct inet_sock *inet_sk(const struct sock *sk)
301{
302	return (struct inet_sock *)sk;
303}
304
305static inline void __inet_sk_copy_descendant(struct sock *sk_to,
306					     const struct sock *sk_from,
307					     const int ancestor_size)
308{
309	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
310	       sk_from->sk_prot->obj_size - ancestor_size);
311}
312
313int inet_sk_rebuild_header(struct sock *sk);
314
315/**
316 * inet_sk_state_load - read sk->sk_state for lockless contexts
317 * @sk: socket pointer
318 *
319 * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
320 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
321 */
322static inline int inet_sk_state_load(const struct sock *sk)
323{
324	/* state change might impact lockless readers. */
325	return smp_load_acquire(&sk->sk_state);
326}
327
328/**
329 * inet_sk_state_store - update sk->sk_state
330 * @sk: socket pointer
331 * @newstate: new state
332 *
333 * Paired with inet_sk_state_load(). Should be used in contexts where
334 * state change might impact lockless readers.
335 */
336void inet_sk_state_store(struct sock *sk, int newstate);
337
338void inet_sk_set_state(struct sock *sk, int state);
339
340static inline unsigned int __inet_ehashfn(const __be32 laddr,
341					  const __u16 lport,
342					  const __be32 faddr,
343					  const __be16 fport,
344					  u32 initval)
345{
346	return jhash_3words((__force __u32) laddr,
347			    (__force __u32) faddr,
348			    ((__u32) lport) << 16 | (__force __u32)fport,
349			    initval);
350}
351
352struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
353				      struct sock *sk_listener,
354				      bool attach_listener);
355
356static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
357{
358	__u8 flags = 0;
359
360	if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
361		flags |= FLOWI_FLAG_ANYSRC;
362	return flags;
363}
364
365static inline void inet_inc_convert_csum(struct sock *sk)
366{
367	inet_sk(sk)->convert_csum++;
368}
369
370static inline void inet_dec_convert_csum(struct sock *sk)
371{
372	if (inet_sk(sk)->convert_csum > 0)
373		inet_sk(sk)->convert_csum--;
374}
375
376static inline bool inet_get_convert_csum(struct sock *sk)
377{
378	return !!inet_sk(sk)->convert_csum;
379}
380
381
382static inline bool inet_can_nonlocal_bind(struct net *net,
383					  struct inet_sock *inet)
384{
385	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
386		inet->freebind || inet->transparent;
387}
388
389#endif	/* _INET_SOCK_H */
390