xref: /kernel/linux/linux-6.6/include/net/inet_sock.h (revision 62306a36)
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	u32 mark = READ_ONCE(sk->sk_mark);
111
112	if (!mark && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
113		return skb->mark;
114
115	return mark;
116}
117
118static inline int inet_request_bound_dev_if(const struct sock *sk,
119					    struct sk_buff *skb)
120{
121	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
122#ifdef CONFIG_NET_L3_MASTER_DEV
123	struct net *net = sock_net(sk);
124
125	if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
126		return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
127#endif
128
129	return bound_dev_if;
130}
131
132static inline int inet_sk_bound_l3mdev(const struct sock *sk)
133{
134#ifdef CONFIG_NET_L3_MASTER_DEV
135	struct net *net = sock_net(sk);
136
137	if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
138		return l3mdev_master_ifindex_by_index(net,
139						      sk->sk_bound_dev_if);
140#endif
141
142	return 0;
143}
144
145static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
146				     int dif, int sdif)
147{
148	if (!bound_dev_if)
149		return !sdif || l3mdev_accept;
150	return bound_dev_if == dif || bound_dev_if == sdif;
151}
152
153static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,
154					int dif, int sdif)
155{
156#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
157	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
158				 bound_dev_if, dif, sdif);
159#else
160	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
161#endif
162}
163
164struct inet_cork {
165	unsigned int		flags;
166	__be32			addr;
167	struct ip_options	*opt;
168	unsigned int		fragsize;
169	int			length; /* Total length of all frames */
170	struct dst_entry	*dst;
171	u8			tx_flags;
172	__u8			ttl;
173	__s16			tos;
174	char			priority;
175	__u16			gso_size;
176	u64			transmit_time;
177	u32			mark;
178};
179
180struct inet_cork_full {
181	struct inet_cork	base;
182	struct flowi		fl;
183};
184
185struct ip_mc_socklist;
186struct ipv6_pinfo;
187struct rtable;
188
189/** struct inet_sock - representation of INET sockets
190 *
191 * @sk - ancestor class
192 * @pinet6 - pointer to IPv6 control block
193 * @inet_daddr - Foreign IPv4 addr
194 * @inet_rcv_saddr - Bound local IPv4 addr
195 * @inet_dport - Destination port
196 * @inet_num - Local port
197 * @inet_flags - various atomic flags
198 * @inet_saddr - Sending source
199 * @uc_ttl - Unicast TTL
200 * @inet_sport - Source port
201 * @inet_id - ID counter for DF pkts
202 * @tos - TOS
203 * @mc_ttl - Multicasting TTL
204 * @uc_index - Unicast outgoing device index
205 * @mc_index - Multicast device index
206 * @mc_list - Group array
207 * @cork - info to build ip hdr on each ip frag while socket is corked
208 */
209struct inet_sock {
210	/* sk and pinet6 has to be the first two members of inet_sock */
211	struct sock		sk;
212#if IS_ENABLED(CONFIG_IPV6)
213	struct ipv6_pinfo	*pinet6;
214#endif
215	/* Socket demultiplex comparisons on incoming packets. */
216#define inet_daddr		sk.__sk_common.skc_daddr
217#define inet_rcv_saddr		sk.__sk_common.skc_rcv_saddr
218#define inet_dport		sk.__sk_common.skc_dport
219#define inet_num		sk.__sk_common.skc_num
220
221	unsigned long		inet_flags;
222	__be32			inet_saddr;
223	__s16			uc_ttl;
224	__be16			inet_sport;
225	struct ip_options_rcu __rcu	*inet_opt;
226	atomic_t		inet_id;
227
228	__u8			tos;
229	__u8			min_ttl;
230	__u8			mc_ttl;
231	__u8			pmtudisc;
232	__u8			rcv_tos;
233	__u8			convert_csum;
234	int			uc_index;
235	int			mc_index;
236	__be32			mc_addr;
237	struct {
238		__u16 lo;
239		__u16 hi;
240	}			local_port_range;
241
242	struct ip_mc_socklist __rcu	*mc_list;
243	struct inet_cork_full	cork;
244};
245
246#define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
247#define IPCORK_ALLFRAG	2	/* always fragment (for ipv6 for now) */
248
249enum {
250	INET_FLAGS_PKTINFO	= 0,
251	INET_FLAGS_TTL		= 1,
252	INET_FLAGS_TOS		= 2,
253	INET_FLAGS_RECVOPTS	= 3,
254	INET_FLAGS_RETOPTS	= 4,
255	INET_FLAGS_PASSSEC	= 5,
256	INET_FLAGS_ORIGDSTADDR	= 6,
257	INET_FLAGS_CHECKSUM	= 7,
258	INET_FLAGS_RECVFRAGSIZE	= 8,
259
260	INET_FLAGS_RECVERR	= 9,
261	INET_FLAGS_RECVERR_RFC4884 = 10,
262	INET_FLAGS_FREEBIND	= 11,
263	INET_FLAGS_HDRINCL	= 12,
264	INET_FLAGS_MC_LOOP	= 13,
265	INET_FLAGS_MC_ALL	= 14,
266	INET_FLAGS_TRANSPARENT	= 15,
267	INET_FLAGS_IS_ICSK	= 16,
268	INET_FLAGS_NODEFRAG	= 17,
269	INET_FLAGS_BIND_ADDRESS_NO_PORT = 18,
270	INET_FLAGS_DEFER_CONNECT = 19,
271};
272
273/* cmsg flags for inet */
274#define IP_CMSG_PKTINFO		BIT(INET_FLAGS_PKTINFO)
275#define IP_CMSG_TTL		BIT(INET_FLAGS_TTL)
276#define IP_CMSG_TOS		BIT(INET_FLAGS_TOS)
277#define IP_CMSG_RECVOPTS	BIT(INET_FLAGS_RECVOPTS)
278#define IP_CMSG_RETOPTS		BIT(INET_FLAGS_RETOPTS)
279#define IP_CMSG_PASSSEC		BIT(INET_FLAGS_PASSSEC)
280#define IP_CMSG_ORIGDSTADDR	BIT(INET_FLAGS_ORIGDSTADDR)
281#define IP_CMSG_CHECKSUM	BIT(INET_FLAGS_CHECKSUM)
282#define IP_CMSG_RECVFRAGSIZE	BIT(INET_FLAGS_RECVFRAGSIZE)
283
284#define IP_CMSG_ALL	(IP_CMSG_PKTINFO | IP_CMSG_TTL |		\
285			 IP_CMSG_TOS | IP_CMSG_RECVOPTS |		\
286			 IP_CMSG_RETOPTS | IP_CMSG_PASSSEC |		\
287			 IP_CMSG_ORIGDSTADDR | IP_CMSG_CHECKSUM |	\
288			 IP_CMSG_RECVFRAGSIZE)
289
290static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet)
291{
292	return READ_ONCE(inet->inet_flags) & IP_CMSG_ALL;
293}
294
295#define inet_test_bit(nr, sk)			\
296	test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
297#define inet_set_bit(nr, sk)			\
298	set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
299#define inet_clear_bit(nr, sk)			\
300	clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
301#define inet_assign_bit(nr, sk, val)		\
302	assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)
303
304/**
305 * sk_to_full_sk - Access to a full socket
306 * @sk: pointer to a socket
307 *
308 * SYNACK messages might be attached to request sockets.
309 * Some places want to reach the listener in this case.
310 */
311static inline struct sock *sk_to_full_sk(struct sock *sk)
312{
313#ifdef CONFIG_INET
314	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
315		sk = inet_reqsk(sk)->rsk_listener;
316#endif
317	return sk;
318}
319
320/* sk_to_full_sk() variant with a const argument */
321static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
322{
323#ifdef CONFIG_INET
324	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
325		sk = ((const struct request_sock *)sk)->rsk_listener;
326#endif
327	return sk;
328}
329
330static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
331{
332	return sk_to_full_sk(skb->sk);
333}
334
335#define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
336
337static inline void __inet_sk_copy_descendant(struct sock *sk_to,
338					     const struct sock *sk_from,
339					     const int ancestor_size)
340{
341	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
342	       sk_from->sk_prot->obj_size - ancestor_size);
343}
344
345int inet_sk_rebuild_header(struct sock *sk);
346
347/**
348 * inet_sk_state_load - read sk->sk_state for lockless contexts
349 * @sk: socket pointer
350 *
351 * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
352 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
353 */
354static inline int inet_sk_state_load(const struct sock *sk)
355{
356	/* state change might impact lockless readers. */
357	return smp_load_acquire(&sk->sk_state);
358}
359
360/**
361 * inet_sk_state_store - update sk->sk_state
362 * @sk: socket pointer
363 * @newstate: new state
364 *
365 * Paired with inet_sk_state_load(). Should be used in contexts where
366 * state change might impact lockless readers.
367 */
368void inet_sk_state_store(struct sock *sk, int newstate);
369
370void inet_sk_set_state(struct sock *sk, int state);
371
372static inline unsigned int __inet_ehashfn(const __be32 laddr,
373					  const __u16 lport,
374					  const __be32 faddr,
375					  const __be16 fport,
376					  u32 initval)
377{
378	return jhash_3words((__force __u32) laddr,
379			    (__force __u32) faddr,
380			    ((__u32) lport) << 16 | (__force __u32)fport,
381			    initval);
382}
383
384struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
385				      struct sock *sk_listener,
386				      bool attach_listener);
387
388static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
389{
390	__u8 flags = 0;
391
392	if (inet_test_bit(TRANSPARENT, sk) || inet_test_bit(HDRINCL, sk))
393		flags |= FLOWI_FLAG_ANYSRC;
394	return flags;
395}
396
397static inline void inet_inc_convert_csum(struct sock *sk)
398{
399	inet_sk(sk)->convert_csum++;
400}
401
402static inline void inet_dec_convert_csum(struct sock *sk)
403{
404	if (inet_sk(sk)->convert_csum > 0)
405		inet_sk(sk)->convert_csum--;
406}
407
408static inline bool inet_get_convert_csum(struct sock *sk)
409{
410	return !!inet_sk(sk)->convert_csum;
411}
412
413
414static inline bool inet_can_nonlocal_bind(struct net *net,
415					  struct inet_sock *inet)
416{
417	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
418		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
419		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
420}
421
422static inline bool inet_addr_valid_or_nonlocal(struct net *net,
423					       struct inet_sock *inet,
424					       __be32 addr,
425					       int addr_type)
426{
427	return inet_can_nonlocal_bind(net, inet) ||
428		addr == htonl(INADDR_ANY) ||
429		addr_type == RTN_LOCAL ||
430		addr_type == RTN_MULTICAST ||
431		addr_type == RTN_BROADCAST;
432}
433
434#endif	/* _INET_SOCK_H */
435