xref: /linux/include/net/inet_sock.h (revision 55d0969c451159cff86949b38c39171cab962069)
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  */
39 struct 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 
58 struct ip_options_rcu {
59 	struct rcu_head rcu;
60 	struct ip_options opt;
61 };
62 
63 struct ip_options_data {
64 	struct ip_options_rcu	opt;
65 	char			data[40];
66 };
67 
68 struct 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 
103 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
104 {
105 	return (struct inet_request_sock *)sk;
106 }
107 
108 static 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 
118 static 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 
132 static 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 
145 static 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 
153 static inline bool inet_sk_bound_dev_eq(const struct net *net,
154 					int bound_dev_if,
155 					int dif, int sdif)
156 {
157 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
158 	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
159 				 bound_dev_if, dif, sdif);
160 #else
161 	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
162 #endif
163 }
164 
165 struct inet_cork {
166 	unsigned int		flags;
167 	__be32			addr;
168 	struct ip_options	*opt;
169 	unsigned int		fragsize;
170 	int			length; /* Total length of all frames */
171 	struct dst_entry	*dst;
172 	u8			tx_flags;
173 	__u8			ttl;
174 	__s16			tos;
175 	char			priority;
176 	__u16			gso_size;
177 	u64			transmit_time;
178 	u32			mark;
179 };
180 
181 struct inet_cork_full {
182 	struct inet_cork	base;
183 	struct flowi		fl;
184 };
185 
186 struct ip_mc_socklist;
187 struct ipv6_pinfo;
188 struct rtable;
189 
190 /** struct inet_sock - representation of INET sockets
191  *
192  * @sk - ancestor class
193  * @pinet6 - pointer to IPv6 control block
194  * @inet_daddr - Foreign IPv4 addr
195  * @inet_rcv_saddr - Bound local IPv4 addr
196  * @inet_dport - Destination port
197  * @inet_num - Local port
198  * @inet_flags - various atomic flags
199  * @inet_saddr - Sending source
200  * @uc_ttl - Unicast TTL
201  * @inet_sport - Source port
202  * @inet_id - ID counter for DF pkts
203  * @tos - TOS
204  * @mc_ttl - Multicasting TTL
205  * @uc_index - Unicast outgoing device index
206  * @mc_index - Multicast device index
207  * @mc_list - Group array
208  * @cork - info to build ip hdr on each ip frag while socket is corked
209  */
210 struct inet_sock {
211 	/* sk and pinet6 has to be the first two members of inet_sock */
212 	struct sock		sk;
213 #if IS_ENABLED(CONFIG_IPV6)
214 	struct ipv6_pinfo	*pinet6;
215 #endif
216 	/* Socket demultiplex comparisons on incoming packets. */
217 #define inet_daddr		sk.__sk_common.skc_daddr
218 #define inet_rcv_saddr		sk.__sk_common.skc_rcv_saddr
219 #define inet_dport		sk.__sk_common.skc_dport
220 #define inet_num		sk.__sk_common.skc_num
221 
222 	unsigned long		inet_flags;
223 	__be32			inet_saddr;
224 	__s16			uc_ttl;
225 	__be16			inet_sport;
226 	struct ip_options_rcu __rcu	*inet_opt;
227 	atomic_t		inet_id;
228 
229 	__u8			tos;
230 	__u8			min_ttl;
231 	__u8			mc_ttl;
232 	__u8			pmtudisc;
233 	__u8			rcv_tos;
234 	__u8			convert_csum;
235 	int			uc_index;
236 	int			mc_index;
237 	__be32			mc_addr;
238 	u32			local_port_range;	/* high << 16 | low */
239 
240 	struct ip_mc_socklist __rcu	*mc_list;
241 	struct inet_cork_full	cork;
242 };
243 
244 #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
245 
246 enum {
247 	INET_FLAGS_PKTINFO	= 0,
248 	INET_FLAGS_TTL		= 1,
249 	INET_FLAGS_TOS		= 2,
250 	INET_FLAGS_RECVOPTS	= 3,
251 	INET_FLAGS_RETOPTS	= 4,
252 	INET_FLAGS_PASSSEC	= 5,
253 	INET_FLAGS_ORIGDSTADDR	= 6,
254 	INET_FLAGS_CHECKSUM	= 7,
255 	INET_FLAGS_RECVFRAGSIZE	= 8,
256 
257 	INET_FLAGS_RECVERR	= 9,
258 	INET_FLAGS_RECVERR_RFC4884 = 10,
259 	INET_FLAGS_FREEBIND	= 11,
260 	INET_FLAGS_HDRINCL	= 12,
261 	INET_FLAGS_MC_LOOP	= 13,
262 	INET_FLAGS_MC_ALL	= 14,
263 	INET_FLAGS_TRANSPARENT	= 15,
264 	INET_FLAGS_IS_ICSK	= 16,
265 	INET_FLAGS_NODEFRAG	= 17,
266 	INET_FLAGS_BIND_ADDRESS_NO_PORT = 18,
267 	INET_FLAGS_DEFER_CONNECT = 19,
268 	INET_FLAGS_MC6_LOOP	= 20,
269 	INET_FLAGS_RECVERR6_RFC4884 = 21,
270 	INET_FLAGS_MC6_ALL	= 22,
271 	INET_FLAGS_AUTOFLOWLABEL_SET = 23,
272 	INET_FLAGS_AUTOFLOWLABEL = 24,
273 	INET_FLAGS_DONTFRAG	= 25,
274 	INET_FLAGS_RECVERR6	= 26,
275 	INET_FLAGS_REPFLOW	= 27,
276 	INET_FLAGS_RTALERT_ISOLATE = 28,
277 	INET_FLAGS_SNDFLOW	= 29,
278 	INET_FLAGS_RTALERT	= 30,
279 };
280 
281 /* cmsg flags for inet */
282 #define IP_CMSG_PKTINFO		BIT(INET_FLAGS_PKTINFO)
283 #define IP_CMSG_TTL		BIT(INET_FLAGS_TTL)
284 #define IP_CMSG_TOS		BIT(INET_FLAGS_TOS)
285 #define IP_CMSG_RECVOPTS	BIT(INET_FLAGS_RECVOPTS)
286 #define IP_CMSG_RETOPTS		BIT(INET_FLAGS_RETOPTS)
287 #define IP_CMSG_PASSSEC		BIT(INET_FLAGS_PASSSEC)
288 #define IP_CMSG_ORIGDSTADDR	BIT(INET_FLAGS_ORIGDSTADDR)
289 #define IP_CMSG_CHECKSUM	BIT(INET_FLAGS_CHECKSUM)
290 #define IP_CMSG_RECVFRAGSIZE	BIT(INET_FLAGS_RECVFRAGSIZE)
291 
292 #define IP_CMSG_ALL	(IP_CMSG_PKTINFO | IP_CMSG_TTL |		\
293 			 IP_CMSG_TOS | IP_CMSG_RECVOPTS |		\
294 			 IP_CMSG_RETOPTS | IP_CMSG_PASSSEC |		\
295 			 IP_CMSG_ORIGDSTADDR | IP_CMSG_CHECKSUM |	\
296 			 IP_CMSG_RECVFRAGSIZE)
297 
298 static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet)
299 {
300 	return READ_ONCE(inet->inet_flags) & IP_CMSG_ALL;
301 }
302 
303 #define inet_test_bit(nr, sk)			\
304 	test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
305 #define inet_set_bit(nr, sk)			\
306 	set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
307 #define inet_clear_bit(nr, sk)			\
308 	clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
309 #define inet_assign_bit(nr, sk, val)		\
310 	assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)
311 
312 /**
313  * sk_to_full_sk - Access to a full socket
314  * @sk: pointer to a socket
315  *
316  * SYNACK messages might be attached to request sockets.
317  * Some places want to reach the listener in this case.
318  */
319 static inline struct sock *sk_to_full_sk(struct sock *sk)
320 {
321 #ifdef CONFIG_INET
322 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
323 		sk = inet_reqsk(sk)->rsk_listener;
324 #endif
325 	return sk;
326 }
327 
328 /* sk_to_full_sk() variant with a const argument */
329 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
330 {
331 #ifdef CONFIG_INET
332 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
333 		sk = ((const struct request_sock *)sk)->rsk_listener;
334 #endif
335 	return sk;
336 }
337 
338 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
339 {
340 	return sk_to_full_sk(skb->sk);
341 }
342 
343 #define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
344 
345 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
346 					     const struct sock *sk_from,
347 					     const int ancestor_size)
348 {
349 	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
350 	       sk_from->sk_prot->obj_size - ancestor_size);
351 }
352 
353 int inet_sk_rebuild_header(struct sock *sk);
354 
355 /**
356  * inet_sk_state_load - read sk->sk_state for lockless contexts
357  * @sk: socket pointer
358  *
359  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
360  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
361  */
362 static inline int inet_sk_state_load(const struct sock *sk)
363 {
364 	/* state change might impact lockless readers. */
365 	return smp_load_acquire(&sk->sk_state);
366 }
367 
368 /**
369  * inet_sk_state_store - update sk->sk_state
370  * @sk: socket pointer
371  * @newstate: new state
372  *
373  * Paired with inet_sk_state_load(). Should be used in contexts where
374  * state change might impact lockless readers.
375  */
376 void inet_sk_state_store(struct sock *sk, int newstate);
377 
378 void inet_sk_set_state(struct sock *sk, int state);
379 
380 static inline unsigned int __inet_ehashfn(const __be32 laddr,
381 					  const __u16 lport,
382 					  const __be32 faddr,
383 					  const __be16 fport,
384 					  u32 initval)
385 {
386 	return jhash_3words((__force __u32) laddr,
387 			    (__force __u32) faddr,
388 			    ((__u32) lport) << 16 | (__force __u32)fport,
389 			    initval);
390 }
391 
392 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
393 				      struct sock *sk_listener,
394 				      bool attach_listener);
395 
396 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
397 {
398 	__u8 flags = 0;
399 
400 	if (inet_test_bit(TRANSPARENT, sk) || inet_test_bit(HDRINCL, sk))
401 		flags |= FLOWI_FLAG_ANYSRC;
402 	return flags;
403 }
404 
405 static inline void inet_inc_convert_csum(struct sock *sk)
406 {
407 	inet_sk(sk)->convert_csum++;
408 }
409 
410 static inline void inet_dec_convert_csum(struct sock *sk)
411 {
412 	if (inet_sk(sk)->convert_csum > 0)
413 		inet_sk(sk)->convert_csum--;
414 }
415 
416 static inline bool inet_get_convert_csum(struct sock *sk)
417 {
418 	return !!inet_sk(sk)->convert_csum;
419 }
420 
421 
422 static inline bool inet_can_nonlocal_bind(struct net *net,
423 					  struct inet_sock *inet)
424 {
425 	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
426 		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
427 		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
428 }
429 
430 static inline bool inet_addr_valid_or_nonlocal(struct net *net,
431 					       struct inet_sock *inet,
432 					       __be32 addr,
433 					       int addr_type)
434 {
435 	return inet_can_nonlocal_bind(net, inet) ||
436 		addr == htonl(INADDR_ANY) ||
437 		addr_type == RTN_LOCAL ||
438 		addr_type == RTN_MULTICAST ||
439 		addr_type == RTN_BROADCAST;
440 }
441 
442 #endif	/* _INET_SOCK_H */
443