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 #include <linux/android_kabi.h>
21 
22 #include <net/flow.h>
23 #include <net/sock.h>
24 #include <net/request_sock.h>
25 #include <net/netns/hash.h>
26 #include <net/tcp_states.h>
27 #include <net/l3mdev.h>
28 
29 /** struct ip_options - IP Options
30  *
31  * @faddr - Saved first hop address
32  * @nexthop - Saved nexthop address in LSRR and SSRR
33  * @is_strictroute - Strict source route
34  * @srr_is_hit - Packet destination addr was our one
35  * @is_changed - IP checksum more not valid
36  * @rr_needaddr - Need to record addr of outgoing dev
37  * @ts_needtime - Need to record timestamp
38  * @ts_needaddr - Need to record addr of outgoing dev
39  */
40 struct ip_options {
41 	__be32		faddr;
42 	__be32		nexthop;
43 	unsigned char	optlen;
44 	unsigned char	srr;
45 	unsigned char	rr;
46 	unsigned char	ts;
47 	unsigned char	is_strictroute:1,
48 			srr_is_hit:1,
49 			is_changed:1,
50 			rr_needaddr:1,
51 			ts_needtime:1,
52 			ts_needaddr:1;
53 	unsigned char	router_alert;
54 	unsigned char	cipso;
55 	unsigned char	__pad2;
56 	unsigned char	__data[];
57 };
58 
59 struct ip_options_rcu {
60 	struct rcu_head rcu;
61 	struct ip_options opt;
62 };
63 
64 struct ip_options_data {
65 	struct ip_options_rcu	opt;
66 	char			data[40];
67 };
68 
69 struct inet_request_sock {
70 	struct request_sock	req;
71 #define ir_loc_addr		req.__req_common.skc_rcv_saddr
72 #define ir_rmt_addr		req.__req_common.skc_daddr
73 #define ir_num			req.__req_common.skc_num
74 #define ir_rmt_port		req.__req_common.skc_dport
75 #define ir_v6_rmt_addr		req.__req_common.skc_v6_daddr
76 #define ir_v6_loc_addr		req.__req_common.skc_v6_rcv_saddr
77 #define ir_iif			req.__req_common.skc_bound_dev_if
78 #define ir_cookie		req.__req_common.skc_cookie
79 #define ireq_net		req.__req_common.skc_net
80 #define ireq_state		req.__req_common.skc_state
81 #define ireq_family		req.__req_common.skc_family
82 
83 	u16			snd_wscale : 4,
84 				rcv_wscale : 4,
85 				tstamp_ok  : 1,
86 				sack_ok	   : 1,
87 				wscale_ok  : 1,
88 				ecn_ok	   : 1,
89 				acked	   : 1,
90 				no_srccheck: 1,
91 				smc_ok	   : 1;
92 	u32                     ir_mark;
93 	union {
94 		struct ip_options_rcu __rcu	*ireq_opt;
95 #if IS_ENABLED(CONFIG_IPV6)
96 		struct {
97 			struct ipv6_txoptions	*ipv6_opt;
98 			struct sk_buff		*pktopts;
99 		};
100 #endif
101 	};
102 };
103 
inet_rsk(const struct request_sock * sk)104 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
105 {
106 	return (struct inet_request_sock *)sk;
107 }
108 
inet_request_mark(const struct sock * sk,struct sk_buff * skb)109 static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
110 {
111 	u32 mark = READ_ONCE(sk->sk_mark);
112 
113 	if (!mark && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
114 		return skb->mark;
115 
116 	return mark;
117 }
118 
inet_request_bound_dev_if(const struct sock * sk,struct sk_buff * skb)119 static inline int inet_request_bound_dev_if(const struct sock *sk,
120 					    struct sk_buff *skb)
121 {
122 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
123 #ifdef CONFIG_NET_L3_MASTER_DEV
124 	struct net *net = sock_net(sk);
125 
126 	if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
127 		return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
128 #endif
129 
130 	return bound_dev_if;
131 }
132 
inet_sk_bound_l3mdev(const struct sock * sk)133 static inline int inet_sk_bound_l3mdev(const struct sock *sk)
134 {
135 #ifdef CONFIG_NET_L3_MASTER_DEV
136 	struct net *net = sock_net(sk);
137 
138 	if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
139 		return l3mdev_master_ifindex_by_index(net,
140 						      sk->sk_bound_dev_if);
141 #endif
142 
143 	return 0;
144 }
145 
inet_bound_dev_eq(bool l3mdev_accept,int bound_dev_if,int dif,int sdif)146 static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
147 				     int dif, int sdif)
148 {
149 	if (!bound_dev_if)
150 		return !sdif || l3mdev_accept;
151 	return bound_dev_if == dif || bound_dev_if == sdif;
152 }
153 
inet_sk_bound_dev_eq(const struct net * net,int bound_dev_if,int dif,int sdif)154 static inline bool inet_sk_bound_dev_eq(const struct net *net,
155 					int bound_dev_if,
156 					int dif, int sdif)
157 {
158 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
159 	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
160 				 bound_dev_if, dif, sdif);
161 #else
162 	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
163 #endif
164 }
165 
166 struct inet_cork {
167 	unsigned int		flags;
168 	__be32			addr;
169 	struct ip_options	*opt;
170 	unsigned int		fragsize;
171 	int			length; /* Total length of all frames */
172 	struct dst_entry	*dst;
173 	u8			tx_flags;
174 	__u8			ttl;
175 	__s16			tos;
176 	char			priority;
177 	__u16			gso_size;
178 	u64			transmit_time;
179 	u32			mark;
180 };
181 
182 struct inet_cork_full {
183 	struct inet_cork	base;
184 	struct flowi		fl;
185 };
186 
187 struct ip_mc_socklist;
188 struct ipv6_pinfo;
189 struct rtable;
190 
191 /** struct inet_sock - representation of INET sockets
192  *
193  * @sk - ancestor class
194  * @pinet6 - pointer to IPv6 control block
195  * @inet_daddr - Foreign IPv4 addr
196  * @inet_rcv_saddr - Bound local IPv4 addr
197  * @inet_dport - Destination port
198  * @inet_num - Local port
199  * @inet_flags - various atomic flags
200  * @inet_saddr - Sending source
201  * @uc_ttl - Unicast TTL
202  * @inet_sport - Source port
203  * @inet_id - ID counter for DF pkts
204  * @tos - TOS
205  * @mc_ttl - Multicasting TTL
206  * @uc_index - Unicast outgoing device index
207  * @mc_index - Multicast device index
208  * @mc_list - Group array
209  * @cork - info to build ip hdr on each ip frag while socket is corked
210  */
211 struct inet_sock {
212 	/* sk and pinet6 has to be the first two members of inet_sock */
213 	struct sock		sk;
214 #if IS_ENABLED(CONFIG_IPV6)
215 	struct ipv6_pinfo	*pinet6;
216 #endif
217 	/* Socket demultiplex comparisons on incoming packets. */
218 #define inet_daddr		sk.__sk_common.skc_daddr
219 #define inet_rcv_saddr		sk.__sk_common.skc_rcv_saddr
220 #define inet_dport		sk.__sk_common.skc_dport
221 #define inet_num		sk.__sk_common.skc_num
222 
223 	unsigned long		inet_flags;
224 	__be32			inet_saddr;
225 	__s16			uc_ttl;
226 	__be16			inet_sport;
227 	struct ip_options_rcu __rcu	*inet_opt;
228 	atomic_t		inet_id;
229 
230 	__u8			tos;
231 	__u8			min_ttl;
232 	__u8			mc_ttl;
233 	__u8			pmtudisc;
234 	__u8			rcv_tos;
235 	__u8			convert_csum;
236 	int			uc_index;
237 	int			mc_index;
238 	__be32			mc_addr;
239 	u32			local_port_range;	/* high << 16 | low */
240 
241 	struct ip_mc_socklist __rcu	*mc_list;
242 	struct inet_cork_full	cork;
243 
244 	ANDROID_KABI_RESERVE(1);
245 	ANDROID_KABI_RESERVE(2);
246 };
247 
248 #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
249 
250 enum {
251 	INET_FLAGS_PKTINFO	= 0,
252 	INET_FLAGS_TTL		= 1,
253 	INET_FLAGS_TOS		= 2,
254 	INET_FLAGS_RECVOPTS	= 3,
255 	INET_FLAGS_RETOPTS	= 4,
256 	INET_FLAGS_PASSSEC	= 5,
257 	INET_FLAGS_ORIGDSTADDR	= 6,
258 	INET_FLAGS_CHECKSUM	= 7,
259 	INET_FLAGS_RECVFRAGSIZE	= 8,
260 
261 	INET_FLAGS_RECVERR	= 9,
262 	INET_FLAGS_RECVERR_RFC4884 = 10,
263 	INET_FLAGS_FREEBIND	= 11,
264 	INET_FLAGS_HDRINCL	= 12,
265 	INET_FLAGS_MC_LOOP	= 13,
266 	INET_FLAGS_MC_ALL	= 14,
267 	INET_FLAGS_TRANSPARENT	= 15,
268 	INET_FLAGS_IS_ICSK	= 16,
269 	INET_FLAGS_NODEFRAG	= 17,
270 	INET_FLAGS_BIND_ADDRESS_NO_PORT = 18,
271 	INET_FLAGS_DEFER_CONNECT = 19,
272 	INET_FLAGS_MC6_LOOP	= 20,
273 	INET_FLAGS_RECVERR6_RFC4884 = 21,
274 	INET_FLAGS_MC6_ALL	= 22,
275 	INET_FLAGS_AUTOFLOWLABEL_SET = 23,
276 	INET_FLAGS_AUTOFLOWLABEL = 24,
277 	INET_FLAGS_DONTFRAG	= 25,
278 	INET_FLAGS_RECVERR6	= 26,
279 	INET_FLAGS_REPFLOW	= 27,
280 	INET_FLAGS_RTALERT_ISOLATE = 28,
281 	INET_FLAGS_SNDFLOW	= 29,
282 	INET_FLAGS_RTALERT	= 30,
283 };
284 
285 /* cmsg flags for inet */
286 #define IP_CMSG_PKTINFO		BIT(INET_FLAGS_PKTINFO)
287 #define IP_CMSG_TTL		BIT(INET_FLAGS_TTL)
288 #define IP_CMSG_TOS		BIT(INET_FLAGS_TOS)
289 #define IP_CMSG_RECVOPTS	BIT(INET_FLAGS_RECVOPTS)
290 #define IP_CMSG_RETOPTS		BIT(INET_FLAGS_RETOPTS)
291 #define IP_CMSG_PASSSEC		BIT(INET_FLAGS_PASSSEC)
292 #define IP_CMSG_ORIGDSTADDR	BIT(INET_FLAGS_ORIGDSTADDR)
293 #define IP_CMSG_CHECKSUM	BIT(INET_FLAGS_CHECKSUM)
294 #define IP_CMSG_RECVFRAGSIZE	BIT(INET_FLAGS_RECVFRAGSIZE)
295 
296 #define IP_CMSG_ALL	(IP_CMSG_PKTINFO | IP_CMSG_TTL |		\
297 			 IP_CMSG_TOS | IP_CMSG_RECVOPTS |		\
298 			 IP_CMSG_RETOPTS | IP_CMSG_PASSSEC |		\
299 			 IP_CMSG_ORIGDSTADDR | IP_CMSG_CHECKSUM |	\
300 			 IP_CMSG_RECVFRAGSIZE)
301 
inet_cmsg_flags(const struct inet_sock * inet)302 static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet)
303 {
304 	return READ_ONCE(inet->inet_flags) & IP_CMSG_ALL;
305 }
306 
307 #define inet_test_bit(nr, sk)			\
308 	test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
309 #define inet_set_bit(nr, sk)			\
310 	set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
311 #define inet_clear_bit(nr, sk)			\
312 	clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
313 #define inet_assign_bit(nr, sk, val)		\
314 	assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)
315 
316 /**
317  * sk_to_full_sk - Access to a full socket
318  * @sk: pointer to a socket
319  *
320  * SYNACK messages might be attached to request sockets.
321  * Some places want to reach the listener in this case.
322  */
sk_to_full_sk(struct sock * sk)323 static inline struct sock *sk_to_full_sk(struct sock *sk)
324 {
325 #ifdef CONFIG_INET
326 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
327 		sk = inet_reqsk(sk)->rsk_listener;
328 #endif
329 	return sk;
330 }
331 
332 /* sk_to_full_sk() variant with a const argument */
sk_const_to_full_sk(const struct sock * sk)333 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
334 {
335 #ifdef CONFIG_INET
336 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
337 		sk = ((const struct request_sock *)sk)->rsk_listener;
338 #endif
339 	return sk;
340 }
341 
skb_to_full_sk(const struct sk_buff * skb)342 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
343 {
344 	return sk_to_full_sk(skb->sk);
345 }
346 
347 #define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
348 
__inet_sk_copy_descendant(struct sock * sk_to,const struct sock * sk_from,const int ancestor_size)349 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
350 					     const struct sock *sk_from,
351 					     const int ancestor_size)
352 {
353 	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
354 	       sk_from->sk_prot->obj_size - ancestor_size);
355 }
356 
357 int inet_sk_rebuild_header(struct sock *sk);
358 
359 /**
360  * inet_sk_state_load - read sk->sk_state for lockless contexts
361  * @sk: socket pointer
362  *
363  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
364  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
365  */
inet_sk_state_load(const struct sock * sk)366 static inline int inet_sk_state_load(const struct sock *sk)
367 {
368 	/* state change might impact lockless readers. */
369 	return smp_load_acquire(&sk->sk_state);
370 }
371 
372 /**
373  * inet_sk_state_store - update sk->sk_state
374  * @sk: socket pointer
375  * @newstate: new state
376  *
377  * Paired with inet_sk_state_load(). Should be used in contexts where
378  * state change might impact lockless readers.
379  */
380 void inet_sk_state_store(struct sock *sk, int newstate);
381 
382 void inet_sk_set_state(struct sock *sk, int state);
383 
__inet_ehashfn(const __be32 laddr,const __u16 lport,const __be32 faddr,const __be16 fport,u32 initval)384 static inline unsigned int __inet_ehashfn(const __be32 laddr,
385 					  const __u16 lport,
386 					  const __be32 faddr,
387 					  const __be16 fport,
388 					  u32 initval)
389 {
390 	return jhash_3words((__force __u32) laddr,
391 			    (__force __u32) faddr,
392 			    ((__u32) lport) << 16 | (__force __u32)fport,
393 			    initval);
394 }
395 
396 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
397 				      struct sock *sk_listener,
398 				      bool attach_listener);
399 
inet_sk_flowi_flags(const struct sock * sk)400 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
401 {
402 	__u8 flags = 0;
403 
404 	if (inet_test_bit(TRANSPARENT, sk) || inet_test_bit(HDRINCL, sk))
405 		flags |= FLOWI_FLAG_ANYSRC;
406 	return flags;
407 }
408 
inet_inc_convert_csum(struct sock * sk)409 static inline void inet_inc_convert_csum(struct sock *sk)
410 {
411 	inet_sk(sk)->convert_csum++;
412 }
413 
inet_dec_convert_csum(struct sock * sk)414 static inline void inet_dec_convert_csum(struct sock *sk)
415 {
416 	if (inet_sk(sk)->convert_csum > 0)
417 		inet_sk(sk)->convert_csum--;
418 }
419 
inet_get_convert_csum(struct sock * sk)420 static inline bool inet_get_convert_csum(struct sock *sk)
421 {
422 	return !!inet_sk(sk)->convert_csum;
423 }
424 
425 
inet_can_nonlocal_bind(struct net * net,struct inet_sock * inet)426 static inline bool inet_can_nonlocal_bind(struct net *net,
427 					  struct inet_sock *inet)
428 {
429 	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
430 		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
431 		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
432 }
433 
inet_addr_valid_or_nonlocal(struct net * net,struct inet_sock * inet,__be32 addr,int addr_type)434 static inline bool inet_addr_valid_or_nonlocal(struct net *net,
435 					       struct inet_sock *inet,
436 					       __be32 addr,
437 					       int addr_type)
438 {
439 	return inet_can_nonlocal_bind(net, inet) ||
440 		addr == htonl(INADDR_ANY) ||
441 		addr_type == RTN_LOCAL ||
442 		addr_type == RTN_MULTICAST ||
443 		addr_type == RTN_BROADCAST;
444 }
445 
446 #endif	/* _INET_SOCK_H */
447