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 
inet_rsk(const struct request_sock * sk)103 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
104 {
105 	return (struct inet_request_sock *)sk;
106 }
107 
inet_request_mark(const struct sock * sk,struct sk_buff * skb)108 static 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 
inet_request_bound_dev_if(const struct sock * sk,struct sk_buff * skb)117 static 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 
inet_sk_bound_l3mdev(const struct sock * sk)131 static 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 
inet_bound_dev_eq(bool l3mdev_accept,int bound_dev_if,int dif,int sdif)144 static 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 
inet_sk_bound_dev_eq(struct net * net,int bound_dev_if,int dif,int sdif)152 static 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 
163 struct 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 
179 struct inet_cork_full {
180 	struct inet_cork	base;
181 	struct flowi		fl;
182 };
183 
184 struct ip_mc_socklist;
185 struct ipv6_pinfo;
186 struct 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  */
208 struct 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 	struct ip_options_rcu __rcu	*inet_opt;
224 	__be16			inet_sport;
225 	__u16			inet_id;
226 
227 	__u8			tos;
228 	__u8			min_ttl;
229 	__u8			mc_ttl;
230 	__u8			pmtudisc;
231 	__u8			recverr:1,
232 				is_icsk:1,
233 				freebind:1,
234 				hdrincl:1,
235 				mc_loop:1,
236 				transparent:1,
237 				mc_all:1,
238 				nodefrag:1;
239 	__u8			bind_address_no_port:1,
240 				recverr_rfc4884:1,
241 				defer_connect:1; /* Indicates that fastopen_connect is set
242 						  * and cookie exists so we defer connect
243 						  * until first data frame is written
244 						  */
245 	__u8			rcv_tos;
246 	__u8			convert_csum;
247 	int			uc_index;
248 	int			mc_index;
249 	__be32			mc_addr;
250 	struct ip_mc_socklist __rcu	*mc_list;
251 	struct inet_cork_full	cork;
252 	struct {
253 		__u16 lo;
254 		__u16 hi;
255 	}			local_port_range;
256 };
257 
258 #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
259 #define IPCORK_ALLFRAG	2	/* always fragment (for ipv6 for now) */
260 
261 /* cmsg flags for inet */
262 #define IP_CMSG_PKTINFO		BIT(0)
263 #define IP_CMSG_TTL		BIT(1)
264 #define IP_CMSG_TOS		BIT(2)
265 #define IP_CMSG_RECVOPTS	BIT(3)
266 #define IP_CMSG_RETOPTS		BIT(4)
267 #define IP_CMSG_PASSSEC		BIT(5)
268 #define IP_CMSG_ORIGDSTADDR	BIT(6)
269 #define IP_CMSG_CHECKSUM	BIT(7)
270 #define IP_CMSG_RECVFRAGSIZE	BIT(8)
271 
sk_is_inet(struct sock * sk)272 static inline bool sk_is_inet(struct sock *sk)
273 {
274 	return sk->sk_family == AF_INET || sk->sk_family == AF_INET6;
275 }
276 
277 /**
278  * sk_to_full_sk - Access to a full socket
279  * @sk: pointer to a socket
280  *
281  * SYNACK messages might be attached to request sockets.
282  * Some places want to reach the listener in this case.
283  */
sk_to_full_sk(struct sock * sk)284 static inline struct sock *sk_to_full_sk(struct sock *sk)
285 {
286 #ifdef CONFIG_INET
287 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
288 		sk = inet_reqsk(sk)->rsk_listener;
289 #endif
290 	return sk;
291 }
292 
293 /* sk_to_full_sk() variant with a const argument */
sk_const_to_full_sk(const struct sock * sk)294 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
295 {
296 #ifdef CONFIG_INET
297 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
298 		sk = ((const struct request_sock *)sk)->rsk_listener;
299 #endif
300 	return sk;
301 }
302 
skb_to_full_sk(const struct sk_buff * skb)303 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
304 {
305 	return sk_to_full_sk(skb->sk);
306 }
307 
inet_sk(const struct sock * sk)308 static inline struct inet_sock *inet_sk(const struct sock *sk)
309 {
310 	return (struct inet_sock *)sk;
311 }
312 
__inet_sk_copy_descendant(struct sock * sk_to,const struct sock * sk_from,const int ancestor_size)313 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
314 					     const struct sock *sk_from,
315 					     const int ancestor_size)
316 {
317 	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
318 	       sk_from->sk_prot->obj_size - ancestor_size);
319 }
320 
321 int inet_sk_rebuild_header(struct sock *sk);
322 
323 /**
324  * inet_sk_state_load - read sk->sk_state for lockless contexts
325  * @sk: socket pointer
326  *
327  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
328  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
329  */
inet_sk_state_load(const struct sock * sk)330 static inline int inet_sk_state_load(const struct sock *sk)
331 {
332 	/* state change might impact lockless readers. */
333 	return smp_load_acquire(&sk->sk_state);
334 }
335 
336 /**
337  * inet_sk_state_store - update sk->sk_state
338  * @sk: socket pointer
339  * @newstate: new state
340  *
341  * Paired with inet_sk_state_load(). Should be used in contexts where
342  * state change might impact lockless readers.
343  */
344 void inet_sk_state_store(struct sock *sk, int newstate);
345 
346 void inet_sk_set_state(struct sock *sk, int state);
347 
__inet_ehashfn(const __be32 laddr,const __u16 lport,const __be32 faddr,const __be16 fport,u32 initval)348 static inline unsigned int __inet_ehashfn(const __be32 laddr,
349 					  const __u16 lport,
350 					  const __be32 faddr,
351 					  const __be16 fport,
352 					  u32 initval)
353 {
354 	return jhash_3words((__force __u32) laddr,
355 			    (__force __u32) faddr,
356 			    ((__u32) lport) << 16 | (__force __u32)fport,
357 			    initval);
358 }
359 
360 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
361 				      struct sock *sk_listener,
362 				      bool attach_listener);
363 
inet_sk_flowi_flags(const struct sock * sk)364 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
365 {
366 	__u8 flags = 0;
367 
368 	if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
369 		flags |= FLOWI_FLAG_ANYSRC;
370 	return flags;
371 }
372 
inet_inc_convert_csum(struct sock * sk)373 static inline void inet_inc_convert_csum(struct sock *sk)
374 {
375 	inet_sk(sk)->convert_csum++;
376 }
377 
inet_dec_convert_csum(struct sock * sk)378 static inline void inet_dec_convert_csum(struct sock *sk)
379 {
380 	if (inet_sk(sk)->convert_csum > 0)
381 		inet_sk(sk)->convert_csum--;
382 }
383 
inet_get_convert_csum(struct sock * sk)384 static inline bool inet_get_convert_csum(struct sock *sk)
385 {
386 	return !!inet_sk(sk)->convert_csum;
387 }
388 
389 
inet_can_nonlocal_bind(struct net * net,struct inet_sock * inet)390 static inline bool inet_can_nonlocal_bind(struct net *net,
391 					  struct inet_sock *inet)
392 {
393 	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
394 		inet->freebind || inet->transparent;
395 }
396 
inet_addr_valid_or_nonlocal(struct net * net,struct inet_sock * inet,__be32 addr,int addr_type)397 static inline bool inet_addr_valid_or_nonlocal(struct net *net,
398 					       struct inet_sock *inet,
399 					       __be32 addr,
400 					       int addr_type)
401 {
402 	return inet_can_nonlocal_bind(net, inet) ||
403 		addr == htonl(INADDR_ANY) ||
404 		addr_type == RTN_LOCAL ||
405 		addr_type == RTN_MULTICAST ||
406 		addr_type == RTN_BROADCAST;
407 }
408 
409 #endif	/* _INET_SOCK_H */
410