xref: /openbmc/linux/include/net/inet_sock.h (revision 829c6524)
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(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 
164 struct 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 
180 struct inet_cork_full {
181 	struct inet_cork	base;
182 	struct flowi		fl;
183 };
184 
185 struct ip_mc_socklist;
186 struct ipv6_pinfo;
187 struct 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_saddr - Sending source
198  * @uc_ttl - Unicast TTL
199  * @inet_sport - Source port
200  * @inet_id - ID counter for DF pkts
201  * @tos - TOS
202  * @mc_ttl - Multicasting TTL
203  * @is_icsk - is this an inet_connection_sock?
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  */
209 struct 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 	__be32			inet_saddr;
222 	__s16			uc_ttl;
223 	__u16			cmsg_flags;
224 	struct ip_options_rcu __rcu	*inet_opt;
225 	__be16			inet_sport;
226 	__u16			inet_id;
227 
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 	struct {
254 		__u16 lo;
255 		__u16 hi;
256 	}			local_port_range;
257 };
258 
259 #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
260 #define IPCORK_ALLFRAG	2	/* always fragment (for ipv6 for now) */
261 
262 /* cmsg flags for inet */
263 #define IP_CMSG_PKTINFO		BIT(0)
264 #define IP_CMSG_TTL		BIT(1)
265 #define IP_CMSG_TOS		BIT(2)
266 #define IP_CMSG_RECVOPTS	BIT(3)
267 #define IP_CMSG_RETOPTS		BIT(4)
268 #define IP_CMSG_PASSSEC		BIT(5)
269 #define IP_CMSG_ORIGDSTADDR	BIT(6)
270 #define IP_CMSG_CHECKSUM	BIT(7)
271 #define IP_CMSG_RECVFRAGSIZE	BIT(8)
272 
273 static inline bool sk_is_inet(struct sock *sk)
274 {
275 	return sk->sk_family == AF_INET || sk->sk_family == AF_INET6;
276 }
277 
278 /**
279  * sk_to_full_sk - Access to a full socket
280  * @sk: pointer to a socket
281  *
282  * SYNACK messages might be attached to request sockets.
283  * Some places want to reach the listener in this case.
284  */
285 static inline struct sock *sk_to_full_sk(struct sock *sk)
286 {
287 #ifdef CONFIG_INET
288 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
289 		sk = inet_reqsk(sk)->rsk_listener;
290 #endif
291 	return sk;
292 }
293 
294 /* sk_to_full_sk() variant with a const argument */
295 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
296 {
297 #ifdef CONFIG_INET
298 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
299 		sk = ((const struct request_sock *)sk)->rsk_listener;
300 #endif
301 	return sk;
302 }
303 
304 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
305 {
306 	return sk_to_full_sk(skb->sk);
307 }
308 
309 #define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
310 
311 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
312 					     const struct sock *sk_from,
313 					     const int ancestor_size)
314 {
315 	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
316 	       sk_from->sk_prot->obj_size - ancestor_size);
317 }
318 
319 int inet_sk_rebuild_header(struct sock *sk);
320 
321 /**
322  * inet_sk_state_load - read sk->sk_state for lockless contexts
323  * @sk: socket pointer
324  *
325  * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
326  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
327  */
328 static inline int inet_sk_state_load(const struct sock *sk)
329 {
330 	/* state change might impact lockless readers. */
331 	return smp_load_acquire(&sk->sk_state);
332 }
333 
334 /**
335  * inet_sk_state_store - update sk->sk_state
336  * @sk: socket pointer
337  * @newstate: new state
338  *
339  * Paired with inet_sk_state_load(). Should be used in contexts where
340  * state change might impact lockless readers.
341  */
342 void inet_sk_state_store(struct sock *sk, int newstate);
343 
344 void inet_sk_set_state(struct sock *sk, int state);
345 
346 static inline unsigned int __inet_ehashfn(const __be32 laddr,
347 					  const __u16 lport,
348 					  const __be32 faddr,
349 					  const __be16 fport,
350 					  u32 initval)
351 {
352 	return jhash_3words((__force __u32) laddr,
353 			    (__force __u32) faddr,
354 			    ((__u32) lport) << 16 | (__force __u32)fport,
355 			    initval);
356 }
357 
358 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
359 				      struct sock *sk_listener,
360 				      bool attach_listener);
361 
362 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
363 {
364 	__u8 flags = 0;
365 
366 	if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
367 		flags |= FLOWI_FLAG_ANYSRC;
368 	return flags;
369 }
370 
371 static inline void inet_inc_convert_csum(struct sock *sk)
372 {
373 	inet_sk(sk)->convert_csum++;
374 }
375 
376 static inline void inet_dec_convert_csum(struct sock *sk)
377 {
378 	if (inet_sk(sk)->convert_csum > 0)
379 		inet_sk(sk)->convert_csum--;
380 }
381 
382 static inline bool inet_get_convert_csum(struct sock *sk)
383 {
384 	return !!inet_sk(sk)->convert_csum;
385 }
386 
387 
388 static inline bool inet_can_nonlocal_bind(struct net *net,
389 					  struct inet_sock *inet)
390 {
391 	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
392 		inet->freebind || inet->transparent;
393 }
394 
395 static inline bool inet_addr_valid_or_nonlocal(struct net *net,
396 					       struct inet_sock *inet,
397 					       __be32 addr,
398 					       int addr_type)
399 {
400 	return inet_can_nonlocal_bind(net, inet) ||
401 		addr == htonl(INADDR_ANY) ||
402 		addr_type == RTN_LOCAL ||
403 		addr_type == RTN_MULTICAST ||
404 		addr_type == RTN_BROADCAST;
405 }
406 
407 #endif	/* _INET_SOCK_H */
408