xref: /linux/include/net/inet_sock.h (revision 995231c820e3bd3633cb38bf4ea6f2541e1da331)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Definitions for inet_sock
7  *
8  * Authors:	Many, reorganised here by
9  * 		Arnaldo Carvalho de Melo <acme@mandriva.com>
10  *
11  *		This program is free software; you can redistribute it and/or
12  *		modify it under the terms of the GNU General Public License
13  *		as published by the Free Software Foundation; either version
14  *		2 of the License, or (at your option) any later version.
15  */
16 #ifndef _INET_SOCK_H
17 #define _INET_SOCK_H
18 
19 #include <linux/bitops.h>
20 #include <linux/kmemcheck.h>
21 #include <linux/string.h>
22 #include <linux/types.h>
23 #include <linux/jhash.h>
24 #include <linux/netdevice.h>
25 
26 #include <net/flow.h>
27 #include <net/sock.h>
28 #include <net/request_sock.h>
29 #include <net/netns/hash.h>
30 #include <net/tcp_states.h>
31 #include <net/l3mdev.h>
32 
33 /** struct ip_options - IP Options
34  *
35  * @faddr - Saved first hop address
36  * @nexthop - Saved nexthop address in LSRR and SSRR
37  * @is_strictroute - Strict source route
38  * @srr_is_hit - Packet destination addr was our one
39  * @is_changed - IP checksum more not valid
40  * @rr_needaddr - Need to record addr of outgoing dev
41  * @ts_needtime - Need to record timestamp
42  * @ts_needaddr - Need to record addr of outgoing dev
43  */
44 struct ip_options {
45 	__be32		faddr;
46 	__be32		nexthop;
47 	unsigned char	optlen;
48 	unsigned char	srr;
49 	unsigned char	rr;
50 	unsigned char	ts;
51 	unsigned char	is_strictroute:1,
52 			srr_is_hit:1,
53 			is_changed:1,
54 			rr_needaddr:1,
55 			ts_needtime:1,
56 			ts_needaddr:1;
57 	unsigned char	router_alert;
58 	unsigned char	cipso;
59 	unsigned char	__pad2;
60 	unsigned char	__data[0];
61 };
62 
63 struct ip_options_rcu {
64 	struct rcu_head rcu;
65 	struct ip_options opt;
66 };
67 
68 struct ip_options_data {
69 	struct ip_options_rcu	opt;
70 	char			data[40];
71 };
72 
73 struct inet_request_sock {
74 	struct request_sock	req;
75 #define ir_loc_addr		req.__req_common.skc_rcv_saddr
76 #define ir_rmt_addr		req.__req_common.skc_daddr
77 #define ir_num			req.__req_common.skc_num
78 #define ir_rmt_port		req.__req_common.skc_dport
79 #define ir_v6_rmt_addr		req.__req_common.skc_v6_daddr
80 #define ir_v6_loc_addr		req.__req_common.skc_v6_rcv_saddr
81 #define ir_iif			req.__req_common.skc_bound_dev_if
82 #define ir_cookie		req.__req_common.skc_cookie
83 #define ireq_net		req.__req_common.skc_net
84 #define ireq_state		req.__req_common.skc_state
85 #define ireq_family		req.__req_common.skc_family
86 
87 	kmemcheck_bitfield_begin(flags);
88 	u16			snd_wscale : 4,
89 				rcv_wscale : 4,
90 				tstamp_ok  : 1,
91 				sack_ok	   : 1,
92 				wscale_ok  : 1,
93 				ecn_ok	   : 1,
94 				acked	   : 1,
95 				no_srccheck: 1,
96 				smc_ok	   : 1;
97 	kmemcheck_bitfield_end(flags);
98 	u32                     ir_mark;
99 	union {
100 		struct ip_options_rcu __rcu	*ireq_opt;
101 #if IS_ENABLED(CONFIG_IPV6)
102 		struct {
103 			struct ipv6_txoptions	*ipv6_opt;
104 			struct sk_buff		*pktopts;
105 		};
106 #endif
107 	};
108 };
109 
110 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
111 {
112 	return (struct inet_request_sock *)sk;
113 }
114 
115 static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
116 {
117 	if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)
118 		return skb->mark;
119 
120 	return sk->sk_mark;
121 }
122 
123 static inline int inet_request_bound_dev_if(const struct sock *sk,
124 					    struct sk_buff *skb)
125 {
126 #ifdef CONFIG_NET_L3_MASTER_DEV
127 	struct net *net = sock_net(sk);
128 
129 	if (!sk->sk_bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
130 		return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
131 #endif
132 
133 	return sk->sk_bound_dev_if;
134 }
135 
136 struct inet_cork {
137 	unsigned int		flags;
138 	__be32			addr;
139 	struct ip_options	*opt;
140 	unsigned int		fragsize;
141 	int			length; /* Total length of all frames */
142 	struct dst_entry	*dst;
143 	u8			tx_flags;
144 	__u8			ttl;
145 	__s16			tos;
146 	char			priority;
147 };
148 
149 struct inet_cork_full {
150 	struct inet_cork	base;
151 	struct flowi		fl;
152 };
153 
154 struct ip_mc_socklist;
155 struct ipv6_pinfo;
156 struct rtable;
157 
158 /** struct inet_sock - representation of INET sockets
159  *
160  * @sk - ancestor class
161  * @pinet6 - pointer to IPv6 control block
162  * @inet_daddr - Foreign IPv4 addr
163  * @inet_rcv_saddr - Bound local IPv4 addr
164  * @inet_dport - Destination port
165  * @inet_num - Local port
166  * @inet_saddr - Sending source
167  * @uc_ttl - Unicast TTL
168  * @inet_sport - Source port
169  * @inet_id - ID counter for DF pkts
170  * @tos - TOS
171  * @mc_ttl - Multicasting TTL
172  * @is_icsk - is this an inet_connection_sock?
173  * @uc_index - Unicast outgoing device index
174  * @mc_index - Multicast device index
175  * @mc_list - Group array
176  * @cork - info to build ip hdr on each ip frag while socket is corked
177  */
178 struct inet_sock {
179 	/* sk and pinet6 has to be the first two members of inet_sock */
180 	struct sock		sk;
181 #if IS_ENABLED(CONFIG_IPV6)
182 	struct ipv6_pinfo	*pinet6;
183 #endif
184 	/* Socket demultiplex comparisons on incoming packets. */
185 #define inet_daddr		sk.__sk_common.skc_daddr
186 #define inet_rcv_saddr		sk.__sk_common.skc_rcv_saddr
187 #define inet_dport		sk.__sk_common.skc_dport
188 #define inet_num		sk.__sk_common.skc_num
189 
190 	__be32			inet_saddr;
191 	__s16			uc_ttl;
192 	__u16			cmsg_flags;
193 	__be16			inet_sport;
194 	__u16			inet_id;
195 
196 	struct ip_options_rcu __rcu	*inet_opt;
197 	int			rx_dst_ifindex;
198 	__u8			tos;
199 	__u8			min_ttl;
200 	__u8			mc_ttl;
201 	__u8			pmtudisc;
202 	__u8			recverr:1,
203 				is_icsk:1,
204 				freebind:1,
205 				hdrincl:1,
206 				mc_loop:1,
207 				transparent:1,
208 				mc_all:1,
209 				nodefrag:1;
210 	__u8			bind_address_no_port:1,
211 				defer_connect:1; /* Indicates that fastopen_connect is set
212 						  * and cookie exists so we defer connect
213 						  * until first data frame is written
214 						  */
215 	__u8			rcv_tos;
216 	__u8			convert_csum;
217 	int			uc_index;
218 	int			mc_index;
219 	__be32			mc_addr;
220 	struct ip_mc_socklist __rcu	*mc_list;
221 	struct inet_cork_full	cork;
222 };
223 
224 #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
225 #define IPCORK_ALLFRAG	2	/* always fragment (for ipv6 for now) */
226 
227 /* cmsg flags for inet */
228 #define IP_CMSG_PKTINFO		BIT(0)
229 #define IP_CMSG_TTL		BIT(1)
230 #define IP_CMSG_TOS		BIT(2)
231 #define IP_CMSG_RECVOPTS	BIT(3)
232 #define IP_CMSG_RETOPTS		BIT(4)
233 #define IP_CMSG_PASSSEC		BIT(5)
234 #define IP_CMSG_ORIGDSTADDR	BIT(6)
235 #define IP_CMSG_CHECKSUM	BIT(7)
236 #define IP_CMSG_RECVFRAGSIZE	BIT(8)
237 
238 /**
239  * sk_to_full_sk - Access to a full socket
240  * @sk: pointer to a socket
241  *
242  * SYNACK messages might be attached to request sockets.
243  * Some places want to reach the listener in this case.
244  */
245 static inline struct sock *sk_to_full_sk(struct sock *sk)
246 {
247 #ifdef CONFIG_INET
248 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
249 		sk = inet_reqsk(sk)->rsk_listener;
250 #endif
251 	return sk;
252 }
253 
254 /* sk_to_full_sk() variant with a const argument */
255 static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
256 {
257 #ifdef CONFIG_INET
258 	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
259 		sk = ((const struct request_sock *)sk)->rsk_listener;
260 #endif
261 	return sk;
262 }
263 
264 static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
265 {
266 	return sk_to_full_sk(skb->sk);
267 }
268 
269 static inline struct inet_sock *inet_sk(const struct sock *sk)
270 {
271 	return (struct inet_sock *)sk;
272 }
273 
274 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
275 					     const struct sock *sk_from,
276 					     const int ancestor_size)
277 {
278 	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
279 	       sk_from->sk_prot->obj_size - ancestor_size);
280 }
281 #if !(IS_ENABLED(CONFIG_IPV6))
282 static inline void inet_sk_copy_descendant(struct sock *sk_to,
283 					   const struct sock *sk_from)
284 {
285 	__inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
286 }
287 #endif
288 
289 int inet_sk_rebuild_header(struct sock *sk);
290 
291 static inline unsigned int __inet_ehashfn(const __be32 laddr,
292 					  const __u16 lport,
293 					  const __be32 faddr,
294 					  const __be16 fport,
295 					  u32 initval)
296 {
297 	return jhash_3words((__force __u32) laddr,
298 			    (__force __u32) faddr,
299 			    ((__u32) lport) << 16 | (__force __u32)fport,
300 			    initval);
301 }
302 
303 struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
304 				      struct sock *sk_listener,
305 				      bool attach_listener);
306 
307 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
308 {
309 	__u8 flags = 0;
310 
311 	if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
312 		flags |= FLOWI_FLAG_ANYSRC;
313 	return flags;
314 }
315 
316 static inline void inet_inc_convert_csum(struct sock *sk)
317 {
318 	inet_sk(sk)->convert_csum++;
319 }
320 
321 static inline void inet_dec_convert_csum(struct sock *sk)
322 {
323 	if (inet_sk(sk)->convert_csum > 0)
324 		inet_sk(sk)->convert_csum--;
325 }
326 
327 static inline bool inet_get_convert_csum(struct sock *sk)
328 {
329 	return !!inet_sk(sk)->convert_csum;
330 }
331 
332 #endif	/* _INET_SOCK_H */
333