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 
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 
31 /** struct ip_options - IP Options
32  *
33  * @faddr - Saved first hop address
34  * @nexthop - Saved nexthop address in LSRR and SSRR
35  * @is_data - Options in __data, rather than skb
36  * @is_strictroute - Strict source route
37  * @srr_is_hit - Packet destination addr was our one
38  * @is_changed - IP checksum more not valid
39  * @rr_needaddr - Need to record addr of outgoing dev
40  * @ts_needtime - Need to record timestamp
41  * @ts_needaddr - Need to record addr of outgoing dev
42  */
43 struct ip_options {
44 	__be32		faddr;
45 	__be32		nexthop;
46 	unsigned char	optlen;
47 	unsigned char	srr;
48 	unsigned char	rr;
49 	unsigned char	ts;
50 	unsigned char	is_strictroute:1,
51 			srr_is_hit:1,
52 			is_changed:1,
53 			rr_needaddr:1,
54 			ts_needtime:1,
55 			ts_needaddr:1;
56 	unsigned char	router_alert;
57 	unsigned char	cipso;
58 	unsigned char	__pad2;
59 	unsigned char	__data[0];
60 };
61 
62 struct ip_options_rcu {
63 	struct rcu_head rcu;
64 	struct ip_options opt;
65 };
66 
67 struct ip_options_data {
68 	struct ip_options_rcu	opt;
69 	char			data[40];
70 };
71 
72 struct inet_request_sock {
73 	struct request_sock	req;
74 #if IS_ENABLED(CONFIG_IPV6)
75 	u16			inet6_rsk_offset;
76 #endif
77 	__be16			loc_port;
78 	__be32			loc_addr;
79 	__be32			rmt_addr;
80 	__be16			rmt_port;
81 	kmemcheck_bitfield_begin(flags);
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 	kmemcheck_bitfield_end(flags);
91 	struct ip_options_rcu	*opt;
92 };
93 
inet_rsk(const struct request_sock * sk)94 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
95 {
96 	return (struct inet_request_sock *)sk;
97 }
98 
99 struct inet_cork {
100 	unsigned int		flags;
101 	__be32			addr;
102 	struct ip_options	*opt;
103 	unsigned int		fragsize;
104 	struct dst_entry	*dst;
105 	int			length; /* Total length of all frames */
106 	struct page		*page;
107 	u32			off;
108 	u8			tx_flags;
109 };
110 
111 struct inet_cork_full {
112 	struct inet_cork	base;
113 	struct flowi		fl;
114 };
115 
116 struct ip_mc_socklist;
117 struct ipv6_pinfo;
118 struct rtable;
119 
120 /** struct inet_sock - representation of INET sockets
121  *
122  * @sk - ancestor class
123  * @pinet6 - pointer to IPv6 control block
124  * @inet_daddr - Foreign IPv4 addr
125  * @inet_rcv_saddr - Bound local IPv4 addr
126  * @inet_dport - Destination port
127  * @inet_num - Local port
128  * @inet_saddr - Sending source
129  * @uc_ttl - Unicast TTL
130  * @inet_sport - Source port
131  * @inet_id - ID counter for DF pkts
132  * @tos - TOS
133  * @mc_ttl - Multicasting TTL
134  * @is_icsk - is this an inet_connection_sock?
135  * @uc_index - Unicast outgoing device index
136  * @mc_index - Multicast device index
137  * @mc_list - Group array
138  * @cork - info to build ip hdr on each ip frag while socket is corked
139  */
140 struct inet_sock {
141 	/* sk and pinet6 has to be the first two members of inet_sock */
142 	struct sock		sk;
143 #if IS_ENABLED(CONFIG_IPV6)
144 	struct ipv6_pinfo	*pinet6;
145 #endif
146 	/* Socket demultiplex comparisons on incoming packets. */
147 #define inet_daddr		sk.__sk_common.skc_daddr
148 #define inet_rcv_saddr		sk.__sk_common.skc_rcv_saddr
149 
150 	__be16			inet_dport;
151 	__u16			inet_num;
152 	__be32			inet_saddr;
153 	__s16			uc_ttl;
154 	__u16			cmsg_flags;
155 	__be16			inet_sport;
156 	__u16			inet_id;
157 
158 	struct ip_options_rcu __rcu	*inet_opt;
159 	__u8			tos;
160 	__u8			min_ttl;
161 	__u8			mc_ttl;
162 	__u8			pmtudisc;
163 	__u8			recverr:1,
164 				is_icsk:1,
165 				freebind:1,
166 				hdrincl:1,
167 				mc_loop:1,
168 				transparent:1,
169 				mc_all:1,
170 				nodefrag:1;
171 	__u8			rcv_tos;
172 	int			uc_index;
173 	int			mc_index;
174 	__be32			mc_addr;
175 	struct ip_mc_socklist __rcu	*mc_list;
176 	struct inet_cork_full	cork;
177 };
178 
179 #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
180 #define IPCORK_ALLFRAG	2	/* always fragment (for ipv6 for now) */
181 
inet_sk(const struct sock * sk)182 static inline struct inet_sock *inet_sk(const struct sock *sk)
183 {
184 	return (struct inet_sock *)sk;
185 }
186 
__inet_sk_copy_descendant(struct sock * sk_to,const struct sock * sk_from,const int ancestor_size)187 static inline void __inet_sk_copy_descendant(struct sock *sk_to,
188 					     const struct sock *sk_from,
189 					     const int ancestor_size)
190 {
191 	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
192 	       sk_from->sk_prot->obj_size - ancestor_size);
193 }
194 #if !(IS_ENABLED(CONFIG_IPV6))
inet_sk_copy_descendant(struct sock * sk_to,const struct sock * sk_from)195 static inline void inet_sk_copy_descendant(struct sock *sk_to,
196 					   const struct sock *sk_from)
197 {
198 	__inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
199 }
200 #endif
201 
202 extern int inet_sk_rebuild_header(struct sock *sk);
203 
204 extern u32 inet_ehash_secret;
205 extern u32 ipv6_hash_secret;
206 extern void build_ehash_secret(void);
207 
inet_ehashfn(struct net * net,const __be32 laddr,const __u16 lport,const __be32 faddr,const __be16 fport)208 static inline unsigned int inet_ehashfn(struct net *net,
209 					const __be32 laddr, const __u16 lport,
210 					const __be32 faddr, const __be16 fport)
211 {
212 	return jhash_3words((__force __u32) laddr,
213 			    (__force __u32) faddr,
214 			    ((__u32) lport) << 16 | (__force __u32)fport,
215 			    inet_ehash_secret + net_hash_mix(net));
216 }
217 
inet_sk_ehashfn(const struct sock * sk)218 static inline int inet_sk_ehashfn(const struct sock *sk)
219 {
220 	const struct inet_sock *inet = inet_sk(sk);
221 	const __be32 laddr = inet->inet_rcv_saddr;
222 	const __u16 lport = inet->inet_num;
223 	const __be32 faddr = inet->inet_daddr;
224 	const __be16 fport = inet->inet_dport;
225 	struct net *net = sock_net(sk);
226 
227 	return inet_ehashfn(net, laddr, lport, faddr, fport);
228 }
229 
inet_reqsk_alloc(struct request_sock_ops * ops)230 static inline struct request_sock *inet_reqsk_alloc(struct request_sock_ops *ops)
231 {
232 	struct request_sock *req = reqsk_alloc(ops);
233 	struct inet_request_sock *ireq = inet_rsk(req);
234 
235 	if (req != NULL) {
236 		kmemcheck_annotate_bitfield(ireq, flags);
237 		ireq->opt = NULL;
238 	}
239 
240 	return req;
241 }
242 
inet_sk_flowi_flags(const struct sock * sk)243 static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
244 {
245 	__u8 flags = 0;
246 
247 	if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
248 		flags |= FLOWI_FLAG_ANYSRC;
249 	if (sk->sk_protocol == IPPROTO_TCP)
250 		flags |= FLOWI_FLAG_PRECOW_METRICS;
251 	return flags;
252 }
253 
254 #endif	/* _INET_SOCK_H */
255