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  	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  
inet_request_bound_dev_if(const struct sock * sk,struct sk_buff * skb)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  
inet_sk_bound_l3mdev(const struct sock * sk)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  
inet_bound_dev_eq(bool l3mdev_accept,int bound_dev_if,int dif,int sdif)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  
inet_sk_bound_dev_eq(struct net * net,int bound_dev_if,int dif,int sdif)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_flags - various atomic flags
198   * @inet_saddr - Sending source
199   * @uc_ttl - Unicast TTL
200   * @inet_sport - Source port
201   * @inet_id - ID counter for DF pkts
202   * @tos - TOS
203   * @mc_ttl - Multicasting TTL
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  	unsigned long		inet_flags;
222  	__be32			inet_saddr;
223  	__s16			uc_ttl;
224  	__be16			inet_sport;
225  	struct ip_options_rcu __rcu	*inet_opt;
226  	atomic_t		inet_id;
227  
228  	__u8			tos;
229  	__u8			min_ttl;
230  	__u8			mc_ttl;
231  	__u8			pmtudisc;
232  	__u8			rcv_tos;
233  	__u8			convert_csum;
234  	int			uc_index;
235  	int			mc_index;
236  	__be32			mc_addr;
237  	struct {
238  		__u16 lo;
239  		__u16 hi;
240  	}			local_port_range;
241  
242  	struct ip_mc_socklist __rcu	*mc_list;
243  	struct inet_cork_full	cork;
244  };
245  
246  #define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
247  #define IPCORK_ALLFRAG	2	/* always fragment (for ipv6 for now) */
248  
249  enum {
250  	INET_FLAGS_PKTINFO	= 0,
251  	INET_FLAGS_TTL		= 1,
252  	INET_FLAGS_TOS		= 2,
253  	INET_FLAGS_RECVOPTS	= 3,
254  	INET_FLAGS_RETOPTS	= 4,
255  	INET_FLAGS_PASSSEC	= 5,
256  	INET_FLAGS_ORIGDSTADDR	= 6,
257  	INET_FLAGS_CHECKSUM	= 7,
258  	INET_FLAGS_RECVFRAGSIZE	= 8,
259  
260  	INET_FLAGS_RECVERR	= 9,
261  	INET_FLAGS_RECVERR_RFC4884 = 10,
262  	INET_FLAGS_FREEBIND	= 11,
263  	INET_FLAGS_HDRINCL	= 12,
264  	INET_FLAGS_MC_LOOP	= 13,
265  	INET_FLAGS_MC_ALL	= 14,
266  	INET_FLAGS_TRANSPARENT	= 15,
267  	INET_FLAGS_IS_ICSK	= 16,
268  	INET_FLAGS_NODEFRAG	= 17,
269  	INET_FLAGS_BIND_ADDRESS_NO_PORT = 18,
270  	INET_FLAGS_DEFER_CONNECT = 19,
271  };
272  
273  /* cmsg flags for inet */
274  #define IP_CMSG_PKTINFO		BIT(INET_FLAGS_PKTINFO)
275  #define IP_CMSG_TTL		BIT(INET_FLAGS_TTL)
276  #define IP_CMSG_TOS		BIT(INET_FLAGS_TOS)
277  #define IP_CMSG_RECVOPTS	BIT(INET_FLAGS_RECVOPTS)
278  #define IP_CMSG_RETOPTS		BIT(INET_FLAGS_RETOPTS)
279  #define IP_CMSG_PASSSEC		BIT(INET_FLAGS_PASSSEC)
280  #define IP_CMSG_ORIGDSTADDR	BIT(INET_FLAGS_ORIGDSTADDR)
281  #define IP_CMSG_CHECKSUM	BIT(INET_FLAGS_CHECKSUM)
282  #define IP_CMSG_RECVFRAGSIZE	BIT(INET_FLAGS_RECVFRAGSIZE)
283  
284  #define IP_CMSG_ALL	(IP_CMSG_PKTINFO | IP_CMSG_TTL |		\
285  			 IP_CMSG_TOS | IP_CMSG_RECVOPTS |		\
286  			 IP_CMSG_RETOPTS | IP_CMSG_PASSSEC |		\
287  			 IP_CMSG_ORIGDSTADDR | IP_CMSG_CHECKSUM |	\
288  			 IP_CMSG_RECVFRAGSIZE)
289  
inet_cmsg_flags(const struct inet_sock * inet)290  static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet)
291  {
292  	return READ_ONCE(inet->inet_flags) & IP_CMSG_ALL;
293  }
294  
295  #define inet_test_bit(nr, sk)			\
296  	test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
297  #define inet_set_bit(nr, sk)			\
298  	set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
299  #define inet_clear_bit(nr, sk)			\
300  	clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
301  #define inet_assign_bit(nr, sk, val)		\
302  	assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)
303  
sk_is_inet(struct sock * sk)304  static inline bool sk_is_inet(struct sock *sk)
305  {
306  	return sk->sk_family == AF_INET || sk->sk_family == AF_INET6;
307  }
308  
309  /**
310   * sk_to_full_sk - Access to a full socket
311   * @sk: pointer to a socket
312   *
313   * SYNACK messages might be attached to request sockets.
314   * Some places want to reach the listener in this case.
315   */
sk_to_full_sk(struct sock * sk)316  static inline struct sock *sk_to_full_sk(struct sock *sk)
317  {
318  #ifdef CONFIG_INET
319  	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
320  		sk = inet_reqsk(sk)->rsk_listener;
321  #endif
322  	return sk;
323  }
324  
325  /* sk_to_full_sk() variant with a const argument */
sk_const_to_full_sk(const struct sock * sk)326  static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
327  {
328  #ifdef CONFIG_INET
329  	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
330  		sk = ((const struct request_sock *)sk)->rsk_listener;
331  #endif
332  	return sk;
333  }
334  
skb_to_full_sk(const struct sk_buff * skb)335  static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
336  {
337  	return sk_to_full_sk(skb->sk);
338  }
339  
340  #define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
341  
__inet_sk_copy_descendant(struct sock * sk_to,const struct sock * sk_from,const int ancestor_size)342  static inline void __inet_sk_copy_descendant(struct sock *sk_to,
343  					     const struct sock *sk_from,
344  					     const int ancestor_size)
345  {
346  	memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
347  	       sk_from->sk_prot->obj_size - ancestor_size);
348  }
349  
350  int inet_sk_rebuild_header(struct sock *sk);
351  
352  /**
353   * inet_sk_state_load - read sk->sk_state for lockless contexts
354   * @sk: socket pointer
355   *
356   * Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
357   * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
358   */
inet_sk_state_load(const struct sock * sk)359  static inline int inet_sk_state_load(const struct sock *sk)
360  {
361  	/* state change might impact lockless readers. */
362  	return smp_load_acquire(&sk->sk_state);
363  }
364  
365  /**
366   * inet_sk_state_store - update sk->sk_state
367   * @sk: socket pointer
368   * @newstate: new state
369   *
370   * Paired with inet_sk_state_load(). Should be used in contexts where
371   * state change might impact lockless readers.
372   */
373  void inet_sk_state_store(struct sock *sk, int newstate);
374  
375  void inet_sk_set_state(struct sock *sk, int state);
376  
__inet_ehashfn(const __be32 laddr,const __u16 lport,const __be32 faddr,const __be16 fport,u32 initval)377  static inline unsigned int __inet_ehashfn(const __be32 laddr,
378  					  const __u16 lport,
379  					  const __be32 faddr,
380  					  const __be16 fport,
381  					  u32 initval)
382  {
383  	return jhash_3words((__force __u32) laddr,
384  			    (__force __u32) faddr,
385  			    ((__u32) lport) << 16 | (__force __u32)fport,
386  			    initval);
387  }
388  
389  struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
390  				      struct sock *sk_listener,
391  				      bool attach_listener);
392  
inet_sk_flowi_flags(const struct sock * sk)393  static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
394  {
395  	__u8 flags = 0;
396  
397  	if (inet_test_bit(TRANSPARENT, sk) || inet_test_bit(HDRINCL, sk))
398  		flags |= FLOWI_FLAG_ANYSRC;
399  	return flags;
400  }
401  
inet_inc_convert_csum(struct sock * sk)402  static inline void inet_inc_convert_csum(struct sock *sk)
403  {
404  	inet_sk(sk)->convert_csum++;
405  }
406  
inet_dec_convert_csum(struct sock * sk)407  static inline void inet_dec_convert_csum(struct sock *sk)
408  {
409  	if (inet_sk(sk)->convert_csum > 0)
410  		inet_sk(sk)->convert_csum--;
411  }
412  
inet_get_convert_csum(struct sock * sk)413  static inline bool inet_get_convert_csum(struct sock *sk)
414  {
415  	return !!inet_sk(sk)->convert_csum;
416  }
417  
418  
inet_can_nonlocal_bind(struct net * net,struct inet_sock * inet)419  static inline bool inet_can_nonlocal_bind(struct net *net,
420  					  struct inet_sock *inet)
421  {
422  	return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
423  		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
424  		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
425  }
426  
inet_addr_valid_or_nonlocal(struct net * net,struct inet_sock * inet,__be32 addr,int addr_type)427  static inline bool inet_addr_valid_or_nonlocal(struct net *net,
428  					       struct inet_sock *inet,
429  					       __be32 addr,
430  					       int addr_type)
431  {
432  	return inet_can_nonlocal_bind(net, inet) ||
433  		addr == htonl(INADDR_ANY) ||
434  		addr_type == RTN_LOCAL ||
435  		addr_type == RTN_MULTICAST ||
436  		addr_type == RTN_BROADCAST;
437  }
438  
439  #endif	/* _INET_SOCK_H */
440