1 /*
2  * NET		An implementation of the SOCKET network access protocol.
3  *		This is the master header file for the Linux NET layer,
4  *		or, in plain English: the networking handling part of the
5  *		kernel.
6  *
7  * Version:	@(#)net.h	1.0.3	05/25/93
8  *
9  * Authors:	Orest Zborowski, <obz@Kodak.COM>
10  *		Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *
13  *		This program is free software; you can redistribute it and/or
14  *		modify it under the terms of the GNU General Public License
15  *		as published by the Free Software Foundation; either version
16  *		2 of the License, or (at your option) any later version.
17  */
18 #ifndef _LINUX_NET_H
19 #define _LINUX_NET_H
20 
21 #include <linux/stringify.h>
22 #include <linux/random.h>
23 #include <linux/wait.h>
24 #include <linux/fcntl.h>	/* For O_CLOEXEC and O_NONBLOCK */
25 #include <linux/rcupdate.h>
26 #include <linux/once.h>
27 #include <linux/fs.h>
28 
29 #include <uapi/linux/net.h>
30 
31 struct poll_table_struct;
32 struct pipe_inode_info;
33 struct inode;
34 struct file;
35 struct net;
36 
37 /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
38  * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
39  * Eventually all flags will be in sk->sk_wq->flags.
40  */
41 #define SOCKWQ_ASYNC_NOSPACE	0
42 #define SOCKWQ_ASYNC_WAITDATA	1
43 #define SOCK_NOSPACE		2
44 #define SOCK_PASSCRED		3
45 #define SOCK_PASSSEC		4
46 
47 #ifndef ARCH_HAS_SOCKET_TYPES
48 /**
49  * enum sock_type - Socket types
50  * @SOCK_STREAM: stream (connection) socket
51  * @SOCK_DGRAM: datagram (conn.less) socket
52  * @SOCK_RAW: raw socket
53  * @SOCK_RDM: reliably-delivered message
54  * @SOCK_SEQPACKET: sequential packet socket
55  * @SOCK_DCCP: Datagram Congestion Control Protocol socket
56  * @SOCK_PACKET: linux specific way of getting packets at the dev level.
57  *		  For writing rarp and other similar things on the user level.
58  *
59  * When adding some new socket type please
60  * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
61  * overrides this enum for binary compat reasons.
62  */
63 enum sock_type {
64 	SOCK_STREAM	= 1,
65 	SOCK_DGRAM	= 2,
66 	SOCK_RAW	= 3,
67 	SOCK_RDM	= 4,
68 	SOCK_SEQPACKET	= 5,
69 	SOCK_DCCP	= 6,
70 	SOCK_PACKET	= 10,
71 };
72 
73 #define SOCK_MAX (SOCK_PACKET + 1)
74 /* Mask which covers at least up to SOCK_MASK-1.  The
75  * remaining bits are used as flags. */
76 #define SOCK_TYPE_MASK 0xf
77 
78 /* Flags for socket, socketpair, accept4 */
79 #define SOCK_CLOEXEC	O_CLOEXEC
80 #ifndef SOCK_NONBLOCK
81 #define SOCK_NONBLOCK	O_NONBLOCK
82 #endif
83 
84 #endif /* ARCH_HAS_SOCKET_TYPES */
85 
86 enum sock_shutdown_cmd {
87 	SHUT_RD,
88 	SHUT_WR,
89 	SHUT_RDWR,
90 };
91 
92 struct socket_wq {
93 	/* Note: wait MUST be first field of socket_wq */
94 	wait_queue_head_t	wait;
95 	struct fasync_struct	*fasync_list;
96 	unsigned long		flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
97 	struct rcu_head		rcu;
98 } ____cacheline_aligned_in_smp;
99 
100 /**
101  *  struct socket - general BSD socket
102  *  @state: socket state (%SS_CONNECTED, etc)
103  *  @type: socket type (%SOCK_STREAM, etc)
104  *  @flags: socket flags (%SOCK_NOSPACE, etc)
105  *  @ops: protocol specific socket operations
106  *  @file: File back pointer for gc
107  *  @sk: internal networking protocol agnostic socket representation
108  *  @wq: wait queue for several uses
109  */
110 struct socket {
111 	socket_state		state;
112 
113 	short			type;
114 
115 	unsigned long		flags;
116 
117 	struct socket_wq	*wq;
118 
119 	struct file		*file;
120 	struct sock		*sk;
121 	const struct proto_ops	*ops;
122 };
123 
124 struct vm_area_struct;
125 struct page;
126 struct sockaddr;
127 struct msghdr;
128 struct module;
129 struct sk_buff;
130 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
131 			       unsigned int, size_t);
132 
133 struct proto_ops {
134 	int		family;
135 	struct module	*owner;
136 	int		(*release)   (struct socket *sock);
137 	int		(*bind)	     (struct socket *sock,
138 				      struct sockaddr *myaddr,
139 				      int sockaddr_len);
140 	int		(*connect)   (struct socket *sock,
141 				      struct sockaddr *vaddr,
142 				      int sockaddr_len, int flags);
143 	int		(*socketpair)(struct socket *sock1,
144 				      struct socket *sock2);
145 	int		(*accept)    (struct socket *sock,
146 				      struct socket *newsock, int flags, bool kern);
147 	int		(*getname)   (struct socket *sock,
148 				      struct sockaddr *addr,
149 				      int peer);
150 	__poll_t	(*poll)	     (struct file *file, struct socket *sock,
151 				      struct poll_table_struct *wait);
152 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
153 				      unsigned long arg);
154 #ifdef CONFIG_COMPAT
155 	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
156 				      unsigned long arg);
157 #endif
158 	int		(*listen)    (struct socket *sock, int len);
159 	int		(*shutdown)  (struct socket *sock, int flags);
160 	int		(*setsockopt)(struct socket *sock, int level,
161 				      int optname, char __user *optval, unsigned int optlen);
162 	int		(*getsockopt)(struct socket *sock, int level,
163 				      int optname, char __user *optval, int __user *optlen);
164 #ifdef CONFIG_COMPAT
165 	int		(*compat_setsockopt)(struct socket *sock, int level,
166 				      int optname, char __user *optval, unsigned int optlen);
167 	int		(*compat_getsockopt)(struct socket *sock, int level,
168 				      int optname, char __user *optval, int __user *optlen);
169 #endif
170 	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
171 				      size_t total_len);
172 	/* Notes for implementing recvmsg:
173 	 * ===============================
174 	 * msg->msg_namelen should get updated by the recvmsg handlers
175 	 * iff msg_name != NULL. It is by default 0 to prevent
176 	 * returning uninitialized memory to user space.  The recvfrom
177 	 * handlers can assume that msg.msg_name is either NULL or has
178 	 * a minimum size of sizeof(struct sockaddr_storage).
179 	 */
180 	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
181 				      size_t total_len, int flags);
182 	int		(*mmap)	     (struct file *file, struct socket *sock,
183 				      struct vm_area_struct * vma);
184 	ssize_t		(*sendpage)  (struct socket *sock, struct page *page,
185 				      int offset, size_t size, int flags);
186 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
187 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
188 	int		(*set_peek_off)(struct sock *sk, int val);
189 	int		(*peek_len)(struct socket *sock);
190 
191 	/* The following functions are called internally by kernel with
192 	 * sock lock already held.
193 	 */
194 	int		(*read_sock)(struct sock *sk, read_descriptor_t *desc,
195 				     sk_read_actor_t recv_actor);
196 	int		(*sendpage_locked)(struct sock *sk, struct page *page,
197 					   int offset, size_t size, int flags);
198 	int		(*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
199 					  size_t size);
200 	int		(*set_rcvlowat)(struct sock *sk, int val);
201 };
202 
203 #define DECLARE_SOCKADDR(type, dst, src)	\
204 	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
205 
206 struct net_proto_family {
207 	int		family;
208 	int		(*create)(struct net *net, struct socket *sock,
209 				  int protocol, int kern);
210 	struct module	*owner;
211 };
212 
213 struct iovec;
214 struct kvec;
215 
216 enum {
217 	SOCK_WAKE_IO,
218 	SOCK_WAKE_WAITD,
219 	SOCK_WAKE_SPACE,
220 	SOCK_WAKE_URG,
221 };
222 
223 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
224 int sock_register(const struct net_proto_family *fam);
225 void sock_unregister(int family);
226 bool sock_is_registered(int family);
227 int __sock_create(struct net *net, int family, int type, int proto,
228 		  struct socket **res, int kern);
229 int sock_create(int family, int type, int proto, struct socket **res);
230 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
231 int sock_create_lite(int family, int type, int proto, struct socket **res);
232 struct socket *sock_alloc(void);
233 void sock_release(struct socket *sock);
234 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
235 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
236 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
237 struct socket *sockfd_lookup(int fd, int *err);
238 struct socket *sock_from_file(struct file *file, int *err);
239 #define		     sockfd_put(sock) fput(sock->file)
240 int net_ratelimit(void);
241 
242 #define net_ratelimited_function(function, ...)			\
243 do {								\
244 	if (net_ratelimit())					\
245 		function(__VA_ARGS__);				\
246 } while (0)
247 
248 #define net_emerg_ratelimited(fmt, ...)				\
249 	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
250 #define net_alert_ratelimited(fmt, ...)				\
251 	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
252 #define net_crit_ratelimited(fmt, ...)				\
253 	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
254 #define net_err_ratelimited(fmt, ...)				\
255 	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
256 #define net_notice_ratelimited(fmt, ...)			\
257 	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
258 #define net_warn_ratelimited(fmt, ...)				\
259 	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
260 #define net_info_ratelimited(fmt, ...)				\
261 	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
262 #if defined(CONFIG_DYNAMIC_DEBUG)
263 #define net_dbg_ratelimited(fmt, ...)					\
264 do {									\
265 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
266 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
267 	    net_ratelimit())						\
268 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
269 		                   ##__VA_ARGS__);			\
270 } while (0)
271 #elif defined(DEBUG)
272 #define net_dbg_ratelimited(fmt, ...)				\
273 	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
274 #else
275 #define net_dbg_ratelimited(fmt, ...)				\
276 	do {							\
277 		if (0)						\
278 			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
279 	} while (0)
280 #endif
281 
282 #define net_get_random_once(buf, nbytes)			\
283 	get_random_once((buf), (nbytes))
284 #define net_get_random_once_wait(buf, nbytes)			\
285 	get_random_once_wait((buf), (nbytes))
286 
287 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
288 		   size_t num, size_t len);
289 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
290 			  struct kvec *vec, size_t num, size_t len);
291 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
292 		   size_t num, size_t len, int flags);
293 
294 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
295 int kernel_listen(struct socket *sock, int backlog);
296 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
297 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
298 		   int flags);
299 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
300 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
301 int kernel_getsockopt(struct socket *sock, int level, int optname, char *optval,
302 		      int *optlen);
303 int kernel_setsockopt(struct socket *sock, int level, int optname, char *optval,
304 		      unsigned int optlen);
305 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
306 		    size_t size, int flags);
307 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
308 			   size_t size, int flags);
309 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
310 
311 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
312 u32 kernel_sock_ip_overhead(struct sock *sk);
313 
314 #define MODULE_ALIAS_NETPROTO(proto) \
315 	MODULE_ALIAS("net-pf-" __stringify(proto))
316 
317 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
318 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
319 
320 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
321 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
322 		     "-type-" __stringify(type))
323 
324 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
325 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
326 		     name)
327 #endif	/* _LINUX_NET_H */
328