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 /**
87  * enum sock_shutdown_cmd - Shutdown types
88  * @SHUT_RD: shutdown receptions
89  * @SHUT_WR: shutdown transmissions
90  * @SHUT_RDWR: shutdown receptions/transmissions
91  */
92 enum sock_shutdown_cmd {
93 	SHUT_RD,
94 	SHUT_WR,
95 	SHUT_RDWR,
96 };
97 
98 struct socket_wq {
99 	/* Note: wait MUST be first field of socket_wq */
100 	wait_queue_head_t	wait;
101 	struct fasync_struct	*fasync_list;
102 	unsigned long		flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
103 	struct rcu_head		rcu;
104 } ____cacheline_aligned_in_smp;
105 
106 /**
107  *  struct socket - general BSD socket
108  *  @state: socket state (%SS_CONNECTED, etc)
109  *  @type: socket type (%SOCK_STREAM, etc)
110  *  @flags: socket flags (%SOCK_NOSPACE, etc)
111  *  @ops: protocol specific socket operations
112  *  @file: File back pointer for gc
113  *  @sk: internal networking protocol agnostic socket representation
114  *  @wq: wait queue for several uses
115  */
116 struct socket {
117 	socket_state		state;
118 
119 	short			type;
120 
121 	unsigned long		flags;
122 
123 	struct socket_wq	*wq;
124 
125 	struct file		*file;
126 	struct sock		*sk;
127 	const struct proto_ops	*ops;
128 };
129 
130 struct vm_area_struct;
131 struct page;
132 struct sockaddr;
133 struct msghdr;
134 struct module;
135 struct sk_buff;
136 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
137 			       unsigned int, size_t);
138 
139 struct proto_ops {
140 	int		family;
141 	struct module	*owner;
142 	int		(*release)   (struct socket *sock);
143 	int		(*bind)	     (struct socket *sock,
144 				      struct sockaddr *myaddr,
145 				      int sockaddr_len);
146 	int		(*connect)   (struct socket *sock,
147 				      struct sockaddr *vaddr,
148 				      int sockaddr_len, int flags);
149 	int		(*socketpair)(struct socket *sock1,
150 				      struct socket *sock2);
151 	int		(*accept)    (struct socket *sock,
152 				      struct socket *newsock, int flags, bool kern);
153 	int		(*getname)   (struct socket *sock,
154 				      struct sockaddr *addr,
155 				      int peer);
156 	__poll_t	(*poll)	     (struct file *file, struct socket *sock,
157 				      struct poll_table_struct *wait);
158 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
159 				      unsigned long arg);
160 #ifdef CONFIG_COMPAT
161 	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
162 				      unsigned long arg);
163 #endif
164 	int		(*listen)    (struct socket *sock, int len);
165 	int		(*shutdown)  (struct socket *sock, int flags);
166 	int		(*setsockopt)(struct socket *sock, int level,
167 				      int optname, char __user *optval, unsigned int optlen);
168 	int		(*getsockopt)(struct socket *sock, int level,
169 				      int optname, char __user *optval, int __user *optlen);
170 #ifdef CONFIG_COMPAT
171 	int		(*compat_setsockopt)(struct socket *sock, int level,
172 				      int optname, char __user *optval, unsigned int optlen);
173 	int		(*compat_getsockopt)(struct socket *sock, int level,
174 				      int optname, char __user *optval, int __user *optlen);
175 #endif
176 	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
177 				      size_t total_len);
178 	/* Notes for implementing recvmsg:
179 	 * ===============================
180 	 * msg->msg_namelen should get updated by the recvmsg handlers
181 	 * iff msg_name != NULL. It is by default 0 to prevent
182 	 * returning uninitialized memory to user space.  The recvfrom
183 	 * handlers can assume that msg.msg_name is either NULL or has
184 	 * a minimum size of sizeof(struct sockaddr_storage).
185 	 */
186 	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
187 				      size_t total_len, int flags);
188 	int		(*mmap)	     (struct file *file, struct socket *sock,
189 				      struct vm_area_struct * vma);
190 	ssize_t		(*sendpage)  (struct socket *sock, struct page *page,
191 				      int offset, size_t size, int flags);
192 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
193 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
194 	int		(*set_peek_off)(struct sock *sk, int val);
195 	int		(*peek_len)(struct socket *sock);
196 
197 	/* The following functions are called internally by kernel with
198 	 * sock lock already held.
199 	 */
200 	int		(*read_sock)(struct sock *sk, read_descriptor_t *desc,
201 				     sk_read_actor_t recv_actor);
202 	int		(*sendpage_locked)(struct sock *sk, struct page *page,
203 					   int offset, size_t size, int flags);
204 	int		(*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
205 					  size_t size);
206 	int		(*set_rcvlowat)(struct sock *sk, int val);
207 };
208 
209 #define DECLARE_SOCKADDR(type, dst, src)	\
210 	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
211 
212 struct net_proto_family {
213 	int		family;
214 	int		(*create)(struct net *net, struct socket *sock,
215 				  int protocol, int kern);
216 	struct module	*owner;
217 };
218 
219 struct iovec;
220 struct kvec;
221 
222 enum {
223 	SOCK_WAKE_IO,
224 	SOCK_WAKE_WAITD,
225 	SOCK_WAKE_SPACE,
226 	SOCK_WAKE_URG,
227 };
228 
229 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
230 int sock_register(const struct net_proto_family *fam);
231 void sock_unregister(int family);
232 bool sock_is_registered(int family);
233 int __sock_create(struct net *net, int family, int type, int proto,
234 		  struct socket **res, int kern);
235 int sock_create(int family, int type, int proto, struct socket **res);
236 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
237 int sock_create_lite(int family, int type, int proto, struct socket **res);
238 struct socket *sock_alloc(void);
239 void sock_release(struct socket *sock);
240 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
241 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
242 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
243 struct socket *sockfd_lookup(int fd, int *err);
244 struct socket *sock_from_file(struct file *file, int *err);
245 #define		     sockfd_put(sock) fput(sock->file)
246 int net_ratelimit(void);
247 
248 #define net_ratelimited_function(function, ...)			\
249 do {								\
250 	if (net_ratelimit())					\
251 		function(__VA_ARGS__);				\
252 } while (0)
253 
254 #define net_emerg_ratelimited(fmt, ...)				\
255 	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
256 #define net_alert_ratelimited(fmt, ...)				\
257 	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
258 #define net_crit_ratelimited(fmt, ...)				\
259 	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
260 #define net_err_ratelimited(fmt, ...)				\
261 	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
262 #define net_notice_ratelimited(fmt, ...)			\
263 	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
264 #define net_warn_ratelimited(fmt, ...)				\
265 	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
266 #define net_info_ratelimited(fmt, ...)				\
267 	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
268 #if defined(CONFIG_DYNAMIC_DEBUG)
269 #define net_dbg_ratelimited(fmt, ...)					\
270 do {									\
271 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
272 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
273 	    net_ratelimit())						\
274 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
275 		                   ##__VA_ARGS__);			\
276 } while (0)
277 #elif defined(DEBUG)
278 #define net_dbg_ratelimited(fmt, ...)				\
279 	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
280 #else
281 #define net_dbg_ratelimited(fmt, ...)				\
282 	do {							\
283 		if (0)						\
284 			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
285 	} while (0)
286 #endif
287 
288 #define net_get_random_once(buf, nbytes)			\
289 	get_random_once((buf), (nbytes))
290 #define net_get_random_once_wait(buf, nbytes)			\
291 	get_random_once_wait((buf), (nbytes))
292 
293 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
294 		   size_t num, size_t len);
295 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
296 			  struct kvec *vec, size_t num, size_t len);
297 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
298 		   size_t num, size_t len, int flags);
299 
300 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
301 int kernel_listen(struct socket *sock, int backlog);
302 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
303 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
304 		   int flags);
305 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
306 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
307 int kernel_getsockopt(struct socket *sock, int level, int optname, char *optval,
308 		      int *optlen);
309 int kernel_setsockopt(struct socket *sock, int level, int optname, char *optval,
310 		      unsigned int optlen);
311 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
312 		    size_t size, int flags);
313 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
314 			   size_t size, int flags);
315 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
316 
317 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
318 u32 kernel_sock_ip_overhead(struct sock *sk);
319 
320 #define MODULE_ALIAS_NETPROTO(proto) \
321 	MODULE_ALIAS("net-pf-" __stringify(proto))
322 
323 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
324 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
325 
326 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
327 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
328 		     "-type-" __stringify(type))
329 
330 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
331 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
332 		     name)
333 #endif	/* _LINUX_NET_H */
334