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/kmemcheck.h>
26 #include <linux/rcupdate.h>
27 #include <linux/once.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 	kmemcheck_bitfield_begin(type);
114 	short			type;
115 	kmemcheck_bitfield_end(type);
116 
117 	unsigned long		flags;
118 
119 	struct socket_wq __rcu	*wq;
120 
121 	struct file		*file;
122 	struct sock		*sk;
123 	const struct proto_ops	*ops;
124 };
125 
126 struct vm_area_struct;
127 struct page;
128 struct sockaddr;
129 struct msghdr;
130 struct module;
131 
132 struct proto_ops {
133 	int		family;
134 	struct module	*owner;
135 	int		(*release)   (struct socket *sock);
136 	int		(*bind)	     (struct socket *sock,
137 				      struct sockaddr *myaddr,
138 				      int sockaddr_len);
139 	int		(*connect)   (struct socket *sock,
140 				      struct sockaddr *vaddr,
141 				      int sockaddr_len, int flags);
142 	int		(*socketpair)(struct socket *sock1,
143 				      struct socket *sock2);
144 	int		(*accept)    (struct socket *sock,
145 				      struct socket *newsock, int flags);
146 	int		(*getname)   (struct socket *sock,
147 				      struct sockaddr *addr,
148 				      int *sockaddr_len, int peer);
149 	unsigned int	(*poll)	     (struct file *file, struct socket *sock,
150 				      struct poll_table_struct *wait);
151 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
152 				      unsigned long arg);
153 #ifdef CONFIG_COMPAT
154 	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
155 				      unsigned long arg);
156 #endif
157 	int		(*listen)    (struct socket *sock, int len);
158 	int		(*shutdown)  (struct socket *sock, int flags);
159 	int		(*setsockopt)(struct socket *sock, int level,
160 				      int optname, char __user *optval, unsigned int optlen);
161 	int		(*getsockopt)(struct socket *sock, int level,
162 				      int optname, char __user *optval, int __user *optlen);
163 #ifdef CONFIG_COMPAT
164 	int		(*compat_setsockopt)(struct socket *sock, int level,
165 				      int optname, char __user *optval, unsigned int optlen);
166 	int		(*compat_getsockopt)(struct socket *sock, int level,
167 				      int optname, char __user *optval, int __user *optlen);
168 #endif
169 	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
170 				      size_t total_len);
171 	/* Notes for implementing recvmsg:
172 	 * ===============================
173 	 * msg->msg_namelen should get updated by the recvmsg handlers
174 	 * iff msg_name != NULL. It is by default 0 to prevent
175 	 * returning uninitialized memory to user space.  The recvfrom
176 	 * handlers can assume that msg.msg_name is either NULL or has
177 	 * a minimum size of sizeof(struct sockaddr_storage).
178 	 */
179 	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
180 				      size_t total_len, int flags);
181 	int		(*mmap)	     (struct file *file, struct socket *sock,
182 				      struct vm_area_struct * vma);
183 	ssize_t		(*sendpage)  (struct socket *sock, struct page *page,
184 				      int offset, size_t size, int flags);
185 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
186 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
187 	int		(*set_peek_off)(struct sock *sk, int val);
188 };
189 
190 #define DECLARE_SOCKADDR(type, dst, src)	\
191 	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
192 
193 struct net_proto_family {
194 	int		family;
195 	int		(*create)(struct net *net, struct socket *sock,
196 				  int protocol, int kern);
197 	struct module	*owner;
198 };
199 
200 struct iovec;
201 struct kvec;
202 
203 enum {
204 	SOCK_WAKE_IO,
205 	SOCK_WAKE_WAITD,
206 	SOCK_WAKE_SPACE,
207 	SOCK_WAKE_URG,
208 };
209 
210 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
211 int sock_register(const struct net_proto_family *fam);
212 void sock_unregister(int family);
213 int __sock_create(struct net *net, int family, int type, int proto,
214 		  struct socket **res, int kern);
215 int sock_create(int family, int type, int proto, struct socket **res);
216 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
217 int sock_create_lite(int family, int type, int proto, struct socket **res);
218 void sock_release(struct socket *sock);
219 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
220 int sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
221 		 int flags);
222 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
223 struct socket *sockfd_lookup(int fd, int *err);
224 struct socket *sock_from_file(struct file *file, int *err);
225 #define		     sockfd_put(sock) fput(sock->file)
226 int net_ratelimit(void);
227 
228 #define net_ratelimited_function(function, ...)			\
229 do {								\
230 	if (net_ratelimit())					\
231 		function(__VA_ARGS__);				\
232 } while (0)
233 
234 #define net_emerg_ratelimited(fmt, ...)				\
235 	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
236 #define net_alert_ratelimited(fmt, ...)				\
237 	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
238 #define net_crit_ratelimited(fmt, ...)				\
239 	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
240 #define net_err_ratelimited(fmt, ...)				\
241 	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
242 #define net_notice_ratelimited(fmt, ...)			\
243 	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
244 #define net_warn_ratelimited(fmt, ...)				\
245 	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
246 #define net_info_ratelimited(fmt, ...)				\
247 	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
248 #if defined(CONFIG_DYNAMIC_DEBUG)
249 #define net_dbg_ratelimited(fmt, ...)					\
250 do {									\
251 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
252 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
253 	    net_ratelimit())						\
254 		__dynamic_pr_debug(&descriptor, fmt, ##__VA_ARGS__);	\
255 } while (0)
256 #elif defined(DEBUG)
257 #define net_dbg_ratelimited(fmt, ...)				\
258 	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
259 #else
260 #define net_dbg_ratelimited(fmt, ...)				\
261 	do {							\
262 		if (0)						\
263 			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
264 	} while (0)
265 #endif
266 
267 #define net_get_random_once(buf, nbytes)			\
268 	get_random_once((buf), (nbytes))
269 
270 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
271 		   size_t num, size_t len);
272 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
273 		   size_t num, size_t len, int flags);
274 
275 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
276 int kernel_listen(struct socket *sock, int backlog);
277 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
278 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
279 		   int flags);
280 int kernel_getsockname(struct socket *sock, struct sockaddr *addr,
281 		       int *addrlen);
282 int kernel_getpeername(struct socket *sock, struct sockaddr *addr,
283 		       int *addrlen);
284 int kernel_getsockopt(struct socket *sock, int level, int optname, char *optval,
285 		      int *optlen);
286 int kernel_setsockopt(struct socket *sock, int level, int optname, char *optval,
287 		      unsigned int optlen);
288 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
289 		    size_t size, int flags);
290 int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg);
291 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
292 
293 #define MODULE_ALIAS_NETPROTO(proto) \
294 	MODULE_ALIAS("net-pf-" __stringify(proto))
295 
296 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
297 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
298 
299 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
300 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
301 		     "-type-" __stringify(type))
302 
303 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
304 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
305 		     name)
306 #endif	/* _LINUX_NET_H */
307