xref: /linux-6.15/include/linux/net.h (revision 509edd95)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * NET		An implementation of the SOCKET network access protocol.
4  *		This is the master header file for the Linux NET layer,
5  *		or, in plain English: the networking handling part of the
6  *		kernel.
7  *
8  * Version:	@(#)net.h	1.0.3	05/25/93
9  *
10  * Authors:	Orest Zborowski, <[email protected]>
11  *		Ross Biro
12  *		Fred N. van Kempen, <[email protected]>
13  */
14 #ifndef _LINUX_NET_H
15 #define _LINUX_NET_H
16 
17 #include <linux/stringify.h>
18 #include <linux/random.h>
19 #include <linux/wait.h>
20 #include <linux/fcntl.h>	/* For O_CLOEXEC and O_NONBLOCK */
21 #include <linux/rcupdate.h>
22 #include <linux/once.h>
23 #include <linux/fs.h>
24 #include <linux/sockptr.h>
25 
26 #include <uapi/linux/net.h>
27 
28 struct poll_table_struct;
29 struct pipe_inode_info;
30 struct inode;
31 struct file;
32 struct net;
33 
34 /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
35  * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
36  * Eventually all flags will be in sk->sk_wq->flags.
37  */
38 #define SOCKWQ_ASYNC_NOSPACE	0
39 #define SOCKWQ_ASYNC_WAITDATA	1
40 #define SOCK_NOSPACE		2
41 #define SOCK_PASSCRED		3
42 #define SOCK_PASSSEC		4
43 
44 #ifndef ARCH_HAS_SOCKET_TYPES
45 /**
46  * enum sock_type - Socket types
47  * @SOCK_STREAM: stream (connection) socket
48  * @SOCK_DGRAM: datagram (conn.less) socket
49  * @SOCK_RAW: raw socket
50  * @SOCK_RDM: reliably-delivered message
51  * @SOCK_SEQPACKET: sequential packet socket
52  * @SOCK_DCCP: Datagram Congestion Control Protocol socket
53  * @SOCK_PACKET: linux specific way of getting packets at the dev level.
54  *		  For writing rarp and other similar things on the user level.
55  *
56  * When adding some new socket type please
57  * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
58  * overrides this enum for binary compat reasons.
59  */
60 enum sock_type {
61 	SOCK_STREAM	= 1,
62 	SOCK_DGRAM	= 2,
63 	SOCK_RAW	= 3,
64 	SOCK_RDM	= 4,
65 	SOCK_SEQPACKET	= 5,
66 	SOCK_DCCP	= 6,
67 	SOCK_PACKET	= 10,
68 };
69 
70 #define SOCK_MAX (SOCK_PACKET + 1)
71 /* Mask which covers at least up to SOCK_MASK-1.  The
72  * remaining bits are used as flags. */
73 #define SOCK_TYPE_MASK 0xf
74 
75 /* Flags for socket, socketpair, accept4 */
76 #define SOCK_CLOEXEC	O_CLOEXEC
77 #ifndef SOCK_NONBLOCK
78 #define SOCK_NONBLOCK	O_NONBLOCK
79 #endif
80 
81 #endif /* ARCH_HAS_SOCKET_TYPES */
82 
83 /**
84  * enum sock_shutdown_cmd - Shutdown types
85  * @SHUT_RD: shutdown receptions
86  * @SHUT_WR: shutdown transmissions
87  * @SHUT_RDWR: shutdown receptions/transmissions
88  */
89 enum sock_shutdown_cmd {
90 	SHUT_RD,
91 	SHUT_WR,
92 	SHUT_RDWR,
93 };
94 
95 struct socket_wq {
96 	/* Note: wait MUST be first field of socket_wq */
97 	wait_queue_head_t	wait;
98 	struct fasync_struct	*fasync_list;
99 	unsigned long		flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
100 	struct rcu_head		rcu;
101 } ____cacheline_aligned_in_smp;
102 
103 /**
104  *  struct socket - general BSD socket
105  *  @state: socket state (%SS_CONNECTED, etc)
106  *  @type: socket type (%SOCK_STREAM, etc)
107  *  @flags: socket flags (%SOCK_NOSPACE, etc)
108  *  @ops: protocol specific socket operations
109  *  @file: File back pointer for gc
110  *  @sk: internal networking protocol agnostic socket representation
111  *  @wq: wait queue for several uses
112  */
113 struct socket {
114 	socket_state		state;
115 
116 	short			type;
117 
118 	unsigned long		flags;
119 
120 	struct file		*file;
121 	struct sock		*sk;
122 	const struct proto_ops	*ops;
123 
124 	struct socket_wq	wq;
125 };
126 
127 struct vm_area_struct;
128 struct page;
129 struct sockaddr;
130 struct msghdr;
131 struct module;
132 struct sk_buff;
133 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
134 			       unsigned int, size_t);
135 
136 struct proto_ops {
137 	int		family;
138 	struct module	*owner;
139 	int		(*release)   (struct socket *sock);
140 	int		(*bind)	     (struct socket *sock,
141 				      struct sockaddr *myaddr,
142 				      int sockaddr_len);
143 	int		(*connect)   (struct socket *sock,
144 				      struct sockaddr *vaddr,
145 				      int sockaddr_len, int flags);
146 	int		(*socketpair)(struct socket *sock1,
147 				      struct socket *sock2);
148 	int		(*accept)    (struct socket *sock,
149 				      struct socket *newsock, int flags, bool kern);
150 	int		(*getname)   (struct socket *sock,
151 				      struct sockaddr *addr,
152 				      int peer);
153 	__poll_t	(*poll)	     (struct file *file, struct socket *sock,
154 				      struct poll_table_struct *wait);
155 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
156 				      unsigned long arg);
157 #ifdef CONFIG_COMPAT
158 	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
159 				      unsigned long arg);
160 #endif
161 	int		(*gettstamp) (struct socket *sock, void __user *userstamp,
162 				      bool timeval, bool time32);
163 	int		(*listen)    (struct socket *sock, int len);
164 	int		(*shutdown)  (struct socket *sock, int flags);
165 	int		(*setsockopt)(struct socket *sock, int level,
166 				      int optname, sockptr_t optval,
167 				      unsigned int optlen);
168 	int		(*getsockopt)(struct socket *sock, int level,
169 				      int optname, char __user *optval, int __user *optlen);
170 	void		(*show_fdinfo)(struct seq_file *m, struct socket *sock);
171 	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
172 				      size_t total_len);
173 	/* Notes for implementing recvmsg:
174 	 * ===============================
175 	 * msg->msg_namelen should get updated by the recvmsg handlers
176 	 * iff msg_name != NULL. It is by default 0 to prevent
177 	 * returning uninitialized memory to user space.  The recvfrom
178 	 * handlers can assume that msg.msg_name is either NULL or has
179 	 * a minimum size of sizeof(struct sockaddr_storage).
180 	 */
181 	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
182 				      size_t total_len, int flags);
183 	int		(*mmap)	     (struct file *file, struct socket *sock,
184 				      struct vm_area_struct * vma);
185 	ssize_t		(*sendpage)  (struct socket *sock, struct page *page,
186 				      int offset, size_t size, int flags);
187 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
188 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
189 	int		(*set_peek_off)(struct sock *sk, int val);
190 	int		(*peek_len)(struct socket *sock);
191 
192 	/* The following functions are called internally by kernel with
193 	 * sock lock already held.
194 	 */
195 	int		(*read_sock)(struct sock *sk, read_descriptor_t *desc,
196 				     sk_read_actor_t recv_actor);
197 	int		(*sendpage_locked)(struct sock *sk, struct page *page,
198 					   int offset, size_t size, int flags);
199 	int		(*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
200 					  size_t size);
201 	int		(*set_rcvlowat)(struct sock *sk, int val);
202 };
203 
204 #define DECLARE_SOCKADDR(type, dst, src)	\
205 	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
206 
207 struct net_proto_family {
208 	int		family;
209 	int		(*create)(struct net *net, struct socket *sock,
210 				  int protocol, int kern);
211 	struct module	*owner;
212 };
213 
214 struct iovec;
215 struct kvec;
216 
217 enum {
218 	SOCK_WAKE_IO,
219 	SOCK_WAKE_WAITD,
220 	SOCK_WAKE_SPACE,
221 	SOCK_WAKE_URG,
222 };
223 
224 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
225 int sock_register(const struct net_proto_family *fam);
226 void sock_unregister(int family);
227 bool sock_is_registered(int family);
228 int __sock_create(struct net *net, int family, int type, int proto,
229 		  struct socket **res, int kern);
230 int sock_create(int family, int type, int proto, struct socket **res);
231 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
232 int sock_create_lite(int family, int type, int proto, struct socket **res);
233 struct socket *sock_alloc(void);
234 void sock_release(struct socket *sock);
235 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
236 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
237 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
238 struct socket *sockfd_lookup(int fd, int *err);
239 struct socket *sock_from_file(struct file *file, int *err);
240 #define		     sockfd_put(sock) fput(sock->file)
241 int net_ratelimit(void);
242 
243 #define net_ratelimited_function(function, ...)			\
244 do {								\
245 	if (net_ratelimit())					\
246 		function(__VA_ARGS__);				\
247 } while (0)
248 
249 #define net_emerg_ratelimited(fmt, ...)				\
250 	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
251 #define net_alert_ratelimited(fmt, ...)				\
252 	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
253 #define net_crit_ratelimited(fmt, ...)				\
254 	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
255 #define net_err_ratelimited(fmt, ...)				\
256 	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
257 #define net_notice_ratelimited(fmt, ...)			\
258 	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
259 #define net_warn_ratelimited(fmt, ...)				\
260 	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
261 #define net_info_ratelimited(fmt, ...)				\
262 	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
263 #if defined(CONFIG_DYNAMIC_DEBUG) || \
264 	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
265 #define net_dbg_ratelimited(fmt, ...)					\
266 do {									\
267 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
268 	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
269 	    net_ratelimit())						\
270 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
271 		                   ##__VA_ARGS__);			\
272 } while (0)
273 #elif defined(DEBUG)
274 #define net_dbg_ratelimited(fmt, ...)				\
275 	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
276 #else
277 #define net_dbg_ratelimited(fmt, ...)				\
278 	do {							\
279 		if (0)						\
280 			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
281 	} while (0)
282 #endif
283 
284 #define net_get_random_once(buf, nbytes)			\
285 	get_random_once((buf), (nbytes))
286 #define net_get_random_once_wait(buf, nbytes)			\
287 	get_random_once_wait((buf), (nbytes))
288 
289 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
290 		   size_t num, size_t len);
291 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
292 			  struct kvec *vec, size_t num, size_t len);
293 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
294 		   size_t num, size_t len, int flags);
295 
296 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
297 int kernel_listen(struct socket *sock, int backlog);
298 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
299 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
300 		   int flags);
301 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
302 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
303 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
304 		    size_t size, int flags);
305 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
306 			   size_t size, int flags);
307 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
308 
309 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
310 u32 kernel_sock_ip_overhead(struct sock *sk);
311 
312 #define MODULE_ALIAS_NETPROTO(proto) \
313 	MODULE_ALIAS("net-pf-" __stringify(proto))
314 
315 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
316 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
317 
318 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
319 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
320 		     "-type-" __stringify(type))
321 
322 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
323 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
324 		     name)
325 #endif	/* _LINUX_NET_H */
326