xref: /linux-6.15/include/linux/net.h (revision ca64d84e)
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 
25 #include <uapi/linux/net.h>
26 
27 struct poll_table_struct;
28 struct pipe_inode_info;
29 struct inode;
30 struct file;
31 struct net;
32 
33 /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
34  * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
35  * Eventually all flags will be in sk->sk_wq->flags.
36  */
37 #define SOCKWQ_ASYNC_NOSPACE	0
38 #define SOCKWQ_ASYNC_WAITDATA	1
39 #define SOCK_NOSPACE		2
40 #define SOCK_PASSCRED		3
41 #define SOCK_PASSSEC		4
42 
43 #ifndef ARCH_HAS_SOCKET_TYPES
44 /**
45  * enum sock_type - Socket types
46  * @SOCK_STREAM: stream (connection) socket
47  * @SOCK_DGRAM: datagram (conn.less) socket
48  * @SOCK_RAW: raw socket
49  * @SOCK_RDM: reliably-delivered message
50  * @SOCK_SEQPACKET: sequential packet socket
51  * @SOCK_DCCP: Datagram Congestion Control Protocol socket
52  * @SOCK_PACKET: linux specific way of getting packets at the dev level.
53  *		  For writing rarp and other similar things on the user level.
54  *
55  * When adding some new socket type please
56  * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
57  * overrides this enum for binary compat reasons.
58  */
59 enum sock_type {
60 	SOCK_STREAM	= 1,
61 	SOCK_DGRAM	= 2,
62 	SOCK_RAW	= 3,
63 	SOCK_RDM	= 4,
64 	SOCK_SEQPACKET	= 5,
65 	SOCK_DCCP	= 6,
66 	SOCK_PACKET	= 10,
67 };
68 
69 #define SOCK_MAX (SOCK_PACKET + 1)
70 /* Mask which covers at least up to SOCK_MASK-1.  The
71  * remaining bits are used as flags. */
72 #define SOCK_TYPE_MASK 0xf
73 
74 /* Flags for socket, socketpair, accept4 */
75 #define SOCK_CLOEXEC	O_CLOEXEC
76 #ifndef SOCK_NONBLOCK
77 #define SOCK_NONBLOCK	O_NONBLOCK
78 #endif
79 
80 #endif /* ARCH_HAS_SOCKET_TYPES */
81 
82 /**
83  * enum sock_shutdown_cmd - Shutdown types
84  * @SHUT_RD: shutdown receptions
85  * @SHUT_WR: shutdown transmissions
86  * @SHUT_RDWR: shutdown receptions/transmissions
87  */
88 enum sock_shutdown_cmd {
89 	SHUT_RD,
90 	SHUT_WR,
91 	SHUT_RDWR,
92 };
93 
94 struct socket_wq {
95 	/* Note: wait MUST be first field of socket_wq */
96 	wait_queue_head_t	wait;
97 	struct fasync_struct	*fasync_list;
98 	unsigned long		flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
99 	struct rcu_head		rcu;
100 } ____cacheline_aligned_in_smp;
101 
102 /**
103  *  struct socket - general BSD socket
104  *  @state: socket state (%SS_CONNECTED, etc)
105  *  @type: socket type (%SOCK_STREAM, etc)
106  *  @flags: socket flags (%SOCK_NOSPACE, etc)
107  *  @ops: protocol specific socket operations
108  *  @file: File back pointer for gc
109  *  @sk: internal networking protocol agnostic socket representation
110  *  @wq: wait queue for several uses
111  */
112 struct socket {
113 	socket_state		state;
114 
115 	short			type;
116 
117 	unsigned long		flags;
118 
119 	struct file		*file;
120 	struct sock		*sk;
121 	const struct proto_ops	*ops;
122 
123 	struct socket_wq	wq;
124 };
125 
126 struct vm_area_struct;
127 struct page;
128 struct sockaddr;
129 struct msghdr;
130 struct module;
131 struct sk_buff;
132 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
133 			       unsigned int, size_t);
134 
135 struct proto_ops {
136 	int		family;
137 	struct module	*owner;
138 	int		(*release)   (struct socket *sock);
139 	int		(*bind)	     (struct socket *sock,
140 				      struct sockaddr *myaddr,
141 				      int sockaddr_len);
142 	int		(*connect)   (struct socket *sock,
143 				      struct sockaddr *vaddr,
144 				      int sockaddr_len, int flags);
145 	int		(*socketpair)(struct socket *sock1,
146 				      struct socket *sock2);
147 	int		(*accept)    (struct socket *sock,
148 				      struct socket *newsock, int flags, bool kern);
149 	int		(*getname)   (struct socket *sock,
150 				      struct sockaddr *addr,
151 				      int peer);
152 	__poll_t	(*poll)	     (struct file *file, struct socket *sock,
153 				      struct poll_table_struct *wait);
154 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
155 				      unsigned long arg);
156 #ifdef CONFIG_COMPAT
157 	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
158 				      unsigned long arg);
159 #endif
160 	int		(*gettstamp) (struct socket *sock, void __user *userstamp,
161 				      bool timeval, bool time32);
162 	int		(*listen)    (struct socket *sock, int len);
163 	int		(*shutdown)  (struct socket *sock, int flags);
164 	int		(*setsockopt)(struct socket *sock, int level,
165 				      int optname, char __user *optval, unsigned int optlen);
166 	int		(*getsockopt)(struct socket *sock, int level,
167 				      int optname, char __user *optval, int __user *optlen);
168 #ifdef CONFIG_COMPAT
169 	int		(*compat_setsockopt)(struct socket *sock, int level,
170 				      int optname, char __user *optval, unsigned int optlen);
171 	int		(*compat_getsockopt)(struct socket *sock, int level,
172 				      int optname, char __user *optval, int __user *optlen);
173 #endif
174 	void		(*show_fdinfo)(struct seq_file *m, struct socket *sock);
175 	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
176 				      size_t total_len);
177 	/* Notes for implementing recvmsg:
178 	 * ===============================
179 	 * msg->msg_namelen should get updated by the recvmsg handlers
180 	 * iff msg_name != NULL. It is by default 0 to prevent
181 	 * returning uninitialized memory to user space.  The recvfrom
182 	 * handlers can assume that msg.msg_name is either NULL or has
183 	 * a minimum size of sizeof(struct sockaddr_storage).
184 	 */
185 	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
186 				      size_t total_len, int flags);
187 	int		(*mmap)	     (struct file *file, struct socket *sock,
188 				      struct vm_area_struct * vma);
189 	ssize_t		(*sendpage)  (struct socket *sock, struct page *page,
190 				      int offset, size_t size, int flags);
191 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
192 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
193 	int		(*set_peek_off)(struct sock *sk, int val);
194 	int		(*peek_len)(struct socket *sock);
195 
196 	/* The following functions are called internally by kernel with
197 	 * sock lock already held.
198 	 */
199 	int		(*read_sock)(struct sock *sk, read_descriptor_t *desc,
200 				     sk_read_actor_t recv_actor);
201 	int		(*sendpage_locked)(struct sock *sk, struct page *page,
202 					   int offset, size_t size, int flags);
203 	int		(*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
204 					  size_t size);
205 	int		(*set_rcvlowat)(struct sock *sk, int val);
206 };
207 
208 #define DECLARE_SOCKADDR(type, dst, src)	\
209 	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
210 
211 struct net_proto_family {
212 	int		family;
213 	int		(*create)(struct net *net, struct socket *sock,
214 				  int protocol, int kern);
215 	struct module	*owner;
216 };
217 
218 struct iovec;
219 struct kvec;
220 
221 enum {
222 	SOCK_WAKE_IO,
223 	SOCK_WAKE_WAITD,
224 	SOCK_WAKE_SPACE,
225 	SOCK_WAKE_URG,
226 };
227 
228 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
229 int sock_register(const struct net_proto_family *fam);
230 void sock_unregister(int family);
231 bool sock_is_registered(int family);
232 int __sock_create(struct net *net, int family, int type, int proto,
233 		  struct socket **res, int kern);
234 int sock_create(int family, int type, int proto, struct socket **res);
235 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
236 int sock_create_lite(int family, int type, int proto, struct socket **res);
237 struct socket *sock_alloc(void);
238 void sock_release(struct socket *sock);
239 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
240 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
241 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
242 struct socket *sockfd_lookup(int fd, int *err);
243 struct socket *sock_from_file(struct file *file, int *err);
244 #define		     sockfd_put(sock) fput(sock->file)
245 int net_ratelimit(void);
246 
247 #define net_ratelimited_function(function, ...)			\
248 do {								\
249 	if (net_ratelimit())					\
250 		function(__VA_ARGS__);				\
251 } while (0)
252 
253 #define net_emerg_ratelimited(fmt, ...)				\
254 	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
255 #define net_alert_ratelimited(fmt, ...)				\
256 	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
257 #define net_crit_ratelimited(fmt, ...)				\
258 	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
259 #define net_err_ratelimited(fmt, ...)				\
260 	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
261 #define net_notice_ratelimited(fmt, ...)			\
262 	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
263 #define net_warn_ratelimited(fmt, ...)				\
264 	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
265 #define net_info_ratelimited(fmt, ...)				\
266 	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
267 #if defined(CONFIG_DYNAMIC_DEBUG)
268 #define net_dbg_ratelimited(fmt, ...)					\
269 do {									\
270 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
271 	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
272 	    net_ratelimit())						\
273 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
274 		                   ##__VA_ARGS__);			\
275 } while (0)
276 #elif defined(DEBUG)
277 #define net_dbg_ratelimited(fmt, ...)				\
278 	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
279 #else
280 #define net_dbg_ratelimited(fmt, ...)				\
281 	do {							\
282 		if (0)						\
283 			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
284 	} while (0)
285 #endif
286 
287 #define net_get_random_once(buf, nbytes)			\
288 	get_random_once((buf), (nbytes))
289 #define net_get_random_once_wait(buf, nbytes)			\
290 	get_random_once_wait((buf), (nbytes))
291 
292 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
293 		   size_t num, size_t len);
294 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
295 			  struct kvec *vec, size_t num, size_t len);
296 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
297 		   size_t num, size_t len, int flags);
298 
299 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
300 int kernel_listen(struct socket *sock, int backlog);
301 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
302 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
303 		   int flags);
304 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
305 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
306 int kernel_getsockopt(struct socket *sock, int level, int optname, char *optval,
307 		      int *optlen);
308 int kernel_setsockopt(struct socket *sock, int level, int optname, char *optval,
309 		      unsigned int optlen);
310 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
311 		    size_t size, int flags);
312 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
313 			   size_t size, int flags);
314 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
315 
316 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
317 u32 kernel_sock_ip_overhead(struct sock *sk);
318 
319 #define MODULE_ALIAS_NETPROTO(proto) \
320 	MODULE_ALIAS("net-pf-" __stringify(proto))
321 
322 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
323 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
324 
325 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
326 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
327 		     "-type-" __stringify(type))
328 
329 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
330 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
331 		     name)
332 #endif	/* _LINUX_NET_H */
333