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, <obz@Kodak.COM>
11  *		Ross Biro
12  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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/mm.h>
25 #include <linux/sockptr.h>
26 
27 #include <uapi/linux/net.h>
28 
29 struct poll_table_struct;
30 struct pipe_inode_info;
31 struct inode;
32 struct file;
33 struct net;
34 
35 /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
36  * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
37  * Eventually all flags will be in sk->sk_wq->flags.
38  */
39 #define SOCKWQ_ASYNC_NOSPACE	0
40 #define SOCKWQ_ASYNC_WAITDATA	1
41 #define SOCK_NOSPACE		2
42 #define SOCK_PASSCRED		3
43 #define SOCK_PASSSEC		4
44 
45 #ifndef ARCH_HAS_SOCKET_TYPES
46 /**
47  * enum sock_type - Socket types
48  * @SOCK_STREAM: stream (connection) socket
49  * @SOCK_DGRAM: datagram (conn.less) socket
50  * @SOCK_RAW: raw socket
51  * @SOCK_RDM: reliably-delivered message
52  * @SOCK_SEQPACKET: sequential packet socket
53  * @SOCK_DCCP: Datagram Congestion Control Protocol socket
54  * @SOCK_PACKET: linux specific way of getting packets at the dev level.
55  *		  For writing rarp and other similar things on the user level.
56  *
57  * When adding some new socket type please
58  * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
59  * overrides this enum for binary compat reasons.
60  */
61 enum sock_type {
62 	SOCK_STREAM	= 1,
63 	SOCK_DGRAM	= 2,
64 	SOCK_RAW	= 3,
65 	SOCK_RDM	= 4,
66 	SOCK_SEQPACKET	= 5,
67 	SOCK_DCCP	= 6,
68 	SOCK_PACKET	= 10,
69 };
70 
71 #define SOCK_MAX (SOCK_PACKET + 1)
72 /* Mask which covers at least up to SOCK_MASK-1.  The
73  * remaining bits are used as flags. */
74 #define SOCK_TYPE_MASK 0xf
75 
76 /* Flags for socket, socketpair, accept4 */
77 #define SOCK_CLOEXEC	O_CLOEXEC
78 #ifndef SOCK_NONBLOCK
79 #define SOCK_NONBLOCK	O_NONBLOCK
80 #endif
81 
82 #endif /* ARCH_HAS_SOCKET_TYPES */
83 
84 /**
85  * enum sock_shutdown_cmd - Shutdown types
86  * @SHUT_RD: shutdown receptions
87  * @SHUT_WR: shutdown transmissions
88  * @SHUT_RDWR: shutdown receptions/transmissions
89  */
90 enum sock_shutdown_cmd {
91 	SHUT_RD,
92 	SHUT_WR,
93 	SHUT_RDWR,
94 };
95 
96 struct socket_wq {
97 	/* Note: wait MUST be first field of socket_wq */
98 	wait_queue_head_t	wait;
99 	struct fasync_struct	*fasync_list;
100 	unsigned long		flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
101 	struct rcu_head		rcu;
102 } ____cacheline_aligned_in_smp;
103 
104 /**
105  *  struct socket - general BSD socket
106  *  @state: socket state (%SS_CONNECTED, etc)
107  *  @type: socket type (%SOCK_STREAM, etc)
108  *  @flags: socket flags (%SOCK_NOSPACE, etc)
109  *  @ops: protocol specific socket operations
110  *  @file: File back pointer for gc
111  *  @sk: internal networking protocol agnostic socket representation
112  *  @wq: wait queue for several uses
113  */
114 struct socket {
115 	socket_state		state;
116 
117 	short			type;
118 
119 	unsigned long		flags;
120 
121 	struct file		*file;
122 	struct sock		*sk;
123 	const struct proto_ops	*ops;
124 
125 	struct socket_wq	wq;
126 };
127 
128 /*
129  * "descriptor" for what we're up to with a read.
130  * This allows us to use the same read code yet
131  * have multiple different users of the data that
132  * we read from a file.
133  *
134  * The simplest case just copies the data to user
135  * mode.
136  */
137 typedef struct {
138 	size_t written;
139 	size_t count;
140 	union {
141 		char __user *buf;
142 		void *data;
143 	} arg;
144 	int error;
145 } read_descriptor_t;
146 
147 struct vm_area_struct;
148 struct page;
149 struct sockaddr;
150 struct msghdr;
151 struct module;
152 struct sk_buff;
153 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
154 			       unsigned int, size_t);
155 
156 struct proto_ops {
157 	int		family;
158 	struct module	*owner;
159 	int		(*release)   (struct socket *sock);
160 	int		(*bind)	     (struct socket *sock,
161 				      struct sockaddr *myaddr,
162 				      int sockaddr_len);
163 	int		(*connect)   (struct socket *sock,
164 				      struct sockaddr *vaddr,
165 				      int sockaddr_len, int flags);
166 	int		(*socketpair)(struct socket *sock1,
167 				      struct socket *sock2);
168 	int		(*accept)    (struct socket *sock,
169 				      struct socket *newsock, int flags, bool kern);
170 	int		(*getname)   (struct socket *sock,
171 				      struct sockaddr *addr,
172 				      int peer);
173 	__poll_t	(*poll)	     (struct file *file, struct socket *sock,
174 				      struct poll_table_struct *wait);
175 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
176 				      unsigned long arg);
177 #ifdef CONFIG_COMPAT
178 	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
179 				      unsigned long arg);
180 #endif
181 	int		(*gettstamp) (struct socket *sock, void __user *userstamp,
182 				      bool timeval, bool time32);
183 	int		(*listen)    (struct socket *sock, int len);
184 	int		(*shutdown)  (struct socket *sock, int flags);
185 	int		(*setsockopt)(struct socket *sock, int level,
186 				      int optname, sockptr_t optval,
187 				      unsigned int optlen);
188 	int		(*getsockopt)(struct socket *sock, int level,
189 				      int optname, char __user *optval, int __user *optlen);
190 	void		(*show_fdinfo)(struct seq_file *m, struct socket *sock);
191 	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
192 				      size_t total_len);
193 	/* Notes for implementing recvmsg:
194 	 * ===============================
195 	 * msg->msg_namelen should get updated by the recvmsg handlers
196 	 * iff msg_name != NULL. It is by default 0 to prevent
197 	 * returning uninitialized memory to user space.  The recvfrom
198 	 * handlers can assume that msg.msg_name is either NULL or has
199 	 * a minimum size of sizeof(struct sockaddr_storage).
200 	 */
201 	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
202 				      size_t total_len, int flags);
203 	int		(*mmap)	     (struct file *file, struct socket *sock,
204 				      struct vm_area_struct * vma);
205 	ssize_t		(*sendpage)  (struct socket *sock, struct page *page,
206 				      int offset, size_t size, int flags);
207 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
208 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
209 	int		(*set_peek_off)(struct sock *sk, int val);
210 	int		(*peek_len)(struct socket *sock);
211 
212 	/* The following functions are called internally by kernel with
213 	 * sock lock already held.
214 	 */
215 	int		(*read_sock)(struct sock *sk, read_descriptor_t *desc,
216 				     sk_read_actor_t recv_actor);
217 	int		(*sendpage_locked)(struct sock *sk, struct page *page,
218 					   int offset, size_t size, int flags);
219 	int		(*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
220 					  size_t size);
221 	int		(*set_rcvlowat)(struct sock *sk, int val);
222 };
223 
224 #define DECLARE_SOCKADDR(type, dst, src)	\
225 	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
226 
227 struct net_proto_family {
228 	int		family;
229 	int		(*create)(struct net *net, struct socket *sock,
230 				  int protocol, int kern);
231 	struct module	*owner;
232 };
233 
234 struct iovec;
235 struct kvec;
236 
237 enum {
238 	SOCK_WAKE_IO,
239 	SOCK_WAKE_WAITD,
240 	SOCK_WAKE_SPACE,
241 	SOCK_WAKE_URG,
242 };
243 
244 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
245 int sock_register(const struct net_proto_family *fam);
246 void sock_unregister(int family);
247 bool sock_is_registered(int family);
248 int __sock_create(struct net *net, int family, int type, int proto,
249 		  struct socket **res, int kern);
250 int sock_create(int family, int type, int proto, struct socket **res);
251 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
252 int sock_create_lite(int family, int type, int proto, struct socket **res);
253 struct socket *sock_alloc(void);
254 void sock_release(struct socket *sock);
255 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
256 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
257 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
258 struct socket *sockfd_lookup(int fd, int *err);
259 struct socket *sock_from_file(struct file *file);
260 #define		     sockfd_put(sock) fput(sock->file)
261 int net_ratelimit(void);
262 
263 #define net_ratelimited_function(function, ...)			\
264 do {								\
265 	if (net_ratelimit())					\
266 		function(__VA_ARGS__);				\
267 } while (0)
268 
269 #define net_emerg_ratelimited(fmt, ...)				\
270 	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
271 #define net_alert_ratelimited(fmt, ...)				\
272 	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
273 #define net_crit_ratelimited(fmt, ...)				\
274 	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
275 #define net_err_ratelimited(fmt, ...)				\
276 	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
277 #define net_notice_ratelimited(fmt, ...)			\
278 	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
279 #define net_warn_ratelimited(fmt, ...)				\
280 	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
281 #define net_info_ratelimited(fmt, ...)				\
282 	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
283 #if defined(CONFIG_DYNAMIC_DEBUG) || \
284 	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
285 #define net_dbg_ratelimited(fmt, ...)					\
286 do {									\
287 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
288 	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
289 	    net_ratelimit())						\
290 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
291 		                   ##__VA_ARGS__);			\
292 } while (0)
293 #elif defined(DEBUG)
294 #define net_dbg_ratelimited(fmt, ...)				\
295 	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
296 #else
297 #define net_dbg_ratelimited(fmt, ...)				\
298 	do {							\
299 		if (0)						\
300 			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
301 	} while (0)
302 #endif
303 
304 #define net_get_random_once(buf, nbytes)			\
305 	get_random_once((buf), (nbytes))
306 #define net_get_random_once_wait(buf, nbytes)			\
307 	get_random_once_wait((buf), (nbytes))
308 
309 /*
310  * E.g. XFS meta- & log-data is in slab pages, or bcache meta
311  * data pages, or other high order pages allocated by
312  * __get_free_pages() without __GFP_COMP, which have a page_count
313  * of 0 and/or have PageSlab() set. We cannot use send_page for
314  * those, as that does get_page(); put_page(); and would cause
315  * either a VM_BUG directly, or __page_cache_release a page that
316  * would actually still be referenced by someone, leading to some
317  * obscure delayed Oops somewhere else.
318  */
sendpage_ok(struct page * page)319 static inline bool sendpage_ok(struct page *page)
320 {
321 	return !PageSlab(page) && page_count(page) >= 1;
322 }
323 
324 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
325 		   size_t num, size_t len);
326 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
327 			  struct kvec *vec, size_t num, size_t len);
328 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
329 		   size_t num, size_t len, int flags);
330 
331 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
332 int kernel_listen(struct socket *sock, int backlog);
333 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
334 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
335 		   int flags);
336 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
337 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
338 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
339 		    size_t size, int flags);
340 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
341 			   size_t size, int flags);
342 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
343 
344 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
345 u32 kernel_sock_ip_overhead(struct sock *sk);
346 
347 #define MODULE_ALIAS_NETPROTO(proto) \
348 	MODULE_ALIAS("net-pf-" __stringify(proto))
349 
350 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
351 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
352 
353 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
354 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
355 		     "-type-" __stringify(type))
356 
357 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
358 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
359 		     name)
360 #endif	/* _LINUX_NET_H */
361