xref: /openbmc/linux/include/linux/net.h (revision 1ded5e5a)
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 #define SOCK_SUPPORT_ZC		5
45 #define SOCK_CUSTOM_SOCKOPT	6
46 #define SOCK_PASSPIDFD		7
47 
48 #ifndef ARCH_HAS_SOCKET_TYPES
49 /**
50  * enum sock_type - Socket types
51  * @SOCK_STREAM: stream (connection) socket
52  * @SOCK_DGRAM: datagram (conn.less) socket
53  * @SOCK_RAW: raw socket
54  * @SOCK_RDM: reliably-delivered message
55  * @SOCK_SEQPACKET: sequential packet socket
56  * @SOCK_DCCP: Datagram Congestion Control Protocol socket
57  * @SOCK_PACKET: linux specific way of getting packets at the dev level.
58  *		  For writing rarp and other similar things on the user level.
59  *
60  * When adding some new socket type please
61  * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
62  * overrides this enum for binary compat reasons.
63  */
64 enum sock_type {
65 	SOCK_STREAM	= 1,
66 	SOCK_DGRAM	= 2,
67 	SOCK_RAW	= 3,
68 	SOCK_RDM	= 4,
69 	SOCK_SEQPACKET	= 5,
70 	SOCK_DCCP	= 6,
71 	SOCK_PACKET	= 10,
72 };
73 
74 #define SOCK_MAX (SOCK_PACKET + 1)
75 /* Mask which covers at least up to SOCK_MASK-1.  The
76  * remaining bits are used as flags. */
77 #define SOCK_TYPE_MASK 0xf
78 
79 /* Flags for socket, socketpair, accept4 */
80 #define SOCK_CLOEXEC	O_CLOEXEC
81 #ifndef SOCK_NONBLOCK
82 #define SOCK_NONBLOCK	O_NONBLOCK
83 #endif
84 
85 #endif /* ARCH_HAS_SOCKET_TYPES */
86 
87 /**
88  * enum sock_shutdown_cmd - Shutdown types
89  * @SHUT_RD: shutdown receptions
90  * @SHUT_WR: shutdown transmissions
91  * @SHUT_RDWR: shutdown receptions/transmissions
92  */
93 enum sock_shutdown_cmd {
94 	SHUT_RD,
95 	SHUT_WR,
96 	SHUT_RDWR,
97 };
98 
99 struct socket_wq {
100 	/* Note: wait MUST be first field of socket_wq */
101 	wait_queue_head_t	wait;
102 	struct fasync_struct	*fasync_list;
103 	unsigned long		flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
104 	struct rcu_head		rcu;
105 } ____cacheline_aligned_in_smp;
106 
107 /**
108  *  struct socket - general BSD socket
109  *  @state: socket state (%SS_CONNECTED, etc)
110  *  @type: socket type (%SOCK_STREAM, etc)
111  *  @flags: socket flags (%SOCK_NOSPACE, etc)
112  *  @ops: protocol specific socket operations
113  *  @file: File back pointer for gc
114  *  @sk: internal networking protocol agnostic socket representation
115  *  @wq: wait queue for several uses
116  */
117 struct socket {
118 	socket_state		state;
119 
120 	short			type;
121 
122 	unsigned long		flags;
123 
124 	struct file		*file;
125 	struct sock		*sk;
126 	const struct proto_ops	*ops; /* Might change with IPV6_ADDRFORM or MPTCP. */
127 
128 	struct socket_wq	wq;
129 };
130 
131 /*
132  * "descriptor" for what we're up to with a read.
133  * This allows us to use the same read code yet
134  * have multiple different users of the data that
135  * we read from a file.
136  *
137  * The simplest case just copies the data to user
138  * mode.
139  */
140 typedef struct {
141 	size_t written;
142 	size_t count;
143 	union {
144 		char __user *buf;
145 		void *data;
146 	} arg;
147 	int error;
148 } read_descriptor_t;
149 
150 struct vm_area_struct;
151 struct page;
152 struct sockaddr;
153 struct msghdr;
154 struct module;
155 struct sk_buff;
156 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
157 			       unsigned int, size_t);
158 typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *);
159 
160 
161 struct proto_ops {
162 	int		family;
163 	struct module	*owner;
164 	int		(*release)   (struct socket *sock);
165 	int		(*bind)	     (struct socket *sock,
166 				      struct sockaddr *myaddr,
167 				      int sockaddr_len);
168 	int		(*connect)   (struct socket *sock,
169 				      struct sockaddr *vaddr,
170 				      int sockaddr_len, int flags);
171 	int		(*socketpair)(struct socket *sock1,
172 				      struct socket *sock2);
173 	int		(*accept)    (struct socket *sock,
174 				      struct socket *newsock, int flags, bool kern);
175 	int		(*getname)   (struct socket *sock,
176 				      struct sockaddr *addr,
177 				      int peer);
178 	__poll_t	(*poll)	     (struct file *file, struct socket *sock,
179 				      struct poll_table_struct *wait);
180 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
181 				      unsigned long arg);
182 #ifdef CONFIG_COMPAT
183 	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
184 				      unsigned long arg);
185 #endif
186 	int		(*gettstamp) (struct socket *sock, void __user *userstamp,
187 				      bool timeval, bool time32);
188 	int		(*listen)    (struct socket *sock, int len);
189 	int		(*shutdown)  (struct socket *sock, int flags);
190 	int		(*setsockopt)(struct socket *sock, int level,
191 				      int optname, sockptr_t optval,
192 				      unsigned int optlen);
193 	int		(*getsockopt)(struct socket *sock, int level,
194 				      int optname, char __user *optval, int __user *optlen);
195 	void		(*show_fdinfo)(struct seq_file *m, struct socket *sock);
196 	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
197 				      size_t total_len);
198 	/* Notes for implementing recvmsg:
199 	 * ===============================
200 	 * msg->msg_namelen should get updated by the recvmsg handlers
201 	 * iff msg_name != NULL. It is by default 0 to prevent
202 	 * returning uninitialized memory to user space.  The recvfrom
203 	 * handlers can assume that msg.msg_name is either NULL or has
204 	 * a minimum size of sizeof(struct sockaddr_storage).
205 	 */
206 	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
207 				      size_t total_len, int flags);
208 	int		(*mmap)	     (struct file *file, struct socket *sock,
209 				      struct vm_area_struct * vma);
210 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
211 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
212 	void		(*splice_eof)(struct socket *sock);
213 	int		(*set_peek_off)(struct sock *sk, int val);
214 	int		(*peek_len)(struct socket *sock);
215 
216 	/* The following functions are called internally by kernel with
217 	 * sock lock already held.
218 	 */
219 	int		(*read_sock)(struct sock *sk, read_descriptor_t *desc,
220 				     sk_read_actor_t recv_actor);
221 	/* This is different from read_sock(), it reads an entire skb at a time. */
222 	int		(*read_skb)(struct sock *sk, skb_read_actor_t recv_actor);
223 	int		(*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
224 					  size_t size);
225 	int		(*set_rcvlowat)(struct sock *sk, int val);
226 };
227 
228 #define DECLARE_SOCKADDR(type, dst, src)	\
229 	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
230 
231 struct net_proto_family {
232 	int		family;
233 	int		(*create)(struct net *net, struct socket *sock,
234 				  int protocol, int kern);
235 	struct module	*owner;
236 };
237 
238 struct iovec;
239 struct kvec;
240 
241 enum {
242 	SOCK_WAKE_IO,
243 	SOCK_WAKE_WAITD,
244 	SOCK_WAKE_SPACE,
245 	SOCK_WAKE_URG,
246 };
247 
248 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
249 int sock_register(const struct net_proto_family *fam);
250 void sock_unregister(int family);
251 bool sock_is_registered(int family);
252 int __sock_create(struct net *net, int family, int type, int proto,
253 		  struct socket **res, int kern);
254 int sock_create(int family, int type, int proto, struct socket **res);
255 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
256 int sock_create_lite(int family, int type, int proto, struct socket **res);
257 struct socket *sock_alloc(void);
258 void sock_release(struct socket *sock);
259 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
260 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
261 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
262 struct socket *sockfd_lookup(int fd, int *err);
263 struct socket *sock_from_file(struct file *file);
264 #define		     sockfd_put(sock) fput(sock->file)
265 int net_ratelimit(void);
266 
267 #define net_ratelimited_function(function, ...)			\
268 do {								\
269 	if (net_ratelimit())					\
270 		function(__VA_ARGS__);				\
271 } while (0)
272 
273 #define net_emerg_ratelimited(fmt, ...)				\
274 	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
275 #define net_alert_ratelimited(fmt, ...)				\
276 	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
277 #define net_crit_ratelimited(fmt, ...)				\
278 	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
279 #define net_err_ratelimited(fmt, ...)				\
280 	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
281 #define net_notice_ratelimited(fmt, ...)			\
282 	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
283 #define net_warn_ratelimited(fmt, ...)				\
284 	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
285 #define net_info_ratelimited(fmt, ...)				\
286 	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
287 #if defined(CONFIG_DYNAMIC_DEBUG) || \
288 	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
289 #define net_dbg_ratelimited(fmt, ...)					\
290 do {									\
291 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
292 	if (DYNAMIC_DEBUG_BRANCH(descriptor) &&				\
293 	    net_ratelimit())						\
294 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
295 		                   ##__VA_ARGS__);			\
296 } while (0)
297 #elif defined(DEBUG)
298 #define net_dbg_ratelimited(fmt, ...)				\
299 	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
300 #else
301 #define net_dbg_ratelimited(fmt, ...)				\
302 	do {							\
303 		if (0)						\
304 			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
305 	} while (0)
306 #endif
307 
308 #define net_get_random_once(buf, nbytes)			\
309 	get_random_once((buf), (nbytes))
310 
311 /*
312  * E.g. XFS meta- & log-data is in slab pages, or bcache meta
313  * data pages, or other high order pages allocated by
314  * __get_free_pages() without __GFP_COMP, which have a page_count
315  * of 0 and/or have PageSlab() set. We cannot use send_page for
316  * those, as that does get_page(); put_page(); and would cause
317  * either a VM_BUG directly, or __page_cache_release a page that
318  * would actually still be referenced by someone, leading to some
319  * obscure delayed Oops somewhere else.
320  */
sendpage_ok(struct page * page)321 static inline bool sendpage_ok(struct page *page)
322 {
323 	return !PageSlab(page) && page_count(page) >= 1;
324 }
325 
326 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
327 		   size_t num, size_t len);
328 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
329 			  struct kvec *vec, size_t num, size_t len);
330 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
331 		   size_t num, size_t len, int flags);
332 
333 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
334 int kernel_listen(struct socket *sock, int backlog);
335 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
336 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
337 		   int flags);
338 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
339 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
340 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
341 
342 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
343 u32 kernel_sock_ip_overhead(struct sock *sk);
344 
345 #define MODULE_ALIAS_NETPROTO(proto) \
346 	MODULE_ALIAS("net-pf-" __stringify(proto))
347 
348 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
349 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
350 
351 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
352 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
353 		     "-type-" __stringify(type))
354 
355 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
356 	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
357 		     name)
358 #endif	/* _LINUX_NET_H */
359