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
29struct poll_table_struct;
30struct pipe_inode_info;
31struct inode;
32struct file;
33struct 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 */
61enum 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 */
90enum sock_shutdown_cmd {
91 SHUT_RD,
92 SHUT_WR,
93 SHUT_RDWR,
94};
95
96struct 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 */
114struct 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 */
137typedef 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
147struct vm_area_struct;
148struct page;
149struct sockaddr;
150struct msghdr;
151struct module;
152struct sk_buff;
153typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
154 unsigned int, size_t);
155typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *);
156
157
158struct proto_ops {
159 int family;
160 struct module *owner;
161 int (*release) (struct socket *sock);
162 int (*bind) (struct socket *sock,
163 struct sockaddr *myaddr,
164 int sockaddr_len);
165 int (*connect) (struct socket *sock,
166 struct sockaddr *vaddr,
167 int sockaddr_len, int flags);
168 int (*socketpair)(struct socket *sock1,
169 struct socket *sock2);
170 int (*accept) (struct socket *sock,
171 struct socket *newsock, int flags, bool kern);
172 int (*getname) (struct socket *sock,
173 struct sockaddr *addr,
174 int peer);
175 __poll_t (*poll) (struct file *file, struct socket *sock,
176 struct poll_table_struct *wait);
177 int (*ioctl) (struct socket *sock, unsigned int cmd,
178 unsigned long arg);
179#ifdef CONFIG_COMPAT
180 int (*compat_ioctl) (struct socket *sock, unsigned int cmd,
181 unsigned long arg);
182#endif
183 int (*gettstamp) (struct socket *sock, void __user *userstamp,
184 bool timeval, bool time32);
185 int (*listen) (struct socket *sock, int len);
186 int (*shutdown) (struct socket *sock, int flags);
187 int (*setsockopt)(struct socket *sock, int level,
188 int optname, sockptr_t optval,
189 unsigned int optlen);
190 int (*getsockopt)(struct socket *sock, int level,
191 int optname, char __user *optval, int __user *optlen);
192 void (*show_fdinfo)(struct seq_file *m, struct socket *sock);
193 int (*sendmsg) (struct socket *sock, struct msghdr *m,
194 size_t total_len);
195 /* Notes for implementing recvmsg:
196 * ===============================
197 * msg->msg_namelen should get updated by the recvmsg handlers
198 * iff msg_name != NULL. It is by default 0 to prevent
199 * returning uninitialized memory to user space. The recvfrom
200 * handlers can assume that msg.msg_name is either NULL or has
201 * a minimum size of sizeof(struct sockaddr_storage).
202 */
203 int (*recvmsg) (struct socket *sock, struct msghdr *m,
204 size_t total_len, int flags);
205 int (*mmap) (struct file *file, struct socket *sock,
206 struct vm_area_struct * vma);
207 ssize_t (*sendpage) (struct socket *sock, struct page *page,
208 int offset, size_t size, int flags);
209 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
210 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
211 int (*set_peek_off)(struct sock *sk, int val);
212 int (*peek_len)(struct socket *sock);
213
214 /* The following functions are called internally by kernel with
215 * sock lock already held.
216 */
217 int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
218 sk_read_actor_t recv_actor);
219 /* This is different from read_sock(), it reads an entire skb at a time. */
220 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor);
221 int (*sendpage_locked)(struct sock *sk, struct page *page,
222 int offset, size_t size, int flags);
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
231struct 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
238struct iovec;
239struct kvec;
240
241enum {
242 SOCK_WAKE_IO,
243 SOCK_WAKE_WAITD,
244 SOCK_WAKE_SPACE,
245 SOCK_WAKE_URG,
246};
247
248int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
249int sock_register(const struct net_proto_family *fam);
250void sock_unregister(int family);
251bool sock_is_registered(int family);
252int __sock_create(struct net *net, int family, int type, int proto,
253 struct socket **res, int kern);
254int sock_create(int family, int type, int proto, struct socket **res);
255int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
256int sock_create_lite(int family, int type, int proto, struct socket **res);
257struct socket *sock_alloc(void);
258void sock_release(struct socket *sock);
259int sock_sendmsg(struct socket *sock, struct msghdr *msg);
260int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
261struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
262struct socket *sockfd_lookup(int fd, int *err);
263struct socket *sock_from_file(struct file *file);
264#define sockfd_put(sock) fput(sock->file)
265int net_ratelimit(void);
266
267#define net_ratelimited_function(function, ...) \
268do { \
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, ...) \
290do { \
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 */
321static inline bool sendpage_ok(struct page *page)
322{
323 return !PageSlab(page) && page_count(page) >= 1;
324}
325
326int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
327 size_t num, size_t len);
328int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
329 struct kvec *vec, size_t num, size_t len);
330int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
331 size_t num, size_t len, int flags);
332
333int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
334int kernel_listen(struct socket *sock, int backlog);
335int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
336int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
337 int flags);
338int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
339int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
340int kernel_sendpage(struct socket *sock, struct page *page, int offset,
341 size_t size, int flags);
342int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
343 size_t size, int flags);
344int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
345
346/* Routine returns the IP overhead imposed by a (caller-protected) socket. */
347u32 kernel_sock_ip_overhead(struct sock *sk);
348
349#define MODULE_ALIAS_NETPROTO(proto) \
350 MODULE_ALIAS("net-pf-" __stringify(proto))
351
352#define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
353 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
354
355#define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
356 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
357 "-type-" __stringify(type))
358
359#define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
360 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
361 name)
362#endif /* _LINUX_NET_H */
363

source code of linux/include/linux/net.h