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#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 */
64enum 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 */
93enum sock_shutdown_cmd {
94 SHUT_RD,
95 SHUT_WR,
96 SHUT_RDWR,
97};
98
99struct 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 */
117struct 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 */
140typedef 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
150struct vm_area_struct;
151struct page;
152struct sockaddr;
153struct msghdr;
154struct module;
155struct sk_buff;
156typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
157 unsigned int, size_t);
158typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *);
159
160
161struct 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
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 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
303#endif
304
305#define net_get_random_once(buf, nbytes) \
306 get_random_once((buf), (nbytes))
307
308/*
309 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
310 * data pages, or other high order pages allocated by
311 * __get_free_pages() without __GFP_COMP, which have a page_count
312 * of 0 and/or have PageSlab() set. We cannot use send_page for
313 * those, as that does get_page(); put_page(); and would cause
314 * either a VM_BUG directly, or __page_cache_release a page that
315 * would actually still be referenced by someone, leading to some
316 * obscure delayed Oops somewhere else.
317 */
318static inline bool sendpage_ok(struct page *page)
319{
320 return !PageSlab(page) && page_count(page) >= 1;
321}
322
323int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
324 size_t num, size_t len);
325int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
326 struct kvec *vec, size_t num, size_t len);
327int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
328 size_t num, size_t len, int flags);
329
330int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
331int kernel_listen(struct socket *sock, int backlog);
332int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
333int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
334 int flags);
335int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
336int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
337int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
338
339/* Routine returns the IP overhead imposed by a (caller-protected) socket. */
340u32 kernel_sock_ip_overhead(struct sock *sk);
341
342#define MODULE_ALIAS_NETPROTO(proto) \
343 MODULE_ALIAS("net-pf-" __stringify(proto))
344
345#define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
346 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
347
348#define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
349 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
350 "-type-" __stringify(type))
351
352#define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
353 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
354 name)
355#endif /* _LINUX_NET_H */
356

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