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 */
39enum socket_flags {
40 SOCKWQ_ASYNC_NOSPACE,
41 SOCKWQ_ASYNC_WAITDATA,
42 SOCK_NOSPACE,
43 SOCK_SUPPORT_ZC,
44 SOCK_CUSTOM_SOCKOPT,
45};
46
47#ifndef ARCH_HAS_SOCKET_TYPES
48/**
49 * enum sock_type - Socket types
50 * @SOCK_STREAM: stream (connection) socket
51 * @SOCK_DGRAM: datagram (conn.less) socket
52 * @SOCK_RAW: raw socket
53 * @SOCK_RDM: reliably-delivered message
54 * @SOCK_SEQPACKET: sequential packet socket
55 * @SOCK_DCCP: Datagram Congestion Control Protocol socket
56 * @SOCK_PACKET: linux specific way of getting packets at the dev level.
57 * For writing rarp and other similar things on the user level.
58 *
59 * When adding some new socket type please
60 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
61 * overrides this enum for binary compat reasons.
62 */
63enum sock_type {
64 SOCK_STREAM = 1,
65 SOCK_DGRAM = 2,
66 SOCK_RAW = 3,
67 SOCK_RDM = 4,
68 SOCK_SEQPACKET = 5,
69 SOCK_DCCP = 6,
70 SOCK_PACKET = 10,
71};
72#endif /* ARCH_HAS_SOCKET_TYPES */
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#define SOCK_COREDUMP O_NOCTTY
85
86/**
87 * enum sock_shutdown_cmd - Shutdown types
88 * @SHUT_RD: shutdown receptions
89 * @SHUT_WR: shutdown transmissions
90 * @SHUT_RDWR: shutdown receptions/transmissions
91 */
92enum sock_shutdown_cmd {
93 SHUT_RD,
94 SHUT_WR,
95 SHUT_RDWR,
96};
97
98struct socket_wq {
99 /* Note: wait MUST be first field of socket_wq */
100 wait_queue_head_t wait;
101 struct fasync_struct *fasync_list;
102 unsigned long flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
103 struct rcu_head rcu;
104} ____cacheline_aligned_in_smp;
105
106/**
107 * struct socket - general BSD socket
108 * @state: socket state (%SS_CONNECTED, etc)
109 * @type: socket type (%SOCK_STREAM, etc)
110 * @flags: socket flags (%SOCK_NOSPACE, etc)
111 * @ops: protocol specific socket operations
112 * @file: File back pointer for gc
113 * @sk: internal networking protocol agnostic socket representation
114 * @wq: wait queue for several uses
115 */
116struct socket {
117 socket_state state;
118
119 short type;
120
121 unsigned long flags;
122
123 struct file *file;
124 struct sock *sk;
125 const struct proto_ops *ops; /* Might change with IPV6_ADDRFORM or MPTCP. */
126
127 struct socket_wq wq;
128};
129
130/*
131 * "descriptor" for what we're up to with a read.
132 * This allows us to use the same read code yet
133 * have multiple different users of the data that
134 * we read from a file.
135 *
136 * The simplest case just copies the data to user
137 * mode.
138 */
139typedef struct {
140 size_t written;
141 size_t count;
142 union {
143 char __user *buf;
144 void *data;
145 } arg;
146 int error;
147} read_descriptor_t;
148
149struct vm_area_struct;
150struct page;
151struct sockaddr;
152struct msghdr;
153struct module;
154struct sk_buff;
155struct proto_accept_arg;
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,
175 struct proto_accept_arg *arg);
176 int (*getname) (struct socket *sock,
177 struct sockaddr *addr,
178 int peer);
179 __poll_t (*poll) (struct file *file, struct socket *sock,
180 struct poll_table_struct *wait);
181 int (*ioctl) (struct socket *sock, unsigned int cmd,
182 unsigned long arg);
183#ifdef CONFIG_COMPAT
184 int (*compat_ioctl) (struct socket *sock, unsigned int cmd,
185 unsigned long arg);
186#endif
187 int (*gettstamp) (struct socket *sock, void __user *userstamp,
188 bool timeval, bool time32);
189 int (*listen) (struct socket *sock, int len);
190 int (*shutdown) (struct socket *sock, int flags);
191 int (*setsockopt)(struct socket *sock, int level,
192 int optname, sockptr_t optval,
193 unsigned int optlen);
194 int (*getsockopt)(struct socket *sock, int level,
195 int optname, char __user *optval, int __user *optlen);
196 void (*show_fdinfo)(struct seq_file *m, struct socket *sock);
197 int (*sendmsg) (struct socket *sock, struct msghdr *m,
198 size_t total_len);
199 /* Notes for implementing recvmsg:
200 * ===============================
201 * msg->msg_namelen should get updated by the recvmsg handlers
202 * iff msg_name != NULL. It is by default 0 to prevent
203 * returning uninitialized memory to user space. The recvfrom
204 * handlers can assume that msg.msg_name is either NULL or has
205 * a minimum size of sizeof(struct sockaddr_storage).
206 */
207 int (*recvmsg) (struct socket *sock, struct msghdr *m,
208 size_t total_len, int flags);
209 int (*mmap) (struct file *file, struct socket *sock,
210 struct vm_area_struct * vma);
211 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
212 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
213 void (*splice_eof)(struct socket *sock);
214 int (*set_peek_off)(struct sock *sk, int val);
215 int (*peek_len)(struct socket *sock);
216
217 /* The following functions are called internally by kernel with
218 * sock lock already held.
219 */
220 int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
221 sk_read_actor_t recv_actor);
222 /* This is different from read_sock(), it reads an entire skb at a time. */
223 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor);
224 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
225 size_t size);
226 int (*set_rcvlowat)(struct sock *sk, int val);
227};
228
229#define DECLARE_SOCKADDR(type, dst, src) \
230 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
231
232struct net_proto_family {
233 int family;
234 int (*create)(struct net *net, struct socket *sock,
235 int protocol, int kern);
236 struct module *owner;
237};
238
239struct iovec;
240struct kvec;
241
242enum {
243 SOCK_WAKE_IO,
244 SOCK_WAKE_WAITD,
245 SOCK_WAKE_SPACE,
246 SOCK_WAKE_URG,
247};
248
249int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
250int sock_register(const struct net_proto_family *fam);
251void sock_unregister(int family);
252bool sock_is_registered(int family);
253int __sock_create(struct net *net, int family, int type, int proto,
254 struct socket **res, int kern);
255int sock_create(int family, int type, int proto, struct socket **res);
256int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
257int sock_create_lite(int family, int type, int proto, struct socket **res);
258struct socket *sock_alloc(void);
259void sock_release(struct socket *sock);
260int sock_sendmsg(struct socket *sock, struct msghdr *msg);
261int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
262struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
263struct socket *sockfd_lookup(int fd, int *err);
264struct socket *sock_from_file(struct file *file);
265#define sockfd_put(sock) fput(sock->file)
266int net_ratelimit(void);
267
268#define net_ratelimited_function(function, ...) \
269do { \
270 if (net_ratelimit()) \
271 function(__VA_ARGS__); \
272} while (0)
273
274#define net_emerg_ratelimited(fmt, ...) \
275 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
276#define net_alert_ratelimited(fmt, ...) \
277 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
278#define net_crit_ratelimited(fmt, ...) \
279 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
280#define net_err_ratelimited(fmt, ...) \
281 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
282#define net_notice_ratelimited(fmt, ...) \
283 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
284#define net_warn_ratelimited(fmt, ...) \
285 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
286#define net_info_ratelimited(fmt, ...) \
287 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
288#if defined(CONFIG_DYNAMIC_DEBUG) || \
289 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
290#define net_dbg_ratelimited(fmt, ...) \
291do { \
292 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
293 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \
294 net_ratelimit()) \
295 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
296 ##__VA_ARGS__); \
297} while (0)
298#elif defined(DEBUG)
299#define net_dbg_ratelimited(fmt, ...) \
300 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
301#else
302#define net_dbg_ratelimited(fmt, ...) \
303 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
304#endif
305
306#define net_get_random_once(buf, nbytes) \
307 get_random_once((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 */
319static inline bool sendpage_ok(struct page *page)
320{
321 return !PageSlab(page) && page_count(page) >= 1;
322}
323
324/*
325 * Check sendpage_ok on contiguous pages.
326 */
327static inline bool sendpages_ok(struct page *page, size_t len, size_t offset)
328{
329 struct page *p = page + (offset >> PAGE_SHIFT);
330 size_t count = 0;
331
332 while (count < len) {
333 if (!sendpage_ok(page: p))
334 return false;
335
336 p++;
337 count += PAGE_SIZE;
338 }
339
340 return true;
341}
342
343int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
344 size_t num, size_t len);
345int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
346 size_t num, size_t len, int flags);
347
348int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
349int kernel_listen(struct socket *sock, int backlog);
350int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
351int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
352 int flags);
353int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
354int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
355int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
356
357/* Routine returns the IP overhead imposed by a (caller-protected) socket. */
358u32 kernel_sock_ip_overhead(struct sock *sk);
359
360#define MODULE_ALIAS_NETPROTO(proto) \
361 MODULE_ALIAS("net-pf-" __stringify(proto))
362
363#define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
364 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
365
366#define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
367 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
368 "-type-" __stringify(type))
369
370#define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
371 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
372 name)
373#endif /* _LINUX_NET_H */
374