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