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 #define PROTO_CMSG_DATA_ONLY 0x0001
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 */
63 enum 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
73 #define SOCK_MAX (SOCK_PACKET + 1)
74 /* Mask which covers at least up to SOCK_MASK-1. The
75 * remaining bits are used as flags. */
76 #define SOCK_TYPE_MASK 0xf
77
78 /* Flags for socket, socketpair, accept4 */
79 #define SOCK_CLOEXEC O_CLOEXEC
80 #ifndef SOCK_NONBLOCK
81 #define SOCK_NONBLOCK O_NONBLOCK
82 #endif
83
84 #endif /* ARCH_HAS_SOCKET_TYPES */
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 */
92 enum sock_shutdown_cmd {
93 SHUT_RD,
94 SHUT_WR,
95 SHUT_RDWR,
96 };
97
98 struct 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 */
116 struct 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;
126
127 struct socket_wq wq;
128 };
129
130 struct vm_area_struct;
131 struct page;
132 struct sockaddr;
133 struct msghdr;
134 struct module;
135 struct sk_buff;
136 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
137 unsigned int, size_t);
138
139 struct proto_ops {
140 int family;
141 unsigned int flags;
142 struct module *owner;
143 int (*release) (struct socket *sock);
144 int (*bind) (struct socket *sock,
145 struct sockaddr *myaddr,
146 int sockaddr_len);
147 int (*connect) (struct socket *sock,
148 struct sockaddr *vaddr,
149 int sockaddr_len, int flags);
150 int (*socketpair)(struct socket *sock1,
151 struct socket *sock2);
152 int (*accept) (struct socket *sock,
153 struct socket *newsock, int flags, bool kern);
154 int (*getname) (struct socket *sock,
155 struct sockaddr *addr,
156 int peer);
157 __poll_t (*poll) (struct file *file, struct socket *sock,
158 struct poll_table_struct *wait);
159 int (*ioctl) (struct socket *sock, unsigned int cmd,
160 unsigned long arg);
161 #ifdef CONFIG_COMPAT
162 int (*compat_ioctl) (struct socket *sock, unsigned int cmd,
163 unsigned long arg);
164 #endif
165 int (*gettstamp) (struct socket *sock, void __user *userstamp,
166 bool timeval, bool time32);
167 int (*listen) (struct socket *sock, int len);
168 int (*shutdown) (struct socket *sock, int flags);
169 int (*setsockopt)(struct socket *sock, int level,
170 int optname, sockptr_t optval,
171 unsigned int optlen);
172 int (*getsockopt)(struct socket *sock, int level,
173 int optname, char __user *optval, int __user *optlen);
174 void (*show_fdinfo)(struct seq_file *m, struct socket *sock);
175 int (*sendmsg) (struct socket *sock, struct msghdr *m,
176 size_t total_len);
177 /* Notes for implementing recvmsg:
178 * ===============================
179 * msg->msg_namelen should get updated by the recvmsg handlers
180 * iff msg_name != NULL. It is by default 0 to prevent
181 * returning uninitialized memory to user space. The recvfrom
182 * handlers can assume that msg.msg_name is either NULL or has
183 * a minimum size of sizeof(struct sockaddr_storage).
184 */
185 int (*recvmsg) (struct socket *sock, struct msghdr *m,
186 size_t total_len, int flags);
187 int (*mmap) (struct file *file, struct socket *sock,
188 struct vm_area_struct * vma);
189 ssize_t (*sendpage) (struct socket *sock, struct page *page,
190 int offset, size_t size, int flags);
191 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
192 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
193 int (*set_peek_off)(struct sock *sk, int val);
194 int (*peek_len)(struct socket *sock);
195
196 /* The following functions are called internally by kernel with
197 * sock lock already held.
198 */
199 int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
200 sk_read_actor_t recv_actor);
201 int (*sendpage_locked)(struct sock *sk, struct page *page,
202 int offset, size_t size, int flags);
203 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
204 size_t size);
205 int (*set_rcvlowat)(struct sock *sk, int val);
206 };
207
208 #define DECLARE_SOCKADDR(type, dst, src) \
209 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
210
211 struct net_proto_family {
212 int family;
213 int (*create)(struct net *net, struct socket *sock,
214 int protocol, int kern);
215 struct module *owner;
216 };
217
218 struct iovec;
219 struct kvec;
220
221 enum {
222 SOCK_WAKE_IO,
223 SOCK_WAKE_WAITD,
224 SOCK_WAKE_SPACE,
225 SOCK_WAKE_URG,
226 };
227
228 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
229 int sock_register(const struct net_proto_family *fam);
230 void sock_unregister(int family);
231 bool sock_is_registered(int family);
232 int __sock_create(struct net *net, int family, int type, int proto,
233 struct socket **res, int kern);
234 int sock_create(int family, int type, int proto, struct socket **res);
235 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
236 int sock_create_lite(int family, int type, int proto, struct socket **res);
237 struct socket *sock_alloc(void);
238 void sock_release(struct socket *sock);
239 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
240 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
241 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
242 struct socket *sockfd_lookup(int fd, int *err);
243 struct socket *sock_from_file(struct file *file, int *err);
244 #define sockfd_put(sock) fput(sock->file)
245 int net_ratelimit(void);
246
247 #define net_ratelimited_function(function, ...) \
248 do { \
249 if (net_ratelimit()) \
250 function(__VA_ARGS__); \
251 } while (0)
252
253 #define net_emerg_ratelimited(fmt, ...) \
254 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
255 #define net_alert_ratelimited(fmt, ...) \
256 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
257 #define net_crit_ratelimited(fmt, ...) \
258 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
259 #define net_err_ratelimited(fmt, ...) \
260 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
261 #define net_notice_ratelimited(fmt, ...) \
262 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
263 #define net_warn_ratelimited(fmt, ...) \
264 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
265 #define net_info_ratelimited(fmt, ...) \
266 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
267 #if defined(CONFIG_DYNAMIC_DEBUG) || \
268 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
269 #define net_dbg_ratelimited(fmt, ...) \
270 do { \
271 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
272 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \
273 net_ratelimit()) \
274 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
275 ##__VA_ARGS__); \
276 } while (0)
277 #elif defined(DEBUG)
278 #define net_dbg_ratelimited(fmt, ...) \
279 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
280 #else
281 #define net_dbg_ratelimited(fmt, ...) \
282 do { \
283 if (0) \
284 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
285 } while (0)
286 #endif
287
288 #define net_get_random_once(buf, nbytes) \
289 get_random_once((buf), (nbytes))
290 #define net_get_random_once_wait(buf, nbytes) \
291 get_random_once_wait((buf), (nbytes))
292
293 /*
294 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
295 * data pages, or other high order pages allocated by
296 * __get_free_pages() without __GFP_COMP, which have a page_count
297 * of 0 and/or have PageSlab() set. We cannot use send_page for
298 * those, as that does get_page(); put_page(); and would cause
299 * either a VM_BUG directly, or __page_cache_release a page that
300 * would actually still be referenced by someone, leading to some
301 * obscure delayed Oops somewhere else.
302 */
sendpage_ok(struct page * page)303 static inline bool sendpage_ok(struct page *page)
304 {
305 return !PageSlab(page) && page_count(page) >= 1;
306 }
307
308 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
309 size_t num, size_t len);
310 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
311 struct kvec *vec, size_t num, size_t len);
312 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
313 size_t num, size_t len, int flags);
314
315 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
316 int kernel_listen(struct socket *sock, int backlog);
317 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
318 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
319 int flags);
320 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
321 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
322 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
323 size_t size, int flags);
324 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
325 size_t size, int flags);
326 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
327
328 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
329 u32 kernel_sock_ip_overhead(struct sock *sk);
330
331 #define MODULE_ALIAS_NETPROTO(proto) \
332 MODULE_ALIAS("net-pf-" __stringify(proto))
333
334 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
335 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
336
337 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
338 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
339 "-type-" __stringify(type))
340
341 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
342 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
343 name)
344 #endif /* _LINUX_NET_H */
345