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 #define SOCK_SUPPORT_ZC 5
45
46 #ifndef ARCH_HAS_SOCKET_TYPES
47 /**
48 * enum sock_type - Socket types
49 * @SOCK_STREAM: stream (connection) socket
50 * @SOCK_DGRAM: datagram (conn.less) socket
51 * @SOCK_RAW: raw socket
52 * @SOCK_RDM: reliably-delivered message
53 * @SOCK_SEQPACKET: sequential packet socket
54 * @SOCK_DCCP: Datagram Congestion Control Protocol socket
55 * @SOCK_PACKET: linux specific way of getting packets at the dev level.
56 * For writing rarp and other similar things on the user level.
57 *
58 * When adding some new socket type please
59 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
60 * overrides this enum for binary compat reasons.
61 */
62 enum sock_type {
63 SOCK_STREAM = 1,
64 SOCK_DGRAM = 2,
65 SOCK_RAW = 3,
66 SOCK_RDM = 4,
67 SOCK_SEQPACKET = 5,
68 SOCK_DCCP = 6,
69 SOCK_PACKET = 10,
70 };
71
72 #define SOCK_MAX (SOCK_PACKET + 1)
73 /* Mask which covers at least up to SOCK_MASK-1. The
74 * remaining bits are used as flags. */
75 #define SOCK_TYPE_MASK 0xf
76
77 /* Flags for socket, socketpair, accept4 */
78 #define SOCK_CLOEXEC O_CLOEXEC
79 #ifndef SOCK_NONBLOCK
80 #define SOCK_NONBLOCK O_NONBLOCK
81 #endif
82
83 #endif /* ARCH_HAS_SOCKET_TYPES */
84
85 /**
86 * enum sock_shutdown_cmd - Shutdown types
87 * @SHUT_RD: shutdown receptions
88 * @SHUT_WR: shutdown transmissions
89 * @SHUT_RDWR: shutdown receptions/transmissions
90 */
91 enum sock_shutdown_cmd {
92 SHUT_RD,
93 SHUT_WR,
94 SHUT_RDWR,
95 };
96
97 struct socket_wq {
98 /* Note: wait MUST be first field of socket_wq */
99 wait_queue_head_t wait;
100 struct fasync_struct *fasync_list;
101 unsigned long flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
102 struct rcu_head rcu;
103 } ____cacheline_aligned_in_smp;
104
105 /**
106 * struct socket - general BSD socket
107 * @state: socket state (%SS_CONNECTED, etc)
108 * @type: socket type (%SOCK_STREAM, etc)
109 * @flags: socket flags (%SOCK_NOSPACE, etc)
110 * @ops: protocol specific socket operations
111 * @file: File back pointer for gc
112 * @sk: internal networking protocol agnostic socket representation
113 * @wq: wait queue for several uses
114 */
115 struct socket {
116 socket_state state;
117
118 short type;
119
120 unsigned long flags;
121
122 struct file *file;
123 struct sock *sk;
124 const struct proto_ops *ops;
125
126 struct socket_wq wq;
127 };
128
129 /*
130 * "descriptor" for what we're up to with a read.
131 * This allows us to use the same read code yet
132 * have multiple different users of the data that
133 * we read from a file.
134 *
135 * The simplest case just copies the data to user
136 * mode.
137 */
138 typedef struct {
139 size_t written;
140 size_t count;
141 union {
142 char __user *buf;
143 void *data;
144 } arg;
145 int error;
146 } read_descriptor_t;
147
148 struct vm_area_struct;
149 struct page;
150 struct sockaddr;
151 struct msghdr;
152 struct module;
153 struct sk_buff;
154 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
155 unsigned int, size_t);
156 typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *);
157
158
159 struct proto_ops {
160 int family;
161 struct module *owner;
162 int (*release) (struct socket *sock);
163 int (*bind) (struct socket *sock,
164 struct sockaddr *myaddr,
165 int sockaddr_len);
166 int (*connect) (struct socket *sock,
167 struct sockaddr *vaddr,
168 int sockaddr_len, int flags);
169 int (*socketpair)(struct socket *sock1,
170 struct socket *sock2);
171 int (*accept) (struct socket *sock,
172 struct socket *newsock, int flags, bool kern);
173 int (*getname) (struct socket *sock,
174 struct sockaddr *addr,
175 int peer);
176 __poll_t (*poll) (struct file *file, struct socket *sock,
177 struct poll_table_struct *wait);
178 int (*ioctl) (struct socket *sock, unsigned int cmd,
179 unsigned long arg);
180 #ifdef CONFIG_COMPAT
181 int (*compat_ioctl) (struct socket *sock, unsigned int cmd,
182 unsigned long arg);
183 #endif
184 int (*gettstamp) (struct socket *sock, void __user *userstamp,
185 bool timeval, bool time32);
186 int (*listen) (struct socket *sock, int len);
187 int (*shutdown) (struct socket *sock, int flags);
188 int (*setsockopt)(struct socket *sock, int level,
189 int optname, sockptr_t optval,
190 unsigned int optlen);
191 int (*getsockopt)(struct socket *sock, int level,
192 int optname, char __user *optval, int __user *optlen);
193 void (*show_fdinfo)(struct seq_file *m, struct socket *sock);
194 int (*sendmsg) (struct socket *sock, struct msghdr *m,
195 size_t total_len);
196 /* Notes for implementing recvmsg:
197 * ===============================
198 * msg->msg_namelen should get updated by the recvmsg handlers
199 * iff msg_name != NULL. It is by default 0 to prevent
200 * returning uninitialized memory to user space. The recvfrom
201 * handlers can assume that msg.msg_name is either NULL or has
202 * a minimum size of sizeof(struct sockaddr_storage).
203 */
204 int (*recvmsg) (struct socket *sock, struct msghdr *m,
205 size_t total_len, int flags);
206 int (*mmap) (struct file *file, struct socket *sock,
207 struct vm_area_struct * vma);
208 ssize_t (*sendpage) (struct socket *sock, struct page *page,
209 int offset, size_t size, int flags);
210 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
211 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
212 int (*set_peek_off)(struct sock *sk, int val);
213 int (*peek_len)(struct socket *sock);
214
215 /* The following functions are called internally by kernel with
216 * sock lock already held.
217 */
218 int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
219 sk_read_actor_t recv_actor);
220 /* This is different from read_sock(), it reads an entire skb at a time. */
221 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor);
222 int (*sendpage_locked)(struct sock *sk, struct page *page,
223 int offset, size_t size, int flags);
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
232 struct 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
239 struct iovec;
240 struct kvec;
241
242 enum {
243 SOCK_WAKE_IO,
244 SOCK_WAKE_WAITD,
245 SOCK_WAKE_SPACE,
246 SOCK_WAKE_URG,
247 };
248
249 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
250 int sock_register(const struct net_proto_family *fam);
251 void sock_unregister(int family);
252 bool sock_is_registered(int family);
253 int __sock_create(struct net *net, int family, int type, int proto,
254 struct socket **res, int kern);
255 int sock_create(int family, int type, int proto, struct socket **res);
256 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
257 int sock_create_lite(int family, int type, int proto, struct socket **res);
258 struct socket *sock_alloc(void);
259 void sock_release(struct socket *sock);
260 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
261 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
262 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
263 struct socket *sockfd_lookup(int fd, int *err);
264 struct socket *sock_from_file(struct file *file);
265 #define sockfd_put(sock) fput(sock->file)
266 int net_ratelimit(void);
267
268 #define net_ratelimited_function(function, ...) \
269 do { \
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, ...) \
291 do { \
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 do { \
304 if (0) \
305 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
306 } while (0)
307 #endif
308
309 #define net_get_random_once(buf, nbytes) \
310 get_random_once((buf), (nbytes))
311
312 /*
313 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
314 * data pages, or other high order pages allocated by
315 * __get_free_pages() without __GFP_COMP, which have a page_count
316 * of 0 and/or have PageSlab() set. We cannot use send_page for
317 * those, as that does get_page(); put_page(); and would cause
318 * either a VM_BUG directly, or __page_cache_release a page that
319 * would actually still be referenced by someone, leading to some
320 * obscure delayed Oops somewhere else.
321 */
sendpage_ok(struct page * page)322 static inline bool sendpage_ok(struct page *page)
323 {
324 return !PageSlab(page) && page_count(page) >= 1;
325 }
326
327 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
328 size_t num, size_t len);
329 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
330 struct kvec *vec, size_t num, size_t len);
331 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
332 size_t num, size_t len, int flags);
333
334 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
335 int kernel_listen(struct socket *sock, int backlog);
336 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
337 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
338 int flags);
339 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
340 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
341 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
342 size_t size, int flags);
343 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
344 size_t size, int flags);
345 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
346
347 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
348 u32 kernel_sock_ip_overhead(struct sock *sk);
349
350 #define MODULE_ALIAS_NETPROTO(proto) \
351 MODULE_ALIAS("net-pf-" __stringify(proto))
352
353 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
354 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
355
356 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
357 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
358 "-type-" __stringify(type))
359
360 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
361 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
362 name)
363 #endif /* _LINUX_NET_H */
364