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 #include <linux/android_kabi.h>
27
28 #include <uapi/linux/net.h>
29
30 struct poll_table_struct;
31 struct pipe_inode_info;
32 struct inode;
33 struct file;
34 struct net;
35
36 /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
37 * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
38 * Eventually all flags will be in sk->sk_wq->flags.
39 */
40 #define SOCKWQ_ASYNC_NOSPACE 0
41 #define SOCKWQ_ASYNC_WAITDATA 1
42 #define SOCK_NOSPACE 2
43 #define SOCK_PASSCRED 3
44 #define SOCK_PASSSEC 4
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 struct vm_area_struct;
130 struct page;
131 struct sockaddr;
132 struct msghdr;
133 struct module;
134 struct sk_buff;
135 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
136 unsigned int, size_t);
137
138 struct proto_ops {
139 int family;
140 struct module *owner;
141 int (*release) (struct socket *sock);
142 int (*bind) (struct socket *sock,
143 struct sockaddr *myaddr,
144 int sockaddr_len);
145 int (*connect) (struct socket *sock,
146 struct sockaddr *vaddr,
147 int sockaddr_len, int flags);
148 int (*socketpair)(struct socket *sock1,
149 struct socket *sock2);
150 int (*accept) (struct socket *sock,
151 struct socket *newsock, int flags, bool kern);
152 int (*getname) (struct socket *sock,
153 struct sockaddr *addr,
154 int peer);
155 __poll_t (*poll) (struct file *file, struct socket *sock,
156 struct poll_table_struct *wait);
157 int (*ioctl) (struct socket *sock, unsigned int cmd,
158 unsigned long arg);
159 #ifdef CONFIG_COMPAT
160 int (*compat_ioctl) (struct socket *sock, unsigned int cmd,
161 unsigned long arg);
162 #endif
163 int (*gettstamp) (struct socket *sock, void __user *userstamp,
164 bool timeval, bool time32);
165 int (*listen) (struct socket *sock, int len);
166 int (*shutdown) (struct socket *sock, int flags);
167 int (*setsockopt)(struct socket *sock, int level,
168 int optname, sockptr_t optval,
169 unsigned int optlen);
170 int (*getsockopt)(struct socket *sock, int level,
171 int optname, char __user *optval, int __user *optlen);
172 void (*show_fdinfo)(struct seq_file *m, struct socket *sock);
173 int (*sendmsg) (struct socket *sock, struct msghdr *m,
174 size_t total_len);
175 /* Notes for implementing recvmsg:
176 * ===============================
177 * msg->msg_namelen should get updated by the recvmsg handlers
178 * iff msg_name != NULL. It is by default 0 to prevent
179 * returning uninitialized memory to user space. The recvfrom
180 * handlers can assume that msg.msg_name is either NULL or has
181 * a minimum size of sizeof(struct sockaddr_storage).
182 */
183 int (*recvmsg) (struct socket *sock, struct msghdr *m,
184 size_t total_len, int flags);
185 int (*mmap) (struct file *file, struct socket *sock,
186 struct vm_area_struct * vma);
187 ssize_t (*sendpage) (struct socket *sock, struct page *page,
188 int offset, size_t size, int flags);
189 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
190 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
191 int (*set_peek_off)(struct sock *sk, int val);
192 int (*peek_len)(struct socket *sock);
193
194 /* The following functions are called internally by kernel with
195 * sock lock already held.
196 */
197 int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
198 sk_read_actor_t recv_actor);
199 int (*sendpage_locked)(struct sock *sk, struct page *page,
200 int offset, size_t size, int flags);
201 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
202 size_t size);
203 int (*set_rcvlowat)(struct sock *sk, int val);
204
205 ANDROID_KABI_RESERVE(1);
206 ANDROID_KABI_RESERVE(2);
207 ANDROID_KABI_RESERVE(3);
208 ANDROID_KABI_RESERVE(4);
209 };
210
211 #define DECLARE_SOCKADDR(type, dst, src) \
212 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
213
214 struct net_proto_family {
215 int family;
216 int (*create)(struct net *net, struct socket *sock,
217 int protocol, int kern);
218 struct module *owner;
219 };
220
221 struct iovec;
222 struct kvec;
223
224 enum {
225 SOCK_WAKE_IO,
226 SOCK_WAKE_WAITD,
227 SOCK_WAKE_SPACE,
228 SOCK_WAKE_URG,
229 };
230
231 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
232 int sock_register(const struct net_proto_family *fam);
233 void sock_unregister(int family);
234 bool sock_is_registered(int family);
235 int __sock_create(struct net *net, int family, int type, int proto,
236 struct socket **res, int kern);
237 int sock_create(int family, int type, int proto, struct socket **res);
238 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
239 int sock_create_lite(int family, int type, int proto, struct socket **res);
240 struct socket *sock_alloc(void);
241 void sock_release(struct socket *sock);
242 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
243 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
244 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
245 struct socket *sockfd_lookup(int fd, int *err);
246 struct socket *sock_from_file(struct file *file);
247 #define sockfd_put(sock) fput(sock->file)
248 int net_ratelimit(void);
249
250 #define net_ratelimited_function(function, ...) \
251 do { \
252 if (net_ratelimit()) \
253 function(__VA_ARGS__); \
254 } while (0)
255
256 #define net_emerg_ratelimited(fmt, ...) \
257 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
258 #define net_alert_ratelimited(fmt, ...) \
259 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
260 #define net_crit_ratelimited(fmt, ...) \
261 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
262 #define net_err_ratelimited(fmt, ...) \
263 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
264 #define net_notice_ratelimited(fmt, ...) \
265 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
266 #define net_warn_ratelimited(fmt, ...) \
267 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
268 #define net_info_ratelimited(fmt, ...) \
269 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
270 #if defined(CONFIG_DYNAMIC_DEBUG) || \
271 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
272 #define net_dbg_ratelimited(fmt, ...) \
273 do { \
274 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
275 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \
276 net_ratelimit()) \
277 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
278 ##__VA_ARGS__); \
279 } while (0)
280 #elif defined(DEBUG)
281 #define net_dbg_ratelimited(fmt, ...) \
282 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
283 #else
284 #define net_dbg_ratelimited(fmt, ...) \
285 do { \
286 if (0) \
287 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
288 } while (0)
289 #endif
290
291 #define net_get_random_once(buf, nbytes) \
292 get_random_once((buf), (nbytes))
293 #define net_get_random_once_wait(buf, nbytes) \
294 get_random_once_wait((buf), (nbytes))
295
296 /*
297 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
298 * data pages, or other high order pages allocated by
299 * __get_free_pages() without __GFP_COMP, which have a page_count
300 * of 0 and/or have PageSlab() set. We cannot use send_page for
301 * those, as that does get_page(); put_page(); and would cause
302 * either a VM_BUG directly, or __page_cache_release a page that
303 * would actually still be referenced by someone, leading to some
304 * obscure delayed Oops somewhere else.
305 */
sendpage_ok(struct page * page)306 static inline bool sendpage_ok(struct page *page)
307 {
308 return !PageSlab(page) && page_count(page) >= 1;
309 }
310
311 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
312 size_t num, size_t len);
313 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
314 struct kvec *vec, size_t num, size_t len);
315 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
316 size_t num, size_t len, int flags);
317
318 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
319 int kernel_listen(struct socket *sock, int backlog);
320 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
321 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
322 int flags);
323 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
324 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
325 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
326 size_t size, int flags);
327 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
328 size_t size, int flags);
329 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
330
331 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
332 u32 kernel_sock_ip_overhead(struct sock *sk);
333
334 #define MODULE_ALIAS_NETPROTO(proto) \
335 MODULE_ALIAS("net-pf-" __stringify(proto))
336
337 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
338 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
339
340 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
341 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
342 "-type-" __stringify(type))
343
344 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
345 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
346 name)
347 #endif /* _LINUX_NET_H */
348