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 #define SOCK_SUPPORT_ZC 5
46 #define SOCK_CUSTOM_SOCKOPT 6
47 #define SOCK_PASSPIDFD 7
48
49 #ifndef ARCH_HAS_SOCKET_TYPES
50 /**
51 * enum sock_type - Socket types
52 * @SOCK_STREAM: stream (connection) socket
53 * @SOCK_DGRAM: datagram (conn.less) socket
54 * @SOCK_RAW: raw socket
55 * @SOCK_RDM: reliably-delivered message
56 * @SOCK_SEQPACKET: sequential packet socket
57 * @SOCK_DCCP: Datagram Congestion Control Protocol socket
58 * @SOCK_PACKET: linux specific way of getting packets at the dev level.
59 * For writing rarp and other similar things on the user level.
60 *
61 * When adding some new socket type please
62 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
63 * overrides this enum for binary compat reasons.
64 */
65 enum sock_type {
66 SOCK_STREAM = 1,
67 SOCK_DGRAM = 2,
68 SOCK_RAW = 3,
69 SOCK_RDM = 4,
70 SOCK_SEQPACKET = 5,
71 SOCK_DCCP = 6,
72 SOCK_PACKET = 10,
73 };
74
75 #define SOCK_MAX (SOCK_PACKET + 1)
76 /* Mask which covers at least up to SOCK_MASK-1. The
77 * remaining bits are used as flags. */
78 #define SOCK_TYPE_MASK 0xf
79
80 /* Flags for socket, socketpair, accept4 */
81 #define SOCK_CLOEXEC O_CLOEXEC
82 #ifndef SOCK_NONBLOCK
83 #define SOCK_NONBLOCK O_NONBLOCK
84 #endif
85
86 #endif /* ARCH_HAS_SOCKET_TYPES */
87
88 /**
89 * enum sock_shutdown_cmd - Shutdown types
90 * @SHUT_RD: shutdown receptions
91 * @SHUT_WR: shutdown transmissions
92 * @SHUT_RDWR: shutdown receptions/transmissions
93 */
94 enum sock_shutdown_cmd {
95 SHUT_RD,
96 SHUT_WR,
97 SHUT_RDWR,
98 };
99
100 struct socket_wq {
101 /* Note: wait MUST be first field of socket_wq */
102 wait_queue_head_t wait;
103 struct fasync_struct *fasync_list;
104 unsigned long flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
105 struct rcu_head rcu;
106 } ____cacheline_aligned_in_smp;
107
108 /**
109 * struct socket - general BSD socket
110 * @state: socket state (%SS_CONNECTED, etc)
111 * @type: socket type (%SOCK_STREAM, etc)
112 * @flags: socket flags (%SOCK_NOSPACE, etc)
113 * @ops: protocol specific socket operations
114 * @file: File back pointer for gc
115 * @sk: internal networking protocol agnostic socket representation
116 * @wq: wait queue for several uses
117 */
118 struct socket {
119 socket_state state;
120
121 short type;
122
123 unsigned long flags;
124
125 struct file *file;
126 struct sock *sk;
127 const struct proto_ops *ops; /* Might change with IPV6_ADDRFORM or MPTCP. */
128
129 struct socket_wq wq;
130 };
131
132 /*
133 * "descriptor" for what we're up to with a read.
134 * This allows us to use the same read code yet
135 * have multiple different users of the data that
136 * we read from a file.
137 *
138 * The simplest case just copies the data to user
139 * mode.
140 */
141 typedef struct {
142 size_t written;
143 size_t count;
144 union {
145 char __user *buf;
146 void *data;
147 } arg;
148 int error;
149 } read_descriptor_t;
150
151 struct vm_area_struct;
152 struct page;
153 struct sockaddr;
154 struct msghdr;
155 struct module;
156 struct sk_buff;
157 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
158 unsigned int, size_t);
159 typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *);
160
161
162 struct proto_ops {
163 int family;
164 struct module *owner;
165 int (*release) (struct socket *sock);
166 int (*bind) (struct socket *sock,
167 struct sockaddr *myaddr,
168 int sockaddr_len);
169 int (*connect) (struct socket *sock,
170 struct sockaddr *vaddr,
171 int sockaddr_len, int flags);
172 int (*socketpair)(struct socket *sock1,
173 struct socket *sock2);
174 int (*accept) (struct socket *sock,
175 struct socket *newsock, int flags, bool kern);
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 ANDROID_KABI_RESERVE(1);
229 ANDROID_KABI_RESERVE(2);
230 ANDROID_KABI_RESERVE(3);
231 ANDROID_KABI_RESERVE(4);
232 };
233
234 #define DECLARE_SOCKADDR(type, dst, src) \
235 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
236
237 struct net_proto_family {
238 int family;
239 int (*create)(struct net *net, struct socket *sock,
240 int protocol, int kern);
241 struct module *owner;
242 };
243
244 struct iovec;
245 struct kvec;
246
247 enum {
248 SOCK_WAKE_IO,
249 SOCK_WAKE_WAITD,
250 SOCK_WAKE_SPACE,
251 SOCK_WAKE_URG,
252 };
253
254 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
255 int sock_register(const struct net_proto_family *fam);
256 void sock_unregister(int family);
257 bool sock_is_registered(int family);
258 int __sock_create(struct net *net, int family, int type, int proto,
259 struct socket **res, int kern);
260 int sock_create(int family, int type, int proto, struct socket **res);
261 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
262 int sock_create_lite(int family, int type, int proto, struct socket **res);
263 struct socket *sock_alloc(void);
264 void sock_release(struct socket *sock);
265 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
266 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
267 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
268 struct socket *sockfd_lookup(int fd, int *err);
269 struct socket *sock_from_file(struct file *file);
270 #define sockfd_put(sock) fput(sock->file)
271 int net_ratelimit(void);
272
273 #define net_ratelimited_function(function, ...) \
274 do { \
275 if (net_ratelimit()) \
276 function(__VA_ARGS__); \
277 } while (0)
278
279 #define net_emerg_ratelimited(fmt, ...) \
280 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
281 #define net_alert_ratelimited(fmt, ...) \
282 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
283 #define net_crit_ratelimited(fmt, ...) \
284 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
285 #define net_err_ratelimited(fmt, ...) \
286 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
287 #define net_notice_ratelimited(fmt, ...) \
288 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
289 #define net_warn_ratelimited(fmt, ...) \
290 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
291 #define net_info_ratelimited(fmt, ...) \
292 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
293 #if defined(CONFIG_DYNAMIC_DEBUG) || \
294 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
295 #define net_dbg_ratelimited(fmt, ...) \
296 do { \
297 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
298 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \
299 net_ratelimit()) \
300 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
301 ##__VA_ARGS__); \
302 } while (0)
303 #elif defined(DEBUG)
304 #define net_dbg_ratelimited(fmt, ...) \
305 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
306 #else
307 #define net_dbg_ratelimited(fmt, ...) \
308 do { \
309 if (0) \
310 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
311 } while (0)
312 #endif
313
314 #define net_get_random_once(buf, nbytes) \
315 get_random_once((buf), (nbytes))
316
317 /*
318 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
319 * data pages, or other high order pages allocated by
320 * __get_free_pages() without __GFP_COMP, which have a page_count
321 * of 0 and/or have PageSlab() set. We cannot use send_page for
322 * those, as that does get_page(); put_page(); and would cause
323 * either a VM_BUG directly, or __page_cache_release a page that
324 * would actually still be referenced by someone, leading to some
325 * obscure delayed Oops somewhere else.
326 */
sendpage_ok(struct page * page)327 static inline bool sendpage_ok(struct page *page)
328 {
329 return !PageSlab(page) && page_count(page) >= 1;
330 }
331
332 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
333 size_t num, size_t len);
334 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
335 struct kvec *vec, size_t num, size_t len);
336 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
337 size_t num, size_t len, int flags);
338
339 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
340 int kernel_listen(struct socket *sock, int backlog);
341 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
342 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
343 int flags);
344 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
345 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
346 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
347
348 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
349 u32 kernel_sock_ip_overhead(struct sock *sk);
350
351 #define MODULE_ALIAS_NETPROTO(proto) \
352 MODULE_ALIAS("net-pf-" __stringify(proto))
353
354 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
355 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
356
357 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
358 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
359 "-type-" __stringify(type))
360
361 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
362 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
363 name)
364 #endif /* _LINUX_NET_H */
365