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 #define SOCK_CUSTOM_SOCKOPT 6
46 #define SOCK_PASSPIDFD 7
47
48 #ifndef ARCH_HAS_SOCKET_TYPES
49 /**
50 * enum sock_type - Socket types
51 * @SOCK_STREAM: stream (connection) socket
52 * @SOCK_DGRAM: datagram (conn.less) socket
53 * @SOCK_RAW: raw socket
54 * @SOCK_RDM: reliably-delivered message
55 * @SOCK_SEQPACKET: sequential packet socket
56 * @SOCK_DCCP: Datagram Congestion Control Protocol socket
57 * @SOCK_PACKET: linux specific way of getting packets at the dev level.
58 * For writing rarp and other similar things on the user level.
59 *
60 * When adding some new socket type please
61 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
62 * overrides this enum for binary compat reasons.
63 */
64 enum sock_type {
65 SOCK_STREAM = 1,
66 SOCK_DGRAM = 2,
67 SOCK_RAW = 3,
68 SOCK_RDM = 4,
69 SOCK_SEQPACKET = 5,
70 SOCK_DCCP = 6,
71 SOCK_PACKET = 10,
72 };
73
74 #define SOCK_MAX (SOCK_PACKET + 1)
75 /* Mask which covers at least up to SOCK_MASK-1. The
76 * remaining bits are used as flags. */
77 #define SOCK_TYPE_MASK 0xf
78
79 /* Flags for socket, socketpair, accept4 */
80 #define SOCK_CLOEXEC O_CLOEXEC
81 #ifndef SOCK_NONBLOCK
82 #define SOCK_NONBLOCK O_NONBLOCK
83 #endif
84
85 #endif /* ARCH_HAS_SOCKET_TYPES */
86
87 /**
88 * enum sock_shutdown_cmd - Shutdown types
89 * @SHUT_RD: shutdown receptions
90 * @SHUT_WR: shutdown transmissions
91 * @SHUT_RDWR: shutdown receptions/transmissions
92 */
93 enum sock_shutdown_cmd {
94 SHUT_RD,
95 SHUT_WR,
96 SHUT_RDWR,
97 };
98
99 struct socket_wq {
100 /* Note: wait MUST be first field of socket_wq */
101 wait_queue_head_t wait;
102 struct fasync_struct *fasync_list;
103 unsigned long flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
104 struct rcu_head rcu;
105 } ____cacheline_aligned_in_smp;
106
107 /**
108 * struct socket - general BSD socket
109 * @state: socket state (%SS_CONNECTED, etc)
110 * @type: socket type (%SOCK_STREAM, etc)
111 * @flags: socket flags (%SOCK_NOSPACE, etc)
112 * @ops: protocol specific socket operations
113 * @file: File back pointer for gc
114 * @sk: internal networking protocol agnostic socket representation
115 * @wq: wait queue for several uses
116 */
117 struct socket {
118 socket_state state;
119
120 short type;
121
122 unsigned long flags;
123
124 struct file *file;
125 struct sock *sk;
126 const struct proto_ops *ops; /* Might change with IPV6_ADDRFORM or MPTCP. */
127
128 struct socket_wq wq;
129 };
130
131 /*
132 * "descriptor" for what we're up to with a read.
133 * This allows us to use the same read code yet
134 * have multiple different users of the data that
135 * we read from a file.
136 *
137 * The simplest case just copies the data to user
138 * mode.
139 */
140 typedef struct {
141 size_t written;
142 size_t count;
143 union {
144 char __user *buf;
145 void *data;
146 } arg;
147 int error;
148 } read_descriptor_t;
149
150 struct vm_area_struct;
151 struct page;
152 struct sockaddr;
153 struct msghdr;
154 struct module;
155 struct sk_buff;
156 struct proto_accept_arg;
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,
176 struct proto_accept_arg *arg);
177 int (*getname) (struct socket *sock,
178 struct sockaddr *addr,
179 int peer);
180 __poll_t (*poll) (struct file *file, struct socket *sock,
181 struct poll_table_struct *wait);
182 int (*ioctl) (struct socket *sock, unsigned int cmd,
183 unsigned long arg);
184 #ifdef CONFIG_COMPAT
185 int (*compat_ioctl) (struct socket *sock, unsigned int cmd,
186 unsigned long arg);
187 #endif
188 int (*gettstamp) (struct socket *sock, void __user *userstamp,
189 bool timeval, bool time32);
190 int (*listen) (struct socket *sock, int len);
191 int (*shutdown) (struct socket *sock, int flags);
192 int (*setsockopt)(struct socket *sock, int level,
193 int optname, sockptr_t optval,
194 unsigned int optlen);
195 int (*getsockopt)(struct socket *sock, int level,
196 int optname, char __user *optval, int __user *optlen);
197 void (*show_fdinfo)(struct seq_file *m, struct socket *sock);
198 int (*sendmsg) (struct socket *sock, struct msghdr *m,
199 size_t total_len);
200 /* Notes for implementing recvmsg:
201 * ===============================
202 * msg->msg_namelen should get updated by the recvmsg handlers
203 * iff msg_name != NULL. It is by default 0 to prevent
204 * returning uninitialized memory to user space. The recvfrom
205 * handlers can assume that msg.msg_name is either NULL or has
206 * a minimum size of sizeof(struct sockaddr_storage).
207 */
208 int (*recvmsg) (struct socket *sock, struct msghdr *m,
209 size_t total_len, int flags);
210 int (*mmap) (struct file *file, struct socket *sock,
211 struct vm_area_struct * vma);
212 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
213 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
214 void (*splice_eof)(struct socket *sock);
215 int (*set_peek_off)(struct sock *sk, int val);
216 int (*peek_len)(struct socket *sock);
217
218 /* The following functions are called internally by kernel with
219 * sock lock already held.
220 */
221 int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
222 sk_read_actor_t recv_actor);
223 /* This is different from read_sock(), it reads an entire skb at a time. */
224 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor);
225 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
226 size_t size);
227 int (*set_rcvlowat)(struct sock *sk, int val);
228 };
229
230 #define DECLARE_SOCKADDR(type, dst, src) \
231 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
232
233 struct net_proto_family {
234 int family;
235 int (*create)(struct net *net, struct socket *sock,
236 int protocol, int kern);
237 struct module *owner;
238 };
239
240 struct iovec;
241 struct kvec;
242
243 enum {
244 SOCK_WAKE_IO,
245 SOCK_WAKE_WAITD,
246 SOCK_WAKE_SPACE,
247 SOCK_WAKE_URG,
248 };
249
250 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
251 int sock_register(const struct net_proto_family *fam);
252 void sock_unregister(int family);
253 bool sock_is_registered(int family);
254 int __sock_create(struct net *net, int family, int type, int proto,
255 struct socket **res, int kern);
256 int sock_create(int family, int type, int proto, struct socket **res);
257 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
258 int sock_create_lite(int family, int type, int proto, struct socket **res);
259 struct socket *sock_alloc(void);
260 void sock_release(struct socket *sock);
261 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
262 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
263 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
264 struct socket *sockfd_lookup(int fd, int *err);
265 struct socket *sock_from_file(struct file *file);
266 #define sockfd_put(sock) fput(sock->file)
267 int net_ratelimit(void);
268
269 #define net_ratelimited_function(function, ...) \
270 do { \
271 if (net_ratelimit()) \
272 function(__VA_ARGS__); \
273 } while (0)
274
275 #define net_emerg_ratelimited(fmt, ...) \
276 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
277 #define net_alert_ratelimited(fmt, ...) \
278 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
279 #define net_crit_ratelimited(fmt, ...) \
280 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
281 #define net_err_ratelimited(fmt, ...) \
282 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
283 #define net_notice_ratelimited(fmt, ...) \
284 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
285 #define net_warn_ratelimited(fmt, ...) \
286 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
287 #define net_info_ratelimited(fmt, ...) \
288 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
289 #if defined(CONFIG_DYNAMIC_DEBUG) || \
290 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
291 #define net_dbg_ratelimited(fmt, ...) \
292 do { \
293 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
294 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \
295 net_ratelimit()) \
296 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
297 ##__VA_ARGS__); \
298 } while (0)
299 #elif defined(DEBUG)
300 #define net_dbg_ratelimited(fmt, ...) \
301 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
302 #else
303 #define net_dbg_ratelimited(fmt, ...) \
304 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
305 #endif
306
307 #define net_get_random_once(buf, nbytes) \
308 get_random_once((buf), (nbytes))
309
310 /*
311 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
312 * data pages, or other high order pages allocated by
313 * __get_free_pages() without __GFP_COMP, which have a page_count
314 * of 0 and/or have PageSlab() set. We cannot use send_page for
315 * those, as that does get_page(); put_page(); and would cause
316 * either a VM_BUG directly, or __page_cache_release a page that
317 * would actually still be referenced by someone, leading to some
318 * obscure delayed Oops somewhere else.
319 */
320 static inline bool sendpage_ok(struct page *page)
321 {
322 return !PageSlab(page) && page_count(page) >= 1;
323 }
324
325 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
326 size_t num, size_t len);
327 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
328 struct kvec *vec, size_t num, size_t len);
329 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
330 size_t num, size_t len, int flags);
331
332 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
333 int kernel_listen(struct socket *sock, int backlog);
334 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
335 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
336 int flags);
337 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
338 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
339 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
340
341 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
342 u32 kernel_sock_ip_overhead(struct sock *sk);
343
344 #define MODULE_ALIAS_NETPROTO(proto) \
345 MODULE_ALIAS("net-pf-" __stringify(proto))
346
347 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
348 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
349
350 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
351 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
352 "-type-" __stringify(type))
353
354 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
355 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
356 name)
357 #endif /* _LINUX_NET_H */
358
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