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 enum socket_flags {
40 SOCKWQ_ASYNC_NOSPACE,
41 SOCKWQ_ASYNC_WAITDATA,
42 SOCK_NOSPACE,
43 SOCK_SUPPORT_ZC,
44 SOCK_CUSTOM_SOCKOPT,
45 };
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 #endif /* ARCH_HAS_SOCKET_TYPES */
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 #define SOCK_COREDUMP O_NOCTTY
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; /* Might change with IPV6_ADDRFORM or MPTCP. */
126
127 struct socket_wq wq;
128 };
129
130 /*
131 * "descriptor" for what we're up to with a read.
132 * This allows us to use the same read code yet
133 * have multiple different users of the data that
134 * we read from a file.
135 *
136 * The simplest case just copies the data to user
137 * mode.
138 */
139 typedef struct {
140 size_t written;
141 size_t count;
142 union {
143 char __user *buf;
144 void *data;
145 } arg;
146 int error;
147 } read_descriptor_t;
148
149 struct vm_area_struct;
150 struct page;
151 struct msghdr;
152 struct module;
153 struct sk_buff;
154 struct proto_accept_arg;
155 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
156 unsigned int, size_t);
157 typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *);
158
159
160 struct proto_ops {
161 int family;
162 struct module *owner;
163 int (*release) (struct socket *sock);
164 int (*bind) (struct socket *sock,
165 struct sockaddr_unsized *myaddr,
166 int sockaddr_len);
167 int (*connect) (struct socket *sock,
168 struct sockaddr_unsized *vaddr,
169 int sockaddr_len, int flags);
170 int (*socketpair)(struct socket *sock1,
171 struct socket *sock2);
172 int (*accept) (struct socket *sock,
173 struct socket *newsock,
174 struct proto_accept_arg *arg);
175 int (*getname) (struct socket *sock,
176 struct sockaddr *addr,
177 int peer);
178 __poll_t (*poll) (struct file *file, struct socket *sock,
179 struct poll_table_struct *wait);
180 int (*ioctl) (struct socket *sock, unsigned int cmd,
181 unsigned long arg);
182 #ifdef CONFIG_COMPAT
183 int (*compat_ioctl) (struct socket *sock, unsigned int cmd,
184 unsigned long arg);
185 #endif
186 int (*gettstamp) (struct socket *sock, void __user *userstamp,
187 bool timeval, bool time32);
188 int (*listen) (struct socket *sock, int len);
189 int (*shutdown) (struct socket *sock, int flags);
190 int (*setsockopt)(struct socket *sock, int level,
191 int optname, sockptr_t optval,
192 unsigned int optlen);
193 int (*getsockopt)(struct socket *sock, int level,
194 int optname, char __user *optval, int __user *optlen);
195 void (*show_fdinfo)(struct seq_file *m, struct socket *sock);
196 int (*sendmsg) (struct socket *sock, struct msghdr *m,
197 size_t total_len);
198 /* Notes for implementing recvmsg:
199 * ===============================
200 * msg->msg_namelen should get updated by the recvmsg handlers
201 * iff msg_name != NULL. It is by default 0 to prevent
202 * returning uninitialized memory to user space. The recvfrom
203 * handlers can assume that msg.msg_name is either NULL or has
204 * a minimum size of sizeof(struct sockaddr_storage).
205 */
206 int (*recvmsg) (struct socket *sock, struct msghdr *m,
207 size_t total_len, int flags);
208 int (*mmap) (struct file *file, struct socket *sock,
209 struct vm_area_struct * vma);
210 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos,
211 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
212 void (*splice_eof)(struct socket *sock);
213 int (*set_peek_off)(struct sock *sk, int val);
214 int (*peek_len)(struct socket *sock);
215
216 /* The following functions are called internally by kernel with
217 * sock lock already held.
218 */
219 int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
220 sk_read_actor_t recv_actor);
221 /* This is different from read_sock(), it reads an entire skb at a time. */
222 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor);
223 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
224 size_t size);
225 int (*set_rcvlowat)(struct sock *sk, int val);
226 };
227
228 #define DECLARE_SOCKADDR(type, dst, src) \
229 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
230
231 struct net_proto_family {
232 int family;
233 int (*create)(struct net *net, struct socket *sock,
234 int protocol, int kern);
235 struct module *owner;
236 };
237
238 struct iovec;
239 struct kvec;
240
241 enum {
242 SOCK_WAKE_IO,
243 SOCK_WAKE_WAITD,
244 SOCK_WAKE_SPACE,
245 SOCK_WAKE_URG,
246 };
247
248 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
249 int sock_register(const struct net_proto_family *fam);
250 void sock_unregister(int family);
251 bool sock_is_registered(int family);
252 int __sock_create(struct net *net, int family, int type, int proto,
253 struct socket **res, int kern);
254 int sock_create(int family, int type, int proto, struct socket **res);
255 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
256 int sock_create_lite(int family, int type, int proto, struct socket **res);
257 struct socket *sock_alloc(void);
258 void sock_release(struct socket *sock);
259 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
260 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
261 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
262 struct socket *sockfd_lookup(int fd, int *err);
263 struct socket *sock_from_file(struct file *file);
264 #define sockfd_put(sock) fput(sock->file)
265 int net_ratelimit(void);
266
267 #define net_ratelimited_function(function, ...) \
268 do { \
269 if (net_ratelimit()) \
270 function(__VA_ARGS__); \
271 } while (0)
272
273 #define net_emerg_ratelimited(fmt, ...) \
274 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
275 #define net_alert_ratelimited(fmt, ...) \
276 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
277 #define net_crit_ratelimited(fmt, ...) \
278 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
279 #define net_err_ratelimited(fmt, ...) \
280 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
281 #define net_notice_ratelimited(fmt, ...) \
282 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
283 #define net_warn_ratelimited(fmt, ...) \
284 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
285 #define net_info_ratelimited(fmt, ...) \
286 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
287 #if defined(CONFIG_DYNAMIC_DEBUG) || \
288 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
289 #define net_dbg_ratelimited(fmt, ...) \
290 do { \
291 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
292 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \
293 net_ratelimit()) \
294 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
295 ##__VA_ARGS__); \
296 } while (0)
297 #elif defined(DEBUG)
298 #define net_dbg_ratelimited(fmt, ...) \
299 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
300 #else
301 #define net_dbg_ratelimited(fmt, ...) \
302 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
303 #endif
304
305 #define net_get_random_once(buf, nbytes) \
306 get_random_once((buf), (nbytes))
307
308 /*
309 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
310 * data pages, or other high order pages allocated by
311 * __get_free_pages() without __GFP_COMP, which have a page_count
312 * of 0 and/or have PageSlab() set. We cannot use send_page for
313 * those, as that does get_page(); put_page(); and would cause
314 * either a VM_BUG directly, or __page_cache_release a page that
315 * would actually still be referenced by someone, leading to some
316 * obscure delayed Oops somewhere else.
317 */
sendpage_ok(struct page * page)318 static inline bool sendpage_ok(struct page *page)
319 {
320 return !PageSlab(page) && page_count(page) >= 1;
321 }
322
323 /*
324 * Check sendpage_ok on contiguous pages.
325 */
sendpages_ok(struct page * page,size_t len,size_t offset)326 static inline bool sendpages_ok(struct page *page, size_t len, size_t offset)
327 {
328 struct page *p = page + (offset >> PAGE_SHIFT);
329 size_t count = 0;
330
331 while (count < len) {
332 if (!sendpage_ok(p))
333 return false;
334
335 p++;
336 count += PAGE_SIZE;
337 }
338
339 return true;
340 }
341
342 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
343 size_t num, size_t len);
344 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
345 size_t num, size_t len, int flags);
346
347 int kernel_bind(struct socket *sock, struct sockaddr_unsized *addr, int addrlen);
348 int kernel_listen(struct socket *sock, int backlog);
349 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
350 int kernel_connect(struct socket *sock, struct sockaddr_unsized *addr, int addrlen,
351 int flags);
352 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
353 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
354 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
355
356 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
357 u32 kernel_sock_ip_overhead(struct sock *sk);
358
359 #define MODULE_ALIAS_NETPROTO(proto) \
360 MODULE_ALIAS("net-pf-" __stringify(proto))
361
362 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
363 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
364
365 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
366 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
367 "-type-" __stringify(type))
368
369 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
370 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
371 name)
372 #endif /* _LINUX_NET_H */
373