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 45 #ifndef ARCH_HAS_SOCKET_TYPES 46 /** 47 * enum sock_type - Socket types 48 * @SOCK_STREAM: stream (connection) socket 49 * @SOCK_DGRAM: datagram (conn.less) socket 50 * @SOCK_RAW: raw socket 51 * @SOCK_RDM: reliably-delivered message 52 * @SOCK_SEQPACKET: sequential packet socket 53 * @SOCK_DCCP: Datagram Congestion Control Protocol socket 54 * @SOCK_PACKET: linux specific way of getting packets at the dev level. 55 * For writing rarp and other similar things on the user level. 56 * 57 * When adding some new socket type please 58 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS 59 * overrides this enum for binary compat reasons. 60 */ 61 enum sock_type { 62 SOCK_STREAM = 1, 63 SOCK_DGRAM = 2, 64 SOCK_RAW = 3, 65 SOCK_RDM = 4, 66 SOCK_SEQPACKET = 5, 67 SOCK_DCCP = 6, 68 SOCK_PACKET = 10, 69 }; 70 71 #define SOCK_MAX (SOCK_PACKET + 1) 72 /* Mask which covers at least up to SOCK_MASK-1. The 73 * remaining bits are used as flags. */ 74 #define SOCK_TYPE_MASK 0xf 75 76 /* Flags for socket, socketpair, accept4 */ 77 #define SOCK_CLOEXEC O_CLOEXEC 78 #ifndef SOCK_NONBLOCK 79 #define SOCK_NONBLOCK O_NONBLOCK 80 #endif 81 82 #endif /* ARCH_HAS_SOCKET_TYPES */ 83 84 /** 85 * enum sock_shutdown_cmd - Shutdown types 86 * @SHUT_RD: shutdown receptions 87 * @SHUT_WR: shutdown transmissions 88 * @SHUT_RDWR: shutdown receptions/transmissions 89 */ 90 enum sock_shutdown_cmd { 91 SHUT_RD, 92 SHUT_WR, 93 SHUT_RDWR, 94 }; 95 96 struct socket_wq { 97 /* Note: wait MUST be first field of socket_wq */ 98 wait_queue_head_t wait; 99 struct fasync_struct *fasync_list; 100 unsigned long flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */ 101 struct rcu_head rcu; 102 } ____cacheline_aligned_in_smp; 103 104 /** 105 * struct socket - general BSD socket 106 * @state: socket state (%SS_CONNECTED, etc) 107 * @type: socket type (%SOCK_STREAM, etc) 108 * @flags: socket flags (%SOCK_NOSPACE, etc) 109 * @ops: protocol specific socket operations 110 * @file: File back pointer for gc 111 * @sk: internal networking protocol agnostic socket representation 112 * @wq: wait queue for several uses 113 */ 114 struct socket { 115 socket_state state; 116 117 short type; 118 119 unsigned long flags; 120 121 struct file *file; 122 struct sock *sk; 123 const struct proto_ops *ops; 124 125 struct socket_wq wq; 126 }; 127 128 /* 129 * "descriptor" for what we're up to with a read. 130 * This allows us to use the same read code yet 131 * have multiple different users of the data that 132 * we read from a file. 133 * 134 * The simplest case just copies the data to user 135 * mode. 136 */ 137 typedef struct { 138 size_t written; 139 size_t count; 140 union { 141 char __user *buf; 142 void *data; 143 } arg; 144 int error; 145 } read_descriptor_t; 146 147 struct vm_area_struct; 148 struct page; 149 struct sockaddr; 150 struct msghdr; 151 struct module; 152 struct sk_buff; 153 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, 154 unsigned int, size_t); 155 156 struct proto_ops { 157 int family; 158 struct module *owner; 159 int (*release) (struct socket *sock); 160 int (*bind) (struct socket *sock, 161 struct sockaddr *myaddr, 162 int sockaddr_len); 163 int (*connect) (struct socket *sock, 164 struct sockaddr *vaddr, 165 int sockaddr_len, int flags); 166 int (*socketpair)(struct socket *sock1, 167 struct socket *sock2); 168 int (*accept) (struct socket *sock, 169 struct socket *newsock, int flags, bool kern); 170 int (*getname) (struct socket *sock, 171 struct sockaddr *addr, 172 int peer); 173 __poll_t (*poll) (struct file *file, struct socket *sock, 174 struct poll_table_struct *wait); 175 int (*ioctl) (struct socket *sock, unsigned int cmd, 176 unsigned long arg); 177 #ifdef CONFIG_COMPAT 178 int (*compat_ioctl) (struct socket *sock, unsigned int cmd, 179 unsigned long arg); 180 #endif 181 int (*gettstamp) (struct socket *sock, void __user *userstamp, 182 bool timeval, bool time32); 183 int (*listen) (struct socket *sock, int len); 184 int (*shutdown) (struct socket *sock, int flags); 185 int (*setsockopt)(struct socket *sock, int level, 186 int optname, sockptr_t optval, 187 unsigned int optlen); 188 int (*getsockopt)(struct socket *sock, int level, 189 int optname, char __user *optval, int __user *optlen); 190 void (*show_fdinfo)(struct seq_file *m, struct socket *sock); 191 int (*sendmsg) (struct socket *sock, struct msghdr *m, 192 size_t total_len); 193 /* Notes for implementing recvmsg: 194 * =============================== 195 * msg->msg_namelen should get updated by the recvmsg handlers 196 * iff msg_name != NULL. It is by default 0 to prevent 197 * returning uninitialized memory to user space. The recvfrom 198 * handlers can assume that msg.msg_name is either NULL or has 199 * a minimum size of sizeof(struct sockaddr_storage). 200 */ 201 int (*recvmsg) (struct socket *sock, struct msghdr *m, 202 size_t total_len, int flags); 203 int (*mmap) (struct file *file, struct socket *sock, 204 struct vm_area_struct * vma); 205 ssize_t (*sendpage) (struct socket *sock, struct page *page, 206 int offset, size_t size, int flags); 207 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos, 208 struct pipe_inode_info *pipe, size_t len, unsigned int flags); 209 int (*set_peek_off)(struct sock *sk, int val); 210 int (*peek_len)(struct socket *sock); 211 212 /* The following functions are called internally by kernel with 213 * sock lock already held. 214 */ 215 int (*read_sock)(struct sock *sk, read_descriptor_t *desc, 216 sk_read_actor_t recv_actor); 217 int (*sendpage_locked)(struct sock *sk, struct page *page, 218 int offset, size_t size, int flags); 219 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg, 220 size_t size); 221 int (*set_rcvlowat)(struct sock *sk, int val); 222 }; 223 224 #define DECLARE_SOCKADDR(type, dst, src) \ 225 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; }) 226 227 struct net_proto_family { 228 int family; 229 int (*create)(struct net *net, struct socket *sock, 230 int protocol, int kern); 231 struct module *owner; 232 }; 233 234 struct iovec; 235 struct kvec; 236 237 enum { 238 SOCK_WAKE_IO, 239 SOCK_WAKE_WAITD, 240 SOCK_WAKE_SPACE, 241 SOCK_WAKE_URG, 242 }; 243 244 int sock_wake_async(struct socket_wq *sk_wq, int how, int band); 245 int sock_register(const struct net_proto_family *fam); 246 void sock_unregister(int family); 247 bool sock_is_registered(int family); 248 int __sock_create(struct net *net, int family, int type, int proto, 249 struct socket **res, int kern); 250 int sock_create(int family, int type, int proto, struct socket **res); 251 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res); 252 int sock_create_lite(int family, int type, int proto, struct socket **res); 253 struct socket *sock_alloc(void); 254 void sock_release(struct socket *sock); 255 int sock_sendmsg(struct socket *sock, struct msghdr *msg); 256 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags); 257 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname); 258 struct socket *sockfd_lookup(int fd, int *err); 259 struct socket *sock_from_file(struct file *file); 260 #define sockfd_put(sock) fput(sock->file) 261 int net_ratelimit(void); 262 263 #define net_ratelimited_function(function, ...) \ 264 do { \ 265 if (net_ratelimit()) \ 266 function(__VA_ARGS__); \ 267 } while (0) 268 269 #define net_emerg_ratelimited(fmt, ...) \ 270 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__) 271 #define net_alert_ratelimited(fmt, ...) \ 272 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__) 273 #define net_crit_ratelimited(fmt, ...) \ 274 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__) 275 #define net_err_ratelimited(fmt, ...) \ 276 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__) 277 #define net_notice_ratelimited(fmt, ...) \ 278 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__) 279 #define net_warn_ratelimited(fmt, ...) \ 280 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__) 281 #define net_info_ratelimited(fmt, ...) \ 282 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__) 283 #if defined(CONFIG_DYNAMIC_DEBUG) || \ 284 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) 285 #define net_dbg_ratelimited(fmt, ...) \ 286 do { \ 287 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \ 288 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \ 289 net_ratelimit()) \ 290 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ 291 ##__VA_ARGS__); \ 292 } while (0) 293 #elif defined(DEBUG) 294 #define net_dbg_ratelimited(fmt, ...) \ 295 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__) 296 #else 297 #define net_dbg_ratelimited(fmt, ...) \ 298 do { \ 299 if (0) \ 300 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ 301 } while (0) 302 #endif 303 304 #define net_get_random_once(buf, nbytes) \ 305 get_random_once((buf), (nbytes)) 306 #define net_get_random_once_wait(buf, nbytes) \ 307 get_random_once_wait((buf), (nbytes)) 308 309 /* 310 * E.g. XFS meta- & log-data is in slab pages, or bcache meta 311 * data pages, or other high order pages allocated by 312 * __get_free_pages() without __GFP_COMP, which have a page_count 313 * of 0 and/or have PageSlab() set. We cannot use send_page for 314 * those, as that does get_page(); put_page(); and would cause 315 * either a VM_BUG directly, or __page_cache_release a page that 316 * would actually still be referenced by someone, leading to some 317 * obscure delayed Oops somewhere else. 318 */ 319 static inline bool sendpage_ok(struct page *page) 320 { 321 return !PageSlab(page) && page_count(page) >= 1; 322 } 323 324 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 325 size_t num, size_t len); 326 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg, 327 struct kvec *vec, size_t num, size_t len); 328 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 329 size_t num, size_t len, int flags); 330 331 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen); 332 int kernel_listen(struct socket *sock, int backlog); 333 int kernel_accept(struct socket *sock, struct socket **newsock, int flags); 334 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen, 335 int flags); 336 int kernel_getsockname(struct socket *sock, struct sockaddr *addr); 337 int kernel_getpeername(struct socket *sock, struct sockaddr *addr); 338 int kernel_sendpage(struct socket *sock, struct page *page, int offset, 339 size_t size, int flags); 340 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset, 341 size_t size, int flags); 342 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how); 343 344 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */ 345 u32 kernel_sock_ip_overhead(struct sock *sk); 346 347 #define MODULE_ALIAS_NETPROTO(proto) \ 348 MODULE_ALIAS("net-pf-" __stringify(proto)) 349 350 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \ 351 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto)) 352 353 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \ 354 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 355 "-type-" __stringify(type)) 356 357 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \ 358 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 359 name) 360 #endif /* _LINUX_NET_H */ 361