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, <[email protected]> 11 * Ross Biro 12 * Fred N. van Kempen, <[email protected]> 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 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 73 #define SOCK_MAX (SOCK_PACKET + 1) 74 /* Mask which covers at least up to SOCK_MASK-1. The 75 * remaining bits are used as flags. */ 76 #define SOCK_TYPE_MASK 0xf 77 78 /* Flags for socket, socketpair, accept4 */ 79 #define SOCK_CLOEXEC O_CLOEXEC 80 #ifndef SOCK_NONBLOCK 81 #define SOCK_NONBLOCK O_NONBLOCK 82 #endif 83 84 #endif /* ARCH_HAS_SOCKET_TYPES */ 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; 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 sockaddr; 152 struct msghdr; 153 struct module; 154 struct sk_buff; 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 *myaddr, 166 int sockaddr_len); 167 int (*connect) (struct socket *sock, 168 struct sockaddr *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, int flags, bool kern); 174 int (*getname) (struct socket *sock, 175 struct sockaddr *addr, 176 int peer); 177 __poll_t (*poll) (struct file *file, struct socket *sock, 178 struct poll_table_struct *wait); 179 int (*ioctl) (struct socket *sock, unsigned int cmd, 180 unsigned long arg); 181 #ifdef CONFIG_COMPAT 182 int (*compat_ioctl) (struct socket *sock, unsigned int cmd, 183 unsigned long arg); 184 #endif 185 int (*gettstamp) (struct socket *sock, void __user *userstamp, 186 bool timeval, bool time32); 187 int (*listen) (struct socket *sock, int len); 188 int (*shutdown) (struct socket *sock, int flags); 189 int (*setsockopt)(struct socket *sock, int level, 190 int optname, sockptr_t optval, 191 unsigned int optlen); 192 int (*getsockopt)(struct socket *sock, int level, 193 int optname, char __user *optval, int __user *optlen); 194 void (*show_fdinfo)(struct seq_file *m, struct socket *sock); 195 int (*sendmsg) (struct socket *sock, struct msghdr *m, 196 size_t total_len); 197 /* Notes for implementing recvmsg: 198 * =============================== 199 * msg->msg_namelen should get updated by the recvmsg handlers 200 * iff msg_name != NULL. It is by default 0 to prevent 201 * returning uninitialized memory to user space. The recvfrom 202 * handlers can assume that msg.msg_name is either NULL or has 203 * a minimum size of sizeof(struct sockaddr_storage). 204 */ 205 int (*recvmsg) (struct socket *sock, struct msghdr *m, 206 size_t total_len, int flags); 207 int (*mmap) (struct file *file, struct socket *sock, 208 struct vm_area_struct * vma); 209 ssize_t (*sendpage) (struct socket *sock, struct page *page, 210 int offset, size_t size, int flags); 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 (*sendpage_locked)(struct sock *sk, struct page *page, 225 int offset, size_t size, int flags); 226 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg, 227 size_t size); 228 int (*set_rcvlowat)(struct sock *sk, int val); 229 }; 230 231 #define DECLARE_SOCKADDR(type, dst, src) \ 232 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; }) 233 234 struct net_proto_family { 235 int family; 236 int (*create)(struct net *net, struct socket *sock, 237 int protocol, int kern); 238 struct module *owner; 239 }; 240 241 struct iovec; 242 struct kvec; 243 244 enum { 245 SOCK_WAKE_IO, 246 SOCK_WAKE_WAITD, 247 SOCK_WAKE_SPACE, 248 SOCK_WAKE_URG, 249 }; 250 251 int sock_wake_async(struct socket_wq *sk_wq, int how, int band); 252 int sock_register(const struct net_proto_family *fam); 253 void sock_unregister(int family); 254 bool sock_is_registered(int family); 255 int __sock_create(struct net *net, int family, int type, int proto, 256 struct socket **res, int kern); 257 int sock_create(int family, int type, int proto, struct socket **res); 258 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res); 259 int sock_create_lite(int family, int type, int proto, struct socket **res); 260 struct socket *sock_alloc(void); 261 void sock_release(struct socket *sock); 262 int sock_sendmsg(struct socket *sock, struct msghdr *msg); 263 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags); 264 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname); 265 struct socket *sockfd_lookup(int fd, int *err); 266 struct socket *sock_from_file(struct file *file); 267 #define sockfd_put(sock) fput(sock->file) 268 int net_ratelimit(void); 269 270 #define net_ratelimited_function(function, ...) \ 271 do { \ 272 if (net_ratelimit()) \ 273 function(__VA_ARGS__); \ 274 } while (0) 275 276 #define net_emerg_ratelimited(fmt, ...) \ 277 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__) 278 #define net_alert_ratelimited(fmt, ...) \ 279 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__) 280 #define net_crit_ratelimited(fmt, ...) \ 281 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__) 282 #define net_err_ratelimited(fmt, ...) \ 283 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__) 284 #define net_notice_ratelimited(fmt, ...) \ 285 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__) 286 #define net_warn_ratelimited(fmt, ...) \ 287 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__) 288 #define net_info_ratelimited(fmt, ...) \ 289 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__) 290 #if defined(CONFIG_DYNAMIC_DEBUG) || \ 291 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) 292 #define net_dbg_ratelimited(fmt, ...) \ 293 do { \ 294 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \ 295 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \ 296 net_ratelimit()) \ 297 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ 298 ##__VA_ARGS__); \ 299 } while (0) 300 #elif defined(DEBUG) 301 #define net_dbg_ratelimited(fmt, ...) \ 302 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__) 303 #else 304 #define net_dbg_ratelimited(fmt, ...) \ 305 do { \ 306 if (0) \ 307 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ 308 } while (0) 309 #endif 310 311 #define net_get_random_once(buf, nbytes) \ 312 get_random_once((buf), (nbytes)) 313 314 /* 315 * E.g. XFS meta- & log-data is in slab pages, or bcache meta 316 * data pages, or other high order pages allocated by 317 * __get_free_pages() without __GFP_COMP, which have a page_count 318 * of 0 and/or have PageSlab() set. We cannot use send_page for 319 * those, as that does get_page(); put_page(); and would cause 320 * either a VM_BUG directly, or __page_cache_release a page that 321 * would actually still be referenced by someone, leading to some 322 * obscure delayed Oops somewhere else. 323 */ 324 static inline bool sendpage_ok(struct page *page) 325 { 326 return !PageSlab(page) && page_count(page) >= 1; 327 } 328 329 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 330 size_t num, size_t len); 331 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg, 332 struct kvec *vec, size_t num, size_t len); 333 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 334 size_t num, size_t len, int flags); 335 336 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen); 337 int kernel_listen(struct socket *sock, int backlog); 338 int kernel_accept(struct socket *sock, struct socket **newsock, int flags); 339 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen, 340 int flags); 341 int kernel_getsockname(struct socket *sock, struct sockaddr *addr); 342 int kernel_getpeername(struct socket *sock, struct sockaddr *addr); 343 int kernel_sendpage(struct socket *sock, struct page *page, int offset, 344 size_t size, int flags); 345 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset, 346 size_t size, int flags); 347 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how); 348 349 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */ 350 u32 kernel_sock_ip_overhead(struct sock *sk); 351 352 #define MODULE_ALIAS_NETPROTO(proto) \ 353 MODULE_ALIAS("net-pf-" __stringify(proto)) 354 355 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \ 356 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto)) 357 358 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \ 359 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 360 "-type-" __stringify(type)) 361 362 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \ 363 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 364 name) 365 #endif /* _LINUX_NET_H */ 366