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 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 typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *); 156 157 158 struct proto_ops { 159 int family; 160 struct module *owner; 161 int (*release) (struct socket *sock); 162 int (*bind) (struct socket *sock, 163 struct sockaddr *myaddr, 164 int sockaddr_len); 165 int (*connect) (struct socket *sock, 166 struct sockaddr *vaddr, 167 int sockaddr_len, int flags); 168 int (*socketpair)(struct socket *sock1, 169 struct socket *sock2); 170 int (*accept) (struct socket *sock, 171 struct socket *newsock, int flags, bool kern); 172 int (*getname) (struct socket *sock, 173 struct sockaddr *addr, 174 int peer); 175 __poll_t (*poll) (struct file *file, struct socket *sock, 176 struct poll_table_struct *wait); 177 int (*ioctl) (struct socket *sock, unsigned int cmd, 178 unsigned long arg); 179 #ifdef CONFIG_COMPAT 180 int (*compat_ioctl) (struct socket *sock, unsigned int cmd, 181 unsigned long arg); 182 #endif 183 int (*gettstamp) (struct socket *sock, void __user *userstamp, 184 bool timeval, bool time32); 185 int (*listen) (struct socket *sock, int len); 186 int (*shutdown) (struct socket *sock, int flags); 187 int (*setsockopt)(struct socket *sock, int level, 188 int optname, sockptr_t optval, 189 unsigned int optlen); 190 int (*getsockopt)(struct socket *sock, int level, 191 int optname, char __user *optval, int __user *optlen); 192 void (*show_fdinfo)(struct seq_file *m, struct socket *sock); 193 int (*sendmsg) (struct socket *sock, struct msghdr *m, 194 size_t total_len); 195 /* Notes for implementing recvmsg: 196 * =============================== 197 * msg->msg_namelen should get updated by the recvmsg handlers 198 * iff msg_name != NULL. It is by default 0 to prevent 199 * returning uninitialized memory to user space. The recvfrom 200 * handlers can assume that msg.msg_name is either NULL or has 201 * a minimum size of sizeof(struct sockaddr_storage). 202 */ 203 int (*recvmsg) (struct socket *sock, struct msghdr *m, 204 size_t total_len, int flags); 205 int (*mmap) (struct file *file, struct socket *sock, 206 struct vm_area_struct * vma); 207 ssize_t (*sendpage) (struct socket *sock, struct page *page, 208 int offset, size_t size, int flags); 209 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos, 210 struct pipe_inode_info *pipe, size_t len, unsigned int flags); 211 int (*set_peek_off)(struct sock *sk, int val); 212 int (*peek_len)(struct socket *sock); 213 214 /* The following functions are called internally by kernel with 215 * sock lock already held. 216 */ 217 int (*read_sock)(struct sock *sk, read_descriptor_t *desc, 218 sk_read_actor_t recv_actor); 219 /* This is different from read_sock(), it reads an entire skb at a time. */ 220 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor); 221 int (*sendpage_locked)(struct sock *sk, struct page *page, 222 int offset, size_t size, int flags); 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 do { \ 303 if (0) \ 304 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ 305 } while (0) 306 #endif 307 308 #define net_get_random_once(buf, nbytes) \ 309 get_random_once((buf), (nbytes)) 310 311 /* 312 * E.g. XFS meta- & log-data is in slab pages, or bcache meta 313 * data pages, or other high order pages allocated by 314 * __get_free_pages() without __GFP_COMP, which have a page_count 315 * of 0 and/or have PageSlab() set. We cannot use send_page for 316 * those, as that does get_page(); put_page(); and would cause 317 * either a VM_BUG directly, or __page_cache_release a page that 318 * would actually still be referenced by someone, leading to some 319 * obscure delayed Oops somewhere else. 320 */ 321 static inline bool sendpage_ok(struct page *page) 322 { 323 return !PageSlab(page) && page_count(page) >= 1; 324 } 325 326 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 327 size_t num, size_t len); 328 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg, 329 struct kvec *vec, size_t num, size_t len); 330 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 331 size_t num, size_t len, int flags); 332 333 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen); 334 int kernel_listen(struct socket *sock, int backlog); 335 int kernel_accept(struct socket *sock, struct socket **newsock, int flags); 336 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen, 337 int flags); 338 int kernel_getsockname(struct socket *sock, struct sockaddr *addr); 339 int kernel_getpeername(struct socket *sock, struct sockaddr *addr); 340 int kernel_sendpage(struct socket *sock, struct page *page, int offset, 341 size_t size, int flags); 342 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset, 343 size_t size, int flags); 344 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how); 345 346 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */ 347 u32 kernel_sock_ip_overhead(struct sock *sk); 348 349 #define MODULE_ALIAS_NETPROTO(proto) \ 350 MODULE_ALIAS("net-pf-" __stringify(proto)) 351 352 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \ 353 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto)) 354 355 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \ 356 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 357 "-type-" __stringify(type)) 358 359 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \ 360 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 361 name) 362 #endif /* _LINUX_NET_H */ 363