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 46 #ifndef ARCH_HAS_SOCKET_TYPES 47 /** 48 * enum sock_type - Socket types 49 * @SOCK_STREAM: stream (connection) socket 50 * @SOCK_DGRAM: datagram (conn.less) socket 51 * @SOCK_RAW: raw socket 52 * @SOCK_RDM: reliably-delivered message 53 * @SOCK_SEQPACKET: sequential packet socket 54 * @SOCK_DCCP: Datagram Congestion Control Protocol socket 55 * @SOCK_PACKET: linux specific way of getting packets at the dev level. 56 * For writing rarp and other similar things on the user level. 57 * 58 * When adding some new socket type please 59 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS 60 * overrides this enum for binary compat reasons. 61 */ 62 enum sock_type { 63 SOCK_STREAM = 1, 64 SOCK_DGRAM = 2, 65 SOCK_RAW = 3, 66 SOCK_RDM = 4, 67 SOCK_SEQPACKET = 5, 68 SOCK_DCCP = 6, 69 SOCK_PACKET = 10, 70 }; 71 72 #define SOCK_MAX (SOCK_PACKET + 1) 73 /* Mask which covers at least up to SOCK_MASK-1. The 74 * remaining bits are used as flags. */ 75 #define SOCK_TYPE_MASK 0xf 76 77 /* Flags for socket, socketpair, accept4 */ 78 #define SOCK_CLOEXEC O_CLOEXEC 79 #ifndef SOCK_NONBLOCK 80 #define SOCK_NONBLOCK O_NONBLOCK 81 #endif 82 83 #endif /* ARCH_HAS_SOCKET_TYPES */ 84 85 /** 86 * enum sock_shutdown_cmd - Shutdown types 87 * @SHUT_RD: shutdown receptions 88 * @SHUT_WR: shutdown transmissions 89 * @SHUT_RDWR: shutdown receptions/transmissions 90 */ 91 enum sock_shutdown_cmd { 92 SHUT_RD, 93 SHUT_WR, 94 SHUT_RDWR, 95 }; 96 97 struct socket_wq { 98 /* Note: wait MUST be first field of socket_wq */ 99 wait_queue_head_t wait; 100 struct fasync_struct *fasync_list; 101 unsigned long flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */ 102 struct rcu_head rcu; 103 } ____cacheline_aligned_in_smp; 104 105 /** 106 * struct socket - general BSD socket 107 * @state: socket state (%SS_CONNECTED, etc) 108 * @type: socket type (%SOCK_STREAM, etc) 109 * @flags: socket flags (%SOCK_NOSPACE, etc) 110 * @ops: protocol specific socket operations 111 * @file: File back pointer for gc 112 * @sk: internal networking protocol agnostic socket representation 113 * @wq: wait queue for several uses 114 */ 115 struct socket { 116 socket_state state; 117 118 short type; 119 120 unsigned long flags; 121 122 struct file *file; 123 struct sock *sk; 124 const struct proto_ops *ops; 125 126 struct socket_wq wq; 127 }; 128 129 /* 130 * "descriptor" for what we're up to with a read. 131 * This allows us to use the same read code yet 132 * have multiple different users of the data that 133 * we read from a file. 134 * 135 * The simplest case just copies the data to user 136 * mode. 137 */ 138 typedef struct { 139 size_t written; 140 size_t count; 141 union { 142 char __user *buf; 143 void *data; 144 } arg; 145 int error; 146 } read_descriptor_t; 147 148 struct vm_area_struct; 149 struct page; 150 struct sockaddr; 151 struct msghdr; 152 struct module; 153 struct sk_buff; 154 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, 155 unsigned int, size_t); 156 typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *); 157 158 159 struct proto_ops { 160 int family; 161 struct module *owner; 162 int (*release) (struct socket *sock); 163 int (*bind) (struct socket *sock, 164 struct sockaddr *myaddr, 165 int sockaddr_len); 166 int (*connect) (struct socket *sock, 167 struct sockaddr *vaddr, 168 int sockaddr_len, int flags); 169 int (*socketpair)(struct socket *sock1, 170 struct socket *sock2); 171 int (*accept) (struct socket *sock, 172 struct socket *newsock, int flags, bool kern); 173 int (*getname) (struct socket *sock, 174 struct sockaddr *addr, 175 int peer); 176 __poll_t (*poll) (struct file *file, struct socket *sock, 177 struct poll_table_struct *wait); 178 int (*ioctl) (struct socket *sock, unsigned int cmd, 179 unsigned long arg); 180 #ifdef CONFIG_COMPAT 181 int (*compat_ioctl) (struct socket *sock, unsigned int cmd, 182 unsigned long arg); 183 #endif 184 int (*gettstamp) (struct socket *sock, void __user *userstamp, 185 bool timeval, bool time32); 186 int (*listen) (struct socket *sock, int len); 187 int (*shutdown) (struct socket *sock, int flags); 188 int (*setsockopt)(struct socket *sock, int level, 189 int optname, sockptr_t optval, 190 unsigned int optlen); 191 int (*getsockopt)(struct socket *sock, int level, 192 int optname, char __user *optval, int __user *optlen); 193 void (*show_fdinfo)(struct seq_file *m, struct socket *sock); 194 int (*sendmsg) (struct socket *sock, struct msghdr *m, 195 size_t total_len); 196 /* Notes for implementing recvmsg: 197 * =============================== 198 * msg->msg_namelen should get updated by the recvmsg handlers 199 * iff msg_name != NULL. It is by default 0 to prevent 200 * returning uninitialized memory to user space. The recvfrom 201 * handlers can assume that msg.msg_name is either NULL or has 202 * a minimum size of sizeof(struct sockaddr_storage). 203 */ 204 int (*recvmsg) (struct socket *sock, struct msghdr *m, 205 size_t total_len, int flags); 206 int (*mmap) (struct file *file, struct socket *sock, 207 struct vm_area_struct * vma); 208 ssize_t (*sendpage) (struct socket *sock, struct page *page, 209 int offset, size_t size, int flags); 210 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos, 211 struct pipe_inode_info *pipe, size_t len, unsigned int flags); 212 int (*set_peek_off)(struct sock *sk, int val); 213 int (*peek_len)(struct socket *sock); 214 215 /* The following functions are called internally by kernel with 216 * sock lock already held. 217 */ 218 int (*read_sock)(struct sock *sk, read_descriptor_t *desc, 219 sk_read_actor_t recv_actor); 220 /* This is different from read_sock(), it reads an entire skb at a time. */ 221 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor); 222 int (*sendpage_locked)(struct sock *sk, struct page *page, 223 int offset, size_t size, int flags); 224 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg, 225 size_t size); 226 int (*set_rcvlowat)(struct sock *sk, int val); 227 }; 228 229 #define DECLARE_SOCKADDR(type, dst, src) \ 230 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; }) 231 232 struct net_proto_family { 233 int family; 234 int (*create)(struct net *net, struct socket *sock, 235 int protocol, int kern); 236 struct module *owner; 237 }; 238 239 struct iovec; 240 struct kvec; 241 242 enum { 243 SOCK_WAKE_IO, 244 SOCK_WAKE_WAITD, 245 SOCK_WAKE_SPACE, 246 SOCK_WAKE_URG, 247 }; 248 249 int sock_wake_async(struct socket_wq *sk_wq, int how, int band); 250 int sock_register(const struct net_proto_family *fam); 251 void sock_unregister(int family); 252 bool sock_is_registered(int family); 253 int __sock_create(struct net *net, int family, int type, int proto, 254 struct socket **res, int kern); 255 int sock_create(int family, int type, int proto, struct socket **res); 256 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res); 257 int sock_create_lite(int family, int type, int proto, struct socket **res); 258 struct socket *sock_alloc(void); 259 void sock_release(struct socket *sock); 260 int sock_sendmsg(struct socket *sock, struct msghdr *msg); 261 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags); 262 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname); 263 struct socket *sockfd_lookup(int fd, int *err); 264 struct socket *sock_from_file(struct file *file); 265 #define sockfd_put(sock) fput(sock->file) 266 int net_ratelimit(void); 267 268 #define net_ratelimited_function(function, ...) \ 269 do { \ 270 if (net_ratelimit()) \ 271 function(__VA_ARGS__); \ 272 } while (0) 273 274 #define net_emerg_ratelimited(fmt, ...) \ 275 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__) 276 #define net_alert_ratelimited(fmt, ...) \ 277 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__) 278 #define net_crit_ratelimited(fmt, ...) \ 279 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__) 280 #define net_err_ratelimited(fmt, ...) \ 281 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__) 282 #define net_notice_ratelimited(fmt, ...) \ 283 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__) 284 #define net_warn_ratelimited(fmt, ...) \ 285 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__) 286 #define net_info_ratelimited(fmt, ...) \ 287 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__) 288 #if defined(CONFIG_DYNAMIC_DEBUG) || \ 289 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) 290 #define net_dbg_ratelimited(fmt, ...) \ 291 do { \ 292 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \ 293 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \ 294 net_ratelimit()) \ 295 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ 296 ##__VA_ARGS__); \ 297 } while (0) 298 #elif defined(DEBUG) 299 #define net_dbg_ratelimited(fmt, ...) \ 300 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__) 301 #else 302 #define net_dbg_ratelimited(fmt, ...) \ 303 do { \ 304 if (0) \ 305 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ 306 } while (0) 307 #endif 308 309 #define net_get_random_once(buf, nbytes) \ 310 get_random_once((buf), (nbytes)) 311 312 /* 313 * E.g. XFS meta- & log-data is in slab pages, or bcache meta 314 * data pages, or other high order pages allocated by 315 * __get_free_pages() without __GFP_COMP, which have a page_count 316 * of 0 and/or have PageSlab() set. We cannot use send_page for 317 * those, as that does get_page(); put_page(); and would cause 318 * either a VM_BUG directly, or __page_cache_release a page that 319 * would actually still be referenced by someone, leading to some 320 * obscure delayed Oops somewhere else. 321 */ 322 static inline bool sendpage_ok(struct page *page) 323 { 324 return !PageSlab(page) && page_count(page) >= 1; 325 } 326 327 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 328 size_t num, size_t len); 329 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg, 330 struct kvec *vec, size_t num, size_t len); 331 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 332 size_t num, size_t len, int flags); 333 334 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen); 335 int kernel_listen(struct socket *sock, int backlog); 336 int kernel_accept(struct socket *sock, struct socket **newsock, int flags); 337 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen, 338 int flags); 339 int kernel_getsockname(struct socket *sock, struct sockaddr *addr); 340 int kernel_getpeername(struct socket *sock, struct sockaddr *addr); 341 int kernel_sendpage(struct socket *sock, struct page *page, int offset, 342 size_t size, int flags); 343 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset, 344 size_t size, int flags); 345 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how); 346 347 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */ 348 u32 kernel_sock_ip_overhead(struct sock *sk); 349 350 #define MODULE_ALIAS_NETPROTO(proto) \ 351 MODULE_ALIAS("net-pf-" __stringify(proto)) 352 353 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \ 354 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto)) 355 356 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \ 357 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 358 "-type-" __stringify(type)) 359 360 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \ 361 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 362 name) 363 #endif /* _LINUX_NET_H */ 364