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 #define SOCK_CUSTOM_SOCKOPT 6 46 #define SOCK_PASSPIDFD 7 47 48 #ifndef ARCH_HAS_SOCKET_TYPES 49 /** 50 * enum sock_type - Socket types 51 * @SOCK_STREAM: stream (connection) socket 52 * @SOCK_DGRAM: datagram (conn.less) socket 53 * @SOCK_RAW: raw socket 54 * @SOCK_RDM: reliably-delivered message 55 * @SOCK_SEQPACKET: sequential packet socket 56 * @SOCK_DCCP: Datagram Congestion Control Protocol socket 57 * @SOCK_PACKET: linux specific way of getting packets at the dev level. 58 * For writing rarp and other similar things on the user level. 59 * 60 * When adding some new socket type please 61 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS 62 * overrides this enum for binary compat reasons. 63 */ 64 enum sock_type { 65 SOCK_STREAM = 1, 66 SOCK_DGRAM = 2, 67 SOCK_RAW = 3, 68 SOCK_RDM = 4, 69 SOCK_SEQPACKET = 5, 70 SOCK_DCCP = 6, 71 SOCK_PACKET = 10, 72 }; 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 85 #endif /* ARCH_HAS_SOCKET_TYPES */ 86 87 /** 88 * enum sock_shutdown_cmd - Shutdown types 89 * @SHUT_RD: shutdown receptions 90 * @SHUT_WR: shutdown transmissions 91 * @SHUT_RDWR: shutdown receptions/transmissions 92 */ 93 enum sock_shutdown_cmd { 94 SHUT_RD, 95 SHUT_WR, 96 SHUT_RDWR, 97 }; 98 99 struct socket_wq { 100 /* Note: wait MUST be first field of socket_wq */ 101 wait_queue_head_t wait; 102 struct fasync_struct *fasync_list; 103 unsigned long flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */ 104 struct rcu_head rcu; 105 } ____cacheline_aligned_in_smp; 106 107 /** 108 * struct socket - general BSD socket 109 * @state: socket state (%SS_CONNECTED, etc) 110 * @type: socket type (%SOCK_STREAM, etc) 111 * @flags: socket flags (%SOCK_NOSPACE, etc) 112 * @ops: protocol specific socket operations 113 * @file: File back pointer for gc 114 * @sk: internal networking protocol agnostic socket representation 115 * @wq: wait queue for several uses 116 */ 117 struct socket { 118 socket_state state; 119 120 short type; 121 122 unsigned long flags; 123 124 struct file *file; 125 struct sock *sk; 126 const struct proto_ops *ops; /* Might change with IPV6_ADDRFORM or MPTCP. */ 127 128 struct socket_wq wq; 129 }; 130 131 /* 132 * "descriptor" for what we're up to with a read. 133 * This allows us to use the same read code yet 134 * have multiple different users of the data that 135 * we read from a file. 136 * 137 * The simplest case just copies the data to user 138 * mode. 139 */ 140 typedef struct { 141 size_t written; 142 size_t count; 143 union { 144 char __user *buf; 145 void *data; 146 } arg; 147 int error; 148 } read_descriptor_t; 149 150 struct vm_area_struct; 151 struct page; 152 struct sockaddr; 153 struct msghdr; 154 struct module; 155 struct sk_buff; 156 struct proto_accept_arg; 157 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, 158 unsigned int, size_t); 159 typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *); 160 161 162 struct proto_ops { 163 int family; 164 struct module *owner; 165 int (*release) (struct socket *sock); 166 int (*bind) (struct socket *sock, 167 struct sockaddr *myaddr, 168 int sockaddr_len); 169 int (*connect) (struct socket *sock, 170 struct sockaddr *vaddr, 171 int sockaddr_len, int flags); 172 int (*socketpair)(struct socket *sock1, 173 struct socket *sock2); 174 int (*accept) (struct socket *sock, 175 struct socket *newsock, 176 struct proto_accept_arg *arg); 177 int (*getname) (struct socket *sock, 178 struct sockaddr *addr, 179 int peer); 180 __poll_t (*poll) (struct file *file, struct socket *sock, 181 struct poll_table_struct *wait); 182 int (*ioctl) (struct socket *sock, unsigned int cmd, 183 unsigned long arg); 184 #ifdef CONFIG_COMPAT 185 int (*compat_ioctl) (struct socket *sock, unsigned int cmd, 186 unsigned long arg); 187 #endif 188 int (*gettstamp) (struct socket *sock, void __user *userstamp, 189 bool timeval, bool time32); 190 int (*listen) (struct socket *sock, int len); 191 int (*shutdown) (struct socket *sock, int flags); 192 int (*setsockopt)(struct socket *sock, int level, 193 int optname, sockptr_t optval, 194 unsigned int optlen); 195 int (*getsockopt)(struct socket *sock, int level, 196 int optname, char __user *optval, int __user *optlen); 197 void (*show_fdinfo)(struct seq_file *m, struct socket *sock); 198 int (*sendmsg) (struct socket *sock, struct msghdr *m, 199 size_t total_len); 200 /* Notes for implementing recvmsg: 201 * =============================== 202 * msg->msg_namelen should get updated by the recvmsg handlers 203 * iff msg_name != NULL. It is by default 0 to prevent 204 * returning uninitialized memory to user space. The recvfrom 205 * handlers can assume that msg.msg_name is either NULL or has 206 * a minimum size of sizeof(struct sockaddr_storage). 207 */ 208 int (*recvmsg) (struct socket *sock, struct msghdr *m, 209 size_t total_len, int flags); 210 int (*mmap) (struct file *file, struct socket *sock, 211 struct vm_area_struct * vma); 212 ssize_t (*splice_read)(struct socket *sock, loff_t *ppos, 213 struct pipe_inode_info *pipe, size_t len, unsigned int flags); 214 void (*splice_eof)(struct socket *sock); 215 int (*set_peek_off)(struct sock *sk, int val); 216 int (*peek_len)(struct socket *sock); 217 218 /* The following functions are called internally by kernel with 219 * sock lock already held. 220 */ 221 int (*read_sock)(struct sock *sk, read_descriptor_t *desc, 222 sk_read_actor_t recv_actor); 223 /* This is different from read_sock(), it reads an entire skb at a time. */ 224 int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor); 225 int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg, 226 size_t size); 227 int (*set_rcvlowat)(struct sock *sk, int val); 228 }; 229 230 #define DECLARE_SOCKADDR(type, dst, src) \ 231 type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; }) 232 233 struct net_proto_family { 234 int family; 235 int (*create)(struct net *net, struct socket *sock, 236 int protocol, int kern); 237 struct module *owner; 238 }; 239 240 struct iovec; 241 struct kvec; 242 243 enum { 244 SOCK_WAKE_IO, 245 SOCK_WAKE_WAITD, 246 SOCK_WAKE_SPACE, 247 SOCK_WAKE_URG, 248 }; 249 250 int sock_wake_async(struct socket_wq *sk_wq, int how, int band); 251 int sock_register(const struct net_proto_family *fam); 252 void sock_unregister(int family); 253 bool sock_is_registered(int family); 254 int __sock_create(struct net *net, int family, int type, int proto, 255 struct socket **res, int kern); 256 int sock_create(int family, int type, int proto, struct socket **res); 257 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res); 258 int sock_create_lite(int family, int type, int proto, struct socket **res); 259 struct socket *sock_alloc(void); 260 void sock_release(struct socket *sock); 261 int sock_sendmsg(struct socket *sock, struct msghdr *msg); 262 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags); 263 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname); 264 struct socket *sockfd_lookup(int fd, int *err); 265 struct socket *sock_from_file(struct file *file); 266 #define sockfd_put(sock) fput(sock->file) 267 int net_ratelimit(void); 268 269 #define net_ratelimited_function(function, ...) \ 270 do { \ 271 if (net_ratelimit()) \ 272 function(__VA_ARGS__); \ 273 } while (0) 274 275 #define net_emerg_ratelimited(fmt, ...) \ 276 net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__) 277 #define net_alert_ratelimited(fmt, ...) \ 278 net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__) 279 #define net_crit_ratelimited(fmt, ...) \ 280 net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__) 281 #define net_err_ratelimited(fmt, ...) \ 282 net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__) 283 #define net_notice_ratelimited(fmt, ...) \ 284 net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__) 285 #define net_warn_ratelimited(fmt, ...) \ 286 net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__) 287 #define net_info_ratelimited(fmt, ...) \ 288 net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__) 289 #if defined(CONFIG_DYNAMIC_DEBUG) || \ 290 (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) 291 #define net_dbg_ratelimited(fmt, ...) \ 292 do { \ 293 DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \ 294 if (DYNAMIC_DEBUG_BRANCH(descriptor) && \ 295 net_ratelimit()) \ 296 __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ 297 ##__VA_ARGS__); \ 298 } while (0) 299 #elif defined(DEBUG) 300 #define net_dbg_ratelimited(fmt, ...) \ 301 net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__) 302 #else 303 #define net_dbg_ratelimited(fmt, ...) \ 304 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) 305 #endif 306 307 #define net_get_random_once(buf, nbytes) \ 308 get_random_once((buf), (nbytes)) 309 310 /* 311 * E.g. XFS meta- & log-data is in slab pages, or bcache meta 312 * data pages, or other high order pages allocated by 313 * __get_free_pages() without __GFP_COMP, which have a page_count 314 * of 0 and/or have PageSlab() set. We cannot use send_page for 315 * those, as that does get_page(); put_page(); and would cause 316 * either a VM_BUG directly, or __page_cache_release a page that 317 * would actually still be referenced by someone, leading to some 318 * obscure delayed Oops somewhere else. 319 */ sendpage_ok(struct page * page)320 static inline bool sendpage_ok(struct page *page) 321 { 322 return !PageSlab(page) && page_count(page) >= 1; 323 } 324 325 /* 326 * Check sendpage_ok on contiguous pages. 327 */ sendpages_ok(struct page * page,size_t len,size_t offset)328 static inline bool sendpages_ok(struct page *page, size_t len, size_t offset) 329 { 330 struct page *p = page + (offset >> PAGE_SHIFT); 331 size_t count = 0; 332 333 while (count < len) { 334 if (!sendpage_ok(p)) 335 return false; 336 337 p++; 338 count += PAGE_SIZE; 339 } 340 341 return true; 342 } 343 344 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 345 size_t num, size_t len); 346 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg, 347 struct kvec *vec, size_t num, size_t len); 348 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, 349 size_t num, size_t len, int flags); 350 351 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen); 352 int kernel_listen(struct socket *sock, int backlog); 353 int kernel_accept(struct socket *sock, struct socket **newsock, int flags); 354 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen, 355 int flags); 356 int kernel_getsockname(struct socket *sock, struct sockaddr *addr); 357 int kernel_getpeername(struct socket *sock, struct sockaddr *addr); 358 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how); 359 360 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */ 361 u32 kernel_sock_ip_overhead(struct sock *sk); 362 363 #define MODULE_ALIAS_NETPROTO(proto) \ 364 MODULE_ALIAS("net-pf-" __stringify(proto)) 365 366 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \ 367 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto)) 368 369 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \ 370 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 371 "-type-" __stringify(type)) 372 373 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \ 374 MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \ 375 name) 376 #endif /* _LINUX_NET_H */ 377