linux/include/linux/net.h
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   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
  25#include <uapi/linux/net.h>
  26
  27struct poll_table_struct;
  28struct pipe_inode_info;
  29struct inode;
  30struct file;
  31struct net;
  32
  33/* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
  34 * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
  35 * Eventually all flags will be in sk->sk_wq->flags.
  36 */
  37#define SOCKWQ_ASYNC_NOSPACE    0
  38#define SOCKWQ_ASYNC_WAITDATA   1
  39#define SOCK_NOSPACE            2
  40#define SOCK_PASSCRED           3
  41#define SOCK_PASSSEC            4
  42
  43#ifndef ARCH_HAS_SOCKET_TYPES
  44/**
  45 * enum sock_type - Socket types
  46 * @SOCK_STREAM: stream (connection) socket
  47 * @SOCK_DGRAM: datagram (conn.less) socket
  48 * @SOCK_RAW: raw socket
  49 * @SOCK_RDM: reliably-delivered message
  50 * @SOCK_SEQPACKET: sequential packet socket
  51 * @SOCK_DCCP: Datagram Congestion Control Protocol socket
  52 * @SOCK_PACKET: linux specific way of getting packets at the dev level.
  53 *                For writing rarp and other similar things on the user level.
  54 *
  55 * When adding some new socket type please
  56 * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
  57 * overrides this enum for binary compat reasons.
  58 */
  59enum sock_type {
  60        SOCK_STREAM     = 1,
  61        SOCK_DGRAM      = 2,
  62        SOCK_RAW        = 3,
  63        SOCK_RDM        = 4,
  64        SOCK_SEQPACKET  = 5,
  65        SOCK_DCCP       = 6,
  66        SOCK_PACKET     = 10,
  67};
  68
  69#define SOCK_MAX (SOCK_PACKET + 1)
  70/* Mask which covers at least up to SOCK_MASK-1.  The
  71 * remaining bits are used as flags. */
  72#define SOCK_TYPE_MASK 0xf
  73
  74/* Flags for socket, socketpair, accept4 */
  75#define SOCK_CLOEXEC    O_CLOEXEC
  76#ifndef SOCK_NONBLOCK
  77#define SOCK_NONBLOCK   O_NONBLOCK
  78#endif
  79
  80#endif /* ARCH_HAS_SOCKET_TYPES */
  81
  82/**
  83 * enum sock_shutdown_cmd - Shutdown types
  84 * @SHUT_RD: shutdown receptions
  85 * @SHUT_WR: shutdown transmissions
  86 * @SHUT_RDWR: shutdown receptions/transmissions
  87 */
  88enum sock_shutdown_cmd {
  89        SHUT_RD,
  90        SHUT_WR,
  91        SHUT_RDWR,
  92};
  93
  94struct socket_wq {
  95        /* Note: wait MUST be first field of socket_wq */
  96        wait_queue_head_t       wait;
  97        struct fasync_struct    *fasync_list;
  98        unsigned long           flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
  99        struct rcu_head         rcu;
 100} ____cacheline_aligned_in_smp;
 101
 102/**
 103 *  struct socket - general BSD socket
 104 *  @state: socket state (%SS_CONNECTED, etc)
 105 *  @type: socket type (%SOCK_STREAM, etc)
 106 *  @flags: socket flags (%SOCK_NOSPACE, etc)
 107 *  @ops: protocol specific socket operations
 108 *  @file: File back pointer for gc
 109 *  @sk: internal networking protocol agnostic socket representation
 110 *  @wq: wait queue for several uses
 111 */
 112struct socket {
 113        socket_state            state;
 114
 115        short                   type;
 116
 117        unsigned long           flags;
 118
 119        struct file             *file;
 120        struct sock             *sk;
 121        const struct proto_ops  *ops;
 122
 123        struct socket_wq        wq;
 124};
 125
 126struct vm_area_struct;
 127struct page;
 128struct sockaddr;
 129struct msghdr;
 130struct module;
 131struct sk_buff;
 132typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
 133                               unsigned int, size_t);
 134
 135struct proto_ops {
 136        int             family;
 137        struct module   *owner;
 138        int             (*release)   (struct socket *sock);
 139        int             (*bind)      (struct socket *sock,
 140                                      struct sockaddr *myaddr,
 141                                      int sockaddr_len);
 142        int             (*connect)   (struct socket *sock,
 143                                      struct sockaddr *vaddr,
 144                                      int sockaddr_len, int flags);
 145        int             (*socketpair)(struct socket *sock1,
 146                                      struct socket *sock2);
 147        int             (*accept)    (struct socket *sock,
 148                                      struct socket *newsock, int flags, bool kern);
 149        int             (*getname)   (struct socket *sock,
 150                                      struct sockaddr *addr,
 151                                      int peer);
 152        __poll_t        (*poll)      (struct file *file, struct socket *sock,
 153                                      struct poll_table_struct *wait);
 154        int             (*ioctl)     (struct socket *sock, unsigned int cmd,
 155                                      unsigned long arg);
 156#ifdef CONFIG_COMPAT
 157        int             (*compat_ioctl) (struct socket *sock, unsigned int cmd,
 158                                      unsigned long arg);
 159#endif
 160        int             (*gettstamp) (struct socket *sock, void __user *userstamp,
 161                                      bool timeval, bool time32);
 162        int             (*listen)    (struct socket *sock, int len);
 163        int             (*shutdown)  (struct socket *sock, int flags);
 164        int             (*setsockopt)(struct socket *sock, int level,
 165                                      int optname, char __user *optval, unsigned int optlen);
 166        int             (*getsockopt)(struct socket *sock, int level,
 167                                      int optname, char __user *optval, int __user *optlen);
 168#ifdef CONFIG_COMPAT
 169        int             (*compat_setsockopt)(struct socket *sock, int level,
 170                                      int optname, char __user *optval, unsigned int optlen);
 171        int             (*compat_getsockopt)(struct socket *sock, int level,
 172                                      int optname, char __user *optval, int __user *optlen);
 173#endif
 174        int             (*sendmsg)   (struct socket *sock, struct msghdr *m,
 175                                      size_t total_len);
 176        /* Notes for implementing recvmsg:
 177         * ===============================
 178         * msg->msg_namelen should get updated by the recvmsg handlers
 179         * iff msg_name != NULL. It is by default 0 to prevent
 180         * returning uninitialized memory to user space.  The recvfrom
 181         * handlers can assume that msg.msg_name is either NULL or has
 182         * a minimum size of sizeof(struct sockaddr_storage).
 183         */
 184        int             (*recvmsg)   (struct socket *sock, struct msghdr *m,
 185                                      size_t total_len, int flags);
 186        int             (*mmap)      (struct file *file, struct socket *sock,
 187                                      struct vm_area_struct * vma);
 188        ssize_t         (*sendpage)  (struct socket *sock, struct page *page,
 189                                      int offset, size_t size, int flags);
 190        ssize_t         (*splice_read)(struct socket *sock,  loff_t *ppos,
 191                                       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
 192        int             (*set_peek_off)(struct sock *sk, int val);
 193        int             (*peek_len)(struct socket *sock);
 194
 195        /* The following functions are called internally by kernel with
 196         * sock lock already held.
 197         */
 198        int             (*read_sock)(struct sock *sk, read_descriptor_t *desc,
 199                                     sk_read_actor_t recv_actor);
 200        int             (*sendpage_locked)(struct sock *sk, struct page *page,
 201                                           int offset, size_t size, int flags);
 202        int             (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
 203                                          size_t size);
 204        int             (*set_rcvlowat)(struct sock *sk, int val);
 205};
 206
 207#define DECLARE_SOCKADDR(type, dst, src)        \
 208        type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
 209
 210struct net_proto_family {
 211        int             family;
 212        int             (*create)(struct net *net, struct socket *sock,
 213                                  int protocol, int kern);
 214        struct module   *owner;
 215};
 216
 217struct iovec;
 218struct kvec;
 219
 220enum {
 221        SOCK_WAKE_IO,
 222        SOCK_WAKE_WAITD,
 223        SOCK_WAKE_SPACE,
 224        SOCK_WAKE_URG,
 225};
 226
 227int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
 228int sock_register(const struct net_proto_family *fam);
 229void sock_unregister(int family);
 230bool sock_is_registered(int family);
 231int __sock_create(struct net *net, int family, int type, int proto,
 232                  struct socket **res, int kern);
 233int sock_create(int family, int type, int proto, struct socket **res);
 234int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
 235int sock_create_lite(int family, int type, int proto, struct socket **res);
 236struct socket *sock_alloc(void);
 237void sock_release(struct socket *sock);
 238int sock_sendmsg(struct socket *sock, struct msghdr *msg);
 239int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
 240struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
 241struct socket *sockfd_lookup(int fd, int *err);
 242struct socket *sock_from_file(struct file *file, int *err);
 243#define              sockfd_put(sock) fput(sock->file)
 244int net_ratelimit(void);
 245
 246#define net_ratelimited_function(function, ...)                 \
 247do {                                                            \
 248        if (net_ratelimit())                                    \
 249                function(__VA_ARGS__);                          \
 250} while (0)
 251
 252#define net_emerg_ratelimited(fmt, ...)                         \
 253        net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
 254#define net_alert_ratelimited(fmt, ...)                         \
 255        net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
 256#define net_crit_ratelimited(fmt, ...)                          \
 257        net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
 258#define net_err_ratelimited(fmt, ...)                           \
 259        net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
 260#define net_notice_ratelimited(fmt, ...)                        \
 261        net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
 262#define net_warn_ratelimited(fmt, ...)                          \
 263        net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
 264#define net_info_ratelimited(fmt, ...)                          \
 265        net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
 266#if defined(CONFIG_DYNAMIC_DEBUG)
 267#define net_dbg_ratelimited(fmt, ...)                                   \
 268do {                                                                    \
 269        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);                 \
 270        if (DYNAMIC_DEBUG_BRANCH(descriptor) &&                         \
 271            net_ratelimit())                                            \
 272                __dynamic_pr_debug(&descriptor, pr_fmt(fmt),            \
 273                                   ##__VA_ARGS__);                      \
 274} while (0)
 275#elif defined(DEBUG)
 276#define net_dbg_ratelimited(fmt, ...)                           \
 277        net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
 278#else
 279#define net_dbg_ratelimited(fmt, ...)                           \
 280        do {                                                    \
 281                if (0)                                          \
 282                        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
 283        } while (0)
 284#endif
 285
 286#define net_get_random_once(buf, nbytes)                        \
 287        get_random_once((buf), (nbytes))
 288#define net_get_random_once_wait(buf, nbytes)                   \
 289        get_random_once_wait((buf), (nbytes))
 290
 291int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 292                   size_t num, size_t len);
 293int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 294                          struct kvec *vec, size_t num, size_t len);
 295int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 296                   size_t num, size_t len, int flags);
 297
 298int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
 299int kernel_listen(struct socket *sock, int backlog);
 300int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
 301int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
 302                   int flags);
 303int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
 304int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
 305int kernel_getsockopt(struct socket *sock, int level, int optname, char *optval,
 306                      int *optlen);
 307int kernel_setsockopt(struct socket *sock, int level, int optname, char *optval,
 308                      unsigned int optlen);
 309int kernel_sendpage(struct socket *sock, struct page *page, int offset,
 310                    size_t size, int flags);
 311int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
 312                           size_t size, int flags);
 313int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
 314
 315/* Routine returns the IP overhead imposed by a (caller-protected) socket. */
 316u32 kernel_sock_ip_overhead(struct sock *sk);
 317
 318#define MODULE_ALIAS_NETPROTO(proto) \
 319        MODULE_ALIAS("net-pf-" __stringify(proto))
 320
 321#define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
 322        MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
 323
 324#define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
 325        MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
 326                     "-type-" __stringify(type))
 327
 328#define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
 329        MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
 330                     name)
 331#endif  /* _LINUX_NET_H */
 332