LXR linux/include/linux/net.h

   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
  29struct poll_table_struct;
  30struct pipe_inode_info;
  31struct inode;
  32struct file;
  33struct 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 */
  61enum 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 */
  90enum sock_shutdown_cmd {
  91        SHUT_RD,
  92        SHUT_WR,
  93        SHUT_RDWR,
  94};
  95
  96struct 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 */
 114struct 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
 128struct vm_area_struct;
 129struct page;
 130struct sockaddr;
 131struct msghdr;
 132struct module;
 133struct sk_buff;
 134typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
 135                               unsigned int, size_t);
 136
 137struct proto_ops {
 138        int             family;
 139        struct module   *owner;
 140        int             (*release)   (struct socket *sock);
 141        int             (*bind)      (struct socket *sock,
 142                                      struct sockaddr *myaddr,
 143                                      int sockaddr_len);
 144        int             (*connect)   (struct socket *sock,
 145                                      struct sockaddr *vaddr,
 146                                      int sockaddr_len, int flags);
 147        int             (*socketpair)(struct socket *sock1,
 148                                      struct socket *sock2);
 149        int             (*accept)    (struct socket *sock,
 150                                      struct socket *newsock, int flags, bool kern);
 151        int             (*getname)   (struct socket *sock,
 152                                      struct sockaddr *addr,
 153                                      int peer);
 154        __poll_t        (*poll)      (struct file *file, struct socket *sock,
 155                                      struct poll_table_struct *wait);
 156        int             (*ioctl)     (struct socket *sock, unsigned int cmd,
 157                                      unsigned long arg);
 158#ifdef CONFIG_COMPAT
 159        int             (*compat_ioctl) (struct socket *sock, unsigned int cmd,
 160                                      unsigned long arg);
 161#endif
 162        int             (*gettstamp) (struct socket *sock, void __user *userstamp,
 163                                      bool timeval, bool time32);
 164        int             (*listen)    (struct socket *sock, int len);
 165        int             (*shutdown)  (struct socket *sock, int flags);
 166        int             (*setsockopt)(struct socket *sock, int level,
 167                                      int optname, sockptr_t optval,
 168                                      unsigned int optlen);
 169        int             (*getsockopt)(struct socket *sock, int level,
 170                                      int optname, char __user *optval, int __user *optlen);
 171        void            (*show_fdinfo)(struct seq_file *m, struct socket *sock);
 172        int             (*sendmsg)   (struct socket *sock, struct msghdr *m,
 173                                      size_t total_len);
 174        /* Notes for implementing recvmsg:
 175         * ===============================
 176         * msg->msg_namelen should get updated by the recvmsg handlers
 177         * iff msg_name != NULL. It is by default 0 to prevent
 178         * returning uninitialized memory to user space.  The recvfrom
 179         * handlers can assume that msg.msg_name is either NULL or has
 180         * a minimum size of sizeof(struct sockaddr_storage).
 181         */
 182        int             (*recvmsg)   (struct socket *sock, struct msghdr *m,
 183                                      size_t total_len, int flags);
 184        int             (*mmap)      (struct file *file, struct socket *sock,
 185                                      struct vm_area_struct * vma);
 186        ssize_t         (*sendpage)  (struct socket *sock, struct page *page,
 187                                      int offset, size_t size, int flags);
 188        ssize_t         (*splice_read)(struct socket *sock,  loff_t *ppos,
 189                                       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
 190        int             (*set_peek_off)(struct sock *sk, int val);
 191        int             (*peek_len)(struct socket *sock);
 192
 193        /* The following functions are called internally by kernel with
 194         * sock lock already held.
 195         */
 196        int             (*read_sock)(struct sock *sk, read_descriptor_t *desc,
 197                                     sk_read_actor_t recv_actor);
 198        int             (*sendpage_locked)(struct sock *sk, struct page *page,
 199                                           int offset, size_t size, int flags);
 200        int             (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
 201                                          size_t size);
 202        int             (*set_rcvlowat)(struct sock *sk, int val);
 203};
 204
 205#define DECLARE_SOCKADDR(type, dst, src)        \
 206        type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
 207
 208struct net_proto_family {
 209        int             family;
 210        int             (*create)(struct net *net, struct socket *sock,
 211                                  int protocol, int kern);
 212        struct module   *owner;
 213};
 214
 215struct iovec;
 216struct kvec;
 217
 218enum {
 219        SOCK_WAKE_IO,
 220        SOCK_WAKE_WAITD,
 221        SOCK_WAKE_SPACE,
 222        SOCK_WAKE_URG,
 223};
 224
 225int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
 226int sock_register(const struct net_proto_family *fam);
 227void sock_unregister(int family);
 228bool sock_is_registered(int family);
 229int __sock_create(struct net *net, int family, int type, int proto,
 230                  struct socket **res, int kern);
 231int sock_create(int family, int type, int proto, struct socket **res);
 232int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
 233int sock_create_lite(int family, int type, int proto, struct socket **res);
 234struct socket *sock_alloc(void);
 235void sock_release(struct socket *sock);
 236int sock_sendmsg(struct socket *sock, struct msghdr *msg);
 237int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
 238struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
 239struct socket *sockfd_lookup(int fd, int *err);
 240struct socket *sock_from_file(struct file *file);
 241#define              sockfd_put(sock) fput(sock->file)
 242int net_ratelimit(void);
 243
 244#define net_ratelimited_function(function, ...)                 \
 245do {                                                            \
 246        if (net_ratelimit())                                    \
 247                function(__VA_ARGS__);                          \
 248} while (0)
 249
 250#define net_emerg_ratelimited(fmt, ...)                         \
 251        net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
 252#define net_alert_ratelimited(fmt, ...)                         \
 253        net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
 254#define net_crit_ratelimited(fmt, ...)                          \
 255        net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
 256#define net_err_ratelimited(fmt, ...)                           \
 257        net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
 258#define net_notice_ratelimited(fmt, ...)                        \
 259        net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
 260#define net_warn_ratelimited(fmt, ...)                          \
 261        net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
 262#define net_info_ratelimited(fmt, ...)                          \
 263        net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
 264#if defined(CONFIG_DYNAMIC_DEBUG) || \
 265        (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
 266#define net_dbg_ratelimited(fmt, ...)                                   \
 267do {                                                                    \
 268        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);                 \
 269        if (DYNAMIC_DEBUG_BRANCH(descriptor) &&                         \
 270            net_ratelimit())                                            \
 271                __dynamic_pr_debug(&descriptor, pr_fmt(fmt),            \
 272                                   ##__VA_ARGS__);                      \
 273} while (0)
 274#elif defined(DEBUG)
 275#define net_dbg_ratelimited(fmt, ...)                           \
 276        net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
 277#else
 278#define net_dbg_ratelimited(fmt, ...)                           \
 279        do {                                                    \
 280                if (0)                                          \
 281                        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
 282        } while (0)
 283#endif
 284
 285#define net_get_random_once(buf, nbytes)                        \
 286        get_random_once((buf), (nbytes))
 287#define net_get_random_once_wait(buf, nbytes)                   \
 288        get_random_once_wait((buf), (nbytes))
 289
 290/*
 291 * E.g. XFS meta- & log-data is in slab pages, or bcache meta
 292 * data pages, or other high order pages allocated by
 293 * __get_free_pages() without __GFP_COMP, which have a page_count
 294 * of 0 and/or have PageSlab() set. We cannot use send_page for
 295 * those, as that does get_page(); put_page(); and would cause
 296 * either a VM_BUG directly, or __page_cache_release a page that
 297 * would actually still be referenced by someone, leading to some
 298 * obscure delayed Oops somewhere else.
 299 */
 300static inline bool sendpage_ok(struct page *page)
 301{
 302        return !PageSlab(page) && page_count(page) >= 1;
 303}
 304
 305int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 306                   size_t num, size_t len);
 307int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 308                          struct kvec *vec, size_t num, size_t len);
 309int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 310                   size_t num, size_t len, int flags);
 311
 312int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
 313int kernel_listen(struct socket *sock, int backlog);
 314int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
 315int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
 316                   int flags);
 317int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
 318int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
 319int kernel_sendpage(struct socket *sock, struct page *page, int offset,
 320                    size_t size, int flags);
 321int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
 322                           size_t size, int flags);
 323int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
 324
 325/* Routine returns the IP overhead imposed by a (caller-protected) socket. */
 326u32 kernel_sock_ip_overhead(struct sock *sk);
 327
 328#define MODULE_ALIAS_NETPROTO(proto) \
 329        MODULE_ALIAS("net-pf-" __stringify(proto))
 330
 331#define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
 332        MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
 333
 334#define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
 335        MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
 336                     "-type-" __stringify(type))
 337
 338#define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
 339        MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
 340                     name)
 341#endif  /* _LINUX_NET_H */
 342