include/linux/net.h

   1 /*
   2  * NET          An implementation of the SOCKET network access protocol.
   3  *              This is the master header file for the Linux NET layer,
   4  *              or, in plain English: the networking handling part of the
   5  *              kernel.
   6  *
   7  * Version:     @(#)net.h       1.0.3   05/25/93
   8  *
   9  * Authors:     Orest Zborowski, <obz@Kodak.COM>
  10  *              Ross Biro
  11  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12  *
  13  *              This program is free software; you can redistribute it and/or
  14  *              modify it under the terms of the GNU General Public License
  15  *              as published by the Free Software Foundation; either version
  16  *              2 of the License, or (at your option) any later version.
  17  */
  18 #ifndef _LINUX_NET_H
  19 #define _LINUX_NET_H
  20
  21 #include <linux/stringify.h>
  22 #include <linux/random.h>
  23 #include <linux/wait.h>
  24 #include <linux/fcntl.h>        /* For O_CLOEXEC and O_NONBLOCK */
  25 #include <linux/rcupdate.h>
  26 #include <linux/once.h>
  27 #include <linux/fs.h>
  28
  29 #include <uapi/linux/net.h>
  30
  31 struct poll_table_struct;
  32 struct pipe_inode_info;
  33 struct inode;
  34 struct file;
  35 struct net;
  36
  37 /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
  38  * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
  39  * Eventually all flags will be in sk->sk_wq->flags.
  40  */
  41 #define SOCKWQ_ASYNC_NOSPACE    0
  42 #define SOCKWQ_ASYNC_WAITDATA   1
  43 #define SOCK_NOSPACE            2
  44 #define SOCK_PASSCRED           3
  45 #define SOCK_PASSSEC            4
  46
  47 #ifndef ARCH_HAS_SOCKET_TYPES
  48 /**
  49  * enum sock_type - Socket types
  50  * @SOCK_STREAM: stream (connection) socket
  51  * @SOCK_DGRAM: datagram (conn.less) socket
  52  * @SOCK_RAW: raw socket
  53  * @SOCK_RDM: reliably-delivered message
  54  * @SOCK_SEQPACKET: sequential packet socket
  55  * @SOCK_DCCP: Datagram Congestion Control Protocol socket
  56  * @SOCK_PACKET: linux specific way of getting packets at the dev level.
  57  *                For writing rarp and other similar things on the user level.
  58  *
  59  * When adding some new socket type please
  60  * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
  61  * overrides this enum for binary compat reasons.
  62  */
  63 enum sock_type {
  64         SOCK_STREAM     = 1,
  65         SOCK_DGRAM      = 2,
  66         SOCK_RAW        = 3,
  67         SOCK_RDM        = 4,
  68         SOCK_SEQPACKET  = 5,
  69         SOCK_DCCP       = 6,
  70         SOCK_PACKET     = 10,
  71 };
  72
  73 #define SOCK_MAX (SOCK_PACKET + 1)
  74 /* Mask which covers at least up to SOCK_MASK-1.  The
  75  * remaining bits are used as flags. */
  76 #define SOCK_TYPE_MASK 0xf
  77
  78 /* Flags for socket, socketpair, accept4 */
  79 #define SOCK_CLOEXEC    O_CLOEXEC
  80 #ifndef SOCK_NONBLOCK
  81 #define SOCK_NONBLOCK   O_NONBLOCK
  82 #endif
  83
  84 #endif /* ARCH_HAS_SOCKET_TYPES */
  85
  86 enum sock_shutdown_cmd {
  87         SHUT_RD,
  88         SHUT_WR,
  89         SHUT_RDWR,
  90 };
  91
  92 struct socket_wq {
  93         /* Note: wait MUST be first field of socket_wq */
  94         wait_queue_head_t       wait;
  95         struct fasync_struct    *fasync_list;
  96         unsigned long           flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
  97         struct rcu_head         rcu;
  98 } ____cacheline_aligned_in_smp;
  99
 100 /**
 101  *  struct socket - general BSD socket
 102  *  @state: socket state (%SS_CONNECTED, etc)
 103  *  @type: socket type (%SOCK_STREAM, etc)
 104  *  @flags: socket flags (%SOCK_NOSPACE, etc)
 105  *  @ops: protocol specific socket operations
 106  *  @file: File back pointer for gc
 107  *  @sk: internal networking protocol agnostic socket representation
 108  *  @wq: wait queue for several uses
 109  */
 110 struct socket {
 111         socket_state            state;
 112
 113         short                   type;
 114
 115         unsigned long           flags;
 116
 117         struct socket_wq        *wq;
 118
 119         struct file             *file;
 120         struct sock             *sk;
 121         const struct proto_ops  *ops;
 122 };
 123
 124 struct vm_area_struct;
 125 struct page;
 126 struct sockaddr;
 127 struct msghdr;
 128 struct module;
 129 struct sk_buff;
 130 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
 131                                unsigned int, size_t);
 132
 133 struct proto_ops {
 134         int             family;
 135         struct module   *owner;
 136         int             (*release)   (struct socket *sock);
 137         int             (*bind)      (struct socket *sock,
 138                                       struct sockaddr *myaddr,
 139                                       int sockaddr_len);
 140         int             (*connect)   (struct socket *sock,
 141                                       struct sockaddr *vaddr,
 142                                       int sockaddr_len, int flags);
 143         int             (*socketpair)(struct socket *sock1,
 144                                       struct socket *sock2);
 145         int             (*accept)    (struct socket *sock,
 146                                       struct socket *newsock, int flags, bool kern);
 147         int             (*getname)   (struct socket *sock,
 148                                       struct sockaddr *addr,
 149                                       int peer);
 150         __poll_t        (*poll)      (struct file *file, struct socket *sock,
 151                                       struct poll_table_struct *wait);
 152         int             (*ioctl)     (struct socket *sock, unsigned int cmd,
 153                                       unsigned long arg);
 154 #ifdef CONFIG_COMPAT
 155         int             (*compat_ioctl) (struct socket *sock, unsigned int cmd,
 156                                       unsigned long arg);
 157 #endif
 158         int             (*listen)    (struct socket *sock, int len);
 159         int             (*shutdown)  (struct socket *sock, int flags);
 160         int             (*setsockopt)(struct socket *sock, int level,
 161                                       int optname, char __user *optval, unsigned int optlen);
 162         int             (*getsockopt)(struct socket *sock, int level,
 163                                       int optname, char __user *optval, int __user *optlen);
 164 #ifdef CONFIG_COMPAT
 165         int             (*compat_setsockopt)(struct socket *sock, int level,
 166                                       int optname, char __user *optval, unsigned int optlen);
 167         int             (*compat_getsockopt)(struct socket *sock, int level,
 168                                       int optname, char __user *optval, int __user *optlen);
 169 #endif
 170         int             (*sendmsg)   (struct socket *sock, struct msghdr *m,
 171                                       size_t total_len);
 172         /* Notes for implementing recvmsg:
 173          * ===============================
 174          * msg->msg_namelen should get updated by the recvmsg handlers
 175          * iff msg_name != NULL. It is by default 0 to prevent
 176          * returning uninitialized memory to user space.  The recvfrom
 177          * handlers can assume that msg.msg_name is either NULL or has
 178          * a minimum size of sizeof(struct sockaddr_storage).
 179          */
 180         int             (*recvmsg)   (struct socket *sock, struct msghdr *m,
 181                                       size_t total_len, int flags);
 182         int             (*mmap)      (struct file *file, struct socket *sock,
 183                                       struct vm_area_struct * vma);
 184         ssize_t         (*sendpage)  (struct socket *sock, struct page *page,
 185                                       int offset, size_t size, int flags);
 186         ssize_t         (*splice_read)(struct socket *sock,  loff_t *ppos,
 187                                        struct pipe_inode_info *pipe, size_t len, unsigned int flags);
 188         int             (*set_peek_off)(struct sock *sk, int val);
 189         int             (*peek_len)(struct socket *sock);
 190
 191         /* The following functions are called internally by kernel with
 192          * sock lock already held.
 193          */
 194         int             (*read_sock)(struct sock *sk, read_descriptor_t *desc,
 195                                      sk_read_actor_t recv_actor);
 196         int             (*sendpage_locked)(struct sock *sk, struct page *page,
 197                                            int offset, size_t size, int flags);
 198         int             (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
 199                                           size_t size);
 200         int             (*set_rcvlowat)(struct sock *sk, int val);
 201 };
 202
 203 #define DECLARE_SOCKADDR(type, dst, src)        \
 204         type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
 205
 206 struct net_proto_family {
 207         int             family;
 208         int             (*create)(struct net *net, struct socket *sock,
 209                                   int protocol, int kern);
 210         struct module   *owner;
 211 };
 212
 213 struct iovec;
 214 struct kvec;
 215
 216 enum {
 217         SOCK_WAKE_IO,
 218         SOCK_WAKE_WAITD,
 219         SOCK_WAKE_SPACE,
 220         SOCK_WAKE_URG,
 221 };
 222
 223 int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
 224 int sock_register(const struct net_proto_family *fam);
 225 void sock_unregister(int family);
 226 bool sock_is_registered(int family);
 227 int __sock_create(struct net *net, int family, int type, int proto,
 228                   struct socket **res, int kern);
 229 int sock_create(int family, int type, int proto, struct socket **res);
 230 int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
 231 int sock_create_lite(int family, int type, int proto, struct socket **res);
 232 struct socket *sock_alloc(void);
 233 void sock_release(struct socket *sock);
 234 int sock_sendmsg(struct socket *sock, struct msghdr *msg);
 235 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
 236 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
 237 struct socket *sockfd_lookup(int fd, int *err);
 238 struct socket *sock_from_file(struct file *file, int *err);
 239 #define              sockfd_put(sock) fput(sock->file)
 240 int net_ratelimit(void);
 241
 242 #define net_ratelimited_function(function, ...)                 \
 243 do {                                                            \
 244         if (net_ratelimit())                                    \
 245                 function(__VA_ARGS__);                          \
 246 } while (0)
 247
 248 #define net_emerg_ratelimited(fmt, ...)                         \
 249         net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
 250 #define net_alert_ratelimited(fmt, ...)                         \
 251         net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
 252 #define net_crit_ratelimited(fmt, ...)                          \
 253         net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
 254 #define net_err_ratelimited(fmt, ...)                           \
 255         net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
 256 #define net_notice_ratelimited(fmt, ...)                        \
 257         net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
 258 #define net_warn_ratelimited(fmt, ...)                          \
 259         net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
 260 #define net_info_ratelimited(fmt, ...)                          \
 261         net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
 262 #if defined(CONFIG_DYNAMIC_DEBUG)
 263 #define net_dbg_ratelimited(fmt, ...)                                   \
 264 do {                                                                    \
 265         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);                 \
 266         if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&        \
 267             net_ratelimit())                                            \
 268                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt),            \
 269                                    ##__VA_ARGS__);                      \
 270 } while (0)
 271 #elif defined(DEBUG)
 272 #define net_dbg_ratelimited(fmt, ...)                           \
 273         net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
 274 #else
 275 #define net_dbg_ratelimited(fmt, ...)                           \
 276         do {                                                    \
 277                 if (0)                                          \
 278                         no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
 279         } while (0)
 280 #endif
 281
 282 #define net_get_random_once(buf, nbytes)                        \
 283         get_random_once((buf), (nbytes))
 284 #define net_get_random_once_wait(buf, nbytes)                   \
 285         get_random_once_wait((buf), (nbytes))
 286
 287 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 288                    size_t num, size_t len);
 289 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 290                           struct kvec *vec, size_t num, size_t len);
 291 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 292                    size_t num, size_t len, int flags);
 293
 294 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
 295 int kernel_listen(struct socket *sock, int backlog);
 296 int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
 297 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
 298                    int flags);
 299 int kernel_getsockname(struct socket *sock, struct sockaddr *addr);
 300 int kernel_getpeername(struct socket *sock, struct sockaddr *addr);
 301 int kernel_getsockopt(struct socket *sock, int level, int optname, char *optval,
 302                       int *optlen);
 303 int kernel_setsockopt(struct socket *sock, int level, int optname, char *optval,
 304                       unsigned int optlen);
 305 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
 306                     size_t size, int flags);
 307 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
 308                            size_t size, int flags);
 309 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
 310
 311 /* Routine returns the IP overhead imposed by a (caller-protected) socket. */
 312 u32 kernel_sock_ip_overhead(struct sock *sk);
 313
 314 #define MODULE_ALIAS_NETPROTO(proto) \
 315         MODULE_ALIAS("net-pf-" __stringify(proto))
 316
 317 #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
 318         MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
 319
 320 #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
 321         MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
 322                      "-type-" __stringify(type))
 323
 324 #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
 325         MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
 326                      name)
 327 #endif  /* _LINUX_NET_H */