net: add documentation to socket.c

Adds missing sphinx documentation to the
socket.c's functions. Also fixes some whitespaces.

I also changed the style of older documentation as an
effort to have an uniform documentation style.

Signed-off-by: Pedro Tammela <pctammela@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pedro Tammela 2019-03-14 10:45:23 -03:00 committed by David S. Miller
parent 228cd2dba2
commit 8a3c245c03
3 changed files with 271 additions and 24 deletions

View File

@ -83,6 +83,12 @@ enum sock_type {
#endif /* ARCH_HAS_SOCKET_TYPES */ #endif /* ARCH_HAS_SOCKET_TYPES */
/**
* enum sock_shutdown_cmd - Shutdown types
* @SHUT_RD: shutdown receptions
* @SHUT_WR: shutdown transmissions
* @SHUT_RDWR: shutdown receptions/transmissions
*/
enum sock_shutdown_cmd { enum sock_shutdown_cmd {
SHUT_RD, SHUT_RD,
SHUT_WR, SHUT_WR,

View File

@ -26,7 +26,7 @@ typedef __kernel_sa_family_t sa_family_t;
/* /*
* 1003.1g requires sa_family_t and that sa_data is char. * 1003.1g requires sa_family_t and that sa_data is char.
*/ */
struct sockaddr { struct sockaddr {
sa_family_t sa_family; /* address family, AF_xxx */ sa_family_t sa_family; /* address family, AF_xxx */
char sa_data[14]; /* 14 bytes of protocol address */ char sa_data[14]; /* 14 bytes of protocol address */
@ -44,7 +44,7 @@ struct linger {
* system, not 4.3. Thus msg_accrights(len) are now missing. They * system, not 4.3. Thus msg_accrights(len) are now missing. They
* belong in an obscure libc emulation or the bin. * belong in an obscure libc emulation or the bin.
*/ */
struct msghdr { struct msghdr {
void *msg_name; /* ptr to socket address structure */ void *msg_name; /* ptr to socket address structure */
int msg_namelen; /* size of socket address structure */ int msg_namelen; /* size of socket address structure */
@ -54,7 +54,7 @@ struct msghdr {
unsigned int msg_flags; /* flags on received message */ unsigned int msg_flags; /* flags on received message */
struct kiocb *msg_iocb; /* ptr to iocb for async requests */ struct kiocb *msg_iocb; /* ptr to iocb for async requests */
}; };
struct user_msghdr { struct user_msghdr {
void __user *msg_name; /* ptr to socket address structure */ void __user *msg_name; /* ptr to socket address structure */
int msg_namelen; /* size of socket address structure */ int msg_namelen; /* size of socket address structure */
@ -122,7 +122,7 @@ struct cmsghdr {
* inside range, given by msg->msg_controllen before using * inside range, given by msg->msg_controllen before using
* ancillary object DATA. --ANK (980731) * ancillary object DATA. --ANK (980731)
*/ */
static inline struct cmsghdr * __cmsg_nxthdr(void *__ctl, __kernel_size_t __size, static inline struct cmsghdr * __cmsg_nxthdr(void *__ctl, __kernel_size_t __size,
struct cmsghdr *__cmsg) struct cmsghdr *__cmsg)
{ {
@ -264,10 +264,10 @@ struct ucred {
/* Maximum queue length specifiable by listen. */ /* Maximum queue length specifiable by listen. */
#define SOMAXCONN 128 #define SOMAXCONN 128
/* Flags we can use with send/ and recv. /* Flags we can use with send/ and recv.
Added those for 1003.1g not all are supported yet Added those for 1003.1g not all are supported yet
*/ */
#define MSG_OOB 1 #define MSG_OOB 1
#define MSG_PEEK 2 #define MSG_PEEK 2
#define MSG_DONTROUTE 4 #define MSG_DONTROUTE 4

View File

@ -384,6 +384,18 @@ static struct file_system_type sock_fs_type = {
* but we take care of internal coherence yet. * but we take care of internal coherence yet.
*/ */
/**
* sock_alloc_file - Bind a &socket to a &file
* @sock: socket
* @flags: file status flags
* @dname: protocol name
*
* Returns the &file bound with @sock, implicitly storing it
* in sock->file. If dname is %NULL, sets to "".
* On failure the return is a ERR pointer (see linux/err.h).
* This function uses GFP_KERNEL internally.
*/
struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname) struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
{ {
struct file *file; struct file *file;
@ -424,6 +436,14 @@ static int sock_map_fd(struct socket *sock, int flags)
return PTR_ERR(newfile); return PTR_ERR(newfile);
} }
/**
* sock_from_file - Return the &socket bounded to @file.
* @file: file
* @err: pointer to an error code return
*
* On failure returns %NULL and assigns -ENOTSOCK to @err.
*/
struct socket *sock_from_file(struct file *file, int *err) struct socket *sock_from_file(struct file *file, int *err)
{ {
if (file->f_op == &socket_file_ops) if (file->f_op == &socket_file_ops)
@ -532,11 +552,11 @@ static const struct inode_operations sockfs_inode_ops = {
}; };
/** /**
* sock_alloc - allocate a socket * sock_alloc - allocate a socket
* *
* Allocate a new inode and socket object. The two are bound together * Allocate a new inode and socket object. The two are bound together
* and initialised. The socket is then returned. If we are out of inodes * and initialised. The socket is then returned. If we are out of inodes
* NULL is returned. * NULL is returned. This functions uses GFP_KERNEL internally.
*/ */
struct socket *sock_alloc(void) struct socket *sock_alloc(void)
@ -561,7 +581,7 @@ struct socket *sock_alloc(void)
EXPORT_SYMBOL(sock_alloc); EXPORT_SYMBOL(sock_alloc);
/** /**
* sock_release - close a socket * sock_release - close a socket
* @sock: socket to close * @sock: socket to close
* *
* The socket is released from the protocol stack if it has a release * The socket is released from the protocol stack if it has a release
@ -617,6 +637,15 @@ void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags)
} }
EXPORT_SYMBOL(__sock_tx_timestamp); EXPORT_SYMBOL(__sock_tx_timestamp);
/**
* sock_sendmsg - send a message through @sock
* @sock: socket
* @msg: message to send
*
* Sends @msg through @sock, passing through LSM.
* Returns the number of bytes sent, or an error code.
*/
static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg) static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
{ {
int ret = sock->ops->sendmsg(sock, msg, msg_data_left(msg)); int ret = sock->ops->sendmsg(sock, msg, msg_data_left(msg));
@ -633,6 +662,18 @@ int sock_sendmsg(struct socket *sock, struct msghdr *msg)
} }
EXPORT_SYMBOL(sock_sendmsg); EXPORT_SYMBOL(sock_sendmsg);
/**
* kernel_sendmsg - send a message through @sock (kernel-space)
* @sock: socket
* @msg: message header
* @vec: kernel vec
* @num: vec array length
* @size: total message data size
*
* Builds the message data with @vec and sends it through @sock.
* Returns the number of bytes sent, or an error code.
*/
int kernel_sendmsg(struct socket *sock, struct msghdr *msg, int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
struct kvec *vec, size_t num, size_t size) struct kvec *vec, size_t num, size_t size)
{ {
@ -641,6 +682,19 @@ int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
} }
EXPORT_SYMBOL(kernel_sendmsg); EXPORT_SYMBOL(kernel_sendmsg);
/**
* kernel_sendmsg_locked - send a message through @sock (kernel-space)
* @sk: sock
* @msg: message header
* @vec: output s/g array
* @num: output s/g array length
* @size: total message data size
*
* Builds the message data with @vec and sends it through @sock.
* Returns the number of bytes sent, or an error code.
* Caller must hold @sk.
*/
int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg, int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
struct kvec *vec, size_t num, size_t size) struct kvec *vec, size_t num, size_t size)
{ {
@ -811,6 +865,16 @@ void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
} }
EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops); EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
/**
* sock_recvmsg - receive a message from @sock
* @sock: socket
* @msg: message to receive
* @flags: message flags
*
* Receives @msg from @sock, passing through LSM. Returns the total number
* of bytes received, or an error.
*/
static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg, static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
int flags) int flags)
{ {
@ -826,20 +890,21 @@ int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
EXPORT_SYMBOL(sock_recvmsg); EXPORT_SYMBOL(sock_recvmsg);
/** /**
* kernel_recvmsg - Receive a message from a socket (kernel space) * kernel_recvmsg - Receive a message from a socket (kernel space)
* @sock: The socket to receive the message from * @sock: The socket to receive the message from
* @msg: Received message * @msg: Received message
* @vec: Input s/g array for message data * @vec: Input s/g array for message data
* @num: Size of input s/g array * @num: Size of input s/g array
* @size: Number of bytes to read * @size: Number of bytes to read
* @flags: Message flags (MSG_DONTWAIT, etc...) * @flags: Message flags (MSG_DONTWAIT, etc...)
* *
* On return the msg structure contains the scatter/gather array passed in the * On return the msg structure contains the scatter/gather array passed in the
* vec argument. The array is modified so that it consists of the unfilled * vec argument. The array is modified so that it consists of the unfilled
* portion of the original array. * portion of the original array.
* *
* The returned value is the total number of bytes received, or an error. * The returned value is the total number of bytes received, or an error.
*/ */
int kernel_recvmsg(struct socket *sock, struct msghdr *msg, int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
struct kvec *vec, size_t num, size_t size, int flags) struct kvec *vec, size_t num, size_t size, int flags)
{ {
@ -1005,6 +1070,13 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
* what to do with it - that's up to the protocol still. * what to do with it - that's up to the protocol still.
*/ */
/**
* get_net_ns - increment the refcount of the network namespace
* @ns: common namespace (net)
*
* Returns the net's common namespace.
*/
struct ns_common *get_net_ns(struct ns_common *ns) struct ns_common *get_net_ns(struct ns_common *ns)
{ {
return &get_net(container_of(ns, struct net, ns))->ns; return &get_net(container_of(ns, struct net, ns))->ns;
@ -1099,6 +1171,19 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
return err; return err;
} }
/**
* sock_create_lite - creates a socket
* @family: protocol family (AF_INET, ...)
* @type: communication type (SOCK_STREAM, ...)
* @protocol: protocol (0, ...)
* @res: new socket
*
* Creates a new socket and assigns it to @res, passing through LSM.
* The new socket initialization is not complete, see kernel_accept().
* Returns 0 or an error. On failure @res is set to %NULL.
* This function internally uses GFP_KERNEL.
*/
int sock_create_lite(int family, int type, int protocol, struct socket **res) int sock_create_lite(int family, int type, int protocol, struct socket **res)
{ {
int err; int err;
@ -1224,6 +1309,21 @@ call_kill:
} }
EXPORT_SYMBOL(sock_wake_async); EXPORT_SYMBOL(sock_wake_async);
/**
* __sock_create - creates a socket
* @net: net namespace
* @family: protocol family (AF_INET, ...)
* @type: communication type (SOCK_STREAM, ...)
* @protocol: protocol (0, ...)
* @res: new socket
* @kern: boolean for kernel space sockets
*
* Creates a new socket and assigns it to @res, passing through LSM.
* Returns 0 or an error. On failure @res is set to %NULL. @kern must
* be set to true if the socket resides in kernel space.
* This function internally uses GFP_KERNEL.
*/
int __sock_create(struct net *net, int family, int type, int protocol, int __sock_create(struct net *net, int family, int type, int protocol,
struct socket **res, int kern) struct socket **res, int kern)
{ {
@ -1333,12 +1433,35 @@ out_release:
} }
EXPORT_SYMBOL(__sock_create); EXPORT_SYMBOL(__sock_create);
/**
* sock_create - creates a socket
* @family: protocol family (AF_INET, ...)
* @type: communication type (SOCK_STREAM, ...)
* @protocol: protocol (0, ...)
* @res: new socket
*
* A wrapper around __sock_create().
* Returns 0 or an error. This function internally uses GFP_KERNEL.
*/
int sock_create(int family, int type, int protocol, struct socket **res) int sock_create(int family, int type, int protocol, struct socket **res)
{ {
return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0); return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
} }
EXPORT_SYMBOL(sock_create); EXPORT_SYMBOL(sock_create);
/**
* sock_create_kern - creates a socket (kernel space)
* @net: net namespace
* @family: protocol family (AF_INET, ...)
* @type: communication type (SOCK_STREAM, ...)
* @protocol: protocol (0, ...)
* @res: new socket
*
* A wrapper around __sock_create().
* Returns 0 or an error. This function internally uses GFP_KERNEL.
*/
int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res) int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res)
{ {
return __sock_create(net, family, type, protocol, res, 1); return __sock_create(net, family, type, protocol, res, 1);
@ -3322,18 +3445,46 @@ static long compat_sock_ioctl(struct file *file, unsigned int cmd,
} }
#endif #endif
/**
* kernel_bind - bind an address to a socket (kernel space)
* @sock: socket
* @addr: address
* @addrlen: length of address
*
* Returns 0 or an error.
*/
int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen) int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
{ {
return sock->ops->bind(sock, addr, addrlen); return sock->ops->bind(sock, addr, addrlen);
} }
EXPORT_SYMBOL(kernel_bind); EXPORT_SYMBOL(kernel_bind);
/**
* kernel_listen - move socket to listening state (kernel space)
* @sock: socket
* @backlog: pending connections queue size
*
* Returns 0 or an error.
*/
int kernel_listen(struct socket *sock, int backlog) int kernel_listen(struct socket *sock, int backlog)
{ {
return sock->ops->listen(sock, backlog); return sock->ops->listen(sock, backlog);
} }
EXPORT_SYMBOL(kernel_listen); EXPORT_SYMBOL(kernel_listen);
/**
* kernel_accept - accept a connection (kernel space)
* @sock: listening socket
* @newsock: new connected socket
* @flags: flags
*
* @flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0.
* If it fails, @newsock is guaranteed to be %NULL.
* Returns 0 or an error.
*/
int kernel_accept(struct socket *sock, struct socket **newsock, int flags) int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
{ {
struct sock *sk = sock->sk; struct sock *sk = sock->sk;
@ -3359,6 +3510,19 @@ done:
} }
EXPORT_SYMBOL(kernel_accept); EXPORT_SYMBOL(kernel_accept);
/**
* kernel_connect - connect a socket (kernel space)
* @sock: socket
* @addr: address
* @addrlen: address length
* @flags: flags (O_NONBLOCK, ...)
*
* For datagram sockets, @addr is the addres to which datagrams are sent
* by default, and the only address from which datagrams are received.
* For stream sockets, attempts to connect to @addr.
* Returns 0 or an error code.
*/
int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen, int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
int flags) int flags)
{ {
@ -3366,18 +3530,48 @@ int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
} }
EXPORT_SYMBOL(kernel_connect); EXPORT_SYMBOL(kernel_connect);
/**
* kernel_getsockname - get the address which the socket is bound (kernel space)
* @sock: socket
* @addr: address holder
*
* Fills the @addr pointer with the address which the socket is bound.
* Returns 0 or an error code.
*/
int kernel_getsockname(struct socket *sock, struct sockaddr *addr) int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
{ {
return sock->ops->getname(sock, addr, 0); return sock->ops->getname(sock, addr, 0);
} }
EXPORT_SYMBOL(kernel_getsockname); EXPORT_SYMBOL(kernel_getsockname);
/**
* kernel_peername - get the address which the socket is connected (kernel space)
* @sock: socket
* @addr: address holder
*
* Fills the @addr pointer with the address which the socket is connected.
* Returns 0 or an error code.
*/
int kernel_getpeername(struct socket *sock, struct sockaddr *addr) int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
{ {
return sock->ops->getname(sock, addr, 1); return sock->ops->getname(sock, addr, 1);
} }
EXPORT_SYMBOL(kernel_getpeername); EXPORT_SYMBOL(kernel_getpeername);
/**
* kernel_getsockopt - get a socket option (kernel space)
* @sock: socket
* @level: API level (SOL_SOCKET, ...)
* @optname: option tag
* @optval: option value
* @optlen: option length
*
* Assigns the option length to @optlen.
* Returns 0 or an error.
*/
int kernel_getsockopt(struct socket *sock, int level, int optname, int kernel_getsockopt(struct socket *sock, int level, int optname,
char *optval, int *optlen) char *optval, int *optlen)
{ {
@ -3400,6 +3594,17 @@ int kernel_getsockopt(struct socket *sock, int level, int optname,
} }
EXPORT_SYMBOL(kernel_getsockopt); EXPORT_SYMBOL(kernel_getsockopt);
/**
* kernel_setsockopt - set a socket option (kernel space)
* @sock: socket
* @level: API level (SOL_SOCKET, ...)
* @optname: option tag
* @optval: option value
* @optlen: option length
*
* Returns 0 or an error.
*/
int kernel_setsockopt(struct socket *sock, int level, int optname, int kernel_setsockopt(struct socket *sock, int level, int optname,
char *optval, unsigned int optlen) char *optval, unsigned int optlen)
{ {
@ -3420,6 +3625,17 @@ int kernel_setsockopt(struct socket *sock, int level, int optname,
} }
EXPORT_SYMBOL(kernel_setsockopt); EXPORT_SYMBOL(kernel_setsockopt);
/**
* kernel_sendpage - send a &page through a socket (kernel space)
* @sock: socket
* @page: page
* @offset: page offset
* @size: total size in bytes
* @flags: flags (MSG_DONTWAIT, ...)
*
* Returns the total amount sent in bytes or an error.
*/
int kernel_sendpage(struct socket *sock, struct page *page, int offset, int kernel_sendpage(struct socket *sock, struct page *page, int offset,
size_t size, int flags) size_t size, int flags)
{ {
@ -3430,6 +3646,18 @@ int kernel_sendpage(struct socket *sock, struct page *page, int offset,
} }
EXPORT_SYMBOL(kernel_sendpage); EXPORT_SYMBOL(kernel_sendpage);
/**
* kernel_sendpage_locked - send a &page through the locked sock (kernel space)
* @sk: sock
* @page: page
* @offset: page offset
* @size: total size in bytes
* @flags: flags (MSG_DONTWAIT, ...)
*
* Returns the total amount sent in bytes or an error.
* Caller must hold @sk.
*/
int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset, int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
size_t size, int flags) size_t size, int flags)
{ {
@ -3443,17 +3671,30 @@ int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
} }
EXPORT_SYMBOL(kernel_sendpage_locked); EXPORT_SYMBOL(kernel_sendpage_locked);
/**
* kernel_shutdown - shut down part of a full-duplex connection (kernel space)
* @sock: socket
* @how: connection part
*
* Returns 0 or an error.
*/
int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how) int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
{ {
return sock->ops->shutdown(sock, how); return sock->ops->shutdown(sock, how);
} }
EXPORT_SYMBOL(kernel_sock_shutdown); EXPORT_SYMBOL(kernel_sock_shutdown);
/* This routine returns the IP overhead imposed by a socket i.e. /**
* the length of the underlying IP header, depending on whether * kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
* this is an IPv4 or IPv6 socket and the length from IP options turned * @sk: socket
* on at the socket. Assumes that the caller has a lock on the socket. *
* This routine returns the IP overhead imposed by a socket i.e.
* the length of the underlying IP header, depending on whether
* this is an IPv4 or IPv6 socket and the length from IP options turned
* on at the socket. Assumes that the caller has a lock on the socket.
*/ */
u32 kernel_sock_ip_overhead(struct sock *sk) u32 kernel_sock_ip_overhead(struct sock *sk)
{ {
struct inet_sock *inet; struct inet_sock *inet;