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Subject[PATCH 4.19 037/109] net: add documentation to socket.c
Date
From: Pedro Tammela <pctammela@gmail.com>

[ Upstream commit 8a3c245c031944f2176118270e7bc5d4fd4a1075 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/net.h | 6 +
include/linux/socket.h | 12 +-
net/socket.c | 277 ++++++++++++++++++++++++++++++++++++++---
3 files changed, 271 insertions(+), 24 deletions(-)

diff --git a/include/linux/net.h b/include/linux/net.h
index e0930678c8bf..41dc703b261c 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -83,6 +83,12 @@ enum sock_type {

#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 {
SHUT_RD,
SHUT_WR,
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 7ed4713d5337..cc1d3f1b7656 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -26,7 +26,7 @@ typedef __kernel_sa_family_t sa_family_t;
/*
* 1003.1g requires sa_family_t and that sa_data is char.
*/
-
+
struct sockaddr {
sa_family_t sa_family; /* address family, AF_xxx */
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
* belong in an obscure libc emulation or the bin.
*/
-
+
struct msghdr {
void *msg_name; /* ptr to 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 */
struct kiocb *msg_iocb; /* ptr to iocb for async requests */
};
-
+
struct user_msghdr {
void __user *msg_name; /* ptr to 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
* ancillary object DATA. --ANK (980731)
*/
-
+
static inline struct cmsghdr * __cmsg_nxthdr(void *__ctl, __kernel_size_t __size,
struct cmsghdr *__cmsg)
{
@@ -264,10 +264,10 @@ struct ucred {
/* Maximum queue length specifiable by listen. */
#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
*/
-
+
#define MSG_OOB 1
#define MSG_PEEK 2
#define MSG_DONTROUTE 4
diff --git a/net/socket.c b/net/socket.c
index 29169045dcfe..1ed7be54815a 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -384,6 +384,18 @@ static struct file_system_type sock_fs_type = {
* 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 *file;
@@ -424,6 +436,14 @@ static int sock_map_fd(struct socket *sock, int flags)
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)
{
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
* 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)
@@ -561,7 +581,7 @@ struct socket *sock_alloc(void)
EXPORT_SYMBOL(sock_alloc);

/**
- * sock_release - close a socket
+ * sock_release - close a socket
* @sock: socket to close
*
* 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);

+/**
+ * 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)
{
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);

+/**
+ * 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,
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);

+/**
+ * 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,
struct kvec *vec, size_t num, size_t size)
{
@@ -789,6 +843,16 @@ void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
}
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,
int flags)
{
@@ -804,20 +868,21 @@ int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
EXPORT_SYMBOL(sock_recvmsg);

/**
- * kernel_recvmsg - Receive a message from a socket (kernel space)
- * @sock: The socket to receive the message from
- * @msg: Received message
- * @vec: Input s/g array for message data
- * @num: Size of input s/g array
- * @size: Number of bytes to read
- * @flags: Message flags (MSG_DONTWAIT, etc...)
+ * kernel_recvmsg - Receive a message from a socket (kernel space)
+ * @sock: The socket to receive the message from
+ * @msg: Received message
+ * @vec: Input s/g array for message data
+ * @num: Size of input s/g array
+ * @size: Number of bytes to read
+ * @flags: Message flags (MSG_DONTWAIT, etc...)
*
- * 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
- * portion of the original array.
+ * 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
+ * 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,
struct kvec *vec, size_t num, size_t size, int flags)
{
@@ -983,6 +1048,13 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
* 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)
{
return &get_net(container_of(ns, struct net, ns))->ns;
@@ -1077,6 +1149,19 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
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 err;
@@ -1202,6 +1287,21 @@ int sock_wake_async(struct socket_wq *wq, int how, int band)
}
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,
struct socket **res, int kern)
{
@@ -1311,12 +1411,35 @@ int __sock_create(struct net *net, int family, int type, int protocol,
}
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)
{
return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
}
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)
{
return __sock_create(net, family, type, protocol, res, 1);
@@ -3273,18 +3396,46 @@ static long compat_sock_ioctl(struct file *file, unsigned int cmd,
}
#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)
{
return sock->ops->bind(sock, addr, addrlen);
}
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)
{
return sock->ops->listen(sock, backlog);
}
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)
{
struct sock *sk = sock->sk;
@@ -3310,6 +3461,19 @@ int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
}
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 flags)
{
@@ -3317,18 +3481,48 @@ int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
}
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)
{
return sock->ops->getname(sock, addr, 0);
}
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)
{
return sock->ops->getname(sock, addr, 1);
}
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,
char *optval, int *optlen)
{
@@ -3351,6 +3545,17 @@ int kernel_getsockopt(struct socket *sock, int level, int optname,
}
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,
char *optval, unsigned int optlen)
{
@@ -3371,6 +3576,17 @@ int kernel_setsockopt(struct socket *sock, int level, int optname,
}
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,
size_t size, int flags)
{
@@ -3381,6 +3597,18 @@ int kernel_sendpage(struct socket *sock, struct page *page, int offset,
}
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,
size_t size, int flags)
{
@@ -3394,17 +3622,30 @@ int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
}
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)
{
return sock->ops->shutdown(sock, how);
}
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
- * 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.
+/**
+ * kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
+ * @sk: 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)
{
struct inet_sock *inet;
--
2.30.2
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