kernel-hacking-2024-linux-steffo/include/linux/socket.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SOCKET_H
#define _LINUX_SOCKET_H


#include <asm/socket.h>			/* arch-dependent defines	*/
#include <linux/sockios.h>		/* the SIOCxxx I/O controls	*/
#include <linux/uio.h>			/* iovec support		*/
#include <linux/types.h>		/* pid_t			*/
#include <linux/compiler.h>		/* __user			*/
#include <uapi/linux/socket.h>

struct file;
struct pid;
struct cred;
struct socket;
struct sock;
struct sk_buff;
struct proto_accept_arg;

#define __sockaddr_check_size(size)	\
	BUILD_BUG_ON(((size) > sizeof(struct __kernel_sockaddr_storage)))

#ifdef CONFIG_PROC_FS
struct seq_file;
extern void socket_seq_show(struct seq_file *seq);
#endif

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	*/
	union {
		char sa_data_min[14];		/* Minimum 14 bytes of protocol address	*/
		DECLARE_FLEX_ARRAY(char, sa_data);
	};
};

struct linger {
	int		l_onoff;	/* Linger active		*/
	int		l_linger;	/* How long to linger for	*/
};

#define sockaddr_storage __kernel_sockaddr_storage

/*
 *	As we do 4.4BSD message passing we use a 4.4BSD message passing
 *	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 */

	int		msg_inq;	/* output, data left in socket */

	struct iov_iter	msg_iter;	/* data */

	/*
	 * Ancillary data. msg_control_user is the user buffer used for the
	 * recv* side when msg_control_is_user is set, msg_control is the kernel
	 * buffer used for all other cases.
	 */
	union {
		void		*msg_control;
		void __user	*msg_control_user;
	};
	bool		msg_control_is_user : 1;
	bool		msg_get_inq : 1;/* return INQ after receive */
	unsigned int	msg_flags;	/* flags on received message */
	__kernel_size_t	msg_controllen;	/* ancillary data buffer length */
	struct kiocb	*msg_iocb;	/* ptr to iocb for async requests */
	struct ubuf_info *msg_ubuf;
	int (*sg_from_iter)(struct sk_buff *skb,
			    struct iov_iter *from, size_t length);
};

struct user_msghdr {
	void		__user *msg_name;	/* ptr to socket address structure */
	int		msg_namelen;		/* size of socket address structure */
	struct iovec	__user *msg_iov;	/* scatter/gather array */
	__kernel_size_t	msg_iovlen;		/* # elements in msg_iov */
	void		__user *msg_control;	/* ancillary data */
	__kernel_size_t	msg_controllen;		/* ancillary data buffer length */
	unsigned int	msg_flags;		/* flags on received message */
};

/* For recvmmsg/sendmmsg */
struct mmsghdr {
	struct user_msghdr  msg_hdr;
	unsigned int        msg_len;
};

/*
 *	POSIX 1003.1g - ancillary data object information
 *	Ancillary data consists of a sequence of pairs of
 *	(cmsghdr, cmsg_data[])
 */

struct cmsghdr {
	__kernel_size_t	cmsg_len;	/* data byte count, including hdr */
        int		cmsg_level;	/* originating protocol */
        int		cmsg_type;	/* protocol-specific type */
};

/*
 *	Ancillary data object information MACROS
 *	Table 5-14 of POSIX 1003.1g
 */

#define __CMSG_NXTHDR(ctl, len, cmsg) __cmsg_nxthdr((ctl),(len),(cmsg))
#define CMSG_NXTHDR(mhdr, cmsg) cmsg_nxthdr((mhdr), (cmsg))

#define CMSG_ALIGN(len) ( ((len)+sizeof(long)-1) & ~(sizeof(long)-1) )

#define CMSG_DATA(cmsg) \
	((void *)(cmsg) + sizeof(struct cmsghdr))
#define CMSG_USER_DATA(cmsg) \
	((void __user *)(cmsg) + sizeof(struct cmsghdr))
#define CMSG_SPACE(len) (sizeof(struct cmsghdr) + CMSG_ALIGN(len))
#define CMSG_LEN(len) (sizeof(struct cmsghdr) + (len))

#define __CMSG_FIRSTHDR(ctl,len) ((len) >= sizeof(struct cmsghdr) ? \
				  (struct cmsghdr *)(ctl) : \
				  (struct cmsghdr *)NULL)
#define CMSG_FIRSTHDR(msg)	__CMSG_FIRSTHDR((msg)->msg_control, (msg)->msg_controllen)
#define CMSG_OK(mhdr, cmsg) ((cmsg)->cmsg_len >= sizeof(struct cmsghdr) && \
			     (cmsg)->cmsg_len <= (unsigned long) \
			     ((mhdr)->msg_controllen - \
			      ((char *)(cmsg) - (char *)(mhdr)->msg_control)))
#define for_each_cmsghdr(cmsg, msg) \
	for (cmsg = CMSG_FIRSTHDR(msg); \
	     cmsg; \
	     cmsg = CMSG_NXTHDR(msg, cmsg))

/*
 *	Get the next cmsg header
 *
 *	PLEASE, do not touch this function. If you think, that it is
 *	incorrect, grep kernel sources and think about consequences
 *	before trying to improve it.
 *
 *	Now it always returns valid, not truncated ancillary object
 *	HEADER. But caller still MUST check, that cmsg->cmsg_len is
 *	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)
{
	struct cmsghdr * __ptr;

	__ptr = (struct cmsghdr*)(((unsigned char *) __cmsg) +  CMSG_ALIGN(__cmsg->cmsg_len));
	if ((unsigned long)((char*)(__ptr+1) - (char *) __ctl) > __size)
		return (struct cmsghdr *)0;

	return __ptr;
}

static inline struct cmsghdr * cmsg_nxthdr (struct msghdr *__msg, struct cmsghdr *__cmsg)
{
	return __cmsg_nxthdr(__msg->msg_control, __msg->msg_controllen, __cmsg);
}

static inline size_t msg_data_left(struct msghdr *msg)
{
	return iov_iter_count(&msg->msg_iter);
}

/* "Socket"-level control message types: */

#define	SCM_RIGHTS	0x01		/* rw: access rights (array of int) */
#define SCM_CREDENTIALS 0x02		/* rw: struct ucred		*/
#define SCM_SECURITY	0x03		/* rw: security label		*/
#define SCM_PIDFD	0x04		/* ro: pidfd (int)		*/

struct ucred {
	__u32	pid;
	__u32	uid;
	__u32	gid;
};

/* Supported address families. */
#define AF_UNSPEC	0
#define AF_UNIX		1	/* Unix domain sockets 		*/
#define AF_LOCAL	1	/* POSIX name for AF_UNIX	*/
#define AF_INET		2	/* Internet IP Protocol 	*/
#define AF_AX25		3	/* Amateur Radio AX.25 		*/
#define AF_IPX		4	/* Novell IPX 			*/
#define AF_APPLETALK	5	/* AppleTalk DDP 		*/
#define AF_NETROM	6	/* Amateur Radio NET/ROM 	*/
#define AF_BRIDGE	7	/* Multiprotocol bridge 	*/
#define AF_ATMPVC	8	/* ATM PVCs			*/
#define AF_X25		9	/* Reserved for X.25 project 	*/
#define AF_INET6	10	/* IP version 6			*/
#define AF_ROSE		11	/* Amateur Radio X.25 PLP	*/
#define AF_DECnet	12	/* Reserved for DECnet project	*/
#define AF_NETBEUI	13	/* Reserved for 802.2LLC project*/
#define AF_SECURITY	14	/* Security callback pseudo AF */
#define AF_KEY		15      /* PF_KEY key management API */
#define AF_NETLINK	16
#define AF_ROUTE	AF_NETLINK /* Alias to emulate 4.4BSD */
#define AF_PACKET	17	/* Packet family		*/
#define AF_ASH		18	/* Ash				*/
#define AF_ECONET	19	/* Acorn Econet			*/
#define AF_ATMSVC	20	/* ATM SVCs			*/
#define AF_RDS		21	/* RDS sockets 			*/
#define AF_SNA		22	/* Linux SNA Project (nutters!) */
#define AF_IRDA		23	/* IRDA sockets			*/
#define AF_PPPOX	24	/* PPPoX sockets		*/
#define AF_WANPIPE	25	/* Wanpipe API Sockets */
#define AF_LLC		26	/* Linux LLC			*/
#define AF_IB		27	/* Native InfiniBand address	*/
#define AF_MPLS		28	/* MPLS */
#define AF_CAN		29	/* Controller Area Network      */
#define AF_TIPC		30	/* TIPC sockets			*/
#define AF_BLUETOOTH	31	/* Bluetooth sockets 		*/
#define AF_IUCV		32	/* IUCV sockets			*/
#define AF_RXRPC	33	/* RxRPC sockets 		*/
#define AF_ISDN		34	/* mISDN sockets 		*/
#define AF_PHONET	35	/* Phonet sockets		*/
#define AF_IEEE802154	36	/* IEEE802154 sockets		*/
#define AF_CAIF		37	/* CAIF sockets			*/
#define AF_ALG		38	/* Algorithm sockets		*/
#define AF_NFC		39	/* NFC sockets			*/
#define AF_VSOCK	40	/* vSockets			*/
#define AF_KCM		41	/* Kernel Connection Multiplexor*/
#define AF_QIPCRTR	42	/* Qualcomm IPC Router          */
#define AF_SMC		43	/* smc sockets: reserve number for
				 * PF_SMC protocol family that
				 * reuses AF_INET address family
				 */
#define AF_XDP		44	/* XDP sockets			*/
#define AF_MCTP		45	/* Management component
				 * transport protocol
				 */

#define AF_MAX		46	/* For now.. */

/* Protocol families, same as address families. */
#define PF_UNSPEC	AF_UNSPEC
#define PF_UNIX		AF_UNIX
#define PF_LOCAL	AF_LOCAL
#define PF_INET		AF_INET
#define PF_AX25		AF_AX25
#define PF_IPX		AF_IPX
#define PF_APPLETALK	AF_APPLETALK
#define	PF_NETROM	AF_NETROM
#define PF_BRIDGE	AF_BRIDGE
#define PF_ATMPVC	AF_ATMPVC
#define PF_X25		AF_X25
#define PF_INET6	AF_INET6
#define PF_ROSE		AF_ROSE
#define PF_DECnet	AF_DECnet
#define PF_NETBEUI	AF_NETBEUI
#define PF_SECURITY	AF_SECURITY
#define PF_KEY		AF_KEY
#define PF_NETLINK	AF_NETLINK
#define PF_ROUTE	AF_ROUTE
#define PF_PACKET	AF_PACKET
#define PF_ASH		AF_ASH
#define PF_ECONET	AF_ECONET
#define PF_ATMSVC	AF_ATMSVC
#define PF_RDS		AF_RDS
#define PF_SNA		AF_SNA
#define PF_IRDA		AF_IRDA
#define PF_PPPOX	AF_PPPOX
#define PF_WANPIPE	AF_WANPIPE
#define PF_LLC		AF_LLC
#define PF_IB		AF_IB
#define PF_MPLS		AF_MPLS
#define PF_CAN		AF_CAN
#define PF_TIPC		AF_TIPC
#define PF_BLUETOOTH	AF_BLUETOOTH
#define PF_IUCV		AF_IUCV
#define PF_RXRPC	AF_RXRPC
#define PF_ISDN		AF_ISDN
#define PF_PHONET	AF_PHONET
#define PF_IEEE802154	AF_IEEE802154
#define PF_CAIF		AF_CAIF
#define PF_ALG		AF_ALG
#define PF_NFC		AF_NFC
#define PF_VSOCK	AF_VSOCK
#define PF_KCM		AF_KCM
#define PF_QIPCRTR	AF_QIPCRTR
#define PF_SMC		AF_SMC
#define PF_XDP		AF_XDP
#define PF_MCTP		AF_MCTP
#define PF_MAX		AF_MAX

/* Maximum queue length specifiable by listen.  */
#define SOMAXCONN	4096

/* 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
#define MSG_TRYHARD     4       /* Synonym for MSG_DONTROUTE for DECnet */
#define MSG_CTRUNC	8
#define MSG_PROBE	0x10	/* Do not send. Only probe path f.e. for MTU */
#define MSG_TRUNC	0x20
#define MSG_DONTWAIT	0x40	/* Nonblocking io		 */
#define MSG_EOR         0x80	/* End of record */
#define MSG_WAITALL	0x100	/* Wait for a full request */
#define MSG_FIN         0x200
#define MSG_SYN		0x400
#define MSG_CONFIRM	0x800	/* Confirm path validity */
#define MSG_RST		0x1000
#define MSG_ERRQUEUE	0x2000	/* Fetch message from error queue */
#define MSG_NOSIGNAL	0x4000	/* Do not generate SIGPIPE */
#define MSG_MORE	0x8000	/* Sender will send more */
#define MSG_WAITFORONE	0x10000	/* recvmmsg(): block until 1+ packets avail */
#define MSG_SENDPAGE_NOPOLICY 0x10000 /* sendpage() internal : do no apply policy */
#define MSG_BATCH	0x40000 /* sendmmsg(): more messages coming */
#define MSG_EOF         MSG_FIN
#define MSG_NO_SHARED_FRAGS 0x80000 /* sendpage() internal : page frags are not shared */
#define MSG_SENDPAGE_DECRYPTED	0x100000 /* sendpage() internal : page may carry
					  * plain text and require encryption
					  */

#define MSG_ZEROCOPY	0x4000000	/* Use user data in kernel path */
#define MSG_SPLICE_PAGES 0x8000000	/* Splice the pages from the iterator in sendmsg() */
#define MSG_FASTOPEN	0x20000000	/* Send data in TCP SYN */
#define MSG_CMSG_CLOEXEC 0x40000000	/* Set close_on_exec for file
					   descriptor received through
					   SCM_RIGHTS */
#if defined(CONFIG_COMPAT)
#define MSG_CMSG_COMPAT	0x80000000	/* This message needs 32 bit fixups */
#else
#define MSG_CMSG_COMPAT	0		/* We never have 32 bit fixups */
#endif

/* Flags to be cleared on entry by sendmsg and sendmmsg syscalls */
#define MSG_INTERNAL_SENDMSG_FLAGS \
	(MSG_SPLICE_PAGES | MSG_SENDPAGE_NOPOLICY | MSG_SENDPAGE_DECRYPTED)

/* Setsockoptions(2) level. Thanks to BSD these must match IPPROTO_xxx */
#define SOL_IP		0
/* #define SOL_ICMP	1	No-no-no! Due to Linux :-) we cannot use SOL_ICMP=1 */
#define SOL_TCP		6
#define SOL_UDP		17
#define SOL_IPV6	41
#define SOL_ICMPV6	58
#define SOL_SCTP	132
#define SOL_UDPLITE	136     /* UDP-Lite (RFC 3828) */
#define SOL_RAW		255
#define SOL_IPX		256
#define SOL_AX25	257
#define SOL_ATALK	258
#define SOL_NETROM	259
#define SOL_ROSE	260
#define SOL_DECNET	261
#define	SOL_X25		262
#define SOL_PACKET	263
#define SOL_ATM		264	/* ATM layer (cell level) */
#define SOL_AAL		265	/* ATM Adaption Layer (packet level) */
#define SOL_IRDA        266
#define SOL_NETBEUI	267
#define SOL_LLC		268
#define SOL_DCCP	269
#define SOL_NETLINK	270
#define SOL_TIPC	271
#define SOL_RXRPC	272
#define SOL_PPPOL2TP	273
#define SOL_BLUETOOTH	274
#define SOL_PNPIPE	275
#define SOL_RDS		276
#define SOL_IUCV	277
#define SOL_CAIF	278
#define SOL_ALG		279
#define SOL_NFC		280
#define SOL_KCM		281
#define SOL_TLS		282
#define SOL_XDP		283
#define SOL_MPTCP	284
#define SOL_MCTP	285
#define SOL_SMC		286
#define SOL_VSOCK	287

/* IPX options */
#define IPX_TYPE	1

extern int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr);
extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data);

struct timespec64;
struct __kernel_timespec;
struct old_timespec32;

struct scm_timestamping_internal {
	struct timespec64 ts[3];
};

extern void put_cmsg_scm_timestamping64(struct msghdr *msg, struct scm_timestamping_internal *tss);
extern void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_internal *tss);

/* The __sys_...msg variants allow MSG_CMSG_COMPAT iff
 * forbid_cmsg_compat==false
 */
extern long __sys_recvmsg(int fd, struct user_msghdr __user *msg,
			  unsigned int flags, bool forbid_cmsg_compat);
extern long __sys_sendmsg(int fd, struct user_msghdr __user *msg,
			  unsigned int flags, bool forbid_cmsg_compat);
extern int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
			  unsigned int vlen, unsigned int flags,
			  struct __kernel_timespec __user *timeout,
			  struct old_timespec32 __user *timeout32);
extern int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg,
			  unsigned int vlen, unsigned int flags,
			  bool forbid_cmsg_compat);
extern long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg,
			       unsigned int flags);
extern long __sys_recvmsg_sock(struct socket *sock, struct msghdr *msg,
			       struct user_msghdr __user *umsg,
			       struct sockaddr __user *uaddr,
			       unsigned int flags);
extern int __copy_msghdr(struct msghdr *kmsg,
			 struct user_msghdr *umsg,
			 struct sockaddr __user **save_addr);

/* helpers which do the actual work for syscalls */
extern int __sys_recvfrom(int fd, void __user *ubuf, size_t size,
			  unsigned int flags, struct sockaddr __user *addr,
			  int __user *addr_len);
extern int __sys_sendto(int fd, void __user *buff, size_t len,
			unsigned int flags, struct sockaddr __user *addr,
			int addr_len);
extern struct file *do_accept(struct file *file, struct proto_accept_arg *arg,
			      struct sockaddr __user *upeer_sockaddr,
			      int __user *upeer_addrlen, int flags);
extern int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
			 int __user *upeer_addrlen, int flags);
extern int __sys_socket(int family, int type, int protocol);
extern struct file *__sys_socket_file(int family, int type, int protocol);
extern int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen);
extern int __sys_bind_socket(struct socket *sock, struct sockaddr_storage *address,
			     int addrlen);
extern int __sys_connect_file(struct file *file, struct sockaddr_storage *addr,
			      int addrlen, int file_flags);
extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
			 int addrlen);
extern int __sys_listen(int fd, int backlog);
extern int __sys_listen_socket(struct socket *sock, int backlog);
extern int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
			     int __user *usockaddr_len);
extern int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
			     int __user *usockaddr_len);
extern int __sys_socketpair(int family, int type, int protocol,
			    int __user *usockvec);
extern int __sys_shutdown_sock(struct socket *sock, int how);
extern int __sys_shutdown(int fd, int how);
#endif /* _LINUX_SOCKET_H */