/* SPDX-License-Identifier: GPL-2.0 */#ifndef __LINUX_NET_SCM_H#define __LINUX_NET_SCM_H #include <linux/limits.h>#include <linux/net.h>#include <linux/cred.h>#include <linux/file.h>#include <linux/security.h>#include <linux/pid.h>#include <linux/nsproxy.h>#include <linux/sched/signal.h>#include <net/compat.h> /* Well, we should have at least one descriptor open * to accept passed FDs 8) */#define SCM_MAX_FD	253 struct scm_creds {	u32	pid;	kuid_t	uid;	kgid_t	gid;}; #ifdef CONFIG_UNIXstruct unix_edge;#endif struct scm_fp_list {	short			count;	short			count_unix;	short			max;#ifdef CONFIG_UNIX	bool			inflight;	bool			dead;	struct list_head	vertices;	struct unix_edge	*edges;#endif	struct user_struct	*user;	struct file		*fp[SCM_MAX_FD];}; struct scm_cookie {	struct pid		*pid;		/* Skb credentials */	struct scm_fp_list	*fp;		/* Passed files		*/	struct scm_creds	creds;		/* Skb credentials	*/#ifdef CONFIG_SECURITY_NETWORK	u32			secid;		/* Passed security ID 	*/#endif}; void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);void __scm_destroy(struct scm_cookie *scm);struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl); #ifdef CONFIG_SECURITY_NETWORKstatic __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm){	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);}#elsestatic __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm){ }#endif /* CONFIG_SECURITY_NETWORK */ static __inline__ void scm_set_cred(struct scm_cookie *scm,				    struct pid *pid, kuid_t uid, kgid_t gid){	scm->pid  = get_pid(pid);	scm->creds.pid = pid_vnr(pid);	scm->creds.uid = uid;	scm->creds.gid = gid;} static __inline__ void scm_destroy_cred(struct scm_cookie *scm){	put_pid(scm->pid);	scm->pid  = NULL;} static __inline__ void scm_destroy(struct scm_cookie *scm){	scm_destroy_cred(scm);	if (scm->fp)		__scm_destroy(scm);} static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,			       struct scm_cookie *scm, bool forcecreds){	memset(scm, 0, sizeof(*scm));	scm->creds.uid = INVALID_UID;	scm->creds.gid = INVALID_GID;	if (forcecreds)		scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());	unix_get_peersec_dgram(sock, scm);	if (msg->msg_controllen <= 0)		return 0;	return __scm_send(sock, msg, scm);} #ifdef CONFIG_SECURITY_NETWORKstatic inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm){	char *secdata;	u32 seclen;	int err; 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {		err = security_secid_to_secctx(scm->secid, &secdata, &seclen); 		if (!err) {			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);			security_release_secctx(secdata, seclen);		}	}} static inline bool scm_has_secdata(struct socket *sock){	return test_bit(SOCK_PASSSEC, &sock->flags);}#elsestatic inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm){ } static inline bool scm_has_secdata(struct socket *sock){	return false;}#endif /* CONFIG_SECURITY_NETWORK */ static __inline__ void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm){	struct file *pidfd_file = NULL;	int len, pidfd; 	/* put_cmsg() doesn't return an error if CMSG is truncated,	 * that's why we need to opencode these checks here.	 */	if (msg->msg_flags & MSG_CMSG_COMPAT)		len = sizeof(struct compat_cmsghdr) + sizeof(int);	else		len = sizeof(struct cmsghdr) + sizeof(int); 	if (msg->msg_controllen < len) {		msg->msg_flags |= MSG_CTRUNC;		return;	} 	if (!scm->pid)		return; 	pidfd = pidfd_prepare(scm->pid, 0, &pidfd_file); 	if (put_cmsg(msg, SOL_SOCKET, SCM_PIDFD, sizeof(int), &pidfd)) {		if (pidfd_file) {			put_unused_fd(pidfd);			fput(pidfd_file);		} 		return;	} 	if (pidfd_file)		fd_install(pidfd, pidfd_file);} static inline bool __scm_recv_common(struct socket *sock, struct msghdr *msg,				     struct scm_cookie *scm, int flags){	if (!msg->msg_control) {		if (test_bit(SOCK_PASSCRED, &sock->flags) ||		    test_bit(SOCK_PASSPIDFD, &sock->flags) ||		    scm->fp || scm_has_secdata(sock))			msg->msg_flags |= MSG_CTRUNC;		scm_destroy(scm);		return false;	} 	if (test_bit(SOCK_PASSCRED, &sock->flags)) {		struct user_namespace *current_ns = current_user_ns();		struct ucred ucreds = {			.pid = scm->creds.pid,			.uid = from_kuid_munged(current_ns, scm->creds.uid),			.gid = from_kgid_munged(current_ns, scm->creds.gid),		};		put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);	} 	scm_passec(sock, msg, scm); 	if (scm->fp)		scm_detach_fds(msg, scm); 	return true;} static inline void scm_recv(struct socket *sock, struct msghdr *msg,			    struct scm_cookie *scm, int flags){	if (!__scm_recv_common(sock, msg, scm, flags))		return; 	scm_destroy_cred(scm);} static inline void scm_recv_unix(struct socket *sock, struct msghdr *msg,				 struct scm_cookie *scm, int flags){	if (!__scm_recv_common(sock, msg, scm, flags))		return; 	if (test_bit(SOCK_PASSPIDFD, &sock->flags))		scm_pidfd_recv(msg, scm); 	scm_destroy_cred(scm);} static inline int scm_recv_one_fd(struct file *f, int __user *ufd,				  unsigned int flags){	if (!ufd)		return -EFAULT;	return receive_fd(f, ufd, flags);} #endif /* __LINUX_NET_SCM_H */