[linux.git] / include / net / scm.h

#ifndef __LINUX_NET_SCM_H
#define __LINUX_NET_SCM_H

#include <linux/limits.h>
#include <linux/net.h>
#include <linux/security.h>
#include <linux/pid.h>
#include <linux/nsproxy.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;
};

struct scm_fp_list {
	short			count;
	short			max;
	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
};

extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
extern void __scm_destroy(struct scm_cookie *scm);
extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);

#ifdef CONFIG_SECURITY_NETWORK
static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
{
	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
}
#else
static __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_NETWORK
static 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);
		}
	}
}
#else
static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
{ }
#endif /* CONFIG_SECURITY_NETWORK */

static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
				struct scm_cookie *scm, int flags)
{
	if (!msg->msg_control) {
		if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
			msg->msg_flags |= MSG_CTRUNC;
		scm_destroy(scm);
		return;
	}

	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_destroy_cred(scm);

	scm_passec(sock, msg, scm);

	if (!scm->fp)
		return;
	
	scm_detach_fds(msg, scm);
}


#endif /* __LINUX_NET_SCM_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef __LINUX_NET_SCM_H
	2	#define __LINUX_NET_SCM_H
	3
	4	#include <linux/limits.h>
	5	#include <linux/net.h>
dc49c1f9	6	#include <linux/security.h>
b488893a PE	7	#include <linux/pid.h>
b488893a PE	8	#include <linux/nsproxy.h>
1da177e4 LT	9
	10	/* Well, we should have at least one descriptor open
	11	* to accept passed FDs 8)
	12	*/
bba14de9	13	#define SCM_MAX_FD 253
1da177e4	14
dbe9a417 EB	15	struct scm_creds {
	16	u32 pid;
	17	kuid_t uid;
	18	kgid_t gid;
	19	};
	20
fd2c3ef7	21	struct scm_fp_list {
bba14de9 ED	22	short count;
bba14de9 ED	23	short max;
f8d570a4	24	struct file *fp[SCM_MAX_FD];
1da177e4 LT	25	};
1da177e4 LT	26
fd2c3ef7	27	struct scm_cookie {
257b5358	28	struct pid pid; / Skb credentials */
1da177e4	29	struct scm_fp_list fp; / Passed files */
dbe9a417	30	struct scm_creds creds; /* Skb credentials */
877ce7c1	31	#ifdef CONFIG_SECURITY_NETWORK
dc49c1f9	32	u32 secid; /* Passed security ID */
877ce7c1	33	#endif
1da177e4 LT	34	};
	35
	36	extern void scm_detach_fds(struct msghdr msg, struct scm_cookie scm);
	37	extern void scm_detach_fds_compat(struct msghdr msg, struct scm_cookie scm);
	38	extern int __scm_send(struct socket sock, struct msghdr msg, struct scm_cookie *scm);
	39	extern void __scm_destroy(struct scm_cookie *scm);
	40	extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
	41
dc49c1f9 CZ	42	#ifdef CONFIG_SECURITY_NETWORK
	43	static __inline__ void unix_get_peersec_dgram(struct socket sock, struct scm_cookie scm)
	44	{
	45	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
	46	}
	47	#else
	48	static __inline__ void unix_get_peersec_dgram(struct socket sock, struct scm_cookie scm)
	49	{ }
	50	#endif /* CONFIG_SECURITY_NETWORK */
	51
257b5358	52	static __inline__ void scm_set_cred(struct scm_cookie *scm,
6b0ee8c0	53	struct pid *pid, kuid_t uid, kgid_t gid)
257b5358 EB	54	{
257b5358 EB	55	scm->pid = get_pid(pid);
dbe9a417	56	scm->creds.pid = pid_vnr(pid);
6b0ee8c0 EB	57	scm->creds.uid = uid;
6b0ee8c0 EB	58	scm->creds.gid = gid;
257b5358 EB	59	}
	60
	61	static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
	62	{
	63	put_pid(scm->pid);
	64	scm->pid = NULL;
257b5358 EB	65	}
257b5358 EB	66
1da177e4 LT	67	static __inline__ void scm_destroy(struct scm_cookie *scm)
1da177e4 LT	68	{
257b5358	69	scm_destroy_cred(scm);
2a6c8c79	70	if (scm->fp)
1da177e4 LT	71	__scm_destroy(scm);
	72	}
	73
	74	static __inline__ int scm_send(struct socket sock, struct msghdr msg,
e0e3cea4	75	struct scm_cookie *scm, bool forcecreds)
1da177e4	76	{
16e57262	77	memset(scm, 0, sizeof(*scm));
6b0ee8c0 EB	78	scm->creds.uid = INVALID_UID;
6b0ee8c0 EB	79	scm->creds.gid = INVALID_GID;
e0e3cea4	80	if (forcecreds)
6e0895c2	81	scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
dc49c1f9	82	unix_get_peersec_dgram(sock, scm);
1da177e4 LT	83	if (msg->msg_controllen <= 0)
	84	return 0;
	85	return __scm_send(sock, msg, scm);
	86	}
	87
877ce7c1 CZ	88	#ifdef CONFIG_SECURITY_NETWORK
	89	static inline void scm_passec(struct socket sock, struct msghdr msg, struct scm_cookie *scm)
	90	{
dc49c1f9 CZ	91	char *secdata;
	92	u32 seclen;
	93	int err;
	94
	95	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
	96	err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
	97
	98	if (!err) {
	99	put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
	100	security_release_secctx(secdata, seclen);
	101	}
	102	}
877ce7c1 CZ	103	}
	104	#else
	105	static inline void scm_passec(struct socket sock, struct msghdr msg, struct scm_cookie *scm)
	106	{ }
	107	#endif /* CONFIG_SECURITY_NETWORK */
	108
1da177e4 LT	109	static __inline__ void scm_recv(struct socket sock, struct msghdr msg,
	110	struct scm_cookie *scm, int flags)
	111	{
fd2c3ef7	112	if (!msg->msg_control) {
1da177e4 LT	113	if (test_bit(SOCK_PASSCRED, &sock->flags) \|\| scm->fp)
1da177e4 LT	114	msg->msg_flags \|= MSG_CTRUNC;
f78a5fda	115	scm_destroy(scm);
1da177e4 LT	116	return;
	117	}
	118
dbe9a417 EB	119	if (test_bit(SOCK_PASSCRED, &sock->flags)) {
	120	struct user_namespace *current_ns = current_user_ns();
	121	struct ucred ucreds = {
	122	.pid = scm->creds.pid,
	123	.uid = from_kuid_munged(current_ns, scm->creds.uid),
	124	.gid = from_kgid_munged(current_ns, scm->creds.gid),
	125	};
	126	put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);
	127	}
1da177e4	128
f78a5fda DM	129	scm_destroy_cred(scm);
f78a5fda DM	130
877ce7c1 CZ	131	scm_passec(sock, msg, scm);
877ce7c1 CZ	132
1da177e4 LT	133	if (!scm->fp)
	134	return;
	135
	136	scm_detach_fds(msg, scm);
	137	}
	138
	139
	140	#endif /* __LINUX_NET_SCM_H */
	141