[deliverable/linux.git] / net / core / scm.c

/* scm.c - Socket level control messages processing.
 *
 * Author:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *              Alignment and value checking mods by Craig Metz
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/signal.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/stat.h>
#include <linux/socket.h>
#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/security.h>
#include <linux/pid.h>
#include <linux/nsproxy.h>
#include <linux/slab.h>

#include <asm/uaccess.h>

#include <net/protocol.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/compat.h>
#include <net/scm.h>
#include <net/cls_cgroup.h>


/*
 *	Only allow a user to send credentials, that they could set with
 *	setu(g)id.
 */

static __inline__ int scm_check_creds(struct ucred *creds)
{
	const struct cred *cred = current_cred();
	kuid_t uid = make_kuid(cred->user_ns, creds->uid);
	kgid_t gid = make_kgid(cred->user_ns, creds->gid);

	if (!uid_valid(uid) || !gid_valid(gid))
		return -EINVAL;

	if ((creds->pid == task_tgid_vnr(current) || nsown_capable(CAP_SYS_ADMIN)) &&
	    ((uid_eq(uid, cred->uid)   || uid_eq(uid, cred->euid) ||
	      uid_eq(uid, cred->suid)) || nsown_capable(CAP_SETUID)) &&
	    ((gid_eq(gid, cred->gid)   || gid_eq(gid, cred->egid) ||
	      gid_eq(gid, cred->sgid)) || nsown_capable(CAP_SETGID))) {
	       return 0;
	}
	return -EPERM;
}

static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
{
	int *fdp = (int*)CMSG_DATA(cmsg);
	struct scm_fp_list *fpl = *fplp;
	struct file **fpp;
	int i, num;

	num = (cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr)))/sizeof(int);

	if (num <= 0)
		return 0;

	if (num > SCM_MAX_FD)
		return -EINVAL;

	if (!fpl)
	{
		fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL);
		if (!fpl)
			return -ENOMEM;
		*fplp = fpl;
		fpl->count = 0;
		fpl->max = SCM_MAX_FD;
	}
	fpp = &fpl->fp[fpl->count];

	if (fpl->count + num > fpl->max)
		return -EINVAL;

	/*
	 *	Verify the descriptors and increment the usage count.
	 */

	for (i=0; i< num; i++)
	{
		int fd = fdp[i];
		struct file *file;

		if (fd < 0 || !(file = fget_raw(fd)))
			return -EBADF;
		*fpp++ = file;
		fpl->count++;
	}
	return num;
}

void __scm_destroy(struct scm_cookie *scm)
{
	struct scm_fp_list *fpl = scm->fp;
	int i;

	if (fpl) {
		scm->fp = NULL;
		for (i=fpl->count-1; i>=0; i--)
			fput(fpl->fp[i]);
		kfree(fpl);
	}
}
EXPORT_SYMBOL(__scm_destroy);

int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
{
	struct cmsghdr *cmsg;
	int err;

	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg))
	{
		err = -EINVAL;

		/* Verify that cmsg_len is at least sizeof(struct cmsghdr) */
		/* The first check was omitted in <= 2.2.5. The reasoning was
		   that parser checks cmsg_len in any case, so that
		   additional check would be work duplication.
		   But if cmsg_level is not SOL_SOCKET, we do not check
		   for too short ancillary data object at all! Oops.
		   OK, let's add it...
		 */
		if (!CMSG_OK(msg, cmsg))
			goto error;

		if (cmsg->cmsg_level != SOL_SOCKET)
			continue;

		switch (cmsg->cmsg_type)
		{
		case SCM_RIGHTS:
			if (!sock->ops || sock->ops->family != PF_UNIX)
				goto error;
			err=scm_fp_copy(cmsg, &p->fp);
			if (err<0)
				goto error;
			break;
		case SCM_CREDENTIALS:
		{
			struct ucred creds;
			kuid_t uid;
			kgid_t gid;
			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
				goto error;
			memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred));
			err = scm_check_creds(&creds);
			if (err)
				goto error;

			p->creds.pid = creds.pid;
			if (!p->pid || pid_vnr(p->pid) != creds.pid) {
				struct pid *pid;
				err = -ESRCH;
				pid = find_get_pid(creds.pid);
				if (!pid)
					goto error;
				put_pid(p->pid);
				p->pid = pid;
			}

			err = -EINVAL;
			uid = make_kuid(current_user_ns(), creds.uid);
			gid = make_kgid(current_user_ns(), creds.gid);
			if (!uid_valid(uid) || !gid_valid(gid))
				goto error;

			p->creds.uid = uid;
			p->creds.gid = gid;

			if (!p->cred ||
			    !uid_eq(p->cred->euid, uid) ||
			    !gid_eq(p->cred->egid, gid)) {
				struct cred *cred;
				err = -ENOMEM;
				cred = prepare_creds();
				if (!cred)
					goto error;

				cred->uid = cred->euid = uid;
				cred->gid = cred->egid = gid;
				if (p->cred)
					put_cred(p->cred);
				p->cred = cred;
			}
			break;
		}
		default:
			goto error;
		}
	}

	if (p->fp && !p->fp->count)
	{
		kfree(p->fp);
		p->fp = NULL;
	}
	return 0;

error:
	scm_destroy(p);
	return err;
}
EXPORT_SYMBOL(__scm_send);

int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
{
	struct cmsghdr __user *cm
		= (__force struct cmsghdr __user *)msg->msg_control;
	struct cmsghdr cmhdr;
	int cmlen = CMSG_LEN(len);
	int err;

	if (MSG_CMSG_COMPAT & msg->msg_flags)
		return put_cmsg_compat(msg, level, type, len, data);

	if (cm==NULL || msg->msg_controllen < sizeof(*cm)) {
		msg->msg_flags |= MSG_CTRUNC;
		return 0; /* XXX: return error? check spec. */
	}
	if (msg->msg_controllen < cmlen) {
		msg->msg_flags |= MSG_CTRUNC;
		cmlen = msg->msg_controllen;
	}
	cmhdr.cmsg_level = level;
	cmhdr.cmsg_type = type;
	cmhdr.cmsg_len = cmlen;

	err = -EFAULT;
	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
		goto out;
	if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
		goto out;
	cmlen = CMSG_SPACE(len);
	if (msg->msg_controllen < cmlen)
		cmlen = msg->msg_controllen;
	msg->msg_control += cmlen;
	msg->msg_controllen -= cmlen;
	err = 0;
out:
	return err;
}
EXPORT_SYMBOL(put_cmsg);

void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
{
	struct cmsghdr __user *cm
		= (__force struct cmsghdr __user*)msg->msg_control;

	int fdmax = 0;
	int fdnum = scm->fp->count;
	struct file **fp = scm->fp->fp;
	int __user *cmfptr;
	int err = 0, i;

	if (MSG_CMSG_COMPAT & msg->msg_flags) {
		scm_detach_fds_compat(msg, scm);
		return;
	}

	if (msg->msg_controllen > sizeof(struct cmsghdr))
		fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
			 / sizeof(int));

	if (fdnum < fdmax)
		fdmax = fdnum;

	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
	     i++, cmfptr++)
	{
		struct socket *sock;
		int new_fd;
		err = security_file_receive(fp[i]);
		if (err)
			break;
		err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags
					  ? O_CLOEXEC : 0);
		if (err < 0)
			break;
		new_fd = err;
		err = put_user(new_fd, cmfptr);
		if (err) {
			put_unused_fd(new_fd);
			break;
		}
		/* Bump the usage count and install the file. */
		sock = sock_from_file(fp[i], &err);
		if (sock) {
			sock_update_netprioidx(sock->sk, current);
			sock_update_classid(sock->sk, current);
		}
		fd_install(new_fd, get_file(fp[i]));
	}

	if (i > 0)
	{
		int cmlen = CMSG_LEN(i*sizeof(int));
		err = put_user(SOL_SOCKET, &cm->cmsg_level);
		if (!err)
			err = put_user(SCM_RIGHTS, &cm->cmsg_type);
		if (!err)
			err = put_user(cmlen, &cm->cmsg_len);
		if (!err) {
			cmlen = CMSG_SPACE(i*sizeof(int));
			msg->msg_control += cmlen;
			msg->msg_controllen -= cmlen;
		}
	}
	if (i < fdnum || (fdnum && fdmax <= 0))
		msg->msg_flags |= MSG_CTRUNC;

	/*
	 * All of the files that fit in the message have had their
	 * usage counts incremented, so we just free the list.
	 */
	__scm_destroy(scm);
}
EXPORT_SYMBOL(scm_detach_fds);

struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
{
	struct scm_fp_list *new_fpl;
	int i;

	if (!fpl)
		return NULL;

	new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),
			  GFP_KERNEL);
	if (new_fpl) {
		for (i = 0; i < fpl->count; i++)
			get_file(fpl->fp[i]);
		new_fpl->max = new_fpl->count;
	}
	return new_fpl;
}
EXPORT_SYMBOL(scm_fp_dup);
Commit	Line	Data
1da177e4 LT	1	/* scm.c - Socket level control messages processing.
	2	*
	3	* Author: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	4	* Alignment and value checking mods by Craig Metz
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/signal.h>
4fc268d2	14	#include <linux/capability.h>
1da177e4 LT	15	#include <linux/errno.h>
	16	#include <linux/sched.h>
	17	#include <linux/mm.h>
	18	#include <linux/kernel.h>
1da177e4 LT	19	#include <linux/stat.h>
	20	#include <linux/socket.h>
	21	#include <linux/file.h>
	22	#include <linux/fcntl.h>
	23	#include <linux/net.h>
	24	#include <linux/interrupt.h>
	25	#include <linux/netdevice.h>
	26	#include <linux/security.h>
b488893a PE	27	#include <linux/pid.h>
b488893a PE	28	#include <linux/nsproxy.h>
5a0e3ad6	29	#include <linux/slab.h>
1da177e4	30
1da177e4 LT	31	#include <asm/uaccess.h>
	32
	33	#include <net/protocol.h>
	34	#include <linux/skbuff.h>
	35	#include <net/sock.h>
	36	#include <net/compat.h>
	37	#include <net/scm.h>
d8429506	38	#include <net/cls_cgroup.h>
1da177e4 LT	39
	40
	41	/*
4ec93edb	42	* Only allow a user to send credentials, that they could set with
1da177e4 LT	43	* setu(g)id.
	44	*/
	45
	46	static __inline__ int scm_check_creds(struct ucred *creds)
	47	{
86a264ab	48	const struct cred *cred = current_cred();
b2e4f544 EB	49	kuid_t uid = make_kuid(cred->user_ns, creds->uid);
	50	kgid_t gid = make_kgid(cred->user_ns, creds->gid);
	51
	52	if (!uid_valid(uid) \|\| !gid_valid(gid))
	53	return -EINVAL;
b6dff3ec	54
00f70de0	55	if ((creds->pid == task_tgid_vnr(current) \|\| nsown_capable(CAP_SYS_ADMIN)) &&
b2e4f544	56	((uid_eq(uid, cred->uid) \|\| uid_eq(uid, cred->euid) \|\|
00f70de0	57	uid_eq(uid, cred->suid)) \|\| nsown_capable(CAP_SETUID)) &&
b2e4f544	58	((gid_eq(gid, cred->gid) \|\| gid_eq(gid, cred->egid) \|\|
00f70de0	59	gid_eq(gid, cred->sgid)) \|\| nsown_capable(CAP_SETGID))) {
1da177e4 LT	60	return 0;
	61	}
	62	return -EPERM;
	63	}
	64
	65	static int scm_fp_copy(struct cmsghdr cmsg, struct scm_fp_list *fplp)
	66	{
	67	int fdp = (int)CMSG_DATA(cmsg);
	68	struct scm_fp_list fpl = fplp;
	69	struct file **fpp;
	70	int i, num;
	71
	72	num = (cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr)))/sizeof(int);
	73
	74	if (num <= 0)
	75	return 0;
	76
	77	if (num > SCM_MAX_FD)
	78	return -EINVAL;
	79
	80	if (!fpl)
	81	{
	82	fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL);
	83	if (!fpl)
	84	return -ENOMEM;
	85	*fplp = fpl;
	86	fpl->count = 0;
bba14de9	87	fpl->max = SCM_MAX_FD;
1da177e4 LT	88	}
	89	fpp = &fpl->fp[fpl->count];
	90
bba14de9	91	if (fpl->count + num > fpl->max)
1da177e4	92	return -EINVAL;
4ec93edb	93
1da177e4 LT	94	/*
	95	* Verify the descriptors and increment the usage count.
	96	*/
4ec93edb	97
1da177e4 LT	98	for (i=0; i< num; i++)
	99	{
	100	int fd = fdp[i];
	101	struct file *file;
	102
326be7b4	103	if (fd < 0 \|\| !(file = fget_raw(fd)))
1da177e4 LT	104	return -EBADF;
	105	*fpp++ = file;
	106	fpl->count++;
	107	}
	108	return num;
	109	}
	110
	111	void __scm_destroy(struct scm_cookie *scm)
	112	{
	113	struct scm_fp_list *fpl = scm->fp;
	114	int i;
	115
	116	if (fpl) {
	117	scm->fp = NULL;
6120d3db AV	118	for (i=fpl->count-1; i>=0; i--)
	119	fput(fpl->fp[i]);
	120	kfree(fpl);
1da177e4 LT	121	}
1da177e4 LT	122	}
9e34a5b5	123	EXPORT_SYMBOL(__scm_destroy);
1da177e4 LT	124
	125	int __scm_send(struct socket sock, struct msghdr msg, struct scm_cookie *p)
	126	{
	127	struct cmsghdr *cmsg;
	128	int err;
	129
	130	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg))
	131	{
	132	err = -EINVAL;
	133
	134	/* Verify that cmsg_len is at least sizeof(struct cmsghdr) */
	135	/* The first check was omitted in <= 2.2.5. The reasoning was
	136	that parser checks cmsg_len in any case, so that
	137	additional check would be work duplication.
4ec93edb	138	But if cmsg_level is not SOL_SOCKET, we do not check
1da177e4 LT	139	for too short ancillary data object at all! Oops.
	140	OK, let's add it...
	141	*/
	142	if (!CMSG_OK(msg, cmsg))
	143	goto error;
	144
	145	if (cmsg->cmsg_level != SOL_SOCKET)
	146	continue;
	147
	148	switch (cmsg->cmsg_type)
	149	{
	150	case SCM_RIGHTS:
76dadd76 EB	151	if (!sock->ops \|\| sock->ops->family != PF_UNIX)
76dadd76 EB	152	goto error;
1da177e4 LT	153	err=scm_fp_copy(cmsg, &p->fp);
	154	if (err<0)
	155	goto error;
	156	break;
	157	case SCM_CREDENTIALS:
b2e4f544	158	{
dbe9a417	159	struct ucred creds;
b2e4f544 EB	160	kuid_t uid;
b2e4f544 EB	161	kgid_t gid;
1da177e4 LT	162	if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
1da177e4 LT	163	goto error;
dbe9a417 EB	164	memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred));
dbe9a417 EB	165	err = scm_check_creds(&creds);
1da177e4 LT	166	if (err)
1da177e4 LT	167	goto error;
257b5358	168
dbe9a417 EB	169	p->creds.pid = creds.pid;
dbe9a417 EB	170	if (!p->pid \|\| pid_vnr(p->pid) != creds.pid) {
257b5358 EB	171	struct pid *pid;
257b5358 EB	172	err = -ESRCH;
dbe9a417	173	pid = find_get_pid(creds.pid);
257b5358 EB	174	if (!pid)
	175	goto error;
	176	put_pid(p->pid);
	177	p->pid = pid;
	178	}
	179
b2e4f544	180	err = -EINVAL;
dbe9a417 EB	181	uid = make_kuid(current_user_ns(), creds.uid);
dbe9a417 EB	182	gid = make_kgid(current_user_ns(), creds.gid);
b2e4f544 EB	183	if (!uid_valid(uid) \|\| !gid_valid(gid))
	184	goto error;
	185
dbe9a417 EB	186	p->creds.uid = uid;
	187	p->creds.gid = gid;
	188
16e57262	189	if (!p->cred \|\|
b2e4f544 EB	190	!uid_eq(p->cred->euid, uid) \|\|
b2e4f544 EB	191	!gid_eq(p->cred->egid, gid)) {
257b5358 EB	192	struct cred *cred;
	193	err = -ENOMEM;
	194	cred = prepare_creds();
	195	if (!cred)
	196	goto error;
	197
b2e4f544 EB	198	cred->uid = cred->euid = uid;
b2e4f544 EB	199	cred->gid = cred->egid = gid;
16e57262 ED	200	if (p->cred)
16e57262 ED	201	put_cred(p->cred);
257b5358 EB	202	p->cred = cred;
257b5358 EB	203	}
1da177e4	204	break;
b2e4f544	205	}
1da177e4 LT	206	default:
	207	goto error;
	208	}
	209	}
	210
	211	if (p->fp && !p->fp->count)
	212	{
	213	kfree(p->fp);
	214	p->fp = NULL;
	215	}
	216	return 0;
4ec93edb	217
1da177e4 LT	218	error:
	219	scm_destroy(p);
	220	return err;
	221	}
9e34a5b5	222	EXPORT_SYMBOL(__scm_send);
1da177e4 LT	223
	224	int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
	225	{
cfcabdcc SH	226	struct cmsghdr __user *cm
cfcabdcc SH	227	= (__force struct cmsghdr __user *)msg->msg_control;
1da177e4 LT	228	struct cmsghdr cmhdr;
	229	int cmlen = CMSG_LEN(len);
	230	int err;
	231
	232	if (MSG_CMSG_COMPAT & msg->msg_flags)
	233	return put_cmsg_compat(msg, level, type, len, data);
	234
	235	if (cm==NULL \|\| msg->msg_controllen < sizeof(*cm)) {
	236	msg->msg_flags \|= MSG_CTRUNC;
	237	return 0; /* XXX: return error? check spec. */
	238	}
	239	if (msg->msg_controllen < cmlen) {
	240	msg->msg_flags \|= MSG_CTRUNC;
	241	cmlen = msg->msg_controllen;
	242	}
	243	cmhdr.cmsg_level = level;
	244	cmhdr.cmsg_type = type;
	245	cmhdr.cmsg_len = cmlen;
	246
	247	err = -EFAULT;
	248	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
4ec93edb	249	goto out;
1da177e4 LT	250	if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
	251	goto out;
	252	cmlen = CMSG_SPACE(len);
1ac70e7a WY	253	if (msg->msg_controllen < cmlen)
1ac70e7a WY	254	cmlen = msg->msg_controllen;
1da177e4 LT	255	msg->msg_control += cmlen;
	256	msg->msg_controllen -= cmlen;
	257	err = 0;
	258	out:
	259	return err;
	260	}
9e34a5b5	261	EXPORT_SYMBOL(put_cmsg);
1da177e4 LT	262
	263	void scm_detach_fds(struct msghdr msg, struct scm_cookie scm)
	264	{
cfcabdcc SH	265	struct cmsghdr __user *cm
cfcabdcc SH	266	= (__force struct cmsghdr __user*)msg->msg_control;
1da177e4 LT	267
	268	int fdmax = 0;
	269	int fdnum = scm->fp->count;
	270	struct file **fp = scm->fp->fp;
	271	int __user *cmfptr;
	272	int err = 0, i;
	273
	274	if (MSG_CMSG_COMPAT & msg->msg_flags) {
	275	scm_detach_fds_compat(msg, scm);
	276	return;
	277	}
	278
	279	if (msg->msg_controllen > sizeof(struct cmsghdr))
	280	fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
	281	/ sizeof(int));
	282
	283	if (fdnum < fdmax)
	284	fdmax = fdnum;
	285
cfcabdcc SH	286	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
cfcabdcc SH	287	i++, cmfptr++)
1da177e4	288	{
48a87cc2	289	struct socket *sock;
1da177e4 LT	290	int new_fd;
	291	err = security_file_receive(fp[i]);
	292	if (err)
	293	break;
4a19542e UD	294	err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags
4a19542e UD	295	? O_CLOEXEC : 0);
1da177e4 LT	296	if (err < 0)
	297	break;
	298	new_fd = err;
	299	err = put_user(new_fd, cmfptr);
	300	if (err) {
	301	put_unused_fd(new_fd);
	302	break;
	303	}
	304	/* Bump the usage count and install the file. */
48a87cc2	305	sock = sock_from_file(fp[i], &err);
d8429506	306	if (sock) {
48a87cc2	307	sock_update_netprioidx(sock->sk, current);
d8429506 DW	308	sock_update_classid(sock->sk, current);
d8429506 DW	309	}
cb0942b8	310	fd_install(new_fd, get_file(fp[i]));
1da177e4 LT	311	}
	312
	313	if (i > 0)
	314	{
	315	int cmlen = CMSG_LEN(i*sizeof(int));
effee6a0	316	err = put_user(SOL_SOCKET, &cm->cmsg_level);
1da177e4 LT	317	if (!err)
	318	err = put_user(SCM_RIGHTS, &cm->cmsg_type);
	319	if (!err)
	320	err = put_user(cmlen, &cm->cmsg_len);
	321	if (!err) {
	322	cmlen = CMSG_SPACE(i*sizeof(int));
	323	msg->msg_control += cmlen;
	324	msg->msg_controllen -= cmlen;
	325	}
	326	}
	327	if (i < fdnum \|\| (fdnum && fdmax <= 0))
	328	msg->msg_flags \|= MSG_CTRUNC;
	329
	330	/*
	331	* All of the files that fit in the message have had their
	332	* usage counts incremented, so we just free the list.
	333	*/
	334	__scm_destroy(scm);
	335	}
9e34a5b5	336	EXPORT_SYMBOL(scm_detach_fds);
1da177e4 LT	337
	338	struct scm_fp_list scm_fp_dup(struct scm_fp_list fpl)
	339	{
	340	struct scm_fp_list *new_fpl;
	341	int i;
	342
	343	if (!fpl)
	344	return NULL;
	345
bba14de9 ED	346	new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),
bba14de9 ED	347	GFP_KERNEL);
1da177e4	348	if (new_fpl) {
bba14de9	349	for (i = 0; i < fpl->count; i++)
1da177e4	350	get_file(fpl->fp[i]);
bba14de9	351	new_fpl->max = new_fpl->count;
1da177e4 LT	352	}
	353	return new_fpl;
	354	}
1da177e4	355	EXPORT_SYMBOL(scm_fp_dup);