[GitHub/mt8127/android_kernel_alcatel_ttab.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_namespace.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) ||
	     ns_capable(current->nsproxy->pid_ns->user_ns, 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>
92f28d97	27	#include <linux/pid_namespace.h>
b488893a PE	28	#include <linux/pid.h>
b488893a PE	29	#include <linux/nsproxy.h>
5a0e3ad6	30	#include <linux/slab.h>
1da177e4	31
1da177e4 LT	32	#include <asm/uaccess.h>
	33
	34	#include <net/protocol.h>
	35	#include <linux/skbuff.h>
	36	#include <net/sock.h>
	37	#include <net/compat.h>
	38	#include <net/scm.h>
d8429506	39	#include <net/cls_cgroup.h>
1da177e4 LT	40
	41
	42	/*
4ec93edb	43	* Only allow a user to send credentials, that they could set with
1da177e4 LT	44	* setu(g)id.
	45	*/
	46
	47	static __inline__ int scm_check_creds(struct ucred *creds)
	48	{
86a264ab	49	const struct cred *cred = current_cred();
b2e4f544 EB	50	kuid_t uid = make_kuid(cred->user_ns, creds->uid);
	51	kgid_t gid = make_kgid(cred->user_ns, creds->gid);
	52
	53	if (!uid_valid(uid) \|\| !gid_valid(gid))
	54	return -EINVAL;
b6dff3ec	55
92f28d97 EB	56	if ((creds->pid == task_tgid_vnr(current) \|\|
92f28d97 EB	57	ns_capable(current->nsproxy->pid_ns->user_ns, CAP_SYS_ADMIN)) &&
b2e4f544	58	((uid_eq(uid, cred->uid) \|\| uid_eq(uid, cred->euid) \|\|
00f70de0	59	uid_eq(uid, cred->suid)) \|\| nsown_capable(CAP_SETUID)) &&
b2e4f544	60	((gid_eq(gid, cred->gid) \|\| gid_eq(gid, cred->egid) \|\|
00f70de0	61	gid_eq(gid, cred->sgid)) \|\| nsown_capable(CAP_SETGID))) {
1da177e4 LT	62	return 0;
	63	}
	64	return -EPERM;
	65	}
	66
	67	static int scm_fp_copy(struct cmsghdr cmsg, struct scm_fp_list *fplp)
	68	{
	69	int fdp = (int)CMSG_DATA(cmsg);
	70	struct scm_fp_list fpl = fplp;
	71	struct file **fpp;
	72	int i, num;
	73
	74	num = (cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr)))/sizeof(int);
	75
	76	if (num <= 0)
	77	return 0;
	78
	79	if (num > SCM_MAX_FD)
	80	return -EINVAL;
	81
	82	if (!fpl)
	83	{
	84	fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL);
	85	if (!fpl)
	86	return -ENOMEM;
	87	*fplp = fpl;
	88	fpl->count = 0;
bba14de9	89	fpl->max = SCM_MAX_FD;
1da177e4 LT	90	}
	91	fpp = &fpl->fp[fpl->count];
	92
bba14de9	93	if (fpl->count + num > fpl->max)
1da177e4	94	return -EINVAL;
4ec93edb	95
1da177e4 LT	96	/*
	97	* Verify the descriptors and increment the usage count.
	98	*/
4ec93edb	99
1da177e4 LT	100	for (i=0; i< num; i++)
	101	{
	102	int fd = fdp[i];
	103	struct file *file;
	104
326be7b4	105	if (fd < 0 \|\| !(file = fget_raw(fd)))
1da177e4 LT	106	return -EBADF;
	107	*fpp++ = file;
	108	fpl->count++;
	109	}
	110	return num;
	111	}
	112
	113	void __scm_destroy(struct scm_cookie *scm)
	114	{
	115	struct scm_fp_list *fpl = scm->fp;
	116	int i;
	117
	118	if (fpl) {
	119	scm->fp = NULL;
6120d3db AV	120	for (i=fpl->count-1; i>=0; i--)
	121	fput(fpl->fp[i]);
	122	kfree(fpl);
1da177e4 LT	123	}
1da177e4 LT	124	}
9e34a5b5	125	EXPORT_SYMBOL(__scm_destroy);
1da177e4 LT	126
	127	int __scm_send(struct socket sock, struct msghdr msg, struct scm_cookie *p)
	128	{
	129	struct cmsghdr *cmsg;
	130	int err;
	131
	132	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg))
	133	{
	134	err = -EINVAL;
	135
	136	/* Verify that cmsg_len is at least sizeof(struct cmsghdr) */
	137	/* The first check was omitted in <= 2.2.5. The reasoning was
	138	that parser checks cmsg_len in any case, so that
	139	additional check would be work duplication.
4ec93edb	140	But if cmsg_level is not SOL_SOCKET, we do not check
1da177e4 LT	141	for too short ancillary data object at all! Oops.
	142	OK, let's add it...
	143	*/
	144	if (!CMSG_OK(msg, cmsg))
	145	goto error;
	146
	147	if (cmsg->cmsg_level != SOL_SOCKET)
	148	continue;
	149
	150	switch (cmsg->cmsg_type)
	151	{
	152	case SCM_RIGHTS:
76dadd76 EB	153	if (!sock->ops \|\| sock->ops->family != PF_UNIX)
76dadd76 EB	154	goto error;
1da177e4 LT	155	err=scm_fp_copy(cmsg, &p->fp);
	156	if (err<0)
	157	goto error;
	158	break;
	159	case SCM_CREDENTIALS:
b2e4f544	160	{
dbe9a417	161	struct ucred creds;
b2e4f544 EB	162	kuid_t uid;
b2e4f544 EB	163	kgid_t gid;
1da177e4 LT	164	if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
1da177e4 LT	165	goto error;
dbe9a417 EB	166	memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred));
dbe9a417 EB	167	err = scm_check_creds(&creds);
1da177e4 LT	168	if (err)
1da177e4 LT	169	goto error;
257b5358	170
dbe9a417 EB	171	p->creds.pid = creds.pid;
dbe9a417 EB	172	if (!p->pid \|\| pid_vnr(p->pid) != creds.pid) {
257b5358 EB	173	struct pid *pid;
257b5358 EB	174	err = -ESRCH;
dbe9a417	175	pid = find_get_pid(creds.pid);
257b5358 EB	176	if (!pid)
	177	goto error;
	178	put_pid(p->pid);
	179	p->pid = pid;
	180	}
	181
b2e4f544	182	err = -EINVAL;
dbe9a417 EB	183	uid = make_kuid(current_user_ns(), creds.uid);
dbe9a417 EB	184	gid = make_kgid(current_user_ns(), creds.gid);
b2e4f544 EB	185	if (!uid_valid(uid) \|\| !gid_valid(gid))
	186	goto error;
	187
dbe9a417 EB	188	p->creds.uid = uid;
	189	p->creds.gid = gid;
	190
16e57262	191	if (!p->cred \|\|
b2e4f544 EB	192	!uid_eq(p->cred->euid, uid) \|\|
b2e4f544 EB	193	!gid_eq(p->cred->egid, gid)) {
257b5358 EB	194	struct cred *cred;
	195	err = -ENOMEM;
	196	cred = prepare_creds();
	197	if (!cred)
	198	goto error;
	199
b2e4f544 EB	200	cred->uid = cred->euid = uid;
b2e4f544 EB	201	cred->gid = cred->egid = gid;
16e57262 ED	202	if (p->cred)
16e57262 ED	203	put_cred(p->cred);
257b5358 EB	204	p->cred = cred;
257b5358 EB	205	}
1da177e4	206	break;
b2e4f544	207	}
1da177e4 LT	208	default:
	209	goto error;
	210	}
	211	}
	212
	213	if (p->fp && !p->fp->count)
	214	{
	215	kfree(p->fp);
	216	p->fp = NULL;
	217	}
	218	return 0;
4ec93edb	219
1da177e4 LT	220	error:
	221	scm_destroy(p);
	222	return err;
	223	}
9e34a5b5	224	EXPORT_SYMBOL(__scm_send);
1da177e4 LT	225
	226	int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
	227	{
cfcabdcc SH	228	struct cmsghdr __user *cm
cfcabdcc SH	229	= (__force struct cmsghdr __user *)msg->msg_control;
1da177e4 LT	230	struct cmsghdr cmhdr;
	231	int cmlen = CMSG_LEN(len);
	232	int err;
	233
	234	if (MSG_CMSG_COMPAT & msg->msg_flags)
	235	return put_cmsg_compat(msg, level, type, len, data);
	236
	237	if (cm==NULL \|\| msg->msg_controllen < sizeof(*cm)) {
	238	msg->msg_flags \|= MSG_CTRUNC;
	239	return 0; /* XXX: return error? check spec. */
	240	}
	241	if (msg->msg_controllen < cmlen) {
	242	msg->msg_flags \|= MSG_CTRUNC;
	243	cmlen = msg->msg_controllen;
	244	}
	245	cmhdr.cmsg_level = level;
	246	cmhdr.cmsg_type = type;
	247	cmhdr.cmsg_len = cmlen;
	248
	249	err = -EFAULT;
	250	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
4ec93edb	251	goto out;
1da177e4 LT	252	if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
	253	goto out;
	254	cmlen = CMSG_SPACE(len);
1ac70e7a WY	255	if (msg->msg_controllen < cmlen)
1ac70e7a WY	256	cmlen = msg->msg_controllen;
1da177e4 LT	257	msg->msg_control += cmlen;
	258	msg->msg_controllen -= cmlen;
	259	err = 0;
	260	out:
	261	return err;
	262	}
9e34a5b5	263	EXPORT_SYMBOL(put_cmsg);
1da177e4 LT	264
	265	void scm_detach_fds(struct msghdr msg, struct scm_cookie scm)
	266	{
cfcabdcc SH	267	struct cmsghdr __user *cm
cfcabdcc SH	268	= (__force struct cmsghdr __user*)msg->msg_control;
1da177e4 LT	269
	270	int fdmax = 0;
	271	int fdnum = scm->fp->count;
	272	struct file **fp = scm->fp->fp;
	273	int __user *cmfptr;
	274	int err = 0, i;
	275
	276	if (MSG_CMSG_COMPAT & msg->msg_flags) {
	277	scm_detach_fds_compat(msg, scm);
	278	return;
	279	}
	280
	281	if (msg->msg_controllen > sizeof(struct cmsghdr))
	282	fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
	283	/ sizeof(int));
	284
	285	if (fdnum < fdmax)
	286	fdmax = fdnum;
	287
cfcabdcc SH	288	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
cfcabdcc SH	289	i++, cmfptr++)
1da177e4	290	{
48a87cc2	291	struct socket *sock;
1da177e4 LT	292	int new_fd;
	293	err = security_file_receive(fp[i]);
	294	if (err)
	295	break;
4a19542e UD	296	err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags
4a19542e UD	297	? O_CLOEXEC : 0);
1da177e4 LT	298	if (err < 0)
	299	break;
	300	new_fd = err;
	301	err = put_user(new_fd, cmfptr);
	302	if (err) {
	303	put_unused_fd(new_fd);
	304	break;
	305	}
	306	/* Bump the usage count and install the file. */
48a87cc2	307	sock = sock_from_file(fp[i], &err);
d8429506	308	if (sock) {
48a87cc2	309	sock_update_netprioidx(sock->sk, current);
d8429506 DW	310	sock_update_classid(sock->sk, current);
d8429506 DW	311	}
cb0942b8	312	fd_install(new_fd, get_file(fp[i]));
1da177e4 LT	313	}
	314
	315	if (i > 0)
	316	{
	317	int cmlen = CMSG_LEN(i*sizeof(int));
effee6a0	318	err = put_user(SOL_SOCKET, &cm->cmsg_level);
1da177e4 LT	319	if (!err)
	320	err = put_user(SCM_RIGHTS, &cm->cmsg_type);
	321	if (!err)
	322	err = put_user(cmlen, &cm->cmsg_len);
	323	if (!err) {
	324	cmlen = CMSG_SPACE(i*sizeof(int));
	325	msg->msg_control += cmlen;
	326	msg->msg_controllen -= cmlen;
	327	}
	328	}
	329	if (i < fdnum \|\| (fdnum && fdmax <= 0))
	330	msg->msg_flags \|= MSG_CTRUNC;
	331
	332	/*
	333	* All of the files that fit in the message have had their
	334	* usage counts incremented, so we just free the list.
	335	*/
	336	__scm_destroy(scm);
	337	}
9e34a5b5	338	EXPORT_SYMBOL(scm_detach_fds);
1da177e4 LT	339
	340	struct scm_fp_list scm_fp_dup(struct scm_fp_list fpl)
	341	{
	342	struct scm_fp_list *new_fpl;
	343	int i;
	344
	345	if (!fpl)
	346	return NULL;
	347
bba14de9 ED	348	new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),
bba14de9 ED	349	GFP_KERNEL);
1da177e4	350	if (new_fpl) {
bba14de9	351	for (i = 0; i < fpl->count; i++)
1da177e4	352	get_file(fpl->fp[i]);
bba14de9	353	new_fpl->max = new_fpl->count;
1da177e4 LT	354	}
	355	return new_fpl;
	356	}
1da177e4	357	EXPORT_SYMBOL(scm_fp_dup);