Commit 3e859adf authored by Al Viro's avatar Al Viro Committed by Arnd Bergmann
Browse files

compat_ioctl: unify copy-in of ppp filters 



Now that isdn4linux is gone, the is only one implementation of PPPIOCSPASS
and PPPIOCSACTIVE in ppp_generic.c, so this is where the compat_ioctl
support should be implemented.

The two commands are implemented in very similar ways, so introduce
new helpers to allow sharing between the two and between native and
compat mode.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
[arnd: rebased, and added changelog text]
Cc: netdev@vger.kernel.org
Cc: linux-ppp@vger.kernel.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent b7aff093

drivers/net/ppp/ppp_generic.c

+108 −61
Original line number Diff line number Diff line
@@ -554,29 +554,58 @@ static __poll_t ppp_poll(struct file *file, poll_table *wait) 
}



#ifdef CONFIG_PPP_FILTER

static int get_filter(void __user *arg, struct sock_filter **p)

static struct bpf_prog *get_filter(struct sock_fprog *uprog)

{

	struct sock_fprog uprog;

	struct sock_filter *code = NULL;

	int len;

	struct sock_fprog_kern fprog;

	struct bpf_prog *res = NULL;

	int err;



	if (copy_from_user(&uprog, arg, sizeof(uprog)))

		return -EFAULT;

	if (!uprog->len)

		return NULL;



	if (!uprog.len) {

		*p = NULL;

		return 0;

	/* uprog->len is unsigned short, so no overflow here */

	fprog.len = uprog->len * sizeof(struct sock_filter);

	fprog.filter = memdup_user(uprog->filter, fprog.len);

	if (IS_ERR(fprog.filter))

		return ERR_CAST(fprog.filter);



	err = bpf_prog_create(&res, &fprog);

	kfree(fprog.filter);



	return err ? ERR_PTR(err) : res;

}



	len = uprog.len * sizeof(struct sock_filter);

	code = memdup_user(uprog.filter, len);

	if (IS_ERR(code))

		return PTR_ERR(code);

static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p)

{

	struct sock_fprog uprog;



	*p = code;

	return uprog.len;

	if (copy_from_user(&uprog, p, sizeof(struct sock_fprog)))

		return ERR_PTR(-EFAULT);

	return get_filter(&uprog);

}

#endif /* CONFIG_PPP_FILTER */



#ifdef CONFIG_COMPAT

struct sock_fprog32 {

	unsigned short len;

	compat_caddr_t filter;

};



#define PPPIOCSPASS32		_IOW('t', 71, struct sock_fprog32)

#define PPPIOCSACTIVE32		_IOW('t', 70, struct sock_fprog32)



static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p)

{

	struct sock_fprog32 uprog32;

	struct sock_fprog uprog;



	if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32)))

		return ERR_PTR(-EFAULT);

	uprog.len = uprog32.len;

	uprog.filter = compat_ptr(uprog32.filter);

	return get_filter(&uprog);

}

#endif

#endif



static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{
@@ -753,55 +782,25 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 


#ifdef CONFIG_PPP_FILTER

	case PPPIOCSPASS:

	case PPPIOCSACTIVE:

	{

		struct sock_filter *code;



		err = get_filter(argp, &code);

		if (err >= 0) {

			struct bpf_prog *pass_filter = NULL;

			struct sock_fprog_kern fprog = {

				.len = err,

				.filter = code,

			};

		struct bpf_prog *filter = ppp_get_filter(argp);

		struct bpf_prog **which;



			err = 0;

			if (fprog.filter)

				err = bpf_prog_create(&pass_filter, &fprog);

			if (!err) {

				ppp_lock(ppp);

				if (ppp->pass_filter)

					bpf_prog_destroy(ppp->pass_filter);

				ppp->pass_filter = pass_filter;

				ppp_unlock(ppp);

			}

			kfree(code);

		}

		if (IS_ERR(filter)) {

			err = PTR_ERR(filter);

			break;

		}

	case PPPIOCSACTIVE:

	{

		struct sock_filter *code;



		err = get_filter(argp, &code);

		if (err >= 0) {

			struct bpf_prog *active_filter = NULL;

			struct sock_fprog_kern fprog = {

				.len = err,

				.filter = code,

			};



			err = 0;

			if (fprog.filter)

				err = bpf_prog_create(&active_filter, &fprog);

			if (!err) {

		if (cmd == PPPIOCSPASS)

			which = &ppp->pass_filter;

		else

			which = &ppp->active_filter;

		ppp_lock(ppp);

				if (ppp->active_filter)

					bpf_prog_destroy(ppp->active_filter);

				ppp->active_filter = active_filter;

		if (*which)

			bpf_prog_destroy(*which);

		*which = filter;

		ppp_unlock(ppp);

			}

			kfree(code);

		}

		err = 0;

		break;

	}

#endif /* CONFIG_PPP_FILTER */
@@ -827,6 +826,51 @@ out: 
	return err;

}



#ifdef CONFIG_COMPAT

static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{

	struct ppp_file *pf;

	int err = -ENOIOCTLCMD;

	void __user *argp = (void __user *)arg;



	mutex_lock(&ppp_mutex);



	pf = file->private_data;

	if (pf && pf->kind == INTERFACE) {

		struct ppp *ppp = PF_TO_PPP(pf);

		switch (cmd) {

#ifdef CONFIG_PPP_FILTER

		case PPPIOCSPASS32:

		case PPPIOCSACTIVE32:

		{

			struct bpf_prog *filter = compat_ppp_get_filter(argp);

			struct bpf_prog **which;



			if (IS_ERR(filter)) {

				err = PTR_ERR(filter);

				break;

			}

			if (cmd == PPPIOCSPASS32)

				which = &ppp->pass_filter;

			else

				which = &ppp->active_filter;

			ppp_lock(ppp);

			if (*which)

				bpf_prog_destroy(*which);

			*which = filter;

			ppp_unlock(ppp);

			err = 0;

			break;

		}

#endif /* CONFIG_PPP_FILTER */

		}

	}

	mutex_unlock(&ppp_mutex);



	return err;

}

#endif



static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,

			struct file *file, unsigned int cmd, unsigned long arg)

{
@@ -895,6 +939,9 @@ static const struct file_operations ppp_device_fops = { 
	.write		= ppp_write,

	.poll		= ppp_poll,

	.unlocked_ioctl	= ppp_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl	= ppp_compat_ioctl,

#endif

	.open		= ppp_open,

	.release	= ppp_release,

	.llseek		= noop_llseek,

fs/compat_ioctl.c

+0 −37
Original line number Diff line number Diff line
@@ -99,40 +99,6 @@ static int sg_grt_trans(struct file *file, 
}

#endif /* CONFIG_BLOCK */



struct sock_fprog32 {

	unsigned short	len;

	compat_caddr_t	filter;

};



#define PPPIOCSPASS32	_IOW('t', 71, struct sock_fprog32)

#define PPPIOCSACTIVE32	_IOW('t', 70, struct sock_fprog32)



static int ppp_sock_fprog_ioctl_trans(struct file *file,

		unsigned int cmd, struct sock_fprog32 __user *u_fprog32)

{

	struct sock_fprog __user *u_fprog64 = compat_alloc_user_space(sizeof(struct sock_fprog));

	void __user *fptr64;

	u32 fptr32;

	u16 flen;



	if (get_user(flen, &u_fprog32->len) ||

	    get_user(fptr32, &u_fprog32->filter))

		return -EFAULT;



	fptr64 = compat_ptr(fptr32);



	if (put_user(flen, &u_fprog64->len) ||

	    put_user(fptr64, &u_fprog64->filter))

		return -EFAULT;



	if (cmd == PPPIOCSPASS32)

		cmd = PPPIOCSPASS;

	else

		cmd = PPPIOCSACTIVE;



	return do_ioctl(file, cmd, (unsigned long) u_fprog64);

}



struct ppp_option_data32 {

	compat_caddr_t	ptr;

	u32			length;
@@ -285,9 +251,6 @@ static long do_ioctl_trans(unsigned int cmd, 
		return ppp_gidle(file, cmd, argp);

	case PPPIOCSCOMPRESS32:

		return ppp_scompress(file, cmd, argp);

	case PPPIOCSPASS32:

	case PPPIOCSACTIVE32:

		return ppp_sock_fprog_ioctl_trans(file, cmd, argp);

#ifdef CONFIG_BLOCK

	case SG_GET_REQUEST_TABLE:

		return sg_grt_trans(file, cmd, argp);

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