atm: 32-bit ioctl compatibility

We lack compat ioctl support through most of the ATM code. This patch
deals with most of it, and I can now at least use BR2684 and PPPoATM
with 32-bit userspace.

I haven't added a .compat_ioctl method to struct atm_ioctl, because
AFAICT none of the current users need any conversion -- so we can just
call the ->ioctl() method in every case. I looked at br2684, clip, lec,
mpc, pppoatm and atmtcp.

In svc_compat_ioctl() the only mangling which is needed is to change
COMPAT_ATM_ADDPARTY to ATM_ADDPARTY. Although it's defined as
	_IOW('a', ATMIOC_SPECIAL+4,struct atm_iobuf)
it doesn't actually _take_ a struct atm_iobuf as an argument -- it takes
a struct sockaddr_atmsvc, which _is_ the same between 32-bit and 64-bit
code, so doesn't need conversion.

Almost all of vcc_ioctl() would have been identical, so I converted that
into a core do_vcc_ioctl() function with an 'int compat' argument.

I've done the same with atm_dev_ioctl(), where there _are_ a few
differences, but still it's relatively contained and there would
otherwise have been a lot of duplication.

I haven't done any of the actual device-specific ioctls, although I've
added a compat_ioctl method to struct atmdev_ops.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 135 insertions, 27 deletions

diff --git a/net/atm/common.h b/net/atm/common.h
index 16f32c1fa1c9..92e2981f479f 100644
--- a/net/atm/common.h
+++ b/net/atm/common.h
@@ -19,6 +19,7 @@ int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
                 size_t total_len);
 unsigned int vcc_poll(struct file *file, struct socket *sock, poll_table *wait);
 int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
+int vcc_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 int vcc_setsockopt(struct socket *sock, int level, int optname,
                    char __user *optval, int optlen);
 int vcc_getsockopt(struct socket *sock, int level, int optname,
diff --git a/net/atm/ioctl.c b/net/atm/ioctl.c
index 7afd8e7754fd..76ed3c8d26e6 100644
--- a/net/atm/ioctl.c
+++ b/net/atm/ioctl.c
@@ -19,6 +19,7 @@
 #include <linux/atmlec.h>
 #include <linux/mutex.h>
 #include <asm/ioctls.h>
+#include <net/compat.h>
 
 #include "resources.h"
 #include "signaling.h"          /* for WAITING and sigd_attach */
@@ -46,7 +47,7 @@ void deregister_atm_ioctl(struct atm_ioctl *ioctl)
 EXPORT_SYMBOL(register_atm_ioctl);
 EXPORT_SYMBOL(deregister_atm_ioctl);
 
-int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+static int do_vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg, int compat)
 {
         struct sock *sk = sock->sk;
         struct atm_vcc *vcc;
@@ -80,13 +81,25 @@ int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                                 goto done;
                         }
                 case SIOCGSTAMP: /* borrowed from IP */
-                        error = sock_get_timestamp(sk, argp);
+#ifdef CONFIG_COMPAT
+                        if (compat)
+                                error = compat_sock_get_timestamp(sk, argp);
+                        else
+#endif
+                                error = sock_get_timestamp(sk, argp);
                         goto done;
                 case SIOCGSTAMPNS: /* borrowed from IP */
-                        error = sock_get_timestampns(sk, argp);
+#ifdef CONFIG_COMPAT
+                        if (compat)
+                                error = compat_sock_get_timestampns(sk, argp);
+                        else
+#endif
+                                error = sock_get_timestampns(sk, argp);
                         goto done;
                 case ATM_SETSC:
-                        printk(KERN_WARNING "ATM_SETSC is obsolete\n");
+                        if (net_ratelimit())
+                                printk(KERN_WARNING "ATM_SETSC is obsolete; used by %s:%d\n",
+                                       current->comm, task_pid_nr(current));
                         error = 0;
                         goto done;
                 case ATMSIGD_CTRL:
@@ -99,12 +112,23 @@ int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                          * info uses kernel pointers as opaque references,
                          * so the holder of the file descriptor can scribble
                          * on the kernel... so we should make sure that we
-                         * have the same privledges that /proc/kcore needs
+                         * have the same privileges that /proc/kcore needs
                          */
                         if (!capable(CAP_SYS_RAWIO)) {
                                 error = -EPERM;
                                 goto done;
                         }
+#ifdef CONFIG_COMPAT
+                        /* WTF? I don't even want to _think_ about making this
+                           work for 32-bit userspace. TBH I don't really want
+                           to think about it at all. dwmw2. */
+                        if (compat) {
+                                if (net_ratelimit())
+                                        printk(KERN_WARNING "32-bit task cannot be atmsigd\n");
+                                error = -EINVAL;
+                                goto done;
+                        }
+#endif
                         error = sigd_attach(vcc);
                         if (!error)
                                 sock->state = SS_CONNECTED;
@@ -155,8 +179,21 @@ int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
         if (error != -ENOIOCTLCMD)
                 goto done;
 
-        error = atm_dev_ioctl(cmd, argp);
+        error = atm_dev_ioctl(cmd, argp, compat);
 
 done:
         return error;
 }
+
+
+int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+        return do_vcc_ioctl(sock, cmd, arg, 0);
+}
+
+#ifdef CONFIG_COMPAT
+int vcc_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+        return do_vcc_ioctl(sock, cmd, arg, 1);
+}
+#endif
diff --git a/net/atm/pvc.c b/net/atm/pvc.c
index 43e8bf5ed001..e1d22d9430dd 100644
--- a/net/atm/pvc.c
+++ b/net/atm/pvc.c
@@ -113,6 +113,9 @@ static const struct proto_ops pvc_proto_ops = {
         .getname =      pvc_getname,
         .poll =         vcc_poll,
         .ioctl =        vcc_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl = vcc_compat_ioctl,
+#endif
         .listen =       sock_no_listen,
         .shutdown =     pvc_shutdown,
         .setsockopt =   pvc_setsockopt,
diff --git a/net/atm/resources.c b/net/atm/resources.c
index a34ba948af96..56b7322ff461 100644
--- a/net/atm/resources.c
+++ b/net/atm/resources.c
@@ -195,20 +195,39 @@ static int fetch_stats(struct atm_dev *dev, struct atm_dev_stats __user *arg, in
 }
 
 
-int atm_dev_ioctl(unsigned int cmd, void __user *arg)
+int atm_dev_ioctl(unsigned int cmd, void __user *arg, int compat)
 {
         void __user *buf;
         int error, len, number, size = 0;
         struct atm_dev *dev;
         struct list_head *p;
         int *tmp_buf, *tmp_p;
-        struct atm_iobuf __user *iobuf = arg;
-        struct atmif_sioc __user *sioc = arg;
+        int __user *sioc_len;
+        int __user *iobuf_len;
+
+#ifndef CONFIG_COMPAT
+        compat = 0; /* Just so the compiler _knows_ */
+#endif
+
         switch (cmd) {
                 case ATM_GETNAMES:
-                        if (get_user(buf, &iobuf->buffer))
-                                return -EFAULT;
-                        if (get_user(len, &iobuf->length))
+
+                        if (compat) {
+#ifdef CONFIG_COMPAT
+                                struct compat_atm_iobuf __user *ciobuf = arg;
+                                compat_uptr_t cbuf;
+                                iobuf_len = &ciobuf->length;
+                                if (get_user(cbuf, &ciobuf->buffer))
+                                        return -EFAULT;
+                                buf = compat_ptr(cbuf);
+#endif
+                        } else {
+                                struct atm_iobuf __user *iobuf = arg;
+                                iobuf_len = &iobuf->length;
+                                if (get_user(buf, &iobuf->buffer))
+                                        return -EFAULT;
+                        }
+                        if (get_user(len, iobuf_len))
                                 return -EFAULT;
                         mutex_lock(&atm_dev_mutex);
                         list_for_each(p, &atm_devs)
@@ -229,7 +248,7 @@ int atm_dev_ioctl(unsigned int cmd, void __user *arg)
                         }
                         mutex_unlock(&atm_dev_mutex);
                         error = ((copy_to_user(buf, tmp_buf, size)) ||
-                                        put_user(size, &iobuf->length))
+                                        put_user(size, iobuf_len))
                                                 ? -EFAULT : 0;
                         kfree(tmp_buf);
                         return error;
@@ -237,13 +256,32 @@ int atm_dev_ioctl(unsigned int cmd, void __user *arg)
                         break;
         }
 
-        if (get_user(buf, &sioc->arg))
-                return -EFAULT;
-        if (get_user(len, &sioc->length))
-                return -EFAULT;
-        if (get_user(number, &sioc->number))
-                return -EFAULT;
-
+        if (compat) {
+#ifdef CONFIG_COMPAT
+                struct compat_atmif_sioc __user *csioc = arg;
+                compat_uptr_t carg;
+
+                sioc_len = &csioc->length;
+                if (get_user(carg, &csioc->arg))
+                        return -EFAULT;
+                buf = compat_ptr(carg);
+
+                if (get_user(len, &csioc->length))
+                        return -EFAULT;
+                if (get_user(number, &csioc->number))
+                        return -EFAULT;
+#endif
+        } else {
+                struct atmif_sioc __user *sioc = arg;
+
+                sioc_len = &sioc->length;
+                if (get_user(buf, &sioc->arg))
+                        return -EFAULT;
+                if (get_user(len, &sioc->length))
+                        return -EFAULT;
+                if (get_user(number, &sioc->number))
+                        return -EFAULT;
+        }
         if (!(dev = try_then_request_module(atm_dev_lookup(number),
                                             "atm-device-%d", number)))
                 return -ENODEV;
@@ -358,7 +396,7 @@ int atm_dev_ioctl(unsigned int cmd, void __user *arg)
                         size = error;
                         /* may return 0, but later on size == 0 means "don't
                            write the length" */
-                        error = put_user(size, &sioc->length)
+                        error = put_user(size, sioc_len)
                                 ? -EFAULT : 0;
                         goto done;
                 case ATM_SETLOOP:
@@ -380,11 +418,21 @@ int atm_dev_ioctl(unsigned int cmd, void __user *arg)
                         }
                         /* fall through */
                 default:
-                        if (!dev->ops->ioctl) {
-                                error = -EINVAL;
-                                goto done;
+                        if (compat) {
+#ifdef CONFIG_COMPAT
+                                if (!dev->ops->compat_ioctl) {
+                                        error = -EINVAL;
+                                        goto done;
+                                }
+                                size = dev->ops->compat_ioctl(dev, cmd, buf);
+#endif
+                        } else {
+                                if (!dev->ops->ioctl) {
+                                        error = -EINVAL;
+                                        goto done;
+                                }
+                                size = dev->ops->ioctl(dev, cmd, buf);
                         }
-                        size = dev->ops->ioctl(dev, cmd, buf);
                         if (size < 0) {
                                 error = (size == -ENOIOCTLCMD ? -EINVAL : size);
                                 goto done;
@@ -392,7 +440,7 @@ int atm_dev_ioctl(unsigned int cmd, void __user *arg)
         }
 
         if (size)
-                error = put_user(size, &sioc->length)
+                error = put_user(size, sioc_len)
                         ? -EFAULT : 0;
         else
                 error = 0;
diff --git a/net/atm/resources.h b/net/atm/resources.h
index 1d004aaaeec1..126fb1840dfb 100644
--- a/net/atm/resources.h
+++ b/net/atm/resources.h
@@ -13,7 +13,7 @@
 extern struct list_head atm_devs;
 extern struct mutex atm_dev_mutex;
 
-int atm_dev_ioctl(unsigned int cmd, void __user *arg);
+int atm_dev_ioctl(unsigned int cmd, void __user *arg, int compat);
 
 
 #ifdef CONFIG_PROC_FS
diff --git a/net/atm/svc.c b/net/atm/svc.c
index de1e4f2f3a43..e9c65500f84e 100644
--- a/net/atm/svc.c
+++ b/net/atm/svc.c
@@ -604,6 +604,22 @@ static int svc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
         return error;
 }
 
+#ifdef CONFIG_COMPAT
+static int svc_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+        /* The definition of ATM_ADDPARTY uses the size of struct atm_iobuf.
+           But actually it takes a struct sockaddr_atmsvc, which doesn't need
+           compat handling. So all we have to do is fix up cmd... */
+        if (cmd == COMPAT_ATM_ADDPARTY)
+                cmd = ATM_ADDPARTY;
+
+        if (cmd == ATM_ADDPARTY || cmd == ATM_DROPPARTY)
+                return svc_ioctl(sock, cmd, arg);
+        else
+                return vcc_compat_ioctl(sock, cmd, arg);
+}
+#endif /* CONFIG_COMPAT */
+
 static const struct proto_ops svc_proto_ops = {
         .family =       PF_ATMSVC,
         .owner =        THIS_MODULE,
@@ -616,6 +632,9 @@ static const struct proto_ops svc_proto_ops = {
         .getname =      svc_getname,
         .poll =         vcc_poll,
         .ioctl =        svc_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl = svc_compat_ioctl,
+#endif
         .listen =       svc_listen,
         .shutdown =     svc_shutdown,
         .setsockopt =   svc_setsockopt,