[PATCH v2 1/3] tpm: vtpm_proxy: Add ioctl to get supported flags

[Stefan Berger]

Add an ioctl to get the supported flags.

Signed-off-by: Stefan Berger <stef...@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm_vtpm_proxy.c | 29 +++++++++++++++++++++++++++++
 include/uapi/linux/vtpm_proxy.h   | 11 +++++++++++
 2 files changed, 40 insertions(+)

diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c 
b/drivers/char/tpm/tpm_vtpm_proxy.c
index 751059d..fb4d207 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -592,6 +592,33 @@ static long vtpmx_ioc_new_dev(struct file *file, unsigned 
int ioctl,
        return 0;
 }
 
+/**
+ * vtpmx_ioc_get_supt_flags - handler for the %VTPM_PROXY_IOC_GET_SUPT_FLAGS
+ *                            ioctl
+ * @file:      /dev/vtpmx
+ * @ioctl:     the ioctl number
+ * @arg:       pointer to the struct vtpmx_proxy_get_supt_flags
+ *
+ * Return the bitfield of supported flags
+ */
+static long vtpmx_ioc_get_supt_flags(struct file *file, unsigned int ioctl,
+                                    unsigned long arg)
+{
+       void __user *argp = (void __user *)arg;
+       struct vtpm_proxy_supt_flags __user *vtpm_supt_flags_p = argp;
+       struct vtpm_proxy_supt_flags flags = {
+               .flags = VTPM_PROXY_FLAGS_ALL,
+       };
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (copy_to_user(vtpm_supt_flags_p, &flags, sizeof(flags)))
+               return -EFAULT;
+
+       return 0;
+}
+
 /*
  * vtpmx_fops_ioctl: ioctl on /dev/vtpmx
  *
@@ -604,6 +631,8 @@ static long vtpmx_fops_ioctl(struct file *f, unsigned int 
ioctl,
        switch (ioctl) {
        case VTPM_PROXY_IOC_NEW_DEV:
                return vtpmx_ioc_new_dev(f, ioctl, arg);
+       case VTPM_PROXY_IOC_GET_SUPT_FLAGS:
+               return vtpmx_ioc_get_supt_flags(f, ioctl, arg);
        default:
                return -ENOIOCTLCMD;
        }
diff --git a/include/uapi/linux/vtpm_proxy.h b/include/uapi/linux/vtpm_proxy.h
index a69e991..83e64e7 100644
--- a/include/uapi/linux/vtpm_proxy.h
+++ b/include/uapi/linux/vtpm_proxy.h
@@ -44,6 +44,17 @@ struct vtpm_proxy_new_dev {
        __u32 minor;         /* output */
 };
 
+/**
+ * struct vtpm_proxy_supt_flags - parameter structure for the
+ *                                %VTPM_PROXY_IOC_GET_SUPT_FLAGS ioctl
+ * @flags: flags supported by the vtpm proxy driver
+ */
+struct vtpm_proxy_supt_flags {
+       __u32 flags;         /* output */
+};
+
 #define VTPM_PROXY_IOC_NEW_DEV _IOWR(0xa1, 0x00, struct vtpm_proxy_new_dev)
+#define VTPM_PROXY_IOC_GET_SUPT_FLAGS \
+                               _IOR(0xa1, 0x01, struct vtpm_proxy_supt_flags)
 
 #endif /* _UAPI_LINUX_VTPM_PROXY_H */
-- 
2.4.3