key: add tpm_send command

Add internal kernel tpm_send() command used to seal/unseal keys.

Changelog:
- replaced module_put in tpm_send() with new tpm_chip_put() wrapper
  (suggested by David Howells)
- Make tpm_send() cmd argument a 'void *' (suggested by David Howells)

Signed-off-by: David Safford <safford@watson.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>

drivers/char/tpm/tpm.c

@@ -780,6 +780,22 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 }
 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 
+int tpm_send(u32 chip_num, void *cmd, size_t buflen)
+{
+	struct tpm_chip *chip;
+	int rc;
+
+	chip = tpm_chip_find_get(chip_num);
+	if (chip == NULL)
+		return -ENODEV;
+
+	rc = transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
+
+	tpm_chip_put(chip);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_send);
+
 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 		      char *buf)
 {

include/linux/tpm.h

@@ -31,12 +31,16 @@
 
 extern int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf);
 extern int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash);
+extern int tpm_send(u32 chip_num, void *cmd, size_t buflen);
 #else
 static inline int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf) {
 	return -ENODEV;
 }
 static inline int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) {
 	return -ENODEV;
 }
+static inline int tpm_send(u32 chip_num, void *cmd, size_t buflen) {
+	return -ENODEV;
+}
 #endif
 #endif