dm crypt: factor IV constructor out to separate function

No functional change.

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index e8e570d000f6246a0183e817f170a9373fe82a82..aa0aca1aea79c3ac4293fef7309bd8d0bc844fe7 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2196,6 +2196,73 @@ static void crypt_dtr(struct dm_target *ti)
        kzfree(cc);
 }
 
+static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
+{
+       struct crypt_config *cc = ti->private;
+
+       if (crypt_integrity_mode(cc))
+               cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
+       else
+               cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
+
+       if (crypt_integrity_hmac(cc)) {
+               cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
+               if (!cc->authenc_key) {
+                       ti->error = "Error allocating authenc key space";
+                       return -ENOMEM;
+               }
+       }
+
+       if (cc->iv_size)
+               /* at least a 64 bit sector number should fit in our buffer */
+               cc->iv_size = max(cc->iv_size,
+                                 (unsigned int)(sizeof(u64) / sizeof(u8)));
+       else if (ivmode) {
+               DMWARN("Selected cipher does not support IVs");
+               ivmode = NULL;
+       }
+
+       /* Choose ivmode, see comments at iv code. */
+       if (ivmode == NULL)
+               cc->iv_gen_ops = NULL;
+       else if (strcmp(ivmode, "plain") == 0)
+               cc->iv_gen_ops = &crypt_iv_plain_ops;
+       else if (strcmp(ivmode, "plain64") == 0)
+               cc->iv_gen_ops = &crypt_iv_plain64_ops;
+       else if (strcmp(ivmode, "essiv") == 0)
+               cc->iv_gen_ops = &crypt_iv_essiv_ops;
+       else if (strcmp(ivmode, "benbi") == 0)
+               cc->iv_gen_ops = &crypt_iv_benbi_ops;
+       else if (strcmp(ivmode, "null") == 0)
+               cc->iv_gen_ops = &crypt_iv_null_ops;
+       else if (strcmp(ivmode, "lmk") == 0) {
+               cc->iv_gen_ops = &crypt_iv_lmk_ops;
+               /*
+                * Version 2 and 3 is recognised according
+                * to length of provided multi-key string.
+                * If present (version 3), last key is used as IV seed.
+                * All keys (including IV seed) are always the same size.
+                */
+               if (cc->key_size % cc->key_parts) {
+                       cc->key_parts++;
+                       cc->key_extra_size = cc->key_size / cc->key_parts;
+               }
+       } else if (strcmp(ivmode, "tcw") == 0) {
+               cc->iv_gen_ops = &crypt_iv_tcw_ops;
+               cc->key_parts += 2; /* IV + whitening */
+               cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
+       } else if (strcmp(ivmode, "random") == 0) {
+               cc->iv_gen_ops = &crypt_iv_random_ops;
+               /* Need storage space in integrity fields. */
+               cc->integrity_iv_size = cc->iv_size;
+       } else {
+               ti->error = "Invalid IV mode";
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 static int crypt_ctr_cipher(struct dm_target *ti,
                            char *cipher_in, char *key)
 {
@@ -2205,7 +2272,6 @@ static int crypt_ctr_cipher(struct dm_target *ti,
        int ret = -EINVAL;
        char dummy;
 
-       /* Convert to crypto api definition? */
        if (strchr(cipher_in, '(')) {
                ti->error = "Bad cipher specification";
                return -EINVAL;
@@ -2276,67 +2342,9 @@ static int crypt_ctr_cipher(struct dm_target *ti,
        }
 
        /* Initialize IV */
-       if (crypt_integrity_mode(cc))
-               cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
-       else
-               cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
-
-       if (crypt_integrity_hmac(cc)) {
-               cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
-               if (!cc->authenc_key) {
-                       ret = -ENOMEM;
-                       ti->error = "Error allocating authenc key space";
-                       goto bad;
-               }
-       }
-
-       if (cc->iv_size)
-               /* at least a 64 bit sector number should fit in our buffer */
-               cc->iv_size = max(cc->iv_size,
-                                 (unsigned int)(sizeof(u64) / sizeof(u8)));
-       else if (ivmode) {
-               DMWARN("Selected cipher does not support IVs");
-               ivmode = NULL;
-       }
-
-       /* Choose ivmode, see comments at iv code. */
-       if (ivmode == NULL)
-               cc->iv_gen_ops = NULL;
-       else if (strcmp(ivmode, "plain") == 0)
-               cc->iv_gen_ops = &crypt_iv_plain_ops;
-       else if (strcmp(ivmode, "plain64") == 0)
-               cc->iv_gen_ops = &crypt_iv_plain64_ops;
-       else if (strcmp(ivmode, "essiv") == 0)
-               cc->iv_gen_ops = &crypt_iv_essiv_ops;
-       else if (strcmp(ivmode, "benbi") == 0)
-               cc->iv_gen_ops = &crypt_iv_benbi_ops;
-       else if (strcmp(ivmode, "null") == 0)
-               cc->iv_gen_ops = &crypt_iv_null_ops;
-       else if (strcmp(ivmode, "lmk") == 0) {
-               cc->iv_gen_ops = &crypt_iv_lmk_ops;
-               /*
-                * Version 2 and 3 is recognised according
-                * to length of provided multi-key string.
-                * If present (version 3), last key is used as IV seed.
-                * All keys (including IV seed) are always the same size.
-                */
-               if (cc->key_size % cc->key_parts) {
-                       cc->key_parts++;
-                       cc->key_extra_size = cc->key_size / cc->key_parts;
-               }
-       } else if (strcmp(ivmode, "tcw") == 0) {
-               cc->iv_gen_ops = &crypt_iv_tcw_ops;
-               cc->key_parts += 2; /* IV + whitening */
-               cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
-       } else if (strcmp(ivmode, "random") == 0) {
-               cc->iv_gen_ops = &crypt_iv_random_ops;
-               /* Need storage space in integrity fields. */
-               cc->integrity_iv_size = cc->iv_size;
-       } else {
-               ret = -EINVAL;
-               ti->error = "Invalid IV mode";
+       ret = crypt_ctr_ivmode(ti, ivmode);
+       if (ret < 0)
                goto bad;
-       }
 
        /* Initialize and set key */
        ret = crypt_set_key(cc, key);