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Diffstat (limited to 'block/crypto.c')
-rw-r--r--block/crypto.c144
1 files changed, 131 insertions, 13 deletions
diff --git a/block/crypto.c b/block/crypto.c
index 921933a5e5..21eed909c1 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -39,6 +39,7 @@ typedef struct BlockCrypto BlockCrypto;
 struct BlockCrypto {
     QCryptoBlock *block;
     bool updating_keys;
+    BdrvChild *header;  /* Reference to the detached LUKS header */
 };
 
 
@@ -63,12 +64,14 @@ static int block_crypto_read_func(QCryptoBlock *block,
                                   Error **errp)
 {
     BlockDriverState *bs = opaque;
+    BlockCrypto *crypto = bs->opaque;
     ssize_t ret;
 
     GLOBAL_STATE_CODE();
     GRAPH_RDLOCK_GUARD_MAINLOOP();
 
-    ret = bdrv_pread(bs->file, offset, buflen, buf, 0);
+    ret = bdrv_pread(crypto->header ? crypto->header : bs->file,
+                     offset, buflen, buf, 0);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "Could not read encryption header");
         return ret;
@@ -84,12 +87,14 @@ static int block_crypto_write_func(QCryptoBlock *block,
                                    Error **errp)
 {
     BlockDriverState *bs = opaque;
+    BlockCrypto *crypto = bs->opaque;
     ssize_t ret;
 
     GLOBAL_STATE_CODE();
     GRAPH_RDLOCK_GUARD_MAINLOOP();
 
-    ret = bdrv_pwrite(bs->file, offset, buflen, buf, 0);
+    ret = bdrv_pwrite(crypto->header ? crypto->header : bs->file,
+                      offset, buflen, buf, 0);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "Could not write encryption header");
         return ret;
@@ -157,6 +162,48 @@ error:
     return ret;
 }
 
+static int coroutine_fn GRAPH_UNLOCKED
+block_crypto_co_format_luks_payload(BlockdevCreateOptionsLUKS *luks_opts,
+                                    Error **errp)
+{
+    BlockDriverState *bs = NULL;
+    BlockBackend *blk = NULL;
+    Error *local_error = NULL;
+    int ret;
+
+    if (luks_opts->size > INT64_MAX) {
+        return -EFBIG;
+    }
+
+    bs = bdrv_co_open_blockdev_ref(luks_opts->file, errp);
+    if (bs == NULL) {
+        return -EIO;
+    }
+
+    blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE,
+                             BLK_PERM_ALL, errp);
+    if (!blk) {
+        ret = -EPERM;
+        goto fail;
+    }
+
+    ret = blk_truncate(blk, luks_opts->size, true,
+                       luks_opts->preallocation, 0, &local_error);
+    if (ret < 0) {
+        if (ret == -EFBIG) {
+            /* Replace the error message with a better one */
+            error_free(local_error);
+            error_setg(errp, "The requested file size is too large");
+        }
+        goto fail;
+    }
+
+    ret = 0;
+
+fail:
+    bdrv_co_unref(bs);
+    return ret;
+}
 
 static QemuOptsList block_crypto_runtime_opts_luks = {
     .name = "crypto",
@@ -184,6 +231,7 @@ static QemuOptsList block_crypto_create_opts_luks = {
         BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG(""),
         BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG(""),
         BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME(""),
+        BLOCK_CRYPTO_OPT_DEF_LUKS_DETACHED_HEADER(""),
         { /* end of list */ }
     },
 };
@@ -262,6 +310,8 @@ static int block_crypto_open_generic(QCryptoBlockFormat format,
                                      int flags,
                                      Error **errp)
 {
+    ERRP_GUARD();
+
     BlockCrypto *crypto = bs->opaque;
     QemuOpts *opts = NULL;
     int ret;
@@ -276,6 +326,13 @@ static int block_crypto_open_generic(QCryptoBlockFormat format,
         return ret;
     }
 
+    crypto->header = bdrv_open_child(NULL, options, "header", bs,
+                                     &child_of_bds, BDRV_CHILD_METADATA,
+                                     true, errp);
+    if (*errp != NULL) {
+        return -EINVAL;
+    }
+
     GRAPH_RDLOCK_GUARD_MAINLOOP();
 
     bs->supported_write_flags = BDRV_REQ_FUA &
@@ -299,6 +356,9 @@ static int block_crypto_open_generic(QCryptoBlockFormat format,
     if (flags & BDRV_O_NO_IO) {
         cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
     }
+    if (crypto->header != NULL) {
+        cflags |= QCRYPTO_BLOCK_OPEN_DETACHED;
+    }
     crypto->block = qcrypto_block_open(open_opts, NULL,
                                        block_crypto_read_func,
                                        bs,
@@ -324,7 +384,9 @@ static int block_crypto_open_generic(QCryptoBlockFormat format,
 static int coroutine_fn GRAPH_UNLOCKED
 block_crypto_co_create_generic(BlockDriverState *bs, int64_t size,
                                QCryptoBlockCreateOptions *opts,
-                               PreallocMode prealloc, Error **errp)
+                               PreallocMode prealloc,
+                               unsigned int flags,
+                               Error **errp)
 {
     int ret;
     BlockBackend *blk;
@@ -344,7 +406,7 @@ block_crypto_co_create_generic(BlockDriverState *bs, int64_t size,
 
     data = (struct BlockCryptoCreateData) {
         .blk = blk,
-        .size = size,
+        .size = flags & QCRYPTO_BLOCK_CREATE_DETACHED ? 0 : size,
         .prealloc = prealloc,
     };
 
@@ -352,6 +414,7 @@ block_crypto_co_create_generic(BlockDriverState *bs, int64_t size,
                                   block_crypto_create_init_func,
                                   block_crypto_create_write_func,
                                   &data,
+                                  flags,
                                   errp);
 
     if (!crypto) {
@@ -638,17 +701,27 @@ static int coroutine_fn GRAPH_UNLOCKED
 block_crypto_co_create_luks(BlockdevCreateOptions *create_options, Error **errp)
 {
     BlockdevCreateOptionsLUKS *luks_opts;
+    BlockDriverState *hdr_bs = NULL;
     BlockDriverState *bs = NULL;
     QCryptoBlockCreateOptions create_opts;
     PreallocMode preallocation = PREALLOC_MODE_OFF;
+    unsigned int cflags = 0;
     int ret;
 
     assert(create_options->driver == BLOCKDEV_DRIVER_LUKS);
     luks_opts = &create_options->u.luks;
 
-    bs = bdrv_co_open_blockdev_ref(luks_opts->file, errp);
-    if (bs == NULL) {
-        return -EIO;
+    if (luks_opts->header == NULL && luks_opts->file == NULL) {
+        error_setg(errp, "Either the parameter 'header' or 'file' must "
+                   "be specified");
+        return -EINVAL;
+    }
+
+    if ((luks_opts->preallocation != PREALLOC_MODE_OFF) &&
+        (luks_opts->file == NULL)) {
+        error_setg(errp, "Parameter 'preallocation' requires 'file' to be "
+                   "specified for formatting LUKS disk");
+        return -EINVAL;
     }
 
     create_opts = (QCryptoBlockCreateOptions) {
@@ -660,15 +733,52 @@ block_crypto_co_create_luks(BlockdevCreateOptions *create_options, Error **errp)
         preallocation = luks_opts->preallocation;
     }
 
-    ret = block_crypto_co_create_generic(bs, luks_opts->size, &create_opts,
-                                         preallocation, errp);
-    if (ret < 0) {
-        goto fail;
+    if (luks_opts->header) {
+        /* LUKS volume with detached header */
+        hdr_bs = bdrv_co_open_blockdev_ref(luks_opts->header, errp);
+        if (hdr_bs == NULL) {
+            return -EIO;
+        }
+
+        cflags |= QCRYPTO_BLOCK_CREATE_DETACHED;
+
+        /* Format the LUKS header node */
+        ret = block_crypto_co_create_generic(hdr_bs, 0, &create_opts,
+                                             PREALLOC_MODE_OFF, cflags, errp);
+        if (ret < 0) {
+            goto fail;
+        }
+
+        /* Format the LUKS payload node */
+        if (luks_opts->file) {
+            ret = block_crypto_co_format_luks_payload(luks_opts, errp);
+            if (ret < 0) {
+                goto fail;
+            }
+        }
+    } else if (luks_opts->file) {
+        /* LUKS volume with none-detached header */
+        bs = bdrv_co_open_blockdev_ref(luks_opts->file, errp);
+        if (bs == NULL) {
+            return -EIO;
+        }
+
+        ret = block_crypto_co_create_generic(bs, luks_opts->size, &create_opts,
+                                             preallocation, cflags, errp);
+        if (ret < 0) {
+            goto fail;
+        }
     }
 
     ret = 0;
 fail:
-    bdrv_co_unref(bs);
+    if (hdr_bs != NULL) {
+        bdrv_co_unref(hdr_bs);
+    }
+
+    if (bs != NULL) {
+        bdrv_co_unref(bs);
+    }
     return ret;
 }
 
@@ -682,6 +792,9 @@ block_crypto_co_create_opts_luks(BlockDriver *drv, const char *filename,
     PreallocMode prealloc;
     char *buf = NULL;
     int64_t size;
+    bool detached_hdr =
+        qemu_opt_get_bool(opts, "detached-header", false);
+    unsigned int cflags = 0;
     int ret;
     Error *local_err = NULL;
 
@@ -721,8 +834,13 @@ block_crypto_co_create_opts_luks(BlockDriver *drv, const char *filename,
         goto fail;
     }
 
+    if (detached_hdr) {
+        cflags |= QCRYPTO_BLOCK_CREATE_DETACHED;
+    }
+
     /* Create format layer */
-    ret = block_crypto_co_create_generic(bs, size, create_opts, prealloc, errp);
+    ret = block_crypto_co_create_generic(bs, size, create_opts,
+                                         prealloc, cflags, errp);
     if (ret < 0) {
         goto fail;
     }