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From: Omar Sandoval <osandov@osandov.com>
To: linux-btrfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH v3 03/11] btrfs-progs: receive: support v2 send stream DATA tlv format
Date: Fri, 22 Jan 2021 12:47:47 -0800	[thread overview]
Message-ID: <58df81982267169d549b982091a4ccb0b3ac4c5d.1611347859.git.osandov@osandov.com> (raw)
In-Reply-To: <cover.1611347187.git.osandov@fb.com>

From: Boris Burkov <borisb@fb.com>

The new format privileges the BTRFS_SEND_A_DATA attribute by
guaranteeing it will always be the last attribute in any command that
needs it, and by implicitly encoding the data length as the difference
between the total command length in the command header and the sizes of
the rest of the attributes (and of course the tlv_type identifying the
DATA attribute). To parse the new stream, we must read the tlv_type and
if it is not DATA, we proceed normally, but if it is DATA, we don't
parse a tlv_len but simply compute the length.

In addition, we add some bounds checking when parsing each chunk of
data, as well as for the tlv_len itself.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 common/send-stream.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/common/send-stream.c b/common/send-stream.c
index 3d3585c3..4d819185 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -165,28 +165,44 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 
 	pos = 0;
 	while (pos < cmd_len) {
-		struct btrfs_tlv_header *tlv_hdr;
 		u16 tlv_type;
-		u16 tlv_len;
 		struct btrfs_send_attribute *send_attr;
 
-		tlv_hdr = (struct btrfs_tlv_header *)data;
-		tlv_type = le16_to_cpu(tlv_hdr->tlv_type);
-		tlv_len = le16_to_cpu(tlv_hdr->tlv_len);
+		if (cmd_len - pos < sizeof(__le16)) {
+			error("send stream is truncated");
+			ret = -EINVAL;
+			goto out;
+		}
+		tlv_type = le16_to_cpu(*(__le16 *)data);
 
 		if (tlv_type == 0 || tlv_type > BTRFS_SEND_A_MAX) {
-			error("invalid tlv in cmd tlv_type = %hu, tlv_len = %hu",
-					tlv_type, tlv_len);
+			error("invalid tlv in cmd tlv_type = %hu", tlv_type);
 			ret = -EINVAL;
 			goto out;
 		}
 
 		send_attr = &sctx->cmd_attrs[tlv_type];
 		send_attr->tlv_type = tlv_type;
-		send_attr->tlv_len = tlv_len;
-		pos += sizeof(*tlv_hdr);
-		data += sizeof(*tlv_hdr);
 
+		pos += sizeof(tlv_type);
+		data += sizeof(tlv_type);
+		if (sctx->version == 2 && tlv_type == BTRFS_SEND_A_DATA) {
+			send_attr->tlv_len = cmd_len - pos;
+		} else {
+			if (cmd_len - pos < sizeof(__le16)) {
+				error("send stream is truncated");
+				ret = -EINVAL;
+				goto out;
+			}
+			send_attr->tlv_len = le16_to_cpu(*(__le16 *)data);
+			pos += sizeof(__le16);
+			data += sizeof(__le16);
+		}
+		if (cmd_len - pos < send_attr->tlv_len) {
+			error("send stream is truncated");
+			ret = -EINVAL;
+			goto out;
+		}
 		send_attr->data = data;
 		pos += send_attr->tlv_len;
 		data += send_attr->tlv_len;
-- 
2.30.0


  parent reply	other threads:[~2021-01-22 20:54 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-22 20:47 [PATCH v3 0/5] btrfs: implement send/receive of compressed extents without decompressing Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 1/5] btrfs: add send stream v2 definitions Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 01/11] btrfs-progs: receive: support v2 send stream larger tlv_len Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 02/11] btrfs-progs: receive: dynamically allocate sctx->read_buf Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 2/5] btrfs: send: write larger chunks when using stream v2 Omar Sandoval
2021-01-22 20:47 ` Omar Sandoval [this message]
2021-01-22 20:47 ` [PATCH v3 3/5] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2 Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 04/11] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 4/5] btrfs: send: send compressed extents with encoded writes Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 05/11] btrfs-progs: receive: add stub implementation for pwritev2 Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 5/5] btrfs: send: enable support for stream v2 and compressed writes Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 06/11] btrfs-progs: receive: process encoded_write commands Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 07/11] btrfs-progs: receive: encoded_write fallback to explicit decode and write Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 08/11] btrfs-progs: receive: process fallocate commands Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 09/11] btrfs-progs: receive: process setflags ioctl commands Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 10/11] btrfs-progs: send: stream v2 ioctl flags Omar Sandoval
2021-01-22 20:47 ` [PATCH v3 11/11] btrfs-progs: receive: add tests for basic encoded_write send/receive Omar Sandoval

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