X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=send-stream.c;h=78f2571ae40be82cbce1b7eb40e80c5293acd6c8;hb=f37ae8d275c2f988c9fc967f8272648fb0118d3d;hp=7b64dc221b6c2d08b9d3f3e7d259b4a8381e4e26;hpb=194666a67290a0b15224598826f487d2ce4d37b0;p=platform%2Fupstream%2Fbtrfs-progs.git

diff --git a/send-stream.c b/send-stream.c
index 7b64dc2..78f2571 100644
--- a/send-stream.c
+++ b/send-stream.c
@@ -33,32 +33,54 @@ struct btrfs_send_stream {
 	struct btrfs_tlv_header *cmd_attrs[BTRFS_SEND_A_MAX + 1];
 	u32 version;
 
+	/*
+	 * end of last successful read, equivalent to start of current
+	 * malformated part of block
+	 */
+	size_t stream_pos;
+
 	struct btrfs_send_ops *ops;
 	void *user;
 };
 
-static int read_buf(struct btrfs_send_stream *sctx, void *buf, size_t len)
+/*
+ * Read len bytes to buf.
+ * Return:
+ *   0 - success
+ * < 0 - negative errno in case of error
+ * > 0 - no data read, EOF
+ */
+static int read_buf(struct btrfs_send_stream *sctx, char *buf, size_t len)
 {
 	int ret;
 	size_t pos = 0;
 
 	while (pos < len) {
-		ret = read(sctx->fd, (char*)buf + pos, len - pos);
-		if (ret < 0) {
+		ssize_t rbytes;
+
+		rbytes = read(sctx->fd, buf + pos, len - pos);
+		if (rbytes < 0) {
 			ret = -errno;
 			error("read from stream failed: %s",
 					strerror(-ret));
 			goto out;
 		}
-		if (ret == 0) {
+		if (rbytes == 0) {
 			ret = 1;
-			goto out;
+			goto out_eof;
 		}
-		pos += ret;
+		pos += rbytes;
 	}
-
 	ret = 0;
 
+out_eof:
+	if (0 < pos && pos < len) {
+		error("short read from stream: expected %zu read %zu", len, pos);
+		ret = -EIO;
+	} else {
+		sctx->stream_pos += pos;
+	}
+
 out:
 	return ret;
 }
@@ -66,22 +88,24 @@ out:
 /*
  * Reads a single command from kernel space and decodes the TLV's into
  * sctx->cmd_attrs
+ *
+ * Returns:
+ *   0 - success
+ * < 0 - an error in the command
  */
 static int read_cmd(struct btrfs_send_stream *sctx)
 {
 	int ret;
-	int cmd;
-	int cmd_len;
-	int tlv_type;
-	int tlv_len;
+	u16 cmd;
+	u32 cmd_len;
 	char *data;
-	int pos;
-	struct btrfs_tlv_header *tlv_hdr;
+	u32 pos;
 	u32 crc;
 	u32 crc2;
 
 	memset(sctx->cmd_attrs, 0, sizeof(sctx->cmd_attrs));
 
+	ASSERT(sizeof(*sctx->cmd_hdr) <= sizeof(sctx->read_buf));
 	ret = read_buf(sctx, sctx->read_buf, sizeof(*sctx->cmd_hdr));
 	if (ret < 0)
 		goto out;
@@ -95,6 +119,13 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 	cmd = le16_to_cpu(sctx->cmd_hdr->cmd);
 	cmd_len = le32_to_cpu(sctx->cmd_hdr->len);
 
+	if (cmd_len + sizeof(*sctx->cmd_hdr) >= sizeof(sctx->read_buf)) {
+		ret = -EINVAL;
+		error("command length %u too big for buffer %zu",
+				cmd_len, sizeof(sctx->read_buf));
+		goto out;
+	}
+
 	data = sctx->read_buf + sizeof(*sctx->cmd_hdr);
 	ret = read_buf(sctx, data, cmd_len);
 	if (ret < 0)
@@ -119,13 +150,17 @@ 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;
+
 		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 (tlv_type <= 0 || tlv_type > BTRFS_SEND_A_MAX ||
-		    tlv_len < 0 || tlv_len > BTRFS_SEND_BUF_SIZE) {
-			error("invalid tlv in cmd tlv_type = %d, tlv_len = %d",
+		if (tlv_type == 0 || tlv_type > BTRFS_SEND_A_MAX
+		    || tlv_len > BTRFS_SEND_BUF_SIZE) {
+			error("invalid tlv in cmd tlv_type = %hu, tlv_len = %hu",
 					tlv_type, tlv_len);
 			ret = -EINVAL;
 			goto out;
@@ -147,7 +182,7 @@ out:
 static int tlv_get(struct btrfs_send_stream *sctx, int attr, void **data, int *len)
 {
 	int ret;
-	struct btrfs_tlv_header *h;
+	struct btrfs_tlv_header *hdr;
 
 	if (attr <= 0 || attr > BTRFS_SEND_A_MAX) {
 		error("invalid attribute requested, attr = %d", attr);
@@ -155,15 +190,15 @@ static int tlv_get(struct btrfs_send_stream *sctx, int attr, void **data, int *l
 		goto out;
 	}
 
-	h = sctx->cmd_attrs[attr];
-	if (!h) {
+	hdr = sctx->cmd_attrs[attr];
+	if (!hdr) {
 		error("attribute %d requested but not present", attr);
 		ret = -ENOENT;
 		goto out;
 	}
 
-	*len = le16_to_cpu(h->tlv_len);
-	*data = h + 1;
+	*len = le16_to_cpu(hdr->tlv_len);
+	*data = hdr + 1;
 
 	ret = 0;
 
@@ -451,12 +486,13 @@ int btrfs_read_and_process_send_stream(int fd,
 	sctx.fd = fd;
 	sctx.ops = ops;
 	sctx.user = user;
+	sctx.stream_pos = 0;
 
-	ret = read_buf(&sctx, &hdr, sizeof(hdr));
+	ret = read_buf(&sctx, (char*)&hdr, sizeof(hdr));
 	if (ret < 0)
 		goto out;
 	if (ret) {
-		ret = 1;
+		ret = -ENODATA;
 		goto out;
 	}