diff --git a/common/send-stream.c b/common/send-stream.c index f87d8043..d6427588 100644 --- a/common/send-stream.c +++ b/common/send-stream.c @@ -35,11 +35,11 @@ struct btrfs_send_attribute { }; struct btrfs_send_stream { - char read_buf[BTRFS_SEND_BUF_SIZE]; + char *read_buf; + size_t read_buf_size; int fd; int cmd; - struct btrfs_cmd_header *cmd_hdr; struct btrfs_send_attribute cmd_attrs[BTRFS_SEND_A_MAX + 1]; u32 version; @@ -111,11 +111,12 @@ static int read_cmd(struct btrfs_send_stream *sctx) u32 pos; u32 crc; u32 crc2; + struct btrfs_cmd_header *cmd_hdr; + size_t buf_len; 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)); + ret = read_buf(sctx, sctx->read_buf, sizeof(*cmd_hdr)); if (ret < 0) goto out; if (ret) { @@ -124,18 +125,26 @@ static int read_cmd(struct btrfs_send_stream *sctx) goto out; } - sctx->cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf; - cmd = le16_to_cpu(sctx->cmd_hdr->cmd); - cmd_len = le32_to_cpu(sctx->cmd_hdr->len); + cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf; + cmd_len = le32_to_cpu(cmd_hdr->len); + cmd = le16_to_cpu(cmd_hdr->cmd); + buf_len = sizeof(*cmd_hdr) + cmd_len; + if (sctx->read_buf_size < buf_len) { + void *new_read_buf; - 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; + new_read_buf = realloc(sctx->read_buf, buf_len); + if (!new_read_buf) { + ret = -ENOMEM; + errno = -ret; + error("failed to reallocate read buffer for cmd: %m"); + goto out; + } + sctx->read_buf = new_read_buf; + sctx->read_buf_size = buf_len; + /* We need to reset cmd_hdr after realloc of sctx->read_buf */ + cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf; } - - data = sctx->read_buf + sizeof(*sctx->cmd_hdr); + data = sctx->read_buf + sizeof(*cmd_hdr); ret = read_buf(sctx, data, cmd_len); if (ret < 0) goto out; @@ -145,11 +154,12 @@ static int read_cmd(struct btrfs_send_stream *sctx) goto out; } - crc = le32_to_cpu(sctx->cmd_hdr->crc); - sctx->cmd_hdr->crc = 0; + crc = le32_to_cpu(cmd_hdr->crc); + /* In send, CRC is computed with header crc = 0, replicate that */ + cmd_hdr->crc = 0; crc2 = crc32c(0, (unsigned char*)sctx->read_buf, - sizeof(*sctx->cmd_hdr) + cmd_len); + sizeof(*cmd_hdr) + cmd_len); if (crc != crc2) { ret = -EINVAL; @@ -537,19 +547,29 @@ int btrfs_read_and_process_send_stream(int fd, goto out; } + sctx.read_buf = malloc(BTRFS_SEND_BUF_SIZE_V1); + if (!sctx.read_buf) { + ret = -ENOMEM; + errno = -ret; + error("unable to allocate send stream read buffer: %m"); + goto out; + } + sctx.read_buf_size = BTRFS_SEND_BUF_SIZE_V1; + while (1) { ret = read_and_process_cmd(&sctx); if (ret < 0) { last_err = ret; errors++; if (max_errors > 0 && errors >= max_errors) - goto out; + break; } else if (ret > 0) { if (!honor_end_cmd) ret = 0; - goto out; + break; } } + free(sctx.read_buf); out: if (last_err && !ret) diff --git a/kernel-shared/send.h b/kernel-shared/send.h index 5ad090e1..06c8b918 100644 --- a/kernel-shared/send.h +++ b/kernel-shared/send.h @@ -25,7 +25,11 @@ #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream" #define BTRFS_SEND_STREAM_VERSION 1 -#define BTRFS_SEND_BUF_SIZE (64 * 1024) +/* + * In send stream v1, no command is larger than 64KiB. In send stream v2, no limit + * should be assumed. + */ +#define BTRFS_SEND_BUF_SIZE_V1 (64 * 1024) #define BTRFS_SEND_READ_SIZE (1024 * 48) enum btrfs_tlv_type {