From 0d3249b927465fdca1765cbd7e17c947364b5ef0 Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Fri, 6 Jul 2012 14:00:27 +0200 Subject: ndr: fix push/pull DATA_BLOB with NDR_NOALIGN MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This change addresses bug 9026. There are 3 use cases for DATA_BLOB marshalling/unmarshalling: 1) ndr_push_DATA_BLOB and ndr_pull_DATA_BLOB when called with LIBNDR_FLAG_ALIGN* alignment flags set, are used to push/pull padding bytes _only_. The length is determined by the alignment required and the current ndr offset. e.g. dcerpc.idl: typedef struct { ... [flag(NDR_ALIGN8)] DATA_BLOB _pad; } dcerpc_request; 2) When called with the LIBNDR_FLAG_REMAINING flag, all remaining bytes in the ndr buffer are pushed/pulled. e.g. dcerpc.idl: typedef struct { ... [flag(NDR_REMAINING)] DATA_BLOB stub_and_verifier; } dcerpc_request; 3) When called without alignment flags, push/pull a uint32 length _and_ a corresponding byte array to/from the ndr buffer. e.g. drsblobs.idl typedef [public] struct { ... DATA_BLOB data; } DsCompressedChunk; The fix for bug 8373 changed the definition of "alignment flags", such that when called with LIBNDR_FLAG_NOALIGN ndr_push/pull_DATA_BLOB behaves as (1: padding bytes) rather than (3: uint32 length + byte array). This breaks marshalling/unmarshalling for the following structures. eventlog.idl: typedef [flag(NDR_NOALIGN|NDR_PAHEX),public] struct { ... DATA_BLOB sid; ... } eventlog_Record_tdb; ntprinting.idl: typedef [flag(NDR_NOALIGN),public] struct { ... DATA_BLOB *nt_dev_private; } ntprinting_devicemode; typedef [flag(NDR_NOALIGN),public] struct { ... DATA_BLOB data; } ntprinting_printer_data; Signed-off-by: Günther Deschner --- librpc/ndr/ndr_basic.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) (limited to 'librpc/ndr') diff --git a/librpc/ndr/ndr_basic.c b/librpc/ndr/ndr_basic.c index 7a4e22ad70..1887838779 100644 --- a/librpc/ndr/ndr_basic.c +++ b/librpc/ndr/ndr_basic.c @@ -1247,16 +1247,21 @@ _PUBLIC_ void ndr_print_DATA_BLOB(struct ndr_print *ndr, const char *name, DATA_ /* - push a DATA_BLOB onto the wire. -*/ + * Push a DATA_BLOB onto the wire. + * 1) When called with LIBNDR_FLAG_ALIGN* alignment flags set, push padding + * bytes _only_. The length is determined by the alignment required and the + * current ndr offset. + * 2) When called with the LIBNDR_FLAG_REMAINING flag, push the byte array to + * the ndr buffer. + * 3) Otherwise, push a uint32 length _and_ a corresponding byte array to the + * ndr buffer. + */ _PUBLIC_ enum ndr_err_code ndr_push_DATA_BLOB(struct ndr_push *ndr, int ndr_flags, DATA_BLOB blob) { if (ndr->flags & LIBNDR_FLAG_REMAINING) { /* nothing to do */ - } else if (ndr->flags & LIBNDR_ALIGN_FLAGS) { - if (ndr->flags & LIBNDR_FLAG_NOALIGN) { - blob.length = 0; - } else if (ndr->flags & LIBNDR_FLAG_ALIGN2) { + } else if (ndr->flags & (LIBNDR_ALIGN_FLAGS & ~LIBNDR_FLAG_NOALIGN)) { + if (ndr->flags & LIBNDR_FLAG_ALIGN2) { blob.length = NDR_ALIGN(ndr, 2); } else if (ndr->flags & LIBNDR_FLAG_ALIGN4) { blob.length = NDR_ALIGN(ndr, 4); @@ -1273,18 +1278,23 @@ _PUBLIC_ enum ndr_err_code ndr_push_DATA_BLOB(struct ndr_push *ndr, int ndr_flag } /* - pull a DATA_BLOB from the wire. -*/ + * Pull a DATA_BLOB from the wire. + * 1) when called with LIBNDR_FLAG_ALIGN* alignment flags set, pull padding + * bytes _only_. The length is determined by the alignment required and the + * current ndr offset. + * 2) When called with the LIBNDR_FLAG_REMAINING flag, pull all remaining bytes + * from the ndr buffer. + * 3) Otherwise, pull a uint32 length _and_ a corresponding byte array from the + * ndr buffer. + */ _PUBLIC_ enum ndr_err_code ndr_pull_DATA_BLOB(struct ndr_pull *ndr, int ndr_flags, DATA_BLOB *blob) { uint32_t length = 0; if (ndr->flags & LIBNDR_FLAG_REMAINING) { length = ndr->data_size - ndr->offset; - } else if (ndr->flags & LIBNDR_ALIGN_FLAGS) { - if (ndr->flags & LIBNDR_FLAG_NOALIGN) { - length = 0; - } else if (ndr->flags & LIBNDR_FLAG_ALIGN2) { + } else if (ndr->flags & (LIBNDR_ALIGN_FLAGS & ~LIBNDR_FLAG_NOALIGN)) { + if (ndr->flags & LIBNDR_FLAG_ALIGN2) { length = NDR_ALIGN(ndr, 2); } else if (ndr->flags & LIBNDR_FLAG_ALIGN4) { length = NDR_ALIGN(ndr, 4); -- cgit