libsqfs: Implement exact matching of fragments

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 17 insertions, 0 deletions

diff --git a/lib/sqfs/block_processor/serial.c b/lib/sqfs/block_processor/serial.c
index daa11fe..b20d5b0 100644
--- a/lib/sqfs/block_processor/serial.c
+++ b/lib/sqfs/block_processor/serial.c
@@ -61,6 +61,22 @@ static int block_processor_sync(sqfs_block_processor_t *proc)
 	return ((serial_block_processor_t *)proc)->status;
 }
 
+static int compare_frag_in_flight(sqfs_block_processor_t *proc,
+				  sqfs_block_t *frag, sqfs_u32 index,
+				  sqfs_u32 offset)
+{
+	if (proc->frag_block == NULL || index != proc->frag_block->index)
+		return -1;
+
+	if (offset >= proc->frag_block->size)
+		return -1;
+
+	if (frag->size > (proc->frag_block->size - offset))
+		return -1;
+
+	return memcmp(proc->frag_block->data + offset, frag->data, frag->size);
+}
+
 int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 				   sqfs_block_processor_t **out)
 {
@@ -82,6 +98,7 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 
 	proc->base.sync = block_processor_sync;
 	proc->base.append_to_work_queue = append_to_work_queue;
+	proc->base.compare_frag_in_flight = compare_frag_in_flight;
 	((sqfs_object_t *)proc)->destroy = block_processor_destroy;
 
 	*out = (sqfs_block_processor_t *)proc;