diff options
| author | Michael Brown <mcb30@ipxe.org> | 2016-01-27 23:27:47 +0000 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2016-01-27 23:27:47 +0000 |
| commit | 4ddd3d99c36d1fd3e8a4b31c1814e7d82ca91081 (patch) | |
| tree | 2c240072efff9c20c97792d4b19750fefff2cd08 /src | |
| parent | fef8e34b6f990de651002e00b60b2a6212369fb5 (diff) | |
| download | ipxe-4ddd3d99c36d1fd3e8a4b31c1814e7d82ca91081.zip ipxe-4ddd3d99c36d1fd3e8a4b31c1814e7d82ca91081.tar.gz ipxe-4ddd3d99c36d1fd3e8a4b31c1814e7d82ca91081.tar.bz2 | |
[slam] Avoid potential division by zero
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/net/udp/slam.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/src/net/udp/slam.c b/src/net/udp/slam.c index 8b26bfb..8fcc976 100644 --- a/src/net/udp/slam.c +++ b/src/net/udp/slam.c @@ -415,6 +415,8 @@ static int slam_pull_value ( struct slam_request *slam, static int slam_pull_header ( struct slam_request *slam, struct io_buffer *iobuf ) { void *header = iobuf->data; + unsigned long total_bytes; + unsigned long block_size; int rc; /* If header matches cached header, just pull it and return */ @@ -431,22 +433,26 @@ static int slam_pull_header ( struct slam_request *slam, */ if ( ( rc = slam_pull_value ( slam, iobuf, NULL ) ) != 0 ) return rc; - if ( ( rc = slam_pull_value ( slam, iobuf, - &slam->total_bytes ) ) != 0 ) + if ( ( rc = slam_pull_value ( slam, iobuf, &total_bytes ) ) != 0 ) return rc; - if ( ( rc = slam_pull_value ( slam, iobuf, - &slam->block_size ) ) != 0 ) + if ( ( rc = slam_pull_value ( slam, iobuf, &block_size ) ) != 0 ) return rc; + /* Sanity check */ + if ( block_size == 0 ) { + DBGC ( slam, "SLAM %p ignoring zero block size\n", slam ); + return -EINVAL; + } + /* Update the cached header */ slam->header_len = ( iobuf->data - header ); assert ( slam->header_len <= sizeof ( slam->header ) ); memcpy ( slam->header, header, slam->header_len ); /* Calculate number of blocks */ - slam->num_blocks = ( ( slam->total_bytes + slam->block_size - 1 ) / - slam->block_size ); - + slam->total_bytes = total_bytes; + slam->block_size = block_size; + slam->num_blocks = ( ( total_bytes + block_size - 1 ) / block_size ); DBGC ( slam, "SLAM %p has total bytes %ld, block size %ld, num " "blocks %ld\n", slam, slam->total_bytes, slam->block_size, slam->num_blocks ); |