diff options
Diffstat (limited to 'src/drivers/net')
| -rw-r--r-- | src/drivers/net/ncm.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/drivers/net/ncm.c b/src/drivers/net/ncm.c index 8a3f9388..0fc3ab79 100644 --- a/src/drivers/net/ncm.c +++ b/src/drivers/net/ncm.c @@ -390,6 +390,7 @@ static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf, size_t ndp_len; size_t pkt_offset; size_t pkt_len; + size_t headroom; size_t len; /* Profile overall bulk IN completion */ @@ -460,13 +461,22 @@ static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf, * while the device is running. We therefore copy the * data to a new I/O buffer even if this is the only * (or last) packet within the buffer. + * + * We reserve enough space at the start of each buffer + * to allow for our own transmission header, to + * support protocols such as ARP which may modify the + * received packet and reuse the same I/O buffer for + * transmission. */ - pkt = alloc_iob ( pkt_len ); + headroom = ( sizeof ( struct ncm_ntb_header ) + + ncm->out.padding ); + pkt = alloc_iob ( headroom + pkt_len ); if ( ! pkt ) { /* Record error and continue */ netdev_rx_err ( netdev, NULL, -ENOMEM ); continue; } + iob_reserve ( pkt, headroom ); memcpy ( iob_put ( pkt, pkt_len ), ( iobuf->data + pkt_offset ), pkt_len ); |