Re: [PATCH] pcap: fix captured frame length
From: Nicolas Pernas Maradei <hidden>
Date: 2016-01-28 18:14:46
Hi Dror, Good catch. What you are saying makes sense and it is also explained in pcap's documentation. Was your setup unusual though? This might sound like a silly question but I don't remember seeing that issue and I should have since your fix is correct. Nico. On 28/01/16 11:09, Dror Birkman wrote:
quoted hunk ↗ jump to hunk
The actual captured length is header.caplen, whereas header.len is the original length on the wire. Signed-off-by: Dror Birkman <redacted> --- Without this fix, if the captured length is smaller than the original length on the wire, mbuf will contain incorrect data. drivers/net/pcap/rte_eth_pcap.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c index f9230eb..1d121f8 100644 --- a/drivers/net/pcap/rte_eth_pcap.c +++ b/drivers/net/pcap/rte_eth_pcap.c@@ -220,25 +220,25 @@ eth_pcap_rx(void *queue, buf_size = (uint16_t)(rte_pktmbuf_data_room_size(pcap_q->mb_pool) - RTE_PKTMBUF_HEADROOM); - if (header.len <= buf_size) { + if (header.caplen <= buf_size) { /* pcap packet will fit in the mbuf, go ahead and copy */ rte_memcpy(rte_pktmbuf_mtod(mbuf, void *), packet, - header.len); - mbuf->data_len = (uint16_t)header.len; + header.caplen); + mbuf->data_len = (uint16_t)header.caplen; } else { /* Try read jumbo frame into multi mbufs. */ if (unlikely(eth_pcap_rx_jumbo(pcap_q->mb_pool, mbuf, packet, - header.len) == -1)) + header.caplen) == -1)) break; } - mbuf->pkt_len = (uint16_t)header.len; + mbuf->pkt_len = (uint16_t)header.caplen; mbuf->port = pcap_q->in_port; bufs[num_rx] = mbuf; num_rx++; - rx_bytes += header.len; + rx_bytes += header.caplen; } pcap_q->rx_pkts += num_rx; pcap_q->rx_bytes += rx_bytes;