[dpdk-dev] [PATCH v4] net/pcap: support snaplen option to truncate packet
Zhike Wang
wangzhike at jd.com
Tue Jul 14 10:26:52 CEST 2020
Introduced "snaplen=<length>" option. It is convenient to truncate
large packets to only capture necessary headers.
Signed-off-by: Zhike Wang <wangzhike at jd.com>
---
app/pdump/main.c | 32 ++++++++++++++++++++++++++-
doc/guides/rel_notes/release_20_08.rst | 4 ++++
doc/guides/tools/pdump.rst | 5 ++++-
drivers/net/pcap/rte_eth_pcap.c | 40 ++++++++++++++++++++++++++++++++--
4 files changed, 77 insertions(+), 4 deletions(-)
diff --git a/app/pdump/main.c b/app/pdump/main.c
index c38c537..1f87310 100644
--- a/app/pdump/main.c
+++ b/app/pdump/main.c
@@ -41,10 +41,12 @@
#define PDUMP_RING_SIZE_ARG "ring-size"
#define PDUMP_MSIZE_ARG "mbuf-size"
#define PDUMP_NUM_MBUFS_ARG "total-num-mbufs"
+#define PDUMP_SNAPLEN_ARG "snaplen"
#define VDEV_NAME_FMT "net_pcap_%s_%d"
#define VDEV_PCAP_ARGS_FMT "tx_pcap=%s"
#define VDEV_IFACE_ARGS_FMT "tx_iface=%s"
+#define VDEV_SNAPLEN_ARGS_FMT "snaplen=%d"
#define TX_STREAM_SIZE 64
#define MP_NAME "pdump_pool_%d"
@@ -97,6 +99,7 @@ enum pdump_by {
PDUMP_RING_SIZE_ARG,
PDUMP_MSIZE_ARG,
PDUMP_NUM_MBUFS_ARG,
+ PDUMP_SNAPLEN_ARG,
NULL
};
@@ -116,6 +119,7 @@ struct pdump_tuples {
uint32_t ring_size;
uint16_t mbuf_data_size;
uint32_t total_num_mbufs;
+ uint16_t snaplen;
/* params for library API call */
uint32_t dir;
@@ -160,7 +164,8 @@ struct parse_val {
" tx-dev=<iface or pcap file>,"
"[ring-size=<ring size>default:16384],"
"[mbuf-size=<mbuf data size>default:2176],"
- "[total-num-mbufs=<number of mbufs>default:65535]'\n",
+ "[total-num-mbufs=<number of mbufs>default:65535],"
+ "[snaplen=<snap length>default:0, meaning no truncation]'\n",
prgname);
}
@@ -370,6 +375,19 @@ struct parse_val {
} else
pt->total_num_mbufs = MBUFS_PER_POOL;
+ /* snaplen parsing and validation */
+ cnt1 = rte_kvargs_count(kvlist, PDUMP_SNAPLEN_ARG);
+ if (cnt1 == 1) {
+ v.min = 1;
+ v.max = UINT16_MAX;
+ ret = rte_kvargs_process(kvlist, PDUMP_SNAPLEN_ARG,
+ &parse_uint_value, &v);
+ if (ret < 0)
+ goto free_kvlist;
+ pt->snaplen = (uint16_t) v.val;
+ } else
+ pt->snaplen = 0;
+
num_tuples++;
free_kvlist:
@@ -692,6 +710,9 @@ struct parse_val {
VDEV_IFACE_ARGS_FMT, pt->rx_dev) :
snprintf(vdev_args, sizeof(vdev_args),
VDEV_PCAP_ARGS_FMT, pt->rx_dev);
+ snprintf(vdev_args + strlen(vdev_args),
+ sizeof(vdev_args) - strlen(vdev_args),
+ ","VDEV_SNAPLEN_ARGS_FMT, pt->snaplen);
if (rte_eal_hotplug_add("vdev", vdev_name,
vdev_args) < 0) {
cleanup_rings();
@@ -722,6 +743,9 @@ struct parse_val {
VDEV_IFACE_ARGS_FMT, pt->tx_dev) :
snprintf(vdev_args, sizeof(vdev_args),
VDEV_PCAP_ARGS_FMT, pt->tx_dev);
+ snprintf(vdev_args + strlen(vdev_args),
+ sizeof(vdev_args) - strlen(vdev_args),
+ ","VDEV_SNAPLEN_ARGS_FMT, pt->snaplen);
if (rte_eal_hotplug_add("vdev", vdev_name,
vdev_args) < 0) {
cleanup_rings();
@@ -762,6 +786,9 @@ struct parse_val {
VDEV_IFACE_ARGS_FMT, pt->rx_dev) :
snprintf(vdev_args, sizeof(vdev_args),
VDEV_PCAP_ARGS_FMT, pt->rx_dev);
+ snprintf(vdev_args + strlen(vdev_args),
+ sizeof(vdev_args) - strlen(vdev_args),
+ ","VDEV_SNAPLEN_ARGS_FMT, pt->snaplen);
if (rte_eal_hotplug_add("vdev", vdev_name,
vdev_args) < 0) {
cleanup_rings();
@@ -799,6 +826,9 @@ struct parse_val {
VDEV_IFACE_ARGS_FMT, pt->tx_dev) :
snprintf(vdev_args, sizeof(vdev_args),
VDEV_PCAP_ARGS_FMT, pt->tx_dev);
+ snprintf(vdev_args + strlen(vdev_args),
+ sizeof(vdev_args) - strlen(vdev_args),
+ ","VDEV_SNAPLEN_ARGS_FMT, pt->snaplen);
if (rte_eal_hotplug_add("vdev", vdev_name,
vdev_args) < 0) {
cleanup_rings();
diff --git a/doc/guides/rel_notes/release_20_08.rst b/doc/guides/rel_notes/release_20_08.rst
index 17d70e7..462c4f3 100644
--- a/doc/guides/rel_notes/release_20_08.rst
+++ b/doc/guides/rel_notes/release_20_08.rst
@@ -171,6 +171,10 @@ New Features
See the :doc:`../sample_app_ug/l2_forward_real_virtual` for more
details of this parameter usage.
+* **Added a devarg to truncate the dumped packets for PCAP vdev.**
+
+ A new devarg ``snaplen`` was introduced to allow users to truncate the
+ dumped packets, and is convenient for capturing with large packet size.
Removed Items
-------------
diff --git a/doc/guides/tools/pdump.rst b/doc/guides/tools/pdump.rst
index 8a499c6..27b9102 100644
--- a/doc/guides/tools/pdump.rst
+++ b/doc/guides/tools/pdump.rst
@@ -45,7 +45,8 @@ The tool has a number of command line options:
tx-dev=<iface or pcap file>),
[ring-size=<ring size>],
[mbuf-size=<mbuf data size>],
- [total-num-mbufs=<number of mbufs>]'
+ [total-num-mbufs=<number of mbufs>],
+ [snaplen=<snap length>]'
The ``--multi`` command line option is optional argument. If passed, capture
will be running on unique cores for all ``--pdump`` options. If ignored,
@@ -114,6 +115,8 @@ default size 2176.
Total number mbufs in mempool. This is used internally for mempool creation. This is an optional parameter with default
value 65535.
+``snaplen``:
+Truncate snaplen bytes of data from each packet. This is an optional parameter with default value 0, meaning no truncation.
Example
-------
diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
index 668cbd1..0d2a4b3 100644
--- a/drivers/net/pcap/rte_eth_pcap.c
+++ b/drivers/net/pcap/rte_eth_pcap.c
@@ -40,6 +40,7 @@
#define ETH_PCAP_IFACE_ARG "iface"
#define ETH_PCAP_PHY_MAC_ARG "phy_mac"
#define ETH_PCAP_INFINITE_RX_ARG "infinite_rx"
+#define ETH_PCAP_SNAPLEN_ARG "snaplen"
#define ETH_PCAP_ARG_MAXLEN 64
@@ -86,6 +87,7 @@ struct pmd_internals {
int single_iface;
int phy_mac;
unsigned int infinite_rx;
+ unsigned int snaplen;
};
struct pmd_process_private {
@@ -114,6 +116,7 @@ struct pmd_devargs_all {
unsigned int is_rx_pcap;
unsigned int is_rx_iface;
unsigned int infinite_rx;
+ unsigned int snaplen;
};
static const char *valid_arguments[] = {
@@ -125,6 +128,7 @@ struct pmd_devargs_all {
ETH_PCAP_IFACE_ARG,
ETH_PCAP_PHY_MAC_ARG,
ETH_PCAP_INFINITE_RX_ARG,
+ ETH_PCAP_SNAPLEN_ARG,
NULL
};
@@ -322,11 +326,13 @@ struct pmd_devargs_all {
pcap_dumper_t *dumper;
unsigned char temp_data[RTE_ETH_PCAP_SNAPLEN];
size_t len, caplen;
+ struct pmd_internals *internal;
pp = rte_eth_devices[dumper_q->port_id].process_private;
dumper = pp->tx_dumper[dumper_q->queue_id];
+ internal = rte_eth_devices[dumper_q->port_id].data->dev_private;
- if (dumper == NULL || nb_pkts == 0)
+ if (dumper == NULL || nb_pkts == 0 || internal == NULL)
return 0;
/* writes the nb_pkts packets to the previously opened pcap file
@@ -339,6 +345,9 @@ struct pmd_devargs_all {
caplen = sizeof(temp_data);
}
+ if (caplen > internal->snaplen)
+ caplen = internal->snaplen;
+
calculate_timestamp(&header.ts);
header.len = len;
header.caplen = caplen;
@@ -1083,6 +1092,21 @@ struct pmd_devargs_all {
}
static int
+get_snaplen_arg(const char *key __rte_unused,
+ const char *value, void *extra_args)
+{
+ if (extra_args) {
+ unsigned int snaplen = (unsigned int)atoi(value);
+ unsigned int *snaplen_p = extra_args;
+
+ if (snaplen == 0)
+ snaplen = RTE_ETH_PCAP_SNAPLEN;
+ *snaplen_p = snaplen;
+ }
+ return 0;
+}
+
+static int
pmd_init_internals(struct rte_vdev_device *vdev,
const unsigned int nb_rx_queues,
const unsigned int nb_tx_queues,
@@ -1291,6 +1315,9 @@ struct pmd_devargs_all {
/* store weather we are using a single interface for rx/tx or not */
internals->single_iface = single_iface;
+ if (devargs_all->is_tx_pcap)
+ internals->snaplen = devargs_all->snaplen;
+
if (single_iface) {
internals->if_index = if_nametoindex(rx_queues->queue[0].name);
@@ -1341,6 +1368,7 @@ struct pmd_devargs_all {
.is_tx_pcap = 0,
.is_tx_iface = 0,
.infinite_rx = 0,
+ .snaplen = RTE_ETH_PCAP_SNAPLEN,
};
name = rte_vdev_device_name(dev);
@@ -1464,6 +1492,13 @@ struct pmd_devargs_all {
if (ret < 0)
goto free_kvlist;
+ if (devargs_all.is_tx_pcap) {
+ ret = rte_kvargs_process(kvlist, ETH_PCAP_SNAPLEN_ARG,
+ &get_snaplen_arg, &devargs_all.snaplen);
+ if (ret < 0)
+ goto free_kvlist;
+ }
+
/*
* We check whether we want to open a TX stream to a real NIC,
* a pcap file, or drop packets on tx
@@ -1587,4 +1622,5 @@ struct pmd_devargs_all {
ETH_PCAP_TX_IFACE_ARG "=<ifc> "
ETH_PCAP_IFACE_ARG "=<ifc> "
ETH_PCAP_PHY_MAC_ARG "=<int>"
- ETH_PCAP_INFINITE_RX_ARG "=<0|1>");
+ ETH_PCAP_INFINITE_RX_ARG "=<0|1>"
+ ETH_PCAP_SNAPLEN_ARG "=<int>");
--
1.8.3.1
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