On 3/13/2022 11:26 AM, Tianli Lai wrote:
snaplen argument would set the length of each packet
that will save to pcap file.
Signed-off-by: Tianli Lai <laitia...@tom.com>
---
doc/guides/nics/pcap_ring.rst | 16 +++++++++-
drivers/net/pcap/pcap_ethdev.c | 58 +++++++++++++++++++++++++---------
2 files changed, 58 insertions(+), 16 deletions(-)
diff --git a/doc/guides/nics/pcap_ring.rst b/doc/guides/nics/pcap_ring.rst
index acb1f00e30..8fb309212f 100644
--- a/doc/guides/nics/pcap_ring.rst
+++ b/doc/guides/nics/pcap_ring.rst
@@ -94,6 +94,13 @@ The different stream types are:
iface=eth0
+* snaplen: Defines the length of one packet that will save pcap file.
+ the length of each packets can be snap by set this value.
+ this value between 64 and 65535.
+
+ snaplen=<packet len>
+
+
Hi Tianli,
This section is "Device Streams", it documents main Rx/Tx streams,
'snaplen' can be a detail for this section, what do you think
to drop it form here, it is already documented below?
Runtime Config Options
^^^^^^^^^^^^^^^^^^^^^^
@@ -132,6 +139,13 @@ Runtime Config Options
In this case, one dummy rx queue is created for each tx queue argument passed
+ - Receive packets on Tx and set the length of packet, for example::
+
What about focusing on the argument description, something like:
- `snaplen`: Set the length of the saved packet size, for example::
+ --vdev 'net_pcap0,tx_pcap=file_tx.pcap,snaplen=100'
+
+In this case, one dummy rx queue is created for each tx queue argument passed
and the length of each packet would not over 100 byte.
+
Don't focus on other parameters (like dummy Rx), please only explain
what 'snaplen' does.
+
Examples of Usage
^^^^^^^^^^^^^^^^^
@@ -140,7 +154,7 @@ Read packets from one pcap file and write them to another:
.. code-block:: console
./<build_dir>/app/dpdk-testpmd -l 0-3 -n 4 \
- --vdev 'net_pcap0,rx_pcap=file_rx.pcap,tx_pcap=file_tx.pcap' \
+ --vdev
'net_pcap0,rx_pcap=file_rx.pcap,tx_pcap=file_tx.pcap,snaplen=100' \
-- --port-topology=chained
Can you add a new sample with 'snaplen', instead of attaching to
existing one?
Read packets from a network interface and write them to a pcap file:
diff --git a/drivers/net/pcap/pcap_ethdev.c b/drivers/net/pcap/pcap_ethdev.c
index ec29fd6bc5..6e111518e7 100644
--- a/drivers/net/pcap/pcap_ethdev.c
+++ b/drivers/net/pcap/pcap_ethdev.c
@@ -33,10 +33,12 @@
#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
#define RTE_PMD_PCAP_MAX_QUEUES 16
+#define RTE_PCAP_MIN_SNAPLEN 64
static char errbuf[PCAP_ERRBUF_SIZE];
static struct timespec start_time;
@@ -93,6 +95,7 @@ struct pmd_internals {
int single_iface;
int phy_mac;
unsigned int infinite_rx;
+ int snaplen;
};
struct pmd_process_private {
@@ -121,6 +124,14 @@ struct pmd_devargs_all {
unsigned int is_rx_pcap;
unsigned int is_rx_iface;
unsigned int infinite_rx;
+ int snaplen;
+};
+struct pmd_devargs_all devargs_all = {
+ .single_iface = 0,
+ .is_tx_pcap = 0,
+ .is_tx_iface = 0,
+ .infinite_rx = 0,
+ .snaplen = RTE_ETH_PCAP_SNAPSHOT_LEN,
};
'devargs_all' is to store user provided devargs per port,
making it a global variable is wrong, it causes problems where there are
multiple ports, please leave it where it is.
static const char *valid_arguments[] = {
@@ -132,6 +143,7 @@ static const char *valid_arguments[] = {
ETH_PCAP_IFACE_ARG,
ETH_PCAP_PHY_MAC_ARG,
ETH_PCAP_INFINITE_RX_ARG,
+ ETH_PCAP_SNAPLEN_ARG,
NULL
};
@@ -384,8 +396,10 @@ eth_pcap_tx_dumper(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
pcap_dumper_t *dumper;
unsigned char temp_data[RTE_ETH_PCAP_SNAPLEN];
size_t len, caplen;
-
- pp = rte_eth_devices[dumper_q->port_id].process_private;
+ struct pmd_internals *internals;
+ struct rte_eth_dev *dev = &rte_eth_devices[dumper_q->port_id];
+ internals = dev->data->dev_private;
+ pp = dev->process_private;
dumper = pp->tx_dumper[dumper_q->queue_id];
if (dumper == NULL || nb_pkts == 0)
@@ -402,6 +416,8 @@ eth_pcap_tx_dumper(void *queue, struct rte_mbuf **bufs,
uint16_t nb_pkts)
}
calculate_timestamp(&header.ts);
+ if ((typeof(internals->snaplen))caplen > internals->snaplen)
+ caplen = internals->snaplen;
When opening pcap interface 'snaplen' is already provided,
what happens if 'caplen' is not set correctly here, won't pcap
library limit the packets to 'snaplen' already?
header.len = len;
header.caplen = caplen;
/* rte_pktmbuf_read() returns a pointer to the data directly
@@ -536,7 +552,7 @@ open_single_iface(const char *iface, pcap_t **pcap)
}
static int
-open_single_tx_pcap(const char *pcap_filename, pcap_dumper_t **dumper)
+open_single_tx_pcap(const char *pcap_filename, pcap_dumper_t **dumper, int
snaplen)
{
pcap_t *tx_pcap;
@@ -546,7 +562,7 @@ open_single_tx_pcap(const char *pcap_filename, pcap_dumper_t **dumper)
* pcap holder.
*/
tx_pcap = pcap_open_dead_with_tstamp_precision(DLT_EN10MB,
- RTE_ETH_PCAP_SNAPSHOT_LEN, PCAP_TSTAMP_PRECISION_NANO);
+ snaplen, PCAP_TSTAMP_PRECISION_NANO);
if (tx_pcap == NULL) {
PMD_LOG(ERR, "Couldn't create dead pcap");
return -1;
@@ -627,7 +643,7 @@ eth_dev_start(struct rte_eth_dev *dev)
if (!pp->tx_dumper[i] &&
strcmp(tx->type, ETH_PCAP_TX_PCAP_ARG) == 0) {
if (open_single_tx_pcap(tx->name,
- &pp->tx_dumper[i]) < 0)
+ &pp->tx_dumper[i], internals->snaplen) < 0)
return -1;
} else if (!pp->tx_pcap[i] &&
strcmp(tx->type, ETH_PCAP_TX_IFACE_ARG) == 0) {
@@ -1055,7 +1071,7 @@ open_tx_pcap(const char *key, const char *value, void
*extra_args)
struct pmd_devargs *dumpers = extra_args;
pcap_dumper_t *dumper;
- if (open_single_tx_pcap(pcap_filename, &dumper) < 0)
+ if (open_single_tx_pcap(pcap_filename, &dumper, devargs_all.snaplen) <
0)
Here 'devargs_all' is used directly since patch makes it global, but
when it is not global anymore, perhaps you can consider to add 'snaplen'
to "struct pmd_devargs" and get it to this function via it.
return -1;
if (add_queue(dumpers, pcap_filename, key, NULL, dumper) < 0) {
@@ -1066,6 +1082,15 @@ open_tx_pcap(const char *key, const char *value, void
*extra_args)
return 0;
}
+static int
+parse_uint_value(const char *key __rte_unused, const char *value, void
*extra_args)
+{
+ char *end;
+ int *val = extra_args;
+ *val = strtoul(value, &end, 10);
Should check 'strtoul' return value and return error accordingly.
+ return 0;
+}
+
/*
* Opens an interface for reading and writing
*/
@@ -1325,10 +1350,10 @@ eth_from_pcaps(struct rte_vdev_device *vdev,
int ret;
ret = eth_from_pcaps_common(vdev, devargs_all, &internals, ð_dev);
-
unrelated change
if (ret < 0)
return ret;
+ internals->snaplen = devargs_all->snaplen; > /* store weather we are using a single interface for rx/tx or not */
internals->single_iface = single_iface;
@@ -1404,13 +1429,6 @@ pmd_pcap_probe(struct rte_vdev_device *dev)
struct pmd_internals *internal;
int ret = 0;
- struct pmd_devargs_all devargs_all = {
- .single_iface = 0,
- .is_tx_pcap = 0,
- .is_tx_iface = 0,
- .infinite_rx = 0,
- };
-
name = rte_vdev_device_name(dev);
PMD_LOG(INFO, "Initializing pmd_pcap for %s", name);
@@ -1444,6 +1462,16 @@ pmd_pcap_probe(struct rte_vdev_device *dev)
return -1;
}
+ if (rte_kvargs_count(kvlist, ETH_PCAP_SNAPLEN_ARG) == 1) {
+ ret = rte_kvargs_process(kvlist, ETH_PCAP_SNAPLEN_ARG,
+ &parse_uint_value, &devargs_all.snaplen);
+ if (ret < 0)
+ goto free_kvlist;
Can you print an error log here?
+ if (devargs_all.snaplen < RTE_PCAP_MIN_SNAPLEN ||
+ devargs_all.snaplen >= RTE_ETH_PCAP_SNAPSHOT_LEN)
+ devargs_all.snaplen = RTE_PCAP_MIN_SNAPLEN;
I think better to return an error here, with a log.
+ }
Can you please move parsing 'ETH_PCAP_SNAPLEN_ARG' argument below in the
function, where Tx related parameters parsed. After
'devargs_all.is_tx_pcap' checks.
And can you please define (and document in above documentation), when
'snaplen' argument is valid?
Like can I use it with only 'iface=' argument? Or does it requires
'tx_pcap' to work? If so this should be checked in the code.
+
/*
* If iface argument is passed we open the NICs and use them for
* reading / writing
@@ -1593,7 +1621,7 @@ pmd_pcap_probe(struct rte_vdev_device *dev)
pp->tx_dumper[i] = dumpers.queue[i].dumper;
pp->tx_pcap[i] = dumpers.queue[i].pcap;
}
-
+ internal->snaplen = devargs_all.snaplen;
This is not required, 'internals' is shared between primary and
secondary, if primary has this parameter, secondary can use it
already.
eth_dev->process_private = pp;
eth_dev->rx_pkt_burst = eth_pcap_rx;
if (devargs_all.is_tx_pcap)
