[v4,2/5] dumpcap: allow multiple invocations
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Commit Message
If dumpcap is run twice with each instance pointing a different
interface, it would fail because of overlap in ring a pool names.
Fix by putting process id in the name.
It is still not allowed to do multiple invocations on the same
interface because only one callback is allowed and only one copy
of mbuf is done. Dumpcap will fail with error in this case:
pdump_prepare_client_request(): client request for pdump enable/disable failed
EAL: Error - exiting with code: 1
Cause: Packet dump enable on 0:net_null0 failed File exists
Fixes: cbb44143be74 ("app/dumpcap: add new packet capture application")
Reported-by: Isaac Boukris <iboukris@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
app/dumpcap/main.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
Comments
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Thursday, 9 November 2023 18.34
>
> If dumpcap is run twice with each instance pointing a different
> interface, it would fail because of overlap in ring a pool names.
> Fix by putting process id in the name.
>
> It is still not allowed to do multiple invocations on the same
> interface because only one callback is allowed and only one copy
> of mbuf is done. Dumpcap will fail with error in this case:
>
> pdump_prepare_client_request(): client request for pdump
> enable/disable failed
> EAL: Error - exiting with code: 1
> Cause: Packet dump enable on 0:net_null0 failed File exists
>
> Fixes: cbb44143be74 ("app/dumpcap: add new packet capture application")
> Reported-by: Isaac Boukris <iboukris@gmail.com>
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> ---
[...]
> + snprintf(ring_name, sizeof(ring_name),
> + "dumpcap-%d", getpid());
Fixed - thank you.
[...]
> + snprintf(pool_name, sizeof(pool_name), "capture_%u", getpid());
Should change from %u to %d here too. ;-)
Either way,
Reviewed-by: Morten Brørup <mb@smartsharesystems.com>
@@ -44,7 +44,6 @@
#include <pcap/pcap.h>
#include <pcap/bpf.h>
-#define RING_NAME "capture-ring"
#define MONITOR_INTERVAL (500 * 1000)
#define MBUF_POOL_CACHE_SIZE 32
#define BURST_SIZE 32
@@ -647,6 +646,7 @@ static void dpdk_init(void)
static struct rte_ring *create_ring(void)
{
struct rte_ring *ring;
+ char ring_name[RTE_RING_NAMESIZE];
size_t size, log2;
/* Find next power of 2 >= size. */
@@ -660,28 +660,28 @@ static struct rte_ring *create_ring(void)
ring_size = size;
}
- ring = rte_ring_lookup(RING_NAME);
- if (ring == NULL) {
- ring = rte_ring_create(RING_NAME, ring_size,
- rte_socket_id(), 0);
- if (ring == NULL)
- rte_exit(EXIT_FAILURE, "Could not create ring :%s\n",
- rte_strerror(rte_errno));
- }
+ /* Want one ring per invocation of program */
+ snprintf(ring_name, sizeof(ring_name),
+ "dumpcap-%d", getpid());
+
+ ring = rte_ring_create(ring_name, ring_size,
+ rte_socket_id(), 0);
+ if (ring == NULL)
+ rte_exit(EXIT_FAILURE, "Could not create ring :%s\n",
+ rte_strerror(rte_errno));
+
return ring;
}
static struct rte_mempool *create_mempool(void)
{
const struct interface *intf;
- static const char pool_name[] = "capture_mbufs";
+ char pool_name[RTE_MEMPOOL_NAMESIZE];
size_t num_mbufs = 2 * ring_size;
struct rte_mempool *mp;
uint32_t data_size = 128;
- mp = rte_mempool_lookup(pool_name);
- if (mp)
- return mp;
+ snprintf(pool_name, sizeof(pool_name), "capture_%u", getpid());
/* Common pool so size mbuf for biggest snap length */
TAILQ_FOREACH(intf, &interfaces, next) {
@@ -826,7 +826,7 @@ static void enable_pdump(struct rte_ring *r, struct rte_mempool *mp)
rte_exit(EXIT_FAILURE,
"Packet dump enable on %u:%s failed %s\n",
intf->port, intf->name,
- rte_strerror(-ret));
+ rte_strerror(rte_errno));
}
if (intf->opts.promisc_mode) {