> From: Stephen Hemminger [mailto:step...@networkplumber.org]
> Sent: Thursday, 21 September 2023 06.24
>
> 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.
>
> Fixes: cbb44143be74 ("app/dumpcap: add new packet capture application")
> Reported-by: Isaac Boukris <ibouk...@gmail.com>
> Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
> ---
> app/dumpcap/main.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/app/dumpcap/main.c b/app/dumpcap/main.c
> index 64294bbfb3e6..37754fd06f4f 100644
> --- a/app/dumpcap/main.c
> +++ b/app/dumpcap/main.c
> @@ -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-%u", getpid());
I'm not sure getpid() is available on Windows. How about:
#ifdef _WIN32
#include <processthreadsapi.h> // With the headers, not here.
"dumpcap-%lu", GetCurrentProcessId());
#else
"dumpcap-%u", getpid());
#endif
> +
> + 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());
Same regarding 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) {
> --
> 2.39.2
