________________________________________ From: [email protected] <[email protected]> on behalf of Sairam Venugopal <[email protected]> Sent: Tuesday, May 8, 2018 10:09 AM To: [email protected] Subject: Re: [ovs-dev] [PATCH] Windows: Trigger an ARP request before sending IPFIX packet
Will send out a V2 with the correct Commit Msg Title. Consider this as an RFC. On 5/8/18, 10:07 AM, "Sairam Venugopal" <[email protected]> wrote: IPFIX templates and flow packets are silently dropped when a corresponding ARP entry is missing for the Collector. The fix is to explicitly trigger an ARP request before sending UDP packets to the collector. Making changes in Windows to maintain the destination IP address as part of the Collector Structure. Since the SendARP is a blocking call, we do not necessarily need to check for a response before sending the IPFIX packets. Keeping the fix specific to Windows since this behavior cannot be reproduced in Linux. Reported-at: https://github.com/openvswitch/ovs-issues/issues/147 Signed-off-by: Sairam Venugopal <[email protected]> --- ofproto/collectors.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/ofproto/collectors.c b/ofproto/collectors.c index bc92332..239599a 100644 --- a/ofproto/collectors.c +++ b/ofproto/collectors.c @@ -27,11 +27,17 @@ #include "sset.h" #include "util.h" #include "openvswitch/vlog.h" +#ifdef WIN32 +#include <iphlpapi.h> +#endif WIN32 VLOG_DEFINE_THIS_MODULE(collectors); struct collectors { int *fds; /* Sockets. */ +#ifdef WIN32 + IPAddr *destIPs; /* Collector's IP address */ +#endif WIN32 size_t n_fds; /* Number of sockets. */ }; @@ -58,6 +64,9 @@ collectors_create(const struct sset *targets, uint16_t default_port, c = xmalloc(sizeof *c); c->fds = xmalloc(sizeof *c->fds * sset_count(targets)); +#ifdef WIN32 + c->destIPs = xmalloc(sizeof *c->destIPs * sset_count(targets)); +#endif c->n_fds = 0; SSET_FOR_EACH (name, targets) { int error; @@ -65,6 +74,13 @@ collectors_create(const struct sset *targets, uint16_t default_port, error = inet_open_active(SOCK_DGRAM, name, default_port, NULL, &fd, 0); if (fd >= 0) { +#ifdef WIN32 + char *target = xstrdup(name); + char *p; + p = target; + c->destIPs[c->n_fds] = htonl(inet_addr(inet_parse_token(&p))); + free(target); +#endif WIN32 c->fds[c->n_fds++] = fd; } else { static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5); @@ -97,6 +113,9 @@ collectors_destroy(struct collectors *c) for (i = 0; i < c->n_fds; i++) { closesocket(c->fds[i]); } +#ifdef WIN32 + free(c->destIPs); +#endif free(c->fds); free(c); } @@ -114,6 +133,12 @@ collectors_send(const struct collectors *c, const void *payload, size_t n) for (i = 0; i < c->n_fds; i++) { static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5); +#ifdef WIN32 + /* Trigger an ARP request before sending an IPFIX packet */ + ULONG MacAddr[2]; + ULONG PhysAddrLen = 6; + SendARP(c->destIPs[i], 0, &MacAddr, &PhysAddrLen); +#endif if (send(c->fds[i], payload, n, 0) == -1) { char *s = describe_fd(c->fds[i]); VLOG_WARN_RL(&rl, "%s: sending to collector failed (%s)", -- 2.9.0.windows.1 _______________________________________________ If the ARP does not resolve, then IPFIX packet is still being sent out. Even though the SendARP() function is synchronous, it might make sense to at least check if the ARP query was resolved, and appropriately log the status of the query. Otherwise this issue cannot be debugged without a live system. Thanks, Shashank _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
