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Fix latency calculation in nfpcapd
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@phaag
phaag committed Aug 29, 2024
1 parent 6d7d179 commit dbaa772
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Showing 3 changed files with 39 additions and 33 deletions.
10 changes: 8 additions & 2 deletions src/nfpcapd/flowtree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -314,12 +314,18 @@ int Link_RevNode(struct FlowNode *node) {

dbg_printf("Link node: ");
dbg_assert(node->rev_node == NULL);
lookup_node.flowKey = node->flowKey;
lookup_node.flowKey._ALIGN = 0;
lookup_node.flowKey.proto = node->flowKey.proto;
lookup_node.flowKey.version = node->flowKey.version;
// reverse lookup key to find reverse node
lookup_node.flowKey.src_addr = node->flowKey.dst_addr;
lookup_node.flowKey.dst_addr = node->flowKey.src_addr;
lookup_node.flowKey.src_port = node->flowKey.dst_port;
lookup_node.flowKey.dst_port = node->flowKey.src_port;
rev_node = Lookup_Node(&lookup_node);
if (rev_node) {
dbg_printf("Found revnode ");
// rev node must not be linked already - otherwise there is an inconsistency
dbg_assert(node->rev_node == NULL);
if (node->rev_node == NULL) {
// link both nodes
node->rev_node = rev_node;
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1 change: 0 additions & 1 deletion src/nfpcapd/flowtree.h
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Original file line number Diff line number Diff line change
Expand Up @@ -130,7 +130,6 @@ struct FlowNode {
uint64_t server;
uint64_t application;
uint32_t flag;
struct timeval t_request;
} latency;
};

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61 changes: 31 additions & 30 deletions src/nfpcapd/pcaproc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -230,62 +230,54 @@ void RotateFile(pcapfile_t *pcapfile, time_t t_CloseRename, int live) {

} // End of RotateFile

// Server latency = t(SYN Server) - t(SYN CLient)
// Server latency = t(SYN ACK Server) - t(SYN CLient)
static inline void SetServer_latency(struct FlowNode *node) {
struct FlowNode *Client_node;
uint64_t latency;

Client_node = node->rev_node;
struct FlowNode *Client_node = node->rev_node;
if (!Client_node) return;

latency = ((uint64_t)node->t_first.tv_sec * (uint64_t)1000000 + (uint64_t)node->t_first.tv_usec) -
((uint64_t)Client_node->t_first.tv_sec * (uint64_t)1000000 + (uint64_t)Client_node->t_first.tv_usec);
uint64_t latency = ((uint64_t)node->t_first.tv_sec * (uint64_t)1000000 + (uint64_t)node->t_first.tv_usec) -
((uint64_t)Client_node->t_first.tv_sec * (uint64_t)1000000 + (uint64_t)Client_node->t_first.tv_usec);

node->latency.server = latency;
Client_node->latency.server = latency;
// set flag, to calc app latency with nex packet from server
node->latency.flag = 2;
// set flag, to calc client latency with nex packet from client
Client_node->latency.flag = 1;
dbg_printf("Server latency: %llu\n", (long long unsigned)latency);

} // End of SetServerClient_latency

// Client latency = t(ACK CLient) - t(SYN Server)
// Client latency = t(ACK CLient) - t(SYN ACK Server)
static inline void SetClient_latency(struct FlowNode *node, struct timeval *t_packet) {
struct FlowNode *Server_node;
uint64_t latency;

Server_node = node->rev_node;
if (!Server_node) return;
struct FlowNode *serverNode = node->rev_node;
if (!serverNode) return;

latency = ((uint64_t)t_packet->tv_sec * (uint64_t)1000000 + (uint64_t)t_packet->tv_usec) -
((uint64_t)Server_node->t_first.tv_sec * (uint64_t)1000000 + (uint64_t)Server_node->t_first.tv_usec);
uint64_t latency = ((uint64_t)t_packet->tv_sec * (uint64_t)1000000 + (uint64_t)t_packet->tv_usec) -
((uint64_t)serverNode->t_last.tv_sec * (uint64_t)1000000 + (uint64_t)serverNode->t_last.tv_usec);

node->latency.client = latency;
Server_node->latency.client = latency;
serverNode->latency.client = latency;
// reset flag
node->latency.flag = 0;
// set flag, to calc application latency with nex packet from server
Server_node->latency.flag = 2;
Server_node->latency.t_request = *t_packet;
dbg_printf("Client latency: %llu\n", (long long unsigned)latency);

} // End of SetClient_latency

// Application latency = t(ACK Server) - t(ACK CLient)
void SetApplication_latency(struct FlowNode *node, struct timeval *t_packet) {
struct FlowNode *Client_node;
uint64_t latency;
struct FlowNode *clientNode = node->rev_node;
if (!clientNode) return;

Client_node = node->rev_node;
if (!Client_node) return;

latency = ((uint64_t)t_packet->tv_sec * (uint64_t)1000000 + (uint64_t)t_packet->tv_usec) -
((uint64_t)node->latency.t_request.tv_sec * (uint64_t)1000000 + (uint64_t)node->latency.t_request.tv_usec);
uint64_t latency = ((uint64_t)t_packet->tv_sec * (uint64_t)1000000 + (uint64_t)t_packet->tv_usec) -
((uint64_t)clientNode->t_last.tv_sec * (uint64_t)1000000 + (uint64_t)clientNode->t_last.tv_usec);

node->latency.application = latency;
Client_node->latency.application = latency;
clientNode->latency.application = latency;
// reset flag
node->latency.flag = 0;
// set flag, to calc application latency with nex packet from server
clientNode->latency.flag = 0;
dbg_printf("Application latency: %llu\n", (long long unsigned)latency);

} // End of SetApplication_latency
Expand Down Expand Up @@ -399,8 +391,17 @@ static inline void ProcessTCPFlow(packetParam_t *packetParam, struct FlowNode *N
// flush node to flow thread
Remove_Node(NewNode);
Push_Node(packetParam->NodeList, NewNode);
return;
}

#ifdef DEVEL
if ((NewNode->flags & 0x3F) == 0x2) {
printf("SYN Node\n");
}
if ((NewNode->flags & 0x37) == 0x12) {
printf("SYN ACK Node\n");
}
#endif
if (packetParam->extendedFlow && Link_RevNode(NewNode)) {
// if we could link this new node, it is the server answer
// -> calculate server latency
Expand All @@ -411,7 +412,7 @@ static inline void ProcessTCPFlow(packetParam_t *packetParam, struct FlowNode *N

assert(Node->memflag == NODE_IN_USE);

// check for first client ACK for client latency
// check for latency flag
if (Node->latency.flag == 1) {
SetClient_latency(Node, &(NewNode->t_first));
} else if (Node->latency.flag == 2) {
Expand Down Expand Up @@ -842,8 +843,8 @@ int ProcessPacket(packetParam_t *packetParam, const struct pcap_pkthdr *hdr, con
if (!Node) Node = New_Node();
Node->flowKey.version = AF_INET6;
Node->t_first.tv_sec = hdr->ts.tv_sec;
Node->t_first.tv_usec = hdr->ts.tv_usec;
Node->t_last.tv_sec = hdr->ts.tv_sec;
Node->t_first.tv_usec = hdr->ts.tv_usec;
Node->t_last.tv_usec = hdr->ts.tv_usec;
Node->bytes = ntohs(ip6->ip6_plen) + size_ip;
Node->ttl = ip6->ip6_ctlun.ip6_un1.ip6_un1_hlim;
Expand Down Expand Up @@ -915,8 +916,8 @@ int ProcessPacket(packetParam_t *packetParam, const struct pcap_pkthdr *hdr, con
if (!Node) Node = New_Node();
Node->flowKey.version = AF_INET;
Node->t_first.tv_sec = hdr->ts.tv_sec;
Node->t_first.tv_usec = hdr->ts.tv_usec;
Node->t_last.tv_sec = hdr->ts.tv_sec;
Node->t_first.tv_usec = hdr->ts.tv_usec;
Node->t_last.tv_usec = hdr->ts.tv_usec;
Node->bytes = ntohs(ip->ip_len);
if (ip_off & IP_DF) Node->fragmentFlags |= flagDF;
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