New implementation for retrieving timestamp

Documentation/polycubectl/polycubectl.rst

@@ -39,6 +39,7 @@ Refer to :doc:`Quick Start <../quickstart>`.
         pbforwarder       service   Policy-Based Forwarder Service
         bridge            service   Bridge Service
         nat               service   NAT Service
+        packetcapture     service   Packetcapture Service
 
         connect           command   Connect ports
         disconnect        command   Disconnect ports

src/services/pcn-packetcapture/src/Packetcapture.cpp

@@ -42,9 +42,12 @@ Packetcapture::Packetcapture(const std::string name, const PacketcaptureJsonObje
     PacketcaptureBase(name) {
 
   /*
-   * The timestamp of the packet is acquired in the fast path using 'bpf_ktime_get_ns()'
+   * The timestamp of the packet is acquired in the fast path using:
+   * if BPF_PROG_TYPE_XDP is TC and ctx->tstamp != 0 we use ctx->tstamp
+   * it returns the current Unix epoch time
+   *
+   * otherwise if BPF_PROG_TYPE_XDP is not TC or ctx->tstamp == 0 we use 'bpf_ktime_get_ns()'
    * This function returns the time elapsed since system booted, in nanoseconds.
-   * See line 59 in Packetcapture_dp_egress.c and Packetcapture_dp_ingress.c
    *
    * The packet's timestamp must be in epoch so now we will store the current
    * time in epoch format and then the packet capture time offset,that was stored in the fast path,
@@ -54,7 +57,7 @@ Packetcapture::Packetcapture(const std::string name, const PacketcaptureJsonObje
    * 'timeval struct ts' rapresents the system start time in epoch calculated as
    * actual time - system uptime
    *
-   * See line 164 of this file for more details
+   * See line 167 of this file for more details
    */
 
 
@@ -155,14 +158,17 @@ void Packetcapture::writeDump(const std::vector<uint8_t> &packet){
     writeHeader = false;
   }
 
-  /*
-   * Here the packet capture time offset must be added to the system boot time stored in epoch format.
-   * See line 61 of this file to see system boot time stored in epoch algorithm
-   */
-
   struct timeval tp;
-  std::chrono::system_clock::duration tp_dur = (timeP + temp_offset).time_since_epoch();
-  to_timeval(tp_dur, tp);
+  if (ts) {
+      /*
+       * Here the packet capture time offset must be added to the system boot time stored in epoch format.
+       * See line 64 of this file to see system boot time stored in epoch algorithm
+       */
+      std::chrono::system_clock::duration tp_dur = (timeP + temp_offset).time_since_epoch();
+      to_timeval(tp_dur, tp);
+  } else {
+      to_timeval(temp_offset, tp);
+  }
 
   p->setTimestampSeconds((uint32_t) tp.tv_sec);
   p->setTimestampMicroseconds((uint32_t) tp.tv_usec);
@@ -195,18 +201,28 @@ void Packetcapture::packet_in(polycube::service::Direction direction,
     const std::vector<uint8_t> &packet) {
 
   Tins::EthernetII pkt(&packet[0], packet.size());
+  uint64_t t;
+  ts = false;
 
   switch (direction) {
     case polycube::service::Direction::INGRESS:
-    temp_offset = std::chrono::nanoseconds(static_cast<unsigned long long>(get_array_table<uint64_t>("packet_timestamp", 0, ProgramType::INGRESS).get(0x0)));
+    t = (((uint64_t) (md.metadata[1]) << 32) | (uint64_t) md.metadata[0]);
+    if (md.metadata[2] == 0) {
+        ts = true;
+    }
+    temp_offset = std::chrono::nanoseconds(t);
     if (getNetworkmode() == true) {
       addPacket(packet);    /* store the packet in the FIFO queue*/
     } else {
       writeDump(packet);
     }
     break;
     case polycube::service::Direction::EGRESS:
-    temp_offset = std::chrono::nanoseconds(static_cast<unsigned long long>(get_array_table<uint64_t>("packet_timestamp", 0, ProgramType::EGRESS).get(0x0)));
+    t = (((uint64_t) (md.metadata[1]) << 32) | (uint64_t) md.metadata[0]);
+    if (md.metadata[2] == 0) {
+        ts = true;
+    }
+    temp_offset = std::chrono::nanoseconds(t);
     if (getNetworkmode() == true) {
       addPacket(packet);    /* store the packet in the FIFO queue*/
     } else {
@@ -295,15 +311,17 @@ void Packetcapture::addPacket(const std::vector<uint8_t> &packet) {
     PacketJsonObject pj;
     auto p = std::shared_ptr<Packet>(new Packet(*this, pj));
 
-  /*
-   * Here the packet capture time offset must be added to the system boot time stored in epoch format.
-   * See line 58 of this file to see system boot time stored in epoch algorithm
-   */
-
     struct timeval tp;
-    std::chrono::system_clock::duration tp_dur = (timeP + temp_offset).time_since_epoch();
-    to_timeval(tp_dur, tp);
-
+    if (ts) {
+        /*
+         * Here the packet capture time offset must be added to the system boot time stored in epoch format.
+         * See line 64 of this file to see system boot time stored in epoch algorithm
+         */
+        std::chrono::system_clock::duration tp_dur = (timeP + temp_offset).time_since_epoch();
+        to_timeval(tp_dur, tp);
+    } else {
+        to_timeval(temp_offset, tp);
+    }
     p->setTimestampSeconds((uint32_t) tp.tv_sec);
     p->setTimestampMicroseconds((uint32_t) tp.tv_usec);
     p->setPacketlen((uint32_t) packet.size());
@@ -378,14 +396,16 @@ void Packetcapture::to_timeval(std::chrono::system_clock::duration& d, struct ti
 }
 
 void Packetcapture::setFilter(const std::string &value) {
-    this->filter = value;
-    logger()->info("Inserted filter: {0}", filter);
-    if (filter == "all") {
-      filterCode = "return pcn_pkt_controller(ctx, md, reason);";
+    logger()->info("Inserted filter: {0}", value);
+    if (value == "all") {
+        filterCode = "if (ctx->tstamp == 0) {\n\tpkt_timestamp = bpf_ktime_get_ns();\n\tmdata[0] = *(&pkt_timestamp);\n\t"
+                     "mdata[1] = (*(&pkt_timestamp)) >> 32;\n\tmdata[2] = 0;\n} else {\n\tmdata[0] = *(&ctx->tstamp);\n\t"
+                     "mdata[1] = (*(&ctx->tstamp)) >> 32;\n\tmdata[2] = 1;\n}\nreturn pcn_pkt_controller_with_metadata(ctx, md, reason, mdata);";
     }else {
         memset(&cbpf, 0, sizeof(cbpf));
-        filterCompile(filter, &cbpf);
+        filterCompile(value, &cbpf);
     }
+    this->filter = value;
     updateFilter();
 }
 
@@ -410,9 +430,8 @@ void Packetcapture::filterCompile(std::string str, struct sock_fprog * cbpf) {
 
     ret = pcap_compile_nopcap(65535, link_type, &_bpf, str.c_str(), 1, 0xffffffff);
     if (ret < 0) {
-      logger()->info("Cannot compile filter: {0}", str);
-      filterCode = "return RX_OK;";
-      return;
+      logger()->error("Cannot compile filter: {0}", str);
+      throw std::runtime_error("Filter not valid");
     }
 
     cbpf->len = _bpf.bf_len;

src/services/pcn-packetcapture/src/Packetcapture.h

@@ -46,6 +46,9 @@ class Packetcapture : public PacketcaptureBase {
  std::chrono::nanoseconds temp_offset;
  std::string filter;
  bool bootstrap = true; /* variable used to set default filter when the service is created */
+ bool ts = false; /* true when service not TC type or sk_buff->tstamp == 0 see line 45
+                   * in Packetcapture_dp_egress.c and Packetcapture_dp_ingress.c
+                   */
 
 private:
     struct sock_fprog cbpf;

src/services/pcn-packetcapture/src/Packetcapture_dp_egress.c

@@ -32,31 +32,15 @@
 #include <uapi/linux/tcp.h>
 #include <uapi/linux/udp.h>
 
-struct eth_hdr {
-    __be64 dst : 48;
-    __be64 src : 48;
-    __be16 proto;
-} __attribute__((packed));
-
-/*
- * BPF map where a single element, packet timestamp
- */
-BPF_ARRAY(packet_timestamp, uint64_t, 1);
-
 
 static __always_inline int handle_rx(struct CTXTYPE *ctx, struct pkt_metadata *md) {
     unsigned int key = 0;
     void *data = (void *)(long)ctx->data;
     void *data_end = (void *)(long)ctx->data_end;
-    struct eth_hdr *ethernet = data;
     u16 reason = 1;
     uint32_t a, x, m[16];
-
-    uint64_t *pkt_timestamp = packet_timestamp.lookup(&key);
-    if (!pkt_timestamp){
-        return RX_DROP;
-    }
-    *pkt_timestamp = bpf_ktime_get_ns();
+    u32 mdata[3];
+    uint64_t pkt_timestamp;
 
     //CUSTOM_FILTER_CODE
 

src/services/pcn-packetcapture/src/Packetcapture_dp_ingress.c

@@ -32,31 +32,15 @@
 #include <uapi/linux/tcp.h>
 #include <uapi/linux/udp.h>
 
-struct eth_hdr {
-    __be64 dst : 48;
-    __be64 src : 48;
-    __be16 proto;
-} __attribute__((packed));
-
-/*
- * BPF map where a single element, packet timestamp
- */
-BPF_ARRAY(packet_timestamp, uint64_t, 1);
-
 
 static __always_inline int handle_rx(struct CTXTYPE *ctx, struct pkt_metadata *md) {
     unsigned int key = 0;
     void *data = (void *)(long)ctx->data;
     void *data_end = (void *)(long)ctx->data_end;
-    struct eth_hdr *ethernet = data;
     u16 reason = 1;
     uint32_t a, x, m[16];
-
-    uint64_t *pkt_timestamp = packet_timestamp.lookup(&key);
-    if (!pkt_timestamp){
-        return RX_DROP;
-    }
-    *pkt_timestamp = bpf_ktime_get_ns();
+    u32 mdata[3];
+    uint64_t pkt_timestamp;
 
     //CUSTOM_FILTER_CODE