add pcap packet stats

src/decpcap.c

@@ -110,6 +110,23 @@ struct dp_handle *dp_open_live(const char *device, int snaplen, int promisc,
   return dp_fillhandle(temp);
 }
 
+/* function to get packet statistics, e.g. dropped packets */
+
+dp_stat dp_stats(struct dp_handle* handle)
+{
+  struct pcap_stat ps;
+  if(pcap_stats(handle->pcap_handle, &ps) == PCAP_ERROR)
+  {
+      fprintf(stderr, "Error getting pcap_stats: %s\n", 
+              pcap_geterr(handle->pcap_handle));
+      ps.ps_recv   = 0;
+      ps.ps_drop   = 0;
+      ps.ps_ifdrop = 0;
+      return ps;
+  }
+  return ps;
+}
+
 /* functions to add callbacks */
 
 void dp_addcb(struct dp_handle *handle, enum dp_packet_type type,

src/decpcap.h

@@ -52,6 +52,7 @@ enum dp_packet_type {
  * pcap
 };*/
 typedef struct pcap_pkthdr dp_header;
+typedef struct pcap_stat dp_stat;
 
 typedef int (*dp_callback)(u_char *, const dp_header *, const u_char *);
 
@@ -69,6 +70,10 @@ struct dp_handle *dp_open_live(const char *device, int snaplen, int promisc,
                                int to_ms, char *filter, char *errbuf);
 struct dp_handle *dp_open_offline(char *fname, char *ebuf);
 
+/* function to get packet statistics, e.g. dropped packets */
+
+dp_stat dp_stats(struct dp_handle* handle);
+
 /* functions to add callbacks */
 
 void dp_addcb(struct dp_handle *handle, enum dp_packet_type type,

src/libnethogs.cpp

@@ -339,3 +339,20 @@ void nethogsmonitor_breakloop() {
   monitor_run_flag = false;
   write(self_pipe.second, "x", 1);
 }
+
+void nethogs_packet_stats(NethogsPackageStats **stats, int *stats_size)
+{
+  
+  *stats = static_cast<NethogsPackageStats *>(malloc(handles.size() * sizeof(NethogsPackageStats)));
+  int i = 0;
+
+  for(auto current_handle = handles.begin(); current_handle != handles.end(); current_handle ++){
+    dp_stat stat = dp_stats(current_handle->content);
+    stats[i]->ps_recv = stat.ps_recv;
+    stats[i]->ps_drop = stat.ps_drop;
+    stats[i]->ps_ifdrop = stat.ps_ifdrop;
+    stats[i]->devicename = current_handle->devicename;
+    i++;
+  }
+  *stats_size = handles.size();
+}

src/libnethogs.h

@@ -7,6 +7,7 @@ extern "C" {
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <sys/types.h>
 
 #define NETHOGS_DSO_VISIBLE __attribute__((visibility("default")))
 #define NETHOGS_DSO_HIDDEN __attribute__((visibility("hidden")))
@@ -32,6 +33,14 @@ typedef struct NethogsMonitorRecord {
   float recv_kbs;
 } NethogsMonitorRecord;
 
+typedef struct NethogsPackageStats
+{
+  u_int ps_recv;           /** number of packets received */
+  u_int ps_drop;           /** number of packets dropped because there was no room in the operating system's buffer when they arrived, because packets weren't being read fast enough */
+  u_int ps_ifdrop;         /** number of packets dropped by the network interface or its driver.  */
+  const char *devicename; /** name of the network interface */
+} NethogsPackageStats;
+
 /**
  * @brief Defines a callback to handle updates about applications
  * @param action NETHOGS_APP_ACTION_SET if data is being added or updated,
@@ -95,6 +104,14 @@ NETHOGS_DSO_VISIBLE int nethogsmonitor_loop_devices(NethogsMonitorCallback cb,
  */
 NETHOGS_DSO_VISIBLE void nethogsmonitor_breakloop();
 
+/**
+ * @brief returns the pcap packet stats per device
+ * 
+ * @param stats C-Style array the will hold the stats
+ * @param stats_size elements and therefore devices in stats
+ */
+NETHOGS_DSO_VISIBLE void nethogs_packet_stats(NethogsPackageStats **stats, int *stats_size);
+
 #undef NETHOGS_DSO_VISIBLE
 #undef NETHOGS_DSO_HIDDEN