updated docs

README.md

@@ -1,6 +1,6 @@
 ## Packet Sniffer
 
-An application which extracts payload and computes payload hash using
+An application which extracts payload and computes sha512 digest of the payload using
 sha256 digest of the payload from live traffic.
 
 The code under `src` has the packet sniffer application. It can capture upto 
@@ -18,14 +18,26 @@ sudo ./sniffer.o -c eth0 # the interface in which packets are received
 
 ## Examples:
 
-For capturing in interface eno1:   `./sniffer.o -c eno1`
+For capturing in interface eno1:   `./sniffer -c eno1`
 
-For using 2 threads: `./sniffer.o -T 2`
+For using 2 threads: `./sniffer -T 2`
 
-For capturing upto 10 seconds: `./sniffer.o -t 10`
+For capturing upto 10 seconds: `./sniffer -t 10`
 
-For choosing output json file name: `./sniffer.o -j output.json`
-
-For help: `./sniffer.o -h`
+For choosing output json file name: `./sniffer -j output.json`
 
+For help: `./sniffer -h`
 
+For duplicate packet detection, to build index for bloom filter
+run the application in mode 1 and to perform detection, rerun it in mode 2.
+```
+./sniffer -m 1  # building bloom filter index
+./sniffer -m 2  # performing detection
+```
+BloomFilter is a probabilistic data structure. Given that the application
+needs to capture `n` packets at a false positive rate of `e`, the configuration can be
+set as
+```
+./sniffer -m 1 -n 10000 -e 0.001
+```
+The same configuration should be used during testing.

docs/duplicate_packet_detection.md

@@ -0,0 +1,4 @@
+## Duplicate Packet Detection
+
+The application uses BloomFilter datatype to detect
+duplicate packets.

docs/socket_options.md

@@ -1,12 +1,17 @@
+## Socket Options
 
-` int sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP));`
+` int sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_IP))`
 
 We use a socket of type AF_PACKET. The term AF_PACKET allows us to send or
  receive packets at layer 2 level. We analyse only IP Protocolsand hence we 
 have set the protocol  level as `ETH_P_IP`. The SOCK_RAW keyword provides
 access to raw network protocol.
 
-PACKET_FANOUT
+### Packet Fanout
 
-We use Packet_fanout_lb for load balancing of traffic across
-all sockets.
+The application uses `PACKET_FANOUT_FLAG_ROLLOVER` as fanout configuration.
+In this mode, if one socket is full, packets are rolled over to another group.
+This helps in capture at high speed. Each thread of the application handles
+a single socket and each socket is associated with a ring buffer. When one socket gets
+full, this options helps in loading other sockets. It gets more time for the threads to
+finish processing of packets in a thread.

src/bloom_filter.cc

@@ -115,7 +115,6 @@ int BloomFilter::check(std::string message) const{
      * 1: hash is found in the table
      * 0: hash is not found in the table
      */
-    std::cout << "In hash check ";
     for(int i=0; i<this->k; ++i){
         long hash = compute_hash(message, i);
         if(this->bit_array[hash] == 0)