clean-up trailing whitespace (#453)

These changes have been mostly auto-generated with: find . -type f -print0 | xargs -0 perl -pi -e 's/ +$//' Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
2022-02-24 10:49:16 -05:00
parent 071b89ad30
commit 50f397b249
42 changed files with 275 additions and 275 deletions
@@ -14,7 +14,7 @@ would be in a single pod of a fat tree topology.
 ![topology](./firewall-topo.png)

 Switch s1 will be configured with a P4 program that implements a
-simple stateful firewall (`firewall.p4`), the rest of the switches will run the 
+simple stateful firewall (`firewall.p4`), the rest of the switches will run the
 basic IPv4 router program (`basic.p4`) from the previous exercise.

 The firewall on s1 should have the following functionality:
@@ -62,21 +62,21 @@ up a switch in Mininet to test its behavior.
   [pod-topo/topology.json](./pod-topo/topology.json)

 2. You should now see a Mininet command prompt. Try to run some iperf
-   TCP flows between the hosts. TCP flows within the internal 
+   TCP flows between the hosts. TCP flows within the internal
   network should work:
   ```bash
   mininet> iperf h1 h2
   ```

-   TCP flows from hosts in the internal network to the outside hosts 
+   TCP flows from hosts in the internal network to the outside hosts
   should also work:
   ```bash
   mininet> iperf h1 h3
-   ```   
+   ```

-   TCP flows from the outside hosts to hosts inside the 
-   internal network should NOT work. However, since the firewall is not 
-   implemented yet, the following should work: 
+   TCP flows from the outside hosts to hosts inside the
+   internal network should NOT work. However, since the firewall is not
+   implemented yet, the following should work:
   ```bash
   mininet> iperf h3 h1
   ```
@@ -118,11 +118,11 @@ logic replaced by `TODO` comments. Your implementation should follow
 the structure given in this file --- replace each `TODO` with logic
 implementing the missing piece.

-**High-level Approach:** We will use a bloom filter with two hash functions 
-to check if a packet coming into the internal network is a part of 
-an already established TCP connection. We will use two different register 
-arrays for the bloom filter, each to be updated by a hash function. 
-Using different register arrays makes our design amenable to high-speed 
+**High-level Approach:** We will use a bloom filter with two hash functions
+to check if a packet coming into the internal network is a part of
+an already established TCP connection. We will use two different register
+arrays for the bloom filter, each to be updated by a hash function.
+Using different register arrays makes our design amenable to high-speed
 P4 targets that typically allow only one access to a register array per packet.

 A complete `firewall.p4` will contain the following components:
@@ -130,32 +130,32 @@ A complete `firewall.p4` will contain the following components:
 1. Header type definitions for Ethernet (`ethernet_t`), IPv4 (`ipv4_t`) and TCP (`tcp_t`).
 2. Parsers for Ethernet, IPv4 and TCP that populate `ethernet_t`, `ipv4_t` and `tcp_t` fields.
 3. An action to drop a packet, using `mark_to_drop()`.
-4. An action (called `compute_hashes`) to compute the bloom filter's two hashes using hash 
-algorithms `crc16` and `crc32`. The hashes will be computed on the packet 5-tuple consisting 
-of IPv4 source and  destination addresses, source and destination port numbers and 
+4. An action (called `compute_hashes`) to compute the bloom filter's two hashes using hash
+algorithms `crc16` and `crc32`. The hashes will be computed on the packet 5-tuple consisting
+of IPv4 source and  destination addresses, source and destination port numbers and
 the IPv4 protocol type.
-5. An action (`ipv4_forward`) and a table (`ipv4_lpm`) that will perform basic 
+5. An action (`ipv4_forward`) and a table (`ipv4_lpm`) that will perform basic
 IPv4 forwarding (adopted from `basic.p4`).
-6. An action (called `set_direction`) that will simply set a one-bit direction variable 
+6. An action (called `set_direction`) that will simply set a one-bit direction variable
 as per the action's parameter.
-7. A table (called `check_ports`) that will read the ingress and egress port of a packet 
-(after IPv4 forwarding) and invoke `set_direction`. The direction will be set to `1`, 
+7. A table (called `check_ports`) that will read the ingress and egress port of a packet
+(after IPv4 forwarding) and invoke `set_direction`. The direction will be set to `1`,
 if the packet is incoming into the internal network. Otherwise, the direction will be set to `0`.
 To achieve this, the file `pod-topo/s1-runtime.json` contains the appropriate control plane
 entries for the `check_ports` table.
 8. A control that will:
    1. First apply the table `ipv4_lpm` if the packet has a valid IPv4 header.
    2. Then if the TCP header is valid, apply the `check_ports` table to determine the direction.
-    3. Apply the `compute_hashes` action to compute the two hash values which are the bit positions 
-    in the two register arrays of the bloom filter (`reg_pos_one` and `reg_pos_two`). 
-    When the direction is `1` i.e. the packet is incoming into the internal network, 
-    `compute_hashes` will be invoked by swapping the source and destination IPv4 addresses 
-    and the source and destination ports. This is to check against bloom filter's set bits 
+    3. Apply the `compute_hashes` action to compute the two hash values which are the bit positions
+    in the two register arrays of the bloom filter (`reg_pos_one` and `reg_pos_two`).
+    When the direction is `1` i.e. the packet is incoming into the internal network,
+    `compute_hashes` will be invoked by swapping the source and destination IPv4 addresses
+    and the source and destination ports. This is to check against bloom filter's set bits
    when the TCP connection was initially made from the internal network.
-    4. **TODO:** If the TCP packet is going out of the internal network and is a SYN packet, 
-    set both the bloom filter arrays at the computed bit positions (`reg_pos_one` and `reg_pos_two`). 
-    Else, if the TCP packet is entering the internal network, 
-    read both the bloom filter arrays at the computed bit positions and drop the packet if 
+    4. **TODO:** If the TCP packet is going out of the internal network and is a SYN packet,
+    set both the bloom filter arrays at the computed bit positions (`reg_pos_one` and `reg_pos_two`).
+    Else, if the TCP packet is entering the internal network,
+    read both the bloom filter arrays at the computed bit positions and drop the packet if
    either is not set.
 9. A deparser that emits the Ethernet, IPv4 and TCP headers in the right order.
 10. A `package` instantiation supplied with the parser, control, and deparser.
@@ -171,18 +171,18 @@ h3 and h1 should be blocked by the firewall.

 ### Food for thought

-You may have noticed that in this simple stateful firewall, we are adding 
-new TCP connections to the bloom filter (based on outgoing SYN packets). 
-However, we are not removing them in case of TCP connection teardown 
-(FIN packets). How would you implement the removal of TCP connections that are 
+You may have noticed that in this simple stateful firewall, we are adding
+new TCP connections to the bloom filter (based on outgoing SYN packets).
+However, we are not removing them in case of TCP connection teardown
+(FIN packets). How would you implement the removal of TCP connections that are
 no longer active?

-Things to consider: 
- - Can we simply set the bloom filter array bits to `0` on 
- receiving a FIN packet? What happens when there is one hash collision in 
+Things to consider:
+ - Can we simply set the bloom filter array bits to `0` on
+ receiving a FIN packet? What happens when there is one hash collision in
 the bloom filter arrays between two _active_ TCP connections?
- - How can we modify our bloom filter structure so that the deletion 
- operation can be properly supported? 
+ - How can we modify our bloom filter structure so that the deletion
+ operation can be properly supported?

 ### Troubleshooting

@@ -74,7 +74,7 @@ parser MyParser(packet_in packet,
 ************   C H E C K S U M    V E R I F I C A T I O N   *************
 *************************************************************************/

-control MyVerifyChecksum(inout headers hdr, inout metadata meta) {   
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
    apply {  }
 }

@@ -89,14 +89,14 @@ control MyIngress(inout headers hdr,
    action drop() {
        mark_to_drop(standard_metadata);
    }
-    
+
    action ipv4_forward(macAddr_t dstAddr, egressSpec_t port) {
        standard_metadata.egress_spec = port;
        hdr.ethernet.srcAddr = hdr.ethernet.dstAddr;
        hdr.ethernet.dstAddr = dstAddr;
        hdr.ipv4.ttl = hdr.ipv4.ttl - 1;
    }
-    
+
    table ipv4_lpm {
        key = {
            hdr.ipv4.dstAddr: lpm;
@@ -109,7 +109,7 @@ control MyIngress(inout headers hdr,
        size = 1024;
        default_action = drop();
    }
-    
+
    apply {
        if (hdr.ipv4.isValid()) {
            ipv4_lpm.apply();
@@ -133,10 +133,10 @@ control MyEgress(inout headers hdr,

 control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
     apply {
-	update_checksum(
-	    hdr.ipv4.isValid(),
+        update_checksum(
+            hdr.ipv4.isValid(),
            { hdr.ipv4.version,
-	      hdr.ipv4.ihl,
+              hdr.ipv4.ihl,
              hdr.ipv4.diffserv,
              hdr.ipv4.totalLen,
              hdr.ipv4.identification,
@@ -108,7 +108,7 @@ parser MyParser(packet_in packet,
 ************   C H E C K S U M    V E R I F I C A T I O N   *************
 *************************************************************************/

-control MyVerifyChecksum(inout headers hdr, inout metadata meta) {   
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
    apply {  }
 }

@@ -154,7 +154,7 @@ control MyIngress(inout headers hdr,
        hdr.ethernet.dstAddr = dstAddr;
        hdr.ipv4.ttl = hdr.ipv4.ttl - 1;
    }
-    
+
    table ipv4_lpm {
        key = {
            hdr.ipv4.dstAddr: lpm;
@@ -184,7 +184,7 @@ control MyIngress(inout headers hdr,
        size = 1024;
        default_action = NoAction();
    }
-    
+
    apply {
        if (hdr.ipv4.isValid()){
            ipv4_lpm.apply();
@@ -232,10 +232,10 @@ control MyEgress(inout headers hdr,

 control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
     apply {
-	update_checksum(
-	    hdr.ipv4.isValid(),
+        update_checksum(
+            hdr.ipv4.isValid(),
            { hdr.ipv4.version,
-	      hdr.ipv4.ihl,
+              hdr.ipv4.ihl,
              hdr.ipv4.diffserv,
              hdr.ipv4.totalLen,
              hdr.ipv4.identification,
@@ -108,7 +108,7 @@ parser MyParser(packet_in packet,
 ************   C H E C K S U M    V E R I F I C A T I O N   *************
 *************************************************************************/

-control MyVerifyChecksum(inout headers hdr, inout metadata meta) {   
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
    apply {  }
 }

@@ -154,7 +154,7 @@ control MyIngress(inout headers hdr,
        hdr.ethernet.dstAddr = dstAddr;
        hdr.ipv4.ttl = hdr.ipv4.ttl - 1;
    }
-    
+
    table ipv4_lpm {
        key = {
            hdr.ipv4.dstAddr: lpm;
@@ -184,7 +184,7 @@ control MyIngress(inout headers hdr,
        size = 1024;
        default_action = NoAction();
    }
-    
+
    apply {
        if (hdr.ipv4.isValid()){
            ipv4_lpm.apply();
@@ -238,10 +238,10 @@ control MyEgress(inout headers hdr,

 control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
     apply {
-	update_checksum(
-	    hdr.ipv4.isValid(),
+        update_checksum(
+            hdr.ipv4.isValid(),
            { hdr.ipv4.version,
-	      hdr.ipv4.ihl,
+              hdr.ipv4.ihl,
              hdr.ipv4.diffserv,
              hdr.ipv4.totalLen,
              hdr.ipv4.identification,