Re: pkg/55446 (scapy function send() does not work)

[tmp%bh0.amt.ru@localhost]

The following reply was made to PR pkg/55446; it has been noted by GNATS.

From: tmp%bh0.amt.ru@localhost
To: gnats-bugs%netbsd.org@localhost, gutteridge%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        pkgsrc-bugs%netbsd.org@localhost, tmp%bh0.amt.ru@localhost
Cc: 
Subject: Re: pkg/55446 (scapy function send() does not work)
Date: Fri, 10 Jul 2020 23:34:11 +0300

 On 07/06/20 01:25, David H. Gutteridge wrote:
 > The following reply was made to PR pkg/55446; it has been noted by GNATS.
 >
 > From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
 > To: gnats-bugs%netbsd.org@localhost
 > Cc: 
 > Subject: Re: pkg/55446 (scapy function send() does not work)
 > Date: Sun, 05 Jul 2020 18:24:07 -0400
 >
 >  I hadn't had occasion to try interacting with a loopback device with
 >  Scapy before, but I borrowed that example from the Scapy test suite
 >  (where it recorded a pass for me on NetBSD 8.1 when I ran it while
 >  doing the last package update), but, the difference is, their test
 >  example targets the IP address "8.8.8.8".
 
 I tried "8.8.8.8", the result was:
 
 # scapy 
 INFO: Can't import matplotlib. Won't be able to plot.
 INFO: Can't import PyX. Won't be able to use psdump() or pdfdump().
 INFO: No IPv6 support in kernel
 WARNING: No route found for IPv6 destination :: (no default route?)
 INFO: Can't import python-cryptography v1.7+. Disabled WEP decryption/encryption. (Dot11)
 INFO: Can't import python-cryptography v1.7+. Disabled IPsec encryption/authentication.
 WARNING: IPython not available. Using standard Python shell instead.
 AutoCompletion, History are disabled.
                                       
                      aSPY//YASa       
              apyyyyCY//////////YCa       |
             sY//////YSpcs  scpCY//Pp     | Welcome to Scapy
  ayp ayyyyyyySCP//Pp           syY//C    | Version git-archive.dev304758016
  AYAsAYYYYYYYY///Ps              cY//S   |
          pCCCCY//p          cSSps y//Y   | https://github.com/secdev/scapy
          SPPPP///a          pP///AC//Y   |
               A//A            cyP////C   | Have fun!
               p///Ac            sC///a   |
               P////YCpc           A//A   | Craft me if you can.
        scccccp///pSP///p          p//Y   |                   -- IPv6 layer
       sY/////////y  caa           S//P   |
        cayCyayP//Ya              pY/Ya
         sY/PsY////YCc          aC//Yp 
          sc  sccaCY//PCypaapyCP//YSs  
                   spCPY//////YPSps    
                        ccaacs         
                                       
 >>> sendp(IP(dst="8.8.8.8")/ICMP()/"test"
 ... help
   File "<console>", line 2
     help
        ^
 SyntaxError: invalid syntax
 >>> 
 
 I realized that something went wrong.
 
 > Anyway, you'll want to have a
 >  look at the following link in the Scapy documentation:
 >  
 >  https://scapy.readthedocs.io/en/latest/troubleshooting.html#i-can-t-ping-127-0-0-1-scapy-does-not-work-with-127-0-0-1-or-on-the-loopback-interface
 
 I tried the above, the result was:
 
 # scapy
 INFO: Can't import matplotlib. Won't be able to plot.
 INFO: Can't import PyX. Won't be able to use psdump() or pdfdump().
 INFO: No IPv6 support in kernel
 WARNING: No route found for IPv6 destination :: (no default route?)
 INFO: Can't import python-cryptography v1.7+. Disabled WEP decryption/encryption. (Dot11)
 INFO: Can't import python-cryptography v1.7+. Disabled IPsec encryption/authentication.
 WARNING: IPython not available. Using standard Python shell instead.
 AutoCompletion, History are disabled.
                                       
                      aSPY//YASa       
              apyyyyCY//////////YCa       |
             sY//////YSpcs  scpCY//Pp     | Welcome to Scapy
  ayp ayyyyyyySCP//Pp           syY//C    | Version git-archive.dev304758016
  AYAsAYYYYYYYY///Ps              cY//S   |
          pCCCCY//p          cSSps y//Y   | https://github.com/secdev/scapy
          SPPPP///a          pP///AC//Y   |
               A//A            cyP////C   | Have fun!
               p///Ac            sC///a   |
               P////YCpc           A//A   | Wanna support scapy? Rate it on
        scccccp///pSP///p          p//Y   | sectools!
       sY/////////y  caa           S//P   | http://sectools.org/tool/scapy/
        cayCyayP//Ya              pY/Ya   |             -- Satoshi Nakamoto
         sY/PsY////YCc          aC//Yp    |
          sc  sccaCY//PCypaapyCP//YSs  
                   spCPY//////YPSps    
                        ccaacs         
                                       
 >>> conf.L3socket
 <L3bpfSocket: read/write packets using BPF>
 >>> conf.L3socket=L3RawSocket
 >>> conf.L3socket
 <L3RawSocket: Layer 3 using Raw sockets (PF_INET/SOCK_RAW)>
 >>> p=IP(dst="127.0.0.1")/ICMP()/"test"
 >>> p.show2()
 ###[ IP ]### 
   version= 4
   ihl= 5
   tos= 0x0
   len= 32
   id= 1
   flags= 
   frag= 0
   ttl= 64
   proto= icmp
   chksum= 0x7cda
   src= 127.0.0.1
   dst= 127.0.0.1
   \options\
 ###[ ICMP ]### 
      type= echo-request
      code= 0
      chksum= 0x1026
      id= 0x0
      seq= 0x0
 ###[ Raw ]### 
         load= 'test'
 
 >>> send(p)
 Traceback (most recent call last):
   File "<console>", line 1, in <module>
   File "/usr/pkg/lib/python3.7/site-packages/scapy/sendrecv.py", line 316, in send
     socket = socket or conf.L3socket(*args, **kargs)
   File "/usr/pkg/lib/python3.7/site-packages/scapy/supersocket.py", line 150, in __init__
     self.ins = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(type))  # noqa: E501
 AttributeError: module 'socket' has no attribute 'AF_PACKET'
 
 >  Separately...
 >  
 >  >I'd like to clarify the environment of the bug:
 >  >(1) I have no active Ethernet or SLIP interfaces;
 >  >(2) I have active Wi-Fi and tun interfaces.
 >  >
 >  >According to the "man 4 bpf": "A packet can be sent out on the network
 >  >by writing to a bpf file descriptor. The writes are unbuffered, meaning
 >  >only one packet can be processed per write. Currently, only writes to
 >  >Ethernets and SLIP links are supported."
 >  
 >  I think there may be a documentation issue or two there. That last
 >  statement is perhaps outdated (I haven't checked in detail), and refers
 >  to writes to a link layer which Wi-Fi devices also use. (Note your
 >  tcpdump output states your iwi0 device's "link-type" is "Ethernet".)
 >  
 >  From looking at Scapy commits, it seems NetBSD 8 was the release they
 >  developed against. So generally we should expect at minimum it's more
 >  likely to work on 8.x than newer releases.
 >  
 >  I don't use Scapy much; I was using bits of it before for specific
 >  purposes, but not most of its functionality, so issues with it haven't
 >  been a priority for me to chase. I think in this case some of this
 >  issue is better directed to the Scapy project. (I will look into the
 >  bpf documentation aspect.)
 >  
 >  Dave
 
 OK. I'll write to the Scapy project.
 
 
 --
 Alexei