Suricata

Hi,

packet retransmissions from client to server seem to be dropped by Suricata if client has previously sent a FIN packet to server. This could be why our FTP uploads get stuck when network load is high.

In our tests, we are uploading several thousands of 8 KB files from client (192.168.2.2) to server (192.168.3.3). You can see in the attached files a report with the packets of a stuck FTP-DATA connection as captured from the client and from the server. Also, I have attached the suricata debug output belonging to that connection.

Packet No. 43992 in the client-side capture was not received by the server. Client sent finally a FIN and several retransmissions of the lost packet latter, but Suricata might have dropped them because of its transition to CLOSE_WAIT state.

Suricata build info:

This is Suricata version 2.0 RELEASE
Features: DEBUG NFQ PCAP_SET_BUFF LIBPCAP_VERSION_MAJOR=1 AF_PACKET HAVE_PACKET_FANOUT LIBCAP_NG LIBNET1.1 HAVE_HTP_URI_NORMALIZE_HOOK PCRE_JIT 
SIMD support: none
Atomic intrisics: 1 2 4 8 byte(s)
64-bits, Little-endian architecture
GCC version 4.7.2, C version 199901
L1 cache line size (CLS)=64
compiled with LibHTP v0.5.10, linked against LibHTP v0.5.10
Suricata Configuration:
  AF_PACKET support:                       yes
  PF_RING support:                         no
  NFQueue support:                         yes
  IPFW support:                            no
  DAG enabled:                             no
  Napatech enabled:                        no
  Unix socket enabled:                     no
  Detection enabled:                       yes

  libnss support:                          no
  libnspr support:                         no
  libjansson support:                      no
  Prelude support:                         no
  PCRE jit:                                yes
  libluajit:                               no
  libgeoip:                                no
  Non-bundled htp:                         no
  Old barnyard2 support:                   no
  CUDA enabled:                            no

  Suricatasc install:                      yes

  Unit tests enabled:                      no
  Debug output enabled:                    yes
  Debug validation enabled:                no
  Profiling enabled:                       no
  Profiling locks enabled:                 no
  Coccinelle / spatch:                     no

Generic build parameters:
  Installation prefix (--prefix):          /opt/suricata-2.0debug
  Configuration directory (--sysconfdir):  /etc/suricata/
  Log directory (--localstatedir) :        /var/local/suricata-2.0debug/log/suricata/

  Host:                                    x86_64-unknown-linux-gnu
  GCC binary:                              gcc
  GCC Protect enabled:                     no
  GCC march native enabled:                no
  GCC Profile enabled:                     no