About

ofpstr is openflow stringer library and it converts string into openflow binary message, like ovs-ofctl flow rule arguments. It can also convert binary message back to string representation. The syntax is DIFFERENT from ovs-ofctl, using more direct naming as is defined in the spec. For example, ovs-ofctl use dl_vlan for vlan tagging, which is not present in openflow 1.3 spec. ofpstr use vlan_vid for this.

usage

There are two modes of oxm and ofp_mod_flow.

oxm example:

import ofpstr.oxm
# string to binary message
oxm_msg,parsed_len = ofpstr.oxm.str2oxm("in_port=1,vlan_vid=0x1,eth_type=0x0800")
# binary message to string
print(ofpstr.oxm.oxm2str(oxm_msg))

ofp_mod_flow example:

import ofpstr.ofp4
# string to binary message
ofp_flow_mod_msg = ofpstr.ofp4.str2mod("in_port=1,@apply,output=controller", xid=16)
# binary message to string
print(ofpstr.ofp4.mod2str(ofp_flow_mod_msg))
# in_port=1,@apply,output=controller

general syntax

Tokens are separated by comma, field may take argument with = separator. argument may have mask with “/” separator. Examples:

# integer mode
metadata=0x01/0x0F
tunnel_id=10
# mac mode
eth_dst=01:00:00:00:00:00/01:00:00:00:00:00
# ipv4 mode
ipv4_src=192.168.1.0/24
ipv4_src=192.168.1.0/255.255.255.0
# ipv6 mode
ipv6_src=::
# port mode may use special names or integer
in_port=controller
in_port=1
# pkt mode use two integer representing (namespace,ns_type)
packet_type=0:1
# hex mode use hex string (like binascii hex)
dot11_frame_ctrl=c000/ff00
# ssid mode use string directly
dot11_ssid=TestAP

Full oxm list follows:

• integer mode: metadata, eth_type, vlan_vid, vlan_pcp, ip_dscp, ip_ecn, ip_proto, tcp_src, tcp_dst, udp_src, udp_dst, sctp_src, sctp_dst, icmpv4_type, icmpv4_code, arp_op, ipv6_label, icmpv6_type, icmpv6_code, mpls_bale, mpls_tc, mpls_bos, pbb_isid, tunnel_id, ipv6_exthdr, pbb_uca, tcp_flags, nxm_in_port, nxm_eth_type, nxm_vlan_tci, nxm_ip_tos, nxm_ip_proto, nxm_tcp_src, nxm_tcp_dst, nxm_udp_src, nxm_udp_dst, nxm_icmp_type, nxm_icmp_code, nxm_arp_op, nxm_reg0, nxm_reg1, nxm_reg2, nxm_reg3, nxm_reg4, nxm_reg5, nxm_reg6, nxm_reg7, nxm_tun_id, nxm_icmpv6_type, nxm_icmpv6_code, nxm_ip_frag, nxm_ipv6_label, nxm_ip_ecn, nxm_ip_ttl, nxm_pkt_mark, nxm_tcp_flags, nxm_dp_hash, nxm_recirc_id, nxm_conj_id, nxm_tun_gbp_id, nxm_tun_gbp_flags, dot11, dot11_public_action, dot11_tag, radiotap_tsft, radiotap_flags, radiotap_lock_quality, radiotap_tx_attenuation, radiotap_db_tx_attenuation, radiotap_antenna, radiotap_db_antsignal, radiotap_db_antnoise, radiotap_rx_flags, radiotap_tx_flags, radiotap_rts_retries, radiotap_data_retries, radiotap_dbm_antsignal, radiotap_dbm_antnoise, radiotap_dbm_tx_power

• mac mode: eth_dst, eth_src, arp_sha, arp_tha, ipv6_nd_sll, ipv6_nd_tll, nxm_eth_dst, nxm_eth_src, nxm_arp_sha, nxm_arp_tha, nxm_nd_sll, nxm_nd_tll, dot11_addr1, dot11_addr2, dot11_addr3, dot11_addr4

• ipv4 mode: ipv4_src, ipv4_dst, arp_spa, arp_tpa, nxm_ip_src, nxm_ip_dst, nxm_arp_spa, nxm_arp_tpa, nxm_tun_ipv4_src, nxm_tun_ipv4_dst

• ipv6 mode: ipv6_src, ipv6_dst, ipv6_nd_target, nxm_ipv6_src, nxm_ipv6_dst, nxm_nd_target

• port mode: in_port, in_phy_port, actset_output

• pkt mode: packet_type

• hex mode: dot11_frame_ctrl, dot11_action_category, dot11_tag_vendor, radiotap_fhss

• ssid mode: dot11_ssid

• rate mode: radiotap_rate

• ch mode: radiotap_channel

• comp mode: radiotap_mcs, radiotap_ampdu_status

• vht mode: radiotap_vht

Actions may take arguments in function style. oxm with set_ prefix will be set_field action. Some nxm actions accepts only function style. Examples:

# alias for set_vlan_vid=10
set_vlan_vid(10)
# nicira extensions
cnt_ids(0x1,0x2,0x3)
reg_load(nxm_vlan_tci=0xa/0x0fff)
reg_load2(nxm_vlan_tci=0xa/0x0fff)
reg_move(nxm_eth_dst=nxm_eth_src)
reg_move(nxm_eth_dst[0:4]=nxm_eth_src[4:8])
resubmit(in_port)
resubmit(1)
resubmit_table(in_port,all)
resubmit_table(1,1)
set_tunnel(0x11223344)
set_tunnel64(0x1122334455667788)
pop_queue()
note(some text)
multipath(eth_src,50,hrw,12,0x0,nxm_reg0[0:4])
bundle(eth_src,50,active_backup,nxm_in_port,slaves(1,2,3))
bundle_load(symmetric_l4,60,hrw,nxm_in_port,nxm_reg0[0:16],slaves(2,3))
output_reg(in_port)
output_reg(in_port[0:1])
output_reg2(in_port)
output_reg2(in_port[0:1])
learn(nxm_in_port=0x10,nxm_eth_dst=nxm_eth_src,reg_load(nxm_reg1[16:32]=nxm_in_port))
exit()

• integer mode: output, set_mpls_ttl, push_vlan, pop_mpls, push_mpls, set_queue, group, set_nw_ttl, push_pbb,

• flag mode: copy_ttl_out, copy_ttl_in, dec_mpls_ttl, dec_nw_ttl, pop_pbb

Advanced features

In addition to OFPT_FLOW_MOD, several openflow methods are provided:

import ofpstr.ofp4

# OFPMP_FLOW
ofpstr.ofp4.text2mpflow
ofpstr.ofp4.mpflow2text

# OFPT_GROUP
ofpstr.ofp4.str2group
ofpstr.ofp4.group2str

# OFPMP_GROUP / OFPT_MULTIPART_*
ofpstr.ofp4.text2mpgroup
ofpstr.ofp4.mpgroup2text

# OFPMP_GROUP_DESC / OFPT_MULTIPART_*
ofpstr.ofp4.text2mpgroupdesc
ofpstr.ofp4.mpgroupdesc2text

Note these functions were rewritten in 0.2,

LICENSE

ofpstr is available under Apache 2.0 License and Python Software Foundation License.