Sreeju Sreedhar | e3fefd9 | 2019-04-02 15:57:15 -0700 | [diff] [blame^] | 1 | |
| 2 | # Copyright 2017-present Open Networking Foundation |
| 3 | # |
| 4 | # Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | # you may not use this file except in compliance with the License. |
| 6 | # You may obtain a copy of the License at |
| 7 | # |
| 8 | # http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | # |
| 10 | # Unless required by applicable law or agreed to in writing, software |
| 11 | # distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | # See the License for the specific language governing permissions and |
| 14 | # limitations under the License. |
| 15 | |
| 16 | |
| 17 | """ |
| 18 | Utility parsing functions |
| 19 | """ |
| 20 | |
| 21 | import sys |
| 22 | import socket |
| 23 | import packet as scapy |
| 24 | |
| 25 | def parse_mac(mac_str): |
| 26 | """ |
| 27 | Parse a MAC address |
| 28 | |
| 29 | Parse a MAC address ':' separated string of hex digits to an |
| 30 | array of integer values. '00:d0:05:5d:24:00' => [0, 208, 5, 93, 36, 0] |
| 31 | @param mac_str The string to convert |
| 32 | @return Array of 6 integer values |
| 33 | """ |
| 34 | return map(lambda val: int(val, 16), mac_str.split(":")) |
| 35 | |
| 36 | def parse_ip(ip_str): |
| 37 | """ |
| 38 | Parse an IP address |
| 39 | |
| 40 | Parse an IP address '.' separated string of decimal digits to an |
| 41 | host ordered integer. '172.24.74.77' => |
| 42 | @param ip_str The string to convert |
| 43 | @return Integer value |
| 44 | """ |
| 45 | array = map(lambda val: int(val), ip_str.split(".")) |
| 46 | val = 0 |
| 47 | for a in array: |
| 48 | val <<= 8 |
| 49 | val += a |
| 50 | return val |
| 51 | |
| 52 | def parse_ipv6(ip_str): |
| 53 | """ |
| 54 | Parse an IPv6 address |
| 55 | |
| 56 | Parse a textual IPv6 address and return a 16 byte binary string. |
| 57 | """ |
| 58 | return socket.inet_pton(socket.AF_INET6, ip_str) |
| 59 | |
| 60 | def packet_type_classify(ether): |
| 61 | try: |
| 62 | dot1q = ether[scapy.Dot1Q] |
| 63 | except: |
| 64 | dot1q = None |
| 65 | |
| 66 | try: |
| 67 | ip = ether[scapy.IP] |
| 68 | except: |
| 69 | ip = None |
| 70 | |
| 71 | try: |
| 72 | tcp = ether[scapy.TCP] |
| 73 | except: |
| 74 | tcp = None |
| 75 | |
| 76 | try: |
| 77 | udp = ether[scapy.UDP] |
| 78 | except: |
| 79 | udp = None |
| 80 | |
| 81 | try: |
| 82 | icmp = ether[scapy.ICMP] |
| 83 | except: |
| 84 | icmp = None |
| 85 | |
| 86 | try: |
| 87 | arp = ether[scapy.ARP] |
| 88 | except: |
| 89 | arp = None |
| 90 | return (dot1q, ip, tcp, udp, icmp, arp) |
| 91 | |
| 92 | def packet_to_flow_match(packet): |
| 93 | """ |
| 94 | Create a flow match that matches packet with the given wildcards |
| 95 | |
| 96 | @param packet The packet to use as a flow template |
| 97 | @return An loxi.of10.match object |
| 98 | |
| 99 | @todo check min length of packet |
| 100 | """ |
| 101 | import ofp |
| 102 | if ofp.OFP_VERSION == 1: |
| 103 | return packet_to_flow_match_v1(packet) |
| 104 | elif ofp.OFP_VERSION == 3: |
| 105 | return packet_to_flow_match_v3(packet) |
| 106 | elif ofp.OFP_VERSION == 4: |
| 107 | return packet_to_flow_match_v4(packet) |
| 108 | elif ofp.OFP_VERSION == 5: |
| 109 | return packet_to_flow_match_v5(packet) |
| 110 | else: |
| 111 | raise NotImplementedError() |
| 112 | |
| 113 | def packet_to_flow_match_v1(packet): |
| 114 | """ |
| 115 | OpenFlow 1.0 implementation of packet_to_flow_match |
| 116 | """ |
| 117 | import loxi.of10 as ofp |
| 118 | |
| 119 | if type(packet) == type(""): |
| 120 | ether = scapy.Ether(packet) |
| 121 | else: |
| 122 | ether = packet |
| 123 | |
| 124 | # For now, assume ether IP packet and ignore wildcards |
| 125 | try: |
| 126 | (dot1q, ip, tcp, udp, icmp, arp) = packet_type_classify(ether) |
| 127 | except: |
| 128 | raise ValueError("could not classify packet") |
| 129 | |
| 130 | match = ofp.match() |
| 131 | match.wildcards = ofp.OFPFW_ALL |
| 132 | #@todo Check if packet is other than L2 format |
| 133 | match.eth_dst = parse_mac(ether.dst) |
| 134 | match.wildcards &= ~ofp.OFPFW_DL_DST |
| 135 | match.eth_src = parse_mac(ether.src) |
| 136 | match.wildcards &= ~ofp.OFPFW_DL_SRC |
| 137 | match.eth_type = ether.type |
| 138 | match.wildcards &= ~ofp.OFPFW_DL_TYPE |
| 139 | |
| 140 | if dot1q: |
| 141 | match.vlan_vid = dot1q.vlan |
| 142 | match.vlan_pcp = dot1q.prio |
| 143 | match.eth_type = dot1q.type |
| 144 | else: |
| 145 | match.vlan_vid = ofp.OFP_VLAN_NONE |
| 146 | match.vlan_pcp = 0 |
| 147 | match.wildcards &= ~ofp.OFPFW_DL_VLAN |
| 148 | match.wildcards &= ~ofp.OFPFW_DL_VLAN_PCP |
| 149 | |
| 150 | if ip: |
| 151 | match.ipv4_src = parse_ip(ip.src) |
| 152 | match.wildcards &= ~ofp.OFPFW_NW_SRC_MASK |
| 153 | match.ipv4_dst = parse_ip(ip.dst) |
| 154 | match.wildcards &= ~ofp.OFPFW_NW_DST_MASK |
| 155 | match.ip_dscp = ip.tos |
| 156 | match.wildcards &= ~ofp.OFPFW_NW_TOS |
| 157 | |
| 158 | if tcp: |
| 159 | match.ip_proto = 6 |
| 160 | match.wildcards &= ~ofp.OFPFW_NW_PROTO |
| 161 | elif not tcp and udp: |
| 162 | tcp = udp |
| 163 | match.ip_proto = 17 |
| 164 | match.wildcards &= ~ofp.OFPFW_NW_PROTO |
| 165 | |
| 166 | if tcp: |
| 167 | match.tcp_src = tcp.sport |
| 168 | match.wildcards &= ~ofp.OFPFW_TP_SRC |
| 169 | match.tcp_dst = tcp.dport |
| 170 | match.wildcards &= ~ofp.OFPFW_TP_DST |
| 171 | |
| 172 | if icmp: |
| 173 | match.ip_proto = 1 |
| 174 | match.tcp_src = icmp.type |
| 175 | match.tcp_dst = icmp.code |
| 176 | match.wildcards &= ~ofp.OFPFW_NW_PROTO |
| 177 | |
| 178 | if arp: |
| 179 | match.ip_proto = arp.op |
| 180 | match.wildcards &= ~ofp.OFPFW_NW_PROTO |
| 181 | match.ipv4_src = parse_ip(arp.psrc) |
| 182 | match.wildcards &= ~ofp.OFPFW_NW_SRC_MASK |
| 183 | match.ipv4_dst = parse_ip(arp.pdst) |
| 184 | match.wildcards &= ~ofp.OFPFW_NW_DST_MASK |
| 185 | |
| 186 | return match |
| 187 | |
| 188 | def packet_to_flow_match_v3(packet): |
| 189 | """ |
| 190 | OpenFlow 1.2 implementation of packet_to_flow_match |
| 191 | """ |
| 192 | import loxi.of12 as ofp |
| 193 | return packet_to_flow_match_oxm(packet, ofp) |
| 194 | |
| 195 | def packet_to_flow_match_v4(packet): |
| 196 | """ |
| 197 | OpenFlow 1.3 implementation of packet_to_flow_match |
| 198 | """ |
| 199 | import loxi.of13 as ofp |
| 200 | return packet_to_flow_match_oxm(packet, ofp) |
| 201 | |
| 202 | def packet_to_flow_match_v5(packet): |
| 203 | """ |
| 204 | OpenFlow 1.3 implementation of packet_to_flow_match |
| 205 | """ |
| 206 | import loxi.of14 as ofp |
| 207 | return packet_to_flow_match_oxm(packet, ofp) |
| 208 | |
| 209 | def packet_to_flow_match_oxm(packet, ofp): |
| 210 | def parse_ether_layer(layer, match): |
| 211 | assert(type(layer) == scapy.Ether) |
| 212 | match.oxm_list.append(ofp.oxm.eth_dst(parse_mac(layer.dst))) |
| 213 | match.oxm_list.append(ofp.oxm.eth_src(parse_mac(layer.src))) |
| 214 | |
| 215 | if type(layer.payload) == scapy.Dot1Q: |
| 216 | layer = layer.payload |
| 217 | match.oxm_list.append(ofp.oxm.eth_type(layer.type)) |
| 218 | match.oxm_list.append(ofp.oxm.vlan_vid(ofp.OFPVID_PRESENT|layer.vlan)) |
| 219 | match.oxm_list.append(ofp.oxm.vlan_pcp(layer.prio)) |
| 220 | else: |
| 221 | match.oxm_list.append(ofp.oxm.eth_type(layer.type)) |
| 222 | match.oxm_list.append(ofp.oxm.vlan_vid(ofp.OFP_VLAN_NONE)) |
| 223 | |
| 224 | if type(layer.payload) == scapy.IP: |
| 225 | parse_ipv4_layer(layer.payload, match) |
| 226 | elif type(layer.payload) == scapy.IPv6: |
| 227 | parse_ipv6_layer(layer.payload, match) |
| 228 | elif type(layer.payload) == scapy.ARP: |
| 229 | parse_arp_layer(layer.payload, match) |
| 230 | # TODO MPLS |
| 231 | |
| 232 | def parse_ipv4_layer(layer, match): |
| 233 | assert(type(layer) == scapy.IP) |
| 234 | match.oxm_list.append(ofp.oxm.ip_proto(layer.proto)) |
| 235 | match.oxm_list.append(ofp.oxm.ip_dscp(layer.tos >> 2)) |
| 236 | match.oxm_list.append(ofp.oxm.ip_ecn(layer.tos & 3)) |
| 237 | match.oxm_list.append(ofp.oxm.ipv4_src(parse_ip(layer.src))) |
| 238 | match.oxm_list.append(ofp.oxm.ipv4_dst(parse_ip(layer.dst))) |
| 239 | |
| 240 | if type(layer.payload) == scapy.TCP: |
| 241 | parse_tcp_layer(layer.payload, match) |
| 242 | elif type(layer.payload) == scapy.UDP: |
| 243 | parse_udp_layer(layer.payload, match) |
| 244 | elif type(layer.payload) == scapy.ICMP: |
| 245 | parse_icmpv4_layer(layer.payload, match) |
| 246 | # TODO SCTP |
| 247 | |
| 248 | def parse_tcp_layer(layer, match): |
| 249 | assert(type(layer) == scapy.TCP) |
| 250 | match.oxm_list.append(ofp.oxm.tcp_src(layer.sport)) |
| 251 | match.oxm_list.append(ofp.oxm.tcp_dst(layer.dport)) |
| 252 | |
| 253 | def parse_udp_layer(layer, match): |
| 254 | assert(type(layer) == scapy.UDP) |
| 255 | match.oxm_list.append(ofp.oxm.udp_src(layer.sport)) |
| 256 | match.oxm_list.append(ofp.oxm.udp_dst(layer.dport)) |
| 257 | |
| 258 | def parse_icmpv4_layer(layer, match): |
| 259 | assert(type(layer) == scapy.ICMP) |
| 260 | match.oxm_list.append(ofp.oxm.icmpv4_type(layer.type)) |
| 261 | match.oxm_list.append(ofp.oxm.icmpv4_code(layer.code)) |
| 262 | |
| 263 | def parse_arp_layer(layer, match): |
| 264 | assert(type(layer) == scapy.ARP) |
| 265 | match.oxm_list.append(ofp.oxm.arp_op(layer.op)) |
| 266 | match.oxm_list.append(ofp.oxm.arp_spa(parse_ip(layer.psrc))) |
| 267 | match.oxm_list.append(ofp.oxm.arp_tpa(parse_ip(layer.pdst))) |
| 268 | match.oxm_list.append(ofp.oxm.arp_sha(parse_mac(layer.hwsrc))) |
| 269 | match.oxm_list.append(ofp.oxm.arp_tha(parse_mac(layer.hwdst))) |
| 270 | |
| 271 | def parse_ipv6_layer(layer, match): |
| 272 | assert(type(layer) == scapy.IPv6) |
| 273 | # TODO handle chained headers |
| 274 | match.oxm_list.append(ofp.oxm.ip_proto(layer.nh)) |
| 275 | match.oxm_list.append(ofp.oxm.ip_dscp(layer.tc >> 2)) |
| 276 | match.oxm_list.append(ofp.oxm.ip_ecn(layer.tc & 3)) |
| 277 | match.oxm_list.append(ofp.oxm.ipv6_src(parse_ipv6(layer.src))) |
| 278 | match.oxm_list.append(ofp.oxm.ipv6_dst(parse_ipv6(layer.dst))) |
| 279 | match.oxm_list.append(ofp.oxm.ipv6_flabel(layer.fl)) |
| 280 | |
| 281 | if type(layer.payload) == scapy.TCP: |
| 282 | parse_tcp_layer(layer.payload, match) |
| 283 | elif type(layer.payload) == scapy.UDP: |
| 284 | parse_udp_layer(layer.payload, match) |
| 285 | elif layer.nh == 0x3a: |
| 286 | parse_icmpv6_layer(layer.payload, match) |
| 287 | # TODO ND |
| 288 | # TODO SCTP |
| 289 | |
| 290 | def parse_icmpv6_layer(layer, match): |
| 291 | match.oxm_list.append(ofp.oxm.icmpv6_type(layer.type)) |
| 292 | match.oxm_list.append(ofp.oxm.icmpv6_code(layer.code)) |
| 293 | |
| 294 | if type(packet) == type(""): |
| 295 | ether = scapy.Ether(packet) |
| 296 | else: |
| 297 | ether = packet |
| 298 | |
| 299 | match = ofp.match() |
| 300 | parse_ether_layer(packet, match) |
| 301 | return match |