packet_rs/parser/
fast.rs

1use crate::headers::*;
2use crate::types::*;
3use crate::PacketSlice;
4
5pub fn parse<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
6    let length: u16 = ((arr[12] as u16) << 8) | arr[13] as u16;
7    if length < 1500 {
8        parse_dot3(arr)
9    } else {
10        parse_ethernet(arr)
11    }
12}
13pub fn parse_dot3<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
14    let dot3 = Dot3Slice::from(&arr[0..Dot3::size()]);
15    let mut pkt = parse_llc(&arr[Dot3::size()..]);
16    pkt.insert(dot3);
17    pkt
18}
19pub fn parse_llc<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
20    let llc = LLCSlice::from(&arr[0..LLC::size()]);
21    let mut pkt = if arr[0] == 0xAA && arr[1] == 0xAA && arr[2] == 0x03 {
22        parse_snap(&arr[LLC::size()..])
23    } else {
24        accept(&arr[LLC::size()..])
25    };
26    pkt.insert(llc);
27    pkt
28}
29pub fn parse_snap<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
30    let snap = SNAPSlice::from(&arr[0..SNAP::size()]);
31    let mut pkt = accept(&arr[SNAP::size()..]);
32    pkt.insert(snap);
33    pkt
34}
35pub fn parse_ethernet<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
36    let eth = EtherSlice::from(&arr[0..Ether::size()]);
37    let etype = EtherType::try_from(eth.etype() as u16);
38    let mut pkt = match etype {
39        Ok(EtherType::DOT1Q) => parse_vlan(&arr[Ether::size()..]),
40        Ok(EtherType::ARP) => parse_arp(&arr[Ether::size()..]),
41        Ok(EtherType::IPV4) => parse_ipv4(&arr[Ether::size()..]),
42        Ok(EtherType::IPV6) => parse_ipv6(&arr[Ether::size()..]),
43        Ok(EtherType::MPLS) => parse_mpls(&arr[Ether::size()..]),
44        _ => accept(&arr[Ether::size()..]),
45    };
46    pkt.insert(eth);
47    pkt
48}
49pub fn parse_vlan<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
50    let vlan = VlanSlice::from(&arr[0..Vlan::size()]);
51    let etype = EtherType::try_from(vlan.etype() as u16);
52    let mut pkt = match etype {
53        Ok(EtherType::DOT1Q) => parse_vlan(&arr[Vlan::size()..]),
54        Ok(EtherType::ARP) => parse_arp(&arr[Vlan::size()..]),
55        Ok(EtherType::IPV4) => parse_ipv4(&arr[Vlan::size()..]),
56        Ok(EtherType::IPV6) => parse_ipv6(&arr[Vlan::size()..]),
57        Ok(EtherType::MPLS) => parse_mpls(&arr[Vlan::size()..]),
58        _ => accept(&arr[Vlan::size()..]),
59    };
60    pkt.insert(vlan);
61    pkt
62}
63pub fn parse_mpls<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
64    let mpls = MPLSSlice::from(&arr[0..MPLS::size()]);
65    let bos = mpls.bos();
66    let mut pkt = if bos == 1 {
67        parse_mpls_bos(&arr[MPLS::size()..])
68    } else {
69        parse_mpls(&arr[MPLS::size()..])
70    };
71    pkt.insert(mpls);
72    pkt
73}
74pub fn parse_mpls_bos<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
75    let mpls = MPLSSlice::from(&arr[0..MPLS::size()]);
76    let mut pkt = match IpType::try_from(arr[MPLS::size()] >> 4 & 0xf) {
77        Ok(IpType::V4) => parse_ipv4(&arr[MPLS::size()..]),
78        Ok(IpType::V6) => parse_ipv6(&arr[MPLS::size()..]),
79        _ => parse_ethernet(&arr[MPLS::size()..]),
80    };
81    pkt.insert(mpls);
82    pkt
83}
84pub fn parse_ipv4<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
85    let ipv4 = IPv4Slice::from(&arr[0..IPv4::size()]);
86    let proto = IpProtocol::try_from(ipv4.protocol() as u8);
87    let mut pkt = match proto {
88        Ok(IpProtocol::ICMP) => parse_icmp(&arr[IPv4::size()..]),
89        Ok(IpProtocol::IPIP) => parse_ipv4(&arr[IPv4::size()..]),
90        Ok(IpProtocol::TCP) => parse_tcp(&arr[IPv4::size()..]),
91        Ok(IpProtocol::UDP) => parse_udp(&arr[IPv4::size()..]),
92        Ok(IpProtocol::IPV6) => parse_ipv6(&arr[IPv4::size()..]),
93        Ok(IpProtocol::GRE) => parse_gre(&arr[IPv4::size()..]),
94        _ => accept(&arr[IPv4::size()..]),
95    };
96    pkt.insert(ipv4);
97    pkt
98}
99pub fn parse_ipv6<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
100    let ipv6 = IPv6Slice::from(&arr[0..IPv6::size()]);
101    let next_hdr = IpProtocol::try_from(ipv6.next_hdr() as u8);
102    let mut pkt = match next_hdr {
103        Ok(IpProtocol::ICMPV6) => parse_icmp(&arr[IPv6::size()..]),
104        Ok(IpProtocol::IPIP) => parse_ipv4(&arr[IPv6::size()..]),
105        Ok(IpProtocol::TCP) => parse_tcp(&arr[IPv6::size()..]),
106        Ok(IpProtocol::UDP) => parse_udp(&arr[IPv6::size()..]),
107        Ok(IpProtocol::IPV6) => parse_ipv6(&arr[IPv6::size()..]),
108        Ok(IpProtocol::GRE) => parse_gre(&arr[IPv6::size()..]),
109        _ => accept(&arr[IPv6::size()..]),
110    };
111    pkt.insert(ipv6);
112    pkt
113}
114pub fn parse_gre<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
115    let gre = GRESlice::from(&arr[0..GRE::size()]);
116    let proto = EtherType::try_from(gre.proto() as u16);
117    let chksum_present = gre.chksum_present();
118    let seqnum_present = gre.seqnum_present();
119    let key_present = gre.key_present();
120    let mut offset = 0;
121    offset += GRE::size();
122    let gco = if chksum_present == 1 {
123        let p = Some(GREChksumOffsetSlice::from(
124            &arr[offset..offset + GREChksumOffset::size()],
125        ));
126        offset += GREChksumOffset::size();
127        p
128    } else {
129        None
130    };
131    let gk = if key_present == 1 {
132        let p = Some(GREKeySlice::from(&arr[offset..offset + GREKey::size()]));
133        offset += GREKey::size();
134        p
135    } else {
136        None
137    };
138    let gsn = if seqnum_present == 1 {
139        let p = Some(GRESequenceNumSlice::from(
140            &arr[offset..offset + GRESequenceNum::size()],
141        ));
142        offset += GRESequenceNum::size();
143        p
144    } else {
145        None
146    };
147    let mut pkt = match proto {
148        Ok(EtherType::IPV4) => parse_ipv4(&arr[offset..]),
149        Ok(EtherType::IPV6) => parse_ipv6(&arr[offset..]),
150        Ok(EtherType::ERSPANII) => parse_erspan2(&arr[offset..]),
151        Ok(EtherType::ERSPANIII) => parse_erspan3(&arr[offset..]),
152        _ => accept(&arr[offset..]),
153    };
154    if let Some(p) = gco {
155        pkt.insert(p);
156    }
157    if let Some(p) = gk {
158        pkt.insert(p);
159    }
160    if let Some(p) = gsn {
161        pkt.insert(p);
162    }
163    pkt.insert(gre);
164    pkt
165}
166pub fn parse_erspan2<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
167    let erspan2 = ERSPAN2Slice::from(&arr[0..ERSPAN2::size()]);
168    let mut pkt = parse_ethernet(&arr[ERSPAN2::size()..]);
169    pkt.insert(erspan2);
170    pkt
171}
172pub fn parse_erspan3<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
173    let erspan3 = ERSPAN3Slice::from(&arr[0..ERSPAN3::size()]);
174    let o = erspan3.o();
175    let mut offset = 0;
176    offset += ERSPAN3::size();
177    let platform = if o == 1 {
178        let p = Some(ERSPANPLATFORMSlice::from(
179            &arr[offset..offset + ERSPANPLATFORM::size()],
180        ));
181        offset += ERSPANPLATFORM::size();
182        p
183    } else {
184        None
185    };
186    let mut pkt = parse_ethernet(&arr[offset..]);
187    if let Some(p) = platform {
188        pkt.insert(p);
189    }
190    pkt.insert(erspan3);
191    pkt
192}
193pub fn parse_arp<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
194    let mut pkt = accept(&arr[ARP::size()..]);
195    pkt.insert(ARPSlice::from(&arr[0..ARP::size()]));
196    pkt
197}
198pub fn parse_icmp<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
199    let mut pkt = accept(&arr[ICMP::size()..]);
200    pkt.insert(ICMPSlice::from(&arr[0..ICMP::size()]));
201    pkt
202}
203pub fn parse_tcp<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
204    let mut pkt = accept(&arr[TCP::size()..]);
205    pkt.insert(TCPSlice::from(&arr[0..TCP::size()]));
206    pkt
207}
208pub fn parse_udp<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
209    let udp = UDPSlice::from(&arr[0..UDP::size()]);
210    let dst = udp.dst() as u16;
211    let mut pkt = match dst {
212        UDP_PORT_VXLAN => parse_vxlan(&arr[UDP::size()..]),
213        _ => accept(&arr[UDP::size()..]),
214    };
215    pkt.insert(udp);
216    pkt
217}
218pub fn parse_vxlan<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
219    let mut pkt = parse_ethernet(&arr[Vxlan::size()..]);
220    pkt.insert(VxlanSlice::from(&arr[0..Vxlan::size()]));
221    pkt
222}
223fn accept<'a>(arr: &'a [u8]) -> PacketSlice<'a> {
224    let mut pkt = PacketSlice::new();
225    pkt.set_payload(arr);
226    pkt
227}