From 743c38725f49318cf52f6e996d8611bcc9667be5 Mon Sep 17 00:00:00 2001
From: Hatter Jiang <jht5945@gmail.com>
Date: Fri, 6 Nov 2020 00:04:41 +0800
Subject: [PATCH] feat: add ip

---
 __network/ip/Cargo.lock |  5 +++
 __network/ip/Cargo.toml |  9 +++++
 __network/ip/src/lib.rs | 84 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+)
 create mode 100644 __network/ip/Cargo.lock
 create mode 100644 __network/ip/Cargo.toml
 create mode 100644 __network/ip/src/lib.rs

diff --git a/__network/ip/Cargo.lock b/__network/ip/Cargo.lock
new file mode 100644
index 0000000..187d085
--- /dev/null
+++ b/__network/ip/Cargo.lock
@@ -0,0 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "ip"
+version = "0.1.0"
diff --git a/__network/ip/Cargo.toml b/__network/ip/Cargo.toml
new file mode 100644
index 0000000..08073ba
--- /dev/null
+++ b/__network/ip/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "ip"
+version = "0.1.0"
+authors = ["Hatter Jiang <jht5945@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/__network/ip/src/lib.rs b/__network/ip/src/lib.rs
new file mode 100644
index 0000000..af34ee6
--- /dev/null
+++ b/__network/ip/src/lib.rs
@@ -0,0 +1,84 @@
+
+enum IpType {
+    ICMP = 0x01,
+    TCP = 0x06,
+    UDP = 0x11,
+}
+
+#[derive(Debug, Clone)]
+struct IpPackage {
+    version: u8, // 4bits
+    hlen: u8,    // 4bits,
+    type_of_service: u8, // 8bits
+    total_length: u16, // 16bits
+    identification: u16, // 16bits
+    flags: u8, // 4bits
+    fragment_offset: u16, // 12 bits
+    ttl: u8, // 8bits
+    protocol: u8, // 8bits
+    header_checksum: u16, // 16bits
+    source_ip_address: [u8; 4], // 32bits
+    destination_ip_address: [u8; 4], // 32bits
+    ip_options: [u8; 3], // 24bits
+    data: Vec<u8>,
+}
+
+impl  IpPackage {
+    fn parse(bytes: &[u8]) -> Result<Self, String> {
+        if bytes.len() < 24 {
+            return Err("Length < 24".to_owned());
+        }
+        let mut bytes_iter = bytes.iter();
+        let ver_hlen = bytes_iter.next().unwrap();
+        let version = (ver_hlen >> 4) & 0x0f as u8;
+        let hlen = ver_hlen & 0x0f as u8;
+        let type_of_service = *bytes_iter.next().unwrap();
+        let total_length_bytes = [*bytes_iter.next().unwrap(), *bytes_iter.next().unwrap()];
+        let total_length = u16::from_be_bytes(total_length_bytes);
+        let identification_bytes = [*bytes_iter.next().unwrap(), *bytes_iter.next().unwrap()];
+        let identification = u16::from_be_bytes(identification_bytes);
+        let tmp = *bytes_iter.next().unwrap();
+        let flags = (tmp >> 4) & 0x0f as u8;
+        let fragment_offset_bytes = [tmp & 0x0f, *bytes_iter.next().unwrap()];
+        let fragment_offset = u16::from_be_bytes(fragment_offset_bytes);
+        let ttl = *bytes_iter.next().unwrap();
+        let protocol = *bytes_iter.next().unwrap();
+        let header_checksum_bytes = [*bytes_iter.next().unwrap(), *bytes_iter.next().unwrap()];
+        let header_checksum = u16::from_be_bytes(header_checksum_bytes);
+        let source_ip_address = [
+            *bytes_iter.next().unwrap(), *bytes_iter.next().unwrap(),
+            *bytes_iter.next().unwrap(), *bytes_iter.next().unwrap()
+        ];
+        let destination_ip_address = [
+            *bytes_iter.next().unwrap(), *bytes_iter.next().unwrap(),
+            *bytes_iter.next().unwrap(), *bytes_iter.next().unwrap()
+        ];
+        let ip_options = [
+            *bytes_iter.next().unwrap(), *bytes_iter.next().unwrap(), *bytes_iter.next().unwrap()
+        ];
+        bytes_iter.next(); // padding
+        let data = bytes[24..].to_vec();
+
+        Ok(Self{
+            version, hlen, type_of_service, total_length,
+            identification, flags, fragment_offset, ttl, protocol,
+            header_checksum, source_ip_address, destination_ip_address, ip_options, data,
+        })
+    }
+}
+
+#[test]
+fn test_ip_package_parse() {
+    let icmp_ip_package = vec![
+        0x45, 0x00, 0x00, 0x54, 0x36, 0x55, 0x40, 0x00, 0x40, 0x01, 0x30, 0x6D, 0xC0, 0xA8,
+        0x03, 0x2F, 0x08, 0x08, 0x08, 0x08, 0x08, 0x00, 0x6C, 0x47, 0x08, 0xBF, 0x00, 0x01,
+        0xE8, 0x4D, 0xA3, 0x5F, 0x00, 0x00, 0x00, 0x00, 0x33, 0x78, 0x05, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B,
+        0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29,
+        0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37
+    ];
+
+    let package = IpPackage::parse(&icmp_ip_package).unwrap();
+    println!("{:#?}", package);
+    assert_eq!(0x04, package.version);
+}
\ No newline at end of file