tlv_tool: Add hexstring option.

tools/tlv_tool/Cargo.toml

@@ -10,3 +10,4 @@ matter-iot = { path = "../../matter" }
 log = {version = "0.4.14", features = ["max_level_trace", "release_max_level_warn"]}
 simple_logger = "1.16.0"
 clap = "2.34"
+hex = "0.4"

tools/tlv_tool/README.md

@@ -5,6 +5,9 @@ A simple tool for printing Matter TLVs or Matter-encoded certificates.
 $ # For printing a Matter TLV List
 $ tlv_tool --hex "15, 24, 0, 1, 18"
 
+$ # For printing a Matter TLV List in hexstring
+$ tlv_tool --hexstring "1524000118"
+
 $ # For printing a Matter encoded certificate
 $ tlv_tool --cert "0x15, 0x00"
 ```

tools/tlv_tool/src/main.rs

@@ -21,6 +21,41 @@ use matter::tlv;
 use simple_logger::SimpleLogger;
 use std::process;
 
+fn decode_to_slice_radix<T: AsRef<str>>(data: T, out: &mut [u8], radix: u32) -> &[u8] {
+    let data = data.as_ref();
+
+    let list = data.split(',');
+    let mut index = 0;
+    for byte in list {
+        let byte = byte.strip_prefix("0x").unwrap_or(byte);
+        if let Ok(b) = u8::from_str_radix(byte, radix) {
+            out[index] = b;
+            index += 1;
+        } else {
+            eprintln!("Skipping unknown byte: {}", byte);
+        }
+        if index >= out.len() {
+            eprintln!("Input too long");
+            process::exit(1);
+        }
+    }
+    &out[..index]
+}
+
+fn print_tlv(matches: &clap::ArgMatches<'_>, tlv_list: &[u8]) {
+    if matches.is_present("cert") {
+        let cert = cert::Cert::new(tlv_list).unwrap();
+        println!("{}", cert);
+    } else if matches.is_present("as-asn1") {
+        let mut asn1_cert = [0_u8; 1024];
+        let cert = cert::Cert::new(tlv_list).unwrap();
+        let len = cert.as_asn1(&mut asn1_cert).unwrap();
+        println!("{:02x?}", &asn1_cert[..len]);
+    } else {
+        tlv::print_tlv_list(tlv_list);
+    }
+}
+
 fn main() {
     SimpleLogger::new()
         .with_level(log::LevelFilter::Trace)
@@ -42,6 +77,12 @@ fn main() {
                 .long("dec")
                 .help("The input is in Decimal"),
         )
+        .arg(
+            Arg::with_name("hexstring")
+                .short("H")
+                .long("hexstring")
+                .help("The input is in Hexadecimal String"),
+        )
         .arg(
             Arg::with_name("cert")
                 .long("cert")
@@ -55,14 +96,12 @@ fn main() {
         .arg(Arg::with_name("tlvs").help("List of TLVs").required(true))
         .get_matches();
 
-    // Assume hexadecimal by-default
-    let base = if m.is_present("hex") {
-        16
-    } else if m.is_present("dec") {
-        10
-    } else {
-        16
-    };
+    if m.is_present("hex") || m.is_present("dec") {
+        if m.is_present("hexstring") {
+            eprintln!("Cannot use --hexstring with --hex or --dec");
+            process::exit(1);
+        }
+    }
 
     let list: String = m
         .value_of("tlvs")
@@ -70,33 +109,24 @@ fn main() {
         .chars()
         .filter(|c| !c.is_whitespace())
         .collect();
-    let list = list.split(',');
-    let mut tlv_list: [u8; 1024] = [0; 1024];
-    let mut index = 0;
-    for byte in list {
-        let byte = byte.strip_prefix("0x").unwrap_or(byte);
-        if let Ok(b) = u8::from_str_radix(byte, base) {
-            tlv_list[index] = b;
-            index += 1;
-        } else {
-            eprintln!("Skipping unknown byte: {}", byte);
-        }
-        if index >= 1024 {
-            eprintln!("Input too long");
-            process::exit(1);
-        }
-    }
 
-    //    println!("Decoding: {:x?}", &tlv_list[..index]);
-    if m.is_present("cert") {
-        let cert = cert::Cert::new(&tlv_list[..index]).unwrap();
-        println!("{}", cert);
-    } else if m.is_present("as-asn1") {
-        let mut asn1_cert = [0_u8; 1024];
-        let cert = cert::Cert::new(&tlv_list[..index]).unwrap();
-        let len = cert.as_asn1(&mut asn1_cert).unwrap();
-        println!("{:02x?}", &asn1_cert[..len]);
+    if m.is_present("hexstring") {
+        let tlv_list = hex::decode(list).unwrap();
+        print_tlv(&m, &tlv_list);
     } else {
-        tlv::print_tlv_list(&tlv_list[..index]);
+        // Assume hexadecimal by-default
+        let base = if m.is_present("hex") {
+            16
+        } else if m.is_present("dec") {
+            10
+        } else {
+            16
+        };
+
+        let mut tlv_list: [u8; 1024] = [0; 1024];
+        let tlv_list = decode_to_slice_radix(list, &mut tlv_list, base);
+
+        //    println!("Decoding: {:x?}", &tlv_list[..index]);
+        print_tlv(&m, tlv_list);
     }
 }