pldm: hash transferred data instead of accumulating

We don't do anything with the incoming file data, so just hash instead,
and print out an info!() message with the transfer result.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>

Author: jk-ozlabs

Cargo.lock

@@ -9,7 +9,7 @@ categories = ["network-programming", "hardware-support"]
 
 [features]
 nvme-mi = ["dep:nvme-mi-dev"]
-pldm = ["dep:pldm", "dep:pldm-file", "dep:pldm-platform"]
+pldm = ["dep:hex", "dep:pldm", "dep:pldm-file", "dep:pldm-platform", "dep:sha2"]
 
 [dependencies]
 anyhow = "1.0.86"
@@ -22,6 +22,7 @@ embedded-io-adapters = { version = "0.6", features = [ "futures-03" ] }
 embedded-io-async = { version = "0.6" }
 futures = "0.3.31"
 futures-io = "0.3.30"
+hex = { version = "0.4.3", optional = true }
 log = "0.4.22"
 mctp = "0.2.0"
 mctp-estack = { git = "https://github.com/CodeConstruct/mctp-rs", rev = "851360ed19ef78f2e7672daa90900cb4f38ad0b6", package = "mctp-estack" }
@@ -30,6 +31,7 @@ polling = "3.7.4"
 pldm = { git = "https://github.com/CodeConstruct/mctp-rs", rev = "851360ed19ef78f2e7672daa90900cb4f38ad0b6", package = "pldm", optional = true }
 pldm-file = { git = "https://github.com/CodeConstruct/mctp-rs", rev = "851360ed19ef78f2e7672daa90900cb4f38ad0b6", package = "pldm-file", optional = true }
 pldm-platform = { git = "https://github.com/CodeConstruct/mctp-rs", rev = "851360ed19ef78f2e7672daa90900cb4f38ad0b6", package = "pldm-platform", optional = true }
+sha2 = {version = "0.10.9", optional = true }
 simplelog = "0.12.2"
 smol = "2.0.0"
 usbredirparser = { git = "https://github.com/CodeConstruct/usbredir-rs", branch = "main", package = "usbredirparser" }

Cargo.toml

@@ -2,6 +2,7 @@
 
 use anyhow::{bail, Context, Result};
 use log::{debug, info, warn};
+use sha2::{Digest, Sha256};
 
 use mctp_estack::{control::ControlEvent, router::Router};
 use pldm::{control::requester::negotiate_transfer_parameters, PldmError};
@@ -63,28 +64,30 @@ async fn pldm_file(
 
     debug!("Open: {fd:?}");
 
-    let mut buf = Vec::new();
+    let mut hash = Sha256::new();
     let req_len = size;
+    let mut cur_len = 0usize;
 
     debug!("Reading...");
     let res = df_read_with(chan, fd, 0, req_len, |part| {
-        debug!(
-            "  {} bytes, {}/{req_len}",
-            part.len(),
-            buf.len() + part.len()
-        );
-        if buf.len() + part.len() > req_len {
+        cur_len += part.len();
+        debug!("  {} bytes, {cur_len}/{req_len}", part.len());
+        if cur_len > req_len {
             warn!("  data overflow!");
             Err(PldmError::NoSpace)
         } else {
-            buf.extend_from_slice(part);
+            hash.update(part);
             Ok(())
         }
     })
     .await;
 
     debug!("Read: {res:?}");
 
+    let hex = hex::encode(hash.finalize());
+
+    info!("Transfer complete. {cur_len} bytes, sha256 {hex}");
+
     let attrs = DfCloseAttributes::empty();
     let res = df_close(chan, fd, attrs).await;