bastion: serve full-driver iPXE for UEFI x86_64, replace stale PV binaries

snponly.efi rides the firmware's NII/UNDI stack, and on some NICs that
stack cannot receive unicast frames: DHCP (broadcast) succeeds, then every
ARP reply is lost and the boot.ipxe HTTP fetch times out. Observed on
thebeast's onboard NIC 2026-10-19 -- tcpdump on labmaster showed it
answering every ARP request within microseconds while iPXE re-asked for
ten seconds and gave up. The full build probes native NIC drivers first
and falls back to snp/nii, so hardware that worked before is unaffected.

The data dir is a persistent volume, so copy-if-missing would have kept
serving the old snponly binary forever; image-shipped binaries now replace
on content change (copyIfChanged).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DceLLgGmyS7zTGLaLNjQBd

bastion/Dockerfile.bastion

@@ -35,7 +35,7 @@ FROM --platform=$BUILDPLATFORM fedora:43 AS ipxe-builder
 
 RUN dnf install -y git gcc make perl-interpreter xz-devel gcc-aarch64-linux-gnu && dnf clean all
 RUN git clone --depth=1 https://github.com/ipxe/ipxe.git /tmp/ipxe
-RUN cd /tmp/ipxe/src && make bin-x86_64-efi/snp.efi && \
+RUN cd /tmp/ipxe/src && make bin-x86_64-efi/snp.efi bin-x86_64-efi/ipxe.efi && \
     make CROSS_COMPILE=aarch64-linux-gnu- bin-arm64-efi/snp.efi
 
 # ── Stage 2: Production runtime (Fedora -- needs dnsmasq) ───────
@@ -58,6 +58,15 @@ RUN dnf install -y \
 # boot from CD-ROM/USB -- it requires PXE chainloading)
 COPY --from=ipxe-builder /tmp/ipxe/src/bin-x86_64-efi/snp.efi /usr/share/ipxe/ipxe-snp-x86_64.efi
 COPY --from=ipxe-builder /tmp/ipxe/src/bin-arm64-efi/snp.efi /usr/share/ipxe/arm64-efi/ipxe-snp.efi
+# Full iPXE build (native NIC drivers + snp + nii fallback), served as the
+# default UEFI x86_64 PXE binary. snponly rides the firmware's NII/UNDI stack,
+# and on some NICs that stack cannot RECEIVE UNICAST frames: DHCP (broadcast)
+# works, then every ARP reply is lost and HTTP times out. Observed on
+# thebeast's onboard NIC 2026-10-19 (tcpdump: labmaster answered every ARP
+# request within microseconds, iPXE kept re-asking). A native driver bypasses
+# the firmware stack entirely; NICs without one still fall back to snp/nii,
+# so machines that worked before are unaffected.
+COPY --from=ipxe-builder /tmp/ipxe/src/bin-x86_64-efi/ipxe.efi /usr/share/ipxe/ipxe-full-x86_64.efi
 
 # Install pnpm
 RUN npm install -g pnpm@9

bastion/src/bastion/src/main.ts

@@ -16,16 +16,19 @@ import { BastionConnection } from "./services/labd-connection.js";
 import { progressBus } from "./services/progress-events.js";
 import { ensureBootIso } from "./routes/boot-iso.js";
 
-function copyIfMissing(src: string, dest: string, label: string): void {
+// For binaries that ship WITH the image: the data dir is a persistent volume,
-  if (existsSync(dest)) {
+// so a copy-if-missing would keep serving whatever build landed there first,
-    logger.info(`  ${label} -- cached`);
+// forever, across image upgrades. Compare content and replace on change.
-    return;
+function copyIfChanged(src: string, dest: string, label: string): void {
-  }
   if (!existsSync(src)) {
     throw new Error(`${label}: source not found at ${src}`);
   }
+  if (existsSync(dest) && readFileSync(dest).equals(readFileSync(src))) {
+    logger.info(`  ${label} -- up to date`);
+    return;
+  }
   copyFileSync(src, dest);
-  logger.info(`  ${label} -- copied from ${src}`);
+  logger.info(`  ${label} -- installed from ${src}`);
 }
 
 function download(url: string, dest: string, label: string): void {
@@ -254,18 +257,21 @@ export async function startBastion(overrides: Partial<BastionConfig> = {}): Prom
   if (config.skipArtifacts !== true) {
     logger.info(`Preparing boot artifacts (Fedora ${config.fedoraVersion} ${config.arch})...`);
 
-    copyIfMissing(
+    copyIfChanged(
       "/usr/share/ipxe/undionly.kpxe",
       `${config.tftpDir}/undionly.kpxe`,
       "iPXE BIOS",
     );
-    copyIfMissing(
+    // Full build (native drivers + snp/nii fallback), NOT snponly: the
-      "/usr/share/ipxe/ipxe-snponly-x86_64.efi",
+    // firmware NII stack snponly rides cannot receive unicast on some NICs
+    // (thebeast 2026-10-19: DHCP fine, every ARP reply lost, HTTP timeout).
+    copyIfChanged(
+      "/usr/share/ipxe/ipxe-full-x86_64.efi",
       `${config.tftpDir}/ipxe.efi`,
       "iPXE UEFI x86_64",
     );
     try {
-      copyIfMissing(
+      copyIfChanged(
         "/usr/share/ipxe/arm64-efi/snponly.efi",
         `${config.tftpDir}/ipxe-arm64.efi`,
         "iPXE UEFI arm64",