Add tests for emulation of /proc/sys/kernel/random.

Sysbox now emulates /proc/sys/kernel/random inside
the container. Add tests to verify the emulation is
correct.

Signed-off-by: Cesar Talledo <[email protected]>

Author: ctalledo

tests/helpers/uuid.bash

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+#
+# uuid related helpers
+#
+# Note: these should not use bats, so as to allow their use
+# when manually reproducing tests.
+#
+
+# verifies the given uuid is valid (e.g., similar to "abaee0f3-5cd9-4824-a5ac-9d49e83e2721")
+function is_valid_uuid() {
+  local uuid="$1"
+  if [[ $uuid =~ ^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$ ]]; then
+    return 0
+  else
+    return 1
+  fi
+}

tests/sysfs/procSysKernelRandom.bats

@@ -0,0 +1,108 @@
+# Testing of handler for /proc/sys/kernel/random
+
+load ../helpers/fs
+load ../helpers/run
+load ../helpers/uuid
+load ../helpers/sysbox
+load ../helpers/sysbox-health
+
+function setup() {
+  setup_busybox
+}
+
+function teardown() {
+  teardown_busybox syscont
+  sysbox_log_check
+}
+
+@test "/proc/sys/kernel/random/uuid lookup() operation" {
+  sv_runc run -d --console-socket $CONSOLE_SOCKET syscont
+  [ "$status" -eq 0 ]
+
+  sv_runc exec syscont sh -c "ls -lrt /proc/sys/kernel/random/uuid"
+  [ "$status" -eq 0 ]
+
+  verify_root_ro "${output}"
+}
+
+@test "/proc/sys/kernel/random/uuid read" {
+  sv_runc run -d --console-socket $CONSOLE_SOCKET syscont
+  [ "$status" -eq 0 ]
+
+  sv_runc exec syscont sh -c "cat /proc/sys/kernel/random/uuid"
+  [ "$status" -eq 0 ]
+
+  is_valid_uuid "$output"
+}
+
+@test "/proc/sys/kernel/random/uuid read unique each time" {
+  sv_runc run -d --console-socket $CONSOLE_SOCKET syscont
+  [ "$status" -eq 0 ]
+
+  declare -A uuid_map
+
+  for i in $(seq 1 10); do
+    sv_runc exec syscont sh -c "cat /proc/sys/kernel/random/uuid"
+    [ "$status" -eq 0 ]
+
+    uuid=$output
+    is_valid_uuid "$uuid"
+
+    # check we haven't seen this uuid before
+    [[ -z ${uuid_map[$uuid]} ]]
+
+    uuid_map[$uuid]=1
+  done
+}
+
+@test "/proc/sys/kernel/random/uuid write" {
+  sv_runc run -d --console-socket $CONSOLE_SOCKET syscont
+  [ "$status" -eq 0 ]
+
+  sv_runc exec syscont sh -c "echo 0 > /proc/sys/kernel/random/uuid"
+  [ "$status" -ne 0 ]
+}
+
+@test "/proc/sys/kernel/random dir" {
+  sv_runc run -d --console-socket $CONSOLE_SOCKET syscont
+  [ "$status" -eq 0 ]
+
+  # check number of files in the container's /proc/sys/kernel/random matches host
+  sv_runc exec syscont sh -c "ls -l /proc/sys/kernel/random/uuid | wc -l"
+  [ "$status" -eq 0 ]
+  cnum=$output
+  hnum=$(ls -l /proc/sys/kernel/random/uuid | wc -l)
+  [ $cnum -eq $hnum ]
+
+  # read from each of the files in /proc/sys/kernel/random (except uuid), and
+  # compare the one in the host to the corresponding one in the container.
+  for file in /proc/sys/kernel/random/*; do
+    if [[ $(basename "$file") == "uuid" ]]; then
+      continue
+    fi
+
+    if [[ -r "$file" ]]; then
+      hfile=$(cat "$file")
+
+      sv_runc exec syscont sh -c "cat $file"
+      [ "$status" -eq 0 ]
+      cfile=$output
+
+      echo "hfile = $hfile"
+      echo "cfile = $cfile"
+
+      [[ "$hfile" == "$cfile" ]]
+    fi
+  done
+
+  # check that writes to files in /proc/sys/kernel/random (except uuid) fail
+  # with EPERM.
+  for file in /proc/sys/kernel/random/*; do
+    if [[ $(basename "$file") == "uuid" ]]; then
+      continue
+    fi
+    sv_runc exec syscont sh -c "echo 0 > $file"
+    [ "$status" -ne 0 ]
+  done
+
+}