. "$BST_LIB"
# BST-TIMEOUT: 900
# dhcp-relay 4.4.3-P1 -- ISC's DHCP relay agent, dhcrelay, built alone out of
# the ISC DHCP tree (meta-openembedded/meta-networking, whose 0001 patch drops
# every other Makefile.am target). Test-plan entry BRINTOS-2077.
#
# A relay agent sits between a client broadcast domain and a DHCP server on
# another one. THIS MACHINE HAS NEITHER, and that is the subject rather than an
# obstacle: what is asserted here is that dhcrelay says what it cannot do, with
# the status it documents, and exits -- and that everything it can decide
# WITHOUT a wire it decides correctly.
#
# ---------------------------------------------------------------------------
# THREE WALLS, IN THE ORDER main() MEETS THEM. Getting them the wrong way round
# is what makes a case assert the wrong thing, so they are named up front.
#
#  1. THE PRE-PASS. main() scans argv for -d, --version and --help/-h BEFORE it
#     does anything else, and answers the last two with exit(0) on the spot.
#     Those two cases therefore need no -d and touch nothing.
#
#  2. THE FORK. Without -d, dhcrelay forks a daemon BEFORE parsing its options:
#     the parent blocks reading a byte from a pipe the child writes only once it
#     has reached the daemon block. Every usage-error case below passes -d, not
#     for tidiness but because otherwise it is the CHILD that reports and the
#     parent's status that is scored. One case deliberately does not, to
#     exercise the handshake itself.
#
#  3. THE PACKET SOCKET. configure selects the LPF arm here (config.h defines
#     HAVE_LPF, and includes/osdep.h turns that into USE_LPF_SEND/RECEIVE), so
#     the FIRST thing discover_interfaces() does for a requested interface is
#     socket(PF_PACKET, SOCK_RAW, ETH_P_ALL) in common/lpf.c:83. This kernel is
#     built `# CONFIG_PACKET is not set' (arch/wasm32/configs/wasm32_defconfig:
#     "raw sockets -- no consumer on the v0.1 surface"), the same absence
#     88-dhcpcd.test records from the client side. So every run that names an
#     interface is expected to stop there.
#
# ---------------------------------------------------------------------------
# THE TICKET'S SECOND ASSERTION IS NOT WHAT THE SOURCE DOES, and the suite pins
# the real answer rather than the expected one. `dhcrelay -i <absent-if>' does
# NOT report "<if>: not found": common/discover.c:775 reaches that log_fatal
# only inside `if (!(tmp->flags & INTERFACE_REQUESTED))', which cannot hold for
# an interface the command line requested -- on a DHCPv6 build, which this is
# (configure reports `dhcpv6: yes'). The weeding branch is skipped and the run
# falls through to the packet socket of wall 3, which fails identically whether
# the interface exists or not. Both cases are scored here, and `absent-if-same-
# wall' asserts they agree, so the finding is recorded rather than hidden.
#
# ---------------------------------------------------------------------------
# TWO MORE ASSERTIONS THE SOURCE DOES NOT HONOUR, kept as green cases stating
# what it really does:
#
#   -c <hops>   relay/dhcrelay.c:429 is `hcount = atoi(argv[i]); if (hcount <=
#               255) max_hop_count = hcount;'. There is NO lower bound and no
#               numeric check, so -c -1 and -c brintos are both ACCEPTED (atoi
#               gives -1 and 0). Only > 255 is rejected.
#   -A <length> line 496 rejects only `> DHCP_MTU_MAX' (1500, includes/dhcp.h:
#               41). -A 0 is accepted.
#
# A suite that asserted the documented intent would red on a correct build of
# this package, which is the failure mode this file is written to avoid.
#
# ---------------------------------------------------------------------------
# WHAT IS *NOT* RUN, AND WHY. `dhcrelay <server>' with no -d and no -i would
# fork, and the child would reach dispatch() and stay resident for the rest of
# the boot -- discover_interfaces() SKIPS loopback and non-broadcast interfaces
# (common/discover.c:629-637), so nothing is registered, nothing fails, and
# maybe_setup_fallback() leaves it with a UDP socket and an empty event loop.
# A stray daemon would outlive this suite and every suite after it. The same
# shape IS exercised, bounded and in the foreground, by `resident-without-if'
# below, which this suite kills at its own bound.
#
# Every invocation is bounded by dr_run's /proc/uptime loop rather than by
# timeout(1), which can kill nothing dr_run cannot (brintos/linux#21) and whose
# timer never fired before the brintos/linux#77 fix.

require dhcrelay dhcp-relay/present

DR=/usr/sbin/dhcrelay
W=${TMPDIR:-/tmp}/bst-dhcp-relay.$$
rm -rf "$W"; mkdir -p "$W" || { bst_notok dhcp-relay/workdir "cannot create $W"; exit 0; }

BOUND=45            # per invocation. Every case here either reports and exits
                    # at once or does not intend to return at all, so this is a
                    # hang detector rather than a work budget.

# dr_run <bound> <cmd...> -- run bounded, with stdout at $W/out and stderr at
# $W/err and no result line of its own. DR_RC is the exit status, or 124 when
# the bound expired and the child was killed. DR_TEXT is both streams joined,
# DR_STDOUT stdout alone. Copied from bst_probe's shape for the reasons its own
# header gives: a completion sentinel rather than `kill -0' (a fast child's
# zombie reads as alive forever), /proc/uptime as the clock, and nothing but
# builtins beside the `sleep 1' in the loop body.
DR_RC=0
DR_TEXT=
DR_STDOUT=
dr_run() {
  _dr_bound=$1; shift
  rm -f "$W/out" "$W/err" "$W/rc"
  { "$@" >"$W/out" 2>"$W/err"; echo $? >"$W/rc"; } &
  _dr_pid=$!
  _dr_t0=
  if [ -r /proc/uptime ] && read -r _dr_u _ < /proc/uptime; then _dr_t0=${_dr_u%.*}; fi
  _dr_ticks=0
  DR_RC=124
  while [ ! -e "$W/rc" ]; do
    _dr_d=$_dr_ticks
    if [ -n "$_dr_t0" ] && read -r _dr_u _ < /proc/uptime; then
      _dr_d=$(( ${_dr_u%.*} - _dr_t0 ))
    fi
    if [ "$_dr_d" -ge "$_dr_bound" ]; then
      kill -9 "$_dr_pid" 2>/dev/null
      wait "$_dr_pid" 2>/dev/null
      DR_RC=124
      break
    fi
    sleep 1
    _dr_ticks=$((_dr_ticks + 1))
  done
  if [ -e "$W/rc" ]; then
    DR_RC=0
    # $W is under $TMPDIR, so this redirect is on tmpfs and cannot take the
    # dup2->513 path brintos/linux#73 describes for the virtiofs root.
    [ -s "$W/rc" ] && read -r DR_RC < "$W/rc" 2>/dev/null
    case "$DR_RC" in ''|*[!0-9]*) DR_RC=0 ;; esac
  fi
  DR_STDOUT=$(cat "$W/out" 2>/dev/null)
  DR_TEXT=$(cat "$W/out" "$W/err" 2>/dev/null)
}

# dr_has / dr_hasnt <id> <needle> -- score the run dr_run just did.
dr_has() {
  case "$DR_TEXT" in
    *"$2"*) bst_ok "$1" ;;
    *) bst_notok "$1" "want:'$2' got:'$(_bst_1line "$DR_TEXT")'" ;;
  esac
}
dr_hasnt() {
  case "$DR_TEXT" in
    *"$2"*) bst_notok "$1" "did not expect:'$2' in '$(_bst_1line "$DR_TEXT")'" ;;
    *) bst_ok "$1" ;;
  esac
}

# dr_usage_error <id-stem> <needle> -- the whole shape of one usage() refusal in
# one call: bounded, exit 1, and the specific message present. usage() prints
# the four banner lines, then the specific error (site.h:319 defines
# PRINT_SPECIFIC_CL_ERRORS), then log_fatal(DHCRELAY_USAGE) -- so the usage text
# is asserted too, which is what separates usage() from a bare log_fatal.
dr_usage_error() {
  _du_id=$1; _du_want=$2; shift 2
  dr_run "$BOUND" "$@"
  check_eq "dhcp-relay/$_du_id-rc" "1" "$DR_RC"
  dr_has "dhcp-relay/$_du_id" "$_du_want"
  dr_has "dhcp-relay/$_du_id-usage" "Usage: dhcrelay"
}

# dr_accepted <id> <cmd...> -- the option parsed CLEANLY: the run got all the
# way to the "No servers specified." check, which sits after the whole option
# loop and before discover_interfaces(). Asserting acceptance positively like
# this is what keeps it from passing on a run that died even earlier.
dr_accepted() {
  _da_id=$1; shift
  dr_run "$BOUND" "$@"
  check_eq "dhcp-relay/$_da_id-rc" "1" "$DR_RC"
  dr_has "dhcp-relay/$_da_id" "No servers specified."
}

# ------------------------------------------------------------- inventory --
check_eq dhcp-relay/inventory "yes" "$([ -x "$DR" ] && echo yes)"

# The bare name a user types must be this binary; `command -v' reads root's
# actual PATH, so this also catches an image on which /usr/sbin lost its place.
check_eq dhcp-relay/on-path "$DR" "$(command -v dhcrelay 2>/dev/null)"

# The 0001 patch reduces Makefile.am to the relay alone. If the server or the
# client ever appeared they would be unported binaries nobody asserted, so
# their absence is pinned rather than assumed.
check_eq dhcp-relay/relay-only "" "$(ls /usr/sbin/dhcpd /usr/sbin/dhclient /usr/bin/omshell 2>/dev/null)"

# CONFFILES:${PN}. The init script refuses to start without this file, so a red
# here separates "not shipped" from "shipped and wrong".
check dhcp-relay/default-shipped test -f /etc/default/dhcp-relay
for k in SERVERS INTERFACES OPTIONS; do
  check "dhcp-relay/default-key-$k" grep -q "^$k=" /etc/default/dhcp-relay
done

# "systemd" is not in DISTRO_FEATURES, so systemd.bbclass packages nothing and
# do_install's `else' arm installs the sysvinit script instead. Both halves are
# asserted: the script present, and dhcrelay's OWN unit absent. Asserted against
# the unit name rather than against /lib/systemd existing, because other
# packages on this image ship units into that directory and the wider assertion
# would red on a file dhcp-relay never wrote.
check dhcp-relay/initscript-shipped test -x /etc/init.d/dhcp-relay
check_eq dhcp-relay/no-systemd-unit "" \
  "$(ls -d /lib/systemd/system/dhcrelay* /usr/lib/systemd/system/dhcrelay* 2>/dev/null)"

# The init script and includes/dhcpd.h:1611 must agree about where the pid file
# goes -- LOCALSTATEDIR is compiled in as "/var", so both say /var/run/
# dhcrelay.pid. A disagreement means `stop' would not find a running daemon.
check dhcp-relay/initscript-pidpath grep -q '^DHCRELAYPID=/var/run/dhcrelay.pid$' /etc/init.d/dhcp-relay

# -doc IS INSTALLED AND -dev / -staticdev ARE NOT, and that is not a matter of
# taste: the recipe declares RCONFLICTS:${PN}-dev = "bind-dev", because both
# packages carry the bundled bind's headers and archives under the same paths --
# and this image already installs `bind'. So the four man pages ship and the
# headers do not. Read back from the built .deb, those four are ISC DHCP's OWN --
# dhcrelay.8, omapi.3, dhcp-eval.5, dhcp-options.5 -- and none of bind's, which
# is why -doc needs no RCONFLICTS against bind-doc the way -dev needs one against
# bind-dev. Both halves are pinned: a -dev that appeared here would be a
# package-manager conflict on the next image that also wanted bind-dev.
check dhcp-relay/manpage-shipped test -f /usr/share/man/man8/dhcrelay.8
# Asserted over libdhcp.a and libomapi.a specifically -- dhcp's OWN archives,
# which no other package on this image ships -- rather than over the bind ones
# they sit beside, so a red here names dhcp-relay-staticdev and cannot be
# triggered by somebody else adding bind-staticdev later.
check_eq dhcp-relay/no-staticdev "" "$(ls /usr/lib/libdhcp.a /usr/lib/libomapi.a 2>/dev/null)"
check_eq dhcp-relay/no-dev "" "$(ls /usr/include/dhcpctl/dhcpctl.h /usr/include/omapip/omapip.h 2>/dev/null)"

# dhcp-relay converts under BRINTOS_PACKAGE_SHARED, so dhcp's own libdhcp and
# libomapi ship as shared objects beside the bundled bind's. Presence is asserted
# on dhcp's two alone, which no other package ships; the shape is asserted on
# all six, so a dangling link or an empty file reads red.
check dhcp-relay/libdhcp-shared  sh -c 'set -- /usr/lib/libdhcp.so.*;  [ -e "$1" ]'
check dhcp-relay/libomapi-shared sh -c 'set -- /usr/lib/libomapi.so.*; [ -e "$1" ]'
bst_lib_shape dhcp-relay/lib-shape \
  '/usr/lib/libisc*.so*' '/usr/lib/libdns*.so*' '/usr/lib/libisccfg*.so*' \
  '/usr/lib/libirs*.so*' '/usr/lib/libdhcp*.so*' '/usr/lib/libomapi*.so*'

# ------------------------------------------------- the pre-pass, wall 1 --
# --version and --help are answered inside main()'s first loop, ahead of the
# fork, the option parser and every socket. A red in this block separates "the
# binary is broken" from every case below it.
dr_run "$BOUND" "$DR" --version
check_eq dhcp-relay/version-rc "0" "$DR_RC"
dr_has dhcp-relay/version "isc-dhcrelay-4.4.3-P1"

# log_info() writes through errwarn.c's log_perror arm, which is write(2) to
# STDERR_FILENO. A port whose diagnostics moved to stdout would still "work"
# while breaking every consumer that reads dhcrelay the documented way.
check_eq dhcp-relay/version-on-stderr "" "$DR_STDOUT"

dr_run "$BOUND" "$DR" -h
check_eq dhcp-relay/help-rc "0" "$DR_RC"
dr_has dhcp-relay/help-usage "Usage: dhcrelay [-4] [-d] [-q] [-a] [-D]"
DR_HELP_SHORT=$DR_TEXT

# The -6 synopsis is the DHCPv6 half of DHCRELAY_USAGE and is compiled in only
# when DHCPv6 is defined -- which is what makes the `Command not used for
# DHCPv6' cases below reachable at all, so it is asserted rather than assumed.
dr_has dhcp-relay/help-v6-synopsis "dhcrelay -6   [-d] [-q] [-I] [-c <hops>]"

# RELAY_PORT is off (configure reports `relay-port: no'), so -rp is not in the
# synopsis. This pins the build's feature set from the artifact rather than from
# the configure log.
dr_hasnt dhcp-relay/help-no-relay-port "-rp <relay-port>"

# usage() substitutes isc_file_basename(progname), so an absolute argv[0] must
# still print the bare name.
dr_hasnt dhcp-relay/help-basename "Usage: /usr/sbin/dhcrelay"

dr_run "$BOUND" "$DR" --help
check_eq dhcp-relay/help-long-rc "0" "$DR_RC"
check_eq dhcp-relay/help-long-same "$DR_HELP_SHORT" "$DR_TEXT"

# ------------------------------------ the option parser, all behind -d --
# The ticket's first assertion: no upstream server is the documented usage
# error. It is a bare log_fatal (relay/dhcrelay.c:730), NOT usage(), so the
# banner and the synopsis are absent -- which is asserted, because scoring it
# with dr_usage_error would have been wrong in a way nothing else would catch.
dr_run "$BOUND" "$DR" -d
check_eq dhcp-relay/no-servers-rc "1" "$DR_RC"
dr_has dhcp-relay/no-servers "No servers specified."
dr_hasnt dhcp-relay/no-servers-not-usage "Usage: dhcrelay"
# log_fatal's own tail, six lines of bug-reporting advice and then "exiting.".
# Asserting it is how a genuine fatal is told apart from a message printed on
# the way to somewhere else.
dr_has dhcp-relay/no-servers-exiting "exiting."

dr_usage_error unknown-opt "Unknown command: -Z" "$DR" -d -Z
# usage() prints the four banner lines before the specific error; the version in
# them comes from PACKAGE_VERSION, the same string --version prints.
dr_has dhcp-relay/unknown-opt-banner "Internet Systems Consortium DHCP Relay Agent 4.4.3-P1"

dr_usage_error noarg-c  "No argument for command: -c"  "$DR" -d -c
dr_usage_error noarg-i  "No argument for command: -i"  "$DR" -d -i
dr_usage_error noarg-pf "No argument for command: -pf" "$DR" -d -pf
dr_usage_error noarg-A  "No argument for command: -A"  "$DR" -d -A
dr_usage_error noarg-m  "No argument for command: -m"  "$DR" -d -m
dr_usage_error noarg-U  "No argument for command: -U"  "$DR" -d -U

# ------------------------------------------------------- -c, the hop count --
dr_usage_error hops-over "Bad hop count to -c: 256" "$DR" -d -c 256
# 255 is the last accepted value -- the comparison is `<= 255'. The boundary is
# what a regression moves first.
dr_accepted hops-max "$DR" -d -c 255
# NO LOWER BOUND AND NO NUMERIC CHECK. atoi("-1") is -1 and atoi("brintos") is
# 0, both <= 255, so both are taken. Green here means the source behaves as
# read; a red means upstream added the validation this ticket assumed it had.
dr_accepted hops-negative "$DR" -d -c -1
dr_accepted hops-nonnumeric "$DR" -d -c brintos

# --------------------------------------- -A, the agent-option packet length --
dr_run "$BOUND" "$DR" -d -A 65535
check_eq dhcp-relay/maxlen-over-rc "1" "$DR_RC"
dr_has dhcp-relay/maxlen-over "packet length exceeds"
# Also a bare log_fatal rather than usage(), for the same reason as -c above but
# a different code path, so it is pinned separately.
dr_hasnt dhcp-relay/maxlen-over-not-usage "Usage: dhcrelay"
dr_accepted maxlen-max "$DR" -d -A 1500      # DHCP_MTU_MAX, includes/dhcp.h:41
dr_accepted maxlen-zero "$DR" -d -A 0        # no lower bound

# ---------------------------------------------- -m, the agent-option policy --
dr_usage_error mode-unknown "Unknown argument to -m: brintos" "$DR" -d -m brintos
for m in append replace forward discard; do
  dr_accepted "mode-$m" "$DR" -d -m "$m"
done
# The comparison is strcasecmp, so the spelling is case-insensitive.
dr_accepted mode-uppercase "$DR" -d -m APPEND

# ----------------------------------------------------- -g, the giaddr --
dr_usage_error gateway-bad "Invalid gateway address 'brintos'" "$DR" -d -g brintos
dr_accepted gateway-good "$DR" -d -g 10.77.0.1

# --------------------------------------------- -i / -iu / -id, the name --
# request_v4_interface() (relay/dhcrelay.c:2156) refuses `len >= sizeof(tmp->
# name)', and that field is char[IFNAMSIZ] with IFNAMSIZ 16 -- so 16 characters
# is already too long and 15 is the last accepted length. The message names the
# measured length, which is the field a bounds regression moves.
LONGIF=abcdefghijklmnop      # 16
OKIF=abcdefghijklmno        # 15
for f in i iu id; do
  dr_run "$BOUND" "$DR" -d "-$f" "$LONGIF"
  check_eq "dhcp-relay/ifname-long-$f-rc" "1" "$DR_RC"
  dr_has "dhcp-relay/ifname-long-$f" "$LONGIF: interface name too long (is 16)"
done
# It is a log_fatal, not usage() -- the one refusal in the -i family that prints
# no synopsis. Asserted once, on the -i arm.
dr_run "$BOUND" "$DR" -d -i "$LONGIF"
dr_hasnt dhcp-relay/ifname-long-not-usage "Usage: dhcrelay"
# 15 characters is accepted, and the run reaches the server check -- which also
# says the name was never looked up on the way past, since no such interface
# exists.
dr_accepted ifname-15 "$DR" -d -i "$OKIF"

# ----------------------------------------------- the two protocol families --
# These are reachable only because DHCPv6 is compiled in; help-v6-synopsis above
# is what says so independently.
dr_usage_error v6-rejects-v4-opt "Command not used for DHCPv6: -a" "$DR" -d -6 -a
dr_usage_error v4-rejects-v6-opt "Command not used for DHCPv4: -l" "$DR" -d -4 -l lo
dr_usage_error proto-already-set "Protocol already set, -6 inappropriate" "$DR" -d -4 -6

# ------------------------------------------------------- name resolution --
# A server argument that is neither an address nor a resolvable name is
# log_error, NOT log_fatal (relay/dhcrelay.c:643) -- the run continues, collects
# no server, and stops at the check further down. Both halves are asserted,
# because "it failed" alone would also pass if the resolver failure had been
# made fatal, which would be a behaviour change nobody would see.
dr_run "$BOUND" "$DR" -d no-such-host.brintos.invalid
check_eq dhcp-relay/host-unknown-rc "1" "$DR_RC"
dr_has dhcp-relay/host-unknown "no-such-host.brintos.invalid: host unknown"
dr_has dhcp-relay/host-unknown-continues "No servers specified."

# ------------------------------------------------ wall 3, the packet socket --
# THE TICKET'S THIRD ASSERTION. A literal address IS accepted as a server -- it
# goes through inet_aton, not the resolver -- so this run gets past the check
# every case above stopped at, and reaches discover_interfaces(). That is the
# only way to prove the address was taken, and it is what puts the run against
# the packet socket.
#
# Two spellings of the failure are documented, chosen by errno: common/lpf.c:85
# tests a set of "this family is not supported" values and prints the
# CONFIG_PACKET advice, and anything else falls through to "Open a socket for
# LPF: %m". Either is a correct report of the same absence; which one arrives
# is a fact about the kernel's errno, not about this port, so the branch is
# recorded and then asserted to be CONSISTENT rather than pinned to a guess.
DR_WALL=
dr_wall() {
  _dw_id=$1
  case "$DR_TEXT" in
    *"CONFIG_PACKET (Packet socket) and CONFIG_FILTER"*) _dw_b=config-packet ;;
    *"Open a socket for LPF:"*)                          _dw_b=lpf-socket ;;
    *"Failed to get interface index:"*)                  _dw_b=ifindex ;;
    *"Bind socket to interface:"*)                       _dw_b=lpf-bind ;;
    *) bst_notok "$_dw_id" "no documented packet-socket failure in '$(_bst_1line "$DR_TEXT")'"
       return 1 ;;
  esac
  [ -n "$DR_WALL" ] || DR_WALL=$_dw_b
  bst_ok "$_dw_id"
  return 0
}

dr_run "$BOUND" "$DR" -d -i lo 10.77.0.1
# Terminating is the assertion. A relay that stayed resident on a machine with
# no packet socket is the failure this ticket exists to exclude.
check_eq dhcp-relay/lo-terminates "no" "$([ "$DR_RC" = 124 ] && echo yes || echo no)"
check_eq dhcp-relay/lo-rc "1" "$DR_RC"
dr_wall dhcp-relay/lo-wall
# It got past "No servers specified.", which is what says 10.77.0.1 was accepted
# as a server rather than the run having stopped earlier for an unrelated reason.
dr_hasnt dhcp-relay/lo-server-accepted "No servers specified."

# THE SAME WALL FOR AN INTERFACE THAT DOES NOT EXIST -- see the header. This is
# where the ticket expected "<if>: not found"; on a DHCPv6 build that branch is
# unreachable for a requested interface, and the run stops at the packet socket
# exactly as the loopback one did.
dr_run "$BOUND" "$DR" -d -i brintos0 10.77.0.1
check_eq dhcp-relay/absent-if-terminates "no" "$([ "$DR_RC" = 124 ] && echo yes || echo no)"
check_eq dhcp-relay/absent-if-rc "1" "$DR_RC"
DR_FIRST_WALL=$DR_WALL
dr_wall dhcp-relay/absent-if-wall
check_eq dhcp-relay/absent-if-same-wall "$DR_FIRST_WALL" "$DR_WALL"
dr_hasnt dhcp-relay/absent-if-not-found "brintos0: not found"

# --------------------------------------------------------- -q, the quiet arm --
# -q does two things -- it skips the four banner lines and sets log_perror = 0
# -- and the ORDER is the whole of what this arm asserts. BOTH happen at
# relay/dhcrelay.c:687-693, AFTER the argv loop has finished. So -q silences
# everything from 693 onward, which is where the banner and the packet socket
# of wall 3 both live, and NOTHING the loop itself already logged: `-i' is one
# of the options that logs, line 448 calling request_v4_interface(), whose
# log_debug at line 2166 announces the request before -q has taken effect.
#
# The run is therefore not silent, it is one line long. That single line is
# asserted whole rather than as an emptiness, so a red says which half moved:
# the exact match is also what pins the fatal as silenced, since the wall would
# otherwise print here exactly as it does in the -i cases above.
#
# This is measured, not read off the source -- BRINTOS-2077's phase-A entry
# predicted a wholly silent run, and batch-2048's verify produced the request
# line. It matters for the init script, whose start-stop-daemon line passes -q:
# with no syslogd on this image the fatal is lost outright, while this one line
# still reaches whatever holds the daemon's stderr.
dr_run "$BOUND" "$DR" -d -q -i lo 10.77.0.1
check_eq dhcp-relay/quiet-rc "1" "$DR_RC"
dr_hasnt dhcp-relay/quiet-no-banner \
         "Internet Systems Consortium DHCP Relay Agent 4.4.3-P1"
check_eq dhcp-relay/quiet-only-request \
         "Requesting: lo as upstream: Y downstream: Y" "$DR_TEXT"

# ------------------------------------------------------------ the pid file --
# The pid file is written inside `if (!no_daemon)', so a foreground run writes
# none -- neither the compiled-in default nor a path given with -pf. Asserted
# over a path this test owns as well as the real one, so a red says which.
check_eq dhcp-relay/no-default-pidfile "" "$(ls /var/run/dhcrelay.pid 2>/dev/null)"
dr_run "$BOUND" "$DR" -d -pf "$W/relay.pid" -i lo 10.77.0.1
check_eq dhcp-relay/pf-rc "1" "$DR_RC"
check_eq dhcp-relay/pf-not-written "" "$(ls "$W/relay.pid" 2>/dev/null)"
# --no-pid is accepted as an option in its own right.
dr_accepted no-pid "$DR" -d --no-pid

# ---------------------------------------------------- wall 2, the fork --
# The one case that does NOT pass -d. The parent forks, blocks on the pipe, and
# the child dies at the packet socket without ever writing its byte; the
# parent's read returns 0 and it _exit(1)s. So a green here is a fork(2), a
# pipe(2) and the handshake between them all working -- and the child's
# diagnostic still reaches the shared stderr, because log_perror is not cleared
# until after discover_interfaces().
#
# It is safe to run only because it names an interface: without one the child
# would reach dispatch() and never return. See the header.
dr_run "$BOUND" "$DR" -i lo 10.77.0.1
check_eq dhcp-relay/fork-terminates "no" "$([ "$DR_RC" = 124 ] && echo yes || echo no)"
check_eq dhcp-relay/fork-rc "1" "$DR_RC"
dr_wall dhcp-relay/fork-child-reported

# ------------------------------------- what a relay with nothing to do does --
# In the FOREGROUND, so this suite owns the process and kills it at the bound.
# With no -i, discover_interfaces() registers nothing at all -- loopback and
# non-broadcast interfaces are skipped, and this machine has only loopback -- so
# there is no packet socket to fail on, maybe_setup_fallback() gives it a UDP
# socket, and dispatch() waits for packets that cannot arrive. STAYING RESIDENT
# IS THE CORRECT BEHAVIOUR FOR A DAEMON IN THAT POSITION, and it is asserted
# positively: exiting instead would mean one of the two skips above had changed,
# which is exactly the regression that would make the non-foreground form of
# this command leak a daemon into every later suite.
dr_run 30 "$DR" -d 10.77.0.1
check_eq dhcp-relay/resident-without-if "yes" "$([ "$DR_RC" = 124 ] && echo yes || echo no)"

rm -rf "$W"