This is a direct dump from systemd git.

======

SYSTEMD_DIR=../systemd
COMMIT=608807c163921b0dfbaf646b3ec19fc9b71e6451

(
  cd "$SYSTEMD_DIR"
  git checkout "$COMMIT"
  git reset --hard
  git clean -fdx
)

git ls-files -z :/src/systemd/src/ \
                :/shared/systemd/src/ \
                :/shared/nm-utils/unaligned.h | \
  xargs -0 rm -f

nm_copy_sd_shared() {
    mkdir -p "./shared/systemd/$(dirname "$1")"
    cp "$SYSTEMD_DIR/$1" "./shared/systemd/$1"
}

nm_copy_sd_core() {
    mkdir -p "./src/systemd/$(dirname "$1")"
    cp "$SYSTEMD_DIR/$1" "./src/systemd/$1"
}

nm_copy_sd_nmutils() {
    mkdir -p "./shared/nm-utils/"
    cp "$SYSTEMD_DIR/$1" "./shared/nm-utils/${1##*/}"
}

nm_copy_sd_core "src/libsystemd-network/arp-util.c"
nm_copy_sd_core "src/libsystemd-network/arp-util.h"
nm_copy_sd_core "src/libsystemd-network/dhcp-identifier.c"
nm_copy_sd_core "src/libsystemd-network/dhcp-identifier.h"
nm_copy_sd_core "src/libsystemd-network/dhcp-internal.h"
nm_copy_sd_core "src/libsystemd-network/dhcp-lease-internal.h"
nm_copy_sd_core "src/libsystemd-network/dhcp-network.c"
nm_copy_sd_core "src/libsystemd-network/dhcp-option.c"
nm_copy_sd_core "src/libsystemd-network/dhcp-packet.c"
nm_copy_sd_core "src/libsystemd-network/dhcp-protocol.h"
nm_copy_sd_core "src/libsystemd-network/dhcp6-internal.h"
nm_copy_sd_core "src/libsystemd-network/dhcp6-lease-internal.h"
nm_copy_sd_core "src/libsystemd-network/dhcp6-network.c"
nm_copy_sd_core "src/libsystemd-network/dhcp6-option.c"
nm_copy_sd_core "src/libsystemd-network/dhcp6-protocol.h"
nm_copy_sd_core "src/libsystemd-network/lldp-internal.h"
nm_copy_sd_core "src/libsystemd-network/lldp-neighbor.c"
nm_copy_sd_core "src/libsystemd-network/lldp-neighbor.h"
nm_copy_sd_core "src/libsystemd-network/lldp-network.c"
nm_copy_sd_core "src/libsystemd-network/lldp-network.h"
nm_copy_sd_core "src/libsystemd-network/network-internal.c"
nm_copy_sd_core "src/libsystemd-network/network-internal.h"
nm_copy_sd_core "src/libsystemd-network/sd-dhcp-client.c"
nm_copy_sd_core "src/libsystemd-network/sd-dhcp-lease.c"
nm_copy_sd_core "src/libsystemd-network/sd-dhcp6-client.c"
nm_copy_sd_core "src/libsystemd-network/sd-dhcp6-lease.c"
nm_copy_sd_core "src/libsystemd-network/sd-ipv4acd.c"
nm_copy_sd_core "src/libsystemd-network/sd-ipv4ll.c"
nm_copy_sd_core "src/libsystemd-network/sd-lldp.c"
nm_copy_sd_core "src/libsystemd/sd-event/event-source.h"
nm_copy_sd_core "src/libsystemd/sd-event/event-util.c"
nm_copy_sd_core "src/libsystemd/sd-event/event-util.h"
nm_copy_sd_core "src/libsystemd/sd-event/sd-event.c"
nm_copy_sd_core "src/libsystemd/sd-id128/id128-util.c"
nm_copy_sd_core "src/libsystemd/sd-id128/id128-util.h"
nm_copy_sd_core "src/libsystemd/sd-id128/sd-id128.c"
nm_copy_sd_core "src/systemd/_sd-common.h"
nm_copy_sd_core "src/systemd/sd-dhcp-client.h"
nm_copy_sd_core "src/systemd/sd-dhcp-lease.h"
nm_copy_sd_core "src/systemd/sd-dhcp6-client.h"
nm_copy_sd_core "src/systemd/sd-dhcp6-lease.h"
nm_copy_sd_core "src/systemd/sd-event.h"
nm_copy_sd_core "src/systemd/sd-id128.h"
nm_copy_sd_core "src/systemd/sd-ipv4acd.h"
nm_copy_sd_core "src/systemd/sd-ipv4ll.h"
nm_copy_sd_core "src/systemd/sd-lldp.h"
nm_copy_sd_core "src/systemd/sd-ndisc.h"
nm_copy_sd_nmutils "src/basic/unaligned.h"
nm_copy_sd_shared "src/basic/alloc-util.c"
nm_copy_sd_shared "src/basic/alloc-util.h"
nm_copy_sd_shared "src/basic/async.h"
nm_copy_sd_shared "src/basic/env-file.c"
nm_copy_sd_shared "src/basic/env-file.h"
nm_copy_sd_shared "src/basic/env-util.c"
nm_copy_sd_shared "src/basic/env-util.h"
nm_copy_sd_shared "src/basic/errno-util.h"
nm_copy_sd_shared "src/basic/escape.c"
nm_copy_sd_shared "src/basic/escape.h"
nm_copy_sd_shared "src/basic/ether-addr-util.c"
nm_copy_sd_shared "src/basic/ether-addr-util.h"
nm_copy_sd_shared "src/basic/extract-word.c"
nm_copy_sd_shared "src/basic/extract-word.h"
nm_copy_sd_shared "src/basic/fd-util.c"
nm_copy_sd_shared "src/basic/fd-util.h"
nm_copy_sd_shared "src/basic/fileio.c"
nm_copy_sd_shared "src/basic/fileio.h"
nm_copy_sd_shared "src/basic/format-util.c"
nm_copy_sd_shared "src/basic/format-util.h"
nm_copy_sd_shared "src/basic/fs-util.c"
nm_copy_sd_shared "src/basic/fs-util.h"
nm_copy_sd_shared "src/basic/hash-funcs.c"
nm_copy_sd_shared "src/basic/hash-funcs.h"
nm_copy_sd_shared "src/basic/hashmap.c"
nm_copy_sd_shared "src/basic/hashmap.h"
nm_copy_sd_shared "src/basic/hexdecoct.c"
nm_copy_sd_shared "src/basic/hexdecoct.h"
nm_copy_sd_shared "src/basic/hostname-util.c"
nm_copy_sd_shared "src/basic/hostname-util.h"
nm_copy_sd_shared "src/basic/in-addr-util.c"
nm_copy_sd_shared "src/basic/in-addr-util.h"
nm_copy_sd_shared "src/basic/io-util.c"
nm_copy_sd_shared "src/basic/io-util.h"
nm_copy_sd_shared "src/basic/list.h"
nm_copy_sd_shared "src/basic/log.h"
nm_copy_sd_shared "src/basic/macro.h"
nm_copy_sd_shared "src/basic/memory-util.c"
nm_copy_sd_shared "src/basic/memory-util.h"
nm_copy_sd_shared "src/basic/mempool.c"
nm_copy_sd_shared "src/basic/mempool.h"
nm_copy_sd_shared "src/basic/missing_fcntl.h"
nm_copy_sd_shared "src/basic/missing_socket.h"
nm_copy_sd_shared "src/basic/missing_stat.h"
nm_copy_sd_shared "src/basic/missing_type.h"
nm_copy_sd_shared "src/basic/parse-util.c"
nm_copy_sd_shared "src/basic/parse-util.h"
nm_copy_sd_shared "src/basic/path-util.c"
nm_copy_sd_shared "src/basic/path-util.h"
nm_copy_sd_shared "src/basic/prioq.c"
nm_copy_sd_shared "src/basic/prioq.h"
nm_copy_sd_shared "src/basic/process-util.c"
nm_copy_sd_shared "src/basic/process-util.h"
nm_copy_sd_shared "src/basic/random-util.c"
nm_copy_sd_shared "src/basic/random-util.h"
nm_copy_sd_shared "src/basic/set.h"
nm_copy_sd_shared "src/basic/signal-util.h"
nm_copy_sd_shared "src/basic/siphash24.h"
nm_copy_sd_shared "src/basic/socket-util.c"
nm_copy_sd_shared "src/basic/socket-util.h"
nm_copy_sd_shared "src/basic/sort-util.h"
nm_copy_sd_shared "src/basic/sparse-endian.h"
nm_copy_sd_shared "src/basic/stat-util.c"
nm_copy_sd_shared "src/basic/stat-util.h"
nm_copy_sd_shared "src/basic/stdio-util.h"
nm_copy_sd_shared "src/basic/string-table.c"
nm_copy_sd_shared "src/basic/string-table.h"
nm_copy_sd_shared "src/basic/string-util.c"
nm_copy_sd_shared "src/basic/string-util.h"
nm_copy_sd_shared "src/basic/strv.c"
nm_copy_sd_shared "src/basic/strv.h"
nm_copy_sd_shared "src/basic/strxcpyx.c"
nm_copy_sd_shared "src/basic/strxcpyx.h"
nm_copy_sd_shared "src/basic/time-util.c"
nm_copy_sd_shared "src/basic/time-util.h"
nm_copy_sd_shared "src/basic/tmpfile-util.c"
nm_copy_sd_shared "src/basic/tmpfile-util.h"
nm_copy_sd_shared "src/basic/umask-util.h"
nm_copy_sd_shared "src/basic/utf8.c"
nm_copy_sd_shared "src/basic/utf8.h"
nm_copy_sd_shared "src/basic/util.c"
nm_copy_sd_shared "src/basic/util.h"
nm_copy_sd_shared "src/shared/dns-domain.c"
nm_copy_sd_shared "src/shared/dns-domain.h"