Roflin
fd95643593
sudo ./scripts/fsp-server.py --root /workspace --password alltheroms
Swiss streams games over FSP/UDP rather than TCP, so hosting an image needs an
FSP server. Serves a directory read-only: VERSION, STAT, GET_DIR, GET_FILE,
BYE, with CC_ERR for anything else. Reports the achieved read rate every two
seconds, which is the measurement this was really built for -- the 850 KB/s
figure came from the menu's lwIP/TCP path and says nothing about streaming.
The protocol was taken from Swiss's own two clients rather than from memory,
because they disagree about nothing but exercise different commands:
cube/swiss/source/devices/fsp/fsplib.c (menu: browse, stat, read)
cube/patches/bba/tcpip.c (in-game streaming reads)
Details that are easy to get wrong, all verified against that source:
* checksum: sum = total_size + every byte with the checksum byte zeroed,
then sum += sum >> 8, low 8 bits.
* password: the data field is "path\npassword\0" -- the '\n' REPLACES the
path's terminating NUL (fsplib buildfilename), it is not appended after it.
* GET_DIR: entries are time(4) size(4) type(1) name(NUL) padded to 4 bytes;
the client reads blocks until one is shorter than the first, so the whole
listing then an EMPTY reply is what terminates it. dirpos % 4 != 0 is
rejected outright by fsplib, hence the alignment padding.
* STAT: the same 9-byte time/size/type prefix; type 0 means ENOENT.
* GET_FILE: sequence AND position must be echoed -- the in-game client
discards any reply where either differs.
* ⚠️ a GET_FILE reply must be a multiple of 32 bytes unless it is the tail,
because the in-game client does
data_size = MIN(requested, OSRoundDown32B(reply_len))
so a non-32-aligned reply is silently rounded DOWN and the stream stalls.
test-fsp-server.py runs a real server on 127.0.0.1 and drives it with a client
that packs requests exactly as Swiss does: checksums verify both ways, STAT
returns the true size, GET_DIR parses with fsplib's own walk and the second
page is empty, GET_FILE returns byte-exact data at three offsets with seq and
pos echoed, a 1024-byte request comes back 32-aligned, a wrong password gives
CC_ERR, and ../../etc/passwd is refused.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
133 lines
4.9 KiB
Python
Executable File
133 lines
4.9 KiB
Python
Executable File
#!/usr/bin/env python3
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"""Self-test for fsp-server.py, using a client that packs requests the way
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Swiss's fsplib/tcpip.c do (path\\npassword\\0, 2-byte xlen, v2 checksum)."""
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import os, socket, struct, subprocess, sys, tempfile, time
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HSIZE = 12
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CC_VERSION, CC_ERR, CC_GET_DIR, CC_GET_FILE, CC_STAT = 0x10, 0x40, 0x41, 0x42, 0x4D
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PW = "alltheroms"
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fails = []
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def csum(pkt):
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t = len(pkt) + sum(pkt)
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t += t >> 8
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return t & 0xFF
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def req(cmd, seq, pos, path, pw=PW, extra=b""):
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data = path.encode() + (b"\n" + pw.encode() if pw else b"") + b"\0"
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body = struct.pack("!BBHHHI", cmd, 0, 0x1234, seq, len(data), pos) + data + extra
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return body[:1] + bytes([csum(body)]) + body[2:]
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def parse(pkt):
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cmd, cs, key, seq, ln, pos = struct.unpack("!BBHHHI", pkt[:HSIZE])
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zeroed = pkt[:1] + b"\0" + pkt[2:]
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return dict(cmd=cmd, seq=seq, pos=pos, data=pkt[HSIZE:HSIZE + ln],
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csum_ok=csum(zeroed) == cs)
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tmp = tempfile.mkdtemp()
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PAYLOAD = bytes((i * 7 + 3) & 0xFF for i in range(8192))
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open(os.path.join(tmp, "dvd.iso"), "wb").write(PAYLOAD)
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os.mkdir(os.path.join(tmp, "subdir"))
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srv = subprocess.Popen(
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[sys.executable, "-I", "scripts/fsp-server.py", "--root", tmp,
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"--password", PW, "--bind", "127.0.0.1", "--port", "2121", "--quiet-reads"],
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stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT)
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time.sleep(1.0)
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s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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s.settimeout(3.0)
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A = ("127.0.0.1", 2121)
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def rt(pkt):
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s.sendto(pkt, A)
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return parse(s.recv(2048))
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try:
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# T1 checksum both ways
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r = rt(req(CC_VERSION, 1, 0, ""))
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if r["cmd"] != CC_VERSION or not r["csum_ok"]:
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fails.append(f"T1 VERSION: cmd {r['cmd']:#04x} csum_ok {r['csum_ok']}")
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else:
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print("T1 VERSION answered, reply checksum verifies")
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# T2 STAT returns the real size
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r = rt(req(CC_STAT, 2, 0, "/dvd.iso"))
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t, sz, ty = struct.unpack("!IIB", r["data"][:9])
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if sz != len(PAYLOAD) or ty != 0x01:
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fails.append(f"T2 STAT size {sz} type {ty}, want {len(PAYLOAD)} / 1")
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else:
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print(f"T2 STAT -> size {sz}, type FILE")
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# T3 GET_DIR lists the file and the subdir, and parses as fsplib does
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r = rt(req(CC_GET_DIR, 3, 0, "/"))
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d, i, found = r["data"], 0, {}
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while i + 9 <= len(d):
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ty = d[i + 8]
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if ty == 0x00:
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break
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sz = struct.unpack("!I", d[i + 4:i + 8])[0]
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end = d.index(b"\0", i + 9)
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found[d[i + 9:end].decode()] = (ty, sz)
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i = end + 1
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i += (-i) % 4
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if found.get("dvd.iso") != (0x01, len(PAYLOAD)) or found.get("subdir", (0,))[0] != 0x02:
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fails.append(f"T3 GET_DIR entries wrong: {found}")
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else:
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print(f"T3 GET_DIR -> {found}")
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if (len(r['data'])) % 4:
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fails.append("T3 dir block not 4-byte aligned (fsplib rejects dirpos%4)")
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# T4 second GET_DIR page must be EMPTY so the client stops looping
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r2 = rt(req(CC_GET_DIR, 4, len(r["data"]), "/"))
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if len(r2["data"]) != 0:
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fails.append(f"T4 second dir page returned {len(r2['data'])} B, want 0")
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else:
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print("T4 second GET_DIR page empty -> client terminates")
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# T5 GET_FILE: right bytes, and sequence+position ECHOED (the in-game
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# client discards a reply whose seq or pos does not match)
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for pos, want in ((0, 1024), (4096, 1024), (8000, 1024)):
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r = rt(req(CC_GET_FILE, 10 + pos, pos, "/dvd.iso",
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extra=struct.pack("!H", want)))
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exp = PAYLOAD[pos:pos + want]
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if r["data"] != exp:
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fails.append(f"T5 GET_FILE pos={pos}: {len(r['data'])} B, "
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f"want {len(exp)}, match={r['data']==exp}")
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elif r["seq"] != 10 + pos or r["pos"] != pos:
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fails.append(f"T5 seq/pos not echoed: seq {r['seq']} pos {r['pos']}")
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print("T5 GET_FILE at 0 / 4096 / EOF-straddle: bytes exact, seq+pos echoed")
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# T6 a 32-aligned request must give a 32-aligned reply, or the in-game
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# client's OSRoundDown32B silently truncates and the transfer stalls
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r = rt(req(CC_GET_FILE, 99, 0, "/dvd.iso", extra=struct.pack("!H", 1024)))
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if len(r["data"]) % 32:
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fails.append(f"T6 reply {len(r['data'])} B is not a multiple of 32")
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else:
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print(f"T6 1024 B request -> {len(r['data'])} B, 32-aligned")
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# T7 wrong password must be refused
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r = rt(req(CC_STAT, 7, 0, "/dvd.iso", pw="wrong"))
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if r["cmd"] != CC_ERR:
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fails.append(f"T7 wrong password accepted (cmd {r['cmd']:#04x})")
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else:
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print("T7 wrong password -> CC_ERR")
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# T8 path traversal must not escape the root
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r = rt(req(CC_STAT, 8, 0, "/../../etc/passwd"))
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t, sz, ty = struct.unpack("!IIB", (r["data"] + b"\0" * 9)[:9])
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if r["cmd"] != CC_ERR and ty != 0:
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fails.append(f"T8 traversal escaped the root: type {ty} size {sz}")
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else:
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print("T8 ../../etc/passwd refused")
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finally:
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srv.terminate()
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print("\nFAILURES:\n " + "\n ".join(fails) if fails else
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"\nAll fsp-server self-tests passed.")
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sys.exit(1 if fails else 0)
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