unsloth/studio/backend/routes/settings.py
Daniel Han 80d3434d61
Studio: require signed capability tokens for /p preview links (#6666)
* Studio: require signed capability tokens for /p preview links

The public /p preview routes added in #6486 run model load and chat
generation as the admin user with no authentication. The only gate is the
preview ref, a deterministic outputs-root path (run or run/checkpoint) that
is guessable rather than secret. On a network-reachable Studio (--secure
tunnel or -H 0.0.0.0), an unauthenticated caller who guesses a ref can
consume GPU and probe a private fine-tuned checkpoint.

Make the share link an unguessable, revocable capability:

- Sign the canonical ref with a dedicated server-side secret (HMAC-SHA256,
  stored in app_secrets, independent of the JWT/login secret).
- Require a valid token on every /p chat, models, and page request before
  resolving a checkpoint or loading a model; missing or invalid tokens get a
  generic 404 so the surface never confirms a ref exists.
- Accept the token via ?k= (browser link and preview page) or
  Authorization: Bearer (OpenAI-compatible clients).
- Rotate the secret to revoke every outstanding link
  (POST /api/settings/preview-links/rotate).
- Clamp preview generation (max_tokens/max_completion_tokens <= 1024, n = 1)
  and set Referrer-Policy: no-referrer on the page so the token is not
  leaked via Referer.

Training history hands the authenticated owner the signed token, and the
copy-link button builds /p/{ref}?k={sig}.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Studio: honor a lower caller token limit in the preview clamp

Codex review: when only the legacy max_tokens was sent, the clamp left
max_completion_tokens at the 1024 default, and _effective_max_tokens prefers
max_completion_tokens, so a request like max_tokens=16 could still generate up
to 1024 tokens. Derive one effective limit (max_completion_tokens wins, else the
legacy max_tokens) and pin both fields to it so a caller's lower limit is kept.

* Studio: add preview kill switch, rate limit, and revoke-links UI

Follow-ups to the /p preview capability work:

- Public-sharing kill switch: a persisted setting (default on) gates the public
  /p surface. When off, every preview request 404s even with a valid token, and
  the owner UI stops offering share links. GET/PUT /api/settings/preview-sharing;
  enforced in _verify_or_404.
- Per-IP rate limit on the preview chat route: a coarse in-process sliding-window
  limiter (20 req/min/IP) returns 429 + Retry-After before the GPU lock is taken.
  Client IP honors X-Forwarded-For only when UNSLOTH_STUDIO_TRUST_FORWARDED is
  set, matching the login limiter's trust model.
- Settings UI: a "Preview sharing" section with the public-sharing toggle and a
  "Revoke all preview links" button (confirm dialog) that rotates the secret.

Tests cover the kill switch (404 when off), the 429 path, the sliding window,
client-IP trust behavior, and the setting default.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Studio: fix preview-fields sharing arg and refresh sigs after revoke

Codex review:
- P1: get_training_run_detail and update_training_run called _preview_fields
  with only output_dir after it gained a required sharing_on parameter, raising
  a 500 TypeError once get_run succeeded. Pass get_preview_sharing_enabled() at
  both sites; add a detail-endpoint regression test.
- P2: after rotating the preview secret from settings, the history grid still
  held stale preview_sig values, so a freshly copied link would 404. Emit
  emitTrainingRunsChanged() after a successful revoke so the grid refetches
  freshly signed refs.

* Studio: harden preview sharing controls (Codex review)

- Fail closed: a read failure on the preview-sharing kill switch now returns
  False instead of defaulting to enabled, so an unavailable settings DB can't
  reopen the public surface. A missing key still defaults to enabled.
- Per-IP rate limit behind the managed Cloudflare tunnel: client_ip now honors
  CF-Connecting-IP when the socket peer is loopback, so tunneled visitors are
  keyed by their real IP instead of collapsing onto the local cloudflared peer.
- GET /p no longer mints key/share_url when sharing is disabled; it returns
  sharing_enabled=false so clients don't distribute links that 404.
- Settings UI: toggling public sharing emits the training-runs-changed event so
  the history grid shows/hides Copy preview link without a manual refresh.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Studio: harden preview rate limiter and IP keying (Opus review)

From a two-agent review of the PR:

- Rate limiter no longer evicts an active bucket when the table is full: a flood
  of distinct keys could otherwise cycle out a throttled bucket and reset its
  counter. Evict only aged-out buckets; if the table is full of live clients,
  fail closed (deny the new key) instead.
- client_ip keys on the rightmost (proxy-appended) X-Forwarded-For hop when the
  trust env is set; the leftmost is client-spoofable. Documented the
  append/overwrite-proxy assumption.
- _verify_or_404 checks the capability token before the kill-switch DB read, so
  unauthenticated /p spam can't be used as an unbounded settings-DB sink and the
  response is identical regardless of the sharing on/off state.

Tests: nested run/checkpoint happy path + wrong-ref rejection, the eviction
fail-closed behavior, and route-level coverage for the rotate / preview-sharing
settings endpoints.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-06-25 21:40:48 -07:00

254 lines
8.4 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
from typing import Literal, Optional
from urllib.parse import unquote, urlsplit
from fastapi import APIRouter, Depends
from pydantic import BaseModel, ConfigDict, Field, field_validator
from auth.authentication import get_current_subject
from auth.storage import rotate_preview_link_secret
from loggers import get_logger
from utils.utils import safe_error_detail, log_and_http_error
from utils.personalization_settings import (
MAX_AVATAR_DATA_URL_BYTES,
PERSONALIZATION_VERSION,
get_personalization,
set_personalization,
)
from utils.upload_limits import (
MAX_UPLOAD_LIMIT_MB,
MIN_UPLOAD_LIMIT_MB,
default_upload_limit_mb,
get_upload_limit_mb,
set_upload_limit_mb,
upload_limit_bytes,
upload_limit_label,
)
from utils.helper_precache_settings import (
DEFAULT_HELPER_PRECACHE_ENABLED,
get_helper_precache_enabled,
helper_model_disabled_by_env,
set_helper_precache_enabled,
)
from utils.preview_sharing_settings import (
DEFAULT_PREVIEW_SHARING_ENABLED,
get_preview_sharing_enabled,
set_preview_sharing_enabled,
)
router = APIRouter()
logger = get_logger(__name__)
class UploadLimitPayload(BaseModel):
max_upload_size_mb: int = Field(..., ge = MIN_UPLOAD_LIMIT_MB, le = MAX_UPLOAD_LIMIT_MB)
class UploadLimitResponse(BaseModel):
max_upload_size_mb: int
max_upload_size_bytes: int
max_upload_size_label: str
default_upload_size_mb: int
min_upload_size_mb: int = MIN_UPLOAD_LIMIT_MB
max_allowed_upload_size_mb: int = MAX_UPLOAD_LIMIT_MB
class HelperPrecachePayload(BaseModel):
enabled: bool
class HelperPrecacheResponse(BaseModel):
enabled: bool
default_enabled: bool = DEFAULT_HELPER_PRECACHE_ENABLED
disabled_by_env: bool
def _upload_limit_response(limit_mb: int) -> UploadLimitResponse:
return UploadLimitResponse(
max_upload_size_mb = limit_mb,
max_upload_size_bytes = upload_limit_bytes(limit_mb),
max_upload_size_label = upload_limit_label(limit_mb),
default_upload_size_mb = default_upload_limit_mb(),
)
def _helper_precache_response(enabled: bool | None = None) -> HelperPrecacheResponse:
return HelperPrecacheResponse(
enabled = get_helper_precache_enabled() if enabled is None else enabled,
disabled_by_env = helper_model_disabled_by_env(),
)
@router.get("/upload-limit", response_model = UploadLimitResponse)
def get_upload_limit(current_subject: str = Depends(get_current_subject)) -> UploadLimitResponse:
return _upload_limit_response(get_upload_limit_mb())
@router.put("/upload-limit", response_model = UploadLimitResponse)
def update_upload_limit(
payload: UploadLimitPayload, current_subject: str = Depends(get_current_subject)
) -> UploadLimitResponse:
try:
limit_mb = set_upload_limit_mb(payload.max_upload_size_mb)
except ValueError as exc:
raise log_and_http_error(
exc,
400,
safe_error_detail(exc, fallback = "Invalid upload limit."),
event = "settings.update_upload_limit_failed",
log = logger,
) from exc
return _upload_limit_response(limit_mb)
@router.get("/helper-precache", response_model = HelperPrecacheResponse)
def get_helper_precache(
current_subject: str = Depends(get_current_subject),
) -> HelperPrecacheResponse:
return _helper_precache_response()
@router.put("/helper-precache", response_model = HelperPrecacheResponse)
def update_helper_precache(
payload: HelperPrecachePayload, current_subject: str = Depends(get_current_subject)
) -> HelperPrecacheResponse:
try:
enabled = set_helper_precache_enabled(payload.enabled)
except ValueError as exc:
raise log_and_http_error(
exc,
400,
safe_error_detail(exc, fallback = "Invalid Helper LLM pre-cache setting."),
event = "settings.update_helper_precache_failed",
log = logger,
) from exc
return _helper_precache_response(enabled)
class PreviewLinkRotateResponse(BaseModel):
rotated: bool = True
@router.post("/preview-links/rotate", response_model = PreviewLinkRotateResponse)
def rotate_preview_links(
current_subject: str = Depends(get_current_subject),
) -> PreviewLinkRotateResponse:
"""Rotate the preview-link signing secret, revoking every previously shared `/p` link."""
rotate_preview_link_secret()
logger.info("settings.preview_links_rotated subject=%s", current_subject)
return PreviewLinkRotateResponse(rotated = True)
class PreviewSharingPayload(BaseModel):
enabled: bool
class PreviewSharingResponse(BaseModel):
enabled: bool
default_enabled: bool = DEFAULT_PREVIEW_SHARING_ENABLED
@router.get("/preview-sharing", response_model = PreviewSharingResponse)
def get_preview_sharing(
current_subject: str = Depends(get_current_subject),
) -> PreviewSharingResponse:
return PreviewSharingResponse(enabled = get_preview_sharing_enabled())
@router.put("/preview-sharing", response_model = PreviewSharingResponse)
def update_preview_sharing(
payload: PreviewSharingPayload, current_subject: str = Depends(get_current_subject)
) -> PreviewSharingResponse:
"""Enable/disable the public `/p` preview surface. When off, links 404 even with a token."""
try:
enabled = set_preview_sharing_enabled(payload.enabled)
except ValueError as exc:
raise log_and_http_error(
exc,
400,
safe_error_detail(exc, fallback = "Invalid preview sharing setting."),
event = "settings.update_preview_sharing_failed",
log = logger,
) from exc
logger.info("settings.preview_sharing_updated subject=%s enabled=%s", current_subject, enabled)
return PreviewSharingResponse(enabled = enabled)
def _is_bundled_avatar_url(value: str) -> bool:
parsed = urlsplit(value)
if parsed.scheme or parsed.netloc:
return False
path = unquote(parsed.path).lstrip("/")
if ".." in path.split("/"):
return False
marker = "Sloth emojis/"
if marker not in path:
return False
return path[path.index(marker) :].lower().endswith(".png")
class PersonalizationProfile(BaseModel):
model_config = ConfigDict(extra = "ignore")
displayName: str = Field("", max_length = 200)
nickname: str = Field("", max_length = 200)
avatarDataUrl: Optional[str] = Field(None, max_length = MAX_AVATAR_DATA_URL_BYTES)
avatarShape: Literal["circle", "rounded"] = "circle"
@field_validator("avatarDataUrl")
@classmethod
def _validate_avatar(cls, value: Optional[str]) -> Optional[str]:
if not value:
return value
if not value.startswith("data:image/") and not _is_bundled_avatar_url(value):
raise ValueError("avatarDataUrl must be an image data URL or bundled avatar.")
return value
class PersonalizationAppearance(BaseModel):
model_config = ConfigDict(extra = "ignore")
theme: Literal["light", "dark", "system"] = "system"
language: Optional[str] = Field(None, max_length = 20)
class PersonalizationPayload(BaseModel):
model_config = ConfigDict(extra = "ignore")
version: int = PERSONALIZATION_VERSION
profile: PersonalizationProfile = Field(default_factory = PersonalizationProfile)
appearance: PersonalizationAppearance = Field(default_factory = PersonalizationAppearance)
class PersonalizationResponse(PersonalizationPayload):
saved: bool = False
@router.get("/personalization", response_model = PersonalizationResponse)
def get_personalization_settings(
current_subject: str = Depends(get_current_subject),
) -> PersonalizationResponse:
stored = get_personalization()
response = PersonalizationResponse.model_validate(stored or {})
response.saved = bool(stored)
return response
@router.put("/personalization", response_model = PersonalizationPayload)
def update_personalization_settings(
payload: PersonalizationPayload, current_subject: str = Depends(get_current_subject)
) -> PersonalizationPayload:
try:
set_personalization(payload.model_dump())
except ValueError as exc:
raise log_and_http_error(
exc,
400,
safe_error_detail(exc, fallback = "Invalid personalization settings."),
event = "settings.update_personalization_failed",
log = logger,
) from exc
return payload