llama-stack/llama_stack/providers/inline/safety/prompt_guard/prompt_guard.py
Ashwin Bharambe c1f7ba3aed
Split safety into (llama-guard, prompt-guard, code-scanner) (#400)
Splits the meta-reference safety implementation into three distinct providers:

- inline::llama-guard
- inline::prompt-guard
- inline::code-scanner

Note that this PR is a backward incompatible change to the llama stack server. I have added deprecation_error field to ProviderSpec -- the server reads it and immediately barfs. This is used to direct the user with a specific message on what action to perform. An automagical "config upgrade" is a bit too much work to implement right now :/

(Note that we will be gradually prefixing all inline providers with inline:: -- I am only doing this for this set of new providers because otherwise existing configuration files will break even more badly.)
2024-11-11 09:29:18 -08:00

120 lines
4.1 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
from typing import Any, Dict, List
import torch
from termcolor import cprint
from transformers import AutoModelForSequenceClassification, AutoTokenizer
from llama_stack.distribution.utils.model_utils import model_local_dir
from llama_stack.apis.inference import * # noqa: F403
from llama_stack.apis.safety import * # noqa: F403
from llama_models.llama3.api.datatypes import * # noqa: F403
from llama_stack.providers.datatypes import ShieldsProtocolPrivate
from .config import PromptGuardConfig, PromptGuardType
PROMPT_GUARD_MODEL = "Prompt-Guard-86M"
class PromptGuardSafetyImpl(Safety, ShieldsProtocolPrivate):
def __init__(self, config: PromptGuardConfig, _deps) -> None:
self.config = config
async def initialize(self) -> None:
model_dir = model_local_dir(PROMPT_GUARD_MODEL)
self.shield = PromptGuardShield(model_dir, self.config)
async def shutdown(self) -> None:
pass
async def register_shield(self, shield: Shield) -> None:
if shield.shield_type != ShieldType.prompt_guard:
raise ValueError(f"Unsupported shield type: {shield.shield_type}")
async def run_shield(
self,
shield_id: str,
messages: List[Message],
params: Dict[str, Any] = None,
) -> RunShieldResponse:
shield = await self.shield_store.get_shield(shield_id)
if not shield:
raise ValueError(f"Unknown shield {shield_id}")
return await self.shield.run(messages)
class PromptGuardShield:
def __init__(
self,
model_dir: str,
config: PromptGuardConfig,
threshold: float = 0.9,
temperature: float = 1.0,
):
assert (
model_dir is not None
), "Must provide a model directory for prompt injection shield"
if temperature <= 0:
raise ValueError("Temperature must be greater than 0")
self.config = config
self.temperature = temperature
self.threshold = threshold
self.device = "cuda"
# load model and tokenizer
self.tokenizer = AutoTokenizer.from_pretrained(model_dir)
self.model = AutoModelForSequenceClassification.from_pretrained(
model_dir, device_map=self.device
)
async def run(self, messages: List[Message]) -> RunShieldResponse:
message = messages[-1]
text = interleaved_text_media_as_str(message.content)
# run model on messages and return response
inputs = self.tokenizer(text, return_tensors="pt")
inputs = {name: tensor.to(self.model.device) for name, tensor in inputs.items()}
with torch.no_grad():
outputs = self.model(**inputs)
logits = outputs[0]
probabilities = torch.softmax(logits / self.temperature, dim=-1)
score_embedded = probabilities[0, 1].item()
score_malicious = probabilities[0, 2].item()
cprint(
f"Ran PromptGuardShield and got Scores: Embedded: {score_embedded}, Malicious: {score_malicious}",
color="magenta",
)
violation = None
if self.config.guard_type == PromptGuardType.injection.value and (
score_embedded + score_malicious > self.threshold
):
violation = SafetyViolation(
violation_level=ViolationLevel.ERROR,
user_message="Sorry, I cannot do this.",
metadata={
"violation_type": f"prompt_injection:embedded={score_embedded},malicious={score_malicious}",
},
)
elif (
self.config.guard_type == PromptGuardType.jailbreak.value
and score_malicious > self.threshold
):
violation = SafetyViolation(
violation_level=ViolationLevel.ERROR,
violation_type=f"prompt_injection:malicious={score_malicious}",
violation_return_message="Sorry, I cannot do this.",
)
return RunShieldResponse(violation=violation)