dnsrecon/providers/base_provider.py

# dnsrecon/providers/base_provider.py

import time
import requests
import threading
import os
import json
from abc import ABC, abstractmethod
from typing import List, Dict, Any, Optional, Tuple

from core.logger import get_forensic_logger
from core.graph_manager import RelationshipType


class RateLimiter:
    """Simple rate limiter for API calls."""

    def __init__(self, requests_per_minute: int):
        """
        Initialize rate limiter.

        Args:
            requests_per_minute: Maximum requests allowed per minute
        """
        self.requests_per_minute = requests_per_minute
        self.min_interval = 60.0 / requests_per_minute
        self.last_request_time = 0

    def wait_if_needed(self) -> None:
        """Wait if necessary to respect rate limits."""
        current_time = time.time()
        time_since_last = current_time - self.last_request_time

        if time_since_last < self.min_interval:
            sleep_time = self.min_interval - time_since_last
            time.sleep(sleep_time)

        self.last_request_time = time.time()


class BaseProvider(ABC):
    """
    Abstract base class for all DNSRecon data providers.
    Now supports session-specific configuration.
    """

    def __init__(self, name: str, rate_limit: int = 60, timeout: int = 30, session_config=None):
        """
        Initialize base provider with session-specific configuration.

        Args:
            name: Provider name for logging
            rate_limit: Requests per minute limit (default override)
            timeout: Request timeout in seconds
            session_config: Session-specific configuration
        """
        # Use session config if provided, otherwise fall back to global config
        if session_config is not None:
            self.config = session_config
            actual_rate_limit = self.config.get_rate_limit(name)
            actual_timeout = self.config.default_timeout
        else:
            # Fallback to global config for backwards compatibility
            from config import config as global_config
            self.config = global_config
            actual_rate_limit = rate_limit
            actual_timeout = timeout

        self.name = name
        self.rate_limiter = RateLimiter(actual_rate_limit)
        self.timeout = actual_timeout
        self._local = threading.local()
        self.logger = get_forensic_logger()
        self._stop_event = None

        # Caching configuration (per session)
        self.cache_dir = f'.cache/{id(self.config)}'  # Unique cache per session config
        self.cache_expiry = 12 * 3600  # 12 hours in seconds
        if not os.path.exists(self.cache_dir):
            os.makedirs(self.cache_dir)

        # Statistics (per provider instance)
        self.total_requests = 0
        self.successful_requests = 0
        self.failed_requests = 0
        self.total_relationships_found = 0

        print(f"Initialized {name} provider with session-specific config (rate: {actual_rate_limit}/min)")

    @property
    def session(self):
        if not hasattr(self._local, 'session'):
            self._local.session = requests.Session()
            self._local.session.headers.update({
                'User-Agent': 'DNSRecon/1.0 (Passive Reconnaissance Tool)'
            })
        return self._local.session

    @abstractmethod
    def get_name(self) -> str:
        """Return the provider name."""
        pass

    @abstractmethod
    def is_available(self) -> bool:
        """Check if the provider is available and properly configured."""
        pass

    @abstractmethod
    def query_domain(self, domain: str) -> List[Tuple[str, str, RelationshipType, float, Dict[str, Any]]]:
        """
        Query the provider for information about a domain.

        Args:
            domain: Domain to investigate

        Returns:
            List of tuples: (source_node, target_node, relationship_type, confidence, raw_data)
        """
        pass

    @abstractmethod
    def query_ip(self, ip: str) -> List[Tuple[str, str, RelationshipType, float, Dict[str, Any]]]:
        """
        Query the provider for information about an IP address.

        Args:
            ip: IP address to investigate

        Returns:
            List of tuples: (source_node, target_node, relationship_type, confidence, raw_data)
        """
        pass

    def make_request(self, url: str, method: str = "GET",
                    params: Optional[Dict[str, Any]] = None,
                    headers: Optional[Dict[str, str]] = None,
                    target_indicator: str = "",
                    max_retries: int = 3) -> Optional[requests.Response]:
        """
        Make a rate-limited HTTP request with forensic logging and retry logic.
        Now supports cancellation via stop_event from scanner.
        """
        # Check for cancellation before starting
        if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
            print(f"Request cancelled before start: {url}")
            return None

        # Create a unique cache key
        cache_key = f"{self.name}_{hash(f'{method}:{url}:{json.dumps(params, sort_keys=True)}')}.json"
        cache_path = os.path.join(self.cache_dir, cache_key)

        # Check cache
        if os.path.exists(cache_path):
            cache_age = time.time() - os.path.getmtime(cache_path)
            if cache_age < self.cache_expiry:
                print(f"Returning cached response for: {url}")
                with open(cache_path, 'r') as f:
                    cached_data = json.load(f)
                    response = requests.Response()
                    response.status_code = cached_data['status_code']
                    response._content = cached_data['content'].encode('utf-8')
                    response.headers = cached_data['headers']
                    return response

        for attempt in range(max_retries + 1):
            # Check for cancellation before each attempt
            if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
                print(f"Request cancelled during attempt {attempt + 1}: {url}")
                return None

            # Apply rate limiting (but reduce wait time if cancellation is requested)
            if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
                break
            
            self.rate_limiter.wait_if_needed()

            # Check again after rate limiting
            if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
                print(f"Request cancelled after rate limiting: {url}")
                return None

            start_time = time.time()
            response = None
            error = None

            try:
                self.total_requests += 1

                # Prepare request
                request_headers = self.session.headers.copy()
                if headers:
                    request_headers.update(headers)

                print(f"Making {method} request to: {url} (attempt {attempt + 1})")

                # Use shorter timeout if termination is requested
                request_timeout = self.timeout
                if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
                    request_timeout = min(5, self.timeout)  # Max 5 seconds if termination requested

                # Make request
                if method.upper() == "GET":
                    response = self.session.get(
                        url,
                        params=params,
                        headers=request_headers,
                        timeout=request_timeout
                    )
                elif method.upper() == "POST":
                    response = self.session.post(
                        url,
                        json=params,
                        headers=request_headers,
                        timeout=request_timeout
                    )
                else:
                    raise ValueError(f"Unsupported HTTP method: {method}")

                print(f"Response status: {response.status_code}")
                response.raise_for_status()
                self.successful_requests += 1
                
                # Success - log, cache, and return
                duration_ms = (time.time() - start_time) * 1000
                self.logger.log_api_request(
                    provider=self.name,
                    url=url,
                    method=method.upper(),
                    status_code=response.status_code,
                    response_size=len(response.content),
                    duration_ms=duration_ms,
                    error=None,
                    target_indicator=target_indicator
                )
                # Cache the successful response to disk
                with open(cache_path, 'w') as f:
                    json.dump({
                        'status_code': response.status_code,
                        'content': response.text,
                        'headers': dict(response.headers)
                    }, f)
                return response

            except requests.exceptions.RequestException as e:
                error = str(e)
                self.failed_requests += 1
                print(f"Request failed (attempt {attempt + 1}): {error}")
                
                # Check for cancellation before retrying
                if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
                    print(f"Request cancelled, not retrying: {url}")
                    break
                
                # Check if we should retry
                if attempt < max_retries and self._should_retry(e):
                    backoff_time = (2 ** attempt) * 1  # Exponential backoff: 1s, 2s, 4s
                    print(f"Retrying in {backoff_time} seconds...")
                    
                    # Shorter backoff if termination is requested
                    if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
                        backoff_time = min(0.5, backoff_time)
                    
                    # Sleep with cancellation checking
                    sleep_start = time.time()
                    while time.time() - sleep_start < backoff_time:
                        if hasattr(self, '_stop_event') and self._stop_event and self._stop_event.is_set():
                            print(f"Request cancelled during backoff: {url}")
                            return None
                        time.sleep(0.1)  # Check every 100ms
                    continue
                else:
                    break

            except Exception as e:
                error = f"Unexpected error: {str(e)}"
                self.failed_requests += 1
                print(f"Unexpected error: {error}")
                break

        # All attempts failed - log and return None
        duration_ms = (time.time() - start_time) * 1000
        self.logger.log_api_request(
            provider=self.name,
            url=url,
            method=method.upper(),
            status_code=response.status_code if response else None,
            response_size=len(response.content) if response else None,
            duration_ms=duration_ms,
            error=error,
            target_indicator=target_indicator
        )
        
        return None

    def set_stop_event(self, stop_event: threading.Event) -> None:
        """
        Set the stop event for this provider to enable cancellation.
        
        Args:
            stop_event: Threading event to signal cancellation
        """
        self._stop_event = stop_event

    def _should_retry(self, exception: requests.exceptions.RequestException) -> bool:
        """
        Determine if a request should be retried based on the exception.
        
        Args:
            exception: The request exception that occurred
            
        Returns:
            True if the request should be retried
        """
        # Retry on connection errors, timeouts, and 5xx server errors
        if isinstance(exception, (requests.exceptions.ConnectionError, 
                                requests.exceptions.Timeout)):
            return True
        
        if isinstance(exception, requests.exceptions.HTTPError):
            if hasattr(exception, 'response') and exception.response:
                # Retry on server errors (5xx) but not client errors (4xx)
                return exception.response.status_code >= 500
        
        return False

    def log_relationship_discovery(self, source_node: str, target_node: str,
                                 relationship_type: RelationshipType,
                                 confidence_score: float,
                                 raw_data: Dict[str, Any],
                                 discovery_method: str) -> None:
        """
        Log discovery of a new relationship.

        Args:
            source_node: Source node identifier
            target_node: Target node identifier
            relationship_type: Type of relationship
            confidence_score: Confidence score
            raw_data: Raw data from provider
            discovery_method: Method used for discovery
        """
        self.total_relationships_found += 1

        self.logger.log_relationship_discovery(
            source_node=source_node,
            target_node=target_node,
            relationship_type=relationship_type.relationship_name,
            confidence_score=confidence_score,
            provider=self.name,
            raw_data=raw_data,
            discovery_method=discovery_method
        )

    def get_statistics(self) -> Dict[str, Any]:
        """
        Get provider statistics.

        Returns:
            Dictionary containing provider performance metrics
        """
        return {
            'name': self.name,
            'total_requests': self.total_requests,
            'successful_requests': self.successful_requests,
            'failed_requests': self.failed_requests,
            'success_rate': (self.successful_requests / self.total_requests * 100) if self.total_requests > 0 else 0,
            'relationships_found': self.total_relationships_found,
            'rate_limit': self.rate_limiter.requests_per_minute
        }