Files
gemini-cli/packages/cli/src/config/policy-toml-loader.ts

395 lines
12 KiB
TypeScript

/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import {
type PolicyRule,
PolicyDecision,
type ApprovalMode,
} from '@google/gemini-cli-core';
import fs from 'node:fs/promises';
import path from 'node:path';
import toml from '@iarna/toml';
import { z, type ZodError } from 'zod';
/**
* Schema for a single policy rule in the TOML file (before transformation).
*/
const PolicyRuleSchema = z.object({
toolName: z.union([z.string(), z.array(z.string())]).optional(),
mcpName: z.string().optional(),
argsPattern: z.string().optional(),
commandPrefix: z.union([z.string(), z.array(z.string())]).optional(),
commandRegex: z.string().optional(),
decision: z.nativeEnum(PolicyDecision),
// Priority must be in range [0, 999] to prevent tier overflow.
// With tier transformation (tier + priority/1000), this ensures:
// - Tier 1 (default): range [1.000, 1.999]
// - Tier 2 (user): range [2.000, 2.999]
// - Tier 3 (admin): range [3.000, 3.999]
priority: z
.number({
required_error: 'priority is required',
invalid_type_error: 'priority must be a number',
})
.int({ message: 'priority must be an integer' })
.min(0, { message: 'priority must be >= 0' })
.max(999, {
message:
'priority must be <= 999 to prevent tier overflow. Priorities >= 1000 would jump to the next tier.',
}),
modes: z.array(z.string()).optional(),
});
/**
* Schema for the entire policy TOML file.
*/
const PolicyFileSchema = z.object({
rule: z.array(PolicyRuleSchema),
});
/**
* Type for a raw policy rule from TOML (before transformation).
*/
type PolicyRuleToml = z.infer<typeof PolicyRuleSchema>;
/**
* Types of errors that can occur while loading policy files.
*/
export type PolicyFileErrorType =
| 'file_read'
| 'toml_parse'
| 'schema_validation'
| 'rule_validation'
| 'regex_compilation';
/**
* Detailed error information for policy file loading failures.
*/
export interface PolicyFileError {
filePath: string;
fileName: string;
tier: 'default' | 'user' | 'admin';
ruleIndex?: number;
errorType: PolicyFileErrorType;
message: string;
details?: string;
suggestion?: string;
}
/**
* Result of loading policies from TOML files.
*/
export interface PolicyLoadResult {
rules: PolicyRule[];
errors: PolicyFileError[];
}
/**
* Escapes special regex characters in a string for use in a regex pattern.
* This is used for commandPrefix to ensure literal string matching.
*
* @param str The string to escape
* @returns The escaped string safe for use in a regex
*/
function escapeRegex(str: string): string {
return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
}
/**
* Converts a tier number to a human-readable tier name.
*/
function getTierName(tier: number): 'default' | 'user' | 'admin' {
if (tier === 1) return 'default';
if (tier === 2) return 'user';
if (tier === 3) return 'admin';
return 'default';
}
/**
* Formats a Zod validation error into a readable error message.
*/
function formatSchemaError(error: ZodError, ruleIndex: number): string {
const issues = error.issues
.map((issue) => {
const path = issue.path.join('.');
return ` - Field "${path}": ${issue.message}`;
})
.join('\n');
return `Invalid policy rule (rule #${ruleIndex + 1}):\n${issues}`;
}
/**
* Validates shell command convenience syntax rules.
* Returns an error message if invalid, or null if valid.
*/
function validateShellCommandSyntax(
rule: PolicyRuleToml,
ruleIndex: number,
): string | null {
const hasCommandPrefix = rule.commandPrefix !== undefined;
const hasCommandRegex = rule.commandRegex !== undefined;
const hasArgsPattern = rule.argsPattern !== undefined;
if (hasCommandPrefix || hasCommandRegex) {
// Must have exactly toolName = "run_shell_command"
if (rule.toolName !== 'run_shell_command' || Array.isArray(rule.toolName)) {
return (
`Rule #${ruleIndex + 1}: commandPrefix and commandRegex can only be used with toolName = "run_shell_command"\n` +
` Found: toolName = ${JSON.stringify(rule.toolName)}\n` +
` Fix: Set toolName = "run_shell_command" (not an array)`
);
}
// Can't combine with argsPattern
if (hasArgsPattern) {
return (
`Rule #${ruleIndex + 1}: cannot use both commandPrefix/commandRegex and argsPattern\n` +
` These fields are mutually exclusive\n` +
` Fix: Use either commandPrefix/commandRegex OR argsPattern, not both`
);
}
// Can't use both commandPrefix and commandRegex
if (hasCommandPrefix && hasCommandRegex) {
return (
`Rule #${ruleIndex + 1}: cannot use both commandPrefix and commandRegex\n` +
` These fields are mutually exclusive\n` +
` Fix: Use either commandPrefix OR commandRegex, not both`
);
}
}
return null;
}
/**
* Transforms a priority number based on the policy tier.
* Formula: tier + priority/1000
*
* @param priority The priority value from the TOML file
* @param tier The tier (1=default, 2=user, 3=admin)
* @returns The transformed priority
*/
function transformPriority(priority: number, tier: number): number {
return tier + priority / 1000;
}
/**
* Loads and parses policies from TOML files in the specified directories.
*
* This function:
* 1. Scans directories for .toml files
* 2. Parses and validates each file
* 3. Transforms rules (commandPrefix, arrays, mcpName, priorities)
* 4. Filters rules by approval mode
* 5. Collects detailed error information for any failures
*
* @param approvalMode The current approval mode (for filtering rules by mode)
* @param policyDirs Array of directory paths to scan for policy files
* @param getPolicyTier Function to determine tier (1-3) for a directory
* @returns Object containing successfully parsed rules and any errors encountered
*/
export async function loadPoliciesFromToml(
approvalMode: ApprovalMode,
policyDirs: string[],
getPolicyTier: (dir: string) => number,
): Promise<PolicyLoadResult> {
const rules: PolicyRule[] = [];
const errors: PolicyFileError[] = [];
for (const dir of policyDirs) {
const tier = getPolicyTier(dir);
const tierName = getTierName(tier);
// Scan directory for all .toml files
let filesToLoad: string[];
try {
const dirEntries = await fs.readdir(dir, { withFileTypes: true });
filesToLoad = dirEntries
.filter((entry) => entry.isFile() && entry.name.endsWith('.toml'))
.map((entry) => entry.name);
} catch (e) {
const error = e as NodeJS.ErrnoException;
if (error.code === 'ENOENT') {
// Directory doesn't exist, skip it (not an error)
continue;
}
errors.push({
filePath: dir,
fileName: path.basename(dir),
tier: tierName,
errorType: 'file_read',
message: `Failed to read policy directory`,
details: error.message,
});
continue;
}
for (const file of filesToLoad) {
const filePath = path.join(dir, file);
try {
// Read file
const fileContent = await fs.readFile(filePath, 'utf-8');
// Parse TOML
let parsed: unknown;
try {
parsed = toml.parse(fileContent);
} catch (e) {
const error = e as Error;
errors.push({
filePath,
fileName: file,
tier: tierName,
errorType: 'toml_parse',
message: 'TOML parsing failed',
details: error.message,
suggestion:
'Check for syntax errors like missing quotes, brackets, or commas',
});
continue;
}
// Validate schema
const validationResult = PolicyFileSchema.safeParse(parsed);
if (!validationResult.success) {
errors.push({
filePath,
fileName: file,
tier: tierName,
errorType: 'schema_validation',
message: 'Schema validation failed',
details: formatSchemaError(validationResult.error, 0),
suggestion:
'Ensure all required fields (decision, priority) are present with correct types',
});
continue;
}
// Validate shell command convenience syntax
for (let i = 0; i < validationResult.data.rule.length; i++) {
const rule = validationResult.data.rule[i];
const validationError = validateShellCommandSyntax(rule, i);
if (validationError) {
errors.push({
filePath,
fileName: file,
tier: tierName,
ruleIndex: i,
errorType: 'rule_validation',
message: 'Invalid shell command syntax',
details: validationError,
});
// Continue to next rule, don't skip the entire file
}
}
// Transform rules
const parsedRules: PolicyRule[] = validationResult.data.rule
.filter((rule) => {
// Filter by mode
if (!rule.modes || rule.modes.length === 0) {
return true;
}
return rule.modes.includes(approvalMode);
})
.flatMap((rule) => {
// Transform commandPrefix/commandRegex to argsPattern
let effectiveArgsPattern = rule.argsPattern;
const commandPrefixes: string[] = [];
if (rule.commandPrefix) {
const prefixes = Array.isArray(rule.commandPrefix)
? rule.commandPrefix
: [rule.commandPrefix];
commandPrefixes.push(...prefixes);
} else if (rule.commandRegex) {
effectiveArgsPattern = `"command":"${rule.commandRegex}`;
}
// Expand command prefixes to multiple patterns
const argsPatterns: Array<string | undefined> =
commandPrefixes.length > 0
? commandPrefixes.map(
(prefix) => `"command":"${escapeRegex(prefix)}`,
)
: [effectiveArgsPattern];
// For each argsPattern, expand toolName arrays
return argsPatterns.flatMap((argsPattern) => {
const toolNames: Array<string | undefined> = rule.toolName
? Array.isArray(rule.toolName)
? rule.toolName
: [rule.toolName]
: [undefined];
// Create a policy rule for each tool name
return toolNames.map((toolName) => {
// Transform mcpName field to composite toolName format
let effectiveToolName: string | undefined;
if (rule.mcpName && toolName) {
effectiveToolName = `${rule.mcpName}__${toolName}`;
} else if (rule.mcpName) {
effectiveToolName = `${rule.mcpName}__*`;
} else {
effectiveToolName = toolName;
}
const policyRule: PolicyRule = {
toolName: effectiveToolName,
decision: rule.decision,
priority: transformPriority(rule.priority, tier),
};
// Compile regex pattern
if (argsPattern) {
try {
policyRule.argsPattern = new RegExp(argsPattern);
} catch (e) {
const error = e as Error;
errors.push({
filePath,
fileName: file,
tier: tierName,
errorType: 'regex_compilation',
message: 'Invalid regex pattern',
details: `Pattern: ${argsPattern}\nError: ${error.message}`,
suggestion:
'Check regex syntax for errors like unmatched brackets or invalid escape sequences',
});
// Skip this rule if regex compilation fails
return null;
}
}
return policyRule;
});
});
})
.filter((rule): rule is PolicyRule => rule !== null);
rules.push(...parsedRules);
} catch (e) {
const error = e as NodeJS.ErrnoException;
// Catch-all for unexpected errors
if (error.code !== 'ENOENT') {
errors.push({
filePath,
fileName: file,
tier: tierName,
errorType: 'file_read',
message: 'Failed to read policy file',
details: error.message,
});
}
}
}
}
return { rules, errors };
}