YueGuobin 0e6db9a7b6
fix: correct MCP transport security config to actually allow all hosts by default
The MCP library's TransportSecurityMiddleware only supports exact host
matches or "host:*" port wildcards. It does NOT support a standalone "*"
wildcard to mean "allow all hosts" — setting allowed_hosts=["*"] would
reject every connection because no Host header equals "*".

Worse, when transport_security=None was passed to FastMCP while its default
host is "127.0.0.1", FastMCP would auto-enable protection with strict
localhost-only rules, overriding GNS3's intent to allow all hosts.

Root cause analysis:
- FastMCP auto-enables DNS rebinding protection when host is localhost
  and no explicit TransportSecuritySettings is provided
- GNS3 was passing transport_security=None (indirectly via FastMCP's default)
  when protection was disabled, triggering the auto-enable
- The TransportSecuritySettings "allowed_hosts" list does NOT support "*"
  as a catch-all wildcard

This fix:
1. Always pass an explicit TransportSecuritySettings to FastMCP
   - Disabled: TransportSecuritySettings(enable_dns_rebinding_protection=False)
   - Enabled: TransportSecuritySettings(enable_dns_rebinding_protection=True, ...)
2. Restore mcp_allowed_hosts and mcp_allowed_origins config fields
3. Set mcp_enable_dns_rebinding_protection default to False (allow all hosts)

Behaviour:
- Default (no config change): all hosts can connect to MCP server
- With mcp_enable_dns_rebinding_protection=true: only configured hosts
- Aligns with GNS3 server's 0.0.0.0 binding policy
2026-06-05 23:20:57 +08:00

238 lines
8.1 KiB
Python

#
# Copyright (C) 2021 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import socket
from enum import Enum
from pydantic import (
ConfigDict,
BaseModel,
Field,
SecretStr,
FilePath,
DirectoryPath,
field_validator,
model_validator
)
from typing import List
class ControllerSettings(BaseModel):
jwt_secret_key: str = None
jwt_algorithm: str = "HS256"
jwt_access_token_expire_minutes: int = 1440 # 24 hours
default_admin_username: str = "admin"
default_admin_password: SecretStr = SecretStr("admin")
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
class VPCSSettings(BaseModel):
vpcs_path: str = "vpcs"
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
class DynamipsSettings(BaseModel):
allocate_aux_console_ports: bool = False
mmap_support: bool = True
dynamips_path: str = "dynamips"
sparse_memory_support: bool = True
ghost_ios_support: bool = True
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
class IOUSettings(BaseModel):
iourc_path: str = None
license_check: bool = True
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
class QemuSettings(BaseModel):
enable_monitor: bool = True
monitor_host: str = "127.0.0.1"
enable_hardware_acceleration: bool = True
require_hardware_acceleration: bool = False
allow_unsafe_options: bool = False
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
class VirtualBoxSettings(BaseModel):
vboxmanage_path: str = None
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
class VMwareSettings(BaseModel):
vmrun_path: str = None
vmnet_start_range: int = Field(2, ge=1, le=255)
vmnet_end_range: int = Field(255, ge=1, le=255) # should be limited to 19 on Windows
block_host_traffic: bool = False
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
@model_validator(mode="after")
def check_vmnet_port_range(self) -> "VMwareSettings":
if self.vmnet_end_range <= self.vmnet_start_range:
raise ValueError("vmnet_end_range must be > vmnet_start_range")
return self
class WebWiresharkSettings(BaseModel):
enabled: bool = True
image: str = "gns3/web-wireshark:latest"
network_subnet: str = "172.31.0.0/22"
memory: str = "2g"
cpus: float = 1.0
pids_limit: int = 1000
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
class ServerProtocol(str, Enum):
http = "http"
https = "https"
class BuiltinSymbolTheme(str, Enum):
classic = "Classic"
affinity_square_blue = "Affinity-square-blue"
affinity_square_red = "Affinity-square-red"
affinity_square_gray = "Affinity-square-gray"
affinity_circle_blue = "Affinity-circle-blue"
affinity_circle_red = "Affinity-circle-red"
affinity_circle_gray = "Affinity-circle-gray"
class ServerSettings(BaseModel):
local: bool = False
enable_http_auth: bool = True
name: str = f"{socket.gethostname()} (controller)"
protocol: ServerProtocol = ServerProtocol.http
host: str = "0.0.0.0"
port: int = Field(3080, gt=0, le=65535)
secrets_dir: DirectoryPath = None
certfile: FilePath = None
certkey: FilePath = None
enable_ssl: bool = False
images_path: str = "~/GNS3/images"
projects_path: str = "~/GNS3/projects"
appliances_path: str = "~/GNS3/appliances"
symbols_path: str = "~/GNS3/symbols"
configs_path: str = "~/GNS3/configs"
resources_path: str = None
default_symbol_theme: BuiltinSymbolTheme = BuiltinSymbolTheme.affinity_square_blue
allow_raw_images: bool = True
auto_discover_images: bool = True
report_errors: bool = True
additional_images_paths: List[str] = Field(default_factory=list)
console_start_port_range: int = Field(5000, gt=0, le=65535)
console_end_port_range: int = Field(10000, gt=0, le=65535)
vnc_console_start_port_range: int = Field(5900, ge=5900, le=65535)
vnc_console_end_port_range: int = Field(10000, ge=5900, le=65535)
udp_start_port_range: int = Field(10000, gt=0, le=65535)
udp_end_port_range: int = Field(30000, gt=0, le=65535)
ubridge_path: str = "ubridge"
compute_username: str = "gns3"
compute_password: SecretStr = SecretStr("")
allowed_interfaces: List[str] = Field(default_factory=list)
default_nat_interface: str = None
allow_remote_console: bool = False
enable_builtin_templates: bool = True
install_builtin_appliances: bool = True
skills_repo_url: str = "https://github.com/gns3/gns3-skills.git"
skills_repo_branch: str = "main"
skills_auto_update: bool = True
# MCP (Model Context Protocol) transport security settings
# DNS rebinding protection is disabled by default to allow connections
# from any host (aligns with GNS3 server's 0.0.0.0 binding).
# Users with security requirements can enable protection and specify
# allowed hosts using "host:*" port wildcard patterns.
mcp_enable_dns_rebinding_protection: bool = False
mcp_allowed_hosts: list[str] = Field(default_factory=list)
mcp_allowed_origins: list[str] = Field(default_factory=list)
model_config = ConfigDict(validate_assignment=True, str_strip_whitespace=True)
@field_validator("mcp_allowed_hosts", mode="before")
@classmethod
def split_mcp_allowed_hosts(cls, v):
if v and isinstance(v, str):
return v.split(",")
return list()
@field_validator("mcp_allowed_origins", mode="before")
@classmethod
def split_mcp_allowed_origins(cls, v):
if v and isinstance(v, str):
return v.split(",")
return list()
@field_validator("additional_images_paths", mode="before")
@classmethod
def split_additional_images_paths(cls, v):
if v:
return v.split(";")
return list()
@field_validator("allowed_interfaces", mode="before")
@classmethod
def split_allowed_interfaces(cls, v):
if v:
return v.split(",")
return list()
@model_validator(mode="after")
def check_console_port_range(self) -> "ServerSettings":
if self.console_end_port_range <= self.console_start_port_range:
raise ValueError("console_end_port_range must be > console_start_port_range")
return self
@model_validator(mode="after")
def check_vnc_port_range(self) -> "ServerSettings":
if self.vnc_console_end_port_range <= self.vnc_console_start_port_range:
raise ValueError("vnc_console_end_port_range must be > vnc_console_start_port_range")
return self
@model_validator(mode="after")
def check_enable_ssl(self) -> "ServerSettings":
if self.enable_ssl is True:
if not self.certfile:
raise ValueError("SSL is enabled but certfile is not configured")
if not self.certkey:
raise ValueError("SSL is enabled but certkey is not configured")
return self
class ServerConfig(BaseModel):
Server: ServerSettings = ServerSettings()
Controller: ControllerSettings = ControllerSettings()
VPCS: VPCSSettings = VPCSSettings()
Dynamips: DynamipsSettings = DynamipsSettings()
IOU: IOUSettings = IOUSettings()
Qemu: QemuSettings = QemuSettings()
VirtualBox: VirtualBoxSettings = VirtualBoxSettings()
VMware: VMwareSettings = VMwareSettings()
WebWireshark: WebWiresharkSettings = WebWiresharkSettings()