[#3848] Warn if running as root

Servers now all warn if they are running
as root.

src/bin/dhcp4/dhcp4_messages.cc

@@ -157,6 +157,7 @@ extern const isc::log::MessageID DHCP4_RESPONSE_DATA = "DHCP4_RESPONSE_DATA";
 extern const isc::log::MessageID DHCP4_RESPONSE_FQDN_DATA = "DHCP4_RESPONSE_FQDN_DATA";
 extern const isc::log::MessageID DHCP4_RESPONSE_HOSTNAME_DATA = "DHCP4_RESPONSE_HOSTNAME_DATA";
 extern const isc::log::MessageID DHCP4_RESPONSE_HOSTNAME_GENERATE = "DHCP4_RESPONSE_HOSTNAME_GENERATE";
+extern const isc::log::MessageID DHCP4_ROOT_USER_SECURITY_WARN = "DHCP4_ROOT_USER_SECURITY_WARN";
 extern const isc::log::MessageID DHCP4_SECURITY_CHECKS_DISABLED = "DHCP4_SECURITY_CHECKS_DISABLED";
 extern const isc::log::MessageID DHCP4_SERVER_FAILED = "DHCP4_SERVER_FAILED";
 extern const isc::log::MessageID DHCP4_SERVER_INITIATED_DECLINE = "DHCP4_SERVER_INITIATED_DECLINE";
@@ -337,6 +338,7 @@ const char* values[] = {
     "DHCP4_RESPONSE_FQDN_DATA", "%1: including FQDN option in the server's response: %2",
     "DHCP4_RESPONSE_HOSTNAME_DATA", "%1: including Hostname option in the server's response: %2",
     "DHCP4_RESPONSE_HOSTNAME_GENERATE", "%1: server has generated hostname %2 for the client",
+    "DHCP4_ROOT_USER_SECURITY_WARN", "kea-dhcp4 running as root user!",
     "DHCP4_SECURITY_CHECKS_DISABLED", "Invoked with command line option -X, Security checks are disabled!!",
     "DHCP4_SERVER_FAILED", "server failed: %1",
     "DHCP4_SERVER_INITIATED_DECLINE", "%1: Lease for addr %2 has been found to be already in use. The lease will be unavailable for %3 seconds.",

src/bin/dhcp4/dhcp4_messages.h

@@ -158,6 +158,7 @@ extern const isc::log::MessageID DHCP4_RESPONSE_DATA;
 extern const isc::log::MessageID DHCP4_RESPONSE_FQDN_DATA;
 extern const isc::log::MessageID DHCP4_RESPONSE_HOSTNAME_DATA;
 extern const isc::log::MessageID DHCP4_RESPONSE_HOSTNAME_GENERATE;
+extern const isc::log::MessageID DHCP4_ROOT_USER_SECURITY_WARN;
 extern const isc::log::MessageID DHCP4_SECURITY_CHECKS_DISABLED;
 extern const isc::log::MessageID DHCP4_SERVER_FAILED;
 extern const isc::log::MessageID DHCP4_SERVER_INITIATED_DECLINE;

src/bin/dhcp4/dhcp4_messages.mes

@@ -1190,3 +1190,17 @@ expected: the erroneous response is dropped, the request query is displayed.
 An DHCPOFFER for the 0.0.0.0 address was generated for a client requesting
 the v6-only-preferred (108) option but the option is not in the response as
 expected: the erroneous response is dropped, the discover query is displayed.
+
+% DHCP4_SECURITY_CHECKS_DISABLED Invoked with command line option -X, Security checks are disabled!!
+This warning is emitted when internal security checks normally
+performed by kea-dhcp4 have been disabled via command line option '-X'.
+This means the server is not enforcing restrictions on resource
+paths or permissions.  This mode of operation may expose your
+environment to security vulnerabilities and should only be used
+after careful consideration.
+
+% DHCP4_ROOT_USER_SECURITY_WARN kea-dhcp4 running as root user!
+This warning is emitted when kea-dhcp4 is running as a root user.
+While the server will function fully, this mode of operation may
+expose your environment to security vulnerabilities and should
+only be used after careful consideration.

src/bin/dhcp4/main.cc

@@ -246,6 +246,10 @@ main(int argc, char* argv[]) {
             LOG_WARN(dhcp4_logger, DHCP4_DEVELOPMENT_VERSION);
         }
 
+        if (amRoot()) {
+            LOG_WARN(dhcp4_logger, DHCP4_ROOT_USER_SECURITY_WARN);
+        }
+
         if (!PathChecker::shouldEnforceSecurity()) {
             LOG_WARN(dhcp4_logger, DHCP4_SECURITY_CHECKS_DISABLED);
         }

src/bin/dhcp6/dhcp6_messages.cc

@@ -160,6 +160,7 @@ extern const isc::log::MessageID DHCP6_RELEASE_PD_FAIL_WRONG_IAID = "DHCP6_RELEA
 extern const isc::log::MessageID DHCP6_REQUIRED_OPTIONS_CHECK_FAIL = "DHCP6_REQUIRED_OPTIONS_CHECK_FAIL";
 extern const isc::log::MessageID DHCP6_RESERVATIONS_LOOKUP_FIRST_ENABLED = "DHCP6_RESERVATIONS_LOOKUP_FIRST_ENABLED";
 extern const isc::log::MessageID DHCP6_RESPONSE_DATA = "DHCP6_RESPONSE_DATA";
+extern const isc::log::MessageID DHCP6_ROOT_USER_SECURITY_WARN = "DHCP6_ROOT_USER_SECURITY_WARN";
 extern const isc::log::MessageID DHCP6_SECURITY_CHECKS_DISABLED = "DHCP6_SECURITY_CHECKS_DISABLED";
 extern const isc::log::MessageID DHCP6_SERVER_FAILED = "DHCP6_SERVER_FAILED";
 extern const isc::log::MessageID DHCP6_SHUTDOWN = "DHCP6_SHUTDOWN";
@@ -336,6 +337,7 @@ const char* values[] = {
     "DHCP6_REQUIRED_OPTIONS_CHECK_FAIL", "%1: %2 message received from %3 failed the following check: %4",
     "DHCP6_RESERVATIONS_LOOKUP_FIRST_ENABLED", "Multi-threading is enabled and host reservations lookup is always performed first.",
     "DHCP6_RESPONSE_DATA", "%1: responding with packet %2 (type %3), packet details: %4",
+    "DHCP6_ROOT_USER_SECURITY_WARN", "kea-dhcp6 running as root user!",
     "DHCP6_SECURITY_CHECKS_DISABLED", "Invoked with command line option -X, Security checks are disabled!!",
     "DHCP6_SERVER_FAILED", "server failed: %1",
     "DHCP6_SHUTDOWN", "server shutdown",

src/bin/dhcp6/dhcp6_messages.h

@@ -161,6 +161,7 @@ extern const isc::log::MessageID DHCP6_RELEASE_PD_FAIL_WRONG_IAID;
 extern const isc::log::MessageID DHCP6_REQUIRED_OPTIONS_CHECK_FAIL;
 extern const isc::log::MessageID DHCP6_RESERVATIONS_LOOKUP_FIRST_ENABLED;
 extern const isc::log::MessageID DHCP6_RESPONSE_DATA;
+extern const isc::log::MessageID DHCP6_ROOT_USER_SECURITY_WARN;
 extern const isc::log::MessageID DHCP6_SECURITY_CHECKS_DISABLED;
 extern const isc::log::MessageID DHCP6_SERVER_FAILED;
 extern const isc::log::MessageID DHCP6_SHUTDOWN;

src/bin/dhcp6/dhcp6_messages.mes

@@ -1167,3 +1167,17 @@ such modification. The clients will remember previous server-id, and will
 use it to extend their leases. As a result, they will have to go through
 a rebinding phase to re-acquire their leases and associate them with a
 new server id.
+
+% DHCP6_SECURITY_CHECKS_DISABLED Invoked with command line option -X, Security checks are disabled!!
+This warning is emitted when internal security checks normally
+performed by kea-dhcp6 have been disabled via command line option '-X'.
+This means the server is not enforcing restrictions on resource
+paths or permissions.  This mode of operation may expose your
+environment to security vulnerabilities and should only be used
+after careful consideration.
+
+% DHCP6_ROOT_USER_SECURITY_WARN kea-dhcp6 running as root user!
+This warning is emitted when kea-dhcp6 is running as a root user.
+While the server will function fully, this mode of operation may
+expose your environment to security vulnerabilities and should
+only be used after careful consideration

src/bin/dhcp6/main.cc

@@ -246,6 +246,10 @@ main(int argc, char* argv[]) {
             LOG_WARN(dhcp6_logger, DHCP6_DEVELOPMENT_VERSION);
         }
 
+        if (amRoot()) {
+            LOG_WARN(dhcp6_logger, DHCP6_ROOT_USER_SECURITY_WARN);
+        }
+
         if (!PathChecker::shouldEnforceSecurity()) {
             LOG_WARN(dhcp6_logger, DHCP6_SECURITY_CHECKS_DISABLED);
         }

src/lib/process/d_controller.cc

@@ -127,10 +127,17 @@ DControllerBase::launch(int argc, char* argv[], const bool test_mode) {
         .arg(getpid())
         .arg(VERSION)
         .arg(PACKAGE_VERSION_TYPE);
+
     // When it is not a stable version dissuade use in production.
     if (std::string(PACKAGE_VERSION_TYPE) == "development") {
         LOG_WARN(dctl_logger, DCTL_DEVELOPMENT_VERSION);
     }
+
+    if (file::amRoot()) {
+        LOG_WARN(dctl_logger, DCTL_ROOT_USER_SECURITY_WARN)
+                .arg(app_name_);
+    }
+
     try {
         // Step 2 is to create and initialize the application process object.
         initProcess();

src/lib/process/process_messages.cc

@@ -27,6 +27,7 @@ extern const isc::log::MessageID DCTL_OPEN_CONFIG_DB = "DCTL_OPEN_CONFIG_DB";
 extern const isc::log::MessageID DCTL_PARSER_FAIL = "DCTL_PARSER_FAIL";
 extern const isc::log::MessageID DCTL_PID_FILE_ERROR = "DCTL_PID_FILE_ERROR";
 extern const isc::log::MessageID DCTL_PROCESS_FAILED = "DCTL_PROCESS_FAILED";
+extern const isc::log::MessageID DCTL_ROOT_USER_SECURITY_WARN = "DCTL_ROOT_USER_SECURITY_WARN";
 extern const isc::log::MessageID DCTL_RUN_PROCESS = "DCTL_RUN_PROCESS";
 extern const isc::log::MessageID DCTL_SHUTDOWN = "DCTL_SHUTDOWN";
 extern const isc::log::MessageID DCTL_SHUTDOWN_SIGNAL_RECVD = "DCTL_SHUTDOWN_SIGNAL_RECVD";
@@ -61,6 +62,7 @@ const char* values[] = {
     "DCTL_PARSER_FAIL", "Parser error: %1",
     "DCTL_PID_FILE_ERROR", "%1 could not create a PID file: %2",
     "DCTL_PROCESS_FAILED", "%1 application execution failed: %2",
+    "DCTL_ROOT_USER_SECURITY_WARN", "%1 running as root user!",
     "DCTL_RUN_PROCESS", "%1 starting application event loop",
     "DCTL_SHUTDOWN", "%1 has shut down, pid: %2, version: %3",
     "DCTL_SHUTDOWN_SIGNAL_RECVD", "OS signal %1 received, starting shutdown",

src/lib/process/process_messages.h

@@ -28,6 +28,7 @@ extern const isc::log::MessageID DCTL_OPEN_CONFIG_DB;
 extern const isc::log::MessageID DCTL_PARSER_FAIL;
 extern const isc::log::MessageID DCTL_PID_FILE_ERROR;
 extern const isc::log::MessageID DCTL_PROCESS_FAILED;
+extern const isc::log::MessageID DCTL_ROOT_USER_SECURITY_WARN;
 extern const isc::log::MessageID DCTL_RUN_PROCESS;
 extern const isc::log::MessageID DCTL_SHUTDOWN;
 extern const isc::log::MessageID DCTL_SHUTDOWN_SIGNAL_RECVD;

src/lib/process/process_messages.mes

@@ -152,3 +152,9 @@ disabled and the output path specified for a given logger does
 not comply with the supported path. The server will still
 use the specified path but is warning that doing so may pose a
 security risk.
+
+% DCTL_ROOT_USER_SECURITY_WARN %1 running as root user!
+This warning is emitted when the server is running as a root user.
+While the server will function fully, this mode of operation may
+expose your environment to security vulnerabilities and should
+only be used after careful consideration.

src/lib/util/filesystem.cc

@@ -104,6 +104,10 @@ setUmask() {
     }
 }
 
+bool amRoot() {
+    return (getuid() == 0 || geteuid() == 0);
+}
+
 Path::Path(string const& full_name) {
     dir_present_ = false;
     if (!full_name.empty()) {

src/lib/util/filesystem.h

@@ -99,6 +99,13 @@ isSocket(const std::string& path);
 void
 setUmask();
 
+/// @brief Indicates if current user is root
+///
+/// @return True if either the uid or the effective
+/// uid is root.
+bool
+amRoot();
+
 /// @brief Paths on a filesystem
 struct Path {
     /// @brief Constructor