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Diffstat (limited to 'Vland/db/db.py')
| -rw-r--r-- | Vland/db/db.py | 825 |
1 files changed, 825 insertions, 0 deletions
diff --git a/Vland/db/db.py b/Vland/db/db.py new file mode 100644 index 0000000..d5b541b --- /dev/null +++ b/Vland/db/db.py @@ -0,0 +1,825 @@ +#! /usr/bin/python + +# Copyright 2014-2018 Linaro Limited +# Authors: Dave Pigott <dave.pigott@linaro.org>, +# Steve McIntyre <steve.mcintyre@linaro.org> +# +# 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 2 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, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, +# MA 02110-1301, USA. + +import psycopg2 +import psycopg2.extras +import datetime, os, sys +import logging + +TRUNK_ID_NONE = -1 + +# The schema version that this code expects. If it finds an older version (or +# no version!) at startup, it will auto-migrate to the latest version +# +# Version 0: Base, no version found +# +# Version 1: No changes, except adding the version and coping with upgrade +# +# Version 2: Add "lock_reason" field in the port table, and code to deal with +# it +DATABASE_SCHEMA_VERSION = 2 + +from Vland.errors import CriticalError, InputError, NotFoundError + +class VlanDB: + def __init__(self, db_name="vland", username="vland", readonly=True): + try: + self.connection = psycopg2.connect(database=db_name, user=username) + # Create first cursor for normal usage - returns tuples + self.cursor = self.connection.cursor(cursor_factory=psycopg2.extras.NamedTupleCursor) + # Create second cursor for full-row lookups - returns a dict + # instead, much more useful in the admin interface + self.dictcursor = self.connection.cursor(cursor_factory=psycopg2.extras.RealDictCursor) + if not readonly: + self._init_state() + except Exception as e: + logging.error("Failed to access database: %s", e) + raise + + def __del__(self): + self.cursor.close() + self.dictcursor.close() + self.connection.close() + + # Create the state table (if needed) and add its only record + # + # Use the stored record of the expected database schema to track what + # version the on-disk database is, and upgrade it to match the current code + # if necessary. + def _init_state(self): + found_db = False + current_db_version = 0 + try: + sql = "SELECT * FROM state" + self.cursor.execute(sql) + found_db = True + except psycopg2.ProgrammingError: + self.connection.commit() # state doesn't exist; clear error + sql = "CREATE TABLE state (last_modified TIMESTAMP, schema_version INTEGER)" + self.cursor.execute(sql) + # We've just created a version 1 database + current_db_version = 1 + + if found_db: + # Grab the version of the database we have + try: + sql = "SELECT schema_version FROM state" + self.cursor.execute(sql) + current_db_version = self.cursor.fetchone()[0] + # No version found ==> we have "version 0" + except psycopg2.ProgrammingError: + self.connection.commit() # state doesn't exist; clear error + current_db_version = 0 + + # Now delete the existing state record, we'll write a new one in a + # moment + self.cursor.execute('DELETE FROM state') + logging.info("Found a database, version %d", current_db_version) + + # Apply upgrades here! + if current_db_version < 1: + logging.info("Upgrading database to match schema version 1") + sql = "ALTER TABLE state ADD schema_version INTEGER" + self.cursor.execute(sql) + logging.info("Schema version 1 upgrade successful") + + if current_db_version < 2: + logging.info("Upgrading database to match schema version 2") + sql = "ALTER TABLE port ADD lock_reason VARCHAR(64)" + self.cursor.execute(sql) + logging.info("Schema version 2 upgrade successful") + + sql = "INSERT INTO state (last_modified, schema_version) VALUES (%s, %s)" + data = (datetime.datetime.now(), DATABASE_SCHEMA_VERSION) + self.cursor.execute(sql, data) + self.connection.commit() + + # Create a new switch in the database. Switches are really simple + # devices - they're just containers for ports. + # + # Constraints: + # Switches must be uniquely named + def create_switch(self, name): + + switch_id = self.get_switch_id_by_name(name) + if switch_id is not None: + raise InputError("Switch name %s already exists" % name) + + try: + sql = "INSERT INTO switch (name) VALUES (%s) RETURNING switch_id" + data = (name, ) + self.cursor.execute(sql, data) + switch_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + + return switch_id + + # Create a new port in the database. Three of the fields are + # created with default values (is_locked, is_trunk, trunk_id) + # here, and should be updated separately if desired. For the + # current_vlan_id and base_vlan_id fields, *BE CAREFUL* that you + # have already looked up the correct VLAN_ID for each. This is + # *NOT* the same as the VLAN tag (likely to be 1). You Have Been + # Warned! + # + # Constraints: + # 1. The switch referred to must already exist + # 2. The VLANs mentioned here must already exist + # 3. (Switch/name) must be unique + # 4. (Switch/number) must be unique + def create_port(self, switch_id, name, number, current_vlan_id, base_vlan_id): + + switch = self.get_switch_by_id(switch_id) + if switch is None: + raise NotFoundError("Switch ID %d does not exist" % int(switch_id)) + + for vlan_id in (current_vlan_id, base_vlan_id): + vlan = self.get_vlan_by_id(vlan_id) + if vlan is None: + raise NotFoundError("VLAN ID %d does not exist" % int(vlan_id)) + + port_id = self.get_port_by_switch_and_name(switch_id, name) + if port_id is not None: + raise InputError("Already have a port %s on switch ID %d" % (name, int(switch_id))) + + port_id = self.get_port_by_switch_and_number(switch_id, int(number)) + if port_id is not None: + raise InputError("Already have a port %d on switch ID %d" % (int(number), int(switch_id))) + + try: + sql = "INSERT INTO port (name, number, switch_id, is_locked, lock_reason, is_trunk, current_vlan_id, base_vlan_id, trunk_id) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s) RETURNING port_id" + data = (name, number, switch_id, + False, "", + False, + current_vlan_id, base_vlan_id, TRUNK_ID_NONE) + self.cursor.execute(sql, data) + port_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + + return port_id + + # Create a new vlan in the database. We locally add a creation + # timestamp, for debug purposes. If vlans seems to be sticking + # around, we'll be able to see when they were created. + # + # Constraints: + # Names and tags must be unique + # Tags must be in the range 1-4095 (802.1q spec) + # Names can be any free-form text, length 1-32 characters + def create_vlan(self, name, tag, is_base_vlan): + + if int(tag) < 1 or int(tag) > 4095: + raise InputError("VLAN tag %d is outside of the valid range (1-4095)" % int(tag)) + + if (len(name) < 1) or (len(name) > 32): + raise InputError("VLAN name %s is invalid (must be 1-32 chars)" % name) + + vlan_id = self.get_vlan_id_by_name(name) + if vlan_id is not None: + raise InputError("VLAN name %s is already in use" % name) + + vlan_id = self.get_vlan_id_by_tag(tag) + if vlan_id is not None: + raise InputError("VLAN tag %d is already in use" % int(tag)) + + try: + dt = datetime.datetime.now() + sql = "INSERT INTO vlan (name, tag, is_base_vlan, creation_time) VALUES (%s, %s, %s, %s) RETURNING vlan_id" + data = (name, tag, is_base_vlan, dt) + self.cursor.execute(sql, data) + vlan_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + + return vlan_id + + # Create a new trunk in the database, linking two ports. Trunks + # are really simple objects for our use - they're just containers + # for 2 ports. + # + # Constraints: + # 1. Both ports listed must already exist. + # 2. Both ports must be in trunk mode. + # 3. Both must not be locked. + # 4. Both must not already be in a trunk. + def create_trunk(self, port_id1, port_id2): + + for port_id in (port_id1, port_id2): + port = self.get_port_by_id(int(port_id)) + if port is None: + raise NotFoundError("Port ID %d does not exist" % int(port_id)) + if not port['is_trunk']: + raise InputError("Port ID %d is not in trunk mode" % int(port_id)) + if port['is_locked']: + raise InputError("Port ID %d is locked" % int(port_id)) + if port['trunk_id'] != TRUNK_ID_NONE: + raise InputError("Port ID %d is already on trunk ID %d" % (int(port_id), int(port['trunk_id']))) + + try: + # Add the trunk itself + dt = datetime.datetime.now() + sql = "INSERT INTO trunk (creation_time) VALUES (%s) RETURNING trunk_id" + data = (dt, ) + self.cursor.execute(sql, data) + trunk_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + # And update the ports + for port_id in (port_id1, port_id2): + self._set_port_trunk(port_id, trunk_id) + except: + self.delete_trunk(trunk_id) + raise + + return trunk_id + + # Internal helper function + def _delete_row(self, table, field, value): + try: + sql = "DELETE FROM %s WHERE %s = %s" % (table, field, '%s') + data = (value,) + self.cursor.execute(sql, data) + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + + # Delete the specified switch + # + # Constraints: + # 1. The switch must exist + # 2. The switch may not be referenced by any ports - + # delete them first! + def delete_switch(self, switch_id): + switch = self.get_switch_by_id(switch_id) + if switch is None: + raise NotFoundError("Switch ID %d does not exist" % int(switch_id)) + ports = self.get_ports_by_switch(switch_id) + if ports is not None: + raise InputError("Cannot delete switch ID %d when it still has %d ports" % + (int(switch_id), len(ports))) + self._delete_row("switch", "switch_id", switch_id) + return switch_id + + # Delete the specified port + # + # Constraints: + # 1. The port must exist + # 2. The port must not be locked + def delete_port(self, port_id): + port = self.get_port_by_id(port_id) + if port is None: + raise NotFoundError("Port ID %d does not exist" % int(port_id)) + if port['is_locked']: + raise InputError("Cannot delete port ID %d as it is locked" % int(port_id)) + self._delete_row("port", "port_id", port_id) + return port_id + + # Delete the specified VLAN + # + # Constraints: + # 1. The VLAN must exist + # 2. The VLAN may not contain any ports - move or delete them first! + def delete_vlan(self, vlan_id): + vlan = self.get_vlan_by_id(vlan_id) + if vlan is None: + raise NotFoundError("VLAN ID %d does not exist" % int(vlan_id)) + ports = self.get_ports_by_current_vlan(vlan_id) + if ports is not None: + raise InputError("Cannot delete VLAN ID %d when it still has %d ports" % + (int(vlan_id), len(ports))) + ports = self.get_ports_by_base_vlan(vlan_id) + if ports is not None: + raise InputError("Cannot delete VLAN ID %d when it still has %d ports" % + (int(vlan_id), len(ports))) + self._delete_row("vlan", "vlan_id", vlan_id) + return vlan_id + + # Delete the specified trunk + # + # Constraints: + # 1. The trunk must exist + # + # Any ports attached will be detached (i.e. moved to trunk TRUNK_ID_NONE) + def delete_trunk(self, trunk_id): + trunk = self.get_trunk_by_id(trunk_id) + if trunk is None: + raise NotFoundError("Trunk ID %d does not exist" % int(trunk_id)) + ports = self.get_ports_by_trunk(trunk_id) + for port_id in ports: + self._set_port_trunk(port_id, TRUNK_ID_NONE) + self._delete_row("trunk", "trunk_id", trunk_id) + return trunk_id + + # Find the lowest unused VLAN tag and return it + # + # Constraints: + # None + def find_lowest_unused_vlan_tag(self): + sql = "SELECT tag FROM vlan ORDER BY tag ASC" + self.cursor.execute(sql,) + + # Walk through the list, looking for gaps + last = 1 + result = None + + for record in self.cursor: + if (record[0] - last) > 1: + result = last + 1 + break + last = record[0] + + if result is None: + result = last + 1 + + if result > 4093: + raise CriticalError("Can't find any VLAN tags remaining for allocation!") + + return result + + # Grab one column from one row of a query on one column; useful as + # a quick wrapper + def _get_element(self, select_field, table, compare_field, value): + + if value is None: + raise ValueError("Asked to look up using None as a key in %s" % compare_field) + + # We really want to use psycopg's type handling deal with the + # (potentially) user-supplied data in the value field, so we + # have to pass (sql,data) through to cursor.execute. However, + # we can't have psycopg do all the argument substitution here + # as it will quote all the params like the table name. That + # doesn't work. So, we substitute a "%s" for "%s" here so we + # keep it after python's own string substitution. + sql = "SELECT %s FROM %s WHERE %s = %s" % (select_field, table, compare_field, "%s") + + # Now, the next icky thing: we need to make sure that we're + # passing a dict so that psycopg2 can pick it apart properly + # for its own substitution code. We force this with the + # trailing comma here + data = (value, ) + self.cursor.execute(sql, data) + + if self.cursor.rowcount > 0: + return self.cursor.fetchone()[0] + else: + return None + + # Grab one column from one row of a query on 2 columns; useful as + # a quick wrapper + def _get_element2(self, select_field, table, compare_field1, value1, compare_field2, value2): + + if value1 is None: + raise ValueError("Asked to look up using None as a key in %s" % compare_field1) + if value2 is None: + raise ValueError("Asked to look up using None as a key in %s" % compare_field2) + + # We really want to use psycopg's type handling deal with the + # (potentially) user-supplied data in the value field, so we + # have to pass (sql,data) through to cursor.execute. However, + # we can't have psycopg do all the argument substitution here + # as it will quote all the params like the table name. That + # doesn't work. So, we substitute a "%s" for "%s" here so we + # keep it after python's own string substitution. + sql = "SELECT %s FROM %s WHERE %s = %s AND %s = %s" % (select_field, table, compare_field1, "%s", compare_field2, "%s") + + data = (value1, value2) + self.cursor.execute(sql, data) + + if self.cursor.rowcount > 0: + return self.cursor.fetchone()[0] + else: + return None + + # Grab one column from multiple rows of a query; useful as a quick + # wrapper + def _get_multi_elements(self, select_field, table, compare_field, value, sort_field): + + if value is None: + raise ValueError("Asked to look up using None as a key in %s" % compare_field) + + # We really want to use psycopg's type handling deal with the + # (potentially) user-supplied data in the value field, so we + # have to pass (sql,data) through to cursor.execute. However, + # we can't have psycopg do all the argument substitution here + # as it will quote all the params like the table name. That + # doesn't work. So, we substitute a "%s" for "%s" here so we + # keep it after python's own string substitution. + sql = "SELECT %s FROM %s WHERE %s = %s ORDER BY %s ASC" % (select_field, table, compare_field, "%s", sort_field) + + # Now, the next icky thing: we need to make sure that we're + # passing a dict so that psycopg2 can pick it apart properly + # for its own substitution code. We force this with the + # trailing comma here + data = (value, ) + self.cursor.execute(sql, data) + + if self.cursor.rowcount > 0: + results = [] + for record in self.cursor: + results.append(record[0]) + return results + else: + return None + + # Grab one column from multiple rows of a 2-part query; useful as + # a wrapper + def _get_multi_elements2(self, select_field, table, compare_field1, value1, compare_field2, value2, sort_field): + + if value1 is None: + raise ValueError("Asked to look up using None as a key in %s" % compare_field1) + if value2 is None: + raise ValueError("Asked to look up using None as a key in %s" % compare_field2) + + # We really want to use psycopg's type handling deal with the + # (potentially) user-supplied data in the value field, so we + # have to pass (sql,data) through to cursor.execute. However, + # we can't have psycopg do all the argument substitution here + # as it will quote all the params like the table name. That + # doesn't work. So, we substitute a "%s" for "%s" here so we + # keep it after python's own string substitution. + sql = "SELECT %s FROM %s WHERE %s = %s AND %s = %s ORDER by %s ASC" % (select_field, table, compare_field1, "%s", compare_field2, "%s", sort_field) + + data = (value1, value2) + self.cursor.execute(sql, data) + + if self.cursor.rowcount > 0: + results = [] + for record in self.cursor: + results.append(record[0]) + return results + else: + return None + + # Simple lookup: look up a switch by ID, and return all the + # details of that switch. + # + # Returns None on failure. + def get_switch_by_id(self, switch_id): + return self._get_row("switch", "switch_id", int(switch_id)) + + # Simple lookup: look up a switch by name, and return the ID of + # that switch. + # + # Returns None on failure. + def get_switch_id_by_name(self, name): + return self._get_element("switch_id", "switch", "name", name) + + # Simple lookup: look up a switch by ID, and return the name of + # that switch. + # + # Returns None on failure. + def get_switch_name_by_id(self, switch_id): + return self._get_element("name", "switch", "switch_id", int(switch_id)) + + # Simple lookup: look up a port by ID, and return all the details + # of that port. + # + # Returns None on failure. + def get_port_by_id(self, port_id): + return self._get_row("port", "port_id", int(port_id)) + + # Simple lookup: look up a switch by ID, and return the IDs of all + # the ports on that switch. + # + # Returns None on failure. + def get_ports_by_switch(self, switch_id): + return self._get_multi_elements("port_id", "port", "switch_id", int(switch_id), "port_id") + + # More complex lookup: look up all the trunk ports on a switch by + # ID + # + # Returns None on failure. + def get_trunk_port_names_by_switch(self, switch_id): + return self._get_multi_elements2("name", "port", "switch_id", int(switch_id), "is_trunk", True, "port_id") + + # Simple lookup: look up a port by its name and its parent switch + # by ID, and return the ID of the port. + # + # Returns None on failure. + def get_port_by_switch_and_name(self, switch_id, name): + return self._get_element2("port_id", "port", "switch_id", int(switch_id), "name", name) + + # Simple lookup: look up a port by its external name and its + # parent switch by ID, and return the ID of the port. + # + # Returns None on failure. + def get_port_by_switch_and_number(self, switch_id, number): + return self._get_element2("port_id", "port", "switch_id", int(switch_id), "number", int(number)) + + # Simple lookup: look up a port by ID, and return the current VLAN + # id of that port. + # + # Returns None on failure. + def get_current_vlan_id_by_port(self, port_id): + return self._get_element("current_vlan_id", "port", "port_id", int(port_id)) + + # Simple lookup: look up a port by ID, and return the mode of that port. + # + # Returns None on failure. + def get_port_mode(self, port_id): + is_trunk = self._get_element("is_trunk", "port", "port_id", int(port_id)) + if is_trunk is not None: + if is_trunk: + return "trunk" + else: + return "access" + return None + + # Simple lookup: look up a port by ID, and return the base VLAN + # id of that port. + # + # Returns None on failure. + def get_base_vlan_id_by_port(self, port_id): + return self._get_element("base_vlan_id", "port", "port_id", int(port_id)) + + # Simple lookup: look up a current VLAN by ID, and return the IDs + # of all the ports on that VLAN. + # + # Returns None on failure. + def get_ports_by_current_vlan(self, vlan_id): + return self._get_multi_elements("port_id", "port", "current_vlan_id", int(vlan_id), "port_id") + + # Simple lookup: look up a base VLAN by ID, and return the IDs + # of all the ports on that VLAN. + # + # Returns None on failure. + def get_ports_by_base_vlan(self, vlan_id): + return self._get_multi_elements("port_id", "port", "base_vlan_id", int(vlan_id), "port_id") + + # Simple lookup: look up a trunk by ID, and return the IDs of the + # ports on both ends of that trunk. + # + # Returns None on failure. + def get_ports_by_trunk(self, trunk_id): + return self._get_multi_elements("port_id", "port", "trunk_id", int(trunk_id), "port_id") + + # Simple lookup: look up a VLAN by ID, and return all the details + # of that VLAN. + # + # Returns None on failure. + def get_vlan_by_id(self, vlan_id): + return self._get_row("vlan", "vlan_id", int(vlan_id)) + + # Simple lookup: look up a VLAN by name, and return the ID of that + # VLAN. + # + # Returns None on failure. + def get_vlan_id_by_name(self, name): + return self._get_element("vlan_id", "vlan", "name", name) + + # Simple lookup: look up a VLAN by tag, and return the ID of that + # VLAN. + # + # Returns None on failure. + def get_vlan_id_by_tag(self, tag): + return self._get_element("vlan_id", "vlan", "tag", int(tag)) + + # Simple lookup: look up a VLAN by ID, and return the name of that + # VLAN. + # + # Returns None on failure. + def get_vlan_name_by_id(self, vlan_id): + return self._get_element("name", "vlan", "vlan_id", int(vlan_id)) + + # Simple lookup: look up a VLAN by ID, and return the tag of that + # VLAN. + # + # Returns None on failure. + def get_vlan_tag_by_id(self, vlan_id): + return self._get_element("tag", "vlan", "vlan_id", int(vlan_id)) + + # Simple lookup: look up a trunk by ID, and return all the details + # of that trunk. + # + # Returns None on failure. + def get_trunk_by_id(self, trunk_id): + return self._get_row("trunk", "trunk_id", int(trunk_id)) + + # Get the last-modified time for the database + def get_last_modified_time(self): + sql = "SELECT last_modified FROM state" + self.cursor.execute(sql) + return self.cursor.fetchone()[0] + + # Grab one row of a query on one column; useful as a quick wrapper + def _get_row(self, table, field, value): + + # We really want to use psycopg's type handling deal with the + # (potentially) user-supplied data in the value field, so we + # have to pass (sql,data) through to cursor.execute. However, + # we can't have psycopg do all the argument substitution here + # as it will quote all the params like the table name. That + # doesn't work. So, we substitute a "%s" for "%s" here so we + # keep it after python's own string substitution. + sql = "SELECT * FROM %s WHERE %s = %s" % (table, field, "%s") + + # Now, the next icky thing: we need to make sure that we're + # passing a dict so that psycopg2 can pick it apart properly + # for its own substitution code. We force this with the + # trailing comma here + data = (value, ) + self.dictcursor.execute(sql, data) + return self.dictcursor.fetchone() + + # (Un)Lock a port in the database. This can only be done through + # the admin interface, and will stop API users from modifying + # settings on the port. Use this to lock down ports that are used + # for PDUs and other core infrastructure + def set_port_is_locked(self, port_id, is_locked, lock_reason=""): + port = self.get_port_by_id(port_id) + if port is None: + raise NotFoundError("Port ID %d does not exist" % int(port_id)) + try: + sql = "UPDATE port SET is_locked=%s, lock_reason=%s WHERE port_id=%s RETURNING port_id" + data = (is_locked, lock_reason, port_id) + self.cursor.execute(sql, data) + port_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise InputError("lock failed on Port ID %d" % int(port_id)) + return port_id + + # Set the mode of a port in the database. Valid values for mode + # are "trunk" and "access" + def set_port_mode(self, port_id, mode): + port = self.get_port_by_id(port_id) + if port is None: + raise NotFoundError("Port ID %d does not exist" % int(port_id)) + if mode == "access": + is_trunk = False + elif mode == "trunk": + is_trunk = True + else: + raise InputError("Port mode %s is not valid" % mode) + try: + sql = "UPDATE port SET is_trunk=%s WHERE port_id=%s RETURNING port_id" + data = (is_trunk, port_id) + self.cursor.execute(sql, data) + port_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + return port_id + + # Set the current vlan of a port in the database. The VLAN is + # passed by ID. + # + # Constraints: + # 1. The port must already exist + # 2. The port must not be a trunk port + # 3. The port must not be locked + # 1. The VLAN must already exist in the database + def set_current_vlan(self, port_id, vlan_id): + port = self.get_port_by_id(port_id) + if port is None: + raise NotFoundError("Port ID %d does not exist" % int(port_id)) + + if port['is_trunk'] or port['is_locked']: + raise CriticalError("The port is locked") + + vlan = self.get_vlan_by_id(vlan_id) + if vlan is None: + raise NotFoundError("VLAN ID %d does not exist" % int(vlan_id)) + + try: + sql = "UPDATE port SET current_vlan_id=%s WHERE port_id=%s RETURNING port_id" + data = (vlan_id, port_id) + self.cursor.execute(sql, data) + port_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + return port_id + + # Set the base vlan of a port in the database. The VLAN is + # passed by ID. + # + # Constraints: + # 1. The port must already exist + # 2. The port must not be a trunk port + # 3. The port must not be locked + # 4. The VLAN must already exist in the database + def set_base_vlan(self, port_id, vlan_id): + port = self.get_port_by_id(port_id) + if port is None: + raise NotFoundError("Port ID %d does not exist" % int(port_id)) + + if port['is_trunk'] or port['is_locked']: + raise CriticalError("The port is locked") + + vlan = self.get_vlan_by_id(vlan_id) + if vlan is None: + raise NotFoundError("VLAN ID %d does not exist" % int(vlan_id)) + if not vlan['is_base_vlan']: + raise InputError("VLAN ID %d is not a base VLAN" % int(vlan_id)) + + try: + sql = "UPDATE port SET base_vlan_id=%s WHERE port_id=%s RETURNING port_id" + data = (vlan_id, port_id) + self.cursor.execute(sql, data) + port_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + return port_id + + # Internal function: Attach a port to a trunk in the database. + # + # Constraints: + # 1. The port must already exist + # 2. The port must not be locked + def _set_port_trunk(self, port_id, trunk_id): + port = self.get_port_by_id(port_id) + if port is None: + raise NotFoundError("Port ID %d does not exist" % int(port_id)) + if port['is_locked']: + raise CriticalError("The port is locked") + try: + sql = "UPDATE port SET trunk_id=%s WHERE port_id=%s RETURNING port_id" + data = (int(trunk_id), int(port_id)) + self.cursor.execute(sql, data) + port_id = self.cursor.fetchone()[0] + self.cursor.execute("UPDATE state SET last_modified=%s", (datetime.datetime.now(),)) + self.connection.commit() + except: + self.connection.rollback() + raise + return port_id + + # Trivial helper function to return all the rows in a given table + def _dump_table(self, table, order): + result = [] + self.dictcursor.execute("SELECT * FROM %s ORDER by %s ASC" % (table, order)) + record = self.dictcursor.fetchone() + while record != None: + result.append(record) + record = self.dictcursor.fetchone() + return result + + def all_switches(self): + return self._dump_table("switch", "switch_id") + + def all_ports(self): + return self._dump_table("port", "port_id") + + def all_vlans(self): + return self._dump_table("vlan", "vlan_id") + + def all_trunks(self): + return self._dump_table("trunk", "trunk_id") + +if __name__ == '__main__': + db = VlanDB() + s = db.all_switches() + print 'The DB knows about %d switch(es)' % len(s) + print s + p = db.all_ports() + print 'The DB knows about %d port(s)' % len(p) + print p + v = db.all_vlans() + print 'The DB knows about %d vlan(s)' % len(v) + print v + t = db.all_trunks() + print 'The DB knows about %d trunks(s)' % len(t) + print t + + print 'First free VLAN tag is %d' % db.find_lowest_unused_vlan_tag() |