diff options
Diffstat (limited to 'src/ejabberd_odbc.erl')
| -rw-r--r-- | src/ejabberd_odbc.erl | 613 |
1 files changed, 613 insertions, 0 deletions
diff --git a/src/ejabberd_odbc.erl b/src/ejabberd_odbc.erl new file mode 100644 index 000000000..b530f8f29 --- /dev/null +++ b/src/ejabberd_odbc.erl @@ -0,0 +1,613 @@ +%%%---------------------------------------------------------------------- +%%% File : ejabberd_odbc.erl +%%% Author : Alexey Shchepin <alexey@process-one.net> +%%% Purpose : Serve ODBC connection +%%% Created : 8 Dec 2004 by Alexey Shchepin <alexey@process-one.net> +%%% +%%% +%%% ejabberd, Copyright (C) 2002-2013 ProcessOne +%%% +%%% 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., 59 Temple Place, Suite 330, Boston, MA +%%% 02111-1307 USA +%%% +%%%---------------------------------------------------------------------- + +-module(ejabberd_odbc). + +-author('alexey@process-one.net'). + +-define(GEN_FSM, p1_fsm). + +-behaviour(?GEN_FSM). + +%% External exports +-export([start/1, start_link/2, + sql_query/2, + sql_query_t/1, + sql_transaction/2, + sql_bloc/2, + escape/1, + escape_like/1, + to_bool/1, + encode_term/1, + decode_term/1, + keep_alive/1]). + +%% gen_fsm callbacks +-export([init/1, handle_event/3, handle_sync_event/4, + handle_info/3, terminate/3, print_state/1, + code_change/4]). + +%% gen_fsm states +-export([connecting/2, connecting/3, + session_established/2, session_established/3]). + +-include("ejabberd.hrl"). +-include("logger.hrl"). + +-record(state, + {db_ref = self() :: pid(), + db_type = odbc :: pgsql | mysql | odbc, + start_interval = 0 :: non_neg_integer(), + host = <<"">> :: binary(), + max_pending_requests_len :: non_neg_integer(), + pending_requests = {0, queue:new()} :: {non_neg_integer(), queue()}}). + +-define(STATE_KEY, ejabberd_odbc_state). + +-define(NESTING_KEY, ejabberd_odbc_nesting_level). + +-define(TOP_LEVEL_TXN, 0). + +-define(MAX_TRANSACTION_RESTARTS, 10). + +-define(PGSQL_PORT, 5432). + +-define(MYSQL_PORT, 3306). + +-define(TRANSACTION_TIMEOUT, 60000). + +-define(KEEPALIVE_TIMEOUT, 60000). + +-define(KEEPALIVE_QUERY, <<"SELECT 1;">>). + +%%-define(DBGFSM, true). + +-ifdef(DBGFSM). + +-define(FSMOPTS, [{debug, [trace]}]). + +-else. + +-define(FSMOPTS, []). + +-endif. + +%%%---------------------------------------------------------------------- +%%% API +%%%---------------------------------------------------------------------- +start(Host) -> + (?GEN_FSM):start(ejabberd_odbc, [Host], + fsm_limit_opts() ++ (?FSMOPTS)). + +start_link(Host, StartInterval) -> + (?GEN_FSM):start_link(ejabberd_odbc, + [Host, StartInterval], + fsm_limit_opts() ++ (?FSMOPTS)). + +-type sql_query() :: [sql_query() | binary()]. +-type sql_query_result() :: {updated, non_neg_integer()} | + {error, binary()} | + {selected, [binary()], + [[binary()]]}. + +-spec sql_query(binary(), sql_query()) -> sql_query_result(). + +sql_query(Host, Query) -> + sql_call(Host, {sql_query, Query}). + +%% SQL transaction based on a list of queries +%% This function automatically +-spec sql_transaction(binary(), [sql_query()] | fun(() -> any())) -> + {atomic, any()} | + {aborted, any()}. + +sql_transaction(Host, Queries) + when is_list(Queries) -> + F = fun () -> + lists:foreach(fun (Query) -> sql_query_t(Query) end, + Queries) + end, + sql_transaction(Host, F); +%% SQL transaction, based on a erlang anonymous function (F = fun) +sql_transaction(Host, F) when is_function(F) -> + sql_call(Host, {sql_transaction, F}). + +%% SQL bloc, based on a erlang anonymous function (F = fun) +sql_bloc(Host, F) -> sql_call(Host, {sql_bloc, F}). + +sql_call(Host, Msg) -> + case get(?STATE_KEY) of + undefined -> + (?GEN_FSM):sync_send_event(ejabberd_odbc_sup:get_random_pid(Host), + {sql_cmd, Msg, now()}, + ?TRANSACTION_TIMEOUT); + _State -> nested_op(Msg) + end. + +keep_alive(PID) -> + (?GEN_FSM):sync_send_event(PID, + {sql_cmd, {sql_query, ?KEEPALIVE_QUERY}, now()}, + ?KEEPALIVE_TIMEOUT). + +-spec sql_query_t(sql_query()) -> sql_query_result(). + +%% This function is intended to be used from inside an sql_transaction: +sql_query_t(Query) -> + QRes = sql_query_internal(Query), + case QRes of + {error, Reason} -> throw({aborted, Reason}); + Rs when is_list(Rs) -> + case lists:keysearch(error, 1, Rs) of + {value, {error, Reason}} -> throw({aborted, Reason}); + _ -> QRes + end; + _ -> QRes + end. + +%% Escape character that will confuse an SQL engine +escape(S) -> + << <<(odbc_queries:escape(Char))/binary>> || <<Char>> <= S >>. + +%% Escape character that will confuse an SQL engine +%% Percent and underscore only need to be escaped for pattern matching like +%% statement +escape_like(S) when is_binary(S) -> + << <<(escape_like(C))/binary>> || <<C>> <= S >>; +escape_like($%) -> <<"\\%">>; +escape_like($_) -> <<"\\_">>; +escape_like(C) when is_integer(C), C >= 0, C =< 255 -> odbc_queries:escape(C). + +to_bool(<<"t">>) -> true; +to_bool(<<"true">>) -> true; +to_bool(<<"1">>) -> true; +to_bool(true) -> true; +to_bool(1) -> true; +to_bool(_) -> false. + +encode_term(Term) -> + escape(list_to_binary( + erl_prettypr:format(erl_syntax:abstract(Term)))). + +decode_term(Bin) -> + Str = binary_to_list(<<Bin/binary, ".">>), + {ok, Tokens, _} = erl_scan:string(Str), + {ok, Term} = erl_parse:parse_term(Tokens), + Term. + +%%%---------------------------------------------------------------------- +%%% Callback functions from gen_fsm +%%%---------------------------------------------------------------------- +init([Host, StartInterval]) -> + case ejabberd_config:get_local_option( + {odbc_keepalive_interval, Host}, + fun(I) when is_integer(I), I>0 -> I end) of + undefined -> + ok; + KeepaliveInterval -> + timer:apply_interval(KeepaliveInterval * 1000, ?MODULE, + keep_alive, [self()]) + end, + [DBType | _] = db_opts(Host), + (?GEN_FSM):send_event(self(), connect), + ejabberd_odbc_sup:add_pid(Host, self()), + {ok, connecting, + #state{db_type = DBType, host = Host, + max_pending_requests_len = max_fsm_queue(), + pending_requests = {0, queue:new()}, + start_interval = StartInterval}}. + +connecting(connect, #state{host = Host} = State) -> + ConnectRes = case db_opts(Host) of + [mysql | Args] -> apply(fun mysql_connect/5, Args); + [pgsql | Args] -> apply(fun pgsql_connect/5, Args); + [odbc | Args] -> apply(fun odbc_connect/1, Args) + end, + {_, PendingRequests} = State#state.pending_requests, + case ConnectRes of + {ok, Ref} -> + erlang:monitor(process, Ref), + lists:foreach(fun (Req) -> + (?GEN_FSM):send_event(self(), Req) + end, + queue:to_list(PendingRequests)), + {next_state, session_established, + State#state{db_ref = Ref, + pending_requests = {0, queue:new()}}}; + {error, Reason} -> + ?INFO_MSG("~p connection failed:~n** Reason: ~p~n** " + "Retry after: ~p seconds", + [State#state.db_type, Reason, + State#state.start_interval div 1000]), + (?GEN_FSM):send_event_after(State#state.start_interval, + connect), + {next_state, connecting, State} + end; +connecting(Event, State) -> + ?WARNING_MSG("unexpected event in 'connecting': ~p", + [Event]), + {next_state, connecting, State}. + +connecting({sql_cmd, {sql_query, ?KEEPALIVE_QUERY}, + _Timestamp}, + From, State) -> + (?GEN_FSM):reply(From, + {error, <<"SQL connection failed">>}), + {next_state, connecting, State}; +connecting({sql_cmd, Command, Timestamp} = Req, From, + State) -> + ?DEBUG("queuing pending request while connecting:~n\t~p", + [Req]), + {Len, PendingRequests} = State#state.pending_requests, + NewPendingRequests = if Len < + State#state.max_pending_requests_len -> + {Len + 1, + queue:in({sql_cmd, Command, From, Timestamp}, + PendingRequests)}; + true -> + lists:foreach(fun ({sql_cmd, _, To, + _Timestamp}) -> + (?GEN_FSM):reply(To, + {error, + <<"SQL connection failed">>}) + end, + queue:to_list(PendingRequests)), + {1, + queue:from_list([{sql_cmd, Command, From, + Timestamp}])} + end, + {next_state, connecting, + State#state{pending_requests = NewPendingRequests}}; +connecting(Request, {Who, _Ref}, State) -> + ?WARNING_MSG("unexpected call ~p from ~p in 'connecting'", + [Request, Who]), + {reply, {error, badarg}, connecting, State}. + +session_established({sql_cmd, Command, Timestamp}, From, + State) -> + run_sql_cmd(Command, From, State, Timestamp); +session_established(Request, {Who, _Ref}, State) -> + ?WARNING_MSG("unexpected call ~p from ~p in 'session_establ" + "ished'", + [Request, Who]), + {reply, {error, badarg}, session_established, State}. + +session_established({sql_cmd, Command, From, Timestamp}, + State) -> + run_sql_cmd(Command, From, State, Timestamp); +session_established(Event, State) -> + ?WARNING_MSG("unexpected event in 'session_established': ~p", + [Event]), + {next_state, session_established, State}. + +handle_event(_Event, StateName, State) -> + {next_state, StateName, State}. + +handle_sync_event(_Event, _From, StateName, State) -> + {reply, {error, badarg}, StateName, State}. + +code_change(_OldVsn, StateName, State, _Extra) -> + {ok, StateName, State}. + +%% We receive the down signal when we loose the MySQL connection (we are +%% monitoring the connection) +handle_info({'DOWN', _MonitorRef, process, _Pid, _Info}, + _StateName, State) -> + (?GEN_FSM):send_event(self(), connect), + {next_state, connecting, State}; +handle_info(Info, StateName, State) -> + ?WARNING_MSG("unexpected info in ~p: ~p", + [StateName, Info]), + {next_state, StateName, State}. + +terminate(_Reason, _StateName, State) -> + ejabberd_odbc_sup:remove_pid(State#state.host, self()), + case State#state.db_type of + mysql -> catch mysql_conn:stop(State#state.db_ref); + _ -> ok + end, + ok. + +%%---------------------------------------------------------------------- +%% Func: print_state/1 +%% Purpose: Prepare the state to be printed on error log +%% Returns: State to print +%%---------------------------------------------------------------------- +print_state(State) -> State. + +%%%---------------------------------------------------------------------- +%%% Internal functions +%%%---------------------------------------------------------------------- + +run_sql_cmd(Command, From, State, Timestamp) -> + case timer:now_diff(now(), Timestamp) div 1000 of + Age when Age < (?TRANSACTION_TIMEOUT) -> + put(?NESTING_KEY, ?TOP_LEVEL_TXN), + put(?STATE_KEY, State), + abort_on_driver_error(outer_op(Command), From); + Age -> + ?ERROR_MSG("Database was not available or too slow, " + "discarding ~p milliseconds old request~n~p~n", + [Age, Command]), + {next_state, session_established, State} + end. + +%% Only called by handle_call, only handles top level operations. +%% @spec outer_op(Op) -> {error, Reason} | {aborted, Reason} | {atomic, Result} +outer_op({sql_query, Query}) -> + sql_query_internal(Query); +outer_op({sql_transaction, F}) -> + outer_transaction(F, ?MAX_TRANSACTION_RESTARTS, <<"">>); +outer_op({sql_bloc, F}) -> execute_bloc(F). + +%% Called via sql_query/transaction/bloc from client code when inside a +%% nested operation +nested_op({sql_query, Query}) -> + sql_query_internal(Query); +nested_op({sql_transaction, F}) -> + NestingLevel = get(?NESTING_KEY), + if NestingLevel =:= (?TOP_LEVEL_TXN) -> + outer_transaction(F, ?MAX_TRANSACTION_RESTARTS, <<"">>); + true -> inner_transaction(F) + end; +nested_op({sql_bloc, F}) -> execute_bloc(F). + +%% Never retry nested transactions - only outer transactions +inner_transaction(F) -> + PreviousNestingLevel = get(?NESTING_KEY), + case get(?NESTING_KEY) of + ?TOP_LEVEL_TXN -> + {backtrace, T} = process_info(self(), backtrace), + ?ERROR_MSG("inner transaction called at outer txn " + "level. Trace: ~s", + [T]), + erlang:exit(implementation_faulty); + _N -> ok + end, + put(?NESTING_KEY, PreviousNestingLevel + 1), + Result = (catch F()), + put(?NESTING_KEY, PreviousNestingLevel), + case Result of + {aborted, Reason} -> {aborted, Reason}; + {'EXIT', Reason} -> {'EXIT', Reason}; + {atomic, Res} -> {atomic, Res}; + Res -> {atomic, Res} + end. + +outer_transaction(F, NRestarts, _Reason) -> + PreviousNestingLevel = get(?NESTING_KEY), + case get(?NESTING_KEY) of + ?TOP_LEVEL_TXN -> ok; + _N -> + {backtrace, T} = process_info(self(), backtrace), + ?ERROR_MSG("outer transaction called at inner txn " + "level. Trace: ~s", + [T]), + erlang:exit(implementation_faulty) + end, + sql_query_internal(<<"begin;">>), + put(?NESTING_KEY, PreviousNestingLevel + 1), + Result = (catch F()), + put(?NESTING_KEY, PreviousNestingLevel), + case Result of + {aborted, Reason} when NRestarts > 0 -> + sql_query_internal(<<"rollback;">>), + outer_transaction(F, NRestarts - 1, Reason); + {aborted, Reason} when NRestarts =:= 0 -> + ?ERROR_MSG("SQL transaction restarts exceeded~n** " + "Restarts: ~p~n** Last abort reason: " + "~p~n** Stacktrace: ~p~n** When State " + "== ~p", + [?MAX_TRANSACTION_RESTARTS, Reason, + erlang:get_stacktrace(), get(?STATE_KEY)]), + sql_query_internal(<<"rollback;">>), + {aborted, Reason}; + {'EXIT', Reason} -> + sql_query_internal(<<"rollback;">>), {aborted, Reason}; + Res -> sql_query_internal(<<"commit;">>), {atomic, Res} + end. + +execute_bloc(F) -> + case catch F() of + {aborted, Reason} -> {aborted, Reason}; + {'EXIT', Reason} -> {aborted, Reason}; + Res -> {atomic, Res} + end. + +sql_query_internal(Query) -> + State = get(?STATE_KEY), + Res = case State#state.db_type of + odbc -> + to_odbc(odbc:sql_query(State#state.db_ref, Query, + (?TRANSACTION_TIMEOUT) - 1000)); + pgsql -> + pgsql_to_odbc(pgsql:squery(State#state.db_ref, Query)); + mysql -> + ?DEBUG("MySQL, Send query~n~p~n", [Query]), + %%squery to be able to specify result_type = binary + %%[Query] because mysql_conn expect query to be a list (elements can be binaries, or iolist) + %% but doesn't accept just a binary + R = mysql_to_odbc(mysql_conn:squery(State#state.db_ref, + [Query], self(), + [{timeout, (?TRANSACTION_TIMEOUT) - 1000}, + {result_type, binary}])), + %% ?INFO_MSG("MySQL, Received result~n~p~n", [R]), + R + end, + case Res of + {error, <<"No SQL-driver information available.">>} -> + {updated, 0}; + _Else -> Res + end. + +%% Generate the OTP callback return tuple depending on the driver result. +abort_on_driver_error({error, <<"query timed out">>} = + Reply, + From) -> + (?GEN_FSM):reply(From, Reply), + {stop, timeout, get(?STATE_KEY)}; +abort_on_driver_error({error, + <<"Failed sending data on socket", _/binary>>} = + Reply, + From) -> + (?GEN_FSM):reply(From, Reply), + {stop, closed, get(?STATE_KEY)}; +abort_on_driver_error(Reply, From) -> + (?GEN_FSM):reply(From, Reply), + {next_state, session_established, get(?STATE_KEY)}. + +%% == pure ODBC code + +%% part of init/1 +%% Open an ODBC database connection +odbc_connect(SQLServer) -> + ejabberd:start_app(odbc), + odbc:connect(SQLServer, [{scrollable_cursors, off}]). + +%% == Native PostgreSQL code + +%% part of init/1 +%% Open a database connection to PostgreSQL +pgsql_connect(Server, Port, DB, Username, Password) -> + case pgsql:connect([{host, Server}, + {database, DB}, + {user, Username}, + {password, Password}, + {port, Port}, + {as_binary, true}]) of + {ok, Ref} -> + pgsql:squery(Ref, [<<"alter database ">>, DB, <<" set ">>, + <<"standard_conforming_strings='off';">>]), + {ok, Ref}; + Err -> + Err + end. + +%% Convert PostgreSQL query result to Erlang ODBC result formalism +pgsql_to_odbc({ok, PGSQLResult}) -> + case PGSQLResult of + [Item] -> pgsql_item_to_odbc(Item); + Items -> [pgsql_item_to_odbc(Item) || Item <- Items] + end. + +pgsql_item_to_odbc({<<"SELECT", _/binary>>, Rows, + Recs}) -> + {selected, [element(1, Row) || Row <- Rows], Recs}; +pgsql_item_to_odbc(<<"INSERT ", OIDN/binary>>) -> + [_OID, N] = str:tokens(OIDN, <<" ">>), + {updated, jlib:binary_to_integer(N)}; +pgsql_item_to_odbc(<<"DELETE ", N/binary>>) -> + {updated, jlib:binary_to_integer(N)}; +pgsql_item_to_odbc(<<"UPDATE ", N/binary>>) -> + {updated, jlib:binary_to_integer(N)}; +pgsql_item_to_odbc({error, Error}) -> {error, Error}; +pgsql_item_to_odbc(_) -> {updated, undefined}. + +%% == Native MySQL code + +%% part of init/1 +%% Open a database connection to MySQL +mysql_connect(Server, Port, DB, Username, Password) -> + case mysql_conn:start(binary_to_list(Server), Port, + binary_to_list(Username), binary_to_list(Password), + binary_to_list(DB), fun log/3) + of + {ok, Ref} -> + mysql_conn:fetch(Ref, [<<"set names 'utf8';">>], + self()), + {ok, Ref}; + Err -> Err + end. + +%% Convert MySQL query result to Erlang ODBC result formalism +mysql_to_odbc({updated, MySQLRes}) -> + {updated, mysql:get_result_affected_rows(MySQLRes)}; +mysql_to_odbc({data, MySQLRes}) -> + mysql_item_to_odbc(mysql:get_result_field_info(MySQLRes), + mysql:get_result_rows(MySQLRes)); +mysql_to_odbc({error, MySQLRes}) + when is_binary(MySQLRes) -> + {error, MySQLRes}; +mysql_to_odbc({error, MySQLRes}) -> + {error, mysql:get_result_reason(MySQLRes)}. + +%% When tabular data is returned, convert it to the ODBC formalism +mysql_item_to_odbc(Columns, Recs) -> + {selected, [element(2, Column) || Column <- Columns], Recs}. + +to_odbc({selected, Columns, Recs}) -> + {selected, Columns, [tuple_to_list(Rec) || Rec <- Recs]}; +to_odbc(Res) -> + Res. + +log(Level, Format, Args) -> + case Level of + debug -> ?DEBUG(Format, Args); + normal -> ?INFO_MSG(Format, Args); + error -> ?ERROR_MSG(Format, Args) + end. + +db_opts(Host) -> + case ejabberd_config:get_local_option( + {odbc_server, Host}, + fun({Type, Server, DB, User, Pass}) -> + {Type, + iolist_to_binary(Server), + case Type of + mysql -> ?MYSQL_PORT; + pgsql -> ?PGSQL_PORT + end, + iolist_to_binary(DB), + iolist_to_binary(User), + iolist_to_binary(Pass)}; + ({Type, Server, Port, DB, User, Pass}) + when ((Type == mysql) or (Type == pgsql)) + and (is_integer(Port) and ((Port > 0) + and (Port < 65536))) -> + {Type, + iolist_to_binary(Server), + Port, + iolist_to_binary(DB), + iolist_to_binary(User), + iolist_to_binary(Pass)}; + (S) -> + iolist_to_binary(S) + end, <<"localhost">>) of + {Type, Server, Port, DB, User, Pass} -> + [Type, Server, Port, DB, User, Pass]; + SQLServer -> + [odbc, SQLServer] + end. + +max_fsm_queue() -> + ejabberd_config:get_local_option( + max_fsm_queue, + fun(N) when is_integer(N), N > 0 -> N end). + +fsm_limit_opts() -> + case max_fsm_queue() of + N when is_integer(N) -> [{max_queue, N}]; + _ -> [] + end. |