diff options
| -rw-r--r-- | doc/src/sgml/runtime.sgml | 89 | ||||
| -rw-r--r-- | src/backend/parser/scan.l | 37 | ||||
| -rw-r--r-- | src/backend/utils/misc/guc.c | 40 | ||||
| -rw-r--r-- | src/backend/utils/misc/postgresql.conf.sample | 3 | ||||
| -rw-r--r-- | src/bin/psql/tab-complete.c | 3 | ||||
| -rw-r--r-- | src/include/parser/gramparse.h | 13 |
6 files changed, 146 insertions, 39 deletions
diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 9b728ae7f44..cbebe6e17a0 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.301.4.7 2005/06/17 16:46:45 momjian Exp $ +$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.301.4.8 2006/05/21 20:11:25 tgl Exp $ --> <chapter id="runtime"> @@ -3490,39 +3490,31 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' </listitem> </varlistentry> - <varlistentry id="guc-regex-flavor" xreflabel="regex_flavor"> - <term><varname>regex_flavor</varname> (<type>string</type>)</term> - <indexterm><primary>regular expressions</></> + <varlistentry id="guc-backslash-quote" xreflabel="backslash_quote"> + <term><varname>backslash_quote</varname> (<type>string</type>)</term> + <indexterm><primary>strings</><secondary>backslash quotes</></> <indexterm> - <primary><varname>regex_flavor</> configuration parameter</primary> + <primary><varname>backslash_quote</> configuration parameter</primary> </indexterm> <listitem> <para> - The regular expression <quote>flavor</> can be set to - <literal>advanced</>, <literal>extended</>, or <literal>basic</>. - The default is <literal>advanced</>. The <literal>extended</> - setting may be useful for exact backwards compatibility with - pre-7.4 releases of <productname>PostgreSQL</>. See - <xref linkend="posix-syntax-details"> for details. - </para> - </listitem> - </varlistentry> - - <varlistentry id="guc-sql-inheritance" xreflabel="sql_inheritance"> - <term><varname>sql_inheritance</varname> (<type>boolean</type>)</term> - <indexterm> - <primary><varname>sql_inheritance</> configuration parameter</primary> - </indexterm> - <indexterm><primary>inheritance</></> - <listitem> - <para> - This controls the inheritance semantics, in particular whether - subtables are included by various commands by default. They were - not included in versions prior to 7.1. If you need the old - behavior you can set this variable to off, but in the long run - you are encouraged to change your applications to use the - <literal>ONLY</literal> key word to exclude subtables. See - <xref linkend="ddl-inherit"> for more information about inheritance. + This controls whether a quote mark can be represented by + <literal>\'</> in a string literal. The preferred, SQL-standard way + to represent a quote mark is by doubling it (<literal>''</>) but + <productname>PostgreSQL</> has historically also accepted + <literal>\'</>. However, use of <literal>\'</> creates security risks + because in some client character set encodings, there are multibyte + characters in which the last byte is numerically equivalent to ASCII + <literal>\</>. If client-side code does escaping incorrectly then a + SQL-injection attack is possible. This risk can be prevented by + making the server reject queries in which a quote mark appears to be + escaped by a backslash. + The allowed values of <varname>backslash_quote</> are + <literal>on</> (allow <literal>\'</> always), + <literal>off</> (reject always), and + <literal>safe_encoding</> (allow only if client encoding does not + allow ASCII <literal>\</> within a multibyte character). + <literal>safe_encoding</> is the default setting. </para> </listitem> </varlistentry> @@ -3560,6 +3552,43 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' </listitem> </varlistentry> + <varlistentry id="guc-regex-flavor" xreflabel="regex_flavor"> + <term><varname>regex_flavor</varname> (<type>string</type>)</term> + <indexterm><primary>regular expressions</></> + <indexterm> + <primary><varname>regex_flavor</> configuration parameter</primary> + </indexterm> + <listitem> + <para> + The regular expression <quote>flavor</> can be set to + <literal>advanced</>, <literal>extended</>, or <literal>basic</>. + The default is <literal>advanced</>. The <literal>extended</> + setting may be useful for exact backwards compatibility with + pre-7.4 releases of <productname>PostgreSQL</>. See + <xref linkend="posix-syntax-details"> for details. + </para> + </listitem> + </varlistentry> + + <varlistentry id="guc-sql-inheritance" xreflabel="sql_inheritance"> + <term><varname>sql_inheritance</varname> (<type>boolean</type>)</term> + <indexterm> + <primary><varname>sql_inheritance</> configuration parameter</primary> + </indexterm> + <indexterm><primary>inheritance</></> + <listitem> + <para> + This controls the inheritance semantics, in particular whether + subtables are included by various commands by default. They were + not included in versions prior to 7.1. If you need the old + behavior you can set this variable to off, but in the long run + you are encouraged to change your applications to use the + <literal>ONLY</literal> key word to exclude subtables. See + <xref linkend="ddl-inherit"> for more information about inheritance. + </para> + </listitem> + </varlistentry> + </variablelist> </sect3> <sect3 id="runtime-config-compatible-clients"> diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l index 433e42bf6a0..f0a424a8d02 100644 --- a/src/backend/parser/scan.l +++ b/src/backend/parser/scan.l @@ -10,7 +10,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.119.4.1 2005/08/16 00:48:29 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.119.4.2 2006/05/21 20:11:25 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -36,6 +36,15 @@ static int xcdepth = 0; /* depth of nesting in slash-star comments */ static char *dolqstart; /* current $foo$ quote start string */ /* + * GUC variables. This is a DIRECT violation of the warning given at the + * head of gram.y, ie flex/bison code must not depend on any GUC variables; + * as such, changing their values can induce very unintuitive behavior. + * But we shall have to live with it as a short-term thing until the switch + * to SQL-standard string syntax is complete. + */ +BackslashQuoteType backslash_quote = BACKSLASH_QUOTE_SAFE_ENCODING; + +/* * literalbuf is used to accumulate literal values when multiple rules * are needed to parse a single literal. Call startlit to reset buffer * to empty, addlit to add text. Note that the buffer is palloc'd and @@ -49,6 +58,7 @@ static int literalalloc; /* current allocated buffer size */ static void addlit(char *ytext, int yleng); static void addlitchar(unsigned char ychar); static char *litbufdup(void); +static int pg_err_position(void); /* * When we parse a token that requires multiple lexer rules to process, @@ -391,6 +401,17 @@ other . addlit(yytext, yyleng); } <xq>{xqescape} { + if (yytext[1] == '\'') + { + if (backslash_quote == BACKSLASH_QUOTE_OFF || + (backslash_quote == BACKSLASH_QUOTE_SAFE_ENCODING && + PG_ENCODING_IS_CLIENT_ONLY(pg_get_client_encoding()))) + ereport(ERROR, + (errcode(ERRCODE_INVALID_USE_OF_ESCAPE_CHARACTER), + errmsg("unsafe use of \\' in a string literal"), + errhint("Use '' to write quotes in strings. \\' is insecure in client-only encodings."), + errposition(pg_err_position()))); + } addlitchar(unescape_single_char(yytext[1])); } <xq>{xqoctesc} { @@ -613,14 +634,20 @@ other . %% -void -yyerror(const char *message) +static int +pg_err_position(void) { const char *loc = token_start ? token_start : yytext; - int cursorpos; /* in multibyte encodings, return index in characters not bytes */ - cursorpos = pg_mbstrlen_with_len(scanbuf, loc - scanbuf) + 1; + return pg_mbstrlen_with_len(scanbuf, loc - scanbuf) + 1; +} + +void +yyerror(const char *message) +{ + const char *loc = token_start ? token_start : yytext; + int cursorpos = pg_err_position(); if (*loc == YY_END_OF_BUFFER_CHAR) { diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index c1fa6fc5686..05b7b1a68df 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -10,7 +10,7 @@ * Written by Peter Eisentraut <[email protected]>. * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.252.4.3 2006/02/12 22:33:14 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.252.4.4 2006/05/21 20:11:25 tgl Exp $ * *-------------------------------------------------------------------- */ @@ -42,6 +42,7 @@ #include "optimizer/geqo.h" #include "optimizer/paths.h" #include "optimizer/prep.h" +#include "parser/gramparse.h" #include "parser/parse_expr.h" #include "parser/parse_relation.h" #include "parser/scansup.h" @@ -113,6 +114,7 @@ static bool assign_stage_log_stats(bool newval, bool doit, GucSource source); static bool assign_log_stats(bool newval, bool doit, GucSource source); static bool assign_transaction_read_only(bool newval, bool doit, GucSource source); static const char *assign_canonical_path(const char *newval, bool doit, GucSource source); +static const char *assign_backslash_quote(const char *newval, bool doit, GucSource source); /* @@ -169,6 +171,7 @@ static char *log_destination_string; static bool phony_autocommit; static bool session_auth_is_superuser; static double phony_random_seed; +static char *backslash_quote_string; static char *client_encoding_string; static char *datestyle_string; static char *default_iso_level_string; @@ -1424,6 +1427,15 @@ static struct config_string ConfigureNamesString[] = }, { + {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS, + gettext_noop("Sets whether \"\\'\" is allowed in string literals."), + gettext_noop("Valid values are ON, OFF, and SAFE_ENCODING.") + }, + &backslash_quote_string, + "safe_encoding", assign_backslash_quote, NULL + }, + + { {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE, gettext_noop("Sets the client's character set encoding."), NULL, @@ -5613,6 +5625,32 @@ assign_log_stats(bool newval, bool doit, GucSource source) return true; } +static const char * +assign_backslash_quote(const char *newval, bool doit, GucSource source) +{ + BackslashQuoteType bq; + bool bqbool; + + /* + * Although only "on", "off", and "safe_encoding" are documented, + * we use parse_bool so we can accept all the likely variants of + * "on" and "off". + */ + if (pg_strcasecmp(newval, "safe_encoding") == 0) + bq = BACKSLASH_QUOTE_SAFE_ENCODING; + else if (parse_bool(newval, &bqbool)) + { + bq = bqbool ? BACKSLASH_QUOTE_ON : BACKSLASH_QUOTE_OFF; + } + else + return NULL; /* reject */ + + if (doit) + backslash_quote = bq; + + return newval; +} + static bool assign_transaction_read_only(bool newval, bool doit, GucSource source) { diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 021b732096d..61d0bfebf3f 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -311,9 +311,10 @@ # - Previous Postgres Versions - #add_missing_from = true +#backslash_quote = safe_encoding # on, off, or safe_encoding +#default_with_oids = true #regex_flavor = advanced # advanced, extended, or basic #sql_inheritance = true -#default_with_oids = true # - Other Platforms & Clients - diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c index 0b9e369185d..5f40705d8a4 100644 --- a/src/bin/psql/tab-complete.c +++ b/src/bin/psql/tab-complete.c @@ -3,7 +3,7 @@ * * Copyright (c) 2000-2005, PostgreSQL Global Development Group * - * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.120.4.1 2005/05/04 14:25:30 tgl Exp $ + * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.120.4.2 2006/05/21 20:11:25 tgl Exp $ */ /*---------------------------------------------------------------------- @@ -512,6 +512,7 @@ psql_completion(char *text, int start, int end) */ "add_missing_from", "australian_timezones", + "backslash_quote", "client_encoding", "client_min_messages", "commit_delay", diff --git a/src/include/parser/gramparse.h b/src/include/parser/gramparse.h index 8095ef2300a..8e577980a2d 100644 --- a/src/include/parser/gramparse.h +++ b/src/include/parser/gramparse.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/parser/gramparse.h,v 1.31 2004/12/31 22:03:38 pgsql Exp $ + * $PostgreSQL: pgsql/src/include/parser/gramparse.h,v 1.31.4.1 2006/05/21 20:11:25 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -18,6 +18,17 @@ #include "nodes/parsenodes.h" +typedef enum +{ + BACKSLASH_QUOTE_OFF, + BACKSLASH_QUOTE_ON, + BACKSLASH_QUOTE_SAFE_ENCODING +} BackslashQuoteType; + +/* GUC variables in scan.l (every one of these is a bad idea :-() */ +extern BackslashQuoteType backslash_quote; + + /* from parser.c */ extern int yylex(void); |