psql: fix \connect with URIs and conninfo strings

psql was already accepting conninfo strings as the first parameter in
\connect, but the way it worked wasn't sane; some of the other
parameters would get the previous connection's values, causing it to
connect to a completely unexpected server or, more likely, not finding
any server at all because of completely wrong combinations of
parameters.

Fix by explicitely checking for a conninfo-looking parameter in the
dbname position; if one is found, use its complete specification rather
than mix with the other arguments.  Also, change tab-completion to not
try to complete conninfo/URI-looking "dbnames" and document that
conninfos are accepted as first argument.

There was a weak consensus to backpatch this, because while the behavior
of using the dbname as a conninfo is nowhere documented for \connect, it
is reasonable to expect that it works because it does work in many other
contexts.  Therefore this is backpatched all the way back to 9.0.

To implement this, routines previously private to libpq have been
duplicated so that psql can decide what looks like a conninfo/URI
string.  In back branches, just duplicate the same code all the way back
to 9.2, where URIs where introduced; 9.0 and 9.1 have a simpler version.
In master, the routines are moved to src/common and renamed.

Author: David Fetter, Andrew Dunstan.  Some editorialization by me
(probably earning a Gierth's "Sloppy" badge in the process.)
Reviewers: Andrew Gierth, Erik Rijkers, Pavel Stěhule, Stephen Frost,
Robert Haas, Andrew Dunstan.
This commit is contained in:
Alvaro Herrera 2015-04-01 20:00:07 -03:00
parent a0efc71453
commit fcef161729
8 changed files with 175 additions and 79 deletions

View File

@ -796,23 +796,31 @@ testdb=>
</varlistentry>
<varlistentry>
<term><literal>\c</literal> or <literal>\connect</literal> <literal>[ <replaceable class="parameter">dbname</replaceable> [ <replaceable class="parameter">username</replaceable> ] [ <replaceable class="parameter">host</replaceable> ] [ <replaceable class="parameter">port</replaceable> ] ]</literal></term>
<term><literal>\c</literal> or <literal>\connect</literal> <literal>[ <replaceable class="parameter">dbname</replaceable> [ <replaceable class="parameter">username</replaceable> ] [ <replaceable class="parameter">host</replaceable> ] [ <replaceable class="parameter">port</replaceable> ] ] | <replaceable class="parameter">conninfo</replaceable> </literal></term>
<listitem>
<para>
Establishes a new connection to a <productname>PostgreSQL</>
server. If the new connection is successfully made, the
previous connection is closed. If any of <replaceable
class="parameter">dbname</replaceable>, <replaceable
class="parameter">username</replaceable>, <replaceable
class="parameter">host</replaceable> or <replaceable
class="parameter">port</replaceable> are omitted or specified
as <literal>-</literal>, the value of that parameter from the
previous connection is used. If there is no previous
connection, the <application>libpq</application> default for
the parameter's value is used.
server. The connection parameters to use can be specified either
using a positional syntax, or using <literal>conninfo</> connection
strings as detailed in <xref linkend="libpq-connstring">.
</para>
<para>
When using positional parameters, if any of
<replaceable class="parameter">dbname</replaceable>,
<replaceable class="parameter">username</replaceable>,
<replaceable class="parameter">host</replaceable> or
<replaceable class="parameter">port</replaceable> are omitted or
specified as <literal>-</literal>, the value of that parameter from
the previous connection is used; if there is no previous connection,
the <application>libpq</application> default for the parameter's value
is used. When using <literal>conninfo</> strings, no values from the
previous connection are used for the new connection.
</para>
<para>
If the new connection is successfully made, the previous
connection is closed.
If the connection attempt failed (wrong user name, access
denied, etc.), the previous connection will only be kept if
<application>psql</application> is in interactive mode. When
@ -822,6 +830,16 @@ testdb=&gt;
mechanism that scripts are not accidentally acting on the
wrong database on the other hand.
</para>
<para>
Examples:
</para>
<programlisting>
=&gt; \c mydb myuser host.dom 6432
=&gt; \c service=foo
=&gt; \c "host=localhost port=5432 dbname=mydb connect_timeout=10 sslmode=disable"
=&gt; \c postgresql://tom@localhost/mydb?application_name=myapp
</programlisting>
</listitem>
</varlistentry>

View File

@ -31,6 +31,7 @@
#include <sys/stat.h> /* for stat() */
#endif
#include "common/connstrings.h"
#include "portability/instr_time.h"
#include "libpq-fe.h"
@ -1608,6 +1609,8 @@ do_connect(char *dbname, char *user, char *host, char *port)
PGconn *o_conn = pset.db,
*n_conn;
char *password = NULL;
bool keep_password;
bool has_connection_string;
if (!o_conn && (!dbname || !user || !host || !port))
{
@ -1621,8 +1624,7 @@ do_connect(char *dbname, char *user, char *host, char *port)
return false;
}
if (!dbname)
dbname = PQdb(o_conn);
/* grab values from the old connection, unless supplied by caller */
if (!user)
user = PQuser(o_conn);
if (!host)
@ -1630,6 +1632,27 @@ do_connect(char *dbname, char *user, char *host, char *port)
if (!port)
port = PQport(o_conn);
has_connection_string =
dbname ? libpq_connstring_is_recognized(dbname) : false;
/*
* Any change in the parameters read above makes us discard the password.
* We also discard it if we're to use a conninfo rather than the positional
* syntax.
*/
keep_password =
((strcmp(user, PQuser(o_conn)) == 0) &&
(!host || strcmp(host, PQhost(o_conn)) == 0) &&
(strcmp(port, PQport(o_conn)) == 0) &&
!has_connection_string);
/*
* Grab dbname from old connection unless supplied by caller. No password
* discard if this changes: passwords aren't (usually) database-specific.
*/
if (!dbname)
dbname = PQdb(o_conn);
/*
* If the user asked to be prompted for a password, ask for one now. If
* not, use the password from the old connection, provided the username
@ -1644,9 +1667,13 @@ do_connect(char *dbname, char *user, char *host, char *port)
{
password = prompt_for_password(user);
}
else if (o_conn && user && strcmp(PQuser(o_conn), user) == 0)
else if (o_conn && keep_password)
{
password = pg_strdup(PQpass(o_conn));
password = PQpass(o_conn);
if (password && *password)
password = pg_strdup(password);
else
password = NULL;
}
while (true)
@ -1654,32 +1681,39 @@ do_connect(char *dbname, char *user, char *host, char *port)
#define PARAMS_ARRAY_SIZE 8
const char **keywords = pg_malloc(PARAMS_ARRAY_SIZE * sizeof(*keywords));
const char **values = pg_malloc(PARAMS_ARRAY_SIZE * sizeof(*values));
int paramnum = 0;
keywords[0] = "host";
values[0] = host;
keywords[1] = "port";
values[1] = port;
keywords[2] = "user";
values[2] = user;
keywords[3] = "password";
values[3] = password;
keywords[4] = "dbname";
values[4] = dbname;
keywords[5] = "fallback_application_name";
values[5] = pset.progname;
keywords[6] = "client_encoding";
values[6] = (pset.notty || getenv("PGCLIENTENCODING")) ? NULL : "auto";
keywords[7] = NULL;
values[7] = NULL;
keywords[0] = "dbname";
values[0] = dbname;
if (!has_connection_string)
{
keywords[++paramnum] = "host";
values[paramnum] = host;
keywords[++paramnum] = "port";
values[paramnum] = port;
keywords[++paramnum] = "user";
values[paramnum] = user;
}
keywords[++paramnum] = "password";
values[paramnum] = password;
keywords[++paramnum] = "fallback_application_name";
values[paramnum] = pset.progname;
keywords[++paramnum] = "client_encoding";
values[paramnum] = (pset.notty || getenv("PGCLIENTENCODING")) ? NULL : "auto";
/* add array terminator */
keywords[++paramnum] = NULL;
values[paramnum] = NULL;
n_conn = PQconnectdbParams(keywords, values, true);
free(keywords);
free(values);
pg_free(keywords);
pg_free(values);
/* We can immediately discard the password -- no longer needed */
if (password)
free(password);
pg_free(password);
if (PQstatus(n_conn) == CONNECTION_OK)
break;

View File

@ -260,11 +260,11 @@ slashUsage(unsigned short int pager)
fprintf(output, _("Connection\n"));
if (currdb)
fprintf(output, _(" \\c[onnect] [DBNAME|- USER|- HOST|- PORT|-]\n"
fprintf(output, _(" \\c[onnect] {[DBNAME|- USER|- HOST|- PORT|-] | conninfo}\n"
" connect to new database (currently \"%s\")\n"),
currdb);
else
fprintf(output, _(" \\c[onnect] [DBNAME|- USER|- HOST|- PORT|-]\n"
fprintf(output, _(" \\c[onnect] {[DBNAME|- USER|- HOST|- PORT|-] | conninfo}\n"
" connect to new database (currently no connection)\n"));
fprintf(output, _(" \\encoding [ENCODING] show or set client encoding\n"));
fprintf(output, _(" \\password [USERNAME] securely change the password for a user\n"));

View File

@ -52,6 +52,7 @@
#include "libpq-fe.h"
#include "pqexpbuffer.h"
#include "common.h"
#include "common/connstrings.h"
#include "settings.h"
#include "stringutils.h"
@ -3706,10 +3707,18 @@ psql_completion(const char *text, int start, int end)
COMPLETE_WITH_LIST_CS(my_list);
}
else if (strcmp(prev_wd, "\\connect") == 0 || strcmp(prev_wd, "\\c") == 0)
COMPLETE_WITH_QUERY(Query_for_list_of_databases);
{
if (!libpq_connstring_is_recognized(text))
COMPLETE_WITH_QUERY(Query_for_list_of_databases);
/* TODO: URI/service completion. Nothing for now */
}
else if (strcmp(prev2_wd, "\\connect") == 0 || strcmp(prev2_wd, "\\c") == 0)
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
{
if (!libpq_connstring_is_recognized(prev_wd))
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
}
else if (strncmp(prev_wd, "\\da", strlen("\\da")) == 0)
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_aggregates, NULL);

View File

@ -26,7 +26,7 @@ LIBS += $(PTHREAD_LIBS)
OBJS_COMMON = exec.o pg_crc.o pg_lzcompress.o pgfnames.o psprintf.o relpath.o \
rmtree.o string.o username.o wait_error.o
OBJS_FRONTEND = $(OBJS_COMMON) fe_memutils.o restricted_token.o
OBJS_FRONTEND = $(OBJS_COMMON) fe_memutils.o restricted_token.o connstrings.o
OBJS_SRV = $(OBJS_COMMON:%.o=%_srv.o)

53
src/common/connstrings.c Normal file
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@ -0,0 +1,53 @@
/*
* connstrings.c
* connecting string processing functions
*
* Copyright (c) 2012-2015, PostgreSQL Global Development Group
*
* src/include/common/connstrings.c
*/
#include "postgres_fe.h"
#include <string.h>
#include "common/connstrings.h"
/* The connection URI must start with either of the following designators: */
static const char uri_designator[] = "postgresql://";
static const char short_uri_designator[] = "postgres://";
/*
* Checks if connection string starts with either of the valid URI prefix
* designators.
*
* Returns the URI prefix length, 0 if the string doesn't contain a URI prefix.
*/
int
libpq_connstring_uri_prefix_length(const char *connstr)
{
if (strncmp(connstr, uri_designator,
sizeof(uri_designator) - 1) == 0)
return sizeof(uri_designator) - 1;
if (strncmp(connstr, short_uri_designator,
sizeof(short_uri_designator) - 1) == 0)
return sizeof(short_uri_designator) - 1;
return 0;
}
/*
* Recognized connection string either starts with a valid URI prefix or
* contains a "=" in it.
*
* Must be consistent with parse_connection_string: anything for which this
* returns true should at least look like it's parseable by that routine.
*/
bool
libpq_connstring_is_recognized(const char *connstr)
{
return libpq_connstring_uri_prefix_length(connstr) != 0 ||
strchr(connstr, '=') != NULL;
}

View File

@ -0,0 +1,16 @@
/*
* connstrings.h
* connecting string processing prototypes
*
* Copyright (c) 2012-2015, PostgreSQL Global Development Group
*
* src/include/common/connstrings.h
*/
#ifndef CONNSTRINGS_H
#define CONNSTRINGS_H
extern int libpq_connstring_uri_prefix_length(const char *connstr);
extern bool libpq_connstring_is_recognized(const char *connstr);
#endif /* CONNSTRINGS_H */

View File

@ -22,6 +22,7 @@
#include <time.h>
#include <unistd.h>
#include "common/connstrings.h"
#include "libpq-fe.h"
#include "libpq-int.h"
#include "fe-auth.h"
@ -339,8 +340,6 @@ static void closePGconn(PGconn *conn);
static PQconninfoOption *conninfo_init(PQExpBuffer errorMessage);
static PQconninfoOption *parse_connection_string(const char *conninfo,
PQExpBuffer errorMessage, bool use_defaults);
static int uri_prefix_length(const char *connstr);
static bool recognized_connection_string(const char *connstr);
static PQconninfoOption *conninfo_parse(const char *conninfo,
PQExpBuffer errorMessage, bool use_defaults);
static PQconninfoOption *conninfo_array_parse(const char *const * keywords,
@ -971,7 +970,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
* If the dbName parameter contains what looks like a connection string,
* parse it into conn struct using connectOptions1.
*/
if (dbName && recognized_connection_string(dbName))
if (dbName && libpq_connstring_is_recognized(dbName))
{
if (!connectOptions1(conn, dbName))
return conn;
@ -4185,46 +4184,13 @@ parse_connection_string(const char *connstr, PQExpBuffer errorMessage,
bool use_defaults)
{
/* Parse as URI if connection string matches URI prefix */
if (uri_prefix_length(connstr) != 0)
if (libpq_connstring_uri_prefix_length(connstr) != 0)
return conninfo_uri_parse(connstr, errorMessage, use_defaults);
/* Parse as default otherwise */
return conninfo_parse(connstr, errorMessage, use_defaults);
}
/*
* Checks if connection string starts with either of the valid URI prefix
* designators.
*
* Returns the URI prefix length, 0 if the string doesn't contain a URI prefix.
*/
static int
uri_prefix_length(const char *connstr)
{
if (strncmp(connstr, uri_designator,
sizeof(uri_designator) - 1) == 0)
return sizeof(uri_designator) - 1;
if (strncmp(connstr, short_uri_designator,
sizeof(short_uri_designator) - 1) == 0)
return sizeof(short_uri_designator) - 1;
return 0;
}
/*
* Recognized connection string either starts with a valid URI prefix or
* contains a "=" in it.
*
* Must be consistent with parse_connection_string: anything for which this
* returns true should at least look like it's parseable by that routine.
*/
static bool
recognized_connection_string(const char *connstr)
{
return uri_prefix_length(connstr) != 0 || strchr(connstr, '=') != NULL;
}
/*
* Subroutine for parse_connection_string
*
@ -4400,7 +4366,7 @@ conninfo_parse(const char *conninfo, PQExpBuffer errorMessage,
*
* If expand_dbname is non-zero, and the value passed for the first occurrence
* of "dbname" keyword is a connection string (as indicated by
* recognized_connection_string) then parse and process it, overriding any
* libpq_connstring_is_recognized) then parse and process it, overriding any
* previously processed conflicting keywords. Subsequent keywords will take
* precedence, however.
*/
@ -4431,7 +4397,7 @@ conninfo_array_parse(const char *const * keywords, const char *const * values,
* defaults here -- those get picked up later. We only want to
* override for those parameters actually passed.
*/
if (recognized_connection_string(pvalue))
if (libpq_connstring_is_recognized(pvalue))
{
dbname_options = parse_connection_string(pvalue, errorMessage, false);
if (dbname_options == NULL)
@ -4722,7 +4688,7 @@ conninfo_uri_parse_options(PQconninfoOption *options, const char *uri,
start = buf;
/* Skip the URI prefix */
prefix_len = uri_prefix_length(uri);
prefix_len = libpq_connstring_uri_prefix_length(uri);
if (prefix_len == 0)
{
/* Should never happen */