postgresql/contrib/adminpack/adminpack.c

590 lines
14 KiB
C

/*-------------------------------------------------------------------------
*
* adminpack.c
*
*
* Copyright (c) 2002-2022, PostgreSQL Global Development Group
*
* Author: Andreas Pflug <pgadmin@pse-consulting.de>
*
* IDENTIFICATION
* contrib/adminpack/adminpack.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <sys/file.h>
#include <sys/stat.h>
#include <unistd.h>
#include "catalog/pg_authid.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "postmaster/syslogger.h"
#include "storage/fd.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datetime.h"
#ifdef WIN32
#ifdef rename
#undef rename
#endif
#ifdef unlink
#undef unlink
#endif
#endif
PG_MODULE_MAGIC;
PG_FUNCTION_INFO_V1(pg_file_write);
PG_FUNCTION_INFO_V1(pg_file_write_v1_1);
PG_FUNCTION_INFO_V1(pg_file_sync);
PG_FUNCTION_INFO_V1(pg_file_rename);
PG_FUNCTION_INFO_V1(pg_file_rename_v1_1);
PG_FUNCTION_INFO_V1(pg_file_unlink);
PG_FUNCTION_INFO_V1(pg_file_unlink_v1_1);
PG_FUNCTION_INFO_V1(pg_logdir_ls);
PG_FUNCTION_INFO_V1(pg_logdir_ls_v1_1);
static int64 pg_file_write_internal(text *file, text *data, bool replace);
static bool pg_file_rename_internal(text *file1, text *file2, text *file3);
static Datum pg_logdir_ls_internal(FunctionCallInfo fcinfo);
/*-----------------------
* some helper functions
*/
/*
* Convert a "text" filename argument to C string, and check it's allowable.
*
* Filename may be absolute or relative to the DataDir, but we only allow
* absolute paths that match DataDir.
*/
static char *
convert_and_check_filename(text *arg)
{
char *filename = text_to_cstring(arg);
canonicalize_path(filename); /* filename can change length here */
/*
* Members of the 'pg_write_server_files' role are allowed to access any
* files on the server as the PG user, so no need to do any further checks
* here.
*/
if (has_privs_of_role(GetUserId(), ROLE_PG_WRITE_SERVER_FILES))
return filename;
/*
* User isn't a member of the pg_write_server_files role, so check if it's
* allowable
*/
if (is_absolute_path(filename))
{
/* Allow absolute paths if within DataDir */
if (!path_is_prefix_of_path(DataDir, filename))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("absolute path not allowed")));
}
else if (!path_is_relative_and_below_cwd(filename))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("path must be in or below the current directory")));
return filename;
}
/*
* check for superuser, bark if not.
*/
static void
requireSuperuser(void)
{
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("only superuser may access generic file functions")));
}
/* ------------------------------------
* pg_file_write - old version
*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.1 installations
* these functions could be called by any user.
*/
Datum
pg_file_write(PG_FUNCTION_ARGS)
{
text *file = PG_GETARG_TEXT_PP(0);
text *data = PG_GETARG_TEXT_PP(1);
bool replace = PG_GETARG_BOOL(2);
int64 count = 0;
requireSuperuser();
count = pg_file_write_internal(file, data, replace);
PG_RETURN_INT64(count);
}
/* ------------------------------------
* pg_file_write_v1_1 - Version 1.1
*
* As of adminpack version 1.1, we no longer need to check if the user
* is a superuser because we REVOKE EXECUTE on the function from PUBLIC.
* Users can then grant access to it based on their policies.
*
* Otherwise identical to pg_file_write (above).
*/
Datum
pg_file_write_v1_1(PG_FUNCTION_ARGS)
{
text *file = PG_GETARG_TEXT_PP(0);
text *data = PG_GETARG_TEXT_PP(1);
bool replace = PG_GETARG_BOOL(2);
int64 count = 0;
count = pg_file_write_internal(file, data, replace);
PG_RETURN_INT64(count);
}
/* ------------------------------------
* pg_file_write_internal - Workhorse for pg_file_write functions.
*
* This handles the actual work for pg_file_write.
*/
static int64
pg_file_write_internal(text *file, text *data, bool replace)
{
FILE *f;
char *filename;
int64 count = 0;
filename = convert_and_check_filename(file);
if (!replace)
{
struct stat fst;
if (stat(filename, &fst) >= 0)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_FILE),
errmsg("file \"%s\" exists", filename)));
f = AllocateFile(filename, "wb");
}
else
f = AllocateFile(filename, "ab");
if (!f)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\" for writing: %m",
filename)));
count = fwrite(VARDATA_ANY(data), 1, VARSIZE_ANY_EXHDR(data), f);
if (count != VARSIZE_ANY_EXHDR(data) || FreeFile(f))
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write file \"%s\": %m", filename)));
return (count);
}
/* ------------------------------------
* pg_file_sync
*
* We REVOKE EXECUTE on the function from PUBLIC.
* Users can then grant access to it based on their policies.
*/
Datum
pg_file_sync(PG_FUNCTION_ARGS)
{
char *filename;
struct stat fst;
filename = convert_and_check_filename(PG_GETARG_TEXT_PP(0));
if (stat(filename, &fst) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat file \"%s\": %m", filename)));
fsync_fname_ext(filename, S_ISDIR(fst.st_mode), false, ERROR);
PG_RETURN_VOID();
}
/* ------------------------------------
* pg_file_rename - old version
*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.1 installations
* these functions could be called by any user.
*/
Datum
pg_file_rename(PG_FUNCTION_ARGS)
{
text *file1;
text *file2;
text *file3;
bool result;
requireSuperuser();
if (PG_ARGISNULL(0) || PG_ARGISNULL(1))
PG_RETURN_NULL();
file1 = PG_GETARG_TEXT_PP(0);
file2 = PG_GETARG_TEXT_PP(1);
if (PG_ARGISNULL(2))
file3 = NULL;
else
file3 = PG_GETARG_TEXT_PP(2);
result = pg_file_rename_internal(file1, file2, file3);
PG_RETURN_BOOL(result);
}
/* ------------------------------------
* pg_file_rename_v1_1 - Version 1.1
*
* As of adminpack version 1.1, we no longer need to check if the user
* is a superuser because we REVOKE EXECUTE on the function from PUBLIC.
* Users can then grant access to it based on their policies.
*
* Otherwise identical to pg_file_write (above).
*/
Datum
pg_file_rename_v1_1(PG_FUNCTION_ARGS)
{
text *file1;
text *file2;
text *file3;
bool result;
if (PG_ARGISNULL(0) || PG_ARGISNULL(1))
PG_RETURN_NULL();
file1 = PG_GETARG_TEXT_PP(0);
file2 = PG_GETARG_TEXT_PP(1);
if (PG_ARGISNULL(2))
file3 = NULL;
else
file3 = PG_GETARG_TEXT_PP(2);
result = pg_file_rename_internal(file1, file2, file3);
PG_RETURN_BOOL(result);
}
/* ------------------------------------
* pg_file_rename_internal - Workhorse for pg_file_rename functions.
*
* This handles the actual work for pg_file_rename.
*/
static bool
pg_file_rename_internal(text *file1, text *file2, text *file3)
{
char *fn1,
*fn2,
*fn3;
int rc;
fn1 = convert_and_check_filename(file1);
fn2 = convert_and_check_filename(file2);
if (file3 == NULL)
fn3 = NULL;
else
fn3 = convert_and_check_filename(file3);
if (access(fn1, W_OK) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("file \"%s\" is not accessible: %m", fn1)));
return false;
}
if (fn3 && access(fn2, W_OK) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("file \"%s\" is not accessible: %m", fn2)));
return false;
}
rc = access(fn3 ? fn3 : fn2, W_OK);
if (rc >= 0 || errno != ENOENT)
{
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_FILE),
errmsg("cannot rename to target file \"%s\"",
fn3 ? fn3 : fn2)));
}
if (fn3)
{
if (rename(fn2, fn3) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" to \"%s\": %m",
fn2, fn3)));
}
if (rename(fn1, fn2) != 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" to \"%s\": %m",
fn1, fn2)));
if (rename(fn3, fn2) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" back to \"%s\": %m",
fn3, fn2)));
}
else
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FILE),
errmsg("renaming \"%s\" to \"%s\" was reverted",
fn2, fn3)));
}
}
}
else if (rename(fn1, fn2) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" to \"%s\": %m", fn1, fn2)));
}
return true;
}
/* ------------------------------------
* pg_file_unlink - old version
*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.1 installations
* these functions could be called by any user.
*/
Datum
pg_file_unlink(PG_FUNCTION_ARGS)
{
char *filename;
requireSuperuser();
filename = convert_and_check_filename(PG_GETARG_TEXT_PP(0));
if (access(filename, W_OK) < 0)
{
if (errno == ENOENT)
PG_RETURN_BOOL(false);
else
ereport(ERROR,
(errcode_for_file_access(),
errmsg("file \"%s\" is not accessible: %m", filename)));
}
if (unlink(filename) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not unlink file \"%s\": %m", filename)));
PG_RETURN_BOOL(false);
}
PG_RETURN_BOOL(true);
}
/* ------------------------------------
* pg_file_unlink_v1_1 - Version 1.1
*
* As of adminpack version 1.1, we no longer need to check if the user
* is a superuser because we REVOKE EXECUTE on the function from PUBLIC.
* Users can then grant access to it based on their policies.
*
* Otherwise identical to pg_file_unlink (above).
*/
Datum
pg_file_unlink_v1_1(PG_FUNCTION_ARGS)
{
char *filename;
filename = convert_and_check_filename(PG_GETARG_TEXT_PP(0));
if (access(filename, W_OK) < 0)
{
if (errno == ENOENT)
PG_RETURN_BOOL(false);
else
ereport(ERROR,
(errcode_for_file_access(),
errmsg("file \"%s\" is not accessible: %m", filename)));
}
if (unlink(filename) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not unlink file \"%s\": %m", filename)));
PG_RETURN_BOOL(false);
}
PG_RETURN_BOOL(true);
}
/* ------------------------------------
* pg_logdir_ls - Old version
*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.1 installations
* these functions could be called by any user.
*/
Datum
pg_logdir_ls(PG_FUNCTION_ARGS)
{
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("only superuser can list the log directory")));
return (pg_logdir_ls_internal(fcinfo));
}
/* ------------------------------------
* pg_logdir_ls_v1_1 - Version 1.1
*
* As of adminpack version 1.1, we no longer need to check if the user
* is a superuser because we REVOKE EXECUTE on the function from PUBLIC.
* Users can then grant access to it based on their policies.
*
* Otherwise identical to pg_logdir_ls (above).
*/
Datum
pg_logdir_ls_v1_1(PG_FUNCTION_ARGS)
{
return (pg_logdir_ls_internal(fcinfo));
}
static Datum
pg_logdir_ls_internal(FunctionCallInfo fcinfo)
{
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
bool randomAccess;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
AttInMetadata *attinmeta;
DIR *dirdesc;
struct dirent *de;
MemoryContext oldcontext;
if (strcmp(Log_filename, "postgresql-%Y-%m-%d_%H%M%S.log") != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("the log_filename parameter must equal 'postgresql-%%Y-%%m-%%d_%%H%%M%%S.log'")));
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("materialize mode required, but it is not allowed in this context")));
/* The tupdesc and tuplestore must be created in ecxt_per_query_memory */
oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
tupdesc = CreateTemplateTupleDesc(2);
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "starttime",
TIMESTAMPOID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "filename",
TEXTOID, -1, 0);
randomAccess = (rsinfo->allowedModes & SFRM_Materialize_Random) != 0;
tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
attinmeta = TupleDescGetAttInMetadata(tupdesc);
dirdesc = AllocateDir(Log_directory);
while ((de = ReadDir(dirdesc, Log_directory)) != NULL)
{
char *values[2];
HeapTuple tuple;
char timestampbuf[32];
char *field[MAXDATEFIELDS];
char lowstr[MAXDATELEN + 1];
int dtype;
int nf,
ftype[MAXDATEFIELDS];
fsec_t fsec;
int tz = 0;
struct pg_tm date;
/*
* Default format: postgresql-YYYY-MM-DD_HHMMSS.log
*/
if (strlen(de->d_name) != 32
|| strncmp(de->d_name, "postgresql-", 11) != 0
|| de->d_name[21] != '_'
|| strcmp(de->d_name + 28, ".log") != 0)
continue;
/* extract timestamp portion of filename */
strcpy(timestampbuf, de->d_name + 11);
timestampbuf[17] = '\0';
/* parse and decode expected timestamp to verify it's OK format */
if (ParseDateTime(timestampbuf, lowstr, MAXDATELEN, field, ftype, MAXDATEFIELDS, &nf))
continue;
if (DecodeDateTime(field, ftype, nf, &dtype, &date, &fsec, &tz))
continue;
/* Seems the timestamp is OK; prepare and return tuple */
values[0] = timestampbuf;
values[1] = psprintf("%s/%s", Log_directory, de->d_name);
tuple = BuildTupleFromCStrings(attinmeta, values);
tuplestore_puttuple(tupstore, tuple);
}
FreeDir(dirdesc);
return (Datum) 0;
}