mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-10-05 12:06:56 +02:00
234a02b2a8
Get rid of VARATT_SIZE and VARATT_DATA, which were simply redundant with VARSIZE and VARDATA, and as a consequence almost no code was using the longer names. Rename the length fields of struct varlena and various derived structures to catch anyplace that was accessing them directly; and clean up various places so caught. In itself this patch doesn't change any behavior at all, but it is necessary infrastructure if we hope to play any games with the representation of varlena headers. Greg Stark and Tom Lane
274 lines
6.9 KiB
C
274 lines
6.9 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* genfile.c
|
|
* Functions for direct access to files
|
|
*
|
|
*
|
|
* Copyright (c) 2004-2007, PostgreSQL Global Development Group
|
|
*
|
|
* Author: Andreas Pflug <pgadmin@pse-consulting.de>
|
|
*
|
|
* IDENTIFICATION
|
|
* $PostgreSQL: pgsql/src/backend/utils/adt/genfile.c,v 1.16 2007/02/27 23:48:08 tgl Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include <sys/file.h>
|
|
#include <sys/stat.h>
|
|
#include <unistd.h>
|
|
#include <dirent.h>
|
|
|
|
#include "access/heapam.h"
|
|
#include "catalog/pg_type.h"
|
|
#include "funcapi.h"
|
|
#include "miscadmin.h"
|
|
#include "postmaster/syslogger.h"
|
|
#include "storage/fd.h"
|
|
#include "utils/builtins.h"
|
|
#include "utils/memutils.h"
|
|
#include "utils/timestamp.h"
|
|
|
|
typedef struct
|
|
{
|
|
char *location;
|
|
DIR *dirdesc;
|
|
} directory_fctx;
|
|
|
|
|
|
/*
|
|
* 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 or Log_directory.
|
|
*/
|
|
static char *
|
|
convert_and_check_filename(text *arg)
|
|
{
|
|
int input_len = VARSIZE(arg) - VARHDRSZ;
|
|
char *filename = palloc(input_len + 1);
|
|
|
|
memcpy(filename, VARDATA(arg), input_len);
|
|
filename[input_len] = '\0';
|
|
|
|
canonicalize_path(filename); /* filename can change length here */
|
|
|
|
/* Disallow ".." in the path */
|
|
if (path_contains_parent_reference(filename))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("reference to parent directory (\"..\") not allowed"))));
|
|
|
|
if (is_absolute_path(filename))
|
|
{
|
|
/* Allow absolute references within DataDir */
|
|
if (path_is_prefix_of_path(DataDir, filename))
|
|
return filename;
|
|
/* The log directory might be outside our datadir, but allow it */
|
|
if (is_absolute_path(Log_directory) &&
|
|
path_is_prefix_of_path(Log_directory, filename))
|
|
return filename;
|
|
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("absolute path not allowed"))));
|
|
return NULL; /* keep compiler quiet */
|
|
}
|
|
else
|
|
{
|
|
return filename;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Read a section of a file, returning it as text
|
|
*/
|
|
Datum
|
|
pg_read_file(PG_FUNCTION_ARGS)
|
|
{
|
|
text *filename_t = PG_GETARG_TEXT_P(0);
|
|
int64 seek_offset = PG_GETARG_INT64(1);
|
|
int64 bytes_to_read = PG_GETARG_INT64(2);
|
|
char *buf;
|
|
size_t nbytes;
|
|
FILE *file;
|
|
char *filename;
|
|
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to read files"))));
|
|
|
|
filename = convert_and_check_filename(filename_t);
|
|
|
|
if ((file = AllocateFile(filename, PG_BINARY_R)) == NULL)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" for reading: %m",
|
|
filename)));
|
|
|
|
if (fseeko(file, (off_t) seek_offset,
|
|
(seek_offset >= 0) ? SEEK_SET : SEEK_END) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not seek in file \"%s\": %m", filename)));
|
|
|
|
if (bytes_to_read < 0)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("requested length cannot be negative")));
|
|
|
|
/* not sure why anyone thought that int64 length was a good idea */
|
|
if (bytes_to_read > (MaxAllocSize - VARHDRSZ))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("requested length too large")));
|
|
|
|
buf = palloc((Size) bytes_to_read + VARHDRSZ);
|
|
|
|
nbytes = fread(VARDATA(buf), 1, (size_t) bytes_to_read, file);
|
|
|
|
if (ferror(file))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m", filename)));
|
|
|
|
SET_VARSIZE(buf, nbytes + VARHDRSZ);
|
|
|
|
FreeFile(file);
|
|
pfree(filename);
|
|
|
|
PG_RETURN_TEXT_P(buf);
|
|
}
|
|
|
|
/*
|
|
* stat a file
|
|
*/
|
|
Datum
|
|
pg_stat_file(PG_FUNCTION_ARGS)
|
|
{
|
|
text *filename_t = PG_GETARG_TEXT_P(0);
|
|
char *filename;
|
|
struct stat fst;
|
|
Datum values[6];
|
|
bool isnull[6];
|
|
HeapTuple tuple;
|
|
TupleDesc tupdesc;
|
|
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to get file information"))));
|
|
|
|
filename = convert_and_check_filename(filename_t);
|
|
|
|
if (stat(filename, &fst) < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not stat file \"%s\": %m", filename)));
|
|
|
|
/*
|
|
* This record type had better match the output parameters declared for me
|
|
* in pg_proc.h.
|
|
*/
|
|
tupdesc = CreateTemplateTupleDesc(6, false);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 1,
|
|
"size", INT8OID, -1, 0);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 2,
|
|
"access", TIMESTAMPTZOID, -1, 0);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 3,
|
|
"modification", TIMESTAMPTZOID, -1, 0);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 4,
|
|
"change", TIMESTAMPTZOID, -1, 0);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 5,
|
|
"creation", TIMESTAMPTZOID, -1, 0);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 6,
|
|
"isdir", BOOLOID, -1, 0);
|
|
BlessTupleDesc(tupdesc);
|
|
|
|
memset(isnull, false, sizeof(isnull));
|
|
|
|
values[0] = Int64GetDatum((int64) fst.st_size);
|
|
values[1] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_atime));
|
|
values[2] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_mtime));
|
|
/* Unix has file status change time, while Win32 has creation time */
|
|
#if !defined(WIN32) && !defined(__CYGWIN__)
|
|
values[3] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
|
|
isnull[4] = true;
|
|
#else
|
|
isnull[3] = true;
|
|
values[4] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
|
|
#endif
|
|
values[5] = BoolGetDatum(fst.st_mode & S_IFDIR);
|
|
|
|
tuple = heap_form_tuple(tupdesc, values, isnull);
|
|
|
|
pfree(filename);
|
|
|
|
PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
|
|
}
|
|
|
|
|
|
/*
|
|
* List a directory (returns the filenames only)
|
|
*/
|
|
Datum
|
|
pg_ls_dir(PG_FUNCTION_ARGS)
|
|
{
|
|
FuncCallContext *funcctx;
|
|
struct dirent *de;
|
|
directory_fctx *fctx;
|
|
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to get directory listings"))));
|
|
|
|
if (SRF_IS_FIRSTCALL())
|
|
{
|
|
MemoryContext oldcontext;
|
|
|
|
funcctx = SRF_FIRSTCALL_INIT();
|
|
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
|
|
|
|
fctx = palloc(sizeof(directory_fctx));
|
|
fctx->location = convert_and_check_filename(PG_GETARG_TEXT_P(0));
|
|
|
|
fctx->dirdesc = AllocateDir(fctx->location);
|
|
|
|
if (!fctx->dirdesc)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open directory \"%s\": %m",
|
|
fctx->location)));
|
|
|
|
funcctx->user_fctx = fctx;
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
funcctx = SRF_PERCALL_SETUP();
|
|
fctx = (directory_fctx *) funcctx->user_fctx;
|
|
|
|
while ((de = ReadDir(fctx->dirdesc, fctx->location)) != NULL)
|
|
{
|
|
int len = strlen(de->d_name);
|
|
text *result;
|
|
|
|
if (strcmp(de->d_name, ".") == 0 ||
|
|
strcmp(de->d_name, "..") == 0)
|
|
continue;
|
|
|
|
result = palloc(len + VARHDRSZ);
|
|
SET_VARSIZE(result, len + VARHDRSZ);
|
|
memcpy(VARDATA(result), de->d_name, len);
|
|
|
|
SRF_RETURN_NEXT(funcctx, PointerGetDatum(result));
|
|
}
|
|
|
|
FreeDir(fctx->dirdesc);
|
|
|
|
SRF_RETURN_DONE(funcctx);
|
|
}
|