--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * genfile.c
+ * Functions for direct access to files
+ *
+ *
+ * Copyright (c) 2004-2005, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ * $PostgreSQL$
+ *
+ *-------------------------------------------------------------------------
+ */
+#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"
+
+
+typedef struct
+{
+ char *location;
+ DIR *dirdesc;
+} directory_fctx;
+
+
+/*
+ * Validate a path and convert to absolute form.
+ *
+ * Argument may be absolute or relative to the DataDir (but we only allow
+ * absolute paths that match DataDir or Log_directory).
+ */
+static char *
+check_and_make_absolute(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
+ {
+ char *absname = palloc(strlen(DataDir) + strlen(filename) + 2);
+
+ sprintf(absname, "%s/%s", DataDir, filename);
+ pfree(filename);
+ return absname;
+ }
+}
+
+
+/*
+ * 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 = check_and_make_absolute(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 may not 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)));
+
+ VARATT_SIZEP(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 = check_and_make_absolute(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 (actually, in system_views.sql at the moment).
+ */
+ 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(S_ISDIR(fst.st_mode));
+
+ 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 = check_and_make_absolute(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);
+ VARATT_SIZEP(result) = len + VARHDRSZ;
+ memcpy(VARDATA(result), de->d_name, len);
+
+ SRF_RETURN_NEXT(funcctx, PointerGetDatum(result));
+ }
+
+ FreeDir(fctx->dirdesc);
+
+ SRF_RETURN_DONE(funcctx);
+}
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