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lnav/src/fstat_vtab.cc

546 lines
18 KiB
C++

/**
* Copyright (c) 2017, Timothy Stack
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Timothy Stack nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "fstat_vtab.hh"
#include <glob.h>
#include <grp.h>
#include <pwd.h>
#include <string.h>
#include <sys/stat.h>
#include "base/auto_mem.hh"
#include "base/fs_util.hh"
#include "base/injector.hh"
#include "base/lnav_log.hh"
#include "bound_tags.hh"
#include "config.h"
#include <filesystem>
#include "sql_help.hh"
#include "sql_util.hh"
#include "vtab_module.hh"
namespace {
enum {
FSTAT_COL_PARENT,
FSTAT_COL_NAME,
FSTAT_COL_DEV,
FSTAT_COL_INO,
FSTAT_COL_TYPE,
FSTAT_COL_MODE,
FSTAT_COL_NLINK,
FSTAT_COL_UID,
FSTAT_COL_USER,
FSTAT_COL_GID,
FSTAT_COL_GROUP,
FSTAT_COL_RDEV,
FSTAT_COL_SIZE,
FSTAT_COL_BLKSIZE,
FSTAT_COL_BLOCKS,
FSTAT_COL_ATIME,
FSTAT_COL_MTIME,
FSTAT_COL_CTIME,
FSTAT_COL_ERROR,
FSTAT_COL_PATTERN,
FSTAT_COL_DATA,
};
/**
* @feature f0:sql.tables.fstat
*/
struct fstat_table {
static constexpr const char* NAME = "fstat";
static constexpr const char* CREATE_STMT = R"(
-- The fstat() table-valued function allows you to query the file system.
CREATE TABLE fstat (
st_parent TEXT,
st_name TEXT,
st_dev INTEGER,
st_ino INTEGER,
st_type TEXT,
st_mode INTEGER,
st_nlink INTEGER,
st_uid TEXT,
st_user TEXT,
st_gid TEXT,
st_group TEXT,
st_rdev INTEGER,
st_size INTEGER,
st_blksize INTEGER,
st_blocks INTEGER,
st_atime DATETIME,
st_mtime DATETIME,
st_ctime DATETIME,
error TEXT,
pattern TEXT HIDDEN,
data BLOB HIDDEN
);
)";
struct cursor {
sqlite3_vtab_cursor base;
std::string c_pattern;
static_root_mem<glob_t, globfree> c_glob;
size_t c_path_index{0};
struct stat c_stat;
std::string c_error;
explicit cursor(sqlite3_vtab* vt) : base({vt})
{
memset(&this->c_stat, 0, sizeof(this->c_stat));
}
void load_stat()
{
auto rc = lstat(this->c_glob->gl_pathv[this->c_path_index],
&this->c_stat);
if (rc == -1) {
this->c_error = strerror(errno);
}
}
int next()
{
if (this->c_path_index < this->c_glob->gl_pathc) {
this->c_path_index += 1;
this->load_stat();
}
return SQLITE_OK;
}
int reset() { return SQLITE_OK; }
int eof() { return this->c_path_index >= this->c_glob->gl_pathc; }
int get_rowid(sqlite3_int64& rowid_out)
{
rowid_out = this->c_path_index;
return SQLITE_OK;
}
};
int get_column(const cursor& vc, sqlite3_context* ctx, int col)
{
const char* path = vc.c_glob->gl_pathv[vc.c_path_index];
char time_buf[32];
switch (col) {
case FSTAT_COL_PARENT: {
const char* slash = strrchr(path, '/');
if (slash == nullptr) {
sqlite3_result_text(ctx, ".", 1, SQLITE_STATIC);
} else if (path[1] == '\0') {
sqlite3_result_text(ctx, "", 0, SQLITE_STATIC);
} else {
sqlite3_result_text(
ctx, path, slash - path + 1, SQLITE_TRANSIENT);
}
break;
}
case FSTAT_COL_NAME: {
const char* slash = strrchr(path, '/');
if (slash == nullptr) {
sqlite3_result_text(ctx, path, -1, SQLITE_TRANSIENT);
} else {
sqlite3_result_text(ctx, slash + 1, -1, SQLITE_TRANSIENT);
}
break;
}
case FSTAT_COL_DEV:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_dev);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_INO:
if (vc.c_error.empty()) {
sqlite3_result_int64(ctx, vc.c_stat.st_ino);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_TYPE:
if (!vc.c_error.empty()) {
sqlite3_result_null(ctx);
} else if (S_ISREG(vc.c_stat.st_mode)) {
sqlite3_result_text(ctx, "reg", 3, SQLITE_STATIC);
} else if (S_ISBLK(vc.c_stat.st_mode)) {
sqlite3_result_text(ctx, "blk", 3, SQLITE_STATIC);
} else if (S_ISCHR(vc.c_stat.st_mode)) {
sqlite3_result_text(ctx, "chr", 3, SQLITE_STATIC);
} else if (S_ISDIR(vc.c_stat.st_mode)) {
sqlite3_result_text(ctx, "dir", 3, SQLITE_STATIC);
} else if (S_ISFIFO(vc.c_stat.st_mode)) {
sqlite3_result_text(ctx, "fifo", 4, SQLITE_STATIC);
} else if (S_ISLNK(vc.c_stat.st_mode)) {
sqlite3_result_text(ctx, "lnk", 3, SQLITE_STATIC);
} else if (S_ISSOCK(vc.c_stat.st_mode)) {
sqlite3_result_text(ctx, "sock", 3, SQLITE_STATIC);
}
break;
case FSTAT_COL_MODE:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_mode & 0777);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_NLINK:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_nlink);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_UID:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_uid);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_USER: {
if (vc.c_error.empty()) {
struct passwd* pw = getpwuid(vc.c_stat.st_uid);
if (pw != nullptr) {
sqlite3_result_text(
ctx, pw->pw_name, -1, SQLITE_TRANSIENT);
} else {
sqlite3_result_int(ctx, vc.c_stat.st_uid);
}
} else {
sqlite3_result_null(ctx);
}
break;
}
case FSTAT_COL_GID:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_gid);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_GROUP: {
if (vc.c_error.empty()) {
struct group* gr = getgrgid(vc.c_stat.st_gid);
if (gr != nullptr) {
sqlite3_result_text(
ctx, gr->gr_name, -1, SQLITE_TRANSIENT);
} else {
sqlite3_result_int(ctx, vc.c_stat.st_gid);
}
} else {
sqlite3_result_null(ctx);
}
break;
}
case FSTAT_COL_RDEV:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_rdev);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_SIZE:
if (vc.c_error.empty()) {
sqlite3_result_int64(ctx, vc.c_stat.st_size);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_BLKSIZE:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_blksize);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_BLOCKS:
if (vc.c_error.empty()) {
sqlite3_result_int(ctx, vc.c_stat.st_blocks);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_ATIME:
if (vc.c_error.empty()) {
sql_strftime(
time_buf, sizeof(time_buf), vc.c_stat.st_atime, 0);
sqlite3_result_text(ctx, time_buf, -1, SQLITE_TRANSIENT);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_MTIME:
if (vc.c_error.empty()) {
sql_strftime(
time_buf, sizeof(time_buf), vc.c_stat.st_mtime, 0);
sqlite3_result_text(ctx, time_buf, -1, SQLITE_TRANSIENT);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_CTIME:
if (vc.c_error.empty()) {
sql_strftime(
time_buf, sizeof(time_buf), vc.c_stat.st_ctime, 0);
sqlite3_result_text(ctx, time_buf, -1, SQLITE_TRANSIENT);
} else {
sqlite3_result_null(ctx);
}
break;
case FSTAT_COL_ERROR:
if (vc.c_error.empty()) {
sqlite3_result_null(ctx);
} else {
to_sqlite(ctx, vc.c_error);
}
break;
case FSTAT_COL_PATTERN:
sqlite3_result_text(ctx,
vc.c_pattern.c_str(),
vc.c_pattern.length(),
SQLITE_TRANSIENT);
break;
case FSTAT_COL_DATA: {
auto fs_path = std::filesystem::path{path};
if (!vc.c_error.empty()) {
sqlite3_result_null(ctx);
} else if (S_ISREG(vc.c_stat.st_mode)) {
auto open_res
= lnav::filesystem::open_file(fs_path, O_RDONLY);
if (open_res.isErr()) {
log_error("unable to read file: %s -- %s",
path,
open_res.unwrapErr().c_str());
sqlite3_result_null(ctx);
} else {
auto buffer = auto_buffer::alloc(vc.c_stat.st_size);
auto fd = open_res.unwrap();
while (true) {
if (buffer.available() == 0) {
buffer.expand_by(4096);
}
auto rc = read(fd,
buffer.next_available(),
buffer.available());
if (rc <= 0) {
break;
}
buffer.resize_by(rc);
}
to_sqlite(ctx, blob_auto_buffer{std::move(buffer)});
}
} else if (S_ISLNK(vc.c_stat.st_mode)) {
auto link_path = std::filesystem::read_symlink(fs_path);
to_sqlite(ctx, link_path.string());
} else {
sqlite3_result_null(ctx);
}
break;
}
}
return SQLITE_OK;
}
#if 0
int update_row(sqlite3_vtab *tab,
sqlite3_int64 &index,
const char *st_parent,
const char *st_name,
int64_t st_dev,
int64_t st_ino,
const char *st_type,
int64_t st_mode,
int64_t st_nlink,
int64_t st_uid,
const char *st_user,
int64_t st_gid,
const char *st_group,
int64_t st_rdev,
int64_t st_size,
int64_t st_blksize,
int64_t st_blocks,
const char *atime,
const char *mtime,
const char *ctime,
const char *pattern) {
};
#endif
};
static int
rcBestIndex(sqlite3_vtab* tab, sqlite3_index_info* pIdxInfo)
{
vtab_index_constraints vic(pIdxInfo);
vtab_index_usage viu(pIdxInfo);
for (auto iter = vic.begin(); iter != vic.end(); ++iter) {
if (iter->op != SQLITE_INDEX_CONSTRAINT_EQ) {
continue;
}
switch (iter->iColumn) {
case FSTAT_COL_PATTERN:
viu.column_used(iter);
break;
}
}
viu.allocate_args(FSTAT_COL_PATTERN, FSTAT_COL_PATTERN, 1);
return SQLITE_OK;
}
static int
rcFilter(sqlite3_vtab_cursor* pVtabCursor,
int idxNum,
const char* idxStr,
int argc,
sqlite3_value** argv)
{
fstat_table::cursor* pCur = (fstat_table::cursor*) pVtabCursor;
if (argc != 1) {
pCur->c_pattern.clear();
return SQLITE_OK;
}
const char* pattern = (const char*) sqlite3_value_text(argv[0]);
pCur->c_pattern = pattern;
auto glob_flags = GLOB_ERR;
if (!lnav::filesystem::is_glob(pCur->c_pattern)) {
glob_flags |= GLOB_NOCHECK;
}
#ifdef GLOB_TILDE
glob_flags |= GLOB_TILDE;
#endif
switch (glob(pattern, glob_flags, nullptr, pCur->c_glob.inout())) {
case GLOB_NOSPACE:
pVtabCursor->pVtab->zErrMsg
= sqlite3_mprintf("No space to perform glob()");
return SQLITE_ERROR;
case GLOB_NOMATCH:
return SQLITE_OK;
}
pCur->load_stat();
return SQLITE_OK;
}
} // namespace
int
register_fstat_vtab(sqlite3* db)
{
static vtab_module<tvt_no_update<fstat_table>> FSTAT_MODULE;
static auto fstat_help
= help_text("fstat",
"A table-valued function for getting information about "
"file paths/globs")
.sql_table_valued_function()
.with_parameter(
{"pattern", "The file path or glob pattern to query."})
.with_result(
{"st_parent", "The parent path of the directory entry"})
.with_result({"st_name", "The name of the directory entry"})
.with_result({"st_dev", "The device number"})
.with_result({"st_ino", "The inode number"})
.with_result(help_text{"st_type", "The type of the entry"}
.with_enum_values({
"reg",
"blk",
"chr",
"dir",
"fifo",
"lnk",
"sock",
}))
.with_result({"st_mode", "The protection mode"})
.with_result(
{"st_nlink", "The number of hard links to the entry"})
.with_result({"st_uid", "The ID of the owning user"})
.with_result({"st_user", "The user name"})
.with_result({"st_gid", "The ID of the owning group"})
.with_result({"st_group", "The group name"})
.with_result({"st_rdev", "The device type"})
.with_result({"st_size", "The size of the entry in bytes"})
.with_result({"st_blksize", "The optimal size for I/O"})
.with_result({"st_blocks", "Blocks allocated for the file"})
.with_result({"st_atime", "The last access time"})
.with_result({"st_mtime", "The last modified time"})
.with_result({"st_ctime", "The creation time"})
.with_result({"error",
"Error message if there was a problem looking up "
"the entry"})
.with_result({"data", "The contents of the file"})
.with_example(help_example{
"To read a file and raise an error if there is a problem",
"SELECT ifnull(data, raise_error('cannot read: ' || st_name, "
"error)) FROM fstat('/non-existent')",
});
int rc;
FSTAT_MODULE.vm_module.xBestIndex = rcBestIndex;
FSTAT_MODULE.vm_module.xFilter = rcFilter;
static auto& lnav_flags = injector::get<unsigned long&, lnav_flags_tag>();
if (lnav_flags & LNF_SECURE_MODE) {
return SQLITE_OK;
}
rc = FSTAT_MODULE.create(db, "fstat");
sqlite_function_help.emplace("fstat", &fstat_help);
fstat_help.index_tags();
ensure(rc == SQLITE_OK);
return rc;
}