1161 lines
34 KiB
C++
1161 lines
34 KiB
C++
/* Copyright (C) 2004-2018 J.F.Dockes
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2.1 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, write to the
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* Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifdef BUILDING_RECOLL
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#include "autoconfig.h"
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#else
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#include "config.h"
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <sys/select.h>
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#include <sys/time.h>
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#include <sys/resource.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <signal.h>
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#include <time.h>
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#include <string.h>
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#include <map>
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#include <vector>
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#include <string>
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#include <stdexcept>
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#ifdef HAVE_SPAWN_H
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#ifndef __USE_GNU
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#define __USE_GNU
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#define undef__USE_GNU
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#endif
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#include <spawn.h>
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#ifdef undef__USE_GNU
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#undef __USE_GNU
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#endif
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#endif
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#include "execmd.h"
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#include "netcon.h"
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#include "closefrom.h"
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#include "smallut.h"
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#ifdef MDU_INCLUDE_LOG
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#include MDU_INCLUDE_LOG
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#else
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#include "log.h"
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#endif
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using namespace std;
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extern char **environ;
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class ExecCmd::Internal {
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public:
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Internal() {
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sigemptyset(&m_blkcld);
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}
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static bool o_useVfork;
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vector<string> m_env;
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ExecCmdAdvise *m_advise{0};
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ExecCmdProvide *m_provide{0};
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bool m_killRequest{false};
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int m_timeoutMs{1000};
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int m_killTimeoutMs{2000};
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int m_rlimit_as_mbytes{0};
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string m_stderrFile;
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// Pipe for data going to the command
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int m_pipein[2]{-1,-1};
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std::shared_ptr<NetconCli> m_tocmd;
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// Pipe for data coming out
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int m_pipeout[2]{-1,-1};
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std::shared_ptr<NetconCli> m_fromcmd;
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// Subprocess id
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pid_t m_pid{-1};
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// Saved sigmask
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sigset_t m_blkcld;
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// Reset internal state indicators. Any resources should have been
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// previously freed
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void reset() {
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m_killRequest = false;
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m_pipein[0] = m_pipein[1] = m_pipeout[0] = m_pipeout[1] = -1;
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m_pid = -1;
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sigemptyset(&m_blkcld);
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}
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// Child process code
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inline void dochild(const std::string& cmd, const char **argv,
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const char **envv, bool has_input, bool has_output);
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};
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bool ExecCmd::Internal::o_useVfork{false};
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ExecCmd::ExecCmd(int)
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{
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m = new Internal();
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if (m) {
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m->reset();
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}
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}
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void ExecCmd::setAdvise(ExecCmdAdvise *adv)
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{
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m->m_advise = adv;
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}
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void ExecCmd::setProvide(ExecCmdProvide *p)
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{
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m->m_provide = p;
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}
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void ExecCmd::setTimeout(int mS)
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{
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if (mS > 30) {
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m->m_timeoutMs = mS;
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}
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}
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void ExecCmd::setKillTimeout(int mS)
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{
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m->m_killTimeoutMs = mS;
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}
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void ExecCmd::setStderr(const std::string& stderrFile)
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{
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m->m_stderrFile = stderrFile;
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}
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pid_t ExecCmd::getChildPid()
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{
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return m->m_pid;
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}
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void ExecCmd::setKill()
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{
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m->m_killRequest = true;
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}
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void ExecCmd::zapChild()
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{
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setKill();
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(void)wait();
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}
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bool ExecCmd::requestChildExit()
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{
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if (m->m_pid > 0) {
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if (kill(m->m_pid, SIGTERM) == 0) {
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return true;
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}
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}
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return false;
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}
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/* From FreeBSD's which command */
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static bool exec_is_there(const char *candidate)
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{
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struct stat fin;
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/* XXX work around access(2) false positives for superuser */
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if (access(candidate, X_OK) == 0 &&
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stat(candidate, &fin) == 0 &&
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S_ISREG(fin.st_mode) &&
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(getuid() != 0 ||
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(fin.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0)) {
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return true;
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}
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return false;
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}
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bool ExecCmd::which(const string& cmd, string& exepath, const char* path)
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{
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if (cmd.empty()) {
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return false;
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}
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if (cmd[0] == '/') {
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if (exec_is_there(cmd.c_str())) {
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exepath = cmd;
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return true;
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} else {
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return false;
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}
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}
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const char *pp;
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if (path) {
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pp = path;
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} else {
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pp = getenv("PATH");
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}
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if (pp == 0) {
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return false;
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}
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vector<string> pels;
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stringToTokens(pp, pels, ":");
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for (vector<string>::iterator it = pels.begin(); it != pels.end(); it++) {
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if (it->empty()) {
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*it = ".";
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}
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string candidate = (it->empty() ? string(".") : *it) + "/" + cmd;
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if (exec_is_there(candidate.c_str())) {
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exepath = candidate;
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return true;
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}
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}
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return false;
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}
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void ExecCmd::useVfork(bool on)
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{
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// Just in case: there are competent people who believe that the
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// dynamic linker can sometimes deadlock if execve() is resolved
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// inside the vfork/exec window. Make sure it's done now. If "/" is
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// an executable file, we have a problem.
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const char *argv[] = {"/", 0};
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execve("/", (char *const *)argv, environ);
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Internal::o_useVfork = on;
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}
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void ExecCmd::putenv(const string& ea)
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{
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m->m_env.push_back(ea);
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}
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void ExecCmd::putenv(const string& name, const string& value)
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{
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string ea = name + "=" + value;
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putenv(ea);
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}
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static void msleep(int millis)
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{
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struct timespec spec;
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spec.tv_sec = millis / 1000;
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spec.tv_nsec = (millis % 1000) * 1000000;
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nanosleep(&spec, 0);
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}
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/** A resource manager to ensure that execcmd cleans up if an exception is
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* raised in the callback, or at different places on errors occurring
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* during method executions */
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class ExecCmdRsrc {
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public:
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ExecCmdRsrc(ExecCmd::Internal *parent)
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: m_parent(parent), m_active(true) {
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}
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void inactivate() {
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m_active = false;
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}
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~ExecCmdRsrc() {
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if (!m_active || !m_parent) {
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return;
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}
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LOGDEB1("~ExecCmdRsrc: working. mypid: " << getpid() << "\n");
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// Better to close the descs first in case the child is waiting in read
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if (m_parent->m_pipein[0] >= 0) {
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close(m_parent->m_pipein[0]);
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}
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if (m_parent->m_pipein[1] >= 0) {
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close(m_parent->m_pipein[1]);
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}
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if (m_parent->m_pipeout[0] >= 0) {
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close(m_parent->m_pipeout[0]);
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}
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if (m_parent->m_pipeout[1] >= 0) {
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close(m_parent->m_pipeout[1]);
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}
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// It's apparently possible for m_pid to be > 0 and getpgid to fail. In
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// this case, we have to conclude that the child process does
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// not exist. Not too sure what causes this, but the previous code
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// definitely tried to call killpg(-1,) from time to time.
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pid_t grp;
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if (m_parent->m_pid > 0 && (grp = getpgid(m_parent->m_pid)) > 0) {
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LOGDEB("ExecCmd: pid " << m_parent->m_pid << " killpg(" << grp <<
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", SIGTERM)\n");
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int ret = killpg(grp, SIGTERM);
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if (ret == 0) {
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int ms_slept{0};
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for (int i = 0; ; i++) {
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int tosleep = i == 0 ? 5 : (i == 1 ? 100 : 1000);
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msleep(tosleep);
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ms_slept += tosleep;
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int status;
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(void)waitpid(m_parent->m_pid, &status, WNOHANG);
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if (kill(m_parent->m_pid, 0) != 0) {
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break;
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}
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// killtimeout == -1 -> never KILL
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if (m_parent->m_killTimeoutMs >= 0 &&
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ms_slept >= m_parent->m_killTimeoutMs) {
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LOGDEB("ExecCmd: killpg(" << grp << ", SIGKILL)\n");
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killpg(grp, SIGKILL);
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(void)waitpid(m_parent->m_pid, &status, WNOHANG);
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break;
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}
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}
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} else {
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LOGERR("ExecCmd: error killing process group " << (grp) <<
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": " << errno << "\n");
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}
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}
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m_parent->m_tocmd.reset();
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m_parent->m_fromcmd.reset();
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pthread_sigmask(SIG_UNBLOCK, &m_parent->m_blkcld, 0);
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m_parent->reset();
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}
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private:
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ExecCmd::Internal *m_parent{nullptr};
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bool m_active{false};
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};
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ExecCmd::~ExecCmd()
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{
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if (m) {
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ExecCmdRsrc r(m);
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}
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if (m) {
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delete m;
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m = nullptr;
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}
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}
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// In child process. Set up pipes and exec command.
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// This must not return. _exit() on error.
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// *** This can be called after a vfork, so no modification of the
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// process memory at all is allowed ***
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// The LOGXX calls should not be there, but they occur only after "impossible"
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// errors, which we would most definitely want to have a hint about.
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//
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// Note that any of the LOGXX calls could block on a mutex set in the
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// father process, so that only absolutely exceptional conditions,
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// should be logged, for debugging and post-mortem purposes
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// If one of the calls block, the problem manifests itself by 20mn
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// (filter timeout) of looping on "ExecCmd::doexec: selectloop
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// returned 1', because the father is waiting on the read descriptor
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inline void ExecCmd::Internal::dochild(const string& cmd, const char **argv,
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const char **envv,
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bool has_input, bool has_output)
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{
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// Start our own process group
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if (setpgid(0, 0)) {
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LOGINFO("ExecCmd::DOCHILD: setpgid(0, 0) failed: errno " << errno <<
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"\n");
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}
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// Restore SIGTERM to default. Really, signal handling should be
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// specified when creating the execmd, there might be other
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// signals to reset. Resetting SIGTERM helps Recoll get rid of its
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// filter children for now though. To be fixed one day...
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// Note that resetting to SIG_DFL is a portable use of
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// signal(). No need for sigaction() here.
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// There is supposedely a risk of problems if another thread was
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// calling a signal-affecting function when vfork was called. This
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// seems acceptable though as no self-respecting thread is going
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// to mess with the global process signal disposition.
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if (signal(SIGTERM, SIG_DFL) == SIG_ERR) {
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//LOGERR("ExecCmd::DOCHILD: signal() failed, errno " << errno << "\n");
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}
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sigset_t sset;
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sigfillset(&sset);
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pthread_sigmask(SIG_UNBLOCK, &sset, 0);
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sigprocmask(SIG_UNBLOCK, &sset, 0);
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#ifdef HAVE_SETRLIMIT
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#if defined RLIMIT_AS || defined RLIMIT_VMEM || defined RLIMIT_DATA
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if (m_rlimit_as_mbytes > 2000 && sizeof(rlim_t) < 8) {
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// Impossible limit, don't use it
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m_rlimit_as_mbytes = 0;
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}
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if (m_rlimit_as_mbytes > 0) {
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struct rlimit ram_limit = {
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static_cast<rlim_t>(m_rlimit_as_mbytes * 1024 * 1024),
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RLIM_INFINITY
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};
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int resource;
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// RLIMIT_AS and RLIMIT_VMEM are usually synonyms when VMEM is
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// defined. RLIMIT_AS is Posix. Both don't really do what we
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// want, because they count e.g. shared lib mappings, which we
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// don't really care about.
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// RLIMIT_DATA only limits the data segment. Modern mallocs
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// use mmap and will not be bound. (Otoh if we only have this,
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// we're probably not modern).
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// So we're unsatisfied either way.
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#ifdef RLIMIT_AS
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resource = RLIMIT_AS;
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#elif defined RLIMIT_VMEM
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resource = RLIMIT_VMEM;
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#else
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resource = RLIMIT_DATA;
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#endif
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setrlimit(resource, &ram_limit);
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}
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#endif
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#endif // have_setrlimit
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if (has_input) {
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close(m_pipein[1]);
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if (m_pipein[0] != 0) {
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dup2(m_pipein[0], 0);
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close(m_pipein[0]);
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}
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}
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if (has_output) {
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close(m_pipeout[0]);
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if (m_pipeout[1] != 1) {
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if (dup2(m_pipeout[1], 1) < 0) {
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LOGERR("ExecCmd::DOCHILD: dup2() failed. errno " <<
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errno << "\n");
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}
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if (close(m_pipeout[1]) < 0) {
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LOGERR("ExecCmd::DOCHILD: close() failed. errno " <<
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errno << "\n");
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}
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}
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}
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// Do we need to redirect stderr ?
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if (!m_stderrFile.empty()) {
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int fd = open(m_stderrFile.c_str(), O_WRONLY | O_CREAT
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#ifdef O_APPEND
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| O_APPEND
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#endif
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, 0600);
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if (fd < 0) {
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close(2);
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} else {
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if (fd != 2) {
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dup2(fd, 2);
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}
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lseek(2, 0, 2);
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}
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}
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// Close all descriptors except 0,1,2
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libclf_closefrom(3);
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execve(cmd.c_str(), (char *const*)argv, (char *const*)envv);
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// Hu ho. This should never have happened as we checked the
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// existence of the executable before calling dochild... Until we
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// did this check, this was the chief cause of LOG mutex deadlock
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LOGERR("ExecCmd::DOCHILD: execve(" << cmd << ") failed. errno " <<
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errno << "\n");
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_exit(127);
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}
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void ExecCmd::setrlimit_as(int mbytes)
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{
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m->m_rlimit_as_mbytes = mbytes;
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}
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int ExecCmd::startExec(const string& cmd, const vector<string>& args,
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bool has_input, bool has_output)
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{
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{
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// Debug and logging
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string command = cmd + " ";
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for (vector<string>::const_iterator it = args.begin();
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it != args.end(); it++) {
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command += "{" + *it + "} ";
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}
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LOGDEB("ExecCmd::startExec: (" << has_input << "|" << has_output <<
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") " << command << "\n");
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}
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// The resource manager ensures resources are freed if we return early
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ExecCmdRsrc e(m);
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if (has_input && pipe(m->m_pipein) < 0) {
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LOGERR("ExecCmd::startExec: pipe(2) failed. errno " << errno << "\n" );
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return -1;
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}
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if (has_output && pipe(m->m_pipeout) < 0) {
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LOGERR("ExecCmd::startExec: pipe(2) failed. errno " << errno << "\n");
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return -1;
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}
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//////////// vfork setup section
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// We do here things that we could/should do after a fork(), but
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// not a vfork(). Does no harm to do it here in both cases, except
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// that it needs cleanup (as compared to doing it just before
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// exec()).
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// Allocate arg vector (2 more for arg0 + final 0)
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typedef const char *Ccharp;
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Ccharp *argv;
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argv = (Ccharp *)malloc((args.size() + 2) * sizeof(char *));
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if (argv == 0) {
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LOGERR("ExecCmd::doexec: malloc() failed. errno " << errno << "\n");
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return -1;
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}
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// Fill up argv
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argv[0] = cmd.c_str();
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int i = 1;
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vector<string>::const_iterator it;
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for (it = args.begin(); it != args.end(); it++) {
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argv[i++] = it->c_str();
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}
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argv[i] = 0;
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// Environment. We first merge our environment and the specified
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// variables in a map<string,string>, overriding existing values,
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// then generate an appropriate char*[]
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Ccharp *envv;
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map<string, string> envmap;
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for (int i = 0; environ[i] != 0; i++) {
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string entry(environ[i]);
|
|
string::size_type eqpos = entry.find_first_of("=");
|
|
if (eqpos == string::npos) {
|
|
continue;
|
|
}
|
|
envmap[entry.substr(0, eqpos)] = entry.substr(eqpos+1);
|
|
}
|
|
for (const auto& entry : m->m_env) {
|
|
string::size_type eqpos = entry.find_first_of("=");
|
|
if (eqpos == string::npos) {
|
|
continue;
|
|
}
|
|
envmap[entry.substr(0, eqpos)] = entry.substr(eqpos+1);
|
|
}
|
|
|
|
// Allocate space for the array + string storage in one block.
|
|
unsigned int allocsize = (envmap.size() + 2) * sizeof(char *);
|
|
for (const auto& it : envmap) {
|
|
allocsize += it.first.size() + 1 + it.second.size() + 1;
|
|
}
|
|
envv = (Ccharp *)malloc(allocsize);
|
|
if (envv == 0) {
|
|
LOGERR("ExecCmd::doexec: malloc() failed. errno " << errno << "\n");
|
|
free(argv);
|
|
return -1;
|
|
}
|
|
// Copy to new env array
|
|
i = 0;
|
|
char *cp = ((char *)envv) + (envmap.size() + 2) * sizeof(char *);
|
|
for (const auto& it : envmap) {
|
|
strcpy(cp, (it.first + "=" + it.second).c_str());
|
|
envv[i++] = cp;
|
|
cp += it.first.size() + 1 + it.second.size() + 1;
|
|
}
|
|
envv[i++] = 0;
|
|
|
|
// As we are going to use execve, not execvp, do the PATH thing.
|
|
string exe;
|
|
if (!which(cmd, exe)) {
|
|
LOGERR("ExecCmd::startExec: " << cmd << " not found\n");
|
|
free(argv);
|
|
free(envv);
|
|
return 127 << 8;
|
|
}
|
|
//////////////////////////////// End vfork child prepare section.
|
|
|
|
#if HAVE_POSIX_SPAWN && USE_POSIX_SPAWN
|
|
// Note that posix_spawn provides no way to setrlimit() the child.
|
|
{
|
|
posix_spawnattr_t attrs;
|
|
posix_spawnattr_init(&attrs);
|
|
short flags;
|
|
posix_spawnattr_getflags(&attrs, &flags);
|
|
|
|
flags |= POSIX_SPAWN_USEVFORK;
|
|
|
|
posix_spawnattr_setpgroup(&attrs, 0);
|
|
flags |= POSIX_SPAWN_SETPGROUP;
|
|
|
|
sigset_t sset;
|
|
sigemptyset(&sset);
|
|
posix_spawnattr_setsigmask(&attrs, &sset);
|
|
flags |= POSIX_SPAWN_SETSIGMASK;
|
|
|
|
sigemptyset(&sset);
|
|
sigaddset(&sset, SIGTERM);
|
|
posix_spawnattr_setsigdefault(&attrs, &sset);
|
|
flags |= POSIX_SPAWN_SETSIGDEF;
|
|
|
|
posix_spawnattr_setflags(&attrs, flags);
|
|
|
|
posix_spawn_file_actions_t facts;
|
|
posix_spawn_file_actions_init(&facts);
|
|
|
|
if (has_input) {
|
|
posix_spawn_file_actions_addclose(&facts, m->m_pipein[1]);
|
|
if (m->m_pipein[0] != 0) {
|
|
posix_spawn_file_actions_adddup2(&facts, m->m_pipein[0], 0);
|
|
posix_spawn_file_actions_addclose(&facts, m->m_pipein[0]);
|
|
}
|
|
}
|
|
if (has_output) {
|
|
posix_spawn_file_actions_addclose(&facts, m->m_pipeout[0]);
|
|
if (m->m_pipeout[1] != 1) {
|
|
posix_spawn_file_actions_adddup2(&facts, m->m_pipeout[1], 1);
|
|
posix_spawn_file_actions_addclose(&facts, m->m_pipeout[1]);
|
|
}
|
|
}
|
|
|
|
// Do we need to redirect stderr ?
|
|
if (!m->m_stderrFile.empty()) {
|
|
int oflags = O_WRONLY | O_CREAT;
|
|
#ifdef O_APPEND
|
|
oflags |= O_APPEND;
|
|
#endif
|
|
posix_spawn_file_actions_addopen(&facts, 2, m->m_stderrFile.c_str(),
|
|
oflags, 0600);
|
|
}
|
|
LOGDEB1("using SPAWN\n");
|
|
|
|
// posix_spawn() does not have any standard way to ask for
|
|
// calling closefrom(). Afaik there is a solaris extension for this,
|
|
// but let's just add all fds
|
|
for (int i = 3; i < libclf_maxfd(); i++) {
|
|
posix_spawn_file_actions_addclose(&facts, i);
|
|
}
|
|
|
|
int ret = posix_spawn(&m->m_pid, exe.c_str(), &facts, &attrs,
|
|
(char *const *)argv, (char *const *)envv);
|
|
posix_spawnattr_destroy(&attrs);
|
|
posix_spawn_file_actions_destroy(&facts);
|
|
if (ret) {
|
|
LOGERR("ExecCmd::startExec: posix_spawn() failed. errno " << ret <<
|
|
"\n");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
#else
|
|
if (Internal::o_useVfork) {
|
|
LOGDEB1("using VFORK\n");
|
|
m->m_pid = vfork();
|
|
} else {
|
|
LOGDEB1("using FORK\n");
|
|
m->m_pid = fork();
|
|
}
|
|
if (m->m_pid < 0) {
|
|
LOGERR("ExecCmd::startExec: fork(2) failed. errno " << errno << "\n");
|
|
return -1;
|
|
}
|
|
if (m->m_pid == 0) {
|
|
// e.inactivate() is not needed. As we do not return, the call
|
|
// stack won't be unwound and destructors of local objects
|
|
// won't be called.
|
|
m->dochild(exe, argv, envv, has_input, has_output);
|
|
// dochild does not return. Just in case...
|
|
_exit(1);
|
|
}
|
|
#endif
|
|
|
|
// Father process
|
|
|
|
////////////////////
|
|
// Vfork cleanup section
|
|
free(argv);
|
|
free(envv);
|
|
///////////////////
|
|
|
|
// Set the process group for the child. This is also done in the
|
|
// child process see wikipedia(Process_group)
|
|
if (setpgid(m->m_pid, m->m_pid)) {
|
|
// This can fail with EACCES if the son has already done execve
|
|
// (linux at least)
|
|
LOGDEB2("ExecCmd: father setpgid(son)(" << m->m_pid << "," <<
|
|
m->m_pid << ") errno " << errno << " (ok)\n");
|
|
}
|
|
|
|
sigemptyset(&m->m_blkcld);
|
|
sigaddset(&m->m_blkcld, SIGCHLD);
|
|
pthread_sigmask(SIG_BLOCK, &m->m_blkcld, 0);
|
|
|
|
if (has_input) {
|
|
close(m->m_pipein[0]);
|
|
m->m_pipein[0] = -1;
|
|
NetconCli *iclicon = new NetconCli();
|
|
iclicon->setconn(m->m_pipein[1]);
|
|
m->m_tocmd = std::shared_ptr<NetconCli>(iclicon);
|
|
}
|
|
if (has_output) {
|
|
close(m->m_pipeout[1]);
|
|
m->m_pipeout[1] = -1;
|
|
NetconCli *oclicon = new NetconCli();
|
|
oclicon->setconn(m->m_pipeout[0]);
|
|
m->m_fromcmd = std::shared_ptr<NetconCli>(oclicon);
|
|
}
|
|
|
|
/* Don't want to undo what we just did ! */
|
|
e.inactivate();
|
|
|
|
return 0;
|
|
}
|
|
|
|
// Netcon callback. Send data to the command's input
|
|
class ExecWriter : public NetconWorker {
|
|
public:
|
|
ExecWriter(const string *input, ExecCmdProvide *provide,
|
|
ExecCmd::Internal *parent)
|
|
: m_cmd(parent), m_input(input), m_cnt(0), m_provide(provide) {
|
|
}
|
|
void shutdown() {
|
|
close(m_cmd->m_pipein[1]);
|
|
m_cmd->m_pipein[1] = -1;
|
|
m_cmd->m_tocmd.reset();
|
|
}
|
|
virtual int data(NetconData *con, Netcon::Event reason) {
|
|
if (!m_input) {
|
|
return -1;
|
|
}
|
|
LOGDEB1("ExecWriter: input m_cnt " << m_cnt << " input length " <<
|
|
m_input->length() << "\n");
|
|
if (m_cnt >= m_input->length()) {
|
|
// Fd ready for more but we got none. Try to get data, else
|
|
// shutdown;
|
|
if (!m_provide) {
|
|
shutdown();
|
|
return 0;
|
|
}
|
|
m_provide->newData();
|
|
if (m_input->empty()) {
|
|
shutdown();
|
|
return 0;
|
|
} else {
|
|
// Ready with new buffer, reset use count
|
|
m_cnt = 0;
|
|
}
|
|
LOGDEB2("ExecWriter: provide m_cnt " << m_cnt <<
|
|
" input length " << m_input->length() << "\n");
|
|
}
|
|
int ret = con->send(m_input->c_str() + m_cnt,
|
|
m_input->length() - m_cnt);
|
|
LOGDEB2("ExecWriter: wrote " << (ret) << " to command\n");
|
|
if (ret <= 0) {
|
|
LOGERR("ExecWriter: data: can't write\n");
|
|
return -1;
|
|
}
|
|
m_cnt += ret;
|
|
return ret;
|
|
}
|
|
private:
|
|
ExecCmd::Internal *m_cmd;
|
|
const string *m_input;
|
|
unsigned int m_cnt; // Current offset inside m_input
|
|
ExecCmdProvide *m_provide;
|
|
};
|
|
|
|
// Netcon callback. Get data from the command output.
|
|
class ExecReader : public NetconWorker {
|
|
public:
|
|
ExecReader(string *output, ExecCmdAdvise *advise)
|
|
: m_output(output), m_advise(advise) {
|
|
}
|
|
virtual int data(NetconData *con, Netcon::Event reason) {
|
|
char buf[8192];
|
|
int n = con->receive(buf, 8192);
|
|
LOGDEB1("ExecReader: got " << (n) << " from command\n");
|
|
if (n < 0) {
|
|
LOGERR("ExecCmd::doexec: receive failed. errno " << errno << "\n");
|
|
} else if (n > 0) {
|
|
m_output->append(buf, n);
|
|
if (m_advise) {
|
|
m_advise->newData(n);
|
|
}
|
|
} // else n == 0, just return
|
|
return n;
|
|
}
|
|
private:
|
|
string *m_output;
|
|
ExecCmdAdvise *m_advise;
|
|
};
|
|
|
|
|
|
int ExecCmd::doexec(const string& cmd, const vector<string>& args,
|
|
const string *input, string *output)
|
|
{
|
|
int status = startExec(cmd, args, input != 0, output != 0);
|
|
if (status) {
|
|
return status;
|
|
}
|
|
|
|
// Cleanup in case we return early
|
|
ExecCmdRsrc e(m);
|
|
SelectLoop myloop;
|
|
int ret = 0;
|
|
if (input || output) {
|
|
// Setup output
|
|
if (output) {
|
|
NetconCli *oclicon = m->m_fromcmd.get();
|
|
if (!oclicon) {
|
|
LOGERR("ExecCmd::doexec: no connection from command\n");
|
|
return -1;
|
|
}
|
|
oclicon->setcallback(std::shared_ptr<NetconWorker>
|
|
(new ExecReader(output, m->m_advise)));
|
|
myloop.addselcon(m->m_fromcmd, Netcon::NETCONPOLL_READ);
|
|
// Give up ownership
|
|
m->m_fromcmd.reset();
|
|
}
|
|
// Setup input
|
|
if (input) {
|
|
NetconCli *iclicon = m->m_tocmd.get();
|
|
if (!iclicon) {
|
|
LOGERR("ExecCmd::doexec: no connection from command\n");
|
|
return -1;
|
|
}
|
|
iclicon->setcallback(std::shared_ptr<NetconWorker>
|
|
(new ExecWriter(input, m->m_provide, m)));
|
|
myloop.addselcon(m->m_tocmd, Netcon::NETCONPOLL_WRITE);
|
|
// Give up ownership
|
|
m->m_tocmd.reset();
|
|
}
|
|
|
|
// Do the actual reading/writing/waiting
|
|
myloop.setperiodichandler(0, 0, m->m_timeoutMs);
|
|
while ((ret = myloop.doLoop()) > 0) {
|
|
LOGDEB("ExecCmd::doexec: selectloop returned " << (ret) << "\n");
|
|
if (m->m_advise) {
|
|
m->m_advise->newData(0);
|
|
}
|
|
if (m->m_killRequest) {
|
|
LOGINFO("ExecCmd::doexec: cancel request\n");
|
|
break;
|
|
}
|
|
}
|
|
LOGDEB0("ExecCmd::doexec: selectloop returned " << (ret) << "\n");
|
|
// Check for interrupt request: we won't want to waitpid()
|
|
if (m->m_advise) {
|
|
m->m_advise->newData(0);
|
|
}
|
|
|
|
// The netcons don't take ownership of the fds: we have to close them
|
|
// (have to do it before wait, this may be the signal the child is
|
|
// waiting for exiting).
|
|
if (input) {
|
|
close(m->m_pipein[1]);
|
|
m->m_pipein[1] = -1;
|
|
}
|
|
if (output) {
|
|
close(m->m_pipeout[0]);
|
|
m->m_pipeout[0] = -1;
|
|
}
|
|
}
|
|
|
|
// Normal return: deactivate cleaner, wait() will do the cleanup
|
|
e.inactivate();
|
|
|
|
int ret1 = ExecCmd::wait();
|
|
if (ret) {
|
|
return -1;
|
|
}
|
|
return ret1;
|
|
}
|
|
|
|
int ExecCmd::send(const string& data)
|
|
{
|
|
NetconCli *con = m->m_tocmd.get();
|
|
if (con == 0) {
|
|
LOGERR("ExecCmd::send: outpipe is closed\n");
|
|
return -1;
|
|
}
|
|
unsigned int nwritten = 0;
|
|
while (nwritten < data.length()) {
|
|
if (m->m_killRequest) {
|
|
break;
|
|
}
|
|
int n = con->send(data.c_str() + nwritten, data.length() - nwritten);
|
|
if (n < 0) {
|
|
LOGERR("ExecCmd::send: send failed\n");
|
|
return -1;
|
|
}
|
|
nwritten += n;
|
|
}
|
|
return nwritten;
|
|
}
|
|
|
|
int ExecCmd::receive(string& data, int cnt)
|
|
{
|
|
NetconCli *con = m->m_fromcmd.get();
|
|
if (con == 0) {
|
|
LOGERR("ExecCmd::receive: inpipe is closed\n");
|
|
return -1;
|
|
}
|
|
const int BS = 4096;
|
|
char buf[BS];
|
|
int ntot = 0;
|
|
do {
|
|
int toread = cnt > 0 ? MIN(cnt - ntot, BS) : BS;
|
|
int n = con->receive(buf, toread);
|
|
if (n < 0) {
|
|
LOGERR("ExecCmd::receive: error\n");
|
|
return -1;
|
|
} else if (n > 0) {
|
|
ntot += n;
|
|
data.append(buf, n);
|
|
} else {
|
|
LOGDEB("ExecCmd::receive: got 0\n");
|
|
break;
|
|
}
|
|
} while (cnt > 0 && ntot < cnt);
|
|
return ntot;
|
|
}
|
|
|
|
int ExecCmd::getline(string& data)
|
|
{
|
|
NetconCli *con = m->m_fromcmd.get();
|
|
if (con == 0) {
|
|
LOGERR("ExecCmd::receive: inpipe is closed\n");
|
|
return -1;
|
|
}
|
|
const int BS = 1024;
|
|
char buf[BS];
|
|
int timeosecs = m->m_timeoutMs / 1000;
|
|
if (timeosecs == 0) {
|
|
timeosecs = 1;
|
|
}
|
|
|
|
// Note that we only go once through here, except in case of
|
|
// timeout, which is why I think that the goto is more expressive
|
|
// than a loop
|
|
again:
|
|
int n = con->getline(buf, BS, timeosecs);
|
|
if (n < 0) {
|
|
if (con->timedout()) {
|
|
LOGDEB0("ExecCmd::getline: select timeout, report and retry\n");
|
|
if (m->m_advise) {
|
|
m->m_advise->newData(0);
|
|
}
|
|
goto again;
|
|
}
|
|
LOGERR("ExecCmd::getline: error\n");
|
|
} else if (n > 0) {
|
|
data.append(buf, n);
|
|
} else {
|
|
LOGDEB("ExecCmd::getline: got 0\n");
|
|
}
|
|
return n;
|
|
}
|
|
|
|
class GetlineWatchdog : public ExecCmdAdvise {
|
|
public:
|
|
GetlineWatchdog(int secs) : m_secs(secs), tstart(time(0)) {}
|
|
void newData(int cnt) {
|
|
if (time(0) - tstart >= m_secs) {
|
|
throw std::runtime_error("getline timeout");
|
|
}
|
|
}
|
|
int m_secs;
|
|
time_t tstart;
|
|
};
|
|
|
|
int ExecCmd::getline(string& data, int timeosecs)
|
|
{
|
|
GetlineWatchdog gwd(timeosecs);
|
|
setAdvise(&gwd);
|
|
try {
|
|
return getline(data);
|
|
} catch (...) {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
|
|
// Wait for command status and clean up all resources.
|
|
// We would like to avoid blocking here too, but there is no simple
|
|
// way to do this. The 2 possible approaches would be to:
|
|
// - Use signals (alarm), waitpid() is interruptible. but signals and
|
|
// threads... This would need a specialized thread, inter-thread comms etc.
|
|
// - Use an intermediary process when starting the command. The
|
|
// process forks a timer process, and the real command, then calls
|
|
// a blocking waitpid on all at the end, and is guaranteed to get
|
|
// at least the timer process status, thus yielding a select()
|
|
// equivalent. This is bad too, because the timeout is on the whole
|
|
// exec, not just the wait
|
|
// Just calling waitpid() with WNOHANG with a sleep() between tries
|
|
// does not work: the first waitpid() usually comes too early and
|
|
// reaps nothing, resulting in almost always one sleep() or more.
|
|
//
|
|
// So no timeout here. This has not been a problem in practise inside recoll.
|
|
// In case of need, using a semi-busy loop with short sleeps
|
|
// increasing from a few mS might work without creating too much
|
|
// overhead.
|
|
int ExecCmd::wait()
|
|
{
|
|
ExecCmdRsrc e(m);
|
|
int status = -1;
|
|
if (!m->m_killRequest && m->m_pid > 0) {
|
|
if (waitpid(m->m_pid, &status, 0) < 0) {
|
|
LOGERR("ExecCmd::waitpid: returned -1 errno " << errno << "\n");
|
|
status = -1;
|
|
}
|
|
LOGDEB("ExecCmd::wait: got status 0x" << (status) << "\n");
|
|
m->m_pid = -1;
|
|
}
|
|
// Let the ExecCmdRsrc cleanup, it will do the killing/waiting if needed
|
|
return status;
|
|
}
|
|
|
|
bool ExecCmd::maybereap(int *status)
|
|
{
|
|
ExecCmdRsrc e(m);
|
|
*status = -1;
|
|
|
|
if (m->m_pid <= 0) {
|
|
// Already waited for ??
|
|
return true;
|
|
}
|
|
|
|
pid_t pid = waitpid(m->m_pid, status, WNOHANG);
|
|
if (pid < 0) {
|
|
LOGERR("ExecCmd::maybereap: returned -1 errno " << errno << "\n");
|
|
m->m_pid = -1;
|
|
return true;
|
|
} else if (pid == 0) {
|
|
LOGDEB1("ExecCmd::maybereap: not exited yet\n");
|
|
e.inactivate();
|
|
return false;
|
|
} else {
|
|
LOGDEB("ExecCmd::maybereap: got status 0x" << (status) << "\n");
|
|
m->m_pid = -1;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// Static
|
|
bool ExecCmd::backtick(const vector<string> cmd, string& out)
|
|
{
|
|
if (cmd.empty()) {
|
|
LOGERR("ExecCmd::backtick: empty command\n");
|
|
return false;
|
|
}
|
|
vector<string>::const_iterator it = cmd.begin();
|
|
it++;
|
|
vector<string> args(it, cmd.end());
|
|
ExecCmd mexec;
|
|
int status = mexec.doexec(*cmd.begin(), args, 0, &out);
|
|
return status == 0;
|
|
}
|
|
|
|
/// ReExec class methods ///////////////////////////////////////////////////
|
|
ReExec::ReExec(int argc, char *args[])
|
|
{
|
|
init(argc, args);
|
|
}
|
|
|
|
void ReExec::init(int argc, char *args[])
|
|
{
|
|
for (int i = 0; i < argc; i++) {
|
|
m_argv.push_back(args[i]);
|
|
}
|
|
m_cfd = open(".", 0);
|
|
char *cd = getcwd(0, 0);
|
|
if (cd) {
|
|
m_curdir = cd;
|
|
}
|
|
free(cd);
|
|
}
|
|
|
|
void ReExec::insertArgs(const vector<string>& args, int idx)
|
|
{
|
|
vector<string>::iterator it;
|
|
unsigned int cmpoffset = (unsigned int) - 1;
|
|
|
|
if (idx == -1 || string::size_type(idx) >= m_argv.size()) {
|
|
it = m_argv.end();
|
|
if (m_argv.size() >= args.size()) {
|
|
cmpoffset = m_argv.size() - args.size();
|
|
}
|
|
} else {
|
|
it = m_argv.begin() + idx;
|
|
if (idx + args.size() <= m_argv.size()) {
|
|
cmpoffset = idx;
|
|
}
|
|
}
|
|
|
|
// Check that the option is not already there
|
|
if (cmpoffset != (unsigned int) - 1) {
|
|
bool allsame = true;
|
|
for (unsigned int i = 0; i < args.size(); i++) {
|
|
if (m_argv[cmpoffset + i] != args[i]) {
|
|
allsame = false;
|
|
break;
|
|
}
|
|
}
|
|
if (allsame) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
m_argv.insert(it, args.begin(), args.end());
|
|
}
|
|
|
|
void ReExec::removeArg(const string& arg)
|
|
{
|
|
for (vector<string>::iterator it = m_argv.begin();
|
|
it != m_argv.end(); it++) {
|
|
if (*it == arg) {
|
|
it = m_argv.erase(it);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Reexecute myself, as close as possible to the initial exec
|
|
void ReExec::reexec()
|
|
{
|
|
|
|
#if 0
|
|
char *cwd;
|
|
cwd = getcwd(0, 0);
|
|
FILE *fp = stdout; //fopen("/tmp/exectrace", "w");
|
|
if (fp) {
|
|
fprintf(fp, "reexec: pwd: [%s] args: ", cwd ? cwd : "getcwd failed");
|
|
for (vector<string>::const_iterator it = m_argv.begin();
|
|
it != m_argv.end(); it++) {
|
|
fprintf(fp, "[%s] ", it->c_str());
|
|
}
|
|
fprintf(fp, "\n");
|
|
}
|
|
#endif
|
|
|
|
// Execute the atexit funcs
|
|
while (!m_atexitfuncs.empty()) {
|
|
(m_atexitfuncs.top())();
|
|
m_atexitfuncs.pop();
|
|
}
|
|
|
|
// Try to get back to the initial working directory
|
|
if (m_cfd < 0 || fchdir(m_cfd) < 0) {
|
|
LOGINFO("ReExec::reexec: fchdir failed, trying chdir\n");
|
|
if (!m_curdir.empty() && chdir(m_curdir.c_str())) {
|
|
LOGERR("ReExec::reexec: chdir failed\n");
|
|
}
|
|
}
|
|
|
|
// Close all descriptors except 0,1,2
|
|
libclf_closefrom(3);
|
|
|
|
// Allocate arg vector (1 more for final 0)
|
|
typedef const char *Ccharp;
|
|
Ccharp *argv;
|
|
argv = (Ccharp *)malloc((m_argv.size() + 1) * sizeof(char *));
|
|
if (argv == 0) {
|
|
LOGERR("ExecCmd::doexec: malloc() failed. errno " << errno << "\n");
|
|
return;
|
|
}
|
|
|
|
// Fill up argv
|
|
int i = 0;
|
|
vector<string>::const_iterator it;
|
|
for (it = m_argv.begin(); it != m_argv.end(); it++) {
|
|
argv[i++] = it->c_str();
|
|
}
|
|
argv[i] = 0;
|
|
execvp(m_argv[0].c_str(), (char *const*)argv);
|
|
}
|