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/*
* gstdvbbackend
*
* gstdvbbackend is a small programm which captures a given set of dvb
* channels from one dvb device and provides the streams via minimal http.
*
*
* Copyright (C) 2011-2016 Christian Pointner <equinox@spreadspace.org>
*
* This file is part of gstdvbbackend.
*
* gstdvbbackend is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* gstdvbbackend is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with gstdvbbackend. If not, see <http://www.gnu.org/licenses/>.
*/
#include "datatypes.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/select.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "sysexec.h"
#include "log.h"
char** dup_ptrptr(char* const ptrptr[])
{
if(!ptrptr)
return NULL;
int n = 0;
while(ptrptr[n])
n++;
char** my_ptrptr;
my_ptrptr = malloc((n+1)*sizeof(char*));
if(!my_ptrptr)
return NULL;
int i;
for(i = 0; i < n; ++i) {
my_ptrptr[i] = strdup(ptrptr[i]);
if(!my_ptrptr[i]) {
i--;
for(; i >= 0; --i)
free(my_ptrptr[i]);
free(my_ptrptr);
return NULL;
}
}
my_ptrptr[n] = NULL;
return my_ptrptr;
}
void free_ptrptr(char** ptrptr)
{
if(!ptrptr)
return;
int i;
for(i = 0; ptrptr[i]; ++i)
free(ptrptr[i]);
free(ptrptr);
}
child_t* new_child(const char* script, char* const argv[], char* const evp[])
{
child_t* new_child;
new_child = malloc(sizeof(child_t));
if(!new_child)
return NULL;
new_child->pid_ = -1;
new_child->err_fd_ = -1;
new_child->script_ = strdup(script);
if(!new_child->script_) {
free(new_child);
return NULL;
}
new_child->argv_ = dup_ptrptr(argv);
if(!new_child->argv_) {
free(new_child->script_);
free(new_child);
return NULL;
}
new_child->evp_ = dup_ptrptr(evp);
if(!new_child->evp_) {
free_ptrptr(new_child->argv_);
free(new_child->script_);
free(new_child);
return NULL;
}
return new_child;
}
void free_child(child_t* child)
{
if(!child)
return;
free_ptrptr(child->argv_);
free_ptrptr(child->evp_);
if(child->script_)
free(child->script_);
if(child->err_fd_ >= 0) close(child->err_fd_);
free(child);
}
child_t* rh_exec(const char* script, char* const argv[], char* const evp[])
{
if(!script)
return NULL;
child_t* child = new_child(script, argv, evp);
if(!child)
return NULL;
int pipefd[2];
if(pipe(pipefd) == -1) {
log_printf(ERROR, "executing script '%s' failed: pipe() error: %s", child->script_, strerror(errno)); // TODO: thread safe strerror
free_child(child);
return NULL;
}
pid_t pid;
pid = fork();
if(pid == -1) {
log_printf(ERROR, "executing script '%s' failed: fork() error: %s", child->script_, strerror(errno)); // TODO: thread safe strerror
close(pipefd[0]);
close(pipefd[1]);
free_child(child);
return NULL;
}
if(!pid) {
int fd;
for (fd=getdtablesize();fd>=0;--fd) // close all file descriptors
if(fd != pipefd[1]) close(fd);
fd = open("/dev/null",O_RDWR); // stdin
if(fd == -1)
log_printf(WARNING, "can't open stdin");
else {
if(dup(fd) == -1) // stdout
log_printf(WARNING, "can't open stdout");
if(dup(fd) == -1) // stderr
log_printf(WARNING, "can't open stderr");
}
execve(child->script_, child->argv_, child->evp_);
// if execve returns, an error occurred, but logging doesn't work
// because we closed all file descriptors, so just write errno to
// pipe and call exit
int ret = write(pipefd[1], (void*)(&errno), sizeof(errno));
if(ret == -1) exit(-1);
exit(-1);
}
close(pipefd[1]);
child->pid_ = pid;
child->err_fd_ = pipefd[0];
log_printf(INFO, "called script '%s' with pid %d", child->script_, child->pid_);
return child;
}
int rh_waitpid(child_t* child, int* status_return)
{
int status = 0;
pid_t pid = waitpid(child->pid_, &status, WNOHANG);
if(!pid || (pid < 0 && errno == ECHILD))
return 0;
if(pid < 0) {
log_printf(ERROR, "waitpid returned with error: %s", strerror(errno)); // TODO: thread safe strerror
return pid;
}
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(child->err_fd_, &rfds);
struct timeval tv = { 0 , 0 };
if(select(child->err_fd_+1, &rfds, NULL, NULL, &tv) == 1) {
int err = 0;
if(read(child->err_fd_, (void*)(&err), sizeof(err)) >= sizeof(err)) {
log_printf(INFO, "script '%s' exec() error: %s", child->script_, strerror(err)); // TODO: thread safe strerror
return -1;
}
}
if(WIFEXITED(status))
log_printf(INFO, "script '%s' (pid %d) returned %d", child->script_, child->pid_, WEXITSTATUS(status));
else if(WIFSIGNALED(status))
log_printf(INFO, "script '%s' (pid %d) terminated after signal %d", child->script_, child->pid_, WTERMSIG(status));
else
log_printf(INFO, "executing script '%s' (pid %d): unkown error", child->script_, child->pid_);
if(status_return) *status_return = status;
return 1;
}
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