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/*
* Copy me if you can.
* by 20h
*
* Copyright (c) 2015 Natanael Copa <ncopa@alpinelinux.org>
*/
#include <err.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <linux/netlink.h>
#include "arg.h"
char *argv0;
pid_t
spawn_handler(int fd, char **argv)
{
pid_t pid = fork();
if (pid < 0)
err(1, "fork");
if (pid == 0) {
if (fd > 0)
dup2(fd, 0);
execv(argv[0], argv);
err(1, argv[0]);
}
return pid;
}
void
sighandler(int sig)
{
switch(sig) {
case SIGHUP:
case SIGINT:
case SIGQUIT:
case SIGABRT:
case SIGTERM:
exit(0);
break;
default:
break;
}
}
void
initsignals(void)
{
signal(SIGHUP, sighandler);
signal(SIGINT, sighandler);
signal(SIGQUIT, sighandler);
signal(SIGABRT, sighandler);
signal(SIGTERM, sighandler);
signal(SIGPIPE, SIG_IGN);
}
int
init_netlink_socket(void)
{
struct sockaddr_nl nls;
int fd, slen;
memset(&nls, 0, sizeof(nls));
nls.nl_family = AF_NETLINK;
nls.nl_pid = getpid();
nls.nl_groups = -1;
fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
if (fd < 0)
err(1, "socket");
/* kernel will not create events bigger than 16kb, but we need
buffer up all events during coldplug */
slen = 1024*1024;
if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &slen,
sizeof(slen)) < 0) {
err(1, "setsockopt");
}
slen = 1;
if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &slen,
sizeof(slen)) < 0) {
err(1, "setsockopt");
}
if (bind(fd, (void *)&nls, sizeof(nls)))
err(1, "bind");
fcntl(fd, F_SETFD, FD_CLOEXEC);
return fd;
}
void
usage(void)
{
errx(1, "usage: %s [-s] [-t triggerpath] runpath [...]\n", argv0);
}
int
main(int argc, char *argv[])
{
struct pollfd fds;
int single_run = 0;
char *trigger_argv[3] = { NULL, NULL, NULL};
pid_t childpid;
int status, r;
ARGBEGIN {
case 's':
single_run = 1;
break;
case 't':
trigger_argv[0] = EARGF(usage());
trigger_argv[1] = trigger_argv[0];
break;
default:
usage();
} ARGEND;
if (argv[0] == NULL)
usage();
fds.events = POLLIN;
fds.fd = init_netlink_socket();
initsignals();
if (trigger_argv[0]) {
childpid = spawn_handler(0, trigger_argv);
r = waitpid(childpid, &status, 0);
}
while (poll(&fds, 1, -1) > -1) {
if (fds.revents & POLLIN) {
childpid = spawn_handler(fds.fd, argv);
r = waitpid(childpid, &status, 0);
if(r == -1) {
warn("waitpid(%d)", childpid);
} else if (single_run && WIFEXITED(status)) {
return WEXITSTATUS(status);
}
}
}
return 0;
}
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