Libevent实例之系统密码保护程序实现

#define MAXSIZE 1024
#define PATH  "/home/heey/libevent_code/" //程序的全局路径

char pawd[MAXSIZE];                       //存放root密码
FILE *logfd;                              //存放日志文件
int isloop = 1;                           //程序是否还在循环监控/etc/shadow文件
struct event_base *base;                    //所有的event事件注册到base中

/*进程守护化*/
static void daemonize(void) {
int i, fd0, fd1, fd2,pid;
struct rlimit rl;
struct sigaction sa;

umask(0);

if (getrlimit(RLIMIT_NOFILE, &rl) < 0) {
fprintf(stderr, "getrlimit(RLIMIT_NOFILE, &rl) failed.\n");
exit(0);
}

//  signal(SIGTTOU, SIG_IGN);
//  signal(SIGTTIN, SIG_IGN);
//  signal(SIGTSTP, SIG_IGN);

if((pid = fork())<0)
{
fprintf(stderr, "can not fork\n");
exit(0);
}
else if(pid != 0 )
exit(0);
setsid();

sa.sa_handler = SIG_IGN;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
if(sigaction(SIGHUP,&sa,NULL) < 0)
{
fprintf(stderr, "can not ignore SIGHUO\n");
exit(0);
}
if((pid = fork()) < 0)
{
fprintf(stderr, "can not fork\n");
exit(0);
}
else if(pid != 0 )
exit(0);

if ( chdir(PATH) < 0)
exit(0);

if (rl.rlim_max == RLIM_INFINITY) {
rl.rlim_max = 1024;
}
for (i = 0; i < rl.rlim_max; i++)
close(i);

fd0 = open("/dev/null", O_RDWR|O_CREAT|O_TRUNC);
fd1 = dup(0);
fd2 = dup(0);
if (fd0 != 0 || fd1 != 1 || fd2 != 2) {
fprintf(stderr, "fd0!=0 || fd1!=1 || fd2!=2\n");
exit(0);
}
}
void getime(char * s)
{
time_t rawtime;
struct tm * timeinfo;
time(&rawtime);
timeinfo = localtime(&rawtime);
sprintf(s,"%d/%d/%d  %d:%d:%d",timeinfo->tm_year+1900,timeinfo->tm_mon+1,timeinfo->tm_mday,timeinfo->tm_hour,timeinfo->tm_min,timeinfo->tm_sec);
}

int cmp_passwd()
{
int pid;
int pipefd[2];
int nread = 0;

char temp[50];

struct spwd *sp;

if(-1 == pipe(pipefd))
{
write_log(logfd,"pipe error");
return -1;
}

sp = getspnam("root");
printf("camparer=------------------\n");
if(strcmp(pawd,sp->sp_pwdp) == 0)
{
write_log(logfd,"root passwd normal");
printf("right----------------------\n");
return 1;
}
else
{
pid = fork();
if(pid == -1)
{
write_log(logfd,"fork error");
return -1;
}
if(pid ==0 )
{
char str1[MAXSIZE];
dup2(pipefd[1],1);
close(pipefd[1]);
memset(str1,0,sizeof(str1));
sprintf(str1,"%s%s",PATH,"destory.sh");
execl(str1,"destory.sh",NULL);
printf("execl failed"); //若exec没有执行成功，打印输出，子进程退出
exit(0);
}
else
{
wait();
char str[MAXSIZE];
memset(str,0,sizeof(str));
nread = read(pipefd[0],str,sizeof(str));
if(nread == -1 )
write_log(logfd,"read pipe error");

printf("parent running\n");
memset(temp,0,sizeof(temp));
sprintf(temp,"%s%s","the root passwd is changed,the exec echo is ",str);
printf("abc %s,%d\n",str,strlen(str));
write_log(logfd,temp);
if(strncmp(str,"ok",2) == 0)
{

write_log(logfd,"the cloudos destory success");
return 0;
}
}
}
}

void cmd_cb(int fd, short event, void *arg)
{

char line[MAXSIZE];
int nread;

printf("in cmd_cb\n");
int old_opt = fcntl(fd,F_GETFL);
int new_opt = old_opt | O_NONBLOCK;
fcntl(fd,F_SETFL,new_opt);
memset(line,0,sizeof(line));

while(nread=read(fd,line,MAXSIZE))
{
if(nread < 0 )  break;
}
isloop = cmp_passwd();
if(isloop == 0)
{
close(fd);
event_base_loopbreak(base);
}
}

void time_cb(int fd, short event, void *arg)
{
struct event * time_event;
struct timeval tv = {60,0};
printf("in time_cb\n");
isloop = cmp_passwd();
if(isloop == 0 )
{
printf("the fd------------------------------- is %d\n",(*((int*)arg)));
close(*((int*)arg));
event_base_loopbreak(base);
}
else
{
time_event = evtimer_new(base,time_cb,arg);
evtimer_add(time_event,&tv);
}
}

int main(int argc,char **argv)
{

struct spwd *sp;

char ch,c;
char str[MAXSIZE];
char time[50];

FILE *fd;
FILE *notifyfp;

int i = 0;
int notifyfd;
int fp;
int nread = 0;
int waitime = 1 ; //检测root密码是否正常的间隔时间

char cmd [] = "inotifywait -rme move,modify,create,delete --timefmt '%F %T' --format '%T=%w%f=%e' /etc";

struct event *cmd_ev;

memset(str,0,sizeof(str));
memset(pawd,0,sizeof(pawd));

while((ch=getopt(argc,argv,"dt:"))!=-1)
{
switch (ch)
{
case 't':  waitime = atoi(optarg);break;
case 'd':  daemonize();break;
}
}

memset(str,0,sizeof(str));
sprintf(str,"%s%s",PATH,"security.log");
logfd = fopen(str,"a+");

memset(str,0,sizeof(str));
sprintf(str,"%s%s",PATH,"security.conf");
fd = fopen(str,"a+");
fp = fileno(fd);
fchmod(fp,S_IRUSR|S_IWUSR);
while((c = getc(fd)) != EOF)
{
pawd[i] = c;
i++;
}
//the security.conf is first created
if(pawd[0] == 0 )
{
sp=getspnam("root");
strcpy(pawd,sp->sp_pwdp);
nread=fputs(pawd,fd);
fclose(fd);
}
else
fclose(fd);

printf("%s\n",pawd);
//printf("%s\n",sp->sp_pwdp);
base = event_init();
notifyfp = popen(cmd,"r");
notifyfd = fileno(notifyfp);

time_cb(0,0,¬ifyfd);
printf("the fd is %d\n",notifyfd);

sleep(5);
if(isloop)
{
cmd_ev = event_new(base, notifyfd,EV_READ | EV_PERSIST, cmd_cb, NULL);
event_add(cmd_ev, NULL);
printf("add successs -------------------------------------\n");
event_base_dispatch(base);
}

printf("--------------------------------ok\n");

fclose(logfd);
}