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#include "csapp.h"
int main(int argc, char **argv) {
long max_fd = sysconf(_SC_OPEN_MAX);
/* Initialize PRNG seed. */
struct timeval tv;
gettimeofday(&tv, NULL);
srandom(tv.tv_usec);
/* This opens a file with password that is checked later. */
int fd_1 = Open("mypasswd", O_RDONLY, 0);
int fd_2 = 3 + random() % (max_fd - 3);
(void)Dup2(fd_1, fd_2);
Close(fd_1);
Lseek(fd_2, 0, SEEK_END);
/* TODO: Something is missing here to fix the issue! */
fcntl(fd_2, F_SETFD, FD_CLOEXEC);
/* Let's suppose a user typed in correct password and was allowed to execute
* a command and they choose to run our program. */
int rc = system("./innocent");
if (rc < 0)
unix_error("System error");
/* At this point we may finally close the file. */
Close(fd_2);
return rc;
}
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