fork_u.c

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

//===>] FUNCTION DECLARATOINS [<===
int run_forked(int argc, char **argv);
int parse_cmdline(int argc, char*  args[]);

//--> global variables <--
int children_active; //0 = kill -- global kill switch for all child processes. Re: while loop in run_forked function
int sys_exec;        //0 = system()
pid_t targetProcess; //pid we will execute on our desired task, all passed in by command line
//last work i did was adding these variables so i could control my loops from command line <TODO>


//===>] CHILD PROCESS USER PROMPT [<===
int user_prompt() {
 char str[1024];

   printf( "Enter a value :");
   fgets(str, 1020, stdin );

   printf( "\nYou entered: ");
   puts( str );

   return 0;
}


//===>] COMMAND LINE PROCESSOR [<===
int parse_cmdline(int argc, char*  args[]) {
int i = 1;
while (i < argc) {
    char *arg = args[i++];
    //attempt to execute a binary from our child
    if (!strcmp(arg, "-e")) {
        printf("Have -e\n");
    } else if (!strcmp(arg, "-w")) {
        if (i >= argc)
            printf("error processing command line i:%i >= argc:%i\n",i,argc);
        char *param = args[i++];
        printf("Have -w %s\n", param);
    } else {
        printf("error processing command line\n");
    }
}

return 0;
}

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

   if( argc == 2 ) {
      printf("The argument supplied is %s\n", argv[1]);
   }
   else if( argc > 2 ) {
      if(parse_cmdline(argc, argv)) {printf("error calling function\n");}
   }
   else {
      printf("One argument expected.\n");
   }

    children_active=1; //This is used to kill the child loop process. 1 = run 0 = kill

    int i;
    pid_t cpid;
    pid_t child_pid;


    //attempts to fork the current process returning the results as pid_t, which is basically int
    cpid = fork();
    //let's grab our child process and route it away to do our bidding
    switch (cpid) {
        case -1: printf("Fork failed; cpid == -1\n");
                 break;
    //means we successfully forked, let's retrieve the process id
        case 0: child_pid = getpid();
        //run away to do child work
        if (run_forked(argc, argv)){
           printf("there was an error returned from function run_forked()");
        }
                exit(0);

    //probably best to hold this instance of toolbox open until we are done forking around
        default: printf("Toolbox is waiting for pid: %d\n", cpid);
                 waitpid(cpid, NULL, 0);
                 printf("Child(s) finished....\n\n\nToolbox finished.\n");
    }
    return 0;
}

int run_forked(int argc, char*  args[]) {
    //<TODO>  this doesn't have a default assignment when ported to toolbox.c
    char *currcon="test_shell";
    //<TODO> this needs to be uncommented when ported to toolbox.c
    //<TODO> getcon(&currcon);

    //Each child will have their own process id
    pid_t child_pid = getpid();
    printf("New child process id: %i\n", child_pid);

        int iLoop=0;     //<TODO> <DEBUG> run away code protection
    int iLoopMax=10;     //<TODO> <DEBUG> run away code protection

    char promptLine[1024];

    printf("[+] droidvoider's toolbox running as uid: %d, gid: %d, context %s\n", getuid(), getgid(), currcon);

    //control loop
    while(children_active) {
        //<TODO> -- add way to exit from cmd line
        if (iLoop > iLoopMax){
           printf("run away program protection, killing child\n");
           children_active=0;
        }

        printf("[+] running as uid: %d, gid: %d\n", getuid(), getgid());

//===>] CHILD PROMPT [<===
   printf( "usage: -e or-s <COMMAND to EXECUTE>\n");
   printf( "example: -s pm disable com.ws.dm\n(would execute system(pm disable com.ws.dm)\n\n\n\n\n");


   printf("Enter a command:");
   fgets(promptLine, 1020, stdin );

   printf( "\nChild %i received the following command: ", child_pid);
   puts( promptLine );
    if (strcmp(promptLine, "x")) {children_active=0;}

        sleep(6);
    iLoop++;
}
printf("while loop exited on loop: %i\n",iLoop);
    //<TODO> this needs to be uncommented when ported to toolbox.c
    //free(currcon);
return 0;
}