Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ctype.h>
#include <ndb.h>
#include "dns.h"
#include "ip.h"

static int domount;
static char *mtpt, *dns, *srv;

static int
setup(int argc, char **argv)
{
        int fd;

        if(argc == 1){
                domount = 0;
                mtpt = argv[0];
        }

        fd = open(dns, ORDWR);
        if(fd < 0){
                if(domount == 0)
                        sysfatal("can't open %s: %r", dns);
                fd = open(srv, ORDWR);
                if(fd < 0)
                        sysfatal("can't open %s: %r", srv);
                if(mount(fd, -1, mtpt, MBEFORE, "") < 0)
                        sysfatal("can't mount(%s, %s): %r", srv, mtpt);
                fd = open(dns, ORDWR);
                if(fd < 0)
                        sysfatal("can't open %s: %r", dns);
        }
        return fd;
}

static void
querydns(int fd, char *line, int n)
{
        char buf[1024];

        seek(fd, 0, 0);
        if(write(fd, line, n) != n) {
                print("!%r\n");
                return;
        }
        seek(fd, 0, 0);
        buf[0] = '\0';
        while((n = read(fd, buf, sizeof(buf))) > 0){
                buf[n] = '\0';
                print("%s\n", buf);
        }
}

static void
query(int fd)
{
        int n, len;
        char *lp, *p, *np;
        char buf[1024], line[1024];
        Biobuf in;

        Binit(&in, 0, OREAD);
        for(print("> "); lp = Brdline(&in, '\n'); print("> ")){
                n = Blinelen(&in) -1;
                while(isspace(lp[n]))
                        lp[n--] = 0;
                n++;
                while(isspace(*lp)){
                        lp++;
                        n--;
                }
                if(!*lp)
                        continue;
                strcpy(line, lp);

                /* default to an "ip" request if alpha, "ptr" if numeric */
                if(strchr(line, ' ') == nil)
                        if(strcmp(ipattr(line), "ip") == 0) {
                                strcat(line, " ptr");
                                n += 4;
                        } else {
                                strcat(line, " ip");
                                n += 3;
                        }

                /* inverse queries may need to be permuted */
                if(n > 4 && strcmp(" ptr", &line[n-4]) == 0 &&
                    cistrstr(line, ".arpa") == nil){
                        /* TODO: reversing v6 addrs is harder */
                        for(p = line; *p; p++)
                                if(*p == ' '){
                                        *p = '.';
                                        break;
                                }
                        np = buf;
                        len = 0;
                        while(p >= line){
                                len++;
                                p--;
                                if(*p == '.'){
                                        memmove(np, p+1, len);
                                        np += len;
                                        len = 0;
                                }
                        }
                        memmove(np, p+1, len);
                        np += len;
                        strcpy(np, "in-addr.arpa ptr"); /* TODO: ip6.arpa for v6 */
                        strcpy(line, buf);
                        n = strlen(line);
                }

                querydns(fd, line, n);
        }
        Bterm(&in);
}

void
main(int argc, char *argv[])
{
        mtpt = "/net";
        dns = "/net/dns";
        srv = "/srv/dns";
        domount = 1;
        ARGBEGIN {
        case 'x':
                mtpt = "/net.alt";
                dns = "/net.alt/dns";
                srv = "/srv/dns_net.alt";
                break;
        default:
                fprint(2, "usage: %s [-x] [dns-mount-point]\n", argv0);
                exits("usage");
        } ARGEND;

        query(setup(argc, argv));
        exits(0);
}