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- #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){
- fprint(2, "can't open %s: %r\n", mtpt);
- exits(0);
- }
- fd = open(srv, ORDWR);
- if(fd < 0){
- print("can't open %s: %r\n", srv);
- exits(0);
- }
- if(mount(fd, -1, mtpt, MBEFORE, "") < 0){
- print("can't mount(%s, %s): %r\n", srv, mtpt);
- exits(0);
- }
- fd = open(mtpt, ORDWR);
- if(fd < 0){
- print("can't open %s: %r\n", mtpt);
- exits(0);
- }
- }
- 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-3]) == 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);
- }
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