| #include <u.h> |
| #include <libc.h> |
| #include <bio.h> |
| #include <ndb.h> |
| #include <ndbhf.h> |
| |
| static void nstrcpy(char*, char*, int); |
| static void mkptrname(char*, char*, int); |
| static Ndbtuple *doquery(int, char *dn, char *type); |
| |
| /* |
| * search for a tuple that has the given 'attr=val' and also 'rattr=x'. |
| * copy 'x' into 'buf' and return the whole tuple. |
| * |
| * return 0 if not found. |
| */ |
| Ndbtuple* |
| dnsquery(char *net, char *val, char *type) |
| { |
| char rip[128]; |
| char *p; |
| Ndbtuple *t; |
| int fd; |
| |
| /* if the address is V4 or V6 null address, give up early vwhoi*/ |
| if(strcmp(val, "::") == 0 || strcmp(val, "0.0.0.0") == 0) |
| return nil; |
| |
| if(net == nil) |
| net = "/net"; |
| snprint(rip, sizeof(rip), "%s/dns", net); |
| fd = open(rip, ORDWR); |
| if(fd < 0){ |
| if(strcmp(net, "/net") == 0) |
| snprint(rip, sizeof(rip), "/srv/dns"); |
| else { |
| snprint(rip, sizeof(rip), "/srv/dns%s", net); |
| p = strrchr(rip, '/'); |
| *p = '_'; |
| } |
| fd = open(rip, ORDWR); |
| if(fd < 0) |
| return nil; |
| if(mount(fd, -1, net, MBEFORE, "") < 0){ |
| close(fd); |
| return nil; |
| } |
| /* fd is now closed */ |
| snprint(rip, sizeof(rip), "%s/dns", net); |
| fd = open(rip, ORDWR); |
| if(fd < 0) |
| return nil; |
| } |
| |
| /* zero out the error string */ |
| werrstr(""); |
| |
| /* if this is a reverse lookup, first lookup the domain name */ |
| if(strcmp(type, "ptr") == 0){ |
| mkptrname(val, rip, sizeof rip); |
| t = doquery(fd, rip, "ptr"); |
| } else |
| t = doquery(fd, val, type); |
| |
| close(fd); |
| return t; |
| } |
| |
| /* |
| * convert address into a reverse lookup address |
| */ |
| static void |
| mkptrname(char *ip, char *rip, int rlen) |
| { |
| char buf[128]; |
| char *p, *np; |
| int len; |
| |
| if(strstr(ip, "in-addr.arpa") || strstr(ip, "IN-ADDR.ARPA")){ |
| nstrcpy(rip, ip, rlen); |
| return; |
| } |
| |
| nstrcpy(buf, ip, sizeof buf); |
| for(p = buf; *p; p++) |
| ; |
| *p = '.'; |
| np = rip; |
| len = 0; |
| while(p >= buf){ |
| 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"); |
| } |
| |
| static void |
| nstrcpy(char *to, char *from, int len) |
| { |
| strncpy(to, from, len); |
| to[len-1] = 0; |
| } |
| |
| static Ndbtuple* |
| doquery(int fd, char *dn, char *type) |
| { |
| char buf[1024]; |
| int n; |
| Ndbtuple *t, *first, *last; |
| |
| seek(fd, 0, 0); |
| snprint(buf, sizeof(buf), "!%s %s", dn, type); |
| if(write(fd, buf, strlen(buf)) < 0) |
| return nil; |
| |
| seek(fd, 0, 0); |
| |
| first = last = nil; |
| |
| for(;;){ |
| n = read(fd, buf, sizeof(buf)-2); |
| if(n <= 0) |
| break; |
| if(buf[n-1] != '\n') |
| buf[n++] = '\n'; /* ndbparsline needs a trailing new line */ |
| buf[n] = 0; |
| |
| /* check for the error condition */ |
| if(buf[0] == '!'){ |
| werrstr("%s", buf+1); |
| return nil; |
| } |
| |
| t = _ndbparseline(buf); |
| if(t != nil){ |
| if(first) |
| last->entry = t; |
| else |
| first = t; |
| last = t; |
| |
| while(last->entry) |
| last = last->entry; |
| } |
| } |
| |
| setmalloctag(first, getcallerpc(&fd)); |
| return first; |
| } |