/* * src/res.c (C)opyright 1992, 1993, 1994 Darren Reed. All rights reserved. * This file may not be distributed without the author's prior permission in * any shape or form. The author takes no responsibility for any damage or * loss of property which results from the use of this software. Distribution * of this file must include this notice. */ /* *INDENT-OFF* */ #include "struct.h" #include "common.h" #include "sys.h" #include "res.h" #include "numeric.h" #include "h.h" #include #ifndef _WIN32 #include #include #endif #include "nameser.h" #include "resolv.h" #include #ifndef lint static char sccsid[] = "@(#)res.c 2.38 4/13/94 (C) 1992 Darren Reed"; #endif ID_Copyright("(C) 1992 Darren Reed"); ID_Notes("2.38 4/13/94"); #undef DEBUG /* because there is a lot of debug code in here :-) */ #define INADDRSZ sizeof(struct IN_ADDR) #define IN6ADDRSZ sizeof(struct IN_ADDR) extern int dn_expand PROTO((char *, char *, char *, char *, int)); extern int dn_skipname PROTO((char *, char *)); extern int res_mkquery PROTO((int, char *, int, int, char *, int, struct rrec *, char *, int)); #ifndef _WIN32 extern int errno, h_errno; #endif extern int highest_fd; extern aClient *local[]; static char hostbuf[512]; /* tq lamego/ptlink ircd */ static char dot[] = "."; static int incache = 0; static CacheTable hashtable[ARES_CACSIZE]; static aCache *cachetop = NULL; static ResRQ *last, *first; static void rem_cache PROTO((aCache *)); static void rem_request PROTO((ResRQ *)); static int do_query_name PROTO((Link *, char *, ResRQ *)); static int do_query_number PROTO((Link *, struct IN_ADDR *, ResRQ *)); static void resend_query PROTO((ResRQ *)); static int proc_answer PROTO((ResRQ *, HEADER *, char *, char *)); static int query_name PROTO((char *, int, int, ResRQ *)); static aCache *make_cache PROTO((ResRQ *)); static aCache *find_cache_name PROTO((char *)); static aCache *find_cache_number PROTO((ResRQ *, char *)); static int add_request PROTO((ResRQ *)); static ResRQ *make_request PROTO((Link *)); static int send_res_msg PROTO((char *, int, int)); static ResRQ *find_id PROTO((int)); static int hash_number PROTO((unsigned char *)); static void update_list PROTO((ResRQ *, aCache *)); static int hash_name PROTO((char *)); #ifdef _WIN32 static void async_dns(void *parm); #endif static struct cacheinfo { int ca_adds; int ca_dels; int ca_expires; int ca_lookups; int ca_na_hits; int ca_nu_hits; int ca_updates; } cainfo; static struct resinfo { int re_errors; int re_nu_look; int re_na_look; int re_replies; int re_requests; int re_resends; int re_sent; int re_timeouts; int re_shortttl; int re_unkrep; } reinfo; int init_resolver(op) int op; { int ret = 0; #ifdef LRAND48 srand48(TStime()); #endif if (op & RES_INITLIST) { bzero((char *)&reinfo, sizeof(reinfo)); first = last = NULL; } if (op & RES_CALLINIT) { ret = res_init(); if (!_res.nscount) { _res.nscount = 1; _res.nsaddr_list[0].SIN_ADDR.S_ADDR = inet_addr("127.0.0.1"); } } if (op & RES_INITSOCK) { #ifndef _WIN32 int on = 0; ret = resfd = socket(AFINET, SOCK_DGRAM, 0); set_non_blocking(resfd, &me); (void) setsockopt(ret, SOL_SOCKET, SO_BROADCAST, (char *)&on, sizeof(on)); #else /* We use Windows internal resolv functions so we have nothing * to do here */ #endif } #ifdef DEBUG if (op & RES_INITDEBG); _res.options |= RES_DEBUG; #endif if (op & RES_INITCACH) { bzero((char *)&cainfo, sizeof(cainfo)); bzero((char *)hashtable, sizeof(hashtable)); } if (op == 0) ret = resfd; return ret; } static int add_request(new) ResRQ *new; { if (!new) return -1; if (!first) first = last = new; else { last->next = new; last = new; } new->next = NULL; reinfo.re_requests++; return 0; } /* * remove a request from the list. This must also free any memory that has * been allocated for temporary storage of DNS results. */ static void rem_request(old) ResRQ *old; { ResRQ **rptr, *r2ptr = NULL; int i; char *s; if (!old) return; #ifdef _WIN32 while (old->locked) Sleep(0); #endif for (rptr = &first; *rptr; r2ptr = *rptr, rptr = &(*rptr)->next) if (*rptr == old) { *rptr = old->next; if (last == old) last = r2ptr; break; } #ifdef DEBUG Debug((DEBUG_INFO,"rem_request:Remove %#x at %#x %#x", old, *rptr, r2ptr)); #endif r2ptr = old; #ifndef _WIN32 if (r2ptr->he.h_name) MyFree((char *)r2ptr->he.h_name); for (i = 0; i < MAXALIASES; i++) if ((s = r2ptr->he.h_aliases[i])) MyFree(s); #else if (r2ptr->he) MyFree(r2ptr->he); #endif if (r2ptr->name) MyFree(r2ptr->name); MyFree(r2ptr); return; } /* * Create a DNS request record for the server. */ static ResRQ *make_request(lp) Link *lp; { ResRQ *nreq; nreq = (ResRQ *)MyMalloc(sizeof(ResRQ)); bzero((char *)nreq, sizeof(ResRQ)); nreq->next = NULL; /* where NULL is non-zero ;) */ nreq->sentat = TStime(); nreq->retries = HOST_RETRIES; nreq->resend = 1; nreq->srch = -1; if (lp) bcopy((char *)lp, (char *)&nreq->cinfo, sizeof(Link)); else bzero((char *)&nreq->cinfo, sizeof(Link)); nreq->timeout = HOST_TIMEOUT; #ifndef _WIN32 nreq->he.h_addrtype = AFINET; nreq->he.h_name = NULL; nreq->he.h_aliases[0] = NULL; #else nreq->he = (struct hostent *)MyMalloc(MAXGETHOSTSTRUCT); bzero((char *)nreq->he, MAXGETHOSTSTRUCT); nreq->he->h_addrtype = AFINET; nreq->he->h_name = NULL; #endif (void)add_request(nreq); return nreq; } /* * Remove queries from the list which have been there too long without * being resolved. */ time_t timeout_query_list(now) time_t now; { ResRQ *rptr, *r2ptr; time_t next = 0, tout; aClient *cptr; Debug((DEBUG_DNS,"timeout_query_list at %s",myctime(now))); for (rptr = first; rptr; rptr = r2ptr) { r2ptr = rptr->next; tout = rptr->sentat + rptr->timeout; #ifndef _WIN32 if (now >= tout) #else if (now >= tout && !rptr->locked) #endif if (--rptr->retries <= 0) { #ifdef DEBUG Debug((DEBUG_ERROR,"timeout %x now %d cptr %x", rptr, now, rptr->cinfo.value.cptr)); #endif reinfo.re_timeouts++; cptr = rptr->cinfo.value.cptr; switch (rptr->cinfo.flags) { case ASYNC_CLIENT : #ifdef SHOWCONNECTINFO sendto_one(cptr, REPORT_FAIL_DNS); #endif ClearDNS(cptr); if (!DoingAuth(cptr)) SetAccess(cptr); break; case ASYNC_SERVER : sendto_ops("Host %s unknown", rptr->name); ClearDNS(cptr); if (check_server(cptr, NULL, NULL, NULL, 1)) (void)exit_client(cptr, cptr, &me, "No Permission"); break; case ASYNC_CONNECT : sendto_ops("Host %s unknown", rptr->name); break; } rem_request(rptr); continue; } else { rptr->sentat = now; rptr->timeout += rptr->timeout; #ifndef _WIN32 resend_query(rptr); #endif tout = now + rptr->timeout; #ifdef DEBUG Debug((DEBUG_INFO,"r %x now %d retry %d c %x", rptr, now, rptr->retries, rptr->cinfo.value.cptr)); #endif } if (!next || tout < next) next = tout; } Debug((DEBUG_DNS,"Next timeout_query_list() at %s, %d", myctime((next > now) ? next : (now + AR_TTL)), (next > now) ? (next - now) : AR_TTL)); return (next > now) ? next : (now + AR_TTL); } /* * del_queries - called by the server to cleanup outstanding queries for * which there no longer exist clients or conf lines. */ void del_queries(cp) char *cp; { ResRQ *rptr, *r2ptr; for (rptr = first; rptr; rptr = r2ptr) { r2ptr = rptr->next; if (cp == rptr->cinfo.value.cp) rem_request(rptr); } } #ifndef _WIN32 /* * sends msg to all nameservers found in the "_res" structure. * This should reflect /etc/resolv.conf. We will get responses * which arent needed but is easier than checking to see if nameserver * isnt present. Returns number of messages successfully sent to * nameservers or -1 if no successful sends. */ static int send_res_msg(msg, len, rcount) char *msg; int len, rcount; { int i; int sent = 0, max; if (!msg) return -1; max = MIN(_res.nscount, rcount); if (_res.options & RES_PRIMARY) max = 1; if (!max) max = 1; for (i = 0; i < max; i++) { _res.nsaddr_list[i].SIN_FAMILY = AFINET; if (sendto(resfd, msg, len, 0, (struct SOCKADDR *) &(_res.nsaddr_list[i]), sizeof(struct SOCKADDR)) == len) { reinfo.re_sent++; sent++; } else Debug((DEBUG_ERROR,"s_r_m:sendto: %d on %d", errno, resfd)); } return (sent) ? sent : -1; } #endif /*_WIN32*/ /* * find a dns request id (id is determined by dn_mkquery) */ static ResRQ *find_id(id) int id; { ResRQ *rptr; for (rptr = first; rptr; rptr = rptr->next) if (rptr->id == id) return rptr; return NULL; } struct hostent *gethost_byname(name, lp) char *name; Link *lp; { aCache *cp; reinfo.re_na_look++; if ((cp = find_cache_name(name))) #ifndef _WIN32 return (struct hostent *)&(cp->he); #else return (struct hostent *)cp->he; #endif if (!lp) return NULL; (void)do_query_name(lp, name, NULL); return NULL; } struct hostent *gethost_byaddr(addr, lp) char *addr; Link *lp; { aCache *cp; reinfo.re_nu_look++; if ((cp = find_cache_number(NULL, addr))) #ifndef _WIN32 return (struct hostent *)&(cp->he); #else return (struct hostent *)cp->he; #endif if (!lp) return NULL; (void)do_query_number(lp, (struct IN_ADDR *)addr, NULL); return NULL; } static int do_query_name(lp, name, rptr) Link *lp; char *name; ResRQ *rptr; { #ifndef _WIN32 char hname[HOSTLEN+1]; int len; (void)strncpy(hname, name, sizeof(hname) - 1); len = strlen(hname); if (rptr && !index(hname, '.') && _res.options & RES_DEFNAMES) { (void)strncat(hname, dot, sizeof(hname) - len - 1); len++; (void)strncat(hname, _res.defdname, sizeof(hname) - len -1); } #endif /* * Store the name passed as the one to lookup and generate other host * names to pass onto the nameserver(s) for lookups. */ if (!rptr) { rptr = make_request(lp); rptr->type = T_A; rptr->name = (char *)MyMalloc(strlen(name) + 1); (void)strcpy(rptr->name, name); } #ifndef _WIN32 return (query_name(hname, C_IN, T_A, rptr)); #else rptr->id = _beginthread(async_dns, 0, (void *)rptr); rptr->sends++; return 0; #endif } /* * Use this to do reverse IP# lookups. */ static int do_query_number(lp, numb, rptr) Link *lp; struct IN_ADDR *numb; ResRQ *rptr; { char ipbuf[128]; u_char *cp; #ifndef _WIN32 cp = (u_char *)&numb->S_ADDR; (void)ircsprintf(ipbuf,"%u.%u.%u.%u.in-addr.arpa.", (u_int)(cp[3]), (u_int)(cp[2]), (u_int)(cp[1]), (u_int)(cp[0])); #endif if (!rptr) { rptr = make_request(lp); rptr->type = T_PTR; rptr->addr.S_ADDR = numb->S_ADDR; #ifndef _WIN32 bcopy((char *)&numb->S_ADDR, (char *)&rptr->he.h_addr, sizeof(struct IN_ADDR)); rptr->he.h_length = sizeof(struct IN_ADDR); #else rptr->he->h_length = sizeof(struct IN_ADDR); #endif } #ifndef _WIN32 return (query_name(ipbuf, C_IN, T_PTR, rptr)); #else rptr->id = _beginthread(async_dns, 0, (void *)rptr); rptr->sends++; return 0; #endif } #ifndef _WIN32 /* * generate a query based on class, type and name. */ static int query_name(name, class, type, rptr) char *name; int class, type; ResRQ *rptr; { struct timeval tv; char buf[MAXPACKET]; int r,s,k = 0; HEADER *hptr; Debug((DEBUG_DNS,"query_name: na %s cl %d ty %d", name, class, type)); bzero(buf, sizeof(buf)); r = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, buf, sizeof(buf)); if (r <= 0) { h_errno = NO_RECOVERY; return r; } hptr = (HEADER *)buf; #ifdef LRAND48 do { hptr->id = htons(ntohs(hptr->id) + k + lrand48() & 0xffff); #else (void) gettimeofday(&tv, NULL); do { /* htons/ntohs can be assembler macros, which cannot be nested. Thus two lines. -Vesa */ u_short nstmp = ntohs(hptr->id) + k + (u_short)(tv.tv_usec & 0xffff); hptr->id = htons(nstmp); #endif /* LRAND48 */ k++; } while (find_id(ntohs(hptr->id))); rptr->id = ntohs(hptr->id); rptr->sends++; s = send_res_msg(buf, r, rptr->sends); if (s == -1) { h_errno = TRY_AGAIN; return -1; } else rptr->sent += s; return 0; } static void resend_query(rptr) ResRQ *rptr; { if (rptr->resend == 0) return; reinfo.re_resends++; switch(rptr->type) { case T_PTR: (void)do_query_number(NULL, &rptr->addr, rptr); break; case T_A: (void)do_query_name(NULL, rptr->name, rptr); break; default: break; } return; } /* * process name server reply. */ static int proc_answer(rptr, hptr, buf, eob) ResRQ *rptr; char *buf, *eob; HEADER *hptr; { char *cp, **alias; struct hent *hp; int class, type, dlen, len, ans = 0, n; struct IN_ADDR dr, *adr; cp = buf + sizeof(HEADER); hp = (struct hent *)&(rptr->he); adr = &hp->h_addr; while (adr->S_ADDR) adr++; alias = hp->h_aliases; while (*alias) alias++; #ifdef _SOLARIS /* brain damaged compiler (Solaris2) it seems */ for (; hptr->qdcount > 0; hptr->qdcount--) #else while (hptr->qdcount-- > 0) #endif if ((n = dn_skipname(cp, eob)) == -1) break; else cp += (n + QFIXEDSZ); /* * proccess each answer sent to us blech. */ while (hptr->ancount-- > 0 && cp && cp < eob) { n = dn_expand(buf, eob, cp, hostbuf, sizeof(hostbuf)); if (n <= 0) break; cp += n; type = (int)_getshort(cp); cp += sizeof(short); class = (int)_getshort(cp); cp += sizeof(short); rptr->ttl = _getlong(cp); /* This should really use the GETLONG macro which advances * the pointer for us, but I don't know if that'll break other * systems. sizeof(_getlong) does not always equal sizeof(time_t). * This is the case on Linux alpha. 4 is the current standard * for this portion of the resolver reply it would seem. * heydowns@borg.com */ #ifdef __alpha cp += 4; #else #ifndef _WIN32 cp += sizeof(rptr->ttl); #else cp += 4; #endif #endif dlen = (int)_getshort(cp); cp += sizeof(short); rptr->type = type; len = strlen(hostbuf); /* name server never returns with trailing '.' */ if (!index(hostbuf,'.') && (_res.options & RES_DEFNAMES)) { (void)strcat(hostbuf, dot); len++; (void)strncat(hostbuf, _res.defdname, sizeof(hostbuf) - 1 - len); len = MIN(len + strlen(_res.defdname), sizeof(hostbuf) - 1); } switch(type) { case T_A : hp->h_length = dlen; if (ans == 1) hp->h_addrtype = (class == C_IN) ? AFINET : AF_UNSPEC; /* Fix for a recently found exploit, fix by Christophe Kalt * Taken from bahamut */ if (dlen != sizeof(dr)) { sendto_realops("Bad IP length (%d) returned for %s", dlen, hostbuf); Debug((DEBUG_DNS, "Bad IP length (%d) returned for %s", dlen, hostbuf)); return(-2); } bcopy(cp, (char *)&dr, dlen); adr->S_ADDR = dr.S_ADDR; Debug((DEBUG_INFO,"got ip # %s for %s", inetntoa((char *)adr), hostbuf)); if (!hp->h_name) { hp->h_name =(char *)MyMalloc(len+1); (void)strcpy(hp->h_name, hostbuf); } ans++; adr++; cp += dlen; break; case T_PTR : if((n = dn_expand(buf, eob, cp, hostbuf, sizeof(hostbuf) )) < 0) { cp = NULL; break; } cp += n; len = strlen(hostbuf); Debug((DEBUG_INFO,"got host %s",hostbuf)); /* * copy the returned hostname into the host name * or alias field if there is a known hostname * already. */ if (hp->h_name) { if (alias >= &(hp->h_aliases[MAXALIASES-1])) break; *alias = (char *)MyMalloc(len + 1); (void)strcpy(*alias++, hostbuf); *alias = NULL; } else { hp->h_name = (char *)MyMalloc(len + 1); (void)strcpy(hp->h_name, hostbuf); } ans++; break; case T_CNAME : cp += dlen; Debug((DEBUG_INFO,"got cname %s", hostbuf)); if (alias >= &(hp->h_aliases[MAXALIASES-1])) break; *alias = (char *)MyMalloc(len + 1); (void)strcpy(*alias++, hostbuf); *alias = NULL; ans++; break; default : #ifdef DEBUG Debug((DEBUG_INFO,"proc_answer: type:%d for:%s", type, hostbuf)); #endif break; } } return ans; } #endif /*_WIN32*/ /* * read a dns reply from the nameserver and process it. */ #ifndef _WIN32 struct hostent *get_res(lp) char *lp; #else struct hostent *get_res(lp, id) char *lp; long id; #endif { #ifndef _WIN32 static char buf[sizeof(HEADER) + MAXPACKET]; HEADER *hptr; struct SOCKADDR_IN sin; int rc, a, len = sizeof(sin), max; #else struct hostent *he; #endif ResRQ *rptr = NULL; aCache *cp; #ifndef _WIN32 rc = recvfrom(resfd, buf, sizeof(buf), 0, (struct SOCKADDR *)&sin, &len); if (rc == -1 || rc <= sizeof(HEADER)) goto getres_err; /* * convert DNS reply reader from Network byte order to CPU byte order. */ hptr = (HEADER *)buf; hptr->id = ntohs(hptr->id); hptr->ancount = ntohs(hptr->ancount); hptr->qdcount = ntohs(hptr->qdcount); hptr->nscount = ntohs(hptr->nscount); hptr->arcount = ntohs(hptr->arcount); #ifdef DEBUG Debug((DEBUG_NOTICE, "get_res:id = %d rcode = %d ancount = %d", hptr->id, hptr->rcode, hptr->ancount)); #endif #endif reinfo.re_replies++; /* * response for an id which we have already received an answer for * just ignore this response. */ #ifndef _WIN32 rptr = find_id(hptr->id); #else rptr = find_id(id); #endif if (!rptr) goto getres_err; #ifndef _WIN32 /* * check against possibly fake replies */ max = MIN(_res.nscount, rptr->sends); if (!max) max = 1; for (a = 0; a < max; a++) if (!_res.nsaddr_list[a].SIN_ADDR.S_ADDR || !bcmp((char *)&sin.SIN_ADDR, (char *)&_res.nsaddr_list[a].SIN_ADDR, sizeof(struct IN_ADDR))) break; if (a == max) { reinfo.re_unkrep++; goto getres_err; } if ((hptr->rcode != NOERROR) || (hptr->ancount == 0)) { switch (hptr->rcode) { case NXDOMAIN: h_errno = TRY_AGAIN; break; case SERVFAIL: h_errno = TRY_AGAIN; break; case NOERROR: h_errno = NO_DATA; break; case FORMERR: case NOTIMP: case REFUSED: default: h_errno = NO_RECOVERY; break; } reinfo.re_errors++; /* ** If a bad error was returned, we stop here and dont send ** send any more (no retries granted). */ if (h_errno != TRY_AGAIN) { Debug((DEBUG_DNS, "Fatal DNS error %d for %d", h_errno, hptr->rcode)); rptr->resend = 0; rptr->retries = 0; } goto getres_err; } a = proc_answer(rptr, hptr, buf, buf+rc); #ifdef DEBUG Debug((DEBUG_INFO,"get_res:Proc answer = %d",a)); #endif if (a && rptr->type == T_PTR) { struct hostent *hp2 = NULL; Debug((DEBUG_DNS, "relookup %s <-> %s", rptr->he.h_name, inetntoa((char *)&rptr->he.h_addr))); /* * Lookup the 'authoritive' name that we were given for the * ip#. By using this call rather than regenerating the * type we automatically gain the use of the cache with no * extra kludges. */ if ((hp2 = gethost_byname(rptr->he.h_name, &rptr->cinfo))) if (lp) bcopy((char *)&rptr->cinfo, lp, sizeof(Link)); /* * If name wasn't found, a request has been queued and it will * be the last one queued. This is rather nasty way to keep * a host alias with the query. -avalon */ if (!hp2 && rptr->he.h_aliases[0]) for (a = 0; rptr->he.h_aliases[a]; a++) { Debug((DEBUG_DNS, "Copied CNAME %s for %s", rptr->he.h_aliases[a], rptr->he.h_name)); last->he.h_aliases[a] = rptr->he.h_aliases[a]; rptr->he.h_aliases[a] = NULL; } rem_request(rptr); return hp2; } if (a > 0) { if (lp) bcopy((char *)&rptr->cinfo, lp, sizeof(Link)); cp = make_cache(rptr); #ifdef DEBUG Debug((DEBUG_INFO,"get_res:cp=%#x rptr=%#x (made)",cp,rptr)); #endif rem_request(rptr); } else if (!rptr->sent) rem_request(rptr); return cp ? (struct hostent *)&cp->he : NULL; getres_err: /* * Reprocess an error if the nameserver didnt tell us to "TRY_AGAIN". */ if (rptr) { if (h_errno != TRY_AGAIN) { /* * If we havent tried with the default domain and its * set, then give it a try next. */ if (_res.options & RES_DEFNAMES && ++rptr->srch == 0) { rptr->retries = _res.retry; rptr->sends = 0; rptr->resend = 1; resend_query(rptr); } else { resend_query(rptr); } } else if (lp) bcopy((char *)&rptr->cinfo, lp, sizeof(Link)); } #else /*_WIN32*/ he = rptr->he; if (he && he->h_name && ((struct IN_ADDR *)he->h_addr)->S_ADDR && rptr->locked < 2) { /* * We only need to re-check the DNS if its a "byaddr" call, * the "byname" calls will work correctly. -Cabal95 */ char tempname[120]; int i; long amt; struct hostent *hp, *he = rptr->he; strcpy(tempname, he->h_name); hp = gethostbyname(tempname); if (hp && !bcmp(hp->h_addr, he->h_addr, sizeof(struct IN_ADDR))) { } else rptr->he->h_name = NULL; } if (lp) bcopy((char *)&rptr->cinfo, lp, sizeof(Link)); cp = make_cache(rptr); # ifdef DEBUG Debug((DEBUG_INFO,"get_res:cp=%#x rptr=%#x (made)", cp, rptr)); # endif rptr->locked = 0; rem_request(rptr); return cp ? (struct hostent *)cp->he : NULL; getres_err: if (lp && rptr) bcopy((char *)&rptr->cinfo, lp, sizeof(Link)); #endif return (struct hostent *)NULL; } static int hash_number(ip) unsigned char *ip; { u_int hashv = 0; /* could use loop but slower */ hashv += (int)*ip++; hashv += hashv + (int)*ip++; hashv += hashv + (int)*ip++; hashv += hashv + (int)*ip++; hashv %= ARES_CACSIZE; return (hashv); } static int hash_name(name) register char *name; { u_int hashv = 0; if (name == NULL) { sendto_realops ("Caught NULL pointer in hash_name(). (Bad thing -- tell rwg.)"); return (0); } for (; *name && *name != '.'; name++) hashv += *name; hashv %= ARES_CACSIZE; return (hashv); } /* ** Add a new cache item to the queue and hash table. */ static aCache *add_to_cache(ocp) aCache *ocp; { aCache *cp = NULL; int hashv; #ifdef DEBUG Debug((DEBUG_INFO, "add_to_cache:ocp %#x he %#x name %#x addrl %#x 0 %#x", ocp, &ocp->he, ocp->he.h_name, ocp->he.h_addr_list, ocp->he.h_addr_list[0])); #endif ocp->list_next = cachetop; cachetop = ocp; #ifndef _WIN32 hashv = hash_name(ocp->he.h_name); #else hashv = hash_name(ocp->he->h_name); #endif ocp->hname_next = hashtable[hashv].name_list; hashtable[hashv].name_list = ocp; #ifndef _WIN32 hashv = hash_number((u_char *)ocp->he.h_addr); #else hashv = hash_number((u_char *)ocp->he->h_addr); #endif ocp->hnum_next = hashtable[hashv].num_list; hashtable[hashv].num_list = ocp; #ifdef DEBUG Debug((DEBUG_INFO, "add_to_cache:added %s[%08x] cache %#x.", # ifndef _WIN32 ocp->he.h_name, ocp->he.h_addr_list[0], ocp)); # else ocp->he->h_name, ocp->he->h_addr_list[0], ocp)); # endif Debug((DEBUG_INFO, "add_to_cache:h1 %d h2 %x lnext %#x namnext %#x numnext %#x", # ifndef _WIN32 hash_name(ocp->he.h_name), hashv, ocp->list_next, # else hash_name(ocp->he->h_name), hashv, ocp->list_next, # endif ocp->hname_next, ocp->hnum_next)); #endif /* * LRU deletion of excessive cache entries. */ if (++incache > MAXCACHED) { for (cp = cachetop; cp->list_next; cp = cp->list_next) ; rem_cache(cp); } cainfo.ca_adds++; return ocp; } /* ** update_list does not alter the cache structure passed. It is assumed that ** it already contains the correct expire time, if it is a new entry. Old ** entries have the expirey time updated. */ static void update_list(rptr, cachep) ResRQ *rptr; aCache *cachep; { aCache **cpp, *cp = cachep; char *s, *t, **base; int i, j; int addrcount; /* ** search for the new cache item in the cache list by hostname. ** If found, move the entry to the top of the list and return. */ cainfo.ca_updates++; for (cpp = &cachetop; *cpp; cpp = &((*cpp)->list_next)) if (cp == *cpp) break; if (!*cpp) return; *cpp = cp->list_next; cp->list_next = cachetop; cachetop = cp; #ifndef _WIN32 if (!rptr) return; #ifdef DEBUG Debug((DEBUG_DEBUG,"u_l:cp %#x na %#x al %#x ad %#x", cp,cp->he.h_name,cp->he.h_aliases,cp->he.h_addr)); Debug((DEBUG_DEBUG,"u_l:rptr %#x h_n %#x", rptr, rptr->he.h_name)); #endif /* * Compare the cache entry against the new record. Add any * previously missing names for this entry. */ for (i = 0; cp->he.h_aliases[i]; i++) ; addrcount = i; for (i = 0, s = rptr->he.h_name; s && i < MAXALIASES; s = rptr->he.h_aliases[i++]) { for (j = 0, t = cp->he.h_name; t && j < MAXALIASES; t = cp->he.h_aliases[j++]) if (!mycmp(t, s)) break; if (!t && j < MAXALIASES-1) { base = cp->he.h_aliases; addrcount++; base = (char **)MyRealloc((char *)base, sizeof(char *) * (addrcount + 1)); cp->he.h_aliases = base; #ifdef DEBUG Debug((DEBUG_DNS,"u_l:add name %s hal %x ac %d", s, cp->he.h_aliases, addrcount)); #endif base[addrcount-1] = s; base[addrcount] = NULL; if (i) rptr->he.h_aliases[i-1] = NULL; else rptr->he.h_name = NULL; } } for (i = 0; cp->he.h_addr_list[i]; i++) ; addrcount = i; /* * Do the same again for IP#'s. */ for (s = (char *)&rptr->he.h_addr.S_ADDR; ((struct IN_ADDR *)s)->S_ADDR; s += sizeof(struct IN_ADDR)) { for (i = 0; (t = cp->he.h_addr_list[i]); i++) if (!bcmp(s, t, sizeof(struct IN_ADDR))) break; if (i >= MAXADDRS || addrcount >= MAXADDRS) break; /* * Oh man this is bad...I *HATE* it. -avalon * * Whats it do ? Reallocate two arrays, one of pointers * to "char *" and the other of IP addresses. Contents of * the IP array *MUST* be preserved and the pointers into * it recalculated. */ if (!t) { base = cp->he.h_addr_list; addrcount++; t = (char *)MyRealloc(*base, addrcount * sizeof(struct IN_ADDR)); base = (char **)MyRealloc((char *)base, (addrcount + 1) * sizeof(char *)); cp->he.h_addr_list = base; #ifdef DEBUG Debug((DEBUG_DNS,"u_l:add IP %x hal %x ac %d", ntohl(((struct IN_ADDR *)s)->S_ADDR), cp->he.h_addr_list, addrcount)); #endif for (; addrcount; addrcount--) { *base++ = t; t += sizeof(struct IN_ADDR); } *base = NULL; bcopy(s, *--base, sizeof(struct IN_ADDR)); } } #endif /*_WIN32*/ return; } static aCache *find_cache_name(name) char *name; { aCache *cp; char *s; int hashv, i; hashv = hash_name(name); cp = hashtable[hashv].name_list; #ifdef DEBUG Debug((DEBUG_DNS,"find_cache_name:find %s : hashv = %d",name,hashv)); #endif for (; cp; cp = cp->hname_next) #ifndef _WIN32 for (i = 0, s = cp->he.h_name; s; s = cp->he.h_aliases[i++]) #else for (i = 0, s = cp->he->h_name; s; s = cp->he->h_aliases[i++]) #endif if (mycmp(s, name) == 0) { cainfo.ca_na_hits++; update_list(NULL, cp); return cp; } for (cp = cachetop; cp; cp = cp->list_next) { /* * if no aliases or the hash value matches, we've already * done this entry and all possiblilities concerning it. */ #ifndef _WIN32 if (!*cp->he.h_aliases) continue; if (hashv == hash_name(cp->he.h_name)) continue; for (i = 0, s = cp->he.h_aliases[i]; s && i < MAXALIASES; i++) if (!mycmp(name, s)) { #else if (!cp->he->h_aliases) continue; if (hashv == hash_name(cp->he->h_name)) continue; for (i = 0, s = cp->he->h_aliases[i]; s && i < MAXALIASES; i++) if (!mycmp(name, s)) { #endif cainfo.ca_na_hits++; update_list(NULL, cp); return cp; } } return NULL; } /* * find a cache entry by ip# and update its expire time */ static aCache *find_cache_number(rptr, numb) ResRQ *rptr; char *numb; { aCache *cp; int hashv,i; #ifdef DEBUG struct IN_ADDR *ip = (struct IN_ADDR *)numb; #endif hashv = hash_number((u_char *)numb); cp = hashtable[hashv].num_list; #if defined(DEBUG) && !defined(INET6) Debug((DEBUG_DNS,"find_cache_number:find %s[%08x]: hashv = %d", inetntoa(numb), ntohl(ip->S_ADDR), hashv)); #endif for (; cp; cp = cp->hnum_next) #ifndef _WIN32 for (i = 0; cp->he.h_addr_list[i]; i++) if (!bcmp(cp->he.h_addr_list[i], numb, sizeof(struct IN_ADDR))) #else for (i = 0; cp->he->h_addr_list && cp->he->h_addr_list[i]; i++) if (!bcmp(cp->he->h_addr_list[i], numb, sizeof(struct IN_ADDR))) #endif { cainfo.ca_nu_hits++; update_list(rptr, cp); return cp; } for (cp = cachetop; cp; cp = cp->list_next) { /* * single address entry...would have been done by hashed * search above... */ #ifndef _WIN32 if (!cp->he.h_addr_list[1]) #else if (!cp->he->h_addr_list[1]) #endif continue; /* * if the first IP# has the same hashnumber as the IP# we * are looking for, its been done already. */ #ifndef _WIN32 if (hashv == hash_number((u_char *)cp->he.h_addr_list[0])) continue; for (i = 1; cp->he.h_addr_list[i]; i++) if (!bcmp(cp->he.h_addr_list[i], numb, sizeof(struct IN_ADDR))) #else if (hashv == hash_number((u_char *)cp->he->h_addr_list[0])) continue; for (i = 1; cp->he->h_addr_list && cp->he->h_addr_list[i]; i++) if (!bcmp(cp->he->h_addr_list[i], numb, sizeof(struct IN_ADDR))) #endif { cainfo.ca_nu_hits++; update_list(rptr, cp); return cp; } } return NULL; } static aCache *make_cache(rptr) ResRQ *rptr; { aCache *cp; int i, n; struct hostent *hp; char *s, **t; /* ** shouldn't happen but it just might... */ #ifndef _WIN32 if (!rptr->he.h_name || !rptr->he.h_addr.S_ADDR) #else if (!rptr->he->h_name || !((struct in_addr *)rptr->he->h_addr)->s_addr) #endif return NULL; /* ** Make cache entry. First check to see if the cache already exists ** and if so, return a pointer to it. */ #ifndef _WIN32 if ((cp = find_cache_number(rptr, (char *)&rptr->he.h_addr.S_ADDR))) return cp; for (i = 1; rptr->he.h_addr_list[i].S_ADDR; i++) if ((cp = find_cache_number(rptr, (char *)&(rptr->he.h_addr_list[i].S_ADDR)))) #else if ((cp = find_cache_number(rptr, (char *)&((struct IN_ADDR *)rptr->he->h_addr)->S_ADDR))) return cp; for (i = 1; rptr->he->h_addr_list[i] && ((struct IN_ADDR *)rptr->he->h_addr_list[i])->S_ADDR; i++) if ((cp = find_cache_number(rptr, (char *)&((struct IN_ADDR *)rptr->he->h_addr_list[i])->S_ADDR ))) #endif return cp; /* ** a matching entry wasnt found in the cache so go and make one up. */ cp = (aCache *)MyMalloc(sizeof(aCache)); bzero((char *)cp, sizeof(aCache)); #ifdef _WIN32 cp->he = (struct hostent *)MyMalloc(MAXGETHOSTSTRUCT); res_copyhostent(rptr->he, cp->he); #else hp = &cp->he; for (i = 0; i < MAXADDRS; i++) #ifdef INET6 if (!WHOSTENTP(rptr->he.h_addr_list[i].S_ADDR)) #else if (!rptr->he.h_addr_list[i].S_ADDR) #endif break; /* ** build two arrays, one for IP#'s, another of pointers to them. */ t = hp->h_addr_list = (char **)MyMalloc(sizeof(char *) * (i+1)); bzero((char *)t, sizeof(char *) * (i+1)); s = (char *)MyMalloc(sizeof(struct IN_ADDR) * i); bzero(s, sizeof(struct IN_ADDR) * i); for (n = 0; n < i; n++, s += sizeof(struct IN_ADDR)) { *t++ = s; bcopy((char *)&(rptr->he.h_addr_list[n].S_ADDR), s, sizeof(struct IN_ADDR)); } *t = (char *)NULL; /* ** an array of pointers to CNAMEs. */ for (i = 0; i < MAXALIASES; i++) if (!rptr->he.h_aliases[i]) break; i++; t = hp->h_aliases = (char **)MyMalloc(sizeof(char *) * i); for (n = 0; n < i; n++, t++) { *t = rptr->he.h_aliases[n]; rptr->he.h_aliases[n] = NULL; } hp->h_addrtype = rptr->he.h_addrtype; hp->h_length = rptr->he.h_length; hp->h_name = rptr->he.h_name; #endif if (rptr->ttl < 600) { reinfo.re_shortttl++; cp->ttl = 600; } else cp->ttl = rptr->ttl; cp->expireat = TStime() + cp->ttl; #ifndef _WIN32 rptr->he.h_name = NULL; #else rptr->he->h_name = NULL; #endif #ifdef DEBUG Debug((DEBUG_INFO,"make_cache:made cache %#x", cp)); #endif return add_to_cache(cp); } /* * rem_cache * delete a cache entry from the cache structures and lists and return * all memory used for the cache back to the memory pool. */ static void rem_cache(ocp) aCache *ocp; { aCache **cp; #ifndef _WIN32 struct hostent *hp = &ocp->he; #else struct hostent *hp = ocp->he; #endif int hashv; aClient *cptr; #ifdef DEBUG Debug((DEBUG_DNS, "rem_cache: ocp %#x hp %#x l_n %#x aliases %#x", ocp, hp, ocp->list_next, hp->h_aliases)); #endif /* ** Cleanup any references to this structure by destroying the ** pointer. */ for (hashv = highest_fd; hashv >= 0; hashv--) if ((cptr = local[hashv]) && (cptr->hostp == hp)) cptr->hostp = NULL; /* * remove cache entry from linked list */ for (cp = &cachetop; *cp; cp = &((*cp)->list_next)) if (*cp == ocp) { *cp = ocp->list_next; break; } /* * remove cache entry from hashed name lists */ hashv = hash_name(hp->h_name); #ifdef DEBUG Debug((DEBUG_DEBUG,"rem_cache: h_name %s hashv %d next %#x first %#x", hp->h_name, hashv, ocp->hname_next, hashtable[hashv].name_list)); #endif for (cp = &hashtable[hashv].name_list; *cp; cp = &((*cp)->hname_next)) if (*cp == ocp) { *cp = ocp->hname_next; break; } /* * remove cache entry from hashed number list */ hashv = hash_number((u_char *)hp->h_addr); #ifdef DEBUG Debug((DEBUG_DEBUG,"rem_cache: h_addr %s hashv %d next %#x first %#x", inetntoa(hp->h_addr), hashv, ocp->hnum_next, hashtable[hashv].num_list)); #endif for (cp = &hashtable[hashv].num_list; *cp; cp = &((*cp)->hnum_next)) if (*cp == ocp) { *cp = ocp->hnum_next; break; } #ifdef _WIN32 MyFree((char *)hp); #else /* * free memory used to hold the various host names and the array * of alias pointers. */ if (hp->h_name) MyFree(hp->h_name); if (hp->h_aliases) { for (hashv = 0; hp->h_aliases[hashv]; hashv++) MyFree(hp->h_aliases[hashv]); MyFree((char *)hp->h_aliases); } /* * free memory used to hold ip numbers and the array of them. */ if (hp->h_addr_list) { if (*hp->h_addr_list) MyFree((char *)*hp->h_addr_list); MyFree((char *)hp->h_addr_list); } #endif /*_WIN32*/ MyFree((char *)ocp); incache--; cainfo.ca_dels++; return; } /* * removes entries from the cache which are older than their expirey times. * returns the time at which the server should next poll the cache. */ time_t expire_cache(now) time_t now; { aCache *cp, *cp2; time_t next = 0; for (cp = cachetop; cp; cp = cp2) { cp2 = cp->list_next; if (now >= cp->expireat) { cainfo.ca_expires++; rem_cache(cp); } else if (!next || next > cp->expireat) next = cp->expireat; } return (next > now) ? next : (now + AR_TTL); } /* * remove all dns cache entries. */ void flush_cache() { aCache *cp; while ((cp = cachetop)) rem_cache(cp); } int m_dns(cptr, sptr, parc, parv) aClient *cptr, *sptr; int parc; char *parv[]; { aCache *cp; int i; if (IsOper(sptr) && parv[1] && *parv[1] == 'l') { for(cp = cachetop; cp; cp = cp->list_next) { sendto_one(sptr, "NOTICE %s :Ex %d ttl %d host %s(%s)", parv[0], cp->expireat - TStime(), cp->ttl, #ifndef _WIN32 cp->he.h_name, inetntoa(cp->he.h_addr)); for (i = 0; cp->he.h_aliases[i]; i++) sendto_one(sptr,"NOTICE %s : %s = %s (CN)", parv[0], cp->he.h_name, cp->he.h_aliases[i]); for (i = 1; cp->he.h_addr_list[i]; i++) sendto_one(sptr,"NOTICE %s : %s = %s (IP)", parv[0], cp->he.h_name, inetntoa(cp->he.h_addr_list[i])); #else cp->he->h_name, inetntoa(cp->he->h_addr)); for (i = 0; cp->he->h_aliases[i]; i++) sendto_one(sptr,"NOTICE %s : %s = %s (CN)", parv[0], cp->he->h_name, cp->he->h_aliases[i]); for (i = 1; cp->he->h_addr_list[i]; i++) sendto_one(sptr,"NOTICE %s : %s = %s (IP)", parv[0], cp->he->h_name, inetntoa(cp->he->h_addr_list[i])); #endif } return 0; } sendto_one(sptr,"NOTICE %s :Ca %d Cd %d Ce %d Cl %d Ch %d:%d Cu %d", sptr->name, cainfo.ca_adds, cainfo.ca_dels, cainfo.ca_expires, cainfo.ca_lookups, cainfo.ca_na_hits, cainfo.ca_nu_hits, cainfo.ca_updates); sendto_one(sptr,"NOTICE %s :Re %d Rl %d/%d Rp %d Rq %d", sptr->name, reinfo.re_errors, reinfo.re_nu_look, reinfo.re_na_look, reinfo.re_replies, reinfo.re_requests); sendto_one(sptr,"NOTICE %s :Ru %d Rsh %d Rs %d(%d) Rt %d", sptr->name, reinfo.re_unkrep, reinfo.re_shortttl, reinfo.re_sent, reinfo.re_resends, reinfo.re_timeouts); return 0; } u_long cres_mem(sptr) aClient *sptr; { register aCache *c = cachetop; register struct hostent *h; register int i; u_long nm = 0, im = 0, sm = 0, ts = 0; for ( ;c ; c = c->list_next) { sm += sizeof(*c); #ifndef _WIN32 h = &c->he; #else h = c->he; #endif for (i = 0; h->h_addr_list[i]; i++) { im += sizeof(char *); im += sizeof(struct IN_ADDR); } im += sizeof(char *); for (i = 0; h->h_aliases[i]; i++) { nm += sizeof(char *); nm += strlen(h->h_aliases[i]); } nm += i - 1; nm += sizeof(char *); if (h->h_name) nm += strlen(h->h_name); } ts = ARES_CACSIZE * sizeof(CacheTable); sendto_one(sptr, ":%s %d %s :RES table %d", me.name, RPL_STATSDEBUG, sptr->name, ts); sendto_one(sptr, ":%s %d %s :Structs %d IP storage %d Name storage %d", me.name, RPL_STATSDEBUG, sptr->name, sm, im, nm); return ts + sm + im + nm; } #ifdef _WIN32 /* * Main thread function for handling DNS requests. */ void async_dns(void *parm) { ResRQ *rptr = (ResRQ *)parm; struct hostent *hp, *he = rptr->he; int i, x; long amt; if (rptr->type == T_A) { rptr->locked = 2; hp = gethostbyname(rptr->name); } else { rptr->locked = 1; hp = gethostbyaddr((char *)(&rptr->addr.S_ADDR), 4, PF_INET); } if ( !hp ) { /* * Now heres a stupid check to forget, this apprently is * what hasbeen causing most of the crashes. I hope anyway. */ do_dns_async(rptr->id); _endthread(); } if ( (hp->h_aliases[0] && (hp->h_aliases[0]-(char *)hp)>MAXGETHOSTSTRUCT) || (hp->h_addr_list[0] && (hp->h_addr_list[0]-(char *)hp)>MAXGETHOSTSTRUCT)) { /* * Seems windows does some weird, aka stupid, stuff with DNS. * If the address is resolved from the HOSTS file, then the * pointers will exceed MAXGETHOSTSTRUCT. Good and bad. Good * because its an easy way to tell if the Admin is spoofing * with his HOSTS file, bad because it also causes invalid * pointers without this check. -Cabal95 */ do_dns_async(rptr->id); _endthread(); } res_copyhostent(hp, rptr->he); do_dns_async(rptr->id); _endthread(); } int res_copyhostent(struct hostent *from, struct hostent *to) { int amt, x, i; to->h_addrtype = from->h_addrtype; to->h_length = from->h_length; /* * Get to "primary" offset in to hostent buffer and copy over * to hostname. */ amt = (long)to + sizeof(struct hostent); to->h_name = (char *)amt; strcpy(to->h_name, from->h_name); amt += strlen(to->h_name)+1; /* Setup tto alias list */ if (amt&0x3) amt = (amt&0xFFFFFFFC)+4; to->h_aliases = (char **)amt; for (x = 0; from->h_aliases[x]; x++) ; x *= sizeof(char *); amt += sizeof(char *); for (i = 0; from->h_aliases[i]; i++) { to->h_aliases[i] = (char *)(amt+x); strcpy(to->h_aliases[i], from->h_aliases[i]); amt += strlen(to->h_aliases[i])+1; if (amt&0x3) amt = (amt&0xFFFFFFFC)+4; } to->h_aliases[i] = NULL; /* Setup tto IP address list */ to->h_addr_list = (char **)amt; for (x = 0; from->h_addr_list[x]; x++) ; x *= sizeof(char *); for (i = 0; from->h_addr_list[i]; i++) { amt += 4; to->h_addr_list[i] = (char *)(amt+x); ((struct IN_ADDR *)to->h_addr_list[i])->S_ADDR = ((struct IN_ADDR *)from->h_addr_list[i])->S_ADDR; } to->h_addr_list[i] = NULL; } #endif /*_WIN32*/