static size_t process_reply(HEADER *header, time_t now,
struct server *server, size_t n)
{
unsigned char *pheader, *sizep;
int munged = 0, is_sign;
size_t plen;
/* If upstream is advertising a larger UDP packet size
than we allow, trim it so that we don't get overlarge
requests for the client. We can't do this for signed packets. */
if ((pheader = find_pseudoheader(header, n, &plen, &sizep, &is_sign)) && !is_sign)
{
unsigned short udpsz;
unsigned char *psave = sizep;
GETSHORT(udpsz, sizep);
if (udpsz > daemon->edns_pktsz)
PUTSHORT(daemon->edns_pktsz, psave);
}
if (header->opcode != QUERY || (header->rcode != NOERROR && header->rcode != NXDOMAIN))
return n;
/* Complain loudly if the upstream server is non-recursive. */
if (!header->ra && header->rcode == NOERROR && ntohs(header->ancount) == 0 &&
server && !(server->flags & SERV_WARNED_RECURSIVE))
{
prettyprint_addr(&server->addr, daemon->namebuff);
my_syslog(LOG_WARNING, _("nameserver %s refused to do a recursive query"), daemon->namebuff);
if (!(daemon->options & OPT_LOG))
server->flags |= SERV_WARNED_RECURSIVE;
}
if (daemon->bogus_addr && header->rcode != NXDOMAIN &&
check_for_bogus_wildcard(header, n, daemon->namebuff, daemon->bogus_addr, now))
{
munged = 1;
header->rcode = NXDOMAIN;
header->aa = 0;
}
else
{
if (header->rcode == NXDOMAIN &&
extract_request(header, n, daemon->namebuff, NULL) &&
check_for_local_domain(daemon->namebuff, now))
{
/* if we forwarded a query for a locally known name (because it was for
an unknown type) and the answer is NXDOMAIN, convert that to NODATA,
since we know that the domain exists, even if upstream doesn't */
munged = 1;
header->aa = 1;
header->rcode = NOERROR;
}
if (extract_addresses(header, n, daemon->namebuff, now))
{
my_syslog(LOG_WARNING, _("possible DNS-rebind attack detected"));
munged = 1;
}
}
/* do this after extract_addresses. Ensure NODATA reply and remove
nameserver info. */
if (munged)
{
header->ancount = htons(0);
header->nscount = htons(0);
header->arcount = htons(0);
}
/* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide
sections of the packet. Find the new length here and put back pseudoheader
if it was removed. */
return resize_packet(header, n, pheader, plen);
}
static unsigned int search_servers(time_t now, struct all_addr **addrpp,
unsigned int qtype, char *qdomain, int *type, char **domain, int *norebind)
{
/* If the query ends in the domain in one of our servers, set
domain to point to that name. We find the largest match to allow both
domain.org and sub.domain.org to exist. */
unsigned int namelen = strlen(qdomain);
unsigned int matchlen = 0;
struct server *serv;
unsigned int flags = 0;
for (serv = daemon->servers; serv; serv=serv->next)
/* domain matches take priority over NODOTS matches */
if ((serv->flags & SERV_FOR_NODOTS) && *type != SERV_HAS_DOMAIN && !strchr(qdomain, '.') && namelen != 0)
{
unsigned int sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
*type = SERV_FOR_NODOTS;
if (serv->flags & SERV_NO_ADDR)
flags = F_NXDOMAIN;
else if (serv->flags & SERV_LITERAL_ADDRESS)
{
if (sflag & qtype)
{
flags = sflag;
if (serv->addr.sa.sa_family == AF_INET)
*addrpp = (struct all_addr *)&serv->addr.in.sin_addr;
#ifdef HAVE_IPV6
else
*addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr;
#endif
}
else if (!flags || (flags & F_NXDOMAIN))
flags = F_NOERR;
}
}
else if (serv->flags & SERV_HAS_DOMAIN)
{
unsigned int domainlen = strlen(serv->domain);
char *matchstart = qdomain + namelen - domainlen;
if (namelen >= domainlen &&
hostname_isequal(matchstart, serv->domain) &&
(domainlen == 0 || namelen == domainlen || *(matchstart-1) == '.' ))
{
if (serv->flags & SERV_NO_REBIND)
*norebind = 1;
else
{
unsigned int sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
/* implement priority rules for --address and --server for same domain.
--address wins if the address is for the correct AF
--server wins otherwise. */
if (domainlen != 0 && domainlen == matchlen)
{
if ((serv->flags & SERV_LITERAL_ADDRESS))
{
if (!(sflag & qtype) && flags == 0)
continue;
}
else
{
if (flags & (F_IPV4 | F_IPV6))
continue;
}
}
if (domainlen >= matchlen)
{
*type = serv->flags & (SERV_HAS_DOMAIN | SERV_USE_RESOLV | SERV_NO_REBIND);
*domain = serv->domain;
matchlen = domainlen;
if (serv->flags & SERV_NO_ADDR)
flags = F_NXDOMAIN;
else if (serv->flags & SERV_LITERAL_ADDRESS)
{
if (sflag & qtype)
{
flags = sflag;
if (serv->addr.sa.sa_family == AF_INET)
*addrpp = (struct all_addr *)&serv->addr.in.sin_addr;
#ifdef HAVE_IPV6
else
*addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr;
#endif
}
else if (!flags || (flags & F_NXDOMAIN))
flags = F_NOERR;
}
else
flags = 0;
}
}
}
}
if (flags == 0 && !(qtype & F_QUERY) &&
option_bool(OPT_NODOTS_LOCAL) && !strchr(qdomain, '.') && namelen != 0)
/* don't forward A or AAAA queries for simple names, except the empty name */
flags = F_NOERR;
if (flags == F_NXDOMAIN && check_for_local_domain(qdomain, now))
flags = F_NOERR;
if (flags)
{
int logflags = 0;
if (flags == F_NXDOMAIN || flags == F_NOERR)
logflags = F_NEG | qtype;
log_query(logflags | flags | F_CONFIG | F_FORWARD, qdomain, *addrpp, NULL);
}
else if ((*type) & SERV_USE_RESOLV)
{
*type = 0; /* use normal servers for this domain */
*domain = NULL;
}
return flags;
}
static unsigned short search_servers(time_t now, struct all_addr **addrpp,
unsigned short qtype, char *qdomain, int *type, char **domain)
{
/* If the query ends in the domain in one of our servers, set
domain to point to that name. We find the largest match to allow both
domain.org and sub.domain.org to exist. */
unsigned int namelen = strlen(qdomain);
unsigned int matchlen = 0;
struct server *serv;
unsigned short flags = 0;
for (serv = daemon->servers; serv; serv=serv->next)
/* domain matches take priority over NODOTS matches */
if ((serv->flags & SERV_FOR_NODOTS) && *type != SERV_HAS_DOMAIN && !strchr(qdomain, '.') && namelen != 0)
{
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
*type = SERV_FOR_NODOTS;
if (serv->flags & SERV_NO_ADDR)
flags = F_NXDOMAIN;
else if (serv->flags & SERV_LITERAL_ADDRESS)
{
if (sflag & qtype)
{
flags = sflag;
if (serv->addr.sa.sa_family == AF_INET)
*addrpp = (struct all_addr *)&serv->addr.in.sin_addr;
#ifdef HAVE_IPV6
else
*addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr;
#endif
}
else if (!flags || (flags & F_NXDOMAIN))
flags = F_NOERR;
}
}
else if (serv->flags & SERV_HAS_DOMAIN)
{
unsigned int domainlen = strlen(serv->domain);
char *matchstart = qdomain + namelen - domainlen;
if (namelen >= domainlen &&
hostname_isequal(matchstart, serv->domain) &&
domainlen >= matchlen &&
(domainlen == 0 || namelen == domainlen || *(serv->domain) == '.' || *(matchstart-1) == '.' ))
{
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
*type = SERV_HAS_DOMAIN;
*domain = serv->domain;
matchlen = domainlen;
if (serv->flags & SERV_NO_ADDR)
flags = F_NXDOMAIN;
else if (serv->flags & SERV_LITERAL_ADDRESS)
{
if (sflag & qtype)
{
flags = sflag;
if (serv->addr.sa.sa_family == AF_INET)
*addrpp = (struct all_addr *)&serv->addr.in.sin_addr;
#ifdef HAVE_IPV6
else
*addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr;
#endif
}
else if (!flags || (flags & F_NXDOMAIN))
flags = F_NOERR;
}
}
}
if (flags == 0 && !(qtype & F_BIGNAME) &&
(daemon->options & OPT_NODOTS_LOCAL) && !strchr(qdomain, '.') && namelen != 0)
/* don't forward simple names, make exception for NS queries and empty name. */
flags = F_NXDOMAIN;
if (flags == F_NXDOMAIN && check_for_local_domain(qdomain, now))
flags = F_NOERR;
if (flags)
{
int logflags = 0;
if (flags == F_NXDOMAIN || flags == F_NOERR)
logflags = F_NEG | qtype;
log_query(logflags | flags | F_CONFIG | F_FORWARD, qdomain, *addrpp, NULL);
}
return flags;
}
static unsigned short search_servers(struct daemon *daemon, time_t now, struct all_addr **addrpp,
unsigned short qtype, char *qdomain, int *type, char **domain)
{
/* If the query ends in the domain in one of our servers, set
domain to point to that name. We find the largest match to allow both
domain.org and sub.domain.org to exist. */
unsigned int namelen = strlen(qdomain);
unsigned int matchlen = 0;
struct server *serv;
unsigned short flags = 0;
for (serv = daemon->servers; serv; serv=serv->next)
/* domain matches take priority over NODOTS matches */
if ((serv->flags & SERV_FOR_NODOTS) && *type != SERV_HAS_DOMAIN && !strchr(qdomain, '.') && namelen != 0)
{
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
*type = SERV_FOR_NODOTS;
if (serv->flags & SERV_NO_ADDR)
flags = F_NXDOMAIN;
else if (serv->flags & SERV_LITERAL_ADDRESS)
{
if (sflag & qtype)
{
flags = sflag;
if (serv->addr.sa.sa_family == AF_INET)
*addrpp = (struct all_addr *)&serv->addr.in.sin_addr;
#ifdef HAVE_IPV6
else
*addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr;
#endif
}
else if (!flags)
flags = F_NOERR;
}
}
else if (serv->flags & SERV_HAS_DOMAIN)
{
unsigned int domainlen = strlen(serv->domain);
char *matchstart = qdomain + namelen - domainlen;
if (namelen >= domainlen &&
hostname_isequal(matchstart, serv->domain) &&
domainlen >= matchlen &&
(domainlen == 0 || namelen == domainlen || *(serv->domain) == '.' || *(matchstart-1) == '.' ))
{
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
*type = SERV_HAS_DOMAIN;
*domain = serv->domain;
matchlen = domainlen;
if (serv->flags & SERV_NO_ADDR)
flags = F_NXDOMAIN;
else if (serv->flags & SERV_LITERAL_ADDRESS)
{
if ((sflag | F_QUERY ) & qtype)
{
flags = qtype;
if (serv->addr.sa.sa_family == AF_INET)
*addrpp = (struct all_addr *)&serv->addr.in.sin_addr;
#ifdef HAVE_IPV6
else
*addrpp = (struct all_addr *)&serv->addr.in6.sin6_addr;
#endif
}
else if (!flags)
flags = F_NOERR;
}
}
}
if (flags & ~(F_NOERR | F_NXDOMAIN)) /* flags set here means a literal found */
{
if (flags & F_QUERY)
log_query(F_CONFIG | F_FORWARD | F_NEG, qdomain, NULL, 0, NULL, 0);
else
log_query(F_CONFIG | F_FORWARD | flags, qdomain, *addrpp, 0, NULL, 0);
}
else if (qtype && (daemon->options & OPT_NODOTS_LOCAL) && !strchr(qdomain, '.') && namelen != 0)
flags = F_NXDOMAIN;
if (flags == F_NXDOMAIN && check_for_local_domain(qdomain, now, daemon))
flags = F_NOERR;
if (flags == F_NXDOMAIN || flags == F_NOERR)
log_query(F_CONFIG | F_FORWARD | F_NEG | qtype | (flags & F_NXDOMAIN), qdomain, NULL, 0, NULL, 0);
return flags;
}
