mirror of
https://github.com/pi-hole/dnsmasq.git
synced 2025-12-19 18:28:25 +00:00
import of dnsmasq-2.9.tar.gz
This commit is contained in:
Simon Kelley
245
src/forward.c
245
src/forward.c
@@ -120,22 +120,27 @@ static struct server *forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
{
|
||||
struct frec *forward;
|
||||
char *domain = NULL;
|
||||
int type = 0;
|
||||
struct server *serv;
|
||||
int forwardall = 0, type = 0;
|
||||
struct all_addr *addrp = NULL;
|
||||
unsigned short flags = 0;
|
||||
unsigned short gotname = extract_request(header, (unsigned int)plen, dnamebuff);
|
||||
|
||||
struct server *start = NULL;
|
||||
|
||||
/* may be recursion not speced or no servers available. */
|
||||
if (!header->rd || !servers)
|
||||
forward = NULL;
|
||||
else if ((forward = lookup_frec_by_sender(ntohs(header->id), udpaddr)))
|
||||
{
|
||||
/* retry on existing query, send to next server */
|
||||
/* retry on existing query, send to all available servers */
|
||||
domain = forward->sentto->domain;
|
||||
if (!(options & OPT_ORDER))
|
||||
{
|
||||
forwardall = 1;
|
||||
last_server = NULL;
|
||||
}
|
||||
type = forward->sentto->flags & SERV_TYPE;
|
||||
if (!(forward->sentto = forward->sentto->next))
|
||||
forward->sentto = servers; /* at end of list, recycle */
|
||||
if (!(start = forward->sentto->next))
|
||||
start = servers; /* at end of list, recycle */
|
||||
header->id = htons(forward->new_id);
|
||||
}
|
||||
else
|
||||
@@ -148,29 +153,25 @@ static struct server *forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
|
||||
unsigned int namelen = strlen(dnamebuff);
|
||||
unsigned int matchlen = 0;
|
||||
|
||||
struct server *serv;
|
||||
|
||||
for (serv=servers; serv; serv=serv->next)
|
||||
/* domain matches take priority over NODOTS matches */
|
||||
if ((serv->flags & SERV_FOR_NODOTS) && type != SERV_HAS_DOMAIN && !strchr(dnamebuff, '.'))
|
||||
{
|
||||
if (serv->flags & SERV_LITERAL_ADDRESS)
|
||||
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
|
||||
type = SERV_FOR_NODOTS;
|
||||
flags = 0;
|
||||
if ((serv->flags & SERV_LITERAL_ADDRESS) && (sflag & gotname))
|
||||
{
|
||||
/* flags gets set if server is in fact an answer */
|
||||
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
|
||||
if (sflag & gotname) /* only OK if addrfamily == query */
|
||||
{
|
||||
type = SERV_FOR_NODOTS;
|
||||
flags = sflag;
|
||||
if (serv->addr.sa.sa_family == AF_INET)
|
||||
addrp = (struct all_addr *)&serv->addr.in.sin_addr;
|
||||
flags = sflag;
|
||||
if (serv->addr.sa.sa_family == AF_INET)
|
||||
addrp = (struct all_addr *)&serv->addr.in.sin_addr;
|
||||
#ifdef HAVE_IPV6
|
||||
else
|
||||
addrp = (struct all_addr *)&serv->addr.in6.sin6_addr;
|
||||
else
|
||||
addrp = (struct all_addr *)&serv->addr.in6.sin6_addr;
|
||||
#endif
|
||||
}
|
||||
}
|
||||
else
|
||||
flags = 0;
|
||||
}
|
||||
else if (serv->flags & SERV_HAS_DOMAIN)
|
||||
{
|
||||
@@ -179,29 +180,20 @@ static struct server *forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
hostname_isequal(dnamebuff + namelen - domainlen, serv->domain) &&
|
||||
domainlen >= matchlen)
|
||||
{
|
||||
if (serv->flags & SERV_LITERAL_ADDRESS)
|
||||
{ /* flags gets set if server is in fact an answer */
|
||||
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
|
||||
if ((sflag | F_QUERY ) & gotname) /* only OK if addrfamily == query */
|
||||
{
|
||||
type = SERV_HAS_DOMAIN;
|
||||
flags = gotname;
|
||||
domain = serv->domain;
|
||||
matchlen = domainlen;
|
||||
if (serv->addr.sa.sa_family == AF_INET)
|
||||
addrp = (struct all_addr *)&serv->addr.in.sin_addr;
|
||||
#ifdef HAVE_IPV6
|
||||
else
|
||||
addrp = (struct all_addr *)&serv->addr.in6.sin6_addr;
|
||||
#endif
|
||||
}
|
||||
}
|
||||
else
|
||||
unsigned short sflag = serv->addr.sa.sa_family == AF_INET ? F_IPV4 : F_IPV6;
|
||||
type = SERV_HAS_DOMAIN;
|
||||
domain = serv->domain;
|
||||
matchlen = domainlen;
|
||||
flags = 0;
|
||||
if ((serv->flags & SERV_LITERAL_ADDRESS) && ((sflag | F_QUERY ) & gotname))
|
||||
{
|
||||
flags = 0; /* may be better match from previous literal */
|
||||
domain = serv->domain;
|
||||
matchlen = domainlen;
|
||||
type = SERV_HAS_DOMAIN;
|
||||
flags = gotname;
|
||||
if (serv->addr.sa.sa_family == AF_INET)
|
||||
addrp = (struct all_addr *)&serv->addr.in.sin_addr;
|
||||
#ifdef HAVE_IPV6
|
||||
else
|
||||
addrp = (struct all_addr *)&serv->addr.in6.sin6_addr;
|
||||
#endif
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -231,10 +223,13 @@ static struct server *forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
otherwise, use the one last known to work. */
|
||||
|
||||
if (type != 0 || (options & OPT_ORDER))
|
||||
forward->sentto = servers;
|
||||
else
|
||||
forward->sentto = last_server;
|
||||
|
||||
start = servers;
|
||||
else if (!(start = last_server))
|
||||
{
|
||||
start = servers;
|
||||
forwardall = 1;
|
||||
}
|
||||
|
||||
forward->source = *udpaddr;
|
||||
forward->dest = *dst_addr;
|
||||
forward->new_id = get_id();
|
||||
@@ -250,52 +245,52 @@ static struct server *forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
|
||||
if (!flags && forward)
|
||||
{
|
||||
struct server *firstsentto = forward->sentto;
|
||||
|
||||
struct server *firstsentto = start;
|
||||
int forwarded = 0;
|
||||
|
||||
while (1)
|
||||
{
|
||||
int logflags = 0;
|
||||
|
||||
if (forward->sentto->addr.sa.sa_family == AF_INET)
|
||||
{
|
||||
logflags = F_SERVER | F_IPV4 | F_FORWARD;
|
||||
addrp = (struct all_addr *)&forward->sentto->addr.in.sin_addr;
|
||||
}
|
||||
#ifdef HAVE_IPV6
|
||||
else
|
||||
{
|
||||
logflags = F_SERVER | F_IPV6 | F_FORWARD;
|
||||
addrp = (struct all_addr *)&forward->sentto->addr.in6.sin6_addr;
|
||||
}
|
||||
#endif
|
||||
/* only send to servers dealing with our domain.
|
||||
domain may be NULL, in which case server->domain
|
||||
must be NULL also. */
|
||||
|
||||
if (type == (forward->sentto->flags & SERV_TYPE) &&
|
||||
(type != SERV_HAS_DOMAIN || hostname_isequal(domain, forward->sentto->domain)))
|
||||
if (type == (start->flags & SERV_TYPE) &&
|
||||
(type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)))
|
||||
{
|
||||
if (forward->sentto->flags & SERV_NO_ADDR)
|
||||
if (start->flags & SERV_NO_ADDR)
|
||||
flags = F_NOERR; /* NULL servers are OK. */
|
||||
else if (!(forward->sentto->flags & SERV_LITERAL_ADDRESS) &&
|
||||
sendto(forward->sentto->sfd->fd, (char *)header, plen, 0,
|
||||
&forward->sentto->addr.sa,
|
||||
sa_len(&forward->sentto->addr)) != -1)
|
||||
else if (!(start->flags & SERV_LITERAL_ADDRESS) &&
|
||||
sendto(start->sfd->fd, (char *)header, plen, 0,
|
||||
&start->addr.sa,
|
||||
sa_len(&start->addr)) != -1)
|
||||
{
|
||||
log_query(logflags, gotname ? dnamebuff : "query", addrp);
|
||||
/* for no-domain, don't update last_server */
|
||||
return domain ? last_server : (forward->sentto->next ? forward->sentto->next : servers);
|
||||
if (!gotname)
|
||||
strcpy(dnamebuff, "query");
|
||||
if (start->addr.sa.sa_family == AF_INET)
|
||||
log_query(F_SERVER | F_IPV4 | F_FORWARD, dnamebuff,
|
||||
(struct all_addr *)&start->addr.in.sin_addr);
|
||||
#ifdef HAVE_IPV6
|
||||
else
|
||||
log_query(F_SERVER | F_IPV6 | F_FORWARD, dnamebuff,
|
||||
(struct all_addr *)&start->addr.in6.sin6_addr);
|
||||
#endif
|
||||
forwarded = 1;
|
||||
forward->sentto = start;
|
||||
if (!forwardall)
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (!(forward->sentto = forward->sentto->next))
|
||||
forward->sentto = servers;
|
||||
if (!(start = start->next))
|
||||
start = servers;
|
||||
|
||||
/* check if we tried all without success */
|
||||
if (forward->sentto == firstsentto)
|
||||
if (start == firstsentto)
|
||||
break;
|
||||
}
|
||||
|
||||
if (forwarded)
|
||||
return last_server;
|
||||
|
||||
/* could not send on, prepare to return */
|
||||
header->id = htons(forward->orig_id);
|
||||
forward->new_id = 0; /* cancel */
|
||||
@@ -312,52 +307,81 @@ static struct server *forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
}
|
||||
|
||||
/* returns new last_server */
|
||||
struct server *reply_query(int fd, int options, char *packet, time_t now,
|
||||
char *dnamebuff, struct server *last_server,
|
||||
struct server *reply_query(struct serverfd *sfd, int options, char *packet, time_t now,
|
||||
char *dnamebuff, struct server *servers, struct server *last_server,
|
||||
struct bogus_addr *bogus_nxdomain, struct doctor *doctors)
|
||||
{
|
||||
/* packet from peer server, extract data for cache, and send to
|
||||
original requester */
|
||||
struct frec *forward;
|
||||
HEADER *header;
|
||||
int n = recv(fd, packet, PACKETSZ, 0);
|
||||
union mysockaddr serveraddr;
|
||||
socklen_t addrlen = sizeof(serveraddr);
|
||||
int n = recvfrom(sfd->fd, packet, PACKETSZ, 0, &serveraddr.sa, &addrlen);
|
||||
|
||||
/* Determine the address of the server replying so that we can mark that as good */
|
||||
serveraddr.sa.sa_family = sfd->source_addr.sa.sa_family;
|
||||
#ifdef HAVE_IPV6
|
||||
if (serveraddr.sa.sa_family == AF_INET6)
|
||||
serveraddr.in6.sin6_flowinfo = htonl(0);
|
||||
#endif
|
||||
|
||||
header = (HEADER *)packet;
|
||||
if (n >= (int)sizeof(HEADER) && header->qr)
|
||||
if (n >= (int)sizeof(HEADER) && header->qr && (forward = lookup_frec(ntohs(header->id))))
|
||||
{
|
||||
if ((forward = lookup_frec(ntohs(header->id))))
|
||||
/* find good server by address if possible, otherwise assume the last one we sent to */
|
||||
if ((forward->sentto->flags & SERV_TYPE) == 0)
|
||||
{
|
||||
if (header->rcode == NOERROR || header->rcode == NXDOMAIN)
|
||||
{
|
||||
if (!forward->sentto->domain)
|
||||
last_server = forward->sentto; /* known good */
|
||||
if (header->opcode == QUERY)
|
||||
{
|
||||
if (!(bogus_nxdomain &&
|
||||
header->rcode == NOERROR &&
|
||||
check_for_bogus_wildcard(header, (unsigned int)n, dnamebuff, bogus_nxdomain, now)))
|
||||
{
|
||||
if (header->rcode == NOERROR && ntohs(header->ancount) != 0)
|
||||
extract_addresses(header, (unsigned int)n, dnamebuff, now, doctors);
|
||||
else if (!(options & OPT_NO_NEG))
|
||||
extract_neg_addrs(header, (unsigned int)n, dnamebuff, now);
|
||||
}
|
||||
}
|
||||
}
|
||||
header->id = htons(forward->orig_id);
|
||||
/* There's no point returning an upstream reply marked as truncated,
|
||||
since that will prod the resolver into moving to TCP - which we
|
||||
don't support. */
|
||||
header->tc = 0; /* goodbye truncate */
|
||||
send_from(forward->fd, options & OPT_NOWILD, packet, n, &forward->source, &forward->dest);
|
||||
forward->new_id = 0; /* cancel */
|
||||
for (last_server = servers; last_server; last_server = last_server->next)
|
||||
if (!(last_server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_NO_ADDR)) &&
|
||||
sockaddr_isequal(&last_server->addr, &serveraddr))
|
||||
break;
|
||||
if (!last_server)
|
||||
last_server = forward->sentto;
|
||||
}
|
||||
|
||||
/* Complain loudly if the upstream server is non-recursive. */
|
||||
if (!header->ra && header->rcode == NOERROR && ntohs(header->ancount) == 0)
|
||||
{
|
||||
char addrbuff[ADDRSTRLEN];
|
||||
#ifdef HAVE_IPV6
|
||||
if (serveraddr.sa.sa_family == AF_INET)
|
||||
inet_ntop(AF_INET, &serveraddr.in.sin_addr, addrbuff, ADDRSTRLEN);
|
||||
else if (serveraddr.sa.sa_family == AF_INET6)
|
||||
inet_ntop(AF_INET6, &serveraddr.in6.sin6_addr, addrbuff, ADDRSTRLEN);
|
||||
#else
|
||||
strcpy(addrbuff, inet_ntoa(serveraddr.in.sin_addr));
|
||||
#endif
|
||||
syslog(LOG_WARNING, "nameserver %s refused to do a recursive query", addrbuff);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if ((header->rcode == NOERROR || header->rcode == NXDOMAIN) && header->opcode == QUERY)
|
||||
{
|
||||
if (!(bogus_nxdomain &&
|
||||
header->rcode == NOERROR &&
|
||||
check_for_bogus_wildcard(header, (unsigned int)n, dnamebuff, bogus_nxdomain, now)))
|
||||
{
|
||||
if (header->rcode == NOERROR && ntohs(header->ancount) != 0)
|
||||
extract_addresses(header, (unsigned int)n, dnamebuff, now, doctors);
|
||||
else if (!(options & OPT_NO_NEG))
|
||||
extract_neg_addrs(header, (unsigned int)n, dnamebuff, now);
|
||||
}
|
||||
}
|
||||
|
||||
header->id = htons(forward->orig_id);
|
||||
/* There's no point returning an upstream reply marked as truncated,
|
||||
since that will prod the resolver into moving to TCP - which we
|
||||
don't support. */
|
||||
header->tc = 0; /* goodbye truncate */
|
||||
send_from(forward->fd, options & OPT_NOWILD, packet, n, &forward->source, &forward->dest);
|
||||
forward->new_id = 0; /* cancel */
|
||||
}
|
||||
|
||||
|
||||
return last_server;
|
||||
}
|
||||
|
||||
struct server *receive_query(struct listener *listen, char *packet, char *mxname,
|
||||
struct server *receive_query(struct listener *listen, char *packet, struct mx_record *mxnames,
|
||||
char *mxtarget, unsigned int options, time_t now,
|
||||
unsigned long local_ttl, char *namebuff,
|
||||
struct iname *names, struct iname *addrs, struct iname *except,
|
||||
@@ -395,7 +419,8 @@ struct server *receive_query(struct listener *listen, char *packet, char *mxname
|
||||
msg.msg_iov = iov;
|
||||
msg.msg_iovlen = 1;
|
||||
|
||||
n = recvmsg(listen->fd, &msg, 0);
|
||||
if ((n = recvmsg(listen->fd, &msg, 0)) == -1)
|
||||
return last_server;
|
||||
|
||||
source_addr.sa.sa_family = listen->family;
|
||||
#ifdef HAVE_IPV6
|
||||
@@ -502,7 +527,7 @@ struct server *receive_query(struct listener *listen, char *packet, char *mxname
|
||||
}
|
||||
|
||||
m = answer_request (header, ((char *) header) + PACKETSZ, (unsigned int)n,
|
||||
mxname, mxtarget, options, now, local_ttl, namebuff);
|
||||
mxnames, mxtarget, options, now, local_ttl, namebuff);
|
||||
if (m >= 1)
|
||||
send_from(listen->fd, options & OPT_NOWILD, (char *)header, m, &source_addr, &dst_addr);
|
||||
else
|
||||
|
||||
Reference in New Issue
Block a user