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Diffstat (limited to 'src/forward.c')
-rw-r--r--src/forward.c136
1 files changed, 116 insertions, 20 deletions
diff --git a/src/forward.c b/src/forward.c
index e46db02..9e8dcd5 100644
--- a/src/forward.c
+++ b/src/forward.c
@@ -20,6 +20,8 @@ static struct frec *lookup_frec(unsigned short id, int fd, int family, void *has
static struct frec *lookup_frec_by_sender(unsigned short id,
union mysockaddr *addr,
void *hash);
+static struct frec *lookup_frec_by_query(void *hash, unsigned int flags);
+
static unsigned short get_id(void);
static void free_frec(struct frec *f);
@@ -238,6 +240,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
int type = SERV_DO_DNSSEC, norebind = 0;
struct all_addr *addrp = NULL;
unsigned int flags = 0;
+ unsigned int fwd_flags = 0;
struct server *start = NULL;
void *hash = hash_questions(header, plen, daemon->namebuff);
#ifdef HAVE_DNSSEC
@@ -247,6 +250,15 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
(void)do_bit;
+ if (header->hb4 & HB4_CD)
+ fwd_flags |= FREC_CHECKING_DISABLED;
+ if (ad_reqd)
+ fwd_flags |= FREC_AD_QUESTION;
+#ifdef HAVE_DNSSEC
+ if (do_bit)
+ fwd_flags |= FREC_DO_QUESTION;
+#endif
+
/* may be no servers available. */
if (forward || (forward = lookup_frec_by_sender(ntohs(header->id), udpaddr, hash)))
{
@@ -322,6 +334,39 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
}
else
{
+ /* Query from new source, but the same query may be in progress
+ from another source. If so, just add this client to the
+ list that will get the reply.
+
+ Note that is the EDNS client subnet option is in use, we can't do this,
+ as the clients (and therefore query EDNS options) will be different
+ for each query. The EDNS subnet code has checks to avoid
+ attacks in this case. */
+ if (!option_bool(OPT_CLIENT_SUBNET) && (forward = lookup_frec_by_query(hash, fwd_flags)))
+ {
+ /* Note whine_malloc() zeros memory. */
+ if (!daemon->free_frec_src &&
+ daemon->frec_src_count < daemon->ftabsize &&
+ (daemon->free_frec_src = whine_malloc(sizeof(struct frec_src))))
+ daemon->frec_src_count++;
+
+ /* If we've been spammed with many duplicates, just drop the query. */
+ if (daemon->free_frec_src)
+ {
+ struct frec_src *new = daemon->free_frec_src;
+ daemon->free_frec_src = new->next;
+ new->next = forward->frec_src.next;
+ forward->frec_src.next = new;
+ new->orig_id = ntohs(header->id);
+ new->source = *udpaddr;
+ new->dest = *dst_addr;
+ new->log_id = daemon->log_id;
+ new->iface = dst_iface;
+ }
+
+ return 1;
+ }
+
if (gotname)
flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind);
@@ -336,15 +381,15 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
if (forward)
{
- forward->source = *udpaddr;
- forward->dest = *dst_addr;
- forward->iface = dst_iface;
- forward->orig_id = ntohs(header->id);
+ forward->frec_src.source = *udpaddr;
+ forward->frec_src.orig_id = ntohs(header->id);
+ forward->frec_src.dest = *dst_addr;
+ forward->frec_src.iface = dst_iface;
forward->new_id = get_id();
forward->fd = udpfd;
memcpy(forward->hash, hash, HASH_SIZE);
forward->forwardall = 0;
- forward->flags = 0;
+ forward->flags = fwd_flags;
if (norebind)
forward->flags |= FREC_NOREBIND;
if (header->hb4 & HB4_CD)
@@ -400,10 +445,10 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
unsigned char *pheader;
/* If a query is retried, use the log_id for the retry when logging the answer. */
- forward->log_id = daemon->log_id;
-
- plen = add_edns0_config(header, plen, ((unsigned char *)header) + PACKETSZ, &forward->source, now, &subnet);
+ forward->frec_src.log_id = daemon->log_id;
+ plen = add_edns0_config(header, plen, ((unsigned char *)header) + PACKETSZ, &forward->frec_src.source, now, &subnet);
+
if (subnet)
forward->flags |= FREC_HAS_SUBNET;
@@ -539,7 +584,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
return 1;
/* could not send on, prepare to return */
- header->id = htons(forward->orig_id);
+ header->id = htons(forward->frec_src.orig_id);
free_frec(forward); /* cancel */
}
@@ -774,8 +819,9 @@ void reply_query(int fd, int family, time_t now)
/* log_query gets called indirectly all over the place, so
pass these in global variables - sorry. */
- daemon->log_display_id = forward->log_id;
- daemon->log_source_addr = &forward->source;
+ daemon->log_display_id = forward->frec_src.log_id;
+ daemon->log_source_addr = &forward->frec_src.source;
+
if (daemon->ignore_addr && RCODE(header) == NOERROR &&
check_for_ignored_address(header, n, daemon->ignore_addr))
@@ -978,6 +1024,7 @@ void reply_query(int fd, int family, time_t now)
#ifdef HAVE_IPV6
new->rfd6 = NULL;
#endif
+ new->frec_src.next = NULL;
new->flags &= ~(FREC_DNSKEY_QUERY | FREC_DS_QUERY);
new->dependent = forward; /* to find query awaiting new one. */
@@ -1099,9 +1146,11 @@ void reply_query(int fd, int family, time_t now)
if ((nn = process_reply(header, now, forward->sentto, (size_t)n, check_rebind, no_cache_dnssec, cache_secure, bogusanswer,
forward->flags & FREC_AD_QUESTION, forward->flags & FREC_DO_QUESTION,
- forward->flags & FREC_ADDED_PHEADER, forward->flags & FREC_HAS_SUBNET, &forward->source)))
+ forward->flags & FREC_ADDED_PHEADER, forward->flags & FREC_HAS_SUBNET, &forward->frec_src.source)))
{
- header->id = htons(forward->orig_id);
+ struct frec_src *src;
+
+ header->id = htons(forward->frec_src.orig_id);
header->hb4 |= HB4_RA; /* recursion if available */
#ifdef HAVE_DNSSEC
/* We added an EDNSO header for the purpose of getting DNSSEC RRs, and set the value of the UDP payload size
@@ -1116,9 +1165,22 @@ void reply_query(int fd, int family, time_t now)
nn = resize_packet(header, nn, NULL, 0);
}
#endif
- send_from(forward->fd, option_bool(OPT_NOWILD) || option_bool (OPT_CLEVERBIND), daemon->packet, nn,
- &forward->source, &forward->dest, forward->iface);
+ for (src = &forward->frec_src; src; src = src->next)
+ {
+ header->id = htons(src->orig_id);
+
+ send_from(forward->fd, option_bool(OPT_NOWILD) || option_bool (OPT_CLEVERBIND), daemon->packet, nn,
+ &src->source, &src->dest, src->iface);
+
+ if (option_bool(OPT_EXTRALOG) && src != &forward->frec_src)
+ {
+ daemon->log_display_id = src->log_id;
+ daemon->log_source_addr = &src->source;
+ log_query(F_UPSTREAM, "query", NULL, "duplicate");
+ }
+ }
}
+
free_frec(forward); /* cancel */
}
}
@@ -2054,6 +2116,17 @@ void free_rfd(struct randfd *rfd)
static void free_frec(struct frec *f)
{
+ struct frec_src *src, *tmp;
+
+ /* add back to freelist of not the record builtin to every frec. */
+ for (src = f->frec_src.next; src; src = tmp)
+ {
+ tmp = src->next;
+ src->next = daemon->free_frec_src;
+ daemon->free_frec_src = src;
+ }
+
+ f->frec_src.next = NULL;
free_rfd(f->rfd4);
f->rfd4 = NULL;
f->sentto = NULL;
@@ -2197,17 +2270,40 @@ static struct frec *lookup_frec_by_sender(unsigned short id,
void *hash)
{
struct frec *f;
+ struct frec_src *src;
+
+ for (f = daemon->frec_list; f; f = f->next)
+ if (f->sentto &&
+ !(f->flags & (FREC_DNSKEY_QUERY | FREC_DS_QUERY)) &&
+ memcmp(hash, f->hash, HASH_SIZE) == 0)
+ for (src = &f->frec_src; src; src = src->next)
+ if (src->orig_id == id &&
+ sockaddr_isequal(&src->source, addr))
+ return f;
+ return NULL;
+}
+
+static struct frec *lookup_frec_by_query(void *hash, unsigned int flags)
+{
+ struct frec *f;
+
+ /* FREC_DNSKEY and FREC_DS_QUERY are never set in flags, so the test below
+ ensures that no frec created for internal DNSSEC query can be returned here. */
+
+#define FLAGMASK (FREC_CHECKING_DISABLED | FREC_AD_QUESTION | FREC_DO_QUESTION \
+ | FREC_HAS_PHEADER | FREC_DNSKEY_QUERY | FREC_DS_QUERY)
+
+
for(f = daemon->frec_list; f; f = f->next)
if (f->sentto &&
- f->orig_id == id &&
- memcmp(hash, f->hash, HASH_SIZE) == 0 &&
- sockaddr_isequal(&f->source, addr))
+ (f->flags & FLAGMASK) == flags &&
+ memcmp(hash, f->hash, HASH_SIZE) == 0)
return f;
-
+
return NULL;
}
-
+
/* Send query packet again, if we can. */
void resend_query()
{
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-29 02:20:34 +0000