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dnsmasq: replace patches with upstream
This commit is contained in:
AmadeusGhost
AmadeusGhost
parent
73baf54567
commit
0d04d79c71
@ -21,6 +21,7 @@ config dnsmasq
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#list bogusnxdomain '64.94.110.11'
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option localservice 1 # disable to allow DNS requests from non-local subnets
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option filter_aaaa 1
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option filter_a 0
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option cachesize 8000
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option mini_ttl 3600
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option ednspacket_max 1232
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@ -930,9 +930,8 @@ dnsmasq_start()
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append_bool "$cfg" rapidcommit "--dhcp-rapid-commit"
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append_bool "$cfg" scriptarp "--script-arp"
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append_bool "$cfg" filter_aaaa "--filter-aaaa"
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append_bool "$cfg" filter_https "--filter-https"
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append_bool "$cfg" filter_unknown "--filter-unknown"
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append_bool "$cfg" filter_aaaa "--filter-AAAA"
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append_bool "$cfg" filter_a "--filter-A"
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append_parm "$cfg" logfacility "--log-facility"
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@ -0,0 +1,204 @@
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From 37a70d39e0cd49f086b757937fa8735e6263cd7a Mon Sep 17 00:00:00 2001
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From: Simon Kelley <simon@thekelleys.org.uk>
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Date: Thu, 7 Oct 2021 23:12:59 +0100
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Subject: [PATCH] Add --filter and --filter-AAAA options.
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---
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CHANGELOG | 5 ++++-
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man/dnsmasq.8 | 6 ++++++
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src/dnsmasq.h | 10 ++++++++--
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src/edns0.c | 2 +-
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src/forward.c | 18 ++++++++++++++----
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src/option.c | 8 +++++++-
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src/rrfilter.c | 37 +++++++++++++++++++++++++++----------
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7 files changed, 67 insertions(+), 19 deletions(-)
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--- a/man/dnsmasq.8
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+++ b/man/dnsmasq.8
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@@ -348,6 +348,12 @@ the public DNS and can cause problems by triggering dial-on-demand links. This f
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to filter such requests. The requests blocked are for records of types SOA and SRV, and type ANY where the
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requested name has underscores, to catch LDAP requests.
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.TP
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+.B --filter-A
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+Remove A records from answers. No IPv4 addresses will be returned.
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+.TP
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+.B --filter-AAAA
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+Remove AAAA records from answers. No IPv6 addresses will be returned.
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+.TP
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.B \-r, --resolv-file=<file>
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Read the IP addresses of the upstream nameservers from <file>, instead of
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/etc/resolv.conf. For the format of this file see
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--- a/src/dnsmasq.h
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+++ b/src/dnsmasq.h
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@@ -275,7 +275,9 @@ struct event_desc {
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#define OPT_UMBRELLA_DEVID 64
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#define OPT_CMARK_ALST_EN 65
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#define OPT_QUIET_TFTP 66
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-#define OPT_LAST 67
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+#define OPT_FILTER_A 67
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+#define OPT_FILTER_AAAA 68
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+#define OPT_LAST 69
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#define OPTION_BITS (sizeof(unsigned int)*8)
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#define OPTION_SIZE ( (OPT_LAST/OPTION_BITS)+((OPT_LAST%OPTION_BITS)!=0) )
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@@ -1735,7 +1737,11 @@ int do_poll(int timeout);
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size_t rrfilter(struct dns_header *header, size_t plen, int mode);
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u16 *rrfilter_desc(int type);
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int expand_workspace(unsigned char ***wkspc, int *szp, int new);
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-
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+/* modes. */
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+#define RRFILTER_EDNS0 0
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+#define RRFILTER_DNSSEC 1
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+#define RRFILTER_A 2
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+#define RRFILTER_AAAA 3
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/* edns0.c */
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unsigned char *find_pseudoheader(struct dns_header *header, size_t plen,
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size_t *len, unsigned char **p, int *is_sign, int *is_last);
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--- a/src/edns0.c
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+++ b/src/edns0.c
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@@ -178,7 +178,7 @@ size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *l
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memcpy(buff, datap, rdlen);
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/* now, delete OPT RR */
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- plen = rrfilter(header, plen, 0);
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+ plen = rrfilter(header, plen, RRFILTER_EDNS0);
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/* Now, force addition of a new one */
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p = NULL;
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--- a/src/forward.c
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+++ b/src/forward.c
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@@ -607,7 +607,7 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
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if (added_pheader)
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{
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/* client didn't send EDNS0, we added one, strip it off before returning answer. */
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- n = rrfilter(header, n, 0);
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+ n = rrfilter(header, n, RRFILTER_EDNS0);
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pheader = NULL;
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}
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else
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@@ -696,7 +696,17 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
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cache_secure = 0;
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}
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}
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-
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+
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+ /* Before extract_addresses() */
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+ if (rcode == NOERROR)
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+ {
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+ if (option_bool(OPT_FILTER_A))
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+ n = rrfilter(header, n, RRFILTER_A);
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+
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+ if (option_bool(OPT_FILTER_AAAA))
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+ n = rrfilter(header, n, RRFILTER_AAAA);
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+ }
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+
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if (extract_addresses(header, n, daemon->namebuff, now, sets, is_sign, check_rebind, no_cache, cache_secure, &doctored))
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{
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my_syslog(LOG_WARNING, _("possible DNS-rebind attack detected: %s"), daemon->namebuff);
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@@ -726,7 +736,7 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
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/* If the requestor didn't set the DO bit, don't return DNSSEC info. */
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if (!do_bit)
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- n = rrfilter(header, n, 1);
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+ n = rrfilter(header, n, RRFILTER_DNSSEC);
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}
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#endif
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@@ -750,7 +760,7 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
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u16 swap = htons((u16)ede);
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n = add_pseudoheader(header, n, limit, daemon->edns_pktsz, EDNS0_OPTION_EDE, (unsigned char *)&swap, 2, do_bit, 1);
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}
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-
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+
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return n;
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}
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--- a/src/option.c
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+++ b/src/option.c
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@@ -174,7 +174,9 @@ struct myoption {
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#define LOPT_CMARK_ALST_EN 365
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#define LOPT_CMARK_ALST 366
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#define LOPT_QUIET_TFTP 367
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-
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+#define LOPT_FILTER_A 369
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+#define LOPT_FILTER_AAAA 370
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+
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#ifdef HAVE_GETOPT_LONG
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static const struct option opts[] =
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#else
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@@ -211,6 +213,8 @@ static const struct myoption opts[] =
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{ "ignore-address", 1, 0, LOPT_IGNORE_ADDR },
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{ "selfmx", 0, 0, 'e' },
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{ "filterwin2k", 0, 0, 'f' },
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+ { "filter-A", 0, 0, LOPT_FILTER_A },
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+ { "filter-AAAA", 0, 0, LOPT_FILTER_AAAA },
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{ "pid-file", 2, 0, 'x' },
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{ "strict-order", 0, 0, 'o' },
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{ "server", 1, 0, 'S' },
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@@ -380,6 +384,8 @@ static struct {
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{ 'e', OPT_SELFMX, NULL, gettext_noop("Return self-pointing MX records for local hosts."), NULL },
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{ 'E', OPT_EXPAND, NULL, gettext_noop("Expand simple names in /etc/hosts with domain-suffix."), NULL },
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{ 'f', OPT_FILTER, NULL, gettext_noop("Don't forward spurious DNS requests from Windows hosts."), NULL },
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+ { LOPT_FILTER_A, OPT_FILTER_A, NULL, gettext_noop("Don't include IPv4 addresses in DNS answers."), NULL },
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+ { LOPT_FILTER_AAAA, OPT_FILTER_AAAA, NULL, gettext_noop("Don't include IPv6 addresses in DNS answers."), NULL },
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{ 'F', ARG_DUP, "<ipaddr>,...", gettext_noop("Enable DHCP in the range given with lease duration."), NULL },
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{ 'g', ARG_ONE, "<groupname>", gettext_noop("Change to this group after startup (defaults to %s)."), CHGRP },
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{ 'G', ARG_DUP, "<hostspec>", gettext_noop("Set address or hostname for a specified machine."), NULL },
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--- a/src/rrfilter.c
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+++ b/src/rrfilter.c
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@@ -156,7 +156,7 @@ static int check_rrs(unsigned char *p, struct dns_header *header, size_t plen, i
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}
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-/* mode is 0 to remove EDNS0, 1 to filter DNSSEC RRs */
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+/* mode may be remove EDNS0 or DNSSEC RRs or remove A or AAAA from answer section. */
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size_t rrfilter(struct dns_header *header, size_t plen, int mode)
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{
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static unsigned char **rrs;
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@@ -192,20 +192,37 @@ size_t rrfilter(struct dns_header *header, size_t plen, int mode)
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if (!ADD_RDLEN(header, p, plen, rdlen))
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return plen;
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- /* Don't remove the answer. */
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- if (i < ntohs(header->ancount) && type == qtype && class == qclass)
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- continue;
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-
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- if (mode == 0) /* EDNS */
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+ if (mode == RRFILTER_EDNS0) /* EDNS */
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{
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/* EDNS mode, remove T_OPT from additional section only */
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if (i < (ntohs(header->nscount) + ntohs(header->ancount)) || type != T_OPT)
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continue;
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}
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- else if (type != T_NSEC && type != T_NSEC3 && type != T_RRSIG)
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- /* DNSSEC mode, remove SIGs and NSECs from all three sections. */
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- continue;
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-
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+ else if (mode == RRFILTER_DNSSEC)
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+ {
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+ if (type != T_NSEC && type != T_NSEC3 && type != T_RRSIG)
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+ /* DNSSEC mode, remove SIGs and NSECs from all three sections. */
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+ continue;
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+
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+ /* Don't remove the answer. */
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+ if (i < ntohs(header->ancount) && type == qtype && class == qclass)
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+ continue;
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+ }
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+ else
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+ {
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+ /* Only looking at answer section now. */
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+ if (i >= ntohs(header->ancount))
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+ break;
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+
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+ if (class != C_IN)
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+ continue;
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+
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+ if (mode == RRFILTER_A && type != T_A)
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+ continue;
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+
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+ if (mode == RRFILTER_AAAA && type != T_AAAA)
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+ continue;
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+ }
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if (!expand_workspace(&rrs, &rr_sz, rr_found + 1))
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return plen;
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@ -1,6 +1,6 @@
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--- a/src/dnsmasq.h
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+++ b/src/dnsmasq.h
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@@ -1116,7 +1116,7 @@ extern struct daemon {
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@@ -1118,7 +1118,7 @@ extern struct daemon {
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int max_logs; /* queue limit */
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int cachesize, ftabsize;
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int port, query_port, min_port, max_port;
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@ -16,10 +16,10 @@
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#define LOPT_CMARK_ALST 366
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#define LOPT_QUIET_TFTP 367
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+#define LOPT_MINTTL 368
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#define LOPT_FILTER_A 369
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#define LOPT_FILTER_AAAA 370
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#ifdef HAVE_GETOPT_LONG
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static const struct option opts[] =
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@@ -292,6 +293,7 @@ static const struct myoption opts[] =
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@@ -296,6 +297,7 @@ static const struct myoption opts[] =
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{ "dhcp-name-match", 1, 0, LOPT_NAME_MATCH },
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{ "dhcp-broadcast", 2, 0, LOPT_BROADCAST },
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{ "neg-ttl", 1, 0, LOPT_NEGTTL },
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@ -27,7 +27,7 @@
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{ "max-ttl", 1, 0, LOPT_MAXTTL },
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{ "min-cache-ttl", 1, 0, LOPT_MINCTTL },
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{ "max-cache-ttl", 1, 0, LOPT_MAXCTTL },
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@@ -425,6 +427,7 @@ static struct {
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@@ -431,6 +433,7 @@ static struct {
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{ 't', ARG_ONE, "<host_name>", gettext_noop("Specify default target in an MX record."), NULL },
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{ 'T', ARG_ONE, "<integer>", gettext_noop("Specify time-to-live in seconds for replies from /etc/hosts."), NULL },
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{ LOPT_NEGTTL, ARG_ONE, "<integer>", gettext_noop("Specify time-to-live in seconds for negative caching."), NULL },
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@ -35,7 +35,7 @@
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{ LOPT_MAXTTL, ARG_ONE, "<integer>", gettext_noop("Specify time-to-live in seconds for maximum TTL to send to clients."), NULL },
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{ LOPT_MAXCTTL, ARG_ONE, "<integer>", gettext_noop("Specify time-to-live ceiling for cache."), NULL },
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{ LOPT_MINCTTL, ARG_ONE, "<integer>", gettext_noop("Specify time-to-live floor for cache."), NULL },
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@@ -3047,6 +3050,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
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@@ -3053,6 +3056,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
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case 'T': /* --local-ttl */
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case LOPT_NEGTTL: /* --neg-ttl */
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@ -43,7 +43,7 @@
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case LOPT_MAXTTL: /* --max-ttl */
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case LOPT_MINCTTL: /* --min-cache-ttl */
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case LOPT_MAXCTTL: /* --max-cache-ttl */
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@@ -3058,6 +3062,8 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
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@@ -3064,6 +3068,8 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
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ret_err(gen_err);
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else if (option == LOPT_NEGTTL)
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daemon->neg_ttl = (unsigned long)ttl;
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@ -1,143 +0,0 @@
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diff --git a/src/cache.c b/src/cache.c
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index 8add610..c94132e 100644
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--- a/src/cache.c
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+++ b/src/cache.c
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@@ -66,6 +66,7 @@ static const struct {
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{ 52, "TLSA" },
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{ 53, "SMIMEA" },
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{ 55, "HIP" },
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+ { 65, "HTTPS"},
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{ 249, "TKEY" },
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{ 250, "TSIG" },
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{ 251, "IXFR" },
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@@ -1805,6 +1806,20 @@ char *record_source(unsigned int index)
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return "<unknown>";
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}
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+// patch: function returns integer 1 if query type is unknown.
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+// known types are defined in cache.c:typestr:36.
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+int is_query_type_unknown(unsigned short type)
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+{
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+ unsigned int i;
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+ for (i = 0; i < (sizeof(typestr)/sizeof(typestr[0])); i++)
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+ if (typestr[i].type == type)
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+ {
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+ return 0;
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+ }
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+ return 1;
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+}
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+// end of patch
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+
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char *querystr(char *desc, unsigned short type)
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{
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unsigned int i;
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diff --git a/src/dns-protocol.h b/src/dns-protocol.h
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index 496a4bb..ed0d64a 100644
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--- a/src/dns-protocol.h
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+++ b/src/dns-protocol.h
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@@ -71,6 +71,7 @@
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#define T_NSEC 47
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#define T_DNSKEY 48
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#define T_NSEC3 50
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+#define T_HTTPS 65
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#define T_TKEY 249
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#define T_TSIG 250
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#define T_AXFR 252
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diff --git a/src/dnsmasq.h b/src/dnsmasq.h
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index 8674823..d067741 100644
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--- a/src/dnsmasq.h
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+++ b/src/dnsmasq.h
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@@ -275,7 +275,10 @@ struct event_desc {
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#define OPT_UMBRELLA_DEVID 64
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#define OPT_CMARK_ALST_EN 65
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#define OPT_QUIET_TFTP 66
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-#define OPT_LAST 67
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+#define OPT_FILTER_AAAA 67
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+#define OPT_FILTER_HTTPS 68
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+#define OPT_FILTER_UNKNOWN 69
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+#define OPT_LAST 70
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#define OPTION_BITS (sizeof(unsigned int)*8)
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#define OPTION_SIZE ( (OPT_LAST/OPTION_BITS)+((OPT_LAST%OPTION_BITS)!=0) )
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@@ -1247,6 +1250,10 @@ void cache_init(void);
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void next_uid(struct crec *crecp);
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void log_query(unsigned int flags, char *name, union all_addr *addr, char *arg);
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char *record_source(unsigned int index);
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+// patch: function returns integer 1 if query type is unknown
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+// known types are defined in cache.c:typestr:36.
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+int is_query_type_unknown(unsigned short type);
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+// end of patch
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char *querystr(char *desc, unsigned short type);
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int cache_find_non_terminal(char *name, time_t now);
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struct crec *cache_find_by_addr(struct crec *crecp,
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diff --git a/src/option.c b/src/option.c
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index ffce9fc..3993c10 100644
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--- a/src/option.c
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+++ b/src/option.c
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@@ -174,6 +174,9 @@ struct myoption {
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#define LOPT_CMARK_ALST 366
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#define LOPT_QUIET_TFTP 367
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#define LOPT_MINTTL 368
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+#define LOPT_FILTER_AAAA 369
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+#define LOPT_FILTER_HTTPS 370
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+#define LOPT_FILTER_UNKNOWN 371
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#ifdef HAVE_GETOPT_LONG
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static const struct option opts[] =
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@@ -353,6 +356,9 @@ static const struct myoption opts[] =
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{ "log-debug", 0, 0, LOPT_LOG_DEBUG },
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{ "umbrella", 2, 0, LOPT_UMBRELLA },
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{ "quiet-tftp", 0, 0, LOPT_QUIET_TFTP },
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+ { "filter-aaaa", 0, 0, LOPT_FILTER_AAAA },
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+ { "filter-https", 0, 0, LOPT_FILTER_HTTPS },
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+ { "filter-unknown", 0, 0, LOPT_FILTER_UNKNOWN },
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{ NULL, 0, 0, 0 }
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};
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@@ -539,6 +545,9 @@ static struct {
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{ LOPT_SCRIPT_TIME, OPT_LEASE_RENEW, NULL, gettext_noop("Call dhcp-script when lease expiry changes."), NULL },
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{ LOPT_UMBRELLA, ARG_ONE, "[=<optspec>]", gettext_noop("Send Cisco Umbrella identifiers including remote IP."), NULL },
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{ LOPT_QUIET_TFTP, OPT_QUIET_TFTP, NULL, gettext_noop("Do not log routine TFTP."), NULL },
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+ { LOPT_FILTER_AAAA, OPT_FILTER_AAAA, NULL, gettext_noop("Filter all AAAA requests."), NULL },
|
||||
+ { LOPT_FILTER_HTTPS, OPT_FILTER_HTTPS, NULL, gettext_noop("Filter all HTTPS/query type 65 requests."), NULL },
|
||||
+ { LOPT_FILTER_UNKNOWN, OPT_FILTER_UNKNOWN, NULL, gettext_noop("Filter all unknown query types (known are defined in cache.c)."), NULL },
|
||||
{ 0, 0, NULL, NULL, NULL }
|
||||
};
|
||||
|
||||
diff --git a/src/rfc1035.c b/src/rfc1035.c
|
||||
index 6fc4f26..395634b 100644
|
||||
--- a/src/rfc1035.c
|
||||
+++ b/src/rfc1035.c
|
||||
@@ -1987,6 +1987,32 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
|
||||
}
|
||||
}
|
||||
|
||||
+ //patch to filter aaaa forwards
|
||||
+ if (qtype == T_AAAA && option_bool(OPT_FILTER_AAAA) ){
|
||||
+ //return a null reply
|
||||
+ ans = 1;
|
||||
+ if (!dryrun) log_query(F_CONFIG | F_IPV6 | F_NEG, name, &addr, NULL);
|
||||
+ break;
|
||||
+ }
|
||||
+ //end of patch
|
||||
+ //patch to filter https/query type 65 forwards
|
||||
+ if (qtype == T_HTTPS && option_bool(OPT_FILTER_HTTPS) ){
|
||||
+ //return a null reply
|
||||
+ ans = 1;
|
||||
+ if (!dryrun) log_query(F_CONFIG | F_IPV4 | F_NEG, name, &addr, NULL);
|
||||
+ break;
|
||||
+ }
|
||||
+ //end of patch
|
||||
+ //patch to filter all unknown query types
|
||||
+ //known types are defined in cache.c:typestr:36.
|
||||
+ if (is_query_type_unknown(qtype) && option_bool(OPT_FILTER_UNKNOWN)) {
|
||||
+ //return a null reply
|
||||
+ ans = 1;
|
||||
+ if (!dryrun) log_query(F_CONFIG | F_NEG, name, NULL, NULL);
|
||||
+ break;
|
||||
+ }
|
||||
+ //end of patch
|
||||
+
|
||||
if (!ans)
|
||||
return 0; /* failed to answer a question */
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user