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Don't listen on random port (#962950)

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This commit is contained in:
Pavel Zhukov 2017-05-25 13:56:21 +02:00
parent 4b70ef00e1
commit 53d20015af
2 changed files with 146 additions and 1 deletions
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136
dhcp-dhclient-ddns_lazy.patch Normal file
View File

@ -0,0 +1,136 @@
diff --git a/common/dns.c b/common/dns.c
index 0f8be80..37878bc 100644
--- a/common/dns.c
+++ b/common/dns.c
@@ -2132,6 +2132,41 @@ void ddns_interlude(isc_task_t *taskp,
}
/*
+ * Moved here from omapip/isclib.c, function dhcp_context_create.
+ * Create dnsclient only before the first use.
+ */
+static isc_result_t
+dns_client_lazy() {
+ isc_result_t result;
+ if (dhcp_gbl_ctx.dnsclient == NULL){
+ result = dns_client_createx2(dhcp_gbl_ctx.mctx,
+ dhcp_gbl_ctx.actx,
+ dhcp_gbl_ctx.taskmgr,
+ dhcp_gbl_ctx.socketmgr,
+ dhcp_gbl_ctx.timermgr,
+ 0,
+ &dhcp_gbl_ctx.dnsclient,
+ dhcp_gbl_ctx.local4_ptr,
+ dhcp_gbl_ctx.local6_ptr);
+ if (result != ISC_R_SUCCESS)
+ return result;
+ /*
+ * If we can't set up the servers we may not be able to
+ * do DDNS but we should continue to try and perform
+ * our basic functions and let the user sort it out.
+ */
+ result = dhcp_dns_client_setservers();
+ if (result != ISC_R_SUCCESS) {
+ log_error("Unable to set resolver from resolv.conf; "
+ "startup continuing but DDNS support "
+ "may be affected");
+ }
+ };
+ return ISC_R_SUCCESS;
+}
+
+
+/*
* This routine does the generic work for sending a ddns message to
* modify the forward record (A or AAAA) and calls one of a set of
* routines to build the specific message.
@@ -2154,6 +2189,10 @@ ddns_modify_fwd(dhcp_ddns_cb_t *ddns_cb, const char *file, int line)
/* Get a pointer to the clientname to make things easier. */
clientname = (unsigned char *)ddns_cb->fwd_name.data;
+ result = dns_client_lazy();
+ if (result != ISC_R_SUCCESS)
+ return result;
+
/* Extract and validate the type of the address. */
if (ddns_cb->address.len == 4) {
ddns_cb->address_type = dns_rdatatype_a;
@@ -2359,6 +2398,10 @@ ddns_modify_ptr(dhcp_ddns_cb_t *ddns_cb, const char *file, int line)
unsigned char buf[256];
int buflen;
+ result = dns_client_lazy();
+ if (result != ISC_R_SUCCESS)
+ return result;
+
/*
* Try to lookup the zone in the zone cache. As with the forward
* case it's okay if we don't have one, the DNS code will try to
diff --git a/includes/omapip/isclib.h b/includes/omapip/isclib.h
index caa388a..7f2719b 100644
--- a/includes/omapip/isclib.h
+++ b/includes/omapip/isclib.h
@@ -98,6 +98,8 @@ typedef struct dhcp_context {
isc_timermgr_t *timermgr;
#if defined (NSUPDATE)
dns_client_t *dnsclient;
+ isc_sockaddr_t *local4_ptr;
+ isc_sockaddr_t *local6_ptr;
#endif
} dhcp_context_t;
diff --git a/omapip/isclib.c b/omapip/isclib.c
index 13f0d3e..36b399d 100644
--- a/omapip/isclib.c
+++ b/omapip/isclib.c
@@ -220,40 +220,22 @@ dhcp_context_create(int flags,
}
#if defined (NSUPDATE)
+ /*
+ * Setting addresses only.
+ * All real work will be done later on if needed to avoid listening
+ * on ddns port if client/server was compiled with ddns support
+ * but not using it.
+ */
if ((flags & DHCP_CONTEXT_POST_DB) != 0) {
- isc_sockaddr_t localaddr4, *localaddr4_ptr = NULL;
- isc_sockaddr_t localaddr6, *localaddr6_ptr = NULL;
+ isc_sockaddr_t localaddr4;
+ isc_sockaddr_t localaddr6;
if (local4 != NULL) {
isc_sockaddr_fromin(&localaddr4, local4, 0);
- localaddr4_ptr = &localaddr4;
+ dhcp_gbl_ctx.local4_ptr = &localaddr4;
}
if (local6 != NULL) {
isc_sockaddr_fromin6(&localaddr6, local6, 0);
- localaddr6_ptr = &localaddr6;
- }
-
- result = dns_client_createx2(dhcp_gbl_ctx.mctx,
- dhcp_gbl_ctx.actx,
- dhcp_gbl_ctx.taskmgr,
- dhcp_gbl_ctx.socketmgr,
- dhcp_gbl_ctx.timermgr,
- 0,
- &dhcp_gbl_ctx.dnsclient,
- localaddr4_ptr,
- localaddr6_ptr);
- if (result != ISC_R_SUCCESS)
- goto cleanup;
-
- /*
- * If we can't set up the servers we may not be able to
- * do DDNS but we should continue to try and perform
- * our basic functions and let the user sort it out.
- */
- result = dhcp_dns_client_setservers();
- if (result != ISC_R_SUCCESS) {
- log_error("Unable to set resolver from resolv.conf; "
- "startup continuing but DDNS support "
- "may be affected");
+ dhcp_gbl_ctx.local6_ptr = &localaddr6;
}
}
#endif

11
dhcp.spec
View File

@ -19,7 +19,7 @@
Summary: Dynamic host configuration protocol software
Name: dhcp
Version: 4.3.5
Release: 5%{?dist}
Release: 7%{?dist}
# NEVER CHANGE THE EPOCH on this package. The previous maintainer (prior to
# dcantrell maintaining the package) made incorrect use of the epoch and
# that's why it is at 12 now. It should have never been used, but it was.
@ -77,6 +77,9 @@ Patch34: dhcp-sd_notify.patch
Patch36: dhcp-option97-pxe-client-id.patch
Patch37: dhcp-stateless-DUID-LLT.patch
Patch38: dhcp-dhclient-preinit6s.patch
Patch39: dhcp-dhclient-ddns_lazy.patch
BuildRequires: autoconf
BuildRequires: automake
@ -343,6 +346,9 @@ rm bind/bind.tar.gz
# dhclient: make sure link-local address is ready in stateless mode (#1263466)
%patch38 -p1 -b .preinit6s
# [ISC-BUGS] #33377.
%patch39 -p1 -b .ddnsport
# DHCLIENT_DEFAULT_PREFIX_LEN 64 -> 128
# https://bugzilla.gnome.org/show_bug.cgi?id=656610
sed -i -e 's|DHCLIENT_DEFAULT_PREFIX_LEN 64|DHCLIENT_DEFAULT_PREFIX_LEN 128|g' includes/site.h
@ -670,6 +676,9 @@ done
%endif
%changelog
* Tue May 23 2017 Pavel Zhukov <pzhukov@redhat.com> - 12:4.3.5-7
- Don't open ddns port until it's needed. Credits to Petr Menšík for the original idea
* Wed Apr 19 2017 Dominika Hodovska <dhodovsk@redhat.com> - 12:4.3.5-5
- don't build doxygen documentation during modular build