[master] Added "-id" command line argument to dhcrelay v4 mode

    Merges in rt41547b.

diff --git a/RELNOTES b/RELNOTES
index 3927402d6c39b5b4d5fd367cb4df3a8f0ace81ea..d858498662579b8fe961a8b04383d842f4df558a 100644 (file)
--- a/RELNOTES
+++ b/RELNOTES
@@ -878,8 +878,10 @@ by Eric Young (eay@cryptsoft.com).
   it runs out.
   [ISC-Bugs #42452]
 
-- Add a new command line option, "-iu", to dhcrelay which allows one
-  or more interfaces to be regisetered to listen only for BOOTP replies.
+- Add DHCPv4-mode, dhcrelay command line options, "-iu" and "-id", that
+  allow interfaces to be upstream or downstream respectively.  Upstream
+  interfaces will accept and forward only BOOTP replies, while downstream
+  interfaces will accept and forward only BOOTP requests.
   [ISC-Bugs #41547]
 
                        Changes since 4.2.0 (new features)

diff --git a/relay/dhcrelay.8 b/relay/dhcrelay.8
index 1091edb7ea4d7e82866b347145becf622cd5602c..517b91a7bc57c18e9e77c33d29667edfb00b01f0 100644 (file)
--- a/relay/dhcrelay.8
+++ b/relay/dhcrelay.8
@@ -77,6 +77,7 @@ dhcrelay - Dynamic Host Configuration Protocol Relay Agent
 .B -i
 .I interfaceN 
 ]
+]
 [
 .B -iu
 .I interface0
@@ -85,9 +86,17 @@ dhcrelay - Dynamic Host Configuration Protocol Relay Agent
 .B -iu
 .I interfaceN
 ]
-.B -l
-.I interface
 ]
+[
+.B -id
+.I interface0
+[
+.B ...
+.B -id
+.I interfaceN
+]
+]
+[
 .B -U
 .I interface
 ]
@@ -219,11 +228,16 @@ all network interfaces, eliminating non-broadcast interfaces if possible,
 and attempt to listen on all of them.
 .TP
 -iu \fIifname\fR
-Specifies an upstream network interface for DHCPv4 relay mode: an
-interface from which replies from servers and other relay agents will be
-accepted.  Multiple interfaces may be specified by using more
-than one \fB-u\fR option.  This argument is intended to be used
-in conjunction with one or more -i arguments.
+Specifies an upstream network interface: an interface from which replies
+from servers and other relay agents will be accepted.  Multiple interfaces
+may be specified by using more than one \fB-iu\fR option.  This argument is
+ intended to be used in conjunction with one or more -i or -id arguments.
+.TP
+-id \fIifname\fR
+Specifies a downstream network interface: an interface from which requests
+from clients and other relay agents will be accepted.  Multiple interfaces
+may be specified by using more than one \fB-id\fR option.  This argument is
+intended to be used in conjunction with one or more -i or -iu arguments.
 .TP
 -m \fIappend\fR|\fIreplace\fR|\fIforward\fR|\fIdiscard\fR
 Control the handling of incoming DHCPv4 packets which already contain

diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c
index 4127fccc20a45fe2b0a79e89c5d20df804afea4c..344cee78474eb3549ae34742c4412898b9f1ba99 100644 (file)
--- a/relay/dhcrelay.c
+++ b/relay/dhcrelay.c
@@ -136,6 +136,8 @@ static int strip_relay_agent_options(struct interface_info *,
                                     struct interface_info **,
                                     struct dhcp_packet *, unsigned);
 
+static void request_v4_interface(const char* name, int flags);
+
 static const char copyright[] =
 "Copyright 2004-2016 Internet Systems Consortium.";
 static const char arr[] = "All rights reserved.";
@@ -154,6 +156,7 @@ char *progname;
 "                     [-m append|replace|forward|discard]\n" \
 "                     [-i interface0 [ ... -i interfaceN]\n" \
 "                     [-iu interface0 [ ... -iu interfaceN]\n" \
+"                     [-id interface0 [ ... -id interfaceN]\n" \
 "                     [-U interface]\n" \
 "                     server0 [ ... serverN]\n\n" \
 "       %s -6   [-d] [-q] [-I] [-c <hops>] [-p <port>]\n" \
@@ -170,6 +173,7 @@ char *progname;
 "                [-m append|replace|forward|discard]\n" \
 "                [-i interface0 [ ... -i interfaceN]\n" \
 "                [-iu interface0 [ ... -iu interfaceN]\n" \
+"                [-id interface0 [ ... -id interfaceN]\n" \
 "                [-U interface]\n" \
 "                server0 [ ... serverN]\n\n"
 #endif
@@ -217,7 +221,6 @@ main(int argc, char **argv) {
        isc_result_t status;
        struct servent *ent;
        struct server_list *sp = NULL;
-       struct interface_info *tmp = NULL;
        char *service_local = NULL, *service_remote = NULL;
        u_int16_t port_local = 0, port_remote = 0;
        int no_daemon = 0, quiet = 0;
@@ -315,21 +318,8 @@ main(int argc, char **argv) {
                        if (++i == argc) {
                                usage(use_noarg, argv[i-1]);
                        }
-                       if (strlen(argv[i]) >= sizeof(tmp->name)) {
-                               log_fatal("%s: interface name too long "
-                                         "(is %ld)",
-                                         argv[i], (long)strlen(argv[i]));
-                       }
-                       status = interface_allocate(&tmp, MDL);
-                       if (status != ISC_R_SUCCESS) {
-                               log_fatal("%s: interface_allocate: %s",
-                                         argv[i],
-                                         isc_result_totext(status));
-                       }
-                       strcpy(tmp->name, argv[i]);
-                       interface_snorf(tmp, (INTERFACE_REQUESTED |
-                                            INTERFACE_STREAMS));
-                       interface_dereference(&tmp, MDL);
+
+                       request_v4_interface(argv[i], INTERFACE_STREAMS);
                } else if (!strcmp(argv[i], "-iu")) {
 #ifdef DHCPv6
                        if (local_family_set && (local_family == AF_INET6)) {
@@ -341,21 +331,21 @@ main(int argc, char **argv) {
                        if (++i == argc) {
                                usage(use_noarg, argv[i-1]);
                        }
-                       if (strlen(argv[i]) >= sizeof(tmp->name)) {
-                               log_fatal("%s: interface name too long "
-                                         "(is %ld)",
-                                         argv[i], (long)strlen(argv[i]));
+
+                       request_v4_interface(argv[i], INTERFACE_UPSTREAM);
+               } else if (!strcmp(argv[i], "-id")) {
+#ifdef DHCPv6
+                       if (local_family_set && (local_family == AF_INET6)) {
+                               usage(use_v4command, argv[i]);
                        }
-                       status = interface_allocate(&tmp, MDL);
-                       if (status != ISC_R_SUCCESS) {
-                               log_fatal("%s: interface_allocate: %s",
-                                         argv[i],
-                                         isc_result_totext(status));
+                       local_family_set = 1;
+                       local_family = AF_INET;
+#endif
+                       if (++i == argc) {
+                               usage(use_noarg, argv[i-1]);
                        }
-                       strcpy(tmp->name, argv[i]);
-                       interface_snorf(tmp, (INTERFACE_REQUESTED |
-                                            INTERFACE_UPSTREAM));
-                       interface_dereference(&tmp, MDL);
+
+                       request_v4_interface(argv[i], INTERFACE_DOWNSTREAM);
                } else if (!strcmp(argv[i], "-a")) {
 #ifdef DHCPv6
                        if (local_family_set && (local_family == AF_INET6)) {
@@ -822,6 +812,11 @@ do_relay4(struct interface_info *ip, struct dhcp_packet *packet,
        if (out)
                return;
 
+       if (!(ip->flags & INTERFACE_DOWNSTREAM)) {
+               log_debug("Dropping request received on %s", ip->name);
+               return;
+       }
+
        /* Add relay agent options if indicated.   If something goes wrong,
         * drop the packet.  Note this may set packet->giaddr if RFC3527
         * is enabled. */
@@ -1878,3 +1873,40 @@ dhcp_set_control_state(control_object_state_t oldstate,
 
        exit(0);
 }
+
+/*!
+ *
+ * \brief Allocate an interface as requested with a given set of flags
+ *
+ * The requested interface is allocated, its flags field is set to
+ * INTERFACE_REQUESTED OR'd with the given flags,  and then added to
+ * the list of interfaces.
+ *
+ * \param name - name of the requested interface
+ * \param flags - additional flags for the interface
+ *
+ * \return Nothing
+ */
+void request_v4_interface(const char* name, int flags) {
+        struct interface_info *tmp = NULL;
+        int len = strlen(name);
+        isc_result_t status;
+
+        if (len >= sizeof(tmp->name)) {
+                log_fatal("%s: interface name too long (is %d)", name, len);
+        }
+
+        status = interface_allocate(&tmp, MDL);
+        if (status != ISC_R_SUCCESS) {
+                log_fatal("%s: interface_allocate: %s", name,
+                          isc_result_totext(status));
+        }
+
+       log_debug("Requesting: %s as upstream: %c downstream: %c", name,
+                 (flags & INTERFACE_UPSTREAM ? 'Y' : 'N'),
+                 (flags & INTERFACE_DOWNSTREAM ? 'Y' : 'N'));
+
+        strncpy(tmp->name, name, len);
+        interface_snorf(tmp, (INTERFACE_REQUESTED | flags));
+        interface_dereference(&tmp, MDL);
+}