From 4fb306df98419d45889dff6a5b4fb0c21f237609 Mon Sep 17 00:00:00 2001

From: Numan Siddique <numans@ovn.org>

Date: Fri, 29 May 2020 23:29:37 +0530

Subject: [PATCH] pinctrl: Support DHCPRELEASE and DHCPINFORM in native OVN

 dhcp responder.

Right now we ignore these dhcp packets. This patch adds the support

as per RFC 2131.

Change-Id: I57091f18212b93e3a366a97120f2a54009fde1d4

Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

Acked-by: Mark Michelson <mmichels@redhat.com>

Signed-off-by: Numan Siddique <numans@ovn.org>

(cherry-picked from upstream ovn master commit e008a4d46020a778b8f1f85b9dfd7c9e9b6fde21)

---

 ovn/controller/pinctrl.c | 125 +++++++++++++++++++++++++++++++--------

 ovn/lib/ovn-l7.h         |  12 ++++

 tests/ovn.at             | 117 +++++++++++++++++++++++++++++++++++-

 3 files changed, 227 insertions(+), 27 deletions(-)

diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c

index 51a0f0224..b9e115a39 100644

--- a/ovn/controller/pinctrl.c

+++ b/ovn/controller/pinctrl.c

@@ -979,11 +979,13 @@ static void

 pinctrl_handle_put_dhcp_opts(

     struct rconn *swconn,

     struct dp_packet *pkt_in, struct ofputil_packet_in *pin,

-    struct ofpbuf *userdata, struct ofpbuf *continuation)

+    struct flow *in_flow, struct ofpbuf *userdata,

+    struct ofpbuf *continuation)

 {

     enum ofp_version version = rconn_get_version(swconn);

     enum ofputil_protocol proto = ofputil_protocol_from_ofp_version(version);

     struct dp_packet *pkt_out_ptr = NULL;

+    struct ofpbuf *dhcp_inform_reply_buf = NULL;

     uint32_t success = 0;

     /* Parse result field. */

@@ -1107,22 +1109,15 @@ pinctrl_handle_put_dhcp_opts(

         VLOG_WARN_RL(&rl, "Missing DHCP message type");

         goto exit;

     }

-    if (*in_dhcp_msg_type != DHCP_MSG_DISCOVER &&

-        *in_dhcp_msg_type != DHCP_MSG_REQUEST) {

-        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);

-        VLOG_WARN_RL(&rl, "Invalid DHCP message type: %d", *in_dhcp_msg_type);

-        goto exit;

-    }

-    uint8_t msg_type;

-    if (*in_dhcp_msg_type == DHCP_MSG_DISCOVER) {

+    struct ofpbuf *reply_dhcp_opts_ptr = userdata;

+    uint8_t msg_type = 0;

+

+    switch (*in_dhcp_msg_type) {

+    case DHCP_MSG_DISCOVER:

         msg_type = DHCP_MSG_OFFER;

-    } else {

-        /* This is a DHCPREQUEST. If the client has requested an IP that

-         * does not match the offered IP address, reply with a NAK. The

-         * requested IP address may be supplied either via Requested IP Address

-         * (opt 50) or via ciaddr, depending on the client's state.

-         */

+        break;

+    case DHCP_MSG_REQUEST: {

         msg_type = DHCP_MSG_ACK;

         if (request_ip != *offer_ip) {

             static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);

@@ -1131,12 +1126,81 @@ pinctrl_handle_put_dhcp_opts(

                          IP_ARGS(*offer_ip));

             msg_type = DHCP_MSG_NAK;

         }

+        break;

+    }

+    case OVN_DHCP_MSG_RELEASE: {

+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(20, 40);

+        const struct eth_header *l2 = dp_packet_eth(pkt_in);

+        VLOG_INFO_RL(&rl, "DHCPRELEASE "ETH_ADDR_FMT " "IP_FMT"",

+                     ETH_ADDR_ARGS(l2->eth_src),

+                     IP_ARGS(in_dhcp_data->ciaddr));

+        break;

+    }

+    case OVN_DHCP_MSG_INFORM: {

+        /* RFC 2131 section 3.4.

+         * Remove all the offer ip related dhcp options and

+         * all the time related dhcp options.

+         * Loop through the dhcp option defined in the userdata buffer

+         * and copy all the options into dhcp_inform_reply_buf skipping

+         * the not required ones.

+         * */

+        msg_type = DHCP_MSG_ACK;

+        in_dhcp_ptr = userdata->data;

+        end = (const char *)userdata->data + userdata->size;

+

+        /* The buf size cannot be greater > userdata->size. */

+        dhcp_inform_reply_buf = ofpbuf_new(userdata->size);

+

+        reply_dhcp_opts_ptr = dhcp_inform_reply_buf;

+        while (in_dhcp_ptr < end) {

+            const struct dhcp_opt_header *in_dhcp_opt =

+                (const struct dhcp_opt_header *)in_dhcp_ptr;

+

+            switch (in_dhcp_opt->code) {

+            case OVN_DHCP_OPT_CODE_NETMASK:

+            case OVN_DHCP_OPT_CODE_LEASE_TIME:

+            case OVN_DHCP_OPT_CODE_T1:

+            case OVN_DHCP_OPT_CODE_T2:

+                break;

+            default:

+                /* Copy the dhcp option to reply_dhcp_opts_ptr. */

+                ofpbuf_put(reply_dhcp_opts_ptr, in_dhcp_opt,

+                           in_dhcp_opt->len + sizeof *in_dhcp_opt);

+                break;

+            }

+

+            in_dhcp_ptr += sizeof *in_dhcp_opt;

+            if (in_dhcp_ptr > end) {

+                break;

+            }

+            in_dhcp_ptr += in_dhcp_opt->len;

+            if (in_dhcp_ptr > end) {

+                break;

+            }

+        }

+

+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(20, 40);

+        VLOG_INFO_RL(&rl, "DHCPINFORM from "ETH_ADDR_FMT " "IP_FMT"",

+                     ETH_ADDR_ARGS(in_flow->dl_src),

+                     IP_ARGS(in_flow->nw_src));

+

+        break;

+    }

+    default: {

+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);

+        VLOG_WARN_RL(&rl, "Invalid DHCP message type: %d", *in_dhcp_msg_type);

+        goto exit;

+    }

+    }

+

+    if (!msg_type) {

+        goto exit;

     }

     /* Frame the DHCP reply packet

-     * Total DHCP options length will be options stored in the userdata +

-     * 16 bytes. Note that the DHCP options stored in userdata are not included

-     * in DHCPNAK messages.

+     * Total DHCP options length will be options stored in the

+     * reply_dhcp_opts_ptr + 16 bytes. Note that the DHCP options stored in

+     * reply_dhcp_opts_ptr are not included in DHCPNAK messages.

      *

      * --------------------------------------------------------------

      *| 4 Bytes (dhcp cookie) | 3 Bytes (option type) | DHCP options |

@@ -1146,7 +1210,7 @@ pinctrl_handle_put_dhcp_opts(

      */

     uint16_t new_l4_size = UDP_HEADER_LEN + DHCP_HEADER_LEN + 16;

     if (msg_type != DHCP_MSG_NAK) {

-        new_l4_size += userdata->size;

+        new_l4_size += reply_dhcp_opts_ptr->size;

     }

     size_t new_packet_size = pkt_in->l4_ofs + new_l4_size;

@@ -1171,12 +1235,18 @@ pinctrl_handle_put_dhcp_opts(

     struct dhcp_header *dhcp_data = dp_packet_put(

         &pkt_out, dp_packet_pull(pkt_in, DHCP_HEADER_LEN), DHCP_HEADER_LEN);

     dhcp_data->op = DHCP_OP_REPLY;

-    dhcp_data->yiaddr = (msg_type == DHCP_MSG_NAK) ? 0 : *offer_ip;

+

+    if (*in_dhcp_msg_type != OVN_DHCP_MSG_INFORM) {

+        dhcp_data->yiaddr = (msg_type == DHCP_MSG_NAK) ? 0 : *offer_ip;

+    } else {

+        dhcp_data->yiaddr = 0;

+    }

+

     dp_packet_put(&pkt_out, &magic_cookie, sizeof(ovs_be32));

     uint16_t out_dhcp_opts_size = 12;

     if (msg_type != DHCP_MSG_NAK) {

-      out_dhcp_opts_size += userdata->size;

+      out_dhcp_opts_size += reply_dhcp_opts_ptr->size;

     }

     uint8_t *out_dhcp_opts = dp_packet_put_zeros(&pkt_out,

                                                  out_dhcp_opts_size);

@@ -1187,8 +1257,9 @@ pinctrl_handle_put_dhcp_opts(

     out_dhcp_opts += 3;

     if (msg_type != DHCP_MSG_NAK) {

-      memcpy(out_dhcp_opts, userdata->data, userdata->size);

-      out_dhcp_opts += userdata->size;

+        memcpy(out_dhcp_opts, reply_dhcp_opts_ptr->data,

+               reply_dhcp_opts_ptr->size);

+        out_dhcp_opts += reply_dhcp_opts_ptr->size;

     }

     /* Padding */

@@ -1236,6 +1307,10 @@ exit:

     if (pkt_out_ptr) {

         dp_packet_uninit(pkt_out_ptr);

     }

+

+    if (dhcp_inform_reply_buf) {

+        ofpbuf_delete(dhcp_inform_reply_buf);

+    }

 }

 static bool

@@ -1936,8 +2011,8 @@ process_packet_in(struct rconn *swconn, const struct ofp_header *msg)

         break;

     case ACTION_OPCODE_PUT_DHCP_OPTS:

-        pinctrl_handle_put_dhcp_opts(swconn, &packet, &pin, &userdata,

-                                     &continuation);

+        pinctrl_handle_put_dhcp_opts(swconn, &packet, &pin, &headers,

+                                     &userdata, &continuation);

         break;

     case ACTION_OPCODE_ND_NA:

diff --git a/ovn/lib/ovn-l7.h b/ovn/lib/ovn-l7.h

index c43218224..f81acb0f4 100644

--- a/ovn/lib/ovn-l7.h

+++ b/ovn/lib/ovn-l7.h

@@ -34,6 +34,14 @@ struct gen_opts_map {

 #define DHCP_BROADCAST_FLAG 0x8000

+/* These are not defined in ovs/lib/dhcp.h and hence defined here with

+ * OVN_DHCP_OPT_CODE_<opt_name>.

+ */

+#define OVN_DHCP_OPT_CODE_NETMASK      1

+#define OVN_DHCP_OPT_CODE_LEASE_TIME   51

+#define OVN_DHCP_OPT_CODE_T1           58

+#define OVN_DHCP_OPT_CODE_T2           59

+

 #define DHCP_OPTION(NAME, CODE, TYPE) \

     {.name = NAME, .code = CODE, .type = TYPE}

@@ -161,6 +169,10 @@ struct dhcp_opt6_header {

     ovs_be16 size;

 };

+/* These are not defined in ovs/lib/dhcp.h, hence defining here. */

+#define OVN_DHCP_MSG_RELEASE        7

+#define OVN_DHCP_MSG_INFORM         8

+

 /* Supported DHCPv6 Message Types */

 #define DHCPV6_MSG_TYPE_SOLICIT     1

 #define DHCPV6_MSG_TYPE_ADVT        2

diff --git a/tests/ovn.at b/tests/ovn.at

index 0c545b0b2..203c1d80f 100644

--- a/tests/ovn.at

+++ b/tests/ovn.at

@@ -4639,6 +4639,12 @@ test_dhcp() {

     done

     if test $offer_ip != 0; then

         local srv_mac=$1 srv_ip=$2 dhcp_reply_type=$3 expected_dhcp_opts=$4

+        local offered_ip=$offer_ip

+        if [[ "$dhcp_type" == "08" ]]; then

+            # DHCP ACK for DHCP INFORM should not have any offer ip.

+            offered_ip=00000000

+        fi

+

         # total IP length will be the IP length of the request packet

         # (which is 272 in our case) + 8 (padding bytes) + (expected_dhcp_opts / 2)

         ip_len=`expr 280 + ${#expected_dhcp_opts} / 2`

@@ -4654,7 +4660,7 @@ test_dhcp() {

         if test $dhcp_reply_type = 06; then

             reply=${reply}00000000

         else

-            reply=${reply}${offer_ip}

+            reply=${reply}${offered_ip}

         fi

         # next server ip address, relay agent ip address, client mac address

         reply=${reply}0000000000000000${src_mac}

@@ -4794,7 +4800,7 @@ rm -f 2.expected

 ciaddr=`ip_to_hex 0 0 0 0`

 offer_ip=0

 request_ip=0

-test_dhcp 2 f00000000002 08 0 $ciaddr $offer_ip $request_ip 0 1 1

+test_dhcp 2 f00000000002 09 0 $ciaddr $offer_ip $request_ip 0 1 1

 # NXT_RESUMEs should be 4.

 OVS_WAIT_UNTIL([test 4 = `cat ofctl_monitor*.log | grep -c NXT_RESUME`])

@@ -4964,6 +4970,113 @@ AT_CHECK([cat 1.packets | cut -c -48], [0], [expout])

 cat 1.expected | cut -c 53- > expout

 AT_CHECK([cat 1.packets | cut -c 53-], [0], [expout])

+reset_pcap_file hv1-vif1 hv1/vif1

+reset_pcap_file hv1-vif2 hv1/vif2

+rm -f 1.expected

+rm -f 2.expected

+

+# Send DHCPRELEASE.

+offer_ip=0

+server_ip=`ip_to_hex 10 0 0 1`

+ciaddr=`ip_to_hex 10 0 0 6`

+request_ip=0

+expected_dhcp_opts=0

+test_dhcp 2 f00000000002 07 0 $ciaddr $offer_ip $request_ip 0 ff1000000001

+

+# NXT_RESUMEs should be 10.

+OVS_WAIT_UNTIL([test 10 = $(cat ofctl_monitor*.log | grep -c NXT_RESUME)])

+

+# There is no reply for this. Check for the INFO log in ovn-controller.log

+AT_CHECK([test 1 = $(cat hv1/ovn-controller.log | \

+grep "DHCPRELEASE f0:00:00:00:00:02 10.0.0.6" -c)])

+

+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets

+AT_CHECK([cat 2.packets], [0], [])

+

+reset_pcap_file hv1-vif1 hv1/vif1

+reset_pcap_file hv1-vif2 hv1/vif2

+rm -f 1.expected

+rm -f 2.expected

+

+# Send DHCPINFORM

+offer_ip=`ip_to_hex 10 0 0 6`

+server_ip=`ip_to_hex 10 0 0 1`

+ciaddr=$offer_ip

+request_ip=0

+src_ip=$offer_ip

+dst_ip=$server_ip

+# In the expected_dhcp_opts we should not see 330400000e10 which is

+# dhcp lease time option and 0104ffffff00 which is subnet mask option.

+expected_dhcp_opts=03040a00000136040a000001

+test_dhcp 2 f00000000002 08 0 $ciaddr $offer_ip $request_ip 1 $src_ip $dst_ip ff1000000001 $server_ip 05 $expected_dhcp_opts

+

+# NXT_RESUMEs should be 11.

+OVS_WAIT_UNTIL([test 11 = $(cat ofctl_monitor*.log | grep -c NXT_RESUME)])

+

+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets

+cat 2.expected | cut -c -48 > expout

+AT_CHECK([cat 2.packets | cut -c -48], [0], [expout])

+# Skipping the IPv4 checksum.

+cat 2.expected | cut -c 53- > expout

+AT_CHECK([cat 2.packets | cut -c 53-], [0], [expout])

+

+# Now add the dhcp option T1 to the dhcp options.

+ovn-nbctl set dhcp_options ${d1} options:T1=4000

+

+reset_pcap_file hv1-vif1 hv1/vif1

+reset_pcap_file hv1-vif2 hv1/vif2

+rm -f 1.expected

+rm -f 2.expected

+

+# Send DHCPREQUEST to make sure that T1 is in the reply dhcp options.

+offer_ip=`ip_to_hex 10 0 0 6`

+server_ip=`ip_to_hex 10 0 0 1`

+ciaddr=$offer_ip

+request_ip=0

+src_ip=$offer_ip

+dst_ip=$server_ip

+# In the expected_dhcp_opts we should not see 330400000e10 which is

+# dhcp lease time option.

+expected_dhcp_opts=3a0400000fa0330400000e100104ffffff0003040a00000136040a000001

+test_dhcp 2 f00000000002 03 0 $ciaddr $offer_ip $request_ip 1 $src_ip $dst_ip ff1000000001 $server_ip 05 $expected_dhcp_opts

+

+# NXT_RESUMEs should be 12.

+OVS_WAIT_UNTIL([test 12 = $(cat ofctl_monitor*.log | grep -c NXT_RESUME)])

+

+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets

+cat 2.expected | cut -c -48 > expout

+AT_CHECK([cat 2.packets | cut -c -48], [0], [expout])

+# Skipping the IPv4 checksum.

+cat 2.expected | cut -c 53- > expout

+AT_CHECK([cat 2.packets | cut -c 53-], [0], [expout])

+

+reset_pcap_file hv1-vif1 hv1/vif1

+reset_pcap_file hv1-vif2 hv1/vif2

+rm -f 1.expected

+rm -f 2.expected

+

+# Now send DHCPINFORM again.

+offer_ip=`ip_to_hex 10 0 0 6`

+server_ip=`ip_to_hex 10 0 0 1`

+ciaddr=00000000

+request_ip=0

+src_ip=$offer_ip

+dst_ip=$server_ip

+# In the expected_dhcp_opts we should not see 330400000e10 which is

+# dhcp lease time option and 0104ffffff00 which is subnet mask option.

+expected_dhcp_opts=03040a00000136040a000001

+test_dhcp 2 f00000000002 08 0 $ciaddr $offer_ip $request_ip 1 $src_ip $dst_ip ff1000000001 $server_ip 05 $expected_dhcp_opts

+

+# NXT_RESUMEs should be 13.

+OVS_WAIT_UNTIL([test 13 = $(cat ofctl_monitor*.log | grep -c NXT_RESUME)])

+

+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/vif2-tx.pcap > 2.packets

+cat 2.expected | cut -c -48 > expout

+AT_CHECK([cat 2.packets | cut -c -48], [0], [expout])

+# Skipping the IPv4 checksum.

+cat 2.expected | cut -c 53- > expout

+AT_CHECK([cat 2.packets | cut -c 53-], [0], [expout])

+

 OVN_CLEANUP([hv1])

 AT_CLEANUP

-- 

2.26.2