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[201803][dhcp_relay] Add support for DHCP client(s) on one VLAN and DHCP server(s) on another #2857

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Merged
lguohan merged 8 commits into from
May 17, 2019
Merged

[201803][dhcp_relay] Add support for DHCP client(s) on one VLAN and DHCP server(s) on another #2857

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c3ef23d
Change URL for isc-dhcp source repository
May 2, 2019
e831527
Port upstream patches to isc-dhcp-relay to support upstream/downstrea…
May 2, 2019
48a3183
Modify supervisor conf to generate dhcrelay commands with '-id' and '…
May 2, 2019
8d75963
Comments; Also clean up jinja2 syntax
May 5, 2019
7beae06
Patch relay to open one socket per interface and send to all servers …
May 5, 2019
f1b5357
Patch relay agent to properly forward BOOTREQUEST only on appropriate…
May 9, 2019
ff4870f
Update patch to properly support interfaces with multiple IP addresse…
May 13, 2019
c5be819
Pass --enable-use-sockets to configure instead of uncommenting USE_SO…
May 15, 2019
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35 changes: 20 additions & 15 deletions dockers/docker-dhcp-relay/docker-dhcp-relay.supervisord.conf.j2
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Original file line number Diff line number Diff line change
Expand Up @@ -32,28 +32,33 @@ stderr_logfile=syslog
{% if num_relays.count > 0 %}
[group:isc-dhcp-relay]
programs=
{%- set add_preceding_comma = { 'flag': False } -%}
{%- for vlan_name in VLAN -%}
{%- if VLAN[vlan_name]['dhcp_servers'] -%}
{%- if add_preceding_comma.flag %},{% endif -%}
{%- set _dummy = add_preceding_comma.update({'flag': True}) -%}
{%- set add_preceding_comma = { 'flag': False } %}
{% for vlan_name in VLAN %}
{% if VLAN[vlan_name]['dhcp_servers'] %}
{% if add_preceding_comma.flag %},{% endif %}
{% set _dummy = add_preceding_comma.update({'flag': True}) %}
isc-dhcp-relay-{{ vlan_name }}
{%- endif %}
{% endfor %}


{# Create a program entry for each DHCP relay agent instance #}
{% for vlan_name in VLAN -%}
{%- if VLAN[vlan_name]['dhcp_servers'] -%}
{% for vlan_name in VLAN %}
{% if VLAN[vlan_name]['dhcp_servers'] %}
[program:isc-dhcp-relay-{{ vlan_name }}]
command=/usr/sbin/dhcrelay -d -m discard -a %%h:%%p %%P --name-alias-map-file /tmp/port-name-alias-map.txt -i {{ vlan_name }}
{%- for (name, prefix) in INTERFACE -%}
{%- if prefix | ipv4 %} -i {{ name }}{% endif -%}
{%- endfor -%}
{%- for (name, prefix) in PORTCHANNEL_INTERFACE -%}
{%- if prefix | ipv4 %} -i {{ name }}{% endif -%}
{%- endfor -%}
{%- for dhcp_server in VLAN[vlan_name]['dhcp_servers'] %} {{ dhcp_server }}{% endfor %}
{# We treat this VLAN as a downstream interface (-id), as we only want to listen for requests #}
command=/usr/sbin/dhcrelay -d -m discard -a %%h:%%p %%P --name-alias-map-file /tmp/port-name-alias-map.txt -id {{ vlan_name }}
{#- We treat all other interfaces as upstream interfaces (-iu), as we only want to listen for replies #}
{% for (name, prefix) in VLAN_INTERFACE %}
{% if prefix | ipv4 and name != vlan_name %} -iu {{ name }}{% endif -%}
{% endfor %}
{% for (name, prefix) in INTERFACE %}
{% if prefix | ipv4 %} -iu {{ name }}{% endif -%}
{% endfor %}
{% for (name, prefix) in PORTCHANNEL_INTERFACE %}
{% if prefix | ipv4 %} -iu {{ name }}{% endif -%}
{% endfor %}
{% for dhcp_server in VLAN[vlan_name]['dhcp_servers'] %} {{ dhcp_server }}{% endfor %}

priority=3
autostart=false
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2 changes: 1 addition & 1 deletion src/isc-dhcp/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ $(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :
rm -rf ./isc-dhcp

# Clone isc-dhcp repo
git clone https://salsa.debian.org/berni/isc-dhcp.git
git clone https://salsa.debian.org/dhcp-team/isc-dhcp.git
pushd ./isc-dhcp

# Reset HEAD to the commit of the proper tag
Expand Down
102 changes: 102 additions & 0 deletions src/isc-dhcp/patch/0005-Port-upstream-changes-from-commit-f2e70402f0f2955f39.patch
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@@ -0,0 +1,102 @@
From 0092eed7a80f38078a38fedf601952d0d25c6183 Mon Sep 17 00:00:00 2001
From: Joe LeVeque <[email protected]>
Date: Thu, 2 May 2019 19:20:59 +0000
Subject: [PATCH 1/2] Port upstream changes from commit
f2e70402f0f2955f392edc4eb2dd835b820e25bc to add '-iu' option

---
common/discover.c | 8 +++++++-
relay/dhcrelay.c | 36 +++++++++++++++++++++++++++++++++++-
2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/common/discover.c b/common/discover.c
index 3cd64a7..e20d9d5 100644
--- a/common/discover.c
+++ b/common/discover.c
@@ -948,8 +948,14 @@ discover_interfaces(int state) {
ir = 0;
else if (state == DISCOVER_UNCONFIGURED)
ir = INTERFACE_REQUESTED | INTERFACE_AUTOMATIC;
- else
+ else {
ir = INTERFACE_REQUESTED;
+ if (state == DISCOVER_RELAY && local_family == AF_INET) {
+ /* We're a v4 relay without specifically requested
+ * interfaces, so mark them all as bidirectional. */
+ ir |= INTERFACE_STREAMS;
+ }
+ }

/* Cycle through the list of interfaces looking for IP addresses. */
while (next_iface(&info, &err, &ifaces)) {
diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c
index 15f0acf..8051e17 100644
--- a/relay/dhcrelay.c
+++ b/relay/dhcrelay.c
@@ -172,6 +172,7 @@ static const char url[] =
" [-m append|replace|forward|discard]\n" \
" [--name-alias-map-file <name-alias-map-file>]\n" \
" [-i interface0 [ ... -i interfaceN]\n" \
+" [-iu interface0 [ ... -iu interfaceN]\n" \
" server0 [ ... serverN]\n\n" \
" dhcrelay -6 [-d] [-q] [-I] [-c <hops>] [-p <port>]\n" \
" [-pf <pid-file>] [--no-pid]\n" \
@@ -188,6 +189,7 @@ static const char url[] =
" [-pf <pid-file>] [--no-pid]\n"\
" [-m append|replace|forward|discard]\n" \
" [-i interface0 [ ... -i interfaceN]\n" \
+" [-iu interface0 [ ... -iu interfaceN]\n" \
" server0 [ ... serverN]\n\n" DHCRELAY_OPTION82_USAGE
#endif

@@ -304,7 +306,34 @@ main(int argc, char **argv) {
isc_result_totext(status));
}
strcpy(tmp->name, argv[i]);
- interface_snorf(tmp, INTERFACE_REQUESTED);
+ interface_snorf(tmp, (INTERFACE_REQUESTED |
+ INTERFACE_STREAMS));
+ interface_dereference(&tmp, MDL);
+ } else if (!strcmp(argv[i], "-iu")) {
+#ifdef DHCPv6
+ if (local_family_set && (local_family == AF_INET6)) {
+ usage();
+ }
+ local_family_set = 1;
+ local_family = AF_INET;
+#endif
+ if (++i == argc) {
+ usage();
+ }
+ 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_UPSTREAM));
interface_dereference(&tmp, MDL);
} else if (!strcmp(argv[i], "-a")) {
#ifdef DHCPv6
@@ -691,6 +720,11 @@ do_relay4(struct interface_info *ip, struct dhcp_packet *packet,

/* If it's a bootreply, forward it to the client. */
if (packet->op == BOOTREPLY) {
+ if (!(ip->flags & INTERFACE_UPSTREAM)) {
+ log_debug("Dropping reply received on %s", ip->name);
+ return;
+ }
+
if (!(packet->flags & htons(BOOTP_BROADCAST)) &&
can_unicast_without_arp(out)) {
to.sin_addr = packet->yiaddr;
--
2.17.1

157 changes: 157 additions & 0 deletions src/isc-dhcp/patch/0006-Port-upstream-changes-from-commit-edd6d8881bc4d8ec4b.patch
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Original file line number Diff line number Diff line change
@@ -0,0 +1,157 @@
From 1d59a7bd4dc9cb3cd13aedf604a15a8589febe43 Mon Sep 17 00:00:00 2001
From: Joe LeVeque <[email protected]>
Date: Thu, 2 May 2019 19:46:42 +0000
Subject: [PATCH 2/2] Port upstream changes from commit
edd6d8881bc4d8ec4b04173c66c1c840756bbe76 to add '-id' option

---
relay/dhcrelay.c | 89 +++++++++++++++++++++++++++++++++---------------
1 file changed, 61 insertions(+), 28 deletions(-)

diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c
index 8051e17..292ba4f 100644
--- a/relay/dhcrelay.c
+++ b/relay/dhcrelay.c
@@ -142,6 +142,8 @@ 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 int load_interface_alias_map(const char *port_alias_map_file_path);
static int get_interface_alias_by_name(const char *if_name, char *if_alias_out);
static void free_interface_alias_map(void);
@@ -173,6 +175,7 @@ static const char url[] =
" [--name-alias-map-file <name-alias-map-file>]\n" \
" [-i interface0 [ ... -i interfaceN]\n" \
" [-iu interface0 [ ... -iu interfaceN]\n" \
+" [-id interface0 [ ... -id interfaceN]\n" \
" server0 [ ... serverN]\n\n" \
" dhcrelay -6 [-d] [-q] [-I] [-c <hops>] [-p <port>]\n" \
" [-pf <pid-file>] [--no-pid]\n" \
@@ -190,6 +193,7 @@ static const char url[] =
" [-m append|replace|forward|discard]\n" \
" [-i interface0 [ ... -i interfaceN]\n" \
" [-iu interface0 [ ... -iu interfaceN]\n" \
+" [-id interface0 [ ... -id interfaceN]\n" \
" server0 [ ... serverN]\n\n" DHCRELAY_OPTION82_USAGE
#endif

@@ -294,21 +298,8 @@ main(int argc, char **argv) {
if (++i == argc) {
usage();
}
- 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)) {
@@ -320,21 +311,21 @@ main(int argc, char **argv) {
if (++i == argc) {
usage();
}
- 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();
}
- 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();
}
- 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)) {
@@ -782,6 +773,11 @@ 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. */
if (!(length = add_relay_agent_options(ip, packet, length,
@@ -1991,6 +1987,43 @@ 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);
+}
+
#define MAX_PORT_CONFIG_LINE_LEN 1024

// Allocates and loads global map g_interface_name_alias_map
--
2.17.1

28 changes: 28 additions & 0 deletions src/isc-dhcp/patch/0007-Add-enable-use-sockets-to-configure-flags-in-debian-.patch
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@@ -0,0 +1,28 @@
From ab779f1d59f27f66e6e6bea89287c810e0a10a0f Mon Sep 17 00:00:00 2001
From: Joe LeVeque <[email protected]>
Date: Wed, 15 May 2019 23:48:08 +0000
Subject: [PATCH 1/3] Add --enable-use-sockets to configure flags in
debian/rules

This defines USE_SOCKETS at compile time which forces dhcrelay
to create and bind separate sockets to each interface
---
debian/rules | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/debian/rules b/debian/rules
index 4184716..46d6527 100755
--- a/debian/rules
+++ b/debian/rules
@@ -23,7 +23,7 @@ CFLAGS+=-D_PATH_DHCLIENT_CONF='\"/etc/dhcp/dhclient.conf\"'
CFLAGS+=-D_PATH_DHCLIENT_DB='\"$(LEASE_PATH)/dhclient.leases\"'
CFLAGS+=-D_PATH_DHCLIENT6_DB='\"$(LEASE_PATH)/dhclient6.leases\"'

-CONFFLAGS=--prefix=/usr --enable-log-pid --enable-paranoia
+CONFFLAGS=--prefix=/usr --enable-log-pid --enable-paranoia --enable-use-sockets

# cross-architecture building
ifneq ($(DEB_HOST_GNU_TYPE),$(DEB_BUILD_GNU_TYPE))
--
2.17.1

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