[DHCP Relay]: Add support for custom Option 82 circuit_id of the form '<hostname>:<portname>' (#747)

* Add docker-dhcp-relay/Dockerfile to .gitignore

* Add isc-dhcp-relay .deb package to image build process, along with my Option 82 patch

* Install custom isc-dhcp-relay in dhcp_relay docker

* Install isc-dhcp-relay build dependencies in sonic-slave Docker container

* Copy the built .deb package to the destination directory

* Add dependencies for isc-dhcp-relay

* Change Option 82 string to '<hostname>:<portname>'

* Install dependencies of .deb files implicitly in Dockerfile

* Remove unused line

* Remove unnecessary space
This commit is contained in:
Joe LeVeque 2017-06-24 12:05:04 -07:00 committed by lguohan
parent 0cdad949e5
commit 017eea8a87
8 changed files with 351 additions and 5 deletions

1
.gitignore vendored
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@ -29,6 +29,7 @@ src/sonic-device-data/src/device/
dockers/docker-base/Dockerfile dockers/docker-base/Dockerfile
dockers/docker-config-engine/Dockerfile dockers/docker-config-engine/Dockerfile
dockers/docker-database/Dockerfile dockers/docker-database/Dockerfile
dockers/docker-dhcp-relay/Dockerfile
dockers/docker-fpm-frr/Dockerfile dockers/docker-fpm-frr/Dockerfile
dockers/docker-fpm-gobgp/Dockerfile dockers/docker-fpm-gobgp/Dockerfile
dockers/docker-fpm-quagga/Dockerfile dockers/docker-fpm-quagga/Dockerfile

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@ -6,8 +6,17 @@ ENV DEBIAN_FRONTEND=noninteractive
# Update apt's cache of available packages # Update apt's cache of available packages
RUN apt-get update RUN apt-get update
# Install isc-dhcp-relay Debian package {% if docker_dhcp_relay_debs.strip() -%}
RUN apt-get -y install isc-dhcp-relay # Copy built Debian packages
{%- for deb in docker_dhcp_relay_debs.split(' ') %}
COPY debs/{{ deb }} debs/
{%- endfor %}
# Install built Debian packages and implicitly install their dependencies
{%- for deb in docker_dhcp_relay_debs.split(' ') %}
RUN dpkg_apt() { [ -f $1 ] && { dpkg -i $1 || apt-get -y install -f; } || return 1; }; dpkg_apt debs/{{ deb }}
{%- endfor %}
{%- endif %}
# Clean up # Clean up
RUN apt-get clean -y; apt-get autoclean -y; apt-get autoremove -y RUN apt-get clean -y; apt-get autoclean -y; apt-get autoremove -y

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@ -24,6 +24,6 @@ INTERFACES="
{%- endif %} {%- endif %}
{%- endfor %}" {%- endfor %}"
# '-a' option provides option 82 circuit id information # '-a' option provides option 82 circuit_id and remote_id information
OPTIONS="-a" OPTIONS="-a \"%h:%p\" \"\""

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@ -2,8 +2,9 @@
DOCKER_DHCP_RELAY = docker-dhcp-relay.gz DOCKER_DHCP_RELAY = docker-dhcp-relay.gz
$(DOCKER_DHCP_RELAY)_PATH = $(DOCKERS_PATH)/docker-dhcp-relay $(DOCKER_DHCP_RELAY)_PATH = $(DOCKERS_PATH)/docker-dhcp-relay
$(DOCKER_DHCP_RELAY)_DEPENDS += $(ISC_DHCP_COMMON) $(ISC_DHCP_RELAY)
$(DOCKER_DHCP_RELAY)_LOAD_DOCKERS = $(DOCKER_CONFIG_ENGINE) $(DOCKER_DHCP_RELAY)_LOAD_DOCKERS = $(DOCKER_CONFIG_ENGINE)
SONIC_SIMPLE_DOCKER_IMAGES += $(DOCKER_DHCP_RELAY) SONIC_DOCKER_IMAGES += $(DOCKER_DHCP_RELAY)
SONIC_INSTALL_DOCKER_IMAGES += $(DOCKER_DHCP_RELAY) SONIC_INSTALL_DOCKER_IMAGES += $(DOCKER_DHCP_RELAY)

13
rules/isc-dhcp.mk Normal file
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@ -0,0 +1,13 @@
# isc-dhcp packages
ISC_DHCP_VERSION = 4.3.1-6
export ISC_DHCP_VERSION
ISC_DHCP_COMMON = isc-dhcp-common_$(ISC_DHCP_VERSION)_amd64.deb
$(ISC_DHCP_COMMON)_SRC_PATH = $(SRC_PATH)/isc-dhcp
SONIC_MAKE_DEBS += $(ISC_DHCP_COMMON)
ISC_DHCP_RELAY = isc-dhcp-relay_$(ISC_DHCP_VERSION)_amd64.deb
$(eval $(call add_derived_package,$(ISC_DHCP_COMMON),$(ISC_DHCP_RELAY)))

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@ -216,6 +216,9 @@ RUN apt-get update && apt-get install -y \
# For sonic config engine testing # For sonic config engine testing
pyangbind pyangbind
# Install dependencies for building isc-dhcp-relay
RUN apt-get -y build-dep isc-dhcp
RUN cd /usr/src/gtest && cmake . && make -C /usr/src/gtest RUN cd /usr/src/gtest && cmake . && make -C /usr/src/gtest
RUN mkdir /var/run/sshd RUN mkdir /var/run/sshd

30
src/isc-dhcp/Makefile Normal file
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@ -0,0 +1,30 @@
.ONESHELL:
SHELL = /bin/bash
.SHELLFLAGS += -e
MAIN_TARGET = isc-dhcp-common_$(ISC_DHCP_VERSION)_amd64.deb
DERIVED_TARGETS = isc-dhcp-relay_$(ISC_DHCP_VERSION)_amd64.deb
$(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :
# Remove any stale files
rm -rf ./isc-dhcp
# Clone isc-dhcp repo
git clone git://anonscm.debian.org/pkg-dhcp/isc-dhcp.git
pushd ./isc-dhcp
git checkout -f debian/4.3.1-6
popd
# Apply patch
patch -p1 < isc-dhcp-4.3.1_dhcrelay-custom-circuit_id-remote_id-and-bridge-iface-support.patch
# Build source and Debian packages
pushd ./isc-dhcp
dpkg-buildpackage -rfakeroot -b -us -uc
popd
# Move the newly-built .deb packages to the destination directory
mv $* $(DERIVED_TARGETS) $(DEST)/
$(addprefix $(DEST)/, $(DERIVED_TARGETS)): $(DEST)/% : $(DEST)/$(MAIN_TARGET)

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@ -0,0 +1,289 @@
This patch adds the following functionality to dhcrelay in isc-dhcp v4.3.1-6:
* Add customizable Circuit ID and Remote ID fields
* Support for obtaining name of physical interface of interfaces that are part of a bridge interface
diff -ruN a/isc-dhcp/relay/dhcrelay.c b/isc-dhcp/relay/dhcrelay.c
--- a/isc-dhcp/relay/dhcrelay.c 2014-08-06 22:35:02.000000000 +0000
+++ b/isc-dhcp/relay/dhcrelay.c 2017-06-08 21:39:53.856192546 +0000
@@ -73,6 +73,8 @@
did not match any known circuit ID. */
int missing_circuit_id = 0; /* Circuit ID option in matching RAI option
was missing. */
+const char *agent_circuit_id_fmt = NULL; /* Circuit ID custom format string. */
+const char *agent_remote_id_fmt = NULL; /* Remote ID custom format string. */
int max_hop_count = 10; /* Maximum hop count */
#ifdef DHCPv6
@@ -140,9 +142,19 @@
static const char url[] =
"For info, please visit https://www.isc.org/software/dhcp/";
+#define DHCRELAY_OPTION82_USAGE \
+"circuit_id/remote_id interpreted sequences are:\n" \
+"\n" \
+" %%%% A single %%\n" \
+" %%h Hostname of device\n" \
+" %%p Name of interface that generated the request\n" \
+" %%P Hardware address of interface that generated the request\n" \
+" %%C Client hardware address\n" \
+" %%I DHCP relay agent IP Address\n" \
+
#ifdef DHCPv6
#define DHCRELAY_USAGE \
-"Usage: dhcrelay [-4] [-d] [-q] [-a] [-D]\n"\
+"Usage: dhcrelay [-4] [-d] [-q] [-a <circuit_id> <remote_id>] [-D]\n"\
" [-A <length>] [-c <hops>] [-p <port>]\n" \
" [-pf <pid-file>] [--no-pid]\n"\
" [-m append|replace|forward|discard]\n" \
@@ -154,14 +166,15 @@
" -l lower0 [ ... -l lowerN]\n" \
" -u upper0 [ ... -u upperN]\n" \
" lower (client link): [address%%]interface[#index]\n" \
-" upper (server link): [address%%]interface"
+" upper (server link): [address%%]interface\n\n" DHCRELAY_OPTION82_USAGE
#else
#define DHCRELAY_USAGE \
-"Usage: dhcrelay [-d] [-q] [-a] [-D] [-A <length>] [-c <hops>] [-p <port>]\n" \
-" [-pf <pid-file>] [--no-pid]\n" \
+"Usage: dhcrelay [-d] [-q] [-a <circuit_id> <remote_id>] [-D]\n" \
+" [-A <length>] [-c <hops>] [-p <port>]\n" \
+" [-pf <pid-file>] [--no-pid]\n"\
" [-m append|replace|forward|discard]\n" \
" [-i interface0 [ ... -i interfaceN]\n" \
-" server0 [ ... serverN]\n\n"
+" server0 [ ... serverN]\n\n" DHCRELAY_OPTION82_USAGE
#endif
static void usage() {
@@ -287,6 +300,15 @@
local_family_set = 1;
local_family = AF_INET;
#endif
+ if (++i == argc)
+ usage();
+
+ if (argv[i] != NULL && argv[i][0] != '-')
+ agent_circuit_id_fmt = argv[i++];
+
+ if (argv[i] != NULL && argv[i][0] != '-')
+ agent_remote_id_fmt = argv[i];
+
add_agent_options = 1;
} else if (!strcmp(argv[i], "-A")) {
#ifdef DHCPv6
@@ -937,6 +959,166 @@
return (-1);
}
+static int
+_bridgefdbquery(const char *hwAddr, char *interface, int *vlanid) {
+
+#define xstr(s) str(s)
+#define str(s) #s
+#define FDB_STRING_LEN 100
+#define FDB_BUFFER_LEN (FDB_STRING_LEN + 1)
+
+/*
+ * Format for sscanf() to read the 1st, 3th, and 5th
+ * space-delimited fields
+ *
+ * bridge fdb show output
+ * 6c:64:1a:00:06:13 dev swp35 vlan 0 master bridge permanent
+ */
+#define FDB_LINE_FORMAT "%" xstr(FDB_STRING_LEN) "s %*s " \
+ "%" xstr(FDB_STRING_LEN) "s %*s %d %*s"
+
+ char cmdstr[FDB_BUFFER_LEN];
+ char buf[FDB_BUFFER_LEN];
+ char macAddr[FDB_BUFFER_LEN];
+
+ if ((interface == NULL) || (vlanid == NULL)) {
+ return 0;
+ }
+ sprintf(cmdstr, "bridge fdb show | grep -m 1 %s", hwAddr);
+ FILE *cmd = popen(cmdstr, "r");
+
+ if (cmd != NULL) {
+ while (fgets(buf, sizeof(buf), cmd)) {
+ sscanf(buf, FDB_LINE_FORMAT, macAddr, interface, vlanid);
+ log_debug ("bridgefdbquery: macAddr:%s interface: %s vlanid %d",
+ macAddr,
+ interface, *vlanid);
+ }
+ pclose(cmd);
+ return 0;
+ }
+
+ return -1;
+}
+
+/*
+ * Format the message that will be used by circuit_id and remote_id
+ */
+static int
+format_relay_agent_rfc3046_msg(struct interface_info *ip, struct dhcp_packet *packet,
+ const char *format, char *msg, size_t msgn) {
+ size_t len = 0;
+ char hostname[HOST_NAME_MAX + 1] = { 0 };
+ char ifname[IFNAMSIZ + 1] = { 0 };
+ char *buf = msg;
+
+ for ( ; format && *format && len < msgn; ++format) {
+ size_t strn = 0;
+ const char *str = NULL;
+
+ if (*format == '%') {
+ switch (*++format) {
+ case '\0':
+ --format;
+ break;
+
+ case '%': /* A literal '%' */
+ str = "%";
+ break;
+
+ case 'h': /* Hostname */
+ gethostname(hostname, HOST_NAME_MAX);
+ str = hostname;
+ break;
+
+ case 'p': /* Name of interface that we received the request from */
+ /*
+ * Query FDB to identify the exact physical interface only when source MAC address
+ * is present and '20: DHCP relay agent IP address' (giaddr) is not present
+ */
+ if (packet->htype && !packet->giaddr.s_addr) {
+ int ret = 0, vlanid = 0;
+
+ ret = _bridgefdbquery(print_hw_addr(packet->htype, packet->hlen, packet->chaddr),
+ ip->name,
+ &vlanid);
+
+ if (ret < 0) {
+ log_debug("MAC Address: %s (interface:%s vlan:%d) not found in bridge fdb show",
+ print_hw_addr (packet->htype, packet->hlen, packet->chaddr),
+ ip->name,
+ vlanid);
+ strncpy(ifname, ip->name, IFNAMSIZ);
+ }
+ else if (strlen(ip->name) > 0) {
+ char cmdstr[256] = { 0 };
+ char cmdout[256] = { 0 };
+
+ log_debug("Adding option 82 interface name for MAC Address: %s as %s",
+ print_hw_addr (packet->htype, packet->hlen, packet->chaddr),
+ ip->name);
+
+ // Translate SONiC interface name to vendor alias
+ sprintf(cmdstr, "sonic-cfggen -m /etc/sonic/minigraph.xml -v \"minigraph_ports['%s'].alias\"", ip->name);
+
+ FILE *cmd = popen(cmdstr, "r");
+
+ if (cmd != NULL) {
+ while (fgets(cmdout, sizeof(cmdout), cmd)) {
+ // Strip any trailing newline
+ if (cmdout[strlen(cmdout) - 1] == '\n')
+ cmdout[strlen(cmdout) - 1] = '\0';
+
+ log_debug ("Retrieved alias %s for interface %s", buf, ip->name);
+ }
+
+ pclose(cmd);
+ }
+
+ strncpy(ifname, cmdout, IFNAMSIZ);
+ }
+
+ str = ifname;
+ }
+ break;
+
+ case 'P': /* Physical address of interface that we received the request from */
+ str = print_hw_addr(ip->hw_address.hbuf[0], ip->hw_address.hlen - 1, &ip->hw_address.hbuf[1]);
+ break;
+
+ case 'C': /* 24: Client hardware address */
+ str = print_hw_addr(packet->htype, packet->hlen, packet->chaddr);
+ break;
+
+ case 'I': /* 20: DHCP relay agent IP address */
+ str = inet_ntoa(packet->giaddr);
+ break;
+
+ default:
+ log_error("Option %%%c is unrecognized and will not be formatted!", *format);
+ continue;
+ }
+
+ if (str)
+ strn = strlen(str);
+ } else {
+ str = format;
+ strn += 1;
+ }
+
+ // Do we have room?
+ if ((strn+len) > msgn) {
+ return 0;
+ }
+
+ memcpy(buf+len, str, strn);
+ len += strn;
+ }
+
+ return len;
+}
+
+
/*
* Examine a packet to see if it's a candidate to have a Relay
* Agent Information option tacked onto its tail. If it is, tack
@@ -948,6 +1130,8 @@
int is_dhcp = 0, mms;
unsigned optlen;
u_int8_t *op, *nextop, *sp, *max, *end_pad = NULL;
+ char circuit_id_buf[255] = { '\0', };
+ char remote_id_buf[255] = { '\0', };
/* If we're not adding agent options to packets, we can skip
this. */
@@ -1077,6 +1261,38 @@
op = sp;
#endif
+ /* option82: custom string for circuit_id */
+ if (agent_circuit_id_fmt) {
+ size_t len = 0;
+
+ len = format_relay_agent_rfc3046_msg(ip, packet, agent_circuit_id_fmt,
+ circuit_id_buf, sizeof(circuit_id_buf));
+
+ if (len > 0) {
+ ip->circuit_id = (uint8_t *)circuit_id_buf;
+ ip->circuit_id_len = len;
+
+ log_debug("sending on %s option82:circuit_id='%s'(%d)",
+ ip->name, (char *)ip->circuit_id, ip->circuit_id_len);
+ }
+ }
+
+ /* option82: custom string for remote_id */
+ if (agent_remote_id_fmt) {
+ size_t len = 0;
+
+ len = format_relay_agent_rfc3046_msg(ip, packet, agent_remote_id_fmt,
+ remote_id_buf, sizeof(remote_id_buf));
+
+ if (len > 0) {
+ ip->remote_id = (uint8_t *)remote_id_buf;
+ ip->remote_id_len = len;
+
+ log_debug("sending on %s option82:remote_id='%s'(%d)",
+ ip->name, (char *)ip->remote_id, ip->remote_id_len);
+ }
+ }
+
/* Sanity check. Had better not ever happen. */
if ((ip->circuit_id_len > 255) ||(ip->circuit_id_len < 1))
log_fatal("Circuit ID length %d out of range [1-255] on "