[ovs-dev] [PATCH v1] Add support for DHCP options - Domain Search List (119) and TFTP server (66).
Ankur Sharma
svc.mail.git at nutanix.com
Tue May 5 00:37:11 UTC 2020
From: Dhathri Purohith <dhathri.purohith at nutanix.com>
1. Add support for DHCP domain search option (119)
Domain search list is encoded according to the specifications in RFC 1035,
section 4.1.4.
2. Fix the data type for DHCP option tftp_server (66)
Currently, DHCP option is of type ipv4. But, according to RFC 2132,
option 66 can be a hostname i.e, we should also accept string type.
In order to be backward compatible, a new type called "host_id" is
introduced, which accepts both ipv4 address and string. Type for DHCP
option 66 is changed to "host_id" instead of ipv4.
OVN northd code that updates the OVN southbound database is enhanced to
consider the change in the type and code for DHCP option, so that the
change in datatype is reflected.
Signed-off-by: Dhathri Purohith <dhathri.purohith at nutanix.com>
---
lib/actions.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++++++-
lib/ovn-l7.h | 5 ++-
northd/ovn-northd.c | 8 +++-
ovn-sb.ovsschema | 3 +-
ovn-sb.xml | 24 ++++++++++++
tests/ovn.at | 9 +++++
tests/test-ovn.c | 3 +-
7 files changed, 158 insertions(+), 5 deletions(-)
diff --git a/lib/actions.c b/lib/actions.c
index 21c0796..e463272 100644
--- a/lib/actions.c
+++ b/lib/actions.c
@@ -1943,7 +1943,12 @@ parse_gen_opt(struct action_context *ctx, struct ovnact_gen_option *o,
return;
}
- if (!strcmp(o->option->type, "str")) {
+ if (!strcmp(o->option->type, "host_id")) {
+ return;
+ }
+
+ if (!strcmp(o->option->type, "str") ||
+ !strcmp(o->option->type, "domains")) {
if (o->value.type != EXPR_C_STRING) {
lexer_error(ctx->lexer, "%s option %s requires string value.",
opts_type, o->option->name);
@@ -2270,6 +2275,110 @@ encode_put_dhcpv4_option(const struct ovnact_gen_option *o,
} else if (!strcmp(o->option->type, "str")) {
opt_header[1] = strlen(c->string);
ofpbuf_put(ofpacts, c->string, opt_header[1]);
+ } else if (!strcmp(o->option->type, "host_id")) {
+ if (o->value.type == EXPR_C_STRING) {
+ opt_header[1] = strlen(c->string);
+ ofpbuf_put(ofpacts, c->string, opt_header[1]);
+ } else {
+ opt_header[1] = sizeof(ovs_be32);
+ ofpbuf_put(ofpacts, &c->value.ipv4, sizeof(ovs_be32));
+ }
+ } else if (!strcmp(o->option->type, "domains")) {
+ /* Please refer to RFC 1035, section 4.1.4 for the format of encoding
+ * domain names. Below is an example for encoding a search list
+ * consisting of the "abc.com" and "xyz.abc.com".
+ *
+ * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+ * |119|14 | 3 |'a'|'b'|'c'| 3 |'c'|'o'|'m'| 0 |'x'|'y'|'z'|xC0|x00|
+ * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+ *
+ * The encoding of "abc.com" ends with 0 to mark the end of the
+ * domain name as required by RFC 1035.
+ *
+ * The encoding of "xyz" (for "xyz.abc.com") ends with the two-octet
+ * compression pointer C000 (hex), which points to offset 0 where
+ * another validly encoded domain name can be found to complete
+ * the name ("abc.com").
+ */
+ typedef struct namemap_node {
+ struct hmap_node node;
+ uint16_t offset;
+ char *name;
+ } namemap_node;
+ struct hmap namemap;
+ hmap_init(&namemap);
+ namemap_node *ref;
+ /* Encoding adds 2 bytes (one for length and one for delimiter) for
+ * every domain name that is unique. If all the domain names are unique
+ * (which probably never happens in real world), then encoded string
+ * could be longer than the original string. Just to be on the safer
+ * side, allocate the (approx.) worst case length here.
+ */
+ uint8_t *dns_encoded = xzalloc(2 * strlen(c->string));
+ uint8_t encode_offset = 0;
+ char *domain_list = xstrdup(c->string), *dom_ptr = NULL;
+ for (char *domain = strtok_r(domain_list, ",", &dom_ptr);
+ domain != NULL;
+ domain = strtok_r(NULL, ",", &dom_ptr)) {
+ if (strlen(domain) > DOMAIN_NAME_MAX_LEN) {
+ VLOG_WARN("Domain names longer than 255 characters are not"
+ "supported");
+ goto out;
+ }
+ char *label_ptr = NULL, *label;
+ for (label = strtok_r(domain, ".", &label_ptr);
+ label != NULL;
+ label = strtok_r(NULL, ".", &label_ptr)) {
+ ref = NULL;
+ /* Check if we have already encoded this label and
+ * fill in the reference, if yes. */
+ uint32_t label_hash = hash_string(label, 0);
+ HMAP_FOR_EACH_IN_BUCKET (ref, node, label_hash, &namemap) {
+ if (!strcmp(label, ref->name)) {
+ uint16_t temp = (0xc0 | htons(ref->offset));
+ memcpy(dns_encoded + encode_offset, &temp,
+ sizeof(temp));
+ encode_offset += sizeof(temp);
+ break;
+ }
+ }
+ /* Break, since we have already filled the offset for this
+ * domain. */
+ if (ref != NULL) {
+ break;
+ } else {
+ /* The label was not encoded before, encode it now and add
+ * the offset to the namemap map. */
+ ref = xzalloc(sizeof *ref);
+ ref->name = xstrdup(label);
+ ref->offset = encode_offset;
+ hmap_insert(&namemap, &ref->node, label_hash);
+
+ uint8_t len = strlen(label);
+ memcpy(dns_encoded + encode_offset, &len, sizeof(uint8_t));
+ encode_offset += sizeof(uint8_t);
+ memcpy(dns_encoded + encode_offset, label, len);
+ encode_offset += len;
+ }
+ }
+ /* Add the end marker (0 byte) to determine the end of the domain.*/
+ if (label == NULL) {
+ uint8_t end = 0;
+ memcpy(dns_encoded + encode_offset, &end, sizeof(uint8_t));
+ encode_offset += sizeof(uint8_t);
+ }
+ }
+ opt_header[1] = encode_offset;
+ ofpbuf_put(ofpacts, dns_encoded, encode_offset);
+
+ out:
+ HMAP_FOR_EACH_POP (ref, node, &namemap) {
+ free(ref->name);
+ free(ref);
+ }
+ hmap_destroy(&namemap);
+ free(domain_list);
+ free(dns_encoded);
}
}
diff --git a/lib/ovn-l7.h b/lib/ovn-l7.h
index cc63d82..f34bc0d 100644
--- a/lib/ovn-l7.h
+++ b/lib/ovn-l7.h
@@ -34,6 +34,7 @@ struct gen_opts_map {
size_t code;
};
+#define DOMAIN_NAME_MAX_LEN 255
#define DHCP_BROADCAST_FLAG 0x8000
#define DHCP_OPTION(NAME, CODE, TYPE) \
@@ -57,7 +58,7 @@ struct gen_opts_map {
#define DHCP_OPT_NIS_SERVER DHCP_OPTION("nis_server", 41, "ipv4")
#define DHCP_OPT_NTP_SERVER DHCP_OPTION("ntp_server", 42, "ipv4")
#define DHCP_OPT_SERVER_ID DHCP_OPTION("server_id", 54, "ipv4")
-#define DHCP_OPT_TFTP_SERVER DHCP_OPTION("tftp_server", 66, "ipv4")
+#define DHCP_OPT_TFTP_SERVER DHCP_OPTION("tftp_server", 66, "host_id")
#define DHCP_OPT_CLASSLESS_STATIC_ROUTE \
DHCP_OPTION("classless_static_route", 121, "static_routes")
@@ -81,6 +82,8 @@ struct gen_opts_map {
#define DHCP_OPT_PATH_PREFIX DHCP_OPTION("path_prefix", 210, "str")
#define DHCP_OPT_TFTP_SERVER_ADDRESS \
DHCP_OPTION("tftp_server_address", 150, "ipv4")
+#define DHCP_OPT_DOMAIN_SEARCH_LIST \
+ DHCP_OPTION("domain_search_list", 119, "domains")
#define DHCP_OPT_ARP_CACHE_TIMEOUT \
DHCP_OPTION("arp_cache_timeout", 35, "uint32")
diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
index e37b346..c897e02 100644
--- a/northd/ovn-northd.c
+++ b/northd/ovn-northd.c
@@ -11358,6 +11358,7 @@ static struct gen_opts_map supported_dhcp_opts[] = {
DHCP_OPT_DOMAIN_NAME,
DHCP_OPT_ARP_CACHE_TIMEOUT,
DHCP_OPT_TCP_KEEPALIVE_INTERVAL,
+ DHCP_OPT_DOMAIN_SEARCH_LIST,
};
static struct gen_opts_map supported_dhcpv6_opts[] = {
@@ -11382,7 +11383,12 @@ check_and_add_supported_dhcp_opts_to_sb_db(struct northd_context *ctx)
struct gen_opts_map *dhcp_opt =
dhcp_opts_find(&dhcp_opts_to_add, opt_row->name);
if (dhcp_opt) {
- hmap_remove(&dhcp_opts_to_add, &dhcp_opt->hmap_node);
+ if (!strcmp(dhcp_opt->type, opt_row->type) &&
+ dhcp_opt->code == opt_row->code) {
+ hmap_remove(&dhcp_opts_to_add, &dhcp_opt->hmap_node);
+ } else {
+ sbrec_dhcp_options_delete(opt_row);
+ }
} else {
sbrec_dhcp_options_delete(opt_row);
}
diff --git a/ovn-sb.ovsschema b/ovn-sb.ovsschema
index d89f8db..d1c1e51 100644
--- a/ovn-sb.ovsschema
+++ b/ovn-sb.ovsschema
@@ -214,7 +214,8 @@
"type": {"key": {
"type": "string",
"enum": ["set", ["bool", "uint8", "uint16", "uint32",
- "ipv4", "static_routes", "str"]]}}}},
+ "ipv4", "static_routes", "str",
+ "host_id", "domains"]]}}}},
"isRoot": true},
"DHCPv6_Options": {
"columns": {
diff --git a/ovn-sb.xml b/ovn-sb.xml
index 3aa7cd4..ddd8bff 100644
--- a/ovn-sb.xml
+++ b/ovn-sb.xml
@@ -3208,6 +3208,30 @@ tcp.flags = RST;
Example. "name=host_name", "code=12", "type=str".
</p>
</dd>
+
+ <dt><code>value: host_id</code></dt>
+ <dd>
+ <p>
+ This indicates that the value of the DHCP option is a host_id.
+ It can either be a host_name or an IP address.
+ </p>
+
+ <p>
+ Example. "name=tftp_server", "code=66", "type=host_id".
+ </p>
+ </dd>
+
+ <dt><code>value: domains</code></dt>
+ <dd>
+ <p>
+ This indicates that the value of the DHCP option is a domain name
+ or a comma separated list of domain names.
+ </p>
+
+ <p>
+ Example. "name=domain_search_list", "code=119", "type=domains".
+ </p>
+ </dd>
</dl>
</column>
</table>
diff --git a/tests/ovn.at b/tests/ovn.at
index c04cd06..80001f7 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -1195,6 +1195,15 @@ reg2[5] = put_dhcp_opts(offerip=10.0.0.4,router=10.0.0.1,netmask=255.255.254.0,m
reg0[15] = put_dhcp_opts(offerip=10.0.0.4,router=10.0.0.1,netmask=255.255.255.0,mtu=1400,ip_forward_enable=1,default_ttl=121,dns_server={8.8.8.8,7.7.7.7},classless_static_route={30.0.0.0/24,10.0.0.4,40.0.0.0/16,10.0.0.6,0.0.0.0/0,10.0.0.1},ethernet_encap=1,router_discovery=0,tftp_server_address={10.0.0.4,10.0.0.5},arp_cache_timeout=10,tcp_keepalive_interval=10);
formats as reg0[15] = put_dhcp_opts(offerip = 10.0.0.4, router = 10.0.0.1, netmask = 255.255.255.0, mtu = 1400, ip_forward_enable = 1, default_ttl = 121, dns_server = {8.8.8.8, 7.7.7.7}, classless_static_route = {30.0.0.0/24, 10.0.0.4, 40.0.0.0/16, 10.0.0.6, 0.0.0.0/0, 10.0.0.1}, ethernet_encap = 1, router_discovery = 0, tftp_server_address = {10.0.0.4, 10.0.0.5}, arp_cache_timeout = 10, tcp_keepalive_interval = 10);
encodes as controller(userdata=00.00.00.02.00.00.00.00.00.01.de.10.00.00.00.6f.0a.00.00.04.03.04.0a.00.00.01.01.04.ff.ff.ff.00.1a.02.05.78.13.01.01.17.01.79.06.08.08.08.08.08.07.07.07.07.79.14.18.1e.00.00.0a.00.00.04.10.28.00.0a.00.00.06.00.0a.00.00.01.24.01.01.1f.01.00.96.08.0a.00.00.04.0a.00.00.05.23.04.00.00.00.0a.26.04.00.00.00.0a,pause)
+reg0[15] = put_dhcp_opts(offerip=10.0.0.4,router=10.0.0.1,netmask=255.255.255.0,mtu=1400,ip_forward_enable=1,default_ttl=121,dns_server={8.8.8.8,7.7.7.7},classless_static_route={30.0.0.0/24,10.0.0.4,40.0.0.0/16,10.0.0.6,0.0.0.0/0,10.0.0.1},ethernet_encap=1,router_discovery=0,tftp_server=10.0.0.10);
+ formats as reg0[15] = put_dhcp_opts(offerip = 10.0.0.4, router = 10.0.0.1, netmask = 255.255.255.0, mtu = 1400, ip_forward_enable = 1, default_ttl = 121, dns_server = {8.8.8.8, 7.7.7.7}, classless_static_route = {30.0.0.0/24, 10.0.0.4, 40.0.0.0/16, 10.0.0.6, 0.0.0.0/0, 10.0.0.1}, ethernet_encap = 1, router_discovery = 0, tftp_server = 10.0.0.10);
+ encodes as controller(userdata=00.00.00.02.00.00.00.00.00.01.de.10.00.00.00.6f.0a.00.00.04.03.04.0a.00.00.01.01.04.ff.ff.ff.00.1a.02.05.78.13.01.01.17.01.79.06.08.08.08.08.08.07.07.07.07.79.14.18.1e.00.00.0a.00.00.04.10.28.00.0a.00.00.06.00.0a.00.00.01.24.01.01.1f.01.00.42.04.0a.00.00.0a,pause)
+reg0[15] = put_dhcp_opts(offerip=10.0.0.4,router=10.0.0.1,netmask=255.255.255.0,mtu=1400,ip_forward_enable=1,default_ttl=121,dns_server={8.8.8.8,7.7.7.7},classless_static_route={30.0.0.0/24,10.0.0.4,40.0.0.0/16,10.0.0.6,0.0.0.0/0,10.0.0.1},ethernet_encap=1,router_discovery=0,tftp_server="tftp_server_test");
+ formats as reg0[15] = put_dhcp_opts(offerip = 10.0.0.4, router = 10.0.0.1, netmask = 255.255.255.0, mtu = 1400, ip_forward_enable = 1, default_ttl = 121, dns_server = {8.8.8.8, 7.7.7.7}, classless_static_route = {30.0.0.0/24, 10.0.0.4, 40.0.0.0/16, 10.0.0.6, 0.0.0.0/0, 10.0.0.1}, ethernet_encap = 1, router_discovery = 0, tftp_server = "tftp_server_test");
+ encodes as controller(userdata=00.00.00.02.00.00.00.00.00.01.de.10.00.00.00.6f.0a.00.00.04.03.04.0a.00.00.01.01.04.ff.ff.ff.00.1a.02.05.78.13.01.01.17.01.79.06.08.08.08.08.08.07.07.07.07.79.14.18.1e.00.00.0a.00.00.04.10.28.00.0a.00.00.06.00.0a.00.00.01.24.01.01.1f.01.00.42.10.74.66.74.70.5f.73.65.72.76.65.72.5f.74.65.73.74,pause)
+reg2[5] = put_dhcp_opts(offerip=10.0.0.4,router=10.0.0.1,netmask=255.255.254.0,mtu=1400,domain_name="ovn.org",wpad="https://example.org",bootfile_name="https://127.0.0.1/boot.ipxe",path_prefix="/tftpboot",domain_search_list="ovn.org,abc.ovn.org");
+ formats as reg2[5] = put_dhcp_opts(offerip = 10.0.0.4, router = 10.0.0.1, netmask = 255.255.254.0, mtu = 1400, domain_name = "ovn.org", wpad = "https://example.org", bootfile_name = "https://127.0.0.1/boot.ipxe", path_prefix = "/tftpboot", domain_search_list = "ovn.org,abc.ovn.org");
+ encodes as controller(userdata=00.00.00.02.00.00.00.00.00.01.de.10.00.00.00.25.0a.00.00.04.03.04.0a.00.00.01.01.04.ff.ff.fe.00.1a.02.05.78.0f.07.6f.76.6e.2e.6f.72.67.fc.13.68.74.74.70.73.3a.2f.2f.65.78.61.6d.70.6c.65.2e.6f.72.67.43.1b.68.74.74.70.73.3a.2f.2f.31.32.37.2e.30.2e.30.2e.31.2f.62.6f.6f.74.2e.69.70.78.65.d2.09.2f.74.66.74.70.62.6f.6f.74.77.0f.03.6f.76.6e.03.6f.72.67.00.03.61.62.63.c0.00,pause)
reg1[0..1] = put_dhcp_opts(offerip = 1.2.3.4, router = 10.0.0.1);
Cannot use 2-bit field reg1[0..1] where 1-bit field is required.
diff --git a/tests/test-ovn.c b/tests/test-ovn.c
index a77d2f1..b43f67f 100644
--- a/tests/test-ovn.c
+++ b/tests/test-ovn.c
@@ -174,7 +174,7 @@ create_gen_opts(struct hmap *dhcp_opts, struct hmap *dhcpv6_opts,
dhcp_opt_add(dhcp_opts, "nis_server", 41, "ipv4");
dhcp_opt_add(dhcp_opts, "ntp_server", 42, "ipv4");
dhcp_opt_add(dhcp_opts, "server_id", 54, "ipv4");
- dhcp_opt_add(dhcp_opts, "tftp_server", 66, "ipv4");
+ dhcp_opt_add(dhcp_opts, "tftp_server", 66, "host_id");
dhcp_opt_add(dhcp_opts, "classless_static_route", 121, "static_routes");
dhcp_opt_add(dhcp_opts, "ip_forward_enable", 19, "bool");
dhcp_opt_add(dhcp_opts, "router_discovery", 31, "bool");
@@ -189,6 +189,7 @@ create_gen_opts(struct hmap *dhcp_opts, struct hmap *dhcpv6_opts,
dhcp_opt_add(dhcp_opts, "tftp_server_address", 150, "ipv4");
dhcp_opt_add(dhcp_opts, "arp_cache_timeout", 35, "uint32");
dhcp_opt_add(dhcp_opts, "tcp_keepalive_interval", 38, "uint32");
+ dhcp_opt_add(dhcp_opts, "domain_search_list", 119, "domains");
/* DHCPv6 options. */
hmap_init(dhcpv6_opts);
--
1.8.3.1
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