On Mon, Jun 1, 2020 at 11:45 PM Ankur Sharma <svc.mail....@nutanix.com>
wrote:
> From: Dhathri Purohith <dhathri.puroh...@nutanix.com>
>
> Domain search list is encoded according to the specifications in RFC 1035,
> section 4.1.4.
>
> Signed-off-by: Dhathri Purohith <dhathri.puroh...@nutanix.com>
> Signed-off-by: Ankur Sharma <ankur.sha...@nutanix.com>
>
Hi Dhathri,
Thanks for the patch. Please see below for a few comments.
Thanks
Numan
> ---
> lib/actions.c | 100
> +++++++++++++++++++++++++++++++++++++++++++++++++++-
> lib/ovn-l7.h | 3 ++
> northd/ovn-northd.c | 1 +
> ovn-sb.ovsschema | 6 ++--
> ovn-sb.xml | 11 ++++++
> tests/ovn.at | 3 ++
> tests/test-ovn.c | 1 +
> 7 files changed, 121 insertions(+), 4 deletions(-)
>
> diff --git a/lib/actions.c b/lib/actions.c
> index f21be6d..8f5ed61 100644
> --- a/lib/actions.c
> +++ b/lib/actions.c
> @@ -1982,7 +1982,8 @@ parse_gen_opt(struct action_context *ctx, struct
> ovnact_gen_option *o,
> return;
> }
>
> - if (!strcmp(o->option->type, "str")) {
> + 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);
> @@ -2317,6 +2318,103 @@ encode_put_dhcpv4_option(const struct
> ovnact_gen_option *o,
> 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;
>
in OVN/OVS generally a struct is not typedef'ed. Please see
https://docs.ovn.org/en/latest/internals/contributing/coding-style.html
I'd suggest to removethe typedef.
> + 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)
> {
>
I think for this usecase, we can use shash and make sure that a label is
added only once to
the shash (shash_add_once()). It will be easier to search for the label.
> + if (!strcmp(label, ref->name)) {
> + ovs_be16 temp = htons(0xc000) |
> 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 38555db..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) \
> @@ -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 ef08414..4ec2034 100644
> --- a/northd/ovn-northd.c
> +++ b/northd/ovn-northd.c
> @@ -11336,6 +11336,7 @@ 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[] = {
> diff --git a/ovn-sb.ovsschema b/ovn-sb.ovsschema
> index 2ec729b..99c5de8 100644
> --- a/ovn-sb.ovsschema
> +++ b/ovn-sb.ovsschema
> @@ -1,7 +1,7 @@
> {
> "name": "OVN_Southbound",
> - "version": "2.8.1",
> - "cksum": "236203406 21905",
> + "version": "2.8.2",
> + "cksum": "464326363 21916",
> "tables": {
> "SB_Global": {
> "columns": {
> @@ -218,7 +218,7 @@
> "type": "string",
> "enum": ["set", ["bool", "uint8", "uint16",
> "uint32",
> "ipv4", "static_routes", "str",
> - "host_id"]]}}}},
> + "host_id", "domains"]]}}}},
> "isRoot": true},
> "DHCPv6_Options": {
> "columns": {
> diff --git a/ovn-sb.xml b/ovn-sb.xml
> index 208fb93..a6da80b 100644
> --- a/ovn-sb.xml
> +++ b/ovn-sb.xml
> @@ -3232,6 +3232,17 @@ tcp.flags = RST;
> </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>
>
You also need to update the ovn-nb.xml documentation.
> + </dd>
> </dl>
> </column>
> </table>
> diff --git a/tests/ovn.at b/tests/ovn.at
> index fa2592c..91ec564 100644
> --- a/tests/ovn.at
> +++ b/tests/ovn.at
> @@ -1218,6 +1218,9 @@ reg0[15] =
> put_dhcp_opts(offerip=10.0.0.4,router=10.0.0.1,netmask=255.255.255.0,
> 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)
>
It will be good to add negative cases of encoding here.
And also enhance the test_dhcp test case.
Thanks
Numan
>
> 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 4391694..b43f67f 100644
> --- a/tests/test-ovn.c
> +++ b/tests/test-ovn.c
> @@ -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
>
> _______________________________________________
> dev mailing list
> d...@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>
>
_______________________________________________
dev mailing list
d...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
