systemd/dhcp: add support for vendor specific DHCP option

This adds support for DHCP option 43 (Vendor Specific Information) to
the internal DHCP client. The option carries an opaque object of n
octets, interpreted by vendor-specific code on the clients and
servers.

(cherry picked from commit 3c2f4a17f9255e2c6da6e6122159a9f993b80480)

4 files changed, 56 insertions, 0 deletions

diff --git a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-lease-internal.h b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-lease-internal.h
index 9e184ac4b5..71f7f143b3 100644
--- a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-lease-internal.h
+++ b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-lease-internal.h
@@ -72,6 +72,8 @@ struct sd_dhcp_lease {
         char *root_path;
         uint8_t *client_id;
         size_t client_id_len;
+        uint8_t *vendor_specific;
+        size_t vendor_specific_size;
 };
 
 int dhcp_lease_new(sd_dhcp_lease **ret);
diff --git a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-protocol.h b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-protocol.h
index abca9422c5..aa37e9b0b5 100644
--- a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-protocol.h
+++ b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/dhcp-protocol.h
@@ -125,6 +125,7 @@ enum {
         DHCP_OPTION_BROADCAST                   = 28,
         DHCP_OPTION_STATIC_ROUTE                = 33,
         DHCP_OPTION_NTP_SERVER                  = 42,
+        DHCP_OPTION_VENDOR_SPECIFIC             = 43,
         DHCP_OPTION_REQUESTED_IP_ADDRESS        = 50,
         DHCP_OPTION_IP_ADDRESS_LEASE_TIME       = 51,
         DHCP_OPTION_OVERLOAD                    = 52,
diff --git a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-lease.c b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-lease.c
index 2d13d503e1..0b5048a663 100644
--- a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-lease.c
@@ -191,6 +191,19 @@ int sd_dhcp_lease_get_routes(sd_dhcp_lease *lease, struct sd_dhcp_route **routes
         return 0;
 }
 
+int sd_dhcp_lease_get_vendor_specific(sd_dhcp_lease *lease, uint8_t **data) {
+        assert_return(lease, -EINVAL);
+        assert_return(data, -EINVAL);
+
+        if (lease->vendor_specific) {
+                *data = lease->vendor_specific;
+                return lease->vendor_specific_size;
+        } else
+                return -ENOENT;
+
+        return 0;
+}
+
 sd_dhcp_lease *sd_dhcp_lease_ref(sd_dhcp_lease *lease) {
         if (lease)
                 assert_se(REFCNT_INC(lease->n_ref) >= 2);
@@ -286,6 +299,24 @@ static int lease_parse_string(const uint8_t *option, size_t len, char **ret) {
         return 0;
 }
 
+static int lease_parse_binary(const uint8_t *option, size_t len, uint8_t **ret) {
+        assert (option);
+        assert (ret);
+
+        if (len >= 1) {
+                uint8_t *data;
+
+                data = memdup(option, len);
+                if (!data)
+                        return -errno;
+
+                free(*ret);
+                *ret = data;
+        }
+
+        return 0;
+}
+
 static int lease_parse_in_addrs_aux(const uint8_t *option, size_t len, struct in_addr **ret, size_t *ret_size, size_t mult) {
         assert(option);
         assert(ret);
@@ -568,6 +599,14 @@ int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option,
                         return r;
 
                 break;
+
+        case DHCP_OPTION_VENDOR_SPECIFIC:
+               r = lease_parse_binary(option, len, &lease->vendor_specific);
+               if (r < 0)
+                       return r;
+               lease->vendor_specific_size = len;
+
+               break;
         }
 
         return 0;
@@ -595,6 +634,7 @@ int sd_dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
         const uint8_t *client_id;
         size_t client_id_len;
         const char *string;
+        uint8_t *data;
         uint16_t mtu;
         struct sd_dhcp_route *routes;
         int r;
@@ -667,6 +707,18 @@ int sd_dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
         if (r >= 0)
                 serialize_dhcp_routes(f, "ROUTES", routes, r);
 
+        r = sd_dhcp_lease_get_vendor_specific(lease, &data);
+        if (r >= 0) {
+                _cleanup_free_ char *option_hex = NULL;
+
+                option_hex = hexmem(data, r);
+                if (!option_hex) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+                fprintf(f, "VENDOR_SPECIFIC=%s\n", option_hex);
+        }
+
         r = sd_dhcp_lease_get_client_id(lease, &client_id, &client_id_len);
         if (r >= 0) {
                 _cleanup_free_ char *client_id_hex = NULL;
diff --git a/src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-lease.h b/src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-lease.h
index 4296b91d8a..079a1bb347 100644
--- a/src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-lease.h
+++ b/src/dhcp-manager/systemd-dhcp/src/systemd/sd-dhcp-lease.h
@@ -45,6 +45,7 @@ int sd_dhcp_lease_get_domainname(sd_dhcp_lease *lease, const char **domainname);
 int sd_dhcp_lease_get_hostname(sd_dhcp_lease *lease, const char **hostname);
 int sd_dhcp_lease_get_root_path(sd_dhcp_lease *lease, const char **root_path);
 int sd_dhcp_lease_get_routes(sd_dhcp_lease *lease, struct sd_dhcp_route **routesgn);
+int sd_dhcp_lease_get_vendor_specific(sd_dhcp_lease *lease, uint8_t **data);
 int sd_dhcp_lease_get_client_id(sd_dhcp_lease *lease, const uint8_t **client_id,
                                 size_t *client_id_len);