From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Sun, 22 Mar 2026 14:39:38 +0000 (+0900)
Subject: dhcp: fix user class and vendor specific option assignment
X-Git-Tag: v260.2~256
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=98983d4f671b5d218423cde96e4e7880dc349e69;p=thirdparty%2Fsystemd.git

dhcp: fix user class and vendor specific option assignment

The commit 6d7cb9a6b8361d2b327222bc12872a3676358bc3 fixes the assignment
of the these options when specified through SendOption=. However, it
breaks when specified through UserClass= or SendVendorOption=.

When UserClass= or SendVendorOption= is specified, the option length is
calculated from the sd_dhcp_client.user_class or .vendor_options. Hence,
we can use 0 for the length in that case.

Follow-up for 6d7cb9a6b8361d2b327222bc12872a3676358bc3.

(cherry picked from commit 55f2fdd508dfe430cc36b9961b09d9eb649c6a83)
---

diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index 4b1cdd0b863..6b6a5ded42e 100644
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -1020,8 +1020,7 @@ static int client_append_common_discover_request_options(sd_dhcp_client *client,
         if (client->user_class) {
                 r = dhcp_option_append(&packet->dhcp, optlen, optoffset, 0,
                                        SD_DHCP_OPTION_USER_CLASS,
-                                       strv_length(client->user_class),
-                                       client->user_class);
+                                       /* optlen= */ 0, client->user_class);
                 if (r < 0)
                         return r;
         }
@@ -1037,7 +1036,7 @@ static int client_append_common_discover_request_options(sd_dhcp_client *client,
                 r = dhcp_option_append(
                                 &packet->dhcp, optlen, optoffset, 0,
                                 SD_DHCP_OPTION_VENDOR_SPECIFIC,
-                                ordered_hashmap_size(client->vendor_options), client->vendor_options);
+                                /* optlen= */ 0, client->vendor_options);
                 if (r < 0)
                         return r;
         }
diff --git a/src/libsystemd-network/sd-dhcp-server.c b/src/libsystemd-network/sd-dhcp-server.c
index d1fe0e22732..d88480a3464 100644
--- a/src/libsystemd-network/sd-dhcp-server.c
+++ b/src/libsystemd-network/sd-dhcp-server.c
@@ -719,7 +719,7 @@ static int server_send_offer_or_ack(
                 r = dhcp_option_append(
                                 &packet->dhcp, req->max_optlen, &offset, 0,
                                 SD_DHCP_OPTION_VENDOR_SPECIFIC,
-                                ordered_set_size(server->vendor_options), server->vendor_options);
+                                /* optlen= */ 0, server->vendor_options);
                 if (r < 0)
                         return r;
         }