DHCP INIT-REBOOT state and others

[jcpvdm]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like

An API/CLI command to trigger a "reboot" of DHCP client(s), without sending a release message, so that a INIT-REBOOT is triggered.
In addition to INIT-REBOOT state, would be nice if could be extended to cover all scenarios. Here's what comes to mind when rebooting/reconnecting clients:

• Reconnect with release message (already implemented)
• Reconnect without release and attempt to perserve old address (INIT-REBOOT state)
• Reconnect without release and forget old address
• Possibility to choose whether to remember dhcp server address or not. -> Use of broadcast and unicast
• Provide an option within the API/CLI instruction to define an idle period between disconnection and subsequent reconnection.

[GIC-de]

I merged your changes with some minor modifications and added commands for DHCP start, stop and release. Please review/test in the branch dhcp-initreboot before merged to dev (ecec7fa).

commit ecec7fae00c77e55f7d867f0bce92fc3226f6e6e (HEAD -> dhcp-initreboot, origin/dhcp-initreboot)
Author: Christian Giese <christian@rtbrick.com>
Date:   Wed Jan 28 10:44:26 2026 +0000

    add commands for DHCP start/stop/release

[GIC-de]

And I renamed "cache" to "keep-address", which is available in configuration and command/api (31d938f).

[jcpvdm]

There is a problem with dhcp start following a dhcp stop (either API triggered or due to timeout during renew):

Jan 28 17:45:50.345423 Total PPS of all streams: 0.00
Jan 28 17:45:50.345749 Opened control socket /run.sock
Jan 28 17:45:50.445623 Resolve network interfaces
Jan 28 17:45:50.445665 All network interfaces resolved
Jan 28 17:45:50.445672 DHCP (ID: 1) Start DHCP
Jan 28 17:45:50.446072 DHCP (ID: 1) DHCP-Discover send
Jan 28 17:45:50.446584 DHCP (ID: 1) DHCP-Offer received
Jan 28 17:45:50.446643 DHCP (ID: 1) DHCP-Request (selecting) send
Jan 28 17:45:50.446892 DHCP (ID: 1) DHCP-ACK received
Jan 28 17:45:50.447166 ALL SESSIONS ESTABLISHED
Jan 28 17:45:56.346278 DHCP (ID: 1) Stop DHCP
Jan 28 17:46:00.346854 DHCP (ID: 1) Start DHCP
Jan 28 17:46:00.347064 DHCP (ID: 1) DHCP-Discover send
Jan 28 17:46:00.347927 DHCP (ID: 1) DHCP-Offer received
Jan 28 17:46:00.347974 DHCP (ID: 1) DHCP-Request (selecting) send
Jan 28 17:46:00.348458 DHCP (ID: 1) DHCP-ACK received
bngblaster: /root/bngblaster/code/bngblaster/src/bbl_session.c:556: bbl_session_update_state: Assertion `g_ctx->sessions_outstanding' failed.
Aborted (core dumped)

Other minor fixes:

diff --git a/code/bngblaster/src/bbl_dhcp.c b/code/bngblaster/src/bbl_dhcp.c
index 63a93607..205c24ca 100644
--- a/code/bngblaster/src/bbl_dhcp.c
+++ b/code/bngblaster/src/bbl_dhcp.c
@@ -16,6 +16,7 @@
  * This function stops the DHCP negotiation.
  *
  * @param session session
+ * @param bool keep_address
  */
 void
 bbl_dhcp_stop(bbl_session_s *session, bool keep_address)
diff --git a/docs/_sources/configuration/dhcp.rst.txt b/docs/_sources/configuration/dhcp.rst.txt
index 1d861865..9279f7af 100644
--- a/docs/_sources/configuration/dhcp.rst.txt
+++ b/docs/_sources/configuration/dhcp.rst.txt
@@ -34,7 +34,7 @@
 +-----------------------------------+----------------------------------------------------------------------+
 | **vendor-class-id**               | | Add DHCP vendor class id/option 60.                                |
 +-----------------------------------+----------------------------------------------------------------------+
-| **keep-address**                  | | Emualtes init-reboot on stop if enabled together with              |
+| **keep-address**                  | | Emulates init-reboot on stop if enabled together with              |
 |                                   | | release-retry set to zero (disabled).                              |
 |                                   | | Default: false                                                     |
 +-----------------------------------+----------------------------------------------------------------------+

[GIC-de]

Should be fixed now (8d0b7dd)

[GIC-de]

Final MR: #369

[jcpvdm]

dhcp-release command does not generate a release message if "release-retry": 0 is in configuration. Can "release-retry" argument be added to dhcp-release command to provide override ability?

[GIC-de]

Currently this is defined globally only, so I could allow to change in that common, but it would apply globally.

[jcpvdm]

I see. Then suggest to add a note in the doc that command will only work if the config is >0 and a condition in the code that returns error otherwise.

Thanks for adding this feature! Tested successfully.

[GIC-de]

Oh yeah, I can easily return an error in the command if release is requests but release retry set to 0. This is possible.

[GIC-de]

Also thanks for your contributions here, which was a great help!