Re: [PATCH v2 2/2] dhcpv6: Inject custom options into DHCPv6 replies

On Thu, 18 Jun 2026 17:35:29 +0530 Anshu Kumari wrote:

Append user-specified options from --dhcpv6-opt to DHCPv6 reply messages. Options are parsed from the stored string value at reply time using dhcpv6_opt_parse(), and skipped with a debug message if they exceed the available space.

Link: https://bugs.passt.top/show_bug.cgi?id=192 Signed-off-by: Anshu Kumari --- v2: - Updated dhcpv6_custom_opts_fill() to parse str at reply time using dhcpv6_opt_parse() instead of copying cached val/len. --- dhcpv6.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)

diff --git a/dhcpv6.c b/dhcpv6.c index 1e1dd0d..6b1e90b 100644 --- a/dhcpv6.c +++ b/dhcpv6.c @@ -748,6 +748,49 @@ static size_t dhcpv6_client_fqdn_fill(const struct iov_tail *data, return offset + sizeof(struct opt_hdr) + opt_len; }

+/** + * dhcpv6_custom_opts_fill() - Append user-specified custom options to reply + * @c: Execution context + * @buf: Response message buffer + * @offset: Current offset in buffer + * + * Return: updated offset after appending custom options + */ +static size_t dhcpv6_custom_opts_fill(const struct ctx *c, + char *buf, int offset) +{ + int i; + + for (i = 0; i < c->dhcpv6_opts_count; i++) { + uint16_t code = c->dhcpv6_opts[i].code; + struct opt_hdr *hdr; + uint8_t val[255];

This should be UINT16_MAX. Other than that, this looks good to me, except for pending comments from David and also my considerations on top of that. -- Stefano