diff options
| author | Dávid Benko <davidbenko@davidbenko.dev> | 2022-07-13 10:33:54 +0300 |
|---|---|---|
| committer | Hans Dedecker <dedeckeh@gmail.com> | 2022-07-13 22:54:00 +0300 |
| commit | 9212bfcbab7681cd30186ac7f1ef4c47bf38c89a (patch) | |
| tree | 4e3dc3de2b8b3346d0bc12f2db25f718ef062f5a | |
| parent | 39b584bcac8770619b545d6ae344758f87028612 (diff) | |
odhcp6c: fix IA discard when T1 > 0 and T2 = 0
My ISP uses DHCPv6 advertisements where IA_PD T1 is non-zero (43200) and
T2 is zero. Current implementation of odhcp6c doesn't handle that and
just switches to stateless mode.
According to RFC 8415, section [21.21](https://datatracker.ietf.org/doc/html/rfc8415#section-21.21):
> If a client receives an IA_PD with T1 greater than T2 and both T1 and
T2 are greater than 0, the client discards the IA_PD option and
processes the remainder of the message as though the server had not
included the IA_PD option.
Currently odhcp6c discards IA_PD option if `t1 > t2`:
https://github.com/openwrt/odhcp6c/blob/39b584bcac8770619b545d6ae344758f87028612/src/dhcpv6.c#L1346-L1347
The same applies for IA_NA.
Fix it by editing IA discard condition according to RFC.
Signed-off-by: Dávid Benko <davidbenko@davidbenko.dev>
| -rw-r--r-- | src/dhcpv6.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/dhcpv6.c b/src/dhcpv6.c index 793b3be..9411dd0 100644 --- a/src/dhcpv6.c +++ b/src/dhcpv6.c @@ -1343,7 +1343,7 @@ static unsigned int dhcpv6_parse_ia(void *opt, void *end) t1 = ntohl(ia_hdr->t1); t2 = ntohl(ia_hdr->t2); - if (t1 > t2) + if (t1 > t2 && t1 > 0 && t2 > 0) return 0; syslog(LOG_INFO, "%s %04x T1 %d T2 %d", ntohs(ia_hdr->type) == DHCPV6_OPT_IA_PD ? "IA_PD" : "IA_NA", ntohl(ia_hdr->iaid), t1, t2); |