[PATCH net-next v3] net: ipv6: seg6: report lwtunnel setup errors via extack
From: Gabriel Goller <hidden>
Date: 2026-09-23 12:02:39
seg6_build_state() rejected invalid configurations with a generic -EINVAL, so "ip route add ... encap seg6 ..." always reported "Invalid argument". Attach an extack message to each of them. The checks themselves and their return values are unchanged. Signed-off-by: Gabriel Goller <redacted> --- v3 (https://lore.kernel.org/all/20260922090851.38978-1-g.goller@proxmox.com/): * format fix * use NL_SET_ERR_MSG_ATTR v2 (https://lore.kernel.org/all/20260918153544.1178884-1-g.goller@proxmox.com/): * dropped tests net/ipv6/seg6_iptunnel.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index 61c6a27bf202..9f1aecc4f215 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c@@ -756,8 +756,11 @@ static int seg6_build_state(struct net *net, struct nlattr *nla, struct seg6_lwt *slwt; int err; - if (family != AF_INET && family != AF_INET6) + if (family != AF_INET && family != AF_INET6) { + NL_SET_ERR_MSG(extack, + "unsupported address family for SRv6 encapsulation"); return -EINVAL; + } err = nla_parse_nested_deprecated(tb, SEG6_IPTUNNEL_MAX, nla, seg6_iptunnel_policy, extack);
@@ -765,8 +768,10 @@ static int seg6_build_state(struct net *net, struct nlattr *nla, if (err < 0) return err; - if (!tb[SEG6_IPTUNNEL_SRH]) + if (!tb[SEG6_IPTUNNEL_SRH]) { + NL_SET_ERR_MSG_ATTR(extack, nla, "missing SRv6 SRH attribute"); return -EINVAL; + } tuninfo = nla_data(tb[SEG6_IPTUNNEL_SRH]); tuninfo_len = nla_len(tb[SEG6_IPTUNNEL_SRH]);
@@ -776,13 +781,18 @@ static int seg6_build_state(struct net *net, struct nlattr *nla, */ min_size = sizeof(*tuninfo) + sizeof(struct ipv6_sr_hdr) + sizeof(struct in6_addr); - if (tuninfo_len < min_size) + if (tuninfo_len < min_size) { + NL_SET_ERR_MSG(extack, "truncated SRv6 SRH attribute"); return -EINVAL; + } switch (tuninfo->mode) { case SEG6_IPTUN_MODE_INLINE: - if (family != AF_INET6) + if (family != AF_INET6) { + NL_SET_ERR_MSG(extack, + "inline mode requires an IPv6 route"); return -EINVAL; + } if (tb[SEG6_IPTUNNEL_SRC]) { NL_SET_ERR_MSG(extack, "incompatible mode for tunsrc");
@@ -798,12 +808,16 @@ static int seg6_build_state(struct net *net, struct nlattr *nla, case SEG6_IPTUN_MODE_L2ENCAP_RED: break; default: + NL_SET_ERR_MSG(extack, "invalid SRv6 encapsulation mode"); return -EINVAL; } /* verify that SRH is consistent */ - if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo), false)) + if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo), + false)) { + NL_SET_ERR_MSG(extack, "invalid SRv6 segment routing header"); return -EINVAL; + } newts = lwtunnel_state_alloc(tuninfo_len + sizeof(*slwt)); if (!newts)
--
2.47.3