Re: [PATCH net-next v5 2/6] ipv6: ioam: Data plane support for Pre-allocated Trace
From: Eric Dumazet <hidden>
Date: 2021-07-21 16:46:17
On 7/20/21 9:42 PM, Justin Iurman wrote:
Implement support for processing the IOAM Pre-allocated Trace with IPv6, see [1] and [2]. Introduce a new IPv6 Hop-by-Hop TLV option, see IANA [3]. A new per-interface sysctl is introduced. The value is a boolean to accept (=1) or ignore (=0, by default) IPv6 IOAM options on ingress for an interface: - net.ipv6.conf.XXX.ioam6_enabled
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quoted hunk ↗ jump to hunk
} +/* IOAM */ + +static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) +{ + struct ioam6_trace_hdr *trace; + struct ioam6_namespace *ns; + struct ioam6_hdr *hdr; + + /* Bad alignment (must be 4n-aligned) */ + if (optoff & 3) + goto drop; + + /* Ignore if IOAM is not enabled on ingress */ + if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled) + goto ignore; + + /* Truncated Option header */ + hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); + if (hdr->opt_len < 2) + goto drop; + + switch (hdr->type) { + case IOAM6_TYPE_PREALLOC: + /* Truncated Pre-allocated Trace header */ + if (hdr->opt_len < 2 + sizeof(*trace)) + goto drop; + + /* Malformed Pre-allocated Trace header */ + trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); + if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) + goto drop; + + /* Ignore if the IOAM namespace is unknown */ + ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id); + if (!ns) + goto ignore; + + if (!skb_valid_dst(skb)) + ip6_route_input(skb); + + ioam6_fill_trace_data(skb, ns, trace); + break; + default: + break; + } + +ignore: + return true; + +drop: + kfree_skb(skb); + return false; +} + /* Jumbo payload */ static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)@@ -999,6 +1056,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = { .type = IPV6_TLV_ROUTERALERT, .func = ipv6_hop_ra, }, + { + .type = IPV6_TLV_IOAM, + .func = ipv6_hop_ioam, + },
It is a bit strange to put a not-yet used option in the midle of the table, before TLV_JUMBO (that some of us use already...)
{
.type = IPV6_TLV_JUMBO,
.func = ipv6_hop_jumbo,