Squashed 'vendor/ruvector/' content from commit b64c2172

git-subtree-dir: vendor/ruvector
git-subtree-split: b64c21726f2bb37286d9ee36a7869fef60cc6900

crates/rvf/rvf-ebpf/bpf/tc_query_route.c

@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// RVF TC Query Router: Priority-Based Query Classification
+//
+// This TC (Traffic Control) classifier inspects incoming UDP packets
+// destined for the RVF query port and classifies them into priority
+// tiers based on the query type encoded in the RVF protocol header.
+//
+// Classification tiers (set via skb->tc_classid):
+//   TC_H_MAKE(1, 1) = "hot" queries   (low-latency, cached vectors)
+//   TC_H_MAKE(1, 2) = "warm" queries  (standard priority)
+//   TC_H_MAKE(1, 3) = "cold" queries  (batch/bulk, best-effort)
+//
+// The query type is determined by inspecting the flags field in the
+// RVF query header that follows the UDP payload.
+//
+// Attach: tc filter add dev <iface> ingress bpf da obj tc_query_route.o
+
+#include "vmlinux.h"
+
+/* ── Configuration ───────────────────────────────────────────────── */
+
+#define RVF_PORT     8080
+#define RVF_MAGIC    0x52564600  /* "RVF\0" big-endian */
+
+/* TC classid helpers: major:minor */
+#define TC_H_MAKE(maj, min)  (((maj) << 16) | (min))
+
+/* Priority classes */
+#define CLASS_HOT    TC_H_MAKE(1, 1)
+#define CLASS_WARM   TC_H_MAKE(1, 2)
+#define CLASS_COLD   TC_H_MAKE(1, 3)
+
+/* RVF query flag bits (in the flags field of the extended header) */
+#define RVF_FLAG_HOT_CACHE   0x01  /* Request L0 (BPF map) cache lookup */
+#define RVF_FLAG_BATCH       0x02  /* Batch query mode */
+#define RVF_FLAG_PREFETCH    0x04  /* Prefetch hint for warming cache */
+#define RVF_FLAG_PRIORITY    0x08  /* Caller-requested high priority */
+
+/* ── RVF query header (same as xdp_distance.c) ──────────────────── */
+
+struct rvf_query_hdr {
+    __u32 magic;       /* RVF_MAGIC */
+    __u16 dimension;   /* vector dimension (network byte order) */
+    __u16 k;           /* top-k requested */
+    __u64 query_id;    /* caller-chosen query identifier */
+    __u32 flags;       /* query flags (network byte order) */
+} __attribute__((packed));
+
+/* ── BPF maps ────────────────────────────────────────────────────── */
+
+/* Per-CPU counters for each priority class */
+struct class_stats {
+    __u64 hot;
+    __u64 warm;
+    __u64 cold;
+    __u64 passthrough;
+};
+
+struct {
+    __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+    __uint(max_entries, 1);
+    __type(key, __u32);
+    __type(value, struct class_stats);
+} tc_stats SEC(".maps");
+
+/* ── Helpers ─────────────────────────────────────────────────────── */
+
+static __always_inline void bump_class(int class_idx)
+{
+    __u32 zero = 0;
+    struct class_stats *s = bpf_map_lookup_elem(&tc_stats, &zero);
+    if (!s)
+        return;
+
+    switch (class_idx) {
+    case 0: s->hot++;         break;
+    case 1: s->warm++;        break;
+    case 2: s->cold++;        break;
+    default: s->passthrough++; break;
+    }
+}
+
+/* ── TC classifier entry point ───────────────────────────────────── */
+
+SEC("tc")
+int rvf_query_classify(struct __sk_buff *skb)
+{
+    /* ── Parse IP protocol and header length ─────────────────────── */
+    __u8 ihl_byte = 0;
+    if (bpf_skb_load_bytes(skb, 0, &ihl_byte, 1) < 0)
+        return TC_ACT_OK;
+
+    __u32 ip_hdr_len = (__u32)(ihl_byte & 0x0F) * 4;
+    if (ip_hdr_len < 20)
+        return TC_ACT_OK;
+
+    __u8 protocol = 0;
+    if (bpf_skb_load_bytes(skb, 9, &protocol, 1) < 0)
+        return TC_ACT_OK;
+
+    if (protocol != IPPROTO_UDP) {
+        bump_class(3);
+        return TC_ACT_OK;
+    }
+
+    /* ── Parse UDP destination port ──────────────────────────────── */
+    __be16 raw_dport = 0;
+    if (bpf_skb_load_bytes(skb, ip_hdr_len + 2, &raw_dport, 2) < 0)
+        return TC_ACT_OK;
+
+    __u16 dport = bpf_ntohs(raw_dport);
+    if (dport != RVF_PORT) {
+        bump_class(3);
+        return TC_ACT_OK;
+    }
+
+    /* ── Parse RVF query header (after 8-byte UDP header) ────────── */
+    __u32 rvf_offset = ip_hdr_len + 8; /* IP hdr + UDP hdr */
+
+    struct rvf_query_hdr qhdr;
+    __bpf_memset(&qhdr, 0, sizeof(qhdr));
+    if (bpf_skb_load_bytes(skb, rvf_offset, &qhdr, sizeof(qhdr)) < 0) {
+        bump_class(3);
+        return TC_ACT_OK;
+    }
+
+    if (qhdr.magic != bpf_htonl(RVF_MAGIC)) {
+        bump_class(3);
+        return TC_ACT_OK;
+    }
+
+    /* ── Classify based on flags ─────────────────────────────────── */
+    __u32 flags = bpf_ntohl(qhdr.flags);
+
+    if (flags & RVF_FLAG_PRIORITY || flags & RVF_FLAG_HOT_CACHE) {
+        /* Hot path: low-latency cached query */
+        skb->tc_classid = CLASS_HOT;
+        bump_class(0);
+        return TC_ACT_OK;
+    }
+
+    if (flags & RVF_FLAG_BATCH) {
+        /* Cold path: bulk/batch query, best-effort */
+        skb->tc_classid = CLASS_COLD;
+        bump_class(2);
+        return TC_ACT_OK;
+    }
+
+    /* Default: warm / standard priority */
+    skb->tc_classid = CLASS_WARM;
+    bump_class(1);
+    return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";