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authorSridhar K. N. Rao <srao@linuxfoundation.org>2022-12-16 17:24:48 +0530
committerSridhar K. N. Rao <srao@linuxfoundation.org>2022-12-19 21:14:08 +0530
commit3409364da8fa46eae8ca22a579e219dc74958079 (patch)
tree83cb1cc72c3c59465d7d3be0f793a896c0ad7a21 /src/bpfswitch/ksrc/xdp_l2fwd.c
parent34147ac299351c44d4f7d135892457fba38a132b (diff)
ebpf: This patch adds ebpf-baremetal test support
Remove object files and binaries Suggestions in systems/Readme. Add license headers. Signed-off-by: Sridhar K. N. Rao <srao@linuxfoundation.org> Change-Id: I5fd481e3ed3eb51e6b8091cbf6d1ec8e3b00cbf0
Diffstat (limited to 'src/bpfswitch/ksrc/xdp_l2fwd.c')
-rw-r--r--src/bpfswitch/ksrc/xdp_l2fwd.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/src/bpfswitch/ksrc/xdp_l2fwd.c b/src/bpfswitch/ksrc/xdp_l2fwd.c
new file mode 100644
index 00000000..750b580d
--- /dev/null
+++ b/src/bpfswitch/ksrc/xdp_l2fwd.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Example of L2 forwarding via XDP. FDB is a <vlan,dmac> hash table
+ * returning device index to redirect packet.
+ *
+ * Copyright (c) 2019-2020 David Ahern <dsahern@gmail.com>
+ * The code is modified to use 2 mac addresses as key instead of
+ * mac address and vlan id as key
+ *
+ */
+#define KBUILD_MODNAME "xdp_l2fwd"
+#include <uapi/linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#include "xdp_fdb.h"
+
+/* For TX-traffic redirect requires net_device ifindex to be in this devmap */
+struct bpf_map_def SEC("maps") xdp_fwd_ports = {
+ .type = BPF_MAP_TYPE_DEVMAP_HASH,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(struct bpf_devmap_val),
+ .max_entries = 512,
+};
+
+/* <vlan,dmac> to device index map */
+struct bpf_map_def SEC("maps") fdb_map = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(struct fdb_key),
+ .value_size = sizeof(u32),
+ .max_entries = 512,
+};
+
+SEC("xdp_l2fwd")
+int xdp_l2fwd_prog(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct bpf_devmap_val *entry;
+ struct vlan_hdr *vhdr = NULL;
+ struct ethhdr *eth;
+ struct fdb_key key;
+ u8 smac[ETH_ALEN];
+ u16 h_proto = 0;
+ void *nh;
+ int rc;
+
+ /* data in context points to ethernet header */
+ eth = data;
+
+ /* set pointer to header after ethernet header */
+ nh = data + sizeof(*eth);
+ if (nh > data_end)
+ return XDP_DROP; // malformed packet
+
+ __builtin_memset(&key, 0, sizeof(key));
+ __builtin_memcpy(key.dmac, eth->h_dest, ETH_ALEN);
+ __builtin_memcpy(key.smac, eth->h_source, ETH_ALEN);
+
+ if (eth->h_proto == htons(ETH_P_8021Q)) {
+ vhdr = nh;
+ if (vhdr + 1 > data_end)
+ return XDP_DROP; // malformed packet
+
+ //key.vlan = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
+ }
+
+ entry = bpf_map_lookup_elem(&fdb_map, &key);
+ if (!entry || entry->ifindex == 0)
+ return XDP_PASS;
+
+ /* Verify redirect index exists in port map */
+ if (!bpf_map_lookup_elem(&xdp_fwd_ports, &entry->ifindex))
+ return XDP_PASS;
+
+ if (vhdr) {
+ /* remove VLAN header before hand off to VM */
+ h_proto = vhdr->h_vlan_encapsulated_proto;
+ __builtin_memcpy(smac, eth->h_source, ETH_ALEN);
+
+ if (bpf_xdp_adjust_head(ctx, sizeof(*vhdr)))
+ return XDP_PASS;
+
+ /* reset data pointers after adjust */
+ data = (void *)(long)ctx->data;
+ data_end = (void *)(long)ctx->data_end;
+ eth = data;
+ if (eth + 1 > data_end)
+ return XDP_DROP;
+
+ __builtin_memcpy(eth->h_dest, key.dmac, ETH_ALEN);
+ __builtin_memcpy(eth->h_source, smac, ETH_ALEN);
+ eth->h_proto = h_proto;
+ }
+
+ return bpf_redirect_map(&xdp_fwd_ports, entry->ifindex, 0);
+}
+
+char _license[] SEC("license") = "GPL";
+int _version SEC("version") = LINUX_VERSION_CODE;