Extend the bpf_fib_lookup() helper by making it to utilize mark if
the BPF_FIB_LOOKUP_MARK flag is set. In order to pass the mark the
four bytes of struct bpf_fib_lookup are used, shared with the
output-only smac/dmac fields.
Signed-off-by: Anton Protopopov <aspsk@xxxxxxxxxxxxx>
Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
---
include/uapi/linux/bpf.h | 20 ++++++++++++++++++--
net/core/filter.c | 12 +++++++++---
tools/include/uapi/linux/bpf.h | 20 ++++++++++++++++++--
3 files changed, 45 insertions(+), 7 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 9585f5345353..96d57e483133 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3394,6 +3394,10 @@ union bpf_attr {
* for the nexthop. If the src addr cannot be derived,
* **BPF_FIB_LKUP_RET_NO_SRC_ADDR** is returned. In this
* case, *params*->dmac and *params*->smac are not set either.
+ * **BPF_FIB_LOOKUP_MARK**
+ * Use the mark present in *params*->mark for the fib lookup.
+ * This option should not be used with BPF_FIB_LOOKUP_DIRECT,
+ * as it only has meaning for full lookups.
*
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** tc cls_act programs.
@@ -7120,6 +7124,7 @@ enum {
BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2),
BPF_FIB_LOOKUP_TBID = (1U << 3),
BPF_FIB_LOOKUP_SRC = (1U << 4),
+ BPF_FIB_LOOKUP_MARK = (1U << 5),
};
enum {
@@ -7197,8 +7202,19 @@ struct bpf_fib_lookup {
__u32 tbid;
};
- __u8 smac[6]; /* ETH_ALEN */
- __u8 dmac[6]; /* ETH_ALEN */
+ union {
+ /* input */
+ struct {
+ __u32 mark; /* policy routing */
+ /* 2 4-byte holes for input */
+ };
+
+ /* output: source and dest mac */
+ struct {
+ __u8 smac[6]; /* ETH_ALEN */
+ __u8 dmac[6]; /* ETH_ALEN */
+ };
+ };
};
struct bpf_redir_neigh {
diff --git a/net/core/filter.c b/net/core/filter.c
index 0c66e4a3fc5b..1205dd777dc2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5884,7 +5884,10 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
} else {
- fl4.flowi4_mark = 0;
+ if (flags & BPF_FIB_LOOKUP_MARK)
+ fl4.flowi4_mark = params->mark;
+ else
+ fl4.flowi4_mark = 0;
fl4.flowi4_secid = 0;
fl4.flowi4_tun_key.tun_id = 0;
fl4.flowi4_uid = sock_net_uid(net, NULL);
@@ -6027,7 +6030,10 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
err = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6, &res,
strict);
} else {
- fl6.flowi6_mark = 0;
+ if (flags & BPF_FIB_LOOKUP_MARK)
+ fl6.flowi6_mark = params->mark;
+ else
+ fl6.flowi6_mark = 0;
fl6.flowi6_secid = 0;
fl6.flowi6_tun_key.tun_id = 0;
fl6.flowi6_uid = sock_net_uid(net, NULL);
@@ -6105,7 +6111,7 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
#define BPF_FIB_LOOKUP_MASK (BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_OUTPUT | \
BPF_FIB_LOOKUP_SKIP_NEIGH | BPF_FIB_LOOKUP_TBID | \
- BPF_FIB_LOOKUP_SRC)
+ BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_MARK)
BPF_CALL_4(bpf_xdp_fib_lookup, struct xdp_buff *, ctx,
struct bpf_fib_lookup *, params, int, plen, u32, flags)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index bf80b614c4db..4c9b5bfbd9c6 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3393,6 +3393,10 @@ union bpf_attr {
* for the nexthop. If the src addr cannot be derived,
* **BPF_FIB_LKUP_RET_NO_SRC_ADDR** is returned. In this
* case, *params*->dmac and *params*->smac are not set either.
+ * **BPF_FIB_LOOKUP_MARK**
+ * Use the mark present in *params*->mark for the fib lookup.
+ * This option should not be used with BPF_FIB_LOOKUP_DIRECT,
+ * as it only has meaning for full lookups.
*
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** tc cls_act programs.
@@ -7119,6 +7123,7 @@ enum {
BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2),
BPF_FIB_LOOKUP_TBID = (1U << 3),
BPF_FIB_LOOKUP_SRC = (1U << 4),
+ BPF_FIB_LOOKUP_MARK = (1U << 5),
};
enum {
@@ -7196,8 +7201,19 @@ struct bpf_fib_lookup {
__u32 tbid;
};
- __u8 smac[6]; /* ETH_ALEN */
- __u8 dmac[6]; /* ETH_ALEN */
+ union {
+ /* input */
+ struct {
+ __u32 mark; /* policy routing */
+ /* 2 4-byte holes for input */
+ };
+
+ /* output: source and dest mac */
+ struct {
+ __u8 smac[6]; /* ETH_ALEN */
+ __u8 dmac[6]; /* ETH_ALEN */
+ };
+ };
};
struct bpf_redir_neigh {
--
2.34.1
