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-rw-r--r--include/net/ipv6_stubs.h5
-rw-r--r--include/uapi/linux/bpf.h10
-rw-r--r--net/core/filter.c18
-rw-r--r--net/ipv6/af_inet6.c1
-rw-r--r--tools/include/uapi/linux/bpf.h10
-rw-r--r--tools/testing/selftests/bpf/prog_tests/fib_lookup.c83
6 files changed, 120 insertions, 7 deletions
diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index c48186bf4737..21da31e1dff5 100644
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -85,6 +85,11 @@ struct ipv6_bpf_stub {
sockptr_t optval, unsigned int optlen);
int (*ipv6_getsockopt)(struct sock *sk, int level, int optname,
sockptr_t optval, sockptr_t optlen);
+ int (*ipv6_dev_get_saddr)(struct net *net,
+ const struct net_device *dst_dev,
+ const struct in6_addr *daddr,
+ unsigned int prefs,
+ struct in6_addr *saddr);
};
extern const struct ipv6_bpf_stub *ipv6_bpf_stub __read_mostly;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index a7d4a1a69f21..e0aa457f94a9 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3264,6 +3264,11 @@ union bpf_attr {
* and *params*->smac will not be set as output. A common
* use case is to call **bpf_redirect_neigh**\ () after
* doing **bpf_fib_lookup**\ ().
+ * **BPF_FIB_LOOKUP_SRC**
+ * Derive and set source IP addr in *params*->ipv{4,6}_src
+ * 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.
*
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** tc cls_act programs.
@@ -6964,6 +6969,7 @@ enum {
BPF_FIB_LOOKUP_OUTPUT = (1U << 1),
BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2),
BPF_FIB_LOOKUP_TBID = (1U << 3),
+ BPF_FIB_LOOKUP_SRC = (1U << 4),
};
enum {
@@ -6976,6 +6982,7 @@ enum {
BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */
BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */
BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */
+ BPF_FIB_LKUP_RET_NO_SRC_ADDR, /* failed to derive IP src addr */
};
struct bpf_fib_lookup {
@@ -7010,6 +7017,9 @@ struct bpf_fib_lookup {
__u32 rt_metric;
};
+ /* input: source address to consider for lookup
+ * output: source address result from lookup
+ */
union {
__be32 ipv4_src;
__u32 ipv6_src[4]; /* in6_addr; network order */
diff --git a/net/core/filter.c b/net/core/filter.c
index a094694899c9..3880bf0b740d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5850,6 +5850,9 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
params->rt_metric = res.fi->fib_priority;
params->ifindex = dev->ifindex;
+ if (flags & BPF_FIB_LOOKUP_SRC)
+ params->ipv4_src = fib_result_prefsrc(net, &res);
+
/* xdp and cls_bpf programs are run in RCU-bh so
* rcu_read_lock_bh is not needed here
*/
@@ -5992,6 +5995,18 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
params->rt_metric = res.f6i->fib6_metric;
params->ifindex = dev->ifindex;
+ if (flags & BPF_FIB_LOOKUP_SRC) {
+ if (res.f6i->fib6_prefsrc.plen) {
+ *src = res.f6i->fib6_prefsrc.addr;
+ } else {
+ err = ipv6_bpf_stub->ipv6_dev_get_saddr(net, dev,
+ &fl6.daddr, 0,
+ src);
+ if (err)
+ return BPF_FIB_LKUP_RET_NO_SRC_ADDR;
+ }
+ }
+
if (flags & BPF_FIB_LOOKUP_SKIP_NEIGH)
goto set_fwd_params;
@@ -6010,7 +6025,8 @@ set_fwd_params:
#endif
#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_SKIP_NEIGH | BPF_FIB_LOOKUP_TBID | \
+ BPF_FIB_LOOKUP_SRC)
BPF_CALL_4(bpf_xdp_fib_lookup, struct xdp_buff *, ctx,
struct bpf_fib_lookup *, params, int, plen, u32, flags)
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index c6ad0d6e99b5..6337fb4504fd 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -1061,6 +1061,7 @@ static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {
.udp6_lib_lookup = __udp6_lib_lookup,
.ipv6_setsockopt = do_ipv6_setsockopt,
.ipv6_getsockopt = do_ipv6_getsockopt,
+ .ipv6_dev_get_saddr = ipv6_dev_get_saddr,
};
static int __init inet6_init(void)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index a7d4a1a69f21..e0aa457f94a9 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3264,6 +3264,11 @@ union bpf_attr {
* and *params*->smac will not be set as output. A common
* use case is to call **bpf_redirect_neigh**\ () after
* doing **bpf_fib_lookup**\ ().
+ * **BPF_FIB_LOOKUP_SRC**
+ * Derive and set source IP addr in *params*->ipv{4,6}_src
+ * 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.
*
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** tc cls_act programs.
@@ -6964,6 +6969,7 @@ enum {
BPF_FIB_LOOKUP_OUTPUT = (1U << 1),
BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2),
BPF_FIB_LOOKUP_TBID = (1U << 3),
+ BPF_FIB_LOOKUP_SRC = (1U << 4),
};
enum {
@@ -6976,6 +6982,7 @@ enum {
BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */
BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */
BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */
+ BPF_FIB_LKUP_RET_NO_SRC_ADDR, /* failed to derive IP src addr */
};
struct bpf_fib_lookup {
@@ -7010,6 +7017,9 @@ struct bpf_fib_lookup {
__u32 rt_metric;
};
+ /* input: source address to consider for lookup
+ * output: source address result from lookup
+ */
union {
__be32 ipv4_src;
__u32 ipv6_src[4]; /* in6_addr; network order */
diff --git a/tools/testing/selftests/bpf/prog_tests/fib_lookup.c b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
index 2fd05649bad1..4ad4cd69152e 100644
--- a/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
+++ b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
@@ -11,9 +11,13 @@
#define NS_TEST "fib_lookup_ns"
#define IPV6_IFACE_ADDR "face::face"
+#define IPV6_IFACE_ADDR_SEC "cafe::cafe"
+#define IPV6_ADDR_DST "face::3"
#define IPV6_NUD_FAILED_ADDR "face::1"
#define IPV6_NUD_STALE_ADDR "face::2"
#define IPV4_IFACE_ADDR "10.0.0.254"
+#define IPV4_IFACE_ADDR_SEC "10.1.0.254"
+#define IPV4_ADDR_DST "10.2.0.254"
#define IPV4_NUD_FAILED_ADDR "10.0.0.1"
#define IPV4_NUD_STALE_ADDR "10.0.0.2"
#define IPV4_TBID_ADDR "172.0.0.254"
@@ -31,6 +35,7 @@ struct fib_lookup_test {
const char *desc;
const char *daddr;
int expected_ret;
+ const char *expected_src;
int lookup_flags;
__u32 tbid;
__u8 dmac[6];
@@ -69,6 +74,22 @@ static const struct fib_lookup_test tests[] = {
.daddr = IPV6_TBID_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
.lookup_flags = BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID, .tbid = 100,
.dmac = DMAC_INIT2, },
+ { .desc = "IPv4 set src addr from netdev",
+ .daddr = IPV4_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .expected_src = IPV4_IFACE_ADDR,
+ .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
+ { .desc = "IPv6 set src addr from netdev",
+ .daddr = IPV6_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .expected_src = IPV6_IFACE_ADDR,
+ .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
+ { .desc = "IPv4 set prefsrc addr from route",
+ .daddr = IPV4_ADDR_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .expected_src = IPV4_IFACE_ADDR_SEC,
+ .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
+ { .desc = "IPv6 set prefsrc addr route",
+ .daddr = IPV6_ADDR_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .expected_src = IPV6_IFACE_ADDR_SEC,
+ .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
};
static int ifindex;
@@ -97,6 +118,13 @@ static int setup_netns(void)
SYS(fail, "ip neigh add %s dev veth1 nud failed", IPV4_NUD_FAILED_ADDR);
SYS(fail, "ip neigh add %s dev veth1 lladdr %s nud stale", IPV4_NUD_STALE_ADDR, DMAC);
+ /* Setup for prefsrc IP addr selection */
+ SYS(fail, "ip addr add %s/24 dev veth1", IPV4_IFACE_ADDR_SEC);
+ SYS(fail, "ip route add %s/32 dev veth1 src %s", IPV4_ADDR_DST, IPV4_IFACE_ADDR_SEC);
+
+ SYS(fail, "ip addr add %s/64 dev veth1 nodad", IPV6_IFACE_ADDR_SEC);
+ SYS(fail, "ip route add %s/128 dev veth1 src %s", IPV6_ADDR_DST, IPV6_IFACE_ADDR_SEC);
+
/* Setup for tbid lookup tests */
SYS(fail, "ip addr add %s/24 dev veth2", IPV4_TBID_ADDR);
SYS(fail, "ip route del %s/24 dev veth2", IPV4_TBID_NET);
@@ -133,9 +161,12 @@ static int set_lookup_params(struct bpf_fib_lookup *params, const struct fib_loo
if (inet_pton(AF_INET6, test->daddr, params->ipv6_dst) == 1) {
params->family = AF_INET6;
- ret = inet_pton(AF_INET6, IPV6_IFACE_ADDR, params->ipv6_src);
- if (!ASSERT_EQ(ret, 1, "inet_pton(IPV6_IFACE_ADDR)"))
- return -1;
+ if (!(test->lookup_flags & BPF_FIB_LOOKUP_SRC)) {
+ ret = inet_pton(AF_INET6, IPV6_IFACE_ADDR, params->ipv6_src);
+ if (!ASSERT_EQ(ret, 1, "inet_pton(IPV6_IFACE_ADDR)"))
+ return -1;
+ }
+
return 0;
}
@@ -143,9 +174,12 @@ static int set_lookup_params(struct bpf_fib_lookup *params, const struct fib_loo
if (!ASSERT_EQ(ret, 1, "convert IP[46] address"))
return -1;
params->family = AF_INET;
- ret = inet_pton(AF_INET, IPV4_IFACE_ADDR, &params->ipv4_src);
- if (!ASSERT_EQ(ret, 1, "inet_pton(IPV4_IFACE_ADDR)"))
- return -1;
+
+ if (!(test->lookup_flags & BPF_FIB_LOOKUP_SRC)) {
+ ret = inet_pton(AF_INET, IPV4_IFACE_ADDR, &params->ipv4_src);
+ if (!ASSERT_EQ(ret, 1, "inet_pton(IPV4_IFACE_ADDR)"))
+ return -1;
+ }
return 0;
}
@@ -156,6 +190,40 @@ static void mac_str(char *b, const __u8 *mac)
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
}
+static void assert_src_ip(struct bpf_fib_lookup *fib_params, const char *expected_src)
+{
+ int ret;
+ __u32 src6[4];
+ __be32 src4;
+
+ switch (fib_params->family) {
+ case AF_INET6:
+ ret = inet_pton(AF_INET6, expected_src, src6);
+ ASSERT_EQ(ret, 1, "inet_pton(expected_src)");
+
+ ret = memcmp(src6, fib_params->ipv6_src, sizeof(fib_params->ipv6_src));
+ if (!ASSERT_EQ(ret, 0, "fib_lookup ipv6 src")) {
+ char str_src6[64];
+
+ inet_ntop(AF_INET6, fib_params->ipv6_src, str_src6,
+ sizeof(str_src6));
+ printf("ipv6 expected %s actual %s ", expected_src,
+ str_src6);
+ }
+
+ break;
+ case AF_INET:
+ ret = inet_pton(AF_INET, expected_src, &src4);
+ ASSERT_EQ(ret, 1, "inet_pton(expected_src)");
+
+ ASSERT_EQ(fib_params->ipv4_src, src4, "fib_lookup ipv4 src");
+
+ break;
+ default:
+ PRINT_FAIL("invalid addr family: %d", fib_params->family);
+ }
+}
+
void test_fib_lookup(void)
{
struct bpf_fib_lookup *fib_params;
@@ -207,6 +275,9 @@ void test_fib_lookup(void)
ASSERT_EQ(skel->bss->fib_lookup_ret, tests[i].expected_ret,
"fib_lookup_ret");
+ if (tests[i].expected_src)
+ assert_src_ip(fib_params, tests[i].expected_src);
+
ret = memcmp(tests[i].dmac, fib_params->dmac, sizeof(tests[i].dmac));
if (!ASSERT_EQ(ret, 0, "dmac not match")) {
char expected[18], actual[18];
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-12 10:18:52 +0000