summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/linux/filter.h2
-rw-r--r--include/uapi/linux/bpf.h32
-rw-r--r--include/uapi/linux/lwtunnel.h23
-rw-r--r--kernel/bpf/verifier.c14
-rw-r--r--net/Kconfig8
-rw-r--r--net/core/Makefile1
-rw-r--r--net/core/filter.c173
-rw-r--r--net/core/lwt_bpf.c396
-rw-r--r--net/core/lwtunnel.c2
-rw-r--r--net/ipv4/route.c37
-rw-r--r--samples/bpf/Makefile4
-rw-r--r--samples/bpf/bpf_helpers.h4
-rw-r--r--samples/bpf/lwt_len_hist.sh37
-rw-r--r--samples/bpf/lwt_len_hist_kern.c82
-rw-r--r--samples/bpf/lwt_len_hist_user.c76
-rw-r--r--samples/bpf/test_lwt_bpf.c253
-rw-r--r--samples/bpf/test_lwt_bpf.sh399
17 files changed, 1527 insertions, 16 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 7f246a281435..7ba644626553 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -438,7 +438,7 @@ struct xdp_buff {
};
/* compute the linear packet data range [data, data_end) which
- * will be accessed by cls_bpf and act_bpf programs
+ * will be accessed by cls_bpf, act_bpf and lwt programs
*/
static inline void bpf_compute_data_end(struct sk_buff *skb)
{
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 1370a9d1456f..22ac82792687 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -101,6 +101,9 @@ enum bpf_prog_type {
BPF_PROG_TYPE_XDP,
BPF_PROG_TYPE_PERF_EVENT,
BPF_PROG_TYPE_CGROUP_SKB,
+ BPF_PROG_TYPE_LWT_IN,
+ BPF_PROG_TYPE_LWT_OUT,
+ BPF_PROG_TYPE_LWT_XMIT,
};
enum bpf_attach_type {
@@ -409,6 +412,16 @@ union bpf_attr {
*
* int bpf_get_numa_node_id()
* Return: Id of current NUMA node.
+ *
+ * int bpf_skb_change_head()
+ * Grows headroom of skb and adjusts MAC header offset accordingly.
+ * Will extends/reallocae as required automatically.
+ * May change skb data pointer and will thus invalidate any check
+ * performed for direct packet access.
+ * @skb: pointer to skb
+ * @len: length of header to be pushed in front
+ * @flags: Flags (unused for now)
+ * Return: 0 on success or negative error
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -453,7 +466,8 @@ union bpf_attr {
FN(skb_pull_data), \
FN(csum_update), \
FN(set_hash_invalid), \
- FN(get_numa_node_id),
+ FN(get_numa_node_id), \
+ FN(skb_change_head),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -537,6 +551,22 @@ struct bpf_tunnel_key {
__u32 tunnel_label;
};
+/* Generic BPF return codes which all BPF program types may support.
+ * The values are binary compatible with their TC_ACT_* counter-part to
+ * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
+ * programs.
+ *
+ * XDP is handled seprately, see XDP_*.
+ */
+enum bpf_ret_code {
+ BPF_OK = 0,
+ /* 1 reserved */
+ BPF_DROP = 2,
+ /* 3-6 reserved */
+ BPF_REDIRECT = 7,
+ /* >127 are reserved for prog type specific return codes */
+};
+
/* User return codes for XDP prog type.
* A valid XDP program must return one of these defined values. All other
* return codes are reserved for future use. Unknown return codes will result
diff --git a/include/uapi/linux/lwtunnel.h b/include/uapi/linux/lwtunnel.h
index 453cc6215bfd..92724cba1eba 100644
--- a/include/uapi/linux/lwtunnel.h
+++ b/include/uapi/linux/lwtunnel.h
@@ -10,6 +10,7 @@ enum lwtunnel_encap_types {
LWTUNNEL_ENCAP_ILA,
LWTUNNEL_ENCAP_IP6,
LWTUNNEL_ENCAP_SEG6,
+ LWTUNNEL_ENCAP_BPF,
__LWTUNNEL_ENCAP_MAX,
};
@@ -43,4 +44,26 @@ enum lwtunnel_ip6_t {
#define LWTUNNEL_IP6_MAX (__LWTUNNEL_IP6_MAX - 1)
+enum {
+ LWT_BPF_PROG_UNSPEC,
+ LWT_BPF_PROG_FD,
+ LWT_BPF_PROG_NAME,
+ __LWT_BPF_PROG_MAX,
+};
+
+#define LWT_BPF_PROG_MAX (__LWT_BPF_PROG_MAX - 1)
+
+enum {
+ LWT_BPF_UNSPEC,
+ LWT_BPF_IN,
+ LWT_BPF_OUT,
+ LWT_BPF_XMIT,
+ LWT_BPF_XMIT_HEADROOM,
+ __LWT_BPF_MAX,
+};
+
+#define LWT_BPF_MAX (__LWT_BPF_MAX - 1)
+
+#define LWT_BPF_MAX_HEADROOM 256
+
#endif /* _UAPI_LWTUNNEL_H_ */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 8740c5fa02fc..8135cb1077ee 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -633,12 +633,19 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, int off,
#define MAX_PACKET_OFF 0xffff
static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
- const struct bpf_call_arg_meta *meta)
+ const struct bpf_call_arg_meta *meta,
+ enum bpf_access_type t)
{
switch (env->prog->type) {
+ case BPF_PROG_TYPE_LWT_IN:
+ case BPF_PROG_TYPE_LWT_OUT:
+ /* dst_input() and dst_output() can't write for now */
+ if (t == BPF_WRITE)
+ return false;
case BPF_PROG_TYPE_SCHED_CLS:
case BPF_PROG_TYPE_SCHED_ACT:
case BPF_PROG_TYPE_XDP:
+ case BPF_PROG_TYPE_LWT_XMIT:
if (meta)
return meta->pkt_access;
@@ -837,7 +844,7 @@ static int check_mem_access(struct bpf_verifier_env *env, u32 regno, int off,
err = check_stack_read(state, off, size, value_regno);
}
} else if (state->regs[regno].type == PTR_TO_PACKET) {
- if (t == BPF_WRITE && !may_access_direct_pkt_data(env, NULL)) {
+ if (t == BPF_WRITE && !may_access_direct_pkt_data(env, NULL, t)) {
verbose("cannot write into packet\n");
return -EACCES;
}
@@ -970,7 +977,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
return 0;
}
- if (type == PTR_TO_PACKET && !may_access_direct_pkt_data(env, meta)) {
+ if (type == PTR_TO_PACKET &&
+ !may_access_direct_pkt_data(env, meta, BPF_READ)) {
verbose("helper access to the packet is not allowed\n");
return -EACCES;
}
diff --git a/net/Kconfig b/net/Kconfig
index 7b6cd340b72b..a1005007224c 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -402,6 +402,14 @@ config LWTUNNEL
weight tunnel endpoint. Tunnel encapsulation parameters are stored
with light weight tunnel state associated with fib routes.
+config LWTUNNEL_BPF
+ bool "Execute BPF program as route nexthop action"
+ depends on LWTUNNEL
+ default y if LWTUNNEL=y
+ ---help---
+ Allows to run BPF programs as a nexthop action following a route
+ lookup for incoming and outgoing packets.
+
config DST_CACHE
bool
default n
diff --git a/net/core/Makefile b/net/core/Makefile
index d6508c2ddca5..f6761b6e3b29 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_NET_PTP_CLASSIFY) += ptp_classifier.o
obj-$(CONFIG_CGROUP_NET_PRIO) += netprio_cgroup.o
obj-$(CONFIG_CGROUP_NET_CLASSID) += netclassid_cgroup.o
obj-$(CONFIG_LWTUNNEL) += lwtunnel.o
+obj-$(CONFIG_LWTUNNEL_BPF) += lwt_bpf.o
obj-$(CONFIG_DST_CACHE) += dst_cache.o
obj-$(CONFIG_HWBM) += hwbm.o
obj-$(CONFIG_NET_DEVLINK) += devlink.o
diff --git a/net/core/filter.c b/net/core/filter.c
index 698a262b8ebb..1c4d0faf22c8 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1689,6 +1689,12 @@ static int __bpf_redirect_no_mac(struct sk_buff *skb, struct net_device *dev,
static int __bpf_redirect_common(struct sk_buff *skb, struct net_device *dev,
u32 flags)
{
+ /* Verify that a link layer header is carried */
+ if (unlikely(skb->mac_header >= skb->network_header)) {
+ kfree_skb(skb);
+ return -ERANGE;
+ }
+
bpf_push_mac_rcsum(skb);
return flags & BPF_F_INGRESS ?
__bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb);
@@ -2188,12 +2194,53 @@ static const struct bpf_func_proto bpf_skb_change_tail_proto = {
.arg3_type = ARG_ANYTHING,
};
+BPF_CALL_3(bpf_skb_change_head, struct sk_buff *, skb, u32, head_room,
+ u64, flags)
+{
+ u32 max_len = __bpf_skb_max_len(skb);
+ u32 new_len = skb->len + head_room;
+ int ret;
+
+ if (unlikely(flags || (!skb_is_gso(skb) && new_len > max_len) ||
+ new_len < skb->len))
+ return -EINVAL;
+
+ ret = skb_cow(skb, head_room);
+ if (likely(!ret)) {
+ /* Idea for this helper is that we currently only
+ * allow to expand on mac header. This means that
+ * skb->protocol network header, etc, stay as is.
+ * Compared to bpf_skb_change_tail(), we're more
+ * flexible due to not needing to linearize or
+ * reset GSO. Intention for this helper is to be
+ * used by an L3 skb that needs to push mac header
+ * for redirection into L2 device.
+ */
+ __skb_push(skb, head_room);
+ memset(skb->data, 0, head_room);
+ skb_reset_mac_header(skb);
+ }
+
+ bpf_compute_data_end(skb);
+ return 0;
+}
+
+static const struct bpf_func_proto bpf_skb_change_head_proto = {
+ .func = bpf_skb_change_head,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_ANYTHING,
+};
+
bool bpf_helper_changes_skb_data(void *func)
{
if (func == bpf_skb_vlan_push ||
func == bpf_skb_vlan_pop ||
func == bpf_skb_store_bytes ||
func == bpf_skb_change_proto ||
+ func == bpf_skb_change_head ||
func == bpf_skb_change_tail ||
func == bpf_skb_pull_data ||
func == bpf_l3_csum_replace ||
@@ -2639,6 +2686,68 @@ cg_skb_func_proto(enum bpf_func_id func_id)
}
}
+static const struct bpf_func_proto *
+lwt_inout_func_proto(enum bpf_func_id func_id)
+{
+ switch (func_id) {
+ case BPF_FUNC_skb_load_bytes:
+ return &bpf_skb_load_bytes_proto;
+ case BPF_FUNC_skb_pull_data:
+ return &bpf_skb_pull_data_proto;
+ case BPF_FUNC_csum_diff:
+ return &bpf_csum_diff_proto;
+ case BPF_FUNC_get_cgroup_classid:
+ return &bpf_get_cgroup_classid_proto;
+ case BPF_FUNC_get_route_realm:
+ return &bpf_get_route_realm_proto;
+ case BPF_FUNC_get_hash_recalc:
+ return &bpf_get_hash_recalc_proto;
+ case BPF_FUNC_perf_event_output:
+ return &bpf_skb_event_output_proto;
+ case BPF_FUNC_get_smp_processor_id:
+ return &bpf_get_smp_processor_id_proto;
+ case BPF_FUNC_skb_under_cgroup:
+ return &bpf_skb_under_cgroup_proto;
+ default:
+ return sk_filter_func_proto(func_id);
+ }
+}
+
+static const struct bpf_func_proto *
+lwt_xmit_func_proto(enum bpf_func_id func_id)
+{
+ switch (func_id) {
+ case BPF_FUNC_skb_get_tunnel_key:
+ return &bpf_skb_get_tunnel_key_proto;
+ case BPF_FUNC_skb_set_tunnel_key:
+ return bpf_get_skb_set_tunnel_proto(func_id);
+ case BPF_FUNC_skb_get_tunnel_opt:
+ return &bpf_skb_get_tunnel_opt_proto;
+ case BPF_FUNC_skb_set_tunnel_opt:
+ return bpf_get_skb_set_tunnel_proto(func_id);
+ case BPF_FUNC_redirect:
+ return &bpf_redirect_proto;
+ case BPF_FUNC_clone_redirect:
+ return &bpf_clone_redirect_proto;
+ case BPF_FUNC_skb_change_tail:
+ return &bpf_skb_change_tail_proto;
+ case BPF_FUNC_skb_change_head:
+ return &bpf_skb_change_head_proto;
+ case BPF_FUNC_skb_store_bytes:
+ return &bpf_skb_store_bytes_proto;
+ case BPF_FUNC_csum_update:
+ return &bpf_csum_update_proto;
+ case BPF_FUNC_l3_csum_replace:
+ return &bpf_l3_csum_replace_proto;
+ case BPF_FUNC_l4_csum_replace:
+ return &bpf_l4_csum_replace_proto;
+ case BPF_FUNC_set_hash_invalid:
+ return &bpf_set_hash_invalid_proto;
+ default:
+ return lwt_inout_func_proto(func_id);
+ }
+}
+
static bool __is_valid_access(int off, int size, enum bpf_access_type type)
{
if (off < 0 || off >= sizeof(struct __sk_buff))
@@ -2676,6 +2785,39 @@ static bool sk_filter_is_valid_access(int off, int size,
return __is_valid_access(off, size, type);
}
+static bool lwt_is_valid_access(int off, int size,
+ enum bpf_access_type type,
+ enum bpf_reg_type *reg_type)
+{
+ switch (off) {
+ case offsetof(struct __sk_buff, tc_classid):
+ return false;
+ }
+
+ if (type == BPF_WRITE) {
+ switch (off) {
+ case offsetof(struct __sk_buff, mark):
+ case offsetof(struct __sk_buff, priority):
+ case offsetof(struct __sk_buff, cb[0]) ...
+ offsetof(struct __sk_buff, cb[4]):
+ break;
+ default:
+ return false;
+ }
+ }
+
+ switch (off) {
+ case offsetof(struct __sk_buff, data):
+ *reg_type = PTR_TO_PACKET;
+ break;
+ case offsetof(struct __sk_buff, data_end):
+ *reg_type = PTR_TO_PACKET_END;
+ break;
+ }
+
+ return __is_valid_access(off, size, type);
+}
+
static int tc_cls_act_prologue(struct bpf_insn *insn_buf, bool direct_write,
const struct bpf_prog *prog)
{
@@ -3007,6 +3149,19 @@ static const struct bpf_verifier_ops cg_skb_ops = {
.convert_ctx_access = sk_filter_convert_ctx_access,
};
+static const struct bpf_verifier_ops lwt_inout_ops = {
+ .get_func_proto = lwt_inout_func_proto,
+ .is_valid_access = lwt_is_valid_access,
+ .convert_ctx_access = sk_filter_convert_ctx_access,
+};
+
+static const struct bpf_verifier_ops lwt_xmit_ops = {
+ .get_func_proto = lwt_xmit_func_proto,
+ .is_valid_access = lwt_is_valid_access,
+ .convert_ctx_access = sk_filter_convert_ctx_access,
+ .gen_prologue = tc_cls_act_prologue,
+};
+
static struct bpf_prog_type_list sk_filter_type __read_mostly = {
.ops = &sk_filter_ops,
.type = BPF_PROG_TYPE_SOCKET_FILTER,
@@ -3032,6 +3187,21 @@ static struct bpf_prog_type_list cg_skb_type __read_mostly = {
.type = BPF_PROG_TYPE_CGROUP_SKB,
};
+static struct bpf_prog_type_list lwt_in_type __read_mostly = {
+ .ops = &lwt_inout_ops,
+ .type = BPF_PROG_TYPE_LWT_IN,
+};
+
+static struct bpf_prog_type_list lwt_out_type __read_mostly = {
+ .ops = &lwt_inout_ops,
+ .type = BPF_PROG_TYPE_LWT_OUT,
+};
+
+static struct bpf_prog_type_list lwt_xmit_type __read_mostly = {
+ .ops = &lwt_xmit_ops,
+ .type = BPF_PROG_TYPE_LWT_XMIT,
+};
+
static int __init register_sk_filter_ops(void)
{
bpf_register_prog_type(&sk_filter_type);
@@ -3039,6 +3209,9 @@ static int __init register_sk_filter_ops(void)
bpf_register_prog_type(&sched_act_type);
bpf_register_prog_type(&xdp_type);
bpf_register_prog_type(&cg_skb_type);
+ bpf_register_prog_type(&lwt_in_type);
+ bpf_register_prog_type(&lwt_out_type);
+ bpf_register_prog_type(&lwt_xmit_type);
return 0;
}
diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
new file mode 100644
index 000000000000..71bb3e2eca08
--- /dev/null
+++ b/net/core/lwt_bpf.c
@@ -0,0 +1,396 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+#include <linux/bpf.h>
+#include <net/lwtunnel.h>
+
+struct bpf_lwt_prog {
+ struct bpf_prog *prog;
+ char *name;
+};
+
+struct bpf_lwt {
+ struct bpf_lwt_prog in;
+ struct bpf_lwt_prog out;
+ struct bpf_lwt_prog xmit;
+ int family;
+};
+
+#define MAX_PROG_NAME 256
+
+static inline struct bpf_lwt *bpf_lwt_lwtunnel(struct lwtunnel_state *lwt)
+{
+ return (struct bpf_lwt *)lwt->data;
+}
+
+#define NO_REDIRECT false
+#define CAN_REDIRECT true
+
+static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_prog *lwt,
+ struct dst_entry *dst, bool can_redirect)
+{
+ int ret;
+
+ /* Preempt disable is needed to protect per-cpu redirect_info between
+ * BPF prog and skb_do_redirect(). The call_rcu in bpf_prog_put() and
+ * access to maps strictly require a rcu_read_lock() for protection,
+ * mixing with BH RCU lock doesn't work.
+ */
+ preempt_disable();
+ rcu_read_lock();
+ bpf_compute_data_end(skb);
+ ret = bpf_prog_run_save_cb(lwt->prog, skb);
+ rcu_read_unlock();
+
+ switch (ret) {
+ case BPF_OK:
+ break;
+
+ case BPF_REDIRECT:
+ if (unlikely(!can_redirect)) {
+ pr_warn_once("Illegal redirect return code in prog %s\n",
+ lwt->name ? : "<unknown>");
+ ret = BPF_OK;
+ } else {
+ ret = skb_do_redirect(skb);
+ if (ret == 0)
+ ret = BPF_REDIRECT;
+ }
+ break;
+
+ case BPF_DROP:
+ kfree_skb(skb);
+ ret = -EPERM;
+ break;
+
+ default:
+ pr_warn_once("bpf-lwt: Illegal return value %u, expect packet loss\n", ret);
+ kfree_skb(skb);
+ ret = -EINVAL;
+ break;
+ }
+
+ preempt_enable();
+
+ return ret;
+}
+
+static int bpf_input(struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct bpf_lwt *bpf;
+ int ret;
+
+ bpf = bpf_lwt_lwtunnel(dst->lwtstate);
+ if (bpf->in.prog) {
+ ret = run_lwt_bpf(skb, &bpf->in, dst, NO_REDIRECT);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (unlikely(!dst->lwtstate->orig_input)) {
+ pr_warn_once("orig_input not set on dst for prog %s\n",
+ bpf->out.name);
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ return dst->lwtstate->orig_input(skb);
+}
+
+static int bpf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct bpf_lwt *bpf;
+ int ret;
+
+ bpf = bpf_lwt_lwtunnel(dst->lwtstate);
+ if (bpf->out.prog) {
+ ret = run_lwt_bpf(skb, &bpf->out, dst, NO_REDIRECT);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (unlikely(!dst->lwtstate->orig_output)) {
+ pr_warn_once("orig_output not set on dst for prog %s\n",
+ bpf->out.name);
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ return dst->lwtstate->orig_output(net, sk, skb);
+}
+
+static int xmit_check_hhlen(struct sk_buff *skb)
+{
+ int hh_len = skb_dst(skb)->dev->hard_header_len;
+
+ if (skb_headroom(skb) < hh_len) {
+ int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
+
+ if (pskb_expand_head(skb, nhead, 0, GFP_ATOMIC))
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int bpf_xmit(struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ struct bpf_lwt *bpf;
+
+ bpf = bpf_lwt_lwtunnel(dst->lwtstate);
+ if (bpf->xmit.prog) {
+ int ret;
+
+ ret = run_lwt_bpf(skb, &bpf->xmit, dst, CAN_REDIRECT);
+ switch (ret) {
+ case BPF_OK:
+ /* If the header was expanded, headroom might be too
+ * small for L2 header to come, expand as needed.
+ */
+ ret = xmit_check_hhlen(skb);
+ if (unlikely(ret))
+ return ret;
+
+ return LWTUNNEL_XMIT_CONTINUE;
+ case BPF_REDIRECT:
+ return LWTUNNEL_XMIT_DONE;
+ default:
+ return ret;
+ }
+ }
+
+ return LWTUNNEL_XMIT_CONTINUE;
+}
+
+static void bpf_lwt_prog_destroy(struct bpf_lwt_prog *prog)
+{
+ if (prog->prog)
+ bpf_prog_put(prog->prog);
+
+ kfree(prog->name);
+}
+
+static void bpf_destroy_state(struct lwtunnel_state *lwt)
+{
+ struct bpf_lwt *bpf = bpf_lwt_lwtunnel(lwt);
+
+ bpf_lwt_prog_destroy(&bpf->in);
+ bpf_lwt_prog_destroy(&bpf->out);
+ bpf_lwt_prog_destroy(&bpf->xmit);
+}
+
+static const struct nla_policy bpf_prog_policy[LWT_BPF_PROG_MAX + 1] = {
+ [LWT_BPF_PROG_FD] = { .type = NLA_U32, },
+ [LWT_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
+ .len = MAX_PROG_NAME },
+};
+
+static int bpf_parse_prog(struct nlattr *attr, struct bpf_lwt_prog *prog,
+ enum bpf_prog_type type)
+{
+ struct nlattr *tb[LWT_BPF_PROG_MAX + 1];
+ struct bpf_prog *p;
+ int ret;
+ u32 fd;
+
+ ret = nla_parse_nested(tb, LWT_BPF_PROG_MAX, attr, bpf_prog_policy);
+ if (ret < 0)
+ return ret;
+
+ if (!tb[LWT_BPF_PROG_FD] || !tb[LWT_BPF_PROG_NAME])
+ return -EINVAL;
+
+ prog->name = nla_memdup(tb[LWT_BPF_PROG_NAME], GFP_KERNEL);
+ if (!prog->name)
+ return -ENOMEM;
+
+ fd = nla_get_u32(tb[LWT_BPF_PROG_FD]);
+ p = bpf_prog_get_type(fd, type);
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+
+ prog->prog = p;
+
+ return 0;
+}
+
+static const struct nla_policy bpf_nl_policy[LWT_BPF_MAX + 1] = {
+ [LWT_BPF_IN] = { .type = NLA_NESTED, },
+ [LWT_BPF_OUT] = { .type = NLA_NESTED, },
+ [LWT_BPF_XMIT] = { .type = NLA_NESTED, },
+ [LWT_BPF_XMIT_HEADROOM] = { .type = NLA_U32 },
+};
+
+static int bpf_build_state(struct net_device *dev, struct nlattr *nla,
+ unsigned int family, const void *cfg,
+ struct lwtunnel_state **ts)
+{
+ struct nlattr *tb[LWT_BPF_MAX + 1];
+ struct lwtunnel_state *newts;
+ struct bpf_lwt *bpf;
+ int ret;
+
+ if (family != AF_INET && family != AF_INET6)
+ return -EAFNOSUPPORT;
+
+ ret = nla_parse_nested(tb, LWT_BPF_MAX, nla, bpf_nl_policy);
+ if (ret < 0)
+ return ret;
+
+ if (!tb[LWT_BPF_IN] && !tb[LWT_BPF_OUT] && !tb[LWT_BPF_XMIT])
+ return -EINVAL;
+
+ newts = lwtunnel_state_alloc(sizeof(*bpf));
+ if (!newts)
+ return -ENOMEM;
+
+ newts->type = LWTUNNEL_ENCAP_BPF;
+ bpf = bpf_lwt_lwtunnel(newts);
+
+ if (tb[LWT_BPF_IN]) {
+ newts->flags |= LWTUNNEL_STATE_INPUT_REDIRECT;
+ ret = bpf_parse_prog(tb[LWT_BPF_IN], &bpf->in,
+ BPF_PROG_TYPE_LWT_IN);
+ if (ret < 0)
+ goto errout;
+ }
+
+ if (tb[LWT_BPF_OUT]) {
+ newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
+ ret = bpf_parse_prog(tb[LWT_BPF_OUT], &bpf->out,
+ BPF_PROG_TYPE_LWT_OUT);
+ if (ret < 0)
+ goto errout;
+ }
+
+ if (tb[LWT_BPF_XMIT]) {
+ newts->flags |= LWTUNNEL_STATE_XMIT_REDIRECT;
+ ret = bpf_parse_prog(tb[LWT_BPF_XMIT], &bpf->xmit,
+ BPF_PROG_TYPE_LWT_XMIT);
+ if (ret < 0)
+ goto errout;
+ }
+
+ if (tb[LWT_BPF_XMIT_HEADROOM]) {
+ u32 headroom = nla_get_u32(tb[LWT_BPF_XMIT_HEADROOM]);
+
+ if (headroom > LWT_BPF_MAX_HEADROOM) {
+ ret = -ERANGE;
+ goto errout;
+ }
+
+ newts->headroom = headroom;
+ }
+
+ bpf->family = family;
+ *ts = newts;
+
+ return 0;
+
+errout:
+ bpf_destroy_state(newts);
+ kfree(newts);
+ return ret;
+}
+
+static int bpf_fill_lwt_prog(struct sk_buff *skb, int attr,
+ struct bpf_lwt_prog *prog)
+{
+ struct nlattr *nest;
+
+ if (!prog->prog)
+ return 0;
+
+ nest = nla_nest_start(skb, attr);
+ if (!nest)
+ return -EMSGSIZE;
+
+ if (prog->name &&
+ nla_put_string(skb, LWT_BPF_PROG_NAME, prog->name))
+ return -EMSGSIZE;
+
+ return nla_nest_end(skb, nest);
+}
+
+static int bpf_fill_encap_info(struct sk_buff *skb, struct lwtunnel_state *lwt)
+{
+ struct bpf_lwt *bpf = bpf_lwt_lwtunnel(lwt);
+
+ if (bpf_fill_lwt_prog(skb, LWT_BPF_IN, &bpf->in) < 0 ||
+ bpf_fill_lwt_prog(skb, LWT_BPF_OUT, &bpf->out) < 0 ||
+ bpf_fill_lwt_prog(skb, LWT_BPF_XMIT, &bpf->xmit) < 0)
+ return -EMSGSIZE;
+
+ return 0;
+}
+
+static int bpf_encap_nlsize(struct lwtunnel_state *lwtstate)
+{
+ int nest_len = nla_total_size(sizeof(struct nlattr)) +
+ nla_total_size(MAX_PROG_NAME) + /* LWT_BPF_PROG_NAME */
+ 0;
+
+ return nest_len + /* LWT_BPF_IN */
+ nest_len + /* LWT_BPF_OUT */
+ nest_len + /* LWT_BPF_XMIT */
+ 0;
+}
+
+int bpf_lwt_prog_cmp(struct bpf_lwt_prog *a, struct bpf_lwt_prog *b)
+{
+ /* FIXME:
+ * The LWT state is currently rebuilt for delete requests which
+ * results in a new bpf_prog instance. Comparing names for now.
+ */
+ if (!a->name && !b->name)
+ return 0;
+
+ if (!a->name || !b->name)
+ return 1;
+
+ return strcmp(a->name, b->name);
+}
+
+static int bpf_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
+{
+ struct bpf_lwt *a_bpf = bpf_lwt_lwtunnel(a);
+ struct bpf_lwt *b_bpf = bpf_lwt_lwtunnel(b);
+
+ return bpf_lwt_prog_cmp(&a_bpf->in, &b_bpf->in) ||
+ bpf_lwt_prog_cmp(&a_bpf->out, &b_bpf->out) ||
+ bpf_lwt_prog_cmp(&a_bpf->xmit, &b_bpf->xmit);
+}
+
+static const struct lwtunnel_encap_ops bpf_encap_ops = {
+ .build_state = bpf_build_state,
+ .destroy_state = bpf_destroy_state,
+ .input = bpf_input,
+ .output = bpf_output,
+ .xmit = bpf_xmit,
+ .fill_encap = bpf_fill_encap_info,
+ .get_encap_size = bpf_encap_nlsize,
+ .cmp_encap = bpf_encap_cmp,
+};
+
+static int __init bpf_lwt_init(void)
+{
+ return lwtunnel_encap_add_ops(&bpf_encap_ops, LWTUNNEL_ENCAP_BPF);
+}
+
+subsys_initcall(bpf_lwt_init)
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index 03976e939818..a5d4e866ce88 100644
--- a/net/core/lwtunnel.c
+++ b/net/core/lwtunnel.c
@@ -41,6 +41,8 @@ static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
return "ILA";
case LWTUNNEL_ENCAP_SEG6:
return "SEG6";
+ case LWTUNNEL_ENCAP_BPF:
+ return "BPF";
case LWTUNNEL_ENCAP_IP6:
case LWTUNNEL_ENCAP_IP:
case LWTUNNEL_ENCAP_NONE:
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 6402d745d192..fa5c037227cb 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1603,6 +1603,19 @@ static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
spin_unlock_bh(&fnhe_lock);
}
+static void set_lwt_redirect(struct rtable *rth)
+{
+ if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
+ rth->dst.lwtstate->orig_output = rth->dst.output;
+ rth->dst.output = lwtunnel_output;
+ }
+
+ if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
+ rth->dst.lwtstate->orig_input = rth->dst.input;
+ rth->dst.input = lwtunnel_input;
+ }
+}
+
/* called in rcu_read_lock() section */
static int __mkroute_input(struct sk_buff *skb,
const struct fib_result *res,
@@ -1692,14 +1705,7 @@ rt_cache:
rth->dst.input = ip_forward;
rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
- if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
- rth->dst.lwtstate->orig_output = rth->dst.output;
- rth->dst.output = lwtunnel_output;
- }
- if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
- rth->dst.lwtstate->orig_input = rth->dst.input;
- rth->dst.input = lwtunnel_input;
- }
+ set_lwt_redirect(rth);
skb_dst_set(skb, &rth->dst);
out:
err = 0;
@@ -1926,8 +1932,18 @@ local_input:
rth->dst.error= -err;
rth->rt_flags &= ~RTCF_LOCAL;
}
+
if (do_cache) {
- if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
+ struct fib_nh *nh = &FIB_RES_NH(res);
+
+ rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
+ if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
+ WARN_ON(rth->dst.input == lwtunnel_input);
+ rth->dst.lwtstate->orig_input = rth->dst.input;
+ rth->dst.input = lwtunnel_input;
+ }
+
+ if (unlikely(!rt_cache_route(nh, rth))) {
rth->dst.flags |= DST_NOCACHE;
rt_add_uncached_list(rth);
}
@@ -2155,8 +2171,7 @@ add:
}
rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
- if (lwtunnel_output_redirect(rth->dst.lwtstate))
- rth->dst.output = lwtunnel_output;
+ set_lwt_redirect(rth);
return rth;
}
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 3ceb5a9d86df..44532fbe4cae 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -29,6 +29,7 @@ hostprogs-y += test_current_task_under_cgroup
hostprogs-y += trace_event
hostprogs-y += sampleip
hostprogs-y += tc_l2_redirect
+hostprogs-y += lwt_len_hist
test_lru_dist-objs := test_lru_dist.o libbpf.o
sock_example-objs := sock_example.o libbpf.o
@@ -59,6 +60,7 @@ test_current_task_under_cgroup-objs := bpf_load.o libbpf.o \
trace_event-objs := bpf_load.o libbpf.o trace_event_user.o
sampleip-objs := bpf_load.o libbpf.o sampleip_user.o
tc_l2_redirect-objs := bpf_load.o libbpf.o tc_l2_redirect_user.o
+lwt_len_hist-objs := bpf_load.o libbpf.o lwt_len_hist_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
@@ -89,6 +91,7 @@ always += xdp2_kern.o
always += test_current_task_under_cgroup_kern.o
always += trace_event_kern.o
always += sampleip_kern.o
+always += lwt_len_hist_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
HOSTCFLAGS += -I$(srctree)/tools/testing/selftests/bpf/
@@ -117,6 +120,7 @@ HOSTLOADLIBES_test_current_task_under_cgroup += -lelf
HOSTLOADLIBES_trace_event += -lelf
HOSTLOADLIBES_sampleip += -lelf
HOSTLOADLIBES_tc_l2_redirect += -l elf
+HOSTLOADLIBES_lwt_len_hist += -l elf
# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
# make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h
index 90f44bd2045e..a246c6122629 100644
--- a/samples/bpf/bpf_helpers.h
+++ b/samples/bpf/bpf_helpers.h
@@ -80,6 +80,8 @@ struct bpf_map_def {
unsigned int map_flags;
};
+static int (*bpf_skb_load_bytes)(void *ctx, int off, void *to, int len) =
+ (void *) BPF_FUNC_skb_load_bytes;
static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
(void *) BPF_FUNC_skb_store_bytes;
static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
@@ -88,6 +90,8 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag
(void *) BPF_FUNC_l4_csum_replace;
static int (*bpf_skb_under_cgroup)(void *ctx, void *map, int index) =
(void *) BPF_FUNC_skb_under_cgroup;
+static int (*bpf_skb_change_head)(void *, int len, int flags) =
+ (void *) BPF_FUNC_skb_change_head;
#if defined(__x86_64__)
diff --git a/samples/bpf/lwt_len_hist.sh b/samples/bpf/lwt_len_hist.sh
new file mode 100644
index 000000000000..7d567744c7fa
--- /dev/null
+++ b/samples/bpf/lwt_len_hist.sh
@@ -0,0 +1,37 @@
+#!/bin/bash
+
+NS1=lwt_ns1
+VETH0=tst_lwt1a
+VETH1=tst_lwt1b
+
+TRACE_ROOT=/sys/kernel/debug/tracing
+
+function cleanup {
+ ip route del 192.168.253.2/32 dev $VETH0 2> /dev/null
+ ip link del $VETH0 2> /dev/null
+ ip link del $VETH1 2> /dev/null
+ ip netns exec $NS1 killall netserver
+ ip netns delete $NS1 2> /dev/null
+}
+
+cleanup
+
+ip netns add $NS1
+ip link add $VETH0 type veth peer name $VETH1
+ip link set dev $VETH0 up
+ip addr add 192.168.253.1/24 dev $VETH0
+ip link set $VETH1 netns $NS1
+ip netns exec $NS1 ip link set dev $VETH1 up
+ip netns exec $NS1 ip addr add 192.168.253.2/24 dev $VETH1
+ip netns exec $NS1 netserver
+
+echo 1 > ${TRACE_ROOT}/tracing_on
+cp /dev/null ${TRACE_ROOT}/trace
+ip route add 192.168.253.2/32 encap bpf out obj lwt_len_hist_kern.o section len_hist dev $VETH0
+netperf -H 192.168.253.2 -t TCP_STREAM
+cat ${TRACE_ROOT}/trace | grep -v '^#'
+./lwt_len_hist
+cleanup
+echo 0 > ${TRACE_ROOT}/tracing_on
+
+exit 0
diff --git a/samples/bpf/lwt_len_hist_kern.c b/samples/bpf/lwt_len_hist_kern.c
new file mode 100644
index 000000000000..df75383280f9
--- /dev/null
+++ b/samples/bpf/lwt_len_hist_kern.c
@@ -0,0 +1,82 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/in.h>
+#include "bpf_helpers.h"
+
+# define printk(fmt, ...) \
+ ({ \
+ char ____fmt[] = fmt; \
+ bpf_trace_printk(____fmt, sizeof(____fmt), \
+ ##__VA_ARGS__); \
+ })
+
+struct bpf_elf_map {
+ __u32 type;
+ __u32 size_key;
+ __u32 size_value;
+ __u32 max_elem;
+ __u32 flags;
+ __u32 id;
+ __u32 pinning;
+};
+
+struct bpf_elf_map SEC("maps") lwt_len_hist_map = {
+ .type = BPF_MAP_TYPE_PERCPU_HASH,
+ .size_key = sizeof(__u64),
+ .size_value = sizeof(__u64),
+ .pinning = 2,
+ .max_elem = 1024,
+};
+
+static unsigned int log2(unsigned int v)
+{
+ unsigned int r;
+ unsigned int shift;
+
+ r = (v > 0xFFFF) << 4; v >>= r;
+ shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+ shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+ shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+ r |= (v >> 1);
+ return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+ unsigned int hi = v >> 32;
+ if (hi)
+ return log2(hi) + 32;
+ else
+ return log2(v);
+}
+
+SEC("len_hist")
+int do_len_hist(struct __sk_buff *skb)
+{
+ __u64 *value, key, init_val = 1;
+
+ key = log2l(skb->len);
+
+ value = bpf_map_lookup_elem(&lwt_len_hist_map, &key);
+ if (value)
+ __sync_fetch_and_add(value, 1);
+ else
+ bpf_map_update_elem(&lwt_len_hist_map, &key, &init_val, BPF_ANY);
+
+ return BPF_OK;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/lwt_len_hist_user.c b/samples/bpf/lwt_len_hist_user.c
new file mode 100644
index 000000000000..05d783fc5daf
--- /dev/null
+++ b/samples/bpf/lwt_len_hist_user.c
@@ -0,0 +1,76 @@
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+
+#include "libbpf.h"
+#include "bpf_util.h"
+
+#define MAX_INDEX 64
+#define MAX_STARS 38
+
+static void stars(char *str, long val, long max, int width)
+{
+ int i;
+
+ for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+ str[i] = '*';
+ if (val > max)
+ str[i - 1] = '+';
+ str[i] = '\0';
+}
+
+int main(int argc, char **argv)
+{
+ unsigned int nr_cpus = bpf_num_possible_cpus();
+ const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map";
+ uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {};
+ uint64_t key = 0, next_key, max_key = 0;
+ char starstr[MAX_STARS];
+ int i, map_fd;
+
+ map_fd = bpf_obj_get(map_filename);
+ if (map_fd < 0) {
+ fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
+ map_filename, strerror(errno), errno);
+ return -1;
+ }
+
+ while (bpf_get_next_key(map_fd, &key, &next_key) == 0) {
+ if (next_key >= MAX_INDEX) {
+ fprintf(stderr, "Key %lu out of bounds\n", next_key);
+ continue;
+ }
+
+ bpf_lookup_elem(map_fd, &next_key, values);
+
+ sum = 0;
+ for (i = 0; i < nr_cpus; i++)
+ sum += values[i];
+
+ data[next_key] = sum;
+ if (sum && next_key > max_key)
+ max_key = next_key;
+
+ if (sum > max_value)
+ max_value = sum;
+
+ key = next_key;
+ }
+
+ for (i = 1; i <= max_key + 1; i++) {
+ stars(starstr, data[i - 1], max_value, MAX_STARS);
+ printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+ (1l << i) >> 1, (1l << i) - 1, data[i - 1],
+ MAX_STARS, starstr);
+ }
+
+ close(map_fd);
+
+ return 0;
+}
diff --git a/samples/bpf/test_lwt_bpf.c b/samples/bpf/test_lwt_bpf.c
new file mode 100644
index 000000000000..bacc8013436b
--- /dev/null
+++ b/samples/bpf/test_lwt_bpf.c
@@ -0,0 +1,253 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <linux/bpf.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/icmpv6.h>
+#include <linux/if_ether.h>
+#include "bpf_helpers.h"
+#include <string.h>
+
+# define printk(fmt, ...) \
+ ({ \
+ char ____fmt[] = fmt; \
+ bpf_trace_printk(____fmt, sizeof(____fmt), \
+ ##__VA_ARGS__); \
+ })
+
+#define CB_MAGIC 1234
+
+/* Test: Pass all packets through */
+SEC("nop")
+int do_nop(struct __sk_buff *skb)
+{
+ return BPF_OK;
+}
+
+/* Test: Verify context information can be accessed */
+SEC("test_ctx")
+int do_test_ctx(struct __sk_buff *skb)
+{
+ skb->cb[0] = CB_MAGIC;
+ printk("len %d hash %d protocol %d\n", skb->len, skb->hash,
+ skb->protocol);
+ printk("cb %d ingress_ifindex %d ifindex %d\n", skb->cb[0],
+ skb->ingress_ifindex, skb->ifindex);
+
+ return BPF_OK;
+}
+
+/* Test: Ensure skb->cb[] buffer is cleared */
+SEC("test_cb")
+int do_test_cb(struct __sk_buff *skb)
+{
+ printk("cb0: %x cb1: %x cb2: %x\n", skb->cb[0], skb->cb[1],
+ skb->cb[2]);
+ printk("cb3: %x cb4: %x\n", skb->cb[3], skb->cb[4]);
+
+ return BPF_OK;
+}
+
+/* Test: Verify skb data can be read */
+SEC("test_data")
+int do_test_data(struct __sk_buff *skb)
+{
+ void *data = (void *)(long)skb->data;
+ void *data_end = (void *)(long)skb->data_end;
+ struct iphdr *iph = data;
+
+ if (data + sizeof(*iph) > data_end) {
+ printk("packet truncated\n");
+ return BPF_DROP;
+ }
+
+ printk("src: %x dst: %x\n", iph->saddr, iph->daddr);
+
+ return BPF_OK;
+}
+
+#define IP_CSUM_OFF offsetof(struct iphdr, check)
+#define IP_DST_OFF offsetof(struct iphdr, daddr)
+#define IP_SRC_OFF offsetof(struct iphdr, saddr)
+#define IP_PROTO_OFF offsetof(struct iphdr, protocol)
+#define TCP_CSUM_OFF offsetof(struct tcphdr, check)
+#define UDP_CSUM_OFF offsetof(struct udphdr, check)
+#define IS_PSEUDO 0x10
+
+static inline int rewrite(struct __sk_buff *skb, uint32_t old_ip,
+ uint32_t new_ip, int rw_daddr)
+{
+ int ret, off = 0, flags = IS_PSEUDO;
+ uint8_t proto;
+
+ ret = bpf_skb_load_bytes(skb, IP_PROTO_OFF, &proto, 1);
+ if (ret < 0) {
+ printk("bpf_l4_csum_replace failed: %d\n", ret);
+ return BPF_DROP;
+ }
+
+ switch (proto) {
+ case IPPROTO_TCP:
+ off = TCP_CSUM_OFF;
+ break;
+
+ case IPPROTO_UDP:
+ off = UDP_CSUM_OFF;
+ flags |= BPF_F_MARK_MANGLED_0;
+ break;
+
+ case IPPROTO_ICMPV6:
+ off = offsetof(struct icmp6hdr, icmp6_cksum);
+ break;
+ }
+
+ if (off) {
+ ret = bpf_l4_csum_replace(skb, off, old_ip, new_ip,
+ flags | sizeof(new_ip));
+ if (ret < 0) {
+ printk("bpf_l4_csum_replace failed: %d\n");
+ return BPF_DROP;
+ }
+ }
+
+ ret = bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
+ if (ret < 0) {
+ printk("bpf_l3_csum_replace failed: %d\n", ret);
+ return BPF_DROP;
+ }
+
+ if (rw_daddr)
+ ret = bpf_skb_store_bytes(skb, IP_DST_OFF, &new_ip, sizeof(new_ip), 0);
+ else
+ ret = bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
+
+ if (ret < 0) {
+ printk("bpf_skb_store_bytes() failed: %d\n", ret);
+ return BPF_DROP;
+ }
+
+ return BPF_OK;
+}
+
+/* Test: Verify skb data can be modified */
+SEC("test_rewrite")
+int do_test_rewrite(struct __sk_buff *skb)
+{
+ uint32_t old_ip, new_ip = 0x3fea8c0;
+ int ret;
+
+ ret = bpf_skb_load_bytes(skb, IP_DST_OFF, &old_ip, 4);
+ if (ret < 0) {
+ printk("bpf_skb_load_bytes failed: %d\n", ret);
+ return BPF_DROP;
+ }
+
+ if (old_ip == 0x2fea8c0) {
+ printk("out: rewriting from %x to %x\n", old_ip, new_ip);
+ return rewrite(skb, old_ip, new_ip, 1);
+ }
+
+ return BPF_OK;
+}
+
+static inline int __do_push_ll_and_redirect(struct __sk_buff *skb)
+{
+ uint64_t smac = SRC_MAC, dmac = DST_MAC;
+ int ret, ifindex = DST_IFINDEX;
+ struct ethhdr ehdr;
+
+ ret = bpf_skb_change_head(skb, 14, 0);
+ if (ret < 0) {
+ printk("skb_change_head() failed: %d\n", ret);
+ }
+
+ ehdr.h_proto = __constant_htons(ETH_P_IP);
+ memcpy(&ehdr.h_source, &smac, 6);
+ memcpy(&ehdr.h_dest, &dmac, 6);
+
+ ret = bpf_skb_store_bytes(skb, 0, &ehdr, sizeof(ehdr), 0);
+ if (ret < 0) {
+ printk("skb_store_bytes() failed: %d\n", ret);
+ return BPF_DROP;
+ }
+
+ return bpf_redirect(ifindex, 0);
+}
+
+SEC("push_ll_and_redirect_silent")
+int do_push_ll_and_redirect_silent(struct __sk_buff *skb)
+{
+ return __do_push_ll_and_redirect(skb);
+}
+
+SEC("push_ll_and_redirect")
+int do_push_ll_and_redirect(struct __sk_buff *skb)
+{
+ int ret, ifindex = DST_IFINDEX;
+
+ ret = __do_push_ll_and_redirect(skb);
+ if (ret >= 0)
+ printk("redirected to %d\n", ifindex);
+
+ return ret;
+}
+
+static inline void __fill_garbage(struct __sk_buff *skb)
+{
+ uint64_t f = 0xFFFFFFFFFFFFFFFF;
+
+ bpf_skb_store_bytes(skb, 0, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 8, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 16, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 24, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 32, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 40, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 48, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 56, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 64, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 72, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 80, &f, sizeof(f), 0);
+ bpf_skb_store_bytes(skb, 88, &f, sizeof(f), 0);
+}
+
+SEC("fill_garbage")
+int do_fill_garbage(struct __sk_buff *skb)
+{
+ __fill_garbage(skb);
+ printk("Set initial 96 bytes of header to FF\n");
+ return BPF_OK;
+}
+
+SEC("fill_garbage_and_redirect")
+int do_fill_garbage_and_redirect(struct __sk_buff *skb)
+{
+ int ifindex = DST_IFINDEX;
+ __fill_garbage(skb);
+ printk("redirected to %d\n", ifindex);
+ return bpf_redirect(ifindex, 0);
+}
+
+/* Drop all packets */
+SEC("drop_all")
+int do_drop_all(struct __sk_buff *skb)
+{
+ printk("dropping with: %d\n", BPF_DROP);
+ return BPF_DROP;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_lwt_bpf.sh b/samples/bpf/test_lwt_bpf.sh
new file mode 100644
index 000000000000..a695ae268c40
--- /dev/null
+++ b/samples/bpf/test_lwt_bpf.sh
@@ -0,0 +1,399 @@
+#!/bin/bash
+
+# Uncomment to see generated bytecode
+#VERBOSE=verbose
+
+NS1=lwt_ns1
+NS2=lwt_ns2
+VETH0=tst_lwt1a
+VETH1=tst_lwt1b
+VETH2=tst_lwt2a
+VETH3=tst_lwt2b
+IPVETH0="192.168.254.1"
+IPVETH1="192.168.254.2"
+IPVETH1b="192.168.254.3"
+
+IPVETH2="192.168.111.1"
+IPVETH3="192.168.111.2"
+
+IP_LOCAL="192.168.99.1"
+
+TRACE_ROOT=/sys/kernel/debug/tracing
+
+function lookup_mac()
+{
+ set +x
+ if [ ! -z "$2" ]; then
+ MAC=$(ip netns exec $2 ip link show $1 | grep ether | awk '{print $2}')
+ else
+ MAC=$(ip link show $1 | grep ether | awk '{print $2}')
+ fi
+ MAC="${MAC//:/}"
+ echo "0x${MAC:10:2}${MAC:8:2}${MAC:6:2}${MAC:4:2}${MAC:2:2}${MAC:0:2}"
+ set -x
+}
+
+function cleanup {
+ set +ex
+ rm test_lwt_bpf.o 2> /dev/null
+ ip link del $VETH0 2> /dev/null
+ ip link del $VETH1 2> /dev/null
+ ip link del $VETH2 2> /dev/null
+ ip link del $VETH3 2> /dev/null
+ ip netns exec $NS1 killall netserver
+ ip netns delete $NS1 2> /dev/null
+ ip netns delete $NS2 2> /dev/null
+ set -ex
+}
+
+function setup_one_veth {
+ ip netns add $1
+ ip link add $2 type veth peer name $3
+ ip link set dev $2 up
+ ip addr add $4/24 dev $2
+ ip link set $3 netns $1
+ ip netns exec $1 ip link set dev $3 up
+ ip netns exec $1 ip addr add $5/24 dev $3
+
+ if [ "$6" ]; then
+ ip netns exec $1 ip addr add $6/32 dev $3
+ fi
+}
+
+function get_trace {
+ set +x
+ cat ${TRACE_ROOT}/trace | grep -v '^#'
+ set -x
+}
+
+function cleanup_routes {
+ ip route del ${IPVETH1}/32 dev $VETH0 2> /dev/null || true
+ ip route del table local local ${IP_LOCAL}/32 dev lo 2> /dev/null || true
+}
+
+function install_test {
+ cleanup_routes
+ cp /dev/null ${TRACE_ROOT}/trace
+
+ OPTS="encap bpf headroom 14 $1 obj test_lwt_bpf.o section $2 $VERBOSE"
+
+ if [ "$1" == "in" ]; then
+ ip route add table local local ${IP_LOCAL}/32 $OPTS dev lo
+ else
+ ip route add ${IPVETH1}/32 $OPTS dev $VETH0
+ fi
+}
+
+function remove_prog {
+ if [ "$1" == "in" ]; then
+ ip route del table local local ${IP_LOCAL}/32 dev lo
+ else
+ ip route del ${IPVETH1}/32 dev $VETH0
+ fi
+}
+
+function filter_trace {
+ # Add newline to allow starting EXPECT= variables on newline
+ NL=$'\n'
+ echo "${NL}$*" | sed -e 's/^.*: : //g'
+}
+
+function expect_fail {
+ set +x
+ echo "FAIL:"
+ echo "Expected: $1"
+ echo "Got: $2"
+ set -x
+ exit 1
+}
+
+function match_trace {
+ set +x
+ RET=0
+ TRACE=$1
+ EXPECT=$2
+ GOT="$(filter_trace "$TRACE")"
+
+ [ "$GOT" != "$EXPECT" ] && {
+ expect_fail "$EXPECT" "$GOT"
+ RET=1
+ }
+ set -x
+ return $RET
+}
+
+function test_start {
+ set +x
+ echo "----------------------------------------------------------------"
+ echo "Starting test: $*"
+ echo "----------------------------------------------------------------"
+ set -x
+}
+
+function failure {
+ get_trace
+ echo "FAIL: $*"
+ exit 1
+}
+
+function test_ctx_xmit {
+ test_start "test_ctx on lwt xmit"
+ install_test xmit test_ctx
+ ping -c 3 $IPVETH1 || {
+ failure "test_ctx xmit: packets are dropped"
+ }
+ match_trace "$(get_trace)" "
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX" || exit 1
+ remove_prog xmit
+}
+
+function test_ctx_out {
+ test_start "test_ctx on lwt out"
+ install_test out test_ctx
+ ping -c 3 $IPVETH1 || {
+ failure "test_ctx out: packets are dropped"
+ }
+ match_trace "$(get_trace)" "
+len 84 hash 0 protocol 0
+cb 1234 ingress_ifindex 0 ifindex 0
+len 84 hash 0 protocol 0
+cb 1234 ingress_ifindex 0 ifindex 0
+len 84 hash 0 protocol 0
+cb 1234 ingress_ifindex 0 ifindex 0" || exit 1
+ remove_prog out
+}
+
+function test_ctx_in {
+ test_start "test_ctx on lwt in"
+ install_test in test_ctx
+ ping -c 3 $IP_LOCAL || {
+ failure "test_ctx out: packets are dropped"
+ }
+ # We will both request & reply packets as the packets will
+ # be from $IP_LOCAL => $IP_LOCAL
+ match_trace "$(get_trace)" "
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1" || exit 1
+ remove_prog in
+}
+
+function test_data {
+ test_start "test_data on lwt $1"
+ install_test $1 test_data
+ ping -c 3 $IPVETH1 || {
+ failure "test_data ${1}: packets are dropped"
+ }
+ match_trace "$(get_trace)" "
+src: 1fea8c0 dst: 2fea8c0
+src: 1fea8c0 dst: 2fea8c0
+src: 1fea8c0 dst: 2fea8c0" || exit 1
+ remove_prog $1
+}
+
+function test_data_in {
+ test_start "test_data on lwt in"
+ install_test in test_data
+ ping -c 3 $IP_LOCAL || {
+ failure "test_data in: packets are dropped"
+ }
+ # We will both request & reply packets as the packets will
+ # be from $IP_LOCAL => $IP_LOCAL
+ match_trace "$(get_trace)" "
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0" || exit 1
+ remove_prog in
+}
+
+function test_cb {
+ test_start "test_cb on lwt $1"
+ install_test $1 test_cb
+ ping -c 3 $IPVETH1 || {
+ failure "test_cb ${1}: packets are dropped"
+ }
+ match_trace "$(get_trace)" "
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0" || exit 1
+ remove_prog $1
+}
+
+function test_cb_in {
+ test_start "test_cb on lwt in"
+ install_test in test_cb
+ ping -c 3 $IP_LOCAL || {
+ failure "test_cb in: packets are dropped"
+ }
+ # We will both request & reply packets as the packets will
+ # be from $IP_LOCAL => $IP_LOCAL
+ match_trace "$(get_trace)" "
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0" || exit 1
+ remove_prog in
+}
+
+function test_drop_all {
+ test_start "test_drop_all on lwt $1"
+ install_test $1 drop_all
+ ping -c 3 $IPVETH1 && {
+ failure "test_drop_all ${1}: Unexpected success of ping"
+ }
+ match_trace "$(get_trace)" "
+dropping with: 2
+dropping with: 2
+dropping with: 2" || exit 1
+ remove_prog $1
+}
+
+function test_drop_all_in {
+ test_start "test_drop_all on lwt in"
+ install_test in drop_all
+ ping -c 3 $IP_LOCAL && {
+ failure "test_drop_all in: Unexpected success of ping"
+ }
+ match_trace "$(get_trace)" "
+dropping with: 2
+dropping with: 2
+dropping with: 2" || exit 1
+ remove_prog in
+}
+
+function test_push_ll_and_redirect {
+ test_start "test_push_ll_and_redirect on lwt xmit"
+ install_test xmit push_ll_and_redirect
+ ping -c 3 $IPVETH1 || {
+ failure "Redirected packets appear to be dropped"
+ }
+ match_trace "$(get_trace)" "
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX" || exit 1
+ remove_prog xmit
+}
+
+function test_no_l2_and_redirect {
+ test_start "test_no_l2_and_redirect on lwt xmit"
+ install_test xmit fill_garbage_and_redirect
+ ping -c 3 $IPVETH1 && {
+ failure "Unexpected success despite lack of L2 header"
+ }
+ match_trace "$(get_trace)" "
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX" || exit 1
+ remove_prog xmit
+}
+
+function test_rewrite {
+ test_start "test_rewrite on lwt xmit"
+ install_test xmit test_rewrite
+ ping -c 3 $IPVETH1 || {
+ failure "Rewritten packets appear to be dropped"
+ }
+ match_trace "$(get_trace)" "
+out: rewriting from 2fea8c0 to 3fea8c0
+out: rewriting from 2fea8c0 to 3fea8c0
+out: rewriting from 2fea8c0 to 3fea8c0" || exit 1
+ remove_prog out
+}
+
+function test_fill_garbage {
+ test_start "test_fill_garbage on lwt xmit"
+ install_test xmit fill_garbage
+ ping -c 3 $IPVETH1 && {
+ failure "test_drop_all ${1}: Unexpected success of ping"
+ }
+ match_trace "$(get_trace)" "
+Set initial 96 bytes of header to FF
+Set initial 96 bytes of header to FF
+Set initial 96 bytes of header to FF" || exit 1
+ remove_prog xmit
+}
+
+function test_netperf_nop {
+ test_start "test_netperf_nop on lwt xmit"
+ install_test xmit nop
+ netperf -H $IPVETH1 -t TCP_STREAM || {
+ failure "packets appear to be dropped"
+ }
+ match_trace "$(get_trace)" ""|| exit 1
+ remove_prog xmit
+}
+
+function test_netperf_redirect {
+ test_start "test_netperf_redirect on lwt xmit"
+ install_test xmit push_ll_and_redirect_silent
+ netperf -H $IPVETH1 -t TCP_STREAM || {
+ failure "Rewritten packets appear to be dropped"
+ }
+ match_trace "$(get_trace)" ""|| exit 1
+ remove_prog xmit
+}
+
+cleanup
+setup_one_veth $NS1 $VETH0 $VETH1 $IPVETH0 $IPVETH1 $IPVETH1b
+setup_one_veth $NS2 $VETH2 $VETH3 $IPVETH2 $IPVETH3
+ip netns exec $NS1 netserver
+echo 1 > ${TRACE_ROOT}/tracing_on
+
+DST_MAC=$(lookup_mac $VETH1 $NS1)
+SRC_MAC=$(lookup_mac $VETH0)
+DST_IFINDEX=$(cat /sys/class/net/$VETH0/ifindex)
+
+CLANG_OPTS="-O2 -target bpf -I ../include/"
+CLANG_OPTS+=" -DSRC_MAC=$SRC_MAC -DDST_MAC=$DST_MAC -DDST_IFINDEX=$DST_IFINDEX"
+clang $CLANG_OPTS -c test_lwt_bpf.c -o test_lwt_bpf.o
+
+test_ctx_xmit
+test_ctx_out
+test_ctx_in
+test_data "xmit"
+test_data "out"
+test_data_in
+test_cb "xmit"
+test_cb "out"
+test_cb_in
+test_drop_all "xmit"
+test_drop_all "out"
+test_drop_all_in
+test_rewrite
+test_push_ll_and_redirect
+test_no_l2_and_redirect
+test_fill_garbage
+test_netperf_nop
+test_netperf_redirect
+
+cleanup
+echo 0 > ${TRACE_ROOT}/tracing_on
+exit 0
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-03-22 07:50:20 +0000