@@ -11,6 +11,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK, cg_sock)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, cg_sock_addr)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_IN, lwt_in)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_XMIT, lwt_xmit)
+BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_SEG6LOCAL, lwt_seg6local)
BPF_PROG_TYPE(BPF_PROG_TYPE_SOCK_OPS, sock_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_SK_SKB, sk_skb)
BPF_PROG_TYPE(BPF_PROG_TYPE_SK_MSG, sk_msg)
@@ -138,6 +138,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_SK_MSG,
BPF_PROG_TYPE_RAW_TRACEPOINT,
BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_PROG_TYPE_LWT_SEG6LOCAL,
};
enum bpf_attach_type {
@@ -25,6 +25,7 @@ enum {
SEG6_LOCAL_NH6,
SEG6_LOCAL_IIF,
SEG6_LOCAL_OIF,
+ SEG6_LOCAL_BPF,
__SEG6_LOCAL_MAX,
};
#define SEG6_LOCAL_MAX (__SEG6_LOCAL_MAX - 1)
@@ -59,6 +60,8 @@ enum {
SEG6_LOCAL_ACTION_END_AS = 13,
/* forward to SR-unaware VNF with masquerading */
SEG6_LOCAL_ACTION_END_AM = 14,
+ /* custom BPF action */
+ SEG6_LOCAL_ACTION_END_BPF = 15,
__SEG6_LOCAL_ACTION_MAX,
};
@@ -1251,6 +1251,7 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
switch (env->prog->type) {
case BPF_PROG_TYPE_LWT_IN:
case BPF_PROG_TYPE_LWT_OUT:
+ case BPF_PROG_TYPE_LWT_SEG6LOCAL:
/* dst_input() and dst_output() can't write for now */
if (t == BPF_WRITE)
return false;
@@ -4268,6 +4268,21 @@ lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
}
}
+static const struct bpf_func_proto *
+lwt_seg6local_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ switch (func_id) {
+ case BPF_FUNC_lwt_seg6_store_bytes:
+ return &bpf_lwt_seg6_store_bytes_proto;
+ case BPF_FUNC_lwt_seg6_action:
+ return &bpf_lwt_seg6_action_proto;
+ case BPF_FUNC_lwt_seg6_adjust_srh:
+ return &bpf_lwt_seg6_adjust_srh_proto;
+ default:
+ return lwt_out_func_proto(func_id, prog);
+ }
+}
+
static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
@@ -5824,6 +5839,16 @@ const struct bpf_prog_ops lwt_xmit_prog_ops = {
.test_run = bpf_prog_test_run_skb,
};
+const struct bpf_verifier_ops lwt_seg6local_verifier_ops = {
+ .get_func_proto = lwt_seg6local_func_proto,
+ .is_valid_access = lwt_is_valid_access,
+ .convert_ctx_access = bpf_convert_ctx_access,
+};
+
+const struct bpf_prog_ops lwt_seg6local_prog_ops = {
+ .test_run = bpf_prog_test_run_skb,
+};
+
const struct bpf_verifier_ops cg_sock_verifier_ops = {
.get_func_proto = sock_filter_func_proto,
.is_valid_access = sock_filter_is_valid_access,
@@ -1,8 +1,9 @@
/*
* SR-IPv6 implementation
*
- * Author:
+ * Authors:
* David Lebrun <david.lebrun@uclouvain.be>
+ * eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
*
*
* This program is free software; you can redistribute it and/or
@@ -32,6 +33,7 @@
#endif
#include <net/seg6_local.h>
#include <linux/etherdevice.h>
+#include <linux/bpf.h>
struct seg6_local_lwt;
@@ -42,6 +44,11 @@ struct seg6_action_desc {
int static_headroom;
};
+struct bpf_lwt_prog {
+ struct bpf_prog *prog;
+ char *name;
+};
+
struct seg6_local_lwt {
int action;
struct ipv6_sr_hdr *srh;
@@ -50,6 +57,7 @@ struct seg6_local_lwt {
struct in6_addr nh6;
int iif;
int oif;
+ struct bpf_lwt_prog bpf;
int headroom;
struct seg6_action_desc *desc;
@@ -449,6 +457,67 @@ static int input_action_end_b6_encap(struct sk_buff *skb,
return err;
}
+static int input_action_end_bpf(struct sk_buff *skb,
+ struct seg6_local_lwt *slwt)
+{
+ struct seg6_bpf_srh_state *srh_state =
+ this_cpu_ptr(&seg6_bpf_srh_states);
+ struct ipv6_sr_hdr *srh;
+ int srhoff = 0;
+ int ret;
+
+ srh = get_and_validate_srh(skb);
+ if (!srh)
+ goto drop;
+ advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
+
+ /* preempt_disable is needed to protect the per-CPU buffer srh_state,
+ * which is also accessed by the bpf_lwt_seg6_* helpers
+ */
+ preempt_disable();
+ srh_state->hdrlen = srh->hdrlen << 3;
+ srh_state->valid = 1;
+
+ rcu_read_lock();
+ bpf_compute_data_pointers(skb);
+ ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
+ rcu_read_unlock();
+
+ switch (ret) {
+ case BPF_OK:
+ case BPF_REDIRECT:
+ break;
+ case BPF_DROP:
+ goto drop;
+ default:
+ pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
+ goto drop;
+ }
+
+ if (unlikely((srh_state->hdrlen & 7) != 0))
+ goto drop;
+
+ if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
+ goto drop;
+ srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
+ srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
+
+ if (!srh_state->valid &&
+ unlikely(!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3)))
+ goto drop;
+
+ preempt_enable();
+
+ if (ret != BPF_REDIRECT)
+ seg6_lookup_nexthop(skb, NULL, 0);
+
+ return dst_input(skb);
+
+drop:
+ kfree_skb(skb);
+ return -EINVAL;
+}
+
static struct seg6_action_desc seg6_action_table[] = {
{
.action = SEG6_LOCAL_ACTION_END,
@@ -495,7 +564,13 @@ static struct seg6_action_desc seg6_action_table[] = {
.attrs = (1 << SEG6_LOCAL_SRH),
.input = input_action_end_b6_encap,
.static_headroom = sizeof(struct ipv6hdr),
- }
+ },
+ {
+ .action = SEG6_LOCAL_ACTION_END_BPF,
+ .attrs = (1 << SEG6_LOCAL_BPF),
+ .input = input_action_end_bpf,
+ },
+
};
static struct seg6_action_desc *__get_action_desc(int action)
@@ -540,6 +615,7 @@ static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
.len = sizeof(struct in6_addr) },
[SEG6_LOCAL_IIF] = { .type = NLA_U32 },
[SEG6_LOCAL_OIF] = { .type = NLA_U32 },
+ [SEG6_LOCAL_BPF] = { .type = NLA_NESTED },
};
static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
@@ -717,6 +793,71 @@ static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
return 0;
}
+#define MAX_PROG_NAME 256
+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 parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt)
+{
+ 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, attrs[SEG6_LOCAL_BPF],
+ bpf_prog_policy, NULL);
+ if (ret < 0)
+ return ret;
+
+ if (!tb[LWT_BPF_PROG_FD] || !tb[LWT_BPF_PROG_NAME])
+ return -EINVAL;
+
+ slwt->bpf.name = nla_memdup(tb[LWT_BPF_PROG_NAME], GFP_KERNEL);
+ if (!slwt->bpf.name)
+ return -ENOMEM;
+
+ fd = nla_get_u32(tb[LWT_BPF_PROG_FD]);
+ p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+
+ slwt->bpf.prog = p;
+
+ return 0;
+}
+
+static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
+{
+ struct nlattr *nest;
+
+ if (!slwt->bpf.prog)
+ return 0;
+
+ nest = nla_nest_start(skb, SEG6_LOCAL_BPF);
+ if (!nest)
+ return -EMSGSIZE;
+
+ if (slwt->bpf.name &&
+ nla_put_string(skb, LWT_BPF_PROG_NAME, slwt->bpf.name))
+ return -EMSGSIZE;
+
+ return nla_nest_end(skb, nest);
+}
+
+static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
+{
+ if (!a->bpf.name && !b->bpf.name)
+ return 0;
+
+ if (!a->bpf.name || !b->bpf.name)
+ return 1;
+
+ return strcmp(a->bpf.name, b->bpf.name);
+}
+
struct seg6_action_param {
int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
@@ -747,6 +888,11 @@ static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
[SEG6_LOCAL_OIF] = { .parse = parse_nla_oif,
.put = put_nla_oif,
.cmp = cmp_nla_oif },
+
+ [SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf,
+ .put = put_nla_bpf,
+ .cmp = cmp_nla_bpf },
+
};
static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
@@ -795,7 +941,6 @@ static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
err = nla_parse_nested(tb, SEG6_LOCAL_MAX, nla, seg6_local_policy,
extack);
-
if (err < 0)
return err;
@@ -884,6 +1029,11 @@ static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
if (attrs & (1 << SEG6_LOCAL_OIF))
nlsize += nla_total_size(4);
+ if (attrs & (1 << SEG6_LOCAL_BPF))
+ nlsize += nla_total_size(sizeof(struct nlattr)) +
+ nla_total_size(MAX_PROG_NAME) +
+ nla_total_size(4);
+
return nlsize;
}