diff options
-rw-r--r-- | include/linux/bpf_types.h | 5 | ||||
-rw-r--r-- | include/net/seg6.h | 7 | ||||
-rw-r--r-- | include/net/seg6_local.h | 32 | ||||
-rw-r--r-- | include/uapi/linux/bpf.h | 97 | ||||
-rw-r--r-- | include/uapi/linux/seg6_local.h | 12 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 1 | ||||
-rw-r--r-- | net/core/filter.c | 393 | ||||
-rw-r--r-- | net/ipv6/Kconfig | 5 | ||||
-rw-r--r-- | net/ipv6/seg6_local.c | 190 | ||||
-rw-r--r-- | tools/include/uapi/linux/bpf.h | 97 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.c | 1 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/Makefile | 6 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/bpf_helpers.h | 12 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/test_lwt_seg6local.c | 437 | ||||
-rwxr-xr-x | tools/testing/selftests/bpf/test_lwt_seg6local.sh | 140 |
15 files changed, 1363 insertions, 72 deletions
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index b67f8793de0d..b161e506dcfc 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -9,9 +9,10 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_XDP, xdp) BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SKB, cg_skb) 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_inout) -BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_inout) +BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_IN, lwt_in) +BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_out) 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) diff --git a/include/net/seg6.h b/include/net/seg6.h index 099bad59dc90..e029e301faa5 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -49,7 +49,11 @@ struct seg6_pernet_data { static inline struct seg6_pernet_data *seg6_pernet(struct net *net) { +#if IS_ENABLED(CONFIG_IPV6) return net->ipv6.seg6_data; +#else + return NULL; +#endif } extern int seg6_init(void); @@ -63,5 +67,6 @@ extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len); extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto); extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh); - +extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, + u32 tbl_id); #endif diff --git a/include/net/seg6_local.h b/include/net/seg6_local.h new file mode 100644 index 000000000000..661fd5b4d3e0 --- /dev/null +++ b/include/net/seg6_local.h @@ -0,0 +1,32 @@ +/* + * SR-IPv6 implementation + * + * 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 + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _NET_SEG6_LOCAL_H +#define _NET_SEG6_LOCAL_H + +#include <linux/percpu.h> +#include <linux/net.h> +#include <linux/ipv6.h> + +extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, + u32 tbl_id); + +struct seg6_bpf_srh_state { + bool valid; + u16 hdrlen; +}; + +DECLARE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states); + +#endif diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 344d2ddcef49..e95fec90c2c1 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -141,6 +141,7 @@ 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 { @@ -1902,6 +1903,90 @@ union bpf_attr { * egress otherwise). This is the only flag supported for now. * Return * **SK_PASS** on success, or **SK_DROP** on error. + * + * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len) + * Description + * Encapsulate the packet associated to *skb* within a Layer 3 + * protocol header. This header is provided in the buffer at + * address *hdr*, with *len* its size in bytes. *type* indicates + * the protocol of the header and can be one of: + * + * **BPF_LWT_ENCAP_SEG6** + * IPv6 encapsulation with Segment Routing Header + * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH, + * the IPv6 header is computed by the kernel. + * **BPF_LWT_ENCAP_SEG6_INLINE** + * Only works if *skb* contains an IPv6 packet. Insert a + * Segment Routing Header (**struct ipv6_sr_hdr**) inside + * the IPv6 header. + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len) + * Description + * Store *len* bytes from address *from* into the packet + * associated to *skb*, at *offset*. Only the flags, tag and TLVs + * inside the outermost IPv6 Segment Routing Header can be + * modified through this helper. + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta) + * Description + * Adjust the size allocated to TLVs in the outermost IPv6 + * Segment Routing Header contained in the packet associated to + * *skb*, at position *offset* by *delta* bytes. Only offsets + * after the segments are accepted. *delta* can be as well + * positive (growing) as negative (shrinking). + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len) + * Description + * Apply an IPv6 Segment Routing action of type *action* to the + * packet associated to *skb*. Each action takes a parameter + * contained at address *param*, and of length *param_len* bytes. + * *action* can be one of: + * + * **SEG6_LOCAL_ACTION_END_X** + * End.X action: Endpoint with Layer-3 cross-connect. + * Type of *param*: **struct in6_addr**. + * **SEG6_LOCAL_ACTION_END_T** + * End.T action: Endpoint with specific IPv6 table lookup. + * Type of *param*: **int**. + * **SEG6_LOCAL_ACTION_END_B6** + * End.B6 action: Endpoint bound to an SRv6 policy. + * Type of param: **struct ipv6_sr_hdr**. + * **SEG6_LOCAL_ACTION_END_B6_ENCAP** + * End.B6.Encap action: Endpoint bound to an SRv6 + * encapsulation policy. + * Type of param: **struct ipv6_sr_hdr**. + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -1976,7 +2061,11 @@ union bpf_attr { FN(fib_lookup), \ FN(sock_hash_update), \ FN(msg_redirect_hash), \ - FN(sk_redirect_hash), + FN(sk_redirect_hash), \ + FN(lwt_push_encap), \ + FN(lwt_seg6_store_bytes), \ + FN(lwt_seg6_adjust_srh), \ + FN(lwt_seg6_action), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -2043,6 +2132,12 @@ enum bpf_hdr_start_off { BPF_HDR_START_NET, }; +/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */ +enum bpf_lwt_encap_mode { + BPF_LWT_ENCAP_SEG6, + BPF_LWT_ENCAP_SEG6_INLINE +}; + /* user accessible mirror of in-kernel sk_buff. * new fields can only be added to the end of this structure */ diff --git a/include/uapi/linux/seg6_local.h b/include/uapi/linux/seg6_local.h index ef2d8c3e76c1..edc138bdc56d 100644 --- a/include/uapi/linux/seg6_local.h +++ b/include/uapi/linux/seg6_local.h @@ -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) @@ -59,10 +60,21 @@ 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, }; #define SEG6_LOCAL_ACTION_MAX (__SEG6_LOCAL_ACTION_MAX - 1) +enum { + SEG6_LOCAL_BPF_PROG_UNSPEC, + SEG6_LOCAL_BPF_PROG, + SEG6_LOCAL_BPF_PROG_NAME, + __SEG6_LOCAL_BPF_PROG_MAX, +}; + +#define SEG6_LOCAL_BPF_PROG_MAX (__SEG6_LOCAL_BPF_PROG_MAX - 1) + #endif diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8c4d9d0fd3ab..967cacf286ea 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1262,6 +1262,7 @@ 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; diff --git a/net/core/filter.c b/net/core/filter.c index ba3ff5aa575a..aa114c4acb25 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -64,6 +64,10 @@ #include <net/ip_fib.h> #include <net/flow.h> #include <net/arp.h> +#include <net/ipv6.h> +#include <linux/seg6_local.h> +#include <net/seg6.h> +#include <net/seg6_local.h> /** * sk_filter_trim_cap - run a packet through a socket filter @@ -3363,28 +3367,6 @@ static const struct bpf_func_proto bpf_xdp_redirect_map_proto = { .arg3_type = ARG_ANYTHING, }; -bool bpf_helper_changes_pkt_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_adjust_room || - func == bpf_skb_pull_data || - func == bpf_clone_redirect || - func == bpf_l3_csum_replace || - func == bpf_l4_csum_replace || - func == bpf_xdp_adjust_head || - func == bpf_xdp_adjust_meta || - func == bpf_msg_pull_data || - func == bpf_xdp_adjust_tail) - return true; - - return false; -} - static unsigned long bpf_skb_copy(void *dst_buff, const void *skb, unsigned long off, unsigned long len) { @@ -4360,6 +4342,264 @@ static const struct bpf_func_proto bpf_skb_fib_lookup_proto = { .arg4_type = ARG_ANYTHING, }; +#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF) +static int bpf_push_seg6_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len) +{ + int err; + struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)hdr; + + if (!seg6_validate_srh(srh, len)) + return -EINVAL; + + switch (type) { + case BPF_LWT_ENCAP_SEG6_INLINE: + if (skb->protocol != htons(ETH_P_IPV6)) + return -EBADMSG; + + err = seg6_do_srh_inline(skb, srh); + break; + case BPF_LWT_ENCAP_SEG6: + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + err = seg6_do_srh_encap(skb, srh, IPPROTO_IPV6); + break; + default: + return -EINVAL; + } + + bpf_compute_data_pointers(skb); + if (err) + return err; + + ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); + skb_set_transport_header(skb, sizeof(struct ipv6hdr)); + + return seg6_lookup_nexthop(skb, NULL, 0); +} +#endif /* CONFIG_IPV6_SEG6_BPF */ + +BPF_CALL_4(bpf_lwt_push_encap, struct sk_buff *, skb, u32, type, void *, hdr, + u32, len) +{ + switch (type) { +#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF) + case BPF_LWT_ENCAP_SEG6: + case BPF_LWT_ENCAP_SEG6_INLINE: + return bpf_push_seg6_encap(skb, type, hdr, len); +#endif + default: + return -EINVAL; + } +} + +static const struct bpf_func_proto bpf_lwt_push_encap_proto = { + .func = bpf_lwt_push_encap, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_MEM, + .arg4_type = ARG_CONST_SIZE +}; + +BPF_CALL_4(bpf_lwt_seg6_store_bytes, struct sk_buff *, skb, u32, offset, + const void *, from, u32, len) +{ +#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF) + struct seg6_bpf_srh_state *srh_state = + this_cpu_ptr(&seg6_bpf_srh_states); + void *srh_tlvs, *srh_end, *ptr; + struct ipv6_sr_hdr *srh; + int srhoff = 0; + + if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0) + return -EINVAL; + + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + srh_tlvs = (void *)((char *)srh + ((srh->first_segment + 1) << 4)); + srh_end = (void *)((char *)srh + sizeof(*srh) + srh_state->hdrlen); + + ptr = skb->data + offset; + if (ptr >= srh_tlvs && ptr + len <= srh_end) + srh_state->valid = 0; + else if (ptr < (void *)&srh->flags || + ptr + len > (void *)&srh->segments) + return -EFAULT; + + if (unlikely(bpf_try_make_writable(skb, offset + len))) + return -EFAULT; + + memcpy(skb->data + offset, from, len); + return 0; +#else /* CONFIG_IPV6_SEG6_BPF */ + return -EOPNOTSUPP; +#endif +} + +static const struct bpf_func_proto bpf_lwt_seg6_store_bytes_proto = { + .func = bpf_lwt_seg6_store_bytes, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_MEM, + .arg4_type = ARG_CONST_SIZE +}; + +BPF_CALL_4(bpf_lwt_seg6_action, struct sk_buff *, skb, + u32, action, void *, param, u32, param_len) +{ +#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF) + struct seg6_bpf_srh_state *srh_state = + this_cpu_ptr(&seg6_bpf_srh_states); + struct ipv6_sr_hdr *srh; + int srhoff = 0; + int err; + + if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0) + return -EINVAL; + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + if (!srh_state->valid) { + if (unlikely((srh_state->hdrlen & 7) != 0)) + return -EBADMSG; + + srh->hdrlen = (u8)(srh_state->hdrlen >> 3); + if (unlikely(!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3))) + return -EBADMSG; + + srh_state->valid = 1; + } + + switch (action) { + case SEG6_LOCAL_ACTION_END_X: + if (param_len != sizeof(struct in6_addr)) + return -EINVAL; + return seg6_lookup_nexthop(skb, (struct in6_addr *)param, 0); + case SEG6_LOCAL_ACTION_END_T: + if (param_len != sizeof(int)) + return -EINVAL; + return seg6_lookup_nexthop(skb, NULL, *(int *)param); + case SEG6_LOCAL_ACTION_END_B6: + err = bpf_push_seg6_encap(skb, BPF_LWT_ENCAP_SEG6_INLINE, + param, param_len); + if (!err) + srh_state->hdrlen = + ((struct ipv6_sr_hdr *)param)->hdrlen << 3; + return err; + case SEG6_LOCAL_ACTION_END_B6_ENCAP: + err = bpf_push_seg6_encap(skb, BPF_LWT_ENCAP_SEG6, + param, param_len); + if (!err) + srh_state->hdrlen = + ((struct ipv6_sr_hdr *)param)->hdrlen << 3; + return err; + default: + return -EINVAL; + } +#else /* CONFIG_IPV6_SEG6_BPF */ + return -EOPNOTSUPP; +#endif +} + +static const struct bpf_func_proto bpf_lwt_seg6_action_proto = { + .func = bpf_lwt_seg6_action, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_MEM, + .arg4_type = ARG_CONST_SIZE +}; + +BPF_CALL_3(bpf_lwt_seg6_adjust_srh, struct sk_buff *, skb, u32, offset, + s32, len) +{ +#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF) + struct seg6_bpf_srh_state *srh_state = + this_cpu_ptr(&seg6_bpf_srh_states); + void *srh_end, *srh_tlvs, *ptr; + struct ipv6_sr_hdr *srh; + struct ipv6hdr *hdr; + int srhoff = 0; + int ret; + + if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0) + return -EINVAL; + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + srh_tlvs = (void *)((unsigned char *)srh + sizeof(*srh) + + ((srh->first_segment + 1) << 4)); + srh_end = (void *)((unsigned char *)srh + sizeof(*srh) + + srh_state->hdrlen); + ptr = skb->data + offset; + + if (unlikely(ptr < srh_tlvs || ptr > srh_end)) + return -EFAULT; + if (unlikely(len < 0 && (void *)((char *)ptr - len) > srh_end)) + return -EFAULT; + + if (len > 0) { + ret = skb_cow_head(skb, len); + if (unlikely(ret < 0)) + return ret; + + ret = bpf_skb_net_hdr_push(skb, offset, len); + } else { + ret = bpf_skb_net_hdr_pop(skb, offset, -1 * len); + } + + bpf_compute_data_pointers(skb); + if (unlikely(ret < 0)) + return ret; + + hdr = (struct ipv6hdr *)skb->data; + hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); + + srh_state->hdrlen += len; + srh_state->valid = 0; + return 0; +#else /* CONFIG_IPV6_SEG6_BPF */ + return -EOPNOTSUPP; +#endif +} + +static const struct bpf_func_proto bpf_lwt_seg6_adjust_srh_proto = { + .func = bpf_lwt_seg6_adjust_srh, + .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_pkt_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_adjust_room || + func == bpf_skb_pull_data || + func == bpf_clone_redirect || + func == bpf_l3_csum_replace || + func == bpf_l4_csum_replace || + func == bpf_xdp_adjust_head || + func == bpf_xdp_adjust_meta || + func == bpf_msg_pull_data || + func == bpf_xdp_adjust_tail || + func == bpf_lwt_push_encap || + func == bpf_lwt_seg6_store_bytes || + func == bpf_lwt_seg6_adjust_srh || + func == bpf_lwt_seg6_action + ) + return true; + + return false; +} + static const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -4544,33 +4784,6 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) } static const struct bpf_func_proto * -lwt_inout_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) -{ - 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 bpf_base_func_proto(func_id); - } -} - -static const struct bpf_func_proto * sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { switch (func_id) { @@ -4636,6 +4849,44 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) } static const struct bpf_func_proto * +lwt_out_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + 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 bpf_base_func_proto(func_id); + } +} + +static const struct bpf_func_proto * +lwt_in_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + switch (func_id) { + case BPF_FUNC_lwt_push_encap: + return &bpf_lwt_push_encap_proto; + default: + return lwt_out_func_proto(func_id, prog); + } +} + +static const struct bpf_func_proto * lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { switch (func_id) { @@ -4666,7 +4917,22 @@ lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_set_hash_invalid: return &bpf_set_hash_invalid_proto; default: - return lwt_inout_func_proto(func_id, prog); + return lwt_out_func_proto(func_id, 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); } } @@ -4774,7 +5040,6 @@ static bool lwt_is_valid_access(int off, int size, return bpf_skb_is_valid_access(off, size, type, prog, info); } - /* Attach type specific accesses */ static bool __sock_filter_check_attach_type(int off, enum bpf_access_type access_type, @@ -6348,13 +6613,23 @@ const struct bpf_prog_ops cg_skb_prog_ops = { .test_run = bpf_prog_test_run_skb, }; -const struct bpf_verifier_ops lwt_inout_verifier_ops = { - .get_func_proto = lwt_inout_func_proto, +const struct bpf_verifier_ops lwt_in_verifier_ops = { + .get_func_proto = lwt_in_func_proto, .is_valid_access = lwt_is_valid_access, .convert_ctx_access = bpf_convert_ctx_access, }; -const struct bpf_prog_ops lwt_inout_prog_ops = { +const struct bpf_prog_ops lwt_in_prog_ops = { + .test_run = bpf_prog_test_run_skb, +}; + +const struct bpf_verifier_ops lwt_out_verifier_ops = { + .get_func_proto = lwt_out_func_proto, + .is_valid_access = lwt_is_valid_access, + .convert_ctx_access = bpf_convert_ctx_access, +}; + +const struct bpf_prog_ops lwt_out_prog_ops = { .test_run = bpf_prog_test_run_skb, }; @@ -6369,6 +6644,16 @@ 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, diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index 11e4e80cf7e9..0eff75525da1 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -329,4 +329,9 @@ config IPV6_SEG6_HMAC If unsure, say N. +config IPV6_SEG6_BPF + def_bool y + depends on IPV6_SEG6_LWTUNNEL + depends on IPV6 = y + endif # IPV6 diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index 45722327375a..cd6e4cab63f6 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -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 @@ -30,7 +31,9 @@ #ifdef CONFIG_IPV6_SEG6_HMAC #include <net/seg6_hmac.h> #endif +#include <net/seg6_local.h> #include <linux/etherdevice.h> +#include <linux/bpf.h> struct seg6_local_lwt; @@ -41,6 +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; @@ -49,6 +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; @@ -140,8 +149,8 @@ static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr) *daddr = *addr; } -static void lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, - u32 tbl_id) +int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, + u32 tbl_id) { struct net *net = dev_net(skb->dev); struct ipv6hdr *hdr = ipv6_hdr(skb); @@ -187,6 +196,7 @@ out: skb_dst_drop(skb); skb_dst_set(skb, dst); + return dst->error; } /* regular endpoint function */ @@ -200,7 +210,7 @@ static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt) advance_nextseg(srh, &ipv6_hdr(skb)->daddr); - lookup_nexthop(skb, NULL, 0); + seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); @@ -220,7 +230,7 @@ static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt) advance_nextseg(srh, &ipv6_hdr(skb)->daddr); - lookup_nexthop(skb, &slwt->nh6, 0); + seg6_lookup_nexthop(skb, &slwt->nh6, 0); return dst_input(skb); @@ -239,7 +249,7 @@ static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt) advance_nextseg(srh, &ipv6_hdr(skb)->daddr); - lookup_nexthop(skb, NULL, slwt->table); + seg6_lookup_nexthop(skb, NULL, slwt->table); return dst_input(skb); @@ -331,7 +341,7 @@ static int input_action_end_dx6(struct sk_buff *skb, if (!ipv6_addr_any(&slwt->nh6)) nhaddr = &slwt->nh6; - lookup_nexthop(skb, nhaddr, 0); + seg6_lookup_nexthop(skb, nhaddr, 0); return dst_input(skb); drop: @@ -380,7 +390,7 @@ static int input_action_end_dt6(struct sk_buff *skb, if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto drop; - lookup_nexthop(skb, NULL, slwt->table); + seg6_lookup_nexthop(skb, NULL, slwt->table); return dst_input(skb); @@ -406,7 +416,7 @@ static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt) ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); skb_set_transport_header(skb, sizeof(struct ipv6hdr)); - lookup_nexthop(skb, NULL, 0); + seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); @@ -438,7 +448,7 @@ static int input_action_end_b6_encap(struct sk_buff *skb, ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); skb_set_transport_header(skb, sizeof(struct ipv6hdr)); - lookup_nexthop(skb, NULL, 0); + seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); @@ -447,6 +457,71 @@ drop: return err; } +DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states); + +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 seg6_bpf_srh_state local_srh_state; + 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(); + + local_srh_state = *srh_state; + preempt_enable(); + + 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((local_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)(local_srh_state.hdrlen >> 3); + + if (!local_srh_state.valid && + unlikely(!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3))) + goto drop; + + 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, @@ -493,7 +568,13 @@ 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) @@ -538,6 +619,7 @@ 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) @@ -715,6 +797,75 @@ 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[SEG6_LOCAL_BPF_PROG_MAX + 1] = { + [SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, }, + [SEG6_LOCAL_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[SEG6_LOCAL_BPF_PROG_MAX + 1]; + struct bpf_prog *p; + int ret; + u32 fd; + + ret = nla_parse_nested(tb, SEG6_LOCAL_BPF_PROG_MAX, + attrs[SEG6_LOCAL_BPF], bpf_prog_policy, NULL); + if (ret < 0) + return ret; + + if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME]) + return -EINVAL; + + slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL); + if (!slwt->bpf.name) + return -ENOMEM; + + fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]); + p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL); + if (IS_ERR(p)) { + kfree(slwt->bpf.name); + 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 (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id)) + return -EMSGSIZE; + + if (slwt->bpf.name && + nla_put_string(skb, SEG6_LOCAL_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); @@ -745,6 +896,11 @@ 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) @@ -830,6 +986,13 @@ static void seg6_local_destroy_state(struct lwtunnel_state *lwt) struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); kfree(slwt->srh); + + if (slwt->desc->attrs & (1 << SEG6_LOCAL_BPF)) { + kfree(slwt->bpf.name); + bpf_prog_put(slwt->bpf.prog); + } + + return; } static int seg6_local_fill_encap(struct sk_buff *skb, @@ -882,6 +1045,11 @@ 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; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 344d2ddcef49..e95fec90c2c1 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -141,6 +141,7 @@ 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 { @@ -1902,6 +1903,90 @@ union bpf_attr { * egress otherwise). This is the only flag supported for now. * Return * **SK_PASS** on success, or **SK_DROP** on error. + * + * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len) + * Description + * Encapsulate the packet associated to *skb* within a Layer 3 + * protocol header. This header is provided in the buffer at + * address *hdr*, with *len* its size in bytes. *type* indicates + * the protocol of the header and can be one of: + * + * **BPF_LWT_ENCAP_SEG6** + * IPv6 encapsulation with Segment Routing Header + * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH, + * the IPv6 header is computed by the kernel. + * **BPF_LWT_ENCAP_SEG6_INLINE** + * Only works if *skb* contains an IPv6 packet. Insert a + * Segment Routing Header (**struct ipv6_sr_hdr**) inside + * the IPv6 header. + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len) + * Description + * Store *len* bytes from address *from* into the packet + * associated to *skb*, at *offset*. Only the flags, tag and TLVs + * inside the outermost IPv6 Segment Routing Header can be + * modified through this helper. + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta) + * Description + * Adjust the size allocated to TLVs in the outermost IPv6 + * Segment Routing Header contained in the packet associated to + * *skb*, at position *offset* by *delta* bytes. Only offsets + * after the segments are accepted. *delta* can be as well + * positive (growing) as negative (shrinking). + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len) + * Description + * Apply an IPv6 Segment Routing action of type *action* to the + * packet associated to *skb*. Each action takes a parameter + * contained at address *param*, and of length *param_len* bytes. + * *action* can be one of: + * + * **SEG6_LOCAL_ACTION_END_X** + * End.X action: Endpoint with Layer-3 cross-connect. + * Type of *param*: **struct in6_addr**. + * **SEG6_LOCAL_ACTION_END_T** + * End.T action: Endpoint with specific IPv6 table lookup. + * Type of *param*: **int**. + * **SEG6_LOCAL_ACTION_END_B6** + * End.B6 action: Endpoint bound to an SRv6 policy. + * Type of param: **struct ipv6_sr_hdr**. + * **SEG6_LOCAL_ACTION_END_B6_ENCAP** + * End.B6.Encap action: Endpoint bound to an SRv6 + * encapsulation policy. + * Type of param: **struct ipv6_sr_hdr**. + * + * A call to this helper is susceptible to change the underlaying + * packet buffer. Therefore, at load time, all checks on pointers + * previously done by the verifier are invalidated and must be + * performed again, if the helper is used in combination with + * direct packet access. + * Return + * 0 on success, or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -1976,7 +2061,11 @@ union bpf_attr { FN(fib_lookup), \ FN(sock_hash_update), \ FN(msg_redirect_hash), \ - FN(sk_redirect_hash), + FN(sk_redirect_hash), \ + FN(lwt_push_encap), \ + FN(lwt_seg6_store_bytes), \ + FN(lwt_seg6_adjust_srh), \ + FN(lwt_seg6_action), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -2043,6 +2132,12 @@ enum bpf_hdr_start_off { BPF_HDR_START_NET, }; +/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */ +enum bpf_lwt_encap_mode { + BPF_LWT_ENCAP_SEG6, + BPF_LWT_ENCAP_SEG6_INLINE +}; + /* user accessible mirror of in-kernel sk_buff. * new fields can only be added to the end of this structure */ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e5cd4a958846..d07e44474848 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1456,6 +1456,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type) case BPF_PROG_TYPE_LWT_IN: case BPF_PROG_TYPE_LWT_OUT: case BPF_PROG_TYPE_LWT_XMIT: + case BPF_PROG_TYPE_LWT_SEG6LOCAL: case BPF_PROG_TYPE_SOCK_OPS: case BPF_PROG_TYPE_SK_SKB: case BPF_PROG_TYPE_CGROUP_DEVICE: diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 49618c9a5638..85044448bbc7 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -33,7 +33,8 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \ sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \ test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \ - test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o + test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o \ + test_lwt_seg6local.o # Order correspond to 'make run_tests' order TEST_PROGS := test_kmod.sh \ @@ -42,7 +43,8 @@ TEST_PROGS := test_kmod.sh \ test_xdp_meta.sh \ test_offload.py \ test_sock_addr.sh \ - test_tunnel.sh + test_tunnel.sh \ + test_lwt_seg6local.sh # Compile but not part of 'make run_tests' TEST_GEN_PROGS_EXTENDED = test_libbpf_open test_sock_addr diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 8f143dfb3700..334d3e8c5e89 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -114,6 +114,18 @@ static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) = static int (*bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params, int plen, __u32 flags) = (void *) BPF_FUNC_fib_lookup; +static int (*bpf_lwt_push_encap)(void *ctx, unsigned int type, void *hdr, + unsigned int len) = + (void *) BPF_FUNC_lwt_push_encap; +static int (*bpf_lwt_seg6_store_bytes)(void *ctx, unsigned int offset, + void *from, unsigned int len) = + (void *) BPF_FUNC_lwt_seg6_store_bytes; +static int (*bpf_lwt_seg6_action)(void *ctx, unsigned int action, void *param, + unsigned int param_len) = + (void *) BPF_FUNC_lwt_seg6_action; +static int (*bpf_lwt_seg6_adjust_srh)(void *ctx, unsigned int offset, + unsigned int len) = + (void *) BPF_FUNC_lwt_seg6_adjust_srh; /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions diff --git a/tools/testing/selftests/bpf/test_lwt_seg6local.c b/tools/testing/selftests/bpf/test_lwt_seg6local.c new file mode 100644 index 000000000000..0575751bc1bc --- /dev/null +++ b/tools/testing/selftests/bpf/test_lwt_seg6local.c @@ -0,0 +1,437 @@ +#include <stddef.h> +#include <inttypes.h> +#include <errno.h> +#include <linux/seg6_local.h> +#include <linux/bpf.h> +#include "bpf_helpers.h" +#include "bpf_endian.h" + +#define bpf_printk(fmt, ...) \ +({ \ + char ____fmt[] = fmt; \ + bpf_trace_printk(____fmt, sizeof(____fmt), \ + ##__VA_ARGS__); \ +}) + +/* Packet parsing state machine helpers. */ +#define cursor_advance(_cursor, _len) \ + ({ void *_tmp = _cursor; _cursor += _len; _tmp; }) + +#define SR6_FLAG_ALERT (1 << 4) + +#define htonll(x) ((bpf_htonl(1)) == 1 ? (x) : ((uint64_t)bpf_htonl((x) & \ + 0xFFFFFFFF) << 32) | bpf_htonl((x) >> 32)) +#define ntohll(x) ((bpf_ntohl(1)) == 1 ? (x) : ((uint64_t)bpf_ntohl((x) & \ + 0xFFFFFFFF) << 32) | bpf_ntohl((x) >> 32)) +#define BPF_PACKET_HEADER __attribute__((packed)) + +struct ip6_t { + unsigned int ver:4; + unsigned int priority:8; + unsigned int flow_label:20; + unsigned short payload_len; + unsigned char next_header; + unsigned char hop_limit; + unsigned long long src_hi; + unsigned long long src_lo; + unsigned long long dst_hi; + unsigned long long dst_lo; +} BPF_PACKET_HEADER; + +struct ip6_addr_t { + unsigned long long hi; + unsigned long long lo; +} BPF_PACKET_HEADER; + +struct ip6_srh_t { + unsigned char nexthdr; + unsigned char hdrlen; + unsigned char type; + unsigned char segments_left; + unsigned char first_segment; + unsigned char flags; + unsigned short tag; + + struct ip6_addr_t segments[0]; +} BPF_PACKET_HEADER; + +struct sr6_tlv_t { + unsigned char type; + unsigned char len; + unsigned char value[0]; +} BPF_PACKET_HEADER; + +__attribute__((always_inline)) struct ip6_srh_t *get_srh(struct __sk_buff *skb) +{ + void *cursor, *data_end; + struct ip6_srh_t *srh; + struct ip6_t *ip; + uint8_t *ipver; + + data_end = (void *)(long)skb->data_end; + cursor = (void *)(long)skb->data; + ipver = (uint8_t *)cursor; + + if ((void *)ipver + sizeof(*ipver) > data_end) + return NULL; + + if ((*ipver >> 4) != 6) + return NULL; + + ip = cursor_advance(cursor, sizeof(*ip)); + if ((void *)ip + sizeof(*ip) > data_end) + return NULL; + + if (ip->next_header != 43) + return NULL; + + srh = cursor_advance(cursor, sizeof(*srh)); + if ((void *)srh + sizeof(*srh) > data_end) + return NULL; + + if (srh->type != 4) + return NULL; + + return srh; +} + +__attribute__((always_inline)) +int update_tlv_pad(struct __sk_buff *skb, uint32_t new_pad, + uint32_t old_pad, uint32_t pad_off) +{ + int err; + + if (new_pad != old_pad) { + err = bpf_lwt_seg6_adjust_srh(skb, pad_off, + (int) new_pad - (int) old_pad); + if (err) + return err; + } + + if (new_pad > 0) { + char pad_tlv_buf[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0}; + struct sr6_tlv_t *pad_tlv = (struct sr6_tlv_t *) pad_tlv_buf; + + pad_tlv->type = SR6_TLV_PADDING; + pad_tlv->len = new_pad - 2; + + err = bpf_lwt_seg6_store_bytes(skb, pad_off, + (void *)pad_tlv_buf, new_pad); + if (err) + return err; + } + + return 0; +} + +__attribute__((always_inline)) +int is_valid_tlv_boundary(struct __sk_buff *skb, struct ip6_srh_t *srh, + uint32_t *tlv_off, uint32_t *pad_size, + uint32_t *pad_off) +{ + uint32_t srh_off, cur_off; + int offset_valid = 0; + int err; + + srh_off = (char *)srh - (char *)(long)skb->data; + // cur_off = end of segments, start of possible TLVs + cur_off = srh_off + sizeof(*srh) + + sizeof(struct ip6_addr_t) * (srh->first_segment + 1); + + *pad_off = 0; + + // we can only go as far as ~10 TLVs due to the BPF max stack size + #pragma clang loop unroll(full) + for (int i = 0; i < 10; i++) { + struct sr6_tlv_t tlv; + + if (cur_off == *tlv_off) + offset_valid = 1; + + if (cur_off >= srh_off + ((srh->hdrlen + 1) << 3)) + break; + + err = bpf_skb_load_bytes(skb, cur_off, &tlv, sizeof(tlv)); + if (err) + return err; + + if (tlv.type == SR6_TLV_PADDING) { + *pad_size = tlv.len + sizeof(tlv); + *pad_off = cur_off; + + if (*tlv_off == srh_off) { + *tlv_off = cur_off; + offset_valid = 1; + } + break; + + } else if (tlv.type == SR6_TLV_HMAC) { + break; + } + + cur_off += sizeof(tlv) + tlv.len; + } // we reached the padding or HMAC TLVs, or the end of the SRH + + if (*pad_off == 0) + *pad_off = cur_off; + + if (*tlv_off == -1) + *tlv_off = cur_off; + else if (!offset_valid) + return -EINVAL; + + return 0; +} + +__attribute__((always_inline)) +int add_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh, uint32_t tlv_off, + struct sr6_tlv_t *itlv, uint8_t tlv_size) +{ + uint32_t srh_off = (char *)srh - (char *)(long)skb->data; + uint8_t len_remaining, new_pad; + uint32_t pad_off = 0; + uint32_t pad_size = 0; + uint32_t partial_srh_len; + int err; + + if (tlv_off != -1) + tlv_off += srh_off; + + if (itlv->type == SR6_TLV_PADDING || itlv->type == SR6_TLV_HMAC) + return -EINVAL; + + err = is_valid_tlv_boundary(skb, srh, &tlv_off, &pad_size, &pad_off); + if (err) + return err; + + err = bpf_lwt_seg6_adjust_srh(skb, tlv_off, sizeof(*itlv) + itlv->len); + if (err) + return err; + + err = bpf_lwt_seg6_store_bytes(skb, tlv_off, (void *)itlv, tlv_size); + if (err) + return err; + + // the following can't be moved inside update_tlv_pad because the + // bpf verifier has some issues with it + pad_off += sizeof(*itlv) + itlv->len; + partial_srh_len = pad_off - srh_off; + len_remaining = partial_srh_len % 8; + new_pad = 8 - len_remaining; + + if (new_pad == 1) // cannot pad for 1 byte only + new_pad = 9; + else if (new_pad == 8) + new_pad = 0; + + return update_tlv_pad(skb, new_pad, pad_size, pad_off); +} + +__attribute__((always_inline)) +int delete_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh, + uint32_t tlv_off) +{ + uint32_t srh_off = (char *)srh - (char *)(long)skb->data; + uint8_t len_remaining, new_pad; + uint32_t partial_srh_len; + uint32_t pad_off = 0; + uint32_t pad_size = 0; + struct sr6_tlv_t tlv; + int err; + + tlv_off += srh_off; + + err = is_valid_tlv_boundary(skb, srh, &tlv_off, &pad_size, &pad_off); + if (err) + return err; + + err = bpf_skb_load_bytes(skb, tlv_off, &tlv, sizeof(tlv)); + if (err) + return err; + + err = bpf_lwt_seg6_adjust_srh(skb, tlv_off, -(sizeof(tlv) + tlv.len)); + if (err) + return err; + + pad_off -= sizeof(tlv) + tlv.len; + partial_srh_len = pad_off - srh_off; + len_remaining = partial_srh_len % 8; + new_pad = 8 - len_remaining; + if (new_pad == 1) // cannot pad for 1 byte only + new_pad = 9; + else if (new_pad == 8) + new_pad = 0; + + return update_tlv_pad(skb, new_pad, pad_size, pad_off); +} + +__attribute__((always_inline)) +int has_egr_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh) +{ + int tlv_offset = sizeof(struct ip6_t) + sizeof(struct ip6_srh_t) + + ((srh->first_segment + 1) << 4); + struct sr6_tlv_t tlv; + + if (bpf_skb_load_bytes(skb, tlv_offset, &tlv, sizeof(struct sr6_tlv_t))) + return 0; + + if (tlv.type == SR6_TLV_EGRESS && tlv.len == 18) { + struct ip6_addr_t egr_addr; + + if (bpf_skb_load_bytes(skb, tlv_offset + 4, &egr_addr, 16)) + return 0; + + // check if egress TLV value is correct + if (ntohll(egr_addr.hi) == 0xfd00000000000000 && + ntohll(egr_addr.lo) == 0x4) + return 1; + } + + return 0; +} + +// This function will push a SRH with segments fd00::1, fd00::2, fd00::3, +// fd00::4 +SEC("encap_srh") +int __encap_srh(struct __sk_buff *skb) +{ + unsigned long long hi = 0xfd00000000000000; + struct ip6_addr_t *seg; + struct ip6_srh_t *srh; + char srh_buf[72]; // room for 4 segments + int err; + + srh = (struct ip6_srh_t *)srh_buf; + srh->nexthdr = 0; + srh->hdrlen = 8; + srh->type = 4; + srh->segments_left = 3; + srh->first_segment = 3; + srh->flags = 0; + srh->tag = 0; + + seg = (struct ip6_addr_t *)((char *)srh + sizeof(*srh)); + + #pragma clang loop unroll(full) + for (unsigned long long lo = 0; lo < 4; lo++) { + seg->lo = htonll(4 - lo); + seg->hi = htonll(hi); + seg = (struct ip6_addr_t *)((char *)seg + sizeof(*seg)); + } + + err = bpf_lwt_push_encap(skb, 0, (void *)srh, sizeof(srh_buf)); + if (err) + return BPF_DROP; + + return BPF_REDIRECT; +} + +// Add an Egress TLV fc00::4, add the flag A, +// and apply End.X action to fc42::1 +SEC("add_egr_x") +int __add_egr_x(struct __sk_buff *skb) +{ + unsigned long long hi = 0xfc42000000000000; + unsigned long long lo = 0x1; + struct ip6_srh_t *srh = get_srh(skb); + uint8_t new_flags = SR6_FLAG_ALERT; + struct ip6_addr_t addr; + int err, offset; + + if (srh == NULL) + return BPF_DROP; + + uint8_t tlv[20] = {2, 18, 0, 0, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4}; + + err = add_tlv(skb, srh, (srh->hdrlen+1) << 3, + (struct sr6_tlv_t *)&tlv, 20); + if (err) + return BPF_DROP; + + offset = sizeof(struct ip6_t) + offsetof(struct ip6_srh_t, flags); + err = bpf_lwt_seg6_store_bytes(skb, offset, + (void *)&new_flags, sizeof(new_flags)); + if (err) + return BPF_DROP; + + addr.lo = htonll(lo); + addr.hi = htonll(hi); + err = bpf_lwt_seg6_action(skb, SEG6_LOCAL_ACTION_END_X, + (void *)&addr, sizeof(addr)); + if (err) + return BPF_DROP; + return BPF_REDIRECT; +} + +// Pop the Egress TLV, reset the flags, change the tag 2442 and finally do a +// simple End action +SEC("pop_egr") +int __pop_egr(struct __sk_buff *skb) +{ + struct ip6_srh_t *srh = get_srh(skb); + uint16_t new_tag = bpf_htons(2442); + uint8_t new_flags = 0; + int err, offset; + + if (srh == NULL) + return BPF_DROP; + + if (srh->flags != SR6_FLAG_ALERT) + return BPF_DROP; + + if (srh->hdrlen != 11) // 4 segments + Egress TLV + Padding TLV + return BPF_DROP; + + if (!has_egr_tlv(skb, srh)) + return BPF_DROP; + + err = delete_tlv(skb, srh, 8 + (srh->first_segment + 1) * 16); + if (err) + return BPF_DROP; + + offset = sizeof(struct ip6_t) + offsetof(struct ip6_srh_t, flags); + if (bpf_lwt_seg6_store_bytes(skb, offset, (void *)&new_flags, + sizeof(new_flags))) + return BPF_DROP; + + offset = sizeof(struct ip6_t) + offsetof(struct ip6_srh_t, tag); + if (bpf_lwt_seg6_store_bytes(skb, offset, (void *)&new_tag, + sizeof(new_tag))) + return BPF_DROP; + + return BPF_OK; +} + +// Inspect if the Egress TLV and flag have been removed, if the tag is correct, +// then apply a End.T action to reach the last segment +SEC("inspect_t") +int __inspect_t(struct __sk_buff *skb) +{ + struct ip6_srh_t *srh = get_srh(skb); + int table = 117; + int err; + + if (srh == NULL) + return BPF_DROP; + + if (srh->flags != 0) + return BPF_DROP; + + if (srh->tag != bpf_htons(2442)) + return BPF_DROP; + + if (srh->hdrlen != 8) // 4 segments + return BPF_DROP; + + err = bpf_lwt_seg6_action(skb, SEG6_LOCAL_ACTION_END_T, + (void *)&table, sizeof(table)); + + if (err) + return BPF_DROP; + + return BPF_REDIRECT; +} + +char __license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_lwt_seg6local.sh b/tools/testing/selftests/bpf/test_lwt_seg6local.sh new file mode 100755 index 000000000000..1c77994b5e71 --- /dev/null +++ b/tools/testing/selftests/bpf/test_lwt_seg6local.sh @@ -0,0 +1,140 @@ +#!/bin/bash +# Connects 6 network namespaces through veths. +# Each NS may have different IPv6 global scope addresses : +# NS1 ---- NS2 ---- NS3 ---- NS4 ---- NS5 ---- NS6 +# fb00::1 fd00::1 fd00::2 fd00::3 fb00::6 +# fc42::1 fd00::4 +# +# All IPv6 packets going to fb00::/16 through NS2 will be encapsulated in a +# IPv6 header with a Segment Routing Header, with segments : +# fd00::1 -> fd00::2 -> fd00::3 -> fd00::4 +# +# 3 fd00::/16 IPv6 addresses are binded to seg6local End.BPF actions : +# - fd00::1 : add a TLV, change the flags and apply a End.X action to fc42::1 +# - fd00::2 : remove the TLV, change the flags, add a tag +# - fd00::3 : apply an End.T action to fd00::4, through routing table 117 +# +# fd00::4 is a simple Segment Routing node decapsulating the inner IPv6 packet. +# Each End.BPF action will validate the operations applied on the SRH by the +# previous BPF program in the chain, otherwise the packet is dropped. +# +# An UDP datagram is sent from fb00::1 to fb00::6. The test succeeds if this +# datagram can be read on NS6 when binding to fb00::6. + +TMP_FILE="/tmp/selftest_lwt_seg6local.txt" + +cleanup() +{ + if [ "$?" = "0" ]; then + echo "selftests: test_lwt_seg6local [PASS]"; + else + echo "selftests: test_lwt_seg6local [FAILED]"; + fi + + set +e + ip netns del ns1 2> /dev/null + ip netns del ns2 2> /dev/null + ip netns del ns3 2> /dev/null + ip netns del ns4 2> /dev/null + ip netns del ns5 2> /dev/null + ip netns del ns6 2> /dev/null + rm -f $TMP_FILE +} + +set -e + +ip netns add ns1 +ip netns add ns2 +ip netns add ns3 +ip netns add ns4 +ip netns add ns5 +ip netns add ns6 + +trap cleanup 0 2 3 6 9 + +ip link add veth1 type veth peer name veth2 +ip link add veth3 type veth peer name veth4 +ip link add veth5 type veth peer name veth6 +ip link add veth7 type veth peer name veth8 +ip link add veth9 type veth peer name veth10 + +ip link set veth1 netns ns1 +ip link set veth2 netns ns2 +ip link set veth3 netns ns2 +ip link set veth4 netns ns3 +ip link set veth5 netns ns3 +ip link set veth6 netns ns4 +ip link set veth7 netns ns4 +ip link set veth8 netns ns5 +ip link set veth9 netns ns5 +ip link set veth10 netns ns6 + +ip netns exec ns1 ip link set dev veth1 up +ip netns exec ns2 ip link set dev veth2 up +ip netns exec ns2 ip link set dev veth3 up +ip netns exec ns3 ip link set dev veth4 up +ip netns exec ns3 ip link set dev veth5 up +ip netns exec ns4 ip link set dev veth6 up +ip netns exec ns4 ip link set dev veth7 up +ip netns exec ns5 ip link set dev veth8 up +ip netns exec ns5 ip link set dev veth9 up +ip netns exec ns6 ip link set dev veth10 up +ip netns exec ns6 ip link set dev lo up + +# All link scope addresses and routes required between veths +ip netns exec ns1 ip -6 addr add fb00::12/16 dev veth1 scope link +ip netns exec ns1 ip -6 route add fb00::21 dev veth1 scope link +ip netns exec ns2 ip -6 addr add fb00::21/16 dev veth2 scope link +ip netns exec ns2 ip -6 addr add fb00::34/16 dev veth3 scope link +ip netns exec ns2 ip -6 route add fb00::43 dev veth3 scope link +ip netns exec ns3 ip -6 route add fb00::65 dev veth5 scope link +ip netns exec ns3 ip -6 addr add fb00::43/16 dev veth4 scope link +ip netns exec ns3 ip -6 addr add fb00::56/16 dev veth5 scope link +ip netns exec ns4 ip -6 addr add fb00::65/16 dev veth6 scope link +ip netns exec ns4 ip -6 addr add fb00::78/16 dev veth7 scope link +ip netns exec ns4 ip -6 route add fb00::87 dev veth7 scope link +ip netns exec ns5 ip -6 addr add fb00::87/16 dev veth8 scope link +ip netns exec ns5 ip -6 addr add fb00::910/16 dev veth9 scope link +ip netns exec ns5 ip -6 route add fb00::109 dev veth9 scope link +ip netns exec ns5 ip -6 route add fb00::109 table 117 dev veth9 scope link +ip netns exec ns6 ip -6 addr add fb00::109/16 dev veth10 scope link + +ip netns exec ns1 ip -6 addr add fb00::1/16 dev lo +ip netns exec ns1 ip -6 route add fb00::6 dev veth1 via fb00::21 + +ip netns exec ns2 ip -6 route add fb00::6 encap bpf in obj test_lwt_seg6local.o sec encap_srh dev veth2 +ip netns exec ns2 ip -6 route add fd00::1 dev veth3 via fb00::43 scope link + +ip netns exec ns3 ip -6 route add fc42::1 dev veth5 via fb00::65 +ip netns exec ns3 ip -6 route add fd00::1 encap seg6local action End.BPF obj test_lwt_seg6local.o sec add_egr_x dev veth4 + +ip netns exec ns4 ip -6 route add fd00::2 encap seg6local action End.BPF obj test_lwt_seg6local.o sec pop_egr dev veth6 +ip netns exec ns4 ip -6 addr add fc42::1 dev lo +ip netns exec ns4 ip -6 route add fd00::3 dev veth7 via fb00::87 + +ip netns exec ns5 ip -6 route add fd00::4 table 117 dev veth9 via fb00::109 +ip netns exec ns5 ip -6 route add fd00::3 encap seg6local action End.BPF obj test_lwt_seg6local.o sec inspect_t dev veth8 + +ip netns exec ns6 ip -6 addr add fb00::6/16 dev lo +ip netns exec ns6 ip -6 addr add fd00::4/16 dev lo + +ip netns exec ns1 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null +ip netns exec ns2 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null +ip netns exec ns3 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null +ip netns exec ns4 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null +ip netns exec ns5 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null + +ip netns exec ns6 sysctl net.ipv6.conf.all.seg6_enabled=1 > /dev/null +ip netns exec ns6 sysctl net.ipv6.conf.lo.seg6_enabled=1 > /dev/null +ip netns exec ns6 sysctl net.ipv6.conf.veth10.seg6_enabled=1 > /dev/null + +ip netns exec ns6 nc -l -6 -u -d 7330 > $TMP_FILE & +ip netns exec ns1 bash -c "echo 'foobar' | nc -w0 -6 -u -p 2121 -s fb00::1 fb00::6 7330" +sleep 5 # wait enough time to ensure the UDP datagram arrived to the last segment +kill -INT $! + +if [[ $(< $TMP_FILE) != "foobar" ]]; then + exit 1 +fi + +exit 0 |