@@ -21,4 +21,9 @@
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;
+};
+
#endif
@@ -729,6 +729,50 @@ union bpf_attr {
* @flags: reserved for future use
* Return: SK_PASS
*
+ * int lwt_push_encap(skb, type, hdr, len)
+ * Push an encapsulation header on top of current packet.
+ * @type: type of header to push :
+ * - BPF_LWT_ENCAP_SEG6 (push an IPv6 Segment Routing Header, struct
+ * ipv6_sr_hdr, the helper will add the outer IPv6 header)
+ * - BPF_LWT_ENCAP_SEG6_INLINE (push an IPv6 Segment Routing Header,
+ * struct ipv6_sr_hdr, inside the existing IPv6 header)
+ * @hdr: pointer where to copy the header from
+ * @len: size of hdr in bytes
+ * Return: 0 on success or negative error
+ *
+ * int lwt_seg6_store_bytes(skb, offset, from, len)
+ * Store bytes into the outermost Segment Routing header of an IPv6 header.
+ * Only the flags, tag and TLVs can be modified.
+ * @skb: pointer to skb
+ * @offset: offset within packet from skb->data
+ * @from: pointer where to copy bytes from
+ * @len: number of bytes to store into packet
+ * Return: 0 on success or negative error
+ *
+ * int lwt_seg6_adjust_srh(skb, offset, delta)
+ * Adjust the size allocated to TLVs in the outermost IPv6 Segment Routing
+ * Header (grow if delta > 0, else shrink)
+ * @skb: pointer to skb
+ * @offset: offset within packet from skb->data where SRH will grow/shrink,
+ * only offsets after the segments are accepted
+ * @delta: a positive/negative integer
+ * Return: 0 on success or negative on error
+ *
+ * int lwt_seg6_action(skb, action, param, param_len)
+ * Apply a IPv6 Segment Routing action on a packet with an IPv6 Segment
+ * Routing Header.
+ * @action:
+ * - End.X: SEG6_LOCAL_ACTION_END_X
+ * (type of param: struct in6_addr)
+ * - End.T: SEG6_LOCAL_ACTION_END_T
+ * (type of param: int)
+ * - End.B6: SEG6_LOCAL_ACTION_END_B6
+ * (type of param: struct ipv6_sr_hdr)
+ * - End.B6.Encap: SEG6_LOCAL_ACTION_END_B6_ENCAP
+ * (type of param: struct ipv6_sr_hdr)
+ * @param: pointer to the parameter required by the action
+ * @param_len: length of param in bytes
+ * Return: 0 on success or negative error
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -794,7 +838,11 @@ union bpf_attr {
FN(msg_redirect_map), \
FN(msg_apply_bytes), \
FN(msg_cork_bytes), \
- FN(msg_pull_data),
+ FN(msg_pull_data), \
+ 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
@@ -852,6 +900,12 @@ enum bpf_adj_room_mode {
BPF_ADJ_ROOM_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
*/
@@ -57,6 +57,10 @@
#include <net/busy_poll.h>
#include <net/tcp.h>
#include <linux/bpf_trace.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
@@ -3013,27 +3017,6 @@ 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)
- return true;
-
- return false;
-}
-
static unsigned long bpf_skb_copy(void *dst_buff, const void *skb,
unsigned long off, unsigned long len)
{
@@ -3597,6 +3580,244 @@ static const struct bpf_func_proto bpf_sock_ops_cb_flags_set_proto = {
.arg2_type = ARG_ANYTHING,
};
+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;
+ }
+ 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);
+}
+
+BPF_CALL_4(bpf_lwt_push_encap, struct sk_buff *, skb, u32, type, void *, hdr,
+ u32, len)
+{
+ switch (type) {
+ case BPF_LWT_ENCAP_SEG6:
+ case BPF_LWT_ENCAP_SEG6_INLINE:
+ return bpf_push_seg6_encap(skb, type, hdr, len);
+ 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)
+{
+ struct seg6_bpf_srh_state *srh_state = (struct seg6_bpf_srh_state *)
+ &skb->cb;
+ 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(ptr, from, len);
+ return 0;
+}
+
+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)
+{
+ struct seg6_bpf_srh_state *srh_state = (struct seg6_bpf_srh_state *)
+ &skb->cb;
+ 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;
+ }
+}
+
+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)
+{
+ struct seg6_bpf_srh_state *srh_state = (struct seg6_bpf_srh_state *)
+ &skb->cb;
+
+ 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);
+ }
+ if (unlikely(ret < 0))
+ return ret;
+
+ hdr = (struct ipv6hdr *)skb->data;
+ hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
+
+ bpf_compute_data_pointers(skb);
+ srh_state->hdrlen += len;
+ srh_state->valid = 0;
+ return 0;
+}
+
+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_lwt_push_encap ||
+ func == bpf_lwt_seg6_store_bytes ||
+ func == bpf_lwt_seg6_adjust_srh
+ )
+ return true;
+
+ return false;
+}
+
static const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)
{