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 + * + * 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 +#include +#include +#include +#include +#include + +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 ? : ""); + 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: