// SPDX-License-Identifier: GPL-2.0-or-later /* * SR-IPv6 implementation * * Authors: * David Lebrun * eBPF support: Mathieu Xhonneux */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_IPV6_SEG6_HMAC #include #endif #include #include #include #include #define SEG6_F_ATTR(i) BIT(i) struct seg6_local_lwt; /* callbacks used for customizing the creation and destruction of a behavior */ struct seg6_local_lwtunnel_ops { int (*build_state)(struct seg6_local_lwt *slwt, const void *cfg, struct netlink_ext_ack *extack); void (*destroy_state)(struct seg6_local_lwt *slwt); }; struct seg6_action_desc { int action; unsigned long attrs; /* The optattrs field is used for specifying all the optional * attributes supported by a specific behavior. * It means that if one of these attributes is not provided in the * netlink message during the behavior creation, no errors will be * returned to the userspace. * * Each attribute can be only of two types (mutually exclusive): * 1) required or 2) optional. * Every user MUST obey to this rule! If you set an attribute as * required the same attribute CANNOT be set as optional and vice * versa. */ unsigned long optattrs; int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt); int static_headroom; struct seg6_local_lwtunnel_ops slwt_ops; }; struct bpf_lwt_prog { struct bpf_prog *prog; char *name; }; /* default length values (expressed in bits) for both Locator-Block and * Locator-Node Function. * * Both SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS *must* be: * i) greater than 0; * ii) evenly divisible by 8. In other terms, the lengths of the * Locator-Block and Locator-Node Function must be byte-aligned (we can * relax this constraint in the future if really needed). * * Moreover, a third condition must hold: * iii) SEG6_LOCAL_LCBLOCK_DBITS + SEG6_LOCAL_LCNODE_FN_DBITS <= 128. * * The correctness of SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS * values are checked during the kernel compilation. If the compilation stops, * check the value of these parameters to see if they meet conditions (i), (ii) * and (iii). */ #define SEG6_LOCAL_LCBLOCK_DBITS 32 #define SEG6_LOCAL_LCNODE_FN_DBITS 16 /* The following next_csid_chk_{cntr,lcblock,lcblock_fn}_bits macros can be * used directly to check whether the lengths (in bits) of Locator-Block and * Locator-Node Function are valid according to (i), (ii), (iii). */ #define next_csid_chk_cntr_bits(blen, flen) \ ((blen) + (flen) > 128) #define next_csid_chk_lcblock_bits(blen) \ ({ \ typeof(blen) __tmp = blen; \ (!__tmp || __tmp > 120 || (__tmp & 0x07)); \ }) #define next_csid_chk_lcnode_fn_bits(flen) \ next_csid_chk_lcblock_bits(flen) /* flag indicating that flavors are set up for a given End* behavior */ #define SEG6_F_LOCAL_FLAVORS SEG6_F_ATTR(SEG6_LOCAL_FLAVORS) #define SEG6_F_LOCAL_FLV_OP(flvname) BIT(SEG6_LOCAL_FLV_OP_##flvname) #define SEG6_F_LOCAL_FLV_NEXT_CSID SEG6_F_LOCAL_FLV_OP(NEXT_CSID) #define SEG6_F_LOCAL_FLV_PSP SEG6_F_LOCAL_FLV_OP(PSP) /* Supported RFC8986 Flavor operations are reported in this bitmask */ #define SEG6_LOCAL_FLV8986_SUPP_OPS SEG6_F_LOCAL_FLV_PSP #define SEG6_LOCAL_END_FLV_SUPP_OPS (SEG6_F_LOCAL_FLV_NEXT_CSID | \ SEG6_LOCAL_FLV8986_SUPP_OPS) #define SEG6_LOCAL_END_X_FLV_SUPP_OPS SEG6_F_LOCAL_FLV_NEXT_CSID struct seg6_flavors_info { /* Flavor operations */ __u32 flv_ops; /* Locator-Block length, expressed in bits */ __u8 lcblock_bits; /* Locator-Node Function length, expressed in bits*/ __u8 lcnode_func_bits; }; enum seg6_end_dt_mode { DT_INVALID_MODE = -EINVAL, DT_LEGACY_MODE = 0, DT_VRF_MODE = 1, }; struct seg6_end_dt_info { enum seg6_end_dt_mode mode; struct net *net; /* VRF device associated to the routing table used by the SRv6 * End.DT4/DT6 behavior for routing IPv4/IPv6 packets. */ int vrf_ifindex; int vrf_table; /* tunneled packet family (IPv4 or IPv6). * Protocol and header length are inferred from family. */ u16 family; }; struct pcpu_seg6_local_counters { u64_stats_t packets; u64_stats_t bytes; u64_stats_t errors; struct u64_stats_sync syncp; }; /* This struct groups all the SRv6 Behavior counters supported so far. * * put_nla_counters() makes use of this data structure to collect all counter * values after the per-CPU counter evaluation has been performed. * Finally, each counter value (in seg6_local_counters) is stored in the * corresponding netlink attribute and sent to user space. * * NB: we don't want to expose this structure to user space! */ struct seg6_local_counters { __u64 packets; __u64 bytes; __u64 errors; }; #define seg6_local_alloc_pcpu_counters(__gfp) \ __netdev_alloc_pcpu_stats(struct pcpu_seg6_local_counters, \ ((__gfp) | __GFP_ZERO)) #define SEG6_F_LOCAL_COUNTERS SEG6_F_ATTR(SEG6_LOCAL_COUNTERS) struct seg6_local_lwt { int action; struct ipv6_sr_hdr *srh; int table; struct in_addr nh4; struct in6_addr nh6; int iif; int oif; struct bpf_lwt_prog bpf; #ifdef CONFIG_NET_L3_MASTER_DEV struct seg6_end_dt_info dt_info; #endif struct seg6_flavors_info flv_info; struct pcpu_seg6_local_counters __percpu *pcpu_counters; int headroom; struct seg6_action_desc *desc; /* unlike the required attrs, we have to track the optional attributes * that have been effectively parsed. */ unsigned long parsed_optattrs; }; static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt) { return (struct seg6_local_lwt *)lwt->data; } static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb) { struct ipv6_sr_hdr *srh; srh = seg6_get_srh(skb, IP6_FH_F_SKIP_RH); if (!srh) return NULL; #ifdef CONFIG_IPV6_SEG6_HMAC if (!seg6_hmac_validate_skb(skb)) return NULL; #endif return srh; } static bool decap_and_validate(struct sk_buff *skb, int proto) { struct ipv6_sr_hdr *srh; unsigned int off = 0; srh = seg6_get_srh(skb, 0); if (srh && srh->segments_left > 0) return false; #ifdef CONFIG_IPV6_SEG6_HMAC if (srh && !seg6_hmac_validate_skb(skb)) return false; #endif if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0) return false; if (!pskb_pull(skb, off)) return false; skb_postpull_rcsum(skb, skb_network_header(skb), off); skb_reset_network_header(skb); skb_reset_transport_header(skb); if (iptunnel_pull_offloads(skb)) return false; return true; } static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr) { struct in6_addr *addr; srh->segments_left--; addr = srh->segments + srh->segments_left; *daddr = *addr; } static int seg6_lookup_any_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, u32 tbl_id, bool local_delivery) { struct net *net = dev_net(skb->dev); struct ipv6hdr *hdr = ipv6_hdr(skb); int flags = RT6_LOOKUP_F_HAS_SADDR; struct dst_entry *dst = NULL; struct rt6_info *rt; struct flowi6 fl6; int dev_flags = 0; memset(&fl6, 0, sizeof(fl6)); fl6.flowi6_iif = skb->dev->ifindex; fl6.daddr = nhaddr ? *nhaddr : hdr->daddr; fl6.saddr = hdr->saddr; fl6.flowlabel = ip6_flowinfo(hdr); fl6.flowi6_mark = skb->mark; fl6.flowi6_proto = hdr->nexthdr; if (nhaddr) fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH; if (!tbl_id) { dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags); } else { struct fib6_table *table; table = fib6_get_table(net, tbl_id); if (!table) goto out; rt = ip6_pol_route(net, table, 0, &fl6, skb, flags); dst = &rt->dst; } /* we want to discard traffic destined for local packet processing, * if @local_delivery is set to false. */ if (!local_delivery) dev_flags |= IFF_LOOPBACK; if (dst && (dst->dev->flags & dev_flags) && !dst->error) { dst_release(dst); dst = NULL; } out: if (!dst) { rt = net->ipv6.ip6_blk_hole_entry; dst = &rt->dst; dst_hold(dst); } skb_dst_drop(skb); skb_dst_set(skb, dst); return dst->error; } int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, u32 tbl_id) { return seg6_lookup_any_nexthop(skb, nhaddr, tbl_id, false); } static __u8 seg6_flv_lcblock_octects(const struct seg6_flavors_info *finfo) { return finfo->lcblock_bits >> 3; } static __u8 seg6_flv_lcnode_func_octects(const struct seg6_flavors_info *finfo) { return finfo->lcnode_func_bits >> 3; } static bool seg6_next_csid_is_arg_zero(const struct in6_addr *addr, const struct seg6_flavors_info *finfo) { __u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo); __u8 blk_octects = seg6_flv_lcblock_octects(finfo); __u8 arg_octects; int i; arg_octects = 16 - blk_octects - fnc_octects; for (i = 0; i < arg_octects; ++i) { if (addr->s6_addr[blk_octects + fnc_octects + i] != 0x00) return false; } return true; } /* assume that DA.Argument length > 0 */ static void seg6_next_csid_advance_arg(struct in6_addr *addr, const struct seg6_flavors_info *finfo) { __u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo); __u8 blk_octects = seg6_flv_lcblock_octects(finfo); /* advance DA.Argument */ memmove(&addr->s6_addr[blk_octects], &addr->s6_addr[blk_octects + fnc_octects], 16 - blk_octects - fnc_octects); memset(&addr->s6_addr[16 - fnc_octects], 0x00, fnc_octects); } static int input_action_end_finish(struct sk_buff *skb, struct seg6_local_lwt *slwt) { seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); } static int input_action_end_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct ipv6_sr_hdr *srh; srh = get_and_validate_srh(skb); if (!srh) goto drop; advance_nextseg(srh, &ipv6_hdr(skb)->daddr); return input_action_end_finish(skb, slwt); drop: kfree_skb(skb); return -EINVAL; } static int end_next_csid_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) { const struct seg6_flavors_info *finfo = &slwt->flv_info; struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; if (seg6_next_csid_is_arg_zero(daddr, finfo)) return input_action_end_core(skb, slwt); /* update DA */ seg6_next_csid_advance_arg(daddr, finfo); return input_action_end_finish(skb, slwt); } static int input_action_end_x_finish(struct sk_buff *skb, struct seg6_local_lwt *slwt) { seg6_lookup_nexthop(skb, &slwt->nh6, 0); return dst_input(skb); } static int input_action_end_x_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct ipv6_sr_hdr *srh; srh = get_and_validate_srh(skb); if (!srh) goto drop; advance_nextseg(srh, &ipv6_hdr(skb)->daddr); return input_action_end_x_finish(skb, slwt); drop: kfree_skb(skb); return -EINVAL; } static int end_x_next_csid_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) { const struct seg6_flavors_info *finfo = &slwt->flv_info; struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; if (seg6_next_csid_is_arg_zero(daddr, finfo)) return input_action_end_x_core(skb, slwt); /* update DA */ seg6_next_csid_advance_arg(daddr, finfo); return input_action_end_x_finish(skb, slwt); } static bool seg6_next_csid_enabled(__u32 fops) { return fops & SEG6_F_LOCAL_FLV_NEXT_CSID; } /* Processing of SRv6 End, End.X, and End.T behaviors can be extended through * the flavors framework. These behaviors must report the subset of (flavor) * operations they currently implement. In this way, if a user specifies a * flavor combination that is not supported by a given End* behavior, the * kernel refuses to instantiate the tunnel reporting the error. */ static int seg6_flv_supp_ops_by_action(int action, __u32 *fops) { switch (action) { case SEG6_LOCAL_ACTION_END: *fops = SEG6_LOCAL_END_FLV_SUPP_OPS; break; case SEG6_LOCAL_ACTION_END_X: *fops = SEG6_LOCAL_END_X_FLV_SUPP_OPS; break; default: return -EOPNOTSUPP; } return 0; } /* We describe the packet state in relation to the absence/presence of the SRH * and the Segment Left (SL) field. * For our purposes, it is not necessary to record the exact value of the SL * when the SID List consists of two or more segments. */ enum seg6_local_pktinfo { /* the order really matters! */ SEG6_LOCAL_PKTINFO_NOHDR = 0, SEG6_LOCAL_PKTINFO_SL_ZERO, SEG6_LOCAL_PKTINFO_SL_ONE, SEG6_LOCAL_PKTINFO_SL_MORE, __SEG6_LOCAL_PKTINFO_MAX, }; #define SEG6_LOCAL_PKTINFO_MAX (__SEG6_LOCAL_PKTINFO_MAX - 1) static enum seg6_local_pktinfo seg6_get_srh_pktinfo(struct ipv6_sr_hdr *srh) { __u8 sgl; if (!srh) return SEG6_LOCAL_PKTINFO_NOHDR; sgl = srh->segments_left; if (sgl < 2) return SEG6_LOCAL_PKTINFO_SL_ZERO + sgl; return SEG6_LOCAL_PKTINFO_SL_MORE; } enum seg6_local_flv_action { SEG6_LOCAL_FLV_ACT_UNSPEC = 0, SEG6_LOCAL_FLV_ACT_END, SEG6_LOCAL_FLV_ACT_PSP, SEG6_LOCAL_FLV_ACT_USP, SEG6_LOCAL_FLV_ACT_USD, __SEG6_LOCAL_FLV_ACT_MAX }; #define SEG6_LOCAL_FLV_ACT_MAX (__SEG6_LOCAL_FLV_ACT_MAX - 1) /* The action table for RFC8986 flavors (see the flv8986_act_tbl below) * contains the actions (i.e. processing operations) to be applied on packets * when flavors are configured for an End* behavior. * By combining the pkinfo data and from the flavors mask, the macro * computes the index used to access the elements (actions) stored in the * action table. The index is structured as follows: * * index * _______________/\________________ * / \ * +----------------+----------------+ * | pf | afm | * +----------------+----------------+ * ph-1 ... p1 p0 fk-1 ... f1 f0 * MSB LSB * * where: * - 'afm' (adjusted flavor mask) is the mask containing a combination of the * RFC8986 flavors currently supported. 'afm' corresponds to the @fm * argument of the macro whose value is righ-shifted by 1 bit. By doing so, * we discard the SEG6_LOCAL_FLV_OP_UNSPEC flag (bit 0 in @fm) which is * never used here; * - 'pf' encodes the packet info (pktinfo) regarding the presence/absence of * the SRH, SL = 0, etc. 'pf' is set with the value of @pf provided as * argument to the macro. */ #define flv8986_act_tbl_idx(pf, fm) \ ((((pf) << bits_per(SEG6_LOCAL_FLV8986_SUPP_OPS)) | \ ((fm) & SEG6_LOCAL_FLV8986_SUPP_OPS)) >> SEG6_LOCAL_FLV_OP_PSP) /* We compute the size of the action table by considering the RFC8986 flavors * actually supported by the kernel. In this way, the size is automatically * adjusted when new flavors are supported. */ #define FLV8986_ACT_TBL_SIZE \ roundup_pow_of_two(flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_MAX, \ SEG6_LOCAL_FLV8986_SUPP_OPS)) /* tbl_cfg(act, pf, fm) macro is used to easily configure the action * table; it accepts 3 arguments: * i) @act, the suffix from SEG6_LOCAL_FLV_ACT_{act} representing * the action that should be applied on the packet; * ii) @pf, the suffix from SEG6_LOCAL_PKTINFO_{pf} reporting the packet * info about the lack/presence of SRH, SRH with SL = 0, etc; * iii) @fm, the mask of flavors. */ #define tbl_cfg(act, pf, fm) \ [flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_##pf, \ (fm))] = SEG6_LOCAL_FLV_ACT_##act /* shorthand for improving readability */ #define F_PSP SEG6_F_LOCAL_FLV_PSP /* The table contains, for each combination of the pktinfo data and * flavors, the action that should be taken on a packet (e.g. * "standard" Endpoint processing, Penultimate Segment Pop, etc). * * By default, table entries not explicitly configured are initialized with the * SEG6_LOCAL_FLV_ACT_UNSPEC action, which generally has the effect of * discarding the processed packet. */ static const u8 flv8986_act_tbl[FLV8986_ACT_TBL_SIZE] = { /* PSP variant for packet where SRH with SL = 1 */ tbl_cfg(PSP, SL_ONE, F_PSP), /* End for packet where the SRH with SL > 1*/ tbl_cfg(END, SL_MORE, F_PSP), }; #undef F_PSP #undef tbl_cfg /* For each flavor defined in RFC8986 (or a combination of them) an action is * performed on the packet. The specific action depends on: * - info extracted from the packet (i.e. pktinfo data) regarding the * lack/presence of the SRH, and if the SRH is available, on the value of * Segment Left field; * - the mask of flavors configured for the specific SRv6 End* behavior. * * The function combines both the pkinfo and the flavors mask to evaluate the * corresponding action to be taken on the packet. */ static enum seg6_local_flv_action seg6_local_flv8986_act_lookup(enum seg6_local_pktinfo pinfo, __u32 flvmask) { unsigned long index; /* check if the provided mask of flavors is supported */ if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS)) return SEG6_LOCAL_FLV_ACT_UNSPEC; index = flv8986_act_tbl_idx(pinfo, flvmask); if (unlikely(index >= FLV8986_ACT_TBL_SIZE)) return SEG6_LOCAL_FLV_ACT_UNSPEC; return flv8986_act_tbl[index]; } /* skb->data must be aligned with skb->network_header */ static bool seg6_pop_srh(struct sk_buff *skb, int srhoff) { struct ipv6_sr_hdr *srh; struct ipv6hdr *iph; __u8 srh_nexthdr; int thoff = -1; int srhlen; int nhlen; if (unlikely(srhoff < sizeof(*iph) || !pskb_may_pull(skb, srhoff + sizeof(*srh)))) return false; srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); srhlen = ipv6_optlen(srh); /* we are about to mangle the pkt, let's check if we can write on it */ if (unlikely(skb_ensure_writable(skb, srhoff + srhlen))) return false; /* skb_ensure_writable() may change skb pointers; evaluate srh again */ srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); srh_nexthdr = srh->nexthdr; if (unlikely(!skb_transport_header_was_set(skb))) goto pull; nhlen = skb_network_header_len(skb); /* we have to deal with the transport header: it could be set before * the SRH, after the SRH, or within it (which is considered wrong, * however). */ if (likely(nhlen <= srhoff)) thoff = nhlen; else if (nhlen >= srhoff + srhlen) /* transport_header is set after the SRH */ thoff = nhlen - srhlen; else /* transport_header falls inside the SRH; hence, we can't * restore the transport_header pointer properly after * SRH removing operation. */ return false; pull: /* we need to pop the SRH: * 1) first of all, we pull out everything from IPv6 header up to SRH * (included) evaluating also the rcsum; * 2) we overwrite (and then remove) the SRH by properly moving the * IPv6 along with any extension header that precedes the SRH; * 3) At the end, we push back the pulled headers (except for SRH, * obviously). */ skb_pull_rcsum(skb, srhoff + srhlen); memmove(skb_network_header(skb) + srhlen, skb_network_header(skb), srhoff); skb_push(skb, srhoff); skb_reset_network_header(skb); skb_mac_header_rebuild(skb); if (likely(thoff >= 0)) skb_set_transport_header(skb, thoff); iph = ipv6_hdr(skb); if (iph->nexthdr == NEXTHDR_ROUTING) { iph->nexthdr = srh_nexthdr; } else { /* we must look for the extension header (EXTH, for short) that * immediately precedes the SRH we have just removed. * Then, we update the value of the EXTH nexthdr with the one * contained in the SRH nexthdr. */ unsigned int off = sizeof(*iph); struct ipv6_opt_hdr *hp, _hdr; __u8 nexthdr = iph->nexthdr; for (;;) { if (unlikely(!ipv6_ext_hdr(nexthdr) || nexthdr == NEXTHDR_NONE)) return false; hp = skb_header_pointer(skb, off, sizeof(_hdr), &_hdr); if (unlikely(!hp)) return false; if (hp->nexthdr == NEXTHDR_ROUTING) { hp->nexthdr = srh_nexthdr; break; } switch (nexthdr) { case NEXTHDR_FRAGMENT: fallthrough; case NEXTHDR_AUTH: /* we expect SRH before FRAG and AUTH */ return false; default: off += ipv6_optlen(hp); break; } nexthdr = hp->nexthdr; } } iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); skb_postpush_rcsum(skb, iph, srhoff); return true; } /* process the packet on the basis of the RFC8986 flavors set for the given * SRv6 End behavior instance. */ static int end_flv8986_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) { const struct seg6_flavors_info *finfo = &slwt->flv_info; enum seg6_local_flv_action action; enum seg6_local_pktinfo pinfo; struct ipv6_sr_hdr *srh; __u32 flvmask; int srhoff; srh = seg6_get_srh(skb, 0); srhoff = srh ? ((unsigned char *)srh - skb->data) : 0; pinfo = seg6_get_srh_pktinfo(srh); #ifdef CONFIG_IPV6_SEG6_HMAC if (srh && !seg6_hmac_validate_skb(skb)) goto drop; #endif flvmask = finfo->flv_ops; if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS)) { pr_warn_once("seg6local: invalid RFC8986 flavors\n"); goto drop; } /* retrieve the action triggered by the combination of pktinfo data and * the flavors mask. */ action = seg6_local_flv8986_act_lookup(pinfo, flvmask); switch (action) { case SEG6_LOCAL_FLV_ACT_END: /* process the packet as the "standard" End behavior */ advance_nextseg(srh, &ipv6_hdr(skb)->daddr); break; case SEG6_LOCAL_FLV_ACT_PSP: advance_nextseg(srh, &ipv6_hdr(skb)->daddr); if (unlikely(!seg6_pop_srh(skb, srhoff))) goto drop; break; case SEG6_LOCAL_FLV_ACT_UNSPEC: fallthrough; default: /* by default, we drop the packet since we could not find a * suitable action. */ goto drop; } return input_action_end_finish(skb, slwt); drop: kfree_skb(skb); return -EINVAL; } /* regular endpoint function */ static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt) { const struct seg6_flavors_info *finfo = &slwt->flv_info; __u32 fops = finfo->flv_ops; if (!fops) return input_action_end_core(skb, slwt); /* check for the presence of NEXT-C-SID since it applies first */ if (seg6_next_csid_enabled(fops)) return end_next_csid_core(skb, slwt); /* the specific processing function to be performed on the packet * depends on the combination of flavors defined in RFC8986 and some * information extracted from the packet, e.g. presence/absence of SRH, * Segment Left = 0, etc. */ return end_flv8986_core(skb, slwt); } /* regular endpoint, and forward to specified nexthop */ static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt) { const struct seg6_flavors_info *finfo = &slwt->flv_info; __u32 fops = finfo->flv_ops; /* check for the presence of NEXT-C-SID since it applies first */ if (seg6_next_csid_enabled(fops)) return end_x_next_csid_core(skb, slwt); return input_action_end_x_core(skb, slwt); } static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct ipv6_sr_hdr *srh; srh = get_and_validate_srh(skb); if (!srh) goto drop; advance_nextseg(srh, &ipv6_hdr(skb)->daddr); seg6_lookup_nexthop(skb, NULL, slwt->table); return dst_input(skb); drop: kfree_skb(skb); return -EINVAL; } /* decapsulate and forward inner L2 frame on specified interface */ static int input_action_end_dx2(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct net *net = dev_net(skb->dev); struct net_device *odev; struct ethhdr *eth; if (!decap_and_validate(skb, IPPROTO_ETHERNET)) goto drop; if (!pskb_may_pull(skb, ETH_HLEN)) goto drop; skb_reset_mac_header(skb); eth = (struct ethhdr *)skb->data; /* To determine the frame's protocol, we assume it is 802.3. This avoids * a call to eth_type_trans(), which is not really relevant for our * use case. */ if (!eth_proto_is_802_3(eth->h_proto)) goto drop; odev = dev_get_by_index_rcu(net, slwt->oif); if (!odev) goto drop; /* As we accept Ethernet frames, make sure the egress device is of * the correct type. */ if (odev->type != ARPHRD_ETHER) goto drop; if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev)) goto drop; skb_orphan(skb); if (skb_warn_if_lro(skb)) goto drop; skb_forward_csum(skb); if (skb->len - ETH_HLEN > odev->mtu) goto drop; skb->dev = odev; skb->protocol = eth->h_proto; return dev_queue_xmit(skb); drop: kfree_skb(skb); return -EINVAL; } static int input_action_end_dx6_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { struct dst_entry *orig_dst = skb_dst(skb); struct in6_addr *nhaddr = NULL; struct seg6_local_lwt *slwt; slwt = seg6_local_lwtunnel(orig_dst->lwtstate); /* The inner packet is not associated to any local interface, * so we do not call netif_rx(). * * If slwt->nh6 is set to ::, then lookup the nexthop for the * inner packet's DA. Otherwise, use the specified nexthop. */ if (!ipv6_addr_any(&slwt->nh6)) nhaddr = &slwt->nh6; seg6_lookup_nexthop(skb, nhaddr, 0); return dst_input(skb); } /* decapsulate and forward to specified nexthop */ static int input_action_end_dx6(struct sk_buff *skb, struct seg6_local_lwt *slwt) { /* this function accepts IPv6 encapsulated packets, with either * an SRH with SL=0, or no SRH. */ if (!decap_and_validate(skb, IPPROTO_IPV6)) goto drop; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto drop; skb_set_transport_header(skb, sizeof(struct ipv6hdr)); nf_reset_ct(skb); if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, dev_net(skb->dev), NULL, skb, NULL, skb_dst(skb)->dev, input_action_end_dx6_finish); return input_action_end_dx6_finish(dev_net(skb->dev), NULL, skb); drop: kfree_skb(skb); return -EINVAL; } static int input_action_end_dx4_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { struct dst_entry *orig_dst = skb_dst(skb); struct seg6_local_lwt *slwt; struct iphdr *iph; __be32 nhaddr; int err; slwt = seg6_local_lwtunnel(orig_dst->lwtstate); iph = ip_hdr(skb); nhaddr = slwt->nh4.s_addr ?: iph->daddr; skb_dst_drop(skb); err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev); if (err) { kfree_skb(skb); return -EINVAL; } return dst_input(skb); } static int input_action_end_dx4(struct sk_buff *skb, struct seg6_local_lwt *slwt) { if (!decap_and_validate(skb, IPPROTO_IPIP)) goto drop; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto drop; skb->protocol = htons(ETH_P_IP); skb_set_transport_header(skb, sizeof(struct iphdr)); nf_reset_ct(skb); if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, dev_net(skb->dev), NULL, skb, NULL, skb_dst(skb)->dev, input_action_end_dx4_finish); return input_action_end_dx4_finish(dev_net(skb->dev), NULL, skb); drop: kfree_skb(skb); return -EINVAL; } #ifdef CONFIG_NET_L3_MASTER_DEV static struct net *fib6_config_get_net(const struct fib6_config *fib6_cfg) { const struct nl_info *nli = &fib6_cfg->fc_nlinfo; return nli->nl_net; } static int __seg6_end_dt_vrf_build(struct seg6_local_lwt *slwt, const void *cfg, u16 family, struct netlink_ext_ack *extack) { struct seg6_end_dt_info *info = &slwt->dt_info; int vrf_ifindex; struct net *net; net = fib6_config_get_net(cfg); /* note that vrf_table was already set by parse_nla_vrftable() */ vrf_ifindex = l3mdev_ifindex_lookup_by_table_id(L3MDEV_TYPE_VRF, net, info->vrf_table); if (vrf_ifindex < 0) { if (vrf_ifindex == -EPERM) { NL_SET_ERR_MSG(extack, "Strict mode for VRF is disabled"); } else if (vrf_ifindex == -ENODEV) { NL_SET_ERR_MSG(extack, "Table has no associated VRF device"); } else { pr_debug("seg6local: SRv6 End.DT* creation error=%d\n", vrf_ifindex); } return vrf_ifindex; } info->net = net; info->vrf_ifindex = vrf_ifindex; info->family = family; info->mode = DT_VRF_MODE; return 0; } /* The SRv6 End.DT4/DT6 behavior extracts the inner (IPv4/IPv6) packet and * routes the IPv4/IPv6 packet by looking at the configured routing table. * * In the SRv6 End.DT4/DT6 use case, we can receive traffic (IPv6+Segment * Routing Header packets) from several interfaces and the outer IPv6 * destination address (DA) is used for retrieving the specific instance of the * End.DT4/DT6 behavior that should process the packets. * * However, the inner IPv4/IPv6 packet is not really bound to any receiving * interface and thus the End.DT4/DT6 sets the VRF (associated with the * corresponding routing table) as the *receiving* interface. * In other words, the End.DT4/DT6 processes a packet as if it has been received * directly by the VRF (and not by one of its slave devices, if any). * In this way, the VRF interface is used for routing the IPv4/IPv6 packet in * according to the routing table configured by the End.DT4/DT6 instance. * * This design allows you to get some interesting features like: * 1) the statistics on rx packets; * 2) the possibility to install a packet sniffer on the receiving interface * (the VRF one) for looking at the incoming packets; * 3) the possibility to leverage the netfilter prerouting hook for the inner * IPv4 packet. * * This function returns: * - the sk_buff* when the VRF rcv handler has processed the packet correctly; * - NULL when the skb is consumed by the VRF rcv handler; * - a pointer which encodes a negative error number in case of error. * Note that in this case, the function takes care of freeing the skb. */ static struct sk_buff *end_dt_vrf_rcv(struct sk_buff *skb, u16 family, struct net_device *dev) { /* based on l3mdev_ip_rcv; we are only interested in the master */ if (unlikely(!netif_is_l3_master(dev) && !netif_has_l3_rx_handler(dev))) goto drop; if (unlikely(!dev->l3mdev_ops->l3mdev_l3_rcv)) goto drop; /* the decap packet IPv4/IPv6 does not come with any mac header info. * We must unset the mac header to allow the VRF device to rebuild it, * just in case there is a sniffer attached on the device. */ skb_unset_mac_header(skb); skb = dev->l3mdev_ops->l3mdev_l3_rcv(dev, skb, family); if (!skb) /* the skb buffer was consumed by the handler */ return NULL; /* when a packet is received by a VRF or by one of its slaves, the * master device reference is set into the skb. */ if (unlikely(skb->dev != dev || skb->skb_iif != dev->ifindex)) goto drop; return skb; drop: kfree_skb(skb); return ERR_PTR(-EINVAL); } static struct net_device *end_dt_get_vrf_rcu(struct sk_buff *skb, struct seg6_end_dt_info *info) { int vrf_ifindex = info->vrf_ifindex; struct net *net = info->net; if (unlikely(vrf_ifindex < 0)) goto error; if (unlikely(!net_eq(dev_net(skb->dev), net))) goto error; return dev_get_by_index_rcu(net, vrf_ifindex); error: return NULL; } static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb, struct seg6_local_lwt *slwt, u16 family) { struct seg6_end_dt_info *info = &slwt->dt_info; struct net_device *vrf; __be16 protocol; int hdrlen; vrf = end_dt_get_vrf_rcu(skb, info); if (unlikely(!vrf)) goto drop; switch (family) { case AF_INET: protocol = htons(ETH_P_IP); hdrlen = sizeof(struct iphdr); break; case AF_INET6: protocol = htons(ETH_P_IPV6); hdrlen = sizeof(struct ipv6hdr); break; case AF_UNSPEC: fallthrough; default: goto drop; } if (unlikely(info->family != AF_UNSPEC && info->family != family)) { pr_warn_once("seg6local: SRv6 End.DT* family mismatch"); goto drop; } skb->protocol = protocol; skb_dst_drop(skb); skb_set_transport_header(skb, hdrlen); nf_reset_ct(skb); return end_dt_vrf_rcv(skb, family, vrf); drop: kfree_skb(skb); return ERR_PTR(-EINVAL); } static int input_action_end_dt4(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct iphdr *iph; int err; if (!decap_and_validate(skb, IPPROTO_IPIP)) goto drop; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto drop; skb = end_dt_vrf_core(skb, slwt, AF_INET); if (!skb) /* packet has been processed and consumed by the VRF */ return 0; if (IS_ERR(skb)) return PTR_ERR(skb); iph = ip_hdr(skb); err = ip_route_input(skb, iph->daddr, iph->saddr, 0, skb->dev); if (unlikely(err)) goto drop; return dst_input(skb); drop: kfree_skb(skb); return -EINVAL; } static int seg6_end_dt4_build(struct seg6_local_lwt *slwt, const void *cfg, struct netlink_ext_ack *extack) { return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET, extack); } static enum seg6_end_dt_mode seg6_end_dt6_parse_mode(struct seg6_local_lwt *slwt) { unsigned long parsed_optattrs = slwt->parsed_optattrs; bool legacy, vrfmode; legacy = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE)); vrfmode = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE)); if (!(legacy ^ vrfmode)) /* both are absent or present: invalid DT6 mode */ return DT_INVALID_MODE; return legacy ? DT_LEGACY_MODE : DT_VRF_MODE; } static enum seg6_end_dt_mode seg6_end_dt6_get_mode(struct seg6_local_lwt *slwt) { struct seg6_end_dt_info *info = &slwt->dt_info; return info->mode; } static int seg6_end_dt6_build(struct seg6_local_lwt *slwt, const void *cfg, struct netlink_ext_ack *extack) { enum seg6_end_dt_mode mode = seg6_end_dt6_parse_mode(slwt); struct seg6_end_dt_info *info = &slwt->dt_info; switch (mode) { case DT_LEGACY_MODE: info->mode = DT_LEGACY_MODE; return 0; case DT_VRF_MODE: return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET6, extack); default: NL_SET_ERR_MSG(extack, "table or vrftable must be specified"); return -EINVAL; } } #endif static int input_action_end_dt6(struct sk_buff *skb, struct seg6_local_lwt *slwt) { if (!decap_and_validate(skb, IPPROTO_IPV6)) goto drop; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto drop; #ifdef CONFIG_NET_L3_MASTER_DEV if (seg6_end_dt6_get_mode(slwt) == DT_LEGACY_MODE) goto legacy_mode; /* DT6_VRF_MODE */ skb = end_dt_vrf_core(skb, slwt, AF_INET6); if (!skb) /* packet has been processed and consumed by the VRF */ return 0; if (IS_ERR(skb)) return PTR_ERR(skb); /* note: this time we do not need to specify the table because the VRF * takes care of selecting the correct table. */ seg6_lookup_any_nexthop(skb, NULL, 0, true); return dst_input(skb); legacy_mode: #endif skb_set_transport_header(skb, sizeof(struct ipv6hdr)); seg6_lookup_any_nexthop(skb, NULL, slwt->table, true); return dst_input(skb); drop: kfree_skb(skb); return -EINVAL; } #ifdef CONFIG_NET_L3_MASTER_DEV static int seg6_end_dt46_build(struct seg6_local_lwt *slwt, const void *cfg, struct netlink_ext_ack *extack) { return __seg6_end_dt_vrf_build(slwt, cfg, AF_UNSPEC, extack); } static int input_action_end_dt46(struct sk_buff *skb, struct seg6_local_lwt *slwt) { unsigned int off = 0; int nexthdr; nexthdr = ipv6_find_hdr(skb, &off, -1, NULL, NULL); if (unlikely(nexthdr < 0)) goto drop; switch (nexthdr) { case IPPROTO_IPIP: return input_action_end_dt4(skb, slwt); case IPPROTO_IPV6: return input_action_end_dt6(skb, slwt); } drop: kfree_skb(skb); return -EINVAL; } #endif /* push an SRH on top of the current one */ static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct ipv6_sr_hdr *srh; int err = -EINVAL; srh = get_and_validate_srh(skb); if (!srh) goto drop; err = seg6_do_srh_inline(skb, slwt->srh); if (err) goto drop; skb_set_transport_header(skb, sizeof(struct ipv6hdr)); seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); drop: kfree_skb(skb); return err; } /* encapsulate within an outer IPv6 header and a specified SRH */ static int input_action_end_b6_encap(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct ipv6_sr_hdr *srh; int err = -EINVAL; srh = get_and_validate_srh(skb); if (!srh) goto drop; advance_nextseg(srh, &ipv6_hdr(skb)->daddr); skb_reset_inner_headers(skb); skb->encapsulation = 1; err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6); if (err) goto drop; skb_set_transport_header(skb, sizeof(struct ipv6hdr)); seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); drop: kfree_skb(skb); return err; } DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states); bool seg6_bpf_has_valid_srh(struct sk_buff *skb) { struct seg6_bpf_srh_state *srh_state = this_cpu_ptr(&seg6_bpf_srh_states); struct ipv6_sr_hdr *srh = srh_state->srh; if (unlikely(srh == NULL)) return false; if (unlikely(!srh_state->valid)) { if ((srh_state->hdrlen & 7) != 0) return false; srh->hdrlen = (u8)(srh_state->hdrlen >> 3); if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3, true)) return false; srh_state->valid = true; } return true; } 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 ret; srh = get_and_validate_srh(skb); if (!srh) { kfree_skb(skb); return -EINVAL; } 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->srh = srh; srh_state->hdrlen = srh->hdrlen << 3; srh_state->valid = true; 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 (srh_state->srh && !seg6_bpf_has_valid_srh(skb)) goto drop; preempt_enable(); if (ret != BPF_REDIRECT) seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); drop: preempt_enable(); kfree_skb(skb); return -EINVAL; } static struct seg6_action_desc seg6_action_table[] = { { .action = SEG6_LOCAL_ACTION_END, .attrs = 0, .optattrs = SEG6_F_LOCAL_COUNTERS | SEG6_F_LOCAL_FLAVORS, .input = input_action_end, }, { .action = SEG6_LOCAL_ACTION_END_X, .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), .optattrs = SEG6_F_LOCAL_COUNTERS | SEG6_F_LOCAL_FLAVORS, .input = input_action_end_x, }, { .action = SEG6_LOCAL_ACTION_END_T, .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), .optattrs = SEG6_F_LOCAL_COUNTERS, .input = input_action_end_t, }, { .action = SEG6_LOCAL_ACTION_END_DX2, .attrs = SEG6_F_ATTR(SEG6_LOCAL_OIF), .optattrs = SEG6_F_LOCAL_COUNTERS, .input = input_action_end_dx2, }, { .action = SEG6_LOCAL_ACTION_END_DX6, .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), .optattrs = SEG6_F_LOCAL_COUNTERS, .input = input_action_end_dx6, }, { .action = SEG6_LOCAL_ACTION_END_DX4, .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH4), .optattrs = SEG6_F_LOCAL_COUNTERS, .input = input_action_end_dx4, }, { .action = SEG6_LOCAL_ACTION_END_DT4, .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), .optattrs = SEG6_F_LOCAL_COUNTERS, #ifdef CONFIG_NET_L3_MASTER_DEV .input = input_action_end_dt4, .slwt_ops = { .build_state = seg6_end_dt4_build, }, #endif }, { .action = SEG6_LOCAL_ACTION_END_DT6, #ifdef CONFIG_NET_L3_MASTER_DEV .attrs = 0, .optattrs = SEG6_F_LOCAL_COUNTERS | SEG6_F_ATTR(SEG6_LOCAL_TABLE) | SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), .slwt_ops = { .build_state = seg6_end_dt6_build, }, #else .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), .optattrs = SEG6_F_LOCAL_COUNTERS, #endif .input = input_action_end_dt6, }, { .action = SEG6_LOCAL_ACTION_END_DT46, .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), .optattrs = SEG6_F_LOCAL_COUNTERS, #ifdef CONFIG_NET_L3_MASTER_DEV .input = input_action_end_dt46, .slwt_ops = { .build_state = seg6_end_dt46_build, }, #endif }, { .action = SEG6_LOCAL_ACTION_END_B6, .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), .optattrs = SEG6_F_LOCAL_COUNTERS, .input = input_action_end_b6, }, { .action = SEG6_LOCAL_ACTION_END_B6_ENCAP, .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), .optattrs = SEG6_F_LOCAL_COUNTERS, .input = input_action_end_b6_encap, .static_headroom = sizeof(struct ipv6hdr), }, { .action = SEG6_LOCAL_ACTION_END_BPF, .attrs = SEG6_F_ATTR(SEG6_LOCAL_BPF), .optattrs = SEG6_F_LOCAL_COUNTERS, .input = input_action_end_bpf, }, }; static struct seg6_action_desc *__get_action_desc(int action) { struct seg6_action_desc *desc; int i, count; count = ARRAY_SIZE(seg6_action_table); for (i = 0; i < count; i++) { desc = &seg6_action_table[i]; if (desc->action == action) return desc; } return NULL; } static bool seg6_lwtunnel_counters_enabled(struct seg6_local_lwt *slwt) { return slwt->parsed_optattrs & SEG6_F_LOCAL_COUNTERS; } static void seg6_local_update_counters(struct seg6_local_lwt *slwt, unsigned int len, int err) { struct pcpu_seg6_local_counters *pcounters; pcounters = this_cpu_ptr(slwt->pcpu_counters); u64_stats_update_begin(&pcounters->syncp); if (likely(!err)) { u64_stats_inc(&pcounters->packets); u64_stats_add(&pcounters->bytes, len); } else { u64_stats_inc(&pcounters->errors); } u64_stats_update_end(&pcounters->syncp); } static int seg6_local_input_core(struct net *net, struct sock *sk, struct sk_buff *skb) { struct dst_entry *orig_dst = skb_dst(skb); struct seg6_action_desc *desc; struct seg6_local_lwt *slwt; unsigned int len = skb->len; int rc; slwt = seg6_local_lwtunnel(orig_dst->lwtstate); desc = slwt->desc; rc = desc->input(skb, slwt); if (!seg6_lwtunnel_counters_enabled(slwt)) return rc; seg6_local_update_counters(slwt, len, rc); return rc; } static int seg6_local_input(struct sk_buff *skb) { if (skb->protocol != htons(ETH_P_IPV6)) { kfree_skb(skb); return -EINVAL; } if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, dev_net(skb->dev), NULL, skb, skb->dev, NULL, seg6_local_input_core); return seg6_local_input_core(dev_net(skb->dev), NULL, skb); } static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = { [SEG6_LOCAL_ACTION] = { .type = NLA_U32 }, [SEG6_LOCAL_SRH] = { .type = NLA_BINARY }, [SEG6_LOCAL_TABLE] = { .type = NLA_U32 }, [SEG6_LOCAL_VRFTABLE] = { .type = NLA_U32 }, [SEG6_LOCAL_NH4] = { .type = NLA_BINARY, .len = sizeof(struct in_addr) }, [SEG6_LOCAL_NH6] = { .type = NLA_BINARY, .len = sizeof(struct in6_addr) }, [SEG6_LOCAL_IIF] = { .type = NLA_U32 }, [SEG6_LOCAL_OIF] = { .type = NLA_U32 }, [SEG6_LOCAL_BPF] = { .type = NLA_NESTED }, [SEG6_LOCAL_COUNTERS] = { .type = NLA_NESTED }, [SEG6_LOCAL_FLAVORS] = { .type = NLA_NESTED }, }; static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { struct ipv6_sr_hdr *srh; int len; srh = nla_data(attrs[SEG6_LOCAL_SRH]); len = nla_len(attrs[SEG6_LOCAL_SRH]); /* SRH must contain at least one segment */ if (len < sizeof(*srh) + sizeof(struct in6_addr)) return -EINVAL; if (!seg6_validate_srh(srh, len, false)) return -EINVAL; slwt->srh = kmemdup(srh, len, GFP_KERNEL); if (!slwt->srh) return -ENOMEM; slwt->headroom += len; return 0; } static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct ipv6_sr_hdr *srh; struct nlattr *nla; int len; srh = slwt->srh; len = (srh->hdrlen + 1) << 3; nla = nla_reserve(skb, SEG6_LOCAL_SRH, len); if (!nla) return -EMSGSIZE; memcpy(nla_data(nla), srh, len); return 0; } static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { int len = (a->srh->hdrlen + 1) << 3; if (len != ((b->srh->hdrlen + 1) << 3)) return 1; return memcmp(a->srh, b->srh, len); } static void destroy_attr_srh(struct seg6_local_lwt *slwt) { kfree(slwt->srh); } static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]); return 0; } static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt) { if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table)) return -EMSGSIZE; return 0; } static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { if (a->table != b->table) return 1; return 0; } static struct seg6_end_dt_info *seg6_possible_end_dt_info(struct seg6_local_lwt *slwt) { #ifdef CONFIG_NET_L3_MASTER_DEV return &slwt->dt_info; #else return ERR_PTR(-EOPNOTSUPP); #endif } static int parse_nla_vrftable(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); if (IS_ERR(info)) return PTR_ERR(info); info->vrf_table = nla_get_u32(attrs[SEG6_LOCAL_VRFTABLE]); return 0; } static int put_nla_vrftable(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); if (IS_ERR(info)) return PTR_ERR(info); if (nla_put_u32(skb, SEG6_LOCAL_VRFTABLE, info->vrf_table)) return -EMSGSIZE; return 0; } static int cmp_nla_vrftable(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { struct seg6_end_dt_info *info_a = seg6_possible_end_dt_info(a); struct seg6_end_dt_info *info_b = seg6_possible_end_dt_info(b); if (info_a->vrf_table != info_b->vrf_table) return 1; return 0; } static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]), sizeof(struct in_addr)); return 0; } static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct nlattr *nla; nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr)); if (!nla) return -EMSGSIZE; memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr)); return 0; } static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr)); } static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]), sizeof(struct in6_addr)); return 0; } static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct nlattr *nla; nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr)); if (!nla) return -EMSGSIZE; memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr)); return 0; } static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr)); } static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]); return 0; } static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt) { if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif)) return -EMSGSIZE; return 0; } static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { if (a->iif != b->iif) return 1; return 0; } static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]); return 0; } static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt) { if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif)) return -EMSGSIZE; return 0; } static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { if (a->oif != b->oif) return 1; 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 netlink_ext_ack *extack) { struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1]; struct bpf_prog *p; int ret; u32 fd; ret = nla_parse_nested_deprecated(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_noflag(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); } static void destroy_attr_bpf(struct seg6_local_lwt *slwt) { kfree(slwt->bpf.name); if (slwt->bpf.prog) bpf_prog_put(slwt->bpf.prog); } static const struct nla_policy seg6_local_counters_policy[SEG6_LOCAL_CNT_MAX + 1] = { [SEG6_LOCAL_CNT_PACKETS] = { .type = NLA_U64 }, [SEG6_LOCAL_CNT_BYTES] = { .type = NLA_U64 }, [SEG6_LOCAL_CNT_ERRORS] = { .type = NLA_U64 }, }; static int parse_nla_counters(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { struct pcpu_seg6_local_counters __percpu *pcounters; struct nlattr *tb[SEG6_LOCAL_CNT_MAX + 1]; int ret; ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_CNT_MAX, attrs[SEG6_LOCAL_COUNTERS], seg6_local_counters_policy, NULL); if (ret < 0) return ret; /* basic support for SRv6 Behavior counters requires at least: * packets, bytes and errors. */ if (!tb[SEG6_LOCAL_CNT_PACKETS] || !tb[SEG6_LOCAL_CNT_BYTES] || !tb[SEG6_LOCAL_CNT_ERRORS]) return -EINVAL; /* counters are always zero initialized */ pcounters = seg6_local_alloc_pcpu_counters(GFP_KERNEL); if (!pcounters) return -ENOMEM; slwt->pcpu_counters = pcounters; return 0; } static int seg6_local_fill_nla_counters(struct sk_buff *skb, struct seg6_local_counters *counters) { if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_PACKETS, counters->packets, SEG6_LOCAL_CNT_PAD)) return -EMSGSIZE; if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_BYTES, counters->bytes, SEG6_LOCAL_CNT_PAD)) return -EMSGSIZE; if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_ERRORS, counters->errors, SEG6_LOCAL_CNT_PAD)) return -EMSGSIZE; return 0; } static int put_nla_counters(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct seg6_local_counters counters = { 0, 0, 0 }; struct nlattr *nest; int rc, i; nest = nla_nest_start(skb, SEG6_LOCAL_COUNTERS); if (!nest) return -EMSGSIZE; for_each_possible_cpu(i) { struct pcpu_seg6_local_counters *pcounters; u64 packets, bytes, errors; unsigned int start; pcounters = per_cpu_ptr(slwt->pcpu_counters, i); do { start = u64_stats_fetch_begin(&pcounters->syncp); packets = u64_stats_read(&pcounters->packets); bytes = u64_stats_read(&pcounters->bytes); errors = u64_stats_read(&pcounters->errors); } while (u64_stats_fetch_retry(&pcounters->syncp, start)); counters.packets += packets; counters.bytes += bytes; counters.errors += errors; } rc = seg6_local_fill_nla_counters(skb, &counters); if (rc < 0) { nla_nest_cancel(skb, nest); return rc; } return nla_nest_end(skb, nest); } static int cmp_nla_counters(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { /* a and b are equal if both have pcpu_counters set or not */ return (!!((unsigned long)a->pcpu_counters)) ^ (!!((unsigned long)b->pcpu_counters)); } static void destroy_attr_counters(struct seg6_local_lwt *slwt) { free_percpu(slwt->pcpu_counters); } static const struct nla_policy seg6_local_flavors_policy[SEG6_LOCAL_FLV_MAX + 1] = { [SEG6_LOCAL_FLV_OPERATION] = { .type = NLA_U32 }, [SEG6_LOCAL_FLV_LCBLOCK_BITS] = { .type = NLA_U8 }, [SEG6_LOCAL_FLV_LCNODE_FN_BITS] = { .type = NLA_U8 }, }; /* check whether the lengths of the Locator-Block and Locator-Node Function * are compatible with the dimension of a C-SID container. */ static int seg6_chk_next_csid_cfg(__u8 block_len, __u8 func_len) { /* Locator-Block and Locator-Node Function cannot exceed 128 bits * (i.e. C-SID container lenghts). */ if (next_csid_chk_cntr_bits(block_len, func_len)) return -EINVAL; /* Locator-Block length must be greater than zero and evenly divisible * by 8. There must be room for a Locator-Node Function, at least. */ if (next_csid_chk_lcblock_bits(block_len)) return -EINVAL; /* Locator-Node Function length must be greater than zero and evenly * divisible by 8. There must be room for the Locator-Block. */ if (next_csid_chk_lcnode_fn_bits(func_len)) return -EINVAL; return 0; } static int seg6_parse_nla_next_csid_cfg(struct nlattr **tb, struct seg6_flavors_info *finfo, struct netlink_ext_ack *extack) { __u8 func_len = SEG6_LOCAL_LCNODE_FN_DBITS; __u8 block_len = SEG6_LOCAL_LCBLOCK_DBITS; int rc; if (tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]) block_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]); if (tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]) func_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]); rc = seg6_chk_next_csid_cfg(block_len, func_len); if (rc < 0) { NL_SET_ERR_MSG(extack, "Invalid Locator Block/Node Function lengths"); return rc; } finfo->lcblock_bits = block_len; finfo->lcnode_func_bits = func_len; return 0; } static int parse_nla_flavors(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { struct seg6_flavors_info *finfo = &slwt->flv_info; struct nlattr *tb[SEG6_LOCAL_FLV_MAX + 1]; int action = slwt->action; __u32 fops, supp_fops; int rc; rc = nla_parse_nested_deprecated(tb, SEG6_LOCAL_FLV_MAX, attrs[SEG6_LOCAL_FLAVORS], seg6_local_flavors_policy, NULL); if (rc < 0) return rc; /* this attribute MUST always be present since it represents the Flavor * operation(s) to be carried out. */ if (!tb[SEG6_LOCAL_FLV_OPERATION]) return -EINVAL; fops = nla_get_u32(tb[SEG6_LOCAL_FLV_OPERATION]); rc = seg6_flv_supp_ops_by_action(action, &supp_fops); if (rc < 0 || (fops & ~supp_fops)) { NL_SET_ERR_MSG(extack, "Unsupported Flavor operation(s)"); return -EOPNOTSUPP; } finfo->flv_ops = fops; if (seg6_next_csid_enabled(fops)) { /* Locator-Block and Locator-Node Function lengths can be * provided by the user space. Otherwise, default values are * applied. */ rc = seg6_parse_nla_next_csid_cfg(tb, finfo, extack); if (rc < 0) return rc; } return 0; } static int seg6_fill_nla_next_csid_cfg(struct sk_buff *skb, struct seg6_flavors_info *finfo) { if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCBLOCK_BITS, finfo->lcblock_bits)) return -EMSGSIZE; if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCNODE_FN_BITS, finfo->lcnode_func_bits)) return -EMSGSIZE; return 0; } static int put_nla_flavors(struct sk_buff *skb, struct seg6_local_lwt *slwt) { struct seg6_flavors_info *finfo = &slwt->flv_info; __u32 fops = finfo->flv_ops; struct nlattr *nest; int rc; nest = nla_nest_start(skb, SEG6_LOCAL_FLAVORS); if (!nest) return -EMSGSIZE; if (nla_put_u32(skb, SEG6_LOCAL_FLV_OPERATION, fops)) { rc = -EMSGSIZE; goto err; } if (seg6_next_csid_enabled(fops)) { rc = seg6_fill_nla_next_csid_cfg(skb, finfo); if (rc < 0) goto err; } return nla_nest_end(skb, nest); err: nla_nest_cancel(skb, nest); return rc; } static int seg6_cmp_nla_next_csid_cfg(struct seg6_flavors_info *finfo_a, struct seg6_flavors_info *finfo_b) { if (finfo_a->lcblock_bits != finfo_b->lcblock_bits) return 1; if (finfo_a->lcnode_func_bits != finfo_b->lcnode_func_bits) return 1; return 0; } static int cmp_nla_flavors(struct seg6_local_lwt *a, struct seg6_local_lwt *b) { struct seg6_flavors_info *finfo_a = &a->flv_info; struct seg6_flavors_info *finfo_b = &b->flv_info; if (finfo_a->flv_ops != finfo_b->flv_ops) return 1; if (seg6_next_csid_enabled(finfo_a->flv_ops)) { if (seg6_cmp_nla_next_csid_cfg(finfo_a, finfo_b)) return 1; } return 0; } static int encap_size_flavors(struct seg6_local_lwt *slwt) { struct seg6_flavors_info *finfo = &slwt->flv_info; int nlsize; nlsize = nla_total_size(0) + /* nest SEG6_LOCAL_FLAVORS */ nla_total_size(4); /* SEG6_LOCAL_FLV_OPERATION */ if (seg6_next_csid_enabled(finfo->flv_ops)) nlsize += nla_total_size(1) + /* SEG6_LOCAL_FLV_LCBLOCK_BITS */ nla_total_size(1); /* SEG6_LOCAL_FLV_LCNODE_FN_BITS */ return nlsize; } struct seg6_action_param { int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack); int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt); int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b); /* optional destroy() callback useful for releasing resources which * have been previously acquired in the corresponding parse() * function. */ void (*destroy)(struct seg6_local_lwt *slwt); }; static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = { [SEG6_LOCAL_SRH] = { .parse = parse_nla_srh, .put = put_nla_srh, .cmp = cmp_nla_srh, .destroy = destroy_attr_srh }, [SEG6_LOCAL_TABLE] = { .parse = parse_nla_table, .put = put_nla_table, .cmp = cmp_nla_table }, [SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4, .put = put_nla_nh4, .cmp = cmp_nla_nh4 }, [SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6, .put = put_nla_nh6, .cmp = cmp_nla_nh6 }, [SEG6_LOCAL_IIF] = { .parse = parse_nla_iif, .put = put_nla_iif, .cmp = cmp_nla_iif }, [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, .destroy = destroy_attr_bpf }, [SEG6_LOCAL_VRFTABLE] = { .parse = parse_nla_vrftable, .put = put_nla_vrftable, .cmp = cmp_nla_vrftable }, [SEG6_LOCAL_COUNTERS] = { .parse = parse_nla_counters, .put = put_nla_counters, .cmp = cmp_nla_counters, .destroy = destroy_attr_counters }, [SEG6_LOCAL_FLAVORS] = { .parse = parse_nla_flavors, .put = put_nla_flavors, .cmp = cmp_nla_flavors }, }; /* call the destroy() callback (if available) for each set attribute in * @parsed_attrs, starting from the first attribute up to the @max_parsed * (excluded) attribute. */ static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed, struct seg6_local_lwt *slwt) { struct seg6_action_param *param; int i; /* Every required seg6local attribute is identified by an ID which is * encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask; * * We scan the 'parsed_attrs' bitmask, starting from the first attribute * up to the @max_parsed (excluded) attribute. * For each set attribute, we retrieve the corresponding destroy() * callback. If the callback is not available, then we skip to the next * attribute; otherwise, we call the destroy() callback. */ for (i = SEG6_LOCAL_SRH; i < max_parsed; ++i) { if (!(parsed_attrs & SEG6_F_ATTR(i))) continue; param = &seg6_action_params[i]; if (param->destroy) param->destroy(slwt); } } /* release all the resources that may have been acquired during parsing * operations. */ static void destroy_attrs(struct seg6_local_lwt *slwt) { unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs; __destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt); } static int parse_nla_optional_attrs(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { struct seg6_action_desc *desc = slwt->desc; unsigned long parsed_optattrs = 0; struct seg6_action_param *param; int err, i; for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; ++i) { if (!(desc->optattrs & SEG6_F_ATTR(i)) || !attrs[i]) continue; /* once here, the i-th attribute is provided by the * userspace AND it is identified optional as well. */ param = &seg6_action_params[i]; err = param->parse(attrs, slwt, extack); if (err < 0) goto parse_optattrs_err; /* current attribute has been correctly parsed */ parsed_optattrs |= SEG6_F_ATTR(i); } /* store in the tunnel state all the optional attributed successfully * parsed. */ slwt->parsed_optattrs = parsed_optattrs; return 0; parse_optattrs_err: __destroy_attrs(parsed_optattrs, i, slwt); return err; } /* call the custom constructor of the behavior during its initialization phase * and after that all its attributes have been parsed successfully. */ static int seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg, struct netlink_ext_ack *extack) { struct seg6_action_desc *desc = slwt->desc; struct seg6_local_lwtunnel_ops *ops; ops = &desc->slwt_ops; if (!ops->build_state) return 0; return ops->build_state(slwt, cfg, extack); } /* call the custom destructor of the behavior which is invoked before the * tunnel is going to be destroyed. */ static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt) { struct seg6_action_desc *desc = slwt->desc; struct seg6_local_lwtunnel_ops *ops; ops = &desc->slwt_ops; if (!ops->destroy_state) return; ops->destroy_state(slwt); } static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt, struct netlink_ext_ack *extack) { struct seg6_action_param *param; struct seg6_action_desc *desc; unsigned long invalid_attrs; int i, err; desc = __get_action_desc(slwt->action); if (!desc) return -EINVAL; if (!desc->input) return -EOPNOTSUPP; slwt->desc = desc; slwt->headroom += desc->static_headroom; /* Forcing the desc->optattrs *set* and the desc->attrs *set* to be * disjoined, this allow us to release acquired resources by optional * attributes and by required attributes independently from each other * without any interference. * In other terms, we are sure that we do not release some the acquired * resources twice. * * Note that if an attribute is configured both as required and as * optional, it means that the user has messed something up in the * seg6_action_table. Therefore, this check is required for SRv6 * behaviors to work properly. */ invalid_attrs = desc->attrs & desc->optattrs; if (invalid_attrs) { WARN_ONCE(1, "An attribute cannot be both required AND optional"); return -EINVAL; } /* parse the required attributes */ for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { if (desc->attrs & SEG6_F_ATTR(i)) { if (!attrs[i]) return -EINVAL; param = &seg6_action_params[i]; err = param->parse(attrs, slwt, extack); if (err < 0) goto parse_attrs_err; } } /* parse the optional attributes, if any */ err = parse_nla_optional_attrs(attrs, slwt, extack); if (err < 0) goto parse_attrs_err; return 0; parse_attrs_err: /* release any resource that may have been acquired during the i-1 * parse() operations. */ __destroy_attrs(desc->attrs, i, slwt); return err; } static int seg6_local_build_state(struct net *net, struct nlattr *nla, unsigned int family, const void *cfg, struct lwtunnel_state **ts, struct netlink_ext_ack *extack) { struct nlattr *tb[SEG6_LOCAL_MAX + 1]; struct lwtunnel_state *newts; struct seg6_local_lwt *slwt; int err; if (family != AF_INET6) return -EINVAL; err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla, seg6_local_policy, extack); if (err < 0) return err; if (!tb[SEG6_LOCAL_ACTION]) return -EINVAL; newts = lwtunnel_state_alloc(sizeof(*slwt)); if (!newts) return -ENOMEM; slwt = seg6_local_lwtunnel(newts); slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]); err = parse_nla_action(tb, slwt, extack); if (err < 0) goto out_free; err = seg6_local_lwtunnel_build_state(slwt, cfg, extack); if (err < 0) goto out_destroy_attrs; newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL; newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT; newts->headroom = slwt->headroom; *ts = newts; return 0; out_destroy_attrs: destroy_attrs(slwt); out_free: kfree(newts); return err; } static void seg6_local_destroy_state(struct lwtunnel_state *lwt) { struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); seg6_local_lwtunnel_destroy_state(slwt); destroy_attrs(slwt); return; } static int seg6_local_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwt) { struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); struct seg6_action_param *param; unsigned long attrs; int i, err; if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action)) return -EMSGSIZE; attrs = slwt->desc->attrs | slwt->parsed_optattrs; for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { if (attrs & SEG6_F_ATTR(i)) { param = &seg6_action_params[i]; err = param->put(skb, slwt); if (err < 0) return err; } } return 0; } static int seg6_local_get_encap_size(struct lwtunnel_state *lwt) { struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); unsigned long attrs; int nlsize; nlsize = nla_total_size(4); /* action */ attrs = slwt->desc->attrs | slwt->parsed_optattrs; if (attrs & SEG6_F_ATTR(SEG6_LOCAL_SRH)) nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE)) nlsize += nla_total_size(4); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH4)) nlsize += nla_total_size(4); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH6)) nlsize += nla_total_size(16); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_IIF)) nlsize += nla_total_size(4); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_OIF)) nlsize += nla_total_size(4); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_BPF)) nlsize += nla_total_size(sizeof(struct nlattr)) + nla_total_size(MAX_PROG_NAME) + nla_total_size(4); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE)) nlsize += nla_total_size(4); if (attrs & SEG6_F_LOCAL_COUNTERS) nlsize += nla_total_size(0) + /* nest SEG6_LOCAL_COUNTERS */ /* SEG6_LOCAL_CNT_PACKETS */ nla_total_size_64bit(sizeof(__u64)) + /* SEG6_LOCAL_CNT_BYTES */ nla_total_size_64bit(sizeof(__u64)) + /* SEG6_LOCAL_CNT_ERRORS */ nla_total_size_64bit(sizeof(__u64)); if (attrs & SEG6_F_ATTR(SEG6_LOCAL_FLAVORS)) nlsize += encap_size_flavors(slwt); return nlsize; } static int seg6_local_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b) { struct seg6_local_lwt *slwt_a, *slwt_b; struct seg6_action_param *param; unsigned long attrs_a, attrs_b; int i; slwt_a = seg6_local_lwtunnel(a); slwt_b = seg6_local_lwtunnel(b); if (slwt_a->action != slwt_b->action) return 1; attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs; attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs; if (attrs_a != attrs_b) return 1; for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { if (attrs_a & SEG6_F_ATTR(i)) { param = &seg6_action_params[i]; if (param->cmp(slwt_a, slwt_b)) return 1; } } return 0; } static const struct lwtunnel_encap_ops seg6_local_ops = { .build_state = seg6_local_build_state, .destroy_state = seg6_local_destroy_state, .input = seg6_local_input, .fill_encap = seg6_local_fill_encap, .get_encap_size = seg6_local_get_encap_size, .cmp_encap = seg6_local_cmp_encap, .owner = THIS_MODULE, }; int __init seg6_local_init(void) { /* If the max total number of defined attributes is reached, then your * kernel build stops here. * * This check is required to avoid arithmetic overflows when processing * behavior attributes and the maximum number of defined attributes * exceeds the allowed value. */ BUILD_BUG_ON(SEG6_LOCAL_MAX + 1 > BITS_PER_TYPE(unsigned long)); /* Check whether the number of defined flavors exceeds the maximum * allowed value. */ BUILD_BUG_ON(SEG6_LOCAL_FLV_OP_MAX + 1 > BITS_PER_TYPE(__u32)); /* If the default NEXT-C-SID Locator-Block/Node Function lengths (in * bits) have been changed with invalid values, kernel build stops * here. */ BUILD_BUG_ON(next_csid_chk_cntr_bits(SEG6_LOCAL_LCBLOCK_DBITS, SEG6_LOCAL_LCNODE_FN_DBITS)); BUILD_BUG_ON(next_csid_chk_lcblock_bits(SEG6_LOCAL_LCBLOCK_DBITS)); BUILD_BUG_ON(next_csid_chk_lcnode_fn_bits(SEG6_LOCAL_LCNODE_FN_DBITS)); /* To be memory efficient, we use 'u8' to represent the different * actions related to RFC8986 flavors. If the kernel build stops here, * it means that it is not possible to correctly encode these actions * with the data type chosen for the action table. */ BUILD_BUG_ON(SEG6_LOCAL_FLV_ACT_MAX > (typeof(flv8986_act_tbl[0]))~0U); return lwtunnel_encap_add_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL); } void seg6_local_exit(void) { lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL); }