#ifndef __NET_NSH_H #define __NET_NSH_H 1 #include <linux/skbuff.h> /* * Network Service Header: * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * |Ver|O|U| TTL | Length |U|U|U|U|MD Type| Next Protocol | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Service Path Identifier (SPI) | Service Index | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | | * ~ Mandatory/Optional Context Headers ~ * | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Version: The version field is used to ensure backward compatibility * going forward with future NSH specification updates. It MUST be set * to 0x0 by the sender, in this first revision of NSH. Given the * widespread implementation of existing hardware that uses the first * nibble after an MPLS label stack for ECMP decision processing, this * document reserves version 01b and this value MUST NOT be used in * future versions of the protocol. Please see [RFC7325] for further * discussion of MPLS-related forwarding requirements. * * O bit: Setting this bit indicates an Operations, Administration, and * Maintenance (OAM) packet. The actual format and processing of SFC * OAM packets is outside the scope of this specification (see for * example [I-D.ietf-sfc-oam-framework] for one approach). * * The O bit MUST be set for OAM packets and MUST NOT be set for non-OAM * packets. The O bit MUST NOT be modified along the SFP. * * SF/SFF/SFC Proxy/Classifier implementations that do not support SFC * OAM procedures SHOULD discard packets with O bit set, but MAY support * a configurable parameter to enable forwarding received SFC OAM * packets unmodified to the next element in the chain. Forwarding OAM * packets unmodified by SFC elements that do not support SFC OAM * procedures may be acceptable for a subset of OAM functions, but can * result in unexpected outcomes for others, thus it is recommended to * analyze the impact of forwarding an OAM packet for all OAM functions * prior to enabling this behavior. The configurable parameter MUST be * disabled by default. * * TTL: Indicates the maximum SFF hops for an SFP. This field is used * for service plane loop detection. The initial TTL value SHOULD be * configurable via the control plane; the configured initial value can * be specific to one or more SFPs. If no initial value is explicitly * provided, the default initial TTL value of 63 MUST be used. Each SFF * involved in forwarding an NSH packet MUST decrement the TTL value by * 1 prior to NSH forwarding lookup. Decrementing by 1 from an incoming * value of 0 shall result in a TTL value of 63. The packet MUST NOT be * forwarded if TTL is, after decrement, 0. * * All other flag fields, marked U, are unassigned and available for * future use, see Section 11.2.1. Unassigned bits MUST be set to zero * upon origination, and MUST be ignored and preserved unmodified by * other NSH supporting elements. Elements which do not understand the * meaning of any of these bits MUST NOT modify their actions based on * those unknown bits. * * Length: The total length, in 4-byte words, of NSH including the Base * Header, the Service Path Header, the Fixed Length Context Header or * Variable Length Context Header(s). The length MUST be 0x6 for MD * Type equal to 0x1, and MUST be 0x2 or greater for MD Type equal to * 0x2. The length of the NSH header MUST be an integer multiple of 4 * bytes, thus variable length metadata is always padded out to a * multiple of 4 bytes. * * MD Type: Indicates the format of NSH beyond the mandatory Base Header * and the Service Path Header. MD Type defines the format of the * metadata being carried. * * 0x0 - This is a reserved value. Implementations SHOULD silently * discard packets with MD Type 0x0. * * 0x1 - This indicates that the format of the header includes a fixed * length Context Header (see Figure 4 below). * * 0x2 - This does not mandate any headers beyond the Base Header and * Service Path Header, but may contain optional variable length Context * Header(s). The semantics of the variable length Context Header(s) * are not defined in this document. The format of the optional * variable length Context Headers is provided in Section 2.5.1. * * 0xF - This value is reserved for experimentation and testing, as per * [RFC3692]. Implementations not explicitly configured to be part of * an experiment SHOULD silently discard packets with MD Type 0xF. * * Next Protocol: indicates the protocol type of the encapsulated data. * NSH does not alter the inner payload, and the semantics on the inner * protocol remain unchanged due to NSH service function chaining. * Please see the IANA Considerations section below, Section 11.2.5. * * This document defines the following Next Protocol values: * * 0x1: IPv4 * 0x2: IPv6 * 0x3: Ethernet * 0x4: NSH * 0x5: MPLS * 0xFE: Experiment 1 * 0xFF: Experiment 2 * * Packets with Next Protocol values not supported SHOULD be silently * dropped by default, although an implementation MAY provide a * configuration parameter to forward them. Additionally, an * implementation not explicitly configured for a specific experiment * [RFC3692] SHOULD silently drop packets with Next Protocol values 0xFE * and 0xFF. * * Service Path Identifier (SPI): Identifies a service path. * Participating nodes MUST use this identifier for Service Function * Path selection. The initial classifier MUST set the appropriate SPI * for a given classification result. * * Service Index (SI): Provides location within the SFP. The initial * classifier for a given SFP SHOULD set the SI to 255, however the * control plane MAY configure the initial value of SI as appropriate * (i.e., taking into account the length of the service function path). * The Service Index MUST be decremented by a value of 1 by Service * Functions or by SFC Proxy nodes after performing required services * and the new decremented SI value MUST be used in the egress packet's * NSH. The initial Classifier MUST send the packet to the first SFF in * the identified SFP for forwarding along an SFP. If re-classification * occurs, and that re-classification results in a new SPI, the * (re)classifier is, in effect, the initial classifier for the * resultant SPI. * * The SI is used in conjunction the with Service Path Identifier for * Service Function Path Selection and for determining the next SFF/SF * in the path. The SI is also valuable when troubleshooting or * reporting service paths. Additionally, while the TTL field is the * main mechanism for service plane loop detection, the SI can also be * used for detecting service plane loops. * * When the Base Header specifies MD Type = 0x1, a Fixed Length Context * Header (16-bytes) MUST be present immediately following the Service * Path Header. The value of a Fixed Length Context * Header that carries no metadata MUST be set to zero. * * When the base header specifies MD Type = 0x2, zero or more Variable * Length Context Headers MAY be added, immediately following the * Service Path Header (see Figure 5). Therefore, Length = 0x2, * indicates that only the Base Header followed by the Service Path * Header are present. The optional Variable Length Context Headers * MUST be of an integer number of 4-bytes. The base header Length * field MUST be used to determine the offset to locate the original * packet or frame for SFC nodes that require access to that * information. * * The format of the optional variable length Context Headers * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Metadata Class | Type |U| Length | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Variable Metadata | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Metadata Class (MD Class): Defines the scope of the 'Type' field to * provide a hierarchical namespace. The IANA Considerations * Section 11.2.4 defines how the MD Class values can be allocated to * standards bodies, vendors, and others. * * Type: Indicates the explicit type of metadata being carried. The * definition of the Type is the responsibility of the MD Class owner. * * Unassigned bit: One unassigned bit is available for future use. This * bit MUST NOT be set, and MUST be ignored on receipt. * * Length: Indicates the length of the variable metadata, in bytes. In * case the metadata length is not an integer number of 4-byte words, * the sender MUST add pad bytes immediately following the last metadata * byte to extend the metadata to an integer number of 4-byte words. * The receiver MUST round up the length field to the nearest 4-byte * word boundary, to locate and process the next field in the packet. * The receiver MUST access only those bytes in the metadata indicated * by the length field (i.e., actual number of bytes) and MUST ignore * the remaining bytes up to the nearest 4-byte word boundary. The * Length may be 0 or greater. * * A value of 0 denotes a Context Header without a Variable Metadata * field. * * [0] https://datatracker.ietf.org/doc/draft-ietf-sfc-nsh/ */ /** * struct nsh_md1_ctx - Keeps track of NSH context data * @nshc<1-4>: NSH Contexts. */ struct nsh_md1_ctx { __be32 context[4]; }; struct nsh_md2_tlv { __be16 md_class; u8 type; u8 length; u8 md_value[]; }; struct nshhdr { __be16 ver_flags_ttl_len; u8 mdtype; u8 np; __be32 path_hdr; union { struct nsh_md1_ctx md1; struct nsh_md2_tlv md2; }; }; /* Masking NSH header fields. */ #define NSH_VER_MASK 0xc000 #define NSH_VER_SHIFT 14 #define NSH_FLAGS_MASK 0x3000 #define NSH_FLAGS_SHIFT 12 #define NSH_TTL_MASK 0x0fc0 #define NSH_TTL_SHIFT 6 #define NSH_LEN_MASK 0x003f #define NSH_LEN_SHIFT 0 #define NSH_MDTYPE_MASK 0x0f #define NSH_MDTYPE_SHIFT 0 #define NSH_SPI_MASK 0xffffff00 #define NSH_SPI_SHIFT 8 #define NSH_SI_MASK 0x000000ff #define NSH_SI_SHIFT 0 /* MD Type Registry. */ #define NSH_M_TYPE1 0x01 #define NSH_M_TYPE2 0x02 #define NSH_M_EXP1 0xFE #define NSH_M_EXP2 0xFF /* NSH Base Header Length */ #define NSH_BASE_HDR_LEN 8 /* NSH MD Type 1 header Length. */ #define NSH_M_TYPE1_LEN 24 /* NSH header maximum Length. */ #define NSH_HDR_MAX_LEN 256 /* NSH context headers maximum Length. */ #define NSH_CTX_HDRS_MAX_LEN 248 static inline struct nshhdr *nsh_hdr(struct sk_buff *skb) { return (struct nshhdr *)skb_network_header(skb); } static inline u16 nsh_hdr_len(const struct nshhdr *nsh) { return ((ntohs(nsh->ver_flags_ttl_len) & NSH_LEN_MASK) >> NSH_LEN_SHIFT) << 2; } static inline u8 nsh_get_ver(const struct nshhdr *nsh) { return (ntohs(nsh->ver_flags_ttl_len) & NSH_VER_MASK) >> NSH_VER_SHIFT; } static inline u8 nsh_get_flags(const struct nshhdr *nsh) { return (ntohs(nsh->ver_flags_ttl_len) & NSH_FLAGS_MASK) >> NSH_FLAGS_SHIFT; } static inline u8 nsh_get_ttl(const struct nshhdr *nsh) { return (ntohs(nsh->ver_flags_ttl_len) & NSH_TTL_MASK) >> NSH_TTL_SHIFT; } static inline void __nsh_set_xflag(struct nshhdr *nsh, u16 xflag, u16 xmask) { nsh->ver_flags_ttl_len = (nsh->ver_flags_ttl_len & ~htons(xmask)) | htons(xflag); } static inline void nsh_set_flags_and_ttl(struct nshhdr *nsh, u8 flags, u8 ttl) { __nsh_set_xflag(nsh, ((flags << NSH_FLAGS_SHIFT) & NSH_FLAGS_MASK) | ((ttl << NSH_TTL_SHIFT) & NSH_TTL_MASK), NSH_FLAGS_MASK | NSH_TTL_MASK); } static inline void nsh_set_flags_ttl_len(struct nshhdr *nsh, u8 flags, u8 ttl, u8 len) { len = len >> 2; __nsh_set_xflag(nsh, ((flags << NSH_FLAGS_SHIFT) & NSH_FLAGS_MASK) | ((ttl << NSH_TTL_SHIFT) & NSH_TTL_MASK) | ((len << NSH_LEN_SHIFT) & NSH_LEN_MASK), NSH_FLAGS_MASK | NSH_TTL_MASK | NSH_LEN_MASK); } int nsh_push(struct sk_buff *skb, const struct nshhdr *pushed_nh); int nsh_pop(struct sk_buff *skb); #endif /* __NET_NSH_H */
Name | Type | Size | Permission | Actions |
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9p | Folder | 0755 |
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bluetooth | Folder | 0755 |
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caif | Folder | 0755 |
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iucv | Folder | 0755 |
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netfilter | Folder | 0755 |
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netns | Folder | 0755 |
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nfc | Folder | 0755 |
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phonet | Folder | 0755 |
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sctp | Folder | 0755 |
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tc_act | Folder | 0755 |
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6lowpan.h | File | 10.03 KB | 0644 |
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Space.h | File | 1.15 KB | 0644 |
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act_api.h | File | 6.38 KB | 0644 |
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addrconf.h | File | 12.63 KB | 0644 |
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af_ieee802154.h | File | 1.55 KB | 0644 |
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af_rxrpc.h | File | 2.79 KB | 0644 |
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af_unix.h | File | 2.22 KB | 0644 |
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af_vsock.h | File | 7.21 KB | 0644 |
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ah.h | File | 382 B | 0644 |
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arp.h | File | 2 KB | 0644 |
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atmclip.h | File | 1.48 KB | 0644 |
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ax25.h | File | 15.02 KB | 0644 |
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ax88796.h | File | 998 B | 0644 |
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bond_3ad.h | File | 9.79 KB | 0644 |
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bond_alb.h | File | 6.6 KB | 0644 |
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bond_options.h | File | 3.92 KB | 0644 |
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bonding.h | File | 19.1 KB | 0644 |
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busy_poll.h | File | 3.8 KB | 0644 |
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calipso.h | File | 2.15 KB | 0644 |
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cfg80211-wext.h | File | 1.95 KB | 0644 |
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cfg80211.h | File | 221.24 KB | 0644 |
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cfg802154.h | File | 10.89 KB | 0644 |
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checksum.h | File | 4.76 KB | 0644 |
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cipso_ipv4.h | File | 8.2 KB | 0644 |
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cls_cgroup.h | File | 2.15 KB | 0644 |
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codel.h | File | 5.65 KB | 0644 |
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codel_impl.h | File | 7.98 KB | 0644 |
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codel_qdisc.h | File | 2.9 KB | 0644 |
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compat.h | File | 2.11 KB | 0644 |
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datalink.h | File | 619 B | 0644 |
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dcbevent.h | File | 1.26 KB | 0644 |
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dcbnl.h | File | 4.2 KB | 0644 |
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devlink.h | File | 13.25 KB | 0644 |
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dn.h | File | 6.88 KB | 0644 |
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dn_dev.h | File | 5.36 KB | 0644 |
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dn_fib.h | File | 3.98 KB | 0644 |
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dn_neigh.h | File | 968 B | 0644 |
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dn_nsp.h | File | 5.83 KB | 0644 |
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dn_route.h | File | 4.36 KB | 0644 |
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dsa.h | File | 13.94 KB | 0644 |
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dsfield.h | File | 1.11 KB | 0644 |
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dst.h | File | 13.48 KB | 0644 |
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dst_cache.h | File | 2.53 KB | 0644 |
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dst_metadata.h | File | 5.39 KB | 0644 |
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dst_ops.h | File | 2 KB | 0644 |
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erspan.h | File | 2.11 KB | 0644 |
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esp.h | File | 877 B | 0644 |
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ethoc.h | File | 538 B | 0644 |
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fib_notifier.h | File | 1.29 KB | 0644 |
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fib_rules.h | File | 4.18 KB | 0644 |
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firewire.h | File | 636 B | 0644 |
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flow.h | File | 6.16 KB | 0644 |
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flow_dissector.h | File | 7.55 KB | 0644 |
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fou.h | File | 549 B | 0644 |
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fq.h | File | 2.67 KB | 0644 |
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fq_impl.h | File | 6.9 KB | 0644 |
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garp.h | File | 2.62 KB | 0644 |
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gen_stats.h | File | 2.34 KB | 0644 |
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genetlink.h | File | 11.3 KB | 0644 |
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geneve.h | File | 1.67 KB | 0644 |
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gre.h | File | 2.99 KB | 0644 |
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gro_cells.h | File | 443 B | 0644 |
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gtp.h | File | 633 B | 0644 |
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gue.h | File | 3.23 KB | 0644 |
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hwbm.h | File | 937 B | 0644 |
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icmp.h | File | 2.01 KB | 0644 |
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ieee80211_radiotap.h | File | 6.63 KB | 0644 |
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ieee802154_netdev.h | File | 9.14 KB | 0644 |
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if_inet6.h | File | 6.13 KB | 0644 |
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ife.h | File | 1.06 KB | 0644 |
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ila.h | File | 498 B | 0644 |
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inet6_connection_sock.h | File | 976 B | 0644 |
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inet6_hashtables.h | File | 3.7 KB | 0644 |
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inet_common.h | File | 1.89 KB | 0644 |
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inet_connection_sock.h | File | 10.48 KB | 0644 |
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inet_ecn.h | File | 6.02 KB | 0644 |
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inet_frag.h | File | 4.51 KB | 0644 |
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inet_hashtables.h | File | 12.91 KB | 0644 |
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inet_sock.h | File | 8.25 KB | 0644 |
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inet_timewait_sock.h | File | 3.82 KB | 0644 |
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inetpeer.h | File | 3.29 KB | 0644 |
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ip.h | File | 18.51 KB | 0644 |
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ip6_checksum.h | File | 2.89 KB | 0644 |
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ip6_fib.h | File | 10.04 KB | 0644 |
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ip6_route.h | File | 7.63 KB | 0644 |
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ip6_tunnel.h | File | 4.72 KB | 0644 |
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ip_fib.h | File | 10.72 KB | 0644 |
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ip_tunnels.h | File | 13.61 KB | 0644 |
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ip_vs.h | File | 46.78 KB | 0644 |
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ipcomp.h | File | 659 B | 0644 |
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ipconfig.h | File | 811 B | 0644 |
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ipv6.h | File | 29.97 KB | 0644 |
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ipv6_frag.h | File | 2.54 KB | 0644 |
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ipx.h | File | 4.4 KB | 0644 |
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iw_handler.h | File | 20.91 KB | 0644 |
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kcm.h | File | 4.96 KB | 0644 |
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l3mdev.h | File | 5.86 KB | 0644 |
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lapb.h | File | 4.75 KB | 0644 |
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lib80211.h | File | 3.92 KB | 0644 |
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llc.h | File | 4.41 KB | 0644 |
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llc_c_ac.h | File | 9.31 KB | 0644 |
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llc_c_ev.h | File | 10.68 KB | 0644 |
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llc_c_st.h | File | 1.72 KB | 0644 |
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llc_conn.h | File | 4.06 KB | 0644 |
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llc_if.h | File | 2.16 KB | 0644 |
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llc_pdu.h | File | 14.44 KB | 0644 |
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llc_s_ac.h | File | 1.55 KB | 0644 |
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llc_s_ev.h | File | 2.2 KB | 0644 |
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llc_s_st.h | File | 947 B | 0644 |
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llc_sap.h | File | 1.08 KB | 0644 |
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lwtunnel.h | File | 5.84 KB | 0644 |
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mac80211.h | File | 230.36 KB | 0644 |
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mac802154.h | File | 15.27 KB | 0644 |
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mip6.h | File | 1.58 KB | 0644 |
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mld.h | File | 2.8 KB | 0644 |
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mpls.h | File | 932 B | 0644 |
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mpls_iptunnel.h | File | 827 B | 0644 |
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mrp.h | File | 3.03 KB | 0644 |
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ncsi.h | File | 1.92 KB | 0644 |
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ndisc.h | File | 13.77 KB | 0644 |
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neighbour.h | File | 15.06 KB | 0644 |
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net_namespace.h | File | 10.08 KB | 0644 |
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net_ratelimit.h | File | 220 B | 0644 |
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netevent.h | File | 910 B | 0644 |
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netlabel.h | File | 20.74 KB | 0644 |
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netlink.h | File | 40.39 KB | 0644 |
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netprio_cgroup.h | File | 1.24 KB | 0644 |
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netrom.h | File | 7.68 KB | 0644 |
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nexthop.h | File | 865 B | 0644 |
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nl802154.h | File | 12.09 KB | 0644 |
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nsh.h | File | 12.31 KB | 0644 |
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p8022.h | File | 447 B | 0644 |
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ping.h | File | 3.45 KB | 0644 |
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pkt_cls.h | File | 17.34 KB | 0644 |
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pkt_sched.h | File | 4.05 KB | 0644 |
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pptp.h | File | 557 B | 0644 |
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protocol.h | File | 4.08 KB | 0644 |
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psample.h | File | 860 B | 0644 |
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psnap.h | File | 351 B | 0644 |
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raw.h | File | 2.07 KB | 0644 |
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rawv6.h | File | 854 B | 0644 |
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red.h | File | 10.45 KB | 0644 |
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regulatory.h | File | 10.12 KB | 0644 |
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request_sock.h | File | 6.46 KB | 0644 |
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rose.h | File | 7.62 KB | 0644 |
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route.h | File | 10.02 KB | 0644 |
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rtnetlink.h | File | 6.13 KB | 0644 |
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sch_generic.h | File | 23.3 KB | 0644 |
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scm.h | File | 3.5 KB | 0644 |
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secure_seq.h | File | 855 B | 0644 |
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seg6.h | File | 1.66 KB | 0644 |
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seg6_hmac.h | File | 1.65 KB | 0644 |
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slhc_vj.h | File | 6.67 KB | 0644 |
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smc.h | File | 440 B | 0644 |
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snmp.h | File | 5.23 KB | 0644 |
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sock.h | File | 69.75 KB | 0644 |
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sock_reuseport.h | File | 863 B | 0644 |
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stp.h | File | 383 B | 0644 |
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strparser.h | File | 3.75 KB | 0644 |
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switchdev.h | File | 6.52 KB | 0644 |
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tcp.h | File | 62.8 KB | 0644 |
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tcp_states.h | File | 1.26 KB | 0644 |
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timewait_sock.h | File | 1.11 KB | 0644 |
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tipc.h | File | 2.34 KB | 0644 |
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tls.h | File | 7.12 KB | 0644 |
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transp_v6.h | File | 2.08 KB | 0644 |
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tso.h | File | 515 B | 0644 |
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tun_proto.h | File | 988 B | 0644 |
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udp.h | File | 12.82 KB | 0644 |
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udp_tunnel.h | File | 5.12 KB | 0644 |
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udplite.h | File | 3.83 KB | 0644 |
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vsock_addr.h | File | 1.05 KB | 0644 |
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vxlan.h | File | 10.43 KB | 0644 |
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wext.h | File | 1.51 KB | 0644 |
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wimax.h | File | 19.97 KB | 0644 |
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x25.h | File | 9.43 KB | 0644 |
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x25device.h | File | 387 B | 0644 |
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xfrm.h | File | 53.72 KB | 0644 |
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