| #include <linux/kernel.h> |
| #include <linux/skbuff.h> |
| #include <linux/export.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| #include <linux/if_vlan.h> |
| #include <net/dsa.h> |
| #include <net/dst_metadata.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <net/gre.h> |
| #include <net/pptp.h> |
| #include <net/tipc.h> |
| #include <linux/igmp.h> |
| #include <linux/icmp.h> |
| #include <linux/sctp.h> |
| #include <linux/dccp.h> |
| #include <linux/if_tunnel.h> |
| #include <linux/if_pppox.h> |
| #include <linux/ppp_defs.h> |
| #include <linux/stddef.h> |
| #include <linux/if_ether.h> |
| #include <linux/mpls.h> |
| #include <linux/tcp.h> |
| #include <net/flow_dissector.h> |
| #include <scsi/fc/fc_fcoe.h> |
| #include <uapi/linux/batadv_packet.h> |
| |
| static void dissector_set_key(struct flow_dissector *flow_dissector, |
| enum flow_dissector_key_id key_id) |
| { |
| flow_dissector->used_keys |= (1 << key_id); |
| } |
| |
| void skb_flow_dissector_init(struct flow_dissector *flow_dissector, |
| const struct flow_dissector_key *key, |
| unsigned int key_count) |
| { |
| unsigned int i; |
| |
| memset(flow_dissector, 0, sizeof(*flow_dissector)); |
| |
| for (i = 0; i < key_count; i++, key++) { |
| /* User should make sure that every key target offset is withing |
| * boundaries of unsigned short. |
| */ |
| BUG_ON(key->offset > USHRT_MAX); |
| BUG_ON(dissector_uses_key(flow_dissector, |
| key->key_id)); |
| |
| dissector_set_key(flow_dissector, key->key_id); |
| flow_dissector->offset[key->key_id] = key->offset; |
| } |
| |
| /* Ensure that the dissector always includes control and basic key. |
| * That way we are able to avoid handling lack of these in fast path. |
| */ |
| BUG_ON(!dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_CONTROL)); |
| BUG_ON(!dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_BASIC)); |
| } |
| EXPORT_SYMBOL(skb_flow_dissector_init); |
| |
| /** |
| * skb_flow_get_be16 - extract be16 entity |
| * @skb: sk_buff to extract from |
| * @poff: offset to extract at |
| * @data: raw buffer pointer to the packet |
| * @hlen: packet header length |
| * |
| * The function will try to retrieve a be32 entity at |
| * offset poff |
| */ |
| static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff, |
| void *data, int hlen) |
| { |
| __be16 *u, _u; |
| |
| u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u); |
| if (u) |
| return *u; |
| |
| return 0; |
| } |
| |
| /** |
| * __skb_flow_get_ports - extract the upper layer ports and return them |
| * @skb: sk_buff to extract the ports from |
| * @thoff: transport header offset |
| * @ip_proto: protocol for which to get port offset |
| * @data: raw buffer pointer to the packet, if NULL use skb->data |
| * @hlen: packet header length, if @data is NULL use skb_headlen(skb) |
| * |
| * The function will try to retrieve the ports at offset thoff + poff where poff |
| * is the protocol port offset returned from proto_ports_offset |
| */ |
| __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, |
| void *data, int hlen) |
| { |
| int poff = proto_ports_offset(ip_proto); |
| |
| if (!data) { |
| data = skb->data; |
| hlen = skb_headlen(skb); |
| } |
| |
| if (poff >= 0) { |
| __be32 *ports, _ports; |
| |
| ports = __skb_header_pointer(skb, thoff + poff, |
| sizeof(_ports), data, hlen, &_ports); |
| if (ports) |
| return *ports; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(__skb_flow_get_ports); |
| |
| static void |
| skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type, |
| struct flow_dissector *flow_dissector, |
| void *target_container) |
| { |
| struct flow_dissector_key_control *ctrl; |
| |
| if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL)) |
| return; |
| |
| ctrl = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_CONTROL, |
| target_container); |
| ctrl->addr_type = type; |
| } |
| |
| void |
| skb_flow_dissect_tunnel_info(const struct sk_buff *skb, |
| struct flow_dissector *flow_dissector, |
| void *target_container) |
| { |
| struct ip_tunnel_info *info; |
| struct ip_tunnel_key *key; |
| |
| /* A quick check to see if there might be something to do. */ |
| if (!dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_KEYID) && |
| !dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) && |
| !dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) && |
| !dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_CONTROL) && |
| !dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_PORTS) && |
| !dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IP) && |
| !dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_OPTS)) |
| return; |
| |
| info = skb_tunnel_info(skb); |
| if (!info) |
| return; |
| |
| key = &info->key; |
| |
| switch (ip_tunnel_info_af(info)) { |
| case AF_INET: |
| skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
| flow_dissector, |
| target_container); |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) { |
| struct flow_dissector_key_ipv4_addrs *ipv4; |
| |
| ipv4 = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, |
| target_container); |
| ipv4->src = key->u.ipv4.src; |
| ipv4->dst = key->u.ipv4.dst; |
| } |
| break; |
| case AF_INET6: |
| skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
| flow_dissector, |
| target_container); |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) { |
| struct flow_dissector_key_ipv6_addrs *ipv6; |
| |
| ipv6 = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, |
| target_container); |
| ipv6->src = key->u.ipv6.src; |
| ipv6->dst = key->u.ipv6.dst; |
| } |
| break; |
| } |
| |
| if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) { |
| struct flow_dissector_key_keyid *keyid; |
| |
| keyid = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_KEYID, |
| target_container); |
| keyid->keyid = tunnel_id_to_key32(key->tun_id); |
| } |
| |
| if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) { |
| struct flow_dissector_key_ports *tp; |
| |
| tp = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_PORTS, |
| target_container); |
| tp->src = key->tp_src; |
| tp->dst = key->tp_dst; |
| } |
| |
| if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) { |
| struct flow_dissector_key_ip *ip; |
| |
| ip = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_IP, |
| target_container); |
| ip->tos = key->tos; |
| ip->ttl = key->ttl; |
| } |
| |
| if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) { |
| struct flow_dissector_key_enc_opts *enc_opt; |
| |
| enc_opt = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ENC_OPTS, |
| target_container); |
| |
| if (info->options_len) { |
| enc_opt->len = info->options_len; |
| ip_tunnel_info_opts_get(enc_opt->data, info); |
| enc_opt->dst_opt_type = info->key.tun_flags & |
| TUNNEL_OPTIONS_PRESENT; |
| } |
| } |
| } |
| EXPORT_SYMBOL(skb_flow_dissect_tunnel_info); |
| |
| static enum flow_dissect_ret |
| __skb_flow_dissect_mpls(const struct sk_buff *skb, |
| struct flow_dissector *flow_dissector, |
| void *target_container, void *data, int nhoff, int hlen) |
| { |
| struct flow_dissector_key_keyid *key_keyid; |
| struct mpls_label *hdr, _hdr[2]; |
| u32 entry, label; |
| |
| if (!dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_MPLS_ENTROPY) && |
| !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| |
| hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, |
| hlen, &_hdr); |
| if (!hdr) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| entry = ntohl(hdr[0].entry); |
| label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT; |
| |
| if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) { |
| struct flow_dissector_key_mpls *key_mpls; |
| |
| key_mpls = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_MPLS, |
| target_container); |
| key_mpls->mpls_label = label; |
| key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK) |
| >> MPLS_LS_TTL_SHIFT; |
| key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK) |
| >> MPLS_LS_TC_SHIFT; |
| key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK) |
| >> MPLS_LS_S_SHIFT; |
| } |
| |
| if (label == MPLS_LABEL_ENTROPY) { |
| key_keyid = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_MPLS_ENTROPY, |
| target_container); |
| key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK); |
| } |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| } |
| |
| static enum flow_dissect_ret |
| __skb_flow_dissect_arp(const struct sk_buff *skb, |
| struct flow_dissector *flow_dissector, |
| void *target_container, void *data, int nhoff, int hlen) |
| { |
| struct flow_dissector_key_arp *key_arp; |
| struct { |
| unsigned char ar_sha[ETH_ALEN]; |
| unsigned char ar_sip[4]; |
| unsigned char ar_tha[ETH_ALEN]; |
| unsigned char ar_tip[4]; |
| } *arp_eth, _arp_eth; |
| const struct arphdr *arp; |
| struct arphdr _arp; |
| |
| if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP)) |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| |
| arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data, |
| hlen, &_arp); |
| if (!arp) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| if (arp->ar_hrd != htons(ARPHRD_ETHER) || |
| arp->ar_pro != htons(ETH_P_IP) || |
| arp->ar_hln != ETH_ALEN || |
| arp->ar_pln != 4 || |
| (arp->ar_op != htons(ARPOP_REPLY) && |
| arp->ar_op != htons(ARPOP_REQUEST))) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp), |
| sizeof(_arp_eth), data, |
| hlen, &_arp_eth); |
| if (!arp_eth) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| key_arp = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ARP, |
| target_container); |
| |
| memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip)); |
| memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip)); |
| |
| /* Only store the lower byte of the opcode; |
| * this covers ARPOP_REPLY and ARPOP_REQUEST. |
| */ |
| key_arp->op = ntohs(arp->ar_op) & 0xff; |
| |
| ether_addr_copy(key_arp->sha, arp_eth->ar_sha); |
| ether_addr_copy(key_arp->tha, arp_eth->ar_tha); |
| |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| } |
| |
| static enum flow_dissect_ret |
| __skb_flow_dissect_gre(const struct sk_buff *skb, |
| struct flow_dissector_key_control *key_control, |
| struct flow_dissector *flow_dissector, |
| void *target_container, void *data, |
| __be16 *p_proto, int *p_nhoff, int *p_hlen, |
| unsigned int flags) |
| { |
| struct flow_dissector_key_keyid *key_keyid; |
| struct gre_base_hdr *hdr, _hdr; |
| int offset = 0; |
| u16 gre_ver; |
| |
| hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), |
| data, *p_hlen, &_hdr); |
| if (!hdr) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| /* Only look inside GRE without routing */ |
| if (hdr->flags & GRE_ROUTING) |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| |
| /* Only look inside GRE for version 0 and 1 */ |
| gre_ver = ntohs(hdr->flags & GRE_VERSION); |
| if (gre_ver > 1) |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| |
| *p_proto = hdr->protocol; |
| if (gre_ver) { |
| /* Version1 must be PPTP, and check the flags */ |
| if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| } |
| |
| offset += sizeof(struct gre_base_hdr); |
| |
| if (hdr->flags & GRE_CSUM) |
| offset += sizeof(((struct gre_full_hdr *) 0)->csum) + |
| sizeof(((struct gre_full_hdr *) 0)->reserved1); |
| |
| if (hdr->flags & GRE_KEY) { |
| const __be32 *keyid; |
| __be32 _keyid; |
| |
| keyid = __skb_header_pointer(skb, *p_nhoff + offset, |
| sizeof(_keyid), |
| data, *p_hlen, &_keyid); |
| if (!keyid) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_GRE_KEYID)) { |
| key_keyid = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_GRE_KEYID, |
| target_container); |
| if (gre_ver == 0) |
| key_keyid->keyid = *keyid; |
| else |
| key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; |
| } |
| offset += sizeof(((struct gre_full_hdr *) 0)->key); |
| } |
| |
| if (hdr->flags & GRE_SEQ) |
| offset += sizeof(((struct pptp_gre_header *) 0)->seq); |
| |
| if (gre_ver == 0) { |
| if (*p_proto == htons(ETH_P_TEB)) { |
| const struct ethhdr *eth; |
| struct ethhdr _eth; |
| |
| eth = __skb_header_pointer(skb, *p_nhoff + offset, |
| sizeof(_eth), |
| data, *p_hlen, &_eth); |
| if (!eth) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| *p_proto = eth->h_proto; |
| offset += sizeof(*eth); |
| |
| /* Cap headers that we access via pointers at the |
| * end of the Ethernet header as our maximum alignment |
| * at that point is only 2 bytes. |
| */ |
| if (NET_IP_ALIGN) |
| *p_hlen = *p_nhoff + offset; |
| } |
| } else { /* version 1, must be PPTP */ |
| u8 _ppp_hdr[PPP_HDRLEN]; |
| u8 *ppp_hdr; |
| |
| if (hdr->flags & GRE_ACK) |
| offset += sizeof(((struct pptp_gre_header *) 0)->ack); |
| |
| ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset, |
| sizeof(_ppp_hdr), |
| data, *p_hlen, _ppp_hdr); |
| if (!ppp_hdr) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| switch (PPP_PROTOCOL(ppp_hdr)) { |
| case PPP_IP: |
| *p_proto = htons(ETH_P_IP); |
| break; |
| case PPP_IPV6: |
| *p_proto = htons(ETH_P_IPV6); |
| break; |
| default: |
| /* Could probably catch some more like MPLS */ |
| break; |
| } |
| |
| offset += PPP_HDRLEN; |
| } |
| |
| *p_nhoff += offset; |
| key_control->flags |= FLOW_DIS_ENCAPSULATION; |
| if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| |
| return FLOW_DISSECT_RET_PROTO_AGAIN; |
| } |
| |
| /** |
| * __skb_flow_dissect_batadv() - dissect batman-adv header |
| * @skb: sk_buff to with the batman-adv header |
| * @key_control: flow dissectors control key |
| * @data: raw buffer pointer to the packet, if NULL use skb->data |
| * @p_proto: pointer used to update the protocol to process next |
| * @p_nhoff: pointer used to update inner network header offset |
| * @hlen: packet header length |
| * @flags: any combination of FLOW_DISSECTOR_F_* |
| * |
| * ETH_P_BATMAN packets are tried to be dissected. Only |
| * &struct batadv_unicast packets are actually processed because they contain an |
| * inner ethernet header and are usually followed by actual network header. This |
| * allows the flow dissector to continue processing the packet. |
| * |
| * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found, |
| * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation, |
| * otherwise FLOW_DISSECT_RET_OUT_BAD |
| */ |
| static enum flow_dissect_ret |
| __skb_flow_dissect_batadv(const struct sk_buff *skb, |
| struct flow_dissector_key_control *key_control, |
| void *data, __be16 *p_proto, int *p_nhoff, int hlen, |
| unsigned int flags) |
| { |
| struct { |
| struct batadv_unicast_packet batadv_unicast; |
| struct ethhdr eth; |
| } *hdr, _hdr; |
| |
| hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen, |
| &_hdr); |
| if (!hdr) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| if (hdr->batadv_unicast.packet_type != BATADV_UNICAST) |
| return FLOW_DISSECT_RET_OUT_BAD; |
| |
| *p_proto = hdr->eth.h_proto; |
| *p_nhoff += sizeof(*hdr); |
| |
| key_control->flags |= FLOW_DIS_ENCAPSULATION; |
| if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) |
| return FLOW_DISSECT_RET_OUT_GOOD; |
| |
| return FLOW_DISSECT_RET_PROTO_AGAIN; |
| } |
| |
| static void |
| __skb_flow_dissect_tcp(const struct sk_buff *skb, |
| struct flow_dissector *flow_dissector, |
| void *target_container, void *data, int thoff, int hlen) |
| { |
| struct flow_dissector_key_tcp *key_tcp; |
| struct tcphdr *th, _th; |
| |
| if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP)) |
| return; |
| |
| th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th); |
| if (!th) |
| return; |
| |
| if (unlikely(__tcp_hdrlen(th) < sizeof(_th))) |
| return; |
| |
| key_tcp = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_TCP, |
| target_container); |
| key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF)); |
| } |
| |
| static void |
| __skb_flow_dissect_ipv4(const struct sk_buff *skb, |
| struct flow_dissector *flow_dissector, |
| void *target_container, void *data, const struct iphdr *iph) |
| { |
| struct flow_dissector_key_ip *key_ip; |
| |
| if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) |
| return; |
| |
| key_ip = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_IP, |
| target_container); |
| key_ip->tos = iph->tos; |
| key_ip->ttl = iph->ttl; |
| } |
| |
| static void |
| __skb_flow_dissect_ipv6(const struct sk_buff *skb, |
| struct flow_dissector *flow_dissector, |
| void *target_container, void *data, const struct ipv6hdr *iph) |
| { |
| struct flow_dissector_key_ip *key_ip; |
| |
| if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) |
| return; |
| |
| key_ip = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_IP, |
| target_container); |
| key_ip->tos = ipv6_get_dsfield(iph); |
| key_ip->ttl = iph->hop_limit; |
| } |
| |
| /* Maximum number of protocol headers that can be parsed in |
| * __skb_flow_dissect |
| */ |
| #define MAX_FLOW_DISSECT_HDRS 15 |
| |
| static bool skb_flow_dissect_allowed(int *num_hdrs) |
| { |
| ++*num_hdrs; |
| |
| return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS); |
| } |
| |
| /** |
| * __skb_flow_dissect - extract the flow_keys struct and return it |
| * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified |
| * @flow_dissector: list of keys to dissect |
| * @target_container: target structure to put dissected values into |
| * @data: raw buffer pointer to the packet, if NULL use skb->data |
| * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol |
| * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) |
| * @hlen: packet header length, if @data is NULL use skb_headlen(skb) |
| * |
| * The function will try to retrieve individual keys into target specified |
| * by flow_dissector from either the skbuff or a raw buffer specified by the |
| * rest parameters. |
| * |
| * Caller must take care of zeroing target container memory. |
| */ |
| bool __skb_flow_dissect(const struct sk_buff *skb, |
| struct flow_dissector *flow_dissector, |
| void *target_container, |
| void *data, __be16 proto, int nhoff, int hlen, |
| unsigned int flags) |
| { |
| struct flow_dissector_key_control *key_control; |
| struct flow_dissector_key_basic *key_basic; |
| struct flow_dissector_key_addrs *key_addrs; |
| struct flow_dissector_key_ports *key_ports; |
| struct flow_dissector_key_icmp *key_icmp; |
| struct flow_dissector_key_tags *key_tags; |
| struct flow_dissector_key_vlan *key_vlan; |
| enum flow_dissect_ret fdret; |
| enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX; |
| int num_hdrs = 0; |
| u8 ip_proto = 0; |
| bool ret; |
| |
| if (!data) { |
| data = skb->data; |
| proto = skb_vlan_tag_present(skb) ? |
| skb->vlan_proto : skb->protocol; |
| nhoff = skb_network_offset(skb); |
| hlen = skb_headlen(skb); |
| #if IS_ENABLED(CONFIG_NET_DSA) |
| if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) && |
| proto == htons(ETH_P_XDSA))) { |
| const struct dsa_device_ops *ops; |
| int offset = 0; |
| |
| ops = skb->dev->dsa_ptr->tag_ops; |
| if (ops->flow_dissect && |
| !ops->flow_dissect(skb, &proto, &offset)) { |
| hlen -= offset; |
| nhoff += offset; |
| } |
| } |
| #endif |
| } |
| |
| /* It is ensured by skb_flow_dissector_init() that control key will |
| * be always present. |
| */ |
| key_control = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_CONTROL, |
| target_container); |
| |
| /* It is ensured by skb_flow_dissector_init() that basic key will |
| * be always present. |
| */ |
| key_basic = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_BASIC, |
| target_container); |
| |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ETH_ADDRS)) { |
| struct ethhdr *eth = eth_hdr(skb); |
| struct flow_dissector_key_eth_addrs *key_eth_addrs; |
| |
| key_eth_addrs = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ETH_ADDRS, |
| target_container); |
| memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs)); |
| } |
| |
| proto_again: |
| fdret = FLOW_DISSECT_RET_CONTINUE; |
| |
| switch (proto) { |
| case htons(ETH_P_IP): { |
| const struct iphdr *iph; |
| struct iphdr _iph; |
| |
| iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); |
| if (!iph || iph->ihl < 5) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| nhoff += iph->ihl * 4; |
| |
| ip_proto = iph->protocol; |
| |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { |
| key_addrs = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
| target_container); |
| |
| memcpy(&key_addrs->v4addrs, &iph->saddr, |
| sizeof(key_addrs->v4addrs)); |
| key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; |
| } |
| |
| if (ip_is_fragment(iph)) { |
| key_control->flags |= FLOW_DIS_IS_FRAGMENT; |
| |
| if (iph->frag_off & htons(IP_OFFSET)) { |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } else { |
| key_control->flags |= FLOW_DIS_FIRST_FRAG; |
| if (!(flags & |
| FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) { |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } |
| } |
| } |
| |
| __skb_flow_dissect_ipv4(skb, flow_dissector, |
| target_container, data, iph); |
| |
| if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) { |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } |
| |
| break; |
| } |
| case htons(ETH_P_IPV6): { |
| const struct ipv6hdr *iph; |
| struct ipv6hdr _iph; |
| |
| iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); |
| if (!iph) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| ip_proto = iph->nexthdr; |
| nhoff += sizeof(struct ipv6hdr); |
| |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { |
| key_addrs = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
| target_container); |
| |
| memcpy(&key_addrs->v6addrs, &iph->saddr, |
| sizeof(key_addrs->v6addrs)); |
| key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| } |
| |
| if ((dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_FLOW_LABEL) || |
| (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && |
| ip6_flowlabel(iph)) { |
| __be32 flow_label = ip6_flowlabel(iph); |
| |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_FLOW_LABEL)) { |
| key_tags = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_FLOW_LABEL, |
| target_container); |
| key_tags->flow_label = ntohl(flow_label); |
| } |
| if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) { |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } |
| } |
| |
| __skb_flow_dissect_ipv6(skb, flow_dissector, |
| target_container, data, iph); |
| |
| if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| |
| break; |
| } |
| case htons(ETH_P_8021AD): |
| case htons(ETH_P_8021Q): { |
| const struct vlan_hdr *vlan = NULL; |
| struct vlan_hdr _vlan; |
| __be16 saved_vlan_tpid = proto; |
| |
| if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX && |
| skb && skb_vlan_tag_present(skb)) { |
| proto = skb->protocol; |
| } else { |
| vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), |
| data, hlen, &_vlan); |
| if (!vlan) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| proto = vlan->h_vlan_encapsulated_proto; |
| nhoff += sizeof(*vlan); |
| } |
| |
| if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) { |
| dissector_vlan = FLOW_DISSECTOR_KEY_VLAN; |
| } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) { |
| dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN; |
| } else { |
| fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
| break; |
| } |
| |
| if (dissector_uses_key(flow_dissector, dissector_vlan)) { |
| key_vlan = skb_flow_dissector_target(flow_dissector, |
| dissector_vlan, |
| target_container); |
| |
| if (!vlan) { |
| key_vlan->vlan_id = skb_vlan_tag_get_id(skb); |
| key_vlan->vlan_priority = |
| (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT); |
| } else { |
| key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & |
| VLAN_VID_MASK; |
| key_vlan->vlan_priority = |
| (ntohs(vlan->h_vlan_TCI) & |
| VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; |
| } |
| key_vlan->vlan_tpid = saved_vlan_tpid; |
| } |
| |
| fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
| break; |
| } |
| case htons(ETH_P_PPP_SES): { |
| struct { |
| struct pppoe_hdr hdr; |
| __be16 proto; |
| } *hdr, _hdr; |
| hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); |
| if (!hdr) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| proto = hdr->proto; |
| nhoff += PPPOE_SES_HLEN; |
| switch (proto) { |
| case htons(PPP_IP): |
| proto = htons(ETH_P_IP); |
| fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
| break; |
| case htons(PPP_IPV6): |
| proto = htons(ETH_P_IPV6); |
| fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
| break; |
| default: |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| break; |
| } |
| case htons(ETH_P_TIPC): { |
| struct tipc_basic_hdr *hdr, _hdr; |
| |
| hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), |
| data, hlen, &_hdr); |
| if (!hdr) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_TIPC)) { |
| key_addrs = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_TIPC, |
| target_container); |
| key_addrs->tipckey.key = tipc_hdr_rps_key(hdr); |
| key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC; |
| } |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } |
| |
| case htons(ETH_P_MPLS_UC): |
| case htons(ETH_P_MPLS_MC): |
| fdret = __skb_flow_dissect_mpls(skb, flow_dissector, |
| target_container, data, |
| nhoff, hlen); |
| break; |
| case htons(ETH_P_FCOE): |
| if ((hlen - nhoff) < FCOE_HEADER_LEN) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| nhoff += FCOE_HEADER_LEN; |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| |
| case htons(ETH_P_ARP): |
| case htons(ETH_P_RARP): |
| fdret = __skb_flow_dissect_arp(skb, flow_dissector, |
| target_container, data, |
| nhoff, hlen); |
| break; |
| |
| case htons(ETH_P_BATMAN): |
| fdret = __skb_flow_dissect_batadv(skb, key_control, data, |
| &proto, &nhoff, hlen, flags); |
| break; |
| |
| default: |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| /* Process result of proto processing */ |
| switch (fdret) { |
| case FLOW_DISSECT_RET_OUT_GOOD: |
| goto out_good; |
| case FLOW_DISSECT_RET_PROTO_AGAIN: |
| if (skb_flow_dissect_allowed(&num_hdrs)) |
| goto proto_again; |
| goto out_good; |
| case FLOW_DISSECT_RET_CONTINUE: |
| case FLOW_DISSECT_RET_IPPROTO_AGAIN: |
| break; |
| case FLOW_DISSECT_RET_OUT_BAD: |
| default: |
| goto out_bad; |
| } |
| |
| ip_proto_again: |
| fdret = FLOW_DISSECT_RET_CONTINUE; |
| |
| switch (ip_proto) { |
| case IPPROTO_GRE: |
| fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector, |
| target_container, data, |
| &proto, &nhoff, &hlen, flags); |
| break; |
| |
| case NEXTHDR_HOP: |
| case NEXTHDR_ROUTING: |
| case NEXTHDR_DEST: { |
| u8 _opthdr[2], *opthdr; |
| |
| if (proto != htons(ETH_P_IPV6)) |
| break; |
| |
| opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), |
| data, hlen, &_opthdr); |
| if (!opthdr) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| ip_proto = opthdr[0]; |
| nhoff += (opthdr[1] + 1) << 3; |
| |
| fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; |
| break; |
| } |
| case NEXTHDR_FRAGMENT: { |
| struct frag_hdr _fh, *fh; |
| |
| if (proto != htons(ETH_P_IPV6)) |
| break; |
| |
| fh = __skb_header_pointer(skb, nhoff, sizeof(_fh), |
| data, hlen, &_fh); |
| |
| if (!fh) { |
| fdret = FLOW_DISSECT_RET_OUT_BAD; |
| break; |
| } |
| |
| key_control->flags |= FLOW_DIS_IS_FRAGMENT; |
| |
| nhoff += sizeof(_fh); |
| ip_proto = fh->nexthdr; |
| |
| if (!(fh->frag_off & htons(IP6_OFFSET))) { |
| key_control->flags |= FLOW_DIS_FIRST_FRAG; |
| if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) { |
| fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; |
| break; |
| } |
| } |
| |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } |
| case IPPROTO_IPIP: |
| proto = htons(ETH_P_IP); |
| |
| key_control->flags |= FLOW_DIS_ENCAPSULATION; |
| if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } |
| |
| fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
| break; |
| |
| case IPPROTO_IPV6: |
| proto = htons(ETH_P_IPV6); |
| |
| key_control->flags |= FLOW_DIS_ENCAPSULATION; |
| if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { |
| fdret = FLOW_DISSECT_RET_OUT_GOOD; |
| break; |
| } |
| |
| fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
| break; |
| |
| |
| case IPPROTO_MPLS: |
| proto = htons(ETH_P_MPLS_UC); |
| fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
| break; |
| |
| case IPPROTO_TCP: |
| __skb_flow_dissect_tcp(skb, flow_dissector, target_container, |
| data, nhoff, hlen); |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) && |
| !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) { |
| key_ports = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_PORTS, |
| target_container); |
| key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, |
| data, hlen); |
| } |
| |
| if (dissector_uses_key(flow_dissector, |
| FLOW_DISSECTOR_KEY_ICMP)) { |
| key_icmp = skb_flow_dissector_target(flow_dissector, |
| FLOW_DISSECTOR_KEY_ICMP, |
| target_container); |
| key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen); |
| } |
| |
| /* Process result of IP proto processing */ |
| switch (fdret) { |
| case FLOW_DISSECT_RET_PROTO_AGAIN: |
| if (skb_flow_dissect_allowed(&num_hdrs)) |
| goto proto_again; |
| break; |
| case FLOW_DISSECT_RET_IPPROTO_AGAIN: |
| if (skb_flow_dissect_allowed(&num_hdrs)) |
| goto ip_proto_again; |
| break; |
| case FLOW_DISSECT_RET_OUT_GOOD: |
| case FLOW_DISSECT_RET_CONTINUE: |
| break; |
| case FLOW_DISSECT_RET_OUT_BAD: |
| default: |
| goto out_bad; |
| } |
| |
| out_good: |
| ret = true; |
| |
| out: |
| key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); |
| key_basic->n_proto = proto; |
| key_basic->ip_proto = ip_proto; |
| |
| return ret; |
| |
| out_bad: |
| ret = false; |
| goto out; |
| } |
| EXPORT_SYMBOL(__skb_flow_dissect); |
| |
| static siphash_key_t hashrnd __read_mostly; |
| static __always_inline void __flow_hash_secret_init(void) |
| { |
| net_get_random_once(&hashrnd, sizeof(hashrnd)); |
| } |
| |
| static const void *flow_keys_hash_start(const struct flow_keys *flow) |
| { |
| BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT); |
| return &flow->FLOW_KEYS_HASH_START_FIELD; |
| } |
| |
| static inline size_t flow_keys_hash_length(const struct flow_keys *flow) |
| { |
| size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); |
| BUILD_BUG_ON(offsetof(typeof(*flow), addrs) != |
| sizeof(*flow) - sizeof(flow->addrs)); |
| |
| switch (flow->control.addr_type) { |
| case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
| diff -= sizeof(flow->addrs.v4addrs); |
| break; |
| case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
| diff -= sizeof(flow->addrs.v6addrs); |
| break; |
| case FLOW_DISSECTOR_KEY_TIPC: |
| diff -= sizeof(flow->addrs.tipckey); |
| break; |
| } |
| return sizeof(*flow) - diff; |
| } |
| |
| __be32 flow_get_u32_src(const struct flow_keys *flow) |
| { |
| switch (flow->control.addr_type) { |
| case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
| return flow->addrs.v4addrs.src; |
| case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
| return (__force __be32)ipv6_addr_hash( |
| &flow->addrs.v6addrs.src); |
| case FLOW_DISSECTOR_KEY_TIPC: |
| return flow->addrs.tipckey.key; |
| default: |
| return 0; |
| } |
| } |
| EXPORT_SYMBOL(flow_get_u32_src); |
| |
| __be32 flow_get_u32_dst(const struct flow_keys *flow) |
| { |
| switch (flow->control.addr_type) { |
| case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
| return flow->addrs.v4addrs.dst; |
| case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
| return (__force __be32)ipv6_addr_hash( |
| &flow->addrs.v6addrs.dst); |
| default: |
| return 0; |
| } |
| } |
| EXPORT_SYMBOL(flow_get_u32_dst); |
| |
| static inline void __flow_hash_consistentify(struct flow_keys *keys) |
| { |
| int addr_diff, i; |
| |
| switch (keys->control.addr_type) { |
| case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
| addr_diff = (__force u32)keys->addrs.v4addrs.dst - |
| (__force u32)keys->addrs.v4addrs.src; |
| if ((addr_diff < 0) || |
| (addr_diff == 0 && |
| ((__force u16)keys->ports.dst < |
| (__force u16)keys->ports.src))) { |
| swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); |
| swap(keys->ports.src, keys->ports.dst); |
| } |
| break; |
| case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
| addr_diff = memcmp(&keys->addrs.v6addrs.dst, |
| &keys->addrs.v6addrs.src, |
| sizeof(keys->addrs.v6addrs.dst)); |
| if ((addr_diff < 0) || |
| (addr_diff == 0 && |
| ((__force u16)keys->ports.dst < |
| (__force u16)keys->ports.src))) { |
| for (i = 0; i < 4; i++) |
| swap(keys->addrs.v6addrs.src.s6_addr32[i], |
| keys->addrs.v6addrs.dst.s6_addr32[i]); |
| swap(keys->ports.src, keys->ports.dst); |
| } |
| break; |
| } |
| } |
| |
| static inline u32 __flow_hash_from_keys(struct flow_keys *keys, |
| const siphash_key_t *keyval) |
| { |
| u32 hash; |
| |
| __flow_hash_consistentify(keys); |
| |
| hash = siphash(flow_keys_hash_start(keys), |
| flow_keys_hash_length(keys), keyval); |
| if (!hash) |
| hash = 1; |
| |
| return hash; |
| } |
| |
| u32 flow_hash_from_keys(struct flow_keys *keys) |
| { |
| __flow_hash_secret_init(); |
| return __flow_hash_from_keys(keys, &hashrnd); |
| } |
| EXPORT_SYMBOL(flow_hash_from_keys); |
| |
| static inline u32 ___skb_get_hash(const struct sk_buff *skb, |
| struct flow_keys *keys, |
| const siphash_key_t *keyval) |
| { |
| skb_flow_dissect_flow_keys(skb, keys, |
| FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); |
| |
| return __flow_hash_from_keys(keys, keyval); |
| } |
| |
| struct _flow_keys_digest_data { |
| __be16 n_proto; |
| u8 ip_proto; |
| u8 padding; |
| __be32 ports; |
| __be32 src; |
| __be32 dst; |
| }; |
| |
| void make_flow_keys_digest(struct flow_keys_digest *digest, |
| const struct flow_keys *flow) |
| { |
| struct _flow_keys_digest_data *data = |
| (struct _flow_keys_digest_data *)digest; |
| |
| BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); |
| |
| memset(digest, 0, sizeof(*digest)); |
| |
| data->n_proto = flow->basic.n_proto; |
| data->ip_proto = flow->basic.ip_proto; |
| data->ports = flow->ports.ports; |
| data->src = flow->addrs.v4addrs.src; |
| data->dst = flow->addrs.v4addrs.dst; |
| } |
| EXPORT_SYMBOL(make_flow_keys_digest); |
| |
| static struct flow_dissector flow_keys_dissector_symmetric __read_mostly; |
| |
| u32 __skb_get_hash_symmetric(const struct sk_buff *skb) |
| { |
| struct flow_keys keys; |
| |
| __flow_hash_secret_init(); |
| |
| memset(&keys, 0, sizeof(keys)); |
| __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys, |
| NULL, 0, 0, 0, |
| FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); |
| |
| return __flow_hash_from_keys(&keys, &hashrnd); |
| } |
| EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric); |
| |
| /** |
| * __skb_get_hash: calculate a flow hash |
| * @skb: sk_buff to calculate flow hash from |
| * |
| * This function calculates a flow hash based on src/dst addresses |
| * and src/dst port numbers. Sets hash in skb to non-zero hash value |
| * on success, zero indicates no valid hash. Also, sets l4_hash in skb |
| * if hash is a canonical 4-tuple hash over transport ports. |
| */ |
| void __skb_get_hash(struct sk_buff *skb) |
| { |
| struct flow_keys keys; |
| u32 hash; |
| |
| __flow_hash_secret_init(); |
| |
| hash = ___skb_get_hash(skb, &keys, &hashrnd); |
| |
| __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); |
| } |
| EXPORT_SYMBOL(__skb_get_hash); |
| |
| __u32 skb_get_hash_perturb(const struct sk_buff *skb, |
| const siphash_key_t *perturb) |
| { |
| struct flow_keys keys; |
| |
| return ___skb_get_hash(skb, &keys, perturb); |
| } |
| EXPORT_SYMBOL(skb_get_hash_perturb); |
| |
| u32 __skb_get_poff(const struct sk_buff *skb, void *data, |
| const struct flow_keys_basic *keys, int hlen) |
| { |
| u32 poff = keys->control.thoff; |
| |
| /* skip L4 headers for fragments after the first */ |
| if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) && |
| !(keys->control.flags & FLOW_DIS_FIRST_FRAG)) |
| return poff; |
| |
| switch (keys->basic.ip_proto) { |
| case IPPROTO_TCP: { |
| /* access doff as u8 to avoid unaligned access */ |
| const u8 *doff; |
| u8 _doff; |
| |
| doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff), |
| data, hlen, &_doff); |
| if (!doff) |
| return poff; |
| |
| poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); |
| break; |
| } |
| case IPPROTO_UDP: |
| case IPPROTO_UDPLITE: |
| poff += sizeof(struct udphdr); |
| break; |
| /* For the rest, we do not really care about header |
| * extensions at this point for now. |
| */ |
| case IPPROTO_ICMP: |
| poff += sizeof(struct icmphdr); |
| break; |
| case IPPROTO_ICMPV6: |
| poff += sizeof(struct icmp6hdr); |
| break; |
| case IPPROTO_IGMP: |
| poff += sizeof(struct igmphdr); |
| break; |
| case IPPROTO_DCCP: |
| poff += sizeof(struct dccp_hdr); |
| break; |
| case IPPROTO_SCTP: |
| poff += sizeof(struct sctphdr); |
| break; |
| } |
| |
| return poff; |
| } |
| |
| /** |
| * skb_get_poff - get the offset to the payload |
| * @skb: sk_buff to get the payload offset from |
| * |
| * The function will get the offset to the payload as far as it could |
| * be dissected. The main user is currently BPF, so that we can dynamically |
| * truncate packets without needing to push actual payload to the user |
| * space and can analyze headers only, instead. |
| */ |
| u32 skb_get_poff(const struct sk_buff *skb) |
| { |
| struct flow_keys_basic keys; |
| |
| if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0)) |
| return 0; |
| |
| return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); |
| } |
| |
| __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) |
| { |
| memset(keys, 0, sizeof(*keys)); |
| |
| memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, |
| sizeof(keys->addrs.v6addrs.src)); |
| memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, |
| sizeof(keys->addrs.v6addrs.dst)); |
| keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| keys->ports.src = fl6->fl6_sport; |
| keys->ports.dst = fl6->fl6_dport; |
| keys->keyid.keyid = fl6->fl6_gre_key; |
| keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); |
| keys->basic.ip_proto = fl6->flowi6_proto; |
| |
| return flow_hash_from_keys(keys); |
| } |
| EXPORT_SYMBOL(__get_hash_from_flowi6); |
| |
| static const struct flow_dissector_key flow_keys_dissector_keys[] = { |
| { |
| .key_id = FLOW_DISSECTOR_KEY_CONTROL, |
| .offset = offsetof(struct flow_keys, control), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_BASIC, |
| .offset = offsetof(struct flow_keys, basic), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
| .offset = offsetof(struct flow_keys, addrs.v4addrs), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
| .offset = offsetof(struct flow_keys, addrs.v6addrs), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_TIPC, |
| .offset = offsetof(struct flow_keys, addrs.tipckey), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_PORTS, |
| .offset = offsetof(struct flow_keys, ports), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_VLAN, |
| .offset = offsetof(struct flow_keys, vlan), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, |
| .offset = offsetof(struct flow_keys, tags), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, |
| .offset = offsetof(struct flow_keys, keyid), |
| }, |
| }; |
| |
| static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = { |
| { |
| .key_id = FLOW_DISSECTOR_KEY_CONTROL, |
| .offset = offsetof(struct flow_keys, control), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_BASIC, |
| .offset = offsetof(struct flow_keys, basic), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
| .offset = offsetof(struct flow_keys, addrs.v4addrs), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
| .offset = offsetof(struct flow_keys, addrs.v6addrs), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_PORTS, |
| .offset = offsetof(struct flow_keys, ports), |
| }, |
| }; |
| |
| static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = { |
| { |
| .key_id = FLOW_DISSECTOR_KEY_CONTROL, |
| .offset = offsetof(struct flow_keys, control), |
| }, |
| { |
| .key_id = FLOW_DISSECTOR_KEY_BASIC, |
| .offset = offsetof(struct flow_keys, basic), |
| }, |
| }; |
| |
| struct flow_dissector flow_keys_dissector __read_mostly; |
| EXPORT_SYMBOL(flow_keys_dissector); |
| |
| struct flow_dissector flow_keys_basic_dissector __read_mostly; |
| EXPORT_SYMBOL(flow_keys_basic_dissector); |
| |
| static int __init init_default_flow_dissectors(void) |
| { |
| skb_flow_dissector_init(&flow_keys_dissector, |
| flow_keys_dissector_keys, |
| ARRAY_SIZE(flow_keys_dissector_keys)); |
| skb_flow_dissector_init(&flow_keys_dissector_symmetric, |
| flow_keys_dissector_symmetric_keys, |
| ARRAY_SIZE(flow_keys_dissector_symmetric_keys)); |
| skb_flow_dissector_init(&flow_keys_basic_dissector, |
| flow_keys_basic_dissector_keys, |
| ARRAY_SIZE(flow_keys_basic_dissector_keys)); |
| return 0; |
| } |
| |
| core_initcall(init_default_flow_dissectors); |