mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 05:20:25 +07:00
2be09de7d6
Lots of conflicts, by happily all cases of overlapping changes, parallel adds, things of that nature. Thanks to Stephen Rothwell, Saeed Mahameed, and others for their guidance in these resolutions. Signed-off-by: David S. Miller <davem@davemloft.net>
372 lines
8.5 KiB
C
372 lines
8.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <limits.h>
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#include <stddef.h>
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#include <stdbool.h>
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#include <string.h>
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#include <linux/pkt_cls.h>
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#include <linux/bpf.h>
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#include <linux/in.h>
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#include <linux/if_ether.h>
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#include <linux/icmp.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/if_packet.h>
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#include <sys/socket.h>
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#include <linux/if_tunnel.h>
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#include <linux/mpls.h>
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#include "bpf_helpers.h"
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#include "bpf_endian.h"
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int _version SEC("version") = 1;
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#define PROG(F) SEC(#F) int bpf_func_##F
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/* These are the identifiers of the BPF programs that will be used in tail
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* calls. Name is limited to 16 characters, with the terminating character and
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* bpf_func_ above, we have only 6 to work with, anything after will be cropped.
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*/
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enum {
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IP,
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IPV6,
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IPV6OP, /* Destination/Hop-by-Hop Options IPv6 Extension header */
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IPV6FR, /* Fragmentation IPv6 Extension Header */
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MPLS,
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VLAN,
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};
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#define IP_MF 0x2000
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#define IP_OFFSET 0x1FFF
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#define IP6_MF 0x0001
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#define IP6_OFFSET 0xFFF8
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struct vlan_hdr {
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__be16 h_vlan_TCI;
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__be16 h_vlan_encapsulated_proto;
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};
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struct gre_hdr {
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__be16 flags;
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__be16 proto;
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};
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struct frag_hdr {
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__u8 nexthdr;
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__u8 reserved;
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__be16 frag_off;
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__be32 identification;
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};
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struct bpf_map_def SEC("maps") jmp_table = {
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.type = BPF_MAP_TYPE_PROG_ARRAY,
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.key_size = sizeof(__u32),
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.value_size = sizeof(__u32),
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.max_entries = 8
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};
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static __always_inline void *bpf_flow_dissect_get_header(struct __sk_buff *skb,
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__u16 hdr_size,
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void *buffer)
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{
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void *data_end = (void *)(long)skb->data_end;
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void *data = (void *)(long)skb->data;
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__u16 thoff = skb->flow_keys->thoff;
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__u8 *hdr;
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/* Verifies this variable offset does not overflow */
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if (thoff > (USHRT_MAX - hdr_size))
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return NULL;
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hdr = data + thoff;
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if (hdr + hdr_size <= data_end)
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return hdr;
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if (bpf_skb_load_bytes(skb, thoff, buffer, hdr_size))
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return NULL;
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return buffer;
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}
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/* Dispatches on ETHERTYPE */
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static __always_inline int parse_eth_proto(struct __sk_buff *skb, __be16 proto)
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{
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struct bpf_flow_keys *keys = skb->flow_keys;
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keys->n_proto = proto;
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switch (proto) {
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case bpf_htons(ETH_P_IP):
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bpf_tail_call(skb, &jmp_table, IP);
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break;
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case bpf_htons(ETH_P_IPV6):
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bpf_tail_call(skb, &jmp_table, IPV6);
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break;
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case bpf_htons(ETH_P_MPLS_MC):
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case bpf_htons(ETH_P_MPLS_UC):
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bpf_tail_call(skb, &jmp_table, MPLS);
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break;
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case bpf_htons(ETH_P_8021Q):
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case bpf_htons(ETH_P_8021AD):
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bpf_tail_call(skb, &jmp_table, VLAN);
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break;
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default:
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/* Protocol not supported */
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return BPF_DROP;
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}
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return BPF_DROP;
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}
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SEC("flow_dissector")
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int _dissect(struct __sk_buff *skb)
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{
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if (!skb->vlan_present)
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return parse_eth_proto(skb, skb->protocol);
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else
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return parse_eth_proto(skb, skb->vlan_proto);
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}
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/* Parses on IPPROTO_* */
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static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto)
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{
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struct bpf_flow_keys *keys = skb->flow_keys;
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void *data_end = (void *)(long)skb->data_end;
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struct icmphdr *icmp, _icmp;
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struct gre_hdr *gre, _gre;
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struct ethhdr *eth, _eth;
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struct tcphdr *tcp, _tcp;
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struct udphdr *udp, _udp;
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keys->ip_proto = proto;
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switch (proto) {
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case IPPROTO_ICMP:
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icmp = bpf_flow_dissect_get_header(skb, sizeof(*icmp), &_icmp);
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if (!icmp)
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return BPF_DROP;
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return BPF_OK;
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case IPPROTO_IPIP:
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keys->is_encap = true;
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return parse_eth_proto(skb, bpf_htons(ETH_P_IP));
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case IPPROTO_IPV6:
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keys->is_encap = true;
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return parse_eth_proto(skb, bpf_htons(ETH_P_IPV6));
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case IPPROTO_GRE:
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gre = bpf_flow_dissect_get_header(skb, sizeof(*gre), &_gre);
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if (!gre)
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return BPF_DROP;
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if (bpf_htons(gre->flags & GRE_VERSION))
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/* Only inspect standard GRE packets with version 0 */
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return BPF_OK;
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keys->thoff += sizeof(*gre); /* Step over GRE Flags and Proto */
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if (GRE_IS_CSUM(gre->flags))
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keys->thoff += 4; /* Step over chksum and Padding */
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if (GRE_IS_KEY(gre->flags))
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keys->thoff += 4; /* Step over key */
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if (GRE_IS_SEQ(gre->flags))
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keys->thoff += 4; /* Step over sequence number */
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keys->is_encap = true;
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if (gre->proto == bpf_htons(ETH_P_TEB)) {
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eth = bpf_flow_dissect_get_header(skb, sizeof(*eth),
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&_eth);
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if (!eth)
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return BPF_DROP;
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keys->thoff += sizeof(*eth);
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return parse_eth_proto(skb, eth->h_proto);
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} else {
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return parse_eth_proto(skb, gre->proto);
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}
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case IPPROTO_TCP:
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tcp = bpf_flow_dissect_get_header(skb, sizeof(*tcp), &_tcp);
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if (!tcp)
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return BPF_DROP;
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if (tcp->doff < 5)
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return BPF_DROP;
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if ((__u8 *)tcp + (tcp->doff << 2) > data_end)
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return BPF_DROP;
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keys->sport = tcp->source;
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keys->dport = tcp->dest;
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return BPF_OK;
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case IPPROTO_UDP:
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case IPPROTO_UDPLITE:
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udp = bpf_flow_dissect_get_header(skb, sizeof(*udp), &_udp);
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if (!udp)
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return BPF_DROP;
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keys->sport = udp->source;
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keys->dport = udp->dest;
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return BPF_OK;
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default:
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return BPF_DROP;
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}
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return BPF_DROP;
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}
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static __always_inline int parse_ipv6_proto(struct __sk_buff *skb, __u8 nexthdr)
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{
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struct bpf_flow_keys *keys = skb->flow_keys;
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keys->ip_proto = nexthdr;
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switch (nexthdr) {
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case IPPROTO_HOPOPTS:
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case IPPROTO_DSTOPTS:
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bpf_tail_call(skb, &jmp_table, IPV6OP);
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break;
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case IPPROTO_FRAGMENT:
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bpf_tail_call(skb, &jmp_table, IPV6FR);
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break;
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default:
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return parse_ip_proto(skb, nexthdr);
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}
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return BPF_DROP;
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}
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PROG(IP)(struct __sk_buff *skb)
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{
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void *data_end = (void *)(long)skb->data_end;
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struct bpf_flow_keys *keys = skb->flow_keys;
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void *data = (void *)(long)skb->data;
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struct iphdr *iph, _iph;
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bool done = false;
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iph = bpf_flow_dissect_get_header(skb, sizeof(*iph), &_iph);
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if (!iph)
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return BPF_DROP;
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/* IP header cannot be smaller than 20 bytes */
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if (iph->ihl < 5)
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return BPF_DROP;
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keys->addr_proto = ETH_P_IP;
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keys->ipv4_src = iph->saddr;
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keys->ipv4_dst = iph->daddr;
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keys->thoff += iph->ihl << 2;
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if (data + keys->thoff > data_end)
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return BPF_DROP;
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if (iph->frag_off & bpf_htons(IP_MF | IP_OFFSET)) {
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keys->is_frag = true;
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if (iph->frag_off & bpf_htons(IP_OFFSET))
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/* From second fragment on, packets do not have headers
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* we can parse.
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*/
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done = true;
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else
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keys->is_first_frag = true;
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}
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if (done)
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return BPF_OK;
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return parse_ip_proto(skb, iph->protocol);
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}
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PROG(IPV6)(struct __sk_buff *skb)
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{
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struct bpf_flow_keys *keys = skb->flow_keys;
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struct ipv6hdr *ip6h, _ip6h;
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ip6h = bpf_flow_dissect_get_header(skb, sizeof(*ip6h), &_ip6h);
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if (!ip6h)
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return BPF_DROP;
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keys->addr_proto = ETH_P_IPV6;
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memcpy(&keys->ipv6_src, &ip6h->saddr, 2*sizeof(ip6h->saddr));
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keys->thoff += sizeof(struct ipv6hdr);
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return parse_ipv6_proto(skb, ip6h->nexthdr);
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}
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PROG(IPV6OP)(struct __sk_buff *skb)
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{
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struct ipv6_opt_hdr *ip6h, _ip6h;
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ip6h = bpf_flow_dissect_get_header(skb, sizeof(*ip6h), &_ip6h);
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if (!ip6h)
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return BPF_DROP;
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/* hlen is in 8-octets and does not include the first 8 bytes
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* of the header
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*/
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skb->flow_keys->thoff += (1 + ip6h->hdrlen) << 3;
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return parse_ipv6_proto(skb, ip6h->nexthdr);
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}
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PROG(IPV6FR)(struct __sk_buff *skb)
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{
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struct bpf_flow_keys *keys = skb->flow_keys;
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struct frag_hdr *fragh, _fragh;
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fragh = bpf_flow_dissect_get_header(skb, sizeof(*fragh), &_fragh);
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if (!fragh)
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return BPF_DROP;
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keys->thoff += sizeof(*fragh);
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keys->is_frag = true;
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if (!(fragh->frag_off & bpf_htons(IP6_OFFSET)))
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keys->is_first_frag = true;
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return parse_ipv6_proto(skb, fragh->nexthdr);
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}
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PROG(MPLS)(struct __sk_buff *skb)
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{
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struct mpls_label *mpls, _mpls;
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mpls = bpf_flow_dissect_get_header(skb, sizeof(*mpls), &_mpls);
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if (!mpls)
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return BPF_DROP;
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return BPF_OK;
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}
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PROG(VLAN)(struct __sk_buff *skb)
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{
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struct bpf_flow_keys *keys = skb->flow_keys;
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struct vlan_hdr *vlan, _vlan;
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__be16 proto;
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/* Peek back to see if single or double-tagging */
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if (bpf_skb_load_bytes(skb, keys->thoff - sizeof(proto), &proto,
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sizeof(proto)))
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return BPF_DROP;
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/* Account for double-tagging */
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if (proto == bpf_htons(ETH_P_8021AD)) {
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vlan = bpf_flow_dissect_get_header(skb, sizeof(*vlan), &_vlan);
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if (!vlan)
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return BPF_DROP;
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if (vlan->h_vlan_encapsulated_proto != bpf_htons(ETH_P_8021Q))
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return BPF_DROP;
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keys->thoff += sizeof(*vlan);
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}
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vlan = bpf_flow_dissect_get_header(skb, sizeof(*vlan), &_vlan);
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if (!vlan)
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return BPF_DROP;
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keys->thoff += sizeof(*vlan);
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/* Only allow 8021AD + 8021Q double tagging and no triple tagging.*/
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if (vlan->h_vlan_encapsulated_proto == bpf_htons(ETH_P_8021AD) ||
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vlan->h_vlan_encapsulated_proto == bpf_htons(ETH_P_8021Q))
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return BPF_DROP;
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return parse_eth_proto(skb, vlan->h_vlan_encapsulated_proto);
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}
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char __license[] SEC("license") = "GPL";
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