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Diffstat (limited to 'src/xdp/common/parsing_helpers.h')
| -rw-r--r-- | src/xdp/common/parsing_helpers.h | 244 |
1 files changed, 0 insertions, 244 deletions
diff --git a/src/xdp/common/parsing_helpers.h b/src/xdp/common/parsing_helpers.h deleted file mode 100644 index c0837e88f..000000000 --- a/src/xdp/common/parsing_helpers.h +++ /dev/null @@ -1,244 +0,0 @@ -/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-clause) */ -/* - * This file contains parsing functions that are used in the packetXX XDP - * programs. The functions are marked as __always_inline, and fully defined in - * this header file to be included in the BPF program. - * - * Each helper parses a packet header, including doing bounds checking, and - * returns the type of its contents if successful, and -1 otherwise. - * - * For Ethernet and IP headers, the content type is the type of the payload - * (h_proto for Ethernet, nexthdr for IPv6), for ICMP it is the ICMP type field. - * All return values are in host byte order. - * - * The versions of the functions included here are slightly expanded versions of - * the functions in the packet01 lesson. For instance, the Ethernet header - * parsing has support for parsing VLAN tags. - */ - -#ifndef __PARSING_HELPERS_H -#define __PARSING_HELPERS_H - -#include <stddef.h> -#include <linux/if_ether.h> -#include <linux/if_packet.h> -#include <linux/ip.h> -#include <linux/ipv6.h> -#include <linux/icmp.h> -#include <linux/icmpv6.h> -#include <linux/udp.h> -#include <linux/tcp.h> - -/* Header cursor to keep track of current parsing position */ -struct hdr_cursor { - void *pos; -}; - -/* - * struct vlan_hdr - vlan header - * @h_vlan_TCI: priority and VLAN ID - * @h_vlan_encapsulated_proto: packet type ID or len - */ -struct vlan_hdr { - __be16 h_vlan_TCI; - __be16 h_vlan_encapsulated_proto; -}; - -/* - * Struct icmphdr_common represents the common part of the icmphdr and icmp6hdr - * structures. - */ -struct icmphdr_common { - __u8 type; - __u8 code; - __sum16 cksum; -}; - -/* Allow users of header file to redefine VLAN max depth */ -#ifndef VLAN_MAX_DEPTH -#define VLAN_MAX_DEPTH 4 -#endif - -static __always_inline int proto_is_vlan(__u16 h_proto) -{ - return !!(h_proto == bpf_htons(ETH_P_8021Q) || - h_proto == bpf_htons(ETH_P_8021AD)); -} - -/* Notice, parse_ethhdr() will skip VLAN tags, by advancing nh->pos and returns - * next header EtherType, BUT the ethhdr pointer supplied still points to the - * Ethernet header. Thus, caller can look at eth->h_proto to see if this was a - * VLAN tagged packet. - */ -static __always_inline int parse_ethhdr(struct hdr_cursor *nh, void *data_end, - struct ethhdr **ethhdr) -{ - struct ethhdr *eth = nh->pos; - int hdrsize = sizeof(*eth); - struct vlan_hdr *vlh; - __u16 h_proto; - int i; - - /* Byte-count bounds check; check if current pointer + size of header - * is after data_end. - */ - if (nh->pos + hdrsize > data_end) - return -1; - - nh->pos += hdrsize; - *ethhdr = eth; - vlh = nh->pos; - h_proto = eth->h_proto; - - /* Use loop unrolling to avoid the verifier restriction on loops; - * support up to VLAN_MAX_DEPTH layers of VLAN encapsulation. - */ - #pragma unroll - for (i = 0; i < VLAN_MAX_DEPTH; i++) { - if (!proto_is_vlan(h_proto)) - break; - - if (vlh + 1 > data_end) - break; - - h_proto = vlh->h_vlan_encapsulated_proto; - vlh++; - } - - nh->pos = vlh; - return h_proto; /* network-byte-order */ -} - -static __always_inline int parse_ip6hdr(struct hdr_cursor *nh, - void *data_end, - struct ipv6hdr **ip6hdr) -{ - struct ipv6hdr *ip6h = nh->pos; - - /* Pointer-arithmetic bounds check; pointer +1 points to after end of - * thing being pointed to. We will be using this style in the remainder - * of the tutorial. - */ - if (ip6h + 1 > data_end) - return -1; - - nh->pos = ip6h + 1; - *ip6hdr = ip6h; - - return ip6h->nexthdr; -} - -static __always_inline int parse_iphdr(struct hdr_cursor *nh, - void *data_end, - struct iphdr **iphdr) -{ - struct iphdr *iph = nh->pos; - int hdrsize; - - if (iph + 1 > data_end) - return -1; - - hdrsize = iph->ihl * 4; - - /* Variable-length IPv4 header, need to use byte-based arithmetic */ - if (nh->pos + hdrsize > data_end) - return -1; - - nh->pos += hdrsize; - *iphdr = iph; - - return iph->protocol; -} - -static __always_inline int parse_icmp6hdr(struct hdr_cursor *nh, - void *data_end, - struct icmp6hdr **icmp6hdr) -{ - struct icmp6hdr *icmp6h = nh->pos; - - if (icmp6h + 1 > data_end) - return -1; - - nh->pos = icmp6h + 1; - *icmp6hdr = icmp6h; - - return icmp6h->icmp6_type; -} - -static __always_inline int parse_icmphdr(struct hdr_cursor *nh, - void *data_end, - struct icmphdr **icmphdr) -{ - struct icmphdr *icmph = nh->pos; - - if (icmph + 1 > data_end) - return -1; - - nh->pos = icmph + 1; - *icmphdr = icmph; - - return icmph->type; -} - -static __always_inline int parse_icmphdr_common(struct hdr_cursor *nh, - void *data_end, - struct icmphdr_common **icmphdr) -{ - struct icmphdr_common *h = nh->pos; - - if (h + 1 > data_end) - return -1; - - nh->pos = h + 1; - *icmphdr = h; - - return h->type; -} - -/* - * parse_udphdr: parse the udp header and return the length of the udp payload - */ -static __always_inline int parse_udphdr(struct hdr_cursor *nh, - void *data_end, - struct udphdr **udphdr) -{ - int len; - struct udphdr *h = nh->pos; - - if (h + 1 > data_end) - return -1; - - nh->pos = h + 1; - *udphdr = h; - - len = bpf_ntohs(h->len) - sizeof(struct udphdr); - if (len < 0) - return -1; - - return len; -} - -/* - * parse_tcphdr: parse and return the length of the tcp header - */ -static __always_inline int parse_tcphdr(struct hdr_cursor *nh, - void *data_end, - struct tcphdr **tcphdr) -{ - int len; - struct tcphdr *h = nh->pos; - - if (h + 1 > data_end) - return -1; - - len = h->doff * 4; - if ((void *) h + len > data_end) - return -1; - - nh->pos = h + 1; - *tcphdr = h; - - return len; -} - -#endif /* __PARSING_HELPERS_H */ |