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c22bdd2825
Convert all SEC("classifier*") uses to a new and strict SEC("tc")
section name. In reference_tracking selftests switch from ambiguous
searching by program title (section name) to non-ambiguous searching by
name in some selftests, getting closer to completely removing
bpf_object__find_program_by_title().
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-4-andrii@kernel.org
137 lines
3.2 KiB
C
137 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <stddef.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <linux/bpf.h>
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#include <linux/stddef.h>
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#include <linux/pkt_cls.h>
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#include <linux/if_ether.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_endian.h>
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#ifndef ctx_ptr
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# define ctx_ptr(field) (void *)(long)(field)
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#endif
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#define ip4_src 0xac100164 /* 172.16.1.100 */
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#define ip4_dst 0xac100264 /* 172.16.2.100 */
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#define ip6_src { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
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0x00, 0x01, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe }
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#define ip6_dst { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
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0x00, 0x02, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe }
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#ifndef v6_equal
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# define v6_equal(a, b) (a.s6_addr32[0] == b.s6_addr32[0] && \
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a.s6_addr32[1] == b.s6_addr32[1] && \
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a.s6_addr32[2] == b.s6_addr32[2] && \
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a.s6_addr32[3] == b.s6_addr32[3])
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#endif
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volatile const __u32 IFINDEX_SRC;
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volatile const __u32 IFINDEX_DST;
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static __always_inline bool is_remote_ep_v4(struct __sk_buff *skb,
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__be32 addr)
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{
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void *data_end = ctx_ptr(skb->data_end);
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void *data = ctx_ptr(skb->data);
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struct iphdr *ip4h;
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if (data + sizeof(struct ethhdr) > data_end)
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return false;
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ip4h = (struct iphdr *)(data + sizeof(struct ethhdr));
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if ((void *)(ip4h + 1) > data_end)
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return false;
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return ip4h->daddr == addr;
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}
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static __always_inline bool is_remote_ep_v6(struct __sk_buff *skb,
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struct in6_addr addr)
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{
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void *data_end = ctx_ptr(skb->data_end);
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void *data = ctx_ptr(skb->data);
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struct ipv6hdr *ip6h;
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if (data + sizeof(struct ethhdr) > data_end)
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return false;
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ip6h = (struct ipv6hdr *)(data + sizeof(struct ethhdr));
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if ((void *)(ip6h + 1) > data_end)
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return false;
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return v6_equal(ip6h->daddr, addr);
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}
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SEC("tc")
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int tc_chk(struct __sk_buff *skb)
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{
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void *data_end = ctx_ptr(skb->data_end);
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void *data = ctx_ptr(skb->data);
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__u32 *raw = data;
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if (data + sizeof(struct ethhdr) > data_end)
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return TC_ACT_SHOT;
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return !raw[0] && !raw[1] && !raw[2] ? TC_ACT_SHOT : TC_ACT_OK;
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}
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SEC("tc")
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int tc_dst(struct __sk_buff *skb)
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{
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__u8 zero[ETH_ALEN * 2];
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bool redirect = false;
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switch (skb->protocol) {
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case __bpf_constant_htons(ETH_P_IP):
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redirect = is_remote_ep_v4(skb, __bpf_constant_htonl(ip4_src));
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break;
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case __bpf_constant_htons(ETH_P_IPV6):
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redirect = is_remote_ep_v6(skb, (struct in6_addr)ip6_src);
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break;
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}
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if (!redirect)
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return TC_ACT_OK;
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__builtin_memset(&zero, 0, sizeof(zero));
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if (bpf_skb_store_bytes(skb, 0, &zero, sizeof(zero), 0) < 0)
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return TC_ACT_SHOT;
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return bpf_redirect_neigh(IFINDEX_SRC, NULL, 0, 0);
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}
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SEC("tc")
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int tc_src(struct __sk_buff *skb)
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{
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__u8 zero[ETH_ALEN * 2];
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bool redirect = false;
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switch (skb->protocol) {
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case __bpf_constant_htons(ETH_P_IP):
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redirect = is_remote_ep_v4(skb, __bpf_constant_htonl(ip4_dst));
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break;
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case __bpf_constant_htons(ETH_P_IPV6):
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redirect = is_remote_ep_v6(skb, (struct in6_addr)ip6_dst);
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break;
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}
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if (!redirect)
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return TC_ACT_OK;
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__builtin_memset(&zero, 0, sizeof(zero));
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if (bpf_skb_store_bytes(skb, 0, &zero, sizeof(zero), 0) < 0)
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return TC_ACT_SHOT;
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return bpf_redirect_neigh(IFINDEX_DST, NULL, 0, 0);
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}
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char __license[] SEC("license") = "GPL";
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