mirror of
https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git
synced 2026-01-20 11:20:29 +01:00
bpf: clat: add macros for header sizes
They make the code more compact and readable.
This commit is contained in:
Beniamino Galvani
parent
79f2e3ffe0
commit
67c1c335af
1 changed files with 47 additions and 84 deletions
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@ -78,6 +78,13 @@ struct ip6_frag {
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__u32 identification;
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} __attribute__((packed));
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#define ETH_H_LEN (sizeof(struct ethhdr))
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#define IP_H_LEN (sizeof(struct iphdr))
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#define IP6_H_LEN (sizeof(struct ipv6hdr))
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#define IP6_FRAG_H_LEN (sizeof(struct ip6_frag))
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#define ICMP_H_LEN (sizeof(struct icmphdr))
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#define ICMP6_H_LEN (sizeof(struct icmp6hdr))
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#define ensure_header(header, skb, data, data_end, offset) \
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_ensure_header((void **) header, (skb), (data), (data_end), sizeof(**(header)), (offset))
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@ -129,23 +136,23 @@ update_l4_checksum(struct __sk_buff *skb,
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void *to_ptr = &ip6h->saddr;
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csum = bpf_csum_diff(from_ptr, 2 * sizeof(__u32), to_ptr, 2 * sizeof(struct in6_addr), 0);
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offset = sizeof(struct ethhdr) + sizeof(struct iphdr);
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offset = ETH_H_LEN + IP_H_LEN;
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ip_type = ip6h->nexthdr;
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} else {
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void *from_ptr = &ip6h->saddr;
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void *to_ptr = &iph->saddr;
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csum = bpf_csum_diff(from_ptr, 2 * sizeof(struct in6_addr), to_ptr, 2 * sizeof(__u32), 0);
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offset = sizeof(struct ethhdr) + sizeof(struct ipv6hdr);
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offset = ETH_H_LEN + IP6_H_LEN;
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ip_type = iph->protocol;
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if (is_inner) {
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offset = offset + sizeof(struct icmp6hdr) + sizeof(struct ipv6hdr);
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offset = offset + ICMP6_H_LEN + IP6_H_LEN;
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}
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}
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if (is_v6_fragment) {
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offset += sizeof(struct ip6_frag);
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offset += IP6_FRAG_H_LEN;
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}
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switch (ip_type) {
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@ -203,11 +210,11 @@ update_icmp_checksum(struct __sk_buff *skb,
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seed);
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if (v4to6) {
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offset = sizeof(struct ethhdr) + sizeof(struct iphdr) + 2;
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offset = ETH_H_LEN + IP_H_LEN + 2;
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} else {
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offset = sizeof(struct ethhdr) + sizeof(struct ipv6hdr) + 2;
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offset = ETH_H_LEN + IP6_H_LEN + 2;
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if (is_inner)
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offset += sizeof(struct icmp6hdr) + sizeof(struct ipv6hdr);
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offset += ICMP6_H_LEN + IP6_H_LEN;
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}
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/* first two bytes of ICMP header, type and code */
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@ -236,7 +243,7 @@ rewrite_icmp(struct __sk_buff *skb, const struct ipv6hdr *ip6h)
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struct icmp6hdr *icmp6;
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__u32 mtu;
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if (!ensure_header(&icmp, skb, &data, &data_end, sizeof(struct ethhdr) + sizeof(struct iphdr)))
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if (!ensure_header(&icmp, skb, &data, &data_end, ETH_H_LEN + IP_H_LEN))
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return -1;
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icmp_buf = *icmp;
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@ -524,7 +531,7 @@ clat_handle_v4(struct __sk_buff *skb)
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struct iphdr *iph;
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struct ethhdr *eth;
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if (!ensure_header(&iph, skb, &data, &data_end, sizeof(struct ethhdr)))
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if (!ensure_header(&iph, skb, &data, &data_end, ETH_H_LEN))
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goto out;
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eth = data;
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@ -563,7 +570,7 @@ clat_handle_v4(struct __sk_buff *skb)
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/* weird definition in ipv6hdr */
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dst_hdr.priority = (iph->tos & 0x70) >> 4;
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dst_hdr.flow_lbl[0] = iph->tos << 4;
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dst_hdr.payload_len = bpf_htons(bpf_ntohs(iph->tot_len) - sizeof(struct iphdr));
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dst_hdr.payload_len = bpf_htons(bpf_ntohs(iph->tot_len) - IP_H_LEN);
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DBG("v4: outgoing pkt to dst %pI4 (%pI6c)\n", &iph->daddr, &dst_hdr.daddr);
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@ -587,7 +594,7 @@ clat_handle_v4(struct __sk_buff *skb)
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data = SKB_DATA(skb);
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data_end = SKB_DATA_END(skb);
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if (!ensure_header(&ip6h, skb, &data, &data_end, sizeof(struct ethhdr)))
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if (!ensure_header(&ip6h, skb, &data, &data_end, ETH_H_LEN))
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goto out;
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eth = data;
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@ -632,11 +639,10 @@ translate_ipv6_header(const struct ipv6hdr *ip6, struct iphdr *ip, __be32 saddr,
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.protocol = ip6->nexthdr == IPPROTO_ICMPV6 ? IPPROTO_ICMP : ip6->nexthdr,
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.saddr = saddr,
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.daddr = daddr,
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.tot_len = bpf_htons(bpf_ntohs(ip6->payload_len) + sizeof(struct iphdr)),
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.tot_len = bpf_htons(bpf_ntohs(ip6->payload_len) + IP_H_LEN),
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};
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ip->check =
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csum_fold_helper(bpf_csum_diff((__be32 *) ip, 0, (__be32 *) ip, sizeof(struct iphdr), 0));
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ip->check = csum_fold_helper(bpf_csum_diff((__be32 *) ip, 0, (__be32 *) ip, IP_H_LEN, 0));
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}
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static __always_inline int
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@ -745,12 +751,7 @@ rewrite_icmpv6_inner(struct __sk_buff *skb, __u32 *csum_diff)
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* -------------------------------------------------------------------------
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*/
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if (!ensure_header(&icmp6,
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skb,
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&data,
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&data_end,
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sizeof(struct ethhdr) + 2 * sizeof(struct ipv6hdr)
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+ sizeof(struct icmp6hdr)))
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if (!ensure_header(&icmp6, skb, &data, &data_end, ETH_H_LEN + 2 * IP6_H_LEN + ICMP6_H_LEN))
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return -1;
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icmp6_buf = *icmp6;
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@ -762,7 +763,7 @@ rewrite_icmpv6_inner(struct __sk_buff *skb, __u32 *csum_diff)
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*icmp = icmp_buf;
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update_icmp_checksum(skb,
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(struct ipv6hdr *) (data + sizeof(struct ethhdr)),
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(struct ipv6hdr *) (data + ETH_H_LEN),
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&icmp6_buf,
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icmp,
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false,
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@ -773,22 +774,13 @@ rewrite_icmpv6_inner(struct __sk_buff *skb, __u32 *csum_diff)
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data_end = SKB_DATA_END(skb);
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data = SKB_DATA(skb);
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if (!ensure_header(&icmp,
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skb,
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&data,
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&data_end,
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sizeof(struct ethhdr) + 2 * sizeof(struct ipv6hdr)
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+ sizeof(struct icmp6hdr)))
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if (!ensure_header(&icmp, skb, &data, &data_end, ETH_H_LEN + 2 * IP6_H_LEN + ICMP6_H_LEN))
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return -1;
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/* Compute the checksum difference between the old ICMPv6 header and the new ICMPv4 one */
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*csum_diff = bpf_csum_diff((__be32 *) &icmp6_buf,
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sizeof(struct icmp6hdr),
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(__be32 *) &icmp6_buf,
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0,
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*csum_diff);
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*csum_diff =
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bpf_csum_diff((__be32 *) icmp, 0, (__be32 *) icmp, sizeof(struct icmphdr), *csum_diff);
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bpf_csum_diff((__be32 *) &icmp6_buf, ICMP6_H_LEN, (__be32 *) &icmp6_buf, 0, *csum_diff);
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*csum_diff = bpf_csum_diff((__be32 *) icmp, 0, (__be32 *) icmp, ICMP_H_LEN, *csum_diff);
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}
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return 0;
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}
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@ -809,11 +801,7 @@ rewrite_ipv6_inner(struct __sk_buff *skb, struct iphdr *dst_hdr, __u32 *csum_dif
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* ----------------------------------------------------------------
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*/
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if (!ensure_header(&ip6h,
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skb,
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&data,
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&data_end,
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sizeof(struct ethhdr) + sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr)))
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if (!ensure_header(&ip6h, skb, &data, &data_end, ETH_H_LEN + IP6_H_LEN + ICMP6_H_LEN))
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return -1;
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if (!v6addr_equal(&ip6h->saddr, &config.local_v6))
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@ -827,14 +815,9 @@ rewrite_ipv6_inner(struct __sk_buff *skb, struct iphdr *dst_hdr, __u32 *csum_dif
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if (csum_diff) {
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/* Checksum difference between the old IPv6 header and the new IPv4 one */
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*csum_diff =
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bpf_csum_diff((__be32 *) ip6h, sizeof(struct ipv6hdr), (__be32 *) ip6h, 0, *csum_diff);
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*csum_diff = bpf_csum_diff((__be32 *) ip6h, IP6_H_LEN, (__be32 *) ip6h, 0, *csum_diff);
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*csum_diff = bpf_csum_diff((__be32 *) dst_hdr,
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0,
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(__be32 *) dst_hdr,
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sizeof(struct iphdr),
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*csum_diff);
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*csum_diff = bpf_csum_diff((__be32 *) dst_hdr, 0, (__be32 *) dst_hdr, IP_H_LEN, *csum_diff);
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}
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switch (dst_hdr->protocol) {
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@ -873,11 +856,7 @@ rewrite_icmpv6(struct __sk_buff *skb, int *out_length_diff)
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* ---------------------------------------------
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*/
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if (!ensure_header(&icmp6,
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skb,
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&data,
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&data_end,
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sizeof(struct ethhdr) + sizeof(struct ipv6hdr)))
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if (!ensure_header(&icmp6, skb, &data, &data_end, ETH_H_LEN + IP6_H_LEN))
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return -1;
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icmp6_buf = *icmp6;
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@ -891,7 +870,7 @@ rewrite_icmpv6(struct __sk_buff *skb, int *out_length_diff)
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/* ICMPv6 non-error message: only translate the header */
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*icmp = icmp_buf;
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update_icmp_checksum(skb,
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(struct ipv6hdr *) (data + sizeof(struct ethhdr)),
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(struct ipv6hdr *) (data + ETH_H_LEN),
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&icmp6_buf,
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icmp,
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false,
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@ -914,25 +893,18 @@ rewrite_icmpv6(struct __sk_buff *skb, int *out_length_diff)
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* to remove the bytes just after the L3 header, and rewrite the ICMP and the inner
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* IP headers.
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*/
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if (bpf_skb_adjust_room(skb,
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(int) sizeof(struct iphdr) - (int) sizeof(struct ipv6hdr),
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BPF_ADJ_ROOM_NET,
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0))
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if (bpf_skb_adjust_room(skb, (int) IP_H_LEN - (int) IP6_H_LEN, BPF_ADJ_ROOM_NET, 0))
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return -1;
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*out_length_diff = (int) sizeof(struct iphdr) - (int) sizeof(struct ipv6hdr);
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*out_length_diff = (int) IP_H_LEN - (int) IP6_H_LEN;
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data_end = SKB_DATA_END(skb);
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data = SKB_DATA(skb);
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if (!ensure_header(&ip,
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skb,
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&data,
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&data_end,
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sizeof(struct ethhdr) + sizeof(struct ipv6hdr) + sizeof(struct icmphdr)))
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if (!ensure_header(&ip, skb, &data, &data_end, ETH_H_LEN + IP6_H_LEN + ICMP_H_LEN))
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return -1;
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icmp = data + sizeof(struct ethhdr) + sizeof(struct ipv6hdr);
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icmp = data + ETH_H_LEN + IP6_H_LEN;
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/* Rewrite the ICMPv6 header with the translated ICMPv4 one */
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*icmp = icmp_buf;
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@ -941,7 +913,7 @@ rewrite_icmpv6(struct __sk_buff *skb, int *out_length_diff)
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/* Update the ICMPv4 checksum according to all the changes in headers */
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update_icmp_checksum(skb,
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(struct ipv6hdr *) (data + sizeof(struct ethhdr)),
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(struct ipv6hdr *) (data + ETH_H_LEN),
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&icmp6_buf,
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icmp,
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false,
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@ -967,7 +939,7 @@ clat_handle_v6(struct __sk_buff *skb)
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int length_diff = 0;
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bool fragmented = false;
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if (!ensure_header(&ip6h, skb, &data, &data_end, sizeof(struct ethhdr)))
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if (!ensure_header(&ip6h, skb, &data, &data_end, ETH_H_LEN))
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goto out;
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eth = data;
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@ -993,14 +965,10 @@ clat_handle_v6(struct __sk_buff *skb)
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if (ip6h->nexthdr != IPPROTO_ICMPV6)
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goto out;
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if (!ensure_header(&icmp6,
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skb,
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&data,
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&data_end,
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sizeof(struct ethhdr) + sizeof(struct ipv6hdr)))
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if (!ensure_header(&icmp6, skb, &data, &data_end, ETH_H_LEN + IP6_H_LEN))
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goto out;
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ip6h = data + sizeof(struct ethhdr);
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ip6h = data + ETH_H_LEN;
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if (icmp6->icmp6_type != ICMPV6_DEST_UNREACH && icmp6->icmp6_type != ICMPV6_TIME_EXCEED
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&& icmp6->icmp6_type != ICMPV6_PKT_TOOBIG)
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@ -1027,18 +995,14 @@ clat_handle_v6(struct __sk_buff *skb)
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int tot_len;
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__u16 offset;
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if (!ensure_header(&frag,
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skb,
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&data,
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&data_end,
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sizeof(struct ethhdr) + sizeof(struct ipv6hdr)))
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if (!ensure_header(&frag, skb, &data, &data_end, ETH_H_LEN + IP6_H_LEN))
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goto out;
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ip6h = data + sizeof(struct ethhdr);
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ip6h = data + ETH_H_LEN;
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/* Translate into an IPv4 fragmented packet, RFC 6145 5.1.1 */
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tot_len = bpf_ntohs(ip6h->payload_len) + sizeof(struct iphdr) - sizeof(struct ip6_frag);
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tot_len = bpf_ntohs(ip6h->payload_len) + IP_H_LEN - IP6_FRAG_H_LEN;
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offset = bpf_ntohs(frag->offset);
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offset = ((offset & 1) << 13) | /* More Fragments flag */
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@ -1058,7 +1022,7 @@ clat_handle_v6(struct __sk_buff *skb)
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};
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dst_hdr.check = csum_fold_helper(
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bpf_csum_diff((__be32 *) &dst_hdr, 0, (__be32 *) &dst_hdr, sizeof(struct iphdr), 0));
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bpf_csum_diff((__be32 *) &dst_hdr, 0, (__be32 *) &dst_hdr, IP_H_LEN, 0));
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fragmented = true;
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@ -1103,15 +1067,14 @@ clat_handle_v6(struct __sk_buff *skb)
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data = SKB_DATA(skb);
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data_end = SKB_DATA_END(skb);
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if (!ensure_header(&ip6h, skb, &data, &data_end, sizeof(struct ethhdr)))
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if (!ensure_header(&ip6h, skb, &data, &data_end, ETH_H_LEN))
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goto out;
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dst_hdr.tot_len =
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bpf_htons(bpf_ntohs(ip6h->payload_len) + length_diff + sizeof(struct iphdr));
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dst_hdr.tot_len = bpf_htons(bpf_ntohs(ip6h->payload_len) + length_diff + IP_H_LEN);
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dst_hdr.check = 0;
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dst_hdr.check = csum_fold_helper(
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bpf_csum_diff((__be32 *) &dst_hdr, 0, (__be32 *) &dst_hdr, sizeof(struct iphdr), 0));
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bpf_csum_diff((__be32 *) &dst_hdr, 0, (__be32 *) &dst_hdr, IP_H_LEN, 0));
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}
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if (bpf_skb_change_proto(skb, bpf_htons(ETH_P_IP), 0))
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@ -1119,14 +1082,14 @@ clat_handle_v6(struct __sk_buff *skb)
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if (fragmented) {
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/* Remove the IPv6 fragment header */
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if (bpf_skb_adjust_room(skb, -(__s32) sizeof(struct ip6_frag), BPF_ADJ_ROOM_NET, 0))
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if (bpf_skb_adjust_room(skb, -(__s32) IP6_FRAG_H_LEN, BPF_ADJ_ROOM_NET, 0))
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goto out;
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}
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data = SKB_DATA(skb);
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data_end = SKB_DATA_END(skb);
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if (!ensure_header(&iph, skb, &data, &data_end, sizeof(struct ethhdr)))
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if (!ensure_header(&iph, skb, &data, &data_end, ETH_H_LEN))
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goto out;
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eth = data;
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