598 lines
15 KiB
C
598 lines
15 KiB
C
#include <linux/if_ether.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/udp.h>
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#include <linux/tcp.h>
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#include <linux/icmp.h>
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#include <linux/icmpv6.h>
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#include <linux/in.h>
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#include <stdatomic.h>
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#include <common/all.h>
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#include <xdp/utils/rl.h>
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#include <xdp/utils/logging.h>
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#include <xdp/utils/helpers.h>
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#include <xdp/utils/maps.h>
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struct
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{
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__uint(priority, 10);
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__uint(XDP_PASS, 1);
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} XDP_RUN_CONFIG(xdp_prog_main);
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SEC("xdp_prog")
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int xdp_prog_main(struct xdp_md *ctx)
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{
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// Initialize data.
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void *data_end = (void *)(long)ctx->data_end;
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void *data = (void *)(long)ctx->data;
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// Scan ethernet header.
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struct ethhdr *eth = data;
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// Check if the ethernet header is valid.
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if (unlikely(eth + 1 > (struct ethhdr *)data_end))
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{
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return XDP_DROP;
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}
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// Check Ethernet protocol.
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if (unlikely(eth->h_proto != htons(ETH_P_IP) && eth->h_proto != htons(ETH_P_IPV6)))
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{
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return XDP_PASS;
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}
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u8 action = 0;
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u64 blocktime = 1;
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// Initialize IP headers.
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struct iphdr *iph = NULL;
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struct ipv6hdr *iph6 = NULL;
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u128 src_ip6 = 0;
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// Set IPv4 and IPv6 common variables.
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if (eth->h_proto == htons(ETH_P_IPV6))
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{
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iph6 = data + sizeof(struct ethhdr);
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if (unlikely(iph6 + 1 > (struct ipv6hdr *)data_end))
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{
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return XDP_DROP;
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}
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memcpy(&src_ip6, &iph6->saddr.in6_u.u6_addr32, sizeof(src_ip6));
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}
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else
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{
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iph = data + sizeof(struct ethhdr);
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if (unlikely(iph + 1 > (struct iphdr *)data_end))
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{
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return XDP_DROP;
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}
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}
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// Check IP header protocols.
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if ((iph6 && iph6->nexthdr != IPPROTO_UDP && iph6->nexthdr != IPPROTO_TCP && iph6->nexthdr != IPPROTO_ICMP) && (iph && iph->protocol != IPPROTO_UDP && iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_ICMP))
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{
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return XDP_PASS;
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}
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// Get stats map.
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u32 key = 0;
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stats_t*stats = bpf_map_lookup_elem(&stats_map, &key);
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u64 now = bpf_ktime_get_ns();
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// Check blacklist map.
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u64 *blocked = NULL;
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if (iph6)
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{
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blocked = bpf_map_lookup_elem(&ip6_blacklist_map, &src_ip6);
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}
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else if (iph)
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{
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blocked = bpf_map_lookup_elem(&ip_blacklist_map, &iph->saddr);
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}
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if (blocked != NULL && *blocked > 0)
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{
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if (now > *blocked)
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{
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// Remove element from map.
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if (iph6)
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{
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bpf_map_delete_elem(&ip6_blacklist_map, &src_ip6);
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}
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else if (iph)
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{
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bpf_map_delete_elem(&ip_blacklist_map, &iph->saddr);
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}
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}
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else
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{
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#ifdef DO_STATS_ON_BLOCK_MAP
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// Increase blocked stats entry.
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if (stats)
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{
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stats->dropped++;
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}
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#endif
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// They're still blocked. Drop the packet.
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return XDP_DROP;
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}
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}
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// Retrieve total packet length.
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u16 pkt_len = data_end - data;
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// Parse layer-4 headers and determine source port and protocol.
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struct tcphdr *tcph = NULL;
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struct udphdr *udph = NULL;
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struct icmphdr *icmph = NULL;
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struct icmp6hdr *icmp6h = NULL;
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u16 src_port = 0;
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#ifdef ENABLE_FILTER_LOGGING
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u16 dst_port = 0;
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#endif
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u8 protocol = 0;
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if (iph6)
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{
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protocol = iph6->nexthdr;
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switch (iph6->nexthdr)
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{
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case IPPROTO_TCP:
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// Scan TCP header.
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tcph = data + sizeof(struct ethhdr) + sizeof(struct ipv6hdr);
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// Check TCP header.
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if (unlikely(tcph + 1 > (struct tcphdr *)data_end))
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{
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return XDP_DROP;
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}
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src_port = tcph->source;
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#ifdef ENABLE_FILTER_LOGGING
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dst_port = tcph->dest;
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#endif
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break;
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case IPPROTO_UDP:
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// Scan UDP header.
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udph = data + sizeof(struct ethhdr) + sizeof(struct ipv6hdr);
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// Check TCP header.
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if (unlikely(udph + 1 > (struct udphdr *)data_end))
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{
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return XDP_DROP;
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}
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src_port = udph->source;
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#ifdef ENABLE_FILTER_LOGGING
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dst_port = udph->dest;
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#endif
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break;
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case IPPROTO_ICMPV6:
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// Scan ICMPv6 header.
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icmp6h = data + sizeof(struct ethhdr) + sizeof(struct ipv6hdr);
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// Check ICMPv6 header.
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if (unlikely(icmp6h + 1 > (struct icmp6hdr *)data_end))
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{
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return XDP_DROP;
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}
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break;
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}
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}
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else if (iph)
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{
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protocol = iph->protocol;
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switch (iph->protocol)
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{
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case IPPROTO_TCP:
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// Scan TCP header.
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tcph = data + sizeof(struct ethhdr) + (iph->ihl * 4);
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// Check TCP header.
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if (unlikely(tcph + 1 > (struct tcphdr *)data_end))
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{
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return XDP_DROP;
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}
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src_port = tcph->source;
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#ifdef ENABLE_FILTER_LOGGING
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dst_port = tcph->dest;
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#endif
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break;
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case IPPROTO_UDP:
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// Scan UDP header.
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udph = data + sizeof(struct ethhdr) + (iph->ihl * 4);
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// Check TCP header.
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if (unlikely(udph + 1 > (struct udphdr *)data_end))
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{
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return XDP_DROP;
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}
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src_port = udph->source;
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#ifdef ENABLE_FILTER_LOGGING
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dst_port = udph->dest;
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#endif
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break;
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case IPPROTO_ICMP:
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// Scan ICMP header.
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icmph = data + sizeof(struct ethhdr) + (iph->ihl * 4);
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// Check ICMP header.
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if (unlikely(icmph + 1 > (struct icmphdr *)data_end))
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{
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return XDP_DROP;
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}
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break;
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}
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}
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// Update client stats (PPS/BPS).
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u64 pps = 0;
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u64 bps = 0;
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if (iph6)
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{
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UpdateIp6Stats(&pps, &bps, &src_ip6, src_port, protocol, pkt_len, now);
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}
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else if (iph)
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{
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UpdateIpStats(&pps, &bps, iph->saddr, src_port, protocol, pkt_len, now);
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}
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for (int i = 0; i < MAX_FILTERS; i++)
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{
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u32 key = i;
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filter_t *filter = bpf_map_lookup_elem(&filters_map, &key);
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// Check if ID is above 0 (if 0, it's an invalid rule).
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if (!filter || filter->id < 1)
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{
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break;
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}
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// Check if the rule is enabled.
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if (!filter->enabled)
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{
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continue;
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}
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// Do specific IPv6.
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if (iph6)
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{
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// Source address.
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if (filter->src_ip6[0] != 0 && (iph6->saddr.in6_u.u6_addr32[0] != filter->src_ip6[0] || iph6->saddr.in6_u.u6_addr32[1] != filter->src_ip6[1] || iph6->saddr.in6_u.u6_addr32[2] != filter->src_ip6[2] || iph6->saddr.in6_u.u6_addr32[3] != filter->src_ip6[3]))
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{
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continue;
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}
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// Destination address.
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if (filter->dst_ip6[0] != 0 && (iph6->daddr.in6_u.u6_addr32[0] != filter->dst_ip6[0] || iph6->daddr.in6_u.u6_addr32[1] != filter->dst_ip6[1] || iph6->daddr.in6_u.u6_addr32[2] != filter->dst_ip6[2] || iph6->daddr.in6_u.u6_addr32[3] != filter->dst_ip6[3]))
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{
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continue;
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}
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#ifdef ALLOW_SINGLE_IP_V4_V6
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if (filter->src_ip != 0 || filter->dst_ip != 0)
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{
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continue;
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}
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#endif
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// Max TTL length.
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if (filter->do_max_ttl && filter->max_ttl > iph6->hop_limit)
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{
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continue;
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}
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// Min TTL length.
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if (filter->do_min_ttl && filter->min_ttl < iph6->hop_limit)
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{
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continue;
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}
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// Max packet length.
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if (filter->do_max_len && filter->max_len > (ntohs(iph6->payload_len) + sizeof(struct ethhdr)))
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{
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continue;
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}
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// Min packet length.
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if (filter->do_min_len && filter->min_len < (ntohs(iph6->payload_len) + sizeof(struct ethhdr)))
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{
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continue;
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}
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}
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else if (iph)
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{
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// Source address.
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if (filter->src_ip)
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{
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if (filter->src_cidr == 32 && iph->saddr != filter->src_ip)
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{
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continue;
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}
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if (!IsIpInRange(iph->saddr, filter->src_ip, filter->src_cidr))
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{
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continue;
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}
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}
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// Destination address.
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if (filter->dst_ip)
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{
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if (filter->dst_cidr == 32 && iph->daddr != filter->dst_ip)
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{
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continue;
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}
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if (!IsIpInRange(iph->daddr, filter->dst_ip, filter->dst_cidr))
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{
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continue;
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}
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}
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#ifdef ALLOW_SINGLE_IP_V4_V6
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if ((filter->src_ip6[0] != 0 || filter->src_ip6[1] != 0 || filter->src_ip6[2] != 0 || filter->src_ip6[3] != 0) || (filter->dst_ip6[0] != 0 || filter->dst_ip6[1] != 0 || filter->dst_ip6[2] != 0 || filter->dst_ip6[3] != 0))
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{
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continue;
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}
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#endif
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// TOS.
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if (filter->do_tos && filter->tos != iph->tos)
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{
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continue;
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}
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// Max TTL length.
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if (filter->do_max_ttl && filter->max_ttl < iph->ttl)
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{
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continue;
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}
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// Min TTL length.
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if (filter->do_min_ttl && filter->min_ttl > iph->ttl)
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{
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continue;
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}
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// Max packet length.
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if (filter->do_max_len && filter->max_len < (ntohs(iph->tot_len) + sizeof(struct ethhdr)))
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{
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continue;
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}
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// Min packet length.
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if (filter->do_min_len && filter->min_len > (ntohs(iph->tot_len) + sizeof(struct ethhdr)))
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{
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continue;
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}
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}
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// PPS.
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if (filter->do_pps && pps < filter->pps)
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{
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continue;
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}
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// BPS.
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if (filter->do_bps && bps < filter->bps)
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{
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continue;
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}
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// Do TCP options.
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if (filter->tcpopts.enabled)
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{
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if (!tcph)
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{
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continue;
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}
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// Source port.
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if (filter->tcpopts.do_sport && htons(filter->tcpopts.sport) != tcph->source)
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{
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continue;
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}
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// Destination port.
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if (filter->tcpopts.do_dport && htons(filter->tcpopts.dport) != tcph->dest)
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{
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continue;
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}
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// URG flag.
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if (filter->tcpopts.do_urg && filter->tcpopts.urg != tcph->urg)
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{
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continue;
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}
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// ACK flag.
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if (filter->tcpopts.do_ack && filter->tcpopts.ack != tcph->ack)
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{
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continue;
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}
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// RST flag.
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if (filter->tcpopts.do_rst && filter->tcpopts.rst != tcph->rst)
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{
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continue;
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}
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// PSH flag.
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if (filter->tcpopts.do_psh && filter->tcpopts.psh != tcph->psh)
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{
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continue;
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}
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// SYN flag.
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if (filter->tcpopts.do_syn && filter->tcpopts.syn != tcph->syn)
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{
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continue;
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}
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// FIN flag.
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if (filter->tcpopts.do_fin && filter->tcpopts.fin != tcph->fin)
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{
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continue;
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}
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// ECE flag.
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if (filter->tcpopts.do_ece && filter->tcpopts.ece != tcph->ece)
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{
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continue;
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}
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// CWR flag.
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if (filter->tcpopts.do_cwr && filter->tcpopts.cwr != tcph->cwr)
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{
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continue;
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}
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}
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else if (filter->udpopts.enabled)
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{
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if (!udph)
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{
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continue;
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}
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// Source port.
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if (filter->udpopts.do_sport && htons(filter->udpopts.sport) != udph->source)
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{
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continue;
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}
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// Destination port.
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if (filter->udpopts.do_dport && htons(filter->udpopts.dport) != udph->dest)
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{
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continue;
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}
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}
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else if (filter->icmpopts.enabled)
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{
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if (icmph)
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{
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// Code.
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if (filter->icmpopts.do_code && filter->icmpopts.code != icmph->code)
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{
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continue;
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}
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// Type.
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if (filter->icmpopts.do_type && filter->icmpopts.type != icmph->type)
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{
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continue;
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}
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}
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else if (icmp6h)
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{
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// Code.
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if (filter->icmpopts.do_code && filter->icmpopts.code != icmp6h->icmp6_code)
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{
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continue;
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}
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// Type.
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if (filter->icmpopts.do_type && filter->icmpopts.type != icmp6h->icmp6_type)
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{
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continue;
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}
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}
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else
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{
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continue;
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}
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}
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#ifdef ENABLE_FILTER_LOGGING
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if (filter->log > 0)
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{
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LogFilterMsg(iph, iph6, src_port, dst_port, protocol, now, pps, bps, i);
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}
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#endif
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// Matched.
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action = filter->action;
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blocktime = filter->blocktime;
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goto matched;
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}
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if (stats)
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{
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stats->passed++;
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}
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return XDP_PASS;
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matched:
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if (action == 0)
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{
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// Before dropping, update the blacklist map.
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if (blocktime > 0)
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{
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u64 newTime = now + (blocktime * NANO_TO_SEC);
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if (iph6)
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{
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bpf_map_update_elem(&ip6_blacklist_map, &src_ip6, &newTime, BPF_ANY);
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}
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else if (iph)
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{
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bpf_map_update_elem(&ip_blacklist_map, &iph->saddr, &newTime, BPF_ANY);
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}
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}
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if (stats)
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{
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stats->dropped++;
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}
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return XDP_DROP;
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}
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else
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{
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|
if (stats)
|
|
{
|
|
stats->allowed++;
|
|
}
|
|
}
|
|
|
|
return XDP_PASS;
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|
|
|
|
__uint(xsk_prog_version, XDP_DISPATCHER_VERSION) SEC(XDP_METADATA_SECTION); |