xdp-geoip: XDP GeoIP location blocklist

XDP GeoIP location blocklist to block IP
from user configured Geo location

Signed-off-by: Vincent Li <[email protected]>

Makefile

@@ -19,7 +19,7 @@ include config.mk
 UTILS := xdp-filter xdp-loader xdp-dump
 
 ifneq ($(BPFTOOL),)
-UTILS += xdp-bench xdp-monitor xdp-trafficgen xdp-synproxy xdp-dnsrrl xdp-udp xdp-dns xdp-sni
+UTILS += xdp-bench xdp-monitor xdp-trafficgen xdp-synproxy xdp-dnsrrl xdp-udp xdp-dns xdp-sni xdp-geoip
 endif
 
 SUBDIRS := lib $(UTILS)

xdp-geoip/Makefile

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+
+XDP_TARGETS := xdp_geoip.bpf
+BPF_SKEL_TARGETS := $(XDP_TARGETS)
+USER_TARGETS := xdp_geoip
+
+LIB_DIR = ../lib
+
+include $(LIB_DIR)/common.mk

xdp-geoip/xdp_geoip.bpf.c

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2024, BPFire.  All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "vmlinux_local.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
+#include <linux/tcp.h>
+#include <linux/in.h>
+
+struct ipv4_lpm_key {
+    __u32 prefixlen;
+    __u32 saddr;
+};
+
+struct {
+    __uint(type, BPF_MAP_TYPE_LPM_TRIE);
+    __uint(max_entries, 1000000);
+    __uint(pinning, LIBBPF_PIN_BY_NAME);
+    __uint(map_flags, BPF_F_NO_PREALLOC);
+    __type(key, struct ipv4_lpm_key);
+    __type(value, __u8);
+} geoip_map SEC(".maps");
+
+SEC("xdp")
+int xdp_geoip(struct xdp_md *ctx) {
+    void *data_end = (void *)(long)ctx->data_end;
+    void *data = (void *)(long)ctx->data;
+    struct ethhdr *eth = data;
+    struct iphdr *iph;
+
+    if ((void *)(eth + 1) > data_end)
+        return XDP_PASS;
+
+    if (eth->h_proto != __constant_htons(ETH_P_IP))
+        return XDP_PASS;
+
+    iph = (struct iphdr *)(eth + 1);
+    if ((void *)(iph + 1) > data_end)
+        return XDP_PASS;
+
+    struct ipv4_lpm_key key = {
+        .prefixlen = 32,
+        .saddr = iph->saddr,
+    };
+
+    __u8 *action = bpf_map_lookup_elem(&geoip_map, &key);
+    if (action && *action == 1) {
+        return XDP_DROP;
+    }
+
+    return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
+

xdp-geoip/xdp_geoip.c

@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2024, BPFire.  All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#define MAP_PATH "/sys/fs/bpf/xdp-geoip/geoip_map"
+#define BATCH_SIZE 1000  // Number of entries per batch
+
+struct ipv4_lpm_key {
+    __u32 prefixlen;
+    __u32 saddr;
+};
+
+// Structure for country code and action
+struct ip_entry {
+    struct ipv4_lpm_key key;
+    __u8 action;
+};
+
+void add_ips_batch(int map_fd, struct ip_entry *entries, size_t count) {
+    struct ipv4_lpm_key keys[BATCH_SIZE];
+    __u8 actions[BATCH_SIZE];
+    for (size_t i = 0; i < count; i++) {
+        keys[i] = entries[i].key;
+        actions[i] = entries[i].action;
+    }
+
+    __u32 num_entries = count;
+    int ret = bpf_map_update_batch(map_fd, keys, actions, &num_entries, NULL);
+    if (ret) {
+        fprintf(stderr, "Batch update failed: %s\n", strerror(errno));
+    } else {
+        printf("Batch update successful\n");
+    }
+}
+
+int main(int argc, char **argv) {
+    if (argc < 3) {
+        printf("Usage: %s <ip_file.txt> <country_code>\n", argv[0]);
+        return 1;
+    }
+
+    char *enabled_country = argv[2];  // Country code provided from web interface
+
+    // Open the BPF map
+    int map_fd = bpf_obj_get(MAP_PATH);
+    if (map_fd < 0) {
+        perror("bpf_obj_get");
+        return 1;
+    }
+
+    FILE *file = fopen(argv[1], "r");
+    if (!file) {
+        perror("fopen");
+        return 1;
+    }
+
+    struct ip_entry entries[BATCH_SIZE];
+    size_t count = 0;
+
+    char line[256];
+    while (fgets(line, sizeof(line), file)) {
+        // Look for lines that start with "add" and a two-letter country code
+        if (strncmp(line, "add ", 4) == 0) {
+            char *country_code = strtok(line + 4, "v");  // Extract the country code
+            strtok(NULL, " ");  // Skip the next token ("hash")
+            char *ip_str = strtok(NULL, " /");  // Extract the IP address
+            char *prefix_str = strtok(NULL, " ");  // Extract the prefix length
+
+            // If country code matches the enabled country, add the IP
+            if (country_code && strcmp(country_code, enabled_country) == 0) {
+                if (ip_str && prefix_str) {
+                    entries[count].key.prefixlen = atoi(prefix_str);
+                    inet_pton(AF_INET, ip_str, &entries[count].key.saddr);
+
+                    // Assuming we block IPs from enabled country
+                    entries[count].action = 1;  // Block
+
+                    count++;
+
+                    if (count == BATCH_SIZE) {
+                        add_ips_batch(map_fd, entries, count);
+                        count = 0;
+                    }
+                }
+            }
+        }
+    }
+
+    // Process any remaining IPs
+    if (count > 0) {
+        add_ips_batch(map_fd, entries, count);
+    }
+
+    fclose(file);
+    close(map_fd);
+    return 0;
+}
+