sendnrw/netbird
2
0
Fork 0
mirror of https://github.com/netbirdio/netbird.git synced 2026-09-19 05:09:06 +02:00
Code Issues Packages Projects Releases Wiki Activity

Fix map reading

Browse Source
This commit is contained in:
Zoltan Papp
2023-08-01 12:15:45 +02:00
parent 9a418e8dbf
commit b5affa1b12
6 changed files with 32 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files
client/internal/dns/forwarder/src/port_fwd.c
+25 -14
View File
@@ -15,6 +15,13 @@
const __u32 map_key_dns_ip = 0;
const __u32 map_key_dns_port = 1;
struct bpf_map_def SEC("maps") xdp_ip_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(__u32),
.max_entries = 10,
};
struct bpf_map_def SEC("maps") xdp_port_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
@@ -25,32 +32,37 @@ struct bpf_map_def SEC("maps") xdp_port_map = {
__be32 dns_ip = 0;
__be16 dns_port = 0;
bool read_port_settings() {
__u16 *value;
__be32 *ip_value;
value = bpf_map_lookup_elem(&xdp_port_map, &map_key_dns_port);
if(!value) {
return false;
}
// 13568 is 53 in big endian
__be16 GENERAL_DNS_PORT = 13568;
dns_port = htons(*value);
bool read_settings() {
__u16 *port_value;
__u32 *ip_value;
ip_value = bpf_map_lookup_elem(&xdp_port_map, &map_key_dns_ip);
// read dns ip
ip_value = bpf_map_lookup_elem(&xdp_ip_map, &map_key_dns_ip);
if(!ip_value) {
return false;
}
dns_ip = htonl(*ip_value);
// read dns port
port_value = bpf_map_lookup_elem(&xdp_port_map, &map_key_dns_port);
if(!port_value) {
return false;
}
dns_port = htons(*port_value);
return true;
}
SEC("xdp")
int xdp_dns_port_fwd(struct xdp_md *ctx) {
if(dns_port == 0) {
if(!read_port_settings()){
if(!read_settings()){
return XDP_PASS;
}
bpf_printk("dns port: %d", dns_port);
bpf_printk("dns ip: %d", dns_ip);
bpf_printk("dns port: %d", ntohs(dns_port));
bpf_printk("dns ip: %d", ntohl(dns_ip));
}
void *data = (void *)(long)ctx->data;
@@ -73,13 +85,12 @@ int xdp_dns_port_fwd(struct xdp_md *ctx) {
return XDP_PASS;
}
// 2130706433 = 127.0.0.1
if (ip->daddr != dns_ip) {
return XDP_PASS;
}
// skip non dns ports
if (udp->source != htons(53)){
if (udp->dest != GENERAL_DNS_PORT){
return XDP_PASS;
}