move diverter fns into their own module

programs/ziti-edge-tunnel/CMakeLists.txt

@@ -42,6 +42,9 @@ if (WIN32)
             windows/log_utils.c
             include/service-utils.h)
 endif ()
+if (LINUX)
+    set(ZITI_INSTANCE_OS linux/diverter.c include/linux/diverter.h)
+endif ()
 
 add_executable(ziti-edge-tunnel ziti-edge-tunnel.c ${NETIF_DRIVER_SOURCE} ${ZITI_INSTANCE_COMMON} ${ZITI_INSTANCE_OS})
 set_property(TARGET ziti-edge-tunnel PROPERTY C_STANDARD 11)

programs/ziti-edge-tunnel/include/linux/diverter.h

@@ -0,0 +1,32 @@
+/*
+ Copyright 2025 NetFoundry Inc.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ https://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+// support interactions with zfw command line utility
+
+#include <stdint.h>
+#include "model/dtos.h"
+
+extern char *diverter_if;
+extern bool diverter;
+extern bool firewall;
+
+void diverter_init(uint32_t dns_prefix, uint32_t dns_prefix_len, const char *tun_name);
+void diverter_quit();
+void init_diverter_interface(const char *interface, const char *direction);
+void diverter_add_svc(const tunnel_service *svc);
+void diverter_remove_svc(const tunnel_service *svc);
+void set_diverter(uint32_t dns_prefix, unsigned char dns_prefix_len, const char *tun_name);
+void diverter_cleanup();

programs/ziti-edge-tunnel/linux/diverter.c

@@ -0,0 +1,264 @@
+/*
+ Copyright NetFoundry Inc.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ https://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <net/if.h>
+
+#include <uv.h>
+
+#include "ziti/ziti_log.h"
+#include "linux/diverter.h"
+#include "../netif_driver/linux/utils.h"
+
+char check_alt[IF_NAMESIZE];
+char *diverter_path = "/opt/openziti/bin";
+char zfw_path[PATH_MAX];
+char *tc_ingress_object = "zfw_tc_ingress.o";
+char *tc_egress_object = "zfw_tc_outbound_track.o";
+char *xdp_ingress_object = "zfw_xdp_tun_ingress.o";
+
+char *diverter_if = NULL;
+bool diverter = false;
+bool firewall = false;
+
+void diverter_init(uint32_t dns_prefix, uint32_t dns_prefix_len, const char *tun_name) {
+    if(!diverter && !firewall){
+        diverter_if = getenv("ZITI_DIVERTER");
+        if(diverter_if && strlen(diverter_if)){
+            diverter = true;
+        }
+        char *zifi_firewall = getenv("ZITI_FIREWALL");
+        if(zifi_firewall && strlen(zifi_firewall)){
+            diverter = true;
+            firewall = true;
+            diverter_if = getenv("ZITI_FIREWALL");
+        }
+    }
+    char *diverter_env_path = getenv("ZFW_OBJECT_PATH");
+    if(diverter_env_path && strlen(diverter_env_path)){
+        diverter_path = diverter_env_path;
+        snprintf(zfw_path, sizeof(zfw_path), "%s/%s", diverter_env_path, "zfw");
+    }else{
+        snprintf(zfw_path, sizeof(zfw_path), "%s/%s", diverter_path, "zfw");
+    }
+    if(diverter && tun_name){
+        if(!firewall){
+            diverter_quit();
+        }
+        if (is_executable(zfw_path)){
+            int count = 0;
+            char *interface = strtok(diverter_if,",");
+            while(interface != NULL){
+                uint32_t idx = if_nametoindex(interface);
+                if (!idx)
+                {
+                    ZITI_LOG(WARN,"Diverter interface not found: %s", interface);
+                    interface = strtok(NULL,",");
+                    continue;
+                }
+                if(if_indextoname(idx, check_alt)){
+                    interface = check_alt;
+                }
+                init_diverter_interface(interface, "ingress");
+                init_diverter_interface(interface, "egress");
+                interface = strtok(NULL,",");
+                count++;
+            }
+            if(count){
+                set_diverter(dns_prefix, dns_prefix_len, tun_name);
+            }else{
+                ZITI_LOG(ERROR,"No valid diverter interfaces found");
+                exit(1);
+            }
+        }else{
+            ZITI_LOG(ERROR, "Diverter binary not found");
+            exit(1);
+        }
+    }
+}
+
+static void diverter_update(const char *ip, uint8_t prefix_len, uint16_t lowport, uint16_t highport, const char *protocol, const char *service_id, const char *action) {
+    int rndm;
+    uv_random(NULL, NULL, &rndm, sizeof(rndm), 0, NULL);
+    unsigned short random_port = 1024 + rndm % (65535 - 1023);
+    // called while uv loop is running, so queue the command to prevent i/o stalls
+    queue_command("%s %s -c %s -m %d -l %d -h %d -t %d -p %s -s %s", zfw_path, action, ip, prefix_len, lowport, highport, random_port, protocol, service_id);
+}
+
+void diverter_quit() {
+    run_command("%s -Q", zfw_path);
+}
+
+void init_diverter_interface(const char *interface, const char *direction) {
+    // run_command is ok here because the uv loop is not yet running when this is called
+    const char *obj = (strcmp(direction, "ingress") == 0 ? tc_ingress_object : tc_egress_object);
+    int ec = run_command("%s -X %s -O %s/%s -z %s", zfw_path, interface, diverter_path, obj, direction);
+    if (ec != 0) {
+        ZITI_LOG(WARN, "zfw -X failed");
+        return;
+    }
+
+    // set tun mode
+    ec = run_command("%s -T %s", zfw_path, interface);
+    if (ec != 0) {
+        ZITI_LOG(WARN, "zfw -T failed");
+        return;
+    }
+
+    // enable ipv6
+    ec = run_command("%s -6 %s", zfw_path, interface);
+    if (ec != 0) {
+        ZITI_LOG(WARN, "zfw -6 failed");
+        return;
+    }
+
+    // pass non-tuple
+    if (!firewall) {
+        run_command("%s -q %s", zfw_path, interface);
+    }
+}
+
+static void bind_diverter_route(const char *ip, uint8_t prefix_len) {
+    // called while uv loop is running, so queue the command to prevent i/o stalls
+    queue_command("%s -B %s -m %d", zfw_path, ip, prefix_len);
+}
+
+static void unbind_diverter_route(const char *ip, uint8_t prefix_len) {
+    // called while uv loop is running, so queue the command to prevent i/o stalls
+    queue_command("%s -J %s -m %d", zfw_path, ip, prefix_len);
+}
+
+void diverter_add_svc(const tunnel_service *svc) {
+    if(svc && diverter){
+        if(svc->Permissions.Dial){
+            for(int x = 0; svc->Addresses && (svc->Addresses[x] != NULL); x++){
+                if(!svc->Addresses[x]->IsHost){
+                    for(int i =  0; (svc->Ports != NULL) && (svc->Ports[i] != NULL); i++){
+                        for(int j =  0; (svc->Protocols != NULL) && (svc->Protocols[j] != NULL); j++){
+                            if((svc->AllowedSourceAddresses && svc->AllowedSourceAddresses[0] != NULL) || firewall){
+                                diverter_update(svc->Addresses[x]->IP, svc->Addresses[x]->Prefix, svc->Ports[i]->Low, svc->Ports[i]->High, svc->Protocols[j], svc->Id, "-I");
+                            }
+                        }
+                    }
+
+                }
+            }
+        }
+        else if(svc->Permissions.Bind){
+            for(int x = 0; svc->AllowedSourceAddresses && (svc->AllowedSourceAddresses[x] != NULL); x++){
+                if(!svc->AllowedSourceAddresses[x]->IsHost){
+                    bind_diverter_route(svc->AllowedSourceAddresses[x]->IP, svc->AllowedSourceAddresses[x]->Prefix);
+                }
+            }
+        }
+    }
+}
+void diverter_remove_svc(const tunnel_service *svc) {
+    if(svc && diverter){
+        if(svc->Permissions.Bind){
+            for(int x = 0; svc->AllowedSourceAddresses && (svc->AllowedSourceAddresses[x] != NULL); x++){
+                if(!svc->AllowedSourceAddresses[x]->IsHost){
+                    unbind_diverter_route(svc->AllowedSourceAddresses[x]->IP, svc->AllowedSourceAddresses[x]->Prefix);
+                }
+            }
+        }
+        if(svc->Permissions.Dial){
+            for(int x = 0; svc->Addresses && (svc->Addresses[x] != NULL); x++){
+                if(!svc->Addresses[x]->IsHost){
+                    for(int i =  0; (svc->Ports != NULL) && (svc->Ports[i] != NULL); i++){
+                        for(int j =  0; (svc->Protocols != NULL) && (svc->Protocols[j] != NULL); j++){
+                            if((svc->AllowedSourceAddresses && svc->AllowedSourceAddresses[0] != NULL) || firewall){
+                                diverter_update(svc->Addresses[x]->IP, svc->Addresses[x]->Prefix, svc->Ports[i]->Low, svc->Ports[i]->High, svc->Protocols[j], svc->Id, "-D");
+                            }
+                        }
+                    }
+
+                }
+            }
+        }
+    }
+}
+
+static void diverter_binding_flush() {
+    // called by exit handler, so run_command is appropriate
+    run_command("%s -F -j", zfw_path);
+}
+
+static void diverter_ingress_flush() {
+    // called by exit handler, so run_command is appropriate
+    run_command("%s -F -z ingress", zfw_path);
+}
+
+static void setup_xdp(const char *tun_name) {
+    // run_command is ok here because the uv loop is not yet running when this is called
+    run_command("/usr/sbin/ip link set %s xdpgeneric obj %s/%s sec xdp_redirect", tun_name, diverter_path, xdp_ingress_object);
+}
+
+static void add_user_rules() {
+    // called by exit handler, so run_command is appropriate
+    run_command("%s -A", zfw_path);
+}
+
+static void disable_firewall() {
+    // run_command is ok here because the uv loop is not yet running when this is called
+    run_command("%s -I -c 0.0.0.0 -m 0 -l 1 -h 65535 -t 0 -p tcp", zfw_path);
+    run_command("%s -I -c 0.0.0.0 -m 0 -l 1 -h 65535 -t 0 -p udp", zfw_path);
+    run_command("%s -I -c :: -m 0 -l 1 -h 65535 -t 0 -p tcp", zfw_path);
+    run_command("%s -I -c :: -m 0 -l 1 -h 65535 -t 0 -p udp", zfw_path);
+}
+
+static void pass_dns_range(uint32_t dns_prefix, uint8_t dns_prefix_len) {
+    // run_command is ok here because the uv loop is not yet running when this is called
+    char prefix[INET_ADDRSTRLEN];
+    inet_ntop(AF_INET, &dns_prefix, prefix, INET_ADDRSTRLEN);
+    run_command("%s -I -c %s -m %d -l 1 -h 65535 -t 65535 -p tcp", zfw_path, prefix, dns_prefix_len);
+    run_command("%s -I -c %s -m %d -l 1 -h 65535 -t 65535 -p udp", zfw_path, prefix, dns_prefix_len);
+}
+
+void set_diverter(uint32_t dns_prefix, uint8_t dns_prefix_len, const char *tun_name)
+{
+    if (!firewall) {
+        ZITI_LOG(INFO,"Starting ziti-edge-tunnel in diverter mode");
+    } else {
+        ZITI_LOG(INFO,"Starting ziti-edge-tunnel in diverter firewall mode");
+    }
+    if (!firewall) {
+        disable_firewall();
+    } else {
+        if (is_executable(zfw_path)) {
+            ZITI_LOG(INFO,"loading user defined FW rules");
+            add_user_rules();
+        } else {
+            ZITI_LOG(DEBUG, "Diverter user defined FW rules not found");
+        }
+        pass_dns_range(dns_prefix, dns_prefix_len);
+    }
+    setup_xdp(tun_name);
+}
+
+void diverter_cleanup(void) {
+    if (diverter && !firewall) {
+        diverter_binding_flush();
+        diverter_quit();
+    } else if (firewall) {
+        diverter_binding_flush();
+        diverter_ingress_flush();
+        add_user_rules();
+    }
+}