update: server daemon of ClearDNS

include/process.h

@@ -1,6 +1,7 @@
 #ifndef _PROCESS_H_
 #define _PROCESS_H_
 
+void server_daemon();
 void init_server(char *init_script, char *custom_script);
 
 #endif

src/CMakeLists.txt

@@ -1,7 +1,13 @@
 cmake_minimum_required(VERSION 2.8.12)
 
 include_directories(${PROJECT_SOURCE_DIR}/include)
+include_directories(/usr/lib/i386-linux-gnu/glib-2.0/include)
+include_directories(/usr/lib/x86_64-linux-gnu/glib-2.0/include)
+include_directories(/usr/lib/aarch64-linux-gnu/glib-2.0/include)
+include_directories(/usr/lib64/glib-2.0/include)
+include_directories(/usr/lib/glib-2.0/include)
+include_directories(/usr/include/glib-2.0)
 
 aux_source_directory(${PROJECT_SOURCE_DIR}/src SRC)
 add_executable(cleardns ${SRC})
-#target_link_libraries(cleardns glib-2.0)
+target_link_libraries(cleardns glib-2.0)

src/cleardns.c

@@ -3,8 +3,6 @@
 #include "common.h"
 #include "process.h"
 
-int debug_mode = 0;
-
 char *init_script = "/usr/bin/load";
 char *custom_script = "/etc/cleardns/custom.sh";
 
@@ -14,14 +12,19 @@ char *upstream_config = "/etc/cleardns/upstream.json";
 
 void show_command(char *title, char **command) {
     int num = 0;
-    fprintf(stderr, "\n%s => ", title);
+    fprintf(stderr, "%s => \"", title);
     while(command[num] != NULL) {
         fprintf(stderr, "%s", command[num++]);
+        if (command[num] != NULL) {
+            fprintf(stderr, " ");
+        }
     }
-    fprintf(stderr, "\n");
+    fprintf(stderr, "\"\n");
 }
 
 int main(int argc, char *argv[]) {
+    int debug_mode = 0;
+    fprintf(stderr, "[ClearDNS] Server start.\n");
     for (char **p = argv; p < argv + argc; ++p) {
         if (!strcmp(*p, "--debug")) { // --debug option
             ++debug_mode;
@@ -30,17 +33,15 @@ int main(int argc, char *argv[]) {
 
     load_start_command(adguard_workdir, overture_config, upstream_config, debug_mode); // generate commands
     if (debug_mode) { // show exec command
-        char *line = "----------------------------------------------------------------";
-        fprintf(stderr, "\n%s%s\n", line, line);
-        show_command("crond", crond_command);
-        show_command("AdGuard", adguard_command);
-        show_command("overture", overture_command);
-        show_command("dnsproxy (domestic)", domestic_dnsproxy_command);
-        show_command("dnsproxy (foreign)", foreign_dnsproxy_command);
-        fprintf(stderr, "\n%s%s\n", line, line);
+        fprintf(stderr, "[ClearDNS] Debug mode.\n");
+        show_command("[ClearDNS] crond", crond_command);
+        show_command("[ClearDNS] adguard", adguard_command);
+        show_command("[ClearDNS] overture", overture_command);
+        show_command("[ClearDNS] dnsproxy (domestic)", domestic_dnsproxy_command);
+        show_command("[ClearDNS] dnsproxy (foreign)", foreign_dnsproxy_command);
     }
 
     init_server(init_script, custom_script);
-
+    server_daemon();
     return 0;
 }

src/common.c

@@ -16,7 +16,7 @@ char** dnsproxy_config(char *port, cJSON *json, int is_debug);
 void load_start_command(char *adguard_workdir, char *overture_config, char *upstream_config, int is_debug);
 
 void error_exit(char *message) { // exit with code 1
-    fprintf(stderr, "%s\n", message);
+    fprintf(stderr, "[ClearDNS] %s\n", message);
     exit(1);
 }
 

src/process.c

@@ -1,11 +1,102 @@
+#include <glib.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/wait.h>
 #include <sys/prctl.h>
+#include "common.h"
 
-void process_exec() {
+int exiting = 0;
 
+pid_t crond_pid = 0;
+pid_t adguard_pid = 0;
+pid_t overture_pid = 0;
+pid_t domestic_dnsproxy_pid = 0;
+pid_t foreign_dnsproxy_pid = 0;
+
+void server_exit();
+void get_sub_exit();
+void server_daemon();
+pid_t process_exec(char **command);
+void init_server(char *init_script, char *custom_script);
+
+void server_exit() { // kill sub-process and exit
+    int status, ret;
+    exiting = 1;
+    fprintf(stderr, "[ClearDNS] Get exit signal.\n");
+
+    if (domestic_dnsproxy_pid != 0) {
+        fprintf(stderr, "[ClearDNS] Kill domestic dnsproxy. (pid = %d)\n", domestic_dnsproxy_pid);
+        kill(domestic_dnsproxy_pid, SIGTERM);
+    }
+    if (foreign_dnsproxy_pid != 0) {
+        fprintf(stderr, "[ClearDNS] Kill foreign dnsproxy. (pid = %d)\n", foreign_dnsproxy_pid);
+        kill(foreign_dnsproxy_pid, SIGTERM);
+    }
+
+    while ((ret = wait(&status)) != -1) {
+        fprintf(stderr, "[ClearDNS] Subprocess exit. (pid = %d)\n", ret);
+    }
+    printf("[ClearDNS] Exit successfully.\n");
+    exit(0);
+}
+
+void get_sub_exit() { // catch child process die
+    int ret, status;
+    int wait_time = 3; // seconds for wait before restart
+    if (exiting) { return; } // server daemon is exiting
+
+    if (domestic_dnsproxy_pid != 0) { // check domestic dnsproxy
+        ret = waitpid(domestic_dnsproxy_pid, &status, WNOHANG); // non-blocking
+        if (ret == -1) {
+            perror("[ClearDNS] Waitpid error");
+            server_exit();
+        } else if (ret) { // process exit
+            domestic_dnsproxy_pid = process_exec(domestic_dnsproxy_command);
+            fprintf(stderr, "[ClearDNS] Catch domestic dnsproxy exit and restart it. (pid = %d)\n", domestic_dnsproxy_pid);
+            sleep(wait_time); // reduce restart frequency
+            return;
+        }
+    }
+
+    if (foreign_dnsproxy_pid != 0) { // check foreign dnsproxy
+        ret = waitpid(foreign_dnsproxy_pid, &status, WNOHANG); // non-blocking
+        if (ret == -1) {
+            perror("[ClearDNS] Waitpid error");
+            server_exit();
+        } else if (ret) { // process exit
+            foreign_dnsproxy_pid = process_exec(foreign_dnsproxy_command);
+            fprintf(stderr, "[ClearDNS] Catch foreign dnsproxy exit and restart it. (pid = %d)\n", foreign_dnsproxy_pid);
+            sleep(wait_time); // reduce restart frequency
+            return;
+        }
+    }
+
+    ret = waitpid(-1, &status, WNOHANG); // waitpid for all sub-process (non-blocking)
+    if (ret == -1) {
+        perror("[ClearDNS] Waitpid error");
+        server_exit();
+    } else if (ret) { // process exit
+        fprintf(stderr, "[ClearDNS] Catch subprocess exit. (pid = %d)\n", ret);
+        return;
+    }
+    fprintf(stderr, "[ClearDNS] Subprocess not found.\n"); // get SIGCHLD signal but not exited subprocess found
+}
+
+pid_t process_exec(char **command) {
+    pid_t pid;
+    char **env = {NULL};
+    if ((pid = fork()) < 0) {
+        perror("[ClearDNS] Fork error");
+        exit(2);
+    } else if (pid == 0) { // child process
+        prctl(PR_SET_PDEATHSIG, SIGKILL); // child process die with father process
+        if (execvpe(command[0], command, env) < 0) {
+            perror("[ClearDNS] Exec error");
+            exit(3);
+        }
+    }
+    return pid;
 }
 
 void init_server(char *init_script, char *custom_script) { // run init script (blocking) / custom script (non-blocking)
@@ -13,32 +104,48 @@ void init_server(char *init_script, char *custom_script) { // run init script (b
     pid_t init_pid, custom_pid;
 
     if ((init_pid = fork()) < 0) {
-        perror("Fork error");
+        perror("[ClearDNS] Fork error");
         exit(2);
     } else if (init_pid == 0) { // child process
         prctl(PR_SET_PDEATHSIG, SIGKILL); // child process die with father process
         if (execlp("/bin/sh", "/bin/sh", init_script, NULL)) {
-            perror("Init error");
+            perror("[ClearDNS] Init error");
             exit(3);
         }
     }
     wait(&status); // blocking wait
-    fprintf(stderr, "Init complete\n");
+    fprintf(stderr, "[ClearDNS] Init complete.\n");
 
     if (access(custom_script, F_OK) >= 0) { // custom script exist
+        fprintf(stderr, "[ClearDNS] Running custom script.\n");
         if ((custom_pid = fork()) < 0) {
-            perror("Fork error");
+            perror("[ClearDNS] Fork error");
             exit(2);
         } else if (custom_pid == 0) { // child process
             prctl(PR_SET_PDEATHSIG, SIGKILL); // child process die with father process
             if (execlp("/bin/sh", "/bin/sh", custom_script, NULL)) {
-                perror("Custom script error");
+                perror("[ClearDNS] Custom script error");
                 exit(3);
             }
         }
+        sleep(1); // wait a moment
     }
 }
 
-void server_daemon() {
+void server_daemon() { // run as a daemon of cleardns
+    int wait_us_time = 200 * 1000; // 200ms
+    signal(SIGINT, server_exit); // catch Ctrl + C (2)
+    signal(SIGTERM, server_exit); // catch exit signal (15)
+    signal(SIGCHLD, get_sub_exit); // callback when child process die
+
+    domestic_dnsproxy_pid = process_exec(domestic_dnsproxy_command);
+    fprintf(stderr, "[ClearDNS] Exec domestic dnsproxy. (pid = %d)\n", domestic_dnsproxy_pid);
+    usleep(wait_us_time);
+
+    foreign_dnsproxy_pid = process_exec(foreign_dnsproxy_command);
+    fprintf(stderr, "[ClearDNS] Exec foreign dnsproxy. (pid = %d)\n", foreign_dnsproxy_pid);
+    usleep(wait_us_time);
 
+    GMainLoop *main_loop = g_main_loop_new(NULL, FALSE);
+    g_main_loop_run(main_loop);
 }