smartdns: follow sysv daemon initialize steps

src/dns_conf.c

@@ -763,7 +763,7 @@ static int _config_domain_rule_each_from_list(const char *file, domain_set_rule_
  line_no = 0;
  while (fgets(line, MAX_LINE_LEN, fp)) {
  line_no++;
- filed_num = sscanf(line, "%256s", domain);
+ filed_num = sscanf(line, "%255s", domain);
  if (filed_num <= 0) {
  continue;
  }
@@ -3198,7 +3198,7 @@ static int _conf_dhcp_lease_dnsmasq_add(const char *file)
  line_no = 0;
  while (fgets(line, MAX_LINE_LEN, fp)) {
  line_no++;
- filed_num = sscanf(line, "%*s %*s %64s %256s %*s", ip, hostname);
+ filed_num = sscanf(line, "%*s %*s %63s %255s %*s", ip, hostname);
  if (filed_num <= 0) {
  continue;
  }

src/lib/conf.c

@@ -377,7 +377,7 @@ static int load_conf_file(const char *file, struct config_item *items, conf_erro
  }
  line_len = 0;
 
- filed_num = sscanf(line, "%63s %8192[^\r\n]s", key, value);
+ filed_num = sscanf(line, "%63s %8191[^\r\n]s", key, value);
  if (filed_num <= 0) {
  continue;
  }

src/smartdns.c

@@ -459,14 +459,16 @@ static int _smartdns_init(void)
  int ret = 0;
  const char *logfile = _smartdns_log_path();
  int i = 0;
+ char logdir[PATH_MAX] = {0};
 
  ret = tlog_init(logfile, dns_conf_log_size, dns_conf_log_num, 0, 0);
  if (ret != 0) {
  tlog(TLOG_ERROR, "start tlog failed.\n");
  goto errout;
  }
 
- if (verbose_screen != 0 || dns_conf_log_console != 0) {
+ safe_strncpy(logdir, _smartdns_log_path(), PATH_MAX);
+ if (verbose_screen != 0 || dns_conf_log_console != 0 || access(dir_name(logdir), W_OK) != 0) {
  tlog_setlogscreen(1);
  }
 
@@ -736,9 +738,11 @@ static void smartdns_test_notify_func(int fd_notify, uint64_t retval)
  }
 }
 
+#define smartdns_close_allfds() close_all_fd(fd_notify);
 int smartdns_main(int argc, char *argv[], int fd_notify)
 #else
 #define smartdns_test_notify(retval)
+#define smartdns_close_allfds() close_all_fd(-1);
 int main(int argc, char *argv[])
 #endif
 {
@@ -750,6 +754,7 @@ int main(int argc, char *argv[])
  int signal_ignore = 0;
  sigset_t empty_sigblock;
  struct stat sb;
+ int daemon_ret = 0;
 
  safe_strncpy(config_file, SMARTDNS_CONF_FILE, MAX_LINE_LEN);
 
@@ -762,17 +767,22 @@ int main(int argc, char *argv[])
  /* patch for Asus router: unblock all signal*/
  sigemptyset(&empty_sigblock);
  sigprocmask(SIG_SETMASK, &empty_sigblock, NULL);
+ smartdns_close_allfds();
 
  while ((opt = getopt(argc, argv, "fhc:p:SvxN:")) != -1) {
  switch (opt) {
  case 'f':
  is_foreground = 1;
  break;
  case 'c':
- snprintf(config_file, sizeof(config_file), "%s", optarg);
+ if (full_path(config_file, sizeof(config_file), optarg) != 0) {
+ snprintf(config_file, sizeof(config_file), "%s", optarg);
+ }
  break;
  case 'p':
- snprintf(pid_file, sizeof(pid_file), "%s", optarg);
+ if (strncmp(optarg, "-", 2) == 0 || full_path(pid_file, sizeof(pid_file), optarg) != 0) {
+ snprintf(pid_file, sizeof(pid_file), "%s", optarg);
+ }
  break;
  case 'S':
  signal_ignore = 1;
@@ -794,33 +804,46 @@ int main(int argc, char *argv[])
  }
  }
 
- if (dns_server_load_conf(config_file) != 0) {
+ ret = dns_server_load_conf(config_file);
+ if (ret != 0) {
  fprintf(stderr, "load config failed.\n");
  goto errout;
  }
 
  if (is_foreground == 0) {
- if (daemon(0, 0) < 0) {
- fprintf(stderr, "run daemon process failed, %s\n", strerror(errno));
+ daemon_ret = run_daemon();
+ if (daemon_ret < 0) {
+ char buff[4096];
+ char *log_path = realpath(_smartdns_log_path(), buff);
+
+ if (log_path != NULL && access(log_path, F_OK) == 0 && daemon_ret != -2) {
+ fprintf(stderr, "run daemon failed, please check log at %s\n", log_path);
+ }
  return 1;
  }
+
+ if (daemon_ret == 0) {
+ return 0;
+ }
  }
 
  if (signal_ignore == 0) {
  _reg_signal();
  }
 
  if (strncmp(pid_file, "-", 2) != 0 && create_pid_file(pid_file) != 0) {
+ ret = -2;
  goto errout;
  }
 
  signal(SIGPIPE, SIG_IGN);
  signal(SIGINT, _sig_exit);
  signal(SIGTERM, _sig_exit);
 
- if (_smartdns_init_pre() != 0) {
+ ret = _smartdns_init_pre();
+ if (ret != 0) {
  fprintf(stderr, "init failed.\n");
- return 1;
+ goto errout;
  }
 
  drop_root_privilege();
@@ -831,11 +854,21 @@ int main(int argc, char *argv[])
  goto errout;
  }
 
+ if (daemon_ret > 0) {
+ ret = daemon_kickoff(daemon_ret, 0);
+ if (ret != 0) {
+ goto errout;
+ }
+ }
+
  smartdns_test_notify(1);
  ret = _smartdns_run();
  _smartdns_exit();
  return ret;
 errout:
+ if (daemon_ret > 0) {
+ daemon_kickoff(daemon_ret, ret);
+ }
  smartdns_test_notify(2);
  return 1;
 }

src/util.c

@@ -25,6 +25,7 @@
 #include "util.h"
 #include <arpa/inet.h>
 #include <ctype.h>
+#include <dirent.h>
 #include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -38,11 +39,13 @@
 #include <openssl/crypto.h>
 #include <openssl/ssl.h>
 #include <openssl/x509v3.h>
+#include <poll.h>
 #include <pthread.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/prctl.h>
+#include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/statvfs.h>
 #include <sys/sysinfo.h>
@@ -806,7 +809,11 @@ int create_pid_file(const char *pid_file)
  }
 
  if (lockf(fd, F_TLOCK, 0) < 0) {
- fprintf(stderr, "Server is already running.\n");
+ memset(buff, 0, TMP_BUFF_LEN_32);
+ if (read(fd, buff, TMP_BUFF_LEN_32) <= 0) {
+ buff[0] = '\0';
+ }
+ fprintf(stderr, "Server is already running, pid is %s", buff);
  goto errout;
  }
 
@@ -831,6 +838,27 @@ int create_pid_file(const char *pid_file)
  return -1;
 }
 
+int full_path(char *normalized_path, int normalized_path_len, const char *path)
+{
+ const char *p = path;
+
+ if (path == NULL || normalized_path == NULL) {
+ return -1;
+ }
+
+ while (*p == ' ') {
+ p++;
+ }
+
+ if (*p == '\0' || *p == '/') {
+ return -1;
+ }
+
+ char buf[PATH_MAX];
+ snprintf(normalized_path, normalized_path_len, "%s/%s", getcwd(buf, sizeof(buf)), path);
+ return 0;
+}
+
 int generate_cert_key(const char *key_path, const char *cert_path, const char *san, int days)
 {
  int ret = -1;
@@ -1479,6 +1507,156 @@ int dns_packet_save(const char *dir, const char *type, const char *from, const v
  return ret;
 }
 
+static void _close_all_fd_by_res(void)
+{
+ struct rlimit lim;
+ int maxfd = 0;
+ int i = 0;
+
+ getrlimit(RLIMIT_NOFILE, &lim);
+
+ maxfd = lim.rlim_cur;
+ if (maxfd > 4096) {
+ maxfd = 4096;
+ }
+
+ for (i = 3; i < maxfd; i++) {
+ close(i);
+ }
+}
+
+void close_all_fd(int keepfd)
+{
+ DIR *dirp;
+ int dir_fd = -1;
+ struct dirent *dentp;
+
+ dirp = opendir("/proc/self/fd");
+ if (dirp == NULL) {
+ goto errout;
+ }
+
+ dir_fd = dirfd(dirp);
+
+ while ((dentp = readdir(dirp)) != NULL) {
+ int fd = atol(dentp->d_name);
+ if (fd < 0) {
+ continue;
+ }
+
+ if (fd == dir_fd || fd == STDIN_FILENO || fd == STDOUT_FILENO || fd == STDERR_FILENO || fd == keepfd) {
+ continue;
+ }
+ close(fd);
+ }
+
+ closedir(dirp);
+ return;
+errout:
+ if (dirp) {
+ closedir(dirp);
+ }
+ _close_all_fd_by_res();
+ return;
+}
+
+int daemon_kickoff(int fd, int status)
+{
+ if (fd <= 0) {
+ return -1;
+ }
+
+ int ret = write(fd, &status, sizeof(status));
+ if (ret != sizeof(status)) {
+ return -1;
+ }
+
+ int fd_null = open("/dev/null", O_RDWR);
+ if (fd_null < 0) {
+ fprintf(stderr, "open /dev/null failed, %s\n", strerror(errno));
+ return -1;
+ }
+
+ dup2(fd_null, STDIN_FILENO);
+ dup2(fd_null, STDOUT_FILENO);
+ dup2(fd_null, STDERR_FILENO);
+
+ if (fd_null > 2) {
+ close(fd_null);
+ }
+
+ close(fd);
+
+ return 0;
+}
+
+int run_daemon()
+{
+ pid_t pid = 0;
+ int fds[2] = {0};
+
+ if (pipe(fds) != 0) {
+ fprintf(stderr, "run daemon process failed, pipe failed, %s\n", strerror(errno));
+ return -1;
+ }
+
+ pid = fork();
+ if (pid < 0) {
+ fprintf(stderr, "run daemon process failed, fork failed, %s\n", strerror(errno));
+ close(fds[0]);
+ close(fds[1]);
+ return -1;
+ } else if (pid > 0) {
+ struct pollfd pfd;
+ int ret = 0;
+ int status = 0;
+
+ close(fds[1]);
+
+ pfd.fd = fds[0];
+ pfd.events = POLLIN;
+ pfd.revents = 0;
+
+ ret = poll(&pfd, 1, 1000);
+ if (ret <= 0) {
+ fprintf(stderr, "run daemon process failed, wait child timeout\n");
+ goto errout;
+ }
+
+ if (!(pfd.revents & POLLIN)) {
+ goto errout;
+ }
+
+ ret = read(fds[0], &status, sizeof(status));
+ if (ret != sizeof(status)) {
+ goto errout;
+ }
+
+ return status;
+ }
+
+ setsid();
+
+ pid = fork();
+ if (pid < 0) {
+ fprintf(stderr, "double fork failed, %s\n", strerror(errno));
+ _exit(1);
+ } else if (pid > 0) {
+ _exit(0);
+ }
+
+ umask(0);
+ if (chdir("/") != 0) {
+ goto errout;
+ }
+ close(fds[0]);
+ return fds[1];
+
+errout:
+ kill(pid, SIGKILL);
+ return -1;
+}
+
 #ifdef DEBUG
 struct _dns_read_packet_info {
  int data_len;
@@ -1604,7 +1782,7 @@ static int _dns_debug_display(struct dns_packet *packet)
  int ret = 0;
 
  ret = dns_get_HTTPS_svcparm_start(rrs, &p, name, DNS_MAX_CNAME_LEN, &ttl, &priority, target,
- DNS_MAX_CNAME_LEN);
+  DNS_MAX_CNAME_LEN);
  if (ret != 0) {
  printf("get HTTPS svcparm failed\n");
  break;