464xlat: rework process id write logic

[lede-routing/.git] / nat46 / src / 464xlatcfg.c

diff --git a/nat46/src/464xlatcfg.c b/nat46/src/464xlatcfg.c
index f1846161db0e0aa6384e493985380b0836685619..0f9ad318126e39a7121e24a71c94b3779433e2a6 100644 (file)
--- a/nat46/src/464xlatcfg.c
+++ b/nat46/src/464xlatcfg.c
@@ -1,6 +1,7 @@
 /* 464xlatcfg.c
  *
  * Copyright (c) 2015 Steven Barth <cyrus@openwrt.org>
+ * Copyright (c) 2017 Hans Dedecker <dedeckeh@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2
@@ -40,8 +41,9 @@ int main(int argc, const char *argv[])
        snprintf(buf, sizeof(buf), "/var/run/%s.pid", argv[1]);
        FILE *fp = fopen(buf, "r");
        if (fp) {
-               fscanf(fp, "%d", &pid);
-               kill(pid, SIGTERM);
+               if (fscanf(fp, "%d", &pid) == 1)
+                       kill(pid, SIGTERM);
+
                unlink(buf);
                fclose(fp);
        }
@@ -52,7 +54,9 @@ int main(int argc, const char *argv[])
        if (!argv[3] || !argv[4] || !(fp = fopen(buf, "wx")))
                return 1;
 
-       signal(SIGTERM, sighandler);
+       signal(SIGTERM, SIG_DFL);
+       setvbuf(fp, NULL, _IOLBF, 0);
+       fprintf(fp, "%d\n", getpid());
 
        prefix[sizeof(prefix) - 1] = 0;
        strncpy(prefix, argv[3], sizeof(prefix) - 1);
@@ -133,6 +137,7 @@ int main(int argc, const char *argv[])
                fclose(stderr);
                chdir("/");
                setsid();
+               signal(SIGTERM, sighandler);
                pause();
 
                nat46 = fopen("/proc/net/nat46/control", "w");
@@ -141,6 +146,7 @@ int main(int argc, const char *argv[])
                        fclose(nat46);
                }
        } else {
+               rewind(fp);
                fprintf(fp, "%d\n", pid);
        }