net/haproxy/patches/0003-MEDIUM-Improve-signal-handling-in-systemd-wrapper.patch

   1 From 62c8565cd5bbda6ac0dd818fa26922eeaef1605c Mon Sep 17 00:00:00 2001
   2 From: Conrad Hoffmann <conrad@soundcloud.com>
   3 Date: Mon, 28 Jul 2014 23:52:20 +0200
   4 Subject: [PATCH 03/13] MEDIUM: Improve signal handling in systemd wrapper.
   5
   6 Move all code out of the signal handlers, since this is potentially
   7 dangerous. To make sure the signal handlers behave as expected, use
   8 sigaction() instead of signal(). That also obsoletes messing with
   9 the signal mask after restart.
  10
  11 Signed-off-by: Conrad Hoffmann <conrad@soundcloud.com>
  12 (cherry picked from commit 5b5ea9c93384da49eea0f67ebed0966d4167b17a)
  13 ---
  14  src/haproxy-systemd-wrapper.c | 37 ++++++++++++++++++++++++-------------
  15  1 file changed, 24 insertions(+), 13 deletions(-)
  16
  17 diff --git a/src/haproxy-systemd-wrapper.c b/src/haproxy-systemd-wrapper.c
  18 index 529b213..90a94ce 100644
  19 --- a/src/haproxy-systemd-wrapper.c
  20 +++ b/src/haproxy-systemd-wrapper.c
  21 @@ -22,6 +22,8 @@
  22  #define SD_DEBUG "<7>"
  23  #define SD_NOTICE "<5>"
  24
  25 +static volatile sig_atomic_t caught_signal;
  26 +
  27  static char *pid_file = "/run/haproxy.pid";
  28  static int wrapper_argc;
  29  static char **wrapper_argv;
  30 @@ -103,7 +105,12 @@ static int read_pids(char ***pid_strv)
  31         return read;
  32  }
  33
  34 -static void sigusr2_handler(int signum __attribute__((unused)))
  35 +static void signal_handler(int signum)
  36 +{
  37 +       caught_signal = signum;
  38 +}
  39 +
  40 +static void do_restart(void)
  41  {
  42         setenv(REEXEC_FLAG, "1", 1);
  43         fprintf(stderr, SD_NOTICE "haproxy-systemd-wrapper: re-executing\n");
  44 @@ -111,7 +118,7 @@ static void sigusr2_handler(int signum __attribute__((unused)))
  45         execv(wrapper_argv[0], wrapper_argv);
  46  }
  47
  48 -static void sigint_handler(int signum __attribute__((unused)))
  49 +static void do_shutdown(void)
  50  {
  51         int i, pid;
  52         char **pid_strv = NULL;
  53 @@ -147,25 +154,21 @@ int main(int argc, char **argv)
  54         --argc; ++argv;
  55         init(argc, argv);
  56
  57 -       signal(SIGINT, &sigint_handler);
  58 -       signal(SIGUSR2, &sigusr2_handler);
  59 +       struct sigaction sa;
  60 +       memset(&sa, 0, sizeof(struct sigaction));
  61 +       sa.sa_handler = &signal_handler;
  62 +       sigaction(SIGUSR2, &sa, NULL);
  63 +       sigaction(SIGINT, &sa, NULL);
  64
  65         if (getenv(REEXEC_FLAG) != NULL) {
  66                 /* We are being re-executed: restart HAProxy gracefully */
  67                 int i;
  68                 char **pid_strv = NULL;
  69                 int nb_pid = read_pids(&pid_strv);
  70 -               sigset_t sigs;
  71
  72                 unsetenv(REEXEC_FLAG);
  73                 spawn_haproxy(pid_strv, nb_pid);
  74
  75 -               /* Unblock SIGUSR2 which was blocked by the signal handler
  76 -                * before re-exec */
  77 -               sigprocmask(SIG_BLOCK, NULL, &sigs);
  78 -               sigdelset(&sigs, SIGUSR2);
  79 -               sigprocmask(SIG_SETMASK, &sigs, NULL);
  80 -
  81                 for (i = 0; i < nb_pid; ++i)
  82                         free(pid_strv[i]);
  83                 free(pid_strv);
  84 @@ -176,8 +179,16 @@ int main(int argc, char **argv)
  85         }
  86
  87         status = -1;
  88 -       while (-1 != wait(&status) || errno == EINTR)
  89 -               ;
  90 +       while (-1 != wait(&status) || errno == EINTR) {
  91 +               if (caught_signal == SIGUSR2) {
  92 +                       caught_signal = 0;
  93 +                       do_restart();
  94 +               }
  95 +               else if (caught_signal == SIGINT) {
  96 +                       caught_signal = 0;
  97 +                       do_shutdown();
  98 +               }
  99 +       }
 100
 101         fprintf(stderr, SD_NOTICE "haproxy-systemd-wrapper: exit, haproxy RC=%d\n",
 102                         status);
 103 --
 104 1.8.5.5
 105