external/ibm-public/postfix/dist/src/util/posix_signals.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      posix_signals 3
   6 /* SUMMARY
   7 /*      POSIX signal handling compatibility
   8 /* SYNOPSIS
   9 /*      #include <posix_signals.h>
  10 /*
  11 /*      int     sigemptyset(m)
  12 /*      sigset_t *m;
  13 /*
  14 /*      int     sigaddset(set, signum)
  15 /*      sigset_t *set;
  16 /*      int     signum;
  17 /*
  18 /*      int     sigprocmask(how, set, old)
  19 /*      int     how;
  20 /*      sigset_t *set;
  21 /*      sigset_t *old;
  22 /*
  23 /*      int     sigaction(sig, act, oact)
  24 /*      int     sig;
  25 /*      struct sigaction *act;
  26 /*      struct sigaction *oact;
  27 /* DESCRIPTION
  28 /*      These routines emulate the POSIX signal handling interface.
  29 /* AUTHOR(S)
  30 /*      Pieter Schoenmakers
  31 /*      Eindhoven University of Technology
  32 /*      P.O. Box 513
  33 /*      5600 MB Eindhoven
  34 /*      The Netherlands
  35 /*--*/
  36
  37 /* System library. */
  38
  39 #include "sys_defs.h"
  40 #include <signal.h>
  41 #include <errno.h>
  42
  43 /* Utility library.*/
  44
  45 #include "posix_signals.h"
  46
  47 #ifdef MISSING_SIGSET_T
  48
  49 int     sigemptyset(sigset_t *m)
  50 {
  51     return *m = 0;
  52 }
  53
  54 int     sigaddset(sigset_t *set, int signum)
  55 {
  56     *set |= sigmask(signum);
  57     return 0;
  58 }
  59
  60 int     sigprocmask(int how, sigset_t *set, sigset_t *old)
  61 {
  62     int previous;
  63
  64     if (how == SIG_BLOCK)
  65         previous = sigblock(*set);
  66     else if (how == SIG_SETMASK)
  67         previous = sigsetmask(*set);
  68     else if (how == SIG_UNBLOCK) {
  69         int     m = sigblock(0);
  70
  71         previous = sigsetmask(m & ~*set);
  72     } else {
  73         errno = EINVAL;
  74         return -1;
  75     }
  76
  77     if (old)
  78         *old = previous;
  79     return 0;
  80 }
  81
  82 #endif
  83
  84 #ifdef MISSING_SIGACTION
  85
  86 static struct sigaction actions[NSIG] = {};
  87
  88 static int sighandle(int signum)
  89 {
  90     if (signum == SIGCHLD) {
  91         /* XXX If the child is just stopped, don't invoke the handler.   */
  92     }
  93     actions[signum].sa_handler(signum);
  94 }
  95
  96 int     sigaction(int sig, struct sigaction *act, struct sigaction *oact)
  97 {
  98     static int initialized = 0;
  99
 100     if (!initialized) {
 101         int     i;
 102
 103         for (i = 0; i < NSIG; i++)
 104             actions[i].sa_handler = SIG_DFL;
 105         initialized = 1;
 106     }
 107     if (sig <= 0 || sig >= NSIG) {
 108         errno = EINVAL;
 109         return -1;
 110     }
 111     if (oact)
 112         *oact = actions[sig];
 113
 114     {
 115         struct sigvec mine = {
 116             sighandle, act->sa_mask,
 117             act->sa_flags & SA_RESTART ? SV_INTERRUPT : 0
 118         };
 119
 120         if (sigvec(sig, &mine, NULL))
 121             return -1;
 122     }
 123
 124     actions[sig] = *act;
 125     return 0;
 126 }
 127
 128 #endif