contrib/sendmail/libsm/notify.c

   1 /*
   2  * Copyright (c) 2016 Proofpoint, Inc. and its suppliers.
   3  *      All rights reserved.
   4  *
   5  * By using this file, you agree to the terms and conditions set
   6  * forth in the LICENSE file which can be found at the top level of
   7  * the sendmail distribution.
   8  *
   9  */
  10
  11 #include <sm/gen.h>
  12
  13 #include <sys/types.h>
  14 #include <signal.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <stdbool.h>
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <string.h>     /* for memset() */
  22
  23 #include <sm/conf.h>    /* FDSET_CAST */
  24 #include <sm/fdset.h>
  25 #include <sm/assert.h>
  26 #include <sm/notify.h>
  27
  28 #if SM_NOTIFY_DEBUG
  29 #define SM_DBG(p)       fprintf p
  30 #else
  31 #define SM_DBG(p)
  32 #endif
  33
  34 static int      Notifypipe[2];
  35 #define NotifyRDpipe Notifypipe[0]
  36 #define NotifyWRpipe Notifypipe[1]
  37
  38 #define CLOSEFD(fd) do { \
  39                 if ((fd) != -1) {       \
  40                         (void) close(fd);       \
  41                         fd = - 1;       \
  42                 }       \
  43         } while (0)     \
  44
  45
  46 /*
  47 **  SM_NOTIFY_INIT -- initialize notify system
  48 **
  49 **      Parameters:
  50 **              flags -- ignored
  51 **
  52 **      Returns:
  53 **              0: success
  54 **              <0: -errno
  55 */
  56
  57 int
  58 sm_notify_init(flags)
  59         int flags;
  60 {
  61         if (pipe(Notifypipe) < 0)
  62                 return -errno;
  63         return 0;
  64 }
  65
  66 /*
  67 **  SM_NOTIFY_START -- start notify system
  68 **
  69 **      Parameters:
  70 **              owner -- owner.
  71 **              flags -- currently ignored.
  72 **
  73 **      Returns:
  74 **              0: success
  75 **              <0: -errno
  76 */
  77
  78 int
  79 sm_notify_start(owner, flags)
  80         bool owner;
  81         int flags;
  82 {
  83         int r;
  84
  85         r = 0;
  86         if (owner)
  87                 CLOSEFD(NotifyWRpipe);
  88         else
  89                 CLOSEFD(NotifyRDpipe);
  90         return r;
  91 }
  92
  93 /*
  94 **  SM_NOTIFY_STOP -- stop notify system
  95 **
  96 **      Parameters:
  97 **              owner -- owner.
  98 **              flags -- currently ignored.
  99 **
 100 **      Returns:
 101 **              0: success
 102 **              <0: -errno
 103 */
 104
 105 int
 106 sm_notify_stop(owner, flags)
 107         bool owner;
 108         int flags;
 109 {
 110         if (owner)
 111                 CLOSEFD(NotifyRDpipe);
 112         else
 113                 CLOSEFD(NotifyWRpipe);
 114         return 0;
 115 }
 116
 117 /*
 118 **  SM_NOTIFY_SND -- send notification
 119 **
 120 **      Parameters:
 121 **              buf -- where to write data
 122 **              buflen -- len of buffer
 123 **
 124 **      Returns:
 125 **              0: success
 126 **              <0: -errno
 127 */
 128
 129 int
 130 sm_notify_snd(buf, buflen)
 131         char *buf;
 132         size_t buflen;
 133 {
 134         int r;
 135         int save_errno;
 136
 137         SM_REQUIRE(buf != NULL);
 138         SM_REQUIRE(buflen > 0);
 139         if (NotifyWRpipe < 0)
 140                 return -EINVAL;
 141
 142         r = write(NotifyWRpipe, buf, buflen);
 143         save_errno = errno;
 144         SM_DBG((stderr, "write=%d, fd=%d, e=%d\n", r, NotifyWRpipe, save_errno));
 145         return r >= 0 ? 0 : -save_errno;
 146 }
 147
 148 /*
 149 **  SM_NOTIFY_RCV -- receive notification
 150 **
 151 **      Parameters:
 152 **              buf -- where to write data
 153 **              buflen -- len of buffer
 154 **              tmo -- timeout
 155 **
 156 **      Returns:
 157 **              0: success
 158 **              <0: -errno
 159 */
 160
 161 int
 162 sm_notify_rcv(buf, buflen, tmo)
 163         char *buf;
 164         size_t buflen;
 165         int tmo;
 166 {
 167         int r;
 168         int save_errno;
 169         fd_set readfds;
 170         struct timeval timeout;
 171
 172         SM_REQUIRE(buf != NULL);
 173         SM_REQUIRE(buflen > 0);
 174         if (NotifyRDpipe < 0)
 175                 return -EINVAL;
 176         FD_ZERO(&readfds);
 177         SM_FD_SET(NotifyRDpipe, &readfds);
 178         timeout.tv_sec = tmo;
 179         timeout.tv_usec = 0;
 180
 181         do {
 182                 r = select(NotifyRDpipe + 1, FDSET_CAST &readfds, NULL, NULL, &timeout);
 183                 save_errno = errno;
 184                 SM_DBG((stderr, "select=%d, fd=%d, e=%d\n", r, NotifyRDpipe, save_errno));
 185         } while (r < 0 && save_errno == EINTR);
 186
 187         if (r <= 0)
 188         {
 189                 SM_DBG((stderr, "select=%d, e=%d\n", r, save_errno));
 190                 return -ETIMEDOUT;
 191         }
 192
 193         /* bogus... need to check again? */
 194         if (!FD_ISSET(NotifyRDpipe, &readfds))
 195                 return -ETIMEDOUT;
 196
 197         r = read(NotifyRDpipe, buf, buflen);
 198         save_errno = errno;
 199         SM_DBG((stderr, "read=%d, e=%d\n", r, save_errno));
 200         if (r == 0)
 201                 return -1;      /* ??? */
 202         if (r < 0)
 203                 return -save_errno;
 204         return r;
 205 }