contrib/sendmail/src/sched.c

   1 /*
   2  * Copyright (c) 2021 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 <sendmail.h>
  12
  13 #if _FFR_DMTRIGGER
  14 #include <sm/sendmail.h>
  15 #include <sm/notify.h>
  16
  17 static ENVELOPE QmEnvelope;
  18
  19 /*
  20 **  Macro for fork():
  21 **  FORK_P1(): parent
  22 **  FORK_C1(): child
  23 **  Note: these are not "universal", e.g.,
  24 **  proc_list_add() might be used in parent or child.
  25 **  maybe check pname != NULL to invoke proc_list_add()?
  26 */
  27
  28 #define FORK_P1(emsg, pname, ptype)     \
  29         do {    \
  30                 (void) sm_blocksignal(SIGCHLD); \
  31                 (void) sm_signal(SIGCHLD, reapchild);   \
  32                 \
  33                 pid = dofork(); \
  34                 if (pid == -1)  \
  35                 {       \
  36                         const char *msg = emsg; \
  37                         const char *err = sm_errstring(errno);  \
  38                 \
  39                         if (LogLevel > 8)       \
  40                                 sm_syslog(LOG_INFO, NOQID, "%s: %s",    \
  41                                           msg, err);    \
  42                         (void) sm_releasesignal(SIGCHLD);       \
  43                         return false;   \
  44                 }       \
  45                 if (pid != 0)   \
  46                 {       \
  47                         proc_list_add(pid, pname, ptype, 0, -1, NULL); \
  48                         /* parent -- pick up intermediate zombie */     \
  49                         (void) sm_releasesignal(SIGCHLD);       \
  50                         return true;    \
  51                 }       \
  52         } while (0)
  53
  54 #define FORK_C1()       \
  55         do {    \
  56                 /* child -- clean up signals */ \
  57                 \
  58                 /* Reset global flags */        \
  59                 RestartRequest = NULL;  \
  60                 RestartWorkGroup = false;       \
  61                 ShutdownRequest = NULL; \
  62                 PendingSignal = 0;      \
  63                 CurrentPid = getpid();  \
  64                 close_sendmail_pid();   \
  65                 \
  66                 /*      \
  67                 **  Initialize exception stack and default exception    \
  68                 **  handler for child process.  \
  69                 */      \
  70                 \
  71                 sm_exc_newthread(fatal_error);  \
  72                 clrcontrol();   \
  73                 proc_list_clear();      \
  74                 \
  75                 (void) sm_releasesignal(SIGCHLD);       \
  76                 (void) sm_signal(SIGCHLD, SIG_DFL);     \
  77                 (void) sm_signal(SIGHUP, SIG_DFL);      \
  78                 (void) sm_signal(SIGTERM, intsig);      \
  79                 \
  80                 /* drop privileges */   \
  81                 if (geteuid() == (uid_t) 0)     \
  82                         (void) drop_privileges(false);  \
  83                 disconnect(1, NULL);    \
  84                 QuickAbort = false;     \
  85                 \
  86         } while (0)
  87
  88 /*
  89 **  QM -- queue "manager"
  90 **
  91 **      Parameters:
  92 **              none.
  93 **
  94 **      Returns:
  95 **              false on error
  96 **
  97 **      Side Effects:
  98 **              fork()s and runs as process to deliver queue entries
  99 */
 100
 101 bool
 102 qm()
 103 {
 104         int r;
 105         pid_t pid;
 106         long tmo;
 107
 108         sm_syslog(LOG_DEBUG, NOQID, "queue manager: start");
 109
 110         FORK_P1("Queue manager -- fork() failed", "QM", PROC_QM);
 111         FORK_C1();
 112
 113         r = sm_notify_start(true, 0);
 114         if (r != 0)
 115                 syserr("sm_notify_start() failed=%d", r);
 116
 117         /*
 118         **  Initially wait indefinitely, then only wait
 119         **  until something needs to get done (not yet implemented).
 120         */
 121
 122         tmo = -1;
 123         while (true)
 124         {
 125                 char buf[64];
 126                 ENVELOPE *e;
 127                 SM_RPOOL_T *rpool;
 128
 129 /*
 130 **  TODO: This should try to receive multiple ids:
 131 **  after it got one, check for more with a very short timeout
 132 **  and collect them in a list.
 133 **  but them some other code should be used to run all of them.
 134 */
 135
 136                 sm_syslog(LOG_DEBUG, NOQID, "queue manager: rcv=start");
 137                 r = sm_notify_rcv(buf, sizeof(buf), tmo);
 138                 if (-ETIMEDOUT == r)
 139                 {
 140                         sm_syslog(LOG_DEBUG, NOQID, "queue manager: rcv=timed_out");
 141                         continue;
 142                 }
 143                 if (r < 0)
 144                 {
 145                         sm_syslog(LOG_DEBUG, NOQID, "queue manager: rcv=%d", r);
 146                         goto end;
 147                 }
 148                 if (r > 0 && r < sizeof(buf))
 149                         buf[r] = '\0';
 150                 buf[sizeof(buf) - 1] = '\0';
 151                 sm_syslog(LOG_DEBUG, NOQID, "queue manager: got=%s", buf);
 152                 CurEnv = &QmEnvelope;
 153                 rpool = sm_rpool_new_x(NULL);
 154                 e = newenvelope(&QmEnvelope, CurEnv, rpool);
 155                 e->e_flags = BlankEnvelope.e_flags;
 156                 e->e_parent = NULL;
 157                 r = sm_io_sscanf(buf, "N:%d:%d:%s", &e->e_qgrp, &e->e_qdir, e->e_id);
 158                 if (r != 3)
 159                 {
 160                         sm_syslog(LOG_DEBUG, NOQID, "queue manager: buf=%s, scan=%d", buf, r);
 161                         goto end;
 162                 }
 163                 dowork(e->e_qgrp, e->e_qdir, e->e_id, true, false, e);
 164         }
 165
 166   end:
 167         sm_syslog(LOG_DEBUG, NOQID, "queue manager: stop");
 168         finis(false, false, EX_OK);
 169         /* NOTREACHED */
 170         return false;
 171 }
 172 #endif /* _FFR_DMTRIGGER */