source/profile/profile.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    store smbd profiling information in shared memory
   4    Copyright (C) Andrew Tridgell 1999
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20 */
  21
  22 #include "includes.h"
  23
  24 #ifdef WITH_PROFILE
  25 #define IPC_PERMS ((S_IRUSR | S_IWUSR) | S_IRGRP | S_IROTH)
  26 #endif /* WITH_PROFILE */
  27
  28 #ifdef WITH_PROFILE
  29 static int shm_id;
  30 static BOOL read_only;
  31 #if defined(HAVE_CLOCK_GETTIME)
  32 clockid_t __profile_clock;
  33 #endif
  34 #endif
  35
  36 struct profile_header *profile_h;
  37 struct profile_stats *profile_p;
  38
  39 BOOL do_profile_flag = False;
  40 BOOL do_profile_times = False;
  41
  42 /****************************************************************************
  43 receive a set profile level message
  44 ****************************************************************************/
  45 void profile_message(int msg_type, struct process_id src, void *buf, size_t len)
  46 {
  47         int level;
  48
  49         memcpy(&level, buf, sizeof(int));
  50 #ifdef WITH_PROFILE
  51         switch (level) {
  52         case 0:         /* turn off profiling */
  53                 do_profile_flag = False;
  54                 do_profile_times = False;
  55                 DEBUG(1,("INFO: Profiling turned OFF from pid %d\n",
  56                          (int)procid_to_pid(&src)));
  57                 break;
  58         case 1:         /* turn on counter profiling only */
  59                 do_profile_flag = True;
  60                 do_profile_times = False;
  61                 DEBUG(1,("INFO: Profiling counts turned ON from pid %d\n",
  62                          (int)procid_to_pid(&src)));
  63                 break;
  64         case 2:         /* turn on complete profiling */
  65                 do_profile_flag = True;
  66                 do_profile_times = True;
  67                 DEBUG(1,("INFO: Full profiling turned ON from pid %d\n",
  68                          (int)procid_to_pid(&src)));
  69                 break;
  70         case 3:         /* reset profile values */
  71                 memset((char *)profile_p, 0, sizeof(*profile_p));
  72                 DEBUG(1,("INFO: Profiling values cleared from pid %d\n",
  73                          (int)procid_to_pid(&src)));
  74                 break;
  75         }
  76 #else /* WITH_PROFILE */
  77         DEBUG(1,("INFO: Profiling support unavailable in this build.\n"));
  78 #endif /* WITH_PROFILE */
  79 }
  80
  81 /****************************************************************************
  82 receive a request profile level message
  83 ****************************************************************************/
  84 void reqprofile_message(int msg_type, struct process_id src,
  85                         void *buf, size_t len)
  86 {
  87         int level;
  88
  89 #ifdef WITH_PROFILE
  90         level = 1 + (do_profile_flag?2:0) + (do_profile_times?4:0);
  91 #else
  92         level = 0;
  93 #endif
  94         DEBUG(1,("INFO: Received REQ_PROFILELEVEL message from PID %u\n",
  95                  (unsigned int)procid_to_pid(&src)));
  96         message_send_pid(src, MSG_PROFILELEVEL, &level, sizeof(int), True);
  97 }
  98
  99 /*******************************************************************
 100   open the profiling shared memory area
 101   ******************************************************************/
 102 #ifdef WITH_PROFILE
 103 BOOL profile_setup(BOOL rdonly)
 104 {
 105         struct shmid_ds shm_ds;
 106
 107         read_only = rdonly;
 108
 109 #if defined(HAVE_CLOCK_GETTIME)
 110         if (this_is_smp()) {
 111                 /* This is faster that gettimeofday, but not fast enough to
 112                  * leave it enabled in production.
 113                  */
 114                 __profile_clock = CLOCK_MONOTONIC;
 115         } else {
 116                 /* CLOCK_PROCESS_CPUTIME_ID is sufficiently fast that the
 117                  * always profiling times is plausible. Unfortunately it is
 118                  * only accurate if we can guarantee we will not be scheduled
 119                  * onto a different CPU between samples. Until there is some
 120                  * way to set processor affinity, we can only use this on
 121                  * uniprocessors.
 122                  */
 123                 __profile_clock = CLOCK_PROCESS_CPUTIME_ID;
 124         }
 125 #endif
 126
 127  again:
 128         /* try to use an existing key */
 129         shm_id = shmget(PROF_SHMEM_KEY, 0, 0);
 130
 131         /* if that failed then create one. There is a race condition here
 132            if we are running from inetd. Bad luck. */
 133         if (shm_id == -1) {
 134                 if (read_only) return False;
 135                 shm_id = shmget(PROF_SHMEM_KEY, sizeof(*profile_h),
 136                                 IPC_CREAT | IPC_EXCL | IPC_PERMS);
 137         }
 138
 139         if (shm_id == -1) {
 140                 DEBUG(0,("Can't create or use IPC area. Error was %s\n",
 141                          strerror(errno)));
 142                 return False;
 143         }
 144
 145
 146         profile_h = (struct profile_header *)shmat(shm_id, 0,
 147                                                    read_only?SHM_RDONLY:0);
 148         if ((long)profile_p == -1) {
 149                 DEBUG(0,("Can't attach to IPC area. Error was %s\n",
 150                          strerror(errno)));
 151                 return False;
 152         }
 153
 154         /* find out who created this memory area */
 155         if (shmctl(shm_id, IPC_STAT, &shm_ds) != 0) {
 156                 DEBUG(0,("ERROR shmctl : can't IPC_STAT. Error was %s\n",
 157                          strerror(errno)));
 158                 return False;
 159         }
 160
 161         if (shm_ds.shm_perm.cuid != sec_initial_uid() ||
 162             shm_ds.shm_perm.cgid != sec_initial_gid()) {
 163                 DEBUG(0,("ERROR: we did not create the shmem "
 164                          "(owned by another user, uid %u, gid %u)\n",
 165                          shm_ds.shm_perm.cuid,
 166                          shm_ds.shm_perm.cgid));
 167                 return False;
 168         }
 169
 170         if (shm_ds.shm_segsz != sizeof(*profile_h)) {
 171                 DEBUG(0,("WARNING: profile size is %d (expected %d). Deleting\n",
 172                          (int)shm_ds.shm_segsz, sizeof(*profile_h)));
 173                 if (shmctl(shm_id, IPC_RMID, &shm_ds) == 0) {
 174                         goto again;
 175                 } else {
 176                         return False;
 177                 }
 178         }
 179
 180         if (!read_only && (shm_ds.shm_nattch == 1)) {
 181                 memset((char *)profile_h, 0, sizeof(*profile_h));
 182                 profile_h->prof_shm_magic = PROF_SHM_MAGIC;
 183                 profile_h->prof_shm_version = PROF_SHM_VERSION;
 184                 DEBUG(3,("Initialised profile area\n"));
 185         }
 186
 187         profile_p = &profile_h->stats;
 188         message_register(MSG_PROFILE, profile_message);
 189         message_register(MSG_REQ_PROFILELEVEL, reqprofile_message);
 190         return True;
 191 }
 192 #endif /* WITH_PROFILE */