ctdb/common/system.c

   1 /*
   2    common system utilities
   3
   4    Copyright (C) Amitay Isaacs  2014
   5    Copyright (C) Martin Schwenke  2014
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "replace.h"
  22 #include "system/filesys.h"
  23 #include "system/shmem.h"
  24 #include "system/network.h"
  25
  26 #include <talloc.h>
  27 #include <libgen.h>
  28
  29 #include "lib/util/debug.h"
  30
  31 #include "protocol/protocol.h"
  32
  33 #include "common/logging.h"
  34 #include "common/system.h"
  35
  36 #ifdef HAVE_SCHED_H
  37 #include <sched.h>
  38 #endif
  39
  40 #ifdef HAVE_PROCINFO_H
  41 #include <procinfo.h>
  42 #endif
  43
  44 #include "lib/util/mkdir_p.h"
  45
  46 /*
  47   if possible, make this task real time
  48  */
  49 bool set_scheduler(void)
  50 {
  51 #ifdef _AIX_
  52 #ifdef HAVE_THREAD_SETSCHED
  53         struct thrdentry64 te;
  54         tid64_t ti;
  55
  56         ti = 0ULL;
  57         if (getthrds64(getpid(), &te, sizeof(te), &ti, 1) != 1) {
  58                 DEBUG(DEBUG_ERR, ("Unable to get thread information\n"));
  59                 return false;
  60         }
  61
  62         if (thread_setsched(te.ti_tid, 0, SCHED_RR) == -1) {
  63                 DEBUG(DEBUG_ERR, ("Unable to set scheduler to SCHED_RR (%s)\n",
  64                                   strerror(errno)));
  65                 return false;
  66         } else {
  67                 return true;
  68         }
  69 #endif
  70 #else /* no AIX */
  71 #ifdef HAVE_SCHED_SETSCHEDULER
  72         struct sched_param p;
  73
  74         p.sched_priority = 1;
  75
  76         if (sched_setscheduler(0, SCHED_FIFO, &p) == -1) {
  77                 DEBUG(DEBUG_CRIT,("Unable to set scheduler to SCHED_FIFO (%s)\n",
  78                          strerror(errno)));
  79                 return false;
  80         } else {
  81                 return true;
  82         }
  83 #endif
  84 #endif
  85         DEBUG(DEBUG_CRIT,("No way to set real-time priority.\n"));
  86         return false;
  87 }
  88
  89 /*
  90   reset scheduler from real-time to normal scheduling
  91  */
  92 void reset_scheduler(void)
  93 {
  94 #ifdef _AIX_
  95 #ifdef HAVE_THREAD_SETSCHED
  96         struct thrdentry64 te;
  97         tid64_t ti;
  98
  99         ti = 0ULL;
 100         if (getthrds64(getpid(), &te, sizeof(te), &ti, 1) != 1) {
 101                 DEBUG(DEBUG_ERR, ("Unable to get thread information\n"));
 102         }
 103         if (thread_setsched(te.ti_tid, 0, SCHED_OTHER) == -1) {
 104                 DEBUG(DEBUG_ERR, ("Unable to set scheduler to SCHED_OTHER\n"));
 105         }
 106 #endif
 107 #else /* no AIX */
 108 #ifdef HAVE_SCHED_SETSCHEDULER
 109         struct sched_param p;
 110
 111         p.sched_priority = 0;
 112         if (sched_setscheduler(0, SCHED_OTHER, &p) == -1) {
 113                 DEBUG(DEBUG_ERR, ("Unable to set scheduler to SCHED_OTHER\n"));
 114         }
 115 #endif
 116 #endif
 117 }
 118
 119 /* we don't lock future pages here; it would increase the chance that
 120  * we'd fail to mmap later on. */
 121 void lockdown_memory(bool valgrinding)
 122 {
 123 #if defined(HAVE_MLOCKALL) && !defined(_AIX_)
 124         /* Extra stack, please! */
 125         char dummy[10000];
 126         memset(dummy, 0, sizeof(dummy));
 127
 128         if (valgrinding) {
 129                 return;
 130         }
 131
 132         /* Ignore when running in local daemons mode */
 133         if (getuid() != 0) {
 134                 return;
 135         }
 136
 137         /* Avoid compiler optimizing out dummy. */
 138         mlock(dummy, sizeof(dummy));
 139         if (mlockall(MCL_CURRENT) != 0) {
 140                 DEBUG(DEBUG_WARNING,("Failed to lockdown memory: %s'\n",
 141                                      strerror(errno)));
 142         }
 143 #endif
 144 }
 145
 146 void ctdb_wait_for_process_to_exit(pid_t pid)
 147 {
 148         while (kill(pid, 0) == 0 || errno != ESRCH) {
 149                 sleep(5);
 150         }
 151 }
 152
 153 #ifdef HAVE_AF_PACKET
 154
 155 bool ctdb_sys_check_iface_exists(const char *iface)
 156 {
 157         int s;
 158         struct ifreq ifr;
 159
 160         s = socket(AF_PACKET, SOCK_RAW, 0);
 161         if (s == -1){
 162                 /* We don't know if the interface exists, so assume yes */
 163                 DBG_ERR("Failed to open raw socket\n");
 164                 return true;
 165         }
 166
 167         strlcpy(ifr.ifr_name, iface, sizeof(ifr.ifr_name));
 168         if (ioctl(s, SIOCGIFINDEX, &ifr) < 0 && errno == ENODEV) {
 169                 DBG_ERR("Interface '%s' not found\n", iface);
 170                 close(s);
 171                 return false;
 172         }
 173         close(s);
 174
 175         return true;
 176 }
 177
 178 #else /* HAVE_AF_PACKET */
 179
 180 bool ctdb_sys_check_iface_exists(const char *iface)
 181 {
 182         /* Not implemented: Interface always considered present */
 183         return true;
 184 }
 185
 186 #endif /* HAVE_AF_PACKET */
 187
 188 #ifdef HAVE_PEERCRED
 189
 190 int ctdb_get_peer_pid(const int fd, pid_t *peer_pid)
 191 {
 192         struct ucred cr;
 193         socklen_t crl = sizeof(struct ucred);
 194         int ret;
 195
 196         ret = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &crl);
 197         if (ret == 0) {
 198                 *peer_pid = cr.pid;
 199         } else {
 200                 *peer_pid = -1;
 201         }
 202         return ret;
 203 }
 204
 205 #else /* HAVE_PEERCRED */
 206
 207 #ifdef _AIX_
 208
 209 int ctdb_get_peer_pid(const int fd, pid_t *peer_pid)
 210 {
 211         struct peercred_struct cr;
 212         socklen_t crl = sizeof(struct peercred_struct);
 213         int ret;
 214
 215         ret = getsockopt(fd, SOL_SOCKET, SO_PEERID, &cr, &crl);
 216         if (ret == 0) {
 217                 *peer_pid = cr.pid;
 218         } else {
 219                 *peer_pid = -1;
 220         }
 221         return ret;
 222 }
 223
 224 #else /* _AIX_ */
 225
 226 int ctdb_get_peer_pid(const int fd, pid_t *peer_pid)
 227 {
 228         /* Not implemented */
 229         *peer_pid = -1;
 230         return ENOSYS;
 231 }
 232
 233 #endif /* _AIX_ */
 234
 235 #endif /* HAVE_PEERCRED */