web/src/alpined.d/signal.c

   1 /* ========================================================================
   2  * Copyright 2006-2008 University of Washington
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * ========================================================================
  11  */
  12
  13 #include <system.h>
  14 #include <general.h>
  15
  16 #include "../../../c-client/c-client.h"
  17
  18 #include "../../../pith/conf.h"
  19 #include "../../../pith/status.h"
  20 #include "../../../pith/signal.h"
  21 #include "../../../pith/debug.h"
  22 #include "../../../pith/adrbklib.h"
  23 #include "../../../pith/remote.h"
  24 #include "../../../pith/imap.h"
  25
  26 #include "alpined.h"
  27 #include "debug.h"
  28
  29
  30 static  int cleanup_called_from_sig_handler;
  31
  32 static  RETSIGTYPE      hup_signal(int);
  33 static  RETSIGTYPE      term_signal(int);
  34 static  RETSIGTYPE      auger_in_signal(int);
  35 int                     fast_clean_up(void);
  36 void                    end_signals(int);
  37 #if     defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
  38 static  RETSIGTYPE      usr1_signal(int);
  39 static  RETSIGTYPE      usr2_signal(int);
  40 #endif
  41
  42
  43 /*----------------------------------------------------------------------
  44     Install handlers for all the signals we care to catch
  45   ----------------------------------------------------------------------*/
  46 void
  47 init_signals(void)
  48 {
  49     /* prepare for unexpected exit */
  50     signal(SIGHUP,  hup_signal);
  51     signal(SIGTERM, term_signal);
  52
  53     /* prepare for unforeseen problems */
  54     signal(SIGILL,  auger_in_signal);
  55     signal(SIGTRAP, auger_in_signal);
  56 #ifdef  SIGEMT
  57     signal(SIGEMT,  auger_in_signal);
  58 #endif
  59     signal(SIGBUS,  auger_in_signal);
  60     signal(SIGSEGV, auger_in_signal);
  61     signal(SIGSYS,  auger_in_signal);
  62
  63 #if     defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
  64     /* Set up SIGUSR2 to {in,de}crement debug level */
  65     signal(SIGUSR1, usr1_signal);
  66     signal(SIGUSR2, usr2_signal);
  67 #endif
  68 }
  69
  70
  71 /*----------------------------------------------------------------------
  72       handle hang up signal -- SIGHUP
  73
  74 Not much to do. Rely on periodic mail file check pointing.
  75   ----------------------------------------------------------------------*/
  76 static RETSIGTYPE
  77 hup_signal(int sig)
  78 {
  79     end_signals(1);
  80     cleanup_called_from_sig_handler = 1;
  81
  82     while(!fast_clean_up())
  83       sleep(1);
  84
  85     if(peSocketName)            /* clean up unix domain socket */
  86       (void) unlink(peSocketName);
  87
  88     exceptional_exit("SIGHUP received", 0);
  89 }
  90
  91
  92 /*----------------------------------------------------------------------
  93       handle terminate signal -- SIGTERM
  94
  95 Not much to do. Rely on periodic mail file check pointing.
  96   ----------------------------------------------------------------------*/
  97 static RETSIGTYPE
  98 term_signal(int sig)
  99 {
 100     end_signals(1);
 101     cleanup_called_from_sig_handler = 1;
 102
 103     while(!fast_clean_up())
 104       sleep(1);
 105
 106     if(peSocketName)            /* clean up unix domain socket */
 107       (void) unlink(peSocketName);
 108
 109     exceptional_exit("SIGTERM received", 0);
 110 }
 111
 112
 113 /*----------------------------------------------------------------------
 114      Handle signals caused by aborts -- SIGSEGV, SIGILL, etc
 115
 116 Call panic which cleans up tty modes and then core dumps
 117   ----------------------------------------------------------------------*/
 118 static RETSIGTYPE
 119 auger_in_signal(int sig)
 120 {
 121     end_signals(1);
 122
 123     if(peSocketName)            /* clean up unix domain socket */
 124       (void) unlink(peSocketName);
 125
 126     snprintf(tmp_20k_buf, SIZEOF_20KBUF, "Abort: signal %d", sig);
 127     alpine_panic(tmp_20k_buf);          /* clean up and get out */
 128     exit(-1);                   /* in case panic doesn't kill us */
 129 }
 130
 131
 132 /*----------------------------------------------------------------------
 133      Handle cleaning up mail streams and tty modes...
 134 Not much to do. Rely on periodic mail file check pointing.  Don't try
 135 cleaning up screen or flushing output since stdout is likely already
 136 gone.  To be safe, though, we'll at least restore the original tty mode.
 137 Also delete any remnant _DATAFILE_ from sending-filters.
 138   ----------------------------------------------------------------------*/
 139 int
 140 fast_clean_up(void)
 141 {
 142     int         i;
 143     MAILSTREAM *m;
 144
 145     if(ps_global->expunge_in_progress)
 146       return(0);
 147
 148     /*
 149      * This gets rid of temporary cache files for remote addrbooks.
 150      */
 151     completely_done_with_adrbks();
 152
 153     /*
 154      * This flushes out deferred changes and gets rid of temporary cache
 155      * files for remote config files.
 156      */
 157     if(ps_global->prc){
 158         if(ps_global->prc->outstanding_pinerc_changes)
 159           write_pinerc(ps_global, Main,
 160                        cleanup_called_from_sig_handler ? WRP_NOUSER : WRP_NONE);
 161
 162         if(ps_global->prc->rd)
 163           rd_close_remdata(&ps_global->prc->rd);
 164
 165         free_pinerc_s(&ps_global->prc);
 166     }
 167
 168     /* as does this */
 169     if(ps_global->post_prc){
 170         if(ps_global->post_prc->outstanding_pinerc_changes)
 171           write_pinerc(ps_global, Post,
 172                        cleanup_called_from_sig_handler ? WRP_NOUSER : WRP_NONE);
 173
 174         if(ps_global->post_prc->rd)
 175           rd_close_remdata(&ps_global->post_prc->rd);
 176
 177         free_pinerc_s(&ps_global->post_prc);
 178     }
 179
 180     /*
 181      * Can't figure out why this section is inside the ifdef, but no
 182      * harm leaving it that way, I guess.
 183      */
 184 #if !defined(DOS) && !defined(OS2)
 185     for(i = 0; i < ps_global->s_pool.nstream; i++){
 186         m = ps_global->s_pool.streams[i];
 187         if(m && !m->lock)
 188           pine_mail_actually_close(m);
 189     }
 190 #endif  /* !DOS */
 191
 192     imap_flush_passwd_cache(TRUE);
 193
 194     if(peSocketName)            /* clean up unix domain socket */
 195       (void) unlink(peSocketName);
 196
 197     dprint((1, "done with fast_clean_up\n"));
 198     return(1);
 199 }
 200
 201
 202
 203 /*----------------------------------------------------------------------
 204     Return all signal handling back to normal
 205   ----------------------------------------------------------------------*/
 206 void
 207 end_signals(int blockem)
 208 {
 209 #ifndef SIG_ERR
 210 #define SIG_ERR (RETSIGTYPE (*)())-1
 211 #endif
 212     if(signal(SIGILL,  blockem ? SIG_IGN : SIG_DFL) != SIG_ERR){
 213         signal(SIGTRAP, blockem ? SIG_IGN : SIG_DFL);
 214 #ifdef  SIGEMT
 215         signal(SIGEMT,  blockem ? SIG_IGN : SIG_DFL);
 216 #endif
 217         signal(SIGBUS,  blockem ? SIG_IGN : SIG_DFL);
 218         signal(SIGSEGV, blockem ? SIG_IGN : SIG_DFL);
 219         signal(SIGSYS,  blockem ? SIG_IGN : SIG_DFL);
 220         signal(SIGHUP,  blockem ? SIG_IGN : SIG_DFL);
 221         signal(SIGTERM, blockem ? SIG_IGN : SIG_DFL);
 222         signal(SIGINT,  blockem ? SIG_IGN : SIG_DFL);
 223     }
 224 }
 225
 226
 227 #if     defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
 228 /*----------------------------------------------------------------------
 229       handle -- SIGUSR1
 230
 231   Increment debug level
 232   ----------------------------------------------------------------------*/
 233 static RETSIGTYPE
 234 usr1_signal(int sig)
 235 {
 236     if(debug < 11)
 237       debug++;
 238
 239     setup_imap_debug();
 240
 241     dprint((SYSDBG_INFO, "Debug level now %d", debug));
 242 }
 243
 244 /*----------------------------------------------------------------------
 245       handle -- SIGUSR2
 246
 247   Decrement debug level
 248   ----------------------------------------------------------------------*/
 249 static RETSIGTYPE
 250 usr2_signal(int sig)
 251 {
 252     if(debug > 0)
 253       debug--;
 254
 255     setup_imap_debug();
 256
 257     dprint((SYSDBG_INFO, "Debug level now %d", debug));
 258
 259 }
 260 #endif
 261
 262
 263 /*
 264  * Command interrupt support.
 265  */
 266 int
 267 intr_handling_on(void)
 268 {
 269     return 0;
 270 }
 271
 272
 273 void
 274 intr_handling_off(void)
 275 {
 276 }