web/src/alpined.d/signal.c

   1 #if !defined(lint) && !defined(DOS)
   2 static char rcsid[] = "$Id: signal.c 91 2006-07-28 19:02:07Z mikes@u.washington.edu $";
   3 #endif
   4
   5 /* ========================================================================
   6  * Copyright 2006-2008 University of Washington
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *     http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * ========================================================================
  15  */
  16
  17 #include <system.h>
  18 #include <general.h>
  19
  20 #include "../../../c-client/c-client.h"
  21
  22 #include "../../../pith/conf.h"
  23 #include "../../../pith/status.h"
  24 #include "../../../pith/signal.h"
  25 #include "../../../pith/debug.h"
  26 #include "../../../pith/adrbklib.h"
  27 #include "../../../pith/remote.h"
  28 #include "../../../pith/imap.h"
  29
  30 #include "alpined.h"
  31 #include "debug.h"
  32
  33
  34 static  int cleanup_called_from_sig_handler;
  35
  36 static  RETSIGTYPE      hup_signal(int);
  37 static  RETSIGTYPE      term_signal(int);
  38 static  RETSIGTYPE      auger_in_signal(int);
  39 int                     fast_clean_up();
  40 void                    end_signals(int);
  41 #if     defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
  42 static  RETSIGTYPE      usr1_signal(int);
  43 static  RETSIGTYPE      usr2_signal(int);
  44 #endif
  45
  46
  47 /*----------------------------------------------------------------------
  48     Install handlers for all the signals we care to catch
  49   ----------------------------------------------------------------------*/
  50 void
  51 init_signals(void)
  52 {
  53     /* prepare for unexpected exit */
  54     signal(SIGHUP,  hup_signal);
  55     signal(SIGTERM, term_signal);
  56
  57     /* prepare for unforseen problems */
  58     signal(SIGILL,  auger_in_signal);
  59     signal(SIGTRAP, auger_in_signal);
  60 #ifdef  SIGEMT
  61     signal(SIGEMT,  auger_in_signal);
  62 #endif
  63     signal(SIGBUS,  auger_in_signal);
  64     signal(SIGSEGV, auger_in_signal);
  65     signal(SIGSYS,  auger_in_signal);
  66
  67 #if     defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
  68     /* Set up SIGUSR2 to {in,de}crement debug level */
  69     signal(SIGUSR1, usr1_signal);
  70     signal(SIGUSR2, usr2_signal);
  71 #endif
  72 }
  73
  74
  75 /*----------------------------------------------------------------------
  76       handle hang up signal -- SIGHUP
  77
  78 Not much to do. Rely on periodic mail file check pointing.
  79   ----------------------------------------------------------------------*/
  80 static RETSIGTYPE
  81 hup_signal(int sig)
  82 {
  83     end_signals(1);
  84     cleanup_called_from_sig_handler = 1;
  85
  86     while(!fast_clean_up())
  87       sleep(1);
  88
  89     if(peSocketName)            /* clean up unix domain socket */
  90       (void) unlink(peSocketName);
  91
  92     exceptional_exit("SIGHUP received", 0);
  93 }
  94
  95
  96 /*----------------------------------------------------------------------
  97       handle terminate signal -- SIGTERM
  98
  99 Not much to do. Rely on periodic mail file check pointing.
 100   ----------------------------------------------------------------------*/
 101 static RETSIGTYPE
 102 term_signal(int sig)
 103 {
 104     end_signals(1);
 105     cleanup_called_from_sig_handler = 1;
 106
 107     while(!fast_clean_up())
 108       sleep(1);
 109
 110     if(peSocketName)            /* clean up unix domain socket */
 111       (void) unlink(peSocketName);
 112
 113     exceptional_exit("SIGTERM received", 0);
 114 }
 115
 116
 117 /*----------------------------------------------------------------------
 118      Handle signals caused by aborts -- SIGSEGV, SIGILL, etc
 119
 120 Call panic which cleans up tty modes and then core dumps
 121   ----------------------------------------------------------------------*/
 122 static RETSIGTYPE
 123 auger_in_signal(int sig)
 124 {
 125     end_signals(1);
 126
 127     if(peSocketName)            /* clean up unix domain socket */
 128       (void) unlink(peSocketName);
 129
 130     snprintf(tmp_20k_buf, SIZEOF_20KBUF, "Abort: signal %d", sig);
 131     alpine_panic(tmp_20k_buf);          /* clean up and get out */
 132     exit(-1);                   /* in case panic doesn't kill us */
 133 }
 134
 135
 136 /*----------------------------------------------------------------------
 137      Handle cleaning up mail streams and tty modes...
 138 Not much to do. Rely on periodic mail file check pointing.  Don't try
 139 cleaning up screen or flushing output since stdout is likely already
 140 gone.  To be safe, though, we'll at least restore the original tty mode.
 141 Also delete any remnant _DATAFILE_ from sending-filters.
 142   ----------------------------------------------------------------------*/
 143 int
 144 fast_clean_up(void)
 145 {
 146     int         i;
 147     MAILSTREAM *m;
 148
 149     if(ps_global->expunge_in_progress)
 150       return(0);
 151
 152     /*
 153      * This gets rid of temporary cache files for remote addrbooks.
 154      */
 155     completely_done_with_adrbks();
 156
 157     /*
 158      * This flushes out deferred changes and gets rid of temporary cache
 159      * files for remote config files.
 160      */
 161     if(ps_global->prc){
 162         if(ps_global->prc->outstanding_pinerc_changes)
 163           write_pinerc(ps_global, Main,
 164                        cleanup_called_from_sig_handler ? WRP_NOUSER : WRP_NONE);
 165
 166         if(ps_global->prc->rd)
 167           rd_close_remdata(&ps_global->prc->rd);
 168
 169         free_pinerc_s(&ps_global->prc);
 170     }
 171
 172     /* as does this */
 173     if(ps_global->post_prc){
 174         if(ps_global->post_prc->outstanding_pinerc_changes)
 175           write_pinerc(ps_global, Post,
 176                        cleanup_called_from_sig_handler ? WRP_NOUSER : WRP_NONE);
 177
 178         if(ps_global->post_prc->rd)
 179           rd_close_remdata(&ps_global->post_prc->rd);
 180
 181         free_pinerc_s(&ps_global->post_prc);
 182     }
 183
 184     /*
 185      * Can't figure out why this section is inside the ifdef, but no
 186      * harm leaving it that way, I guess.
 187      */
 188 #if !defined(DOS) && !defined(OS2)
 189     for(i = 0; i < ps_global->s_pool.nstream; i++){
 190         m = ps_global->s_pool.streams[i];
 191         if(m && !m->lock)
 192           pine_mail_actually_close(m);
 193     }
 194 #endif  /* !DOS */
 195
 196     imap_flush_passwd_cache(TRUE);
 197
 198     if(peSocketName)            /* clean up unix domain socket */
 199       (void) unlink(peSocketName);
 200
 201     dprint((1, "done with fast_clean_up\n"));
 202     return(1);
 203 }
 204
 205
 206
 207 /*----------------------------------------------------------------------
 208     Return all signal handling back to normal
 209   ----------------------------------------------------------------------*/
 210 void
 211 end_signals(int blockem)
 212 {
 213 #ifndef SIG_ERR
 214 #define SIG_ERR (RETSIGTYPE (*)())-1
 215 #endif
 216     if(signal(SIGILL,  blockem ? SIG_IGN : SIG_DFL) != SIG_ERR){
 217         signal(SIGTRAP, blockem ? SIG_IGN : SIG_DFL);
 218 #ifdef  SIGEMT
 219         signal(SIGEMT,  blockem ? SIG_IGN : SIG_DFL);
 220 #endif
 221         signal(SIGBUS,  blockem ? SIG_IGN : SIG_DFL);
 222         signal(SIGSEGV, blockem ? SIG_IGN : SIG_DFL);
 223         signal(SIGSYS,  blockem ? SIG_IGN : SIG_DFL);
 224         signal(SIGHUP,  blockem ? SIG_IGN : SIG_DFL);
 225         signal(SIGTERM, blockem ? SIG_IGN : SIG_DFL);
 226         signal(SIGINT,  blockem ? SIG_IGN : SIG_DFL);
 227     }
 228 }
 229
 230
 231 #if     defined(DEBUG) && defined(SIGUSR1) && defined(SIGUSR2)
 232 /*----------------------------------------------------------------------
 233       handle -- SIGUSR1
 234
 235   Increment debug level
 236   ----------------------------------------------------------------------*/
 237 static RETSIGTYPE
 238 usr1_signal(int sig)
 239 {
 240     if(debug < 11)
 241       debug++;
 242
 243     setup_imap_debug();
 244
 245     dprint((SYSDBG_INFO, "Debug level now %d", debug));
 246 }
 247
 248 /*----------------------------------------------------------------------
 249       handle -- SIGUSR2
 250
 251   Decrement debug level
 252   ----------------------------------------------------------------------*/
 253 static RETSIGTYPE
 254 usr2_signal(int sig)
 255 {
 256     if(debug > 0)
 257       debug--;
 258
 259     setup_imap_debug();
 260
 261     dprint((SYSDBG_INFO, "Debug level now %d", debug));
 262
 263 }
 264 #endif
 265
 266
 267 /*
 268  * Command interrupt support.
 269  */
 270 int
 271 intr_handling_on(void)
 272 {
 273     return 0;
 274 }
 275
 276
 277 void
 278 intr_handling_off(void)
 279 {
 280 }