src/exim_monitor/em_log.c

   1 /* $Cambridge: exim/src/exim_monitor/em_log.c,v 1.6 2009/11/16 19:50:36 nm4 Exp $ */
   2
   3 /*************************************************
   4 *                 Exim Monitor                   *
   5 *************************************************/
   6
   7 /* Copyright (c) University of Cambridge 1995 - 2009 */
   8 /* See the file NOTICE for conditions of use and distribution. */
   9
  10 /* This module contains code for scanning the main log,
  11 extracting information from it, and displaying a "tail". */
  12
  13 #include "em_hdr.h"
  14
  15 #define log_buffer_len 4096      /* For each log entry */
  16
  17 /* If anonymizing, don't alter these strings (this is all an ad hoc hack). */
  18
  19 #ifdef ANONYMIZE
  20 static char *oklist[] = {
  21   "Completed",
  22   "defer",
  23   "from",
  24   "Connection timed out",
  25   "Start queue run: pid=",
  26   "End queue run: pid=",
  27   "host lookup did not complete",
  28   "unexpected disconnection while reading SMTP command from",
  29   "verify failed for SMTP recipient",
  30   "H=",
  31   "U=",
  32   "id=",
  33   "<",
  34   ">",
  35   "(",
  36   ")",
  37   "[",
  38   "]",
  39   "@",
  40   "=",
  41   "*",
  42   ".",
  43   "-",
  44   "\"",
  45   " ",
  46   "\n"};
  47 static int oklist_size = sizeof(oklist) / sizeof(uschar *);
  48 #endif
  49
  50
  51
  52 /*************************************************
  53 *             Write to the log display           *
  54 *************************************************/
  55
  56 static int visible = 0;
  57 static int scrolled = FALSE;
  58 static int size = 0;
  59 static int top = 0;
  60
  61 static void show_log(char *s, ...)
  62 {
  63 int length, newtop;
  64 va_list ap;
  65 XawTextBlock b;
  66 uschar buffer[log_buffer_len + 24];
  67
  68 /* Do nothing if not tailing a log */
  69
  70 if (log_widget == NULL) return;
  71
  72 /* Initialize the text block structure */
  73
  74 b.firstPos = 0;
  75 b.ptr = CS buffer;
  76 b.format = FMT8BIT;
  77
  78 /* We want to know whether the window has been scrolled back or not,
  79 so that we can cease automatically scrolling with new text. This turns
  80 out to be tricky with the text widget. We can detect whether the
  81 scroll bar has been operated by checking on the "top" value, but it's
  82 harder to detect that it has been returned to the bottom. The following
  83 heuristic does its best. */
  84
  85 newtop = XawTextTopPosition(log_widget);
  86 if (newtop != top)
  87   {
  88   if (!scrolled)
  89     {
  90     visible = size - top;      /* save size of window */
  91     scrolled = newtop < top;
  92     }
  93   else if (newtop > size - visible) scrolled = FALSE;
  94   top = newtop;
  95   }
  96
  97 /* Format the text that is to be written. */
  98
  99 va_start(ap, s);
 100 vsprintf(CS buffer, s, ap);
 101 va_end(ap);
 102 length = Ustrlen(buffer);
 103
 104 /* If we are anonymizing for screen shots, flatten various things. */
 105
 106 #ifdef ANONYMIZE
 107   {
 108   uschar *p = buffer + 9;
 109   if (p[6] == '-' && p[13] == '-') p += 17;
 110
 111   while (p < buffer + length)
 112     {
 113     int i;
 114
 115     /* Check for strings to be left alone */
 116
 117     for (i = 0; i < oklist_size; i++)
 118       {
 119       int len = Ustrlen(oklist[i]);
 120       if (Ustrncmp(p, oklist[i], len) == 0)
 121         {
 122         p += len;
 123         break;
 124         }
 125       }
 126     if (i < oklist_size) continue;
 127
 128     /* Leave driver names, size, protocol, alone */
 129
 130     if ((*p == 'D' || *p == 'P' || *p == 'T' || *p == 'S' || *p == 'R') &&
 131         p[1] == '=')
 132       {
 133       p += 2;
 134       while (*p != ' ' && *p != 0) p++;
 135       continue;
 136       }
 137
 138     /* Leave C= text alone */
 139
 140     if (Ustrncmp(p, "C=\"", 3) == 0)
 141       {
 142       p += 3;
 143       while (*p != 0 && *p != '"') p++;
 144       continue;
 145       }
 146
 147     /* Flatten remaining chars */
 148
 149     if (isdigit(*p)) *p++ = 'x';
 150     else if (isalpha(*p)) *p++ = 'x';
 151     else *p++ = '$';
 152     }
 153   }
 154 #endif
 155
 156 /* If this would overflow the buffer, throw away 50% of the
 157 current stuff in the buffer. Code defensively against odd
 158 extreme cases that shouldn't actually arise. */
 159
 160 if (size + length > log_buffer_size)
 161   {
 162   if (size == 0) length = log_buffer_size/2; else
 163     {
 164     int cutcount = log_buffer_size/2;
 165     if (cutcount > size) cutcount = size; else
 166       {
 167       while (cutcount < size && log_display_buffer[cutcount] != '\n')
 168         cutcount++;
 169       cutcount++;
 170       }
 171     b.length = 0;
 172     XawTextReplace(log_widget, 0, cutcount, &b);
 173     size -= cutcount;
 174     top -= cutcount;
 175     if (top < 0) top = 0;
 176     if (top < cutcount) XawTextInvalidate(log_widget, 0, 999999);
 177     xs_SetValues(log_widget, 1, "displayPosition", top);
 178     }
 179   }
 180
 181 /* Insert the new text at the end of the buffer. */
 182
 183 b.length = length;
 184 XawTextReplace(log_widget, 999999, 999999, &b);
 185 size += length;
 186
 187 /* When not scrolled back, we want to keep the bottom line
 188 always visible. Put the insert point at the start of it because
 189 this stops left/right scrolling with some X libraries. */
 190
 191 if (!scrolled)
 192   {
 193   XawTextSetInsertionPoint(log_widget, size - length);
 194   top = XawTextTopPosition(log_widget);
 195   }
 196 }
 197
 198
 199
 200
 201 /*************************************************
 202 *            Function to read the log            *
 203 *************************************************/
 204
 205 /* We read any new log entries, and use their data to
 206 updated total counts for the configured stripcharts.
 207 The count for the queue chart is handled separately.
 208 We also munge the log entries and display a one-line
 209 version in the log window. */
 210
 211 void read_log(void)
 212 {
 213 struct stat statdata;
 214 uschar buffer[log_buffer_len];
 215
 216 /* If log is not yet open, skip all of this. */
 217
 218 if (LOG != NULL)
 219   {
 220   fseek(LOG, log_position, SEEK_SET);
 221
 222   while (Ufgets(buffer, log_buffer_len, LOG) != NULL)
 223     {
 224     uschar *id;
 225     uschar *p = buffer;
 226     void *reset_point;
 227     int length = Ustrlen(buffer);
 228     int i;
 229
 230     /* Skip totally blank lines (paranoia: there shouldn't be any) */
 231
 232     while (*p == ' ' || *p == '\t') p++;
 233     if (*p == '\n') continue;
 234
 235     /* We should now have a complete log entry in the buffer; check
 236     it for various regular expression matches and take appropriate
 237     action. Get the current store point so we can reset to it. */
 238
 239     reset_point = store_get(0);
 240
 241     /* First, update any stripchart data values, noting that the zeroth
 242     stripchart is the queue length, which is handled elsewhere, and the
 243     1st may the a size monitor. */
 244
 245     for (i = stripchart_varstart; i < stripchart_number; i++)
 246       {
 247       if (pcre_exec(stripchart_regex[i], NULL, CS buffer, length, 0, PCRE_EOPT,
 248             NULL, 0) >= 0)
 249         stripchart_total[i]++;
 250       }
 251
 252     /* Munge the log entry and display shortened form on one line.
 253     We omit the date and show only the time. Remove any time zone offset.
 254     Take note of the presence of [pid]. */
 255
 256     if (pcre_exec(yyyymmdd_regex,NULL,CS buffer,length,0,PCRE_EOPT,NULL,0) >= 0)
 257       {
 258       int pidlength = 0;
 259       if ((buffer[20] == '+' || buffer[20] == '-') &&
 260           isdigit(buffer[21]) && buffer[25] == ' ')
 261         memmove(buffer + 20, buffer + 26, Ustrlen(buffer + 26) + 1);
 262       if (buffer[20] == '[')
 263         {
 264         while (Ustrchr("[]0123456789", buffer[20+pidlength++]) != NULL);
 265         }
 266       id = string_copyn(buffer + 20 + pidlength, MESSAGE_ID_LENGTH);
 267       show_log("%s", buffer+11);
 268       }
 269     else
 270       {
 271       id = US"";
 272       show_log("%s", buffer);
 273       }
 274
 275     /* Deal with frozen and unfrozen messages */
 276
 277     if (strstric(buffer, US"frozen", FALSE) != NULL)
 278       {
 279       queue_item *qq = find_queue(id, queue_noop, 0);
 280       if (qq != NULL)
 281         {
 282         if (strstric(buffer, US"unfrozen", FALSE) != NULL)
 283           qq->frozen = FALSE;
 284         else qq->frozen = TRUE;
 285         }
 286       }
 287
 288     /* Notice defer messages, and add the destination if it
 289     isn't already on the list for this message, with a pointer
 290     to the parent if we can. */
 291
 292     if ((p = Ustrstr(buffer, "==")) != NULL)
 293       {
 294       queue_item *qq = find_queue(id, queue_noop, 0);
 295       if (qq != NULL)
 296         {
 297         dest_item *d;
 298         uschar *q, *r;
 299         p += 2;
 300         while (isspace(*p)) p++;
 301         q = p;
 302         while (*p != 0 && !isspace(*p))
 303           {
 304           if (*p++ != '\"') continue;
 305           while (*p != 0)
 306             {
 307             if (*p == '\\') p += 2;
 308               else if (*p++ == '\"') break;
 309             }
 310           }
 311         *p++ = 0;
 312         if ((r = strstric(q, qualify_domain, FALSE)) != NULL &&
 313           *(--r) == '@') *r = 0;
 314
 315         /* If we already have this destination, as tested case-insensitively,
 316         do not add it to the destinations list. */
 317
 318         d = find_dest(qq, q, dest_add, TRUE);
 319
 320         if (d->parent == NULL)
 321           {
 322           while (isspace(*p)) p++;
 323           if (*p == '<')
 324             {
 325             dest_item *dd;
 326             q = ++p;
 327             while (*p != 0 && *p != '>') p++;
 328             *p = 0;
 329             if ((p = strstric(q, qualify_domain, FALSE)) != NULL &&
 330               *(--p) == '@') *p = 0;
 331             dd = find_dest(qq, q, dest_noop, FALSE);
 332             if (dd != NULL && dd != d) d->parent = dd;
 333             }
 334           }
 335         }
 336       }
 337
 338     store_reset(reset_point);
 339     }
 340   }
 341
 342
 343 /* We have to detect when the log file is changed, and switch to the new file.
 344 In practice, for non-datestamped files, this means that some deliveries might
 345 go unrecorded, since they'll be written to the old file, but this usually
 346 happens in the middle of the night, and I don't think the hassle of keeping
 347 track of two log files is worth it.
 348
 349 First we check the datestamped name of the log file if necessary; if it is
 350 different to the file we currently have open, go for the new file. As happens
 351 in Exim itself, we leave in the following inode check, even when datestamping
 352 because it does no harm and will cope should a file actually be renamed for
 353 some reason.
 354
 355 The test for a changed log file is to look up the inode of the file by name and
 356 compare it with the saved inode of the file we currently are processing. This
 357 accords with the usual interpretation of POSIX and other Unix specs that imply
 358 "one file, one inode". However, it appears that on some Digital systems, if an
 359 open file is unlinked, a new file may be created with the same inode while the
 360 old file remains in existence. This can happen if the old log file is renamed,
 361 processed in some way, and then deleted. To work round this, also test for a
 362 link count of zero on the currently open file. */
 363
 364 if (log_datestamping)
 365   {
 366   uschar log_file_wanted[256];
 367   string_format(log_file_wanted, sizeof(log_file_wanted), CS log_file);
 368   if (Ustrcmp(log_file_wanted, log_file_open) != 0)
 369     {
 370     if (LOG != NULL)
 371       {
 372       fclose(LOG);
 373       LOG = NULL;
 374       }
 375     Ustrcpy(log_file_open, log_file_wanted);
 376     }
 377   }
 378
 379 if (LOG == NULL ||
 380     (fstat(fileno(LOG), &statdata) == 0 && statdata.st_nlink == 0) ||
 381     (Ustat(log_file, &statdata) == 0 && log_inode != statdata.st_ino))
 382   {
 383   FILE *TEST;
 384
 385   /* Experiment shows that sometimes you can't immediately open
 386   the new log file - presumably immediately after the old one
 387   is renamed and before the new one exists. Therefore do a
 388   trial open first to be sure. */
 389
 390   if ((TEST = fopen(CS log_file_open, "r")) != NULL)
 391     {
 392     if (LOG != NULL) fclose(LOG);
 393     LOG = TEST;
 394     fstat(fileno(LOG), &statdata);
 395     log_inode = statdata.st_ino;
 396     }
 397   }
 398
 399 /* Save the position we have got to in the log. */
 400
 401 if (LOG != NULL) log_position = ftell(LOG);
 402 }
 403
 404 /* End of em_log.c */