exim_monitor/em_log.c

   1 /*************************************************
   2 *                 Exim Monitor                   *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2016 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 /* This module contains code for scanning the main log,
   9 extracting information from it, and displaying a "tail". */
  10
  11 #include "em_hdr.h"
  12
  13 #define log_buffer_len 4096      /* For each log entry */
  14
  15 /* If anonymizing, don't alter these strings (this is all an ad hoc hack). */
  16
  17 #ifdef ANONYMIZE
  18 static char *oklist[] = {
  19   "Completed",
  20   "defer",
  21   "from",
  22   "Connection timed out",
  23   "Start queue run: pid=",
  24   "End queue run: pid=",
  25   "host lookup did not complete",
  26   "unexpected disconnection while reading SMTP command from",
  27   "verify failed for SMTP recipient",
  28   "H=",
  29   "U=",
  30   "id=",
  31   "<",
  32   ">",
  33   "(",
  34   ")",
  35   "[",
  36   "]",
  37   "@",
  38   "=",
  39   "*",
  40   ".",
  41   "-",
  42   "\"",
  43   " ",
  44   "\n"};
  45 static int oklist_size = sizeof(oklist) / sizeof(uschar *);
  46 #endif
  47
  48
  49
  50 /*************************************************
  51 *             Write to the log display           *
  52 *************************************************/
  53
  54 static int visible = 0;
  55 static int scrolled = FALSE;
  56 static int size = 0;
  57 static int top = 0;
  58
  59 static void show_log(char *s, ...) PRINTF_FUNCTION(1,2);
  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   if (fseek(LOG, log_position, SEEK_SET))
 221     {
 222     perror("logfile fseek");
 223     exit(1);
 224     }
 225
 226   while (Ufgets(buffer, log_buffer_len, LOG) != NULL)
 227     {
 228     uschar *id;
 229     uschar *p = buffer;
 230     void *reset_point;
 231     int length = Ustrlen(buffer);
 232     int i;
 233
 234     /* Skip totally blank lines (paranoia: there shouldn't be any) */
 235
 236     while (*p == ' ' || *p == '\t') p++;
 237     if (*p == '\n') continue;
 238
 239     /* We should now have a complete log entry in the buffer; check
 240     it for various regular expression matches and take appropriate
 241     action. Get the current store point so we can reset to it. */
 242
 243     reset_point = store_get(0);
 244
 245     /* First, update any stripchart data values, noting that the zeroth
 246     stripchart is the queue length, which is handled elsewhere, and the
 247     1st may the a size monitor. */
 248
 249     for (i = stripchart_varstart; i < stripchart_number; i++)
 250       {
 251       if (pcre_exec(stripchart_regex[i], NULL, CS buffer, length, 0, PCRE_EOPT,
 252             NULL, 0) >= 0)
 253         stripchart_total[i]++;
 254       }
 255
 256     /* Munge the log entry and display shortened form on one line.
 257     We omit the date and show only the time. Remove any time zone offset.
 258     Take note of the presence of [pid]. */
 259
 260     if (pcre_exec(yyyymmdd_regex,NULL,CS buffer,length,0,PCRE_EOPT,NULL,0) >= 0)
 261       {
 262       int pidlength = 0;
 263       if ((buffer[20] == '+' || buffer[20] == '-') &&
 264           isdigit(buffer[21]) && buffer[25] == ' ')
 265         memmove(buffer + 20, buffer + 26, Ustrlen(buffer + 26) + 1);
 266       if (buffer[20] == '[')
 267         {
 268         while (Ustrchr("[]0123456789", buffer[20+pidlength++]) != NULL);
 269         }
 270       id = string_copyn(buffer + 20 + pidlength, MESSAGE_ID_LENGTH);
 271       show_log("%s", buffer+11);
 272       }
 273     else
 274       {
 275       id = US"";
 276       show_log("%s", buffer);
 277       }
 278
 279     /* Deal with frozen and unfrozen messages */
 280
 281     if (strstric(buffer, US"frozen", FALSE) != NULL)
 282       {
 283       queue_item *qq = find_queue(id, queue_noop, 0);
 284       if (qq != NULL)
 285         {
 286         if (strstric(buffer, US"unfrozen", FALSE) != NULL)
 287           qq->frozen = FALSE;
 288         else qq->frozen = TRUE;
 289         }
 290       }
 291
 292     /* Notice defer messages, and add the destination if it
 293     isn't already on the list for this message, with a pointer
 294     to the parent if we can. */
 295
 296     if ((p = Ustrstr(buffer, "==")) != NULL)
 297       {
 298       queue_item *qq = find_queue(id, queue_noop, 0);
 299       if (qq != NULL)
 300         {
 301         dest_item *d;
 302         uschar *q, *r;
 303         p += 2;
 304         while (isspace(*p)) p++;
 305         q = p;
 306         while (*p != 0 && !isspace(*p))
 307           {
 308           if (*p++ != '\"') continue;
 309           while (*p != 0)
 310             {
 311             if (*p == '\\') p += 2;
 312               else if (*p++ == '\"') break;
 313             }
 314           }
 315         *p++ = 0;
 316         if ((r = strstric(q, qualify_domain, FALSE)) != NULL &&
 317           *(--r) == '@') *r = 0;
 318
 319         /* If we already have this destination, as tested case-insensitively,
 320         do not add it to the destinations list. */
 321
 322         d = find_dest(qq, q, dest_add, TRUE);
 323
 324         if (d->parent == NULL)
 325           {
 326           while (isspace(*p)) p++;
 327           if (*p == '<')
 328             {
 329             dest_item *dd;
 330             q = ++p;
 331             while (*p != 0 && *p != '>') p++;
 332             *p = 0;
 333             if ((p = strstric(q, qualify_domain, FALSE)) != NULL &&
 334               *(--p) == '@') *p = 0;
 335             dd = find_dest(qq, q, dest_noop, FALSE);
 336             if (dd != NULL && dd != d) d->parent = dd;
 337             }
 338           }
 339         }
 340       }
 341
 342     store_reset(reset_point);
 343     }
 344   }
 345
 346
 347 /* We have to detect when the log file is changed, and switch to the new file.
 348 In practice, for non-datestamped files, this means that some deliveries might
 349 go unrecorded, since they'll be written to the old file, but this usually
 350 happens in the middle of the night, and I don't think the hassle of keeping
 351 track of two log files is worth it.
 352
 353 First we check the datestamped name of the log file if necessary; if it is
 354 different to the file we currently have open, go for the new file. As happens
 355 in Exim itself, we leave in the following inode check, even when datestamping
 356 because it does no harm and will cope should a file actually be renamed for
 357 some reason.
 358
 359 The test for a changed log file is to look up the inode of the file by name and
 360 compare it with the saved inode of the file we currently are processing. This
 361 accords with the usual interpretation of POSIX and other Unix specs that imply
 362 "one file, one inode". However, it appears that on some Digital systems, if an
 363 open file is unlinked, a new file may be created with the same inode while the
 364 old file remains in existence. This can happen if the old log file is renamed,
 365 processed in some way, and then deleted. To work round this, also test for a
 366 link count of zero on the currently open file. */
 367
 368 if (log_datestamping)
 369   {
 370   uschar log_file_wanted[256];
 371   /* Do *not* use "%s" here, we need the %D datestamp in the log_file to
 372    *   be expanded! */
 373   string_format(log_file_wanted, sizeof(log_file_wanted), CS log_file);
 374   if (Ustrcmp(log_file_wanted, log_file_open) != 0)
 375     {
 376     if (LOG != NULL)
 377       {
 378       fclose(LOG);
 379       LOG = NULL;
 380       }
 381     Ustrcpy(log_file_open, log_file_wanted);
 382     }
 383   }
 384
 385 if (LOG == NULL ||
 386     (fstat(fileno(LOG), &statdata) == 0 && statdata.st_nlink == 0) ||
 387     (Ustat(log_file, &statdata) == 0 && log_inode != statdata.st_ino))
 388   {
 389   FILE *TEST;
 390
 391   /* Experiment shows that sometimes you can't immediately open
 392   the new log file - presumably immediately after the old one
 393   is renamed and before the new one exists. Therefore do a
 394   trial open first to be sure. */
 395
 396   if ((TEST = fopen(CS log_file_open, "r")) != NULL)
 397     {
 398     if (LOG != NULL) fclose(LOG);
 399     LOG = TEST;
 400     if (fstat(fileno(LOG), &statdata))
 401       {
 402       fprintf(stderr, "fstat %s: %s\n", log_file_open, strerror(errno));
 403       exit(1);
 404       }
 405     log_inode = statdata.st_ino;
 406     }
 407   }
 408
 409 /* Save the position we have got to in the log. */
 410
 411 if (LOG != NULL) log_position = ftell(LOG);
 412 }
 413
 414 /* End of em_log.c */