Fix regext substring capture variables for null matches. Bug 2933

[exim.git] / src / exim_monitor / em_log.c

diff --git a/src/exim_monitor/em_log.c b/src/exim_monitor/em_log.c
index bd1d462bf9a071738c9bc6053995c97b64c49667..8d85c13f1d2128d6eb6c3961e4e8e70bff462b92 100644 (file)
--- a/src/exim_monitor/em_log.c
+++ b/src/exim_monitor/em_log.c
@@ -2,7 +2,8 @@
 *                 Exim Monitor                   *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainters 2021 - 2022 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* This module contains code for scanning the main log,
@@ -217,15 +218,19 @@ uschar buffer[log_buffer_len];
 
 if (LOG != NULL)
   {
-  fseek(LOG, log_position, SEEK_SET);
+  if (fseek(LOG, log_position, SEEK_SET))
+    {
+    perror("logfile fseek");
+    exit(1);
+    }
 
   while (Ufgets(buffer, log_buffer_len, LOG) != NULL)
     {
     uschar *id;
     uschar *p = buffer;
-    void *reset_point;
+    rmark reset_point;
     int length = Ustrlen(buffer);
-    int i;
+    pcre2_match_data * md = pcre2_match_data_create(1, NULL);
 
     /* Skip totally blank lines (paranoia: there shouldn't be any) */
 
@@ -236,33 +241,31 @@ if (LOG != NULL)
     it for various regular expression matches and take appropriate
     action. Get the current store point so we can reset to it. */
 
-    reset_point = store_get(0);
+    reset_point = store_mark();
 
     /* First, update any stripchart data values, noting that the zeroth
     stripchart is the queue length, which is handled elsewhere, and the
     1st may the a size monitor. */
 
-    for (i = stripchart_varstart; i < stripchart_number; i++)
-      {
-      if (pcre_exec(stripchart_regex[i], NULL, CS buffer, length, 0, PCRE_EOPT,
-            NULL, 0) >= 0)
+    for (int i = stripchart_varstart; i < stripchart_number; i++)
+      if (pcre2_match(stripchart_regex[i], (PCRE2_SPTR)buffer, length,
+                       0, PCRE_EOPT, md, NULL) >= 0)
         stripchart_total[i]++;
-      }
 
     /* Munge the log entry and display shortened form on one line.
     We omit the date and show only the time. Remove any time zone offset.
     Take note of the presence of [pid]. */
 
-    if (pcre_exec(yyyymmdd_regex,NULL,CS buffer,length,0,PCRE_EOPT,NULL,0) >= 0)
+    if (pcre2_match(yyyymmdd_regex, (PCRE2_SPTR) buffer, length, 0, PCRE_EOPT,
+                     md, NULL) >= 0)
       {
       int pidlength = 0;
-      if ((buffer[20] == '+' || buffer[20] == '-') &&
-          isdigit(buffer[21]) && buffer[25] == ' ')
+      if (  (buffer[20] == '+' || buffer[20] == '-')
+         && isdigit(buffer[21]) && buffer[25] == ' ')
         memmove(buffer + 20, buffer + 26, Ustrlen(buffer + 26) + 1);
       if (buffer[20] == '[')
-        {
-        while (Ustrchr("[]0123456789", buffer[20+pidlength++]) != NULL);
-        }
+        while (Ustrchr("[]0123456789", buffer[20+pidlength++]) != NULL)
+         ;
       id = string_copyn(buffer + 20 + pidlength, MESSAGE_ID_LENGTH);
       show_log("%s", buffer+11);
       }
@@ -271,18 +274,15 @@ if (LOG != NULL)
       id = US"";
       show_log("%s", buffer);
       }
+    pcre2_match_data_free(md);
 
     /* Deal with frozen and unfrozen messages */
 
     if (strstric(buffer, US"frozen", FALSE) != NULL)
       {
       queue_item *qq = find_queue(id, queue_noop, 0);
-      if (qq != NULL)
-        {
-        if (strstric(buffer, US"unfrozen", FALSE) != NULL)
-          qq->frozen = FALSE;
-        else qq->frozen = TRUE;
-        }
+      if (qq)
+        qq->frozen = strstric(buffer, US"unfrozen", FALSE) == NULL;
       }
 
     /* Notice defer messages, and add the destination if it
@@ -292,7 +292,7 @@ if (LOG != NULL)
     if ((p = Ustrstr(buffer, "==")) != NULL)
       {
       queue_item *qq = find_queue(id, queue_noop, 0);
-      if (qq != NULL)
+      if (qq)
         {
         dest_item *d;
         uschar *q, *r;
@@ -364,7 +364,10 @@ link count of zero on the currently open file. */
 if (log_datestamping)
   {
   uschar log_file_wanted[256];
-  string_format(log_file_wanted, sizeof(log_file_wanted), "%s", CS log_file);
+  /* Do *not* use "%s" here, we need the %D datestamp in the log_file string to
+  be expanded.  The trailing NULL arg is to quieten preprocessors that need at
+  least one arg for a variadic set in a macro. */
+  string_format(log_file_wanted, sizeof(log_file_wanted), CS log_file, NULL);
   if (Ustrcmp(log_file_wanted, log_file_open) != 0)
     {
     if (LOG != NULL)
@@ -391,7 +394,11 @@ if (LOG == NULL ||
     {
     if (LOG != NULL) fclose(LOG);
     LOG = TEST;
-    fstat(fileno(LOG), &statdata);
+    if (fstat(fileno(LOG), &statdata))
+      {
+      fprintf(stderr, "fstat %s: %s\n", log_file_open, strerror(errno));
+      exit(1);
+      }
     log_inode = statdata.st_ino;
     }
   }