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 367472ecd3a1a520401f1e9daafeb66a4c497a82..8d85c13f1d2128d6eb6c3961e4e8e70bff462b92 100644 (file)
--- a/src/exim_monitor/em_log.c
+++ b/src/exim_monitor/em_log.c
@@ -1,13 +1,12 @@
-/* $Cambridge: exim/src/exim_monitor/em_log.c,v 1.3 2006/02/07 11:18:59 ph10 Exp $ */
-
 /*************************************************
 *                 Exim Monitor                   *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2006 */
+/* 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 smaill log,
+/* This module contains code for scanning the main log,
 extracting information from it, and displaying a "tail". */
 
 #include "em_hdr.h"
@@ -58,6 +57,8 @@ static int scrolled = FALSE;
 static int size = 0;
 static int top = 0;
 
+static void show_log(char *s, ...) PRINTF_FUNCTION(1,2);
+
 static void show_log(char *s, ...)
 {
 int length, newtop;
@@ -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) */
 
@@ -236,28 +241,32 @@ 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. */
+    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)
       {
-      if ((buffer[20] == '+' || buffer[20] == '-') &&
-          isdigit(buffer[21]) && buffer[25] == ' ')
+      int pidlength = 0;
+      if (  (buffer[20] == '+' || buffer[20] == '-')
+         && isdigit(buffer[21]) && buffer[25] == ' ')
         memmove(buffer + 20, buffer + 26, Ustrlen(buffer + 26) + 1);
-      id = string_copyn(buffer + 20, MESSAGE_ID_LENGTH);
+      if (buffer[20] == '[')
+        while (Ustrchr("[]0123456789", buffer[20+pidlength++]) != NULL)
+         ;
+      id = string_copyn(buffer + 20 + pidlength, MESSAGE_ID_LENGTH);
       show_log("%s", buffer+11);
       }
     else
@@ -265,18 +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
@@ -286,7 +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;
@@ -358,7 +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), 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)
@@ -385,7 +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;
     }
   }