Implement "control = debug" ACL control. Fixes: #937

8 files changed, 314 insertions, 169 deletions

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 003ae6db8..02020dc50 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -1,4 +1,4 @@
-. $Cambridge: exim/doc/doc-docbook/spec.xfpt,v 1.79 2010/06/05 23:50:18 pdp Exp $
+. $Cambridge: exim/doc/doc-docbook/spec.xfpt,v 1.80 2010/06/06 00:25:46 pdp Exp $
 .
 . /////////////////////////////////////////////////////////////////////////////
 . This is the primary source of the Exim Manual. It is an xfpt document that is
@@ -25772,6 +25772,23 @@ warn  control = caseful_local_part
 Notice that we put back the lower cased version afterwards, assuming that
 is what is wanted for subsequent tests.
 
+.vitem &*control&~=&~debug/*&<&'options'&>
+.cindex "&ACL;" "enabling debug logging"
+.cindex "debugging" "enabling from an ACL"
+This control turns on debug logging, almost as though Exim had been invoked
+with &`-d`&, with the output going to a new logfile, by default called
+&'debuglog'&.  The filename can be adjusted with the &'tag'& option, which
+may access any variables already defined.  The logging may be adjusted with
+the &'opts'& option, which takes the same values as the &`-d`& command-line
+option.  Some examples (which depend on variables that don't exist in all
+contexts):
+.code
+      control = debug
+      control = debug/tag=.$sender_host_address
+      control = debug/opts=+expand+acl
+      control = debug/tag=.$message_exim_id/opts=+expand
+.endd
+
 .vitem &*control&~=&~enforce_sync*& &&&
        &*control&~=&~no_enforce_sync*&
 .cindex "SMTP" "synchronization checking"
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 0591e4115..b89d1b44c 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -1,9 +1,10 @@
-$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.622 2010/06/05 23:50:18 pdp Exp $
+$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.623 2010/06/06 00:27:52 pdp Exp $
 
 Change log file for Exim from version 4.21
 -------------------------------------------
 
 Exim version 4.73
+-----------------
 
 PP/01 Date: & Message-Id: revert to normally being appended to a message,
       only prepend for the Resent-* case.  Fixes regression introduced in
@@ -33,6 +34,8 @@ PP/08 Bugzilla 926: switch ClamAV to use the new zINSTREAM API for content
 
 PP/09 Implemented reverse_ip expansion operator.
 
+PP/10 Bugzilla 937: provide a "debug" ACL control.
+
 
 Exim version 4.72
 -----------------
diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index 35ed9a399..a8606870c 100644
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.169 2010/06/05 23:50:18 pdp Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.170 2010/06/06 00:27:52 pdp Exp $
 
 New Features in Exim
 --------------------
@@ -51,6 +51,18 @@ Version 4.73
       ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
        -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
 
+ 6. There is a new ACL control called "debug", to enable debug logging.
+    This allows selective logging of certain incoming transactions within
+    production environments, with some care.  It takes two options, "tag"
+    and "opts"; "tag" is included in the filename of the log and "opts"
+    is used as per the -d<options> command-line option.  Examples, which
+    don't all make sense in all contexts:
+
+      control = debug
+      control = debug/tag=.$sender_host_address
+      control = debug/opts=+expand+acl
+      control = debug/tag=.$message_exim_id/opts=+expand
+
 
 Version 4.72
 ------------
diff --git a/src/src/acl.c b/src/src/acl.c
index 8825a8f13..4ad2b01b9 100644
--- a/src/src/acl.c
+++ b/src/src/acl.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/acl.c,v 1.87 2009/11/16 19:50:36 nm4 Exp $ */
+/* $Cambridge: exim/src/src/acl.c,v 1.88 2010/06/06 00:27:52 pdp Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -171,6 +171,7 @@ enum {
   #ifdef EXPERIMENTAL_BRIGHTMAIL
   CONTROL_BMI_RUN,
   #endif
+  CONTROL_DEBUG,
   #ifndef DISABLE_DKIM
   CONTROL_DKIM_VERIFY,
   #endif
@@ -204,6 +205,7 @@ static uschar *controls[] = {
   #ifdef EXPERIMENTAL_BRIGHTMAIL
   US"bmi_run",
   #endif
+  US"debug",
   #ifndef DISABLE_DKIM
   US"dkim_disable_verify",
   #endif
@@ -517,6 +519,8 @@ static unsigned int control_forbids[] = {
   0,                                               /* bmi_run */
   #endif
 
+  0,                                               /* debug */
+
   #ifndef DISABLE_DKIM
   (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)|      /* dkim_disable_verify */
     (1<<ACL_WHERE_NOTSMTP_START),
@@ -598,6 +602,7 @@ static control_def controls_list[] = {
 #ifdef EXPERIMENTAL_BRIGHTMAIL
   { US"bmi_run",                 CONTROL_BMI_RUN, FALSE },
 #endif
+  { US"debug",                   CONTROL_DEBUG, TRUE },
 #ifndef DISABLE_DKIM
   { US"dkim_disable_verify",     CONTROL_DKIM_VERIFY, FALSE },
 #endif
@@ -2416,6 +2421,8 @@ acl_check_condition(int verb, acl_condition_block *cb, int where,
 {
 uschar *user_message = NULL;
 uschar *log_message = NULL;
+uschar *debug_tag = NULL;
+uschar *debug_opts = NULL;
 uschar *p = NULL;
 int rc = OK;
 #ifdef WITH_CONTENT_SCAN
@@ -2703,6 +2710,27 @@ for (; cb != NULL; cb = cb->next)
         }
       break;
 
+      case CONTROL_DEBUG:
+      while (*p == '/')
+        {
+        if (Ustrncmp(p, "/tag=", 5) == 0)
+          {
+          uschar *pp = p + 5;
+          while (*pp != '\0' && *pp != '/') pp++;
+          debug_tag = string_copyn(p+5, pp-p-5);
+          p = pp;
+          }
+        else if (Ustrncmp(p, "/opts=", 6) == 0)
+          {
+          uschar *pp = p + 6;
+          while (*pp != '\0' && *pp != '/') pp++;
+          debug_opts = string_copyn(p+6, pp-p-6);
+          p = pp;
+          }
+        }
+        debug_logging_activate(debug_tag, debug_opts);
+      break;
+
       case CONTROL_SUPPRESS_LOCAL_FIXUPS:
       suppress_local_fixups = TRUE;
       break;
diff --git a/src/src/exim.c b/src/src/exim.c
index c54470bd6..7d1c3b6a6 100644
--- a/src/src/exim.c
+++ b/src/src/exim.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/exim.c,v 1.66 2010/06/05 11:13:29 pdp Exp $ */
+/* $Cambridge: exim/src/src/exim.c,v 1.67 2010/06/06 00:27:52 pdp Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -682,155 +682,6 @@ else
 
 
 /*************************************************
-*         Decode bit settings for log/debug      *
-*************************************************/
-
-/* This function decodes a string containing bit settings in the form of +name
-and/or -name sequences, and sets/unsets bits in a bit string accordingly. It
-also recognizes a numeric setting of the form =<number>, but this is not
-intended for user use. It's an easy way for Exim to pass the debug settings
-when it is re-exec'ed.
-
-The log options are held in two unsigned ints (because there became too many
-for one). The top bit in the table means "put in 2nd selector". This does not
-yet apply to debug options, so the "=" facility sets only the first selector.
-
-The "all" selector, which must be equal to 0xffffffff, is recognized specially.
-It sets all the bits in both selectors. However, there is a facility for then
-unsetting certain bits, because we want to turn off "memory" in the debug case.
-
-A bad value for a debug setting is treated as an unknown option - error message
-to stderr and die. For log settings, which come from the configuration file,
-we write to the log on the way out...
-
-Arguments:
-  selector1      address of the first bit string
-  selector2      address of the second bit string, or NULL
-  notall1        bits to exclude from "all" for selector1
-  notall2        bits to exclude from "all" for selector2
-  string         the configured string
-  options        the table of option names
-  count          size of table
-  which          "log" or "debug"
-
-Returns:         nothing on success - bomb out on failure
-*/
-
-static void
-decode_bits(unsigned int *selector1, unsigned int *selector2, int notall1,
-  int notall2, uschar *string, bit_table *options, int count, uschar *which)
-{
-uschar *errmsg;
-if (string == NULL) return;
-
-if (*string == '=')
-  {
-  char *end;    /* Not uschar */
-  *selector1 = strtoul(CS string+1, &end, 0);
-  if (*end == 0) return;
-  errmsg = string_sprintf("malformed numeric %s_selector setting: %s", which,
-    string);
-  goto ERROR_RETURN;
-  }
-
-/* Handle symbolic setting */
-
-else for(;;)
-  {
-  BOOL adding;
-  uschar *s;
-  int len;
-  bit_table *start, *end;
-
-  while (isspace(*string)) string++;
-  if (*string == 0) return;
-
-  if (*string != '+' && *string != '-')
-    {
-    errmsg = string_sprintf("malformed %s_selector setting: "
-      "+ or - expected but found \"%s\"", which, string);
-    goto ERROR_RETURN;
-    }
-
-  adding = *string++ == '+';
-  s = string;
-  while (isalnum(*string) || *string == '_') string++;
-  len = string - s;
-
-  start = options;
-  end = options + count;
-
-  while (start < end)
-    {
-    bit_table *middle = start + (end - start)/2;
-    int c = Ustrncmp(s, middle->name, len);
-    if (c == 0)
-      {
-      if (middle->name[len] != 0) c = -1; else
-        {
-        unsigned int bit = middle->bit;
-        unsigned int *selector;
-
-        /* The value with all bits set means "force all bits in both selectors"
-        in the case where two are being handled. However, the top bit in the
-        second selector is never set. When setting, some bits can be excluded.
-        */
-
-        if (bit == 0xffffffff)
-          {
-          if (adding)
-            {
-            *selector1 = 0xffffffff ^ notall1;
-            if (selector2 != NULL) *selector2 = 0x7fffffff ^ notall2;
-            }
-          else
-            {
-            *selector1 = 0;
-            if (selector2 != NULL) *selector2 = 0;
-            }
-          }
-
-        /* Otherwise, the 0x80000000 bit means "this value, without the top
-        bit, belongs in the second selector". */
-
-        else
-          {
-          if ((bit & 0x80000000) != 0)
-            {
-            selector = selector2;
-            bit &= 0x7fffffff;
-            }
-          else selector = selector1;
-          if (adding) *selector |= bit; else *selector &= ~bit;
-          }
-        break;  /* Out of loop to match selector name */
-        }
-      }
-    if (c < 0) end = middle; else start = middle + 1;
-    }  /* Loop to match selector name */
-
-  if (start >= end)
-    {
-    errmsg = string_sprintf("unknown %s_selector setting: %c%.*s", which,
-      adding? '+' : '-', len, s);
-    goto ERROR_RETURN;
-    }
-  }    /* Loop for selector names */
-
-/* Handle disasters */
-
-ERROR_RETURN:
-if (Ustrcmp(which, "debug") == 0)
-  {
-  fprintf(stderr, "exim: %s\n", errmsg);
-  exit(EXIT_FAILURE);
-  }
-else log_write(0, LOG_CONFIG|LOG_PANIC_DIE, "%s", errmsg);
-}
-
-
-
-/*************************************************
 *          Show supported features               *
 *************************************************/
 
@@ -2080,7 +1931,7 @@ for (i = 1; i < argc; i++)
         }
       if (*argrest != 0)
         decode_bits(&selector, NULL, D_memory, 0, argrest, debug_options,
-          debug_options_count, US"debug");
+          debug_options_count, US"debug", 0);
       debug_selector = selector;
       }
     break;
@@ -3249,8 +3100,8 @@ readconf_main();
 
 /* Handle the decoding of logging options. */
 
-decode_bits(&log_write_selector, &log_extra_selector, 0, 0, log_selector_string,
-  log_options, log_options_count, US"log");
+decode_bits(&log_write_selector, &log_extra_selector, 0, 0,
+  log_selector_string, log_options, log_options_count, US"log", 0);
 
 DEBUG(D_any)
   {
diff --git a/src/src/functions.h b/src/src/functions.h
index 00f8bb7ba..90c2b1269 100644
--- a/src/src/functions.h
+++ b/src/src/functions.h
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/functions.h,v 1.50 2010/06/05 23:50:18 pdp Exp $ */
+/* $Cambridge: exim/src/src/functions.h,v 1.51 2010/06/06 00:27:52 pdp Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -72,11 +72,14 @@ extern void    daemon_go(void);
 extern int     dcc_process(uschar **);
 #endif
 
+extern void    debug_logging_activate(uschar *, uschar *);
 extern void    debug_print_argv(uschar **);
 extern void    debug_print_ids(uschar *);
 extern void    debug_print_string(uschar *);
 extern void    debug_print_tree(tree_node *);
 extern void    debug_vprintf(char *, va_list);
+extern void    decode_bits(unsigned int *, unsigned int *,
+                  int, int, uschar *, bit_table *, int, uschar *, int);
 extern address_item *deliver_make_addr(uschar *, BOOL);
 extern int     deliver_message(uschar *, BOOL, BOOL);
 extern void    deliver_msglog(const char *, ...);
diff --git a/src/src/log.c b/src/src/log.c
index a5cd10075..1d2c8f5e0 100644
--- a/src/src/log.c
+++ b/src/src/log.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/log.c,v 1.14 2009/11/16 19:50:37 nm4 Exp $ */
+/* $Cambridge: exim/src/src/log.c,v 1.15 2010/06/06 00:27:52 pdp Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -19,9 +19,9 @@ log files was originally contributed by Tony Sheen. */
 #define LOG_MODE_FILE   1
 #define LOG_MODE_SYSLOG 2
 
-enum { lt_main, lt_reject, lt_panic, lt_process };
+enum { lt_main, lt_reject, lt_panic, lt_debug, lt_process };
 
-static uschar *log_names[] = { US"main", US"reject", US"panic", US"process" };
+static uschar *log_names[] = { US"main", US"reject", US"panic", US"debug", US"process" };
 
 
 
@@ -31,6 +31,7 @@ static uschar *log_names[] = { US"main", US"reject", US"panic", US"process" };
 
 static uschar mainlog_name[LOG_NAME_SIZE];
 static uschar rejectlog_name[LOG_NAME_SIZE];
+static uschar debuglog_name[LOG_NAME_SIZE];
 
 static uschar *mainlog_datestamp = NULL;
 static uschar *rejectlog_datestamp = NULL;
@@ -226,16 +227,17 @@ avoid races.
 
 Arguments:
   fd         where to return the resulting file descriptor
-  type       lt_main, lt_reject, lt_panic, or lt_process
+  type       lt_main, lt_reject, lt_panic, lt_debug or lt_process
+  tag        optional tag to include in the name (only hooked up for debug)
 
 Returns:   nothing
 */
 
 static void
-open_log(int *fd, int type)
+open_log(int *fd, int type, uschar *tag)
 {
 uid_t euid;
-BOOL ok;
+BOOL ok, ok2;
 uschar buffer[LOG_NAME_SIZE];
 
 /* Sort out the file name. This depends on the type of log we are opening. The
@@ -282,6 +284,22 @@ else
     rejectlog_datestamp = rejectlog_name + string_datestamp_offset;
     }
 
+  /* and deal with the debug log (which keeps the datestamp, but does not
+  update it) */
+
+  else if (type == lt_debug)
+    {
+    Ustrcpy(debuglog_name, buffer);
+    if (tag)
+      {
+      /* this won't change the offset of the datestamp */
+      ok2 = string_format(buffer, sizeof(buffer), "%s%s",
+          debuglog_name, tag);
+      if (ok2)
+        Ustrcpy(debuglog_name, buffer);
+      }
+    }
+
   /* Remove any datestamp if this is the panic log. This is rare, so there's no
   need to optimize getting the datestamp length. We remove one non-alphanumeric
   char afterwards if at the start, otherwise one before. */
@@ -860,7 +878,7 @@ if ((flags & LOG_MAIN) != 0 &&
 
     if (mainlogfd < 0)
       {
-      open_log(&mainlogfd, lt_main);     /* No return on error */
+      open_log(&mainlogfd, lt_main, NULL);     /* No return on error */
       if (fstat(mainlogfd, &statbuf) >= 0) mainlog_inode = statbuf.st_ino;
       }
 
@@ -984,7 +1002,7 @@ if ((flags & LOG_REJECT) != 0)
 
     if (rejectlogfd < 0)
       {
-      open_log(&rejectlogfd, lt_reject); /* No return on error */
+      open_log(&rejectlogfd, lt_reject, NULL); /* No return on error */
       if (fstat(rejectlogfd, &statbuf) >= 0) rejectlog_inode = statbuf.st_ino;
       }
 
@@ -1005,7 +1023,7 @@ written to a file - never to syslog. */
 if ((flags & LOG_PROCESS) != 0)
   {
   int processlogfd;
-  open_log(&processlogfd, lt_process);  /* No return on error */
+  open_log(&processlogfd, lt_process, NULL);  /* No return on error */
   if ((rc = write(processlogfd, log_buffer, length)) != length)
     {
     log_write_failed(US"process log", length, rc);
@@ -1036,7 +1054,7 @@ if ((flags & LOG_PANIC) != 0)
   if ((logging_mode & LOG_MODE_FILE) != 0)
     {
     panic_recurseflag = TRUE;
-    open_log(&paniclogfd, lt_panic);  /* Won't return on failure */
+    open_log(&paniclogfd, lt_panic, NULL);  /* Won't return on failure */
     panic_recurseflag = FALSE;
 
     if (panic_save_buffer != NULL)
@@ -1079,4 +1097,214 @@ closelog();
 syslog_open = FALSE;
 }
 
+
+
+/*************************************************
+*         Decode bit settings for log/debug      *
+*************************************************/
+
+/* This function decodes a string containing bit settings in the form of +name
+and/or -name sequences, and sets/unsets bits in a bit string accordingly. It
+also recognizes a numeric setting of the form =<number>, but this is not
+intended for user use. It's an easy way for Exim to pass the debug settings
+when it is re-exec'ed.
+
+The log options are held in two unsigned ints (because there became too many
+for one). The top bit in the table means "put in 2nd selector". This does not
+yet apply to debug options, so the "=" facility sets only the first selector.
+
+The "all" selector, which must be equal to 0xffffffff, is recognized specially.
+It sets all the bits in both selectors. However, there is a facility for then
+unsetting certain bits, because we want to turn off "memory" in the debug case.
+
+The action taken for bad values varies depending upon why we're here.
+For log messages, or if the debugging is triggered from config, then we write
+to the log on the way out.  For debug setting triggered from the command-line,
+we treat it as an unknown option: error message to stderr and die.
+
+Arguments:
+  selector1      address of the first bit string
+  selector2      address of the second bit string, or NULL
+  notall1        bits to exclude from "all" for selector1
+  notall2        bits to exclude from "all" for selector2
+  string         the configured string
+  options        the table of option names
+  count          size of table
+  which          "log" or "debug"
+  flags          DEBUG_FROM_CONFIG
+
+Returns:         nothing on success - bomb out on failure
+*/
+
+void
+decode_bits(unsigned int *selector1, unsigned int *selector2, int notall1,
+  int notall2, uschar *string, bit_table *options, int count, uschar *which,
+  int flags)
+{
+uschar *errmsg;
+if (string == NULL) return;
+
+if (*string == '=')
+  {
+  char *end;    /* Not uschar */
+  *selector1 = strtoul(CS string+1, &end, 0);
+  if (*end == 0) return;
+  errmsg = string_sprintf("malformed numeric %s_selector setting: %s", which,
+    string);
+  goto ERROR_RETURN;
+  }
+
+/* Handle symbolic setting */
+
+else for(;;)
+  {
+  BOOL adding;
+  uschar *s;
+  int len;
+  bit_table *start, *end;
+
+  while (isspace(*string)) string++;
+  if (*string == 0) return;
+
+  if (*string != '+' && *string != '-')
+    {
+    errmsg = string_sprintf("malformed %s_selector setting: "
+      "+ or - expected but found \"%s\"", which, string);
+    goto ERROR_RETURN;
+    }
+
+  adding = *string++ == '+';
+  s = string;
+  while (isalnum(*string) || *string == '_') string++;
+  len = string - s;
+
+  start = options;
+  end = options + count;
+
+  while (start < end)
+    {
+    bit_table *middle = start + (end - start)/2;
+    int c = Ustrncmp(s, middle->name, len);
+    if (c == 0)
+      {
+      if (middle->name[len] != 0) c = -1; else
+        {
+        unsigned int bit = middle->bit;
+        unsigned int *selector;
+
+        /* The value with all bits set means "force all bits in both selectors"
+        in the case where two are being handled. However, the top bit in the
+        second selector is never set. When setting, some bits can be excluded.
+        */
+
+        if (bit == 0xffffffff)
+          {
+          if (adding)
+            {
+            *selector1 = 0xffffffff ^ notall1;
+            if (selector2 != NULL) *selector2 = 0x7fffffff ^ notall2;
+            }
+          else
+            {
+            *selector1 = 0;
+            if (selector2 != NULL) *selector2 = 0;
+            }
+          }
+
+        /* Otherwise, the 0x80000000 bit means "this value, without the top
+        bit, belongs in the second selector". */
+
+        else
+          {
+          if ((bit & 0x80000000) != 0)
+            {
+            selector = selector2;
+            bit &= 0x7fffffff;
+            }
+          else selector = selector1;
+          if (adding) *selector |= bit; else *selector &= ~bit;
+          }
+        break;  /* Out of loop to match selector name */
+        }
+      }
+    if (c < 0) end = middle; else start = middle + 1;
+    }  /* Loop to match selector name */
+
+  if (start >= end)
+    {
+    errmsg = string_sprintf("unknown %s_selector setting: %c%.*s", which,
+      adding? '+' : '-', len, s);
+    goto ERROR_RETURN;
+    }
+  }    /* Loop for selector names */
+
+/* Handle disasters */
+
+ERROR_RETURN:
+if (Ustrcmp(which, "debug") == 0)
+  {
+  if (flags & DEBUG_FROM_CONFIG)
+    {
+    log_write(0, LOG_CONFIG|LOG_PANIC, "%s", errmsg);
+    return;
+    }
+  fprintf(stderr, "exim: %s\n", errmsg);
+  exit(EXIT_FAILURE);
+  }
+else log_write(0, LOG_CONFIG|LOG_PANIC_DIE, "%s", errmsg);
+}
+
+
+
+/*************************************************
+*        Activate a debug logfile (late)         *
+*************************************************/
+
+/* Normally, debugging is activated from the command-line; it may be useful
+within the configuration to activate debugging later, based on certain
+conditions.  If debugging is already in progress, we return early, no action
+taken (besides debug-logging that we wanted debug-logging).
+
+Failures in options are not fatal but will result in paniclog entries for the
+misconfiguration.
+
+The first use of this is in ACL logic, "control = debug/tag=foo/opts=+expand"
+which can be combined with conditions, etc, to activate extra logging only
+for certain sources. */
+
+void
+debug_logging_activate(uschar *tag_name, uschar *opts)
+{
+int fd = -1;
+
+if (debug_file)
+  {
+  debug_printf("DEBUGGING ACTIVATED FROM WITHIN CONFIG.\n"
+      "DEBUG: Tag=\"%s\" Opts=\"%s\"\n", tag_name, opts);
+  return;
+  }
+
+if (tag_name != NULL && (Ustrchr(tag_name, '/') != NULL))
+  {
+  log_write(0, LOG_MAIN|LOG_PANIC, "debug tag may not contain a '/' in: %s",
+      tag_name);
+  return;
+  }
+
+debug_selector = D_default;
+if (opts)
+  {
+  decode_bits(&debug_selector, NULL, D_memory, 0, opts,
+      debug_options, debug_options_count, US"debug", DEBUG_FROM_CONFIG);
+  }
+
+open_log(&fd, lt_debug, tag_name);
+
+if (fd != -1)
+  debug_file = fdopen(fd, "w");
+else
+  log_write(0, LOG_MAIN|LOG_PANIC, "unable to open debug log");
+}
+
+
 /* End of log.c */
diff --git a/src/src/macros.h b/src/src/macros.h
index 4db115533..ed90b2535 100644
--- a/src/src/macros.h
+++ b/src/src/macros.h
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/macros.h,v 1.39 2009/11/16 19:50:37 nm4 Exp $ */
+/* $Cambridge: exim/src/src/macros.h,v 1.40 2010/06/06 00:27:52 pdp Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -707,6 +707,9 @@ local_scan.h */
 #define LOG_CONFIG_FOR  (256+128) /* Add " for" instead of ":\n" */
 #define LOG_CONFIG_IN   (512+128) /* Add " in line x[ of file y]" */
 
+/* and for debug_bits() logging action control: */
+#define DEBUG_FROM_CONFIG       0x0001
+
 /* SMTP command identifiers for the smtp_connection_had field that records the
 most recent SMTP commands. Must be kept in step with the list of names in
 smtp_in.c that is used for creating the smtp_no_mail logging action. SCH_NONE