+
+
+/*************************************************
+* 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. The second use is inetd wait mode debug preservation. */
+
+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 ? opts : US"");
+ 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");
+}
+
+