MEDIUM: log-format: relax parsing of '%' followed by unsupported characters
At the moment when a '%' character is followed by any unhandled character,
it is considered as a variable name, and if it cannot be resolved, a warning
is emitted and the configuration goes on.
When we start using log-format for redirect rules, it may happen that some
people accidently use '%' instead of '%%' without understanding the cause
of the issue. Thus we do two things here :
- if a single '%' is followed by a blank or a digit, we fix it and emit a
warning explaining how this should be done ; this ensures that existing
configs continue to work ;
- if a single '%' is followed by an unknown variable name, we report it
and explain how to emit a verbatim '%' in case this is what the user
desired.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 838b33a..b2ef7e3 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -11049,7 +11049,8 @@
the key that would be used to store an entry into a stick table.
Note: spaces must be escaped. A space character is considered as a separator.
-HAproxy will automatically merge consecutive separators.
+In order to emit a verbatim '%', it must be preceeded by another '%' resulting
+in '%%'. HAProxy will automatically merge consecutive separators.
Flags are :
* Q: quote a string
diff --git a/src/log.c b/src/log.c
index dd65e26..3c461a3 100644
--- a/src/log.c
+++ b/src/log.c
@@ -280,12 +280,12 @@
LIST_ADDQ(list_format, &node->list);
}
if (logformat_keywords[j].replace_by)
- Warning("parsing [%s:%d] : deprecated variable '%s' in '%s', please replace it with '%s'\n",
+ Warning("parsing [%s:%d] : deprecated variable '%s' in '%s', please replace it with '%s'.\n",
curproxy->conf.args.file, curproxy->conf.args.line,
logformat_keywords[j].name, fmt_directive(curproxy), logformat_keywords[j].replace_by);
return 0;
} else {
- Warning("parsing [%s:%d] : '%s' : format variable '%s' is reserved for HTTP mode\n",
+ Warning("parsing [%s:%d] : '%s' : format variable '%s' is reserved for HTTP mode.\n",
curproxy->conf.args.file, curproxy->conf.args.line, fmt_directive(curproxy),
logformat_keywords[j].name);
return -1;
@@ -295,7 +295,7 @@
j = var[var_len];
var[var_len] = 0;
- Warning("parsing [%s:%d] : no such format variable '%s' in '%s'\n",
+ Warning("parsing [%s:%d] : no such format variable '%s' in '%s'. If you wanted to emit the '%%' character verbatim, you need to use '%%%%' in log-format expressions.\n",
curproxy->conf.args.file, curproxy->conf.args.line, var, fmt_directive(curproxy));
var[var_len] = j;
return -1;
@@ -442,12 +442,21 @@
cformat = LF_STEXPR;
var = str + 1; // store expr in variable name
}
- else if (isalnum((int)*str)) { // variable name
+ else if (isalpha((int)*str)) { // variable name
cformat = LF_VAR;
var = str;
}
else if (*str == '%')
cformat = LF_TEXT; // convert this character to a litteral (useful for '%')
+ else if (isdigit(*str) || isblank(*str)) {
+ /* single '%' followed by blank or digit, send them both */
+ cformat = LF_TEXT;
+ pformat = LF_TEXT; /* finally we include the previous char as well */
+ sp = str - 1; /* send both the '%' and the current char */
+ Warning("parsing [%s:%d] : Fixed missing '%%' before '%c' at position %d in %s line : '%s'. Please use '%%%%' when you need the '%%' character in a log-format expression.\n",
+ curproxy->conf.args.file, curproxy->conf.args.line, *str, (int)(str - backfmt), fmt_directive(curproxy), fmt);
+
+ }
else
cformat = LF_INIT; // handle other cases of litterals
break;