BUG/MEDIUM: sample: simplify and fix the argument parsing

Some errors may be reported about missing mandatory arguments when some
sample fetch arguments are marked as mandatory and implicit (eg: proxy
names such as in table_cnt or be_conn).

In practice the argument parser already handles all the situations very
well, it's just that the sample fetch parser want to go beyond its role
and starts some controls that it should not do. Simply removing these
useless controls lets make_arg_list() create the correct argument types
when such types are encountered.

This regression was introduced by the recent use of sample_parse_expr()
in ACLs which makes use of its own argument parser, while previously
the arguments were parsed in the ACL function itself. No backport is
needed.

diff --git a/src/sample.c b/src/sample.c
index 8560a0742676229caec43da338f21d706e0ae326..2a114d9af619c494ee4cc63f595403159c94aa84 100644 (file)
--- a/src/sample.c
+++ b/src/sample.c
@@ -600,6 +600,7 @@ struct sample_expr *sample_parse_expr(char **str, int *idx, char **err_msg, stru
        unsigned long prev_type;
        char *fkw = NULL;
        char *ckw = NULL;
+       int err_arg;
 
        begw = str[*idx];
        for (endw = begw; *endw && *endw != '(' && *endw != ','; endw++);
@@ -620,7 +621,8 @@ struct sample_expr *sample_parse_expr(char **str, int *idx, char **err_msg, stru
 
        endt = endw;
        if (*endt == '(') {
-               /* look for the end of this term */
+               /* look for the end of this term and skip the opening parenthesis */
+               endt = ++endw;
                while (*endt && *endt != ')')
                        endt++;
                if (*endt != ')') {
@@ -631,7 +633,9 @@ struct sample_expr *sample_parse_expr(char **str, int *idx, char **err_msg, stru
 
        /* At this point, we have :
         *   - begw : beginning of the keyword
-        *   - endw : end of the keyword (points to next delimiter or '(')
+        *   - endw : end of the keyword, first character not part of keyword
+        *            nor the opening parenthesis (so first character of args
+        *            if present).
         *   - endt : end of the term (=endw or last parenthesis if args are present)
         */
 
@@ -649,31 +653,22 @@ struct sample_expr *sample_parse_expr(char **str, int *idx, char **err_msg, stru
        expr->fetch = fetch;
        expr->arg_p = empty_arg_list;
 
-       if (endt != endw) {
-               int err_arg;
-
-               if (!fetch->arg_mask) {
-                       memprintf(err_msg, "fetch method '%s' does not support any args", fkw);
-                       goto out_error;
-               }
-
-               al->kw = expr->fetch->kw;
-               al->conv = NULL;
-               if (make_arg_list(endw + 1, endt - endw - 1, fetch->arg_mask, &expr->arg_p, err_msg, NULL, &err_arg, al) < 0) {
-                       memprintf(err_msg, "invalid arg %d in fetch method '%s' : %s", err_arg+1, fkw, *err_msg);
-                       goto out_error;
-               }
-
-               if (!expr->arg_p)
-                       expr->arg_p = empty_arg_list;
+       /* Note that we call the argument parser even with an empty string,
+        * this allows it to automatically create entries for mandatory
+        * implicit arguments (eg: local proxy name).
+        */
+       al->kw = expr->fetch->kw;
+       al->conv = NULL;
+       if (make_arg_list(endw, endt - endw, fetch->arg_mask, &expr->arg_p, err_msg, NULL, &err_arg, al) < 0) {
+               memprintf(err_msg, "fetch method '%s' : %s", fkw, *err_msg);
+               goto out_error;
+       }
 
-               if (fetch->val_args && !fetch->val_args(expr->arg_p, err_msg)) {
-                       memprintf(err_msg, "invalid args in fetch method '%s' : %s", fkw, *err_msg);
-                       goto out_error;
-               }
+       if (!expr->arg_p) {
+               expr->arg_p = empty_arg_list;
        }
-       else if (ARGM(fetch->arg_mask)) {
-               memprintf(err_msg, "missing args for fetch method '%s'", fkw);
+       else if (fetch->val_args && !fetch->val_args(expr->arg_p, err_msg)) {
+               memprintf(err_msg, "invalid args in fetch method '%s' : %s", fkw, *err_msg);
                goto out_error;
        }