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MEDIUM: acl: fix the initialization order of the ACL expression

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The ACL expression parser recently became a huge mess like a
spaghetti plate. The keyword is looked up at the beginning, then
sample fetches are processed, then an expression is initialized,
then arguments and converters are parsed but only if the keyword
was an ACL one, etc... Lots of "if" and redundant variables
everywhere making it hard to read and follow.

Let's move the args/conv parsing just after the keyword lookup.
At least now it's consistent that when we leave this if/else
statement, we have a sample expression initialized and full
parsed wherever the elements came from.
This commit is contained in:
Willy Tarreau 2013-12-13 01:24:09 +01:00
parent 131b466f98
commit c37a3c770b
1 changed files with 93 additions and 84 deletions
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177
src/acl.c
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@ -145,68 +145,28 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
int cur_type; int cur_type;
int nbargs; int nbargs;
/* First, we lookd for an ACL keyword. And if we don't find one, then /* First, we look for an ACL keyword. And if we don't find one, then
* we look for a sample fetch keyword. * we look for a sample fetch expression starting with a sample fetch
* keyword.
*/ */
al->ctx = ARGC_ACL; al->ctx = ARGC_ACL; // to report errors while resolving args late
al->kw = *args; al->kw = *args;
al->conv = NULL; al->conv = NULL;
aclkw = find_acl_kw(args[0]); aclkw = find_acl_kw(args[0]);
if (!aclkw || !aclkw->parse) { if (aclkw && aclkw->parse) {
smp = sample_parse_expr((char **)args, &idx, err, al); /* OK we have a real ACL keyword */
if (!smp) {
memprintf(err, "%s in ACL expression '%s'", *err, *args);
goto out_return;
}
}
expr = (struct acl_expr *)calloc(1, sizeof(*expr));
if (!expr) {
memprintf(err, "out of memory when parsing ACL expression");
goto out_return;
}
pattern_init_expr(&expr->pat);
expr->kw = aclkw ? aclkw->kw : smp->fetch->kw;
expr->pat.parse = aclkw ? aclkw->parse : NULL;
expr->pat.match = aclkw ? aclkw->match : NULL;
expr->smp = aclkw ? NULL : smp;
if (!expr->pat.parse) {
/* some types can be automatically converted */
switch (expr->smp ? expr->smp->fetch->out_type : aclkw->smp->out_type) {
case SMP_T_BOOL:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_BOOL];
expr->pat.match = pat_match_fcts[PAT_MATCH_BOOL];
break;
case SMP_T_SINT:
case SMP_T_UINT:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_INT];
expr->pat.match = pat_match_fcts[PAT_MATCH_INT];
break;
case SMP_T_IPV4:
case SMP_T_IPV6:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_IP];
expr->pat.match = pat_match_fcts[PAT_MATCH_IP];
break;
}
}
/* now parse the rest of acl only if "find_acl_kw" match */
if (aclkw) {
/* build new sample expression for this ACL */ /* build new sample expression for this ACL */
expr->smp = calloc(1, sizeof(struct sample_expr)); smp = calloc(1, sizeof(struct sample_expr));
if (!expr->smp) { if (!smp) {
memprintf(err, "out of memory when parsing ACL expression"); memprintf(err, "out of memory when parsing ACL expression");
goto out_return; goto out_return;
} }
LIST_INIT(&(expr->smp->conv_exprs)); LIST_INIT(&(smp->conv_exprs));
expr->smp->fetch = aclkw->smp; smp->fetch = aclkw->smp;
expr->smp->arg_p = empty_arg_list; smp->arg_p = empty_arg_list;
/* look for the begining of the subject arguments */ /* look for the begining of the subject arguments */
for (arg = args[0]; *arg && *arg != '(' && *arg != ','; arg++); for (arg = args[0]; *arg && *arg != '(' && *arg != ','; arg++);
@ -218,8 +178,8 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
while (*endt && *endt != ')') while (*endt && *endt != ')')
endt++; endt++;
if (*endt != ')') { if (*endt != ')') {
memprintf(err, "missing closing ')' after arguments to ACL keyword '%s'", expr->kw); memprintf(err, "missing closing ')' after arguments to ACL keyword '%s'", aclkw->kw);
goto out_free_expr; goto out_free_smp;
} }
} }
@ -230,30 +190,30 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
* if present). * if present).
* - endt : end of the term (=arg or last parenthesis if args are present) * - endt : end of the term (=arg or last parenthesis if args are present)
*/ */
nbargs = make_arg_list(arg, endt - arg, expr->smp->fetch->arg_mask, &expr->smp->arg_p, nbargs = make_arg_list(arg, endt - arg, smp->fetch->arg_mask, &smp->arg_p,
err, NULL, NULL, al); err, NULL, NULL, al);
if (nbargs < 0) { if (nbargs < 0) {
/* note that make_arg_list will have set <err> here */ /* note that make_arg_list will have set <err> here */
memprintf(err, "ACL keyword '%s' : %s", expr->kw, *err); memprintf(err, "ACL keyword '%s' : %s", aclkw->kw, *err);
goto out_free_expr; goto out_free_smp;
} }
if (!expr->smp->arg_p) { if (!smp->arg_p) {
expr->smp->arg_p = empty_arg_list; smp->arg_p = empty_arg_list;
} }
else if (expr->smp->fetch->val_args && !expr->smp->fetch->val_args(expr->smp->arg_p, err)) { else if (smp->fetch->val_args && !smp->fetch->val_args(smp->arg_p, err)) {
/* invalid keyword argument, error must have been /* invalid keyword argument, error must have been
* set by val_args(). * set by val_args().
*/ */
memprintf(err, "in argument to '%s', %s", expr->kw, *err); memprintf(err, "in argument to '%s', %s", aclkw->kw, *err);
goto out_free_expr; goto out_free_smp;
} }
arg = endt; arg = endt;
/* look for the begining of the converters list. Those directly attached /* look for the begining of the converters list. Those directly attached
* to the ACL keyword are found just after <arg> which points to the comma. * to the ACL keyword are found just after <arg> which points to the comma.
*/ */
prev_type = expr->smp->fetch->out_type; prev_type = smp->fetch->out_type;
while (*arg) { while (*arg) {
struct sample_conv *conv; struct sample_conv *conv;
struct sample_conv_expr *conv_expr; struct sample_conv_expr *conv_expr;
@ -264,11 +224,11 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
if (*arg && *arg != ',') { if (*arg && *arg != ',') {
if (ckw) if (ckw)
memprintf(err, "ACL keyword '%s' : missing comma after conv keyword '%s'.", memprintf(err, "ACL keyword '%s' : missing comma after conv keyword '%s'.",
expr->kw, ckw); aclkw->kw, ckw);
else else
memprintf(err, "ACL keyword '%s' : missing comma after fetch keyword.", memprintf(err, "ACL keyword '%s' : missing comma after fetch keyword.",
expr->kw); aclkw->kw);
goto out_free_expr; goto out_free_smp;
} }
while (*arg == ',') /* then trailing commas */ while (*arg == ',') /* then trailing commas */
@ -289,8 +249,8 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
if (!conv) { if (!conv) {
/* Unknown converter method */ /* Unknown converter method */
memprintf(err, "ACL keyword '%s' : unknown conv method '%s'.", memprintf(err, "ACL keyword '%s' : unknown conv method '%s'.",
expr->kw, ckw); aclkw->kw, ckw);
goto out_free_expr; goto out_free_smp;
} }
arg = endw; arg = endw;
@ -300,30 +260,30 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
arg++; arg++;
if (*arg != ')') { if (*arg != ')') {
memprintf(err, "ACL keyword '%s' : syntax error: missing ')' after conv keyword '%s'.", memprintf(err, "ACL keyword '%s' : syntax error: missing ')' after conv keyword '%s'.",
expr->kw, ckw); aclkw->kw, ckw);
goto out_free_expr; goto out_free_smp;
} }
} }
if (conv->in_type >= SMP_TYPES || conv->out_type >= SMP_TYPES) { if (conv->in_type >= SMP_TYPES || conv->out_type >= SMP_TYPES) {
memprintf(err, "ACL keyword '%s' : returns type of conv method '%s' is unknown.", memprintf(err, "ACL keyword '%s' : returns type of conv method '%s' is unknown.",
expr->kw, ckw); aclkw->kw, ckw);
goto out_free_expr; goto out_free_smp;
} }
/* If impossible type conversion */ /* If impossible type conversion */
if (!sample_casts[prev_type][conv->in_type]) { if (!sample_casts[prev_type][conv->in_type]) {
memprintf(err, "ACL keyword '%s' : conv method '%s' cannot be applied.", memprintf(err, "ACL keyword '%s' : conv method '%s' cannot be applied.",
expr->kw, ckw); aclkw->kw, ckw);
goto out_free_expr; goto out_free_smp;
} }
prev_type = conv->out_type; prev_type = conv->out_type;
conv_expr = calloc(1, sizeof(struct sample_conv_expr)); conv_expr = calloc(1, sizeof(struct sample_conv_expr));
if (!conv_expr) if (!conv_expr)
goto out_free_expr; goto out_free_smp;
LIST_ADDQ(&(expr->smp->conv_exprs), &(conv_expr->list)); LIST_ADDQ(&(smp->conv_exprs), &(conv_expr->list));
conv_expr->conv = conv; conv_expr->conv = conv;
if (arg != endw) { if (arg != endw) {
@ -332,17 +292,17 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
if (!conv->arg_mask) { if (!conv->arg_mask) {
memprintf(err, "ACL keyword '%s' : conv method '%s' does not support any args.", memprintf(err, "ACL keyword '%s' : conv method '%s' does not support any args.",
expr->kw, ckw); aclkw->kw, ckw);
goto out_free_expr; goto out_free_smp;
} }
al->kw = expr->smp->fetch->kw; al->kw = smp->fetch->kw;
al->conv = conv_expr->conv->kw; al->conv = conv_expr->conv->kw;
if (make_arg_list(endw + 1, arg - endw - 1, conv->arg_mask, &conv_expr->arg_p, &err_msg, NULL, &err_arg, al) < 0) { if (make_arg_list(endw + 1, arg - endw - 1, conv->arg_mask, &conv_expr->arg_p, &err_msg, NULL, &err_arg, al) < 0) {
memprintf(err, "ACL keyword '%s' : invalid arg %d in conv method '%s' : %s.", memprintf(err, "ACL keyword '%s' : invalid arg %d in conv method '%s' : %s.",
expr->kw, err_arg+1, ckw, err_msg); aclkw->kw, err_arg+1, ckw, err_msg);
free(err_msg); free(err_msg);
goto out_free_expr; goto out_free_smp;
} }
if (!conv_expr->arg_p) if (!conv_expr->arg_p)
@ -350,18 +310,65 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
if (conv->val_args && !conv->val_args(conv_expr->arg_p, conv, &err_msg)) { if (conv->val_args && !conv->val_args(conv_expr->arg_p, conv, &err_msg)) {
memprintf(err, "ACL keyword '%s' : invalid args in conv method '%s' : %s.", memprintf(err, "ACL keyword '%s' : invalid args in conv method '%s' : %s.",
expr->kw, ckw, err_msg); aclkw->kw, ckw, err_msg);
free(err_msg); free(err_msg);
goto out_free_expr; goto out_free_smp;
} }
} }
else if (ARGM(conv->arg_mask)) { else if (ARGM(conv->arg_mask)) {
memprintf(err, "ACL keyword '%s' : missing args for conv method '%s'.", memprintf(err, "ACL keyword '%s' : missing args for conv method '%s'.",
expr->kw, ckw); aclkw->kw, ckw);
goto out_free_expr; goto out_free_smp;
} }
} }
} }
else {
/* This is not an ACL keyword, so we hope this is a sample fetch
* keyword that we're going to transparently use as an ACL. If
* so, we retrieve a completely parsed expression with args and
* convs already done.
*/
smp = sample_parse_expr((char **)args, &idx, err, al);
if (!smp) {
memprintf(err, "%s in ACL expression '%s'", *err, *args);
goto out_return;
}
}
expr = (struct acl_expr *)calloc(1, sizeof(*expr));
if (!expr) {
memprintf(err, "out of memory when parsing ACL expression");
goto out_return;
}
pattern_init_expr(&expr->pat);
expr->kw = aclkw ? aclkw->kw : smp->fetch->kw;
expr->pat.parse = aclkw ? aclkw->parse : NULL;
expr->pat.match = aclkw ? aclkw->match : NULL;
expr->smp = smp;
smp = NULL;
if (!expr->pat.parse) {
/* some types can be automatically converted */
switch (expr->smp ? expr->smp->fetch->out_type : aclkw->smp->out_type) {
case SMP_T_BOOL:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_BOOL];
expr->pat.match = pat_match_fcts[PAT_MATCH_BOOL];
break;
case SMP_T_SINT:
case SMP_T_UINT:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_INT];
expr->pat.match = pat_match_fcts[PAT_MATCH_INT];
break;
case SMP_T_IPV4:
case SMP_T_IPV6:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_IP];
expr->pat.match = pat_match_fcts[PAT_MATCH_IP];
break;
}
}
/* Additional check to protect against common mistakes */ /* Additional check to protect against common mistakes */
cur_type = smp_expr_output_type(expr->smp); cur_type = smp_expr_output_type(expr->smp);
@ -447,6 +454,8 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
prune_acl_expr(expr); prune_acl_expr(expr);
free(expr); free(expr);
free(ckw); free(ckw);
out_free_smp:
free(smp);
out_return: out_return:
return NULL; return NULL;
} }