5 files changed, 46 insertions, 16 deletions

diff --git a/conf.c b/conf.c
index 1411eea..375b9a4 100644
--- a/conf.c
+++ b/conf.c
@@ -157,6 +157,7 @@ static void conf_ports_range_except(const struct ctx *c, char optname,
 		.proto = proto,
 		.flags = flags,
 	};
+	char rulestr[FWD_RULE_STRLEN];
 	unsigned delta = to - first;
 	unsigned base, i;
 
@@ -207,20 +208,28 @@ static void conf_ports_range_except(const struct ctx *c, char optname,
 				rulev.addr = inany_loopback4;
 				fwd_rule_conflict_check(&rulev,
 							fwd->rules, fwd->count);
-				fwd_rule_add(fwd, &rulev);
+				if (fwd_rule_add(fwd, &rulev) < 0)
+					goto fail;
 			}
 			if (c->ifi6) {
 				rulev.addr = inany_loopback6;
 				fwd_rule_conflict_check(&rulev,
 							fwd->rules, fwd->count);
-				fwd_rule_add(fwd, &rulev);
+				if (fwd_rule_add(fwd, &rulev) < 0)
+					goto fail;
 			}
 		} else {
 			fwd_rule_conflict_check(&rule, fwd->rules, fwd->count);
-			fwd_rule_add(fwd, &rule);
+			if (fwd_rule_add(fwd, &rule) < 0)
+				goto fail;
 		}
 		base = i - 1;
 	}
+	return;
+
+fail:
+	die("Unable to add rule %s",
+	    fwd_rule_fmt(&rule, rulestr, sizeof(rulestr)));
 }
 
 /**
diff --git a/fwd.c b/fwd.c
index c963752..3e87169 100644
--- a/fwd.c
+++ b/fwd.c
@@ -335,24 +335,44 @@ void fwd_rule_init(struct ctx *c)
  * fwd_rule_add() - Validate and add a rule to a forwarding table
  * @fwd:	Table to add to
  * @new:	Rule to add
+ *
+ * Return: 0 on success, negative error code on failure
  */
-void fwd_rule_add(struct fwd_table *fwd, const struct fwd_rule *new)
+int fwd_rule_add(struct fwd_table *fwd, const struct fwd_rule *new)
 {
 	/* Flags which can be set from the caller */
 	const uint8_t allowed_flags = FWD_WEAK | FWD_SCAN | FWD_DUAL_STACK_ANY;
 	unsigned num = (unsigned)new->last - new->first + 1;
 	unsigned port;
 
-	assert(!(new->flags & ~allowed_flags));
-	/* Passing a non-wildcard address with DUAL_STACK_ANY is a bug */
-	assert(!(new->flags & FWD_DUAL_STACK_ANY) ||
-	       inany_equals(&new->addr, &inany_any6));
-	assert(new->first <= new->last);
+	if (new->first > new->last) {
+		warn("Rule has invalid port range %u-%u",
+		     new->first, new->last);
+		return -EINVAL;
+	}
+	if (new->flags & ~allowed_flags) {
+		warn("Rule has invalid flags 0x%hhx",
+		     new->flags & ~allowed_flags);
+		return -EINVAL;
+	}
+	if (new->flags & FWD_DUAL_STACK_ANY &&
+	    !inany_equals(&new->addr, &inany_any6)) {
+		char astr[INANY_ADDRSTRLEN];
 
-	if (fwd->count >= ARRAY_SIZE(fwd->rules))
-		die("Too many port forwarding ranges");
-	if ((fwd->sock_count + num) > ARRAY_SIZE(fwd->socks))
-		die("Too many listening sockets");
+		warn("Dual stack rule has non-wildcard address %s",
+		     inany_ntop(&new->addr, astr, sizeof(astr)));
+		return -EINVAL;
+	}
+
+	if (fwd->count >= ARRAY_SIZE(fwd->rules)) {
+		warn("Too many rules (maximum %u)", ARRAY_SIZE(fwd->rules));
+		return -ENOSPC;
+	}
+	if ((fwd->sock_count + num) > ARRAY_SIZE(fwd->socks)) {
+		warn("Rules require too many listening sockets (maximum %u)",
+		     ARRAY_SIZE(fwd->socks));
+		return -ENOSPC;
+	}
 
 	fwd->rulesocks[fwd->count] = &fwd->socks[fwd->sock_count];
 	for (port = new->first; port <= new->last; port++)
@@ -360,6 +380,7 @@ void fwd_rule_add(struct fwd_table *fwd, const struct fwd_rule *new)
 
 	fwd->rules[fwd->count++] = *new;
 	fwd->sock_count += num;
+	return 0;
 }
 
 /**
diff --git a/fwd.h b/fwd.h
index 96b8c60..43bfead 100644
--- a/fwd.h
+++ b/fwd.h
@@ -85,7 +85,7 @@ struct fwd_scan {
 #define FWD_PORT_SCAN_INTERVAL		1000	/* ms */
 
 void fwd_rule_init(struct ctx *c);
-void fwd_rule_add(struct fwd_table *fwd, const struct fwd_rule *new);
+int fwd_rule_add(struct fwd_table *fwd, const struct fwd_rule *new);
 const struct fwd_rule *fwd_rule_search(const struct fwd_table *fwd,
 				       const struct flowside *ini,
 				       uint8_t proto, int hint);
diff --git a/fwd_rule.c b/fwd_rule.c
index 5bc94ef..47d8df1 100644
--- a/fwd_rule.c
+++ b/fwd_rule.c
@@ -45,8 +45,7 @@ const union inany_addr *fwd_rule_addr(const struct fwd_rule *rule)
  */
 __attribute__((noinline))
 #endif
-static const char *fwd_rule_fmt(const struct fwd_rule *rule,
-				char *dst, size_t size)
+const char *fwd_rule_fmt(const struct fwd_rule *rule, char *dst, size_t size)
 {
 	const char *percent = *rule->ifname ? "%" : "";
 	const char *weak = "", *scan = "";
diff --git a/fwd_rule.h b/fwd_rule.h
index f852be3..8506a0c 100644
--- a/fwd_rule.h
+++ b/fwd_rule.h
@@ -51,6 +51,7 @@ struct fwd_rule {
 	 + sizeof(" []%:-  =>  - (best effort) (auto-scan)"))
 
 const union inany_addr *fwd_rule_addr(const struct fwd_rule *rule);
+const char *fwd_rule_fmt(const struct fwd_rule *rule, char *dst, size_t size);
 void fwd_rules_info(const struct fwd_rule *rules, size_t count);
 void fwd_rule_conflict_check(const struct fwd_rule *new,
 			     const struct fwd_rule *rules, size_t count);