[PATCH gwproxy v1 0/2] Fix missing validation of restyp in dns

[PATCH gwproxy v1 0/2] Fix missing validation of restyp in dns

[Ahmad Gani]

The dns test is buggy, when I run make test it always ended up with
EINVAL. And it turned out restyp is not validated in the fetch_addr,
this patch add validation in the initialization stage.

Signed-off-by: Ahmad Gani <reyuki@gnuweeb.org>
---

Ahmad Gani (2):
  dns: add a new restyp GWP_DNS_RESTYP_DEFAULT
  dns: validate restyp on initialization

 src/gwproxy/dns.c | 20 +++++++++++++++++++-
 src/gwproxy/dns.h |  1 +
 2 files changed, 20 insertions(+), 1 deletion(-)


base-commit: ccd2541934c3af56b14bd5bcf7326563d8e2e728
-- 
Ahmad Gani

[PATCH gwproxy v1 1/2] dns: add a new restyp GWP_DNS_RESTYP_DEFAULT

[Ahmad Gani]

The new restyp is required to handle unspecified restyp.

Signed-off-by: Ahmad Gani <reyuki@gnuweeb.org>
---
 src/gwproxy/dns.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/gwproxy/dns.h b/src/gwproxy/dns.h
index c9dea0a10d62..7d62d3f9b89e 100644
--- a/src/gwproxy/dns.h
+++ b/src/gwproxy/dns.h
@@ -31,6 +31,7 @@ struct gwp_dns_entry {
 };
 
 enum {
+	GWP_DNS_RESTYP_DEFAULT		= 0,
 	GWP_DNS_RESTYP_IPV4_ONLY	= 1,
 	GWP_DNS_RESTYP_IPV6_ONLY	= 2,
 	GWP_DNS_RESTYP_PREFER_IPV4	= 3,
-- 
Ahmad Gani

[PATCH gwproxy v1 2/2] dns: validate restyp on initialization

[Ahmad Gani]

Return EINVAL on initialization if restyp is invalid.
And then prefer ipv4 if GWP_DNS_RESTYP_DEFAULT is used.

Fixes: 82c86a7256d6 ("gwproxy/dns: Replace the old DNS cache system with a new one.")
Signed-off-by: Ahmad Gani <reyuki@gnuweeb.org>
---
 src/gwproxy/dns.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/gwproxy/dns.c b/src/gwproxy/dns.c
index f7cbcb2d6e89..b189b33127af 100644
--- a/src/gwproxy/dns.c
+++ b/src/gwproxy/dns.c
@@ -619,7 +619,8 @@ static int fetch_addr(struct gwp_dns_cache_entry *e, struct gwp_sockaddr *addr,
 			if (!fetch_i4(e, addr, port))
 				return -EHOSTUNREACH;
 		}
-	} else if (restyp == GWP_DNS_RESTYP_PREFER_IPV4) {
+	} else if (restyp == GWP_DNS_RESTYP_PREFER_IPV4 ||
+		   restyp == GWP_DNS_RESTYP_DEFAULT) {
 		if (!fetch_i4(e, addr, port)) {
 			if (!fetch_i6(e, addr, port))
 				return -EHOSTUNREACH;
@@ -679,11 +680,28 @@ static void free_cache(struct gwp_dns_cache *cache)
 	cache = NULL;
 }
 
+static inline bool validate_restyp(int restyp)
+{
+	switch (restyp) {
+	case GWP_DNS_RESTYP_DEFAULT:
+	case GWP_DNS_RESTYP_IPV4_ONLY:
+	case GWP_DNS_RESTYP_IPV6_ONLY:
+	case GWP_DNS_RESTYP_PREFER_IPV4:
+	case GWP_DNS_RESTYP_PREFER_IPV6:
+		return true;
+	default:
+		return false;
+	}
+}
+
 int gwp_dns_ctx_init(struct gwp_dns_ctx **ctx_p, const struct gwp_dns_cfg *cfg)
 {
 	struct gwp_dns_ctx *ctx;
 	int r;
 
+	if (!validate_restyp(cfg->restyp))
+		return -EINVAL;
+
 	ctx = calloc(1, sizeof(*ctx));
 	if (!ctx)
 		return -ENOMEM;
-- 
Ahmad Gani

Re: [PATCH gwproxy v1 0/2] Fix missing validation of restyp in dns

[Ammar Faizi]

On Mon, 28 Jul 2025 23:07:56 +0700, Ahmad Gani wrote:
> The dns test is buggy, when I run make test it always ended up with
> EINVAL. And it turned out restyp is not validated in the fetch_addr,
> this patch add validation in the initialization stage.

Applied, thanks!

[1/2] dns: add a new restyp GWP_DNS_RESTYP_DEFAULT
      commit: 3d59d38b8d41e5bb9c6a11f2b0d3f54787c4ff97
[2/2] dns: validate restyp on initialization
      commit: 398bc212124a0ce557fb7069fe976eba111983e1

Best regards,
-- 
Ammar Faizi