diff mbox series

[Openvpn-devel,v1] route.c: change the signature of get_default_gateway()

Message ID 20250129095038.19056-1-gert@greenie.muc.de
State Accepted
Headers show
Series [Openvpn-devel,v1] route.c: change the signature of get_default_gateway() | expand

Commit Message

Gert Doering Jan. 29, 2025, 9:50 a.m. UTC 
From: Lev Stipakov <lev@openvpn.net>

As a preparation of an upcoming refactoring of
get_default_gateway(), add `dest` parameter to
specify destination address to which we are looking
the best route.

Change-Id: I58735fb24bc4a94c803b7dfcd6de87af0f75522a
Signed-off-by: Lev Stipakov <lev@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
---

This change was reviewed on Gerrit and approved by at least one
developer. I request to merge it to master.

Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/878
This mail reflects revision 1 of this Change.

Acked-by according to Gerrit (reflected above):
Gert Doering <gert@greenie.muc.de>

Comments

Gert Doering Jan. 29, 2025, 9:56 a.m. UTC | #1 
As discusssed on IRC, this is the first patch of a series to improve
the IPv4 gateway lookup, aka, "make it as good as the IPv6 implementation".

The problem today is that the IPv4 code only looks for "the default route",
which is not the right answer for "which route and interface is used to
reach the VPN server?" in case of more-specific routes - arguably not the
most common case, but if we can get it right, we should.

This patch does not change anything but add an (unused) "in_addr_t host"
argument to all the get_default_gateway() calls & implementations.  Further
patches will enhance the per-platform implementations to use this info
(if possible).

So the thing to test here is "was any of our platforms overlooked, and
compilation fails" - and the anwswer is "it compiles, ship it!" ;-)

Your patch has been applied to the master branch.

commit 0fcfc8381f60d9f7b4a53afaea223dfee5e18835
Author: Lev Stipakov
Date:   Wed Jan 29 10:50:38 2025 +0100

     route.c: change the signature of get_default_gateway()

     Signed-off-by: Lev Stipakov <lev@openvpn.net>
     Acked-by: Gert Doering <gert@greenie.muc.de>
     Message-Id: <20250129095038.19056-1-gert@greenie.muc.de>
     URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg30685.html
     Signed-off-by: Gert Doering <gert@greenie.muc.de>


--
kind regards,

Gert Doering
diff mbox series

Patch

diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index 4510bea..5a80e6b 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -5866,7 +5866,7 @@ 
             get_ipv6_addr(p[1], &remote, NULL, M_WARN);
         }
         net_ctx_init(NULL, &net_ctx);
-        get_default_gateway(&rgi, &net_ctx);
+        get_default_gateway(&rgi, 0, &net_ctx);
         get_default_gateway_ipv6(&rgi6, &remote, &net_ctx);
         print_default_gateway(M_INFO, &rgi, &rgi6);
         openvpn_exit(OPENVPN_EXIT_STATUS_GOOD); /* exit point */
diff --git a/src/openvpn/route.c b/src/openvpn/route.c
index d17b285..640b0dc 100644
--- a/src/openvpn/route.c
+++ b/src/openvpn/route.c
@@ -655,7 +655,7 @@ 
         rl->spec.flags |= RTSA_DEFAULT_METRIC;
     }
 
-    get_default_gateway(&rl->rgi, ctx);
+    get_default_gateway(&rl->rgi, remote_host, ctx);
     if (rl->rgi.flags & RGI_ADDR_DEFINED)
     {
         setenv_route_addr(es, "net_gateway", rl->rgi.gateway.addr, -1);
@@ -2733,7 +2733,7 @@ 
 }
 
 void
-get_default_gateway(struct route_gateway_info *rgi, openvpn_net_ctx_t *ctx)
+get_default_gateway(struct route_gateway_info *rgi, in_addr_t dest, openvpn_net_ctx_t *ctx)
 {
     struct gc_arena gc = gc_new();
 
@@ -3282,7 +3282,7 @@ 
 #elif defined(TARGET_ANDROID)
 
 void
-get_default_gateway(struct route_gateway_info *rgi, openvpn_net_ctx_t *ctx)
+get_default_gateway(struct route_gateway_info *rgi, in_addr_t dest, openvpn_net_ctx_t *ctx)
 {
     /* Android, set some pseudo GW, addr is in host byte order,
      * Determining the default GW on Android 5.0+ is non trivial
@@ -3323,7 +3323,7 @@ 
 #elif defined(TARGET_LINUX)
 
 void
-get_default_gateway(struct route_gateway_info *rgi, openvpn_net_ctx_t *ctx)
+get_default_gateway(struct route_gateway_info *rgi, in_addr_t dest, openvpn_net_ctx_t *ctx)
 {
     struct gc_arena gc = gc_new();
     int sd = -1;
@@ -3561,7 +3561,7 @@ 
 #define max(a, b) ((a) > (b) ? (a) : (b))
 
 void
-get_default_gateway(struct route_gateway_info *rgi, openvpn_net_ctx_t *ctx)
+get_default_gateway(struct route_gateway_info *rgi, in_addr_t dest, openvpn_net_ctx_t *ctx)
 {
     struct gc_arena gc = gc_new();
     struct rtmsg m_rtmsg;
@@ -3943,7 +3943,7 @@ 
 #elif defined(TARGET_HAIKU)
 
 void
-get_default_gateway(struct route_gateway_info *rgi, openvpn_net_ctx_t *ctx)
+get_default_gateway(struct route_gateway_info *rgi, in_addr_t dest, openvpn_net_ctx_t *ctx)
 {
     CLEAR(*rgi);
 
@@ -4047,7 +4047,7 @@ 
  * may be disabled by missing items.
  */
 void
-get_default_gateway(struct route_gateway_info *rgi, openvpn_net_ctx_t *ctx)
+get_default_gateway(struct route_gateway_info *rgi, in_addr_t dest, openvpn_net_ctx_t *ctx)
 {
     CLEAR(*rgi);
 }
diff --git a/src/openvpn/route.h b/src/openvpn/route.h
index 421e7d2..23603bc 100644
--- a/src/openvpn/route.h
+++ b/src/openvpn/route.h
@@ -328,6 +328,7 @@ 
 bool is_special_addr(const char *addr_str);
 
 void get_default_gateway(struct route_gateway_info *rgi,
+                         in_addr_t dest,
                          openvpn_net_ctx_t *ctx);
 
 void get_default_gateway_ipv6(struct route_ipv6_gateway_info *rgi,
diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
index e4a7b57..6f78a76 100644
--- a/src/openvpn/ssl.c
+++ b/src/openvpn/ssl.c
@@ -1990,7 +1990,7 @@ 
         {
             /* push mac addr */
             struct route_gateway_info rgi;
-            get_default_gateway(&rgi, session->opt->net_ctx);
+            get_default_gateway(&rgi, 0, session->opt->net_ctx);
             if (rgi.flags & RGI_HWADDR_DEFINED)
             {
                 buf_printf(&out, "IV_HWADDR=%s\n", format_hex_ex(rgi.hwaddr, 6, 0, 1, ":", &gc));
diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 33830fc..80f5dff 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -671,7 +671,7 @@ 
     struct route_gateway_info rgi;
     const unsigned int needed = (RGI_ADDR_DEFINED|RGI_NETMASK_DEFINED);
 
-    get_default_gateway(&rgi, ctx);
+    get_default_gateway(&rgi, 0, ctx);
     if ((rgi.flags & needed) == needed)
     {
         const in_addr_t lan_network = rgi.gateway.addr & rgi.gateway.netmask;