From: Gianmarco De Gregori <gianmarco@mandelbit.com>
Date: Fri, 24 Jan 2025 20:51:35 +0000 (+0100)
Subject: mroute: adapt to new protocol handling and hashing improvements
X-Git-Tag: v2.7_alpha1~113
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dda93f30411eec3457a48e94ef599e3f034c87e5;p=thirdparty%2Fopenvpn.git

mroute: adapt to new protocol handling and hashing improvements

Repurposing an unused field and renaming it to 'proto'
instead of introducing a new field. The hashing now
begins at the 'proto' field rather than the 'type'
field. Additionally, the changes ensure that the
correct protocol is consistently used with virtual
addresses ensuring alignment.

Change-Id: Ic66eccb5058fe9c0fae64d8e2ca88728068a92ab
Signed-off-by: Gianmarco De Gregori <gianmarco@mandelbit.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20250124205135.18765-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg30579.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
---

diff --git a/src/openvpn/mroute.c b/src/openvpn/mroute.c
index 80e18b7c..74923cfb 100644
--- a/src/openvpn/mroute.c
+++ b/src/openvpn/mroute.c
@@ -454,6 +454,7 @@ mroute_addr_print_ex(const struct mroute_addr *ma,
                 buf_printf(&out, "UNKNOWN");
                 break;
         }
+        buf_printf(&out, "|%d", maddr.proto);
         return BSTR(&out);
     }
     else
diff --git a/src/openvpn/mroute.h b/src/openvpn/mroute.h
index 8b457d4e..26596953 100644
--- a/src/openvpn/mroute.h
+++ b/src/openvpn/mroute.h
@@ -74,7 +74,7 @@
 
 struct mroute_addr {
     uint8_t len;    /* length of address */
-    uint8_t unused;
+    uint8_t proto;
     uint8_t type;   /* MR_ADDR/MR_WITH flags */
     uint8_t netbits; /* number of bits in network part of address,
                       * valid if MR_WITH_NETBITS is set */
@@ -183,6 +183,15 @@ mroute_extract_addr_from_packet(struct mroute_addr *src,
 {
     unsigned int ret = 0;
     verify_align_4(buf);
+
+    /*
+     * Since we don't really need the protocol on vaddresses for internal VPN
+     * payload packets, make sure we have the same value to avoid hashing insert
+     * and search issues.
+     */
+    src->proto = 0;
+    dest->proto = src->proto;
+
     if (tunnel_type == DEV_TYPE_TUN)
     {
         ret = mroute_extract_addr_ip(src, dest, buf);
@@ -201,6 +210,10 @@ mroute_addr_equal(const struct mroute_addr *a1, const struct mroute_addr *a2)
     {
         return false;
     }
+    if (a1->proto != a2->proto)
+    {
+        return false;
+    }
     if (a1->netbits != a2->netbits)
     {
         return false;
@@ -216,13 +229,13 @@ static inline const uint8_t *
 mroute_addr_hash_ptr(const struct mroute_addr *a)
 {
     /* NOTE: depends on ordering of struct mroute_addr */
-    return (uint8_t *) &a->type;
+    return (uint8_t *) &a->proto;
 }
 
 static inline uint32_t
 mroute_addr_hash_len(const struct mroute_addr *a)
 {
-    return (uint32_t) a->len + 2;
+    return (uint32_t) a->len + 3;
 }
 
 static inline void
diff --git a/src/openvpn/mtcp.c b/src/openvpn/mtcp.c
index 6d1d5a08..62ed044a 100644
--- a/src/openvpn/mtcp.c
+++ b/src/openvpn/mtcp.c
@@ -56,6 +56,7 @@ multi_create_instance_tcp(struct multi_context *m, struct link_socket *ls)
     mi = multi_create_instance(m, NULL, ls);
     if (mi)
     {
+        mi->real.proto = ls->info.proto;
         struct hash_element *he;
         const uint32_t hv = hash_value(hash, &mi->real);
         struct hash_bucket *bucket = hash_bucket(hash, hv);
diff --git a/src/openvpn/mudp.c b/src/openvpn/mudp.c
index 61375784..4f2bbd7a 100644
--- a/src/openvpn/mudp.c
+++ b/src/openvpn/mudp.c
@@ -192,6 +192,7 @@ multi_get_create_instance_udp(struct multi_context *m, bool *floated,
     struct mroute_addr real = {0};
     struct multi_instance *mi = NULL;
     struct hash *hash = m->hash;
+    real.proto = ls->info.proto;
 
     if (mroute_extract_openvpn_sockaddr(&real, &m->top.c2.from.dest, true)
         && m->top.c2.buf.len > 0)
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c
index 3f55dd72..9c8c014f 100644
--- a/src/openvpn/multi.c
+++ b/src/openvpn/multi.c
@@ -794,6 +794,7 @@ multi_create_instance(struct multi_context *m, const struct mroute_addr *real,
         {
             goto err;
         }
+        mi->real.proto = ls->info.proto;
         generate_prefix(mi);
     }
 
@@ -1243,6 +1244,7 @@ multi_learn_in_addr_t(struct multi_context *m,
     CLEAR(remote_si);
     remote_si.addr.in4.sin_family = AF_INET;
     remote_si.addr.in4.sin_addr.s_addr = htonl(a);
+    addr.proto = 0;
     ASSERT(mroute_extract_openvpn_sockaddr(&addr, &remote_si, false));
 
     if (netbits >= 0)
@@ -3548,7 +3550,6 @@ multi_process_incoming_tun(struct multi_context *m, const unsigned int mpp_flags
         const int dev_type = TUNNEL_TYPE(m->top.c1.tuntap);
         int16_t vid = 0;
 
-
 #ifdef MULTI_DEBUG_EVENT_LOOP
         printf("TUN -> TCP/UDP [%d]\n", BLEN(&m->top.c2.buf));
 #endif