Pass remotenumber to pppd. Use the IP address if no remote number is

available, or we're on the LNS side and we don't trust the remote side (default) to provide the correct AVP. Signed-off-by: Jaco Kroon <[email protected]>
xelerance · Jul 11, 2024 · 35033fb · 35033fb
1 parent 09737a1
commit 35033fb
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Showing 3 changed files with 26 additions and 0 deletions.
diff --git a/file.c b/file.c
@@ -676,6 +676,22 @@ int set_pass_peer (char *word, char *value, int context, void *item)
     return 0;
 }
 
+int set_trust_remotenumber (char *word, char *value, int context, void *item)
+{
+    switch (context & ~CONTEXT_DEFAULT)
+    {
+    case CONTEXT_LNS:
+        if (set_boolean (word, value, &(((struct lns *) item)->trust_remotenumber)))
+            return -1;
+        break;
+    default:
+        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
+                  word);
+        return -1;
+    }
+    return 0;
+}
+
 int set_pppoptfile (char *word, char *value, int context, void *item)
 {
     struct lac *l = (struct lac *) item;
@@ -1611,6 +1627,7 @@ struct keyword words[] = {
     {"hostname", &set_hostname},
     {"ppp debug", &set_debug},
     {"pass peer", &set_pass_peer},
+    {"trust remotenumber", &set_trust_remotenumber},
     {"pppoptfile", &set_pppoptfile},
     {"call rws", &set_rws},
     {"tunnel rws", &set_rws},

diff --git a/file.h b/file.h
@@ -97,6 +97,7 @@ struct lns
     int proxyauth;              /* Allow proxy authentication? */
     int debug;                  /* Debug PPP? */
     int pass_peer;              /* Pass peer IP to pppd as ipparam? */
+    int trust_remotenumber;     /* Whether or not to trust remotely supplied "Dialing Number" AVP */
     char pppoptfile[STRLEN];    /* File containing PPP options */
     struct tunnel *t;           /* Tunnel of this, if it's ready */
 };

diff --git a/xl2tpd.c b/xl2tpd.c
@@ -495,6 +495,14 @@ int start_pppd (struct call *c, struct ppp_opts *opts)
     }
 
     {
+        stropt[pos++] = strdup("remotenumber");
+        if (c->dialing[0] && (!c->lns || c->lns->trust_remotenumber)) {
+            /* if a remotenumber is available, and we're a LAC or the remote "dialing number" AVP is trusted */
+            stropt[pos++] = strdup(c->dialing);
+        } else {
+            stropt[pos++] = strdup(IPADDY(c->container->peer.sin_addr));
+        }
+
         struct ppp_opts *p = opts;
         int maxn_opts = sizeof(stropt) / sizeof(stropt[0]) - 1;
         while (p && pos < maxn_opts)