From 95d2ef50f36b9ca6bcdd76992e2af8ad812e27ed Mon Sep 17 00:00:00 2001
From: Jennifer Richards <jennifer@painless-security.com>
Date: Fri, 15 Jul 2016 12:37:05 -0400
Subject: [PATCH] Peer table (work in progress).

---
 include/trp_ptable.h | 28 ++++++++++++++++
 trp/trp_ptable.c     | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+)
 create mode 100644 include/trp_ptable.h
 create mode 100644 trp/trp_ptable.c

diff --git a/include/trp_ptable.h b/include/trp_ptable.h
new file mode 100644
index 0000000..774e0c4
--- /dev/null
+++ b/include/trp_ptable.h
@@ -0,0 +1,28 @@
+#ifndef _TRP_PTABLE_H_
+#define _TRP_PTABLE_H_
+
+#include <talloc.h>
+
+#include <trust_router/tr_name.h>
+#include <trp_internal.h>
+
+typedef struct trp_peer TRP_PEER;
+struct trp_peer {
+  TR_NAME *gssname;
+  unsigned int linkcost;
+  TRP_PEER *next; /* for making a linked list */
+};
+
+typedef struct trp_ptable {
+  TRP_PEER *head; /* head of a peer table list */
+} TRP_PTABLE;
+
+TRP_PTABLE *trp_ptable_new(TALLOC_CTX *memctx);
+void trp_ptable_free(TRP_PTABLE *ptbl);
+TRP_RC trp_ptable_add(TRP_PTABLE *ptbl, TRP_PEER *newpeer);
+TRP_RC trp_ptable_remove(TRP_PTABLE *ptbl, TRP_PEER *peer);
+
+TRP_PEER *trp_peer_new(TALLOC_CTX *memctx);
+void trp_peer_free(TRP_PEER *peer);
+
+#endif /* _TRP_PTABLE_H_ */
diff --git a/trp/trp_ptable.c b/trp/trp_ptable.c
new file mode 100644
index 0000000..6ff4549
--- /dev/null
+++ b/trp/trp_ptable.c
@@ -0,0 +1,92 @@
+#include <talloc.h>
+
+#include <tr_name.h>
+#include <trp_internal.h>
+#include <trp_ptable.h>
+
+static int trp_peer_destructor(void *object)
+{
+  TRP_PEER *peer=talloc_get_type_abort(object, TRP_PEER);
+
+  if (peer->gssname != NULL) {
+    tr_free_name(peer->gssname);
+  }
+  return 0;
+}
+
+TRP_PTABLE *trp_peer_new(TALLOC_CTX *memctx)
+{
+  TRP_PEER *peer=talloc(memctx, TRP_PEER);
+  if (peer!=NULL) {
+    peer->gssname=NULL;
+    peer->linkcost=TRP_METRIC_INFINITY;
+    peer->next=NULL;
+    talloc_set_destructor((void *)peer, trp_peer_destructor);
+  }
+  return peer;
+}
+
+void trp_peer_free(TRP_PEER *peer)
+{
+  talloc_free(peer);
+}
+
+static TRP_PEER trp_peer_tail(TRP_PEER *peer)
+{
+  while (peer->next!=NULL) {
+    peer=peer->next;
+  }
+  return peer;
+}
+
+
+TRP_PTABLE *trp_ptable_new(TALLOC_CTX *memctx)
+{
+  TRP_PTABLE *ptbl=talloc(memctx, TRP_PTABLE);
+  if (ptbl!=NULL) {
+    ptbl->head=NULL;
+  }
+  return ptbl;
+}
+
+void trp_ptable_free(TRP_PTABLE *ptbl)
+{
+  talloc_free(ptbl);
+}
+
+TRP_RC trp_ptable_add(TRP_PTABLE *ptbl, TRP_PEER *newpeer)
+{
+  if (ptbl->head==NULL) {
+    ptbl->head=newpeer;
+  } else {
+    trp_peer_tail(ptbl->head)->next=newpeer;
+    talloc_steal(ptbl, newpeer);
+  }
+  return TRP_SUCCESS;
+}
+
+/* peer pointer is invalid after successful removal. Does nothing and returns
+ * TRP_ERROR if peer is not in the list. */
+TRP_RC trp_ptable_remove(TRP_PTABLE *ptbl, TRP_PEER *peer)
+{
+  TRP_PEER *cur=NULL;
+  TRP_PEER *last=NULL;
+  if (ptbl->head!=NULL) {
+    if (ptbl->head==peer) {
+      /* special case for removing head of list */
+      cur=ptbl->head;
+      ptbl->head=ptbl->head->next; /* advance the head */
+      trp_peer_free(cur);
+    }
+    for (cur=ptbl->head->next; cur!=NULL; last=cur,cur=cur->next) {
+      if (cur==peer) {
+        if (last!=NULL)
+          last->next=cur->next;
+        trp_peer_free(cur);
+        return TRP_SUCCESS;
+      }
+    }
+  }
+  return TRP_ERROR;
+}
+
-- 
2.1.4