[*] Initial commit

lonetix/bgp/parameters.c

@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+/**
+ * \file bgp/parameters.c
+ *
+ * Deals with BGP OPEN parameters.
+ *
+ * \copyright The DoubleFourteen Code Forge (C) All Rights Reserved
+ * \author    Lorenzo Cogotti
+ */
+
+#include "bgp/bgp_local.h"
+
+Judgement Bgp_StartMsgParms(Bgpparmiter *it, Bgpmsg *msg)
+{
+	const Bgpopen *open = Bgp_GetMsgOpen(msg);
+	if (!open)
+		return NG;  // error already set
+
+	Bgp_StartParms(it, BGP_OPENPARMS(open));
+	return OK;  // error already cleared
+}
+
+void Bgp_StartParms(Bgpparmiter *it, const Bgpparmseg *p)
+{
+	it->ptr  = (Uint8 *) p->parms;
+	it->base = it->ptr;
+	it->lim  = it->base + p->len;
+}
+
+Bgpparm *Bgp_NextParm(Bgpparmiter *it)
+{
+	if (it->ptr >= it->lim) {
+		Bgp_SetErrStat(BGPENOERR);
+		return NULL;
+	}
+
+	Bgpparm *p  = (Bgpparm *) it->ptr;
+	size_t left = it->lim - it->ptr;
+	if (left < 2uLL || left < 2uLL + p->len) {
+		Bgp_SetErrStat(BGPETRUNCMSG);
+		return NULL;
+	}
+
+	it->ptr += 2 + p->len;
+	Bgp_SetErrStat(BGPENOERR);
+	return p;
+}
+
+Judgement Bgp_StartMsgCaps(Bgpcapiter *it, Bgpmsg *msg)
+{
+	if (Bgp_StartMsgParms(&it->pi, msg) != OK)
+		return NG;  // error already set
+
+	// Set starting point so Bgp_NextCap() scans for next parameter
+	it->base = it->lim = it->ptr = it->pi.ptr;
+	return OK;
+}
+
+void Bgp_StartCaps(Bgpcapiter *it, const Bgpparmseg *parms)
+{
+	Bgp_StartParms(&it->pi, parms);
+	// Set starting point so Bgp_NextCap() scans for next parameter
+	it->base = it->lim = it->ptr = it->pi.ptr;
+}
+
+Bgpcap *Bgp_NextCap(Bgpcapiter *it)
+{
+	if (it->ptr >= it->lim) {
+		// Try to find another CAPABILITY parameter
+		Bgpparm *p;
+
+		while ((p = Bgp_NextParm(&it->pi)) != NULL) {
+			if (p->code == BGP_PARM_CAPABILITY)
+				break;
+		}
+		if (!p) {
+			// Scanned all parameters, nothing found
+			Bgp_SetErrStat(BGPENOERR);
+			return NULL;
+		}
+
+		// Setup for reading new capabilities from `p`
+		it->base = (Uint8 *) p + 2;
+		it->lim  = it->base + p->len;
+		it->ptr  = it->base;
+	}
+
+	// Return current capability and move over
+	size_t  left = it->lim - it->ptr;
+	Bgpcap *cap  = (Bgpcap *) it->ptr;
+	if (left < 2uLL || left < 2uLL + cap->len) {
+		Bgp_SetErrStat(BGPETRUNCMSG);
+		return NULL;
+	}
+
+	it->ptr += 2 + cap->len;
+	Bgp_SetErrStat(BGPENOERR);
+	return cap;
+}