1 files changed, 174 insertions, 0 deletions
diff --git a/btree.c b/btree.c
new file mode 100644
index 0000000..92912e5
--- /dev/null
+++ b/btree.c
@@ -0,0 +1,174 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <net/if.h>
+
+/* maybe just use 
+http://cjson.sourceforge.net/
+or maybe even better:
+https://bitbucket.org/zserge/jsmn/src
+
+for the parsing? *
+
+
+/* parse downstream configuration file 
+   format:
+     port;vlan;remote-id;subscriber-id;trusted
+
+       port:
+         interface name
+       vlan:
+         vlanid || 0
+       remote-id:
+          string for REMOTE-ID attribute (requires enterprise number as input option)
+       subscriber-id:
+          string for SUBSCRIBER-ID attribute
+       trusted:
+          boolean 0 || 1 indicating whether we allow RELAY-FORW messages from this port
+
+
+   example:
+     eth2;604;123abc;hansen;0
+
+   output:
+     we combine port+vlan into a 32bit value which is used directly as the INTERFACE-ID key
+
+     a structure is allocated with pointers to the remote-id and 
+  
+     a rather large structure is allocated for each new port:
+        
+
+
+
+*/
+
+/* flags */
+#define SUB_F_TRUSTED 1
+#define SUB_F_ALL SUB_F_TRUSTED
+
+/* suscriber struct */
+struct subscriber {
+	int interfaceid;
+	int flags;
+	char *remoteid;
+	char *subscriberid;
+};
+
+/* bintree structure */
+struct e_btree {
+	struct subscriber data;
+	struct e_btree *l,*r;
+	
+};
+
+static struct e_btree *head = NULL;
+
+/* simple recursive bintree insert */
+struct e_btree *binsert(struct e_btree **p, struct subscriber *data)
+{
+	if (!*p) {
+		*p = malloc(sizeof(struct e_btree));
+		if (!*p)
+			return NULL;	/* malloc failed? */
+		(*p)->l = NULL;
+		(*p)->r = NULL;
+		memcpy(&(*p)->data, data, sizeof(struct subscriber));
+		return *p;
+	}
+	if (data->interfaceid < (*p)->data.interfaceid) {
+		fprintf(stderr, "%d < %d\n", data->interfaceid, (*p)->data.interfaceid);
+		return binsert(&(*p)->l, data);
+}
+	fprintf(stderr, "%d > %d\n", data->interfaceid, (*p)->data.interfaceid);
+	return binsert(&(*p)->r, data);
+}
+
+/* simple recursive bintree shift() */
+struct subscriber *bshift(struct e_btree **p, struct subscriber *e)
+{
+	static int level = 0;
+
+	if (!*p)
+		return NULL;  /* finished */
+
+	/* dump right tree */
+	if ((*p)->r)
+		bshift(&(*p)->r, e);
+
+
+	/* we can now finish this node */
+	fprintf(stderr, "going to return ifid=%d now\n", (*p)->data.interfaceid);
+
+	/* dump left tree */
+	if ((*p)->l)
+		bshift(&(*p)->l, e);
+	
+/*	memcpy(e, &(*p)->data, sizeof(*e));
+	free(*p);
+	*p = NULL;
+	return e;
+*/
+	return NULL;
+}
+
+/* global array holding all the entries */
+static struct subscriber sentry[];
+static int nsubscribers = 0;
+
+
+/* strategy: 
+     dynamically allocate entries as they are parsed and temporarily store them in a bintree 
+     allocate an array which is just big enough after parsing
+     store all entries *sorted* in the array
+
+     the reason for not keeping the bintree is that it most likely is very sub-optimal, as the
+     data typically will appear in a semi-sorted order in the configuration file
+
+     use binary search when looking up an entry
+
+     note that lookup is only necessary for down => up packets
+*/
+
+
+int parse_config(char *fname)
+{
+	FILE *f;
+	int n, i = 0;
+	char ifname[IFNAMSIZ];
+	struct subscriber e;
+
+	f = fopen(fname, "r");
+	if (!f) {
+		fprintf(stderr, "%s(): cannot open configuration file \"%s\": %m\n", __FUNCTION__, fname);
+		return -1;
+	}
+	while (n = fscanf(f, " %[^;] ; %u ; %m[^;] ; %m[^;] ; %u ; ", &ifname, &e.interfaceid, &e.remoteid, &e.subscriberid, &e.flags) > 0) {
+		/* FIXME: do cached lookup of ifindex for ifname and add to interfaceid */
+		
+		e.interfaceid &= 0xfff; /* VLAN tags are 12bit only */
+		e.flags &= SUB_F_ALL;	/* mask out invalid flags */
+		fprintf(stderr, "parsed entry %d (ifname=%s, ifid=%d)\n", i, ifname, e.interfaceid);
+		binsert(&head, &e);
+		i++;
+	}
+	fclose(f);
+}
+
+
+int main(int argc, char *argv[])
+{
+	struct subscriber e;
+
+	if (argc < 2)
+		return -1;
+
+	
+	parse_config(argv[1]);
+	
+	while (bshift(&head, &e))
+		;;
+//		fprintf(stderr, "ifid=%d, rid=%s, sid=%s, flags=%d\n", e.interfaceid, e.remoteid, e.subscriberid, e.flags);
+
+	return 0;
+}