Added graph dumping ability based on Markus Goetz's patch.

[oweals/tinc.git] / src / graph.c

diff --git a/src/graph.c b/src/graph.c
index 2fc3b744c4e13fde81ed1d583f6d3b70df304628..b5af2241f51b189b8fafd8268aa6c63112cee8f5 100644 (file)
--- a/src/graph.c
+++ b/src/graph.c
@@ -47,6 +47,7 @@
 #include "system.h"
 
 #include "avl_tree.h"
+#include "config.h"
 #include "connection.h"
 #include "device.h"
 #include "edge.h"
@@ -57,6 +58,8 @@
 #include "subnet.h"
 #include "utils.h"
 
+static bool graph_changed = true;
+
 /* Implementation of Kruskal's algorithm.
    Running time: O(EN)
    Please note that sorting on weight is already done by add_edge().
@@ -306,4 +309,65 @@ void graph(void)
 {
        mst_kruskal();
        sssp_bfs();
+       graph_changed = true;
+}
+
+
+
+/* Dump nodes and edges to a graphviz file.
+          
+   The file can be converted to an image with
+   dot -Tpng graph_filename -o image_filename.png -Gconcentrate=true
+*/
+
+void dump_graph(void)
+{
+       avl_node_t *node;
+       node_t *n;
+       edge_t *e;
+       char *filename = NULL, *tmpname = NULL;
+       FILE *file;
+       
+       if(!graph_changed || !get_config_string(lookup_config(config_tree, "GraphDumpFile"), &filename))
+               return;
+
+       graph_changed = false;
+
+       ifdebug(PROTOCOL) logger(LOG_NOTICE, "Dumping graph");
+       
+       if(filename[0] == '|') {
+               file = popen(filename + 1, "w");
+       } else {
+               asprintf(&tmpname, "%s.new", filename);
+               file = fopen(tmpname, "w");
+       }
+
+       if(!file) {
+               logger(LOG_ERR, "Unable to open graph dump file %s: %s", filename, strerror(errno));
+               free(tmpname);
+               return;
+       }
+
+       fprintf(file, "digraph {\n");
+       
+       /* dump all nodes first */
+       for(node = node_tree->head; node; node = node->next) {
+               n = node->data;
+               fprintf(file, " %s [label = \"%s\"];\n", n->name, n->name);
+       }
+
+       /* now dump all edges */
+       for(node = edge_weight_tree->head; node; node = node->next) {
+               e = node->data;
+               fprintf(file, " %s -> %s;\n", e->from->name, e->to->name);
+       }
+
+       fprintf(file, "}\n");   
+       
+       fclose(file);
+
+       if(filename[0] != '|') {
+               rename(tmpname, filename);
+               free(tmpname);
+       }
 }