mdns vnc stuff

1 files changed, 238 insertions, 0 deletions

diff --git a/mdns-publish-vnc.c b/mdns-publish-vnc.c
new file mode 100644
index 0000000..1a88fa0
--- /dev/null
+++ b/mdns-publish-vnc.c
@@ -0,0 +1,238 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <time.h>
+#include <sys/syslog.h>
+#include <sys/utsname.h>
+
+#include <xs.h>
+
+#include "list.h"
+#include "xenstore.h"
+#include "mdns-publish.h"
+
+/* ------------------------------------------------------------- */
+
+struct dom {
+    int                    domid;
+    char                   name[128];
+    int                    destroyed;
+
+    char                   label[256];
+    int                    vnc_port;
+    int                    published;
+    struct mdns_pub_entry  *entry;
+    
+    struct list_head       next;
+};
+
+static LIST_HEAD(doms);
+static struct utsname uts;
+
+/* ------------------------------------------------------------- */
+
+static struct dom *find_dom(int domid)
+{
+    struct dom *dom;
+    struct list_head *item;
+
+    list_for_each(item, &doms) {
+	dom = list_entry(item, struct dom, next);
+	if (dom->domid == domid)
+	    return dom;
+    }
+    return NULL;
+}
+
+static struct dom *get_dom(int domid)
+{
+    struct dom *dom;
+
+    dom = find_dom(domid);
+    if (!dom) {
+	dom = malloc(sizeof(*dom));
+	memset(dom,0,sizeof(*dom));
+	dom->domid = domid;
+	list_add_tail(&dom->next, &doms);
+    }
+    return dom;
+}
+
+static void try_attach_domain(struct mdns_pub *mdns, struct dom *dom, int boot)
+{
+    if (dom->published)
+	return;
+    if (!strlen(dom->name))
+	return;
+    if (!dom->vnc_port)
+	return;
+
+    snprintf(dom->label, sizeof(dom->label), "host %s, guest %s",
+	     uts.nodename, dom->name);
+    mdns_log_printf(mdns, LOG_INFO, "pub: %s (%d)\n", dom->name, dom->domid);
+    dom->entry = mdns_pub_add(mdns, dom->label, "_rfb._tcp", dom->vnc_port);
+
+    dom->published = 1;
+}
+
+static void try_release_domain(struct mdns_pub *mdns, struct dom *dom)
+{
+    if (!dom->destroyed)
+	return;
+    if (dom->published) {
+	mdns_log_printf(mdns, LOG_INFO, "del: %s (%d)\n", dom->name, dom->domid);
+	mdns_pub_del(dom->entry);
+    }
+    list_del(&dom->next);
+    free(dom);
+}
+
+/* ------------------------------------------------------------- */
+
+static void usage(FILE *fp)
+{
+    fprintf(fp, "usage: [fixme]\n");
+}
+
+int main(int argc, char *argv[])
+{
+    struct mdns_pub *mdns = NULL;
+    struct xs_handle *xenstore = NULL;
+    xs_transaction_t xst;
+    char **vec = NULL;
+    int domid, c;
+    int debug = 0;
+    char path[128], value[128];
+    unsigned int count, i, rc;
+    struct dom *dom;
+    fd_set set;
+
+    for (;;) {
+        if (-1 == (c = getopt(argc, argv, "hd")))
+            break;
+        switch (c) {
+
+	case 'd':
+	    debug++;
+	    break;
+
+        case 'h':
+            usage(stdout);
+            exit(0);
+        default:
+            usage(stderr);
+            exit(1);
+        }
+    }
+
+    mdns_pub_appname = "mdns-publish-vnc";
+    uname(&uts);
+    if (!debug)
+	mdns_daemonize();
+
+    /* connect to xenstore */
+    xenstore = xenstore_open(1,1,1,1);
+    if (NULL == xenstore) {
+	mdns_log_printf(mdns, LOG_ERR, "can't access xenstore, exiting\n");
+	exit(1);
+    }
+    xs_watch(xenstore, "/local/domain", "token");
+
+    mdns = mdns_pub_init(debug);
+    if (NULL == mdns)
+	exit(1);
+    mdns_sigsetup(mdns);
+    mdns_pub_start(mdns);
+
+    /* look for running domains */
+    if (!(xst = xs_transaction_start(xenstore))) {
+	mdns_log_printf(mdns, LOG_ERR, "Oops, can't start xenstore transaction\n");
+	exit(1);
+    }
+    vec = xs_directory(xenstore, xst, "/local/domain", &count);
+    xs_transaction_end(xenstore, xst, 0);
+
+    fprintf(stderr,"looking for existing domains\n");
+    for (i = 0; i < count; i++) {
+	domid = atoi(vec[i]);
+	dom = get_dom(domid);
+	snprintf(path, sizeof(path), "/local/domain/%d/name", domid);
+	xenstore_read(xenstore, path, dom->name, sizeof(dom->name));
+	snprintf(path, sizeof(path), "/local/domain/%d/console/vnc-port", domid);
+	if (0 == xenstore_read(xenstore, path, value, sizeof(value)))
+	    dom->vnc_port = atoi(value);
+	try_attach_domain(mdns, dom, 1);
+    }
+
+    /* main loop */
+    fprintf(stderr,"ok, watching out for changes now\n");
+    for (;;) {
+	if (mdns_pub_appquit)
+	    break;
+
+	FD_ZERO(&set);
+	FD_SET(xs_fileno(xenstore), &set);
+	switch (select(xs_fileno(xenstore)+1, &set, NULL, NULL, NULL)) {
+	case -1:
+	    if (EINTR == errno)
+		continue; /* termsig check */
+	    perror("select");
+	    break;
+	case 0:
+	    fprintf(stderr,"Huh, select() timeout?\n");
+	    mdns_pub_appquit++;
+	    break;
+	default:
+	    break;
+	}
+	
+	if (vec)
+	    free(vec);
+	vec = xs_read_watch(xenstore, &count);
+	if (NULL == vec) {
+	    fprintf(stderr,"xs_read_watch() failed\n");
+	    exit(1);
+	}
+	if (2 != sscanf(vec[XS_WATCH_PATH], "/local/domain/%d/%64s", &domid, path)) {
+	    if (1 != sscanf(vec[XS_WATCH_PATH], "/local/domain/%d", &domid))
+		continue;
+	    strcpy(path, "");
+	}
+	dom = get_dom(domid);
+
+	if (0 == strcmp(path,"")) {
+	    rc = xenstore_read(xenstore, vec[XS_WATCH_PATH], value, sizeof(value));
+	    if (0 != rc)
+		dom->destroyed = 1;
+
+	} else if (0 == strcmp(path, "name")) {
+	    rc = xenstore_read(xenstore, vec[XS_WATCH_PATH], value, sizeof(value));
+	    if (0 != rc)
+		continue;
+	    strcpy(dom->name, value);
+	    mdns_log_printf(mdns, LOG_INFO, "new: %s (%d)\n", dom->name, dom->domid);
+
+	} else if (0 == strcmp(path, "console/vnc-port")) {
+	    rc = xenstore_read(xenstore, vec[XS_WATCH_PATH], value, sizeof(value));
+	    if (0 != rc)
+		continue;
+	    dom->vnc_port = atoi(value);
+
+	} else {
+	    continue;
+
+	}
+
+	try_attach_domain(mdns, dom, 0);
+	try_release_domain(mdns, dom);
+    }
+
+    mdns_pub_del_all(mdns);
+    mdns_pub_stop(mdns);
+    mdns_pub_fini(mdns);
+    return 0;
+}