* add initial implmenentation of a "simple protocol" for usage with nss-mdns

git-svn-id: file:///home/lennart/svn/public/avahi/trunk@113 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

1 files changed, 329 insertions, 0 deletions

diff --git a/avahi-daemon/simple-protocol.c b/avahi-daemon/simple-protocol.c
new file mode 100644
index 0000000..71dd639
--- /dev/null
+++ b/avahi-daemon/simple-protocol.c
@@ -0,0 +1,329 @@
+/* $Id$ */
+
+/***
+  This file is part of avahi.
+ 
+  avahi is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  avahi is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
+  Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with avahi; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/un.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <glib.h>
+
+#include <avahi-core/llist.h>
+
+#include "simple-protocol.h"
+
+#define BUFFER_SIZE (10*1024)
+
+#define UNIX_SOCKET_PATH "/tmp/avahi"
+#define UNIX_SOCKET UNIX_SOCKET_PATH"/socket"
+
+#define CLIENTS_MAX 50
+
+typedef struct Client Client;
+typedef struct Server Server;
+
+struct Client {
+    Server *server;
+    
+    gint fd;
+    GPollFD poll_fd;
+
+    gchar inbuf[BUFFER_SIZE], outbuf[BUFFER_SIZE];
+    guint inbuf_length, outbuf_length;
+    
+    AVAHI_LLIST_FIELDS(Client, clients);
+};
+
+struct Server {
+    GSource source;
+    GMainContext *context;
+    GPollFD poll_fd;
+    gint fd;
+    AVAHI_LLIST_HEAD(Client, clients);
+
+    guint n_clients;
+};
+
+static Server *server = NULL;
+
+static void client_free(Client *c) {
+    g_assert(c);
+
+    g_assert(c->server->n_clients >= 1);
+    c->server->n_clients--;
+    
+    g_source_remove_poll(&c->server->source, &c->poll_fd);
+    close(c->fd);
+    AVAHI_LLIST_REMOVE(Client, clients, c->server->clients, c);
+    g_free(c);
+}
+
+static void client_new(Server *s, int fd) {
+    Client *c;
+
+    g_assert(fd >= 0);
+
+    c = g_new(Client, 1);
+    c->server = s;
+    c->fd = fd;
+
+    c->inbuf_length = c->outbuf_length = 0;
+
+    memset(&c->poll_fd, 0, sizeof(GPollFD));
+    c->poll_fd.fd = fd;
+    c->poll_fd.events = G_IO_IN|G_IO_ERR|G_IO_HUP;
+    g_source_add_poll(&s->source, &c->poll_fd);
+
+    AVAHI_LLIST_PREPEND(Client, clients, s->clients, c);
+    s->n_clients++;
+}
+
+static void client_output(Client *c, const guint8*data, guint size) {
+    guint k, m;
+    
+    g_assert(c);
+    g_assert(data);
+
+    if (!size)
+        return;
+
+    k = sizeof(c->outbuf) - c->outbuf_length;
+    m = size > k ? k : size;
+
+    memcpy(c->outbuf + c->outbuf_length, data, m);
+    c->outbuf_length += m;
+}
+
+static void handle_line(Client *c, const gchar *s) {
+    gchar t[256];
+
+    g_assert(c);
+    g_assert(s);
+
+    snprintf(t, sizeof(t), "you said <%s>\n", s);
+    client_output(c, (guint8*) t, strlen(t));
+}
+
+static void handle_input(Client *c) {
+    g_assert(c);
+
+    for (;;) {
+        gchar *e;
+        guint k;
+
+        if (!(e = memchr(c->inbuf, '\n', c->inbuf_length)))
+            break;
+
+        k = e - (gchar*) c->inbuf;
+        *e = 0;
+        
+        handle_line(c, c->inbuf);
+        c->inbuf_length -= k + 1;
+        memmove(c->inbuf, e+1, c->inbuf_length);
+    }
+}
+
+static void client_work(Client *c) {
+    g_assert(c);
+
+    if ((c->poll_fd.revents & G_IO_IN) && c->inbuf_length < sizeof(c->inbuf)) {
+        ssize_t r;
+        
+        if ((r = read(c->fd, c->inbuf + c->inbuf_length, sizeof(c->inbuf) - c->inbuf_length)) <= 0) {
+            if (r < 0)
+                g_warning("read(): %s", strerror(errno));
+            client_free(c);
+            return;
+        }
+
+        c->inbuf_length += r;
+        g_assert(c->inbuf_length <= sizeof(c->inbuf));
+
+        handle_input(c);
+    }
+
+    if ((c->poll_fd.revents & G_IO_OUT) && c->outbuf_length > 0) {
+        ssize_t r;
+
+        if ((r = write(c->fd, c->outbuf, c->outbuf_length)) < 0) {
+            g_warning("write(): %s", strerror(errno));
+            client_free(c);
+            return;
+        }
+
+        g_assert((guint) r <= c->outbuf_length);
+        c->outbuf_length -= r;
+        
+        if (c->outbuf_length)
+            memmove(c->outbuf, c->outbuf + r, c->outbuf_length - r);
+    }
+
+    c->poll_fd.events =
+        G_IO_ERR |
+        G_IO_HUP |
+        (c->outbuf_length > 0 ? G_IO_OUT : 0) |
+        (c->inbuf_length < sizeof(c->inbuf) ? G_IO_IN : 0);
+}
+
+static gboolean prepare_func(GSource *source, gint *timeout) {
+    g_assert(source);
+    g_assert(timeout);
+    
+    *timeout = -1;
+    return FALSE;
+}
+
+static gboolean check_func(GSource *source) {
+    Server *s = (Server*) source;
+    Client *c;
+    
+    g_assert(s);
+
+    if (s->poll_fd.revents)
+        return TRUE;
+    
+    for (c = s->clients; c; c = c->clients_next)
+        if (c->poll_fd.revents)
+            return TRUE;
+
+    return FALSE;
+}
+
+static gboolean dispatch_func(GSource *source, GSourceFunc callback, gpointer user_data) {
+    Server *s = (Server*) source;
+    Client *c, *n;
+    
+    g_assert(s);
+
+    if (s->poll_fd.revents & G_IO_IN) {
+        gint fd;
+
+        if ((fd = accept(s->fd, NULL, NULL)) < 0)
+            g_warning("accept(): %s", strerror(errno));
+        else
+            client_new(s, fd);
+    } else if (s->poll_fd.revents)
+        g_error("Invalid revents");
+
+    for (c = s->clients; c; c = n) {
+        n = c->clients_next;
+        if (c->poll_fd.revents)
+            client_work(c);
+    }
+    
+    return TRUE;
+}
+
+int simple_protocol_setup(GMainContext *c) {
+    struct sockaddr_un sa;
+    mode_t u;
+
+    static GSourceFuncs source_funcs = {
+        prepare_func,
+        check_func,
+        dispatch_func,
+        NULL,
+        NULL,
+        NULL
+    };
+    
+    g_assert(!server);
+
+    server = (Server*) g_source_new(&source_funcs, sizeof(Server));
+    server->fd = -1;
+    AVAHI_LLIST_HEAD_INIT(Client, server->clients);
+    if (c)
+        g_main_context_ref(server->context = c);
+    else
+        server->context = g_main_context_default();
+    server->clients = NULL;
+
+    u = umask(0000);
+
+    if (mkdir(UNIX_SOCKET_PATH, 0755) < 0 && errno != EEXIST) {
+        g_warning("mkdir(): %s", strerror(errno));
+        goto fail;
+    }
+    
+    if ((server->fd = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0) {
+        g_warning("socket(PF_LOCAL, SOCK_STREAM, 0): %s", strerror(errno));
+        goto fail;
+    }
+
+    memset(&sa, 0, sizeof(sa));
+    sa.sun_family = AF_LOCAL;
+    strncpy(sa.sun_path, UNIX_SOCKET, sizeof(sa.sun_path)-1);
+
+    if (bind(server->fd, &sa, sizeof(sa)) < 0) {
+        g_warning("bind(): %s", strerror(errno));
+        goto fail;
+    }
+    
+    if (listen(server->fd, 2) < 0) {
+        g_warning("listen(): %s", strerror(errno));
+        goto fail;
+    }
+
+    umask(u);
+
+    memset(&server->poll_fd, 0, sizeof(GPollFD));
+    server->poll_fd.fd = server->fd;
+    server->poll_fd.events = G_IO_IN|G_IO_ERR;
+    g_source_add_poll(&server->source, &server->poll_fd);
+
+    g_source_attach(&server->source, server->context);
+    
+    return 0;
+
+fail:
+    
+    umask(u);
+    simple_protocol_shutdown();
+
+    return -1;
+}
+
+void simple_protocol_shutdown(void) {
+
+    if (server) {
+
+        while (server->clients)
+            client_free(server->clients);
+        
+        if (server->fd >= 0) {
+            unlink(UNIX_SOCKET_PATH);
+            close(server->fd);
+        }
+
+        g_main_context_unref(server->context);
+        g_source_destroy(&server->source);
+        g_source_unref(&server->source);
+
+        server = NULL;
+    }
+}