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/* $Id$ */
/***
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 <unistd.h>
#include <errno.h>
#include <string.h>
#include "netlink.h"
struct _AvahiNetlink {
GMainContext *context;
gint fd;
guint seq;
GPollFD poll_fd;
GSource *source;
void (*callback) (AvahiNetlink *nl, struct nlmsghdr *n, gpointer userdata);
gpointer userdata;
};
gboolean avahi_netlink_work(AvahiNetlink *nl, gboolean block) {
g_assert(nl);
for (;;) {
guint8 replybuf[64*1024];
ssize_t bytes;
struct nlmsghdr *p = (struct nlmsghdr *) replybuf;
if ((bytes = recv(nl->fd, replybuf, sizeof(replybuf), block ? 0 : MSG_DONTWAIT)) < 0) {
if (errno == EAGAIN || errno == EINTR)
break;
g_warning("NETLINK: recv() failed");
return FALSE;
}
if (nl->callback) {
for (; bytes > 0; p = NLMSG_NEXT(p, bytes)) {
if (!NLMSG_OK(p, (size_t) bytes)) {
g_warning("NETLINK: packet truncated");
return FALSE;
}
nl->callback(nl, p, nl->userdata);
}
}
if (block)
break;
}
return TRUE;
}
static gboolean prepare_func(GSource *source, gint *timeout) {
g_assert(source);
g_assert(timeout);
*timeout = -1;
return FALSE;
}
static gboolean check_func(GSource *source) {
AvahiNetlink* nl;
g_assert(source);
nl = *((AvahiNetlink**) (((guint8*) source) + sizeof(GSource)));
g_assert(nl);
return nl->poll_fd.revents & (G_IO_IN|G_IO_HUP|G_IO_ERR);
}
static gboolean dispatch_func(GSource *source, GSourceFunc callback, gpointer user_data) {
AvahiNetlink* nl;
g_assert(source);
nl = *((AvahiNetlink**) (((guint8*) source) + sizeof(GSource)));
g_assert(nl);
return avahi_netlink_work(nl, FALSE);
}
AvahiNetlink *avahi_netlink_new(GMainContext *context, gint priority, guint32 groups, void (*cb) (AvahiNetlink *nl, struct nlmsghdr *n, gpointer userdata), gpointer userdata) {
int fd;
struct sockaddr_nl addr;
AvahiNetlink *nl;
static GSourceFuncs source_funcs = {
prepare_func,
check_func,
dispatch_func,
NULL,
NULL,
NULL
};
g_assert(context);
g_assert(cb);
if ((fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) < 0) {
g_critical("NETLINK: socket(PF_NETLINK): %s", strerror(errno));
return NULL;
}
memset(&addr, 0, sizeof(addr));
addr.nl_family = AF_NETLINK;
addr.nl_groups = groups;
addr.nl_pid = getpid();
if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
close(fd);
g_critical("bind(): %s", strerror(errno));
return NULL;
}
nl = g_new(AvahiNetlink, 1);
nl->context = context;
g_main_context_ref(context);
nl->fd = fd;
nl->seq = 0;
nl->callback = cb;
nl->userdata = userdata;
nl->source = g_source_new(&source_funcs, sizeof(GSource) + sizeof(AvahiNetlink*));
*((AvahiNetlink**) (((guint8*) nl->source) + sizeof(GSource))) = nl;
g_source_set_priority(nl->source, priority);
memset(&nl->poll_fd, 0, sizeof(GPollFD));
nl->poll_fd.fd = fd;
nl->poll_fd.events = G_IO_IN|G_IO_ERR|G_IO_HUP;
g_source_add_poll(nl->source, &nl->poll_fd);
g_source_attach(nl->source, nl->context);
return nl;
}
void avahi_netlink_free(AvahiNetlink *nl) {
g_assert(nl);
g_source_destroy(nl->source);
g_source_unref(nl->source);
g_main_context_unref(nl->context);
close(nl->fd);
g_free(nl);
}
int avahi_netlink_send(AvahiNetlink *nl, struct nlmsghdr *m, guint *ret_seq) {
g_assert(nl);
g_assert(m);
m->nlmsg_seq = nl->seq++;
m->nlmsg_flags |= NLM_F_ACK;
if (send(nl->fd, m, m->nlmsg_len, 0) < 0) {
g_warning("NETLINK: send(): %s\n", strerror(errno));
return -1;
}
if (ret_seq)
*ret_seq = m->nlmsg_seq;
return 0;
}
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