initial commit

[catta] / netlink.c

diff --git a/netlink.c b/netlink.c
new file mode 100644 (file)
index 0000000..a04e6c9
--- /dev/null
+++ b/netlink.c
@@ -0,0 +1,154 @@
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#include "netlink.h"
+
+struct _flxNetlink {
+    GMainContext *context;
+    gint fd;
+    guint seq;
+    GPollFD poll_fd;
+    GSource *source;
+    void (*callback) (flxNetlink *nl, struct nlmsghdr *n, gpointer userdata);
+    gpointer userdata;
+    GSourceFuncs source_funcs;
+};
+
+static gboolean work(flxNetlink *nl) {
+    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), 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, bytes)) {
+                    g_warning("NETLINK: packet truncated");
+                    return FALSE;
+                }
+
+                nl->callback(nl, p, nl->userdata);
+            }
+        }
+    }
+
+    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) {
+    flxNetlink* nl;
+    g_assert(source);
+
+    nl = *((flxNetlink**) (((guint8*) source) + sizeof(GSource)));
+    g_assert(nl);
+    
+    return nl->poll_fd.revents & G_IO_IN;
+}
+
+static gboolean dispatch_func(GSource *source, GSourceFunc callback, gpointer user_data) {
+    flxNetlink* nl;
+    g_assert(source);
+
+    nl = *((flxNetlink**) (((guint8*) source) + sizeof(GSource)));
+    g_assert(nl);
+    
+    return work(nl);
+}
+
+flxNetlink *flx_netlink_new(GMainContext *context, guint32 groups, void (*cb) (flxNetlink *nl, struct nlmsghdr *n, gpointer userdata), gpointer userdata) {
+    int fd;
+    struct sockaddr_nl addr;
+    flxNetlink *nl;
+
+    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(flxNetlink, 1);
+    nl->context = context;
+    g_main_context_ref(context);
+    nl->fd = fd;
+    nl->seq = 0;
+    nl->callback = cb;
+    nl->userdata = userdata;
+
+    memset(&nl->source_funcs, 0, sizeof(nl->source_funcs));
+    nl->source_funcs.prepare = prepare_func;
+    nl->source_funcs.check = check_func;
+    nl->source_funcs.dispatch = dispatch_func,
+
+    nl->source = g_source_new(&nl->source_funcs, sizeof(GSource) + sizeof(flxNetlink*));
+    *((flxNetlink**) (((guint8*) nl->source) + sizeof(GSource))) = nl;
+
+    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 flx_netlink_free(flxNetlink *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 flx_netlink_send(flxNetlink *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;
+}