ring: move duplicate/generic code parts from rx/tx into ring.c

We do not want to maintain duplicate code, so move this into a separate
file and name those *_generic() helpers.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/ring.c b/ring.c
new file mode 100644
index 0000000..2899df3
--- /dev/null
+++ b/ring.c
@@ -0,0 +1,64 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2009, 2010 Daniel Borkmann.
+ * Subject to the GPL, version 2.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <linux/if_ether.h>
+
+#include "xmalloc.h"
+#include "die.h"
+#include "ring.h"
+#include "built_in.h"
+
+void mmap_ring_generic(int sock, struct ring *ring)
+{
+	ring->mm_space = mmap(0, ring->mm_len, PROT_READ | PROT_WRITE,
+			      MAP_SHARED | MAP_LOCKED | MAP_POPULATE, sock, 0);
+	if (ring->mm_space == MAP_FAILED)
+		panic("Cannot mmap {TX,RX}_RING!\n");
+}
+
+void alloc_ring_frames_generic(struct ring *ring)
+{
+	int i;
+	size_t len = ring->layout.tp_frame_nr * sizeof(*ring->frames);
+
+	ring->frames = xmalloc_aligned(len, CO_CACHE_LINE_SIZE);
+	fmemset(ring->frames, 0, len);
+
+	for (i = 0; i < ring->layout.tp_frame_nr; ++i) {
+		ring->frames[i].iov_len = ring->layout.tp_frame_size;
+		ring->frames[i].iov_base = ring->mm_space +
+					   (i * ring->layout.tp_frame_size);
+	}
+}
+
+void bind_ring_generic(int sock, struct ring *ring, int ifindex)
+{
+	int ret;
+	/* The {TX,RX}_RING registers itself to the networking stack with
+	 * dev_add_pack(), so we have one single RX_RING for all devs
+	 * otherwise you'll get the packet twice.
+	 */
+	fmemset(&ring->s_ll, 0, sizeof(ring->s_ll));
+
+	ring->s_ll.sll_family = AF_PACKET;
+	ring->s_ll.sll_protocol = htons(ETH_P_ALL);
+	ring->s_ll.sll_ifindex = ifindex;
+	ring->s_ll.sll_hatype = 0;
+	ring->s_ll.sll_halen = 0;
+	ring->s_ll.sll_pkttype = 0;
+
+	ret = bind(sock, (struct sockaddr *) &ring->s_ll, sizeof(ring->s_ll));
+	if (ret < 0)
+		panic("Cannot bind {TX,RX}_RING!\n");
+}