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>

7 files changed, 85 insertions, 72 deletions

diff --git a/astraceroute/Makefile b/astraceroute/Makefile
index 91f0a9e..36e37f0 100644
--- a/astraceroute/Makefile
+++ b/astraceroute/Makefile
@@ -10,4 +10,5 @@ astraceroute-objs =	xmalloc.o \
 			bpf.o \
 			geoip.o \
 			ring_rx.o \
+			ring.o \
 			astraceroute.o
diff --git a/netsniff-ng/Makefile b/netsniff-ng/Makefile
index b50778f..211c726 100644
--- a/netsniff-ng/Makefile
+++ b/netsniff-ng/Makefile
@@ -44,6 +44,7 @@ netsniff-ng-objs =	dissector.o \
 			pcap_mm.o \
 			ring_rx.o \
 			ring_tx.o \
+			ring.o \
 			tprintf.o \
 			tstamping.o \
 			geoip.o \
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");
+}
diff --git a/ring.h b/ring.h
index 1074e8d..93edb01 100644
--- a/ring.h
+++ b/ring.h
@@ -141,4 +141,8 @@ static inline int get_sockopt_tpacket(int sock)
 	return __get_sockopt_tpacket(sock);
 }
 
+extern void mmap_ring_generic(int sock, struct ring *ring);
+extern void alloc_ring_frames_generic(struct ring *ring);
+extern void bind_ring_generic(int sock, struct ring *ring, int ifindex);
+
 #endif /* RING_H */
diff --git a/ring_rx.c b/ring_rx.c
index a3d8e4d..de19568 100644
--- a/ring_rx.c
+++ b/ring_rx.c
@@ -43,9 +43,11 @@ void setup_rx_ring_layout(int sock, struct ring *ring, unsigned int size,
 	ring->layout.tp_block_size = (jumbo_support ?
 				      getpagesize() << 4 :
 				      getpagesize() << 2);
+
 	ring->layout.tp_frame_size = (jumbo_support ?
 				      TPACKET_ALIGNMENT << 12 :
 				      TPACKET_ALIGNMENT << 7);
+
 	ring->layout.tp_block_nr = size / ring->layout.tp_block_size;
 	ring->layout.tp_frame_nr = ring->layout.tp_block_size /
 				   ring->layout.tp_frame_size *
@@ -77,6 +79,7 @@ void create_rx_ring(int sock, struct ring *ring, int verbose)
 retry:
 	ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->raw,
 			 v3 ? sizeof(ring->layout3) : sizeof(ring->layout));
+
 	if (errno == ENOMEM && ring->layout.tp_block_nr > 1) {
 		ring->layout.tp_block_nr >>= 1;
 		ring->layout.tp_frame_nr = ring->layout.tp_block_size / 
@@ -98,49 +101,15 @@ retry:
 
 void mmap_rx_ring(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) {
-		destroy_rx_ring(sock, ring);
-		panic("Cannot mmap RX_RING!\n");
-	}
+	mmap_ring_generic(sock, ring);
 }
 
 void alloc_rx_ring_frames(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);
-	}
+	alloc_ring_frames_generic(ring);
 }
 
 void bind_rx_ring(int sock, struct ring *ring, int ifindex)
 {
-	int ret;
-	/*
-	 * The 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) {
-		destroy_rx_ring(sock, ring);
-		panic("Cannot bind RX_RING!\n");
-	}
+	bind_ring_generic(sock, ring, ifindex);
 }
diff --git a/ring_tx.c b/ring_tx.c
index f4f06a1..18216ac 100644
--- a/ring_tx.c
+++ b/ring_tx.c
@@ -53,25 +53,28 @@ void setup_tx_ring_layout(int sock, struct ring *ring, unsigned int size,
 	ring->layout.tp_block_size = (jumbo_support ?
 				      getpagesize() << 4 :
 				      getpagesize() << 2);
+
 	ring->layout.tp_frame_size = (jumbo_support ?
 				      TPACKET_ALIGNMENT << 12 :
 				      TPACKET_ALIGNMENT << 7);
+
 	ring->layout.tp_block_nr = size / ring->layout.tp_block_size;
 	ring->layout.tp_frame_nr = ring->layout.tp_block_size /
 				   ring->layout.tp_frame_size *
 				   ring->layout.tp_block_nr;
 
+	set_sockopt_tpacket_v2(sock);
+
 	ring_verify_layout(ring);
 }
 
 void create_tx_ring(int sock, struct ring *ring, int verbose)
 {
 	int ret;
-
-	set_sockopt_tpacket_v2(sock);
 retry:
 	ret = setsockopt(sock, SOL_PACKET, PACKET_TX_RING, &ring->layout,
 			 sizeof(ring->layout));
+
 	if (errno == ENOMEM && ring->layout.tp_block_nr > 1) {
 		ring->layout.tp_block_nr >>= 1;
 		ring->layout.tp_frame_nr = ring->layout.tp_block_size / 
@@ -94,45 +97,15 @@ retry:
 
 void mmap_tx_ring(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) {
-		destroy_tx_ring(sock, ring);
-		panic("Cannot mmap TX_RING!\n");
-	}
+	mmap_ring_generic(sock, ring);
 }
 
 void alloc_tx_ring_frames(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);
-	}
+	alloc_ring_frames_generic(ring);
 }
 
 void bind_tx_ring(int sock, struct ring *ring, int ifindex)
 {
-	int ret;
-
-	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) {
-		destroy_tx_ring(sock, ring);
-		panic("Cannot bind TX_RING!\n");
-	}
+	bind_ring_generic(sock, ring, ifindex);
 }
diff --git a/trafgen/Makefile b/trafgen/Makefile
index b34b98c..8257ad1 100644
--- a/trafgen/Makefile
+++ b/trafgen/Makefile
@@ -7,6 +7,7 @@ trafgen-objs =	xmalloc.o \
 		xutils.o \
 		mac80211.o \
 		ring_tx.o \
+		ring.o \
 		trafgen_lexer.yy.o \
 		trafgen_parser.tab.o \
 		trafgen.o