[3/4] linux-generic: pktio: add pcap pktio type

Message ID 1438788402-9250-3-git-send-email-stuart.haslam@linaro.org
State New
Headers show

Commit Message

Stuart Haslam Aug. 5, 2015, 3:26 p.m.
Create a new pktio type that allows for reading from and writing to a
pcap capture file. This is intended to be used as a simple way of
injecting test packets into an application for functional testing and
can be used as it is with some of the existing example applications.

To use this interface the name passed to odp_pktio_open() must begin
with "pcap:" and be in the format;

 pcap:in=test.pcap:out=test_out.pcap:loops=10

   in      the name of the input pcap file. If no input file is given
           attempts to receive from the pktio will just return no
           packets.
   out     the name of the output pcap file. If no output file is
           given any packets transmitted over the interface will just
           be freed.
   loops   the number of times to iterate through the input file, set
           to 0 to loop indefinitely. The default value is 1.

Signed-off-by: Stuart Haslam <stuart.haslam@linaro.org>
---
 platform/linux-generic/Makefile.am                 |   4 +
 .../linux-generic/include/odp_packet_io_internal.h |  21 ++
 platform/linux-generic/m4/configure.m4             |  16 ++
 platform/linux-generic/pktio/io_ops.c              |   3 +
 platform/linux-generic/pktio/pcap.c                | 312 +++++++++++++++++++++
 5 files changed, 356 insertions(+)
 create mode 100644 platform/linux-generic/pktio/pcap.c

Patch

diff --git a/platform/linux-generic/Makefile.am b/platform/linux-generic/Makefile.am
index 34ceb20..524c0b6 100644
--- a/platform/linux-generic/Makefile.am
+++ b/platform/linux-generic/Makefile.am
@@ -161,3 +161,7 @@  __LIB__libodp_la_SOURCES = \
 			   odp_version.c \
 			   odp_weak.c \
 			   arch/@ARCH@/odp_time.c
+
+if HAVE_PCAP
+__LIB__libodp_la_SOURCES += pktio/pcap.c
+endif
diff --git a/platform/linux-generic/include/odp_packet_io_internal.h b/platform/linux-generic/include/odp_packet_io_internal.h
index 14532a3..14f7e0c 100644
--- a/platform/linux-generic/include/odp_packet_io_internal.h
+++ b/platform/linux-generic/include/odp_packet_io_internal.h
@@ -38,6 +38,21 @@  typedef struct {
 	odp_bool_t promisc;		/**< promiscuous mode state */
 } pkt_loop_t;
 
+#ifdef HAVE_PCAP
+typedef struct {
+	char *fname_rx;		/**< name of pcap file for rx */
+	char *fname_tx;		/**< name of pcap file for tx */
+	void *rx;		/**< rx pcap handle */
+	void *tx;		/**< tx pcap handle */
+	void *tx_dump;		/**< tx pcap dumper handle */
+	odp_pool_t pool;	/**< rx pool */
+	unsigned char *buf;	/**< per-pktio temp buffer */
+	odp_bool_t promisc;	/**< promiscuous mode requested state */
+	int loops;		/**< number of times to loop rx pcap */
+	int loop_cnt;		/**< number of loops completed */
+} pkt_pcap_t;
+#endif
+
 struct pktio_entry {
 	const struct pktio_if_ops *ops; /**< Implementation specific methods */
 	odp_spinlock_t lock;		/**< entry spinlock */
@@ -51,6 +66,9 @@  struct pktio_entry {
 		pkt_sock_t pkt_sock;		/**< using socket API for IO */
 		pkt_sock_mmap_t pkt_sock_mmap;	/**< using socket mmap
 						 *   API for IO */
+#ifdef HAVE_PCAP
+		pkt_pcap_t pkt_pcap;		/**< Using pcap for IO */
+#endif
 	};
 	classifier_t cls;		/**< classifier linked with this pktio*/
 	char name[PKTIO_NAME_LEN];	/**< name of pktio provided to
@@ -110,6 +128,9 @@  extern const pktio_if_ops_t sock_basic_pktio_ops;
 extern const pktio_if_ops_t sock_mmsg_pktio_ops;
 extern const pktio_if_ops_t sock_mmap_pktio_ops;
 extern const pktio_if_ops_t loopback_pktio_ops;
+#ifdef HAVE_PCAP
+extern const pktio_if_ops_t pcap_pktio_ops;
+#endif
 extern const pktio_if_ops_t * const pktio_if_ops[];
 
 #ifdef __cplusplus
diff --git a/platform/linux-generic/m4/configure.m4 b/platform/linux-generic/m4/configure.m4
index 55124f1..d13d694 100644
--- a/platform/linux-generic/m4/configure.m4
+++ b/platform/linux-generic/m4/configure.m4
@@ -17,3 +17,19 @@  AC_LINK_IFELSE(
     exit -1)
 
 AC_CONFIG_FILES([platform/linux-generic/test/Makefile])
+
+#########################################################################
+# Check for libpcap availability
+#########################################################################
+have_pcap=no
+AC_CHECK_HEADER(pcap/pcap.h,
+    [AC_CHECK_HEADER(pcap/bpf.h,
+        [AC_CHECK_LIB(pcap, pcap_open_offline, have_pcap=yes, [])],
+    [])],
+[])
+
+AM_CONDITIONAL([HAVE_PCAP], [test $have_pcap = yes])
+if test $have_pcap == yes; then
+    AM_CFLAGS="$AM_CFLAGS -DHAVE_PCAP"
+    LIBS="$LIBS -lpcap"
+fi
diff --git a/platform/linux-generic/pktio/io_ops.c b/platform/linux-generic/pktio/io_ops.c
index 6cd3d00..044c2aa 100644
--- a/platform/linux-generic/pktio/io_ops.c
+++ b/platform/linux-generic/pktio/io_ops.c
@@ -12,6 +12,9 @@ 
  * Array must be NULL terminated */
 const pktio_if_ops_t * const pktio_if_ops[]  = {
 	&loopback_pktio_ops,
+#ifdef HAVE_PCAP
+	&pcap_pktio_ops,
+#endif
 	&sock_mmap_pktio_ops,
 	&sock_mmsg_pktio_ops,
 	&sock_basic_pktio_ops,
diff --git a/platform/linux-generic/pktio/pcap.c b/platform/linux-generic/pktio/pcap.c
new file mode 100644
index 0000000..7bb9115
--- /dev/null
+++ b/platform/linux-generic/pktio/pcap.c
@@ -0,0 +1,312 @@ 
+/* Copyright (c) 2015, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:     BSD-3-Clause
+ */
+
+/**
+ * @file
+ *
+ * PCAP pktio type
+ *
+ * This file provides a pktio interface that allows for reading from
+ * and writing to pcap capture files. It is intended to be used as
+ * simple way of injecting test packets into an application for the
+ * purpose of functional testing.
+ *
+ * To use this interface the name passed to odp_pktio_open() must begin
+ * with "pcap:" and be in the format;
+ *
+ * pcap:in=test.pcap:out=test_out.pcap:loops=10
+ *
+ *   in      the name of the input pcap file. If no input file is given
+ *           attempts to receive from the pktio will just return no
+ *           packets. If an input file is specified it must exist and be
+ *           a readable pcap file with a link type of DLT_EN10MB.
+ *   out     the name of the output pcap file. If no output file is
+ *           given any packets transmitted over the interface will just
+ *           be freed. If an output file is specified and the file
+ *           doesn't exist it will be created, if it does exist it will
+ *           be overwritten.
+ *   loops   the number of times to iterate through the input file, set
+ *           to 0 to loop indefinitely. The default value is 1.
+ *
+ * The total length of the string is limited by PKTIO_NAME_LEN.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <odp.h>
+#include <odp_packet_internal.h>
+#include <odp_packet_io_internal.h>
+
+#include <odp/helper/eth.h>
+
+#include <pcap/pcap.h>
+#include <pcap/bpf.h>
+
+#define PKTIO_PCAP_MTU 65536
+
+static int _pcapif_parse_devname(pkt_pcap_t *pcap, const char *devname)
+{
+	char *tok;
+	char in[PKTIO_NAME_LEN];
+
+	if (strncmp(devname, "pcap:", 5) != 0)
+		return -1;
+
+	snprintf(in, sizeof(in), "%s", devname);
+
+	for (tok = strtok(in + 5, ":"); tok; tok = strtok(NULL, ":")) {
+		if (strncmp(tok, "in=", 3) == 0 && !pcap->fname_rx) {
+			tok += 3;
+			pcap->fname_rx = strdup(tok);
+		} else if (strncmp(tok, "out=", 4) == 0 && !pcap->fname_tx) {
+			tok += 4;
+			pcap->fname_tx = strdup(tok);
+		} else if (strncmp(tok, "loops=", 6) == 0) {
+			pcap->loops = atoi(tok + 6);
+			if (pcap->loops < 0) {
+				ODP_ERR("invalid loop count\n");
+				return -1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int _pcapif_init_rx(pkt_pcap_t *pcap)
+{
+	char errbuf[PCAP_ERRBUF_SIZE];
+	int linktype;
+
+	pcap->rx = pcap_open_offline(pcap->fname_rx, errbuf);
+	if (!pcap->rx) {
+		ODP_ERR("failed to open pcap file %s (%s)\n",
+			pcap->fname_rx, errbuf);
+		return -1;
+	}
+
+	linktype = pcap_datalink(pcap->rx);
+	if (linktype != DLT_EN10MB) {
+		ODP_ERR("unsupported datalink type: %d\n", linktype);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int _pcapif_init_tx(pkt_pcap_t *pcap)
+{
+	pcap_t *tx = pcap->rx;
+
+	if (!tx) {
+		/* if there is no rx pcap_t already open for rx, a dummy
+		 * one needs to be opened for writing the dump */
+		tx = pcap_open_dead(DLT_EN10MB, PKTIO_PCAP_MTU);
+		if (!tx) {
+			ODP_ERR("failed to open TX dump\n");
+			return -1;
+		}
+
+		pcap->tx = tx;
+	}
+
+	pcap->buf = malloc(PKTIO_PCAP_MTU);
+	if (!pcap->buf) {
+		ODP_ERR("failed to malloc temp buffer\n");
+		return -1;
+	}
+
+	pcap->tx_dump = pcap_dump_open(tx, pcap->fname_tx);
+	if (!pcap->tx_dump) {
+		ODP_ERR("failed to open dump file %s (%s)\n",
+			pcap->fname_tx, pcap_geterr(tx));
+		return -1;
+	}
+
+	return pcap_dump_flush(pcap->tx_dump);
+}
+
+static int pcapif_init(odp_pktio_t id ODP_UNUSED, pktio_entry_t *pktio_entry,
+		       const char *devname, odp_pool_t pool)
+{
+	pkt_pcap_t *pcap = &pktio_entry->s.pkt_pcap;
+	int ret;
+
+	memset(pcap, 0, sizeof(pkt_pcap_t));
+	pcap->loop_cnt = 1;
+	pcap->loops = 1;
+	pcap->pool = pool;
+
+	ret = _pcapif_parse_devname(pcap, devname);
+
+	if (ret == 0 && pcap->fname_rx)
+		ret = _pcapif_init_rx(pcap);
+
+	if (ret == 0 && pcap->fname_tx)
+		ret = _pcapif_init_tx(pcap);
+
+	if (ret == 0 && (!pcap->rx && !pcap->tx_dump))
+		ret = -1;
+
+	return ret;
+}
+
+static int pcapif_close(pktio_entry_t *pktio_entry)
+{
+	pkt_pcap_t *pcap = &pktio_entry->s.pkt_pcap;
+
+	if (pcap->tx_dump)
+		pcap_dump_close(pcap->tx_dump);
+
+	if (pcap->tx)
+		pcap_close(pcap->tx);
+
+	if (pcap->rx)
+		pcap_close(pcap->rx);
+
+	free(pcap->buf);
+	free(pcap->fname_rx);
+	free(pcap->fname_tx);
+
+	return 0;
+}
+
+static int _pcapif_reopen(pkt_pcap_t *pcap)
+{
+	char errbuf[PCAP_ERRBUF_SIZE];
+
+	if (pcap->loops != 0 && ++pcap->loop_cnt >= pcap->loops)
+		return 1;
+
+	if (pcap->rx)
+		pcap_close(pcap->rx);
+
+	pcap->rx = pcap_open_offline(pcap->fname_rx, errbuf);
+	if (!pcap->rx) {
+		ODP_ERR("failed to reopen pcap file %s (%s)\n",
+			pcap->fname_rx, errbuf);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int pcapif_recv_pkt(pktio_entry_t *pktio_entry, odp_packet_t pkts[],
+			   unsigned len)
+{
+	unsigned i;
+	struct pcap_pkthdr *hdr;
+	const u_char *data;
+	pkt_pcap_t *pcap = &pktio_entry->s.pkt_pcap;
+
+	if (!pcap->rx)
+		return 0;
+
+	for (i = 0; i < len; ) {
+		int ret = pcap_next_ex(pcap->rx, &hdr, &data);
+
+		if (ret == -2) {
+			/* end of file */
+			if (_pcapif_reopen(pcap) == 0)
+				continue;
+			else
+				break;
+		} else if (ret != 1) {
+			break;
+		}
+
+		pkts[i] = odp_packet_alloc(pcap->pool, hdr->caplen);
+		if (odp_unlikely(pkts[i] == ODP_PACKET_INVALID))
+			break;
+
+		if (odp_packet_copydata_in(pkts[i], 0, hdr->caplen, data) != 0)
+			break;
+
+		_odp_packet_reset_parse(pkts[i]);
+
+		i++;
+	}
+
+	return i;
+}
+
+static int _pcapif_dump_pkt(pkt_pcap_t *pcap, odp_packet_t pkt)
+{
+	struct pcap_pkthdr hdr;
+
+	if (!pcap->tx_dump)
+		return 0;
+
+	hdr.caplen = odp_packet_len(pkt);
+	hdr.len = hdr.caplen;
+	(void)gettimeofday(&hdr.ts, NULL);
+
+	if (odp_packet_copydata_out(pkt, 0, hdr.len, pcap->buf) != 0)
+		return -1;
+
+	pcap_dump(pcap->tx_dump, &hdr, pcap->buf);
+	(void)pcap_dump_flush(pcap->tx_dump);
+
+	return 0;
+}
+
+static int pcapif_send_pkt(pktio_entry_t *pktio_entry, odp_packet_t pkts[],
+			   unsigned len)
+{
+	pkt_pcap_t *pcap = &pktio_entry->s.pkt_pcap;
+	unsigned i;
+
+	for (i = 0; i < len; ++i) {
+		if (_pcapif_dump_pkt(pcap, pkts[i]) != 0)
+			break;
+		odp_packet_free(pkts[i]);
+	}
+
+	return i;
+}
+
+static int pcapif_mtu_get(pktio_entry_t *pktio_entry ODP_UNUSED)
+{
+	return PKTIO_PCAP_MTU;
+}
+
+static int pcapif_mac_addr_get(pktio_entry_t *pktio_entry ODP_UNUSED,
+			       void *mac_addr)
+{
+	/* this isn't used for anything, it's just here to keep callers of this
+	 * API happy in cases where the pcap interface is used as a test mock */
+	static const char pcap_mac[] = {0x02, 0xe9, 0x34, 0x80, 0x73, 0x02};
+
+	memcpy(mac_addr, pcap_mac, ODPH_ETHADDR_LEN);
+
+	return ODPH_ETHADDR_LEN;
+}
+
+static int pcapif_promisc_mode_set(pktio_entry_t *pktio_entry,
+				   odp_bool_t enable)
+{
+	pktio_entry->s.pkt_pcap.promisc = enable;
+
+	return 0;
+}
+
+static int pcapif_promisc_mode_get(pktio_entry_t *pktio_entry)
+{
+	return pktio_entry->s.pkt_pcap.promisc;
+}
+
+const pktio_if_ops_t pcap_pktio_ops = {
+	.open = pcapif_init,
+	.close = pcapif_close,
+	.recv = pcapif_recv_pkt,
+	.send = pcapif_send_pkt,
+	.mtu_get = pcapif_mtu_get,
+	.promisc_mode_set = pcapif_promisc_mode_set,
+	.promisc_mode_get = pcapif_promisc_mode_get,
+	.mac_get = pcapif_mac_addr_get
+};