port: add pcap file dump

Originally, sink ports in librte_port releases received mbufs back to
mempool. This patch adds optional packet dumping to PCAP feature in sink
port: the packets will be dumped to user defined PCAP file for storage or
debugging. The user may also choose the sink port's activity: either it
continuously dump the packets to the file, or stops at certain dumping

This feature shares same CONFIG_RTE_PORT_PCAP compiler option as source
port PCAP file support feature. Users can enable or disable this feature
by setting CONFIG_RTE_PORT_PCAP compiler option "y" or "n".

Signed-off-by: Fan Zhang <roy.fan.zhang@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>

diff --git a/lib/librte_port/rte_port_source_sink.c b/lib/librte_port/rte_port_source_sink.c
index 3d4e8d9..05620d6 100644 (file)
--- a/lib/librte_port/rte_port_source_sink.c
+++ b/lib/librte_port/rte_port_source_sink.c
@@ -42,9 +42,12 @@
 #include <rte_memcpy.h>
 
 #ifdef RTE_PORT_PCAP
+#include <rte_ether.h>
 #include <pcap.h>
 #endif
 
+#else
+#undef RTE_PORT_PCAP
 #endif
 
 #include "rte_port_source_sink.h"
@@ -400,12 +403,183 @@ rte_port_source_stats_read(void *port,
 
 struct rte_port_sink {
        struct rte_port_out_stats stats;
+
+       /* PCAP dumper handle and pkts number */
+       void *dumper;
+       uint32_t max_pkts;
+       uint32_t pkt_index;
+       uint32_t dump_finish;
 };
 
+#ifdef RTE_PORT_PCAP
+
+/**
+ * Open PCAP file for dumping packets to the file later
+ *
+ * @param port
+ *   Handle to sink port
+ * @param p
+ *   Sink port parameter
+ * @return
+ *   0 on SUCCESS
+ *   error code otherwise
+ */
+static int
+pcap_sink_open(struct rte_port_sink *port,
+               __rte_unused struct rte_port_sink_params *p)
+{
+       pcap_t *tx_pcap;
+       pcap_dumper_t *pcap_dumper;
+
+       if (p->file_name == NULL) {
+               port->dumper = NULL;
+               port->max_pkts = 0;
+               port->pkt_index = 0;
+               port->dump_finish = 0;
+               return 0;
+       }
+
+       /** Open a dead pcap handler for opening dumper file */
+       tx_pcap = pcap_open_dead(DLT_EN10MB, 65535);
+       if (tx_pcap == NULL)
+               return -ENOENT;
+
+       /* The dumper is created using the previous pcap_t reference */
+       pcap_dumper = pcap_dump_open(tx_pcap, p->file_name);
+       if (pcap_dumper == NULL)
+               return -ENOENT;
+
+       port->dumper = pcap_dumper;
+       port->max_pkts = p->max_n_pkts;
+       port->pkt_index = 0;
+       port->dump_finish = 0;
+
+       return 0;
+}
+
+uint8_t jumbo_pkt_buf[ETHER_MAX_JUMBO_FRAME_LEN];
+
+/**
+ * Dump a packet to PCAP dumper
+ *
+ * @param p
+ *   Handle to sink port
+ * @param mbuf
+ *   Handle to mbuf structure holding the packet
+ */
+static void
+pcap_sink_dump_pkt(struct rte_port_sink *port, struct rte_mbuf *mbuf)
+{
+       uint8_t *pcap_dumper = (uint8_t *)(port->dumper);
+       struct pcap_pkthdr pcap_hdr;
+       uint8_t *pkt;
+
+       /* Maximum num packets already reached */
+       if (port->dump_finish)
+               return;
+
+       pkt = rte_pktmbuf_mtod(mbuf, uint8_t *);
+
+       pcap_hdr.len = mbuf->pkt_len;
+       pcap_hdr.caplen = pcap_hdr.len;
+       gettimeofday(&(pcap_hdr.ts), NULL);
+
+       if (mbuf->nb_segs > 1) {
+               struct rte_mbuf *jumbo_mbuf;
+               uint32_t pkt_index = 0;
+
+               /* if packet size longer than ETHER_MAX_JUMBO_FRAME_LEN,
+                * ignore it.
+                */
+               if (mbuf->pkt_len > ETHER_MAX_JUMBO_FRAME_LEN)
+                       return;
+
+               for (jumbo_mbuf = mbuf; jumbo_mbuf != NULL;
+                               jumbo_mbuf = jumbo_mbuf->next) {
+                       rte_memcpy(&jumbo_pkt_buf[pkt_index],
+                               rte_pktmbuf_mtod(jumbo_mbuf, uint8_t *),
+                               jumbo_mbuf->data_len);
+                       pkt_index += jumbo_mbuf->data_len;
+               }
+
+               jumbo_pkt_buf[pkt_index] = '\0';
+
+               pkt = jumbo_pkt_buf;
+       }
+
+       pcap_dump(pcap_dumper, &pcap_hdr, pkt);
+
+       port->pkt_index++;
+
+       if ((port->max_pkts != 0) && (port->pkt_index >= port->max_pkts)) {
+               port->dump_finish = 1;
+               RTE_LOG(INFO, PORT, "Dumped %u packets to file\n",
+                               port->pkt_index);
+       }
+
+}
+
+/**
+ * Flush pcap dumper
+ *
+ * @param dumper
+ *   Handle to pcap dumper
+ */
+
+static void
+pcap_sink_flush_pkt(void *dumper)
+{
+       pcap_dumper_t *pcap_dumper = (pcap_dumper_t *)dumper;
+
+       pcap_dump_flush(pcap_dumper);
+}
+
+/**
+ * Close a PCAP dumper handle
+ *
+ * @param dumper
+ *   Handle to pcap dumper
+ */
+static void
+pcap_sink_close(void *dumper)
+{
+       pcap_dumper_t *pcap_dumper = (pcap_dumper_t *)dumper;
+
+       pcap_dump_close(pcap_dumper);
+}
+
+#else
+
+static int
+pcap_sink_open(struct rte_port_sink *port,
+               __rte_unused struct rte_port_sink_params *p)
+{
+       port->dumper = NULL;
+       port->max_pkts = 0;
+       port->pkt_index = 0;
+       port->dump_finish = 0;
+
+       return -ENOTSUP;
+}
+
+static void
+pcap_sink_dump_pkt(__rte_unused struct rte_port_sink *port,
+               __rte_unused struct rte_mbuf *mbuf) {}
+
+static void
+pcap_sink_flush_pkt(__rte_unused void *dumper) {}
+
+static void
+pcap_sink_close(__rte_unused void *dumper) {}
+
+#endif
+
 static void *
 rte_port_sink_create(__rte_unused void *params, int socket_id)
 {
        struct rte_port_sink *port;
+       struct rte_port_sink_params *p = params;
+       int status;
 
        /* Memory allocation */
        port = rte_zmalloc_socket("PORT", sizeof(*port),
@@ -415,6 +589,26 @@ rte_port_sink_create(__rte_unused void *params, int socket_id)
                return NULL;
        }
 
+       /* Try to open PCAP file for dumping, if possible */
+       status = pcap_sink_open(port, p);
+       if (status == 0) {
+               if (port->dumper != NULL)
+                       RTE_LOG(INFO, PORT, "Ready to dump packets "
+                               "to file %s\n", p->file_name);
+
+       } else if (status != -ENOTSUP) {
+               if (status == -ENOENT)
+                       RTE_LOG(ERR, PORT, "%s: Failed to open pcap file "
+                               "%s for writing\n", __func__,
+                               p->file_name);
+               else
+                       RTE_LOG(ERR, PORT, "%s: Failed to enable pcap "
+                               "support for unknown reason\n", __func__);
+
+               rte_free(port);
+               port = NULL;
+       }
+
        return port;
 }
 
@@ -424,6 +618,8 @@ rte_port_sink_tx(void *port, struct rte_mbuf *pkt)
        __rte_unused struct rte_port_sink *p = (struct rte_port_sink *) port;
 
        RTE_PORT_SINK_STATS_PKTS_IN_ADD(p, 1);
+       if (p->dumper != NULL)
+               pcap_sink_dump_pkt(p, pkt);
        rte_pktmbuf_free(pkt);
        RTE_PORT_SINK_STATS_PKTS_DROP_ADD(p, 1);
 
@@ -442,12 +638,34 @@ rte_port_sink_tx_bulk(void *port, struct rte_mbuf **pkts,
 
                RTE_PORT_SINK_STATS_PKTS_IN_ADD(p, n_pkts);
                RTE_PORT_SINK_STATS_PKTS_DROP_ADD(p, n_pkts);
+
+               if (p->dumper) {
+                       for (i = 0; i < n_pkts; i++) {
+                               struct rte_mbuf *pkt = pkts[i];
+
+                               pcap_sink_dump_pkt(p, pkt);
+                       }
+               }
+
                for (i = 0; i < n_pkts; i++) {
                        struct rte_mbuf *pkt = pkts[i];
 
                        rte_pktmbuf_free(pkt);
                }
+
        } else {
+               if (p->dumper) {
+                       uint64_t dump_pkts_mask = pkts_mask;
+                       uint32_t pkt_index;
+
+                       for ( ; dump_pkts_mask; ) {
+                               pkt_index = __builtin_ctzll(
+                                       dump_pkts_mask);
+                               pcap_sink_dump_pkt(p, pkts[pkt_index]);
+                               dump_pkts_mask &= ~(1LLU << pkt_index);
+                       }
+               }
+
                for ( ; pkts_mask; ) {
                        uint32_t pkt_index = __builtin_ctzll(pkts_mask);
                        uint64_t pkt_mask = 1LLU << pkt_index;
@@ -463,6 +681,34 @@ rte_port_sink_tx_bulk(void *port, struct rte_mbuf **pkts,
        return 0;
 }
 
+static int
+rte_port_sink_flush(void *port)
+{
+       struct rte_port_sink *p = (struct rte_port_sink *)port;
+
+       if (p->dumper != NULL)
+               pcap_sink_flush_pkt(p->dumper);
+
+       return 0;
+}
+
+static int
+rte_port_sink_free(void *port)
+{
+       struct rte_port_sink *p =
+                       (struct rte_port_sink *)port;
+       /* Check input parameters */
+       if (p == NULL)
+               return 0;
+
+       if (p->dumper != NULL)
+               pcap_sink_close(p->dumper);
+
+       rte_free(p);
+
+       return 0;
+}
+
 static int
 rte_port_sink_stats_read(void *port, struct rte_port_out_stats *stats,
                int clear)
@@ -491,9 +737,9 @@ struct rte_port_in_ops rte_port_source_ops = {
 
 struct rte_port_out_ops rte_port_sink_ops = {
        .f_create = rte_port_sink_create,
-       .f_free = NULL,
+       .f_free = rte_port_sink_free,
        .f_tx = rte_port_sink_tx,
        .f_tx_bulk = rte_port_sink_tx_bulk,
-       .f_flush = NULL,
+       .f_flush = rte_port_sink_flush,
        .f_stats = rte_port_sink_stats_read,
 };

diff --git a/lib/librte_port/rte_port_source_sink.h b/lib/librte_port/rte_port_source_sink.h
index 522d10d..917abe4 100644 (file)
--- a/lib/librte_port/rte_port_source_sink.h
+++ b/lib/librte_port/rte_port_source_sink.h
@@ -69,7 +69,16 @@ struct rte_port_source_params {
 /** source port operations */
 extern struct rte_port_in_ops rte_port_source_ops;
 
-/** sink port parameters: NONE */
+/** sink port parameters */
+struct rte_port_sink_params {
+       /** The full path of the pcap file to write the packets to */
+       char *file_name;
+       /** The maximum number of packets write to the pcap file.
+        *  If this value is 0, the "infinite" write will be carried
+        *  out.
+        */
+       uint32_t max_n_pkts;
+};
 
 /** sink port operations */
 extern struct rte_port_out_ops rte_port_sink_ops;