pcap-based dispatch tracer

To facilitate dispatch trajectory tracing, vlib_buffer_t decoding, etc.
through Wireshark

Change-Id: I31356b9fa1f40cba8830aaf10a86a9fbb7546438
Signed-off-by: Dave Barach <dave@barachs.net>

4 files changed, 581 insertions, 0 deletions

diff --git a/src/vppinfra/CMakeLists.txt b/src/vppinfra/CMakeLists.txt
index 6e1a4fd861a..4f0d16bd568 100644
--- a/src/vppinfra/CMakeLists.txt
+++ b/src/vppinfra/CMakeLists.txt
@@ -56,6 +56,7 @@ set(VPPINFRA_SRCS
   macros.c
   maplog.c
   mhash.c
+  pcap.c
   pmalloc.c
   pool.c
   ptclosure.c
@@ -135,6 +136,8 @@ set(VPPINFRA_HEADERS
   mheap_bootstrap.h
   mheap.h
   os.h
+  pcap.h
+  pcap_funcs.h
   pipeline.h
   pmalloc.h
   pool.h
diff --git a/src/vppinfra/pcap.c b/src/vppinfra/pcap.c
new file mode 100644
index 00000000000..8f644e30f1d
--- /dev/null
+++ b/src/vppinfra/pcap.c
@@ -0,0 +1,269 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * pcap.c: libpcap packet capture format
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <sys/fcntl.h>
+#include <vppinfra/pcap.h>
+
+/**
+ * @file
+ * @brief PCAP function.
+ *
+ * Usage:
+ *
+ * <code><pre>
+ * \#include <vppinfra/pcap.h>
+ *
+ * static pcap_main_t pcap = {
+ *  .file_name = "/tmp/ip4",
+ *  .n_packets_to_capture = 2,
+ *  .packet_type = PCAP_PACKET_TYPE_ip,
+ * };
+ * </pre></code>
+ *
+ * To add a buffer:
+ *
+ *  <code><pre>pcap_add_buffer (&pcap, vm, pi0, 128);</pre></code>
+ *
+ * File will be written after @c n_packets_to_capture or call to pcap_write (&amp;pcap).
+ *
+*/
+
+/**
+ * @brief Close PCAP file
+ *
+ * @return rc - clib_error_t
+ *
+ */
+clib_error_t *
+pcap_close (pcap_main_t * pm)
+{
+  close (pm->file_descriptor);
+  pm->flags &= ~PCAP_MAIN_INIT_DONE;
+  pm->file_descriptor = -1;
+  return 0;
+}
+
+/**
+ * @brief Write PCAP file
+ *
+ * @return rc - clib_error_t
+ *
+ */
+clib_error_t *
+pcap_write (pcap_main_t * pm)
+{
+  clib_error_t *error = 0;
+
+  if (!(pm->flags & PCAP_MAIN_INIT_DONE))
+    {
+      pcap_file_header_t fh;
+      int n;
+
+      if (!pm->file_name)
+	pm->file_name = "/tmp/vnet.pcap";
+
+      pm->file_descriptor =
+	open (pm->file_name, O_CREAT | O_TRUNC | O_WRONLY, 0664);
+      if (pm->file_descriptor < 0)
+	{
+	  error =
+	    clib_error_return_unix (0, "failed to open `%s'", pm->file_name);
+	  goto done;
+	}
+
+      pm->flags |= PCAP_MAIN_INIT_DONE;
+      pm->n_packets_captured = 0;
+      pm->n_pcap_data_written = 0;
+      clib_spinlock_init (&pm->lock);
+
+      /* Write file header. */
+      clib_memset (&fh, 0, sizeof (fh));
+      fh.magic = 0xa1b2c3d4;
+      fh.major_version = 2;
+      fh.minor_version = 4;
+      fh.time_zone = 0;
+      fh.max_packet_size_in_bytes = 1 << 16;
+      fh.packet_type = pm->packet_type;
+      n = write (pm->file_descriptor, &fh, sizeof (fh));
+      if (n != sizeof (fh))
+	{
+	  if (n < 0)
+	    error =
+	      clib_error_return_unix (0, "write file header `%s'",
+				      pm->file_name);
+	  else
+	    error =
+	      clib_error_return (0, "short write of file header `%s'",
+				 pm->file_name);
+	  goto done;
+	}
+    }
+
+  while (vec_len (pm->pcap_data) > pm->n_pcap_data_written)
+    {
+      int n = vec_len (pm->pcap_data) - pm->n_pcap_data_written;
+
+      n = write (pm->file_descriptor,
+		 vec_elt_at_index (pm->pcap_data, pm->n_pcap_data_written),
+		 n);
+
+      if (n < 0 && unix_error_is_fatal (errno))
+	{
+	  error = clib_error_return_unix (0, "write `%s'", pm->file_name);
+	  goto done;
+	}
+      pm->n_pcap_data_written += n;
+    }
+
+  if (pm->n_pcap_data_written >= vec_len (pm->pcap_data))
+    {
+      vec_reset_length (pm->pcap_data);
+      pm->n_pcap_data_written = 0;
+    }
+
+  if (pm->n_packets_captured >= pm->n_packets_to_capture)
+    pcap_close (pm);
+
+done:
+  if (error)
+    {
+      if (pm->file_descriptor >= 0)
+	close (pm->file_descriptor);
+    }
+  return error;
+}
+
+/**
+ * @brief Read PCAP file
+ *
+ * @return rc - clib_error_t
+ *
+ */
+clib_error_t *
+pcap_read (pcap_main_t * pm)
+{
+  clib_error_t *error = 0;
+  int fd, need_swap, n;
+  pcap_file_header_t fh;
+  pcap_packet_header_t ph;
+
+  fd = open (pm->file_name, O_RDONLY);
+  if (fd < 0)
+    {
+      error = clib_error_return_unix (0, "open `%s'", pm->file_name);
+      goto done;
+    }
+
+  if (read (fd, &fh, sizeof (fh)) != sizeof (fh))
+    {
+      error =
+	clib_error_return_unix (0, "read file header `%s'", pm->file_name);
+      goto done;
+    }
+
+  need_swap = 0;
+  if (fh.magic == 0xd4c3b2a1)
+    {
+      need_swap = 1;
+#define _(t,f) fh.f = clib_byte_swap_##t (fh.f);
+      foreach_pcap_file_header;
+#undef _
+    }
+
+  if (fh.magic != 0xa1b2c3d4)
+    {
+      error = clib_error_return (0, "bad magic `%s'", pm->file_name);
+      goto done;
+    }
+
+  pm->min_packet_bytes = 0;
+  pm->max_packet_bytes = 0;
+  while ((n = read (fd, &ph, sizeof (ph))) != 0)
+    {
+      u8 *data;
+      u64 timestamp;
+      u32 timestamp_sec;
+      u32 timestamp_usec;
+
+      if (need_swap)
+	{
+#define _(t,f) ph.f = clib_byte_swap_##t (ph.f);
+	  foreach_pcap_packet_header;
+#undef _
+	}
+
+      data = vec_new (u8, ph.n_bytes_in_packet);
+      if (read (fd, data, ph.n_packet_bytes_stored_in_file) !=
+	  ph.n_packet_bytes_stored_in_file)
+	{
+	  error = clib_error_return (0, "short read `%s'", pm->file_name);
+	  goto done;
+	}
+
+      if (vec_len (pm->packets_read) == 0)
+	pm->min_packet_bytes = pm->max_packet_bytes = ph.n_bytes_in_packet;
+      else
+	{
+	  pm->min_packet_bytes =
+	    clib_min (pm->min_packet_bytes, ph.n_bytes_in_packet);
+	  pm->max_packet_bytes =
+	    clib_max (pm->max_packet_bytes, ph.n_bytes_in_packet);
+	}
+
+      timestamp_sec = ph.time_in_sec;
+      timestamp_usec = ph.time_in_usec;
+      timestamp = ((u64) timestamp_sec) * 1000000 + (u64) timestamp_usec;
+      vec_add1 (pm->packets_read, data);
+      vec_add1 (pm->timestamps, timestamp);
+    }
+
+done:
+  if (fd >= 0)
+    close (fd);
+  return error;
+
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vppinfra/pcap.h b/src/vppinfra/pcap.h
new file mode 100644
index 00000000000..5889a793401
--- /dev/null
+++ b/src/vppinfra/pcap.h
@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * pcap.h: libpcap packet capture format
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+/**
+ * @file
+ * @brief PCAP utility definitions
+ */
+#ifndef included_vppinfra_pcap_h
+#define included_vppinfra_pcap_h
+
+#include <vppinfra/types.h>
+#include <vppinfra/cache.h>
+#include <vppinfra/mem.h>
+#include <vppinfra/lock.h>
+
+/**
+ * @brief Packet types supported by PCAP
+ *
+ * These codes end up in the pcap file header.
+ * If you decide to build a wireshark dissector,
+ * you'll need to know that these codes are mapped
+ * through the pcap_to_wtap_map[] array in .../wiretap/pcap-common.c.
+ *
+ * For example:
+ *
+ *   { 160,		WTAP_ENCAP_USER13 },
+ *
+ * A file with (vpp) packet type PCAP_PACKET_TYPE_user13
+ * aka 160, will need a top-level dissector registered to
+ * deal with WTAP_ENCAP_USER13 [=58].
+ *
+ * Something like so:
+ *
+ * dissector_add_uint("wtap_encap", WTAP_ENCAP_USER13, vpp_dissector_handle);
+ *
+ * null 0
+ * ethernet 1
+ * ppp 9
+ * ip 12
+ * hdlc 104
+ * user0 147 ... user15 162
+ */
+#define foreach_vnet_pcap_packet_type           \
+  _ (null, 0)					\
+  _ (ethernet, 1)				\
+  _ (ppp, 9)					\
+  _ (ip, 12)					\
+  _ (hdlc, 104)                                 \
+  _ (user0,    147)                             \
+  _ (user1,    148)                             \
+  _ (user2,    149)                             \
+  _ (user3,    150)                             \
+  _ (user4,    151)                             \
+  _ (user5,    152)                             \
+  _ (user6,    153)                             \
+  _ (user7,    154)                             \
+  _ (user8,    155)                             \
+  _ (user9,    156)                             \
+  _ (user10,   157)                             \
+  _ (user11,   158)                             \
+  _ (user12,   159)                             \
+  _ (user13,   160)                             \
+  _ (user14,   161)                             \
+  _ (user15,   162)
+
+typedef enum
+{
+#define _(f,n) PCAP_PACKET_TYPE_##f = (n),
+  foreach_vnet_pcap_packet_type
+#undef _
+} pcap_packet_type_t;
+
+#define foreach_pcap_file_header			\
+  /** 0xa1b2c3d4 host byte order.			\
+     0xd4c3b2a1 => need to byte swap everything. */	\
+  _ (u32, magic)					\
+							\
+  /** Currently major 2 minor 4. */			\
+  _ (u16, major_version)				\
+  _ (u16, minor_version)				\
+							\
+  /** 0 for GMT. */					\
+  _ (u32, time_zone)					\
+							\
+  /** Accuracy of timestamps.  Typically set to 0. */	\
+  _ (u32, sigfigs)					\
+							\
+  /** Size of largest packet in file. */                \
+  _ (u32, max_packet_size_in_bytes)			\
+							\
+  /** One of vnet_pcap_packet_type_t. */                \
+  _ (u32, packet_type)
+
+/** File header struct */
+typedef struct
+{
+#define _(t, f) t f;
+  foreach_pcap_file_header
+#undef _
+} pcap_file_header_t;
+
+#define foreach_pcap_packet_header					\
+  /** Time stamp in seconds  */                                         \
+  _ (u32, time_in_sec)							\
+  /** Time stamp in microseconds. */                                    \
+  _ (u32, time_in_usec)							\
+									\
+  /** Number of bytes stored in file. */                                \
+  _ (u32, n_packet_bytes_stored_in_file)				\
+  /** Number of bytes in actual packet. */                              \
+  _ (u32, n_bytes_in_packet)
+
+/** Packet header. */
+typedef struct
+{
+#define _(t, f) t f;
+  foreach_pcap_packet_header
+#undef _
+  /** Packet data follows. */
+  u8 data[0];
+} pcap_packet_header_t;
+
+/**
+ * @brief PCAP main state data structure
+ */
+typedef struct
+{
+  /** spinlock to protect e.g. pcap_data */
+  clib_spinlock_t lock;
+
+  /** File name of pcap output. */
+  char *file_name;
+
+  /** Number of packets to capture. */
+  u32 n_packets_to_capture;
+
+  /** Packet type */
+  pcap_packet_type_t packet_type;
+
+  /** Number of packets currently captured. */
+  u32 n_packets_captured;
+
+  /** flags */
+  u32 flags;
+#define PCAP_MAIN_INIT_DONE (1 << 0)
+
+  /** File descriptor for reading/writing. */
+  int file_descriptor;
+
+  /** Bytes written */
+  u32 n_pcap_data_written;
+
+  /** Vector of pcap data. */
+  u8 *pcap_data;
+
+  /** Packets read from file. */
+  u8 **packets_read;
+
+  /** Timestamps */
+  u64 *timestamps;
+
+  /** Min/Max Packet bytes */
+  u32 min_packet_bytes, max_packet_bytes;
+} pcap_main_t;
+
+#endif /* included_vppinfra_pcap_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vppinfra/pcap_funcs.h b/src/vppinfra/pcap_funcs.h
new file mode 100644
index 00000000000..364f4be2333
--- /dev/null
+++ b/src/vppinfra/pcap_funcs.h
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef included_vppinfra_pcap_funcs_h
+#define included_vppinfra_pcap_funcs_h
+
+/** Write out data to output file. */
+clib_error_t *pcap_write (pcap_main_t * pm);
+
+/** Read data from file. */
+clib_error_t *pcap_read (pcap_main_t * pm);
+
+/**
+ * @brief Add packet
+ *
+ * @param *pm - pcap_main_t
+ * @param time_now - f64
+ * @param n_bytes_in_trace - u32
+ * @param n_bytes_in_packet - u32
+ *
+ * @return Packet Data
+ *
+ */
+static inline void *
+pcap_add_packet (pcap_main_t * pm,
+		 f64 time_now, u32 n_bytes_in_trace, u32 n_bytes_in_packet)
+{
+  pcap_packet_header_t *h;
+  u8 *d;
+
+  vec_add2 (pm->pcap_data, d, sizeof (h[0]) + n_bytes_in_trace);
+  h = (void *) (d);
+  h->time_in_sec = time_now;
+  h->time_in_usec = 1e6 * (time_now - h->time_in_sec);
+  h->n_packet_bytes_stored_in_file = n_bytes_in_trace;
+  h->n_bytes_in_packet = n_bytes_in_packet;
+  pm->n_packets_captured++;
+  return h->data;
+}
+
+/**
+ * @brief Add buffer (vlib_buffer_t) to the trace
+ *
+ * @param *pm - pcap_main_t
+ * @param *vm - vlib_main_t
+ * @param buffer_index - u32
+ * @param n_bytes_in_trace - u32
+ *
+ */
+static inline void
+pcap_add_buffer (pcap_main_t * pm,
+		 struct vlib_main_t *vm, u32 buffer_index,
+		 u32 n_bytes_in_trace)
+{
+  vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
+  u32 n = vlib_buffer_length_in_chain (vm, b);
+  i32 n_left = clib_min (n_bytes_in_trace, n);
+  f64 time_now = vlib_time_now (vm);
+  void *d;
+
+  if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
+    {
+      clib_spinlock_lock_if_init (&pm->lock);
+      d = pcap_add_packet (pm, time_now, n_left, n);
+      while (1)
+	{
+	  u32 copy_length = clib_min ((u32) n_left, b->current_length);
+	  clib_memcpy_fast (d, b->data + b->current_data, copy_length);
+	  n_left -= b->current_length;
+	  if (n_left <= 0)
+	    break;
+	  d += b->current_length;
+	  ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
+	  b = vlib_get_buffer (vm, b->next_buffer);
+	}
+      clib_spinlock_unlock_if_init (&pm->lock);
+    }
+}
+
+#endif /* included_vppinfra_pcap_funcs_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */