vppinfra: add mapped pcap file support

Type: feature

Change-Id: Ic720d56a6f8901efde2a58519bc9aa553205a9a6
Signed-off-by: Gary Boon <gboon@cisco.com>
Signed-off-by: Dave Barach <dave@barachs.net>

3 files changed, 506 insertions, 0 deletions

diff --git a/src/vppinfra/CMakeLists.txt b/src/vppinfra/CMakeLists.txt
index 9c5804602a1..6cd30876fa0 100644
--- a/src/vppinfra/CMakeLists.txt
+++ b/src/vppinfra/CMakeLists.txt
@@ -56,6 +56,7 @@ set(VPPINFRA_SRCS
   macros.c
   maplog.c
   mhash.c
+  mpcap.c
   pcap.c
   pmalloc.c
   pool.c
@@ -136,6 +137,7 @@ set(VPPINFRA_HEADERS
   mhash.h
   mheap_bootstrap.h
   mheap.h
+  mpcap.h
   os.h
   pcap.h
   pcap_funcs.h
diff --git a/src/vppinfra/mpcap.c b/src/vppinfra/mpcap.c
new file mode 100644
index 00000000000..902f52f1870
--- /dev/null
+++ b/src/vppinfra/mpcap.c
@@ -0,0 +1,247 @@
+/*
+ * Copyright (c) 2019 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.
+ */
+
+#include <sys/fcntl.h>
+#include <vppinfra/mpcap.h>
+
+/*
+ * Unfortunately, the "make test" infra won't work with mapped pcap files.
+ * Given enough work [mostly in .py code], one could fix that.
+ */
+
+/**
+ * @file
+ * @brief mapped pcap file support
+ *
+ * Usage:
+ *
+ * <code><pre>
+ * \#include <vnet/unix/mpcap.h>
+ *
+ * static mpcap_main_t mpcap = {
+ *  .file_name = "/tmp/ip4",
+ *  .n_packets_to_capture = 2,
+ *  .packet_type = MPCAP_PACKET_TYPE_ip,
+ * };
+ * </pre></code>
+ *
+ * To add a buffer:
+ *
+ *  <code><pre>mpcap_add_buffer (&mpcap, vm, pi0, 128);</pre></code>
+ *
+ * File will be written after @c n_packets_to_capture
+ * or call to mpcap_close
+ *
+ */
+
+/**
+ * @brief Close a mapped pcap file
+ * @param mpcap_main_t * pm
+ * @return rc - clib_error_t
+ *
+ */
+clib_error_t *
+mpcap_close (mpcap_main_t * pm)
+{
+  u64 actual_size = pm->current_va - pm->file_baseva;
+
+  /* Not open? Done... */
+  if ((pm->flags & MPCAP_FLAG_INIT_DONE) == 0)
+    return 0;
+
+  (void) munmap (pm->file_baseva, pm->max_file_size);
+  pm->file_baseva = 0;
+  pm->current_va = 0;
+  pm->flags &= ~MPCAP_FLAG_INIT_DONE;
+
+  if ((pm->flags & MPCAP_FLAG_WRITE_ENABLE) == 0)
+    return 0;
+
+  if (truncate (pm->file_name, actual_size) < 0)
+    clib_unix_warning ("setting file size to %llu", actual_size);
+
+  return 0;
+}
+
+/**
+ * @brief Initialize a mapped pcap file
+ * @param mpcap_main_t * pm
+ * @return rc - clib_error_t
+ *
+ */
+clib_error_t *
+mpcap_init (mpcap_main_t * pm)
+{
+  mpcap_file_header_t *fh;
+  u8 zero = 0;
+  int fd;
+
+  if (pm->flags & MPCAP_FLAG_INIT_DONE)
+    return 0;
+
+  if (!pm->file_name)
+    pm->file_name = "/tmp/vnet.mpcap";
+
+  if (pm->flags & MPCAP_FLAG_THREAD_SAFE)
+    clib_spinlock_init (&pm->lock);
+
+  fd = open (pm->file_name, O_CREAT | O_TRUNC | O_RDWR, 0664);
+  if (fd < 0)
+    {
+      return clib_error_return_unix (0, "failed to create `%s'",
+				     pm->file_name);
+    }
+
+  if (pm->max_file_size == 0ULL)
+    pm->max_file_size = MPCAP_DEFAULT_FILE_SIZE;
+
+  /* Round to a multiple of the page size */
+  pm->max_file_size += (u64) clib_mem_get_page_size ();
+  pm->max_file_size &= ~(u64) clib_mem_get_page_size ();
+
+  /* Set file size. */
+  if (lseek (fd, pm->max_file_size - 1, SEEK_SET) == (off_t) - 1)
+    {
+      close (fd);
+      (void) unlink (pm->file_name);
+      return clib_error_return_unix (0, "file size seek");
+    }
+
+  if (write (fd, &zero, 1) != 1)
+    {
+      close (fd);
+      (void) unlink (pm->file_name);
+      return clib_error_return_unix (0, "file size write");
+    }
+
+  pm->file_baseva = mmap (0, pm->max_file_size,
+			  PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+  if (pm->file_baseva == (u8 *) MAP_FAILED)
+    {
+      clib_error_t *error = clib_error_return_unix (0, "mmap");
+      close (fd);
+      (void) unlink (pm->file_name);
+      return error;
+    }
+  (void) close (fd);
+
+  pm->flags |= MPCAP_FLAG_INIT_DONE | MPCAP_FLAG_WRITE_ENABLE;
+  pm->n_packets_captured = 0;
+  pm->n_mpcap_data_written = 0;
+
+  /* Initialize file header */
+  fh = pm->file_header = (mpcap_file_header_t *) pm->file_baseva;
+  pm->current_va = pm->file_baseva + 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;
+  return 0;
+}
+
+
+/**
+ * @brief mmap a mapped pcap file, e.g. to read from another process
+ * @param pcap_main_t *pm
+ * @return rc - clib_error_t
+ */
+clib_error_t *
+mpcap_map (mpcap_main_t * pm)
+{
+  clib_error_t *error = 0;
+  int fd = -1;
+  mpcap_file_header_t *fh;
+  mpcap_packet_header_t *ph;
+  struct stat statb;
+  u64 packets_read = 0;
+  u32 min_packet_bytes = ~0;
+  u32 max_packet_bytes = 0;
+
+  if (stat (pm->file_name, &statb) < 0)
+    {
+      error = clib_error_return_unix (0, "stat `%s'", pm->file_name);
+      goto done;
+    }
+
+  fd = open (pm->file_name, O_RDONLY);
+  if (fd < 0)
+    {
+      error = clib_error_return_unix (0, "open `%s'", pm->file_name);
+      goto done;
+    }
+
+  if (statb.st_size < sizeof (*fh) + sizeof (*ph))
+    {
+      error = clib_error_return_unix (0, "`%s' is too short", pm->file_name);
+      goto done;
+    }
+
+  pm->max_file_size = statb.st_size;
+  pm->file_baseva = mmap (0, statb.st_size, PROT_READ, MAP_SHARED, fd, 0);
+  if (pm->file_baseva == (u8 *) MAP_FAILED)
+    {
+      error = clib_error_return_unix (0, "mmap");
+      goto done;
+    }
+
+  pm->flags |= MPCAP_FLAG_INIT_DONE;
+  fh = pm->file_header = (mpcap_file_header_t *) pm->file_baseva;
+  ph = (mpcap_packet_header_t *) (fh + 1);
+
+  if (fh->magic != 0xa1b2c3d4)
+    {
+      error = clib_error_return (0, "bad magic `%s'", pm->file_name);
+      goto done;
+    }
+
+  /* for the client's convenience, count packets; compute min/max sizes */
+  while (ph < (mpcap_packet_header_t *) pm->file_baseva + pm->max_file_size)
+    {
+      if (ph->n_packet_bytes_stored_in_file == 0)
+	break;
+
+      packets_read++;
+      min_packet_bytes =
+	ph->n_packet_bytes_stored_in_file <
+	min_packet_bytes ? ph->n_packet_bytes_stored_in_file :
+	min_packet_bytes;
+      max_packet_bytes =
+	ph->n_packet_bytes_stored_in_file >
+	max_packet_bytes ? ph->n_packet_bytes_stored_in_file :
+	max_packet_bytes;
+
+      ph = (mpcap_packet_header_t *)
+	(((u8 *) (ph)) + sizeof (*ph) + ph->n_packet_bytes_stored_in_file);
+    }
+  pm->packets_read = packets_read;
+  pm->min_packet_bytes = min_packet_bytes;
+  pm->max_packet_bytes = max_packet_bytes;
+
+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/mpcap.h b/src/vppinfra/mpcap.h
new file mode 100644
index 00000000000..1710702d8bd
--- /dev/null
+++ b/src/vppinfra/mpcap.h
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 2018 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.
+ */
+
+/**
+ * @file
+ * @brief MPCAP utility definitions
+ */
+#ifndef included_vnet_mpcap_h
+#define included_vnet_mpcap_h
+
+#include <vlib/vlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <vppinfra/time_range.h>
+
+/**
+ * @brief Packet types supported by MPCAP
+ *
+ * null 0
+ * ethernet 1
+ * ppp 9
+ * ip 12
+ * hdlc 104
+ */
+#define foreach_vnet_mpcap_packet_type          \
+  _ (null, 0)                                   \
+  _ (ethernet, 1)                               \
+  _ (ppp, 9)                                    \
+  _ (ip, 12)                                    \
+  _ (hdlc, 104)
+
+typedef enum
+{
+#define _(f,n) MPCAP_PACKET_TYPE_##f = (n),
+  foreach_vnet_mpcap_packet_type
+#undef _
+} mpcap_packet_type_t;
+
+#define foreach_mpcap_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_mpcap_packet_type_t. */               \
+  _ (u32, packet_type)
+
+/** File header struct */
+typedef struct
+{
+#define _(t, f) t f;
+  foreach_mpcap_file_header
+#undef _
+} mpcap_file_header_t;
+
+#define foreach_mpcap_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_mpcap_packet_header
+#undef _
+  /** Packet data follows. */
+  u8 data[0];
+} mpcap_packet_header_t;
+
+/**
+ * @brief MPCAP main state data structure
+ */
+typedef struct
+{
+  /** File name of mpcap output. */
+  char *file_name;
+
+  /** spinlock, initialized if flagged MPCAP_FLAG_THREAD_SAFE */
+  clib_spinlock_t lock;
+
+  /** Number of packets to capture. */
+  u32 n_packets_to_capture;
+
+  /** Packet type */
+  mpcap_packet_type_t packet_type;
+
+  /** Maximum file size */
+  u64 max_file_size;
+
+  /** Base address */
+  u8 *file_baseva;
+
+  /** current memory address */
+  u8 *current_va;
+
+  /** Number of packets currently captured. */
+  u32 n_packets_captured;
+
+  /** Pointer to file header in svm, for ease of updating */
+  mpcap_file_header_t *file_header;
+
+  /** flags */
+  u32 flags;
+#define MPCAP_FLAG_INIT_DONE (1 << 0)
+#define MPCAP_FLAG_THREAD_SAFE (1 << 1)
+#define MPCAP_FLAG_WRITE_ENABLE (1 << 2)
+
+  /** Bytes written */
+  u32 n_mpcap_data_written;
+
+  /** Vector of mpcap data. */
+  u8 *mpcap_data;
+
+  /** Packets in mapped mpcap file. */
+  u64 packets_read;
+
+  /** Min/Max Packet bytes */
+  u32 min_packet_bytes, max_packet_bytes;
+} mpcap_main_t;
+
+/* Some sensible default size */
+#define MPCAP_DEFAULT_FILE_SIZE (10<<20)
+
+/** initialize a mpcap file (for writing) */
+clib_error_t *mpcap_init (mpcap_main_t * pm);
+
+/** Flush / unmap a mpcap file */
+clib_error_t *mpcap_close (mpcap_main_t * pm);
+
+/** mmap a mpcap data file. */
+clib_error_t *mpcap_map (mpcap_main_t * pm);
+
+/**
+ * @brief Add packet
+ *
+ * @param *pm - mpcap_main_t
+ * @param time_now - f64
+ * @param n_bytes_in_trace - u32
+ * @param n_bytes_in_packet - u32
+ *
+ * @return Packet Data
+ *
+ */
+static inline void *
+mpcap_add_packet (mpcap_main_t * pm,
+		  f64 time_now, u32 n_bytes_in_trace, u32 n_bytes_in_packet)
+{
+  mpcap_packet_header_t *h;
+  u8 *d;
+
+  /* File already closed? */
+  if (PREDICT_FALSE (pm->flags & MPCAP_FLAG_INIT_DONE) == 0)
+    return 0;
+
+  d = pm->current_va;
+  pm->current_va += sizeof (h[0]) + n_bytes_in_trace;
+
+  /* Out of space? */
+  if (PREDICT_FALSE (pm->current_va >= pm->file_baseva + pm->max_file_size))
+    return 0;
+  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 - mpcap_main_t
+ * @param *vm - vlib_main_t
+ * @param time_now - f64
+ * @param buffer_index - u32
+ * @param n_bytes_in_trace - u32
+ *
+ */
+static inline void
+mpcap_add_buffer (mpcap_main_t * pm,
+		  vlib_main_t * vm,
+		  f64 time_now, 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);
+  void *d;
+
+  clib_spinlock_lock_if_init (&pm->lock);
+
+  d = mpcap_add_packet (pm, time_now, n_left, n);
+  if (PREDICT_FALSE (d == 0))
+    {
+      mpcap_close (pm);
+      clib_spinlock_unlock_if_init (&pm->lock);
+      return;
+    }
+
+  while (1)
+    {
+      u32 copy_length = clib_min ((u32) n_left, b->current_length);
+      clib_memcpy (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);
+    }
+  if (pm->n_packets_captured >= pm->n_packets_to_capture)
+    mpcap_close (pm);
+
+  clib_spinlock_unlock_if_init (&pm->lock);
+}
+
+#endif /* included_vnet_mpcap_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */