[HICN-713] Transport Library Major Refactoring 2

Co-authored-by: Luca Muscariello <muscariello@ieee.org>
Co-authored-by: Michele Papalini <micpapal@cisco.com>
Co-authored-by: Olivier Roques <oroques+fdio@cisco.com>
Co-authored-by: Giulio Grassi <gigrassi@cisco.com>
Signed-off-by: Mauro Sardara <msardara@cisco.com>
Change-Id: I5b2c667bad66feb45abdb5effe22ed0f6c85d1c2

11 files changed, 982 insertions, 45 deletions

diff --git a/telemetry/CMakeLists.txt b/telemetry/CMakeLists.txt
index 53fd04f01..fbb929529 100644
--- a/telemetry/CMakeLists.txt
+++ b/telemetry/CMakeLists.txt
@@ -12,7 +12,7 @@
 # limitations under the License.
 
 
-cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.10 FATAL_ERROR)
 
 if ((CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR) OR 
     (BUILD_HICNPLUGIN AND "${CMAKE_SYSTEM_NAME}" STREQUAL "Linux"))
diff --git a/telemetry/vpp-collectd/CMakeLists.txt b/telemetry/vpp-collectd/CMakeLists.txt
index 8f82745f2..7afb3f432 100644
--- a/telemetry/vpp-collectd/CMakeLists.txt
+++ b/telemetry/vpp-collectd/CMakeLists.txt
@@ -11,8 +11,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
-
 set(COLLECTD_PLUGINS hicn-collectd-plugins)
 project(hicn-collectd-plugins)
 
diff --git a/telemetry/vpp-collectd/cmake/Modules/Packaging.cmake b/telemetry/vpp-collectd/cmake/Modules/Packaging.cmake
index dc4629a26..72da05d02 100644
--- a/telemetry/vpp-collectd/cmake/Modules/Packaging.cmake
+++ b/telemetry/vpp-collectd/cmake/Modules/Packaging.cmake
@@ -16,7 +16,7 @@
 ######################
 
 set(${COLLECTD_PLUGINS}_DESCRIPTION
-  "A high-performance Hybrid ICN forwarder as a plugin to VPP."
+  "VPP and hICN plugins for collectd"
   CACHE STRING "Description for deb/rpm package."
 )
 
diff --git a/telemetry/vpp-collectd/common/README.md b/telemetry/vpp-collectd/common/README.md
new file mode 100644
index 000000000..e3b9c74f6
--- /dev/null
+++ b/telemetry/vpp-collectd/common/README.md
@@ -0,0 +1,12 @@
+# Headers for collectd plugins
+
+These headers are required for plugin development but are not shipped with the
+`collectd` Ubuntu 20.04 package (as of May 2021):
+
+* [common.h](https://github.com/collectd/collectd/blob/main/src/utils/common/common.h)
+* [plugin.h](https://github.com/collectd/collectd/blob/main/src/daemon/plugin.h)
+* [meta_data.h](https://github.com/collectd/collectd/blob/main/src/utils/metadata/meta_data.h)
+
+Related issues:
+* [GitHub](https://github.com/collectd/collectd/issues/3881)
+* [Ubuntu](https://bugs.launchpad.net/ubuntu/+source/collectd/+bug/1929079)
diff --git a/telemetry/vpp-collectd/common/common.h b/telemetry/vpp-collectd/common/common.h
new file mode 100644
index 000000000..fce2d12bb
--- /dev/null
+++ b/telemetry/vpp-collectd/common/common.h
@@ -0,0 +1,405 @@
+/**
+ * collectd - src/common.h
+ * Copyright (C) 2005-2014  Florian octo Forster
+ *
+ * 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.
+ *
+ * Authors:
+ *   Florian octo Forster <octo at collectd.org>
+ *   Niki W. Waibel <niki.waibel@gmx.net>
+ **/
+
+#ifndef COMMON_H
+#define COMMON_H
+
+#include "collectd.h"
+
+#include "plugin.h"
+
+#if HAVE_PWD_H
+#include <pwd.h>
+#endif
+
+#define sfree(ptr)                                                             \
+  do {                                                                         \
+    free(ptr);                                                                 \
+    (ptr) = NULL;                                                              \
+  } while (0)
+
+#define STATIC_ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
+
+#define IS_TRUE(s)                                                             \
+  ((strcasecmp("true", (s)) == 0) || (strcasecmp("yes", (s)) == 0) ||          \
+   (strcasecmp("on", (s)) == 0))
+#define IS_FALSE(s)                                                            \
+  ((strcasecmp("false", (s)) == 0) || (strcasecmp("no", (s)) == 0) ||          \
+   (strcasecmp("off", (s)) == 0))
+
+struct rate_to_value_state_s {
+  value_t last_value;
+  cdtime_t last_time;
+  gauge_t residual;
+};
+typedef struct rate_to_value_state_s rate_to_value_state_t;
+
+struct value_to_rate_state_s {
+  value_t last_value;
+  cdtime_t last_time;
+};
+typedef struct value_to_rate_state_s value_to_rate_state_t;
+
+char *sstrncpy(char *dest, const char *src, size_t n);
+
+__attribute__((format(printf, 3, 4))) int ssnprintf(char *str, size_t size,
+                                                    char const *format, ...);
+
+__attribute__((format(printf, 1, 2))) char *ssnprintf_alloc(char const *format,
+                                                            ...);
+
+char *sstrdup(const char *s);
+size_t sstrnlen(const char *s, size_t n);
+char *sstrndup(const char *s, size_t n);
+void *smalloc(size_t size);
+char *sstrerror(int errnum, char *buf, size_t buflen);
+
+#ifndef ERRBUF_SIZE
+#define ERRBUF_SIZE 256
+#endif
+
+#define STRERROR(e) sstrerror((e), (char[ERRBUF_SIZE]){0}, ERRBUF_SIZE)
+#define STRERRNO STRERROR(errno)
+
+/*
+ * NAME
+ *   sread
+ *
+ * DESCRIPTION
+ *   Reads exactly `n' bytes or fails. Syntax and other behavior is analogous
+ *   to `read(2)'.
+ *
+ * PARAMETERS
+ *   `fd'          File descriptor to write to.
+ *   `buf'         Buffer that is to be written.
+ *   `count'       Number of bytes in the buffer.
+ *
+ * RETURN VALUE
+ *   Zero upon success or non-zero if an error occurred. `errno' is set in this
+ *   case.
+ */
+int sread(int fd, void *buf, size_t count);
+
+/*
+ * NAME
+ *   swrite
+ *
+ * DESCRIPTION
+ *   Writes exactly `n' bytes or fails. Syntax and other behavior is analogous
+ *   to `write(2)'.
+ *
+ * PARAMETERS
+ *   `fd'          File descriptor to write to.
+ *   `buf'         Buffer that is to be written.
+ *   `count'       Number of bytes in the buffer.
+ *
+ * RETURN VALUE
+ *   Zero upon success or non-zero if an error occurred. `errno' is set in this
+ *   case.
+ */
+int swrite(int fd, const void *buf, size_t count);
+
+/*
+ * NAME
+ *   strsplit
+ *
+ * DESCRIPTION
+ *   Splits a string into parts and stores pointers to the parts in `fields'.
+ *   The characters split at are: " ", "\t", "\r", and "\n".
+ *
+ * PARAMETERS
+ *   `string'      String to split. This string will be modified. `fields' will
+ *                 contain pointers to parts of this string, so free'ing it
+ *                 will destroy `fields' as well.
+ *   `fields'      Array of strings where pointers to the parts will be stored.
+ *   `size'        Number of elements in the array. No more than `size'
+ *                 pointers will be stored in `fields'.
+ *
+ * RETURN VALUE
+ *    Returns the number of parts stored in `fields'.
+ */
+int strsplit(char *string, char **fields, size_t size);
+
+/*
+ * NAME
+ *   strjoin
+ *
+ * DESCRIPTION
+ *   Joins together several parts of a string using `sep' as a separator. This
+ *   is equivalent to the Perl built-in `join'.
+ *
+ * PARAMETERS
+ *   `dst'         Buffer where the result is stored. Can be NULL if you need to
+ *                 determine the required buffer size only.
+ *   `dst_len'     Length of the destination buffer. No more than this many
+ *                 bytes will be written to the memory pointed to by `dst',
+ *                 including the trailing null-byte. Must be zero if dst is
+ *                 NULL.
+ *   `fields'      Array of strings to be joined.
+ *   `fields_num'  Number of elements in the `fields' array.
+ *   `sep'         String to be inserted between any two elements of `fields'.
+ *                 This string is neither prepended nor appended to the result.
+ *                 Instead of passing "" (empty string) one can pass NULL.
+ *
+ * RETURN VALUE
+ *   Returns the number of characters in the resulting string, excluding a
+ *   tailing null byte. If this value is greater than or equal to "dst_len", the
+ *   result in "dst" is truncated (but still null terminated). On error a
+ *   negative value is returned.
+ */
+int strjoin(char *dst, size_t dst_len, char **fields, size_t fields_num,
+            const char *sep);
+
+/*
+ * NAME
+ *   escape_slashes
+ *
+ * DESCRIPTION
+ *   Removes slashes ("/") from "buffer". If buffer contains a single slash,
+ *   the result will be "root". Leading slashes are removed. All other slashes
+ *   are replaced with underscores ("_").
+ *   This function is used by plugin_dispatch_values() to escape all parts of
+ *   the identifier.
+ *
+ * PARAMETERS
+ *   `buffer'         String to be escaped.
+ *   `buffer_size'    Size of the buffer. No more then this many bytes will be
+ *                    written to `buffer', including the trailing null-byte.
+ *
+ * RETURN VALUE
+ *   Returns zero upon success and a value smaller than zero upon failure.
+ */
+int escape_slashes(char *buffer, size_t buffer_size);
+
+/**
+ * NAME
+ *   escape_string
+ *
+ * DESCRIPTION
+ *   escape_string quotes and escapes a string to be usable with collectd's
+ *   plain text protocol. "simple" strings are left as they are, for example if
+ *   buffer is 'simple' before the call, it will remain 'simple'. However, if
+ *   buffer contains 'more "complex"' before the call, the returned buffer will
+ *   contain '"more \"complex\""'.
+ *
+ *   If the buffer is too small to contain the escaped string, the string will
+ *   be truncated. However, leading and trailing double quotes, as well as an
+ *   ending null byte are guaranteed.
+ *
+ * RETURN VALUE
+ *   Returns zero on success, even if the string was truncated. Non-zero on
+ *   failure.
+ */
+int escape_string(char *buffer, size_t buffer_size);
+
+/*
+ * NAME
+ *   replace_special
+ *
+ * DESCRIPTION
+ *   Replaces any special characters (anything that's not alpha-numeric or a
+ *   dash) with an underscore.
+ *
+ *   E.g. "foo$bar&" would become "foo_bar_".
+ *
+ * PARAMETERS
+ *   `buffer'      String to be handled.
+ *   `buffer_size' Length of the string. The function returns after
+ *                 encountering a null-byte or reading this many bytes.
+ */
+void replace_special(char *buffer, size_t buffer_size);
+
+/*
+ * NAME
+ *   strunescape
+ *
+ * DESCRIPTION
+ *   Replaces any escaped characters in a string with the appropriate special
+ *   characters. The following escaped characters are recognized:
+ *
+ *     \t -> <tab>
+ *     \n -> <newline>
+ *     \r -> <carriage return>
+ *
+ *   For all other escacped characters only the backslash will be removed.
+ *
+ * PARAMETERS
+ *   `buf'         String to be unescaped.
+ *   `buf_len'     Length of the string, including the terminating null-byte.
+ *
+ * RETURN VALUE
+ *   Returns zero upon success, a value less than zero else.
+ */
+int strunescape(char *buf, size_t buf_len);
+
+/**
+ * Removed trailing newline characters (CR and LF) from buffer, which must be
+ * null terminated. Returns the length of the resulting string.
+ */
+__attribute__((nonnull(1))) size_t strstripnewline(char *buffer);
+
+/*
+ * NAME
+ *   timeval_cmp
+ *
+ * DESCRIPTION
+ *   Compare the two time values `tv0' and `tv1' and store the absolut value
+ *   of the difference in the time value pointed to by `delta' if it does not
+ *   equal NULL.
+ *
+ * RETURN VALUE
+ *   Returns an integer less than, equal to, or greater than zero if `tv0' is
+ *   less than, equal to, or greater than `tv1' respectively.
+ */
+int timeval_cmp(struct timeval tv0, struct timeval tv1, struct timeval *delta);
+
+/* make sure tv_usec stores less than a second */
+#define NORMALIZE_TIMEVAL(tv)                                                  \
+  do {                                                                         \
+    (tv).tv_sec += (tv).tv_usec / 1000000;                                     \
+    (tv).tv_usec = (tv).tv_usec % 1000000;                                     \
+  } while (0)
+
+/* make sure tv_sec stores less than a second */
+#define NORMALIZE_TIMESPEC(tv)                                                 \
+  do {                                                                         \
+    (tv).tv_sec += (tv).tv_nsec / 1000000000;                                  \
+    (tv).tv_nsec = (tv).tv_nsec % 1000000000;                                  \
+  } while (0)
+
+int check_create_dir(const char *file_orig);
+
+#ifdef HAVE_LIBKSTAT
+#if HAVE_KSTAT_H
+#include <kstat.h>
+#endif
+int get_kstat(kstat_t **ksp_ptr, char *module, int instance, char *name);
+long long get_kstat_value(kstat_t *ksp, char *name);
+#endif
+
+#ifndef HAVE_HTONLL
+unsigned long long ntohll(unsigned long long n);
+unsigned long long htonll(unsigned long long n);
+#endif
+
+#if FP_LAYOUT_NEED_NOTHING
+#define ntohd(d) (d)
+#define htond(d) (d)
+#elif FP_LAYOUT_NEED_ENDIANFLIP || FP_LAYOUT_NEED_INTSWAP
+double ntohd(double d);
+double htond(double d);
+#else
+#error                                                                         \
+    "Don't know how to convert between host and network representation of doubles."
+#endif
+
+int format_name(char *ret, int ret_len, const char *hostname,
+                const char *plugin, const char *plugin_instance,
+                const char *type, const char *type_instance);
+#define FORMAT_VL(ret, ret_len, vl)                                            \
+  format_name(ret, ret_len, (vl)->host, (vl)->plugin, (vl)->plugin_instance,   \
+              (vl)->type, (vl)->type_instance)
+int format_values(char *ret, size_t ret_len, const data_set_t *ds,
+                  const value_list_t *vl, bool store_rates);
+
+int parse_identifier(char *str, char **ret_host, char **ret_plugin,
+                     char **ret_plugin_instance, char **ret_type,
+                     char **ret_type_instance, char *default_host);
+int parse_identifier_vl(const char *str, value_list_t *vl);
+int parse_value(const char *value, value_t *ret_value, int ds_type);
+int parse_values(char *buffer, value_list_t *vl, const data_set_t *ds);
+
+/* parse_value_file reads "path" and parses its content as an integer or
+ * floating point, depending on "ds_type". On success, the value is stored in
+ * "ret_value" and zero is returned. On failure, a non-zero value is returned.
+ */
+int parse_value_file(char const *path, value_t *ret_value, int ds_type);
+
+#if !HAVE_GETPWNAM_R
+struct passwd;
+int getpwnam_r(const char *name, struct passwd *pwbuf, char *buf, size_t buflen,
+               struct passwd **pwbufp);
+#endif
+
+int notification_init(notification_t *n, int severity, const char *message,
+                      const char *host, const char *plugin,
+                      const char *plugin_instance, const char *type,
+                      const char *type_instance);
+#define NOTIFICATION_INIT_VL(n, vl)                                            \
+  notification_init(n, NOTIF_FAILURE, NULL, (vl)->host, (vl)->plugin,          \
+                    (vl)->plugin_instance, (vl)->type, (vl)->type_instance)
+
+typedef int (*dirwalk_callback_f)(const char *dirname, const char *filename,
+                                  void *user_data);
+int walk_directory(const char *dir, dirwalk_callback_f callback,
+                   void *user_data, int hidden);
+/* Returns the number of bytes read or negative on error. */
+ssize_t read_file_contents(char const *filename, void *buf, size_t bufsize);
+/* Writes the contents of the file into the buffer with a trailing NUL.
+ * Returns the number of bytes written to the buffer or negative on error. */
+ssize_t read_text_file_contents(char const *filename, char *buf,
+                                size_t bufsize);
+
+counter_t counter_diff(counter_t old_value, counter_t new_value);
+
+/* Convert a rate back to a value_t. When converting to a derive_t, counter_t
+ * or absolute_t, take fractional residuals into account. This is important
+ * when scaling counters, for example.
+ * Returns zero on success. Returns EAGAIN when called for the first time; in
+ * this case the value_t is invalid and the next call should succeed. Other
+ * return values indicate an error. */
+int rate_to_value(value_t *ret_value, gauge_t rate,
+                  rate_to_value_state_t *state, int ds_type, cdtime_t t);
+
+int value_to_rate(gauge_t *ret_rate, value_t value, int ds_type, cdtime_t t,
+                  value_to_rate_state_t *state);
+
+/* Converts a service name (a string) to a port number
+ * (in the range [1-65535]). Returns less than zero on error. */
+int service_name_to_port_number(const char *service_name);
+
+/* Sets various, non-default, socket options */
+void set_sock_opts(int sockfd);
+
+/** Parse a string to a derive_t value. Returns zero on success or non-zero on
+ * failure. If failure is returned, ret_value is not touched. */
+int strtoderive(const char *string, derive_t *ret_value);
+
+/** Parse a string to a gauge_t value. Returns zero on success or non-zero on
+ * failure. If failure is returned, ret_value is not touched. */
+int strtogauge(const char *string, gauge_t *ret_value);
+
+int strarray_add(char ***ret_array, size_t *ret_array_len, char const *str);
+void strarray_free(char **array, size_t array_len);
+
+/** Check if the current process benefits from the capability passed in
+ * argument. Returns zero if it does, less than zero if it doesn't or on error.
+ * See capabilities(7) for the list of possible capabilities.
+ * */
+int check_capability(int arg);
+
+#endif /* COMMON_H */
diff --git a/telemetry/vpp-collectd/common/meta_data.h b/telemetry/vpp-collectd/common/meta_data.h
new file mode 100644
index 000000000..203b14607
--- /dev/null
+++ b/telemetry/vpp-collectd/common/meta_data.h
@@ -0,0 +1,71 @@
+/**
+ * collectd - src/meta_data.h
+ * Copyright (C) 2008-2011  Florian octo Forster
+ *
+ * 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.
+ *
+ * Authors:
+ *   Florian octo Forster <octo at collectd.org>
+ **/
+
+#ifndef META_DATA_H
+#define META_DATA_H
+
+#include "collectd.h"
+
+/*
+ * Defines
+ */
+#define MD_TYPE_STRING 1
+#define MD_TYPE_SIGNED_INT 2
+#define MD_TYPE_UNSIGNED_INT 3
+#define MD_TYPE_DOUBLE 4
+#define MD_TYPE_BOOLEAN 5
+
+struct meta_data_s;
+typedef struct meta_data_s meta_data_t;
+
+meta_data_t *meta_data_create(void);
+meta_data_t *meta_data_clone(meta_data_t *orig);
+int meta_data_clone_merge(meta_data_t **dest, meta_data_t *orig);
+void meta_data_destroy(meta_data_t *md);
+
+int meta_data_exists(meta_data_t *md, const char *key);
+int meta_data_type(meta_data_t *md, const char *key);
+int meta_data_toc(meta_data_t *md, char ***toc);
+int meta_data_delete(meta_data_t *md, const char *key);
+
+int meta_data_add_string(meta_data_t *md, const char *key, const char *value);
+int meta_data_add_signed_int(meta_data_t *md, const char *key, int64_t value);
+int meta_data_add_unsigned_int(meta_data_t *md, const char *key,
+                               uint64_t value);
+int meta_data_add_double(meta_data_t *md, const char *key, double value);
+int meta_data_add_boolean(meta_data_t *md, const char *key, bool value);
+
+int meta_data_get_string(meta_data_t *md, const char *key, char **value);
+int meta_data_get_signed_int(meta_data_t *md, const char *key, int64_t *value);
+int meta_data_get_unsigned_int(meta_data_t *md, const char *key,
+                               uint64_t *value);
+int meta_data_get_double(meta_data_t *md, const char *key, double *value);
+int meta_data_get_boolean(meta_data_t *md, const char *key, bool *value);
+
+/* Returns the value as a string, regardless of the type. */
+int meta_data_as_string(meta_data_t *md, const char *key, char **value);
+
+#endif /* META_DATA_H */
diff --git a/telemetry/vpp-collectd/common/plugin.h b/telemetry/vpp-collectd/common/plugin.h
new file mode 100644
index 000000000..0e75adc9b
--- /dev/null
+++ b/telemetry/vpp-collectd/common/plugin.h
@@ -0,0 +1,485 @@
+/**
+ * collectd - src/daemon/plugin.h
+ * Copyright (C) 2005-2014  Florian octo Forster
+ *
+ * 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.
+ *
+ * Authors:
+ *   Florian octo Forster <octo at collectd.org>
+ *   Sebastian Harl <sh at tokkee.org>
+ **/
+
+#ifndef PLUGIN_H
+#define PLUGIN_H
+
+#include "collectd.h"
+
+#include "configfile.h"
+#include "meta_data.h"
+#include "utils_time.h"
+
+#include <inttypes.h>
+#include <pthread.h>
+
+#define DS_TYPE_COUNTER 0
+#define DS_TYPE_GAUGE 1
+#define DS_TYPE_DERIVE 2
+#define DS_TYPE_ABSOLUTE 3
+
+#define DS_TYPE_TO_STRING(t)                                                   \
+  (t == DS_TYPE_COUNTER)                                                       \
+      ? "counter"                                                              \
+      : (t == DS_TYPE_GAUGE)                                                   \
+            ? "gauge"                                                          \
+            : (t == DS_TYPE_DERIVE)                                            \
+                  ? "derive"                                                   \
+                  : (t == DS_TYPE_ABSOLUTE) ? "absolute" : "unknown"
+
+#ifndef LOG_ERR
+#define LOG_ERR 3
+#endif
+#ifndef LOG_WARNING
+#define LOG_WARNING 4
+#endif
+#ifndef LOG_NOTICE
+#define LOG_NOTICE 5
+#endif
+#ifndef LOG_INFO
+#define LOG_INFO 6
+#endif
+#ifndef LOG_DEBUG
+#define LOG_DEBUG 7
+#endif
+
+#define NOTIF_MAX_MSG_LEN 256
+
+#define NOTIF_FAILURE 1
+#define NOTIF_WARNING 2
+#define NOTIF_OKAY 4
+
+#define plugin_interval (plugin_get_ctx().interval)
+
+/*
+ * Public data types
+ */
+struct identifier_s {
+  char *host;
+  char *plugin;
+  char *plugin_instance;
+  char *type;
+  char *type_instance;
+};
+typedef struct identifier_s identifier_t;
+
+typedef unsigned long long counter_t;
+typedef double gauge_t;
+typedef int64_t derive_t;
+typedef uint64_t absolute_t;
+
+union value_u {
+  counter_t counter;
+  gauge_t gauge;
+  derive_t derive;
+  absolute_t absolute;
+};
+typedef union value_u value_t;
+
+struct value_list_s {
+  value_t *values;
+  size_t values_len;
+  cdtime_t time;
+  cdtime_t interval;
+  char host[DATA_MAX_NAME_LEN];
+  char plugin[DATA_MAX_NAME_LEN];
+  char plugin_instance[DATA_MAX_NAME_LEN];
+  char type[DATA_MAX_NAME_LEN];
+  char type_instance[DATA_MAX_NAME_LEN];
+  meta_data_t *meta;
+};
+typedef struct value_list_s value_list_t;
+
+#define VALUE_LIST_INIT                                                        \
+  { .values = NULL, .meta = NULL }
+
+struct data_source_s {
+  char name[DATA_MAX_NAME_LEN];
+  int type;
+  double min;
+  double max;
+};
+typedef struct data_source_s data_source_t;
+
+struct data_set_s {
+  char type[DATA_MAX_NAME_LEN];
+  size_t ds_num;
+  data_source_t *ds;
+};
+typedef struct data_set_s data_set_t;
+
+enum notification_meta_type_e {
+  NM_TYPE_STRING,
+  NM_TYPE_SIGNED_INT,
+  NM_TYPE_UNSIGNED_INT,
+  NM_TYPE_DOUBLE,
+  NM_TYPE_BOOLEAN
+};
+
+typedef struct notification_meta_s {
+  char name[DATA_MAX_NAME_LEN];
+  enum notification_meta_type_e type;
+  union {
+    const char *nm_string;
+    int64_t nm_signed_int;
+    uint64_t nm_unsigned_int;
+    double nm_double;
+    bool nm_boolean;
+  } nm_value;
+  struct notification_meta_s *next;
+} notification_meta_t;
+
+typedef struct notification_s {
+  int severity;
+  cdtime_t time;
+  char message[NOTIF_MAX_MSG_LEN];
+  char host[DATA_MAX_NAME_LEN];
+  char plugin[DATA_MAX_NAME_LEN];
+  char plugin_instance[DATA_MAX_NAME_LEN];
+  char type[DATA_MAX_NAME_LEN];
+  char type_instance[DATA_MAX_NAME_LEN];
+  notification_meta_t *meta;
+} notification_t;
+
+struct user_data_s {
+  void *data;
+  void (*free_func)(void *);
+};
+typedef struct user_data_s user_data_t;
+
+enum cache_event_type_e { CE_VALUE_NEW, CE_VALUE_UPDATE, CE_VALUE_EXPIRED };
+
+typedef struct cache_event_s {
+  enum cache_event_type_e type;
+  const value_list_t *value_list;
+  const char *value_list_name;
+  int ret;
+} cache_event_t;
+
+struct plugin_ctx_s {
+  char *name;
+  cdtime_t interval;
+  cdtime_t flush_interval;
+  cdtime_t flush_timeout;
+};
+typedef struct plugin_ctx_s plugin_ctx_t;
+
+/*
+ * Callback types
+ */
+typedef int (*plugin_init_cb)(void);
+typedef int (*plugin_read_cb)(user_data_t *);
+typedef int (*plugin_write_cb)(const data_set_t *, const value_list_t *,
+                               user_data_t *);
+typedef int (*plugin_flush_cb)(cdtime_t timeout, const char *identifier,
+                               user_data_t *);
+/* "missing" callback. Returns less than zero on failure, zero if other
+ * callbacks should be called, greater than zero if no more callbacks should be
+ * called. */
+typedef int (*plugin_missing_cb)(const value_list_t *, user_data_t *);
+/* "cache event" callback. CE_VALUE_NEW events are sent to all registered
+ * callbacks. Callback should check if it interested in further CE_VALUE_UPDATE
+ * and CE_VALUE_EXPIRED events for metric and set event->ret = 1 if so.
+ */
+typedef int (*plugin_cache_event_cb)(cache_event_t *, user_data_t *);
+typedef void (*plugin_log_cb)(int severity, const char *message, user_data_t *);
+typedef int (*plugin_shutdown_cb)(void);
+typedef int (*plugin_notification_cb)(const notification_t *, user_data_t *);
+/*
+ * NAME
+ *  plugin_set_dir
+ *
+ * DESCRIPTION
+ *  Sets the current `plugindir'
+ *
+ * ARGUMENTS
+ *  `dir'       Path to the plugin directory
+ *
+ * NOTES
+ *  If `dir' is NULL the compiled in default `PLUGINDIR' is used.
+ */
+void plugin_set_dir(const char *dir);
+
+/*
+ * NAME
+ *  plugin_load
+ *
+ * DESCRIPTION
+ *  Searches the current `plugindir' (see `plugin_set_dir') for the plugin
+ *  named $type and loads it. Afterwards the plugin's `module_register'
+ *  function is called, which then calls `plugin_register' to register callback
+ *  functions.
+ *
+ * ARGUMENTS
+ *  `name'      Name of the plugin to load.
+ *  `global'    Make this plugins symbols available for other shared libraries.
+ *
+ * RETURN VALUE
+ *  Returns zero upon success, a value greater than zero if no plugin was found
+ *  and a value below zero if an error occurs.
+ *
+ * NOTES
+ *  Re-loading an already loaded module is detected and zero is returned in
+ *  this case.
+ */
+int plugin_load(const char *name, bool global);
+bool plugin_is_loaded(char const *name);
+
+int plugin_init_all(void);
+void plugin_read_all(void);
+int plugin_read_all_once(void);
+int plugin_shutdown_all(void);
+
+/*
+ * NAME
+ *  plugin_write
+ *
+ * DESCRIPTION
+ *  Calls the write function of the given plugin with the provided data set and
+ *  value list. It differs from `plugin_dispatch_values' in that it does not
+ *  update the cache, does not do threshold checking, call the chain subsystem
+ *  and so on. It looks up the requested plugin and invokes the function, end
+ *  of story.
+ *
+ * ARGUMENTS
+ *  plugin     Name of the plugin. If NULL, the value is sent to all registered
+ *             write functions.
+ *  ds         Pointer to the data_set_t structure. If NULL, the data set is
+ *             looked up according to the `type' member in the `vl' argument.
+ *  vl         The actual value to be processed. Must not be NULL.
+ *
+ * RETURN VALUE
+ *  Returns zero upon success or non-zero if an error occurred. If `plugin' is
+ *  NULL and more than one plugin is called, an error is only returned if *all*
+ *  plugins fail.
+ *
+ * NOTES
+ *  This is the function used by the `write' built-in target. May be used by
+ *  other target plugins.
+ */
+int plugin_write(const char *plugin, const data_set_t *ds,
+                 const value_list_t *vl);
+
+int plugin_flush(const char *plugin, cdtime_t timeout, const char *identifier);
+
+/*
+ * The `plugin_register_*' functions are used to make `config', `init',
+ * `read', `write' and `shutdown' functions known to the plugin
+ * infrastructure. Also, the data-formats are made public like this.
+ */
+int plugin_register_config(const char *name,
+                           int (*callback)(const char *key, const char *val),
+                           const char **keys, int keys_num);
+int plugin_register_complex_config(const char *type,
+                                   int (*callback)(oconfig_item_t *));
+int plugin_register_init(const char *name, plugin_init_cb callback);
+int plugin_register_read(const char *name, int (*callback)(void));
+/* "user_data" will be freed automatically, unless
+ * "plugin_register_complex_read" returns an error (non-zero). */
+int plugin_register_complex_read(const char *group, const char *name,
+                                 plugin_read_cb callback, cdtime_t interval,
+                                 user_data_t const *user_data);
+int plugin_register_write(const char *name, plugin_write_cb callback,
+                          user_data_t const *user_data);
+int plugin_register_flush(const char *name, plugin_flush_cb callback,
+                          user_data_t const *user_data);
+int plugin_register_missing(const char *name, plugin_missing_cb callback,
+                            user_data_t const *user_data);
+int plugin_register_cache_event(const char *name,
+                                plugin_cache_event_cb callback,
+                                user_data_t const *ud);
+int plugin_register_shutdown(const char *name, plugin_shutdown_cb callback);
+int plugin_register_data_set(const data_set_t *ds);
+int plugin_register_log(const char *name, plugin_log_cb callback,
+                        user_data_t const *user_data);
+int plugin_register_notification(const char *name,
+                                 plugin_notification_cb callback,
+                                 user_data_t const *user_data);
+
+int plugin_unregister_config(const char *name);
+int plugin_unregister_complex_config(const char *name);
+int plugin_unregister_init(const char *name);
+int plugin_unregister_read(const char *name);
+int plugin_unregister_read_group(const char *group);
+int plugin_unregister_write(const char *name);
+int plugin_unregister_flush(const char *name);
+int plugin_unregister_missing(const char *name);
+int plugin_unregister_cache_event(const char *name);
+int plugin_unregister_shutdown(const char *name);
+int plugin_unregister_data_set(const char *name);
+int plugin_unregister_log(const char *name);
+int plugin_unregister_notification(const char *name);
+
+/*
+ * NAME
+ *  plugin_log_available_writers
+ *
+ * DESCRIPTION
+ *  This function can be called to output a list of _all_ registered
+ *  writers to the logfacility.
+ *  Since some writers dynamically build their name it can be hard for
+ *  the configuring person to know it. This function will fill this gap.
+ */
+void plugin_log_available_writers(void);
+
+/*
+ * NAME
+ *  plugin_dispatch_values
+ *
+ * DESCRIPTION
+ *  This function is called by reading processes with the values they've
+ *  aquired. The function fetches the data-set definition (that has been
+ *  registered using `plugin_register_data_set') and calls _all_ registered
+ *  write-functions.
+ *
+ * ARGUMENTS
+ *  `vl'        Value list of the values that have been read by a `read'
+ *              function.
+ */
+int plugin_dispatch_values(value_list_t const *vl);
+
+/*
+ * NAME
+ *  plugin_dispatch_multivalue
+ *
+ * SYNOPSIS
+ *  plugin_dispatch_multivalue (vl, true, DS_TYPE_GAUGE,
+ *                              "free", 42.0,
+ *                              "used", 58.0,
+ *                              NULL);
+ *
+ * DESCRIPTION
+ *  Takes a list of type instances and values and dispatches that in a batch,
+ *  making sure that all values have the same time stamp. If "store_percentage"
+ *  is set to true, the "type" is set to "percent" and a percentage is
+ *  calculated and dispatched, rather than the absolute values. Values that are
+ *  NaN are dispatched as NaN and will not influence the total.
+ *
+ *  The variadic arguments is a list of type_instance / type pairs, that are
+ *  interpreted as type "char const *" and type, encoded by their corresponding
+ *  "store_type":
+ *
+ *     - "gauge_t"    when "DS_TYPE_GAUGE"
+ *     - "absolute_t" when "DS_TYPE_ABSOLUTE"
+ *     - "derive_t"   when "DS_TYPE_DERIVE"
+ *     - "counter_t"  when "DS_TYPE_COUNTER"
+ *
+ *  The last argument must be
+ *  a NULL pointer to signal end-of-list.
+ *
+ * RETURNS
+ *  The number of values it failed to dispatch (zero on success).
+ */
+__attribute__((sentinel)) int plugin_dispatch_multivalue(value_list_t const *vl,
+                                                         bool store_percentage,
+                                                         int store_type, ...);
+
+int plugin_dispatch_missing(const value_list_t *vl);
+void plugin_dispatch_cache_event(enum cache_event_type_e event_type,
+                                 unsigned long callbacks_mask, const char *name,
+                                 const value_list_t *vl);
+
+int plugin_dispatch_notification(const notification_t *notif);
+
+void plugin_log(int level, const char *format, ...)
+    __attribute__((format(printf, 2, 3)));
+
+/* These functions return the parsed severity or less than zero on failure. */
+int parse_log_severity(const char *severity);
+int parse_notif_severity(const char *severity);
+
+#define ERROR(...) plugin_log(LOG_ERR, __VA_ARGS__)
+#define WARNING(...) plugin_log(LOG_WARNING, __VA_ARGS__)
+#define NOTICE(...) plugin_log(LOG_NOTICE, __VA_ARGS__)
+#define INFO(...) plugin_log(LOG_INFO, __VA_ARGS__)
+#if COLLECT_DEBUG
+#define DEBUG(...) plugin_log(LOG_DEBUG, __VA_ARGS__)
+#else              /* COLLECT_DEBUG */
+#define DEBUG(...) /* noop */
+#endif             /* ! COLLECT_DEBUG */
+
+/* This will log messages, prefixed by plugin name */
+void daemon_log(int level, const char *format, ...)
+    __attribute__((format(printf, 2, 3)));
+
+#define P_ERROR(...) daemon_log(LOG_ERR, __VA_ARGS__)
+#define P_WARNING(...) daemon_log(LOG_WARNING, __VA_ARGS__)
+#define P_NOTICE(...) daemon_log(LOG_NOTICE, __VA_ARGS__)
+#define P_INFO(...) daemon_log(LOG_INFO, __VA_ARGS__)
+
+const data_set_t *plugin_get_ds(const char *name);
+
+int plugin_notification_meta_add_string(notification_t *n, const char *name,
+                                        const char *value);
+int plugin_notification_meta_add_signed_int(notification_t *n, const char *name,
+                                            int64_t value);
+int plugin_notification_meta_add_unsigned_int(notification_t *n,
+                                              const char *name, uint64_t value);
+int plugin_notification_meta_add_double(notification_t *n, const char *name,
+                                        double value);
+int plugin_notification_meta_add_boolean(notification_t *n, const char *name,
+                                         bool value);
+
+int plugin_notification_meta_copy(notification_t *dst,
+                                  const notification_t *src);
+
+int plugin_notification_meta_free(notification_meta_t *n);
+
+/*
+ * Plugin context management.
+ */
+
+void plugin_init_ctx(void);
+
+plugin_ctx_t plugin_get_ctx(void);
+plugin_ctx_t plugin_set_ctx(plugin_ctx_t ctx);
+
+/*
+ * NAME
+ *  plugin_get_interval
+ *
+ * DESCRIPTION
+ *  This function returns the current value of the plugin's interval. The
+ *  return value will be strictly greater than zero in all cases. If
+ *  everything else fails, it will fall back to 10 seconds.
+ */
+cdtime_t plugin_get_interval(void);
+
+/*
+ * Context-aware thread management.
+ */
+
+int plugin_thread_create(pthread_t *thread, void *(*start_routine)(void *),
+                         void *arg, char const *name);
+
+/*
+ * Plugins need to implement this
+ */
+
+void module_register(void);
+
+#endif /* PLUGIN_H */
diff --git a/telemetry/vpp-collectd/vpp-hicn/CMakeLists.txt b/telemetry/vpp-collectd/vpp-hicn/CMakeLists.txt
index 3703515dc..9db20be38 100644
--- a/telemetry/vpp-collectd/vpp-hicn/CMakeLists.txt
+++ b/telemetry/vpp-collectd/vpp-hicn/CMakeLists.txt
@@ -11,7 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.10 FATAL_ERROR)
 
 # Dependencies
 find_package(Collectd REQUIRED)
@@ -36,7 +36,8 @@ list(APPEND INCLUDE_DIRS
     ${HICNPLUGIN_INCLUDE_DIRS}
     ${SAFE_VAPI_INCLUDE_DIRS}
     ${VPP_INCLUDE_DIRS}
-    ${CMAKE_CURRENT_SOURCE_DIR})
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    "${CMAKE_CURRENT_SOURCE_DIR}/../common")
 
 list(APPEND LIBRARIES
     ${VPP_LIBRARY_VAPICLIENT}
diff --git a/telemetry/vpp-collectd/vpp-hicn/vpp_hicn.c b/telemetry/vpp-collectd/vpp-hicn/vpp_hicn.c
index 4228ac6e6..b6bc3af49 100644
--- a/telemetry/vpp-collectd/vpp-hicn/vpp_hicn.c
+++ b/telemetry/vpp-collectd/vpp-hicn/vpp_hicn.c
@@ -15,8 +15,7 @@
 
 /* Keep order as it is */
 #include <config.h>
-#include <collectd.h>
-#include <plugin.h>
+#include "common.h"
 
 #define counter_t vpp_counter_t
 #include <vapi/hicn.api.vapi.h>
@@ -26,15 +25,6 @@
 DEFINE_VAPI_MSG_IDS_HICN_API_JSON
 vapi_ctx_t vapi_ctx;
 
-#define STATIC_ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
-
-#define IS_TRUE(s)                                                             \
-  ((strcasecmp("true", (s)) == 0) || (strcasecmp("yes", (s)) == 0) ||          \
-   (strcasecmp("on", (s)) == 0))
-#define IS_FALSE(s)                                                            \
-  ((strcasecmp("false", (s)) == 0) || (strcasecmp("no", (s)) == 0) ||          \
-   (strcasecmp("off", (s)) == 0))
-
 /************** OPTIONS ***********************************/
 static const char *config_keys[2] = {
     "Verbose",
@@ -181,12 +171,6 @@ static data_set_t dtx_ds = {
 /**********************************************************/
 /********** UTILITY FUNCTIONS *****************************/
 /**********************************************************/
-char *sstrncpy(char *dest, const char *src, size_t n) {
-  strncpy(dest, src, n);
-  dest[n - 1] = '\0';
-  return dest;
-}
-
 /*
  * Utility function used by the read callback to populate a
  * value_list_t and pass it to plugin_dispatch_values.
@@ -214,7 +198,6 @@ static int submit(const char *plugin_instance, const char *type,
 /**********************************************************/
 /********** CALLBACK FUNCTIONS ****************************/
 /**********************************************************/
-
 /*
  * This function is called for each configuration item.
  */
diff --git a/telemetry/vpp-collectd/vpp/CMakeLists.txt b/telemetry/vpp-collectd/vpp/CMakeLists.txt
index 464ab42d8..c36787355 100644
--- a/telemetry/vpp-collectd/vpp/CMakeLists.txt
+++ b/telemetry/vpp-collectd/vpp/CMakeLists.txt
@@ -11,8 +11,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
-
 # Dependencies
 find_package(Vpp REQUIRED)
 find_package(Collectd REQUIRED)
@@ -23,7 +21,8 @@ list(APPEND SOURCE_FILES
 list(APPEND INCLUDE_DIRS
     ${COLLECTD_INCLUDE_DIRS}
     ${VPP_INCLUDE_DIRS}
-    ${CMAKE_CURRENT_SOURCE_DIR})
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    "${CMAKE_CURRENT_SOURCE_DIR}/../common")
 
 list(APPEND LIBRARIES
     ${VPP_LIBRARY_VPPAPICLIENT}
diff --git a/telemetry/vpp-collectd/vpp/vpp.c b/telemetry/vpp-collectd/vpp/vpp.c
index 8bf5182a8..dcf956c93 100644
--- a/telemetry/vpp-collectd/vpp/vpp.c
+++ b/telemetry/vpp-collectd/vpp/vpp.c
@@ -15,23 +15,13 @@
 
 /* Keep order as it is */
 #include <config.h>
-#include <collectd.h>
-#include <plugin.h>
+#include "common.h"
 
 #define counter_t vpp_counter_t
 #include <vpp-api/client/stat_client.h>
 #include <vppinfra/vec.h>
 #undef counter_t
 
-#define STATIC_ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
-
-#define IS_TRUE(s)                                                             \
-  ((strcasecmp("true", (s)) == 0) || (strcasecmp("yes", (s)) == 0) ||          \
-   (strcasecmp("on", (s)) == 0))
-#define IS_FALSE(s)                                                            \
-  ((strcasecmp("false", (s)) == 0) || (strcasecmp("no", (s)) == 0) ||          \
-   (strcasecmp("off", (s)) == 0))
-
 /************** OPTIONS ***********************************/
 static const char *config_keys[2] = {
     "Verbose",
@@ -157,12 +147,6 @@ static data_set_t if_tx_broadcast_ds = {
 /**********************************************************/
 /********** UTILITY FUNCTIONS *****************************/
 /**********************************************************/
-char *sstrncpy(char *dest, const char *src, size_t n) {
-  strncpy(dest, src, n);
-  dest[n - 1] = '\0';
-  return dest;
-}
-
 /*
  * Utility function used by the read callback to populate a
  * value_list_t and pass it to plugin_dispatch_values.
@@ -245,7 +229,6 @@ static int get_data_set(const char *stat_name, data_set_t *data_set_ptr) {
 /**********************************************************/
 /********** CALLBACK FUNCTIONS ****************************/
 /**********************************************************/
-
 /*
  * This function is called for each configuration item.
  */