[dpdk-dev] [PATCH v2] eal: fix querying DPDK version at runtime

[Bruce Richardson <bruce.richardson@intel.com>]

For using a DPDK application, such as OVS, which is dynamically linked, the
DPDK version in use should always report the actual version, not the
version used at build time. This incorrect behaviour can be seen by
building OVS against one version of DPDK and running it against a later
one. Using "ovs-vsctl list Open_vSwitch" to query basic info, the
dpdk_version returned will be the build version not the currently running
one - which can be verified using the DPDK telemetry library client.

  $ sudo ovs-vsctl list Open_vSwitch | grep dpdk_version
  dpdk_version        : "DPDK 20.11.0-rc4"

  $ echo quit | sudo dpdk-telemetry.py
  Connecting to /var/run/dpdk/rte/dpdk_telemetry.v2
  {"version": "DPDK 21.02.0-rc2", "pid": 405659, "max_output_len": 16384}
  -->

To fix this, we need to convert the rte_version() function, and any other
necessary parts of the rte_version.h, to be actual functions in EAL, not
just inlines/macros. The only complication in doing so is that telemetry
library cannot call rte_version() directly, and instead needs the version
string passed in on init.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
v2:
	rebased on top of main for 21.05 consideration.
---
 lib/librte_eal/common/meson.build    |  2 +
 lib/librte_eal/common/rte_version.c  | 46 ++++++++++++++++++++
 lib/librte_eal/freebsd/eal.c         |  1 +
 lib/librte_eal/include/rte_version.h | 63 ++++++++++++++++------------
 lib/librte_eal/linux/eal.c           |  1 +
 lib/librte_eal/version.map           |  7 ++++
 lib/librte_telemetry/rte_telemetry.h |  2 +-
 lib/librte_telemetry/telemetry.c     | 12 +++---
 8 files changed, 101 insertions(+), 33 deletions(-)
 create mode 100644 lib/librte_eal/common/rte_version.c

diff --git a/lib/librte_eal/common/meson.build b/lib/librte_eal/common/meson.build
index 39d427297..70bd854fe 100644
--- a/lib/librte_eal/common/meson.build
+++ b/lib/librte_eal/common/meson.build
@@ -36,6 +36,7 @@ if is_windows
 		'rte_random.c',
 		'rte_reciprocal.c',
 		'rte_service.c',
+		'rte_version.c',
 	)
 	subdir_done()
 endif
@@ -79,6 +80,7 @@ sources += files(
 	'rte_random.c',
 	'rte_reciprocal.c',
 	'rte_service.c',
+	'rte_version.c',
 )

 if is_linux
diff --git a/lib/librte_eal/common/rte_version.c b/lib/librte_eal/common/rte_version.c
new file mode 100644
index 000000000..4ae5d66c8
--- /dev/null
+++ b/lib/librte_eal/common/rte_version.c
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2021 Intel Corporation
+ */
+
+#include <rte_version.h>
+
+const char *
+rte_version_prefix(void) { return RTE_VER_PREFIX; }
+
+unsigned int
+rte_version_year(void) { return RTE_VER_YEAR; }
+
+unsigned int
+rte_version_month(void) { return RTE_VER_MONTH; }
+
+unsigned int
+rte_version_minor(void) { return RTE_VER_MINOR; }
+
+const char *
+rte_version_suffix(void) { return RTE_VER_SUFFIX; }
+
+unsigned int
+rte_version_release(void) { return RTE_VER_RELEASE; }
+
+const char *
+rte_version(void)
+{
+	static char version[32];
+	if (version[0] != 0)
+		return version;
+	if (strlen(RTE_VER_SUFFIX) == 0)
+		snprintf(version, sizeof(version), "%s %d.%02d.%d",
+				RTE_VER_PREFIX,
+				RTE_VER_YEAR,
+				RTE_VER_MONTH,
+				RTE_VER_MINOR);
+		else
+			snprintf(version, sizeof(version), "%s %d.%02d.%d%s%d",
+				RTE_VER_PREFIX,
+				RTE_VER_YEAR,
+				RTE_VER_MONTH,
+				RTE_VER_MINOR,
+				RTE_VER_SUFFIX,
+				RTE_VER_RELEASE);
+	return version;
+}
diff --git a/lib/librte_eal/freebsd/eal.c b/lib/librte_eal/freebsd/eal.c
index 51478358c..3f4dde6f8 100644
--- a/lib/librte_eal/freebsd/eal.c
+++ b/lib/librte_eal/freebsd/eal.c
@@ -943,6 +943,7 @@ rte_eal_init(int argc, char **argv)
 	if (!internal_conf->no_telemetry) {
 		const char *error_str = NULL;
 		if (rte_telemetry_init(rte_eal_get_runtime_dir(),
+				rte_version(),
 				&internal_conf->ctrl_cpuset, &error_str)
 				!= 0) {
 			rte_eal_init_alert(error_str);
diff --git a/lib/librte_eal/include/rte_version.h b/lib/librte_eal/include/rte_version.h
index f7a3a1ebc..2f3f727b4 100644
--- a/lib/librte_eal/include/rte_version.h
+++ b/lib/librte_eal/include/rte_version.h
@@ -28,38 +28,47 @@ extern "C" {
  * All version numbers in one to compare with RTE_VERSION_NUM()
  */
 #define RTE_VERSION RTE_VERSION_NUM( \
-			RTE_VER_YEAR, \
-			RTE_VER_MONTH, \
-			RTE_VER_MINOR, \
-			RTE_VER_RELEASE)
+			rte_version_year(), \
+			rte_version_month(), \
+			rte_version_minor(), \
+			rte_version_release())
+
+/**
+ * Function to return DPDK version prefix string
+ */
+const char *rte_version_prefix(void);
+
+/**
+ * Function to return DPDK version year
+ */
+unsigned int rte_version_year(void);
+
+/**
+ * Function to return DPDK version month
+ */
+unsigned int rte_version_month(void);
+
+/**
+ * Function to return DPDK minor version number
+ */
+unsigned int rte_version_minor(void);
+
+/**
+ * Function to return DPDK version suffix for any release candidates
+ */
+const char *rte_version_suffix(void);
+
+/**
+ * Function to return DPDK version release candidate value
+ */
+unsigned int rte_version_release(void);

 /**
  * Function returning version string
  * @return
- *     string
+ *     DPDK version string
  */
-static inline const char *
-rte_version(void)
-{
-	static char version[32];
-	if (version[0] != 0)
-		return version;
-	if (strlen(RTE_VER_SUFFIX) == 0)
-		snprintf(version, sizeof(version), "%s %d.%02d.%d",
-			RTE_VER_PREFIX,
-			RTE_VER_YEAR,
-			RTE_VER_MONTH,
-			RTE_VER_MINOR);
-	else
-		snprintf(version, sizeof(version), "%s %d.%02d.%d%s%d",
-			RTE_VER_PREFIX,
-			RTE_VER_YEAR,
-			RTE_VER_MONTH,
-			RTE_VER_MINOR,
-			RTE_VER_SUFFIX,
-			RTE_VER_RELEASE);
-	return version;
-}
+const char *rte_version(void);

 #ifdef __cplusplus
 }
diff --git a/lib/librte_eal/linux/eal.c b/lib/librte_eal/linux/eal.c
index 32b48c3de..349292611 100644
--- a/lib/librte_eal/linux/eal.c
+++ b/lib/librte_eal/linux/eal.c
@@ -1316,6 +1316,7 @@ rte_eal_init(int argc, char **argv)
 	if (!internal_conf->no_telemetry) {
 		const char *error_str = NULL;
 		if (rte_telemetry_init(rte_eal_get_runtime_dir(),
+				rte_version(),
 				&internal_conf->ctrl_cpuset, &error_str)
 				!= 0) {
 			rte_eal_init_alert(error_str);
diff --git a/lib/librte_eal/version.map b/lib/librte_eal/version.map
index fce90a112..756c60ed1 100644
--- a/lib/librte_eal/version.map
+++ b/lib/librte_eal/version.map
@@ -199,6 +199,13 @@ DPDK_21 {
 	rte_uuid_is_null;
 	rte_uuid_parse;
 	rte_uuid_unparse;
+	rte_version;
+	rte_version_minor;
+	rte_version_month;
+	rte_version_prefix;
+	rte_version_release;
+	rte_version_suffix;
+	rte_version_year;
 	rte_vfio_clear_group;
 	rte_vfio_container_create;
 	rte_vfio_container_destroy;
diff --git a/lib/librte_telemetry/rte_telemetry.h b/lib/librte_telemetry/rte_telemetry.h
index f8e54dc68..f7c8534b8 100644
--- a/lib/librte_telemetry/rte_telemetry.h
+++ b/lib/librte_telemetry/rte_telemetry.h
@@ -311,7 +311,7 @@ rte_telemetry_register_cmd(const char *cmd, telemetry_cb fn, const char *help);
  */
 __rte_internal
 int
-rte_telemetry_init(const char *runtime_dir, rte_cpuset_t *cpuset,
+rte_telemetry_init(const char *runtime_dir, const char *rte_version, rte_cpuset_t *cpuset,
 		const char **err_str);

 /**
diff --git a/lib/librte_telemetry/telemetry.c b/lib/librte_telemetry/telemetry.c
index b142729da..14b4ff5ea 100644
--- a/lib/librte_telemetry/telemetry.c
+++ b/lib/librte_telemetry/telemetry.c
@@ -15,7 +15,6 @@
 #include <rte_string_fns.h>
 #include <rte_common.h>
 #include <rte_spinlock.h>
-#include <rte_version.h>

 #include "rte_telemetry.h"
 #include "telemetry_json.h"
@@ -48,6 +47,8 @@ struct socket {
 static struct socket v2_socket; /* socket for v2 telemetry */
 static struct socket v1_socket; /* socket for v1 telemetry */
 #endif /* !RTE_EXEC_ENV_WINDOWS */
+
+static const char *telemetry_version; /* save rte_version */
 static char telemetry_log_error[1024]; /* Will contain error on init failure */
 /* list of command callbacks, with one command registered by default */
 static struct cmd_callback callbacks[TELEMETRY_MAX_CALLBACKS];
@@ -105,7 +106,7 @@ json_info(const char *cmd __rte_unused, const char *params __rte_unused,
 		struct rte_tel_data *d)
 {
 	rte_tel_data_start_dict(d);
-	rte_tel_data_add_dict_string(d, "version", rte_version());
+	rte_tel_data_add_dict_string(d, "version", telemetry_version);
 	rte_tel_data_add_dict_int(d, "pid", getpid());
 	rte_tel_data_add_dict_int(d, "max_output_len", MAX_OUTPUT_LEN);
 	return 0;
@@ -303,7 +304,7 @@ client_handler(void *sock_id)
 	char info_str[1024];
 	snprintf(info_str, sizeof(info_str),
 			"{\"version\":\"%s\",\"pid\":%d,\"max_output_len\":%d}",
-			rte_version(), getpid(), MAX_OUTPUT_LEN);
+			telemetry_version, getpid(), MAX_OUTPUT_LEN);
 	if (write(s, info_str, strlen(info_str)) < 0) {
 		close(s);
 		return NULL;
@@ -481,9 +482,10 @@ telemetry_v2_init(const char *runtime_dir, rte_cpuset_t *cpuset)
 #endif /* !RTE_EXEC_ENV_WINDOWS */

 int32_t
-rte_telemetry_init(const char *runtime_dir, rte_cpuset_t *cpuset,
-		const char **err_str)
+rte_telemetry_init(const char *runtime_dir, const char *rte_version,
+		rte_cpuset_t *cpuset, const char **err_str)
 {
+	telemetry_version = rte_version;
 #ifndef RTE_EXEC_ENV_WINDOWS
 	if (telemetry_v2_init(runtime_dir, cpuset) != 0) {
 		*err_str = telemetry_log_error;
--
2.27.0