[dpdk-dev] [PATCH 12/12] eal: add eal telemetry callbacks

[Ciara Power <ciara.power@intel.com>]

From: Bruce Richardson <bruce.richardson@intel.com>

EAL now registers commands to provide some basic info from EAL.

Example:
Connecting to /var/run/dpdk/rte/dpdk_telemetry.66307
--> /
{"/": ["/", "/eal/app_params", "/eal/params", "/eal/version",
 "/ethdev/list", "/ethdev/stats", "/rawdev/list", "/rawdev/stats"]}
--> /eal/app_params
{"/eal/app_params": ["-i"]}
--> /eal/params
{"/eal/params": ["./app/dpdk-testpmd", "--telemetry"]}
--> /eal/version
{"/eal/version": "DPDK 20.05.0-rc0"}

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: Ciara Power <ciara.power@intel.com>
---
 lib/librte_eal/common/eal_common_options.c | 70 ++++++++++++++++++++++
 lib/librte_eal/common/eal_options.h        |  3 +
 lib/librte_eal/freebsd/eal/eal.c           |  5 ++
 lib/librte_eal/linux/eal/eal.c             |  5 ++
 4 files changed, 83 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 386566b3d..78cd1f825 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -29,6 +29,7 @@
 #include <rte_version.h>
 #include <rte_devargs.h>
 #include <rte_memcpy.h>
+#include <rte_telemetry.h>
 
 #include "eal_internal_cfg.h"
 #include "eal_options.h"
@@ -132,6 +133,75 @@ static int master_lcore_parsed;
 static int mem_parsed;
 static int core_parsed;
 
+static char **eal_args;
+static char **eal_app_args;
+
+#define EAL_PARAM_REQ "/eal/params"
+#define EAL_APP_PARAM_REQ "/eal/app_params"
+
+/* callback handler for telemetry library to report out EAL flags */
+int
+handle_eal_info_request(const char *cmd, const char *params __rte_unused,
+		char *buffer, int buf_len)
+{
+	char **args;
+	int used = 0;
+	int i = 0;
+
+	if (strcmp(cmd, EAL_PARAM_REQ) == 0)
+		args = eal_args;
+	else if (strcmp(cmd, EAL_APP_PARAM_REQ) == 0)
+		args = eal_app_args;
+	else /* version */
+		return snprintf(buffer, buf_len, "\"%s\"", rte_version());
+
+	if (args == NULL || args[0] == NULL)
+		return snprintf(buffer, buf_len, "[]"); /* empty list */
+
+	used = strlcpy(buffer, "[", buf_len);
+	while (args[i] != NULL)
+		used += snprintf(buffer + used, buf_len - used, "\"%s\",",
+				args[i++]);
+	buffer[used - 1] = ']';
+	return used;
+}
+
+int
+eal_save_args(int argc, char **argv)
+{
+	int i, j;
+
+	/* clone argv to report out later. We overprovision, but
+	 * this does not waste huge amounts of memory
+	 */
+	eal_args = calloc(argc + 1, sizeof(*eal_args));
+	if (eal_args == NULL)
+		return -1;
+
+	for (i = 0; i < argc; i++) {
+		eal_args[i] = strdup(argv[i]);
+		if (strcmp(argv[i], "--") == 0)
+			break;
+	}
+	eal_args[i++] = NULL; /* always finish with NULL */
+	rte_telemetry_register_cmd(EAL_PARAM_REQ, handle_eal_info_request);
+
+	/* allow reporting of any app args we know about too */
+	if (i == argc)
+		return 0;
+
+	eal_app_args = calloc(argc - i + 1, sizeof(*eal_args));
+	if (eal_app_args == NULL)
+		return -1;
+
+	for (j = 0; i < argc; j++, i++)
+		eal_app_args[j] = strdup(argv[i]);
+	eal_app_args[j] = NULL;
+	rte_telemetry_register_cmd(EAL_APP_PARAM_REQ, handle_eal_info_request);
+
+	return 0;
+}
+
 static int
 eal_option_device_add(enum rte_devtype type, const char *optarg)
 {
diff --git a/lib/librte_eal/common/eal_options.h b/lib/librte_eal/common/eal_options.h
index 225ad4bb5..5373e9f5e 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -88,5 +88,8 @@ int eal_check_common_options(struct internal_config *internal_cfg);
 void eal_common_usage(void);
 enum rte_proc_type_t eal_proc_type_detect(void);
 int eal_plugins_init(void);
+int eal_save_args(int argc, char **argv);
+int handle_eal_info_request(const char *cmd, const char *params __rte_unused,
+		char *buffer, int buf_len);
 
 #endif /* EAL_OPTIONS_H */
diff --git a/lib/librte_eal/freebsd/eal/eal.c b/lib/librte_eal/freebsd/eal/eal.c
index 54acafc31..e18bf59f9 100644
--- a/lib/librte_eal/freebsd/eal/eal.c
+++ b/lib/librte_eal/freebsd/eal/eal.c
@@ -725,6 +725,9 @@ rte_eal_init(int argc, char **argv)
 
 	eal_reset_internal_config(&internal_config);
 
+	/* clone argv to report out later in telemetry */
+	eal_save_args(argc, argv);
+
 	/* set log level as early as possible */
 	eal_log_level_parse(argc, argv);
 
@@ -960,6 +963,8 @@ rte_eal_init(int argc, char **argv)
 			rte_eal_init_alert(error_str);
 			return -1;
 		}
+		rte_telemetry_register_cmd("/eal/version",
+				handle_eal_info_request);
 	}
 
 	eal_mcfg_complete();
diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
index 8eeffe9aa..a68b66a1e 100644
--- a/lib/librte_eal/linux/eal/eal.c
+++ b/lib/librte_eal/linux/eal/eal.c
@@ -992,6 +992,9 @@ rte_eal_init(int argc, char **argv)
 	/* set log level as early as possible */
 	eal_log_level_parse(argc, argv);
 
+	/* clone argv to report out later in telemetry */
+	eal_save_args(argc, argv);
+
 	if (rte_eal_cpu_init() < 0) {
 		rte_eal_init_alert("Cannot detect lcores.");
 		rte_errno = ENOTSUP;
@@ -1299,6 +1302,8 @@ rte_eal_init(int argc, char **argv)
 			rte_eal_init_alert(error_str);
 			return -1;
 		}
+		rte_telemetry_register_cmd("/eal/version",
+				handle_eal_info_request);
 	}
 
 	eal_mcfg_complete();
-- 
2.17.1