[v4,13/18] telemetry: introduce telemetry backward compatibility

  The new telemetry will now open a socket using the old telemetry path,
to ensure backward compatibility. This is not yet initialised, as it
would clash with the existing telemetry, to be removed in a later patch.
This means that both old and new telemetry socket interfaces are
handled in a common way.

Signed-off-by: Ciara Power <ciara.power@intel.com>

---
v4: Added legacy callback typedef
---
 lib/librte_metrics/rte_metrics_telemetry.c    | 113 +++++++++
 lib/librte_telemetry/Makefile                 |   1 +
 lib/librte_telemetry/meson.build              |   2 +-
 lib/librte_telemetry/rte_telemetry_legacy.h   |  87 +++++++
 .../rte_telemetry_version.map                 |   2 +
 lib/librte_telemetry/telemetry.c              |  31 +++
 lib/librte_telemetry/telemetry_legacy.c       | 227 ++++++++++++++++++
 7 files changed, 462 insertions(+), 1 deletion(-)
 create mode 100644 lib/librte_telemetry/rte_telemetry_legacy.h
 create mode 100644 lib/librte_telemetry/telemetry_legacy.c
  

> On Apr 24, 2020, at 7:41 AM, Power, Ciara <ciara.power@intel.com> wrote:
> 
> The new telemetry will now open a socket using the old telemetry path,
> to ensure backward compatibility. This is not yet initialised, as it
> would clash with the existing telemetry, to be removed in a later patch.
> This means that both old and new telemetry socket interfaces are
> handled in a common way.
> 
> Signed-off-by: Ciara Power <ciara.power@intel.com>
> 
> ---
> v4: Added legacy callback typedef
> ---
> lib/librte_metrics/rte_metrics_telemetry.c    | 113 +++++++++
> lib/librte_telemetry/Makefile                 |   1 +
> lib/librte_telemetry/meson.build              |   2 +-
> lib/librte_telemetry/rte_telemetry_legacy.h   |  87 +++++++
> .../rte_telemetry_version.map                 |   2 +
> lib/librte_telemetry/telemetry.c              |  31 +++
> lib/librte_telemetry/telemetry_legacy.c       | 227 ++++++++++++++++++
> 7 files changed, 462 insertions(+), 1 deletion(-)
> create mode 100644 lib/librte_telemetry/rte_telemetry_legacy.h
> create mode 100644 lib/librte_telemetry/telemetry_legacy.c
> 
> diff --git a/lib/librte_metrics/rte_metrics_telemetry.c b/lib/librte_metrics/rte_metrics_telemetry.c
> index 31d505551b..49de9d74b5 100644
> --- a/lib/librte_metrics/rte_metrics_telemetry.c
> +++ b/lib/librte_metrics/rte_metrics_telemetry.c
> @@ -8,6 +8,7 @@
> #include <rte_string_fns.h>
> #ifdef RTE_LIBRTE_TELEMETRY
> #include <rte_telemetry_internal.h>
> +#include <rte_telemetry_legacy.h>
> #endif
> 
> #include "rte_metrics.h"
> @@ -417,6 +418,112 @@ rte_metrics_tel_extract_data(struct telemetry_encode_param *ep, json_t *data)
> 	return 0;
> }
> 
> +static int
> +rte_metrics_tel_initial_metrics_setup(void)
> +{
> +	int ret;
> +	rte_metrics_init(rte_socket_id());
> +
> +	if (!tel_met_data.metrics_register_done) {
> +		ret = rte_metrics_tel_reg_all_ethdev(
> +			&tel_met_data.metrics_register_done,
> +			tel_met_data.reg_index);
> +		if (ret < 0)
> +			return ret;
> +	}
> +	return 0;
> +}
> +
> +static int
> +handle_ports_all_stats_values(const char *cmd __rte_unused,
> +		const char *params __rte_unused,
> +		char *buffer, int buf_len)
> +{
> +	struct telemetry_encode_param ep;
> +	int ret, used = 0;
> +	char *json_buffer = NULL;
> +
> +	ret = rte_metrics_tel_initial_metrics_setup();
> +	if (ret < 0)
> +		return ret;
> +
> +	memset(&ep, 0, sizeof(ep));
> +	ret = rte_metrics_tel_get_port_stats_ids(&ep);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = rte_metrics_tel_get_ports_stats_json(&ep, tel_met_data.reg_index,
> +			&json_buffer);
> +	if (ret < 0)
> +		return ret;
> +
> +	used += strlcpy(buffer, json_buffer, buf_len);
> +	return used;
> +}
> +
> +static int
> +handle_global_stats_values(const char *cmd __rte_unused,
> +		const char *params __rte_unused,
> +		char *buffer, int buf_len)
> +{
> +	char *json_buffer = NULL;
> +	struct telemetry_encode_param ep = { .type = GLOBAL_STATS };
> +	int ret, used = 0;
> +
> +	ret = rte_metrics_tel_initial_metrics_setup();
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = rte_metrics_tel_encode_json_format(&ep, &json_buffer);
> +	if (ret < 0) {
> +		METRICS_LOG_ERR("JSON encode function failed");
> +		return ret;
> +	}
> +	used += strlcpy(buffer, json_buffer, buf_len);
> +	return used;
> +}
> +
> +static int
> +handle_ports_stats_values_by_name(const char *cmd __rte_unused,
> +		const char *params,
> +		char *buffer, int buf_len)
> +{
> +	char *json_buffer = NULL;
> +	struct telemetry_encode_param ep;
> +	int ret, used = 0;
> +	json_t *data;
> +	json_error_t error;
> +
> +	ret = rte_metrics_tel_initial_metrics_setup();
> +	if (ret < 0)
> +		return ret;
> +
> +	data = json_loads(params, 0, &error);
> +	if (!data) {
> +		METRICS_LOG_WARN("Could not load JSON object from data passed in : %s",
> +				error.text);
> +		return -EPERM;
> +	} else if (!json_is_object(data)) {
> +		METRICS_LOG_WARN("JSON Request data is not a JSON object");
> +		json_decref(data);
> +		return -EINVAL;
> +	}
> +
> +	ret = rte_metrics_tel_extract_data(&ep, data);
> +	if (ret < 0) {
> +		METRICS_LOG_ERR("Extract data function failed");
> +		return ret;
> +	}
> +
> +	ret = rte_metrics_tel_encode_json_format(&ep, &json_buffer);
> +	if (ret < 0) {
> +		METRICS_LOG_ERR("JSON encode function failed");
> +		return ret;
> +	}
> +	used += strlcpy(buffer, json_buffer, buf_len);
> +	return used;
> +}
> +
> RTE_INIT(metrics_ctor)
> {
> #ifdef RTE_LIBRTE_TELEMETRY
> @@ -428,6 +535,12 @@ RTE_INIT(metrics_ctor)
> 		.extract_data = rte_metrics_tel_extract_data
> 	};
> 	rte_telemetry_set_metrics_fns(&fns); /* assign them to telemetry lib */
> +	rte_telemetry_legacy_register("ports_all_stat_values", DATA_NOT_REQ,
> +			handle_ports_all_stats_values);
> +	rte_telemetry_legacy_register("global_stat_values", DATA_NOT_REQ,
> +			handle_global_stats_values);
> +	rte_telemetry_legacy_register("ports_stats_values_by_name", DATA_REQ,
> +			handle_ports_stats_values_by_name);
> #endif
> 	metrics_log_level = rte_log_register("lib.metrics");
> 	if (metrics_log_level >= 0)
> diff --git a/lib/librte_telemetry/Makefile b/lib/librte_telemetry/Makefile
> index 5457d1ed4f..260dce3e3d 100644
> --- a/lib/librte_telemetry/Makefile
> +++ b/lib/librte_telemetry/Makefile
> @@ -25,6 +25,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += rte_telemetry_parser.c
> SRCS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += rte_telemetry_parser_test.c
> SRCS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += telemetry.c
> SRCS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += telemetry_data.c
> +SRCS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += telemetry_legacy.c
> 
> # export include files
> SYMLINK-$(CONFIG_RTE_LIBRTE_TELEMETRY)-include := rte_telemetry.h
> diff --git a/lib/librte_telemetry/meson.build b/lib/librte_telemetry/meson.build
> index 80926936a5..5bcef6c81f 100644
> --- a/lib/librte_telemetry/meson.build
> +++ b/lib/librte_telemetry/meson.build
> @@ -4,7 +4,7 @@
> includes = [global_inc]
> 
> sources = files('rte_telemetry.c', 'rte_telemetry_parser.c', 'rte_telemetry_parser_test.c',
> -	'telemetry.c', 'telemetry_data.c')
> +	'telemetry.c', 'telemetry_data.c', 'telemetry_legacy.c')
> headers = files('rte_telemetry.h', 'rte_telemetry_internal.h', 'rte_telemetry_parser.h')
> includes += include_directories('../librte_metrics')
> 
> diff --git a/lib/librte_telemetry/rte_telemetry_legacy.h b/lib/librte_telemetry/rte_telemetry_legacy.h
> new file mode 100644
> index 0000000000..c83f9a8d90
> --- /dev/null
> +++ b/lib/librte_telemetry/rte_telemetry_legacy.h
> @@ -0,0 +1,87 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#ifndef _RTE_TELEMETRY_LEGACY_H_
> +#define _RTE_TELEMETRY_LEGACY_H_
> +
> +#include <rte_compat.h>
> +#include "rte_telemetry.h"
> +
> +/**
> + * @internal
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice
> +
> + * @file
> + * RTE Telemetry Legacy
> + *
> + ***/
> +
> +/**
> + * @internal
> + * Value representing if data is required for the command
> + */
> +enum rte_telemetry_legacy_data_req {
> +	DATA_NOT_REQ = 0,
> +	DATA_REQ
> +};
> +
> +/**
> + * This telemetry callback is used when registering a legacy telemetry command.
> + * It handles getting and formatting stats to be returned to telemetry when
> + * requested. Stats up to buf_len in length are put in the buffer.
> + *
> + * @param cmd
> + * The cmd that was requested by the client.
> + * @param params
> + * Contains data required by the callback function.
> + * @param buffer
> + * A buffer to hold the formatted response.
> + * @param buf_len
> + * Length of the buffer.
> + *
> + * @return
> + * Length of buffer used on success.
> + * @return
> + * Negative integer on error.
> + */
> +typedef int (*telemetry_legacy_cb)(const char *cmd, const char *params,
> +		char *buffer, int buf_len);
> +
> +/**
> + * @internal
> + * Counter for the number of registered legacy callbacks
> + */
> +extern int num_legacy_callbacks;
> +
> +/**
> + * @internal
> + * Used for handling data received over the legacy telemetry socket.
> + *
> + * @return
> + * Void.
> + */
> +void *
> +legacy_client_handler(void *sock_id);
> +
> +/**
> + * @internal
> + *
> + * Used when registering a command and callback function with
> + * telemetry legacy support.
> + *
> + * @return
> + *  0 on success.
> + * @return
> + *  -EINVAL for invalid parameters failure.
> + *  @return
> + *  -ENOENT if max callbacks limit has been reached.
> + */
> +__rte_experimental
> +int
> +rte_telemetry_legacy_register(const char *cmd,
> +		enum rte_telemetry_legacy_data_req data_req,
> +		telemetry_legacy_cb fn);
> +
> +#endif
> diff --git a/lib/librte_telemetry/rte_telemetry_version.map b/lib/librte_telemetry/rte_telemetry_version.map
> index e433ce58b7..36eac75c4e 100644
> --- a/lib/librte_telemetry/rte_telemetry_version.map
> +++ b/lib/librte_telemetry/rte_telemetry_version.map
> @@ -17,6 +17,8 @@ EXPERIMENTAL {
> 	rte_tel_data_start_array;
> 	rte_tel_data_start_dict;
> 	rte_tel_data_string;
> +	rte_telemetry_legacy_init;
> +	rte_telemetry_legacy_register;
> 
> 	local: *;
> };
> diff --git a/lib/librte_telemetry/telemetry.c b/lib/librte_telemetry/telemetry.c
> index 63986378d8..f7e51be07c 100644
> --- a/lib/librte_telemetry/telemetry.c
> +++ b/lib/librte_telemetry/telemetry.c
> @@ -18,6 +18,7 @@
> #include "rte_telemetry.h"
> #include "telemetry_json.h"
> #include "telemetry_data.h"
> +#include "rte_telemetry_legacy.h"
> 
> #define MAX_CMD_LEN 56
> #define MAX_HELP_LEN 64
> @@ -38,6 +39,7 @@ struct socket {
> 	handler fn;
> };
> static struct socket v2_socket; /* socket for v2 telemetry */
> +static struct socket v1_socket; /* socket for v1 telemetry */
> 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];
> @@ -298,6 +300,8 @@ unlink_sockets(void)
> {
> 	if (v2_socket.path[0])
> 		unlink(v2_socket.path);
> +	if (v1_socket.path[0])
> +		unlink(v1_socket.path);
> }
> 
> static int
> @@ -337,6 +341,33 @@ create_socket(char *path)
> 	return -1;
> }
> 
> +static int __rte_unused /* will be used in future commit */
> +telemetry_legacy_init(const char *runtime_dir)
> +{
> +	pthread_t t_old;
> +
> +	if (num_legacy_callbacks == 1) {
> +		snprintf(telemetry_log_error, sizeof(telemetry_log_error),
> +			 "No legacy callbacks, legacy socket not created");
> +		return -1;
> +	}
> +
> +	v1_socket.fn = legacy_client_handler;
> +	if ((size_t) snprintf(v1_socket.path, sizeof(v1_socket.path),
> +			"%s/telemetry", runtime_dir)
> +			>= sizeof(v1_socket.path)) {
> +		snprintf(telemetry_log_error, sizeof(telemetry_log_error),
> +				"Error with socket binding, path too long");
> +		return -1;
> +	}
> +	v1_socket.sock = create_socket(v1_socket.path);
> +	if (v1_socket.sock < 0)
> +		return -1;
> +	pthread_create(&t_old, NULL, socket_listener, &v1_socket);
> +
> +	return 0;
> +}
> +
> static int
> telemetry_v2_init(const char *runtime_dir)
> {
> diff --git a/lib/librte_telemetry/telemetry_legacy.c b/lib/librte_telemetry/telemetry_legacy.c
> new file mode 100644
> index 0000000000..bdf7492cda
> --- /dev/null
> +++ b/lib/librte_telemetry/telemetry_legacy.c
> @@ -0,0 +1,227 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#include <unistd.h>
> +#include <sys/socket.h>
> +#include <sys/un.h>
> +#include <pthread.h>
> +
> +/* we won't link against libbsd, so just always use DPDKs-specific strlcpy */
> +#undef RTE_USE_LIBBSD
> +#include <rte_string_fns.h>
> +#include <rte_common.h>
> +#include <rte_spinlock.h>
> +
> +#include "rte_telemetry_legacy.h"
> +
> +#define MAX_LEN 128
> +#define BUF_SIZE 1024
> +#define CLIENTS_UNREG_ACTION "\"action\":2"
> +#define CLIENTS_CMD "\"command\":\"clients\""
> +#define CLIENTS_DATA "\"data\":{\"client_path\":\""
> +#define STATS_ACTION "\"action\":0"
> +#define DATA_REQ_LABEL "\"data\":"
> +#define TELEMETRY_LEGACY_MAX_CALLBACKS 4
> +
> +
> +static int
> +register_client(const char *cmd __rte_unused,
> +		const char *params __rte_unused,
> +		char *buffer, int buf_len);
> +
> +struct json_command {
> +	char action[MAX_LEN];
> +	char cmd[MAX_LEN];
> +	char data[MAX_LEN];
> +	telemetry_legacy_cb fn;
> +
> +};
> +
> +struct json_command callbacks[TELEMETRY_LEGACY_MAX_CALLBACKS] = {
> +		{
> +			.action = "\"action\":1",
> +			.cmd = CLIENTS_CMD,
> +			.data = CLIENTS_DATA,
> +			.fn = register_client
> +		}
> +};
> +int num_legacy_callbacks = 1;
> +static rte_spinlock_t callback_sl = RTE_SPINLOCK_INITIALIZER;
> +
> +int
> +rte_telemetry_legacy_register(const char *cmd,
> +		enum rte_telemetry_legacy_data_req data_req,
> +		telemetry_legacy_cb fn)
> +{
> +	if (fn == NULL)
> +		return -EINVAL;
> +	if (num_legacy_callbacks >= (int) RTE_DIM(callbacks))
> +		return -ENOENT;
> +
> +	rte_spinlock_lock(&callback_sl);
> +	strlcpy(callbacks[num_legacy_callbacks].action, STATS_ACTION, MAX_LEN);
> +	snprintf(callbacks[num_legacy_callbacks].cmd, MAX_LEN,
> +			"\"command\":\"%s\"", cmd);
> +	snprintf(callbacks[num_legacy_callbacks].data, MAX_LEN,
> +			data_req ? "%s{\"" : "%snull",
> +			DATA_REQ_LABEL);
> +	callbacks[num_legacy_callbacks].fn = fn;
> +	num_legacy_callbacks++;
> +	rte_spinlock_unlock(&callback_sl);
> +
> +	return 0;
> +}
> +
> +static int
> +register_client(const char *cmd __rte_unused, const char *params,
> +		char *buffer __rte_unused, int buf_len __rte_unused)
> +{
> +	pthread_t th;
> +	char data[BUF_SIZE];
> +	int fd;
> +	struct sockaddr_un addrs;
> +
> +	strlcpy(data, strchr(params, ':'), sizeof(data));
> +	memcpy(data, &data[strlen(":\"")], strlen(data));
> +	*strchr(data, '\"') = 0;
> +
> +	fd = socket(AF_UNIX, SOCK_SEQPACKET, 0);
> +	addrs.sun_family = AF_UNIX;
> +	strlcpy(addrs.sun_path, data, sizeof(addrs.sun_path));
> +
> +	if (connect(fd, (struct sockaddr *)&addrs, sizeof(addrs)) == -1) {
> +		perror("\nClient connection error\n");
> +		return -1;
> +	}
> +	pthread_create(&th, NULL, &legacy_client_handler,
> +			(void *)(uintptr_t)fd);
> +	return 0;
> +}
> +
> +static int
> +send_error_response(int s, int err)
> +{
> +	const char *desc;
> +	char out_buf[100000];
> +
> +	switch (err) {
> +	case -ENOMEM:
> +		desc = "Memory Allocation Error";
> +		break;
> +	case -EINVAL:
> +		desc = "Invalid Argument 404";
> +		break;
> +	case -EPERM:
> +		desc = "Unknown";
> +		break;
> +	default:
> +		/* Default case keeps behaviour of Telemetry library */
> +		printf("\nInvalid error type: %d\n", err);
> +		return -EINVAL;
> +	}
> +	int used = snprintf(out_buf, sizeof(out_buf), "{\"status_code\": "
> +			"\"Status Error: %s\", \"data\": null}", desc);
> +	if (write(s, out_buf, used) < 0) {
> +		perror("Error writing to socket");
> +		return -1;
> +	}
> +	return 0;
> +}
> +
> +static void
> +perform_command(telemetry_legacy_cb fn, const char *param, int s)
> +{
> +	char out_buf[100000];
> +	int ret, used = 0;
> +
> +	ret = fn("", param, out_buf, sizeof(out_buf));
> +	if (ret < 0) {
> +		ret = send_error_response(s, ret);
> +		if (ret < 0)
> +			printf("\nCould not send error response\n");
> +		return;
> +	}
> +	used += ret;
> +	if (write(s, out_buf, used) < 0)
> +		perror("Error writing to socket");
> +}
> +
> +static int
> +parse_client_request(char *buffer, int buf_len, int s)
> +{
> +	int i;
> +	char *data = buffer + buf_len;
> +	telemetry_legacy_cb fn = NULL;
> +	const char *valid_sep = ",}";
> +	if (buffer[0] != '{' || buffer[buf_len - 1] != '}')
> +		return -EPERM;
> +
> +	if (strstr(buffer, CLIENTS_UNREG_ACTION) && strstr(buffer, CLIENTS_CMD)
> +			&& strstr(buffer, CLIENTS_DATA))
> +		return 0;
> +
> +	for (i = 0; i < num_legacy_callbacks; i++) {
> +		char *action_ptr = strstr(buffer, callbacks[i].action);
> +		char *cmd_ptr = strstr(buffer, callbacks[i].cmd);
> +		char *data_ptr = strstr(buffer, callbacks[i].data);
> +		if (!action_ptr || !cmd_ptr || !data_ptr)
> +			continue;
> +
> +		char action_sep = action_ptr[strlen(callbacks[i].action)];
> +		char cmd_sep = cmd_ptr[strlen(callbacks[i].cmd)];
> +		if (!(strchr(valid_sep, action_sep) && strchr(valid_sep,
> +				cmd_sep)))
> +			return -EPERM;
> +		char data_sep;
> +
> +		if (!strchr(data_ptr, '{'))
> +			data_sep = data_ptr[strlen(callbacks[i].data)];
> +		else {
> +			char *data_end = strchr(data_ptr, '}');
> +			data = data_ptr + strlen(DATA_REQ_LABEL);
> +			data_sep = data_end[1];
> +			data_end[1] = 0;
> +		}
> +		if (!strchr(valid_sep, data_sep))
> +			return -EPERM;
> +		fn = callbacks[i].fn;
> +		break;
> +	}
> +
> +	if (!fn)
> +		return -EINVAL;
> +	perform_command(fn, data, s);
> +	return 0;
> +}
> +
> +void *
> +legacy_client_handler(void *sock_id)
> +{
> +	int s = (int)(uintptr_t)sock_id;
> +	int ret;
> +	char buffer_recv[BUF_SIZE];
> +	/* receive data is not null terminated */
> +	int bytes = read(s, buffer_recv, sizeof(buffer_recv));
> +	buffer_recv[bytes] = 0;

Same here bytes could be negative.
> +
> +	while (bytes > 0) {
> +		int i, j;
> +		char buffer[BUF_SIZE];
> +		for (i = 0, j = 0; buffer_recv[i] != '\0'; i++) {
> +			buffer[j] = buffer_recv[i];
> +			j += !isspace(buffer_recv[i]);
> +		}
> +		buffer[j] = 0;
> +		ret = parse_client_request(buffer, j, s);
> +		if (ret < 0) {
> +			ret = send_error_response(s, ret);
> +			if (ret < 0)
> +				printf("\nCould not send error response\n");
> +		}
> +		bytes = read(s, buffer_recv, sizeof(buffer_recv));
> +		buffer_recv[bytes] = 0;

Same here negative return value.
> +	}
> +	close(s);
> +	return NULL;
> +}
> -- 
> 2.17.1
>