[dpdk-dev] [PATCH v5 07/10] examples/power: add json string handling

[David Hunt <david.hunt@intel.com>]

Add JSON string handling to vm_power_manager for JSON strings received
through the fifo. The format of the JSON strings are detailed in the
next patch, the vm_power_manager user guide documentation updates.

This patch introduces a new dependency on Jansson, a C library for
encoding, decoding and manipulating JSON data. To compile the sample app
you now need to have installed libjansson4 and libjansson-dev (these may
be named slightly differently depending on your Operating System)

Signed-off-by: David Hunt <david.hunt@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 examples/vm_power_manager/Makefile          |   6 +
 examples/vm_power_manager/channel_monitor.c | 269 ++++++++++++++++++--
 2 files changed, 250 insertions(+), 25 deletions(-)

diff --git a/examples/vm_power_manager/Makefile b/examples/vm_power_manager/Makefile
index 13a5205ba..50147c05d 100644
--- a/examples/vm_power_manager/Makefile
+++ b/examples/vm_power_manager/Makefile
@@ -31,6 +31,12 @@ CFLAGS += $(WERROR_FLAGS)
 
 LDLIBS += -lvirt
 
+JANSSON := $(shell pkg-config --exists jansson; echo $$?)
+ifeq ($(JANSSON), 0)
+LDLIBS += $(shell pkg-config --libs jansson)
+CFLAGS += -DUSE_JANSSON
+endif
+
 ifeq ($(CONFIG_RTE_BUILD_SHARED_LIB),y)
 
 ifeq ($(CONFIG_RTE_LIBRTE_IXGBE_PMD),y)
diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
index 53a4efe45..73a0451f3 100644
--- a/examples/vm_power_manager/channel_monitor.c
+++ b/examples/vm_power_manager/channel_monitor.c
@@ -9,11 +9,18 @@
 #include <signal.h>
 #include <errno.h>
 #include <string.h>
+#include <fcntl.h>
 #include <sys/types.h>
 #include <sys/epoll.h>
 #include <sys/queue.h>
 #include <sys/time.h>
-
+#include <sys/socket.h>
+#include <sys/select.h>
+#ifdef USE_JANSSON
+#include <jansson.h>
+#else
+#pragma message "Jansson dev libs unavailable, not including JSON parsing"
+#endif
 #include <rte_log.h>
 #include <rte_memory.h>
 #include <rte_malloc.h>
@@ -35,6 +42,8 @@
 
 uint64_t vsi_pkt_count_prev[384];
 uint64_t rdtsc_prev[384];
+#define MAX_JSON_STRING_LEN 1024
+char json_data[MAX_JSON_STRING_LEN];
 
 double time_period_ms = 1;
 static volatile unsigned run_loop = 1;
@@ -43,6 +52,132 @@ static unsigned int policy_is_set;
 static struct epoll_event *global_events_list;
 static struct policy policies[MAX_CLIENTS];
 
+#ifdef USE_JANSSON
+static int
+parse_json_to_pkt(json_t *element, struct channel_packet *pkt)
+{
+	const char *key;
+	json_t *value;
+	int ret;
+
+	memset(pkt, 0, sizeof(struct channel_packet));
+
+	pkt->nb_mac_to_monitor = 0;
+	pkt->t_boost_status.tbEnabled = false;
+	pkt->workload = LOW;
+	pkt->policy_to_use = TIME;
+	pkt->command = PKT_POLICY;
+	pkt->core_type = CORE_TYPE_PHYSICAL;
+
+	json_object_foreach(element, key, value) {
+		if (!strcmp(key, "policy")) {
+			/* Recurse in to get the contents of profile */
+			ret = parse_json_to_pkt(value, pkt);
+			if (ret)
+				return ret;
+		} else if (!strcmp(key, "instruction")) {
+			/* Recurse in to get the contents of instruction */
+			ret = parse_json_to_pkt(value, pkt);
+			if (ret)
+				return ret;
+		} else if (!strcmp(key, "name")) {
+			strcpy(pkt->vm_name, json_string_value(value));
+		} else if (!strcmp(key, "command")) {
+			char command[32];
+			snprintf(command, 32, "%s", json_string_value(value));
+			if (!strcmp(command, "power")) {
+				pkt->command = CPU_POWER;
+			} else if (!strcmp(command, "create")) {
+				pkt->command = PKT_POLICY;
+			} else if (!strcmp(command, "destroy")) {
+				pkt->command = PKT_POLICY_REMOVE;
+			} else {
+				RTE_LOG(ERR, CHANNEL_MONITOR,
+					"Invalid command received in JSON\n");
+				return -1;
+			}
+		} else if (!strcmp(key, "policy_type")) {
+			char command[32];
+			snprintf(command, 32, "%s", json_string_value(value));
+			if (!strcmp(command, "TIME")) {
+				pkt->policy_to_use = TIME;
+			} else if (!strcmp(command, "TRAFFIC")) {
+				pkt->policy_to_use = TRAFFIC;
+			} else if (!strcmp(command, "WORKLOAD")) {
+				pkt->policy_to_use = WORKLOAD;
+			} else if (!strcmp(command, "BRANCH_RATIO")) {
+				pkt->policy_to_use = BRANCH_RATIO;
+			} else {
+				RTE_LOG(ERR, CHANNEL_MONITOR,
+					"Wrong policy_type received in JSON\n");
+				return -1;
+			}
+		} else if (!strcmp(key, "busy_hours")) {
+			unsigned int i;
+			size_t size = json_array_size(value);
+
+			for (i = 0; i < size; i++) {
+				int hour = (int)json_integer_value(
+						json_array_get(value, i));
+				pkt->timer_policy.busy_hours[i] = hour;
+			}
+		} else if (!strcmp(key, "quiet_hours")) {
+			unsigned int i;
+			size_t size = json_array_size(value);
+
+			for (i = 0; i < size; i++) {
+				int hour = (int)json_integer_value(
+						json_array_get(value, i));
+				pkt->timer_policy.quiet_hours[i] = hour;
+			}
+		} else if (!strcmp(key, "core_list")) {
+			unsigned int i;
+			size_t size = json_array_size(value);
+
+			for (i = 0; i < size; i++) {
+				int core = (int)json_integer_value(
+						json_array_get(value, i));
+				pkt->vcpu_to_control[i] = core;
+			}
+			pkt->num_vcpu = size;
+		} else if (!strcmp(key, "avg_packet_thresh")) {
+			pkt->traffic_policy.avg_max_packet_thresh =
+					(uint32_t)json_integer_value(value);
+		} else if (!strcmp(key, "max_packet_thresh")) {
+			pkt->traffic_policy.max_max_packet_thresh =
+					(uint32_t)json_integer_value(value);
+		} else if (!strcmp(key, "unit")) {
+			char unit[32];
+			snprintf(unit, 32, "%s", json_string_value(value));
+			if (!strcmp(unit, "SCALE_UP")) {
+				pkt->unit = CPU_POWER_SCALE_UP;
+			} else if (!strcmp(unit, "SCALE_DOWN")) {
+				pkt->unit = CPU_POWER_SCALE_DOWN;
+			} else if (!strcmp(unit, "SCALE_MAX")) {
+				pkt->unit = CPU_POWER_SCALE_MAX;
+			} else if (!strcmp(unit, "SCALE_MIN")) {
+				pkt->unit = CPU_POWER_SCALE_MIN;
+			} else if (!strcmp(unit, "ENABLE_TURBO")) {
+				pkt->unit = CPU_POWER_ENABLE_TURBO;
+			} else if (!strcmp(unit, "DISABLE_TURBO")) {
+				pkt->unit = CPU_POWER_DISABLE_TURBO;
+			} else {
+				RTE_LOG(ERR, CHANNEL_MONITOR,
+					"Invalid command received in JSON\n");
+				return -1;
+			}
+		} else if (!strcmp(key, "resource_id")) {
+			pkt->resource_id = (uint32_t)json_integer_value(value);
+		} else {
+			RTE_LOG(ERR, CHANNEL_MONITOR,
+				"Unknown key received in JSON string: %s\n",
+				key);
+		}
+	}
+	return 0;
+}
+#endif
+
 void channel_monitor_exit(void)
 {
 	run_loop = 0;
@@ -555,6 +690,103 @@ channel_monitor_init(void)
 	return 0;
 }
 
+static void
+read_binary_packet(struct channel_info *chan_info)
+{
+	struct channel_packet pkt;
+	void *buffer = &pkt;
+	int buffer_len = sizeof(pkt);
+	int n_bytes, err = 0;
+
+	while (buffer_len > 0) {
+		n_bytes = read(chan_info->fd,
+				buffer, buffer_len);
+		if (n_bytes == buffer_len)
+			break;
+		if (n_bytes == -1) {
+			err = errno;
+			RTE_LOG(DEBUG, CHANNEL_MONITOR,
+				"Received error on "
+				"channel '%s' read: %s\n",
+				chan_info->channel_path,
+				strerror(err));
+			remove_channel(&chan_info);
+			break;
+		}
+		buffer = (char *)buffer + n_bytes;
+		buffer_len -= n_bytes;
+	}
+	if (!err)
+		process_request(&pkt, chan_info);
+}
+
+#ifdef USE_JANSSON
+static void
+read_json_packet(struct channel_info *chan_info)
+{
+	struct channel_packet pkt;
+	int n_bytes, ret;
+	json_t *root;
+	json_error_t error;
+
+	/* read opening brace to closing brace */
+	do {
+		int idx = 0;
+		int indent = 0;
+		do {
+			n_bytes = read(chan_info->fd, &json_data[idx], 1);
+			if (n_bytes == 0)
+				break;
+			if (json_data[idx] == '{')
+				indent++;
+			if (json_data[idx] == '}')
+				indent--;
+			if ((indent > 0) || (idx > 0))
+				idx++;
+			if (indent == 0)
+				json_data[idx] = 0;
+			if (idx >= MAX_JSON_STRING_LEN-1)
+				break;
+		} while (indent > 0);
+
+		if (indent > 0)
+			/*
+			 * We've broken out of the read loop without getting
+			 * a closing brace, so throw away the data
+			 */
+			json_data[idx] = 0;
+
+		if (strlen(json_data) == 0)
+			continue;
+
+		printf("got [%s]\n", json_data);
+
+		root = json_loads(json_data, 0, &error);
+
+		if (root) {
+			/*
+			 * Because our data is now in the json
+			 * object, we can overwrite the pkt
+			 * with a channel_packet struct, using
+			 * parse_json_to_pkt()
+			 */
+			ret = parse_json_to_pkt(root, &pkt);
+			json_decref(root);
+			if (ret) {
+				RTE_LOG(ERR, CHANNEL_MONITOR,
+					"Error validating JSON profile data\n");
+				break;
+			}
+			process_request(&pkt, chan_info);
+		} else {
+			RTE_LOG(ERR, CHANNEL_MONITOR,
+					"JSON error on line %d: %s\n",
+					error.line, error.text);
+		}
+	} while (n_bytes > 0);
+}
+#endif
+
 void
 run_channel_monitor(void)
 {
@@ -578,31 +810,18 @@ run_channel_monitor(void)
 			}
 			if (global_events_list[i].events & EPOLLIN) {
 
-				int n_bytes, err = 0;
-				struct channel_packet pkt;
-				void *buffer = &pkt;
-				int buffer_len = sizeof(pkt);
-
-				while (buffer_len > 0) {
-					n_bytes = read(chan_info->fd,
-							buffer, buffer_len);
-					if (n_bytes == buffer_len)
-						break;
-					if (n_bytes == -1) {
-						err = errno;
-						RTE_LOG(DEBUG, CHANNEL_MONITOR,
-							"Received error on "
-							"channel '%s' read: %s\n",
-							chan_info->channel_path,
-							strerror(err));
-						remove_channel(&chan_info);
-						break;
-					}
-					buffer = (char *)buffer + n_bytes;
-					buffer_len -= n_bytes;
+				switch (chan_info->type) {
+				case CHANNEL_TYPE_BINARY:
+					read_binary_packet(chan_info);
+					break;
+#ifdef USE_JANSSON
+				case CHANNEL_TYPE_JSON:
+					read_json_packet(chan_info);
+					break;
+#endif
+				default:
+					break;
 				}
-				if (!err)
-					process_request(&pkt, chan_info);
 			}
 		}
 		rte_delay_us(time_period_ms*1000);
-- 
2.17.1