JSON load balancer config file

examples/load_balancer/load_balancer.c

@@ -69,10 +69,14 @@
 #include "onvm_flow_table.h"
 #include "onvm_nflib.h"
 #include "onvm_pkt_helper.h"
+#include "onvm_config_common.h"
+#include "cJSON.h"
 
 #define NF_TAG "load_balancer"
 #define TABLE_SIZE 65536
 
+enum lb_policy {RROBIN, RANDOM, WEIGHTED_RANDOM};
+
 /* Struct for load balancer information */
 struct loadbalance {
         struct onvm_ft *ft;
@@ -95,6 +99,14 @@ struct loadbalance {
 
         /* config file */
         char *cfg_filename;
+
+        /* LB policy */
+        // char *policy;
+        enum lb_policy policy;
+
+        /* structures to store server weights */
+        int *weights;
+        int total_weight;
 };
 
 /* Struct for backend servers */
@@ -115,6 +127,9 @@ struct loadbalance *lb;
 /* number of package between each print */
 static uint32_t print_delay = 1000000;
 
+/* switch for turning on debug mode */
+static int debug_mode = 0;
+
 /* onvm struct for port info lookup */
 extern struct port_info *ports;
 
@@ -136,6 +151,7 @@ usage(const char *progname) {
         printf(" - `-t SERVER_PORT` : server port ID\n");
         printf(" - `-f SERVER_CONFIG` : backend server config file\n");
         printf(" - `-p <print_delay>`: number of packets between each print, e.g. `-p 1` prints every packets.\n");
+        printf(" - `-d`: debug info including when connections are recieved and when packets are recieved.\n");
 }
 
 /*
@@ -164,7 +180,7 @@ parse_app_args(int argc, char *argv[], const char *progname) {
         lb->client_port = RTE_MAX_ETHPORTS;
         lb->server_port = RTE_MAX_ETHPORTS;
 
-        while ((c = getopt(argc, argv, "c:r:s:t:f:p:")) != -1) {
+        while ((c = getopt(argc, argv, "c:r:s:t:f:p:d")) != -1) {
                 switch (c) {
                         case 'c':
                                 ret = parse_iface_ip(strdup(optarg), &lb->ip_lb_client);
@@ -192,11 +208,12 @@ parse_app_args(int argc, char *argv[], const char *progname) {
                         case 'p':
                                 print_delay = strtoul(optarg, NULL, 10);
                                 break;
+                        case 'd':
+                                debug_mode = 1;
+                                break;
                         case '?':
                                 usage(progname);
-                                if (optopt == 'd')
-                                        RTE_LOG(INFO, APP, "Option -%c requires an argument.\n", optopt);
-                                else if (optopt == 'p')
+                                if (optopt == 'p')
                                         RTE_LOG(INFO, APP, "Option -%c requires an argument.\n", optopt);
                                 else if (isprint(optopt))
                                         RTE_LOG(INFO, APP, "Unknown option `-%c'.\n", optopt);
@@ -240,49 +257,81 @@ parse_app_args(int argc, char *argv[], const char *progname) {
 /*
  * This function parses the backend config. It takes the filename
  * and fills up the backend_server array. This includes the mac and ip
- * address of the backend servers
+ * address of the backend servers as well as their weights
  */
 static int
-parse_backend_config(void) {
-        int ret, temp, i;
-        char ip[32];
-        char mac[32];
-        FILE *cfg;
+parse_backend_json_config(void) {
+        int ret, i;
+        i = 0;
 
-        cfg = fopen(lb->cfg_filename, "r");
-        if (cfg == NULL) {
-                rte_exit(EXIT_FAILURE, "Error openning server \'%s\' config\n", lb->cfg_filename);
-        }
-        ret = fscanf(cfg, "%*s %d", &temp);
-        if (temp <= 0) {
-                rte_exit(EXIT_FAILURE, "Error parsing config, need at least one server configurations\n");
+        cJSON *config_json = onvm_config_parse_file(lb->cfg_filename);
+        cJSON *list_size = NULL;
+        cJSON *policy = NULL;
+        cJSON *ip_addr = NULL;
+        cJSON *mac_addr = NULL;
+        cJSON *weight = NULL;
+
+        if (config_json == NULL) {
+                rte_exit(EXIT_FAILURE, "%s file could not be parsed or was not found. Assure"
+                                       " the directory to the config file is being specified.\n", lb->cfg_filename);
         }
-        lb->server_count = temp;
+
+        config_json = config_json -> child;
+
+        list_size = cJSON_GetObjectItem(config_json, "list_size");
+        policy = cJSON_GetObjectItem(config_json, "policy");
+
+        if (list_size == NULL) rte_exit(EXIT_FAILURE, "list_size not found/invalid\n");
+        if (policy == NULL) rte_exit(EXIT_FAILURE, "policy not found/invalid\n");
+
+
+        lb->server_count = list_size->valueint;
+
+        if (!strcmp(policy->valuestring, "RROBIN")) lb->policy = RROBIN;
+        else if (!strcmp(policy->valuestring, "RANDOM")) lb->policy = RANDOM;
+        else if (!strcmp(policy->valuestring, "WEIGHTED_RANDOM")) lb->policy = WEIGHTED_RANDOM;
+        else rte_exit(EXIT_FAILURE, "Invalid policy. Check server.json\n");
+
+        lb->weights = (int*)calloc(lb->server_count,sizeof(int));
 
         lb->server = (struct backend_server *)rte_malloc("backend server info",
                                                          sizeof(struct backend_server) * lb->server_count, 0);
         if (lb->server == NULL) {
                 rte_exit(EXIT_FAILURE, "Malloc failed, can't allocate server information\n");
         }
 
-        for (i = 0; i < lb->server_count; i++) {
-                ret = fscanf(cfg, "%s %s", ip, mac);
-                if (ret != 2) {
-                        rte_exit(EXIT_FAILURE, "Invalid backend config structure\n");
-                }
+        config_json = config_json->next;
+
+        while (config_json != NULL) {
+                ip_addr = cJSON_GetObjectItem(config_json, "ip");
+                mac_addr =  cJSON_GetObjectItem(config_json, "mac_addr");
+                weight = cJSON_GetObjectItem(config_json, "weight");
 
-                ret = onvm_pkt_parse_ip(ip, &lb->server[i].d_ip);
+                if (ip_addr == NULL) rte_exit(EXIT_FAILURE, "IP not found/invalid\n");
+                if (mac_addr == NULL) rte_exit(EXIT_FAILURE, "MAC address not found/invalid\n");
+
+
+                ret = onvm_pkt_parse_ip(ip_addr->valuestring, &lb->server[i].d_ip);
                 if (ret < 0) {
                         rte_exit(EXIT_FAILURE, "Error parsing config IP address #%d\n", i);
                 }
-
-                ret = onvm_pkt_parse_mac(mac, lb->server[i].d_addr_bytes);
+                ret = onvm_pkt_parse_mac(mac_addr->valuestring, lb->server[i].d_addr_bytes);
                 if (ret < 0) {
                         rte_exit(EXIT_FAILURE, "Error parsing config MAC address #%d\n", i);
                 }
+
+                if (lb->policy != WEIGHTED_RANDOM) lb->weights[i] = 1;
+                else {
+                        if (weight == NULL) rte_exit(EXIT_FAILURE, "Weight not found/invalid\n");
+                        lb->weights[i] = weight->valueint;
+                        lb->total_weight += weight->valueint;
+                }
+                config_json = config_json->next;
+                i++;
         }
+        if ( i != lb->server_count) rte_exit(EXIT_FAILURE, "Invalid list_size in config file\n");
+        cJSON_Delete(config_json);
 
-        fclose(cfg);
         printf("\nARP config:\n");
         for (i = 0; i < lb->server_count; i++) {
                 printf("%" PRIu8 ".%" PRIu8 ".%" PRIu8 ".%" PRIu8 " ", (lb->server[i].d_ip >> 24) & 0xFF,
@@ -460,10 +509,34 @@ table_add_entry(struct onvm_ft_ipv4_5tuple *key, struct flow_info **flow) {
         }
 
         lb->num_stored++;
-        data->dest = lb->num_stored % lb->server_count;
+
+        int i, wrand, cur_weight_sum;
+        switch (lb->policy)
+        {
+        case RANDOM:
+                data->dest = rand() % lb->server_count;
+                break;
+        case RROBIN:
+                data->dest = lb->num_stored % lb->server_count;
+                break;
+        case WEIGHTED_RANDOM:
+                wrand = rand() % lb->total_weight;
+                cur_weight_sum=0;
+                for (i = 0; i < lb->server_count; i++) {
+                        cur_weight_sum+=lb->weights[i];
+                        if(wrand < cur_weight_sum) {
+                                data->dest=i;
+                                break;
+                        }
+                }
+                break;
+        default:
+                rte_exit(EXIT_FAILURE, "Invalid policy while adding entry to table!\n");
+                break;
+        }
+
         data->last_pkt_cycles = lb->elapsed_cycles;
         data->is_active = 0;
-
         *flow = data;
 
         return 0;
@@ -555,6 +628,7 @@ packet_handler(struct rte_mbuf *pkt, struct onvm_pkt_meta *meta,
                 for (i = 0; i < RTE_ETHER_ADDR_LEN; i++) {
                         flow_info->s_addr_bytes[i] = ehdr->s_addr.addr_bytes[i];
                 }
+                if(debug_mode) printf("New connection made with server %d.\n",flow_info->dest);
         }
 
         if (pkt->port == lb->server_port) {
@@ -600,6 +674,10 @@ main(int argc, char *argv[]) {
         int arg_offset;
         const char *progname = argv[0];
 
+        time_t t;
+	/* Intializes RANDOM number generator */
+	srand((unsigned) time(&t));
+
         nf_local_ctx = onvm_nflib_init_nf_local_ctx();
         onvm_nflib_start_signal_handler(nf_local_ctx, NULL);
 
@@ -636,14 +714,16 @@ main(int argc, char *argv[]) {
         }
 
         validate_iface_config();
-        parse_backend_config();
+        parse_backend_json_config();
 
         lb->expire_time = 32;
         lb->elapsed_cycles = rte_get_tsc_cycles();
 
         onvm_nflib_run(nf_local_ctx);
 
         onvm_nflib_stop(nf_local_ctx);
+
+        free(lb->weights);
         onvm_ft_free(lb->ft);
         rte_free(lb);
         printf("If we reach here, program is ending\n");

examples/load_balancer/server.json

@@ -0,0 +1,18 @@
+{
+    "Info" : {
+        "list_size": 2,
+        "policy": "random"
+    },
+
+    "Server0": {
+        "ip": "10.10.1.2",
+        "mac_addr": "90:e2:ba:ac:16:34",
+        "weight": 1
+    },
+
+    "Server1": {
+        "ip": "10.10.1.3",
+        "mac_addr": "90:e2:ba:b3:bb:7d",
+        "weight": 1
+    }
+}