Optimize inserting filters into BPF map.

src/common/types.h

@@ -62,10 +62,8 @@ struct icmp_opts
 
 struct filter
 {
-    u8 id;
+    unsigned int set : 1;
-
     unsigned int log : 1;
-
     unsigned int enabled : 1;
 
     u8 action;

src/loader/utils/config.c

@@ -57,7 +57,7 @@ void SetCfgDefaults(config__t *cfg)
     {
         filter_t* filter = &cfg->filters[i];
 
-        filter->id = 0;
+        filter->set = 0;
         filter->enabled = 1;
 
         filter->log = 0;
@@ -318,9 +318,6 @@ int ReadCfg(config__t *cfg, config_overrides_t* overrides)
         return 1;
     }
 
-    // Set filter count.
-    int filters = 0;
-
     for (int i = 0; i < config_setting_length(setting); i++)
     {
         filter_t* filter = &cfg->filters[i];
@@ -633,8 +630,8 @@ int ReadCfg(config__t *cfg, config_overrides_t* overrides)
             filter->icmpopts.do_type = 1;
         }
 
-        // Assign ID and increase filter count.
+        // Make sure filter is set.
-        filter->id = ++filters;
+        filter->set = 1;
     }
 
     config_destroy(&conf);
@@ -682,7 +679,7 @@ void PrintConfig(config__t* cfg)
     {
         filter_t *filter = &cfg->filters[i];
 
-        if (filter->id < 1)
+        if (!filter->set)
         {
             break;
         }
@@ -690,7 +687,6 @@ void PrintConfig(config__t* cfg)
         printf("\t\tFilter #%d:\n", (i + 1));
 
         // Main.
-        printf("\t\t\tID => %d\n", filter->id);
         printf("\t\t\tLog => %d\n", filter->log);
         printf("\t\t\tEnabled => %d\n", filter->enabled);
         printf("\t\t\tAction => %d (0 = Block, 1 = Allow).\n\n", filter->action);

src/loader/utils/xdp.c

@@ -187,35 +187,40 @@ int AttachXdp(struct xdp_program *prog, char** mode, int ifidx, u8 detach, cmdli
 void UpdateFilters(int filters_map, config__t *cfg)
 {
     int ret;
+    int cur_idx = 0;
 
     // Add a filter to the filter maps.
     for (int i = 0; i < MAX_FILTERS; i++)
     {
+        filter_t* filter = &cfg->filters[i];
+
         // Delete previous rule from BPF map.
         // We do this in the case rules were edited and were put out of order since the key doesn't uniquely map to a specific rule.
         u32 key = i;
 
         bpf_map_delete_elem(filters_map, &key);
 
-        // Check if we have a valid filter.
+        // Only insert set and enabled filters.
-        if (cfg->filters[i].id < 1)
+        if (!filter->set || !filter->enabled)
         {
             continue;
         }
 
         // Create value array (max CPUs in size) since we're using a per CPU map.
-        filter_t filter[MAX_CPUS];
+        filter_t filter_cpus[MAX_CPUS];
-        memset(filter, 0, sizeof(filter));
+        memset(filter_cpus, 0, sizeof(filter_cpus));
 
         for (int j = 0; j < MAX_CPUS; j++)
         {
-            filter[j] = cfg->filters[i];
+            filter_cpus[j] = *filter;
         }
 
         // Attempt to update BPF map.
-        if ((ret = bpf_map_update_elem(filters_map, &i, &filter, BPF_ANY)) != 0)
+        if ((ret = bpf_map_update_elem(filters_map, &cur_idx, &filter_cpus, BPF_ANY)) != 0)
         {
             fprintf(stderr, "[WARNING] Failed to update filter #%d due to BPF update error (%d)...\n", i, ret);
         }
+
+        cur_idx++;
     }
 }

src/xdp/prog.c

@@ -275,17 +275,11 @@ int xdp_prog_main(struct xdp_md *ctx)
         filter_t *filter = bpf_map_lookup_elem(&filters_map, &key);
 
         // Check if ID is above 0 (if 0, it's an invalid rule).
-        if (!filter || filter->id < 1)
+        if (!filter || !filter->set)
         {
             break;
         }
 
-        // Check if the rule is enabled.
-        if (!filter->enabled)
-        {
-            continue;
-        }
-
         // Do specific IPv6.
         if (iph6)
         {