Cleanup and organize a lot of Loader code.

src/loader/prog.c

@@ -1,440 +1,82 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <string.h>
-#include <errno.h>
 #include <signal.h>
-#include <linux/types.h>
 #include <time.h>
-#include <getopt.h>
+
 #include <sys/resource.h>
 #include <sys/sysinfo.h>
 #include <sys/stat.h>
-#include <fcntl.h>
 
 #include <net/if.h>
-#include <linux/if_link.h>
-#include <arpa/inet.h>
-
-#include <bpf.h>
-#include <libbpf.h>
-#include <xdp/libxdp.h>
-
-#include  <common/all.h>
 
 #include <loader/utils/cmdline.h>
 #include <loader/utils/config.h>
+#include <loader/utils/xdp.h>
+#include <loader/utils/stats.h>
 #include <loader/utils/helpers.h>
 
-// Other variables.
+int cont = 1;
-static u8 cont = 1;
-static int filtersmap = -1;
-static int statsmap = -1;
-
-void SignalHndl(int tmp)
-{
-    cont = 0;
-}
-
-/**
- * Updates the filter's BPF map.
- * 
- * @param cfg A pointer to the config structure.
- * 
- * @return Void
-*/
-void UpdateFilters(config__t *cfg)
-{
-    // Loop through all filters and delete the 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.
-    for (u8 i = 0; i < MAX_FILTERS; i++)
-    {
-        u32 key = i;
-
-        bpf_map_delete_elem(filtersmap, &key);
-    }
-
-    // Add a filter to the filter maps.
-    for (u32 i = 0; i < MAX_FILTERS; i++)
-    {
-        // Check if we have a valid ID.
-        if (cfg->filters[i].id < 1)
-        {
-            break;
-        }
-
-        // Create value array (max CPUs in size) since we're using a per CPU map.
-        filter_t filter[MAX_CPUS];
-        memset(filter, 0, sizeof(filter));
-
-        for (int j = 0; j < MAX_CPUS; j++)
-        {
-            filter[j] = cfg->filters[i];
-        }
-
-        // Attempt to update BPF map.
-        if (bpf_map_update_elem(filtersmap, &i, &filter, BPF_ANY) == -1)
-        {
-            fprintf(stderr, "Error updating BPF item #%d\n", i);
-        }
-    }
-}
-
-/**
- * Loads the config on the file system.
- * 
- * @param cfg A pointer to the config structure.
- * @param cfgfile The path to the config file.
- * 
- * @return 0 on success or -1 on error.
-*/
-int LoadConfig(config__t *cfg, char *cfgfile)
-{
-    // Open config file.
-    if (OpenCfg(cfgfile) != 0)
-    {
-        fprintf(stderr, "Error opening filters file: %s\n", cfgfile);
-        
-        return -1;
-    }
-
-    SetCfgDefaults(cfg);
-
-    memset(cfg->filters, 0, sizeof(cfg->filters));
-
-    // Read config and check for errors.
-    if (ReadCfg(cfg) != 0)
-    {
-        fprintf(stderr, "Error reading filters file.\n");
-
-        return -1;
-    }
-
-    return 0;
-}
-
-/**
- * Finds a BPF map's FD.
- * 
- * @param prog A pointer to the XDP program structure.
- * @param mapname The name of the map to retrieve.
- * 
- * @return The map's FD.
-*/
-int FindMapFd(struct xdp_program *prog, const char *mapname)
-{
-    int fd = -1;
-
-    struct bpf_object *obj = xdp_program__bpf_obj(prog);
-
-    if (obj == NULL)
-    {
-        fprintf(stderr, "Error finding BPF object from XDP program.\n");
-
-        goto out;
-    }
-
-    struct bpf_map *map = bpf_object__find_map_by_name(obj, mapname);
-
-    if (!map) 
-    {
-        fprintf(stderr, "Error finding eBPF map: %s\n", mapname);
-
-        goto out;
-    }
-
-    fd = bpf_map__fd(map);
-
-    out:
-        return fd;
-}
-
-/**
- * Loads a BPF object file.
- * 
- * @param filename The path to the BPF object file.
- * 
- * @return XDP program structure (pointer) or NULL.
-*/
-struct xdp_program *LoadBpfObj(const char *filename)
-{
-    struct xdp_program *prog = xdp_program__open_file(filename, "xdp_prog", NULL);
-
-    if (prog == NULL)
-    {
-        // The main function handles this error.
-        return NULL;
-    }
-
-    return prog;
-}
-
-/**
- * Attempts to attach or detach (progfd = -1) a BPF/XDP program to an interface.
- * 
- * @param prog A pointer to the XDP program structure.
- * @param ifidx The index to the interface to attach to.
- * @param detach If above 0, attempts to detach XDP program.
- * @param cmd A pointer to a cmdline struct that includes command line arguments (mostly checking for offload/HW mode set).
- * 
- * @return 0 on success and 1 on error.
- */
-int AttachXdp(struct xdp_program *prog, int ifidx, u8 detach, cmdline_t *cmd)
-{
-    int err;
-
-    u32 mode = XDP_MODE_NATIVE;
-    char *smode;
-
-    smode = "DRV/native";
-
-    if (cmd->offload)
-    {
-        smode = "HW/offload";
-
-        mode = XDP_MODE_HW;
-    }
-    else if (cmd->skb)
-    {
-        smode = "SKB/generic";
-        mode = XDP_MODE_SKB;
-    }
-
-    u8 exit = 0;
-
-    while (!exit)
-    {
-        // Try loading program with current mode.
-        int err;
-
-        if (detach)
-        {
-            err = xdp_program__detach(prog, ifidx, mode, 0);
-        }
-        else
-        {
-            err = xdp_program__attach(prog, ifidx, mode, 0);
-        }
-
-        if (err)
-        {
-            if (err)
-            {
-                fprintf(stderr, "Could not attach with mode %s (%s) (%d).\n", smode, strerror(-err), -err);
-            }
-
-            // Decrease mode.
-            switch (mode)
-            {
-                case XDP_MODE_HW:
-                    mode = XDP_MODE_NATIVE;
-                    smode = "DRV/native";
-
-                    break;
-
-                case XDP_MODE_NATIVE:
-                    mode = XDP_MODE_SKB;
-                    smode = "SKB/generic";
-
-                    break;
-
-                case XDP_MODE_SKB:
-                    // Exit loop.
-                    exit = 1;
-                    smode = NULL;
-                    
-                    break;
-            }
-
-            // Retry.
-            continue;
-        }
-        
-        // Success, so break current loop.
-        break;
-    }
-
-    // If exit is set to 1 or smode is NULL, it indicates full failure.
-    if (exit || smode == NULL)
-    {
-        fprintf(stderr, "Error attaching XDP program.\n");
-
-        return 1;
-    }
-
-    fprintf(stdout, "Loaded XDP program on mode %s.\n", smode);
-
-    return 0;
-}
-
 struct stat conf_stat;
 
 int main(int argc, char *argv[])
 {
     // Parse the command line.
-    cmdline_t cmd = 
+    cmdline_t cmd = {0};
-    {
+    cmd.cfgfile = CONFIG_DEFAULT_PATH;
-        .cfgfile = "/etc/xdpfw/xdpfw.conf",
-        .help = 0,
-        .list = 0,
-        .offload = 0
-    };
 
     ParseCommandLine(&cmd, argc, argv);
 
-    // Check for help menu.
+    // Check for help.
     if (cmd.help)
     {
-        fprintf(stdout, "Usage:\n" \
+        PrintHelpMenu();
-            "--config -c => Config file location (default is /etc/xdpfw/xdpfw.conf).\n" \
-            "--offload -o => Tries to load the XDP program in hardware/offload mode.\n" \
-            "--skb -s => Force the XDP program to load with SKB mode instead of DRV.\n" \
-            "--time -t => How long to run the program for in seconds before exiting. 0 or not set = infinite.\n" \
-            "--list -l => Print config details including filters (this will exit program after done).\n" \
-            "--help -h => Print help menu.\n");
 
         return EXIT_SUCCESS;
     }
 
     // Raise RLimit.
-    struct rlimit rl = {RLIM_INFINITY, RLIM_INFINITY};
+    struct rlimit rl = { RLIM_INFINITY, RLIM_INFINITY };
 
     if (setrlimit(RLIMIT_MEMLOCK, &rl)) 
     {
-        fprintf(stderr, "Error setting rlimit.\n");
+        fprintf(stderr, "Error setting rlimit. Please make sure this program is ran as root!\n");
 
         return EXIT_FAILURE;
     }
 
-    // Check for --config argument.
-    if (cmd.cfgfile == NULL)
-    {
-        // Assign default.
-        cmd.cfgfile = "/etc/xdpfw/xdpfw.conf";
-    }
-
     // Initialize config.
     config__t cfg = {0};
 
     SetCfgDefaults(&cfg);
 
-    // Update config.
+    // Load config.
     LoadConfig(&cfg, cmd.cfgfile);
 
     // Check for list option.
     if (cmd.list)
     {
-        fprintf(stdout, "Current Settings:\n");
+        PrintConfig(&cfg);
-        fprintf(stdout, "Interface Name => %s\n", cfg.interface);
-        fprintf(stdout, "Update Time => %d\n", cfg.updatetime);
-        fprintf(stdout, "Stdout Update Time => %d\n\n", cfg.stdout_update_time);
-
-        for (uint16_t i = 0; i < MAX_FILTERS; i++)
-        {
-            filter_t *filter = &cfg.filters[i];
-
-            if (filter->id < 1)
-            {
-                break;
-            }
-
-            fprintf(stdout, "Filter #%d:\n", (i + 1));
-
-            // Main.
-            fprintf(stdout, "\tID => %d\n", filter->id);
-            fprintf(stdout, "\tEnabled => %d\n", filter->enabled);
-            fprintf(stdout, "\tAction => %d (0 = Block, 1 = Allow).\n\n", filter->action);
-
-            // IP Options.
-            fprintf(stdout, "\tIP Options\n");
-
-            // IP addresses require additional code for string printing.
-            struct sockaddr_in sin;
-            sin.sin_addr.s_addr = filter->src_ip;
-            fprintf(stdout, "\t\tSource IPv4 => %s\n", inet_ntoa(sin.sin_addr));
-            fprintf(stdout, "\t\tSource CIDR => %d\n", filter->src_cidr);
-
-            struct sockaddr_in din;
-            din.sin_addr.s_addr = filter->dst_ip;
-            fprintf(stdout, "\t\tDestination IPv4 => %s\n", inet_ntoa(din.sin_addr));
-            fprintf(stdout, "\t\tDestination CIDR => %d\n", filter->dst_cidr);
-
-            struct in6_addr sin6;
-            memcpy(&sin6, &filter->src_ip6, sizeof(sin6));
-            
-            char srcipv6[INET6_ADDRSTRLEN];
-            inet_ntop(AF_INET6, &sin6, srcipv6, sizeof(srcipv6));
-
-            fprintf(stdout, "\t\tSource IPv6 => %s\n", srcipv6);
-
-            struct in6_addr din6;
-            memcpy(&din6, &filter->dst_ip6, sizeof(din6));
-
-            char dstipv6[INET6_ADDRSTRLEN];
-            inet_ntop(AF_INET6, &din6, dstipv6, sizeof(dstipv6));
-
-            fprintf(stdout, "\t\tDestination IPv6 => %s\n", dstipv6);
-
-            // Other IP header information.
-            fprintf(stdout, "\t\tMax Length => %d\n", filter->max_len);
-            fprintf(stdout, "\t\tMin Length => %d\n", filter->min_len);
-            fprintf(stdout, "\t\tMax TTL => %d\n", filter->max_ttl);
-            fprintf(stdout, "\t\tMin TTL => %d\n", filter->min_ttl);
-            fprintf(stdout, "\t\tTOS => %d\n", filter->tos);
-            fprintf(stdout, "\t\tPPS => %llu\n", filter->pps);
-            fprintf(stdout, "\t\tBPS => %llu\n", filter->bps);
-            fprintf(stdout, "\t\tBlock Time => %llu\n\n", filter->blocktime);
-
-            // TCP Options.
-            fprintf(stdout, "\tTCP Options\n");
-            fprintf(stdout, "\t\tTCP Enabled => %d\n", filter->tcpopts.enabled);
-            fprintf(stdout, "\t\tTCP Source Port => %d\n", filter->tcpopts.sport);
-            fprintf(stdout, "\t\tTCP Destination Port => %d\n", filter->tcpopts.dport);
-            fprintf(stdout, "\t\tTCP URG Flag => %d\n", filter->tcpopts.urg);
-            fprintf(stdout, "\t\tTCP ACK Flag => %d\n", filter->tcpopts.ack);
-            fprintf(stdout, "\t\tTCP RST Flag => %d\n", filter->tcpopts.rst);
-            fprintf(stdout, "\t\tTCP PSH Flag => %d\n", filter->tcpopts.psh);
-            fprintf(stdout, "\t\tTCP SYN Flag => %d\n", filter->tcpopts.syn);
-            fprintf(stdout, "\t\tTCP FIN Flag => %d\n", filter->tcpopts.fin);
-            fprintf(stdout, "\t\tTCP ECE Flag => %d\n", filter->tcpopts.ece);
-            fprintf(stdout, "\t\tTCP CWR Flag => %d\n\n", filter->tcpopts.cwr);
-
-            // UDP Options.
-            fprintf(stdout, "\tUDP Options\n");
-            fprintf(stdout, "\t\tUDP Enabled => %d\n", filter->udpopts.enabled);
-            fprintf(stdout, "\t\tUDP Source Port => %d\n", filter->udpopts.sport);
-            fprintf(stdout, "\t\tUDP Destination Port => %d\n\n", filter->udpopts.dport);
-
-            // ICMP Options.
-            fprintf(stdout, "\tICMP Options\n");
-            fprintf(stdout, "\t\tICMP Enabled => %d\n", filter->icmpopts.enabled);
-            fprintf(stdout, "\t\tICMP Code => %d\n", filter->icmpopts.code);
-            fprintf(stdout, "\t\tICMP Type => %d\n", filter->icmpopts.type);
-
-            fprintf(stdout, "\n\n");
-        }
 
         return EXIT_SUCCESS;
     }
 
-    // Get device.
+    // Get interface index.
-    int ifidx;
+    int ifidx = if_nametoindex(cfg.interface);
 
-    if ((ifidx = if_nametoindex(cfg.interface)) < 0)
+    if (ifidx < 0)
     {
         fprintf(stderr, "Error finding device %s.\n", cfg.interface);
 
         return EXIT_FAILURE;
     }
 
-    // XDP variables.
-    const char *filename = "/etc/xdpfw/xdp_prog.o";
-
     // Load BPF object.
-    struct xdp_program *prog = LoadBpfObj(filename);
+    struct xdp_program *prog = LoadBpfObj(XDP_OBJ_PATH);
 
     if (prog == NULL)
     {
-        fprintf(stderr, "Error loading eBPF object file. File name => %s.\n", filename);
+        fprintf(stderr, "Error loading eBPF object file. File name => %s.\n", XDP_OBJ_PATH);
 
         return EXIT_FAILURE;
     }
@@ -442,22 +84,25 @@ int main(int argc, char *argv[])
     // Attach XDP program.
     if (AttachXdp(prog, ifidx, 0, &cmd))
     {
+        fprintf(stderr, "Error attaching XDP program.\n");
+
         return EXIT_FAILURE;
     }
 
     // Retrieve BPF maps.
-    filtersmap = FindMapFd(prog, "filters_map");
+    int filters_map = FindMapFd(prog, "filters_map");
-    statsmap = FindMapFd(prog, "stats_map");
 
     // Check for valid maps.
-    if (filtersmap < 0)
+    if (filters_map < 0)
     {
         fprintf(stderr, "Error finding 'filters_map' BPF map.\n");
 
         return EXIT_FAILURE;
     }
 
-    if (statsmap < 0)
+    int stats_map = FindMapFd(prog, "stats_map");
+
+    if (stats_map < 0)
     {
         fprintf(stderr, "Error finding 'stats_map' BPF map.\n");
 
@@ -465,7 +110,7 @@ int main(int argc, char *argv[])
     }
 
     // Update BPF maps.
-    UpdateFilters(&cfg);
+    UpdateFilters(filters_map, &cfg);
 
     // Signal.
     signal(SIGINT, SignalHndl);
@@ -473,30 +118,30 @@ int main(int argc, char *argv[])
     // Receive CPU count for stats map parsing.
     int cpus = get_nprocs_conf();
 
-    unsigned int endTime = (cmd.time > 0) ? time(NULL) + cmd.time : 0;
+    unsigned int end_time = (cmd.time > 0) ? time(NULL) + cmd.time : 0;
 
-    // Create last updated variable.
+    // Create last updated variables.
-    time_t lastupdatecheck = time(NULL);
+    time_t last_update_check = time(NULL);
-    time_t lastupdated = time(NULL);
+    time_t last_config_check = time(NULL);
 
     unsigned int sleep_time = cfg.stdout_update_time * 1000;
 
     while (cont)
     {
         // Get current time.
-        time_t curTime = time(NULL);
+        time_t cur_time = time(NULL);
 
         // Check if we should end the program.
-        if (endTime > 0 && curTime >= endTime)
+        if (end_time > 0 && cur_time >= end_time)
         {
             break;
         }
 
         // Check for auto-update.
-        if (cfg.updatetime > 0 && (curTime - lastupdatecheck) > cfg.updatetime)
+        if (cfg.updatetime > 0 && (cur_time - last_update_check) > cfg.updatetime)
         {
             // Check if config file have been modified
-            if (stat(cmd.cfgfile, &conf_stat) == 0 && conf_stat.st_mtime > lastupdated) {
+            if (stat(cmd.cfgfile, &conf_stat) == 0 && conf_stat.st_mtime > last_config_check) {
                 // Memleak fix for strdup() in LoadConfig()
                 // Before updating it again, we need to free the old return value
                 free(cfg.interface);
@@ -505,54 +150,23 @@ int main(int argc, char *argv[])
                 LoadConfig(&cfg, cmd.cfgfile);
 
                 // Update BPF maps.
-                UpdateFilters(&cfg);
+                UpdateFilters(filters_map, &cfg);
 
                 // Update timer
-                lastupdated = time(NULL);
+                last_config_check = time(NULL);
             }
 
             // Update last updated variable.
-            lastupdatecheck = time(NULL);
+            last_update_check = time(NULL);
         }
 
-        // Update stats.
+        // Calculate and display stats if enabled.
         if (!cfg.nostats)
         {
-            u32 key = 0;
+            if (CalculateStats(stats_map, cpus))
-
-            stats_t stats[MAX_CPUS];
-            memset(stats, 0, sizeof(stats));
-
-            u64 allowed = 0;
-            u64 dropped = 0;
-            u64 passed = 0;
-            
-            if (bpf_map_lookup_elem(statsmap, &key, stats) != 0)
             {
-                fprintf(stderr, "Error performing stats map lookup. Stats map FD => %d.\n", statsmap);
+                fprintf(stderr, "Error calculating packet stats. Stats map FD => %d.\n", stats_map);
-
-                continue;
             }
-
-            for (int i = 0; i < cpus; i++)
-            {
-                // Although this should NEVER happen, I'm seeing very strange behavior in the following GitHub issue.
-                // https://github.com/gamemann/XDP-Firewall/issues/10
-                // Therefore, before accessing stats[i], make sure the pointer to the specific CPU ID is not NULL.
-                if (&stats[i] == NULL)
-                {
-                    fprintf(stderr, "Stats array at CPU ID #%d is NULL! Skipping...\n", i);
-
-                    continue;
-                }
-
-                allowed += stats[i].allowed;
-                dropped += stats[i].dropped;
-                passed += stats[i].passed;
-            }
-
-            fflush(stdout);
-            fprintf(stdout, "\rAllowed: %llu | Dropped: %llu | Passed: %llu", allowed, dropped, passed);
         }
 
         usleep(sleep_time);

src/loader/utils/cmdline.c

@@ -17,7 +17,7 @@ const struct option opts[] =
  * @param cmd A pointer to the cmdline structure.
  * 
  * @return Void
-*/
+ */
 void ParseCommandLine(cmdline_t *cmd, int argc, char *argv[])
 {
     int c;

src/loader/utils/config.c

@@ -2,7 +2,40 @@
 
 #include <loader/utils/helpers.h>
 
-FILE *file;
+static FILE *file;
+
+/**
+ * Loads the config from the file system.
+ * 
+ * @param cfg A pointer to the config structure.
+ * @param cfg_file The path to the config file.
+ * 
+ * @return 0 on success or -1 on error.
+ */
+int LoadConfig(config__t *cfg, char *cfg_file)
+{
+    // Open config file.
+    if (OpenCfg(cfg_file) != 0)
+    {
+        fprintf(stderr, "Error opening filters file: %s\n", cfg_file);
+        
+        return -1;
+    }
+
+    SetCfgDefaults(cfg);
+
+    memset(cfg->filters, 0, sizeof(cfg->filters));
+
+    // Read config and check for errors.
+    if (ReadCfg(cfg) != 0)
+    {
+        fprintf(stderr, "Error reading filters file.\n");
+
+        return -1;
+    }
+
+    return 0;
+}
 
 /**
  * Sets the config structure's default values.
@@ -10,7 +43,7 @@ FILE *file;
  * @param cfg A pointer to the config structure.
  * 
  * @return Void
-*/
+ */
 void SetCfgDefaults(config__t *cfg)
 {
     cfg->updatetime = 0;
@@ -18,7 +51,7 @@ void SetCfgDefaults(config__t *cfg)
     cfg->nostats = 0;
     cfg->stdout_update_time = 1000;
 
-    for (u16 i = 0; i < MAX_FILTERS; i++)
+    for (int i = 0; i < MAX_FILTERS; i++)
     {
         cfg->filters[i].id = 0;
         cfg->filters[i].enabled = 0;
@@ -26,7 +59,7 @@ void SetCfgDefaults(config__t *cfg)
         cfg->filters[i].src_ip = 0;
         cfg->filters[i].dst_ip = 0;
 
-        for (u8 j = 0; j < 4; j++)
+        for (int j = 0; j < 4; j++)
         {
             cfg->filters[i].src_ip6[j] = 0;
             cfg->filters[i].dst_ip6[j] = 0;
@@ -80,11 +113,11 @@ void SetCfgDefaults(config__t *cfg)
 /**
  * Opens the config file.
  * 
- * @param filename Path to config file.
+ * @param file_name Path to config file.
  * 
  * @return 0 on success or 1 on error.
-*/
+ */
-int OpenCfg(const char *filename)
+int OpenCfg(const char *file_name)
 {
     // Close any existing files.
     if (file != NULL)
@@ -94,7 +127,7 @@ int OpenCfg(const char *filename)
         file = NULL;
     }
 
-    file = fopen(filename, "r");
+    file = fopen(file_name, "r");
 
     if (file == NULL)
     {
@@ -110,7 +143,7 @@ int OpenCfg(const char *filename)
  * @param cfg A pointer to the config structure.
  * 
  * @return 0 on success or 1/-1 on error.
-*/
+ */
 int ReadCfg(config__t *cfg)
 {
     // Not sure why this would be set to NULL after checking for it in OpenConfig(), but just for safety.
@@ -189,7 +222,7 @@ int ReadCfg(config__t *cfg)
     // Set filter count.
     int filters = 0;
 
-    for (u8 i = 0; i < config_setting_length(setting); i++)
+    for (int i = 0; i < config_setting_length(setting); i++)
     {
         config_setting_t* filter = config_setting_get_elem(setting, i);
 
@@ -251,10 +284,7 @@ int ReadCfg(config__t *cfg)
 
             inet_pton(AF_INET6, sip6, &in);
 
-            for (u8 j = 0; j < 4; j++)
+            memcpy(cfg->filters[i].src_ip6, in.__in6_u.__u6_addr32, 4);
-            {
-                cfg->filters[i].src_ip6[j] = in.__in6_u.__u6_addr32[j];
-            }
         }
 
         // Destination IP (IPv6) (not required).
@@ -266,10 +296,7 @@ int ReadCfg(config__t *cfg)
 
             inet_pton(AF_INET6, dip6, &in);
 
-            for (u8 j = 0; j < 4; j++)
+            memcpy(cfg->filters[i].dst_ip6, in.__in6_u.__u6_addr32, 4);
-            {
-                cfg->filters[i].dst_ip6[j] = in.__in6_u.__u6_addr32[j];
-            }
         }
 
         // Minimum TTL (not required).
@@ -509,3 +536,103 @@ int ReadCfg(config__t *cfg)
 
     return 0;
 }
+
+/**
+ * Prints config settings.
+ * 
+ * @param cfg A pointer to the config structure.
+ * 
+ * @return void
+ */
+void PrintConfig(config__t* cfg)
+{
+    fprintf(stdout, "Current Settings:\n");
+    fprintf(stdout, "Interface Name => %s\n", cfg->interface);
+    fprintf(stdout, "Update Time => %d\n", cfg->updatetime);
+    fprintf(stdout, "Stdout Update Time => %d\n\n", cfg->stdout_update_time);
+
+    for (int i = 0; i < MAX_FILTERS; i++)
+    {
+        filter_t *filter = &cfg->filters[i];
+
+        if (filter->id < 1)
+        {
+            break;
+        }
+
+        fprintf(stdout, "Filter #%d:\n", (i + 1));
+
+        // Main.
+        fprintf(stdout, "\tID => %d\n", filter->id);
+        fprintf(stdout, "\tEnabled => %d\n", filter->enabled);
+        fprintf(stdout, "\tAction => %d (0 = Block, 1 = Allow).\n\n", filter->action);
+
+        // IP Options.
+        fprintf(stdout, "\tIP Options\n");
+
+        // IP addresses require additional code for string printing.
+        struct sockaddr_in sin;
+        sin.sin_addr.s_addr = filter->src_ip;
+        fprintf(stdout, "\t\tSource IPv4 => %s\n", inet_ntoa(sin.sin_addr));
+        fprintf(stdout, "\t\tSource CIDR => %d\n", filter->src_cidr);
+
+        struct sockaddr_in din;
+        din.sin_addr.s_addr = filter->dst_ip;
+        fprintf(stdout, "\t\tDestination IPv4 => %s\n", inet_ntoa(din.sin_addr));
+        fprintf(stdout, "\t\tDestination CIDR => %d\n", filter->dst_cidr);
+
+        struct in6_addr sin6;
+        memcpy(&sin6, &filter->src_ip6, sizeof(sin6));
+        
+        char srcipv6[INET6_ADDRSTRLEN];
+        inet_ntop(AF_INET6, &sin6, srcipv6, sizeof(srcipv6));
+
+        fprintf(stdout, "\t\tSource IPv6 => %s\n", srcipv6);
+
+        struct in6_addr din6;
+        memcpy(&din6, &filter->dst_ip6, sizeof(din6));
+
+        char dstipv6[INET6_ADDRSTRLEN];
+        inet_ntop(AF_INET6, &din6, dstipv6, sizeof(dstipv6));
+
+        fprintf(stdout, "\t\tDestination IPv6 => %s\n", dstipv6);
+
+        // Other IP header information.
+        fprintf(stdout, "\t\tMax Length => %d\n", filter->max_len);
+        fprintf(stdout, "\t\tMin Length => %d\n", filter->min_len);
+        fprintf(stdout, "\t\tMax TTL => %d\n", filter->max_ttl);
+        fprintf(stdout, "\t\tMin TTL => %d\n", filter->min_ttl);
+        fprintf(stdout, "\t\tTOS => %d\n", filter->tos);
+        fprintf(stdout, "\t\tPPS => %llu\n", filter->pps);
+        fprintf(stdout, "\t\tBPS => %llu\n", filter->bps);
+        fprintf(stdout, "\t\tBlock Time => %llu\n\n", filter->blocktime);
+
+        // TCP Options.
+        fprintf(stdout, "\tTCP Options\n");
+        fprintf(stdout, "\t\tTCP Enabled => %d\n", filter->tcpopts.enabled);
+        fprintf(stdout, "\t\tTCP Source Port => %d\n", filter->tcpopts.sport);
+        fprintf(stdout, "\t\tTCP Destination Port => %d\n", filter->tcpopts.dport);
+        fprintf(stdout, "\t\tTCP URG Flag => %d\n", filter->tcpopts.urg);
+        fprintf(stdout, "\t\tTCP ACK Flag => %d\n", filter->tcpopts.ack);
+        fprintf(stdout, "\t\tTCP RST Flag => %d\n", filter->tcpopts.rst);
+        fprintf(stdout, "\t\tTCP PSH Flag => %d\n", filter->tcpopts.psh);
+        fprintf(stdout, "\t\tTCP SYN Flag => %d\n", filter->tcpopts.syn);
+        fprintf(stdout, "\t\tTCP FIN Flag => %d\n", filter->tcpopts.fin);
+        fprintf(stdout, "\t\tTCP ECE Flag => %d\n", filter->tcpopts.ece);
+        fprintf(stdout, "\t\tTCP CWR Flag => %d\n\n", filter->tcpopts.cwr);
+
+        // UDP Options.
+        fprintf(stdout, "\tUDP Options\n");
+        fprintf(stdout, "\t\tUDP Enabled => %d\n", filter->udpopts.enabled);
+        fprintf(stdout, "\t\tUDP Source Port => %d\n", filter->udpopts.sport);
+        fprintf(stdout, "\t\tUDP Destination Port => %d\n\n", filter->udpopts.dport);
+
+        // ICMP Options.
+        fprintf(stdout, "\tICMP Options\n");
+        fprintf(stdout, "\t\tICMP Enabled => %d\n", filter->icmpopts.enabled);
+        fprintf(stdout, "\t\tICMP Code => %d\n", filter->icmpopts.code);
+        fprintf(stdout, "\t\tICMP Type => %d\n", filter->icmpopts.type);
+
+        fprintf(stdout, "\n\n");
+    }
+}

src/loader/utils/config.h

@@ -10,6 +10,8 @@
 
 #include <arpa/inet.h>
 
+#define CONFIG_DEFAULT_PATH "/etc/xdpfw/xdpfw.conf"
+
 struct config
 {
     char *interface;
@@ -19,6 +21,9 @@ struct config
     filter_t filters[MAX_FILTERS];
 } typedef config__t; // config_t is taken by libconfig -.-
 
+int LoadConfig(config__t *cfg, char *cfg_file);
 void SetCfgDefaults(config__t *cfg);
+void PrintConfig(config__t* cfg);
+
 int OpenCfg(const char *filename);
 int ReadCfg(config__t *cfg);

src/loader/utils/helpers.c

@@ -1,12 +1,40 @@
 #include <loader/utils/helpers.h>
 
+/**
+ * Prints help menu.
+ * 
+ * @return void
+ */
+void PrintHelpMenu()
+{
+    fprintf(stdout, "Usage:\n" \
+        "--config -c => Config file location (default is /etc/xdpfw/xdpfw.conf).\n" \
+        "--offload -o => Tries to load the XDP program in hardware/offload mode.\n" \
+        "--skb -s => Force the XDP program to load with SKB mode instead of DRV.\n" \
+        "--time -t => How long to run the program for in seconds before exiting. 0 or not set = infinite.\n" \
+        "--list -l => Print config details including filters (this will exit program after done).\n" \
+        "--help -h => Print help menu.\n");
+}
+
+/**
+ * Handles signals from user.
+ * 
+ * @param code Signal code.
+ * 
+ * @return void
+ */
+void SignalHndl(int code)
+{
+    cont = 0;
+}
+
 /**
  * Parses an IP string with CIDR support. Stores IP in network byte order in ip.ip and CIDR in ip.cidr.
  * 
  * @param ip The IP string.
  * 
  * @return Returns an IP structure with IP and CIDR. 
-*/
+ */
 ip_range_t ParseIpCidr(const char *ip)
 {
     ip_range_t ret = {0};
@@ -22,7 +50,7 @@ ip_range_t ParseIpCidr(const char *ip)
 
         if (token)
         {
-            ret.cidr = (unsigned int) strtoul(token, NULL, 10);
+            ret.cidr = (u8) strtoul(token, NULL, 10);
         }
     }
 

src/loader/utils/helpers.h

@@ -10,7 +10,11 @@
 struct ip_range
 {
     u32 ip;
-    u32 cidr;
+    u8 cidr;
 } typedef ip_range_t;
 
-ip_range_t ParseIpCidr(const char *ip);
+extern int cont;
+
+void PrintHelpMenu();
+void SignalHndl(int code);
+ip_range_t ParseIpCidr(const char* ip);