dfgdk

.clang-format

@@ -0,0 +1,2 @@
+BasedOnStyle: LLVM
+IndentWidth: 4

.gitignore

@@ -1,4 +1,4 @@
 .ccls-cache
-build
+objects
 jsfw
 plan

Makefile

@@ -1,13 +1,13 @@
 Q=@
 CC=gcc
-CFLAGS=-g -Wall
+CFLAGS=-g -Wall -Wno-format-truncation
 LDFLAGS=
-BUILD_DIR=./build
+BUILD_DIR=./objects
 BIN=jsfw
 
-RUNARGS=client /dev/input/js0 localhost 7776
+RUNARGS=client localhost 7776
 
-SOURCES=main.c hid.c
+SOURCES=$(wildcard *.c)
 
 OBJECTS:=$(patsubst %.c,$(BUILD_DIR)/%.o,$(SOURCES))
 

client.h

@@ -0,0 +1,6 @@
+#ifndef CLIENT_H
+#define CLIENT_H
+
+
+
+#endif

hashmap.c

@@ -1,10 +1,15 @@
-#include "hashmap.h"
+#include <math.h>
+#include <stdio.h>
 #include <stdlib.h>
 
-int seed = 0;
+#include "hashmap.h"
+#include "util.h"
+
+uint32_t seed = 0;
 
 void init_seed() {
-    if(seed) return;
+    if (seed)
+        return;
     seed = random();
 }
 
@@ -12,28 +17,16 @@ void init_seed() {
 // Is taken from the internet because I needed a simple hash function
 // --------------------------------------------------------
 
-#define PRIME1  0x9E3779B1U  /*!< 0b10011110001101110111100110110001 */
+#define PRIME1 0x9E3779B1U /*!< 0b10011110001101110111100110110001 */
-#define PRIME2  0x85EBCA77U  /*!< 0b10000101111010111100101001110111 */
+#define PRIME2 0x85EBCA77U /*!< 0b10000101111010111100101001110111 */
-#define PRIME3  0xC2B2AE3DU  /*!< 0b11000010101100101010111000111101 */
+#define PRIME3 0xC2B2AE3DU /*!< 0b11000010101100101010111000111101 */
-#define PRIME4  0x27D4EB2FU  /*!< 0b00100111110101001110101100101111 */
+#define PRIME4 0x27D4EB2FU /*!< 0b00100111110101001110101100101111 */
-#define PRIME5  0x165667B1U  /*!< 0b00010110010101100110011110110001 */
+#define PRIME5 0x165667B1U /*!< 0b00010110010101100110011110110001 */
 
-uint32_t _rotl(const uint32_t value, int shift) {
+uint32_t xxhash32(uint8_t *data, size_t len) {
-    if ((shift &= sizeof(value)*8 - 1) == 0)
+    size_t end = len;
-      return value;
+    size_t offset = 0;
-    return (value << shift) | (value >> (sizeof(value)*8 - shift));
+    uint32_t h32;
-}
-
-uint32_t _rotr(const uint32_t value, int shift) {
-    if ((shift &= sizeof(value)*8 - 1) == 0)
-      return value;
-    return (value >> shift) | (value << (sizeof(value)*8 - shift));
-}
-
-uint32_t hash(uint8_t * data, int len) {
-    int end = len;
-    int offset = 0;
-    int h32;
     if (len >= 16) {
         int limit = end - 16;
         uint32_t v1 = seed + PRIME1 + PRIME2;
@@ -42,38 +35,40 @@ uint32_t hash(uint8_t * data, int len) {
         uint32_t v4 = seed - PRIME1;
 
         do {
-            v1 += (*(uint32_t*)(data + offset)) * PRIME2;
+            v1 += (*(uint32_t *)(data + offset)) * PRIME2;
-            v1 = _rotl(v1, 13);
+            v1 = rotl(v1, 13);
             v1 *= PRIME1;
             offset += 4;
-            v2 += (*(uint32_t*)(data + offset)) * PRIME2;
+            v2 += (*(uint32_t *)(data + offset)) * PRIME2;
-            v2 = _rotl(v2, 13);
+            v2 = rotl(v2, 13);
             v2 *= PRIME1;
             offset += 4;
-            v3 += (*(uint32_t*)(data + offset)) * PRIME2;
+            v3 += (*(uint32_t *)(data + offset)) * PRIME2;
-            v3 = _rotl(v3, 13);
+            v3 = rotl(v3, 13);
             v3 *= PRIME1;
             offset += 4;
-            v4 += (*(uint32_t*)(data + offset)) * PRIME2;
+            v4 += (*(uint32_t *)(data + offset)) * PRIME2;
-            v4 = _rotl(v4, 13);
+            v4 = rotl(v4, 13);
             v4 *= PRIME1;
             offset += 4;
-        } while(offset <= limit);
+        } while (offset <= limit);
         // main loop ends
         // mix
-        h32 = _rotl(v1, 1) + _rotl(v2, 7) + _rotl(v3, 12) + _rotl(v4, 18);
+        h32 = rotl(v1, 1) + rotl(v2, 7) + rotl(v3, 12) + rotl(v4, 18);
     } else {
         h32 = seed + PRIME5;
     }
 
-    for(h32 += len; offset <= end - 4; offset += 4) {
+    if (end > 4) {
-        h32 += (*(uint32_t*)(data + offset)) * PRIME3;
+        for (h32 += len; offset <= end - 4; offset += 4) {
-        h32 = _rotl(h32, 17) * PRIME4;
+            h32 += (*(uint32_t *)(data + offset)) * PRIME3;
+            h32 = rotl(h32, 17) * PRIME4;
+        }
     }
 
-    while(offset < end) {
+    while (offset < end) {
         h32 += (data[offset] & 255) * PRIME5;
-        h32 = _rotl(h32, 11) * PRIME1;
+        h32 = rotl(h32, 11) * PRIME1;
         ++offset;
     }
 
@@ -88,4 +83,264 @@ uint32_t hash(uint8_t * data, int len) {
 // --------------------------------------------------------
 // To here
 
+// Po2
+#define INIT_BUCKET_COUNT 32
+#define HEADER_SIZE sizeof(void *)
+#define GROW_THRESHOLD 75
+// The size of an entry for a data size of <size>
+#define ENTRY(size) (HEADER_SIZE + size)
+// Each entry is composed of a 8 bytes header and the data (or garbage if there
+// is none). The 8 bytes header is either a non null pointer to the key or zero
+// if the bucket is empty
 
+static inline void handle_alloc_error() {
+    printf("Error when allocating (OOM?)\n");
+    exit(1);
+}
+
+Map map_new(size_t data_size) {
+    Map map = {};
+    map.bucket_count = INIT_BUCKET_COUNT;
+    map.data_size = data_size;
+    map.used = 0;
+    map.buckets = calloc(INIT_BUCKET_COUNT, ENTRY(data_size));
+    map.mask = INIT_BUCKET_COUNT - 1;
+    if (!map.buckets)
+        handle_alloc_error();
+    return map;
+}
+
+// Double the size of the map
+void map_grow(Map *map) {
+    size_t entry_size = ENTRY(map->data_size);
+
+    size_t new_bucket_count = map->bucket_count * 2;
+    void *new_alloc = calloc(new_bucket_count, entry_size);
+    size_t new_mask = (map->mask << 1) + 1;
+    if (!new_alloc)
+        handle_alloc_error();
+    void *current = map->buckets;
+
+    for (int i = 0; i < map->bucket_count; i++) {
+        void *header = *(void **)current;
+        if (header == NULL)
+            continue; // skip if unused
+        size_t len = *(size_t *)header;
+        void *key = header + sizeof(size_t);
+
+        uint32_t hash = xxhash32(key, len);
+        uint32_t index = hash & new_mask;
+        void *dst_bucket = new_alloc + index * entry_size;
+
+        while (*(void **)dst_bucket != NULL) {
+            dst_bucket += entry_size;
+            index++;
+            if (index == new_bucket_count) {
+                index = 0;
+                dst_bucket = new_alloc;
+            }
+        }
+
+        *(void **)dst_bucket = header; // set key of new bucket
+        memcpy(dst_bucket + HEADER_SIZE, current + HEADER_SIZE,
+               map->data_size); // set value of new bucket
+
+        current += entry_size;
+    }
+
+    free(map->buckets);
+    map->buckets = new_alloc;
+    map->mask = new_mask;
+    map->bucket_count = new_bucket_count;
+}
+
+void map_insert(Map *map, uint8_t *key, size_t key_len, void *data) {
+    uint32_t hash = xxhash32(key, key_len);
+    size_t index = hash & map->mask;
+    size_t entry_size = ENTRY(map->data_size);
+    void *bucket = map->buckets + index * entry_size;
+    // Go to next empty bucket
+    while (*(void **)bucket != NULL) {
+        bucket += entry_size;
+        index++;
+        if (index == map->bucket_count) {
+            index = 0;
+            bucket = map->buckets;
+        }
+    }
+    // memory for the key: the size + the data
+    void *key_buf = malloc(sizeof(size_t) + key_len);
+    if (!key_buf)
+        handle_alloc_error();
+    *(size_t *)key_buf = key_len;                   // write key_len
+    memcpy(key_buf + sizeof(size_t), key, key_len); // write key
+
+    *(void **)bucket = key_buf;
+    memcpy(bucket + HEADER_SIZE, data, map->data_size);
+    map->used++;
+
+    if (map->used * 100 / map->bucket_count > GROW_THRESHOLD) {
+        map_grow(map);
+    }
+}
+
+inline static void *map_find(Map *map, uint8_t *key, size_t key_len) {
+    uint32_t hash = xxhash32(key, key_len);
+    size_t index = hash & map->mask;
+    size_t entry_size = ENTRY(map->data_size);
+    void *bucket = map->buckets + index * entry_size;
+    size_t start_index = index;
+    while (1) {
+        void *header = *(void **)bucket;
+        if (header) {
+            size_t cur_key_len = *(size_t *)header;
+            void *cur_key = header + sizeof(size_t);
+            if (cur_key_len == key_len && memcmp(cur_key, key, key_len) == 0)
+                break; // We found the bucket (usally the first one)
+        }
+
+        bucket += entry_size;
+        index++;
+        // Go back to begining if we went to the end;
+        if (index == map->bucket_count) {
+            index = 0;
+            bucket = map->buckets;
+        }
+        // If we went over every entry without finding the bucket
+        if (index == start_index) {
+            return NULL;
+        }
+    }
+    return bucket;
+}
+
+bool map_contains(Map *map, uint8_t *key, size_t key_len) {
+    return map_find(map, key, key_len) != NULL;
+}
+
+void map_get(Map *map, uint8_t *key, size_t key_len, void *data) {
+    void *bucket = map_find(map, key, key_len);
+    if (!bucket) {
+        printf("ERR (map_get): key not in map\n");
+        return;
+    }
+    memcpy(data, bucket + HEADER_SIZE, map->data_size);
+}
+
+void map_remove(Map *map, uint8_t *key, size_t key_len, void *data) {
+    void *bucket = map_find(map, key, key_len);
+    if (!bucket) {
+        printf("ERR (map_remove): key not in map\n");
+        return;
+    }
+
+    if (data != NULL)
+        memcpy(data, bucket + HEADER_SIZE, map->data_size);
+
+    void *key_ptr = *(void **)bucket;
+    free(key_ptr);
+    *(void **)bucket = NULL;
+    map->used--;
+}
+
+static inline size_t map_next_index_from(Map *map, size_t from) {
+    if (from >= map->bucket_count)
+        return -1;
+    for (int i = from; i < map->bucket_count; i++) {
+        void *bucket = map->buckets + i * ENTRY(map->data_size);
+        if (*(void **)bucket != NULL)
+            return i;
+    }
+    return -1;
+}
+
+MapIter map_iter(Map *map) {
+    MapIter iter;
+    iter.map = map;
+    iter.next = map_next_index_from(map, 0);
+    return iter;
+}
+
+bool map_iter_has_next(MapIter *iter) { return iter->next != -1; }
+
+void map_iter_next(MapIter *iter, void **key, size_t *key_len, void **data) {
+    void *bucket =
+        iter->map->buckets + ENTRY(iter->map->data_size) * iter->next;
+    if (key)
+        *key = (*(void **)bucket) + sizeof(size_t);
+    if (key_len)
+        *key_len = **(size_t **)bucket;
+    if (data)
+        *data = bucket + HEADER_SIZE;
+    iter->next = map_next_index_from(iter->map, iter->next + 1);
+}
+
+void _center(size_t length, char *format, uintmax_t value) {
+    size_t l = snprintf(NULL, 0, format, value);
+    char str[l + 1];
+    int padleft = (length - l) / 2;
+    int padright = length - l - padleft;
+    snprintf(str, l + 1, format, value);
+    printf("%*s%s%*s", padleft, "", str, padright, "");
+}
+
+void _centers(size_t length, char * s) {
+    size_t l = strlen(s);
+    char str[l + 1];
+    int padleft = (length - l) / 2;
+    int padright = length - l - padleft;
+    snprintf(str, l + 1, "%s", s);
+    printf("%*s%s%*s", padleft, "", str, padright, "");
+}
+
+void map_debug(Map map, char *format) {
+    printf("%s", "┌────────┬───────────────┬───────────┬─────────┐\n");
+    printf("%s", "│  map   │ buckets count │ data size │ members │\n");
+    printf("%s", "├────────┼───────────────┼───────────┼─────────┤\n");
+    printf("%s", "│ values │");
+    _center(15, "%lu", map.bucket_count);
+    printf("%s", "│");
+    _center(11, "%lu", map.data_size);
+    printf("%s", "│");
+    _center(9, "%lu", map.used);
+    printf("%s", "│\n");
+    printf("%s", "└────────┴───────────────┴───────────┴─────────┘\n");
+    bool last_occ = true;
+    bool last_n = false;
+    for (size_t i = 0; i < map.bucket_count; i++) {
+        void * e = map.buckets + map.data_size * i;
+        bool locc = last_occ;
+        last_occ = *(void**)e != NULL;
+        if (!locc && !last_occ)
+            continue;
+        if (locc && !last_occ) {
+            if (i == 0) {
+                printf("%s", "┌──────────────────────────────────────────┐\n");
+            } else if (!last_n) {
+                printf("%s",
+                       "\033[1A├────┴──────────────────┴──────────────────┤\n");
+            } else {
+                printf("%s",
+                       "\033[1A┌────┴──────────────────┴──────────────────┤\n");
+            }
+            printf("%s", "│                   .....                  │\n");
+            printf("%s", "├────┬──────────────────┬──────────────────┤\n");
+            continue;
+        }
+        printf("%s", "│");
+        _center(4, "%lu", i);
+        printf("%s", "│");
+        void * ptr = *(void**)e;
+        _centers(18, ptr == NULL ? "N/A" : ptr + sizeof(size_t));
+        printf("%s", "│");
+        _center(18, format, *(uint32_t *)(e + HEADER_SIZE));
+        printf("%s", "│\n");
+        printf("├────┼──────────────────┼──────────────────┤\n");
+    }
+    if (last_occ) {
+        printf("\033[1A└────┴──────────────────┴──────────────────┘\n");
+    } else {
+        printf("\033[1A└──────────────────────────────────────────┘\n");
+    }
+    printf("\n\n");
+}

hashmap.h

@@ -1,6 +1,68 @@
 #ifndef HASHMAP_H
 #define HASHMAP_H
 #include <stdint.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
 
+// A hashmap
+typedef struct {
+    // Pointer to allocation for buckets
+    void * buckets;
+    // Typically sizeof(T) for Map<_, T>
+    size_t data_size;
+    // Always a power of 2
+    size_t bucket_count;
+    // How many used buckets are there
+    size_t used;
+    size_t mask;
+} Map;
 
+typedef struct {
+    Map * map;
+    size_t next;
+} MapIter;
+
+// Create a new map of a type
+#define map_of(type) map_new(sizeof(type))
+// Create a new map holding value of a size
+Map map_new(size_t data_size);
+// Insert a key value pair in the map
+void map_insert(Map * map, uint8_t * key, size_t key_len, void * data);
+// Test if a key exist within a map
+bool map_contains(Map * map, uint8_t * key, size_t key_len);
+// Get the value of a key in the map into data
+void map_get(Map * map, uint8_t * key, size_t key_len, void * data);
+// Remove a key value pair from the map, if data is not NULL, write value to it.
+void map_remove(Map * map, uint8_t * key, size_t key_len, void * data);
+// Get an iterator of the map
+MapIter map_iter(Map * map);
+// Test if there is a next
+bool map_iter_has_next(MapIter * iter);
+// Get the next value, if key is not NULL, put a pointer to the key in key, if key_len is not NULL
+// put the len of the key in key_len, if data is not null, put a pointer to the data in data.
+void map_iter_next(MapIter * iter, void ** key, size_t * key_len, void ** data);
+
+// map_insert with a string key
+static inline void map_insert_str(Map * map, const char * key, void * data) {
+    size_t len = strlen(key) + 1;
+    map_insert(map, (void *)key, len, data);
+}
+// map_contains with a string key
+static inline bool map_contains_str(Map * map, const char * key) {
+    size_t len = strlen(key) + 1;
+    return map_contains(map, (void *)key, len);
+}
+// map_get with a string key
+static inline void map_get_str(Map * map, const char * key, void * data) {
+    size_t len = strlen(key) + 1;
+    map_get(map, (void *)key, len, data);
+}
+// map_remove with a string key
+static inline void map_remove_str(Map * map, const char * key, void * data) {
+    size_t len = strlen(key) + 1;
+    map_remove(map, (void *)key, len, data);
+}
+
+void map_debug(Map map, char *format);
 #endif

hid.c

@@ -1,17 +1,236 @@
-#include <stdlib.h>
+#include<stdlib.h>
-#include <dirent.h>
+#include<dirent.h>
-#include <stdio.h>
+#include<string.h>
+#include<stdio.h>
+#include<sys/ioctl.h>
+#include<linux/input.h>
+#include<fcntl.h>
+#include<linux/uinput.h>
+#include<linux/input.h>
+#include<linux/joystick.h>
+#include<stdbool.h>
+#include<time.h>
 
-void hid_main() {
+#include "hid.h"
-  DIR *d;
+#include "vec.h"
-  struct dirent *dir;
+#include "main.h"
-  d =  opendir("/sys/class/hidraw");
+
-  if(d) {
+// List of uniq of the currently known devices
-    while ((dir = readdir(d)) != NULL) {
+static Vec devices;
-      if(dir->d_type != DT_LNK) continue;
+// List of the new devices of a poll, static to keep the allocation alive
-      printf("%s\n", dir->d_ino);
+static Vec new_devices;
+// Queue of devices to be taken by connections
+static Vec devices_queue;
+// Mutex for the device queue
+static pthread_mutex_t devices_queue_mutex = PTHREAD_MUTEX_INITIALIZER;
+// Condvar notified on device queue update
+static pthread_cond_t devices_queue_cond = PTHREAD_COND_INITIALIZER;
+// Mutex for devices
+static pthread_mutex_t devices_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+// uniqs are just hexadecimal numbers with colons in between each byte
+uniq_t parse_uniq(char uniq[17]) {
+    uniq_t res = 0;
+    for(int i = 0; i < 17; i++) {
+        char c = uniq[i];
+        int digit;
+        if(c >= '0' && c <= '9') digit = c - '0';
+        else if(c >= 'a' && c <= 'f') digit = c - 'a' + 10;
+        else if(c >= 'A' && c <= 'F') digit = c - 'A' + 10;
+        else continue;
+        res <<= 4;
+        res += digit;
     }
-    closedir(d);
+    return res;
-  }
+}
-  exit(0);
+
+bool filter_event(int fd, char * event) {
+    char device_path[64];
+    snprintf(device_path, 64, "/sys/class/input/%s/device", event);
+
+    DIR * device_dir = opendir(device_path);
+    struct dirent * device_dirent;
+
+    bool found = false;
+    while((device_dirent = readdir(device_dir)) != NULL) {
+        if(device_dirent->d_type == DT_DIR && strncmp(device_dirent->d_name, "js", 2) == 0) {
+            found = true;
+            break;
+        }
+    }
+
+    if(!found) {
+        return false;
+    }
+    
+    uint16_t info[4];
+    ioctl(fd, EVIOCGID, info);
+    return info[1] == 0x054c && info[2] == 0x05c4;
+}
+
+void poll_devices_init() {
+    devices = vec_of(uniq_t);
+    new_devices = vec_of(PhysicalDevice);
+    devices_queue = vec_of(PhysicalDevice);
+}
+
+PhysicalDevice get_device() {
+    pthread_mutex_lock(&devices_queue_mutex);
+    if(devices_queue.len > 0){
+        PhysicalDevice r;
+        vec_pop(&devices_queue, &r);
+        pthread_mutex_unlock(&devices_queue_mutex);
+
+        return r;
+    }
+    while(devices_queue.len == 0) {
+        pthread_cond_wait(&devices_queue_cond, &devices_queue_mutex);
+    }
+    
+    PhysicalDevice res;
+    vec_pop(&devices_queue, &res);
+    if(devices_queue.len > 0) {
+        pthread_cond_signal(&devices_queue_cond);
+    }
+    pthread_mutex_unlock(&devices_queue_mutex);
+    return res;
+}
+
+void return_device(PhysicalDevice * dev) {
+    close(dev->event);
+    close(dev->hidraw);
+    pthread_mutex_lock(&devices_mutex);
+    for(int i = 0; i < devices.len; i++) {
+        uniq_t * uniq = vec_get(&devices, i);
+        if(*uniq == dev->uniq) {
+            vec_remove(&devices, i, NULL);
+            break;
+        }
+    }
+    pthread_mutex_unlock(&devices_mutex);
+}
+
+void poll_devices() {
+    vec_clear(&new_devices);
+
+    DIR * input_dir = opendir("/sys/class/input");
+    struct dirent * input;
+    while((input = readdir(input_dir)) != NULL) {
+        // Ignore if the entry isn't a linkg or doesn't start with event
+        if(input->d_type != DT_LNK || strncmp(input->d_name, "event", 5) != 0) {
+            continue;
+        }
+
+        PhysicalDevice dev = {};
+
+        char event_path[64];
+        snprintf(event_path, 64, "/dev/input/%s", input->d_name);
+
+        dev.event = open(event_path, O_RDONLY);
+
+        if(dev.event < 0) {
+            continue;
+        }
+
+        char name[256] = {};
+        ioctl(dev.event, EVIOCGNAME(256), name);
+
+        if(!filter_event(dev.event, input->d_name)) goto skip;
+
+        uniq_t uniq;
+        {
+            char uniq_str[17] = {};
+
+            char uniq_path[256];
+            snprintf(uniq_path, 256, "/sys/class/input/%s/device/uniq", input->d_name);
+
+            int uniq_fd = open(uniq_path, O_RDONLY);
+
+            if(uniq_fd < 0) goto skip;
+
+            read(uniq_fd, uniq_str, 17);
+            uniq = parse_uniq(uniq_str);
+
+            close(uniq_fd);
+
+            // If we couldn't parse the uniq (this assumes uniq can't be zero, which is probably alright)
+            if(uniq == 0) goto skip;
+        }
+
+        bool found = false;
+
+        pthread_mutex_lock(&devices_mutex);
+        for(int i = 0; i < devices.len; i++) {
+            uniq_t * dev_uniq = vec_get(&devices, i);
+            if(*dev_uniq == uniq) {
+                found = true;
+                break;
+            }
+        }
+        pthread_mutex_unlock(&devices_mutex);
+
+        if(found) goto skip;
+
+        dev.uniq = uniq;
+
+        char hidraw_path[64];
+
+        {
+            char hidraw_path[256];
+            snprintf(hidraw_path, 256, "/sys/class/input/%s/device/device/hidraw", input->d_name);
+
+            DIR * hidraw_dir = opendir(hidraw_path);
+            struct dirent * hidraw = NULL;
+            while((hidraw = readdir(hidraw_dir)) != NULL) {
+                if(strncmp(hidraw->d_name, "hidraw", 6) == 0) break;
+            }
+
+            if(hidraw == NULL) {
+                printf("Couldn't get hidraw of %s", input->d_name);
+                continue;
+            }
+
+            snprintf(hidraw_path, 64, "/dev/%s", hidraw->d_name);
+
+            closedir(hidraw_dir);
+        }
+
+        dev.hidraw = open(hidraw_path, O_WRONLY);
+        if(dev.hidraw < 0) goto skip;
+
+        pthread_mutex_lock(&devices_mutex);
+        vec_push(&devices, &uniq);
+        pthread_mutex_unlock(&devices_mutex);
+        vec_push(&new_devices, &dev);
+
+        printf("HID: New device, %s (%s: %012lx)\n", name, input->d_name, dev.uniq);
+        continue;
+
+        // close open file descriptor and continue
+skip:
+        close(dev.event);
+        continue;
+    };
+
+    closedir(input_dir);
+    if(new_devices.len > 0) {
+        pthread_mutex_lock(&devices_queue_mutex);
+        vec_extend(&devices_queue, new_devices.data, new_devices.len);
+        // Signal that there are new devices
+        pthread_cond_signal(&devices_queue_cond);
+        pthread_mutex_unlock(&devices_queue_mutex);
+    }
+}
+
+void * hid_thread() {
+    printf("HID: start\n");
+    poll_devices_init();
+    while(1) {
+        poll_devices();
+        struct timespec ts;
+        ts.tv_sec = 1;
+        ts.tv_nsec = 0;
+        nanosleep(&ts, NULL);
+    }
+    return NULL;
 }

hid.h

@@ -1,7 +1,19 @@
 #ifndef HID_H
 #define HID_H
+#include<stdint.h>
+#include<pthread.h>
+#include "vec.h"
 
+typedef uint64_t uniq_t;
 
-void hid_main();
+typedef struct {
+    int event;
+    int hidraw;
+    uniq_t uniq;
+} PhysicalDevice;
+
+void * hid_thread();
+void return_device(PhysicalDevice * dev);
+PhysicalDevice get_device();
 
 #endif

main.c

@@ -1,29 +1,24 @@
-// vi: set shiftwidth=4 : set softtabstop=4
+#include<stdio.h>
-#include <stdio.h>
+#include<sys/ioctl.h>
-#include <sys/ioctl.h>
+#include<linux/joystick.h>
-#include <linux/joystick.h>
+#include<stdint.h>
-#include <stdint.h>
+#include<fcntl.h>
-#include <fcntl.h>
+#include<stdlib.h>
-#include <stdlib.h>
+#include<string.h>
-#include <string.h>
+#include<stdarg.h>
-#include <stdarg.h>
+#include<unistd.h>
-#include <unistd.h>
+#include<pthread.h>
 
 #include "main.h"
 #include "hid.h"
+#include "server.h"
 
 const char* USAGE[] = {
-        "jsfw client [input] [address] [port]\n",
+        "jsfw client [address] [port]\n",
         "jsfw server [port]\n",
 };
 const size_t EVENT_SIZE = sizeof(struct js_event);
 
-void joystick_debug(Joystick * js) {
-    printf("Joystick");
-    if(js->name) printf(" (%s)", js->name);
-    printf(": %u buttons, %u axes\n", js->button_count, js->axis_count);
-}
-
 void panicf(const char *fmt, ...) {
     va_list args;
     va_start(args, fmt);
@@ -34,49 +29,22 @@ void panicf(const char *fmt, ...) {
 
 uint16_t parse_port(const char * str) {
     long long n = atoll(str);
-    if(n < 0 || n > UINT16_MAX)
+    if(n <= 0 || n > UINT16_MAX)
-        panicf("Invalid port: Expected a number in the range 0..%d, got %lld\n", UINT16_MAX, n);
+        panicf("Invalid port: Expected a number in the range 1..%d, got '%s'\n", UINT16_MAX, str);
     return n;
 }
 
 void server(uint16_t port) {
     printf("Server (port: %u).\n", port);
-    panicf("Uninplemented\n");
+
+    pthread_t _;
+    pthread_create(&_, NULL, hid_thread, NULL);
+
+    server_run(port);
 }
 
-void client(char * input, char * address, uint16_t port) {
+void client(char * address, uint16_t port) {
-    hid_main();
+    printf("JSFW Client (%s:%d)\n", address, port);
-    printf("JSFW Client (%s -> %s:%d)\n", input, address, port);
-    int fd = open(input, O_RDONLY);
-    if(fd < 0) panicf("Couldn't open %s", input);
-
-    Joystick js = {};
-
-    char name[256];
-    int name_len = ioctl(fd, JSIOCGNAME(256), name);
-    if(name_len >= 0) {
-        js.name = malloc(name_len);
-        if(js.name) strncpy(js.name, name, name_len);
-    }
-
-    ioctl(fd, JSIOCGBUTTONS, &js.button_count);
-    ioctl(fd, JSIOCGAXES, &js.axis_count);
-
-    joystick_debug(&js);
-    
-    struct js_event events[128];
-    while(1) {
-        int bytes = read(fd, events, EVENT_SIZE);
-        if(bytes < EVENT_SIZE) {
-            printf("Got %d bytes, expected at least %lu", bytes, EVENT_SIZE);
-            continue;
-        }
-        int count = bytes / EVENT_SIZE;
-        for(int i = 0; i < count; i++) {
-            struct js_event event = events[i];
-            printf("EV | type(%d) number(%d) value(%d) ts(%d)\n", event.type, event.number, event.value, event.time);
-        }
-    }
 }
 
 int main(int argc, char* argv[]) {
@@ -98,13 +66,12 @@ int main(int argc, char* argv[]) {
 
     } else if(strcmp(mode, "client") == 0) {
 
-        if(argc < 5)
+        if(argc < 4)
             panicf("Usage: %s", USAGE[0]);
 
-        char * input = argv[2];
+        char * address = argv[2];
-        char * address = argv[3];
+        uint16_t port = parse_port(argv[3]);
-        uint16_t port = parse_port(argv[4]);
+        client(address, port);
-        client(input, address, port);
 
     } else {
         printf("Unknown mode: '%s'\n", mode);

main.h

@@ -1,11 +1,9 @@
 #ifndef MAIN_H
 #define MAIN_H
-#include <stdint.h>
+#include<stdint.h>
+#include<pthread.h>
+#include "vec.h"
 
-typedef struct {
+void panicf(const char * fmt, ...);
-  char * name;
-  uint8_t button_count;
-  uint8_t axis_count;
-} Joystick;
 
 #endif

net.c

@@ -0,0 +1,87 @@
+#include "net.h"
+
+Message msg_device_info() {
+    MessageDeviceInfo m;
+    m.code = DeviceInfo;
+
+    Message s;
+    s.device_info = m;
+    return s;
+}
+
+int msg_deserialize(const uint8_t * buf, size_t len, Message * dst) {
+    // Decrement len so that it becomes the len of the data without the code.
+    if(len-- < 1) return -1;
+    // This ensures that only a byte is read instead of a full enum value
+    uint8_t code_byte = buf[0];
+    MessageCode code = (MessageCode) code_byte;
+
+    switch(code) {
+        case Heartbeat:
+            if(MSS_HEARTBEAT > len) return -1;
+            dst->code = code;
+            dst->heartbeat.alive = buf[1];
+            return 0;
+        case DeviceInfo:
+            if(MSS_DEVICE_INFO > len) return -1;
+            dst->code = code;
+            return 0;
+        case DeviceReport:
+            if(len < MSS_DEVICE_REPORT) return -1;
+            dst->code = code;
+            return 0;
+        case DeviceDestroy:
+            if(len < MSS_DEVICE_DESTROY) return -1;
+            dst->code = code;
+            return 0;
+        case ControllerState:
+            if(len < MSS_CONTROLLER_STATE) return -1;
+            dst->code = code;
+            dst->controller_state.led[0] =       buf[1];
+            dst->controller_state.led[1] =       buf[2];
+            dst->controller_state.led[2] =       buf[3];
+            dst->controller_state.small_rumble = buf[4];
+            dst->controller_state.big_rumble =   buf[5];
+            dst->controller_state.flash_on =     buf[6];
+            dst->controller_state.flash_off =    buf[7];
+            return 0;
+        default:
+            return -1;
+    }
+}
+
+// The indices have to match with msg_deserialize
+int msg_serialize(uint8_t * buf, size_t len, Message msg) {
+    switch(msg.code) {
+        case Heartbeat:
+            if(MSS_HEARTBEAT >= len) return -1;
+            buf[0] = (uint8_t) msg.code;
+            buf[1] = msg.heartbeat.alive;
+            return 0;
+        case DeviceInfo:
+            if(MSS_DEVICE_INFO >= len) return -1;
+            buf[0] = (uint8_t) msg.code;
+            return 0;
+        case DeviceReport:
+            if(MSS_DEVICE_REPORT >= len) return -1;
+            buf[0] = (uint8_t) msg.code;
+            return 0;
+        case DeviceDestroy:
+            if(MSS_DEVICE_DESTROY >= len) return -1;
+            buf[0] = (uint8_t) msg.code;
+            return 0;
+        case ControllerState:
+            if(MSS_CONTROLLER_STATE >= len) return -1;
+            buf[0] = (uint8_t) msg.code;
+            buf[1] = msg.controller_state.led[0];
+            buf[2] = msg.controller_state.led[1];
+            buf[3] = msg.controller_state.led[2];
+            buf[4] = msg.controller_state.small_rumble;
+            buf[5] = msg.controller_state.big_rumble;
+            buf[6] = msg.controller_state.flash_on;
+            buf[7] = msg.controller_state.flash_off;
+            return 0;
+        default:
+            return -1;
+    }
+}

net.h

@@ -1,4 +1,59 @@
 #ifndef NET_H
 #define NET_H
+#include<stdint.h>
+#include<stdlib.h>
+
+typedef enum {
+    Heartbeat = 0,
+    DeviceInfo = 1,
+    DeviceReport = 2,
+    DeviceDestroy = 3,
+    ControllerState = 4,
+} MessageCode;
+
+typedef struct {
+    MessageCode code;
+    uint8_t alive;
+} MessageHeartbeat;
+#define MSS_HEARTBEAT 1
+// MSS -> Message Serialized Size:
+// Size of the data of the message when serialized (no alignment / padding)
+
+typedef struct {
+    MessageCode code;
+} MessageDeviceInfo;
+#define MSS_DEVICE_INFO 0
+
+typedef struct {
+    MessageCode code;
+} MessageDeviceReport;
+#define MSS_DEVICE_REPORT 0
+
+typedef struct {
+    MessageCode code;
+} MessageDeviceDestroy;
+#define MSS_DEVICE_DESTROY 0
+
+typedef struct  {
+    MessageCode code;
+    uint8_t led[3];
+    uint8_t small_rumble;
+    uint8_t big_rumble;
+    uint8_t flash_on;
+    uint8_t flash_off;
+} MessageControllerState;
+#define MSS_CONTROLLER_STATE 7
+
+typedef union {
+    MessageCode code;
+    MessageHeartbeat heartbeat;
+    MessageDeviceInfo device_info;
+    MessageDeviceReport device_report;
+    MessageDeviceDestroy device_destroy;
+    MessageControllerState controller_state;
+} Message;
+
+int msg_deserialize(const uint8_t * buf, size_t len, Message * dst);
+int msg_serialize(uint8_t * buf, size_t len, Message msg);
 
 #endif

server.c

@@ -0,0 +1,75 @@
+#include<arpa/inet.h>
+#include<sys/socket.h>
+#include<stdint.h>
+#include<pthread.h>
+#include<stdio.h>
+#include<string.h>
+
+#include "main.h"
+#include "vec.h"
+#include "net.h"
+
+struct Connection {
+    int socket;
+    uint32_t id;
+};
+
+void * server_handle_conn(void * args_) {
+    struct Connection * args = args_;
+
+    printf("THREAD(%u): start\n", args->id);
+    while(1) {
+        uint8_t buf[1024];
+        while(1) {
+            int len = recv(args->socket, buf, 1024, MSG_WAITALL);
+            if(len <= 0) break;
+            Message msg;
+            if(msg_deserialize(buf, len, &msg) == 0) {
+                
+            } else {
+                printf("Couldn't parse message.\n");
+            }
+        }
+        printf("THREAD(%u): connection closed\n", args->id);
+    }
+
+    free(args);
+    return NULL;
+}
+
+void server_run(uint16_t port) {
+    printf("SERVER: start\n");
+    int sock = socket(AF_INET, SOCK_STREAM, 0);
+    if(sock < 0) panicf("Couldn't open socket\n");
+    struct sockaddr_in addr = {};
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = htonl(INADDR_ANY);
+    addr.sin_port = htons(port);
+    if(bind(sock, (struct sockaddr*)&addr, sizeof(addr)) != 0)
+        panicf("Couldn't bind to the socket\n");
+    if(listen(sock, 16) != 0)
+        panicf("Couldn't listen on socket\n");
+
+    uint32_t ids = 0;
+    while(1) {
+        struct sockaddr con_addr;
+        socklen_t con_len = sizeof(con_addr);
+        struct Connection conn;
+
+        conn.socket = accept(sock, &con_addr, &con_len);
+
+        if(conn.socket >= 0) {
+            printf("SERVER: got connection\n");
+
+            conn.id = ids++;
+
+            struct Connection * conn_ptr = malloc(sizeof(struct Connection));
+            memcpy(conn_ptr, &conn, sizeof(struct Connection));
+
+            pthread_t thread;
+            pthread_create(&thread, NULL, server_handle_conn, conn_ptr);
+        } else {
+            printf("Couldn't accept connection (%d)\n", conn.socket);
+        }
+    }
+}

server.h

@@ -0,0 +1,7 @@
+#ifndef SERVER_H
+#define SERVER_H
+#include<stdint.h>
+
+void server_run(uint16_t port);
+
+#endif

util.c

@@ -0,0 +1,22 @@
+#include "util.h"
+#include <limits.h>
+
+#ifndef __has_builtin
+#define __has_builtin(_) 0
+#endif
+
+unsigned long log2lu(unsigned long n) {
+#if __has_builtin(__builtin_clz)
+    return sizeof(unsigned long) * CHAR_BIT - __builtin_clz(n) - 1;
+#else
+    unsigned long res = 0;
+    while(n >>= 1) ++res;
+    return res;
+#endif
+}
+
+uint32_t rotl(uint32_t n, unsigned int c) {
+    const unsigned int mask = (CHAR_BIT*sizeof(n) - 1);
+    c &= mask;
+    return (n<<c) | (n>>( (-c)&mask ));
+}

util.h

@@ -0,0 +1,8 @@
+#ifndef UTIL_H
+#define UTIL_H
+#include <stdint.h>
+
+unsigned long log2lu(unsigned long);
+uint32_t rotl (uint32_t n, unsigned int c);
+
+#endif

vec.c

@@ -0,0 +1,100 @@
+#include<stdio.h>
+#include<stdlib.h>
+#include<string.h>
+#include "vec.h"
+
+#define INIT_CAP 8
+
+static void handle_alloc_error() {
+    printf("Error when allocating memory.\n");
+    exit(2);
+}
+
+Vec vec_new(size_t data_size) {
+    return vec_cap(data_size, INIT_CAP);
+}
+
+Vec vec_cap(size_t data_size, size_t initial_capacity) {
+    Vec v;
+    v.cap = initial_capacity;
+    v.len = 0;
+    v.stride = data_size;
+    v.data = malloc(data_size * initial_capacity);
+    return v;
+}
+
+static inline void vec_grow(Vec * v, size_t cap) {
+    if(v->cap >= cap) return;
+    size_t new_cap = cap > v->cap * 2 ? cap : v->cap * 2;
+    void * new_data = realloc(v->data, new_cap * v->stride);
+    if(new_data == NULL) handle_alloc_error();
+    v->data = new_data;
+    v->cap = new_cap;
+}
+
+void vec_push(Vec * v, void * data) {
+    vec_grow(v, v->len + 1);
+    memcpy(v->data + v->stride * v->len++, data, v->stride);
+}
+
+void vec_pop(Vec * v, void * data) {
+    if(v->len == 0) {
+        printf("ERR(vec_pop): Trying to pop an element from an empty vector\n");
+        return;
+    }
+    if(data != NULL)
+        memcpy(data, v->data + v->stride * (v->len - 1), v->stride);
+    v->len--;
+}
+
+void * vec_get(Vec * v, size_t index) {
+    if(index >= v->len) return NULL;
+    return v->data + index * v->stride;
+}
+
+void vec_insert(Vec * v, void * data, size_t index) {
+    if(index > v->len) {
+        printf("ERR(vec_insert): Trying to insert past the end of the vector.\n");
+        return;
+    }
+    vec_grow(v, v->len + 1);
+
+    void * slot = v->data + index * v->stride;
+    if(index < v->len) {
+        memmove(slot + v->stride, slot, (v->len - index) * v->stride);
+    }
+    memcpy(slot, data, v->stride);
+    v->len++;
+}
+
+void vec_remove(Vec * v, size_t index, void * data) {
+    if(v->len == 0) {
+        printf("ERR(vec_remove): Trying to remove an element from an empty vector\n");
+        return;
+    }
+    if(index >= v->len) {
+        printf("ERR(vec_remove): Trying to remove past the end of the vector\n");
+        return;
+    }
+
+    void * slot = v->data + index * v->stride;
+    if(data != NULL)
+        memcpy(data, slot, v->stride);
+    if(index < --v->len)
+        memmove(slot, slot + v->stride, (v->len - index) * v->stride);
+}
+
+void vec_clear(Vec * v) {
+    v->len = 0;
+}
+
+void vec_extend(Vec * v, void * data, size_t len) {
+    if(len == 0) return;
+    vec_grow(v, v->len + len);
+    memcpy(v->data + v->stride * v->len, data, v->stride * len);
+    v->len += len;
+}
+
+void vec_free(Vec v) {
+    free(v.data);
+}

vec.h

@@ -0,0 +1,36 @@
+#ifndef VEC_H
+#define VEC_H
+#include<unistd.h>
+#include<stdint.h>
+
+#define vec_of(type) vec_new(sizeof(type))
+
+typedef struct {
+    void * data;
+    size_t cap;
+    size_t len;
+    size_t stride;
+} Vec;
+
+// Create a new vector
+Vec vec_new(size_t data_size);
+// Create a new vector with an initial capacity
+Vec vec_cap(size_t data_size, size_t initial_capacity);
+// Push an element into the vector
+void vec_push(Vec * v, void * data);
+// Pop an element into the vector, and put it in data if it is not null
+void vec_pop(Vec * v, void * data);
+// Get a pointer to the element at an index, returns NULL if there is no such element
+void * vec_get(Vec * v, size_t index);
+// Insert an element at any index in the vector (except past the end)
+void vec_insert(Vec * v, void * data, size_t index);
+// Remove an element from the vector, and put it in data if it is not NULL
+void vec_remove(Vec * v, size_t index, void * data);
+// Clear the vector
+void vec_clear(Vec * v);
+// Extend the vector with the content of data
+void vec_extend(Vec * v, void * data, size_t len);
+// Free the vector
+void vec_free(Vec v);
+
+#endif