Added DWM

1 files changed, 549 insertions, 0 deletions

diff --git a/patch/ipc/dwm-msg.c b/patch/ipc/dwm-msg.c
new file mode 100644
index 0000000..ca1e1a4
--- /dev/null
+++ b/patch/ipc/dwm-msg.c
@@ -0,0 +1,549 @@
+#include <ctype.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include <yajl/yajl_gen.h>
+
+#define IPC_MAGIC "DWM-IPC"
+// clang-format off
+#define IPC_MAGIC_ARR { 'D', 'W', 'M', '-', 'I', 'P', 'C' }
+// clang-format on
+#define IPC_MAGIC_LEN 7  // Not including null char
+
+#define IPC_EVENT_TAG_CHANGE "tag_change_event"
+#define IPC_EVENT_CLIENT_FOCUS_CHANGE "client_focus_change_event"
+#define IPC_EVENT_LAYOUT_CHANGE "layout_change_event"
+#define IPC_EVENT_MONITOR_FOCUS_CHANGE "monitor_focus_change_event"
+#define IPC_EVENT_FOCUSED_TITLE_CHANGE "focused_title_change_event"
+#define IPC_EVENT_FOCUSED_STATE_CHANGE "focused_state_change_event"
+
+#define YSTR(str) yajl_gen_string(gen, (unsigned char *)str, strlen(str))
+#define YINT(num) yajl_gen_integer(gen, num)
+#define YDOUBLE(num) yajl_gen_double(gen, num)
+#define YBOOL(v) yajl_gen_bool(gen, v)
+#define YNULL() yajl_gen_null(gen)
+#define YARR(body)                                                             \
+  {                                                                            \
+    yajl_gen_array_open(gen);                                                  \
+    body;                                                                      \
+    yajl_gen_array_close(gen);                                                 \
+  }
+#define YMAP(body)                                                             \
+  {                                                                            \
+    yajl_gen_map_open(gen);                                                    \
+    body;                                                                      \
+    yajl_gen_map_close(gen);                                                   \
+  }
+
+typedef unsigned long Window;
+
+const char *DEFAULT_SOCKET_PATH = "/tmp/dwm.sock";
+static int sock_fd = -1;
+static unsigned int ignore_reply = 0;
+
+typedef enum IPCMessageType {
+  IPC_TYPE_RUN_COMMAND = 0,
+  IPC_TYPE_GET_MONITORS = 1,
+  IPC_TYPE_GET_TAGS = 2,
+  IPC_TYPE_GET_LAYOUTS = 3,
+  IPC_TYPE_GET_DWM_CLIENT = 4,
+  IPC_TYPE_SUBSCRIBE = 5,
+  IPC_TYPE_EVENT = 6
+} IPCMessageType;
+
+// Every IPC message must begin with this
+typedef struct dwm_ipc_header {
+  uint8_t magic[IPC_MAGIC_LEN];
+  uint32_t size;
+  uint8_t type;
+} __attribute((packed)) dwm_ipc_header_t;
+
+static int
+recv_message(uint8_t *msg_type, uint32_t *reply_size, uint8_t **reply)
+{
+  uint32_t read_bytes = 0;
+  const int32_t to_read = sizeof(dwm_ipc_header_t);
+  char header[to_read];
+  char *walk = header;
+
+  // Try to read header
+  while (read_bytes < to_read) {
+    ssize_t n = read(sock_fd, header + read_bytes, to_read - read_bytes);
+
+    if (n == 0) {
+      if (read_bytes == 0) {
+        fprintf(stderr, "Unexpectedly reached EOF while reading header.");
+        fprintf(stderr,
+                "Read %" PRIu32 " bytes, expected %" PRIu32 " total bytes.\n",
+                read_bytes, to_read);
+        return -2;
+      } else {
+        fprintf(stderr, "Unexpectedly reached EOF while reading header.");
+        fprintf(stderr,
+                "Read %" PRIu32 " bytes, expected %" PRIu32 " total bytes.\n",
+                read_bytes, to_read);
+        return -3;
+      }
+    } else if (n == -1) {
+      return -1;
+    }
+
+    read_bytes += n;
+  }
+
+  // Check if magic string in header matches
+  if (memcmp(walk, IPC_MAGIC, IPC_MAGIC_LEN) != 0) {
+    fprintf(stderr, "Invalid magic string. Got '%.*s', expected '%s'\n",
+            IPC_MAGIC_LEN, walk, IPC_MAGIC);
+    return -3;
+  }
+
+  walk += IPC_MAGIC_LEN;
+
+  // Extract reply size
+  memcpy(reply_size, walk, sizeof(uint32_t));
+  walk += sizeof(uint32_t);
+
+  // Extract message type
+  memcpy(msg_type, walk, sizeof(uint8_t));
+  walk += sizeof(uint8_t);
+
+  (*reply) = malloc(*reply_size);
+
+  // Extract payload
+  read_bytes = 0;
+  while (read_bytes < *reply_size) {
+    ssize_t n = read(sock_fd, *reply + read_bytes, *reply_size - read_bytes);
+
+    if (n == 0) {
+      fprintf(stderr, "Unexpectedly reached EOF while reading payload.");
+      fprintf(stderr, "Read %" PRIu32 " bytes, expected %" PRIu32 " bytes.\n",
+              read_bytes, *reply_size);
+      free(*reply);
+      return -2;
+    } else if (n == -1) {
+      if (errno == EINTR || errno == EAGAIN) continue;
+      free(*reply);
+      return -1;
+    }
+
+    read_bytes += n;
+  }
+
+  return 0;
+}
+
+static int
+read_socket(IPCMessageType *msg_type, uint32_t *msg_size, char **msg)
+{
+  int ret = -1;
+
+  while (ret != 0) {
+    ret = recv_message((uint8_t *)msg_type, msg_size, (uint8_t **)msg);
+
+    if (ret < 0) {
+      // Try again (non-fatal error)
+      if (ret == -1 && (errno == EINTR || errno == EAGAIN)) continue;
+
+      fprintf(stderr, "Error receiving response from socket. ");
+      fprintf(stderr, "The connection might have been lost.\n");
+      exit(2);
+    }
+  }
+
+  return 0;
+}
+
+static ssize_t
+write_socket(const void *buf, size_t count)
+{
+  size_t written = 0;
+
+  while (written < count) {
+    const ssize_t n =
+        write(sock_fd, ((uint8_t *)buf) + written, count - written);
+
+    if (n == -1) {
+      if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
+        continue;
+      else
+        return n;
+    }
+    written += n;
+  }
+  return written;
+}
+
+static void
+connect_to_socket()
+{
+  struct sockaddr_un addr;
+
+  int sock = socket(AF_UNIX, SOCK_STREAM, 0);
+
+  // Initialize struct to 0
+  memset(&addr, 0, sizeof(struct sockaddr_un));
+
+  addr.sun_family = AF_UNIX;
+  strcpy(addr.sun_path, DEFAULT_SOCKET_PATH);
+
+  connect(sock, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un));
+
+  sock_fd = sock;
+}
+
+static int
+send_message(IPCMessageType msg_type, uint32_t msg_size, uint8_t *msg)
+{
+  dwm_ipc_header_t header = {
+      .magic = IPC_MAGIC_ARR, .size = msg_size, .type = msg_type};
+
+  size_t header_size = sizeof(dwm_ipc_header_t);
+  size_t total_size = header_size + msg_size;
+
+  uint8_t buffer[total_size];
+
+  // Copy header to buffer
+  memcpy(buffer, &header, header_size);
+  // Copy message to buffer
+  memcpy(buffer + header_size, msg, header.size);
+
+  write_socket(buffer, total_size);
+
+  return 0;
+}
+
+static int
+is_float(const char *s)
+{
+  size_t len = strlen(s);
+  int is_dot_used = 0;
+  int is_minus_used = 0;
+
+  // Floats can only have one decimal point in between or digits
+  // Optionally, floats can also be below zero (negative)
+  for (int i = 0; i < len; i++) {
+    if (isdigit(s[i]))
+      continue;
+    else if (!is_dot_used && s[i] == '.' && i != 0 && i != len - 1) {
+      is_dot_used = 1;
+      continue;
+    } else if (!is_minus_used && s[i] == '-' && i == 0) {
+      is_minus_used = 1;
+      continue;
+    } else
+      return 0;
+  }
+
+  return 1;
+}
+
+static int
+is_unsigned_int(const char *s)
+{
+  size_t len = strlen(s);
+
+  // Unsigned int can only have digits
+  for (int i = 0; i < len; i++) {
+    if (isdigit(s[i]))
+      continue;
+    else
+      return 0;
+  }
+
+  return 1;
+}
+
+static int
+is_signed_int(const char *s)
+{
+  size_t len = strlen(s);
+
+  // Signed int can only have digits and a negative sign at the start
+  for (int i = 0; i < len; i++) {
+    if (isdigit(s[i]))
+      continue;
+    else if (i == 0 && s[i] == '-') {
+      continue;
+    } else
+      return 0;
+  }
+
+  return 1;
+}
+
+static void
+flush_socket_reply()
+{
+  IPCMessageType reply_type;
+  uint32_t reply_size;
+  char *reply;
+
+  read_socket(&reply_type, &reply_size, &reply);
+
+  free(reply);
+}
+
+static void
+print_socket_reply()
+{
+  IPCMessageType reply_type;
+  uint32_t reply_size;
+  char *reply;
+
+  read_socket(&reply_type, &reply_size, &reply);
+
+  printf("%.*s\n", reply_size, reply);
+  fflush(stdout);
+  free(reply);
+}
+
+static int
+run_command(const char *name, char *args[], int argc)
+{
+  const unsigned char *msg;
+  size_t msg_size;
+
+  yajl_gen gen = yajl_gen_alloc(NULL);
+
+  // Message format:
+  // {
+  //   "command": "<name>",
+  //   "args": [ ... ]
+  // }
+  // clang-format off
+  YMAP(
+    YSTR("command"); YSTR(name);
+    YSTR("args"); YARR(
+      for (int i = 0; i < argc; i++) {
+        if (is_signed_int(args[i])) {
+          long long num = atoll(args[i]);
+          YINT(num);
+        } else if (is_float(args[i])) {
+          float num = atof(args[i]);
+          YDOUBLE(num);
+        } else {
+          YSTR(args[i]);
+        }
+      }
+    )
+  )
+  // clang-format on
+
+  yajl_gen_get_buf(gen, &msg, &msg_size);
+
+  send_message(IPC_TYPE_RUN_COMMAND, msg_size, (uint8_t *)msg);
+
+  if (!ignore_reply)
+    print_socket_reply();
+  else
+    flush_socket_reply();
+
+  yajl_gen_free(gen);
+
+  return 0;
+}
+
+static int
+get_monitors()
+{
+  send_message(IPC_TYPE_GET_MONITORS, 1, (uint8_t *)"");
+  print_socket_reply();
+  return 0;
+}
+
+static int
+get_tags()
+{
+  send_message(IPC_TYPE_GET_TAGS, 1, (uint8_t *)"");
+  print_socket_reply();
+
+  return 0;
+}
+
+static int
+get_layouts()
+{
+  send_message(IPC_TYPE_GET_LAYOUTS, 1, (uint8_t *)"");
+  print_socket_reply();
+
+  return 0;
+}
+
+static int
+get_dwm_client(Window win)
+{
+  const unsigned char *msg;
+  size_t msg_size;
+
+  yajl_gen gen = yajl_gen_alloc(NULL);
+
+  // Message format:
+  // {
+  //   "client_window_id": "<win>"
+  // }
+  // clang-format off
+  YMAP(
+    YSTR("client_window_id"); YINT(win);
+  )
+  // clang-format on
+
+  yajl_gen_get_buf(gen, &msg, &msg_size);
+
+  send_message(IPC_TYPE_GET_DWM_CLIENT, msg_size, (uint8_t *)msg);
+
+  print_socket_reply();
+
+  yajl_gen_free(gen);
+
+  return 0;
+}
+
+static int
+subscribe(const char *event)
+{
+  const unsigned char *msg;
+  size_t msg_size;
+
+  yajl_gen gen = yajl_gen_alloc(NULL);
+
+  // Message format:
+  // {
+  //   "event": "<event>",
+  //   "action": "subscribe"
+  // }
+  // clang-format off
+  YMAP(
+    YSTR("event"); YSTR(event);
+    YSTR("action"); YSTR("subscribe");
+  )
+  // clang-format on
+
+  yajl_gen_get_buf(gen, &msg, &msg_size);
+
+  send_message(IPC_TYPE_SUBSCRIBE, msg_size, (uint8_t *)msg);
+
+  if (!ignore_reply)
+    print_socket_reply();
+  else
+    flush_socket_reply();
+
+  yajl_gen_free(gen);
+
+  return 0;
+}
+
+static void
+usage_error(const char *prog_name, const char *format, ...)
+{
+  va_list args;
+  va_start(args, format);
+
+  fprintf(stderr, "Error: ");
+  vfprintf(stderr, format, args);
+  fprintf(stderr, "\nusage: %s <command> [...]\n", prog_name);
+  fprintf(stderr, "Try '%s help'\n", prog_name);
+
+  va_end(args);
+  exit(1);
+}
+
+static void
+print_usage(const char *name)
+{
+  printf("usage: %s [options] <command> [...]\n", name);
+  puts("");
+  puts("Commands:");
+  puts("  run_command <name> [args...]    Run an IPC command");
+  puts("");
+  puts("  get_monitors                    Get monitor properties");
+  puts("");
+  puts("  get_tags                        Get list of tags");
+  puts("");
+  puts("  get_layouts                     Get list of layouts");
+  puts("");
+  puts("  get_dwm_client <window_id>      Get dwm client proprties");
+  puts("");
+  puts("  subscribe [events...]           Subscribe to specified events");
+  puts("                                  Options: " IPC_EVENT_TAG_CHANGE ",");
+  puts("                                  " IPC_EVENT_LAYOUT_CHANGE ",");
+  puts("                                  " IPC_EVENT_CLIENT_FOCUS_CHANGE ",");
+  puts("                                  " IPC_EVENT_MONITOR_FOCUS_CHANGE ",");
+  puts("                                  " IPC_EVENT_FOCUSED_TITLE_CHANGE ",");
+  puts("                                  " IPC_EVENT_FOCUSED_STATE_CHANGE);
+  puts("");
+  puts("  help                            Display this message");
+  puts("");
+  puts("Options:");
+  puts("  --ignore-reply                  Don't print reply messages from");
+  puts("                                  run_command and subscribe.");
+  puts("");
+}
+
+int
+main(int argc, char *argv[])
+{
+  const char *prog_name = argv[0];
+
+  connect_to_socket();
+  if (sock_fd == -1) {
+    fprintf(stderr, "Failed to connect to socket\n");
+    return 1;
+  }
+
+  int i = 1;
+  if (i < argc && strcmp(argv[i], "--ignore-reply") == 0) {
+    ignore_reply = 1;
+    i++;
+  }
+
+  if (i >= argc) usage_error(prog_name, "Expected an argument, got none");
+
+  if (!argc || strcmp(argv[i], "help") == 0)
+    print_usage(prog_name);
+  else if (strcmp(argv[i], "run_command") == 0) {
+    if (++i >= argc) usage_error(prog_name, "No command specified");
+    // Command name
+    char *command = argv[i];
+    // Command arguments are everything after command name
+    char **command_args = argv + ++i;
+    // Number of command arguments
+    int command_argc = argc - i;
+    run_command(command, command_args, command_argc);
+  } else if (strcmp(argv[i], "get_monitors") == 0) {
+    get_monitors();
+  } else if (strcmp(argv[i], "get_tags") == 0) {
+    get_tags();
+  } else if (strcmp(argv[i], "get_layouts") == 0) {
+    get_layouts();
+  } else if (strcmp(argv[i], "get_dwm_client") == 0) {
+    if (++i < argc) {
+      if (is_unsigned_int(argv[i])) {
+        Window win = atol(argv[i]);
+        get_dwm_client(win);
+      } else
+        usage_error(prog_name, "Expected unsigned integer argument");
+    } else
+      usage_error(prog_name, "Expected the window id");
+  } else if (strcmp(argv[i], "subscribe") == 0) {
+    if (++i < argc) {
+      for (int j = i; j < argc; j++) subscribe(argv[j]);
+    } else
+      usage_error(prog_name, "Expected event name");
+    // Keep listening for events forever
+    while (1) {
+      print_socket_reply();
+    }
+  } else
+    usage_error(prog_name, "Invalid argument '%s'", argv[i]);
+
+  return 0;
+}
+