#include "ipc.h"
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <yajl/yajl_gen.h>
#include <yajl/yajl_tree.h>
#include "util.h"
#include "yajl_dumps.h"
static struct sockaddr_un sockaddr;
static struct epoll_event sock_epoll_event;
static IPCClientList ipc_clients = NULL;
static int epoll_fd = -1;
static int sock_fd = -1;
static IPCCommand *ipc_commands;
static unsigned int ipc_commands_len;
// Max size is 1 MB
static const uint32_t MAX_MESSAGE_SIZE = 1000000;
static const int IPC_SOCKET_BACKLOG = 5;
/**
* Create IPC socket at specified path and return file descriptor to socket.
* This initializes the static variable sockaddr.
*/
static int
ipc_create_socket(const char *filename)
{
char *normal_filename;
char *parent;
const size_t addr_size = sizeof(struct sockaddr_un);
const int sock_type = SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC;
normalizepath(filename, &normal_filename);
// In case socket file exists
unlink(normal_filename);
// For portability clear the addr structure, since some implementations have
// nonstandard fields in the structure
memset(&sockaddr, 0, addr_size);
parentdir(normal_filename, &parent);
// Create parent directories
mkdirp(parent);
free(parent);
sockaddr.sun_family = AF_LOCAL;
strcpy(sockaddr.sun_path, normal_filename);
free(normal_filename);
sock_fd = socket(AF_LOCAL, sock_type, 0);
if (sock_fd == -1) {
fputs("Failed to create socket\n", stderr);
return -1;
}
DEBUG("Created socket at %s\n", sockaddr.sun_path);
if (bind(sock_fd, (const struct sockaddr *)&sockaddr, addr_size) == -1) {
fputs("Failed to bind socket\n", stderr);
return -1;
}
DEBUG("Socket binded\n");
if (listen(sock_fd, IPC_SOCKET_BACKLOG) < 0) {
fputs("Failed to listen for connections on socket\n", stderr);
return -1;
}
DEBUG("Now listening for connections on socket\n");
return sock_fd;
}
/**
* Internal function used to receive IPC messages from a given file descriptor.
*
* Returns -1 on error reading (could be EAGAIN or EINTR)
* Returns -2 if EOF before header could be read
* Returns -3 if invalid IPC header
* Returns -4 if message length exceeds MAX_MESSAGE_SIZE
*/
static int
ipc_recv_message(int fd, 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) {
const ssize_t n = read(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) {
// errno will still be set
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);
if (*reply_size > MAX_MESSAGE_SIZE) {
fprintf(stderr, "Message too long: %" PRIu32 " bytes. ", *reply_size);
fprintf(stderr, "Maximum message size is: %d\n", MAX_MESSAGE_SIZE);
return -4;
}
// Extract message type
memcpy(msg_type, walk, sizeof(uint8_t));
walk += sizeof(uint8_t);
if (*reply_size > 0)
(*reply) = malloc(*reply_size);
else
return 0;
read_bytes = 0;
while (read_bytes < *reply_size) {
const ssize_t n = read(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) {
// TODO: Should we return and wait for another epoll event?
// This would require saving the partial read in some way.
if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) continue;
free(*reply);
return -1;
}
read_bytes += n;
}
return 0;
}
/**
* Internal function used to write a buffer to a file descriptor
*
* Returns number of bytes written if successful write
* Returns 0 if no bytes were written due to EAGAIN or EWOULDBLOCK
* Returns -1 on unknown error trying to write, errno will carry over from
* write() call
*/
static ssize_t
ipc_write_message(int fd, const void *buf, size_t count)
{
size_t written = 0;
while (written < count) {
const ssize_t n = write(fd, (uint8_t *)buf + written, count - written);
if (n == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK)
return written;
else if (errno == EINTR)
continue;
else
return n;
}
written += n;
DEBUG("Wrote %zu/%zu to client at fd %d\n", written, count, fd);
}
return written;
}
/**
* Initialization for generic event message. This is used to allocate the yajl
* handle, set yajl options, and in the future any other initialization that
* should occur for event messages.
*/
static void
ipc_event_init_message(yajl_gen *gen)
{
*gen = yajl_gen_alloc(NULL);
yajl_gen_config(*gen, yajl_gen_beautify, 1);
}
/**
* Prepares buffers of IPC subscribers of specified event using buffer from yajl
* handle.
*/
static void
ipc_event_prepare_send_message(yajl_gen gen, IPCEvent event)
{
const unsigned char *buffer;
size_t len = 0;
yajl_gen_get_buf(gen, &buffer, &len);
len++; // For null char
for (IPCClient *c = ipc_clients; c; c = c->next) {
if (c->subscriptions & event) {
DEBUG("Sending selected client change event to fd %d\n", c->fd);
ipc_prepare_send_message(c, IPC_TYPE_EVENT, len, (char *)buffer);
}
}
// Not documented, but this frees temp_buffer
yajl_gen_free(gen);
}
/**
* Initialization for generic reply message. This is used to allocate the yajl
* handle, set yajl options, and in the future any other initialization that
* should occur for reply messages.
*/
static void
ipc_reply_init_message(yajl_gen *gen)
{
*gen = yajl_gen_alloc(NULL);
yajl_gen_config(*gen, yajl_gen_beautify, 1);
}
/**
* Prepares the IPC client's buffer with a message using the buffer of the yajl
* handle.
*/
static void
ipc_reply_prepare_send_message(yajl_gen gen, IPCClient *c,
IPCMessageType msg_type)
{
const unsigned char *buffer;
size_t len = 0;
yajl_gen_get_buf(gen, &buffer, &len);
len++; // For null char
ipc_prepare_send_message(c, msg_type, len, (const char *)buffer);
// Not documented, but this frees temp_buffer
yajl_gen_free(gen);
}
/**
* Find the IPCCommand with the specified name
*
* Returns 0 if a command with the specified name was found
* Returns -1 if a command with the specified name could not be found
*/
static int
ipc_get_ipc_command(const char *name, IPCCommand *ipc_command)
{
for (int i = 0; i < ipc_commands_len; i++) {
if (strcmp(ipc_commands[i].name, name) == 0) {
*ipc_command = ipc_commands[i];
return 0;
}
}
return -1;
}
/**
* Parse a IPC_TYPE_RUN_COMMAND message from a client. This function extracts
* the arguments, argument count, argument types, and command name and returns
* the parsed information as an IPCParsedCommand. If this function returns
* successfully, the parsed_command must be freed using
* ipc_free_parsed_command_members.
*
* Returns 0 if the message was successfully parsed
* Returns -1 otherwise
*/
static int
ipc_parse_run_command(char *msg, IPCParsedCommand *parsed_command)
{
char error_buffer[1000];
yajl_val parent = yajl_tree_parse(msg, error_buffer, 1000);
if (parent == NULL) {
fputs("Failed to parse command from client\n", stderr);
fprintf(stderr, "%s\n", error_buffer);
fprintf(stderr, "Tried to parse: %s\n", msg);
return -1;
}
// Format:
// {
// "command": "<command name>"
// "args": [ "arg1", "arg2", ... ]
// }
const char *command_path[] = {"command", 0};
yajl_val command_val = yajl_tree_get(parent, command_path, yajl_t_string);
if (command_val == NULL) {
fputs("No command key found in client message\n", stderr);
yajl_tree_free(parent);
return -1;
}
const char *command_name = YAJL_GET_STRING(command_val);
size_t command_name_len = strlen(command_name);
parsed_command->name = (char *)malloc((command_name_len + 1) * sizeof(char));
strcpy(parsed_command->name, command_name);
DEBUG("Received command: %s\n", parsed_command->name);
const char *args_path[] = {"args", 0};
yajl_val args_val = yajl_tree_get(parent, args_path, yajl_t_array);
if (args_val == NULL) {
fputs("No args key found in client message\n", stderr);
yajl_tree_free(parent);
return -1;
}
unsigned int *argc = &parsed_command->argc;
Arg **args = &parsed_command->args;
ArgType **arg_types = &parsed_command->arg_types;
*argc = args_val->u.array.len;
// If no arguments are specified, make a dummy argument to pass to the
// function. This is just the way dwm's void(Arg*) functions are setup.
if (*argc == 0) {
*args = (Arg *)malloc(sizeof(Arg));
*arg_types = (ArgType *)malloc(sizeof(ArgType));
(*arg_types)[0] = ARG_TYPE_NONE;
(*args)[0].f = 0;
(*argc)++;
} else if (*argc > 0) {
*args = (Arg *)calloc(*argc, sizeof(Arg));
*arg_types = (ArgType *)malloc(*argc * sizeof(ArgType));
for (int i = 0; i < *argc; i++) {
yajl_val arg_val = args_val->u.array.values[i];
if (YAJL_IS_NUMBER(arg_val)) {
if (YAJL_IS_INTEGER(arg_val)) {
// Any values below 0 must be a signed int
if (YAJL_GET_INTEGER(arg_val) < 0) {
(*args)[i].i = YAJL_GET_INTEGER(arg_val);
(*arg_types)[i] = ARG_TYPE_SINT;
DEBUG("i=%ld\n", (*args)[i].i);
// Any values above 0 should be an unsigned int
} else if (YAJL_GET_INTEGER(arg_val) >= 0) {
(*args)[i].ui = YAJL_GET_INTEGER(arg_val);
(*arg_types)[i] = ARG_TYPE_UINT;
DEBUG("ui=%ld\n", (*args)[i].i);
}
// If the number is not an integer, it must be a float
} else {
(*args)[i].f = (float)YAJL_GET_DOUBLE(arg_val);
(*arg_types)[i] = ARG_TYPE_FLOAT;
DEBUG("f=%f\n", (*args)[i].f);
// If argument is not a number, it must be a string
}
} else if (YAJL_IS_STRING(arg_val)) {
char *arg_s = YAJL_GET_STRING(arg_val);
size_t arg_s_size = (strlen(arg_s) + 1) * sizeof(char);
(*args)[i].v = (char *)malloc(arg_s_size);
(*arg_types)[i] = ARG_TYPE_STR;
strcpy((char *)(*args)[i].v, arg_s);
}
}
}
yajl_tree_free(parent);
return 0;
}
/**
* Free the members of a IPCParsedCommand struct
*/
static void
ipc_free_parsed_command_members(IPCParsedCommand *command)
{
for (int i = 0; i < command->argc; i++) {
if (command->arg_types[i] == ARG_TYPE_STR) free((void *)command->args[i].v);
}
free(command->args);
free(command->arg_types);
free(command->name);
}
/**
* Check if the given arguments are the correct length and type. Also do any
* casting to correct the types.
*
* Returns 0 if the arguments were the correct length and types
* Returns -1 if the argument count doesn't match
* Returns -2 if the argument types don't match
*/
static int
ipc_validate_run_command(IPCParsedCommand *parsed, const IPCCommand actual)
{
if (actual.argc != parsed->argc) return -1;
for (int i = 0; i < parsed->argc; i++) {
ArgType ptype = parsed->arg_types[i];
ArgType atype = actual.arg_types[i];
if (ptype != atype) {
if (ptype == ARG_TYPE_UINT && atype == ARG_TYPE_PTR)
// If this argument is supposed to be a void pointer, cast it
parsed->args[i].v = (void *)parsed->args[i].ui;
else if (ptype == ARG_TYPE_UINT && atype == ARG_TYPE_SINT)
// If this argument is supposed to be a signed int, cast it
parsed->args[i].i = parsed->args[i].ui;
else
return -2;
}
}
return 0;
}
/**
* Convert event name to their IPCEvent equivalent enum value
*
* Returns 0 if a valid event name was given
* Returns -1 otherwise
*/
static int
ipc_event_stoi(const char *subscription, IPCEvent *event)
{
if (strcmp(subscription, "tag_change_event") == 0)
*event = IPC_EVENT_TAG_CHANGE;
else if (strcmp(subscription, "client_focus_change_event") == 0)
*event = IPC_EVENT_CLIENT_FOCUS_CHANGE;
else if (strcmp(subscription, "layout_change_event") == 0)
*event = IPC_EVENT_LAYOUT_CHANGE;
else if (strcmp(subscription, "monitor_focus_change_event") == 0)
*event = IPC_EVENT_MONITOR_FOCUS_CHANGE;
else if (strcmp(subscription, "focused_title_change_event") == 0)
*event = IPC_EVENT_FOCUSED_TITLE_CHANGE;
else if (strcmp(subscription, "focused_state_change_event") == 0)
*event = IPC_EVENT_FOCUSED_STATE_CHANGE;
else
return -1;
return 0;
}
/**
* Parse a IPC_TYPE_SUBSCRIBE message from a client. This function extracts the
* event name and the subscription action from the message.
*
* Returns 0 if message was successfully parsed
* Returns -1 otherwise
*/
static int
ipc_parse_subscribe(const char *msg, IPCSubscriptionAction *subscribe,
IPCEvent *event)
{
char error_buffer[100];
yajl_val parent = yajl_tree_parse((char *)msg, error_buffer, 100);
if (parent == NULL) {
fputs("Failed to parse command from client\n", stderr);
fprintf(stderr, "%s\n", error_buffer);
return -1;
}
// Format:
// {
// "event": "<event name>"
// "action": "<subscribe|unsubscribe>"
// }
const char *event_path[] = {"event", 0};
yajl_val event_val = yajl_tree_get(parent, event_path, yajl_t_string);
if (event_val == NULL) {
fputs("No 'event' key found in client message\n", stderr);
return -1;
}
const char *event_str = YAJL_GET_STRING(event_val);
DEBUG("Received event: %s\n", event_str);
if (ipc_event_stoi(event_str, event) < 0) return -1;
const char *action_path[] = {"action", 0};
yajl_val action_val = yajl_tree_get(parent, action_path, yajl_t_string);
if (action_val == NULL) {
fputs("No 'action' key found in client message\n", stderr);
return -1;
}
const char *action = YAJL_GET_STRING(action_val);
if (strcmp(action, "subscribe") == 0)
*subscribe = IPC_ACTION_SUBSCRIBE;
else if (strcmp(action, "unsubscribe") == 0)
*subscribe = IPC_ACTION_UNSUBSCRIBE;
else {
fputs("Invalid action specified for subscription\n", stderr);
return -1;
}
yajl_tree_free(parent);
return 0;
}
/**
* Parse an IPC_TYPE_GET_DWM_CLIENT message from a client. This function
* extracts the window id from the message.
*
* Returns 0 if message was successfully parsed
* Returns -1 otherwise
*/
static int
ipc_parse_get_dwm_client(const char *msg, Window *win)
{
char error_buffer[100];
yajl_val parent = yajl_tree_parse(msg, error_buffer, 100);
if (parent == NULL) {
fputs("Failed to parse message from client\n", stderr);
fprintf(stderr, "%s\n", error_buffer);
return -1;
}
// Format:
// {
// "client_window_id": <client window id>
// }
const char *win_path[] = {"client_window_id", 0};
yajl_val win_val = yajl_tree_get(parent, win_path, yajl_t_number);
if (win_val == NULL) {
fputs("No client window id found in client message\n", stderr);
return -1;
}
*win = YAJL_GET_INTEGER(win_val);
yajl_tree_free(parent);
return 0;
}
/**
* Called when an IPC_TYPE_RUN_COMMAND message is received from a client. This
* function parses, executes the given command, and prepares a reply message to
* the client indicating success/failure.
*
* NOTE: There is currently no check for argument validity beyond the number of
* arguments given and types of arguments. There is also no way to check if the
* function succeeded based on dwm's void(const Arg*) function types. Pointer
* arguments can cause crashes if they are not validated in the function itself.
*
* Returns 0 if message was successfully parsed
* Returns -1 on failure parsing message
*/
static int
ipc_run_command(IPCClient *ipc_client, char *msg)
{
IPCParsedCommand parsed_command;
IPCCommand ipc_command;
// Initialize struct
memset(&parsed_command, 0, sizeof(IPCParsedCommand));
if (ipc_parse_run_command(msg, &parsed_command) < 0) {
ipc_prepare_reply_failure(ipc_client, IPC_TYPE_RUN_COMMAND,
"Failed to parse run command");
return -1;
}
if (ipc_get_ipc_command(parsed_command.name, &ipc_command) < 0) {
ipc_prepare_reply_failure(ipc_client, IPC_TYPE_RUN_COMMAND,
"Command %s not found", parsed_command.name);
ipc_free_parsed_command_members(&parsed_command);
return -1;
}
int res = ipc_validate_run_command(&parsed_command, ipc_command);
if (res < 0) {
if (res == -1)
ipc_prepare_reply_failure(ipc_client, IPC_TYPE_RUN_COMMAND,
"%u arguments provided, %u expected",
parsed_command.argc, ipc_command.argc);
else if (res == -2)
ipc_prepare_reply_failure(ipc_client, IPC_TYPE_RUN_COMMAND,
"Type mismatch");
ipc_free_parsed_command_members(&parsed_command);
return -1;
}
if (parsed_command.argc == 1)
ipc_command.func.single_param(parsed_command.args);
else if (parsed_command.argc > 1)
ipc_command.func.array_param(parsed_command.args, parsed_command.argc);
DEBUG("Called function for command %s\n", parsed_command.name);
ipc_free_parsed_command_members(&parsed_command);
ipc_prepare_reply_success(ipc_client, IPC_TYPE_RUN_COMMAND);
return 0;
}
/**
* Called when an IPC_TYPE_GET_MONITORS message is received from a client. It
* prepares a reply with the properties of all of the monitors in JSON.
*/
static void
ipc_get_monitors(IPCClient *c, Monitor *mons, Monitor *selmon)
{
yajl_gen gen;
ipc_reply_init_message(&gen);
dump_monitors(gen, mons, selmon);
ipc_reply_prepare_send_message(gen, c, IPC_TYPE_GET_MONITORS);
}
/**
* Called when an IPC_TYPE_GET_TAGS message is received from a client. It
* prepares a reply with info about all the tags in JSON.
*/
static void
ipc_get_tags(IPCClient *c, const int tags_len)
{
yajl_gen gen;
ipc_reply_init_message(&gen);
dump_tags(gen, tags_len);
ipc_reply_prepare_send_message(gen, c, IPC_TYPE_GET_TAGS);
}
/**
* Called when an IPC_TYPE_GET_LAYOUTS message is received from a client. It
* prepares a reply with a JSON array of available layouts
*/
static void
ipc_get_layouts(IPCClient *c, const Layout layouts[], const int layouts_len)
{
yajl_gen gen;
ipc_reply_init_message(&gen);
dump_layouts(gen, layouts, layouts_len);
ipc_reply_prepare_send_message(gen, c, IPC_TYPE_GET_LAYOUTS);
}
/**
* Called when an IPC_TYPE_GET_DWM_CLIENT message is received from a client. It
* prepares a JSON reply with the properties of the client with the specified
* window XID.
*
* Returns 0 if the message was successfully parsed and if the client with the
* specified window XID was found
* Returns -1 if the message could not be parsed
*/
static int
ipc_get_dwm_client(IPCClient *ipc_client, const char *msg, const Monitor *mons)
{
Window win;
if (ipc_parse_get_dwm_client(msg, &win) < 0) return -1;
// Find client with specified window XID
for (const Monitor *m = mons; m; m = m->next)
for (Client *c = m->clients; c; c = c->next)
if (c->win == win) {
yajl_gen gen;
ipc_reply_init_message(&gen);
dump_client(gen, c);
ipc_reply_prepare_send_message(gen, ipc_client,
IPC_TYPE_GET_DWM_CLIENT);
return 0;
}
ipc_prepare_reply_failure(ipc_client, IPC_TYPE_GET_DWM_CLIENT,
"Client with window id %d not found", win);
return -1;
}
/**
* Called when an IPC_TYPE_SUBSCRIBE message is received from a client. It
* subscribes/unsubscribes the client from the specified event and replies with
* the result.
*
* Returns 0 if the message was successfully parsed.
* Returns -1 if the message could not be parsed
*/
static int
ipc_subscribe(IPCClient *c, const char *msg)
{
IPCSubscriptionAction action = IPC_ACTION_SUBSCRIBE;
IPCEvent event = 0;
if (ipc_parse_subscribe(msg, &action, &event)) {
ipc_prepare_reply_failure(c, IPC_TYPE_SUBSCRIBE, "Event does not exist");
return -1;
}
if (action == IPC_ACTION_SUBSCRIBE) {
DEBUG("Subscribing client on fd %d to %d\n", c->fd, event);
c->subscriptions |= event;
} else if (action == IPC_ACTION_UNSUBSCRIBE) {
DEBUG("Unsubscribing client on fd %d to %d\n", c->fd, event);
c->subscriptions ^= event;
} else {
ipc_prepare_reply_failure(c, IPC_TYPE_SUBSCRIBE,
"Invalid subscription action");
return -1;
}
ipc_prepare_reply_success(c, IPC_TYPE_SUBSCRIBE);
return 0;
}
int
ipc_init(const char *socket_path, const int p_epoll_fd, IPCCommand commands[],
const int commands_len)
{
// Initialize struct to 0
memset(&sock_epoll_event, 0, sizeof(sock_epoll_event));
int socket_fd = ipc_create_socket(socket_path);
if (socket_fd < 0) return -1;
ipc_commands = commands;
ipc_commands_len = commands_len;
epoll_fd = p_epoll_fd;
// Wake up to incoming connection requests
sock_epoll_event.data.fd = socket_fd;
sock_epoll_event.events = EPOLLIN;
if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, socket_fd, &sock_epoll_event)) {
fputs("Failed to add sock file descriptor to epoll", stderr);
return -1;
}
return socket_fd;
}
void
ipc_cleanup()
{
IPCClient *c = ipc_clients;
// Free clients and their buffers
while (c) {
ipc_drop_client(c);
c = ipc_clients;
}
// Stop waking up for socket events
epoll_ctl(epoll_fd, EPOLL_CTL_DEL, sock_fd, &sock_epoll_event);
// Uninitialize all static variables
epoll_fd = -1;
sock_fd = -1;
ipc_commands = NULL;
ipc_commands_len = 0;
memset(&sock_epoll_event, 0, sizeof(struct epoll_event));
memset(&sockaddr, 0, sizeof(struct sockaddr_un));
// Delete socket
unlink(sockaddr.sun_path);
shutdown(sock_fd, SHUT_RDWR);
close(sock_fd);
}
int
ipc_get_sock_fd()
{
return sock_fd;
}
IPCClient *
ipc_get_client(int fd)
{
return ipc_list_get_client(ipc_clients, fd);
}
int
ipc_is_client_registered(int fd)
{
return (ipc_get_client(fd) != NULL);
}
int
ipc_accept_client()
{
int fd = -1;
struct sockaddr_un client_addr;
socklen_t len = 0;
// For portability clear the addr structure, since some implementations
// have nonstandard fields in the structure
memset(&client_addr, 0, sizeof(struct sockaddr_un));
fd = accept(sock_fd, (struct sockaddr *)&client_addr, &len);
if (fd < 0 && errno != EINTR) {
fputs("Failed to accept IPC connection from client", stderr);
return -1;
}
if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0) {
shutdown(fd, SHUT_RDWR);
close(fd);
fputs("Failed to set flags on new client fd", stderr);
}
IPCClient *nc = ipc_client_new(fd);
if (nc == NULL) return -1;
// Wake up to messages from this client
nc->event.data.fd = fd;
nc->event.events = EPOLLIN | EPOLLHUP;
epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &nc->event);
ipc_list_add_client(&ipc_clients, nc);
DEBUG("%s%d\n", "New client at fd: ", fd);
return fd;
}
int
ipc_drop_client(IPCClient *c)
{
int fd = c->fd;
shutdown(fd, SHUT_RDWR);
int res = close(fd);
if (res == 0) {
struct epoll_event ev;
// Stop waking up to messages from this client
epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, &ev);
ipc_list_remove_client(&ipc_clients, c);
free(c->buffer);
free(c);
DEBUG("Successfully removed client on fd %d\n", fd);
} else if (res < 0 && res != EINTR) {
fprintf(stderr, "Failed to close fd %d\n", fd);
}
return res;
}
int
ipc_read_client(IPCClient *c, IPCMessageType *msg_type, uint32_t *msg_size,
char **msg)
{
int fd = c->fd;
int ret =
ipc_recv_message(fd, (uint8_t *)msg_type, msg_size, (uint8_t **)msg);
if (ret < 0) {
// This will happen if these errors occur while reading header
if (ret == -1 &&
(errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
return -2;
fprintf(stderr, "Error reading message: dropping client at fd %d\n", fd);
ipc_drop_client(c);
return -1;
}
// Make sure receive message is null terminated to avoid parsing issues
if (*msg_size > 0) {
size_t len = *msg_size;
nullterminate(msg, &len);
*msg_size = len;
}
DEBUG("[fd %d] ", fd);
if (*msg_size > 0)
DEBUG("Received message: '%.*s' ", *msg_size, *msg);
else
DEBUG("Received empty message ");
DEBUG("Message type: %" PRIu8 " ", (uint8_t)*msg_type);
DEBUG("Message size: %" PRIu32 "\n", *msg_size);
return 0;
}
ssize_t
ipc_write_client(IPCClient *c)
{
const ssize_t n = ipc_write_message(c->fd, c->buffer, c->buffer_size);
if (n < 0) return n;
// TODO: Deal with client timeouts
if (n == c->buffer_size) {
c->buffer_size = 0;
free(c->buffer);
// No dangling pointers!
c->buffer = NULL;
// Stop waking up when client is ready to receive messages
if (c->event.events & EPOLLOUT) {
c->event.events -= EPOLLOUT;
epoll_ctl(epoll_fd, EPOLL_CTL_MOD, c->fd, &c->event);
}
return n;
}
// Shift unwritten buffer to beginning of buffer and reallocate
c->buffer_size -= n;
memmove(c->buffer, c->buffer + n, c->buffer_size);
c->buffer = (char *)realloc(c->buffer, c->buffer_size);
return n;
}
void
ipc_prepare_send_message(IPCClient *c, const IPCMessageType msg_type,
const uint32_t msg_size, const char *msg)
{
dwm_ipc_header_t header = {
.magic = IPC_MAGIC_ARR, .type = msg_type, .size = msg_size};
uint32_t header_size = sizeof(dwm_ipc_header_t);
uint32_t packet_size = header_size + msg_size;
if (c->buffer == NULL)
c->buffer = (char *)malloc(c->buffer_size + packet_size);
else
c->buffer = (char *)realloc(c->buffer, c->buffer_size + packet_size);
// Copy header to end of client buffer
memcpy(c->buffer + c->buffer_size, &header, header_size);
c->buffer_size += header_size;
// Copy message to end of client buffer
memcpy(c->buffer + c->buffer_size, msg, msg_size);
c->buffer_size += msg_size;
// Wake up when client is ready to receive messages
c->event.events |= EPOLLOUT;
epoll_ctl(epoll_fd, EPOLL_CTL_MOD, c->fd, &c->event);
}
void
ipc_prepare_reply_failure(IPCClient *c, IPCMessageType msg_type,
const char *format, ...)
{
yajl_gen gen;
va_list args;
// Get output size
va_start(args, format);
size_t len = vsnprintf(NULL, 0, format, args);
va_end(args);
char *buffer = (char *)malloc((len + 1) * sizeof(char));
ipc_reply_init_message(&gen);
va_start(args, format);
vsnprintf(buffer, len + 1, format, args);
va_end(args);
dump_error_message(gen, buffer);
ipc_reply_prepare_send_message(gen, c, msg_type);
fprintf(stderr, "[fd %d] Error: %s\n", c->fd, buffer);
free(buffer);
}
void
ipc_prepare_reply_success(IPCClient *c, IPCMessageType msg_type)
{
const char *success_msg = "{\"result\":\"success\"}";
const size_t msg_len = strlen(success_msg) + 1; // +1 for null char
ipc_prepare_send_message(c, msg_type, msg_len, success_msg);
}
void
ipc_tag_change_event(int mon_num, TagState old_state, TagState new_state)
{
yajl_gen gen;
ipc_event_init_message(&gen);
dump_tag_event(gen, mon_num, old_state, new_state);
ipc_event_prepare_send_message(gen, IPC_EVENT_TAG_CHANGE);
}
void
ipc_client_focus_change_event(int mon_num, Client *old_client,
Client *new_client)
{
yajl_gen gen;
ipc_event_init_message(&gen);
dump_client_focus_change_event(gen, old_client, new_client, mon_num);
ipc_event_prepare_send_message(gen, IPC_EVENT_CLIENT_FOCUS_CHANGE);
}
void
ipc_layout_change_event(const int mon_num, const char *old_symbol,
const Layout *old_layout, const char *new_symbol,
const Layout *new_layout)
{
yajl_gen gen;
ipc_event_init_message(&gen);
dump_layout_change_event(gen, mon_num, old_symbol, old_layout, new_symbol,
new_layout);
ipc_event_prepare_send_message(gen, IPC_EVENT_LAYOUT_CHANGE);
}
void
ipc_monitor_focus_change_event(const int last_mon_num, const int new_mon_num)
{
yajl_gen gen;
ipc_event_init_message(&gen);
dump_monitor_focus_change_event(gen, last_mon_num, new_mon_num);
ipc_event_prepare_send_message(gen, IPC_EVENT_MONITOR_FOCUS_CHANGE);
}
void
ipc_focused_title_change_event(const int mon_num, const Window client_id,
const char *old_name, const char *new_name)
{
yajl_gen gen;
ipc_event_init_message(&gen);
dump_focused_title_change_event(gen, mon_num, client_id, old_name, new_name);
ipc_event_prepare_send_message(gen, IPC_EVENT_FOCUSED_TITLE_CHANGE);
}
void
ipc_focused_state_change_event(const int mon_num, const Window client_id,
const ClientState *old_state,
const ClientState *new_state)
{
yajl_gen gen;
ipc_event_init_message(&gen);
dump_focused_state_change_event(gen, mon_num, client_id, old_state,
new_state);
ipc_event_prepare_send_message(gen, IPC_EVENT_FOCUSED_STATE_CHANGE);
}
void
ipc_send_events(Monitor *mons, Monitor **lastselmon, Monitor *selmon)
{
for (Monitor *m = mons; m; m = m->next) {
unsigned int urg = 0, occ = 0, tagset = 0;
for (Client *c = m->clients; c; c = c->next) {
occ |= c->tags;
if (c->isurgent) urg |= c->tags;
}
tagset = m->tagset[m->seltags];
TagState new_state = {.selected = tagset, .occupied = occ, .urgent = urg};
if (memcmp(&m->tagstate, &new_state, sizeof(TagState)) != 0) {
ipc_tag_change_event(m->num, m->tagstate, new_state);
m->tagstate = new_state;
}
if (m->lastsel != m->sel) {
ipc_client_focus_change_event(m->num, m->lastsel, m->sel);
m->lastsel = m->sel;
}
if (strcmp(m->ltsymbol, m->lastltsymbol) != 0 ||
m->lastlt != m->lt[m->sellt]) {
ipc_layout_change_event(m->num, m->lastltsymbol, m->lastlt, m->ltsymbol,
m->lt[m->sellt]);
strcpy(m->lastltsymbol, m->ltsymbol);
m->lastlt = m->lt[m->sellt];
}
if (*lastselmon != selmon) {
if (*lastselmon != NULL)
ipc_monitor_focus_change_event((*lastselmon)->num, selmon->num);
*lastselmon = selmon;
}
Client *sel = m->sel;
if (!sel) continue;
ClientState *o = &m->sel->prevstate;
ClientState n = {.oldstate = sel->oldstate,
.isfixed = sel->isfixed,
.isfloating = sel->isfloating,
.isfullscreen = sel->isfullscreen,
.isurgent = sel->isurgent,
.neverfocus = sel->neverfocus};
if (memcmp(o, &n, sizeof(ClientState)) != 0) {
ipc_focused_state_change_event(m->num, m->sel->win, o, &n);
*o = n;
}
}
}
int
ipc_handle_client_epoll_event(struct epoll_event *ev, Monitor *mons,
Monitor **lastselmon, Monitor *selmon, const int tags_len,
const Layout *layouts, const int layouts_len)
{
int fd = ev->data.fd;
IPCClient *c = ipc_get_client(fd);
if (ev->events & EPOLLHUP) {
DEBUG("EPOLLHUP received from client at fd %d\n", fd);
ipc_drop_client(c);
} else if (ev->events & EPOLLOUT) {
DEBUG("Sending message to client at fd %d...\n", fd);
if (c->buffer_size) ipc_write_client(c);
} else if (ev->events & EPOLLIN) {
IPCMessageType msg_type = 0;
uint32_t msg_size = 0;
char *msg = NULL;
DEBUG("Received message from fd %d\n", fd);
if (ipc_read_client(c, &msg_type, &msg_size, &msg) < 0) return -1;
if (msg_type == IPC_TYPE_GET_MONITORS)
ipc_get_monitors(c, mons, selmon);
else if (msg_type == IPC_TYPE_GET_TAGS)
ipc_get_tags(c, tags_len);
else if (msg_type == IPC_TYPE_GET_LAYOUTS)
ipc_get_layouts(c, layouts, layouts_len);
else if (msg_type == IPC_TYPE_RUN_COMMAND) {
if (ipc_run_command(c, msg) < 0) return -1;
ipc_send_events(mons, lastselmon, selmon);
} else if (msg_type == IPC_TYPE_GET_DWM_CLIENT) {
if (ipc_get_dwm_client(c, msg, mons) < 0) return -1;
} else if (msg_type == IPC_TYPE_SUBSCRIBE) {
if (ipc_subscribe(c, msg) < 0) return -1;
} else {
fprintf(stderr, "Invalid message type received from fd %d", fd);
ipc_prepare_reply_failure(c, msg_type, "Invalid message type: %d",
msg_type);
}
free(msg);
} else {
fprintf(stderr, "Epoll event returned %d from fd %d\n", ev->events, fd);
return -1;
}
return 0;
}
int
ipc_handle_socket_epoll_event(struct epoll_event *ev)
{
if (!(ev->events & EPOLLIN)) return -1;
// EPOLLIN means incoming client connection request
fputs("Received EPOLLIN event on socket\n", stderr);
int new_fd = ipc_accept_client();
return new_fd;
}