/src/tmux/cmd-queue.c

Source
/* $OpenBSD: cmd-queue.c,v 1.123 2026/08/24 20:34:26 nicm Exp $ */

/*
 * Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <ctype.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

/* Command queue flags. */
#define CMDQ_FIRED 0x1
#define CMDQ_WAITING 0x2

/* Command queue item type. */
enum cmdq_type {
  CMDQ_COMMAND,
  CMDQ_CALLBACK,
};

/* Command queue item. */
struct cmdq_item {
  char      *name;
  struct cmdq_list  *queue;
  struct cmdq_item  *next;

  struct client   *client;
  struct client   *target_client;

  enum cmdq_type     type;
  u_int      group;

  u_int      number;
  time_t       time;

  int      flags;

  struct cmdq_state *state;
  struct cmd_find_state  source;
  struct cmd_find_state  target;

  struct cmd_list   *cmdlist;
  struct cmd    *cmd;

  cmdq_cb      cb;
  void      *data;

  TAILQ_ENTRY(cmdq_item)   entry;
};
TAILQ_HEAD(cmdq_item_list, cmdq_item);

/*
 * Command queue state. This is the context for commands on the command queue.
 * It holds information about how the commands were fired (the key and flags),
 * any additional formats for the commands, and the current default target.
 * Multiple commands can share the same state and a command may update the
 * default target.
 */
struct cmdq_state {
  int      references;
  int      flags;

  struct format_tree  *formats;

  struct key_event   event;
  struct cmd_find_state  current;
};

/* Command queue. */
struct cmdq_list {
  struct cmdq_item  *item;
  struct cmdq_item_list  list;
};

/* Get command queue name. */
static const char *
cmdq_name(struct client *c)
{
  static char s[256];

  if (c == NULL)
    return ("<global>");
  if (c->name != NULL)
    xsnprintf(s, sizeof s, "<%s>", c->name);
  else
    xsnprintf(s, sizeof s, "<%p>", c);
  return (s);
}

/* Get command queue from client. */
static struct cmdq_list *
cmdq_get(struct client *c)
{
  static struct cmdq_list *global_queue;

  if (c == NULL) {
    if (global_queue == NULL)
      global_queue = cmdq_new();
    return (global_queue);
  }
  return (c->queue);
}

/* Create a queue. */
struct cmdq_list *
cmdq_new(void)
{
  struct cmdq_list  *queue;

  queue = xcalloc(1, sizeof *queue);
  TAILQ_INIT (&queue->list);
  return (queue);
}

/* Free a queue. */
void
cmdq_free(struct cmdq_list *queue)
{
  if (!TAILQ_EMPTY(&queue->list))
    fatalx("queue not empty");
  free(queue);
}

/* Get item name. */
const char *
cmdq_get_name(struct cmdq_item *item)
{
  return (item->name);
}

/* Get item command. */
struct cmd *
cmdq_get_cmd(struct cmdq_item *item)
{
  return (item->cmd);
}

/* Get item client. */
struct client *
cmdq_get_client(struct cmdq_item *item)
{
  return (item->client);
}

/* Get item target client. */
struct client *
cmdq_get_target_client(struct cmdq_item *item)
{
  return (item->target_client);
}

/* Get item state. */
struct cmdq_state *
cmdq_get_state(struct cmdq_item *item)
{
  return (item->state);
}

/* Get item target. */
struct cmd_find_state *
cmdq_get_target(struct cmdq_item *item)
{
  return (&item->target);
}

/* Get item source. */
struct cmd_find_state *
cmdq_get_source(struct cmdq_item *item)
{
  return (&item->source);
}

/* Get state event. */
struct key_event *
cmdq_get_event(struct cmdq_item *item)
{
  return (&item->state->event);
}

/* Get state current target. */
struct cmd_find_state *
cmdq_get_current(struct cmdq_item *item)
{
  return (&item->state->current);
}

/* Get state flags. */
int
cmdq_get_flags(struct cmdq_item *item)
{
  return (item->state->flags);
}

/* Create a new state. */
struct cmdq_state *
cmdq_new_state(struct cmd_find_state *current, struct key_event *event,
    int flags)
{
  struct cmdq_state *state;

  state = xcalloc(1, sizeof *state);
  state->references = 1;
  state->flags = flags;

  if (event != NULL)
    memcpy(&state->event, event, sizeof state->event);
  else
    state->event.key = KEYC_NONE;
  if (current != NULL && cmd_find_valid_state(current))
    cmd_find_copy_state(&state->current, current);
  else
    cmd_find_clear_state(&state->current, 0);

  return (state);
}

/* Add a reference to a state. */
struct cmdq_state *
cmdq_link_state(struct cmdq_state *state)
{
  state->references++;
  return (state);
}

/* Make a copy of a state. */
struct cmdq_state *
cmdq_copy_state(struct cmdq_state *state, struct cmd_find_state *current)
{
  if (current != NULL)
    return (cmdq_new_state(current, &state->event, state->flags));
  return (cmdq_new_state(&state->current, &state->event, state->flags));
}

/* Free a state. */
void
cmdq_free_state(struct cmdq_state *state)
{
  if (--state->references != 0)
    return;

  if (state->formats != NULL)
    format_free(state->formats);
  free(state);
}

/* Add a format to command queue. */
void
cmdq_add_format(struct cmdq_state *state, const char *key, const char *fmt, ...)
{
  va_list  ap;
  char  *value;

  va_start(ap, fmt);
  xvasprintf(&value, fmt, ap);
  va_end(ap);

  if (state->formats == NULL)
    state->formats = format_create(NULL, NULL, FORMAT_NONE, 0);
  format_add(state->formats, key, "%s", value);

  free(value);
}

/* Add formats to command queue. */
void
cmdq_add_formats(struct cmdq_state *state, struct format_tree *ft)
{
  if (state->formats == NULL)
    state->formats = format_create(NULL, NULL, FORMAT_NONE, 0);
  format_merge(state->formats, ft);
}

/* Merge formats from item. */
void
cmdq_merge_formats(struct cmdq_item *item, struct format_tree *ft)
{
  const struct cmd_entry  *entry;

  if (item->cmd != NULL) {
    entry = cmd_get_entry(item->cmd);
    format_add(ft, "command", "%s", entry->name);
  }
  if (item->state->formats != NULL)
    format_merge(ft, item->state->formats);
}

/* Append an item. */
struct cmdq_item *
cmdq_append(struct client *c, struct cmdq_item *item)
{
  struct cmdq_list  *queue = cmdq_get(c);
  struct cmdq_item  *next;

  do {
    next = item->next;
    item->next = NULL;

    if (c != NULL)
      c->references++;
    item->client = c;

    item->queue = queue;
    TAILQ_INSERT_TAIL(&queue->list, item, entry);
    log_debug("%s %s: %s", __func__, cmdq_name(c), item->name);

    item = next;
  } while (item != NULL);
  return (TAILQ_LAST(&queue->list, cmdq_item_list));
}

/* Insert an item. */
struct cmdq_item *
cmdq_insert_after(struct cmdq_item *after, struct cmdq_item *item)
{
  struct client   *c = after->client;
  struct cmdq_list  *queue = after->queue;
  struct cmdq_item  *next;

  do {
    next = item->next;
    item->next = after->next;
    after->next = item;

    if (c != NULL)
      c->references++;
    item->client = c;

    item->queue = queue;
    TAILQ_INSERT_AFTER(&queue->list, after, item, entry);
    log_debug("%s %s: %s after %s", __func__, cmdq_name(c),
        item->name, after->name);

    after = item;
    item = next;
  } while (item != NULL);
  return (after);
}

/* Insert a hook. */
void
cmdq_insert_hook(__unused struct session *s, struct cmdq_item *item,
    struct cmd_find_state *current, const char *fmt, ...)
{
  struct cmd      *cmd = item->cmd;
  struct args     *args = cmd_get_args(cmd);
  struct args_entry   *ae;
  struct args_value   *av;
  struct event_payload    *ep;
  va_list        ap;
  char        *name, tmp[32], flag, *arguments;
  u_int        i;
  const char      *value;

  if (item->state->flags & CMDQ_STATE_NOHOOKS)
    return;

  va_start(ap, fmt);
  xvasprintf(&name, fmt, ap);
  va_end(ap);

  ep = event_payload_create();
  if (current != NULL)
    event_payload_set_target(ep, current);
  event_payload_set_pointer(ep, "_cmdq_item", item, NULL, NULL);

  arguments = args_print(args);
  event_payload_set_string(ep, "arguments", "%s", arguments);
  free(arguments);

  for (i = 0; i < args_count(args); i++) {
    xsnprintf(tmp, sizeof tmp, "argument_%u", i);
    event_payload_set_string(ep, tmp, "%s", args_string(args, i));
  }
  flag = args_first(args, &ae);
  while (flag != 0) {
    value = args_get(args, flag);
    xsnprintf(tmp, sizeof tmp, "flag_%c", flag);
    if (value == NULL)
      event_payload_set_string(ep, tmp, "1");
    else
      event_payload_set_string(ep, tmp, "%s", value);

    i = 0;
    av = args_first_value(args, flag);
    while (av != NULL) {
      xsnprintf(tmp, sizeof tmp, "flag_%c_%u", flag, i);
      event_payload_set_string(ep, tmp, "%s", av->string);
      i++;
      av = args_next_value(av);
    }

    flag = args_next(&ae);
  }

  events_fire(name, ep);
  free(name);
}

/* Continue processing command queue. */
void
cmdq_continue(struct cmdq_item *item)
{
  item->flags &= ~CMDQ_WAITING;
}

/* Remove an item. */
static void
cmdq_remove(struct cmdq_item *item)
{
  if (item->client != NULL)
    server_client_unref(item->client);
  if (item->cmdlist != NULL)
    cmd_list_free(item->cmdlist);
  cmdq_free_state(item->state);

  TAILQ_REMOVE(&item->queue->list, item, entry);

  free(item->name);
  free(item);
}

/* Remove all subsequent items that match this item's group. */
static void
cmdq_remove_group(struct cmdq_item *item)
{
  struct cmdq_item  *this, *next;

  if (item->group == 0)
    return;
  this = TAILQ_NEXT(item, entry);
  while (this != NULL) {
    next = TAILQ_NEXT(this, entry);
    if (this->group == item->group)
      cmdq_remove(this);
    this = next;
  }
}

/* Empty command callback. */
static enum cmd_retval
cmdq_empty_command(__unused struct cmdq_item *item, __unused void *data)
{
  return (CMD_RETURN_NORMAL);
}

/* Get a command for the command queue. */
struct cmdq_item *
cmdq_get_command(struct cmd_list *cmdlist, struct cmdq_state *state)
{
  struct cmdq_item  *item, *first = NULL, *last = NULL;
  struct cmd    *cmd;
  const struct cmd_entry  *entry;
  int      created = 0;

  if ((cmd = cmd_list_first(cmdlist)) == NULL)
    return (cmdq_get_callback(cmdq_empty_command, NULL));

  if (state == NULL) {
    state = cmdq_new_state(NULL, NULL, 0);
    created = 1;
  }

  while (cmd != NULL) {
    entry = cmd_get_entry(cmd);

    item = xcalloc(1, sizeof *item);
    xasprintf(&item->name, "[%s/%p]", entry->name, item);
    item->type = CMDQ_COMMAND;

    item->group = cmd_get_group(cmd);
    item->state = cmdq_link_state(state);

    item->cmdlist = cmdlist;
    item->cmd = cmd;

    cmdlist->references++;
    log_debug("%s: %s group %u", __func__, item->name, item->group);

    if (first == NULL)
      first = item;
    if (last != NULL)
      last->next = item;
    last = item;

    cmd = cmd_list_next(cmd);
  }

  if (created)
    cmdq_free_state(state);
  return (first);
}

/* Fill in flag for a command. */
static enum cmd_retval
cmdq_find_flag(struct cmdq_item *item, struct cmd_find_state *fs,
    const struct cmd_entry_flag *flag)
{
  const char  *value;

  if (flag->flag == 0) {
    cmd_find_from_client(fs, item->target_client, 0);
    return (CMD_RETURN_NORMAL);
  }

  value = args_get(cmd_get_args(item->cmd), flag->flag);
  if (cmd_find_target(fs, item, value, flag->type, flag->flags) != 0) {
    cmd_find_clear_state(fs, 0);
    return (CMD_RETURN_ERROR);
  }
  return (CMD_RETURN_NORMAL);
}

/* Add message with command. */
static void
cmdq_add_message(struct cmdq_item *item)
{
  struct client   *c = item->client;
  struct cmdq_state *state = item->state;
  const char    *key;
  char      *tmp;
  uid_t                    uid;
  struct passwd   *pw;
  char                    *user = NULL;

  tmp = cmd_print(item->cmd);
  if (c != NULL) {
    uid = proc_get_peer_uid(c->peer);
    if (uid != (uid_t)-1 && uid != getuid()) {
      if ((pw = getpwuid(uid)) != NULL)
        xasprintf(&user, "[%s]", pw->pw_name);
      else
        user = xstrdup("[unknown]");
    } else
      user = xstrdup("");
    if (c->session != NULL && state->event.key != KEYC_NONE) {
      key = key_string_lookup_key(state->event.key, 0);
      server_add_message("%s%s key %s: %s", c->name, user,
          key, tmp);
    } else {
      server_add_message("%s%s command: %s", c->name, user,
          tmp);
    }
    free(user);
  } else
    server_add_message("command: %s", tmp);
  free(tmp);
}

/* Fire command on command queue. */
static enum cmd_retval
cmdq_fire_command(struct cmdq_item *item)
{
  const char    *name = cmdq_name(item->client);
  struct cmdq_state *state = item->state;
  struct cmd    *cmd = item->cmd;
  struct args   *args = cmd_get_args(cmd);
  const struct cmd_entry  *entry = cmd_get_entry(cmd);
  struct client   *tc, *saved = item->client;
  enum cmd_retval    retval;
  struct cmd_find_state *fsp, fs;
  int      flags, quiet = 0;
  char      *tmp;

  if (cfg_finished)
    cmdq_add_message(item);
  if (log_get_level() > 1) {
    tmp = cmd_print(cmd);
    log_debug("%s %s: (%u) %s", __func__, name, item->group, tmp);
    free(tmp);
  }

  flags = !!(state->flags & CMDQ_STATE_CONTROL);
  cmdq_guard(item, "begin", flags);

  if (item->client == NULL)
    item->client = cmd_find_client(item, NULL, 1);

  if (entry->flags & CMD_CLIENT_CANFAIL)
    quiet = 1;
  if (entry->flags & CMD_CLIENT_CFLAG) {
    tc = cmd_find_client(item, args_get(args, 'c'), quiet);
    if (tc == NULL && !quiet) {
      retval = CMD_RETURN_ERROR;
      goto out;
    }
  } else if (entry->flags & CMD_CLIENT_TFLAG) {
    tc = cmd_find_client(item, args_get(args, 't'), quiet);
    if (tc == NULL && !quiet) {
      retval = CMD_RETURN_ERROR;
      goto out;
    }
  } else
    tc = cmd_find_client(item, NULL, 1);
  item->target_client = tc;

  retval = cmdq_find_flag(item, &item->source, &entry->source);
  if (retval == CMD_RETURN_ERROR)
    goto out;
  retval = cmdq_find_flag(item, &item->target, &entry->target);
  if (retval == CMD_RETURN_ERROR)
    goto out;

  retval = entry->exec(cmd, item);
  if (retval == CMD_RETURN_ERROR)
    goto out;

  if (entry->flags & CMD_AFTERHOOK) {
    if (cmd_find_valid_state(&item->target))
      fsp = &item->target;
    else if (cmd_find_valid_state(&item->state->current))
      fsp = &item->state->current;
    else if (cmd_find_from_client(&fs, item->client, 0) == 0)
      fsp = &fs;
    else
      goto out;
    cmdq_insert_hook(fsp->s, item, fsp, "after-%s", entry->name);
  }

out:
  item->client = saved;
  if (retval == CMD_RETURN_ERROR) {
    fsp = NULL;
    if (cmd_find_valid_state(&item->target))
      fsp = &item->target;
    else if (cmd_find_valid_state(&item->state->current))
      fsp = &item->state->current;
    else if (cmd_find_from_client(&fs, item->client, 0) == 0)
      fsp = &fs;
    cmdq_insert_hook(fsp != NULL ? fsp->s : NULL, item, fsp,
        "command-error");
    cmdq_guard(item, "error", flags);
  } else
    cmdq_guard(item, "end", flags);
  return (retval);
}

/* Get a callback for the command queue. */
struct cmdq_item *
cmdq_get_callback1(const char *name, cmdq_cb cb, void *data)
{
  struct cmdq_item  *item;

  item = xcalloc(1, sizeof *item);
  xasprintf(&item->name, "[%s/%p]", name, item);
  item->type = CMDQ_CALLBACK;

  item->group = 0;
  item->state = cmdq_new_state(NULL, NULL, 0);

  item->cb = cb;
  item->data = data;

  return (item);
}

/* Generic error callback. */
static enum cmd_retval
cmdq_error_callback(struct cmdq_item *item, void *data)
{
  char  *error = data;

  cmdq_error(item, "%s", error);
  free(error);

  return (CMD_RETURN_NORMAL);
}

/* Get an error callback for the command queue. */
struct cmdq_item *
cmdq_get_error(const char *error)
{
  return (cmdq_get_callback(cmdq_error_callback, xstrdup(error)));
}

/* Fire callback on callback queue. */
static enum cmd_retval
cmdq_fire_callback(struct cmdq_item *item)
{
  return (item->cb(item, item->data));
}

/* Process next item on command queue. */
u_int
cmdq_next(struct client *c)
{
  struct cmdq_list  *queue = cmdq_get(c);
  const char    *name = cmdq_name(c);
  struct cmdq_item  *item;
  enum cmd_retval    retval;
  u_int      items = 0;
  static u_int     number;

  if (TAILQ_EMPTY(&queue->list)) {
    log_debug("%s %s: empty", __func__, name);
    return (0);
  }
  if (TAILQ_FIRST(&queue->list)->flags & CMDQ_WAITING) {
    log_debug("%s %s: waiting", __func__, name);
    return (0);
  }

  log_debug("%s %s: enter", __func__, name);
  for (;;) {
    item = queue->item = TAILQ_FIRST(&queue->list);
    if (item == NULL)
      break;
    log_debug("%s %s: %s (%d), flags %x", __func__, name,
        item->name, item->type, item->flags);

    /*
     * Any item with the waiting flag set waits until an external
     * event clears the flag (for example, a job - look at
     * run-shell).
     */
    if (item->flags & CMDQ_WAITING)
      goto waiting;

    /*
     * Items are only fired once, once the fired flag is set, a
     * waiting flag can only be cleared by an external event.
     */
    if (~item->flags & CMDQ_FIRED) {
      item->time = time(NULL);
      item->number = ++number;

      switch (item->type) {
      case CMDQ_COMMAND:
        retval = cmdq_fire_command(item);

        /*
         * If a command returns an error, remove any
         * subsequent commands in the same group.
         */
        if (retval == CMD_RETURN_ERROR)
          cmdq_remove_group(item);
        break;
      case CMDQ_CALLBACK:
        retval = cmdq_fire_callback(item);
        break;
      default:
        retval = CMD_RETURN_ERROR;
        break;
      }
      item->flags |= CMDQ_FIRED;

      if (retval == CMD_RETURN_WAIT) {
        item->flags |= CMDQ_WAITING;
        goto waiting;
      }
      items++;
    }
    cmdq_remove(item);
  }
  queue->item = NULL;

  log_debug("%s %s: exit (empty)", __func__, name);
  return (items);

waiting:
  log_debug("%s %s: exit (wait)", __func__, name);
  return (items);
}

/* Get running item if any. */
struct cmdq_item *
cmdq_running(struct client *c)
{
  struct cmdq_list  *queue = cmdq_get(c);

  if (queue->item == NULL)
    return (NULL);
  if (queue->item->flags & CMDQ_WAITING)
    return (NULL);
  return (queue->item);
}

/* Print a guard line. */
void
cmdq_guard(struct cmdq_item *item, const char *guard, int flags)
{
  struct client *c = item->client;
  long     t = item->time;
  u_int    number = item->number;

  if (c != NULL && (c->flags & CLIENT_CONTROL))
    control_write_guard(c, guard, t, number, flags);
}

/* Show message from command. */
void
cmdq_print_data(struct cmdq_item *item, struct evbuffer *evb)
{
  server_client_print(item->client, 1, evb);
}

/* Show message from command. */
void
cmdq_print(struct cmdq_item *item, const char *fmt, ...)
{
  va_list    ap;
  struct evbuffer *evb;

  evb = evbuffer_new();
  if (evb == NULL)
    fatalx("out of memory");

  va_start(ap, fmt);
  evbuffer_add_vprintf(evb, fmt, ap);
  va_end(ap);

  cmdq_print_data(item, evb);
  evbuffer_free(evb);
}

/* Show error from command. */
void
cmdq_error(struct cmdq_item *item, const char *fmt, ...)
{
  struct client *c = item->client;
  struct cmd  *cmd = item->cmd;
  va_list    ap;
  char    *msg, *tmp;
  const char  *file;
  u_int    line;

  va_start(ap, fmt);
  xvasprintf(&msg, fmt, ap);
  va_end(ap);

  log_debug("%s: %s", __func__, msg);

  if (c == NULL) {
    cmd_get_source(cmd, &file, &line);
    if (!cfg_finished) {
      if (file != NULL)
        cfg_add_cause("%s:%u: %s", file, line, msg);
      else
        cfg_add_cause("%s", msg);
    } else {
      if (file != NULL) {
        server_add_message("message: %s:%u: %s", file,
            line, msg);
      } else
        server_add_message("message: %s", msg);
    }
  } else if (c->session == NULL || (c->flags & CLIENT_CONTROL)) {
    server_add_message("%s message: %s", c->name, msg);
    if (~c->flags & CLIENT_UTF8) {
      tmp = msg;
      msg = utf8_sanitize(tmp);
      free(tmp);
    }
    if (c->flags & CLIENT_CONTROL)
      control_write(c, "%s", msg);
    else
      file_error(c, "%s\n", msg);
    c->retval = 1;
  } else {
    *msg = toupper((u_char) *msg);
    status_message_set(c, -1, 1, 0, 0, "%s", msg);
  }

  free(msg);
}

Coverage Report

Created: 2026-08-31 06:30