/src/tmux/server-client.c

Source
/* $OpenBSD$ */

/*
 * Copyright (c) 2009 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 <sys/ioctl.h>
#include <sys/uio.h>

#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

static void server_client_free(int, short, void *);
static void server_client_check_pane_resize(struct window_pane *);
static void server_client_check_pane_buffer(struct window_pane *);
static void server_client_check_window_resize(struct window *);
static key_code server_client_check_mouse(struct client *, struct key_event *);
static void server_client_repeat_timer(int, short, void *);
static void server_client_click_timer(int, short, void *);
static void server_client_check_exit(struct client *);
static void server_client_check_redraw(struct client *);
static void server_client_check_modes(struct client *);
static void server_client_set_title(struct client *);
static void server_client_set_path(struct client *);
static void server_client_reset_state(struct client *);
static void server_client_update_latest(struct client *);
static void server_client_dispatch(struct imsg *, void *);
static int  server_client_dispatch_command(struct client *, struct imsg *);
static int  server_client_dispatch_identify(struct client *, struct imsg *);
static int  server_client_dispatch_shell(struct client *);
static void server_client_report_theme(struct client *, enum client_theme);

/* Compare client windows. */
static int
server_client_window_cmp(struct client_window *cw1,
    struct client_window *cw2)
{
  if (cw1->window < cw2->window)
    return (-1);
  if (cw1->window > cw2->window)
    return (1);
  return (0);
}
RB_GENERATE(client_windows, client_window, entry, server_client_window_cmp);

/* Number of attached clients. */
u_int
server_client_how_many(void)
{
  struct client *c;
  u_int    n;

  n = 0;
  TAILQ_FOREACH(c, &clients, entry) {
    if (c->session != NULL && (~c->flags & CLIENT_UNATTACHEDFLAGS))
      n++;
  }
  return (n);
}

/* Overlay timer callback. */
static void
server_client_overlay_timer(__unused int fd, __unused short events, void *data)
{
  server_client_clear_overlay(data);
}

/* Set an overlay on client. */
void
server_client_set_overlay(struct client *c, u_int delay,
    overlay_check_cb checkcb, overlay_mode_cb modecb,
    overlay_draw_cb drawcb, overlay_key_cb keycb, overlay_free_cb freecb,
    overlay_resize_cb resizecb, void *data)
{
  struct timeval  tv;

  if (c->overlay_draw != NULL)
    server_client_clear_overlay(c);

  tv.tv_sec = delay / 1000;
  tv.tv_usec = (delay % 1000) * 1000L;

  if (event_initialized(&c->overlay_timer))
    evtimer_del(&c->overlay_timer);
  evtimer_set(&c->overlay_timer, server_client_overlay_timer, c);
  if (delay != 0)
    evtimer_add(&c->overlay_timer, &tv);

  c->overlay_check = checkcb;
  c->overlay_mode = modecb;
  c->overlay_draw = drawcb;
  c->overlay_key = keycb;
  c->overlay_free = freecb;
  c->overlay_resize = resizecb;
  c->overlay_data = data;

  if (c->overlay_check == NULL)
    c->tty.flags |= TTY_FREEZE;
  if (c->overlay_mode == NULL)
    c->tty.flags |= TTY_NOCURSOR;
  window_update_focus(c->session->curw->window);
  server_redraw_client(c);
}

/* Clear overlay mode on client. */
void
server_client_clear_overlay(struct client *c)
{
  if (c->overlay_draw == NULL)
    return;

  if (event_initialized(&c->overlay_timer))
    evtimer_del(&c->overlay_timer);

  if (c->overlay_free != NULL)
    c->overlay_free(c, c->overlay_data);

  c->overlay_check = NULL;
  c->overlay_mode = NULL;
  c->overlay_draw = NULL;
  c->overlay_key = NULL;
  c->overlay_free = NULL;
  c->overlay_resize = NULL;
  c->overlay_data = NULL;

  c->tty.flags &= ~(TTY_FREEZE|TTY_NOCURSOR);
  if (c->session != NULL)
    window_update_focus(c->session->curw->window);
  server_redraw_client(c);
}

/* Are these ranges empty? That is, nothing is visible. */
int
server_client_ranges_is_empty(struct visible_ranges *r)
{
  u_int i;

  for (i = 0; i < r->used; i++) {
    if (r->ranges[i].nx != 0)
      return (0);
  }
  return (1);
}

/* Ensure we have space for at least n ranges. */
void
server_client_ensure_ranges(struct visible_ranges *r, u_int n)
{
  if (r->size >= n)
    return;
  r->ranges = xrecallocarray(r->ranges, r->size, n, sizeof *r->ranges);
  r->size = n;
}

/*
 * Given overlay position and dimensions, return parts of the input range which
 * are visible.
 */
void
server_client_overlay_range(u_int x, u_int y, u_int sx, u_int sy, u_int px,
    u_int py, u_int nx, struct visible_ranges *r)
{
  u_int ox, onx;

  /* Trivial case of no overlap in the y direction. */
  if (py < y || py > y + sy - 1) {
    server_client_ensure_ranges(r, 1);
    r->ranges[0].px = px;
    r->ranges[0].nx = nx;
    r->used = 1;
    return;
  }
  server_client_ensure_ranges(r, 2);

  /* Visible bit to the left of the popup. */
  if (px < x) {
    r->ranges[0].px = px;
    r->ranges[0].nx = x - px;
    if (r->ranges[0].nx > nx)
      r->ranges[0].nx = nx;
  } else {
    r->ranges[0].px = 0;
    r->ranges[0].nx = 0;
  }

  /* Visible bit to the right of the popup. */
  ox = x + sx;
  if (px > ox)
    ox = px;
  onx = px + nx;
  if (onx > ox) {
    r->ranges[1].px = ox;
    r->ranges[1].nx = onx - ox;
  } else {
    r->ranges[1].px = 0;
    r->ranges[1].nx = 0;
  }
  r->used = 2;
}

/* Check if this client is inside this server. */
int
server_client_check_nested(struct client *c)
{
  struct environ_entry  *envent;
  struct window_pane  *wp;

  envent = environ_find(c->environ, "TMUX");
  if (envent == NULL || *envent->value == '\0')
    return (0);

  RB_FOREACH(wp, window_pane_tree, &all_window_panes) {
    if (strcmp(wp->tty, c->ttyname) == 0)
      return (1);
  }
  return (0);
}

/* Set client key table. */
void
server_client_set_key_table(struct client *c, const char *name)
{
  if (name == NULL)
    name = server_client_get_key_table(c);

  key_bindings_unref_table(c->keytable);
  c->keytable = key_bindings_get_table(name, 1);
  c->keytable->references++;
  if (gettimeofday(&c->keytable->activity_time, NULL) != 0)
    fatal("gettimeofday failed");
}

static uint64_t
server_client_key_table_activity_diff(struct client *c)
{
  struct timeval  diff;

  timersub(&c->activity_time, &c->keytable->activity_time, &diff);
  return ((diff.tv_sec * 1000ULL) + (diff.tv_usec / 1000ULL));
}

/* Get default key table. */
const char *
server_client_get_key_table(struct client *c)
{
  struct session  *s = c->session;
  const char  *name;

  if (s == NULL)
    return ("root");

  name = options_get_string(s->options, "key-table");
  if (*name == '\0')
    return ("root");
  return (name);
}

/* Is this table the default key table? */
static int
server_client_is_default_key_table(struct client *c, struct key_table *table)
{
  return (strcmp(table->name, server_client_get_key_table(c)) == 0);
}

/* Create a new client. */
struct client *
server_client_create(int fd)
{
  struct client *c;

  setblocking(fd, 0);

  c = xcalloc(1, sizeof *c);
  c->references = 1;
  c->peer = proc_add_peer(server_proc, fd, server_client_dispatch, c);

  if (gettimeofday(&c->creation_time, NULL) != 0)
    fatal("gettimeofday failed");
  memcpy(&c->activity_time, &c->creation_time, sizeof c->activity_time);

  c->environ = environ_create();

  c->fd = -1;
  c->out_fd = -1;

  c->queue = cmdq_new();
  RB_INIT(&c->windows);
  RB_INIT(&c->files);

  c->tty.sx = 80;
  c->tty.sy = 24;
  c->theme = THEME_UNKNOWN;

  status_init(c);
  c->flags |= CLIENT_FOCUSED;

  c->keytable = key_bindings_get_table("root", 1);
  c->keytable->references++;

  evtimer_set(&c->repeat_timer, server_client_repeat_timer, c);
  evtimer_set(&c->click_timer, server_client_click_timer, c);

  c->click_wp = -1;

  TAILQ_INIT(&c->input_requests);

  TAILQ_INSERT_TAIL(&clients, c, entry);
  log_debug("new client %p", c);
  return (c);
}

/* Open client terminal if needed. */
int
server_client_open(struct client *c, char **cause)
{
  const char  *ttynam = _PATH_TTY;

  if (c->flags & CLIENT_CONTROL)
    return (0);

  if (strcmp(c->ttyname, ttynam) == 0||
      ((isatty(STDIN_FILENO) &&
      (ttynam = ttyname(STDIN_FILENO)) != NULL &&
      strcmp(c->ttyname, ttynam) == 0) ||
      (isatty(STDOUT_FILENO) &&
      (ttynam = ttyname(STDOUT_FILENO)) != NULL &&
      strcmp(c->ttyname, ttynam) == 0) ||
      (isatty(STDERR_FILENO) &&
      (ttynam = ttyname(STDERR_FILENO)) != NULL &&
      strcmp(c->ttyname, ttynam) == 0))) {
    xasprintf(cause, "can't use %s", c->ttyname);
    return (-1);
  }

  if (!(c->flags & CLIENT_TERMINAL)) {
    *cause = xstrdup("not a terminal");
    return (-1);
  }

  if (tty_open(&c->tty, cause) != 0)
    return (-1);

  return (0);
}

/* Lost an attached client. */
static void
server_client_attached_lost(struct client *c)
{
  struct session  *s;
  struct window *w;
  struct client *loop;
  struct client *found;

  log_debug("lost attached client %p", c);

  /*
   * By this point the session in the client has been cleared so walk all
   * windows to find any with this client as the latest.
   */
  RB_FOREACH(w, windows, &windows) {
    if (w->latest != c)
      continue;

    found = NULL;
    TAILQ_FOREACH(loop, &clients, entry) {
      s = loop->session;
      if (loop == c || s == NULL || s->curw->window != w)
        continue;
      if (found == NULL || timercmp(&loop->activity_time,
          &found->activity_time, >))
        found = loop;
    }
    if (found != NULL)
      server_client_update_latest(found);
  }
}

/* Set client session. */
void
server_client_set_session(struct client *c, struct session *s)
{
  struct session  *old = c->session;

  if (s != NULL && c->session != NULL && c->session != s)
    c->last_session = c->session;
  else if (s == NULL)
    c->last_session = NULL;
  c->session = s;
  c->flags |= CLIENT_FOCUSED;

  if (old != NULL && old->curw != NULL)
    window_update_focus(old->curw->window);
  if (s != NULL) {
    s->curw->window->latest = c;
    recalculate_sizes();
    window_update_focus(s->curw->window);
    session_update_activity(s, NULL);
    session_theme_changed(s);
    gettimeofday(&s->last_attached_time, NULL);
    s->curw->flags &= ~WINLINK_ALERTFLAGS;
    alerts_check_session(s);
    tty_update_client_offset(c);
    status_timer_start(c);
    notify_client("client-session-changed", c);
    server_redraw_client(c);
  }

  server_check_unattached();
  server_update_socket();
}

/* Lost a client. */
void
server_client_lost(struct client *c)
{
  struct client_file  *cf, *cf1;
  struct client_window  *cw, *cw1;

  c->flags |= CLIENT_DEAD;

  server_client_clear_overlay(c);
  status_prompt_clear(c);
  status_message_clear(c);

  RB_FOREACH_SAFE(cf, client_files, &c->files, cf1) {
    cf->error = EINTR;
    file_fire_done(cf);
  }
  RB_FOREACH_SAFE(cw, client_windows, &c->windows, cw1) {
    RB_REMOVE(client_windows, &c->windows, cw);
    free(cw);
  }

  TAILQ_REMOVE(&clients, c, entry);
  log_debug("lost client %p", c);

  if (c->flags & CLIENT_ATTACHED) {
    server_client_attached_lost(c);
    notify_client("client-detached", c);
  }

  if (c->flags & CLIENT_CONTROL)
    control_stop(c);
  if (c->flags & CLIENT_TERMINAL)
    tty_free(&c->tty);
  free(c->ttyname);
  free(c->clipboard_panes);

  free(c->term_name);
  free(c->term_type);
  tty_term_free_list(c->term_caps, c->term_ncaps);

  status_free(c);
  input_cancel_requests(c);

  free(c->title);
  free((void *)c->cwd);

  evtimer_del(&c->repeat_timer);
  evtimer_del(&c->click_timer);

  key_bindings_unref_table(c->keytable);

  free(c->message_string);
  if (event_initialized(&c->message_timer))
    evtimer_del(&c->message_timer);

  free(c->prompt_saved);
  free(c->prompt_string);
  free(c->prompt_buffer);

  format_lost_client(c);
  environ_free(c->environ);

  proc_remove_peer(c->peer);
  c->peer = NULL;

  if (c->out_fd != -1)
    close(c->out_fd);
  if (c->fd != -1) {
    close(c->fd);
    c->fd = -1;
  }
  server_client_unref(c);

  server_add_accept(0); /* may be more file descriptors now */

  recalculate_sizes();
  server_check_unattached();
  server_update_socket();
}

/* Remove reference from a client. */
void
server_client_unref(struct client *c)
{
  log_debug("unref client %p (%d references)", c, c->references);

  c->references--;
  if (c->references == 0)
    event_once(-1, EV_TIMEOUT, server_client_free, c, NULL);
}

/* Free dead client. */
static void
server_client_free(__unused int fd, __unused short events, void *arg)
{
  struct client *c = arg;

  log_debug("free client %p (%d references)", c, c->references);

  cmdq_free(c->queue);

  if (c->references == 0) {
    free((void *)c->name);
    free((void *)c->user);
    free(c);
  }
}

/* Suspend a client. */
void
server_client_suspend(struct client *c)
{
  struct session  *s = c->session;

  if (s == NULL || (c->flags & CLIENT_UNATTACHEDFLAGS))
    return;

  tty_stop_tty(&c->tty);
  c->flags |= CLIENT_SUSPENDED;
  proc_send(c->peer, MSG_SUSPEND, -1, NULL, 0);
}

/* Detach a client. */
void
server_client_detach(struct client *c, enum msgtype msgtype)
{
  struct session  *s = c->session;

  if (s == NULL || (c->flags & CLIENT_NODETACHFLAGS))
    return;

  c->flags |= CLIENT_EXIT;

  c->exit_type = CLIENT_EXIT_DETACH;
  c->exit_msgtype = msgtype;
  c->exit_session = xstrdup(s->name);
}

/* Execute command to replace a client. */
void
server_client_exec(struct client *c, const char *cmd)
{
  struct session  *s = c->session;
  char    *msg;
  const char  *shell;
  size_t     cmdsize, shellsize;

  if (*cmd == '\0')
    return;
  cmdsize = strlen(cmd) + 1;

  if (s != NULL)
    shell = options_get_string(s->options, "default-shell");
  else
    shell = options_get_string(global_s_options, "default-shell");
  if (!checkshell(shell))
    shell = _PATH_BSHELL;
  shellsize = strlen(shell) + 1;

  msg = xmalloc(cmdsize + shellsize);
  memcpy(msg, cmd, cmdsize);
  memcpy(msg + cmdsize, shell, shellsize);

  proc_send(c->peer, MSG_EXEC, -1, msg, cmdsize + shellsize);
  free(msg);
}

static enum key_code_mouse_location
server_client_check_mouse_in_pane(struct window_pane *wp, u_int px, u_int py,
    u_int *sl_mpos)
{
  struct window   *w = wp->window;
  struct options    *wo = w->options;
  struct window_pane  *fwp;
  int      pane_status, sb, sb_pos, sb_w, sb_pad;
  int      pane_status_line, sl_top, sl_bottom;
  int      bdr_bottom, bdr_top, bdr_right;

  sb = options_get_number(wo, "pane-scrollbars");
  sb_pos = options_get_number(wo, "pane-scrollbars-position");
  pane_status = options_get_number(wo, "pane-border-status");

  if (window_pane_show_scrollbar(wp, sb)) {
    sb_w = wp->scrollbar_style.width;
    sb_pad = wp->scrollbar_style.pad;
  } else {
    sb_w = 0;
    sb_pad = 0;
  }

  if (pane_status == PANE_STATUS_TOP)
    pane_status_line = wp->yoff - 1;
  else if (pane_status == PANE_STATUS_BOTTOM)
    pane_status_line = wp->yoff + wp->sy;
  else
    pane_status_line = -1; /* not used */

  /* Check if point is within the pane or scrollbar. */
  if (((pane_status != PANE_STATUS_OFF &&
      (int)py != pane_status_line && py != wp->yoff + wp->sy) ||
      (wp->yoff == 0 && py < wp->sy) ||
      (py >= wp->yoff && py < wp->yoff + wp->sy)) &&
      ((sb_pos == PANE_SCROLLBARS_RIGHT &&
      (int)px < (int)wp->xoff + (int)wp->sx + sb_pad + sb_w) ||
      (sb_pos == PANE_SCROLLBARS_LEFT &&
      (int)px < (int)wp->xoff + (int)wp->sx - sb_pad - sb_w))) {
    /* Check if in the scrollbar. */
    if ((sb_pos == PANE_SCROLLBARS_RIGHT &&
        ((int)px >= (int)wp->xoff + (int)wp->sx + sb_pad &&
        (int)px < (int)wp->xoff + (int)wp->sx + sb_pad + sb_w)) ||
        (sb_pos == PANE_SCROLLBARS_LEFT &&
        ((int)px >= (int)wp->xoff - sb_pad - sb_w &&
        (int)px < (int)wp->xoff - sb_pad))) {
      /* Check where inside the scrollbar. */
      sl_top = wp->yoff + wp->sb_slider_y;
      sl_bottom = (wp->yoff + wp->sb_slider_y +
          wp->sb_slider_h - 1);
      if ((int)py < sl_top)
        return (KEYC_MOUSE_LOCATION_SCROLLBAR_UP);
      else if ((int)py >= sl_top &&
         (int)py <= sl_bottom) {
        *sl_mpos = (py - wp->sb_slider_y - wp->yoff);
        return (KEYC_MOUSE_LOCATION_SCROLLBAR_SLIDER);
      } else /* py > sl_bottom */
        return (KEYC_MOUSE_LOCATION_SCROLLBAR_DOWN);
    } else {
      /* Must be inside the pane. */
      return (KEYC_MOUSE_LOCATION_PANE);
    }
  } else {
    /* Try the pane borders. */
    TAILQ_FOREACH(fwp, &w->panes, entry) {
      if ((w->flags & WINDOW_ZOOMED) &&
          (~fwp->flags & PANE_ZOOMED))
        continue;
      bdr_top = fwp->yoff - 1;
      bdr_bottom = fwp->yoff + (int)fwp->sy;
      if (sb_pos == PANE_SCROLLBARS_LEFT)
        bdr_right = fwp->xoff + (int)fwp->sx;
      else
        /* PANE_SCROLLBARS_RIGHT or none. */
        bdr_right = fwp->xoff + (int)fwp->sx +
            sb_pad + sb_w;
      if ((int)py >= (int)fwp->yoff - 1 &&
          py <= fwp->yoff + fwp->sy) {
        if ((int)px == bdr_right)
          break;
      }
      if ((int)px >= (int)fwp->xoff - 1 &&
          px <= fwp->xoff + fwp->sx) {
        if ((int)py == bdr_bottom || (int)py == bdr_top)
          break;
      }
    }
    if (fwp != NULL)
      return (KEYC_MOUSE_LOCATION_BORDER);
  }
  return (KEYC_MOUSE_LOCATION_NOWHERE);
}

/* Check for mouse keys. */
static key_code
server_client_check_mouse(struct client *c, struct key_event *event)
{
  struct mouse_event    *m = &event->m;
  struct session      *s = c->session, *fs;
  struct window     *w = s->curw->window;
  struct winlink      *fwl;
  struct window_pane    *wp, *fwp;
  u_int        x, y, sx, sy, px, py, n, sl_mpos = 0;
  u_int        b, bn;
  int        ignore = 0;
  key_code       key;
  struct timeval       tv;
  struct style_range    *sr;
  enum key_code_type     type = KEYC_TYPE_NOTYPE;
  enum key_code_mouse_location   loc = KEYC_MOUSE_LOCATION_NOWHERE;

  log_debug("%s mouse %02x at %u,%u (last %u,%u) (%d)", c->name, m->b,
      m->x, m->y, m->lx, m->ly, c->tty.mouse_drag_flag);

  /* What type of event is this? */
  if (event->key == KEYC_DOUBLECLICK) {
    type = KEYC_TYPE_DOUBLECLICK;
    x = m->x, y = m->y, b = m->b;
    ignore = 1;
    log_debug("double-click at %u,%u", x, y);
  } else if ((m->sgr_type != ' ' &&
      MOUSE_DRAG(m->sgr_b) &&
      MOUSE_RELEASE(m->sgr_b)) ||
      (m->sgr_type == ' ' &&
      MOUSE_DRAG(m->b) &&
      MOUSE_RELEASE(m->b) &&
      MOUSE_RELEASE(m->lb))) {
    type = KEYC_TYPE_MOUSEMOVE;
    x = m->x, y = m->y, b = 0;
    log_debug("move at %u,%u", x, y);
  } else if (MOUSE_DRAG(m->b)) {
    type = KEYC_TYPE_MOUSEDRAG;
    if (c->tty.mouse_drag_flag) {
      x = m->x, y = m->y, b = m->b;
      if (x == m->lx && y == m->ly)
        return (KEYC_UNKNOWN);
      log_debug("drag update at %u,%u", x, y);
    } else {
      x = m->lx, y = m->ly, b = m->lb;
      log_debug("drag start at %u,%u", x, y);
    }
  } else if (MOUSE_WHEEL(m->b)) {
    if ((m->b & MOUSE_MASK_BUTTONS) == MOUSE_WHEEL_UP)
      type = KEYC_TYPE_WHEELUP;
    else
      type = KEYC_TYPE_WHEELDOWN;
    x = m->x, y = m->y, b = m->b;
    log_debug("wheel at %u,%u", x, y);
  } else if (MOUSE_RELEASE(m->b)) {
    type = KEYC_TYPE_MOUSEUP;
    x = m->x, y = m->y, b = m->lb;
    if (m->sgr_type == 'm')
      b = m->sgr_b;
    log_debug("up at %u,%u", x, y);
  } else {
    if (c->flags & CLIENT_DOUBLECLICK) {
      evtimer_del(&c->click_timer);
      c->flags &= ~CLIENT_DOUBLECLICK;
      type = KEYC_TYPE_SECONDCLICK;
      x = m->x, y = m->y, b = m->b;
      log_debug("second-click at %u,%u", x, y);
      c->flags |= CLIENT_TRIPLECLICK;
    } else if (c->flags & CLIENT_TRIPLECLICK) {
      evtimer_del(&c->click_timer);
      c->flags &= ~CLIENT_TRIPLECLICK;
      type = KEYC_TYPE_TRIPLECLICK;
      x = m->x, y = m->y, b = m->b;
      log_debug("triple-click at %u,%u", x, y);
      goto have_event;
    }

    /* DOWN is the only remaining event type. */
    if (type == KEYC_TYPE_NOTYPE) {
      type = KEYC_TYPE_MOUSEDOWN;
      x = m->x, y = m->y, b = m->b;
      log_debug("down at %u,%u", x, y);
      c->flags |= CLIENT_DOUBLECLICK;
    }
  }

have_event:
  if (type == KEYC_TYPE_NOTYPE)
    return (KEYC_UNKNOWN);

  /* Save the session. */
  m->s = s->id;
  m->w = -1;
  m->wp = -1;
  m->ignore = ignore;

  /* Is this on the status line? */
  m->statusat = status_at_line(c);
  m->statuslines = status_line_size(c);
  if (m->statusat != -1 &&
      y >= (u_int)m->statusat &&
      y < m->statusat + m->statuslines) {
    sr = status_get_range(c, x, y - m->statusat);
    if (sr == NULL) {
      loc = KEYC_MOUSE_LOCATION_STATUS_DEFAULT;
    } else {
      switch (sr->type) {
      case STYLE_RANGE_NONE:
        return (KEYC_UNKNOWN);
      case STYLE_RANGE_LEFT:
        log_debug("mouse range: left");
        loc = KEYC_MOUSE_LOCATION_STATUS_LEFT;
        break;
      case STYLE_RANGE_RIGHT:
        log_debug("mouse range: right");
        loc = KEYC_MOUSE_LOCATION_STATUS_RIGHT;
        break;
      case STYLE_RANGE_PANE:
        fwp = window_pane_find_by_id(sr->argument);
        if (fwp == NULL)
          return (KEYC_UNKNOWN);
        m->wp = sr->argument;

        log_debug("mouse range: pane %%%u", m->wp);
        loc = KEYC_MOUSE_LOCATION_STATUS;
        break;
      case STYLE_RANGE_WINDOW:
        fwl = winlink_find_by_index(&s->windows,
            sr->argument);
        if (fwl == NULL)
          return (KEYC_UNKNOWN);
        m->w = fwl->window->id;

        log_debug("mouse range: window @%u", m->w);
        loc = KEYC_MOUSE_LOCATION_STATUS;
        break;
      case STYLE_RANGE_SESSION:
        fs = session_find_by_id(sr->argument);
        if (fs == NULL)
          return (KEYC_UNKNOWN);
        m->s = sr->argument;

        log_debug("mouse range: session $%u", m->s);
        loc = KEYC_MOUSE_LOCATION_STATUS;
        break;
      case STYLE_RANGE_USER:
        log_debug("mouse range: user");
        loc = KEYC_MOUSE_LOCATION_STATUS;
        break;
      case STYLE_RANGE_CONTROL:
        n = sr->argument; /* parsing keeps this < 10 */
        log_debug("mouse range: control %u", n);
        loc = KEYC_MOUSE_LOCATION_CONTROL0 + n;
        break;
      }
    }
  }

  /*
   * Not on status line. Adjust position and check for border, pane, or
   * scrollbar.
   */
  if (loc == KEYC_MOUSE_LOCATION_NOWHERE) {
    if (c->tty.mouse_scrolling_flag)
      loc = KEYC_MOUSE_LOCATION_SCROLLBAR_SLIDER;
    else {
      px = x;
      if (m->statusat == 0 && y >= m->statuslines)
        py = y - m->statuslines;
      else if (m->statusat > 0 && y >= (u_int)m->statusat)
        py = m->statusat - 1;
      else
        py = y;

      tty_window_offset(&c->tty, &m->ox, &m->oy, &sx, &sy);
      log_debug("mouse window @%u at %u,%u (%ux%u)",
          w->id, m->ox, m->oy, sx, sy);
      if (px > sx || py > sy)
        return (KEYC_UNKNOWN);
      px = px + m->ox;
      py = py + m->oy;

      /* Try inside the pane. */
      wp = window_get_active_at(w, px, py);
      if (wp == NULL)
        return (KEYC_UNKNOWN);
      loc = server_client_check_mouse_in_pane(wp, px, py,
          &sl_mpos);

      if (loc == KEYC_MOUSE_LOCATION_PANE) {
        log_debug("mouse %u,%u on pane %%%u", x, y,
            wp->id);
      } else if (loc == KEYC_MOUSE_LOCATION_BORDER) {
        sr = window_pane_border_status_get_range(wp, px,
          py);
        if (sr != NULL) {
          n = sr->argument;
          loc = KEYC_MOUSE_LOCATION_CONTROL0 + n;
        }
        log_debug("mouse on pane %%%u border", wp->id);
      } else if (loc == KEYC_MOUSE_LOCATION_SCROLLBAR_UP ||
          loc == KEYC_MOUSE_LOCATION_SCROLLBAR_SLIDER ||
          loc == KEYC_MOUSE_LOCATION_SCROLLBAR_DOWN) {
        log_debug("mouse on pane %%%u scrollbar",
            wp->id);
      }
      m->wp = wp->id;
      m->w = wp->window->id;
    }
  }

  /* Reset click type or add a click timer if needed. */
  if (type == KEYC_TYPE_MOUSEDOWN ||
      type == KEYC_TYPE_SECONDCLICK ||
      type == KEYC_TYPE_TRIPLECLICK) {
    if (type != KEYC_TYPE_MOUSEDOWN &&
        (m->b != c->click_button ||
        loc != (enum key_code_mouse_location)c->click_loc ||
        m->wp != c->click_wp)) {
      type = KEYC_TYPE_MOUSEDOWN;
      log_debug("click sequence reset at %u,%u", x, y);
      c->flags &= ~CLIENT_TRIPLECLICK;
      c->flags |= CLIENT_DOUBLECLICK;
    }

    if (type != KEYC_TYPE_TRIPLECLICK && KEYC_CLICK_TIMEOUT != 0) {
      memcpy(&c->click_event, m, sizeof c->click_event);
      c->click_button = m->b;
      c->click_loc = loc;
      c->click_wp = m->wp;

      log_debug("click timer started");
      tv.tv_sec = KEYC_CLICK_TIMEOUT / 1000;
      tv.tv_usec = (KEYC_CLICK_TIMEOUT % 1000) * 1000L;
      evtimer_del(&c->click_timer);
      evtimer_add(&c->click_timer, &tv);
    }
  }

  key = KEYC_UNKNOWN;

  /* Stop dragging if needed. */
  if (type != KEYC_TYPE_MOUSEDRAG &&
      type != KEYC_TYPE_WHEELUP &&
      type != KEYC_TYPE_WHEELDOWN &&
      type != KEYC_TYPE_DOUBLECLICK &&
      type != KEYC_TYPE_TRIPLECLICK &&
      c->tty.mouse_drag_flag != 0) {
    if (c->tty.mouse_drag_release != NULL)
      c->tty.mouse_drag_release(c, m);

    c->tty.mouse_drag_update = NULL;
    c->tty.mouse_drag_release = NULL;
    c->tty.mouse_scrolling_flag = 0;

    /*
     * End a mouse drag by passing a MouseDragEnd key corresponding
     * to the button that started the drag.
     */
    type = KEYC_TYPE_MOUSEDRAGEND;
    c->tty.mouse_drag_flag = 0;
    c->tty.mouse_slider_mpos = -1;
  }

  /* Convert to a key binding. */
  if (type == KEYC_TYPE_MOUSEMOVE && loc == KEYC_MOUSE_LOCATION_PANE) {
    key = KEYC_MOUSEMOVE_PANE;
    if (wp != NULL &&
        wp != w->active &&
        options_get_number(s->options, "focus-follows-mouse")) {
      window_set_active_pane(w, wp, 1);
      server_redraw_window_borders(w);
      server_status_window(w);
    }
  }
  if (type == KEYC_TYPE_MOUSEDRAG) {
    if (c->tty.mouse_drag_update != NULL)
      key = KEYC_DRAGGING;

    /*
     * Begin a drag by setting the flag to a non-zero value that
     * corresponds to the mouse button in use. If starting to drag
     * the scrollbar, store the relative position in the slider
     * where the user grabbed.
     */
    c->tty.mouse_drag_flag = MOUSE_BUTTONS(b) + 1;
    if (c->tty.mouse_scrolling_flag == 0 &&
        loc == KEYC_MOUSE_LOCATION_SCROLLBAR_SLIDER) {
      c->tty.mouse_scrolling_flag = 1;
      if (m->statusat == 0) {
        c->tty.mouse_slider_mpos = sl_mpos +
            m->statuslines;
      } else
        c->tty.mouse_slider_mpos = sl_mpos;
    }
  }

  if (key == KEYC_UNKNOWN) {
    /* Adjust the button number. */
    if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_1)
      bn = 1;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_2)
      bn = 2;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_3)
      bn = 3;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_6)
      bn = 6;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_7)
      bn = 7;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_8)
      bn = 8;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_9)
      bn = 9;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_10)
      bn = 10;
    else if (MOUSE_BUTTONS(b) == MOUSE_BUTTON_11)
      bn = 11;
    else
      bn = 0;
    key = KEYC_MAKE_MOUSE_KEY(type, bn, loc);
  }

  /* Apply modifiers if any. */
  if (b & MOUSE_MASK_META)
    key |= KEYC_META;
  if (b & MOUSE_MASK_CTRL)
    key |= KEYC_CTRL;
  if (b & MOUSE_MASK_SHIFT)
    key |= KEYC_SHIFT;

  if (log_get_level() != 0)
    log_debug("mouse key is %s", key_string_lookup_key (key, 1));
  return (key);
}

/* Is this a bracket paste key? */
static int
server_client_is_bracket_paste(struct client *c, key_code key)
{
  if ((key & KEYC_MASK_KEY) == KEYC_PASTE_START) {
    c->flags |= CLIENT_BRACKETPASTING;
    log_debug("%s: bracket paste on", c->name);
    return (0);
  }

  if ((key & KEYC_MASK_KEY) == KEYC_PASTE_END) {
    c->flags &= ~CLIENT_BRACKETPASTING;
    log_debug("%s: bracket paste off", c->name);
    return (0);
  }

  return !!(c->flags & CLIENT_BRACKETPASTING);
}

/* Is this fast enough to probably be a paste? */
static int
server_client_is_assume_paste(struct client *c)
{
  struct session  *s = c->session;
  struct timeval   tv;
  int    t;

  if (c->flags & CLIENT_BRACKETPASTING)
    return (0);
  if ((t = options_get_number(s->options, "assume-paste-time")) == 0)
    return (0);

  timersub(&c->activity_time, &c->last_activity_time, &tv);
  if (tv.tv_sec == 0 && tv.tv_usec < t * 1000) {
    if (c->flags & CLIENT_ASSUMEPASTING)
      return (1);
    c->flags |= CLIENT_ASSUMEPASTING;
    log_debug("%s: assume paste on", c->name);
    return (0);
  }
  if (c->flags & CLIENT_ASSUMEPASTING) {
    c->flags &= ~CLIENT_ASSUMEPASTING;
    log_debug("%s: assume paste off", c->name);
  }
  return (0);
}

/* Has the latest client changed? */
static void
server_client_update_latest(struct client *c)
{
  struct window *w;

  if (c->session == NULL)
    return;
  w = c->session->curw->window;

  if (w->latest == c)
    return;
  w->latest = c;

  if (options_get_number(w->options, "window-size") == WINDOW_SIZE_LATEST)
    recalculate_size(w, 0);

  notify_client("client-active", c);
}

/* Get repeat time. */
static u_int
server_client_repeat_time(struct client *c, struct key_binding *bd)
{
  struct session  *s = c->session;
  u_int    repeat, initial;

  if (~bd->flags & KEY_BINDING_REPEAT)
    return (0);
  repeat = options_get_number(s->options, "repeat-time");
  if (repeat == 0)
    return (0);
  if ((~c->flags & CLIENT_REPEAT) || bd->key != c->last_key) {
    initial = options_get_number(s->options, "initial-repeat-time");
    if (initial != 0)
      repeat = initial;
  }
  return (repeat);
}

/*
 * Handle data key input from client. This owns and can modify the key event it
 * is given and is responsible for freeing it.
 */
static enum cmd_retval
server_client_key_callback(struct cmdq_item *item, void *data)
{
  struct client     *c = cmdq_get_client(item);
  struct key_event    *event = data;
  key_code       key = event->key;
  struct mouse_event    *m = &event->m;
  struct session      *s = c->session;
  struct winlink      *wl;
  struct window_pane    *wp;
  struct window_mode_entry  *wme;
  struct timeval       tv;
  struct key_table    *table, *first;
  struct key_binding    *bd;
  u_int        repeat;
  uint64_t       flags, prefix_delay;
  struct cmd_find_state    fs;
  key_code       key0, prefix, prefix2;

  /* Check the client is good to accept input. */
  if (s == NULL || (c->flags & CLIENT_UNATTACHEDFLAGS))
    goto out;
  wl = s->curw;

  /* Update the activity timer. */
  memcpy(&c->last_activity_time, &c->activity_time,
      sizeof c->last_activity_time);
  if (gettimeofday(&c->activity_time, NULL) != 0)
    fatal("gettimeofday failed");
  session_update_activity(s, &c->activity_time);

  /* Check for mouse keys. */
  m->valid = 0;
  if (key == KEYC_MOUSE || key == KEYC_DOUBLECLICK) {
    if (c->flags & CLIENT_READONLY)
      goto out;
    key = server_client_check_mouse(c, event);
    if (key == KEYC_UNKNOWN)
      goto out;

    m->valid = 1;
    m->key = key;

    /*
     * Mouse drag is in progress, so fire the callback (now that
     * the mouse event is valid).
     */
    if ((key & KEYC_MASK_KEY) == KEYC_DRAGGING) {
      c->tty.mouse_drag_update(c, m);
      goto out;
    }
    event->key = key;
  }

  /* Find affected pane. */
  if (!KEYC_IS_MOUSE(key) || cmd_find_from_mouse(&fs, m, 0) != 0)
    cmd_find_from_client(&fs, c, 0);
  wp = fs.wp;

  /* Forward mouse keys if disabled. */
  if (KEYC_IS_MOUSE(key) && !options_get_number(s->options, "mouse"))
    goto forward_key;

  /* Forward if bracket pasting. */
  if (server_client_is_bracket_paste (c, key))
    goto paste_key;

  /* Treat everything as a regular key when pasting is detected. */
  if (!KEYC_IS_MOUSE(key) &&
      key != KEYC_FOCUS_IN &&
      key != KEYC_FOCUS_OUT &&
      (~key & KEYC_SENT) &&
      server_client_is_assume_paste(c))
    goto paste_key;

  /*
   * Work out the current key table. If the pane is in a mode, use
   * the mode table instead of the default key table.
   */
  if (server_client_is_default_key_table(c, c->keytable) &&
      wp != NULL &&
      (wme = TAILQ_FIRST(&wp->modes)) != NULL &&
      wme->mode->key_table != NULL)
    table = key_bindings_get_table(wme->mode->key_table(wme), 1);
  else
    table = c->keytable;
  first = table;

table_changed:
  /*
   * The prefix always takes precedence and forces a switch to the prefix
   * table, unless we are already there.
   */
  prefix = (key_code)options_get_number(s->options, "prefix");
  prefix2 = (key_code)options_get_number(s->options, "prefix2");
  key0 = (key & (KEYC_MASK_KEY|KEYC_MASK_MODIFIERS));
  if ((key0 == (prefix & (KEYC_MASK_KEY|KEYC_MASK_MODIFIERS)) ||
      key0 == (prefix2 & (KEYC_MASK_KEY|KEYC_MASK_MODIFIERS))) &&
      strcmp(table->name, "prefix") != 0) {
    server_client_set_key_table(c, "prefix");
    server_status_client(c);
    goto out;
  }
  flags = c->flags;

try_again:
  /* Log key table. */
  if (wp == NULL)
    log_debug("key table %s (no pane)", table->name);
  else
    log_debug("key table %s (pane %%%u)", table->name, wp->id);
  if (c->flags & CLIENT_REPEAT)
    log_debug("currently repeating");

  bd = key_bindings_get(table, key0);

  /*
   * If prefix-timeout is enabled and we're in the prefix table, see if
   * the timeout has been exceeded. Revert to the root table if so.
   */
  prefix_delay = options_get_number(global_options, "prefix-timeout");
  if (prefix_delay > 0 &&
      strcmp(table->name, "prefix") == 0 &&
      server_client_key_table_activity_diff(c) > prefix_delay) {
    /*
     * If repeating is active and this is a repeating binding,
     * ignore the timeout.
     */
    if (bd != NULL &&
        (c->flags & CLIENT_REPEAT) &&
        (bd->flags & KEY_BINDING_REPEAT)) {
      log_debug("prefix timeout ignored, repeat is active");
    } else {
      log_debug("prefix timeout exceeded");
      server_client_set_key_table(c, NULL);
      first = table = c->keytable;
      server_status_client(c);
      goto table_changed;
    }
  }

  /* Try to see if there is a key binding in the current table. */
  if (bd != NULL) {
    /*
     * Key was matched in this table. If currently repeating but a
     * non-repeating binding was found, stop repeating and try
     * again in the root table.
     */
    if ((c->flags & CLIENT_REPEAT) &&
        (~bd->flags & KEY_BINDING_REPEAT)) {
      log_debug("found in key table %s (not repeating)",
          table->name);
      server_client_set_key_table(c, NULL);
      first = table = c->keytable;
      c->flags &= ~CLIENT_REPEAT;
      server_status_client(c);
      goto table_changed;
    }
    log_debug("found in key table %s", table->name);

    /*
     * Take a reference to this table to make sure the key binding
     * doesn't disappear.
     */
    table->references++;

    /*
     * If this is a repeating key, start the timer. Otherwise reset
     * the client back to the root table.
     */
    repeat = server_client_repeat_time(c, bd);
    if (repeat != 0) {
      c->flags |= CLIENT_REPEAT;
      c->last_key = bd->key;

      tv.tv_sec = repeat / 1000;
      tv.tv_usec = (repeat % 1000) * 1000L;
      evtimer_del(&c->repeat_timer);
      evtimer_add(&c->repeat_timer, &tv);
    } else {
      c->flags &= ~CLIENT_REPEAT;
      server_client_set_key_table(c, NULL);
    }
    server_status_client(c);

    /* Execute the key binding. */
    key_bindings_dispatch(bd, item, c, event, &fs);
    key_bindings_unref_table(table);
    goto out;
  }

  /*
   * No match, try the ANY key.
   */
  if (key0 != KEYC_ANY) {
    key0 = KEYC_ANY;
    goto try_again;
  }

  /*
   * Binding movement keys is useless since we only turn them on when the
   * application requests, so don't let them exit the prefix table.
   */
  if (key == KEYC_MOUSEMOVE_PANE ||
      key == KEYC_MOUSEMOVE_STATUS ||
      key == KEYC_MOUSEMOVE_STATUS_LEFT ||
      key == KEYC_MOUSEMOVE_STATUS_RIGHT ||
      key == KEYC_MOUSEMOVE_STATUS_DEFAULT ||
      key == KEYC_MOUSEMOVE_BORDER)
    goto forward_key;

  /*
   * No match in this table. If not in the root table or if repeating
   * switch the client back to the root table and try again.
   */
  log_debug("not found in key table %s", table->name);
  if (!server_client_is_default_key_table(c, table) ||
      (c->flags & CLIENT_REPEAT)) {
    log_debug("trying in root table");
    server_client_set_key_table(c, NULL);
    table = c->keytable;
    if (c->flags & CLIENT_REPEAT)
      first = table;
    c->flags &= ~CLIENT_REPEAT;
    server_status_client(c);
    goto table_changed;
  }

  /*
   * No match in the root table either. If this wasn't the first table
   * tried, don't pass the key to the pane.
   */
  if (first != table && (~flags & CLIENT_REPEAT)) {
    server_client_set_key_table(c, NULL);
    server_status_client(c);
    goto out;
  }

forward_key:
  if (wp != NULL &&
      (wp->flags & PANE_EXITED) &&
      !KEYC_IS_MOUSE(key) &&
      !KEYC_IS_PASTE(key) &&
      options_get_number(wp->options, "remain-on-exit") == 3) {
    options_set_number(wp->options, "remain-on-exit", 0);
    server_destroy_pane(wp, 0);
    goto out;
  }
  if (c->flags & CLIENT_READONLY)
    goto out;
  if (wp != NULL)
    window_pane_key(wp, c, s, wl, key, m);
  goto out;

paste_key:
  if (c->flags & CLIENT_READONLY)
    goto out;
  if (event->buf != NULL)
    window_pane_paste(wp, key, event->buf, event->len);
  key = KEYC_NONE;
  goto out;

out:
  if (s != NULL && key != KEYC_FOCUS_OUT)
    server_client_update_latest(c);
  free(event->buf);
  free(event);
  return (CMD_RETURN_NORMAL);
}

/* Handle a key event. */
int
server_client_handle_key(struct client *c, struct key_event *event)
{
  struct session    *s = c->session;
  struct cmdq_item  *item;

  /* Check the client is good to accept input. */
  if (s == NULL || (c->flags & CLIENT_UNATTACHEDFLAGS))
    return (0);

  /*
   * Handle theme reporting keys before overlays so they work even when a
   * popup is open.
   */
  if (event->key == KEYC_REPORT_LIGHT_THEME) {
    server_client_report_theme(c, THEME_LIGHT);
    return (0);
  }
  if (event->key == KEYC_REPORT_DARK_THEME) {
    server_client_report_theme(c, THEME_DARK);
    return (0);
  }

  /*
   * Key presses in overlay mode and the command prompt are a special
   * case. The queue might be blocked so they need to be processed
   * immediately rather than queued.
   */
  if (~c->flags & CLIENT_READONLY) {
    if (c->message_string != NULL) {
      if (c->message_ignore_keys)
        return (0);
      status_message_clear(c);
    }
    if (c->overlay_key != NULL) {
      switch (c->overlay_key(c, c->overlay_data, event)) {
      case 0:
        return (0);
      case 1:
        server_client_clear_overlay(c);
        return (0);
      }
    }
    server_client_clear_overlay(c);
    if (c->prompt_string != NULL) {
      if (status_prompt_key(c, event->key) == 0)
        return (0);
    }
  }

  /*
   * Add the key to the queue so it happens after any commands queued by
   * previous keys.
   */
  item = cmdq_get_callback(server_client_key_callback, event);
  cmdq_append(c, item);
  return (1);
}

/* Client functions that need to happen every loop. */
void
server_client_loop(void)
{
  struct client     *c;
  struct window     *w;
  struct window_pane    *wp;
  struct window_mode_entry  *wme;

  /* Check for window resize. This is done before redrawing. */
  RB_FOREACH(w, windows, &windows)
    server_client_check_window_resize(w);

  /* Notify modes that pane styles may have changed. */
  RB_FOREACH(w, windows, &windows) {
    TAILQ_FOREACH(wp, &w->panes, entry) {
      if (wp->flags & PANE_STYLECHANGED) {
        wme = TAILQ_FIRST(&wp->modes);
        if (wme != NULL &&
            wme->mode->style_changed != NULL)
          wme->mode->style_changed(wme);
      }
    }
  }

  /* Check clients. */
  TAILQ_FOREACH(c, &clients, entry) {
    server_client_check_exit(c);
    if (c->session != NULL && c->session->curw != NULL) {
      server_client_check_modes(c);
      server_client_check_redraw(c);
      server_client_reset_state(c);
    }
  }

  /*
   * Any windows will have been redrawn as part of clients, so clear
   * their flags now.
   */
  RB_FOREACH(w, windows, &windows) {
    TAILQ_FOREACH(wp, &w->panes, entry) {
      if (wp->fd != -1) {
        server_client_check_pane_resize(wp);
        server_client_check_pane_buffer(wp);
      }
      wp->flags &= ~(PANE_REDRAW|PANE_REDRAWSCROLLBAR);
    }
    check_window_name(w);
  }

  /* Send theme updates. */
  RB_FOREACH(w, windows, &windows) {
    TAILQ_FOREACH(wp, &w->panes, entry)
      window_pane_send_theme_update(wp);
  }
}

/* Check if window needs to be resized. */
static void
server_client_check_window_resize(struct window *w)
{
  struct winlink  *wl;

  if (~w->flags & WINDOW_RESIZE)
    return;

  TAILQ_FOREACH(wl, &w->winlinks, wentry) {
    if (wl->session->attached != 0 && wl->session->curw == wl)
      break;
  }
  if (wl == NULL)
    return;

  log_debug("%s: resizing window @%u", __func__, w->id);
  resize_window(w, w->new_sx, w->new_sy, w->new_xpixel, w->new_ypixel);
}

/* Resize timer event. */
static void
server_client_resize_timer(__unused int fd, __unused short events, void *data)
{
  struct window_pane  *wp = data;

  log_debug("%s: %%%u resize timer expired", __func__, wp->id);
  evtimer_del(&wp->resize_timer);
}

/* Check if pane should be resized. */
static void
server_client_check_pane_resize(struct window_pane *wp)
{
  struct window_pane_resize *r;
  struct window_pane_resize *r1;
  struct window_pane_resize *first;
  struct window_pane_resize *last;
  struct timeval       tv = { .tv_usec = 250000 };

  if (TAILQ_EMPTY(&wp->resize_queue))
    return;

  if (!event_initialized(&wp->resize_timer))
    evtimer_set(&wp->resize_timer, server_client_resize_timer, wp);
  if (evtimer_pending(&wp->resize_timer, NULL))
    return;

  log_debug("%s: %%%u needs to be resized", __func__, wp->id);
  TAILQ_FOREACH(r, &wp->resize_queue, entry) {
    log_debug("queued resize: %ux%u -> %ux%u", r->osx, r->osy,
        r->sx, r->sy);
  }

  /*
   * There are three cases that matter:
   *
   * - Only one resize. It can just be applied.
   *
   * - Multiple resizes and the ending size is different from the
   *   starting size. We can discard all resizes except the most recent.
   *
   * - Multiple resizes and the ending size is the same as the starting
   *   size. We must resize at least twice to force the application to
   *   redraw. So apply the first and leave the last on the queue for
   *   next time.
   */
  first = TAILQ_FIRST(&wp->resize_queue);
  last = TAILQ_LAST(&wp->resize_queue, window_pane_resizes);
  if (first == last) {
    /* Only one resize. */
    window_pane_send_resize(wp, first->sx, first->sy);
    TAILQ_REMOVE(&wp->resize_queue, first, entry);
    free(first);
  } else if (last->sx != first->osx || last->sy != first->osy) {
    /* Multiple resizes ending up with a different size. */
    window_pane_send_resize(wp, last->sx, last->sy);
    TAILQ_FOREACH_SAFE(r, &wp->resize_queue, entry, r1) {
      TAILQ_REMOVE(&wp->resize_queue, r, entry);
      free(r);
    }
  } else {
    /*
     * Multiple resizes ending up with the same size. There will
     * not be more than one to the same size in succession so we
     * can just use the last-but-one on the list and leave the last
     * for later. We reduce the time until the next check to avoid
     * a long delay between the resizes.
     */
    r = TAILQ_PREV(last, window_pane_resizes, entry);
    window_pane_send_resize(wp, r->sx, r->sy);
    TAILQ_FOREACH_SAFE(r, &wp->resize_queue, entry, r1) {
      if (r == last)
        break;
      TAILQ_REMOVE(&wp->resize_queue, r, entry);
      free(r);
    }
    tv.tv_usec = 10000;
  }
  evtimer_add(&wp->resize_timer, &tv);
}

/* Check pane buffer size. */
static void
server_client_check_pane_buffer(struct window_pane *wp)
{
  struct evbuffer     *evb = wp->event->input;
  size_t         minimum;
  struct client     *c;
  struct window_pane_offset *wpo;
  int        off = 1, flag;
  u_int        attached_clients = 0;
  size_t         new_size;

  /*
   * Work out the minimum used size. This is the most that can be removed
   * from the buffer.
   */
  minimum = wp->offset.used;
  if (wp->pipe_fd != -1 && wp->pipe_offset.used < minimum)
    minimum = wp->pipe_offset.used;
  TAILQ_FOREACH(c, &clients, entry) {
    if (c->session == NULL)
      continue;
    attached_clients++;

    if (~c->flags & CLIENT_CONTROL) {
      off = 0;
      continue;
    }
    wpo = control_pane_offset(c, wp, &flag);
    if (wpo == NULL) {
      if (!flag)
        off = 0;
      continue;
    }
    if (!flag)
      off = 0;

    window_pane_get_new_data(wp, wpo, &new_size);
    log_debug("%s: %s has %zu bytes used and %zu left for %%%u",
        __func__, c->name, wpo->used - wp->base_offset, new_size,
        wp->id);
    if (wpo->used < minimum)
      minimum = wpo->used;
  }
  if (attached_clients == 0)
    off = 0;
  minimum -= wp->base_offset;
  if (minimum == 0)
    goto out;

  /* Drain the buffer. */
  log_debug("%s: %%%u has %zu minimum (of %zu) bytes used", __func__,
      wp->id, minimum, EVBUFFER_LENGTH(evb));
  evbuffer_drain(evb, minimum);

  /*
   * Adjust the base offset. If it would roll over, all the offsets into
   * the buffer need to be adjusted.
   */
  if (wp->base_offset > SIZE_MAX - minimum) {
    log_debug("%s: %%%u base offset has wrapped", __func__, wp->id);
    wp->offset.used -= wp->base_offset;
    if (wp->pipe_fd != -1)
      wp->pipe_offset.used -= wp->base_offset;
    TAILQ_FOREACH(c, &clients, entry) {
      if (c->session == NULL || (~c->flags & CLIENT_CONTROL))
        continue;
      wpo = control_pane_offset(c, wp, &flag);
      if (wpo != NULL && !flag)
        wpo->used -= wp->base_offset;
    }
    wp->base_offset = minimum;
  } else
    wp->base_offset += minimum;

out:
  /*
   * If there is data remaining, and there are no clients able to consume
   * it, do not read any more. This is true when there are attached
   * clients, all of which are control clients which are not able to
   * accept any more data.
   */
  log_debug("%s: pane %%%u is %s", __func__, wp->id, off ? "off" : "on");
  if (off)
    bufferevent_disable(wp->event, EV_READ);
  else
    bufferevent_enable(wp->event, EV_READ);
}

/*
 * Update cursor position and mode settings. The scroll region and attributes
 * are cleared when idle (waiting for an event) as this is the most likely time
 * a user may interrupt tmux, for example with ~^Z in ssh(1). This is a
 * compromise between excessive resets and likelihood of an interrupt.
 *
 * tty_region/tty_reset/tty_update_mode already take care of not resetting
 * things that are already in their default state.
 */
static void
server_client_reset_state(struct client *c)
{
  struct tty    *tty = &c->tty;
  struct window   *w = c->session->curw->window;
  struct window_pane  *wp = server_client_get_pane(c), *loop;
  struct screen   *s = NULL;
  struct options    *oo = c->session->options;
  int      mode = 0, cursor, flags;
  u_int      cx = 0, cy = 0, ox, oy, sx, sy, n;

  if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
    return;

  /* Disable the block flag. */
  flags = (tty->flags & TTY_BLOCK);
  tty->flags &= ~TTY_BLOCK;

  /* Get mode from overlay if any, else from screen. */
  if (c->overlay_draw != NULL) {
    if (c->overlay_mode != NULL)
      s = c->overlay_mode(c, c->overlay_data, &cx, &cy);
  } else if (c->prompt_string == NULL)
    s = wp->screen;
  else
    s = c->status.active;
  if (s != NULL)
    mode = s->mode;
  if (log_get_level() != 0) {
    log_debug("%s: client %s mode %s", __func__, c->name,
        screen_mode_to_string(mode));
  }

  /* Reset region and margin. */
  tty_region_off(tty);
  tty_margin_off(tty);

  /* Move cursor to pane cursor and offset. */
  if (c->prompt_string != NULL) {
    n = options_get_number(oo, "status-position");
    if (n == 0)
      cy = status_prompt_line_at(c);
    else {
      n = status_line_size(c) - status_prompt_line_at(c);
      if (n <= tty->sy)
        cy = tty->sy - n;
      else
        cy = tty->sy - 1;
    }
    cx = c->prompt_cursor;
  } else if (c->overlay_draw == NULL) {
    cursor = 0;
    tty_window_offset(tty, &ox, &oy, &sx, &sy);
    if (wp->xoff + s->cx >= ox && wp->xoff + s->cx <= ox + sx &&
        wp->yoff + s->cy >= oy && wp->yoff + s->cy <= oy + sy) {
      cursor = 1;

      cx = wp->xoff + s->cx - ox;
      cy = wp->yoff + s->cy - oy;

      if (status_at_line(c) == 0)
        cy += status_line_size(c);
    }
    if (!cursor)
      mode &= ~MODE_CURSOR;
  }
  log_debug("%s: cursor to %u,%u", __func__, cx, cy);
  tty_cursor(tty, cx, cy);

  /*
   * Set mouse mode if requested. To support dragging, always use button
   * mode. For focus-follows-mouse, we need all-motion mode to receive
   * movement events.
   */
  if (options_get_number(oo, "mouse")) {
    if (c->overlay_draw == NULL) {
      mode &= ~ALL_MOUSE_MODES;
      TAILQ_FOREACH(loop, &w->panes, entry) {
        if (loop->screen->mode & MODE_MOUSE_ALL)
          mode |= MODE_MOUSE_ALL;
      }
    }
    if (options_get_number(oo, "focus-follows-mouse"))
      mode |= MODE_MOUSE_ALL;
    else if (~mode & MODE_MOUSE_ALL)
      mode |= MODE_MOUSE_BUTTON;
  }

  /* Clear bracketed paste mode if at the prompt. */
  if (c->overlay_draw == NULL && c->prompt_string != NULL)
    mode &= ~MODE_BRACKETPASTE;

  /* Set the terminal mode and reset attributes. */
  tty_update_mode(tty, mode, s);
  tty_reset(tty);

  /* All writing must be done, send a sync end (if it was started). */
  tty_sync_end(tty);
  tty->flags |= flags;
}

/* Repeat time callback. */
static void
server_client_repeat_timer(__unused int fd, __unused short events, void *data)
{
  struct client *c = data;

  if (c->flags & CLIENT_REPEAT) {
    server_client_set_key_table(c, NULL);
    c->flags &= ~CLIENT_REPEAT;
    server_status_client(c);
  }
}

/* Double-click callback. */
static void
server_client_click_timer(__unused int fd, __unused short events, void *data)
{
  struct client   *c = data;
  struct key_event  *event;

  log_debug("click timer expired");

  if (c->flags & CLIENT_TRIPLECLICK) {
    /*
     * Waiting for a third click that hasn't happened, so this must
     * have been a double click.
     */
    event = xcalloc(1, sizeof *event);
    event->key = KEYC_DOUBLECLICK;
    memcpy(&event->m, &c->click_event, sizeof event->m);
    if (!server_client_handle_key(c, event)) {
      free(event->buf);
      free(event);
    }
  }
  c->flags &= ~(CLIENT_DOUBLECLICK|CLIENT_TRIPLECLICK);
}

/* Check if client should be exited. */
static void
server_client_check_exit(struct client *c)
{
  struct client_file  *cf;
  const char    *name = c->exit_session;
  char      *data;
  size_t       size, msize;

  if (c->flags & (CLIENT_DEAD|CLIENT_EXITED))
    return;
  if (~c->flags & CLIENT_EXIT)
    return;

  if (c->flags & CLIENT_CONTROL) {
    control_discard(c);
    if (!control_all_done(c))
      return;
  }
  RB_FOREACH(cf, client_files, &c->files) {
    if (EVBUFFER_LENGTH(cf->buffer) != 0)
      return;
  }
  c->flags |= CLIENT_EXITED;

  switch (c->exit_type) {
  case CLIENT_EXIT_RETURN:
    if (c->exit_message != NULL)
      msize = strlen(c->exit_message) + 1;
    else
      msize = 0;
    size = (sizeof c->retval) + msize;
    data = xmalloc(size);
    memcpy(data, &c->retval, sizeof c->retval);
    if (c->exit_message != NULL)
      memcpy(data + sizeof c->retval, c->exit_message, msize);
    proc_send(c->peer, MSG_EXIT, -1, data, size);
    free(data);
    break;
  case CLIENT_EXIT_SHUTDOWN:
    proc_send(c->peer, MSG_SHUTDOWN, -1, NULL, 0);
    break;
  case CLIENT_EXIT_DETACH:
    proc_send(c->peer, c->exit_msgtype, -1, name, strlen(name) + 1);
    break;
  }
  free(c->exit_session);
  free(c->exit_message);
}

/* Redraw timer callback. */
static void
server_client_redraw_timer(__unused int fd, __unused short events,
    __unused void *data)
{
  log_debug("redraw timer fired");
}

/*
 * Check if modes need to be updated. Only modes in the current window are
 * updated and it is done when the status line is redrawn.
 */
static void
server_client_check_modes(struct client *c)
{
  struct window     *w = c->session->curw->window;
  struct window_pane    *wp;
  struct window_mode_entry  *wme;

  if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
    return;
  if (~c->flags & CLIENT_REDRAWSTATUS)
    return;
  TAILQ_FOREACH(wp, &w->panes, entry) {
    wme = TAILQ_FIRST(&wp->modes);
    if (wme != NULL && wme->mode->update != NULL)
      wme->mode->update(wme);
  }
}

/* Check for client redraws. */
static void
server_client_check_redraw(struct client *c)
{
  struct session    *s = c->session;
  struct tty    *tty = &c->tty;
  struct window   *w = c->session->curw->window;
  struct window_pane  *wp;
  int      needed, tty_flags, mode = tty->mode;
  uint64_t     client_flags = 0;
  int      redraw_pane, redraw_scrollbar_only;
  u_int      bit = 0;
  struct timeval     tv = { .tv_usec = 1000 };
  static struct event  ev;
  size_t       left;

  if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
    return;
  if (c->flags & CLIENT_ALLREDRAWFLAGS) {
    log_debug("%s: redraw%s%s%s%s%s%s", c->name,
        (c->flags & CLIENT_REDRAWWINDOW) ? " window" : "",
        (c->flags & CLIENT_REDRAWSTATUS) ? " status" : "",
        (c->flags & CLIENT_REDRAWBORDERS) ? " borders" : "",
        (c->flags & CLIENT_REDRAWOVERLAY) ? " overlay" : "",
        (c->flags & CLIENT_REDRAWPANES) ? " panes" : "",
        (c->flags & CLIENT_REDRAWSCROLLBARS) ? " scrollbars" : "");
  }

  /*
   * If there is outstanding data, defer the redraw until it has been
   * consumed. We can just add a timer to get out of the event loop and
   * end up back here.
   */
  needed = 0;
  if (c->flags & CLIENT_ALLREDRAWFLAGS)
    needed = 1;
  else {
    TAILQ_FOREACH(wp, &w->panes, entry) {
      if (wp->flags & PANE_REDRAW) {
        needed = 1;
        client_flags |= CLIENT_REDRAWPANES;
        break;
      }
      if (wp->flags & PANE_REDRAWSCROLLBAR) {
        needed = 1;
        client_flags |= CLIENT_REDRAWSCROLLBARS;
        /* no break - later panes may need redraw */
      }
    }
  }
  if (needed && (left = EVBUFFER_LENGTH(tty->out)) != 0) {
    log_debug("%s: redraw deferred (%zu left)", c->name, left);
    if (!evtimer_initialized(&ev))
      evtimer_set(&ev, server_client_redraw_timer, NULL);
    if (!evtimer_pending(&ev, NULL)) {
      log_debug("redraw timer started");
      evtimer_add(&ev, &tv);
    }

    if (~c->flags & CLIENT_REDRAWWINDOW) {
      TAILQ_FOREACH(wp, &w->panes, entry) {
        if (wp->flags & (PANE_REDRAW)) {
          log_debug("%s: pane %%%u needs redraw",
              c->name, wp->id);
          c->redraw_panes |= (1 << bit);
        } else if (wp->flags & PANE_REDRAWSCROLLBAR) {
          log_debug("%s: pane %%%u scrollbar "
              "needs redraw", c->name, wp->id);
          c->redraw_scrollbars |= (1 << bit);
        }
        if (++bit == 64) {
          /*
           * If more that 64 panes, give up and
           * just redraw the window.
           */
          client_flags &= ~(CLIENT_REDRAWPANES|
              CLIENT_REDRAWSCROLLBARS);
          client_flags |= CLIENT_REDRAWWINDOW;
          break;
        }
      }
      if (c->redraw_panes != 0)
        c->flags |= CLIENT_REDRAWPANES;
      if (c->redraw_scrollbars != 0)
        c->flags |= CLIENT_REDRAWSCROLLBARS;
    }
    c->flags |= client_flags;
    return;
  } else if (needed)
    log_debug("%s: redraw needed", c->name);

  tty_flags = tty->flags & (TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR);
  tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE))|TTY_NOCURSOR;

  if (~c->flags & CLIENT_REDRAWWINDOW) {
    /*
     * If not redrawing the entire window, check whether each pane
     * needs to be redrawn.
     */
    TAILQ_FOREACH(wp, &w->panes, entry) {
      redraw_pane = 0;
      redraw_scrollbar_only = 0;
      if (wp->flags & PANE_REDRAW)
        redraw_pane = 1;
      else if (c->flags & CLIENT_REDRAWPANES) {
        if (c->redraw_panes & (1 << bit))
          redraw_pane = 1;
      } else if (c->flags & CLIENT_REDRAWSCROLLBARS) {
        if (c->redraw_scrollbars & (1 << bit))
          redraw_scrollbar_only = 1;
      }
      bit++;
      if (!redraw_pane && !redraw_scrollbar_only)
        continue;
      if (redraw_scrollbar_only) {
        log_debug("%s: redrawing (scrollbar only) pane "
            "%%%u", __func__, wp->id);
      } else {
        log_debug("%s: redrawing pane %%%u", __func__,
            wp->id);
      }
      screen_redraw_pane(c, wp, redraw_scrollbar_only);
    }
    c->redraw_panes = 0;
    c->redraw_scrollbars = 0;
    c->flags &= ~(CLIENT_REDRAWPANES|CLIENT_REDRAWSCROLLBARS);
  }

  if (c->flags & CLIENT_ALLREDRAWFLAGS) {
    if (options_get_number(s->options, "set-titles")) {
      server_client_set_title(c);
      server_client_set_path(c);
    }
    screen_redraw_screen(c);
  }

  tty->flags = (tty->flags & ~TTY_NOCURSOR)|(tty_flags & TTY_NOCURSOR);
  tty_update_mode(tty, mode, NULL);
  tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR))|
      tty_flags;

  c->flags &= ~(CLIENT_ALLREDRAWFLAGS|CLIENT_STATUSFORCE);

  if (needed) {
    /*
     * We would have deferred the redraw unless the output buffer
     * was empty, so we can record how many bytes the redraw
     * generated.
     */
    c->redraw = EVBUFFER_LENGTH(tty->out);
    log_debug("%s: redraw added %zu bytes", c->name, c->redraw);
  }
}

/* Set client title. */
static void
server_client_set_title(struct client *c)
{
  struct session    *s = c->session;
  const char    *template;
  char      *title;
  struct format_tree  *ft;

  template = options_get_string(s->options, "set-titles-string");

  ft = format_create(c, NULL, FORMAT_NONE, 0);
  format_defaults(ft, c, NULL, NULL, NULL);

  title = format_expand_time(ft, template);
  if (c->title == NULL || strcmp(title, c->title) != 0) {
    free(c->title);
    c->title = xstrdup(title);
    tty_set_title(&c->tty, c->title);
  }
  free(title);

  format_free(ft);
}

/* Set client path. */
static void
server_client_set_path(struct client *c)
{
  struct session  *s = c->session;
  const char  *path;

  if (s->curw == NULL)
    return;
  if (s->curw->window->active->base.path == NULL)
    path = "";
  else
    path = s->curw->window->active->base.path;
  if (c->path == NULL || strcmp(path, c->path) != 0) {
    free(c->path);
    c->path = xstrdup(path);
    tty_set_path(&c->tty, c->path);
  }
}

/* Dispatch message from client. */
static void
server_client_dispatch(struct imsg *imsg, void *arg)
{
  struct client *c = arg;
  ssize_t    datalen;
  struct session  *s;

  if (c->flags & CLIENT_DEAD)
    return;

  if (imsg == NULL) {
    server_client_lost(c);
    return;
  }

  datalen = imsg->hdr.len - IMSG_HEADER_SIZE;

  switch (imsg->hdr.type) {
  case MSG_IDENTIFY_CLIENTPID:
  case MSG_IDENTIFY_CWD:
  case MSG_IDENTIFY_ENVIRON:
  case MSG_IDENTIFY_FEATURES:
  case MSG_IDENTIFY_FLAGS:
  case MSG_IDENTIFY_LONGFLAGS:
  case MSG_IDENTIFY_STDIN:
  case MSG_IDENTIFY_STDOUT:
  case MSG_IDENTIFY_TERM:
  case MSG_IDENTIFY_TERMINFO:
  case MSG_IDENTIFY_TTYNAME:
  case MSG_IDENTIFY_DONE:
    if (server_client_dispatch_identify(c, imsg) != 0)
      goto bad;
    break;
  case MSG_COMMAND:
    if (server_client_dispatch_command(c, imsg) != 0)
      goto bad;
    break;
  case MSG_RESIZE:
    if (datalen != 0)
      goto bad;

    if (c->flags & CLIENT_CONTROL)
      break;
    server_client_update_latest(c);
    tty_resize(&c->tty);
    tty_repeat_requests(&c->tty, 0);
    recalculate_sizes();
    if (c->overlay_resize == NULL)
      server_client_clear_overlay(c);
    else
      c->overlay_resize(c, c->overlay_data);
    server_redraw_client(c);
    if (c->session != NULL)
      notify_client("client-resized", c);
    break;
  case MSG_EXITING:
    if (datalen != 0)
      goto bad;
    server_client_set_session(c, NULL);
    recalculate_sizes();
    tty_close(&c->tty);
    proc_send(c->peer, MSG_EXITED, -1, NULL, 0);
    break;
  case MSG_WAKEUP:
  case MSG_UNLOCK:
    if (datalen != 0)
      goto bad;

    if (!(c->flags & CLIENT_SUSPENDED))
      break;
    c->flags &= ~CLIENT_SUSPENDED;

    if (c->fd == -1 || c->session == NULL) /* exited already */
      break;
    s = c->session;

    if (gettimeofday(&c->activity_time, NULL) != 0)
      fatal("gettimeofday failed");

    tty_start_tty(&c->tty);
    server_redraw_client(c);
    recalculate_sizes();

    if (s != NULL)
      session_update_activity(s, &c->activity_time);
    break;
  case MSG_SHELL:
    if (datalen != 0)
      goto bad;
    if (server_client_dispatch_shell(c) != 0)
      goto bad;
    break;
  case MSG_WRITE_READY:
    file_write_ready(&c->files, imsg);
    break;
  case MSG_READ:
    file_read_data(&c->files, imsg);
    break;
  case MSG_READ_DONE:
    file_read_done(&c->files, imsg);
    break;
  }

  return;

bad:
  log_debug("client %p invalid message type %d", c, imsg->hdr.type);
  proc_kill_peer(c->peer);
}

/* Callback when command is not allowed. */
static enum cmd_retval
server_client_read_only(struct cmdq_item *item, __unused void *data)
{
  cmdq_error(item, "client is read-only");
  return (CMD_RETURN_ERROR);
}

/* Callback for default command. */
static enum cmd_retval
server_client_default_command(struct cmdq_item *item, __unused void *data)
{
  struct client   *c = cmdq_get_client(item);
  struct cmd_list   *cmdlist;
  struct cmdq_item  *new_item;

  cmdlist = options_get_command(global_options, "default-client-command");
  if ((c->flags & CLIENT_READONLY) &&
      !cmd_list_all_have(cmdlist, CMD_READONLY))
    new_item = cmdq_get_callback(server_client_read_only, NULL);
  else
    new_item = cmdq_get_command(cmdlist, NULL);
  cmdq_insert_after(item, new_item);
  return (CMD_RETURN_NORMAL);
}

/* Callback when command is done. */
static enum cmd_retval
server_client_command_done(struct cmdq_item *item, __unused void *data)
{
  struct client *c = cmdq_get_client(item);

  if (~c->flags & CLIENT_ATTACHED)
    c->flags |= CLIENT_EXIT;
  else if (~c->flags & CLIENT_EXIT) {
    if (c->flags & CLIENT_CONTROL)
      control_ready(c);
    tty_send_requests(&c->tty);
  }
  return (CMD_RETURN_NORMAL);
}

/* Handle command message. */
static int
server_client_dispatch_command(struct client *c, struct imsg *imsg)
{
  struct msg_command    data;
  char       *buf;
  size_t        len;
  int       argc = 0;
  char      **argv, *cause;
  struct cmd_parse_result  *pr;
  struct args_value  *values;
  struct cmdq_item   *new_item;

  if (c->flags & CLIENT_EXIT)
    return (0);

  if (imsg->hdr.len - IMSG_HEADER_SIZE < sizeof data)
    return (-1);
  memcpy(&data, imsg->data, sizeof data);

  buf = (char *)imsg->data + sizeof data;
  len = imsg->hdr.len - IMSG_HEADER_SIZE - sizeof data;
  if (len > 0 && buf[len - 1] != '\0')
    return (-1);

  if (cmd_unpack_argv(buf, len, data.argc, &argv) != 0) {
    cause = xstrdup("command too long");
    goto error;
  }

  argc = data.argc;
  if (argc == 0) {
    new_item = cmdq_get_callback(server_client_default_command,
        NULL);
  } else {
    values = args_from_vector(argc, argv);
    pr = cmd_parse_from_arguments(values, argc, NULL);
    switch (pr->status) {
    case CMD_PARSE_ERROR:
      cause = pr->error;
      goto error;
    case CMD_PARSE_SUCCESS:
      break;
    }
    args_free_values(values, argc);
    free(values);
    cmd_free_argv(argc, argv);
    if ((c->flags & CLIENT_READONLY) &&
        !cmd_list_all_have(pr->cmdlist, CMD_READONLY)) {
      new_item = cmdq_get_callback(server_client_read_only,
          NULL);
    } else
      new_item = cmdq_get_command(pr->cmdlist, NULL);
    cmd_list_free(pr->cmdlist);
  }
  cmdq_append(c, new_item);
  cmdq_append(c, cmdq_get_callback(server_client_command_done, NULL));

  return (0);

error:
  cmd_free_argv(argc, argv);

  cmdq_append(c, cmdq_get_error(cause));
  free(cause);

  c->flags |= CLIENT_EXIT;
  return (0);
}

/* Handle identify message. */
static int
server_client_dispatch_identify(struct client *c, struct imsg *imsg)
{
  const char  *data, *home;
  size_t     datalen;
  int    flags, feat;
  uint64_t   longflags;
  char    *name;

  if (c->flags & CLIENT_IDENTIFIED)
    return (-1);

  data = imsg->data;
  datalen = imsg->hdr.len - IMSG_HEADER_SIZE;

  switch (imsg->hdr.type) {
  case MSG_IDENTIFY_FEATURES:
    if (datalen != sizeof feat)
      return (-1);
    memcpy(&feat, data, sizeof feat);
    c->term_features |= feat;
    log_debug("client %p IDENTIFY_FEATURES %s", c,
        tty_get_features(feat));
    break;
  case MSG_IDENTIFY_FLAGS:
    if (datalen != sizeof flags)
      return (-1);
    memcpy(&flags, data, sizeof flags);
    c->flags |= flags;
    log_debug("client %p IDENTIFY_FLAGS %#x", c, flags);
    break;
  case MSG_IDENTIFY_LONGFLAGS:
    if (datalen != sizeof longflags)
      return (-1);
    memcpy(&longflags, data, sizeof longflags);
    c->flags |= longflags;
    log_debug("client %p IDENTIFY_LONGFLAGS %#llx", c,
        (unsigned long long)longflags);
    break;
  case MSG_IDENTIFY_TERM:
    if (datalen == 0 || data[datalen - 1] != '\0')
      return (-1);
    c->term_name = xstrdup(data);
    log_debug("client %p IDENTIFY_TERM %s", c, data);
    break;
  case MSG_IDENTIFY_TERMINFO:
    if (datalen == 0 || data[datalen - 1] != '\0')
      return (-1);
    c->term_caps = xreallocarray(c->term_caps, c->term_ncaps + 1,
        sizeof *c->term_caps);
    c->term_caps[c->term_ncaps++] = xstrdup(data);
    log_debug("client %p IDENTIFY_TERMINFO %s", c, data);
    break;
  case MSG_IDENTIFY_TTYNAME:
    if (datalen == 0 || data[datalen - 1] != '\0')
      return (-1);
    c->ttyname = xstrdup(data);
    log_debug("client %p IDENTIFY_TTYNAME %s", c, data);
    break;
  case MSG_IDENTIFY_CWD:
    if (datalen == 0 || data[datalen - 1] != '\0')
      return (-1);
    if (access(data, X_OK) == 0)
      c->cwd = xstrdup(data);
    else if ((home = find_home()) != NULL)
      c->cwd = xstrdup(home);
    else
      c->cwd = xstrdup("/");
    log_debug("client %p IDENTIFY_CWD %s", c, data);
    break;
  case MSG_IDENTIFY_STDIN:
    if (datalen != 0)
      return (-1);
    c->fd = imsg_get_fd(imsg);
    log_debug("client %p IDENTIFY_STDIN %d", c, c->fd);
    break;
  case MSG_IDENTIFY_STDOUT:
    if (datalen != 0)
      return (-1);
    c->out_fd = imsg_get_fd(imsg);
    log_debug("client %p IDENTIFY_STDOUT %d", c, c->out_fd);
    break;
  case MSG_IDENTIFY_ENVIRON:
    if (datalen == 0 || data[datalen - 1] != '\0')
      return (-1);
    if (strchr(data, '=') != NULL)
      environ_put(c->environ, data, 0);
    log_debug("client %p IDENTIFY_ENVIRON %s", c, data);
    break;
  case MSG_IDENTIFY_CLIENTPID:
    if (datalen != sizeof c->pid)
      return (-1);
    memcpy(&c->pid, data, sizeof c->pid);
    log_debug("client %p IDENTIFY_CLIENTPID %ld", c, (long)c->pid);
    break;
  default:
    break;
  }

  if (imsg->hdr.type != MSG_IDENTIFY_DONE)
    return (0);
  c->flags |= CLIENT_IDENTIFIED;

  if (c->term_name == NULL || *c->term_name == '\0') {
    free(c->term_name);
    c->term_name = xstrdup("unknown");
  }

  if (c->ttyname != NULL && *c->ttyname != '\0')
    name = xstrdup(c->ttyname);
  else
    xasprintf(&name, "client-%ld", (long)c->pid);
  c->name = name;
  log_debug("client %p name is %s", c, c->name);

#ifdef __CYGWIN__
  c->fd = open(c->ttyname, O_RDWR|O_NOCTTY);
  c->out_fd = dup(c->fd);
#endif

  if (c->flags & CLIENT_CONTROL)
    control_start(c);
  else if (c->fd != -1) {
    if (tty_init(&c->tty, c) != 0) {
      close(c->fd);
      c->fd = -1;
    } else {
      tty_resize(&c->tty);
      c->flags |= CLIENT_TERMINAL;
    }
    if (c->out_fd != -1)
      close(c->out_fd);
    c->out_fd = -1;
  }

  /*
   * If this is the first client, load configuration files. Any later
   * clients are allowed to continue with their command even if the
   * config has not been loaded - they might have been run from inside it
   */
  if ((~c->flags & CLIENT_EXIT) &&
       !cfg_finished &&
       c == TAILQ_FIRST(&clients))
    start_cfg();

  return (0);
}

/* Handle shell message. */
static int
server_client_dispatch_shell(struct client *c)
{
  const char  *shell;

  shell = options_get_string(global_s_options, "default-shell");
  if (!checkshell(shell))
    shell = _PATH_BSHELL;
  proc_send(c->peer, MSG_SHELL, -1, shell, strlen(shell) + 1);

  proc_kill_peer(c->peer);
  return (0);
}

/* Get client working directory. */
const char *
server_client_get_cwd(struct client *c, struct session *s)
{
  const char  *home;

  if (!cfg_finished && cfg_client != NULL)
    return (cfg_client->cwd);
  if (c != NULL && c->session == NULL && c->cwd != NULL)
    return (c->cwd);
  if (s != NULL && s->cwd != NULL)
    return (s->cwd);
  if (c != NULL && (s = c->session) != NULL && s->cwd != NULL)
    return (s->cwd);
  if ((home = find_home()) != NULL)
    return (home);
  return ("/");
}

/* Get control client flags. */
static uint64_t
server_client_control_flags(struct client *c, const char *next)
{
  if (strcmp(next, "pause-after") == 0) {
    c->pause_age = 0;
    return (CLIENT_CONTROL_PAUSEAFTER);
  }
  if (sscanf(next, "pause-after=%u", &c->pause_age) == 1) {
    c->pause_age *= 1000;
    return (CLIENT_CONTROL_PAUSEAFTER);
  }
  if (strcmp(next, "no-output") == 0)
    return (CLIENT_CONTROL_NOOUTPUT);
  if (strcmp(next, "wait-exit") == 0)
    return (CLIENT_CONTROL_WAITEXIT);
  return (0);
}

/* Set client flags. */
void
server_client_set_flags(struct client *c, const char *flags)
{
  char  *s, *copy, *next;
  uint64_t flag;
  int  not;

  s = copy = xstrdup(flags);
  while ((next = strsep(&s, ",")) != NULL) {
    not = (*next == '!');
    if (not)
      next++;

    if (c->flags & CLIENT_CONTROL)
      flag = server_client_control_flags(c, next);
    else
      flag = 0;
    if (strcmp(next, "read-only") == 0)
      flag = CLIENT_READONLY;
    else if (strcmp(next, "ignore-size") == 0)
      flag = CLIENT_IGNORESIZE;
    else if (strcmp(next, "active-pane") == 0)
      flag = CLIENT_ACTIVEPANE;
    else if (strcmp(next, "no-detach-on-destroy") == 0)
      flag = CLIENT_NO_DETACH_ON_DESTROY;
    if (flag == 0)
      continue;

    log_debug("client %s set flag %s", c->name, next);
    if (not) {
      if (c->flags & CLIENT_READONLY)
        flag &= ~CLIENT_READONLY;
      c->flags &= ~flag;
    } else
      c->flags |= flag;
    if (flag == CLIENT_CONTROL_NOOUTPUT)
      control_reset_offsets(c);
  }
  free(copy);
  proc_send(c->peer, MSG_FLAGS, -1, &c->flags, sizeof c->flags);
}

/* Get client flags. This is only flags useful to show to users. */
const char *
server_client_get_flags(struct client *c)
{
  static char s[256];
  char    tmp[32];

  *s = '\0';
  if (c->flags & CLIENT_ATTACHED)
    strlcat(s, "attached,", sizeof s);
  if (c->flags & CLIENT_FOCUSED)
    strlcat(s, "focused,", sizeof s);
  if (c->flags & CLIENT_CONTROL)
    strlcat(s, "control-mode,", sizeof s);
  if (c->flags & CLIENT_IGNORESIZE)
    strlcat(s, "ignore-size,", sizeof s);
  if (c->flags & CLIENT_NO_DETACH_ON_DESTROY)
    strlcat(s, "no-detach-on-destroy,", sizeof s);
  if (c->flags & CLIENT_CONTROL_NOOUTPUT)
    strlcat(s, "no-output,", sizeof s);
  if (c->flags & CLIENT_CONTROL_WAITEXIT)
    strlcat(s, "wait-exit,", sizeof s);
  if (c->flags & CLIENT_CONTROL_PAUSEAFTER) {
    xsnprintf(tmp, sizeof tmp, "pause-after=%u,",
        c->pause_age / 1000);
    strlcat(s, tmp, sizeof s);
  }
  if (c->flags & CLIENT_READONLY)
    strlcat(s, "read-only,", sizeof s);
  if (c->flags & CLIENT_ACTIVEPANE)
    strlcat(s, "active-pane,", sizeof s);
  if (c->flags & CLIENT_SUSPENDED)
    strlcat(s, "suspended,", sizeof s);
  if (c->flags & CLIENT_UTF8)
    strlcat(s, "UTF-8,", sizeof s);
  if (*s != '\0')
    s[strlen(s) - 1] = '\0';
  return (s);
}

/* Get client window. */
struct client_window *
server_client_get_client_window(struct client *c, u_int id)
{
  struct client_window  cw = { .window = id };

  return (RB_FIND(client_windows, &c->windows, &cw));
}

/* Add client window. */
struct client_window *
server_client_add_client_window(struct client *c, u_int id)
{
  struct client_window  *cw;

  cw = server_client_get_client_window(c, id);
  if (cw == NULL) {
    cw = xcalloc(1, sizeof *cw);
    cw->window = id;
    RB_INSERT(client_windows, &c->windows, cw);
  }
  return (cw);
}

/* Get client active pane. */
struct window_pane *
server_client_get_pane(struct client *c)
{
  struct session    *s = c->session;
  struct client_window  *cw;

  if (s == NULL)
    return (NULL);

  if (~c->flags & CLIENT_ACTIVEPANE)
    return (s->curw->window->active);
  cw = server_client_get_client_window(c, s->curw->window->id);
  if (cw == NULL)
    return (s->curw->window->active);
  return (cw->pane);
}

/* Set client active pane. */
void
server_client_set_pane(struct client *c, struct window_pane *wp)
{
  struct session    *s = c->session;
  struct client_window  *cw;

  if (s == NULL)
    return;

  cw = server_client_add_client_window(c, s->curw->window->id);
  cw->pane = wp;
  log_debug("%s pane now %%%u", c->name, wp->id);
}

/* Remove pane from client lists. */
void
server_client_remove_pane(struct window_pane *wp)
{
  struct client   *c;
  struct window   *w = wp->window;
  struct client_window  *cw;

  TAILQ_FOREACH(c, &clients, entry) {
    cw = server_client_get_client_window(c, w->id);
    if (cw != NULL && cw->pane == wp) {
      RB_REMOVE(client_windows, &c->windows, cw);
      free(cw);
    }
  }
}

/* Print to a client. */
void
server_client_print(struct client *c, int parse, struct evbuffer *evb)
{
  void        *data = EVBUFFER_DATA(evb);
  size_t         size = EVBUFFER_LENGTH(evb);
  struct window_pane    *wp;
  struct window_mode_entry  *wme;
  char        *sanitized, *msg, *line, empty = '\0';

  if (!parse) {
    utf8_stravisx(&msg, data, size,
        VIS_OCTAL|VIS_CSTYLE|VIS_NOSLASH);
  } else {
    if (size == 0)
      msg = &empty;
    else {
      msg = EVBUFFER_DATA(evb);
      if (msg[size - 1] != '\0')
        evbuffer_add(evb, "", 1);
    }
  }
  log_debug("%s: %s", __func__, msg);

  if (c == NULL)
    goto out;

  if (c->session == NULL || (c->flags & CLIENT_CONTROL)) {
    if (~c->flags & CLIENT_UTF8) {
      sanitized = utf8_sanitize(msg);
      if (c->flags & CLIENT_CONTROL)
        control_write(c, "%s", sanitized);
      else
        file_print(c, "%s\n", sanitized);
      free(sanitized);
    } else {
      if (c->flags & CLIENT_CONTROL)
        control_write(c, "%s", msg);
      else
        file_print(c, "%s\n", msg);
    }
    goto out;
  }

  wp = server_client_get_pane(c);
  wme = TAILQ_FIRST(&wp->modes);
  if (wme == NULL || wme->mode != &window_view_mode)
    window_pane_set_mode(wp, NULL, &window_view_mode, NULL, NULL);
  if (parse) {
    do {
      line = evbuffer_readln(evb, NULL, EVBUFFER_EOL_LF);
      if (line != NULL) {
        window_copy_add(wp, 1, "%s", line);
        free(line);
      }
    } while (line != NULL);

    size = EVBUFFER_LENGTH(evb);
    if (size != 0) {
      line = EVBUFFER_DATA(evb);
      window_copy_add(wp, 1, "%.*s", (int)size, line);
    }
  } else
    window_copy_add(wp, 0, "%s", msg);

out:
  if (!parse)
    free(msg);
}

static void
server_client_report_theme(struct client *c, enum client_theme theme)
{
  if (theme == THEME_LIGHT) {
    c->theme = THEME_LIGHT;
    notify_client("client-light-theme", c);
  } else {
    c->theme = THEME_DARK;
    notify_client("client-dark-theme", c);
  }

  /*
   * Request foreground and background colour again. Don't forward 2031 to
   * panes until a response is received.
   */
  tty_repeat_requests(&c->tty, 1);
}

Coverage Report

Created: 2026-04-09 06:36