From be7784fce269160bfea312e0a76ec1ef240b5f69 Mon Sep 17 00:00:00 2001
From: stefan11111 <stefan11111@shitposting.expert>
Date: Sun, 6 Jul 2025 01:54:48 +0300
Subject: [PATCH] kdrive: add fd notification machinery

This will be needed by Xfbdev's keyboard driver, which cannot work
with input threads yet.

Signed-off-by: stefan11111 <stefan11111@shitposting.expert>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 hw/kdrive/src/kdrive.h |   6 ++
 hw/kdrive/src/kinput.c | 124 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 130 insertions(+)

diff --git a/hw/kdrive/src/kdrive.h b/hw/kdrive/src/kdrive.h
index 37672cd757..b709945aaf 100644
--- a/hw/kdrive/src/kdrive.h
+++ b/hw/kdrive/src/kdrive.h
@@ -431,6 +431,12 @@ void
 void
  KdCloseInput(void);
 
+Bool KdRegisterFd(int fd, void (*read) (int fd, void *closure), void *closure);
+
+void KdUnregisterFds(void *closure, Bool do_close);
+
+void KdUnregisterFd(void *closure, int fd, Bool do_close);
+
 void
 KdEnqueueKeyboardEvent(KdKeyboardInfo * ki, unsigned char scan_code,
                        unsigned char is_up);
diff --git a/hw/kdrive/src/kinput.c b/hw/kdrive/src/kinput.c
index c94a3f4cff..65e66871c8 100644
--- a/hw/kdrive/src/kinput.c
+++ b/hw/kdrive/src/kinput.c
@@ -77,6 +77,22 @@ static KdPointerMatrix kdPointerMatrix = {
      {0, 1, 0}}
 };
 
+#define KD_MAX_INPUT_FDS    8
+
+typedef struct _kdInputFd {
+    int fd;
+    void (*read) (int fd, void *closure);
+    int (*enable) (int fd, void *closure);
+    void (*disable) (int fd, void *closure);
+    void *closure;
+} KdInputFd;
+
+static KdInputFd kdInputFds[KD_MAX_INPUT_FDS];
+static int kdNumInputFds = 0;
+#ifdef KDRIVE_KBD
+static int kdnFds = 0;
+#endif
+
 extern Bool kdRawPointerCoordinates;
 
 extern const char *kdGlobalXkbRules;
@@ -85,6 +101,14 @@ extern const char *kdGlobalXkbLayout;
 extern const char *kdGlobalXkbVariant;
 extern const char *kdGlobalXkbOptions;
 
+#ifdef KDRIVE_KBD
+static void KdSigio(int sig)
+{
+    for (int i = 0; i < kdNumInputFds; i++)
+        (*kdInputFds[i].read) (kdInputFds[i].fd, kdInputFds[i].closure);
+}
+#endif
+
 #ifdef FNONBLOCK
 #define NOBLOCK FNONBLOCK
 #else
@@ -102,6 +126,106 @@ KdResetInputMachine(void)
     }
 }
 
+static void KdNonBlockFd(int fd)
+{
+#ifndef WIN32
+    int flags = fcntl(fd, F_GETFL);
+    flags |= FASYNC | NOBLOCK;
+    fcntl(fd, F_SETFL, flags);
+#endif
+}
+
+static void KdNotifyFd(int fd, int ready, void *data)
+{
+    int i = (int) (intptr_t) data;
+    (*kdInputFds[i].read)(fd, kdInputFds[i].closure);
+}
+
+static void KdAddFd(int fd, int i)
+{
+#ifdef KDRIVE_KBD
+    struct sigaction act;
+
+    sigset_t set;
+
+    kdnFds++;
+    fcntl(fd, F_SETOWN, getpid());
+#endif
+    KdNonBlockFd(fd);
+    InputThreadRegisterDev(fd, KdNotifyFd, (void *) (intptr_t) i);
+#ifdef KDRIVE_KBD
+    memset(&act, '\0', sizeof act);
+    act.sa_handler = KdSigio;
+
+    sigemptyset(&act.sa_mask);
+    sigaddset(&act.sa_mask, SIGIO);
+    sigaddset(&act.sa_mask, SIGALRM);
+    sigaddset(&act.sa_mask, SIGVTALRM);
+    sigaction(SIGIO, &act, 0);
+    sigemptyset(&set);
+    sigprocmask(SIG_SETMASK, &set, 0);
+#endif
+}
+
+static void KdRemoveFd(int fd)
+{
+    InputThreadUnregisterDev(fd);
+#ifndef WIN32
+    int flags = fcntl(fd, F_GETFL);
+    flags &= ~(FASYNC | NOBLOCK);
+    fcntl(fd, F_SETFL, flags);
+#endif
+#ifdef KDRIVE_KBD
+    struct sigaction act;
+    kdnFds--;
+    if (kdnFds == 0) {
+        memset(&act, '\0', sizeof act);
+        act.sa_handler = SIG_IGN;
+        sigemptyset(&act.sa_mask);
+        sigaction(SIGIO, &act, 0);
+    }
+#endif
+}
+
+Bool KdRegisterFd(int fd, void (*read) (int fd, void *closure), void *closure)
+{
+    if (kdNumInputFds == KD_MAX_INPUT_FDS)
+        return FALSE;
+    kdInputFds[kdNumInputFds].fd = fd;
+    kdInputFds[kdNumInputFds].read = read;
+    kdInputFds[kdNumInputFds].enable = 0;
+    kdInputFds[kdNumInputFds].disable = 0;
+    kdInputFds[kdNumInputFds].closure = closure;
+    if (kdInputEnabled)
+        KdAddFd(fd, kdNumInputFds);
+    kdNumInputFds++;
+    return TRUE;
+}
+
+void KdUnregisterFd(void *closure, int fd, Bool do_close)
+{
+    int i, j;
+
+    for (i = 0; i < kdNumInputFds; i++) {
+        if (kdInputFds[i].closure == closure &&
+            (fd == -1 || kdInputFds[i].fd == fd)) {
+            if (kdInputEnabled)
+                KdRemoveFd(kdInputFds[i].fd);
+            if (do_close)
+                close(kdInputFds[i].fd);
+            for (j = i; j < (kdNumInputFds - 1); j++)
+                kdInputFds[j] = kdInputFds[j + 1];
+            kdNumInputFds--;
+            break;
+        }
+    }
+}
+
+void KdUnregisterFds(void *closure, Bool do_close)
+{
+    KdUnregisterFd(closure, -1, do_close);
+}
+
 void
 KdDisableInput(void)
 {