Add daemon command handler loop

This change adds the logic to read a packet from the socket, accept
connections from clients, and close connections from clients that have
hung up. This commit does not yet have support for parsing and handling
the commands, and simply echoes the request back to the client.

daemon/Makefile.am

@@ -15,6 +15,7 @@ x52d_SOURCES = \
 	daemon/x52d_clock.c \
 	daemon/x52d_mouse.c \
 	daemon/x52d_led.c \
+	daemon/x52d_command.c \
 	daemon/x52d_comm_internal.c
 
 x52d_CFLAGS = \
@@ -88,6 +89,7 @@ EXTRA_DIST += \
 	daemon/x52d_device.h \
 	daemon/x52d_io.h \
 	daemon/x52d_mouse.h \
+	daemon/x52d_command.h \
 	daemon/x52dcomm.h \
 	daemon/x52dcomm-internal.h \
 	daemon/x52d.conf

daemon/x52d_command.c

@@ -0,0 +1,166 @@
+/*
+ * Saitek X52 Pro MFD & LED driver - Command processor
+ *
+ * Copyright (C) 2021 Nirenjan Krishnan (nirenjan@nirenjan.org)
+ *
+ * SPDX-License-Identifier: GPL-2.0-only WITH Classpath-exception-2.0
+ */
+
+#include "config.h"
+#include <string.h>
+#include <errno.h>
+#include <poll.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "pinelog.h"
+#include "x52d_const.h"
+#include "x52d_command.h"
+
+#define MAX_CONN    (X52D_MAX_CLIENTS + 1)
+
+#define INVALID_CLIENT -1
+
+static int client_fd[X52D_MAX_CLIENTS];
+static int active_clients;
+
+void x52d_command_init(void)
+{
+    for (int i = 0; i < X52D_MAX_CLIENTS; i++) {
+        client_fd[i] = INVALID_CLIENT;
+    }
+
+    active_clients = 0;
+}
+
+static void register_client(int sock_fd)
+{
+    int fd;
+
+    if (active_clients >= X52D_MAX_CLIENTS) {
+        /* Ignore the incoming connection */
+        return;
+    }
+
+    fd = accept(sock_fd, NULL, NULL);
+    if (fd < 0) {
+        PINELOG_ERROR(_("Error accepting client connection on command socket: %s"),
+                      strerror(errno));
+        return;
+    }
+
+    PINELOG_TRACE("Accepted client %d on command socket", fd);
+
+    for (int i = 0; i < X52D_MAX_CLIENTS; i++) {
+        if (client_fd[i] == INVALID_CLIENT) {
+            client_fd[i] = fd;
+            active_clients++;
+            break;
+        }
+    }
+}
+
+static void deregister_client(int fd)
+{
+    for (int i = 0; i < X52D_MAX_CLIENTS; i++) {
+        if (client_fd[i] == fd) {
+            client_fd[i] = INVALID_CLIENT;
+            active_clients--;
+            close(fd);
+
+            PINELOG_TRACE("Disconnected client %d from command socket", fd);
+            break;
+        }
+    }
+
+}
+
+static void client_error(int fd)
+{
+    int error;
+    socklen_t errlen = sizeof(error);
+
+    getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&error, &errlen);
+    PINELOG_ERROR(_("Error when polling command socket: FD %d, error %d, len %lu"),
+                  fd, error, (unsigned long int)errlen);
+    deregister_client(fd);
+}
+
+static int poll_clients(int sock_fd, struct pollfd *pfd)
+{
+    int pfd_count;
+    int rc;
+
+    memset(pfd, 0, sizeof(*pfd) * MAX_CONN);
+
+    pfd_count = 1;
+    pfd[0].fd = sock_fd;
+    pfd[0].events = POLLIN | POLLERR;
+    for (int i = 0; i < X52D_MAX_CLIENTS; i++) {
+        if (client_fd[i] != INVALID_CLIENT) {
+            pfd[pfd_count].fd = client_fd[i];
+            pfd[pfd_count].events = POLLIN | POLLERR | POLLHUP;
+            pfd_count++;
+        }
+    }
+
+    PINELOG_TRACE("Polling %d file descriptors", pfd_count);
+    rc = poll(pfd, pfd_count, -1);
+    if (rc < 0) {
+        if (errno != EINTR) {
+            PINELOG_ERROR(_("Error when polling for command: %s"), strerror(errno));
+            return -1;
+        }
+    } else if (rc == 0) {
+        PINELOG_INFO(_("Timed out when polling for command"));
+    }
+
+    return rc;
+}
+
+int x52d_command_loop(int sock_fd)
+{
+    struct pollfd pfd[MAX_CONN];
+    int rc;
+    int i;
+
+    rc = poll_clients(sock_fd, pfd);
+    if (rc <= 0) {
+        return -1;
+    }
+
+    for (i = 0; i < MAX_CONN; i++) {
+        if (pfd[i].revents & POLLHUP) {
+            /* Remote hungup */
+            deregister_client(pfd[i].fd);
+        } else if (pfd[i].revents & POLLERR) {
+            /* Error reading from the socket */
+            client_error(pfd[i].fd);
+        } else if (pfd[i].revents & POLLIN) {
+            if (pfd[i].fd == sock_fd) {
+                register_client(sock_fd);
+            } else {
+                char buffer[1024];
+                int sent;
+
+                rc = recv(pfd[i].fd, buffer, sizeof(buffer), 0);
+                if (rc < 0) {
+                    PINELOG_ERROR(_("Error reading from client %d: %s"),
+                                  pfd[i].fd, strerror(errno));
+                    continue;
+                }
+
+                // TODO: Parse and handle command.
+                // Echo it back to the client for now.
+                sent = send(pfd[i].fd, buffer, rc, 0);
+                if (sent != rc) {
+                    PINELOG_ERROR(_("Short write to client %d; expected %d bytes, wrote %d bytes"),
+                                  pfd[i].fd, rc, sent);
+                }
+            }
+        }
+    }
+
+    return 0;
+}

daemon/x52d_command.h

@@ -0,0 +1,15 @@
+/*
+ * Saitek X52 Pro MFD & LED driver - Command processor
+ *
+ * Copyright (C) 2021 Nirenjan Krishnan (nirenjan@nirenjan.org)
+ *
+ * SPDX-License-Identifier: GPL-2.0-only WITH Classpath-exception-2.0
+ */
+
+#ifndef X52D_COMMAND_H
+#define X52D_COMMAND_H
+
+void x52d_command_init(void);
+int x52d_command_loop(int sock_fd);
+
+#endif // !defined X52D_COMMAND_H

daemon/x52d_main.c

@@ -23,6 +23,7 @@
 #include "x52d_device.h"
 #include "x52d_io.h"
 #include "x52d_mouse.h"
+#include "x52d_command.h"
 #include "x52dcomm-internal.h"
 #include "x52dcomm.h"
 #include "pinelog.h"
@@ -356,6 +357,7 @@ int main(int argc, char **argv)
     // Start device threads
     x52d_dev_init();
     x52d_clock_init();
+    x52d_command_init();
     #if defined(HAVE_EVDEV)
     x52d_io_init();
     x52d_mouse_evdev_init();
@@ -371,9 +373,7 @@ int main(int argc, char **argv)
 
     flag_quit = 0;
     while(!flag_quit) {
-        // TODO: Replace with main event loop
+        x52d_command_loop(command_sock_fd);
-        // Let all threads run in background forever
-        sleep(600);
 
         /* Check if we need to reload configuration */
         if (flag_reload) {

po/POTFILES.in

@@ -14,6 +14,7 @@ joytest/x52_test_mfd.c
 
 daemon/x52d_main.c
 daemon/x52d_clock.c
+daemon/x52d_command.c
 daemon/x52d_config.c
 daemon/x52d_config_dump.c
 daemon/x52d_config_parser.c

po/libx52.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: libx52 0.2.3\n"
 "Report-Msgid-Bugs-To: https://github.com/nirenjan/libx52/issues\n"
-"POT-Creation-Date: 2021-11-04 13:37-0700\n"
+"POT-Creation-Date: 2021-11-04 15:33-0700\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -491,17 +491,17 @@ msgstr ""
 msgid "OK"
 msgstr ""
 
-#: daemon/x52d_main.c:63
+#: daemon/x52d_main.c:64
 #, c-format
 msgid "Error %d setting log file: %s\n"
 msgstr ""
 
-#: daemon/x52d_main.c:79
+#: daemon/x52d_main.c:80
 #, c-format
 msgid "Error %d installing handler for signal %d: %s"
 msgstr ""
 
-#: daemon/x52d_main.c:90
+#: daemon/x52d_main.c:91
 #, c-format
 msgid ""
 "Usage: %s [-f] [-v] [-q]\n"
@@ -510,81 +510,81 @@ msgid ""
 "\t[-s command-socket-path]\n"
 msgstr ""
 
-#: daemon/x52d_main.c:121
+#: daemon/x52d_main.c:122
 #, c-format
 msgid "Daemon is already running as PID %u"
 msgstr ""
 
-#: daemon/x52d_main.c:217
+#: daemon/x52d_main.c:218
 #, c-format
 msgid "Error creating command socket: %s"
 msgstr ""
 
-#: daemon/x52d_main.c:224
+#: daemon/x52d_main.c:225
 #, c-format
 msgid "Error getting command socket flags: %s"
 msgstr ""
 
-#: daemon/x52d_main.c:228
+#: daemon/x52d_main.c:229
 #, c-format
 msgid "Error setting command socket flags: %s"
 msgstr ""
 
-#: daemon/x52d_main.c:236
+#: daemon/x52d_main.c:237
 #, c-format
 msgid "Error binding to command socket: %s"
 msgstr ""
 
-#: daemon/x52d_main.c:241
+#: daemon/x52d_main.c:242
 #, c-format
 msgid "Error listening on command socket: %s"
 msgstr ""
 
-#: daemon/x52d_main.c:315
+#: daemon/x52d_main.c:316
 #, c-format
 msgid "Unable to parse configuration override '%s'\n"
 msgstr ""
 
-#: daemon/x52d_main.c:343
+#: daemon/x52d_main.c:344
 #, c-format
 msgid "Foreground = %s"
 msgstr ""
 
-#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
+#: daemon/x52d_main.c:344 daemon/x52d_main.c:345
 msgid "true"
 msgstr ""
 
-#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
+#: daemon/x52d_main.c:344 daemon/x52d_main.c:345
 msgid "false"
 msgstr ""
 
-#: daemon/x52d_main.c:344
-#, c-format
-msgid "Quiet = %s"
-msgstr ""
-
 #: daemon/x52d_main.c:345
 #, c-format
-msgid "Verbosity = %d"
+msgid "Quiet = %s"
 msgstr ""
 
 #: daemon/x52d_main.c:346
 #, c-format
-msgid "Log file = %s"
+msgid "Verbosity = %d"
 msgstr ""
 
 #: daemon/x52d_main.c:347
 #, c-format
-msgid "Config file = %s"
+msgid "Log file = %s"
 msgstr ""
 
 #: daemon/x52d_main.c:348
 #, c-format
-msgid "PID file = %s"
+msgid "Config file = %s"
 msgstr ""
 
 #: daemon/x52d_main.c:349
 #, c-format
+msgid "PID file = %s"
+msgstr ""
+
+#: daemon/x52d_main.c:350
+#, c-format
 msgid "Command socket = %s"
 msgstr ""
 
@@ -659,6 +659,35 @@ msgstr ""
 msgid "Shutting down X52 clock manager thread"
 msgstr ""
 
+#: daemon/x52d_command.c:48
+#, c-format
+msgid "Error accepting client connection on command socket: %s"
+msgstr ""
+
+#: daemon/x52d_command.c:85
+#, c-format
+msgid "Error when polling command socket: FD %d, error %d, len %lu"
+msgstr ""
+
+#: daemon/x52d_command.c:112
+#, c-format
+msgid "Error when polling for command: %s"
+msgstr ""
+
+#: daemon/x52d_command.c:116
+msgid "Timed out when polling for command"
+msgstr ""
+
+#: daemon/x52d_command.c:149
+#, c-format
+msgid "Error reading from client %d: %s"
+msgstr ""
+
+#: daemon/x52d_command.c:158
+#, c-format
+msgid "Short write to client %d; expected %d bytes, wrote %d bytes"
+msgstr ""
+
 #: daemon/x52d_config.c:26
 #, c-format
 msgid "Error %d setting configuration defaults: %s"

po/xx_PL.po

@@ -7,8 +7,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: libx52 0.2.3\n"
 "Report-Msgid-Bugs-To: https://github.com/nirenjan/libx52/issues\n"
-"POT-Creation-Date: 2021-11-04 13:37-0700\n"
+"POT-Creation-Date: 2021-11-04 15:33-0700\n"
-"PO-Revision-Date: 2021-11-04 13:45-0700\n"
+"PO-Revision-Date: 2021-11-04 15:35-0700\n"
 "Last-Translator: Nirenjan Krishnan <nirenjan@gmail.com>\n"
 "Language-Team: Dummy Language for testing i18n\n"
 "Language: xx_PL\n"
@@ -534,17 +534,17 @@ msgstr "Estingtay aracterchay 0x%02x..."
 msgid "OK"
 msgstr "OKay"
 
-#: daemon/x52d_main.c:63
+#: daemon/x52d_main.c:64
 #, c-format
 msgid "Error %d setting log file: %s\n"
 msgstr "Erroray %d ettingsay oglay ilefay: %s\n"
 
-#: daemon/x52d_main.c:79
+#: daemon/x52d_main.c:80
 #, c-format
 msgid "Error %d installing handler for signal %d: %s"
 msgstr "Erroray %d installingay andlerhay orfay ignalsay %d: %s"
 
-#: daemon/x52d_main.c:90
+#: daemon/x52d_main.c:91
 #, c-format
 msgid ""
 "Usage: %s [-f] [-v] [-q]\n"
@@ -557,80 +557,80 @@ msgstr ""
 "\t[-c onfigcay-ilefay] [-p idpay-ilefay]\n"
 "\t[-s ommandcay-ocketsay-athpay]\n"
 
-#: daemon/x52d_main.c:121
+#: daemon/x52d_main.c:122
 #, c-format
 msgid "Daemon is already running as PID %u"
 msgstr "Aemonday isay alreadyay unningray asay IDPay %u"
 
-#: daemon/x52d_main.c:217
+#: daemon/x52d_main.c:218
 #, c-format
 msgid "Error creating command socket: %s"
 msgstr "Erroray eatingcray ommandcay ocketsay: %s"
 
-#: daemon/x52d_main.c:224
+#: daemon/x52d_main.c:225
 #, c-format
 msgid "Error getting command socket flags: %s"
 msgstr "Erroray ettinggay ommandcay ocketsay agsflay: %s"
 
-#: daemon/x52d_main.c:228
+#: daemon/x52d_main.c:229
 #, c-format
 msgid "Error setting command socket flags: %s"
 msgstr "Erroray ettingsay ommandcay ocketsay agsflay: %s"
 
-#: daemon/x52d_main.c:236
+#: daemon/x52d_main.c:237
 #, c-format
 msgid "Error binding to command socket: %s"
 msgstr "Erroray indingbay otay ommandcay ocketsay: %s"
 
-#: daemon/x52d_main.c:241
+#: daemon/x52d_main.c:242
 #, c-format
 msgid "Error listening on command socket: %s"
 msgstr "Erroray isteninglay onay ommandcay ocketsay: %s"
 
-#: daemon/x52d_main.c:315
+#: daemon/x52d_main.c:316
 #, c-format
 msgid "Unable to parse configuration override '%s'\n"
 msgstr "Unableay otay arsepay onfigurationcay overrideay '%s'\n"
 
-#: daemon/x52d_main.c:343
+#: daemon/x52d_main.c:344
 #, c-format
 msgid "Foreground = %s"
 msgstr "Oregroundfay = %s"
 
-#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
+#: daemon/x52d_main.c:344 daemon/x52d_main.c:345
 msgid "true"
 msgstr "uetray"
 
-#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
+#: daemon/x52d_main.c:344 daemon/x52d_main.c:345
 msgid "false"
 msgstr "alsefay"
 
-#: daemon/x52d_main.c:344
+#: daemon/x52d_main.c:345
 #, c-format
 msgid "Quiet = %s"
 msgstr "Uietqay = %s"
 
-#: daemon/x52d_main.c:345
+#: daemon/x52d_main.c:346
 #, c-format
 msgid "Verbosity = %d"
 msgstr "Erbosityvay = %d"
 
-#: daemon/x52d_main.c:346
+#: daemon/x52d_main.c:347
 #, c-format
 msgid "Log file = %s"
 msgstr "Oglay ilefay = %s"
 
-#: daemon/x52d_main.c:347
+#: daemon/x52d_main.c:348
 #, c-format
 msgid "Config file = %s"
 msgstr "Onfigcay ilefay = %s"
 
-#: daemon/x52d_main.c:348
+#: daemon/x52d_main.c:349
 #, c-format
 msgid "PID file = %s"
 msgstr "IDPay ilefay = %s"
 
-#: daemon/x52d_main.c:349
+#: daemon/x52d_main.c:350
 #, c-format
 msgid "Command socket = %s"
 msgstr "Ommandcay ocketsay = %s"
@@ -709,6 +709,37 @@ msgstr "Erroray %d initializingay ockclay eadthray: %s"
 msgid "Shutting down X52 clock manager thread"
 msgstr "Uttingshay ownday X52 ockclay anagermay eadthray"
 
+#: daemon/x52d_command.c:48
+#, c-format
+msgid "Error accepting client connection on command socket: %s"
+msgstr "Erroray acceptingay ientclay onnectioncay onay ommandcay ocketsay: %s"
+
+#: daemon/x52d_command.c:85
+#, c-format
+msgid "Error when polling command socket: FD %d, error %d, len %lu"
+msgstr ""
+"Erroray enwhay ollingpay ommandcay ocketsay: FDay %d, erroray %d, enlay %lu"
+
+#: daemon/x52d_command.c:112
+#, c-format
+msgid "Error when polling for command: %s"
+msgstr "Erroray enwhay ollingpay orfay ommandcay: %s"
+
+#: daemon/x52d_command.c:116
+msgid "Timed out when polling for command"
+msgstr "Imedtay outay enwhay ollingpay orfay ommandcay"
+
+#: daemon/x52d_command.c:149
+#, c-format
+msgid "Error reading from client %d: %s"
+msgstr "Erroray eadingray omfray ientclay %d: %s"
+
+#: daemon/x52d_command.c:158
+#, c-format
+msgid "Short write to client %d; expected %d bytes, wrote %d bytes"
+msgstr ""
+"Ortshay itewray otay ientclay %d; expecteday %d ytesbay, otewray %d ytesbay"
+
 #: daemon/x52d_config.c:26
 #, c-format
 msgid "Error %d setting configuration defaults: %s"