Make X52 daemon listen on a Unix socket

This change makes X52 daemon listen on a Unix socket. This is in
preparation for changes that will read from the socket and allow clients
to communicate with and control the daemon.

daemon/Makefile.am

@@ -14,7 +14,8 @@ x52d_SOURCES = \
 	daemon/x52d_device.c \
 	daemon/x52d_clock.c \
 	daemon/x52d_mouse.c \
-	daemon/x52d_led.c
+	daemon/x52d_led.c \
+	daemon/x52d_comm_internal.c
 
 x52d_CFLAGS = \
 	-I $(top_srcdir) \
@@ -50,7 +51,8 @@ lib_LTLIBRARIES += libx52dcomm.la
 
 # Client library to communicate with X52 daemon
 libx52dcomm_la_SOURCES = \
-	daemon/x52d_comm_client.c
+	daemon/x52d_comm_client.c \
+	daemon/x52d_comm_internal.c
 libx52dcomm_la_CFLAGS = \
 	-I $(top_srcdir) \
 	-DSYSCONFDIR=\"$(sysconfdir)\" \
@@ -87,6 +89,7 @@ EXTRA_DIST += \
 	daemon/x52d_io.h \
 	daemon/x52d_mouse.h \
 	daemon/x52dcomm.h \
+	daemon/x52dcomm-internal.h \
 	daemon/x52d.conf
 
 if HAVE_SYSTEMD

daemon/x52d_comm_client.c

@@ -16,23 +16,18 @@
 #include <unistd.h>
 
 #include "x52dcomm.h"
-#include "x52d_const.h"
+#include "x52dcomm-internal.h"
 
 int x52d_dial_command(const char *sock_path)
 {
     int sock;
-    socklen_t len;
+    int len;
     struct sockaddr_un remote;
     int saved_errno;
 
-    if (sock_path == NULL) {
+    len = x52d_setup_command_sock(sock_path, &remote);
-        sock_path = X52D_SOCK_COMMAND;
+    if (len < 0) {
-    }
+        /* Error when setting up sockaddr */
-
-    len = strlen(sock_path);
-    if (len >= sizeof(remote.sun_path)) {
-        /* Socket path will not fit inside sun_path */
-        errno = E2BIG;
         return -1;
     }
 
@@ -43,15 +38,8 @@ int x52d_dial_command(const char *sock_path)
         return -1;
     }
 
-    /* Setup the sockaddr structure */
-    memset(&remote, 0, sizeof(remote));
-    remote.sun_family = AF_UNIX;
-    /* We've already verified that sock_path will fit, so we don't need strncpy */
-    strcpy(remote.sun_path, sock_path);
-    len += sizeof(remote.sun_family);
-
     /* Connect to the socket */
-    if (connect(sock, (struct sockaddr *)&remote, len) == -1) {
+    if (connect(sock, (struct sockaddr *)&remote, (socklen_t)len) == -1) {
         /* Failure connecting to the socket. Cleanup */
         saved_errno = errno;
         /* close may modify errno, so we save it prior to the call */

daemon/x52d_comm_internal.c

@@ -0,0 +1,51 @@
+/*
+ * Saitek X52 Pro MFD & LED driver - Client communication library
+ *
+ * Copyright (C) 2021 Nirenjan Krishnan (nirenjan@nirenjan.org)
+ *
+ * SPDX-License-Identifier: GPL-2.0-only WITH Classpath-exception-2.0
+ */
+
+#include "config.h"
+
+#include <errno.h>
+#include <string.h>
+
+#include "x52dcomm-internal.h"
+#include "x52d_const.h"
+
+const char * x52d_command_sock_path(const char *sock_path)
+{
+    if (sock_path == NULL) {
+        sock_path = X52D_SOCK_COMMAND;
+    }
+
+    return sock_path;
+}
+
+int x52d_setup_command_sock(const char *sock_path, struct sockaddr_un *remote)
+{
+    int len;
+    if (remote == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    sock_path = x52d_command_sock_path(sock_path);
+
+    len = strlen(sock_path);
+    if ((size_t)len >= sizeof(remote->sun_path)) {
+        /* Socket path will not fit inside sun_path */
+        errno = E2BIG;
+        return -1;
+    }
+
+    /* Setup the sockaddr structure */
+    memset(remote, 0, sizeof(*remote));
+    remote->sun_family = AF_UNIX;
+    /* We've already verified that sock_path will fit, so we don't need strncpy */
+    strcpy(remote->sun_path, sock_path);
+    len += sizeof(remote->sun_family);
+
+    return len;
+}

daemon/x52d_const.h

@@ -23,4 +23,6 @@
 #define N_(x) gettext_noop(x)
 #define _(x) gettext(x)
 
+#define X52D_MAX_CLIENTS    63
+
 #endif // !defined X52D_CONST_H

daemon/x52d_main.c

@@ -14,6 +14,7 @@
 #include <sys/stat.h>
 #include <signal.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <errno.h>
 
 #include "x52d_clock.h"
@@ -22,6 +23,8 @@
 #include "x52d_device.h"
 #include "x52d_io.h"
 #include "x52d_mouse.h"
+#include "x52dcomm-internal.h"
+#include "x52dcomm.h"
 #include "pinelog.h"
 
 static volatile int flag_quit;
@@ -86,7 +89,8 @@ static void usage(int exit_code)
     fprintf(stderr,
             _("Usage: %s [-f] [-v] [-q]\n"
               "\t[-l log-file] [-o override]\n"
-              "\t[-c config-file] [-p pid-file]\n"),
+              "\t[-c config-file] [-p pid-file]\n"
+              "\t[-s command-socket-path]\n"),
             X52D_APP_NAME);
     exit(exit_code);
 }
@@ -194,6 +198,59 @@ static void start_daemon(bool foreground, const char *pid_file)
     }
 }
 
+/* Bind and listen to the command socket */
+static int listen_command(const char *command_sock)
+{
+    int sock_fd;
+    int len;
+    struct sockaddr_un local;
+    int flags;
+
+    len = x52d_setup_command_sock(command_sock, &local);
+    if (len < 0) {
+        return -1;
+    }
+
+    sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+    if (sock_fd < 0) {
+        /* Failure creating the socket. Abort early */
+        PINELOG_ERROR(_("Error creating command socket: %s"), strerror(errno));
+        return -1;
+    }
+
+    /* Mark the socket as non-blocking */
+    flags = fcntl(sock_fd, F_GETFL);
+    if (flags < 0) {
+        PINELOG_ERROR(_("Error getting command socket flags: %s"), strerror(errno));
+        goto sock_failure;
+    }
+    if (fcntl(sock_fd, F_SETFL, flags | O_NONBLOCK) < 0) {
+        PINELOG_ERROR(_("Error setting command socket flags: %s"), strerror(errno));
+        goto sock_failure;
+    }
+
+    /* Cleanup any existing socket */
+    unlink(local.sun_path);
+    if (bind(sock_fd, (struct sockaddr *)&local, (socklen_t)len) < 0) {
+        /* Failure binding socket */
+        PINELOG_ERROR(_("Error binding to command socket: %s"), strerror(errno));
+        goto listen_failure;
+    }
+
+    if (listen(sock_fd, X52D_MAX_CLIENTS) < 0) {
+        PINELOG_ERROR(_("Error listening on command socket: %s"), strerror(errno));
+        goto listen_failure;
+    }
+
+    return sock_fd;
+
+listen_failure:
+    unlink(local.sun_path);
+sock_failure:
+    close(sock_fd);
+    return -1;
+}
+
 int main(int argc, char **argv)
 {
     int verbosity = 0;
@@ -202,7 +259,9 @@ int main(int argc, char **argv)
     char *log_file = NULL;
     char *conf_file = NULL;
     const char *pid_file = NULL;
+    const char *command_sock = NULL;
     int opt;
+    int command_sock_fd;
 
     /* Initialize gettext */
     #if ENABLE_NLS
@@ -224,8 +283,9 @@ int main(int argc, char **argv)
      * -q   silent behavior
      * -l   path to log file
      * -p   path to PID file (only used if running in background)
+     * -s   path to command socket
      */
-    while ((opt = getopt(argc, argv, "fvql:o:c:p:h")) != -1) {
+    while ((opt = getopt(argc, argv, "fvql:o:c:p:s:h")) != -1) {
         switch (opt) {
         case 'f':
             foreground = true;
@@ -266,6 +326,10 @@ int main(int argc, char **argv)
             pid_file = optarg;
             break;
 
+        case 's':
+            command_sock = optarg;
+            break;
+
         case 'h':
             usage(EXIT_SUCCESS);
             break;
@@ -281,6 +345,8 @@ int main(int argc, char **argv)
     PINELOG_DEBUG(_("Verbosity = %d"), verbosity);
     PINELOG_DEBUG(_("Log file = %s"), log_file);
     PINELOG_DEBUG(_("Config file = %s"), conf_file);
+    PINELOG_DEBUG(_("PID file = %s"), pid_file);
+    PINELOG_DEBUG(_("Command socket = %s"), command_sock);
 
     start_daemon(foreground, pid_file);
 
@@ -295,6 +361,11 @@ int main(int argc, char **argv)
     x52d_mouse_evdev_init();
     #endif
 
+    command_sock_fd = listen_command(command_sock);
+    if (command_sock_fd < 0) {
+        goto cleanup;
+    }
+
     // Apply configuration
     x52d_config_apply();
 
@@ -321,6 +392,7 @@ int main(int argc, char **argv)
 
     PINELOG_INFO(_("Received termination signal %s"), strsignal(flag_quit));
 
+cleanup:
     // Stop device threads
     x52d_clock_exit();
     x52d_dev_exit();
@@ -329,6 +401,14 @@ int main(int argc, char **argv)
     x52d_io_exit();
     #endif
 
+    // Close the socket and remove the socket file
+    if (command_sock_fd >= 0) {
+        command_sock = x52d_command_sock_path(command_sock);
+        PINELOG_TRACE("Closing command socket %s", command_sock);
+        close(command_sock_fd);
+        unlink(command_sock);
+    }
+
     // Remove the PID file
     PINELOG_TRACE("Removing PID file %s", pid_file);
     unlink(pid_file);

daemon/x52dcomm-internal.h

@@ -0,0 +1,19 @@
+/*
+ * Saitek X52 Pro MFD & LED driver - communication library interal functions
+ *
+ * Copyright (C) 2021 Nirenjan Krishnan (nirenjan@nirenjan.org)
+ *
+ * SPDX-License-Identifier: GPL-2.0-only WITH Classpath-exception-2.0
+ */
+
+#ifndef X52DCOMM_INTERNAL_H
+#define X52DCOMM_INTERNAL_H
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+const char *x52d_command_sock_path(const char *sock_path);
+int x52d_setup_command_sock(const char *sock_path, struct sockaddr_un *remote);
+
+#endif // !defined X52DCOMM_INTERNAL_H

daemon/x52dcomm.h

@@ -88,3 +88,4 @@ int x52d_send_command(int sock_fd, char *buffer, size_t buflen);
 #endif
 #endif // !defined X52DCOMM_H
 
+

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 10:50-0700\n"
+"POT-Creation-Date: 2021-11-04 13:37-0700\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"
@@ -491,81 +491,117 @@ msgstr ""
 msgid "OK"
 msgstr ""
 
-#: daemon/x52d_main.c:60
+#: daemon/x52d_main.c:63
 #, c-format
 msgid "Error %d setting log file: %s\n"
 msgstr ""
 
-#: daemon/x52d_main.c:76
+#: daemon/x52d_main.c:79
 #, c-format
 msgid "Error %d installing handler for signal %d: %s"
 msgstr ""
 
-#: daemon/x52d_main.c:87
+#: daemon/x52d_main.c:90
 #, c-format
 msgid ""
 "Usage: %s [-f] [-v] [-q]\n"
 "\t[-l log-file] [-o override]\n"
 "\t[-c config-file] [-p pid-file]\n"
+"\t[-s command-socket-path]\n"
 msgstr ""
 
-#: daemon/x52d_main.c:117
+#: daemon/x52d_main.c:121
 #, c-format
 msgid "Daemon is already running as PID %u"
 msgstr ""
 
-#: daemon/x52d_main.c:255
+#: daemon/x52d_main.c:217
+#, c-format
+msgid "Error creating command socket: %s"
+msgstr ""
+
+#: daemon/x52d_main.c:224
+#, c-format
+msgid "Error getting command socket flags: %s"
+msgstr ""
+
+#: daemon/x52d_main.c:228
+#, c-format
+msgid "Error setting command socket flags: %s"
+msgstr ""
+
+#: daemon/x52d_main.c:236
+#, c-format
+msgid "Error binding to command socket: %s"
+msgstr ""
+
+#: daemon/x52d_main.c:241
+#, c-format
+msgid "Error listening on command socket: %s"
+msgstr ""
+
+#: daemon/x52d_main.c:315
 #, c-format
 msgid "Unable to parse configuration override '%s'\n"
 msgstr ""
 
-#: daemon/x52d_main.c:279
+#: daemon/x52d_main.c:343
 #, c-format
 msgid "Foreground = %s"
 msgstr ""
 
-#: daemon/x52d_main.c:279 daemon/x52d_main.c:280
+#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
 msgid "true"
 msgstr ""
 
-#: daemon/x52d_main.c:279 daemon/x52d_main.c:280
+#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
 msgid "false"
 msgstr ""
 
-#: daemon/x52d_main.c:280
+#: daemon/x52d_main.c:344
 #, c-format
 msgid "Quiet = %s"
 msgstr ""
 
-#: daemon/x52d_main.c:281
+#: daemon/x52d_main.c:345
 #, c-format
 msgid "Verbosity = %d"
 msgstr ""
 
-#: daemon/x52d_main.c:282
+#: daemon/x52d_main.c:346
 #, c-format
 msgid "Log file = %s"
 msgstr ""
 
-#: daemon/x52d_main.c:283
+#: daemon/x52d_main.c:347
 #, c-format
 msgid "Config file = %s"
 msgstr ""
 
-#: daemon/x52d_main.c:309
+#: daemon/x52d_main.c:348
+#, c-format
+msgid "PID file = %s"
+msgstr ""
+
+#: daemon/x52d_main.c:349
+#, c-format
+msgid "Command socket = %s"
+msgstr ""
+
+#: daemon/x52d_main.c:380
 msgid "Reloading X52 configuration"
 msgstr ""
 
-#: daemon/x52d_main.c:316
+#: daemon/x52d_main.c:387
 msgid "Saving X52 configuration to disk"
 msgstr ""
 
-#: daemon/x52d_main.c:322
+#: daemon/x52d_main.c:393
 #, c-format
 msgid "Received termination signal %s"
 msgstr ""
 
-#: daemon/x52d_main.c:336
+#: daemon/x52d_main.c:416
 msgid "Shutting down X52 daemon"
 msgstr ""
 

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 10:50-0700\n"
+"POT-Creation-Date: 2021-11-04 13:37-0700\n"
-"PO-Revision-Date: 2021-11-04 10:52-0700\n"
+"PO-Revision-Date: 2021-11-04 13:45-0700\n"
 "Last-Translator: Nirenjan Krishnan <nirenjan@gmail.com>\n"
 "Language-Team: Dummy Language for testing i18n\n"
 "Language: xx_PL\n"
@@ -534,84 +534,121 @@ msgstr "Estingtay aracterchay 0x%02x..."
 msgid "OK"
 msgstr "OKay"
 
-#: daemon/x52d_main.c:60
+#: daemon/x52d_main.c:63
 #, c-format
 msgid "Error %d setting log file: %s\n"
 msgstr "Erroray %d ettingsay oglay ilefay: %s\n"
 
-#: daemon/x52d_main.c:76
+#: daemon/x52d_main.c:79
 #, c-format
 msgid "Error %d installing handler for signal %d: %s"
 msgstr "Erroray %d installingay andlerhay orfay ignalsay %d: %s"
 
-#: daemon/x52d_main.c:87
+#: daemon/x52d_main.c:90
 #, c-format
 msgid ""
 "Usage: %s [-f] [-v] [-q]\n"
 "\t[-l log-file] [-o override]\n"
 "\t[-c config-file] [-p pid-file]\n"
+"\t[-s command-socket-path]\n"
 msgstr ""
 "Usageay: %s [-f] [-v] [-q]\n"
 "\t[-l oglay-ilefay] [-o overrideay]\n"
 "\t[-c onfigcay-ilefay] [-p idpay-ilefay]\n"
+"\t[-s ommandcay-ocketsay-athpay]\n"
 
-#: daemon/x52d_main.c:117
+#: daemon/x52d_main.c:121
 #, c-format
 msgid "Daemon is already running as PID %u"
 msgstr "Aemonday isay alreadyay unningray asay IDPay %u"
 
-#: daemon/x52d_main.c:255
+#: daemon/x52d_main.c:217
+#, c-format
+msgid "Error creating command socket: %s"
+msgstr "Erroray eatingcray ommandcay ocketsay: %s"
+
+#: daemon/x52d_main.c:224
+#, c-format
+msgid "Error getting command socket flags: %s"
+msgstr "Erroray ettinggay ommandcay ocketsay agsflay: %s"
+
+#: daemon/x52d_main.c:228
+#, c-format
+msgid "Error setting command socket flags: %s"
+msgstr "Erroray ettingsay ommandcay ocketsay agsflay: %s"
+
+#: daemon/x52d_main.c:236
+#, c-format
+msgid "Error binding to command socket: %s"
+msgstr "Erroray indingbay otay ommandcay ocketsay: %s"
+
+#: daemon/x52d_main.c:241
+#, c-format
+msgid "Error listening on command socket: %s"
+msgstr "Erroray isteninglay onay ommandcay ocketsay: %s"
+
+#: daemon/x52d_main.c:315
 #, c-format
 msgid "Unable to parse configuration override '%s'\n"
 msgstr "Unableay otay arsepay onfigurationcay overrideay '%s'\n"
 
-#: daemon/x52d_main.c:279
+#: daemon/x52d_main.c:343
 #, c-format
 msgid "Foreground = %s"
 msgstr "Oregroundfay = %s"
 
-#: daemon/x52d_main.c:279 daemon/x52d_main.c:280
+#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
 msgid "true"
 msgstr "uetray"
 
-#: daemon/x52d_main.c:279 daemon/x52d_main.c:280
+#: daemon/x52d_main.c:343 daemon/x52d_main.c:344
 msgid "false"
 msgstr "alsefay"
 
-#: daemon/x52d_main.c:280
+#: daemon/x52d_main.c:344
 #, c-format
 msgid "Quiet = %s"
 msgstr "Uietqay = %s"
 
-#: daemon/x52d_main.c:281
+#: daemon/x52d_main.c:345
 #, c-format
 msgid "Verbosity = %d"
 msgstr "Erbosityvay = %d"
 
-#: daemon/x52d_main.c:282
+#: daemon/x52d_main.c:346
 #, c-format
 msgid "Log file = %s"
 msgstr "Oglay ilefay = %s"
 
-#: daemon/x52d_main.c:283
+#: daemon/x52d_main.c:347
 #, c-format
 msgid "Config file = %s"
 msgstr "Onfigcay ilefay = %s"
 
-#: daemon/x52d_main.c:309
+#: daemon/x52d_main.c:348
+#, c-format
+msgid "PID file = %s"
+msgstr "IDPay ilefay = %s"
+
+#: daemon/x52d_main.c:349
+#, c-format
+msgid "Command socket = %s"
+msgstr "Ommandcay ocketsay = %s"
+
+#: daemon/x52d_main.c:380
 msgid "Reloading X52 configuration"
 msgstr "Eloadingray X52 onfigurationcay"
 
-#: daemon/x52d_main.c:316
+#: daemon/x52d_main.c:387
 msgid "Saving X52 configuration to disk"
 msgstr "Avingsay X52 onfigurationcay otay iskday"
 
-#: daemon/x52d_main.c:322
+#: daemon/x52d_main.c:393
 #, c-format
 msgid "Received termination signal %s"
 msgstr "Eceivedray erminationtay ignalsay %s"
 
-#: daemon/x52d_main.c:336
+#: daemon/x52d_main.c:416
 msgid "Shutting down X52 daemon"
 msgstr "Uttingshay ownday X52 aemonday"