[SERVER] IPC over unix socket

[SERVER] Print connected clients and used images

9 files changed, 234 insertions, 138 deletions

diff --git a/src/config.h b/src/config.h
index c839f6e..e9d564a 100644
--- a/src/config.h
+++ b/src/config.h
@@ -33,6 +33,6 @@
 
 // misc
 #define DEFAULT_CONFIG_FILE "/etc/dnbd3-server.conf"
-#define SERVER_PID_FILE "/tmp/dnbd3-server.pid"
+#define UNIX_SOCKET "/tmp/dnbd3-server.sock"
 
 #endif /* CONFIG_H_ */
diff --git a/src/server/ipc.c b/src/server/ipc.c
new file mode 100644
index 0000000..b5651ac
--- /dev/null
+++ b/src/server/ipc.c
@@ -0,0 +1,179 @@
+/*
+ * This file is part of the Distributed Network Block Device 3
+ *
+ * Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
+ *
+ * This file may be licensed under the terms of of the
+ * GNU General Public License Version 2 (the ``GPL'').
+ *
+ * Software distributed under the License is distributed
+ * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
+ * express or implied. See the GPL for the specific language
+ * governing rights and limitations.
+ *
+ * You should have received a copy of the GPL along with this
+ * program. If not, go to http://www.gnu.org/licenses/gpl.html
+ * or write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdio.h>
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include "ipc.h"
+#include "config.h"
+#include "server.h"
+#include "utils.h"
+
+void* dnbd3_ipc_receive()
+{
+    int server_sock, client_sock;
+    struct sockaddr_un server, client;
+    unsigned int len = sizeof(client);
+
+    GSList *iterator = NULL;
+
+    // Create socket
+    if ((server_sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
+    {
+        perror("ERROR: IPC socket");
+        exit(EXIT_FAILURE);
+    }
+
+    server.sun_family = AF_UNIX;
+    strcpy(server.sun_path, UNIX_SOCKET);
+    unlink(UNIX_SOCKET);
+
+    // Bind to socket
+    if (bind(server_sock, &server, sizeof(server.sun_family) + strlen(server.sun_path)) < 0)
+    {
+        perror("ERROR: IPC bind");
+        exit(EXIT_FAILURE);
+    }
+
+    // Listen on socket
+    if (listen(server_sock, 5) < 0)
+    {
+        perror("ERROR: IPC listen");
+        exit(EXIT_FAILURE);
+    }
+
+    while (1)
+    {
+        int cmd;
+        int num = 0;
+        char buf[4096];
+
+        // Accept connection
+        if ((client_sock = accept(server_sock, &client, &len)) < 0)
+        {
+            perror("ERROR: IPC accept");
+            exit(EXIT_FAILURE);
+        }
+
+        recv(client_sock, &cmd, sizeof(int), MSG_WAITALL);
+
+        switch (cmd)
+        {
+        case IPC_EXIT:
+            close(server_sock);
+            dnbd3_cleanup();
+            break;
+
+        case IPC_RELOAD:
+            printf("INFO: Reloading configuration...\n");
+            pthread_spin_lock(&_spinlock);
+            dnbd3_reload_config(_config_file_name);
+            pthread_spin_unlock(&_spinlock);
+            break;
+
+        case IPC_INFO:
+            num = g_slist_length(_dnbd3_clients);
+            send(client_sock, &num, sizeof(int), MSG_WAITALL); // send number of clients
+            for (iterator = _dnbd3_clients; iterator; iterator = iterator->next)
+            {
+                dnbd3_client_t *client = iterator->data;
+                if (client->image)
+                {
+                    sprintf(buf, "%s\t%s\n", client->ip, client->image->file);
+                    send(client_sock, buf, sizeof(buf), MSG_WAITALL);
+                }
+            }
+            close(client_sock);
+            break;
+
+        default:
+            printf("ERROR: Unknown command: %i", cmd);
+            break;
+
+        }
+
+    }
+
+    close(server_sock);
+}
+
+void dnbd3_ipc_send(int cmd)
+{
+    int client_sock;
+    struct sockaddr_un server;
+
+    // Create socket
+    if ((client_sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
+    {
+        perror("ERROR: IPC socket");
+        exit(EXIT_FAILURE);
+    }
+
+    server.sun_family = AF_UNIX;
+    strcpy(server.sun_path, UNIX_SOCKET);
+
+    // Connect to server
+    if (connect(client_sock, &server, sizeof(server.sun_family) + strlen(server.sun_path)) < 0)
+    {
+        perror("ERROR: IPC connect");
+        exit(EXIT_FAILURE);
+    }
+
+    int i, num = 0;
+    char buf[4096];
+
+    switch (cmd)
+    {
+    case IPC_EXIT:
+        send(client_sock, &cmd, sizeof(int), MSG_WAITALL);
+        break;
+
+    case IPC_RELOAD:
+        send(client_sock, &cmd, sizeof(int), MSG_WAITALL);
+        break;
+
+    case IPC_INFO:
+        send(client_sock, &cmd, sizeof(int), MSG_WAITALL);
+        recv(client_sock, &num, sizeof(int), MSG_WAITALL);
+
+        printf("INFO: Number clients connected: %i\n", num);
+
+        for (i = 0; i < num; i++)
+        {
+            if (recv(client_sock, &buf, sizeof(buf), MSG_WAITALL) > 0)
+                printf("INFO: %s", buf);
+        }
+
+        break;
+
+    default:
+        printf("ERROR: Unknown command: %i", cmd);
+        break;
+
+    }
+
+    close(client_sock);
+}
diff --git a/src/server/signal.h b/src/server/ipc.h
index d91babf..b08ce3c 100644
--- a/src/server/signal.h
+++ b/src/server/ipc.h
@@ -18,13 +18,15 @@
  *
  */
 
-#ifndef SIGNAL_H_
-#define SIGNAL_H_
+#ifndef IPC_H_
+#define IPC_H_
 
-void dnbd3_handle_sigpipe(int signum);
+#define IPC_EXIT 0
+#define IPC_RELOAD 1
+#define IPC_INFO 2
 
-void dnbd3_handle_sighup(int signum);
+void* dnbd3_ipc_receive();
 
-void dnbd3_handle_sigterm(int signum);
+void dnbd3_ipc_send(int cmd);
 
-#endif /* SIGNAL_H_ */
+#endif /* IPC_H_ */
diff --git a/src/server/net.c b/src/server/net.c
index 4f0e5a4..f49305b 100644
--- a/src/server/net.c
+++ b/src/server/net.c
@@ -60,6 +60,7 @@ void *dnbd3_handle_query(void *dnbd3_client)
             {
                 image_file = open(image->file, O_RDONLY);
                 reply.filesize = image->filesize;
+                client->image = image;
             }
             else
             {
diff --git a/src/server/server.c b/src/server/server.c
index a324682..4309989 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -31,8 +31,8 @@
 
 #include "server.h"
 #include "utils.h"
-#include "signal.h"
 #include "net.h"
+#include "ipc.h"
 
 int _sock;
 
@@ -47,9 +47,10 @@ void dnbd3_print_help(char* argv_0)
     printf("Usage: %s [OPTIONS]...\n", argv_0);
     printf("Start the DNBD3 server\n");
     printf("-f or --file \t\t Configuration file (default /etc/dnbd3-server.conf)\n");
-    printf("-n or --nodaemon \t\t Start server in foreground\n");
+    printf("-n or --nodaemon \t Start server in foreground\n");
     printf("-r or --reload \t\t Reload configuration file\n");
     printf("-s or --stop \t\t Stop running dnbd3-server\n");
+    printf("-i or --info \t\t Print connected clients and used images\n");
     printf("-h or --help \t\t Show this help text and quit\n");
     printf("-v or --version \t Show version and quit\n");
     exit(0);
@@ -76,7 +77,7 @@ void dnbd3_cleanup()
 
     close(_sock);
     free(_images);
-    dnbd3_delete_pid_file();
+    unlink(UNIX_SOCKET);
     exit(EXIT_SUCCESS);
 }
 
@@ -85,13 +86,14 @@ int main(int argc, char* argv[])
     int demonize = 1;
     int opt = 0;
     int longIndex = 0;
-    static const char *optString = "f:nrshv?";
+    static const char *optString = "f:nrsihv?";
     static const struct option longOpts[] =
     {
     { "file", required_argument, NULL, 'f' },
     { "nodaemon", no_argument, NULL, 'n' },
     { "reload", no_argument, NULL, 'r' },
     { "stop", no_argument, NULL, 's' },
+    { "info", no_argument, NULL, 'i' },
     { "help", no_argument, NULL, 'h' },
     { "version", no_argument, NULL, 'v' } };
 
@@ -109,11 +111,15 @@ int main(int argc, char* argv[])
             break;
         case 'r':
             printf("INFO: Reloading configuration file...\n");
-            dnbd3_send_signal(SIGHUP);
+            dnbd3_ipc_send(IPC_RELOAD);
             return EXIT_SUCCESS;
         case 's':
             printf("INFO: Stopping running server...\n");
-            dnbd3_send_signal(SIGTERM);
+            dnbd3_ipc_send(IPC_EXIT);
+            return EXIT_SUCCESS;
+        case 'i':
+            printf("INFO: Requesting information...\n");
+            dnbd3_ipc_send(IPC_INFO);
             return EXIT_SUCCESS;
         case 'h':
             dnbd3_print_help(argv[0]);
@@ -136,7 +142,6 @@ int main(int argc, char* argv[])
 
     // setup signal handler
     signal(SIGPIPE, dnbd3_handle_sigpipe);
-    signal(SIGHUP, dnbd3_handle_sighup);
     signal(SIGTERM, dnbd3_handle_sigterm);
     signal(SIGINT, dnbd3_handle_sigterm);
 
@@ -151,7 +156,10 @@ int main(int argc, char* argv[])
     timeout.tv_sec = SERVER_SOCKET_TIMEOUT;
     timeout.tv_usec = 0;
 
-    dnbd3_write_pid_file(getpid());
+    // setup icp
+    pthread_t thread_ipc;
+    pthread_create(&(thread_ipc), NULL, dnbd3_ipc_receive, NULL);
+
     printf("INFO: Server is ready...\n");
 
     // main loop
@@ -173,6 +181,7 @@ int main(int argc, char* argv[])
         strcpy(dnbd3_client->ip, inet_ntoa(client.sin_addr));
         dnbd3_client->sock = fd;
         dnbd3_client->thread = &thread;
+        dnbd3_client->image = NULL;
 
         _dnbd3_clients = g_slist_append(_dnbd3_clients, dnbd3_client);
 
diff --git a/src/server/server.h b/src/server/server.h
index 303d6ee..dd8584c 100644
--- a/src/server/server.h
+++ b/src/server/server.h
@@ -30,13 +30,6 @@
 
 typedef struct
 {
-    int sock;
-    char ip[16];
-    pthread_t *thread;
-} dnbd3_client_t;
-
-typedef struct
-{
     char *file;
     off_t filesize;
     char **servers;
@@ -45,13 +38,20 @@ typedef struct
     int rid;
 } dnbd3_image_t;
 
+typedef struct
+{
+    int sock;
+    char ip[16];
+    pthread_t *thread;
+    dnbd3_image_t *image;
+} dnbd3_client_t;
+
 extern GSList *_dnbd3_clients;
 extern pthread_spinlock_t _spinlock;
 extern char *_config_file_name;
 extern dnbd3_image_t *_images;
 extern size_t _num_images;
 
-
 void dnbd3_cleanup();
 
 #endif /* SERVER_H_ */
diff --git a/src/server/signal.c b/src/server/signal.c
deleted file mode 100644
index 443742f..0000000
--- a/src/server/signal.c
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * This file is part of the Distributed Network Block Device 3
- *
- * Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
- *
- * This file may be licensed under the terms of of the
- * GNU General Public License Version 2 (the ``GPL'').
- *
- * Software distributed under the License is distributed
- * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
- * express or implied. See the GPL for the specific language
- * governing rights and limitations.
- *
- * You should have received a copy of the GPL along with this
- * program. If not, go to http://www.gnu.org/licenses/gpl.html
- * or write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- */
-
-#include <stdio.h>
-#include <pthread.h>
-
-#include "server.h"
-#include "utils.h"
-
-void dnbd3_handle_sigpipe(int signum)
-{
-    printf("ERROR: SIGPIPE received!\n");
-}
-
-void dnbd3_handle_sighup(int signum)
-{
-    printf("INFO: SIGHUP received!\n");
-    printf("INFO: Reloading configuration...\n");
-    pthread_spin_lock(&_spinlock);
-    dnbd3_reload_config(_config_file_name);
-    pthread_spin_unlock(&_spinlock);
-}
-
-void dnbd3_handle_sigterm(int signum)
-{
-    printf("INFO: SIGTERM or SIGINT received!\n");
-    dnbd3_cleanup();
-}
diff --git a/src/server/utils.c b/src/server/utils.c
index f3a4c5e..67d91c9 100644
--- a/src/server/utils.c
+++ b/src/server/utils.c
@@ -18,72 +18,12 @@
  *
  */
 
-#include "server.h"
-#include "utils.h"
-
-#include <stdio.h>
 #include <stdlib.h>
-#include <signal.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 
-
-void dnbd3_write_pid_file(pid_t pid)
-{
-    FILE *f = fopen(SERVER_PID_FILE, "w");
-    if (f != NULL)
-    {
-        fprintf(f, "%i", pid);
-        fclose(f);
-    }
-    else
-    {
-        printf("ERROR: Couldn't write pid file (%s).\n", SERVER_PID_FILE);
-    }
-}
-
-pid_t dnbd3_read_pid_file()
-{
-    pid_t pid = 0;
-
-    FILE *f = fopen(SERVER_PID_FILE, "r");
-    if (f != NULL)
-    {
-        fscanf(f, "%i", &pid);
-        fclose(f);
-    }
-    else
-    {
-        printf("ERROR: Couldn't read pid file (%s).\n", SERVER_PID_FILE);
-    }
-
-    return pid;
-}
-
-void dnbd3_delete_pid_file()
-{
-    if (unlink(SERVER_PID_FILE) != 0)
-    {
-        printf("ERROR: Couldn't delete pid file (%s).\n", SERVER_PID_FILE);
-    }
-}
-
-void dnbd3_send_signal(int signum)
-{
-    pid_t pid = dnbd3_read_pid_file();
-    if (pid != 0)
-    {
-        if (kill(pid, signum) != 0)
-        {
-            printf("ERROR: dnbd3-server is not running\n");
-            dnbd3_delete_pid_file();
-        }
-    }
-    else
-    {
-        printf("ERROR: dnbd3-server is not running\n");
-    }
-}
+#include "server.h"
+#include "utils.h"
 
 void dnbd3_load_config(char *file)
 {
@@ -124,7 +64,7 @@ void dnbd3_load_config(char *file)
     }
 
     g_strfreev(groups);
-    g_key_file_free (gkf);
+    g_key_file_free(gkf);
 }
 
 void dnbd3_reload_config(char* config_file_name)
@@ -139,10 +79,22 @@ dnbd3_image_t* dnbd3_get_image(int vid, int rid)
     // TODO: find better data structure
     dnbd3_image_t *result = NULL;
     int i;
-    for (i = 0; i < _num_images; ++i) {
+    for (i = 0; i < _num_images; ++i)
+    {
         if (_images[i].vid == vid && _images[i].rid == rid)
             result = &_images[i];
 
     }
     return result;
 }
+
+void dnbd3_handle_sigpipe(int signum)
+{
+    printf("ERROR: SIGPIPE received!\n");
+}
+
+void dnbd3_handle_sigterm(int signum)
+{
+    printf("INFO: SIGTERM or SIGINT received!\n");
+    dnbd3_cleanup();
+}
diff --git a/src/server/utils.h b/src/server/utils.h
index 6ac51ff..e6bd6a9 100644
--- a/src/server/utils.h
+++ b/src/server/utils.h
@@ -26,14 +26,12 @@
 #ifndef UTILS_H_
 #define UTILS_H_
 
-pid_t dnbd3_read_pid_file();
-void dnbd3_write_pid_file(pid_t pid);
-void dnbd3_delete_pid_file();
-
-void dnbd3_send_signal(int signum);
-
 void dnbd3_load_config(char *file);
 void dnbd3_reload_config(char* config_file_name);
+
 dnbd3_image_t* dnbd3_get_image(int vid, int rid);
 
+void dnbd3_handle_sigpipe(int signum);
+void dnbd3_handle_sigterm(int signum);
+
 #endif /* UTILS_H_ */