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LU-2456 lnet: Dynamic LNet Configuration (DLC) IOCTL changes
[fs/lustre-release.git] / libcfs / libcfs / module.c
index efd4213..8eeca56 100644 (file)
  */
 
 #define DEBUG_SUBSYSTEM S_LNET
+/* TODO - This will be completed in the subsequent patches.
+ * For this patch the MAX is hardcoded, in the next patch
+ * the value will be set to the largest data structure that
+ * can be sent from user space */
+#define LIBCFS_MAX_IOCTL_BUF_LEN 2048
 
 #include <libcfs/libcfs.h>
 #include <libcfs/libcfs_crypto.h>
@@ -218,41 +223,54 @@ int libcfs_deregister_ioctl(struct libcfs_ioctl_handler *hand)
 }
 EXPORT_SYMBOL(libcfs_deregister_ioctl);
 
-static int libcfs_ioctl_int(struct cfs_psdev_file *pfile,unsigned long cmd,
-                            void *arg, struct libcfs_ioctl_data *data)
+static int libcfs_ioctl_handle(struct cfs_psdev_file *pfile, unsigned long cmd,
+                              void *arg, struct libcfs_ioctl_hdr *hdr)
 {
-        int err = -EINVAL;
-        ENTRY;
-
-        switch (cmd) {
-        case IOC_LIBCFS_CLEAR_DEBUG:
-                libcfs_debug_clear_buffer();
-                RETURN(0);
-        /*
-         * case IOC_LIBCFS_PANIC:
-         * Handled in arch/cfs_module.c
-         */
-        case IOC_LIBCFS_MARK_DEBUG:
-                if (data->ioc_inlbuf1 == NULL ||
-                    data->ioc_inlbuf1[data->ioc_inllen1 - 1] != '\0')
-                        RETURN(-EINVAL);
-                libcfs_debug_mark_buffer(data->ioc_inlbuf1);
-                RETURN(0);
-        case IOC_LIBCFS_MEMHOG:
-                if (pfile->private_data == NULL) {
-                        err = -EINVAL;
-                } else {
-                        kportal_memhog_free(pfile->private_data);
-                        /* XXX The ioc_flags is not GFP flags now, need to be fixed */
-                        err = kportal_memhog_alloc(pfile->private_data,
-                                                   data->ioc_count,
-                                                   data->ioc_flags);
-                        if (err != 0)
-                                kportal_memhog_free(pfile->private_data);
-                }
-                break;
-
-        case IOC_LIBCFS_PING_TEST: {
+       struct libcfs_ioctl_data *data = NULL;
+       int err;
+       ENTRY;
+
+       /* TODO: this is going to change in subsequent patches
+        * to exclude messages which use the new data structures */
+       if ((cmd <= IOC_LIBCFS_LNETST) ||
+           (cmd >= IOC_LIBCFS_REGISTER_MYNID)) {
+               data = container_of(hdr, struct libcfs_ioctl_data, ioc_hdr);
+               err = libcfs_ioctl_data_adjust(data);
+               if (err != 0) {
+                       RETURN(err);
+               }
+       }
+
+       switch (cmd) {
+       case IOC_LIBCFS_CLEAR_DEBUG:
+               libcfs_debug_clear_buffer();
+               RETURN(0);
+       /*
+        * case IOC_LIBCFS_PANIC:
+        * Handled in arch/cfs_module.c
+        */
+       case IOC_LIBCFS_MARK_DEBUG:
+               if (data->ioc_inlbuf1 == NULL ||
+                   data->ioc_inlbuf1[data->ioc_inllen1 - 1] != '\0')
+                       RETURN(-EINVAL);
+               libcfs_debug_mark_buffer(data->ioc_inlbuf1);
+               RETURN(0);
+       case IOC_LIBCFS_MEMHOG:
+               if (pfile->private_data == NULL) {
+                       err = -EINVAL;
+               } else {
+                       kportal_memhog_free(pfile->private_data);
+                       /* XXX The ioc_flags is not GFP flags now, need to
+                        * be fixed */
+                       err = kportal_memhog_alloc(pfile->private_data,
+                                                  data->ioc_count,
+                                                  data->ioc_flags);
+                       if (err != 0)
+                               kportal_memhog_free(pfile->private_data);
+               }
+               break;
+
+       case IOC_LIBCFS_PING_TEST: {
                extern void (kping_client)(struct libcfs_ioctl_data *);
                void (*ping)(struct libcfs_ioctl_data *);
 
@@ -269,17 +287,17 @@ static int libcfs_ioctl_int(struct cfs_psdev_file *pfile,unsigned long cmd,
                RETURN(0);
        }
 
-        default: {
+       default: {
                struct libcfs_ioctl_handler *hand;
 
                err = -EINVAL;
                down_read(&ioctl_list_sem);
                list_for_each_entry(hand, &ioctl_list, item) {
-                       err = hand->handle_ioctl(cmd, data);
+                       err = hand->handle_ioctl(cmd, hdr);
                        if (err != -EINVAL) {
                                if (err == 0)
                                        err = libcfs_ioctl_popdata(arg,
-                                                       data, sizeof (*data));
+                                                       hdr, hdr->ioc_len);
                                break;
                        }
                }
@@ -294,27 +312,39 @@ static int libcfs_ioctl_int(struct cfs_psdev_file *pfile,unsigned long cmd,
 static int libcfs_ioctl(struct cfs_psdev_file *pfile,
                        unsigned long cmd, void *arg)
 {
-       char    *buf;
-       struct libcfs_ioctl_data *data;
+       struct libcfs_ioctl_hdr *hdr;
        int err = 0;
+       __u32 buf_len;
        ENTRY;
 
-       LIBCFS_ALLOC_GFP(buf, 1024, GFP_IOFS);
-       if (buf == NULL)
+       err = libcfs_ioctl_getdata_len(arg, &buf_len);
+       if (err != 0)
+               RETURN(err);
+
+       /*
+        * do a check here to restrict the size of the memory
+        * to allocate to guard against DoS attacks.
+        */
+       if (buf_len > LIBCFS_MAX_IOCTL_BUF_LEN) {
+               CERROR("LNET: user buffer exceeds kernel buffer\n");
+               RETURN(-EINVAL);
+       }
+
+       LIBCFS_ALLOC_GFP(hdr, buf_len, GFP_IOFS);
+       if (hdr == NULL)
                RETURN(-ENOMEM);
 
-        /* 'cmd' and permissions get checked in our arch-specific caller */
-        if (libcfs_ioctl_getdata(buf, buf + 800, (void *)arg)) {
-                CERROR("PORTALS ioctl: data error\n");
-                GOTO(out, err = -EINVAL);
-        }
-        data = (struct libcfs_ioctl_data *)buf;
+       /* 'cmd' and permissions get checked in our arch-specific caller */
+       if (libcfs_ioctl_getdata(hdr, buf_len, arg)) {
+               CERROR("LNET ioctl: data error\n");
+               GOTO(out, err = -EINVAL);
+       }
 
-        err = libcfs_ioctl_int(pfile, cmd, arg, data);
+       err = libcfs_ioctl_handle(pfile, cmd, arg, hdr);
 
 out:
-        LIBCFS_FREE(buf, 1024);
-        RETURN(err);
+       LIBCFS_FREE(hdr, buf_len);
+       RETURN(err);
 }