1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright 2009 Sun Microsystems, Inc. All rights reserved
30 * Use is subject to license terms.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * Author: Nathan Rutman <nathan.rutman@sun.com>
38 * Kernel <-> userspace communication routines.
39 * Using pipes for all arches.
42 #define DEBUG_SUBSYSTEM S_CLASS
45 #include <libcfs/libcfs.h>
48 /* This is the userspace side. */
50 /** Start the userspace side of a KUC pipe.
51 * @param link Private descriptor for pipe/socket.
52 * @param groups KUC broadcast group to listen to
53 * (can be null for unicast to this pid)
55 int libcfs_ukuc_start(lustre_kernelcomm *link, int group)
62 link->lk_rfd = pfd[0];
63 link->lk_wfd = pfd[1];
64 link->lk_group = group;
65 link->lk_uid = getpid();
69 int libcfs_ukuc_stop(lustre_kernelcomm *link)
73 return close(link->lk_rfd);
76 #define lhsz sizeof(*kuch)
78 /** Read a message from the link.
79 * Allocates memory, returns handle
81 * @param link Private descriptor for pipe/socket.
82 * @param buf Buffer to read into
83 * @param maxsize Maximum message size allowed
84 * @param transport Only listen to messages on this transport
85 * (and the generic transport)
87 int libcfs_ukuc_msg_get(lustre_kernelcomm *link, char *buf, int maxsize,
93 memset(buf, 0, maxsize);
95 CDEBUG(D_KUC, "Waiting for message from kernel on fd %d\n",
99 /* Read header first to get message size */
100 rc = read(link->lk_rfd, buf, lhsz);
105 kuch = (struct kuc_hdr *)buf;
107 CDEBUG(D_KUC, " Received message mg=%x t=%d m=%d l=%d\n",
108 kuch->kuc_magic, kuch->kuc_transport, kuch->kuc_msgtype,
111 if (kuch->kuc_magic != KUC_MAGIC) {
112 CERROR("bad message magic %x != %x\n",
113 kuch->kuc_magic, KUC_MAGIC);
118 if (kuch->kuc_msglen > maxsize) {
124 rc = read(link->lk_rfd, buf + lhsz, kuch->kuc_msglen - lhsz);
129 if (rc < (kuch->kuc_msglen - lhsz)) {
130 CERROR("short read: got %d of %d bytes\n",
131 rc, kuch->kuc_msglen);
136 if (kuch->kuc_transport == transport ||
137 kuch->kuc_transport == KUC_TRANSPORT_GENERIC) {
140 /* Drop messages for other transports */
145 #else /* LUSTRE_UTILS */
146 /* This is the kernel side (liblustre as well). */
149 * libcfs_kkuc_msg_put - send an message from kernel to userspace
150 * @param fp to send the message to
151 * @param payload Payload data. First field of payload is always
154 int libcfs_kkuc_msg_put(cfs_file_t *filp, void *payload)
156 struct kuc_hdr *kuch = (struct kuc_hdr *)payload;
159 if (filp == NULL || IS_ERR(filp))
162 if (kuch->kuc_magic != KUC_MAGIC) {
163 CERROR("KernelComm: bad magic %x\n", kuch->kuc_magic);
168 rc = cfs_user_write(filp, (char *)payload, kuch->kuc_msglen, 0);
172 CWARN("message send failed (%d)\n", rc);
174 CDEBUG(D_KUC, "Sent message rc=%d, fp=%p\n", rc, filp);
178 CFS_EXPORT_SYMBOL(libcfs_kkuc_msg_put);
180 /* Broadcast groups are global across all mounted filesystems;
181 * i.e. registering for a group on 1 fs will get messages for that
182 * group from any fs */
183 /** A single group reigstration has a uid and a file pointer */
189 static cfs_list_t kkuc_groups[KUC_GRP_MAX+1] = {};
190 /* Protect message sending against remove and adds */
191 static CFS_DECLARE_RWSEM(kg_sem);
193 /** Add a receiver to a broadcast group
194 * @param filp pipe to write into
195 * @param uid identidier for this receiver
196 * @param group group number
198 int libcfs_kkuc_group_add(cfs_file_t *filp, int uid, int group)
200 struct kkuc_reg *reg;
202 if (group > KUC_GRP_MAX) {
203 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
207 /* fput in group_rem */
211 /* freed in group_rem */
212 reg = cfs_alloc(sizeof(*reg), 0);
219 cfs_down_write(&kg_sem);
220 if (kkuc_groups[group].next == NULL)
221 CFS_INIT_LIST_HEAD(&kkuc_groups[group]);
222 cfs_list_add(®->kr_chain, &kkuc_groups[group]);
223 cfs_up_write(&kg_sem);
225 CDEBUG(D_KUC, "Added uid=%d fp=%p to group %d\n", uid, filp, group);
229 CFS_EXPORT_SYMBOL(libcfs_kkuc_group_add);
231 int libcfs_kkuc_group_rem(int uid, int group)
233 struct kkuc_reg *reg, *next;
236 if (kkuc_groups[group].next == NULL)
240 /* Broadcast a shutdown message */
243 lh.kuc_magic = KUC_MAGIC;
244 lh.kuc_transport = KUC_TRANSPORT_GENERIC;
245 lh.kuc_msgtype = KUC_MSG_SHUTDOWN;
246 lh.kuc_msglen = sizeof(lh);
247 libcfs_kkuc_group_put(group, &lh);
250 cfs_down_write(&kg_sem);
251 cfs_list_for_each_entry_safe(reg, next, &kkuc_groups[group], kr_chain) {
252 if ((uid == 0) || (uid == reg->kr_uid)) {
253 cfs_list_del(®->kr_chain);
254 CDEBUG(D_KUC, "Removed uid=%d fp=%p from group %d\n",
255 reg->kr_uid, reg->kr_fp, group);
256 cfs_put_file(reg->kr_fp);
260 cfs_up_write(&kg_sem);
264 CFS_EXPORT_SYMBOL(libcfs_kkuc_group_rem);
266 int libcfs_kkuc_group_put(int group, void *payload)
268 struct kkuc_reg *reg;
272 cfs_down_read(&kg_sem);
273 cfs_list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
274 rc = libcfs_kkuc_msg_put(reg->kr_fp, payload);
276 cfs_up_read(&kg_sem);
280 CFS_EXPORT_SYMBOL(libcfs_kkuc_group_put);
282 #endif /* LUSTRE_UTILS */