| /* |
| * GPL HEADER START |
| * |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 only, |
| * as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License version 2 for more details (a copy is included |
| * in the LICENSE file that accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License |
| * version 2 along with this program; If not, see |
| * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf |
| * |
| * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| * |
| * GPL HEADER END |
| */ |
| /* |
| * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. |
| * Use is subject to license terms. |
| * |
| * Copyright (c) 2012, Intel Corporation. |
| */ |
| /* |
| * This file is part of Lustre, http://www.lustre.org/ |
| * Lustre is a trademark of Sun Microsystems, Inc. |
| * |
| * Author: Nathan Rutman <nathan.rutman@sun.com> |
| * |
| * Kernel <-> userspace communication routines. |
| * Using pipes for all arches. |
| */ |
| |
| #define DEBUG_SUBSYSTEM S_CLASS |
| #define D_KUC D_OTHER |
| |
| #include <linux/libcfs/libcfs.h> |
| |
| #ifdef LUSTRE_UTILS |
| /* This is the userspace side. */ |
| |
| /** Start the userspace side of a KUC pipe. |
| * @param link Private descriptor for pipe/socket. |
| * @param groups KUC broadcast group to listen to |
| * (can be null for unicast to this pid) |
| */ |
| int libcfs_ukuc_start(lustre_kernelcomm *link, int group) |
| { |
| int pfd[2]; |
| |
| if (pipe(pfd) < 0) |
| return -errno; |
| |
| memset(link, 0, sizeof(*link)); |
| link->lk_rfd = pfd[0]; |
| link->lk_wfd = pfd[1]; |
| link->lk_group = group; |
| link->lk_uid = getpid(); |
| return 0; |
| } |
| |
| int libcfs_ukuc_stop(lustre_kernelcomm *link) |
| { |
| if (link->lk_wfd > 0) |
| close(link->lk_wfd); |
| return close(link->lk_rfd); |
| } |
| |
| #define lhsz sizeof(*kuch) |
| |
| /** Read a message from the link. |
| * Allocates memory, returns handle |
| * |
| * @param link Private descriptor for pipe/socket. |
| * @param buf Buffer to read into, must include size for kuc_hdr |
| * @param maxsize Maximum message size allowed |
| * @param transport Only listen to messages on this transport |
| * (and the generic transport) |
| */ |
| int libcfs_ukuc_msg_get(lustre_kernelcomm *link, char *buf, int maxsize, |
| int transport) |
| { |
| struct kuc_hdr *kuch; |
| int rc = 0; |
| |
| memset(buf, 0, maxsize); |
| |
| CDEBUG(D_KUC, "Waiting for message from kernel on fd %d\n", |
| link->lk_rfd); |
| |
| while (1) { |
| /* Read header first to get message size */ |
| rc = read(link->lk_rfd, buf, lhsz); |
| if (rc <= 0) { |
| rc = -errno; |
| break; |
| } |
| kuch = (struct kuc_hdr *)buf; |
| |
| CDEBUG(D_KUC, "Received message mg=%x t=%d m=%d l=%d\n", |
| kuch->kuc_magic, kuch->kuc_transport, kuch->kuc_msgtype, |
| kuch->kuc_msglen); |
| |
| if (kuch->kuc_magic != KUC_MAGIC) { |
| CERROR("bad message magic %x != %x\n", |
| kuch->kuc_magic, KUC_MAGIC); |
| rc = -EPROTO; |
| break; |
| } |
| |
| if (kuch->kuc_msglen > maxsize) { |
| rc = -EMSGSIZE; |
| break; |
| } |
| |
| /* Read payload */ |
| rc = read(link->lk_rfd, buf + lhsz, kuch->kuc_msglen - lhsz); |
| if (rc < 0) { |
| rc = -errno; |
| break; |
| } |
| if (rc < (kuch->kuc_msglen - lhsz)) { |
| CERROR("short read: got %d of %d bytes\n", |
| rc, kuch->kuc_msglen); |
| rc = -EPROTO; |
| break; |
| } |
| |
| if (kuch->kuc_transport == transport || |
| kuch->kuc_transport == KUC_TRANSPORT_GENERIC) { |
| return 0; |
| } |
| /* Drop messages for other transports */ |
| } |
| return rc; |
| } |
| |
| #else /* LUSTRE_UTILS */ |
| /* This is the kernel side (liblustre as well). */ |
| |
| /** |
| * libcfs_kkuc_msg_put - send an message from kernel to userspace |
| * @param fp to send the message to |
| * @param payload Payload data. First field of payload is always |
| * struct kuc_hdr |
| */ |
| int libcfs_kkuc_msg_put(struct file *filp, void *payload) |
| { |
| struct kuc_hdr *kuch = (struct kuc_hdr *)payload; |
| ssize_t count = kuch->kuc_msglen; |
| loff_t offset = 0; |
| mm_segment_t fs; |
| int rc = -ENOSYS; |
| |
| if (filp == NULL || IS_ERR(filp)) |
| return -EBADF; |
| |
| if (kuch->kuc_magic != KUC_MAGIC) { |
| CERROR("KernelComm: bad magic %x\n", kuch->kuc_magic); |
| return -ENOSYS; |
| } |
| |
| fs = get_fs(); |
| set_fs(KERNEL_DS); |
| while (count > 0) { |
| rc = vfs_write(filp, (void __force __user *)payload, |
| count, &offset); |
| if (rc < 0) |
| break; |
| count -= rc; |
| payload += rc; |
| rc = 0; |
| } |
| set_fs(fs); |
| |
| if (rc < 0) |
| CWARN("message send failed (%d)\n", rc); |
| else |
| CDEBUG(D_KUC, "Sent message rc=%d, fp=%p\n", rc, filp); |
| |
| return rc; |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_msg_put); |
| |
| /* Broadcast groups are global across all mounted filesystems; |
| * i.e. registering for a group on 1 fs will get messages for that |
| * group from any fs */ |
| /** A single group reigstration has a uid and a file pointer */ |
| struct kkuc_reg { |
| struct list_head kr_chain; |
| int kr_uid; |
| struct file *kr_fp; |
| __u32 kr_data; |
| }; |
| static struct list_head kkuc_groups[KUC_GRP_MAX+1] = {}; |
| /* Protect message sending against remove and adds */ |
| static DECLARE_RWSEM(kg_sem); |
| |
| /** Add a receiver to a broadcast group |
| * @param filp pipe to write into |
| * @param uid identidier for this receiver |
| * @param group group number |
| */ |
| int libcfs_kkuc_group_add(struct file *filp, int uid, int group, __u32 data) |
| { |
| struct kkuc_reg *reg; |
| |
| if (group > KUC_GRP_MAX) { |
| CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group); |
| return -EINVAL; |
| } |
| |
| /* fput in group_rem */ |
| if (filp == NULL) |
| return -EBADF; |
| |
| /* freed in group_rem */ |
| reg = kmalloc(sizeof(*reg), 0); |
| if (reg == NULL) |
| return -ENOMEM; |
| |
| reg->kr_fp = filp; |
| reg->kr_uid = uid; |
| reg->kr_data = data; |
| |
| down_write(&kg_sem); |
| if (kkuc_groups[group].next == NULL) |
| INIT_LIST_HEAD(&kkuc_groups[group]); |
| list_add(®->kr_chain, &kkuc_groups[group]); |
| up_write(&kg_sem); |
| |
| CDEBUG(D_KUC, "Added uid=%d fp=%p to group %d\n", uid, filp, group); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_add); |
| |
| int libcfs_kkuc_group_rem(int uid, int group) |
| { |
| struct kkuc_reg *reg, *next; |
| ENTRY; |
| |
| if (kkuc_groups[group].next == NULL) |
| RETURN(0); |
| |
| if (uid == 0) { |
| /* Broadcast a shutdown message */ |
| struct kuc_hdr lh; |
| |
| lh.kuc_magic = KUC_MAGIC; |
| lh.kuc_transport = KUC_TRANSPORT_GENERIC; |
| lh.kuc_msgtype = KUC_MSG_SHUTDOWN; |
| lh.kuc_msglen = sizeof(lh); |
| libcfs_kkuc_group_put(group, &lh); |
| } |
| |
| down_write(&kg_sem); |
| list_for_each_entry_safe(reg, next, &kkuc_groups[group], kr_chain) { |
| if ((uid == 0) || (uid == reg->kr_uid)) { |
| list_del(®->kr_chain); |
| CDEBUG(D_KUC, "Removed uid=%d fp=%p from group %d\n", |
| reg->kr_uid, reg->kr_fp, group); |
| if (reg->kr_fp != NULL) |
| fput(reg->kr_fp); |
| kfree(reg); |
| } |
| } |
| up_write(&kg_sem); |
| |
| RETURN(0); |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_rem); |
| |
| int libcfs_kkuc_group_put(int group, void *payload) |
| { |
| struct kkuc_reg *reg; |
| int rc = 0; |
| int one_success = 0; |
| ENTRY; |
| |
| down_read(&kg_sem); |
| list_for_each_entry(reg, &kkuc_groups[group], kr_chain) { |
| if (reg->kr_fp != NULL) { |
| rc = libcfs_kkuc_msg_put(reg->kr_fp, payload); |
| if (rc == 0) |
| one_success = 1; |
| else if (rc == -EPIPE) { |
| fput(reg->kr_fp); |
| reg->kr_fp = NULL; |
| } |
| } |
| } |
| up_read(&kg_sem); |
| |
| /* don't return an error if the message has been delivered |
| * at least to one agent */ |
| if (one_success) |
| rc = 0; |
| |
| RETURN(rc); |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_put); |
| |
| /** |
| * Calls a callback function for each link of the given kuc group. |
| * @param group the group to call the function on. |
| * @param cb_func the function to be called. |
| * @param cb_arg iextra argument to be passed to the callback function. |
| */ |
| int libcfs_kkuc_group_foreach(int group, libcfs_kkuc_cb_t cb_func, |
| void *cb_arg) |
| { |
| struct kkuc_reg *reg; |
| int rc = 0; |
| ENTRY; |
| |
| if (group > KUC_GRP_MAX) { |
| CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group); |
| RETURN(-EINVAL); |
| } |
| |
| /* no link for this group */ |
| if (kkuc_groups[group].next == NULL) |
| RETURN(0); |
| |
| down_read(&kg_sem); |
| list_for_each_entry(reg, &kkuc_groups[group], kr_chain) { |
| if (reg->kr_fp != NULL) { |
| rc = cb_func(reg->kr_data, cb_arg); |
| } |
| } |
| up_read(&kg_sem); |
| |
| RETURN(rc); |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_foreach); |
| |
| #endif /* LUSTRE_UTILS */ |