/* * linux/ipc/msgutil.c * Copyright (C) 1999, 2004 Manfred Spraul * * This file is released under GNU General Public Licence version 2 or * (at your option) any later version. * * See the file COPYING for more details. */ #include <linux/spinlock.h> #include <linux/init.h> #include <linux/security.h> #include <linux/slab.h> #include <linux/ipc.h> #include <linux/msg.h> #include <linux/ipc_namespace.h> #include <linux/utsname.h> #include <asm/uaccess.h> #include "util.h" DEFINE_SPINLOCK(mq_lock); /* * The next 2 defines are here bc this is the only file * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE * and not CONFIG_IPC_NS. */ struct ipc_namespace init_ipc_ns = { .count = ATOMIC_INIT(1), .user_ns = &init_user_ns, }; atomic_t nr_ipc_ns = ATOMIC_INIT(1); struct msg_msgseg { struct msg_msgseg* next; /* the next part of the message follows immediately */ }; #define DATALEN_MSG (PAGE_SIZE-sizeof(struct msg_msg)) #define DATALEN_SEG (PAGE_SIZE-sizeof(struct msg_msgseg)) struct msg_msg *load_msg(const void __user *src, int len) { struct msg_msg *msg; struct msg_msgseg **pseg; int err; int alen; alen = len; if (alen > DATALEN_MSG) alen = DATALEN_MSG; msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL); if (msg == NULL) return ERR_PTR(-ENOMEM); msg->next = NULL; msg->security = NULL; if (copy_from_user(msg + 1, src, alen)) { err = -EFAULT; goto out_err; } len -= alen; src = ((char __user *)src) + alen; pseg = &msg->next; while (len > 0) { struct msg_msgseg *seg; alen = len; if (alen > DATALEN_SEG) alen = DATALEN_SEG; seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL); if (seg == NULL) { err = -ENOMEM; goto out_err; } *pseg = seg; seg->next = NULL; if (copy_from_user(seg + 1, src, alen)) { err = -EFAULT; goto out_err; } pseg = &seg->next; len -= alen; src = ((char __user *)src) + alen; } err = security_msg_msg_alloc(msg); if (err) goto out_err; return msg; out_err: free_msg(msg); return ERR_PTR(err); } int store_msg(void __user *dest, struct msg_msg *msg, int len) { int alen; struct msg_msgseg *seg; alen = len; if (alen > DATALEN_MSG) alen = DATALEN_MSG; if (copy_to_user(dest, msg + 1, alen)) return -1; len -= alen; dest = ((char __user *)dest) + alen; seg = msg->next; while (len > 0) { alen = len; if (alen > DATALEN_SEG) alen = DATALEN_SEG; if (copy_to_user(dest, seg + 1, alen)) return -1; len -= alen; dest = ((char __user *)dest) + alen; seg = seg->next; } return 0; } void free_msg(struct msg_msg *msg) { struct msg_msgseg *seg; security_msg_msg_free(msg); seg = msg->next; kfree(msg); while (seg != NULL) { struct msg_msgseg *tmp = seg->next; kfree(seg); seg = tmp; } }