1/*-
2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/types.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/systm.h>
34#include <sys/kthread.h>
35#include <sys/namei.h>
36#include <sys/proc.h>
37#include <sys/filedesc.h>
38#include <sys/fcntl.h>
39#include <sys/linker.h>
40#include <sys/kobj.h>
41
42void
43kobj_free(void *address, size_t size)
44{
45
46	kmem_free(address, size);
47}
48
49void *
50kobj_alloc(size_t size, int flag)
51{
52
53	return (kmem_alloc(size, (flag & KM_NOWAIT) ? KM_NOSLEEP : KM_SLEEP));
54}
55
56void *
57kobj_zalloc(size_t size, int flag)
58{
59	void *p;
60
61	if ((p = kobj_alloc(size, flag)) != NULL)
62		bzero(p, size);
63	return (p);
64}
65
66static void *
67kobj_open_file_vnode(const char *file)
68{
69	struct thread *td = curthread;
70	struct filedesc *fd;
71	struct nameidata nd;
72	int error, flags;
73
74	fd = td->td_proc->p_fd;
75	FILEDESC_XLOCK(fd);
76	if (fd->fd_rdir == NULL) {
77		fd->fd_rdir = rootvnode;
78		vref(fd->fd_rdir);
79	}
80	if (fd->fd_cdir == NULL) {
81		fd->fd_cdir = rootvnode;
82		vref(fd->fd_cdir);
83	}
84	FILEDESC_XUNLOCK(fd);
85
86	flags = FREAD | O_NOFOLLOW;
87	NDINIT(&nd, LOOKUP, 0, UIO_SYSSPACE, file, td);
88	error = vn_open_cred(&nd, &flags, 0, 0, curthread->td_ucred, NULL);
89	if (error != 0)
90		return (NULL);
91	NDFREE(&nd, NDF_ONLY_PNBUF);
92	/* We just unlock so we hold a reference. */
93	VOP_UNLOCK(nd.ni_vp, 0);
94	return (nd.ni_vp);
95}
96
97static void *
98kobj_open_file_loader(const char *file)
99{
100
101	return (preload_search_by_name(file));
102}
103
104struct _buf *
105kobj_open_file(const char *file)
106{
107	struct _buf *out;
108
109	out = kmem_alloc(sizeof(*out), KM_SLEEP);
110	out->mounted = root_mounted();
111	/*
112	 * If root is already mounted we read file using file system,
113	 * if not, we use loader.
114	 */
115	if (out->mounted)
116		out->ptr = kobj_open_file_vnode(file);
117	else
118		out->ptr = kobj_open_file_loader(file);
119	if (out->ptr == NULL) {
120		kmem_free(out, sizeof(*out));
121		return ((struct _buf *)-1);
122	}
123	return (out);
124}
125
126static int
127kobj_get_filesize_vnode(struct _buf *file, uint64_t *size)
128{
129	struct vnode *vp = file->ptr;
130	struct vattr va;
131	int error;
132
133	vn_lock(vp, LK_SHARED | LK_RETRY);
134	error = VOP_GETATTR(vp, &va, curthread->td_ucred);
135	VOP_UNLOCK(vp, 0);
136	if (error == 0)
137		*size = (uint64_t)va.va_size;
138	return (error);
139}
140
141static int
142kobj_get_filesize_loader(struct _buf *file, uint64_t *size)
143{
144	void *ptr;
145
146	ptr = preload_search_info(file->ptr, MODINFO_SIZE);
147	if (ptr == NULL)
148		return (ENOENT);
149	*size = (uint64_t)*(size_t *)ptr;
150	return (0);
151}
152
153int
154kobj_get_filesize(struct _buf *file, uint64_t *size)
155{
156
157	if (file->mounted)
158		return (kobj_get_filesize_vnode(file, size));
159	else
160		return (kobj_get_filesize_loader(file, size));
161}
162
163int
164kobj_read_file_vnode(struct _buf *file, char *buf, unsigned size, unsigned off)
165{
166	struct vnode *vp = file->ptr;
167	struct thread *td = curthread;
168	struct uio auio;
169	struct iovec aiov;
170	int error;
171
172	bzero(&aiov, sizeof(aiov));
173	bzero(&auio, sizeof(auio));
174
175	aiov.iov_base = buf;
176	aiov.iov_len = size;
177
178	auio.uio_iov = &aiov;
179	auio.uio_offset = (off_t)off;
180	auio.uio_segflg = UIO_SYSSPACE;
181	auio.uio_rw = UIO_READ;
182	auio.uio_iovcnt = 1;
183	auio.uio_resid = size;
184	auio.uio_td = td;
185
186	vn_lock(vp, LK_SHARED | LK_RETRY);
187	error = VOP_READ(vp, &auio, IO_UNIT | IO_SYNC, td->td_ucred);
188	VOP_UNLOCK(vp, 0);
189	return (error != 0 ? -1 : size - auio.uio_resid);
190}
191
192int
193kobj_read_file_loader(struct _buf *file, char *buf, unsigned size, unsigned off)
194{
195	char *ptr;
196
197	ptr = preload_fetch_addr(file->ptr);
198	if (ptr == NULL)
199		return (ENOENT);
200	bcopy(ptr + off, buf, size);
201	return (0);
202}
203
204int
205kobj_read_file(struct _buf *file, char *buf, unsigned size, unsigned off)
206{
207
208	if (file->mounted)
209		return (kobj_read_file_vnode(file, buf, size, off));
210	else
211		return (kobj_read_file_loader(file, buf, size, off));
212}
213
214void
215kobj_close_file(struct _buf *file)
216{
217
218	if (file->mounted)
219		vn_close(file->ptr, FREAD, curthread->td_ucred, curthread);
220	kmem_free(file, sizeof(*file));
221}
222