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, vfslocked;
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, MPSAFE, 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	vfslocked = NDHASGIANT(&nd);
92	NDFREE(&nd, NDF_ONLY_PNBUF);
93	/* We just unlock so we hold a reference. */
94	VOP_UNLOCK(nd.ni_vp, 0);
95	VFS_UNLOCK_GIANT(vfslocked);
96	return (nd.ni_vp);
97}
98
99static void *
100kobj_open_file_loader(const char *file)
101{
102
103	return (preload_search_by_name(file));
104}
105
106struct _buf *
107kobj_open_file(const char *file)
108{
109	struct _buf *out;
110
111	out = kmem_alloc(sizeof(*out), KM_SLEEP);
112	out->mounted = root_mounted();
113	/*
114	 * If root is already mounted we read file using file system,
115	 * if not, we use loader.
116	 */
117	if (out->mounted)
118		out->ptr = kobj_open_file_vnode(file);
119	else
120		out->ptr = kobj_open_file_loader(file);
121	if (out->ptr == NULL) {
122		kmem_free(out, sizeof(*out));
123		return ((struct _buf *)-1);
124	}
125	return (out);
126}
127
128static int
129kobj_get_filesize_vnode(struct _buf *file, uint64_t *size)
130{
131	struct vnode *vp = file->ptr;
132	struct vattr va;
133	int error, vfslocked;
134
135	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
136	vn_lock(vp, LK_SHARED | LK_RETRY);
137	error = VOP_GETATTR(vp, &va, curthread->td_ucred);
138	VOP_UNLOCK(vp, 0);
139	if (error == 0)
140		*size = (uint64_t)va.va_size;
141	VFS_UNLOCK_GIANT(vfslocked);
142	return (error);
143}
144
145static int
146kobj_get_filesize_loader(struct _buf *file, uint64_t *size)
147{
148	void *ptr;
149
150	ptr = preload_search_info(file->ptr, MODINFO_SIZE);
151	if (ptr == NULL)
152		return (ENOENT);
153	*size = (uint64_t)*(size_t *)ptr;
154	return (0);
155}
156
157int
158kobj_get_filesize(struct _buf *file, uint64_t *size)
159{
160
161	if (file->mounted)
162		return (kobj_get_filesize_vnode(file, size));
163	else
164		return (kobj_get_filesize_loader(file, size));
165}
166
167int
168kobj_read_file_vnode(struct _buf *file, char *buf, unsigned size, unsigned off)
169{
170	struct vnode *vp = file->ptr;
171	struct thread *td = curthread;
172	struct uio auio;
173	struct iovec aiov;
174	int error, vfslocked;
175
176	bzero(&aiov, sizeof(aiov));
177	bzero(&auio, sizeof(auio));
178
179	aiov.iov_base = buf;
180	aiov.iov_len = size;
181
182	auio.uio_iov = &aiov;
183	auio.uio_offset = (off_t)off;
184	auio.uio_segflg = UIO_SYSSPACE;
185	auio.uio_rw = UIO_READ;
186	auio.uio_iovcnt = 1;
187	auio.uio_resid = size;
188	auio.uio_td = td;
189
190	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
191	vn_lock(vp, LK_SHARED | LK_RETRY);
192	error = VOP_READ(vp, &auio, IO_UNIT | IO_SYNC, td->td_ucred);
193	VOP_UNLOCK(vp, 0);
194	VFS_UNLOCK_GIANT(vfslocked);
195	return (error != 0 ? -1 : size - auio.uio_resid);
196}
197
198int
199kobj_read_file_loader(struct _buf *file, char *buf, unsigned size, unsigned off)
200{
201	char *ptr;
202
203	ptr = preload_fetch_addr(file->ptr);
204	if (ptr == NULL)
205		return (ENOENT);
206	bcopy(ptr + off, buf, size);
207	return (0);
208}
209
210int
211kobj_read_file(struct _buf *file, char *buf, unsigned size, unsigned off)
212{
213
214	if (file->mounted)
215		return (kobj_read_file_vnode(file, buf, size, off));
216	else
217		return (kobj_read_file_loader(file, buf, size, off));
218}
219
220void
221kobj_close_file(struct _buf *file)
222{
223
224	if (file->mounted) {
225		struct vnode *vp = file->ptr;
226		struct thread *td = curthread;
227		int vfslocked;
228
229		vfslocked = VFS_LOCK_GIANT(vp->v_mount);
230		vn_close(vp, FREAD, td->td_ucred, td);
231		VFS_UNLOCK_GIANT(vfslocked);
232	}
233	kmem_free(file, sizeof(*file));
234}
235