xref: /openbsd/sys/dev/firmload.c (revision cecf84d4)
1 /*	$OpenBSD: firmload.c,v 1.12 2015/03/13 23:05:04 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2004 Theo de Raadt <deraadt@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/param.h>
20 #include <sys/systm.h>
21 #include <sys/syslimits.h>
22 #include <sys/namei.h>
23 #include <sys/vnode.h>
24 #include <sys/errno.h>
25 #include <sys/malloc.h>
26 #include <sys/proc.h>
27 #include <sys/device.h>
28 
29 int
30 loadfirmware(const char *name, u_char **bufp, size_t *buflen)
31 {
32 	struct proc *p = curproc;
33 	struct nameidata nid;
34 	char *path, *ptr;
35 	struct iovec iov;
36 	struct uio uio;
37 	struct vattr va;
38 	int error;
39 
40 	if (!rootvp || !vcount(rootvp))
41 		return (EIO);
42 
43 	path = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT);
44 	if (path == NULL)
45 		return (ENOMEM);
46 
47 	if (snprintf(path, MAXPATHLEN, "/etc/firmware/%s", name) >=
48 	    MAXPATHLEN) {
49 		error = ENAMETOOLONG;
50 		goto err;
51 	}
52 
53 	NDINIT(&nid, LOOKUP, NOFOLLOW|LOCKLEAF, UIO_SYSSPACE, path, p);
54 	error = namei(&nid);
55 #ifdef RAMDISK_HOOKS
56 	/* try again with mounted disk */
57 	if (error) {
58 		if (snprintf(path, MAXPATHLEN, "/mnt/etc/firmware/%s", name) >=
59 		    MAXPATHLEN) {
60 			error = ENAMETOOLONG;
61 			goto err;
62 		}
63 
64 		NDINIT(&nid, LOOKUP, NOFOLLOW|LOCKLEAF, UIO_SYSSPACE, path, p);
65 		error = namei(&nid);
66 	}
67 #endif
68 	if (error)
69 		goto err;
70 	error = VOP_GETATTR(nid.ni_vp, &va, p->p_ucred, p);
71 	if (error)
72 		goto fail;
73 	if (nid.ni_vp->v_type != VREG || va.va_size == 0) {
74 		error = EINVAL;
75 		goto fail;
76 	}
77 	if (va.va_size > FIRMWARE_MAX) {
78 		error = E2BIG;
79 		goto fail;
80 	}
81 	ptr = malloc(va.va_size, M_DEVBUF, M_NOWAIT);
82 	if (ptr == NULL) {
83 		error = ENOMEM;
84 		goto fail;
85 	}
86 
87 	iov.iov_base = ptr;
88 	iov.iov_len = va.va_size;
89 	uio.uio_iov = &iov;
90 	uio.uio_iovcnt = 1;
91 	uio.uio_offset = 0;
92 	uio.uio_resid = va.va_size;
93 	uio.uio_segflg = UIO_SYSSPACE;
94 	uio.uio_rw = UIO_READ;
95 	uio.uio_procp = p;
96 
97 	error = VOP_READ(nid.ni_vp, &uio, 0, p->p_ucred);
98 
99 	if (error == 0) {
100 		*bufp = ptr;
101 		*buflen = va.va_size;
102 	} else
103 		free(ptr, M_DEVBUF, 0);
104 
105 fail:
106 	vput(nid.ni_vp);
107 err:
108 	if (path)
109 		free(path, M_TEMP, 0);
110 	return (error);
111 }
112