xref: /openbsd/sys/dev/firmload.c (revision 73471bf0)
1 /*	$OpenBSD: firmload.c,v 1.16 2018/08/13 23:12:39 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 #include <sys/pledge.h>
29 
30 int
31 loadfirmware(const char *name, u_char **bufp, size_t *buflen)
32 {
33 	struct proc *p = curproc;
34 	struct nameidata nid;
35 	char *path, *ptr;
36 	struct iovec iov;
37 	struct uio uio;
38 	struct vattr va;
39 	int error;
40 
41 	if (!rootvp || !vcount(rootvp))
42 		return (EIO);
43 
44 	path = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT);
45 	if (path == NULL)
46 		return (ENOMEM);
47 
48 	if (snprintf(path, MAXPATHLEN, "/etc/firmware/%s", name) >=
49 	    MAXPATHLEN) {
50 		error = ENAMETOOLONG;
51 		goto err;
52 	}
53 
54 	NDINIT(&nid, LOOKUP, NOFOLLOW|LOCKLEAF|KERNELPATH,
55 	    UIO_SYSSPACE, path, p);
56 	nid.ni_pledge = PLEDGE_RPATH;
57 	error = namei(&nid);
58 #ifdef RAMDISK_HOOKS
59 	/* try again with mounted disk */
60 	if (error) {
61 		if (snprintf(path, MAXPATHLEN, "/mnt/etc/firmware/%s", name) >=
62 		    MAXPATHLEN) {
63 			error = ENAMETOOLONG;
64 			goto err;
65 		}
66 
67 		NDINIT(&nid, LOOKUP, NOFOLLOW|LOCKLEAF|KERNELPATH,
68 		    UIO_SYSSPACE, path, p);
69 		nid.ni_pledge = PLEDGE_RPATH;
70 		error = namei(&nid);
71 	}
72 #endif
73 	if (error)
74 		goto err;
75 	error = VOP_GETATTR(nid.ni_vp, &va, p->p_ucred, p);
76 	if (error)
77 		goto fail;
78 	if (nid.ni_vp->v_type != VREG || va.va_size == 0) {
79 		error = EINVAL;
80 		goto fail;
81 	}
82 	if (va.va_size > FIRMWARE_MAX) {
83 		error = E2BIG;
84 		goto fail;
85 	}
86 	ptr = malloc(va.va_size, M_DEVBUF, M_NOWAIT);
87 	if (ptr == NULL) {
88 		error = ENOMEM;
89 		goto fail;
90 	}
91 
92 	iov.iov_base = ptr;
93 	iov.iov_len = va.va_size;
94 	uio.uio_iov = &iov;
95 	uio.uio_iovcnt = 1;
96 	uio.uio_offset = 0;
97 	uio.uio_resid = va.va_size;
98 	uio.uio_segflg = UIO_SYSSPACE;
99 	uio.uio_rw = UIO_READ;
100 	uio.uio_procp = p;
101 
102 	error = VOP_READ(nid.ni_vp, &uio, 0, p->p_ucred);
103 
104 	if (error == 0) {
105 		*bufp = ptr;
106 		*buflen = va.va_size;
107 	} else
108 		free(ptr, M_DEVBUF, va.va_size);
109 
110 fail:
111 	vput(nid.ni_vp);
112 err:
113 	free(path, M_TEMP, MAXPATHLEN);
114 	return (error);
115 }
116