Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.sbin/vmd/vmboot.c	Lines:	0	212	0.0 %
Date:	2017-11-13	Branches:	0	124	0.0 %


/*	$OpenBSD: vmboot.c,v 1.4 2017/08/29 21:10:20 deraadt Exp $	*/

/*
 * Copyright (c) 2016 Reyk Floeter <reyk@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>	/* DEV_BSIZE roundup */
#include <sys/reboot.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/disklabel.h>

#include <ufs/ffs/fs.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ufs/dir.h>

#include <stdio.h>
#include <unistd.h>
#include <ctype.h>
#include <fcntl.h>
#include <err.h>
#include <vis.h>

#include "vmd.h"
#include "vmboot.h"

int	 vmboot_bootconf(char *, size_t, struct vmboot_params *);
int	 vmboot_bootcmd(char *, struct vmboot_params *);
int	 vmboot_bootargs(int argc, char **argv, struct vmboot_params *);
uint32_t vmboot_bootdevice(const char *);

int	 vmboot_strategy(void *, int, daddr32_t, size_t, void *, size_t *);
off_t	 vmboot_findopenbsd(struct open_file *, off_t, struct disklabel *);
void	*vmboot_loadfile(struct open_file *, char *, size_t *);

int
vmboot_bootcmd(char *line, struct vmboot_params *bp)
{
	char *p, *args[16];
	int ac = 0;
	char *last;

	for (args[0] = NULL, (p = strtok_r(line, " ", &last)); p;
	    (p = strtok_r(NULL, " ", &last))) {
		if (ac < (int)(sizeof(args) / sizeof(args[0])) - 1)
			args[ac++] = p;
	}
	if (ac == 0)
		return (0);
	args[ac] = NULL;

	/*
	 * Subset of boot.conf(8) options
	 */
	if (strcmp("boot", args[0]) == 0)
		return (vmboot_bootargs(ac, args, bp));
	else if (strcmp("set", args[0]) == 0) {
		if (ac < 3)
			return (-1);
		if (strcmp("device", args[1]) == 0) {
			if ((size_t)strnvis(bp->vbp_device, args[2],
			    sizeof(bp->vbp_device), VIS_SAFE) >=
			    sizeof(bp->vbp_device)) {
				log_warnx("invalid device name");
				return (-1);
			}
		} else if (strcmp("image", args[1]) == 0) {
			if ((size_t)strnvis(bp->vbp_image, args[2],
			    sizeof(bp->vbp_image), VIS_SAFE) >=
			    sizeof(bp->vbp_image)) {
				log_warnx("invalid image name");
				return (-1);
			}
		}
	}

	return (0);
}

int
vmboot_bootargs(int ac, char **av, struct vmboot_params *bp)
{
	char *p;
	int ch;

	if (ac < 2)
		return (0);

	/*
	 * Syntax is based on boot(8): boot "[hd0a[:/file]] [-asdc]"
	 */
	if (*av[1] != '-') {
		if ((p = strchr(av[1], ':')) != NULL) {
			*p++ = '\0';
			if (!strlen(p)) {
				log_warnx("invalid file syntax");
				return (-1);
			}
			if ((size_t)strnvis(bp->vbp_device, av[1],
			    sizeof(bp->vbp_device), VIS_SAFE) >=
			    sizeof(bp->vbp_device)) {
				log_warnx("invalid device name");
				return (-1);
			}
		} else {
			p = av[1];
		}
		if ((size_t)strnvis(bp->vbp_image, p,
		    sizeof(bp->vbp_image), VIS_SAFE) >= sizeof(bp->vbp_image)) {
			log_warnx("invalid image name");
			return (-1);
		}
		ac--;
		av++;
	}

	optreset = optind = opterr = 1;
	while ((ch = getopt(ac, av, "acds")) != -1) {
		switch (ch) {
		case 'a':
			bp->vbp_howto |= RB_ASKNAME;
			break;
		case 'c':
			bp->vbp_howto |= RB_CONFIG;
			break;
		case 'd':
			bp->vbp_howto |= RB_KDB;
			break;
		case 's':
			bp->vbp_howto |= RB_SINGLE;
			break;
		default:
			log_warnx("invalid boot option: %c", ch);
			return (-1);
		}
	}

	return (0);
}

uint32_t
vmboot_bootdevice(const char *word)
{
	uint32_t	 bootdev = 0;
	int		 disk, part;

	if (strlen(word) != strlen("hd0a")) {
		log_warnx("invalid boot device: %s", word);
		goto done;
	}

	if (strncmp("hd", word, 2) != 0) {
		log_warnx("unsupported boot device type: %s", word);
		goto done;
	}

	disk = (int)word[2];
	part = (int)word[3];

	if (!(isdigit(disk) && isalpha(part) && islower(part))) {
		log_warnx("invalid boot partition: %s", word);
		goto done;
	}

	disk -= '0';
	part -= 'a';

	if (disk != 0 || part > MAXPARTITIONS) {
		log_warnx("cannot boot from device: %s", word);
		goto done;
	}

	bootdev = MAKEBOOTDEV(0x4, 0, 0, disk, part);

 done:
	/* returns 0 on error */
	return (bootdev);
}

int
vmboot_bootconf(char *conf, size_t size, struct vmboot_params *bp)
{
	char	 buf[BUFSIZ];
	FILE	*fp;

	if ((fp = fmemopen(conf, size, "r")) == NULL) {
		log_debug("%s: failed to boot.conf memory stream", __func__);
		return (-1);
	}

	while (fgets(buf, sizeof(buf), fp) != NULL) {
		buf[strcspn(buf, "\n")] = '\0';
		vmboot_bootcmd(buf, bp);
	}
	fclose(fp);

	if (strlen(bp->vbp_device))
		log_debug("%s: set device %s", __func__, bp->vbp_device);
	if (strlen(bp->vbp_image))
		log_debug("%s: set image %s", __func__, bp->vbp_image);
	if (bp->vbp_howto) {
		snprintf(buf, sizeof(buf), "boot -%s%s%s%s",
		    (bp->vbp_howto & RB_ASKNAME) ? "a" : "",
		    (bp->vbp_howto & RB_CONFIG) ? "c" : "",
		    (bp->vbp_howto & RB_KDB) ? "d" : "",
		    (bp->vbp_howto & RB_SINGLE) ? "s" : "");
		log_debug("%s: %s", __func__, buf);
	}

	return (0);
}


/*
 * For ufs.c
 */

struct devsw vmboot_devsw = {
	.dv_name =	"vmboot",
	.dv_strategy =	vmboot_strategy,
	/* other fields are not needed */
};

struct open_file vmboot_file = {
	.f_dev =	&vmboot_devsw,
	.f_devdata =	 NULL
};

int
vmboot_strategy(void *devdata, int rw,
    daddr32_t blk, size_t size, void *buf, size_t *rsize)
{
	struct vmboot_params	*vmboot = devdata;
	ssize_t			 rlen;

	if (vmboot->vbp_fd == -1)
		return (EIO);

	switch (rw) {
	case F_READ:
		rlen = pread(vmboot->vbp_fd, buf, size,
		    (blk + vmboot->vbp_partoff) * DEV_BSIZE);
		if (rlen == -1)
			return (errno);
		*rsize = (size_t)rlen;
		break;
	case F_WRITE:
		rlen = pwrite(vmboot->vbp_fd, buf, size,
		    (blk + vmboot->vbp_partoff) * DEV_BSIZE);
		if (rlen == -1)
			return (errno);
		*rsize = (size_t)rlen;
		break;
	default:
		return (EINVAL);
	}
	return (0);
}

/*
 * Based on findopenbsd() from biosdev.c that was partially written by me.
 */
off_t
vmboot_findopenbsd(struct open_file *f, off_t mbroff, struct disklabel *dl)
{
	struct dos_mbr		 mbr;
	struct dos_partition	*dp;
	off_t			 mbr_eoff = DOSBBSECTOR, nextebr;
	int			 ret, i;
	static int		 maxebr = DOS_MAXEBR;
	size_t			 rsize;
	char			 buf[DEV_BSIZE], *msg;

	if (!maxebr--) {
		log_debug("%s: too many extended partitions", __func__);
		return (-1);
	}

	memset(&mbr, 0, sizeof(mbr));
	ret = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
	    mbroff, sizeof(mbr), &mbr, &rsize);
	if (ret != 0 || rsize != sizeof(mbr)) {
		log_debug("%s: failed to read MBR", __func__);
		return (-1);
	}

	if (mbr.dmbr_sign != DOSMBR_SIGNATURE) {
		log_debug("%s: bad MBR signature", __func__);
		return (-1);
	}

	/* Search for the first OpenBSD partition */
	nextebr = 0;
	for (i = 0; i < NDOSPART; i++) {
		dp = &mbr.dmbr_parts[i];
		if (!dp->dp_size)
			continue;

		if (dp->dp_typ == DOSPTYP_OPENBSD) {
			if (dp->dp_start > (dp->dp_start + mbroff))
				continue;

			/* Load and parse the disk label */
			ret = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
			    dp->dp_start + mbroff + DOS_LABELSECTOR,
			    sizeof(buf), buf, &rsize);
			if (ret != 0 || rsize != sizeof(buf)) {
				log_warn("could not load disk label");
				return (-1);
			}
			if ((msg = getdisklabel(buf, dl)) != NULL) {
				log_warnx("%s", msg);
				return (-1);
			}

			return (dp->dp_start + mbroff);
		}

		if (!nextebr && (dp->dp_typ == DOSPTYP_EXTEND ||
		    dp->dp_typ == DOSPTYP_EXTENDL)) {
			nextebr = dp->dp_start + mbr_eoff;
			if (nextebr < dp->dp_start)
				nextebr = -1;
			if (mbr_eoff == DOSBBSECTOR)
				mbr_eoff = dp->dp_start;
		}
	}

	if (nextebr && nextebr != -1) {
		mbroff = nextebr;
		return (vmboot_findopenbsd(f, mbroff, dl));
	}

	return (-1);
}

void *
vmboot_loadfile(struct open_file *f, char *file, size_t *size)
{
	char		*buf = NULL, *p = NULL;
	struct stat	 st;
	size_t		 rsize;
	int		 ret;

	*size = 0;

	if ((ret = ufs_open(file, f)) != 0)
		return (NULL);

	if ((ret = ufs_stat(f, &st)) != 0) {
		log_debug("%s: failed to stat %s", __func__, file);
		goto done;
	}

	if ((buf = calloc(1, roundup(st.st_size, DEV_BSIZE))) == NULL) {
		log_debug("%s: failed to allocate buffer", __func__);
		goto done;
	}

	if ((ret = ufs_read(f, buf, st.st_size, &rsize)) != 0) {
		log_debug("%s: failed to read %s", __func__, file);
		free(buf);
		goto done;
	}

	*size = st.st_size;
	p = buf;
 done:
	ufs_close(f);
	return (p);
}

FILE *
vmboot_open(int kernel_fd, int disk_fd, struct vmboot_params *vmboot)
{
	char			 file[PATH_MAX];
	char			*buf = NULL;
	size_t			 size;
	FILE			*fp = NULL;
	struct disklabel	 dl;

	memset(vmboot, 0, sizeof(*vmboot));
	memset(&dl, 0, sizeof(dl));

	/* First open kernel directly if specified by fd */
	if (kernel_fd != -1)
		return (fdopen(kernel_fd, "r"));

	if (disk_fd == -1)
		return (NULL);

	vmboot->vbp_fd = disk_fd;
	vmboot_file.f_devdata = vmboot;

	if ((vmboot->vbp_partoff =
	    vmboot_findopenbsd(&vmboot_file, 0, &dl)) == -1) {
		log_debug("%s: could not find openbsd partition", __func__);
		return (NULL);
	}

	/* Set the default kernel boot device and image path */
	strlcpy(vmboot->vbp_device, VM_DEFAULT_DEVICE,
	    sizeof(vmboot->vbp_device));
	strlcpy(vmboot->vbp_image, VM_DEFAULT_KERNEL,
	    sizeof(vmboot->vbp_image));

	/* Try to parse boot.conf to overwrite the default kernel path */
	strlcpy(file, VM_BOOT_CONF, sizeof(file));
	if ((buf = vmboot_loadfile(&vmboot_file, file, &size)) != NULL) {
		if (vmboot_bootconf(buf, size, vmboot) == -1) {
			free(buf);
			return (NULL);
		}
		free(buf);
	}

	/* Parse boot device and find partition in disk label */
	if ((vmboot->vbp_bootdev =
	    vmboot_bootdevice(vmboot->vbp_device)) == 0)
		return (NULL);
	if (B_PARTITION(vmboot->vbp_bootdev) > dl.d_npartitions) {
		log_debug("%s: invalid boot partition: %s",
		    __func__, vmboot->vbp_device);
		return (NULL);
	}
	vmboot->vbp_partoff =
	    dl.d_partitions[B_PARTITION(vmboot->vbp_bootdev)].p_offset;

	/* Load the kernel */
	if ((buf = vmboot_loadfile(&vmboot_file,
	    vmboot->vbp_image, &size)) == NULL) {
		log_debug("%s: failed to open kernel %s:%s", __func__,
		    vmboot->vbp_device, vmboot->vbp_image);
		return (NULL);
	}
	vmboot->vbp_arg = buf;

	if ((fp = fmemopen(buf, size, "r")) == NULL) {
		log_debug("%s: failed to open memory stream", __func__);
		free(buf);
		vmboot->vbp_arg = NULL;
	} else {
		log_debug("%s: kernel %s:%s", __func__,
		    vmboot->vbp_device, vmboot->vbp_image);
	}

	return (fp);
}

void
vmboot_close(FILE *fp, struct vmboot_params *vmboot)
{
	fclose(fp);
	free(vmboot->vbp_arg);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: vmboot.c,v 1.4 2017/08/29 21:10:20 deraadt Exp $ */
2
3			/*
4			* Copyright (c) 2016 Reyk Floeter <reyk@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> /* DEV_BSIZE roundup */
20			#include <sys/reboot.h>
21			#include <sys/time.h>
22			#include <sys/stat.h>
23			#include <sys/disklabel.h>
24
25			#include <ufs/ffs/fs.h>
26			#include <ufs/ufs/dinode.h>
27			#include <ufs/ufs/dir.h>
28
29			#include <stdio.h>
30			#include <unistd.h>
31			#include <ctype.h>
32			#include <fcntl.h>
33			#include <err.h>
34			#include <vis.h>
35
36			#include "vmd.h"
37			#include "vmboot.h"
38
39			int vmboot_bootconf(char , size_t, struct vmboot_params );
40			int vmboot_bootcmd(char , struct vmboot_params );
41			int vmboot_bootargs(int argc, char *argv, struct vmboot_params );
42			uint32_t vmboot_bootdevice(const char *);
43
44			int vmboot_strategy(void , int, daddr32_t, size_t, void , size_t *);
45			off_t vmboot_findopenbsd(struct open_file , off_t, struct disklabel );
46			void vmboot_loadfile(struct open_file , char , size_t );
47
48			int
49			vmboot_bootcmd(char line, struct vmboot_params bp)
50			{
51			char p, args[16];
52			int ac = 0;
53			char *last;
54
55			for (args[0] = NULL, (p = strtok_r(line, " ", &last)); p;
56			(p = strtok_r(NULL, " ", &last))) {
57			if (ac < (int)(sizeof(args) / sizeof(args[0])) - 1)
58			args[ac++] = p;
59			}
60			if (ac == 0)
61			return (0);
62			args[ac] = NULL;
63
64			/*
65			* Subset of boot.conf(8) options
66			*/
67			if (strcmp("boot", args[0]) == 0)
68			return (vmboot_bootargs(ac, args, bp));
69			else if (strcmp("set", args[0]) == 0) {
70			if (ac < 3)
71			return (-1);
72			if (strcmp("device", args[1]) == 0) {
73			if ((size_t)strnvis(bp->vbp_device, args[2],
74			sizeof(bp->vbp_device), VIS_SAFE) >=
75			sizeof(bp->vbp_device)) {
76			log_warnx("invalid device name");
77			return (-1);
78			}
79			} else if (strcmp("image", args[1]) == 0) {
80			if ((size_t)strnvis(bp->vbp_image, args[2],
81			sizeof(bp->vbp_image), VIS_SAFE) >=
82			sizeof(bp->vbp_image)) {
83			log_warnx("invalid image name");
84			return (-1);
85			}
86			}
87			}
88
89			return (0);
90			}
91
92			int
93			vmboot_bootargs(int ac, char *av, struct vmboot_params bp)
94			{
95			char *p;
96			int ch;
97
98			if (ac < 2)
99			return (0);
100
101			/*
102			* Syntax is based on boot(8): boot "[hd0a[:/file]] [-asdc]"
103			*/
104			if (*av[1] != '-') {
105			if ((p = strchr(av[1], ':')) != NULL) {
106			*p++ = '\0';
107			if (!strlen(p)) {
108			log_warnx("invalid file syntax");
109			return (-1);
110			}
111			if ((size_t)strnvis(bp->vbp_device, av[1],
112			sizeof(bp->vbp_device), VIS_SAFE) >=
113			sizeof(bp->vbp_device)) {
114			log_warnx("invalid device name");
115			return (-1);
116			}
117			} else {
118			p = av[1];
119			}
120			if ((size_t)strnvis(bp->vbp_image, p,
121			sizeof(bp->vbp_image), VIS_SAFE) >= sizeof(bp->vbp_image)) {
122			log_warnx("invalid image name");
123			return (-1);
124			}
125			ac--;
126			av++;
127			}
128
129			optreset = optind = opterr = 1;
130			while ((ch = getopt(ac, av, "acds")) != -1) {
131			switch (ch) {
132			case 'a':
133			bp->vbp_howto \|= RB_ASKNAME;
134			break;
135			case 'c':
136			bp->vbp_howto \|= RB_CONFIG;
137			break;
138			case 'd':
139			bp->vbp_howto \|= RB_KDB;
140			break;
141			case 's':
142			bp->vbp_howto \|= RB_SINGLE;
143			break;
144			default:
145			log_warnx("invalid boot option: %c", ch);
146			return (-1);
147			}
148			}
149
150			return (0);
151			}
152
153			uint32_t
154			vmboot_bootdevice(const char *word)
155			{
156			uint32_t bootdev = 0;
157			int disk, part;
158
159			if (strlen(word) != strlen("hd0a")) {
160			log_warnx("invalid boot device: %s", word);
161			goto done;
162			}
163
164			if (strncmp("hd", word, 2) != 0) {
165			log_warnx("unsupported boot device type: %s", word);
166			goto done;
167			}
168
169			disk = (int)word[2];
170			part = (int)word[3];
171
172			if (!(isdigit(disk) && isalpha(part) && islower(part))) {
173			log_warnx("invalid boot partition: %s", word);
174			goto done;
175			}
176
177			disk -= '0';
178			part -= 'a';
179
180			if (disk != 0 \|\| part > MAXPARTITIONS) {
181			log_warnx("cannot boot from device: %s", word);
182			goto done;
183			}
184
185			bootdev = MAKEBOOTDEV(0x4, 0, 0, disk, part);
186
187			done:
188			/* returns 0 on error */
189			return (bootdev);
190			}
191
192			int
193			vmboot_bootconf(char conf, size_t size, struct vmboot_params bp)
194			{
195			char buf[BUFSIZ];
196			FILE *fp;
197
198			if ((fp = fmemopen(conf, size, "r")) == NULL) {
199			log_debug("%s: failed to boot.conf memory stream", __func__);
200			return (-1);
201			}
202
203			while (fgets(buf, sizeof(buf), fp) != NULL) {
204			buf[strcspn(buf, "\n")] = '\0';
205			vmboot_bootcmd(buf, bp);
206			}
207			fclose(fp);
208
209			if (strlen(bp->vbp_device))
210			log_debug("%s: set device %s", __func__, bp->vbp_device);
211			if (strlen(bp->vbp_image))
212			log_debug("%s: set image %s", __func__, bp->vbp_image);
213			if (bp->vbp_howto) {
214			snprintf(buf, sizeof(buf), "boot -%s%s%s%s",
215			(bp->vbp_howto & RB_ASKNAME) ? "a" : "",
216			(bp->vbp_howto & RB_CONFIG) ? "c" : "",
217			(bp->vbp_howto & RB_KDB) ? "d" : "",
218			(bp->vbp_howto & RB_SINGLE) ? "s" : "");
219			log_debug("%s: %s", __func__, buf);
220			}
221
222			return (0);
223			}
224
225
226			/*
227			* For ufs.c
228			*/
229
230			struct devsw vmboot_devsw = {
231			.dv_name = "vmboot",
232			.dv_strategy = vmboot_strategy,
233			/* other fields are not needed */
234			};
235
236			struct open_file vmboot_file = {
237			.f_dev = &vmboot_devsw,
238			.f_devdata = NULL
239			};
240
241			int
242			vmboot_strategy(void *devdata, int rw,
243			daddr32_t blk, size_t size, void buf, size_t rsize)
244			{
245			struct vmboot_params *vmboot = devdata;
246			ssize_t rlen;
247
248			if (vmboot->vbp_fd == -1)
249			return (EIO);
250
251			switch (rw) {
252			case F_READ:
253			rlen = pread(vmboot->vbp_fd, buf, size,
254			(blk + vmboot->vbp_partoff) * DEV_BSIZE);
255			if (rlen == -1)
256			return (errno);
257			*rsize = (size_t)rlen;
258			break;
259			case F_WRITE:
260			rlen = pwrite(vmboot->vbp_fd, buf, size,
261			(blk + vmboot->vbp_partoff) * DEV_BSIZE);
262			if (rlen == -1)
263			return (errno);
264			*rsize = (size_t)rlen;
265			break;
266			default:
267			return (EINVAL);
268			}
269			return (0);
270			}
271
272			/*
273			* Based on findopenbsd() from biosdev.c that was partially written by me.
274			*/
275			off_t
276			vmboot_findopenbsd(struct open_file f, off_t mbroff, struct disklabel dl)
277			{
278			struct dos_mbr mbr;
279			struct dos_partition *dp;
280			off_t mbr_eoff = DOSBBSECTOR, nextebr;
281			int ret, i;
282			static int maxebr = DOS_MAXEBR;
283			size_t rsize;
284			char buf[DEV_BSIZE], *msg;
285
286			if (!maxebr--) {
287			log_debug("%s: too many extended partitions", __func__);
288			return (-1);
289			}
290
291			memset(&mbr, 0, sizeof(mbr));
292			ret = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
293			mbroff, sizeof(mbr), &mbr, &rsize);
294			if (ret != 0 \|\| rsize != sizeof(mbr)) {
295			log_debug("%s: failed to read MBR", __func__);
296			return (-1);
297			}
298
299			if (mbr.dmbr_sign != DOSMBR_SIGNATURE) {
300			log_debug("%s: bad MBR signature", __func__);
301			return (-1);
302			}
303
304			/* Search for the first OpenBSD partition */
305			nextebr = 0;
306			for (i = 0; i < NDOSPART; i++) {
307			dp = &mbr.dmbr_parts[i];
308			if (!dp->dp_size)
309			continue;
310
311			if (dp->dp_typ == DOSPTYP_OPENBSD) {
312			if (dp->dp_start > (dp->dp_start + mbroff))
313			continue;
314
315			/* Load and parse the disk label */
316			ret = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
317			dp->dp_start + mbroff + DOS_LABELSECTOR,
318			sizeof(buf), buf, &rsize);
319			if (ret != 0 \|\| rsize != sizeof(buf)) {
320			log_warn("could not load disk label");
321			return (-1);
322			}
323			if ((msg = getdisklabel(buf, dl)) != NULL) {
324			log_warnx("%s", msg);
325			return (-1);
326			}
327
328			return (dp->dp_start + mbroff);
329			}
330
331			if (!nextebr && (dp->dp_typ == DOSPTYP_EXTEND \|\|
332			dp->dp_typ == DOSPTYP_EXTENDL)) {
333			nextebr = dp->dp_start + mbr_eoff;
334			if (nextebr < dp->dp_start)
335			nextebr = -1;
336			if (mbr_eoff == DOSBBSECTOR)
337			mbr_eoff = dp->dp_start;
338			}
339			}
340
341			if (nextebr && nextebr != -1) {
342			mbroff = nextebr;
343			return (vmboot_findopenbsd(f, mbroff, dl));
344			}
345
346			return (-1);
347			}
348
349			void *
350			vmboot_loadfile(struct open_file f, char file, size_t *size)
351			{
352			char buf = NULL, p = NULL;
353			struct stat st;
354			size_t rsize;
355			int ret;
356
357			*size = 0;
358
359			if ((ret = ufs_open(file, f)) != 0)
360			return (NULL);
361
362			if ((ret = ufs_stat(f, &st)) != 0) {
363			log_debug("%s: failed to stat %s", __func__, file);
364			goto done;
365			}
366
367			if ((buf = calloc(1, roundup(st.st_size, DEV_BSIZE))) == NULL) {
368			log_debug("%s: failed to allocate buffer", __func__);
369			goto done;
370			}
371
372			if ((ret = ufs_read(f, buf, st.st_size, &rsize)) != 0) {
373			log_debug("%s: failed to read %s", __func__, file);
374			free(buf);
375			goto done;
376			}
377
378			*size = st.st_size;
379			p = buf;
380			done:
381			ufs_close(f);
382			return (p);
383			}
384
385			FILE *
386			vmboot_open(int kernel_fd, int disk_fd, struct vmboot_params *vmboot)
387			{
388			char file[PATH_MAX];
389			char *buf = NULL;
390			size_t size;
391			FILE *fp = NULL;
392			struct disklabel dl;
393
394			memset(vmboot, 0, sizeof(*vmboot));
395			memset(&dl, 0, sizeof(dl));
396
397			/* First open kernel directly if specified by fd */
398			if (kernel_fd != -1)
399			return (fdopen(kernel_fd, "r"));
400
401			if (disk_fd == -1)
402			return (NULL);
403
404			vmboot->vbp_fd = disk_fd;
405			vmboot_file.f_devdata = vmboot;
406
407			if ((vmboot->vbp_partoff =
408			vmboot_findopenbsd(&vmboot_file, 0, &dl)) == -1) {
409			log_debug("%s: could not find openbsd partition", __func__);
410			return (NULL);
411			}
412
413			/* Set the default kernel boot device and image path */
414			strlcpy(vmboot->vbp_device, VM_DEFAULT_DEVICE,
415			sizeof(vmboot->vbp_device));
416			strlcpy(vmboot->vbp_image, VM_DEFAULT_KERNEL,
417			sizeof(vmboot->vbp_image));
418
419			/* Try to parse boot.conf to overwrite the default kernel path */
420			strlcpy(file, VM_BOOT_CONF, sizeof(file));
421			if ((buf = vmboot_loadfile(&vmboot_file, file, &size)) != NULL) {
422			if (vmboot_bootconf(buf, size, vmboot) == -1) {
423			free(buf);
424			return (NULL);
425			}
426			free(buf);
427			}
428
429			/* Parse boot device and find partition in disk label */
430			if ((vmboot->vbp_bootdev =
431			vmboot_bootdevice(vmboot->vbp_device)) == 0)
432			return (NULL);
433			if (B_PARTITION(vmboot->vbp_bootdev) > dl.d_npartitions) {
434			log_debug("%s: invalid boot partition: %s",
435			__func__, vmboot->vbp_device);
436			return (NULL);
437			}
438			vmboot->vbp_partoff =
439			dl.d_partitions[B_PARTITION(vmboot->vbp_bootdev)].p_offset;
440
441			/* Load the kernel */
442			if ((buf = vmboot_loadfile(&vmboot_file,
443			vmboot->vbp_image, &size)) == NULL) {
444			log_debug("%s: failed to open kernel %s:%s", __func__,
445			vmboot->vbp_device, vmboot->vbp_image);
446			return (NULL);
447			}
448			vmboot->vbp_arg = buf;
449
450			if ((fp = fmemopen(buf, size, "r")) == NULL) {
451			log_debug("%s: failed to open memory stream", __func__);
452			free(buf);
453			vmboot->vbp_arg = NULL;
454			} else {
455			log_debug("%s: kernel %s:%s", __func__,
456			vmboot->vbp_device, vmboot->vbp_image);
457			}
458
459			return (fp);
460			}
461
462			void
463			vmboot_close(FILE fp, struct vmboot_params vmboot)
464			{
465			fclose(fp);
466			free(vmboot->vbp_arg);
467			}