diff options
Diffstat (limited to 'usr.sbin/vmd/vmboot.c')
| -rw-r--r-- | usr.sbin/vmd/vmboot.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/usr.sbin/vmd/vmboot.c b/usr.sbin/vmd/vmboot.c new file mode 100644 index 00000000000..93b75620f5b --- /dev/null +++ b/usr.sbin/vmd/vmboot.c @@ -0,0 +1,237 @@ +/* $OpenBSD: vmboot.c,v 1.1 2016/11/24 07:58:55 reyk 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> +#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 <fcntl.h> +#include <err.h> + +#include "vmd.h" +#include "vmboot.h" + +int vmboot_strategy(void *, int, daddr32_t, size_t, void *, size_t *); +off_t vmboot_findopenbsd(struct open_file *, off_t); +void *vmboot_loadfile(struct open_file *, char *, size_t *); + +/* + * 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 +}; + +struct vmboot { + int fd; + off_t partoff; +}; + +int +vmboot_strategy(void *devdata, int rw, + daddr32_t blk, size_t size, void *buf, size_t *rsize) +{ + struct vmboot *vmboot = devdata; + ssize_t rlen; + + if (vmboot->fd == -1) + return (EIO); + + switch (rw) { + case F_READ: + rlen = pread(vmboot->fd, buf, size, + (blk + vmboot->partoff) * DEV_BSIZE); + if (rlen == -1) + return (errno); + *rsize = (size_t)rlen; + break; + case F_WRITE: + rlen = pwrite(vmboot->fd, buf, size, + (blk + vmboot->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 dos_mbr mbr; + struct dos_partition *dp; + off_t mbr_eoff = DOSBBSECTOR, nextebr; + int ret, i; + static int maxebr = DOS_MAXEBR; + size_t rsize; + + 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; + 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)); + } + + return (-1); +} + +void * +vmboot_loadfile(struct open_file *f, char *file, size_t *size) +{ + char *buf = NULL; + struct stat st; + size_t rsize; + int ret; + + *size = 0; + + if ((ret = ufs_open(file, f)) != 0) { + log_debug("%s: failed to open hd0a:%s", __func__, file); + goto done; + } + + if ((ret = ufs_stat(f, &st)) != 0) { + log_debug("%s: failed to stat hd0a:%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 hd0a:%s", __func__, file); + goto done; + } + + *size = st.st_size; + done: + ufs_close(f); + return (buf); +} + +FILE * +vmboot_open(int kernel_fd, int disk_fd, void **boot) +{ + char file[PATH_MAX]; + char *buf = NULL; + struct vmboot vmboot; + size_t size; + FILE *fp = NULL; + + *boot = NULL; + + /* First open kernel directly if specified by fd */ + if (kernel_fd != -1) + return (fdopen(kernel_fd, "r")); + + if (disk_fd == -1) + return (NULL); + + memset(&vmboot, 0, sizeof(vmboot)); + vmboot.fd = disk_fd; + vmboot_file.f_devdata = &vmboot; + + /* XXX try and parse hd0a:/etc/boot.conf */ + strlcpy(file, VM_DEFAULT_KERNEL, sizeof(file)); + + if ((vmboot.partoff = vmboot_findopenbsd(&vmboot_file, 0)) == -1) { + log_debug("%s: could not find openbsd partition", __func__); + return (NULL); + } + + if ((buf = vmboot_loadfile(&vmboot_file, file, &size)) == NULL) + return (NULL); + *boot = buf; + + if ((fp = fmemopen(buf, size, "r")) == NULL) { + log_debug("%s: failed to open memory stream", __func__); + free(buf); + *boot = NULL; + } + + return (fp); +} + +void +vmboot_close(FILE *fp, void *boot) +{ + fclose(fp); + free(boot); +} |