/* $OpenBSD: disk.c,v 1.3 2023/10/20 18:53:12 kettenis Exp $ */ /* * Copyright (c) 2019 Visa Hankala * * Permission to use, copy, modify, and/or 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "cmd.h" int disk_proberoot(const char *); int mounted = 0; int rdroot = -1; /* fd that points to the root of the ramdisk */ void disk_init(void) { char rootdevs[1024]; char *devname, *disknames, *ptr; size_t size; int mib[2]; rdroot = open("/", O_RDONLY); if (rdroot == -1) err(1, "failed to open root directory fd"); if (strlen(cmd.bootdev) != 0) return; mib[0] = CTL_HW; mib[1] = HW_DISKNAMES; size = 0; if (sysctl(mib, 2, NULL, &size, NULL, 0) == -1) { fprintf(stderr, "%s: cannot get hw.disknames: %s\n", __func__, strerror(errno)); return; } disknames = malloc(size); if (disknames == NULL) { fprintf(stderr, "%s: out of memory\n", __func__); return; } if (sysctl(mib, 2, disknames, &size, NULL, 0) == -1) { fprintf(stderr, "%s: cannot get hw.disknames: %s\n", __func__, strerror(errno)); free(disknames); return; } printf("probing disks\n"); rootdevs[0] = '\0'; ptr = disknames; while ((devname = strsep(&ptr, ",")) != NULL) { char *duid; duid = strchr(devname, ':'); if (duid == NULL) continue; *duid++ = '\0'; /* Disk without a duid cannot be a root device. */ if (strlen(duid) == 0) continue; if (disk_proberoot(devname)) { if (strlen(cmd.bootdev) == 0) { snprintf(cmd.bootdev, sizeof(cmd.bootdev), "%sa", devname); } (void)strlcat(rootdevs, " ", sizeof(rootdevs)); (void)strlcat(rootdevs, devname, sizeof(rootdevs)); } } if (strlen(rootdevs) != 0) printf("available root devices:%s\n", rootdevs); else printf("no root devices found\n"); } int disk_proberoot(const char *devname) { static const char *const names[] = { "bin", "dev", "etc", "home", "mnt", "root", "sbin", "tmp", "usr", "var", NULL }; struct ufs_args ffs_args; struct stat st; char path[32]; int i, is_root = 1; snprintf(path, sizeof(path), "/dev/%sa", devname); memset(&ffs_args, 0, sizeof(ffs_args)); ffs_args.fspec = path; if (mount(MOUNT_FFS, "/mnt", MNT_RDONLY, &ffs_args) == -1) return 0; for (i = 0; names[i] != NULL; i++) { snprintf(path, sizeof(path), "/mnt/%s", names[i]); if (stat(path, &st) == -1 || !S_ISDIR(st.st_mode)) { is_root = 0; break; } } (void)unmount("/mnt", 0); return is_root; } const char * disk_open(const char *path) { struct ufs_args ffs_args; struct disklabel label; char devname[32]; char *devpath; const char *ptr; int fd; if (mounted) { fprintf(stderr, "%s: cannot nest\n", __func__); return NULL; } ptr = strchr(path, ':'); if (ptr != NULL) { snprintf(devname, sizeof(devname), "%.*s", (int)(ptr - path), path); ptr++; /* skip ':' */ } else { strlcpy(devname, cmd.bootdev, sizeof(devname)); ptr = path; } if (strlen(devname) == 0) { fprintf(stderr, "no device specified\n"); return NULL; } cmd.hasduid = 0; fd = opendev(devname, O_RDONLY, OPENDEV_BLCK, &devpath); if (fd != -1) { if (ioctl(fd, DIOCGDINFO, &label) != -1) { memcpy(cmd.bootduid, label.d_uid, 8); cmd.hasduid = 1; } close(fd); } else { fprintf(stderr, "failed to open device %s: %s\n", devname, strerror(errno)); return NULL; } memset(&ffs_args, 0, sizeof(ffs_args)); ffs_args.fspec = devpath; if (mount(MOUNT_FFS, "/mnt", MNT_NOATIME, &ffs_args) == -1) { if (mount(MOUNT_FFS, "/mnt", MNT_RDONLY, &ffs_args) == -1) { fprintf(stderr, "failed to mount %s: %s\n", devpath, strerror(errno)); return NULL; } fprintf(stderr, "%s: mounted read-only\n", devpath); } if (chroot("/mnt") == -1) { fprintf(stderr, "failed to chroot: %s\n", strerror(errno)); (void)unmount("/mnt", 0); return NULL; } mounted = 1; return ptr; } void disk_close(void) { if (mounted) { (void)fchdir(rdroot); (void)chroot("."); mounted = 0; (void)unmount("/mnt", 0); } }