| // Copyright 2016 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "bootfs.h" |
| #include "util.h" |
| |
| #pragma GCC visibility push(hidden) |
| |
| #include <zircon/boot/bootdata.h> |
| #include <zircon/syscalls.h> |
| #include <string.h> |
| |
| #pragma GCC visibility pop |
| |
| void bootfs_mount(zx_handle_t vmar, zx_handle_t log, zx_handle_t vmo, struct bootfs *fs) { |
| uint64_t size; |
| zx_status_t status = zx_vmo_get_size(vmo, &size); |
| check(log, status, "zx_vmo_get_size failed on bootfs vmo\n"); |
| uintptr_t addr = 0; |
| status = zx_vmar_map(vmar, 0, vmo, 0, size, ZX_VM_FLAG_PERM_READ, &addr); |
| check(log, status, "zx_vmar_map failed on bootfs vmo\n"); |
| fs->contents = (const void*)addr; |
| fs->len = size; |
| status = zx_handle_duplicate( |
| vmo, |
| ZX_RIGHT_READ | ZX_RIGHT_EXECUTE | ZX_RIGHT_MAP | |
| ZX_RIGHT_TRANSFER | ZX_RIGHT_DUPLICATE | ZX_RIGHT_GET_PROPERTY, |
| &fs->vmo); |
| check(log, status, "zx_handle_duplicate failed on bootfs VMO handle\n"); |
| } |
| |
| void bootfs_unmount(zx_handle_t vmar, zx_handle_t log, struct bootfs *fs) { |
| zx_status_t status = zx_vmar_unmap(vmar, (uintptr_t)fs->contents, fs->len); |
| check(log, status, "zx_vmar_unmap failed\n"); |
| status = zx_handle_close(fs->vmo); |
| check(log, status, "zx_handle_close failed\n"); |
| } |
| |
| static const bootfs_entry_t* bootfs_search(zx_handle_t log, |
| struct bootfs *fs, |
| const char* filename) { |
| const void* p = fs->contents; |
| |
| if (fs->len < sizeof(bootfs_header_t)) |
| fail(log, "bootfs is too small"); |
| |
| const bootfs_header_t* hdr = p; |
| if ((hdr->magic != BOOTFS_MAGIC) || (hdr->dirsize > fs->len)) |
| fail(log, "bootfs bad magic or size"); |
| |
| size_t filename_len = strlen(filename) + 1; |
| |
| p += sizeof(bootfs_header_t); |
| size_t avail = hdr->dirsize; |
| |
| while (avail > sizeof(bootfs_entry_t)) { |
| const bootfs_entry_t* e = p; |
| |
| size_t sz = BOOTFS_RECSIZE(e); |
| if ((e->name_len < 1) || (sz > avail)) |
| fail(log, "bootfs has bogus namelen in header"); |
| |
| if (e->name_len == filename_len) { |
| if (!memcmp(e->name, filename, filename_len)) |
| return e; |
| } |
| |
| p += sz; |
| avail -= sz; |
| } |
| |
| return NULL; |
| } |
| |
| zx_handle_t bootfs_open(zx_handle_t log, const char* purpose, |
| struct bootfs *fs, const char* filename) { |
| printl(log, "searching bootfs for '%s'", filename); |
| |
| const bootfs_entry_t* e = bootfs_search(log, fs, filename); |
| if (e == NULL) { |
| printl(log, "file not found"); |
| return ZX_HANDLE_INVALID; |
| } |
| if (e->data_off > fs->len) |
| fail(log, "bogus offset in bootfs header!"); |
| if (fs->len - e->data_off < e->data_len) |
| fail(log, "bogus size in bootfs header!"); |
| |
| // Clone a private copy of the file's subset of the bootfs VMO. |
| // TODO(mcgrathr): Create a plain read-only clone when the feature |
| // is implemented in the VM. |
| zx_handle_t vmo; |
| zx_status_t status = zx_vmo_clone(fs->vmo, ZX_VMO_CLONE_COPY_ON_WRITE, |
| e->data_off, e->data_len, &vmo); |
| if (status != ZX_OK) |
| fail(log, "zx_vmo_clone failed: %d", status); |
| |
| zx_object_set_property(vmo, ZX_PROP_NAME, filename, strlen(filename)); |
| |
| // Drop unnecessary ZX_RIGHT_WRITE rights. |
| // TODO(mcgrathr): Should be superfluous with read-only zx_vmo_clone. |
| status = zx_handle_replace( |
| vmo, |
| ZX_RIGHT_READ | ZX_RIGHT_EXECUTE | ZX_RIGHT_MAP | |
| ZX_RIGHT_TRANSFER | ZX_RIGHT_DUPLICATE | ZX_RIGHT_GET_PROPERTY, |
| &vmo); |
| if (status != ZX_OK) |
| fail(log, "zx_handle_replace failed: %d", status); |
| |
| return vmo; |
| } |