Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 512 insertions, 0 deletions

diff --git a/src/boot/efi/cpio.c b/src/boot/efi/cpio.c
new file mode 100644
index 0000000..5b90e17
--- /dev/null
+++ b/src/boot/efi/cpio.c
@@ -0,0 +1,512 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "cpio.h"
+#include "device-path-util.h"
+#include "measure.h"
+#include "proto/device-path.h"
+#include "util.h"
+
+static char *write_cpio_word(char *p, uint32_t v) {
+        static const char hex[] = "0123456789abcdef";
+
+        assert(p);
+
+        /* Writes a CPIO header 8 character hex value */
+
+        for (size_t i = 0; i < 8; i++)
+                p[7-i] = hex[(v >> (4 * i)) & 0xF];
+
+        return p + 8;
+}
+
+static char *mangle_filename(char *p, const char16_t *f) {
+        char* w;
+
+        assert(p);
+        assert(f);
+
+        /* Basically converts UTF-16 to plain ASCII (note that we filtered non-ASCII filenames beforehand, so
+         * this operation is always safe) */
+
+        for (w = p; *f != 0; f++) {
+                assert(*f <= 0x7fu);
+
+                *(w++) = *f;
+        }
+
+        *(w++) = 0;
+        return w;
+}
+
+static char *pad4(char *p, const char *start) {
+        assert(p);
+        assert(start);
+        assert(p >= start);
+
+        /* Appends NUL bytes to 'p', until the address is divisible by 4, when taken relative to 'start' */
+
+        while ((p - start) % 4 != 0)
+                *(p++) = 0;
+
+        return p;
+}
+
+static EFI_STATUS pack_cpio_one(
+                const char16_t *fname,
+                const void *contents,
+                size_t contents_size,
+                const char *target_dir_prefix,
+                uint32_t access_mode,
+                uint32_t *inode_counter,
+                void **cpio_buffer,
+                size_t *cpio_buffer_size) {
+
+        size_t l, target_dir_prefix_size, fname_size, q;
+        char *a;
+
+        assert(fname);
+        assert(contents_size || contents_size == 0);
+        assert(target_dir_prefix);
+        assert(inode_counter);
+        assert(cpio_buffer);
+        assert(cpio_buffer_size);
+
+        /* Serializes one file in the cpio format understood by the kernel initrd logic.
+         *
+         * See: https://docs.kernel.org/driver-api/early-userspace/buffer-format.html */
+
+        if (contents_size > UINT32_MAX) /* cpio cannot deal with > 32-bit file sizes */
+                return EFI_LOAD_ERROR;
+
+        if (*inode_counter == UINT32_MAX) /* more than 2^32-1 inodes? yikes. cpio doesn't support that either */
+                return EFI_OUT_OF_RESOURCES;
+
+        l = 6 + 13*8 + 1 + 1; /* Fixed CPIO header size, slash separator, and NUL byte after the file name */
+
+        target_dir_prefix_size = strlen8(target_dir_prefix);
+        if (l > SIZE_MAX - target_dir_prefix_size)
+                return EFI_OUT_OF_RESOURCES;
+        l += target_dir_prefix_size;
+
+        fname_size = strlen16(fname);
+        if (l > SIZE_MAX - fname_size)
+                return EFI_OUT_OF_RESOURCES;
+        l += fname_size; /* append space for file name */
+
+        /* CPIO can't deal with fnames longer than 2^32-1 */
+        if (target_dir_prefix_size + fname_size >= UINT32_MAX)
+                return EFI_OUT_OF_RESOURCES;
+
+        /* Align the whole header to 4 byte size */
+        l = ALIGN4(l);
+        if (l == SIZE_MAX) /* overflow check */
+                return EFI_OUT_OF_RESOURCES;
+
+        /* Align the contents to 4 byte size */
+        q = ALIGN4(contents_size);
+        if (q == SIZE_MAX) /* overflow check */
+                return EFI_OUT_OF_RESOURCES;
+
+        if (l > SIZE_MAX - q) /* overflow check */
+                return EFI_OUT_OF_RESOURCES;
+        l += q; /* Add contents to header */
+
+        if (*cpio_buffer_size > SIZE_MAX - l) /* overflow check */
+                return EFI_OUT_OF_RESOURCES;
+        a = xrealloc(*cpio_buffer, *cpio_buffer_size, *cpio_buffer_size + l);
+
+        *cpio_buffer = a;
+        a = (char *) *cpio_buffer + *cpio_buffer_size;
+
+        a = mempcpy(a, "070701", 6); /* magic ID */
+
+        a = write_cpio_word(a, (*inode_counter)++);                         /* inode */
+        a = write_cpio_word(a, access_mode | 0100000 /* = S_IFREG */);      /* mode */
+        a = write_cpio_word(a, 0);                                          /* uid */
+        a = write_cpio_word(a, 0);                                          /* gid */
+        a = write_cpio_word(a, 1);                                          /* nlink */
+
+        /* Note: we don't make any attempt to propagate the mtime here, for two reasons: it's a mess given
+         * that FAT usually is assumed to operate with timezoned timestamps, while UNIX does not. More
+         * importantly though: the modifications times would hamper our goals of providing stable
+         * measurements for the same boots. After all we extend the initrds we generate here into TPM2
+         * PCRs. */
+        a = write_cpio_word(a, 0);                                          /* mtime */
+        a = write_cpio_word(a, contents_size);                              /* size */
+        a = write_cpio_word(a, 0);                                          /* major(dev) */
+        a = write_cpio_word(a, 0);                                          /* minor(dev) */
+        a = write_cpio_word(a, 0);                                          /* major(rdev) */
+        a = write_cpio_word(a, 0);                                          /* minor(rdev) */
+        a = write_cpio_word(a, target_dir_prefix_size + fname_size + 2);    /* fname size */
+        a = write_cpio_word(a, 0);                                          /* "crc" */
+
+        a = mempcpy(a, target_dir_prefix, target_dir_prefix_size);
+        *(a++) = '/';
+        a = mangle_filename(a, fname);
+
+        /* Pad to next multiple of 4 */
+        a = pad4(a, *cpio_buffer);
+
+        a = mempcpy(a, contents, contents_size);
+
+        /* Pad to next multiple of 4 */
+        a = pad4(a, *cpio_buffer);
+
+        assert(a == (char *) *cpio_buffer + *cpio_buffer_size + l);
+        *cpio_buffer_size += l;
+
+        return EFI_SUCCESS;
+}
+
+static EFI_STATUS pack_cpio_dir(
+                const char *path,
+                uint32_t access_mode,
+                uint32_t *inode_counter,
+                void **cpio_buffer,
+                size_t *cpio_buffer_size) {
+
+        size_t l, path_size;
+        char *a;
+
+        assert(path);
+        assert(inode_counter);
+        assert(cpio_buffer);
+        assert(cpio_buffer_size);
+
+        /* Serializes one directory inode in cpio format. Note that cpio archives must first create the dirs
+         * they want to place files in. */
+
+        if (*inode_counter == UINT32_MAX)
+                return EFI_OUT_OF_RESOURCES;
+
+        l = 6 + 13*8 + 1; /* Fixed CPIO header size, and NUL byte after the file name */
+
+        path_size = strlen8(path);
+        if (l > SIZE_MAX - path_size)
+                return EFI_OUT_OF_RESOURCES;
+        l += path_size;
+
+        /* Align the whole header to 4 byte size */
+        l = ALIGN4(l);
+        if (l == SIZE_MAX) /* overflow check */
+                return EFI_OUT_OF_RESOURCES;
+
+        if (*cpio_buffer_size > SIZE_MAX - l) /* overflow check */
+                return EFI_OUT_OF_RESOURCES;
+
+        *cpio_buffer = a = xrealloc(*cpio_buffer, *cpio_buffer_size, *cpio_buffer_size + l);
+        a = (char *) *cpio_buffer + *cpio_buffer_size;
+
+        a = mempcpy(a, "070701", 6); /* magic ID */
+
+        a = write_cpio_word(a, (*inode_counter)++);                         /* inode */
+        a = write_cpio_word(a, access_mode | 0040000 /* = S_IFDIR */);      /* mode */
+        a = write_cpio_word(a, 0);                                          /* uid */
+        a = write_cpio_word(a, 0);                                          /* gid */
+        a = write_cpio_word(a, 1);                                          /* nlink */
+        a = write_cpio_word(a, 0);                                          /* mtime */
+        a = write_cpio_word(a, 0);                                          /* size */
+        a = write_cpio_word(a, 0);                                          /* major(dev) */
+        a = write_cpio_word(a, 0);                                          /* minor(dev) */
+        a = write_cpio_word(a, 0);                                          /* major(rdev) */
+        a = write_cpio_word(a, 0);                                          /* minor(rdev) */
+        a = write_cpio_word(a, path_size + 1);                              /* fname size */
+        a = write_cpio_word(a, 0);                                          /* "crc" */
+
+        a = mempcpy(a, path, path_size + 1);
+
+        /* Pad to next multiple of 4 */
+        a = pad4(a, *cpio_buffer);
+
+        assert(a == (char *) *cpio_buffer + *cpio_buffer_size + l);
+
+        *cpio_buffer_size += l;
+        return EFI_SUCCESS;
+}
+
+static EFI_STATUS pack_cpio_prefix(
+                const char *path,
+                uint32_t dir_mode,
+                uint32_t *inode_counter,
+                void **cpio_buffer,
+                size_t *cpio_buffer_size) {
+
+        EFI_STATUS err;
+
+        assert(path);
+        assert(inode_counter);
+        assert(cpio_buffer);
+        assert(cpio_buffer_size);
+
+        /* Serializes directory inodes of all prefix paths of the specified path in cpio format. Note that
+         * (similar to mkdir -p behaviour) all leading paths are created with 0555 access mode, only the
+         * final dir is created with the specified directory access mode. */
+
+        for (const char *p = path;;) {
+                const char *e;
+
+                e = strchr8(p, '/');
+                if (!e)
+                        break;
+
+                if (e > p) {
+                        _cleanup_free_ char *t = NULL;
+
+                        t = xstrndup8(path, e - path);
+                        if (!t)
+                                return EFI_OUT_OF_RESOURCES;
+
+                        err = pack_cpio_dir(t, 0555, inode_counter, cpio_buffer, cpio_buffer_size);
+                        if (err != EFI_SUCCESS)
+                                return err;
+                }
+
+                p = e + 1;
+        }
+
+        return pack_cpio_dir(path, dir_mode, inode_counter, cpio_buffer, cpio_buffer_size);
+}
+
+static EFI_STATUS pack_cpio_trailer(
+                void **cpio_buffer,
+                size_t *cpio_buffer_size) {
+
+        static const char trailer[] =
+                "070701"
+                "00000000"
+                "00000000"
+                "00000000"
+                "00000000"
+                "00000001"
+                "00000000"
+                "00000000"
+                "00000000"
+                "00000000"
+                "00000000"
+                "00000000"
+                "0000000B"
+                "00000000"
+                "TRAILER!!!\0\0\0"; /* There's a fourth NUL byte appended here, because this is a string */
+
+        /* Generates the cpio trailer record that indicates the end of our initrd cpio archive */
+
+        assert(cpio_buffer);
+        assert(cpio_buffer_size);
+        assert_cc(sizeof(trailer) % 4 == 0);
+
+        *cpio_buffer = xrealloc(*cpio_buffer, *cpio_buffer_size, *cpio_buffer_size + sizeof(trailer));
+        memcpy((uint8_t*) *cpio_buffer + *cpio_buffer_size, trailer, sizeof(trailer));
+        *cpio_buffer_size += sizeof(trailer);
+
+        return EFI_SUCCESS;
+}
+
+EFI_STATUS pack_cpio(
+                EFI_LOADED_IMAGE_PROTOCOL *loaded_image,
+                const char16_t *dropin_dir,
+                const char16_t *match_suffix,
+                const char *target_dir_prefix,
+                uint32_t dir_mode,
+                uint32_t access_mode,
+                uint32_t tpm_pcr,
+                const char16_t *tpm_description,
+                void **ret_buffer,
+                size_t *ret_buffer_size,
+                bool *ret_measured) {
+
+        _cleanup_(file_closep) EFI_FILE *root = NULL, *extra_dir = NULL;
+        size_t dirent_size = 0, buffer_size = 0, n_items = 0, n_allocated = 0;
+        _cleanup_free_ char16_t *rel_dropin_dir = NULL;
+        _cleanup_free_ EFI_FILE_INFO *dirent = NULL;
+        _cleanup_(strv_freep) char16_t **items = NULL;
+        _cleanup_free_ void *buffer = NULL;
+        uint32_t inode = 1; /* inode counter, so that each item gets a new inode */
+        EFI_STATUS err;
+
+        assert(loaded_image);
+        assert(target_dir_prefix);
+        assert(ret_buffer);
+        assert(ret_buffer_size);
+
+        if (!loaded_image->DeviceHandle)
+                goto nothing;
+
+        err = open_volume(loaded_image->DeviceHandle, &root);
+        if (err == EFI_UNSUPPORTED)
+                /* Error will be unsupported if the bootloader doesn't implement the file system protocol on
+                 * its file handles. */
+                goto nothing;
+        if (err != EFI_SUCCESS)
+                return log_error_status(err, "Unable to open root directory: %m");
+
+        if (!dropin_dir) {
+                dropin_dir = rel_dropin_dir = get_extra_dir(loaded_image->FilePath);
+                if (!dropin_dir)
+                        goto nothing;
+        }
+
+        err = open_directory(root, dropin_dir, &extra_dir);
+        if (err == EFI_NOT_FOUND)
+                /* No extra subdir, that's totally OK */
+                goto nothing;
+        if (err != EFI_SUCCESS)
+                return log_error_status(err, "Failed to open extra directory of loaded image: %m");
+
+        for (;;) {
+                _cleanup_free_ char16_t *d = NULL;
+
+                err = readdir(extra_dir, &dirent, &dirent_size);
+                if (err != EFI_SUCCESS)
+                        return log_error_status(err, "Failed to read extra directory of loaded image: %m");
+                if (!dirent) /* End of directory */
+                        break;
+
+                if (dirent->FileName[0] == '.')
+                        continue;
+                if (FLAGS_SET(dirent->Attribute, EFI_FILE_DIRECTORY))
+                        continue;
+                if (match_suffix && !endswith_no_case(dirent->FileName, match_suffix))
+                        continue;
+                if (!is_ascii(dirent->FileName))
+                        continue;
+                if (strlen16(dirent->FileName) > 255) /* Max filename size on Linux */
+                        continue;
+
+                d = xstrdup16(dirent->FileName);
+
+                if (n_items+2 > n_allocated) {
+                        /* We allocate 16 entries at a time, as a matter of optimization */
+                        if (n_items > (SIZE_MAX / sizeof(uint16_t)) - 16) /* Overflow check, just in case */
+                                return log_oom();
+
+                        size_t m = n_items + 16;
+                        items = xrealloc(items, n_allocated * sizeof(uint16_t *), m * sizeof(uint16_t *));
+                        n_allocated = m;
+                }
+
+                items[n_items++] = TAKE_PTR(d);
+                items[n_items] = NULL; /* Let's always NUL terminate, to make freeing via strv_free() easy */
+        }
+
+        if (n_items == 0)
+                /* Empty directory */
+                goto nothing;
+
+        /* Now, sort the files we found, to make this uniform and stable (and to ensure the TPM measurements
+         * are not dependent on read order) */
+        sort_pointer_array((void**) items, n_items, (compare_pointer_func_t) strcmp16);
+
+        /* Generate the leading directory inodes right before adding the first files, to the
+         * archive. Otherwise the cpio archive cannot be unpacked, since the leading dirs won't exist. */
+        err = pack_cpio_prefix(target_dir_prefix, dir_mode, &inode, &buffer, &buffer_size);
+        if (err != EFI_SUCCESS)
+                return log_error_status(err, "Failed to pack cpio prefix: %m");
+
+        for (size_t i = 0; i < n_items; i++) {
+                _cleanup_free_ char *content = NULL;
+                size_t contentsize = 0;  /* avoid false maybe-uninitialized warning */
+
+                err = file_read(extra_dir, items[i], 0, 0, &content, &contentsize);
+                if (err != EFI_SUCCESS) {
+                        log_error_status(err, "Failed to read %ls, ignoring: %m", items[i]);
+                        continue;
+                }
+
+                err = pack_cpio_one(
+                                items[i],
+                                content, contentsize,
+                                target_dir_prefix,
+                                access_mode,
+                                &inode,
+                                &buffer, &buffer_size);
+                if (err != EFI_SUCCESS)
+                        return log_error_status(err, "Failed to pack cpio file %ls: %m", dirent->FileName);
+        }
+
+        err = pack_cpio_trailer(&buffer, &buffer_size);
+        if (err != EFI_SUCCESS)
+                return log_error_status(err, "Failed to pack cpio trailer: %m");
+
+        err = tpm_log_event(
+                        tpm_pcr, POINTER_TO_PHYSICAL_ADDRESS(buffer), buffer_size, tpm_description, ret_measured);
+        if (err != EFI_SUCCESS)
+                return log_error_status(
+                                err,
+                                "Unable to add cpio TPM measurement for PCR %u (%ls), ignoring: %m",
+                                tpm_pcr,
+                                tpm_description);
+
+        *ret_buffer = TAKE_PTR(buffer);
+        *ret_buffer_size = buffer_size;
+
+        return EFI_SUCCESS;
+
+nothing:
+        *ret_buffer = NULL;
+        *ret_buffer_size = 0;
+
+        if (ret_measured)
+                *ret_measured = false;
+
+        return EFI_SUCCESS;
+}
+
+EFI_STATUS pack_cpio_literal(
+                const void *data,
+                size_t data_size,
+                const char *target_dir_prefix,
+                const char16_t *target_filename,
+                uint32_t dir_mode,
+                uint32_t access_mode,
+                uint32_t tpm_pcr,
+                const char16_t *tpm_description,
+                void **ret_buffer,
+                size_t *ret_buffer_size,
+                bool *ret_measured) {
+
+        uint32_t inode = 1; /* inode counter, so that each item gets a new inode */
+        _cleanup_free_ void *buffer = NULL;
+        size_t buffer_size = 0;
+        EFI_STATUS err;
+
+        assert(data || data_size == 0);
+        assert(target_dir_prefix);
+        assert(target_filename);
+        assert(ret_buffer);
+        assert(ret_buffer_size);
+
+        /* Generate the leading directory inodes right before adding the first files, to the
+         * archive. Otherwise the cpio archive cannot be unpacked, since the leading dirs won't exist. */
+
+        err = pack_cpio_prefix(target_dir_prefix, dir_mode, &inode, &buffer, &buffer_size);
+        if (err != EFI_SUCCESS)
+                return log_error_status(err, "Failed to pack cpio prefix: %m");
+
+        err = pack_cpio_one(
+                        target_filename,
+                        data, data_size,
+                        target_dir_prefix,
+                        access_mode,
+                        &inode,
+                        &buffer, &buffer_size);
+        if (err != EFI_SUCCESS)
+                return log_error_status(err, "Failed to pack cpio file %ls: %m", target_filename);
+
+        err = pack_cpio_trailer(&buffer, &buffer_size);
+        if (err != EFI_SUCCESS)
+                return log_error_status(err, "Failed to pack cpio trailer: %m");
+
+        err = tpm_log_event(
+                        tpm_pcr, POINTER_TO_PHYSICAL_ADDRESS(buffer), buffer_size, tpm_description, ret_measured);
+        if (err != EFI_SUCCESS)
+                return log_error_status(
+                                err,
+                                "Unable to add cpio TPM measurement for PCR %u (%ls), ignoring: %m",
+                                tpm_pcr,
+                                tpm_description);
+
+        *ret_buffer = TAKE_PTR(buffer);
+        *ret_buffer_size = buffer_size;
+
+        return EFI_SUCCESS;
+}