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Split up fwup_set_up_update() into bit-sized pieces
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Also, add a lot of descriptions and some gtk-doc markup to each new function.
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@hughsie @vathpela
hughsie authored and vathpela committed Oct 9, 2015
1 parent dab08b5 commit e3b443d
Showing 1 changed file with 212 additions and 113 deletions.
325 changes: 212 additions & 113 deletions linux/libfwup.c
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Original file line number Diff line number Diff line change
Expand Up @@ -732,94 +732,226 @@ set_up_boot_next(void)
return ret;
}

int
fwup_set_up_update(fwup_resource *re, uint64_t hw_inst, int infd)
/**
* fwup_get_existing_media_path:
* @info: the #update_info
*
* Return a media path to use for the update which has already been used by
* this specific GUID.
*
* Returns: a media path, or %NULL if no such path exists.
*/
static char *
fwup_get_existing_media_path (update_info *info)
{
int rc;
char *relpath = NULL;
char *fullpath = NULL;
int fd = -1;
ssize_t sz;
off_t offset;
update_info *info = NULL;
uint8_t *dp_buf = NULL;
uint16_t *ucs2file = NULL;
uint16_t ucs2len = 0;

offset = lseek(infd, 0, SEEK_CUR);
/* never set */
if (!info->dp_ptr)
goto out;
if (efidp_end_entire(info->dp_ptr))
goto out;

rc = get_info(&re->esre.guid, 0, &info);
/* find UCS2 string */
const_efidp idp = (const_efidp)info->dp_ptr;
while (1) {
if (efidp_type(idp) == EFIDP_END_TYPE &&
efidp_subtype(idp) == EFIDP_END_ENTIRE)
break;
if (efidp_type(idp) != EFIDP_MEDIA_TYPE ||
efidp_subtype(idp) !=EFIDP_MEDIA_FILE) {
rc = efidp_next_node(idp, &idp);
if (rc < 0)
break;
continue;
}
ucs2file = (uint16_t *)((uint8_t *)idp + 4);
ucs2len = efidp_node_size(idp) - 4;
break;
}

/* nothing found */
if (!ucs2file || ucs2len <= 0)
goto out;

/* convert to something sane */
relpath = ucs2_to_utf8(ucs2file, ucs2len / sizeof (uint16_t));
if (!relpath)
goto out;

/* convert '\' to '/' */
untilt_slashes(relpath);

/* build a complete path */
rc = asprintf(&fullpath, "/boot/efi/%s", relpath);
if (rc < 0)
goto out;

out:
free(relpath);
return fullpath;
}

/**
* fwup_get_existing_media_path:
* @info: the #update_info
* @path: (out): the path
*
* Opens a suitable file descriptor and sets a media path to use for the update.
*
* Returns: a FD, or -1 for error
*/
static int
get_fd_and_media_path (update_info *info, char **path)
{
char *fullpath = NULL;
int fd = -1;
int rc;

/* look for an existing variable that we've used before for this
* update GUID, and reuse the filename so we don't wind up
* littering the filesystem with old updates */
fullpath = fwup_get_existing_media_path (info);
if (fullpath) {
fd = open(fullpath, O_CREAT|O_TRUNC|O_CLOEXEC|O_RDWR);
if (fd < 0)
warn("open of %s failed", fullpath);
goto out;
}

/* fall back to creating a new file from scratch */
rc = asprintf(&fullpath,
"/boot/efi/EFI/%s/fw/fwupdate-XXXXXX.cap",
FWUP_EFI_DIR_NAME);
if (rc < 0) {
warn("get_info failed.\n");
goto err;
warn("asprintf failed");
goto out;
}
fd = mkostemps(fullpath, 4, O_CREAT|O_TRUNC|O_CLOEXEC|O_RDWR);
if (fd < 0) {
warn("mkostemps(%s) failed", fullpath);
goto out;
}

if (info->dp_ptr && !efidp_end_entire(info->dp_ptr)) {
const_efidp idp = (const_efidp)info->dp_ptr;
while (1) {
if (efidp_type(idp) == EFIDP_END_TYPE &&
efidp_subtype(idp) == EFIDP_END_ENTIRE)
break;
if (efidp_type(idp) != EFIDP_MEDIA_TYPE ||
efidp_subtype(idp) !=EFIDP_MEDIA_FILE) {
rc = efidp_next_node(idp, &idp);
if (rc < 0)
break;
continue;
}
ucs2file = (uint16_t *)((uint8_t *)idp + 4);
ucs2len = efidp_node_size(idp) - 4;
break;
}
/* success, so take ownership of the string */
if (path) {
*path = fullpath;
fullpath = NULL;
}
out:
free(fullpath);
return fd;
}

/**
* set_efidp_header
* @info: the #update_info
* @path: the path
*
* Update the device path.
*
* Returns: a FD, or -1 for error
*/
static int
set_efidp_header (update_info *info, const char *path)
{
int rc = 0;
ssize_t req;
ssize_t sz;
uint8_t *dp_buf = NULL;

/* get the size of the path first */
req = efi_generate_file_device_path(NULL, 0, path,
EFIBOOT_OPTIONS_IGNORE_FS_ERROR|
EFIBOOT_OPTIONS_IGNORE_PMBR_ERR);
if (req < 0) {
rc = -1;
goto out;
}
if (req <= 4) { /* if we just have an end device path,
it's not going to work. */
rc = EINVAL;
goto out;
}

if (!ucs2file || ucs2len <= 0)
goto new;
dp_buf = calloc(1, req);
if (!dp_buf) {
rc = -1;
goto out;
}

char *relpath = ucs2_to_utf8(ucs2file, ucs2len
/ sizeof (uint16_t));
if (!relpath)
goto new;
relpath = onstack(relpath, ucs2len / sizeof (uint16_t) + 1);
/* actually get the path this time */
efidp_header *dp = (efidp_header *)dp_buf;
sz = efi_generate_file_device_path(dp_buf, req, path,
EFIBOOT_OPTIONS_IGNORE_FS_ERROR|
EFIBOOT_OPTIONS_IGNORE_PMBR_ERR);
if (sz < 0) {
rc = -1;
goto out;
}

untilt_slashes(relpath);
/* @info owns this now */
if (info->dp_ptr)
free(info->dp_ptr);
info->dp_ptr = dp;
dp_buf = NULL;
out:
free(dp_buf);
return rc;
}

rc = asprintf(&fullpath, "/boot/efi/%s", relpath);
if (rc < 0) {
free(relpath);
goto new;
}
/**
* fwup_set_up_update
* @re: A %fwup_resource.
* @hw_inst: A hardware instance -- currently unused.
* @infd: file descriptor to the .cap binary
*
* Sets up a UEFI update using a file descriptor.
*
* Returns: -1 on error, @fwup_error being set
*
* Since: 0.3
*/
int
fwup_set_up_update(fwup_resource *re, uint64_t hw_inst, int infd)
{
char *path = NULL;
int fd = -1;
int rc;
off_t offset;
update_info *info = NULL;

rc = open(fullpath, O_CREAT|O_TRUNC|O_CLOEXEC|O_RDWR);
if (rc < 0) {
free(relpath);
goto new;
}
fd = rc;
/* check parameters */
if (infd < 0) {
warn("fd invalid.\n");
rc = -1;
} else {
new:
rc = asprintf(&fullpath,
"/boot/efi/EFI/%s/fw/fwupdate-XXXXXX.cap",
FWUP_EFI_DIR_NAME);
if (rc < 0) {
warn("asprintf failed");
goto err;
}
goto out;
}

rc = mkostemps(fullpath, 4, O_CREAT|O_TRUNC|O_CLOEXEC|O_RDWR);
if (rc < 0) {
int saved_errno = errno;
warn("mkostemps(%s) failed", fullpath);
free(fullpath);
errno = saved_errno;
goto err;
}
fd = rc;
offset = lseek(infd, 0, SEEK_CUR);

/* get device */
rc = get_info(&re->esre.guid, 0, &info);
if (rc < 0) {
warn("get_info failed.\n");
goto out;
}

/* get destination */
fd = get_fd_and_media_path(info, &path);
if (fd < 0) {
rc = -1;
goto out;
}
fullpath = onstack(fullpath, strlen(fullpath)+1);

/* copy the input file to the new home */
while (1) {
char buf[4096];
ssize_t sz;

sz = read(infd, &buf, 4096);
if (sz > 0) {
Expand All @@ -833,7 +965,7 @@ fwup_set_up_update(fwup_resource *re, uint64_t hw_inst, int infd)
if (wsz < 0) {
rc = wsz;
warn("write failed");
goto err;
goto out;
}
off += wsz;
}
Expand All @@ -844,69 +976,36 @@ fwup_set_up_update(fwup_resource *re, uint64_t hw_inst, int infd)
continue;
if (sz < 0) {
warn("read failed");
goto err;
rc = -1;
goto out;
}
if (sz == 0)
break;
}
close(fd);
fd = -1;

if (!info->dp_ptr || efidp_end_entire(info->dp_ptr)) {
ssize_t req;
req = efi_generate_file_device_path(NULL, 0, fullpath,
EFIBOOT_OPTIONS_IGNORE_FS_ERROR|
EFIBOOT_OPTIONS_IGNORE_PMBR_ERR);
if (req < 0)
goto err;
if (req <= 4) { /* if we just have an end device path,
it's not going to work. */
errno = EINVAL;
goto err;
}

dp_buf = calloc(1, req);
if (!dp_buf)
goto err;

efidp_header *dp = (efidp_header *)dp_buf;
sz = efi_generate_file_device_path(dp_buf, req, fullpath,
EFIBOOT_OPTIONS_IGNORE_FS_ERROR|
EFIBOOT_OPTIONS_IGNORE_PMBR_ERR);
if (sz < 0)
goto err;

if (info->dp_ptr)
free(info->dp_ptr);
info->dp_ptr = dp;
}
/* set efidp header */
rc = set_efidp_header(info, path);
if (rc < 0)
goto out;

/* save this to the hardware */
info->status = FWUPDATE_ATTEMPT_UPDATE;

rc = put_info(info);
if (rc < 0) {
warn("put_info failed.\n");
goto err;
goto out;
}

free_info(info);

/* update the firmware before the bootloader runs */
rc = set_up_boot_next();
if (rc < 0) {
fwup_error = errno;
return rc;
}
return 1;
err:
if (rc < 0)
goto out;
out:
fwup_error = errno;
lseek(infd, offset, SEEK_SET);
if (dp_buf)
free(dp_buf);
if (info)
free_info(info);
free_info(info);
if (fd > 0)
close(fd);

return rc;
}

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