[PATCH v2] discover/grub: Add blscfg command support to parse BootLoaderSpec files
Brett Grandbois
brett.grandbois at opengear.com
Thu Mar 15 10:11:01 AEDT 2018
Hi Javier,
From a functional perspective it looks fine to me. We use compiled-in
initramfs and cmdline args so removing the strict checks there had it
work fine once I got our build system spitting out BLS config files.
The only suggestions I have are again related to specification
adherence. As far as I can tell from
https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/ the only
mandatory key is 'linux', everything else is optional. You've accounted
for that in v2 by only requiring the image to be populated which is
filled by the linux key, but you're still relying on the 'title' key to
be present to fill out the id even though title is stated to be
optional. So my suggestions would be:
* in bls_process_pair() move the population of option->id to the
'linux' key path, that way you're guaranteed to have an id assuming
the conf file is conformant
* add new fields in bls_state for title, version, and machine-id and
strdup them if they are found in the conf file
* in bls_finish() have a bit of logic to fill out the option->name
based on what optional fields are available. For example if
state->title is populated then have that directly fill option->name
but if state-title is empty because the key wasn't there then work
your way down to some name based on some mashup of the available
version and/or machine id. The fallback case could be id I guess.
* We don't use devicetrees so it doesn't affect us, but if you're
going this far you might as well add in support for the 'devicetree'
key for everyone who does need it.
Otherwise it looks good to me and thanks for submitting the implementation.
Brett
On 14/03/18 19:28, Javier Martinez Canillas wrote:
> The BootLoaderSpec (BLS) defines a file format for boot configurations,
> so bootloaders can parse these files and create their boot menu entries
> by using the information provided by them [0].
>
> This allow to configure the boot items as drop-in files in a directory
> instead of having to parse and modify a bootloader configuration file.
>
> The GRUB 2 bootloader provides a blscfg command that parses these files
> and creates menu entries using this information. Add support for it.
>
> [0]: https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/
>
> Signed-off-by: Javier Martinez Canillas <javierm at redhat.com>
>
> ---
>
> Hello,
>
> From Fedora 28 there will be an option to use BootLoaderSpec snippets to
> update GRUB's boot menu entries. So I'm posting this patch to allow this
> to also work on ppc64 machines using petitboot, instead of grub-ieee1275.
>
> This can be tested by creating a BLS config under /boot/loader/entries,
> for example following /boot/loader/entries/4.15.6-300.fc27.x86_64.conf:
>
> title Fedora (4.15.6-300.fc27.x86_64) 27 (Twenty Seven)
> linux /vmlinuz-4.15.6-300.fc27.x86_64
> initrd /initramfs-4.15.6-300.fc27.x86_64.img
> options root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root rd.luks.uuid=luks-0b078909-4a1c-4a57-91b8-b9f724e86a1a rd.lvm.lv=fedora/swap rhgb quiet LANG=en_US.UTF-8
> id fedora-20180214051518-4.15.6-300.fc27.x86_64.x86_64
> grub_users $grub_users
> grub_arg --unrestricted
> grub_class kernel
>
> And a grub.cfg that calls the blscfg command, it could just be the following:
>
> blscfg
>
> Best regards,
> Javier
>
> Changes in v2:
> - Allow optional fields, only require the linux field to be present.
> - Remove unused identifier from bls_filter() struct dirent * param.
> - Remove redundant check in builtin_blscfg() while loop.
>
> discover/grub2/Makefile.am | 1 +
> discover/grub2/blscfg.c | 185 +++++++++++++++++++++++++++
> discover/grub2/builtins.c | 9 +-
> discover/parser.c | 16 +++
> discover/parser.h | 8 ++
> test/parser/Makefile.am | 3 +
> test/parser/test-grub2-blscfg-multiple-bls.c | 44 +++++++
> test/parser/test-grub2-blscfg-opts-config.c | 29 +++++
> test/parser/test-grub2-blscfg-opts-grubenv.c | 34 +++++
> test/parser/utils.c | 59 +++++++++
> 10 files changed, 387 insertions(+), 1 deletion(-)
> create mode 100644 discover/grub2/blscfg.c
> create mode 100644 test/parser/test-grub2-blscfg-multiple-bls.c
> create mode 100644 test/parser/test-grub2-blscfg-opts-config.c
> create mode 100644 test/parser/test-grub2-blscfg-opts-grubenv.c
>
> diff --git a/discover/grub2/Makefile.am b/discover/grub2/Makefile.am
> index 130ede88e18c..b240106d7a54 100644
> --- a/discover/grub2/Makefile.am
> +++ b/discover/grub2/Makefile.am
> @@ -15,6 +15,7 @@
> noinst_PROGRAMS += discover/grub2/grub2-parser.ro
>
> discover_grub2_grub2_parser_ro_SOURCES = \
> + discover/grub2/blscfg.c \
> discover/grub2/builtins.c \
> discover/grub2/env.c \
> discover/grub2/grub2.h \
> diff --git a/discover/grub2/blscfg.c b/discover/grub2/blscfg.c
> new file mode 100644
> index 000000000000..4ab863e6b38f
> --- /dev/null
> +++ b/discover/grub2/blscfg.c
> @@ -0,0 +1,185 @@
> +
> +#define _GNU_SOURCE
> +
> +#include <assert.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <dirent.h>
> +
> +#include <log/log.h>
> +#include <file/file.h>
> +#include <talloc/talloc.h>
> +#include <i18n/i18n.h>
> +
> +#include "grub2.h"
> +#include "discover/parser-conf.h"
> +#include "discover/parser.h"
> +
> +#define BLS_DIR "/loader/entries"
> +
> +struct bls_state {
> + struct discover_boot_option *opt;
> + struct grub2_script *script;
> + const char *filename;
> + const char *initrd;
> + const char *image;
> +};
> +
> +static void bls_process_pair(struct conf_context *conf, const char *name,
> + char *value)
> +{
> + struct discover_device *dev = conf->dc->device;
> + struct bls_state *state = conf->parser_info;
> + struct discover_boot_option *opt = state->opt;
> + struct boot_option *option = opt->option;
> + const char *boot_args;
> +
> + if (streq(name, "title")) {
> + option->id = talloc_asprintf(option, "%s#%s", dev->device->id,
> + value);
> + option->name = talloc_strdup(option, value);
> + return;
> + }
> +
> + if (streq(name, "linux")) {
> + state->image = talloc_strdup(state, value);
> + return;
> + }
> +
> + if (streq(name, "initrd")) {
> + state->initrd = talloc_strdup(state, value);
> + return;
> + }
> +
> + if (streq(name, "options")) {
> + if (value[0] == '$') {
> + boot_args = script_env_get(state->script, value + 1);
> + if (!boot_args)
> + return;
> +
> + option->boot_args = talloc_strdup(opt, boot_args);
> + } else {
> + option->boot_args = talloc_strdup(opt, value);
> + }
> + return;
> + }
> +}
> +
> +static void bls_finish(struct conf_context *conf)
> +{
> + struct bls_state *state = conf->parser_info;
> + struct discover_context *dc = conf->dc;
> + struct discover_boot_option *opt = state->opt;
> + const char *root;
> +
> + if (!state->image) {
> + device_handler_status_dev_info(dc->handler, dc->device,
> + _("linux field not found in %s"),
> + state->filename);
> + return;
> + }
> +
> + root = script_env_get(state->script, "root");
> +
> + opt->boot_image = create_grub2_resource(opt, conf->dc->device,
> + root, state->image);
> +
> + if (opt->initrd)
> + opt->initrd = create_grub2_resource(opt, conf->dc->device,
> + root, state->initrd);
> + discover_context_add_boot_option(dc, opt);
> +
> + device_handler_status_dev_info(dc->handler, dc->device,
> + _("Created menu entry from BLS file %s"),
> + state->filename);
> +}
> +
> +static int bls_filter(const struct dirent *ent)
> +{
> + int offset = strlen(ent->d_name) - strlen(".conf");
> +
> + if (offset < 0)
> + return 0;
> +
> + return strncmp(ent->d_name + offset, ".conf", strlen(".conf")) == 0;
> +}
> +
> +static int bls_sort(const struct dirent **ent_a, const struct dirent **ent_b)
> +{
> + return strverscmp((*ent_b)->d_name, (*ent_a)->d_name);
> +}
> +
> +int builtin_blscfg(struct grub2_script *script,
> + void *data __attribute__((unused)),
> + int argc __attribute__((unused)),
> + char *argv[] __attribute__((unused)));
> +
> +int builtin_blscfg(struct grub2_script *script,
> + void *data __attribute__((unused)),
> + int argc __attribute__((unused)),
> + char *argv[] __attribute__((unused)))
> +{
> + struct discover_context *dc = script->ctx;
> + struct dirent **bls_entries;
> + struct conf_context *conf;
> + struct bls_state *state;
> + char *buf, *filename;
> + int n, len, rc = -1;
> +
> + conf = talloc_zero(dc, struct conf_context);
> + if (!conf)
> + return rc;
> +
> + conf->dc = dc;
> + conf->get_pair = conf_get_pair_space;
> + conf->process_pair = bls_process_pair;
> + conf->finish = bls_finish;
> +
> + n = parser_scandir(dc, BLS_DIR, &bls_entries, bls_filter, bls_sort);
> + if (n <= 0)
> + goto err;
> +
> + while (n--) {
> + filename = talloc_asprintf(dc, BLS_DIR"/%s",
> + bls_entries[n]->d_name);
> + if (!filename)
> + break;
> +
> + state = talloc_zero(conf, struct bls_state);
> + if (!state)
> + break;
> +
> + state->opt = discover_boot_option_create(dc, dc->device);
> + if (!state->opt)
> + break;
> +
> + state->script = script;
> + state->filename = filename;
> + conf->parser_info = state;
> +
> + rc = parser_request_file(dc, dc->device, filename, &buf, &len);
> + if (rc)
> + break;
> +
> + conf_parse_buf(conf, buf, len);
> +
> + talloc_free(buf);
> + talloc_free(state);
> + talloc_free(filename);
> + free(bls_entries[n]);
> + }
> +
> + if (n > 0) {
> + device_handler_status_dev_info(dc->handler, dc->device,
> + _("Scanning %s failed"),
> + BLS_DIR);
> + do {
> + free(bls_entries[n]);
> + } while (n-- > 0);
> + }
> +
> + free(bls_entries);
> +err:
> + talloc_free(conf);
> + return rc;
> +}
> diff --git a/discover/grub2/builtins.c b/discover/grub2/builtins.c
> index c16b6390225a..e42821a64a9a 100644
> --- a/discover/grub2/builtins.c
> +++ b/discover/grub2/builtins.c
> @@ -330,7 +330,10 @@ extern int builtin_load_env(struct grub2_script *script,
> int builtin_save_env(struct grub2_script *script,
> void *data __attribute__((unused)),
> int argc, char *argv[]);
> -
> +int builtin_blscfg(struct grub2_script *script,
> + void *data __attribute__((unused)),
> + int argc __attribute__((unused)),
> + char *argv[] __attribute__((unused)));
>
> static struct {
> const char *name;
> @@ -380,6 +383,10 @@ static struct {
> .name = "save_env",
> .fn = builtin_save_env,
> },
> + {
> + .name = "blscfg",
> + .fn = builtin_blscfg,
> + }
> };
>
> static const char *nops[] = {
> diff --git a/discover/parser.c b/discover/parser.c
> index 5598f963e236..9fe1925d94c4 100644
> --- a/discover/parser.c
> +++ b/discover/parser.c
> @@ -128,6 +128,22 @@ out:
> return -1;
> }
>
> +int parser_scandir(struct discover_context *ctx, const char *dirname,
> + struct dirent ***files, int (*filter)(const struct dirent *),
> + int (*comp)(const struct dirent **, const struct dirent **))
> +{
> + char *path;
> + int n;
> +
> + path = talloc_asprintf(ctx, "%s%s", ctx->device->mount_path, dirname);
> + if (!path)
> + return -1;
> +
> + n = scandir(path, files, filter, comp);
> + talloc_free(path);
> + return n;
> +}
> +
> void iterate_parsers(struct discover_context *ctx)
> {
> struct p_item* i;
> diff --git a/discover/parser.h b/discover/parser.h
> index fc165c5aeda4..bff52e30d09f 100644
> --- a/discover/parser.h
> +++ b/discover/parser.h
> @@ -5,6 +5,7 @@
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <unistd.h>
> +#include <dirent.h>
>
> #include "device-handler.h"
>
> @@ -76,5 +77,12 @@ int parser_request_url(struct discover_context *ctx, struct pb_url *url,
> int parser_stat_path(struct discover_context *ctx,
> struct discover_device *dev, const char *path,
> struct stat *statbuf);
> +/* Function used to list the files on a directory. The dirname should
> + * be relative to the discover context device mount path. It returns
> + * the number of files returned in files or a negative value on error.
> + */
> +int parser_scandir(struct discover_context *ctx, const char *dirname,
> + struct dirent ***files, int (*filter)(const struct dirent *),
> + int (*comp)(const struct dirent **, const struct dirent **));
>
> #endif /* _PARSER_H */
> diff --git a/test/parser/Makefile.am b/test/parser/Makefile.am
> index a0795dbcf899..b943408c4942 100644
> --- a/test/parser/Makefile.am
> +++ b/test/parser/Makefile.am
> @@ -40,6 +40,9 @@ parser_TESTS = \
> test/parser/test-grub2-parser-error \
> test/parser/test-grub2-test-file-ops \
> test/parser/test-grub2-single-yocto \
> + test/parser/test-grub2-blscfg-multiple-bls \
> + test/parser/test-grub2-blscfg-opts-config \
> + test/parser/test-grub2-blscfg-opts-grubenv \
> test/parser/test-kboot-single \
> test/parser/test-yaboot-empty \
> test/parser/test-yaboot-single \
> diff --git a/test/parser/test-grub2-blscfg-multiple-bls.c b/test/parser/test-grub2-blscfg-multiple-bls.c
> new file mode 100644
> index 000000000000..8fd218c371e8
> --- /dev/null
> +++ b/test/parser/test-grub2-blscfg-multiple-bls.c
> @@ -0,0 +1,44 @@
> +#include "parser-test.h"
> +
> +#if 0 /* PARSER_EMBEDDED_CONFIG */
> +blscfg
> +#endif
> +
> +void run_test(struct parser_test *test)
> +{
> + struct discover_boot_option *opt;
> + struct discover_context *ctx;
> +
> + test_add_file_string(test, test->ctx->device,
> + "/loader/entries/6c063c8e48904f2684abde8eea303f41-4.15.2-302.fc28.x86_64.conf",
> + "title Fedora (4.15.2-302.fc28.x86_64) 28 (Twenty Eight)\n"
> + "linux /vmlinuz-4.15.2-302.fc28.x86_64\n"
> + "initrd /initramfs-4.15.2-302.fc28.x86_64.img\n"
> + "options root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root\n\n");
> +
> + test_add_file_string(test, test->ctx->device,
> + "/loader/entries/6c063c8e48904f2684abde8eea303f41-4.14.18-300.fc28.x86_64.conf",
> + "title Fedora (4.14.18-300.fc28.x86_64) 28 (Twenty Eight)\n"
> + "linux /vmlinuz-4.14.18-300.fc28.x86_64\n"
> + "initrd /initramfs-4.14.18-300.fc28.x86_64.img\n"
> + "options root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root\n");
> +
> + test_read_conf_embedded(test, "/boot/grub2/grub.cfg");
> +
> + test_run_parser(test, "grub2");
> +
> + ctx = test->ctx;
> +
> + check_boot_option_count(ctx, 2);
> + opt = get_boot_option(ctx, 0);
> +
> + check_name(opt, "Fedora (4.15.2-302.fc28.x86_64) 28 (Twenty Eight)");
> + check_resolved_local_resource(opt->boot_image, ctx->device,
> + "/vmlinuz-4.15.2-302.fc28.x86_64");
> +
> + opt = get_boot_option(ctx, 1);
> +
> + check_name(opt, "Fedora (4.14.18-300.fc28.x86_64) 28 (Twenty Eight)");
> + check_resolved_local_resource(opt->initrd, ctx->device,
> + "/initramfs-4.14.18-300.fc28.x86_64.img");
> +}
> diff --git a/test/parser/test-grub2-blscfg-opts-config.c b/test/parser/test-grub2-blscfg-opts-config.c
> new file mode 100644
> index 000000000000..856aae2adf5f
> --- /dev/null
> +++ b/test/parser/test-grub2-blscfg-opts-config.c
> @@ -0,0 +1,29 @@
> +#include "parser-test.h"
> +
> +#if 0 /* PARSER_EMBEDDED_CONFIG */
> +set kernelopts=root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root
> +blscfg
> +#endif
> +
> +void run_test(struct parser_test *test)
> +{
> + struct discover_boot_option *opt;
> + struct discover_context *ctx;
> +
> + test_add_file_string(test, test->ctx->device,
> + "/loader/entries/6c063c8e48904f2684abde8eea303f41-4.15.2-302.fc28.x86_64.conf",
> + "title Fedora (4.15.2-302.fc28.x86_64) 28 (Twenty Eight)\n"
> + "linux /vmlinuz-4.15.2-302.fc28.x86_64\n"
> + "initrd /initramfs-4.15.2-302.fc28.x86_64.img\n"
> + "options $kernelopts\n");
> +
> + test_read_conf_embedded(test, "/boot/grub2/grub.cfg");
> +
> + test_run_parser(test, "grub2");
> +
> + ctx = test->ctx;
> +
> + opt = get_boot_option(ctx, 0);
> +
> + check_args(opt, "root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root");
> +}
> diff --git a/test/parser/test-grub2-blscfg-opts-grubenv.c b/test/parser/test-grub2-blscfg-opts-grubenv.c
> new file mode 100644
> index 000000000000..c77c589b7707
> --- /dev/null
> +++ b/test/parser/test-grub2-blscfg-opts-grubenv.c
> @@ -0,0 +1,34 @@
> +#include "parser-test.h"
> +
> +#if 0 /* PARSER_EMBEDDED_CONFIG */
> +load_env
> +blscfg
> +#endif
> +
> +void run_test(struct parser_test *test)
> +{
> + struct discover_boot_option *opt;
> + struct discover_context *ctx;
> +
> + test_add_file_string(test, test->ctx->device,
> + "/boot/grub2/grubenv",
> + "# GRUB Environment Block\n"
> + "kernelopts=root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root\n");
> +
> + test_add_file_string(test, test->ctx->device,
> + "/loader/entries/6c063c8e48904f2684abde8eea303f41-4.15.2-302.fc28.x86_64.conf",
> + "title Fedora (4.15.2-302.fc28.x86_64) 28 (Twenty Eight)\n"
> + "linux /vmlinuz-4.15.2-302.fc28.x86_64\n"
> + "initrd /initramfs-4.15.2-302.fc28.x86_64.img\n"
> + "options $kernelopts\n");
> +
> + test_read_conf_embedded(test, "/boot/grub2/grub.cfg");
> +
> + test_run_parser(test, "grub2");
> +
> + ctx = test->ctx;
> +
> + opt = get_boot_option(ctx, 0);
> +
> + check_args(opt, "root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root");
> +}
> diff --git a/test/parser/utils.c b/test/parser/utils.c
> index 8900bd72bebd..683bba7d0379 100644
> --- a/test/parser/utils.c
> +++ b/test/parser/utils.c
> @@ -309,6 +309,65 @@ int parser_replace_file(struct discover_context *ctx,
> return 0;
> }
>
> +int parser_scandir(struct discover_context *ctx, const char *dirname,
> + struct dirent ***files, int (*filter)(const struct dirent *)
> + __attribute__((unused)),
> + int (*comp)(const struct dirent **, const struct dirent **)
> + __attribute__((unused)))
> +{
> + struct parser_test *test = ctx->test_data;
> + struct test_file *f;
> + char *filename;
> + struct dirent **dirents = NULL, **new_dirents;
> + int n = 0, namelen;
> +
> + list_for_each_entry(&test->files, f, list) {
> + if (f->dev != ctx->device)
> + continue;
> +
> + filename = strrchr(f->name, '/');
> + if (!filename)
> + continue;
> +
> + namelen = strlen(filename);
> +
> + if (strncmp(f->name, dirname, strlen(f->name) - namelen))
> + continue;
> +
> + if (!dirents) {
> + dirents = malloc(sizeof(struct dirent *));
> + } else {
> + new_dirents = realloc(dirents, sizeof(struct dirent *)
> + * (n + 1));
> + if (!new_dirents)
> + goto err_cleanup;
> +
> + dirents = new_dirents;
> + }
> +
> + dirents[n] = malloc(sizeof(struct dirent) + namelen + 1);
> +
> + if (!dirents[n])
> + goto err_cleanup;
> +
> + strcpy(dirents[n]->d_name, filename + 1);
> + n++;
> + }
> +
> + *files = dirents;
> +
> + return n;
> +
> +err_cleanup:
> + do {
> + free(dirents[n]);
> + } while (n-- > 0);
> +
> + free(dirents);
> +
> + return -1;
> +}
> +
> struct load_url_result *load_url_async(void *ctx, struct pb_url *url,
> load_url_complete async_cb, void *async_data,
> waiter_cb stdout_cb, void *stdout_data)
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