From: Javier Martinez Canillas Date: Tue, 12 Jun 2018 10:18:34 +0000 (+0200) Subject: discover/grub: Improve BLS grub environment variables expansion X-Git-Tag: v1.9.0~70 X-Git-Url: https://git.ozlabs.org/?p=petitboot;a=commitdiff_plain;h=78a98b9ebc789d9c9c701af95e65292d768eee59 discover/grub: Improve BLS grub environment variables expansion The fields from a BootLoaderSpec file can contain environment variables, in GRUB 2 these are show verbatim and are evaluated later when an entry is selected. But on Petitboot these have to be expanded before creating the GRUB 2 resources and show in the UI the values after the evaluation. The current blscfg handler had a very limited support for variables, it only had support for the options field and also didn't take into account that variables could be mixed with literal values. So for example the following fields were not expanded correctly: linux $bootprefix/vmlinuz options $kernelopts foo=bar options foo=bar $kernelopts options $kernelopts $debugopts Also change some of the tests to cover mixing variables and literals. Signed-off-by: Javier Martinez Canillas Signed-off-by: Samuel Mendoza-Jonas --- diff --git a/discover/grub2/blscfg.c b/discover/grub2/blscfg.c index a381306..d4754aa 100644 --- a/discover/grub2/blscfg.c +++ b/discover/grub2/blscfg.c @@ -2,6 +2,7 @@ #define _GNU_SOURCE #include +#include #include #include #include @@ -34,54 +35,106 @@ struct bls_state { const char *dtb; }; +static char *field_append(struct bls_state *state, int type, char *buffer, + char *start, char *end) +{ + char *temp = talloc_strndup(state, start, end - start + 1); + const char *field = temp; + + if (type == GRUB2_WORD_VAR) { + field = script_env_get(state->script, temp); + if (!field) + return buffer; + } + + if (!buffer) + buffer = talloc_strdup(state->opt, field); + else + buffer = talloc_asprintf_append(buffer, "%s", field); + + return buffer; +} + +static char *expand_field(struct bls_state *state, char *value) +{ + char *buffer = NULL; + char *start = value; + char *end = value; + int type = GRUB2_WORD_TEXT; + + while (*value) { + if (*value == '$') { + if (start != end) { + buffer = field_append(state, type, buffer, + start, end); + if (!buffer) + return NULL; + } + + type = GRUB2_WORD_VAR; + start = value + 1; + } else if (type == GRUB2_WORD_VAR) { + if (!isalnum(*value) && *value != '_') { + buffer = field_append(state, type, buffer, + start, end); + type = GRUB2_WORD_TEXT; + start = value; + } + } + + end = value; + value++; + } + + if (start != end) { + buffer = field_append(state, type, buffer, + start, end); + if (!buffer) + return NULL; + } + + return buffer; +} + static void bls_process_pair(struct conf_context *conf, const char *name, char *value) { 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")) { - state->title = talloc_strdup(state, value); + state->title = expand_field(state, value); return; } if (streq(name, "version")) { - state->version = talloc_strdup(state, value); + state->version = expand_field(state, value); return; } if (streq(name, "machine-id")) { - state->machine_id = talloc_strdup(state, value); + state->machine_id = expand_field(state, value); return; } if (streq(name, "linux")) { - state->image = talloc_strdup(state, value); + state->image = expand_field(state, value); return; } if (streq(name, "initrd")) { - state->initrd = talloc_strdup(state, value); + state->initrd = expand_field(state, value); return; } if (streq(name, "devicetree")) { - state->dtb = talloc_strdup(state, value); + state->dtb = expand_field(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); - } + option->boot_args = expand_field(state, value); return; } } diff --git a/test/parser/test-grub2-blscfg-multiple-bls.c b/test/parser/test-grub2-blscfg-multiple-bls.c index 94f40d1..d15fb24 100644 --- a/test/parser/test-grub2-blscfg-multiple-bls.c +++ b/test/parser/test-grub2-blscfg-multiple-bls.c @@ -1,6 +1,7 @@ #include "parser-test.h" #if 0 /* PARSER_EMBEDDED_CONFIG */ +set os_name=Fedora blscfg #endif @@ -13,14 +14,14 @@ void run_test(struct parser_test *test) 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" + "title $os_name (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" + "title $os_name (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"); diff --git a/test/parser/test-grub2-blscfg-opts-grubenv.c b/test/parser/test-grub2-blscfg-opts-grubenv.c index 544a5de..2dffd1b 100644 --- a/test/parser/test-grub2-blscfg-opts-grubenv.c +++ b/test/parser/test-grub2-blscfg-opts-grubenv.c @@ -22,7 +22,7 @@ void run_test(struct parser_test *test) "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"); + "options $kernelopts debug\n"); test_read_conf_embedded(test, "/boot/grub2/grub.cfg"); @@ -32,5 +32,5 @@ void run_test(struct parser_test *test) opt = get_boot_option(ctx, 0); - check_args(opt, "root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root"); + check_args(opt, "root=/dev/mapper/fedora-root ro rd.lvm.lv=fedora/root debug"); }