diff --git a/docs/interop/qemu-ga.rst b/docs/interop/qemu-ga.rst index e42b370319..fb75cfd8d4 100644 --- a/docs/interop/qemu-ga.rst +++ b/docs/interop/qemu-ga.rst @@ -28,6 +28,20 @@ configuration options on the command line. For the same key, the last option wins, but the lists accumulate (see below for configuration file format). +If an allowed RPCs list is defined in the configuration, then all +RPCs will be blocked by default, except for the allowed list. + +If a blocked RPCs list is defined in the configuration, then all +RPCs will be allowed by default, except for the blocked list. + +If both allowed and blocked RPCs lists are defined in the configuration, +then all RPCs will be blocked by default, then the allowed list will +be applied, followed by the blocked list. + +While filesystems are frozen, all except for a designated safe set +of RPCs will blocked, regardless of what the general configuration +declares. + Options ------- diff --git a/qga/commands-posix.c b/qga/commands-posix.c index f4104f2760..578d29f228 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -1136,12 +1136,6 @@ error: #endif /* HAVE_GETIFADDRS */ -/* add unsupported commands to the list of blocked RPCs */ -GList *ga_command_init_blockedrpcs(GList *blockedrpcs) -{ - return blockedrpcs; -} - /* register init/cleanup routines for stateful command groups */ void ga_command_state_init(GAState *s, GACommandState *cs) { diff --git a/qga/commands-win32.c b/qga/commands-win32.c index 5866cc2e3c..61b36da469 100644 --- a/qga/commands-win32.c +++ b/qga/commands-win32.c @@ -1958,12 +1958,6 @@ done: g_free(rawpasswddata); } -/* add unsupported commands to the list of blocked RPCs */ -GList *ga_command_init_blockedrpcs(GList *blockedrpcs) -{ - return blockedrpcs; -} - /* register init/cleanup routines for stateful command groups */ void ga_command_state_init(GAState *s, GACommandState *cs) { diff --git a/qga/main.c b/qga/main.c index 6ae911eb15..b8f7b1e4a3 100644 --- a/qga/main.c +++ b/qga/main.c @@ -423,58 +423,77 @@ static gint ga_strcmp(gconstpointer str1, gconstpointer str2) return strcmp(str1, str2); } -/* disable commands that aren't safe for fsfreeze */ -static void ga_disable_not_allowed_freeze(const QmpCommand *cmd, void *opaque) +static bool ga_command_is_allowed(const QmpCommand *cmd, GAState *state) { - bool allowed = false; int i = 0; + GAConfig *config = state->config; const char *name = qmp_command_name(cmd); + /* Fallback policy is allow everything */ + bool allowed = true; - while (ga_freeze_allowlist[i] != NULL) { - if (strcmp(name, ga_freeze_allowlist[i]) == 0) { + if (config->allowedrpcs) { + /* + * If an allow-list is given, this changes the fallback + * policy to deny everything + */ + allowed = false; + + if (g_list_find_custom(config->allowedrpcs, name, ga_strcmp) != NULL) { allowed = true; } - i++; } - if (!allowed) { - g_debug("disabling command: %s", name); - qmp_disable_command(&ga_commands, name, "the agent is in frozen state"); + + /* + * If both allowedrpcs and blockedrpcs are set, the blocked + * list will take priority + */ + if (config->blockedrpcs) { + if (g_list_find_custom(config->blockedrpcs, name, ga_strcmp) != NULL) { + allowed = false; + } } + + /* + * If frozen, this filtering must take priority over + * absolutely everything + */ + if (state->frozen) { + allowed = false; + + while (ga_freeze_allowlist[i] != NULL) { + if (strcmp(name, ga_freeze_allowlist[i]) == 0) { + allowed = true; + } + i++; + } + } + + return allowed; } -/* [re-]enable all commands, except those explicitly blocked by user */ -static void ga_enable_non_blocked(const QmpCommand *cmd, void *opaque) +static void ga_apply_command_filters_iter(const QmpCommand *cmd, void *opaque) { - GAState *s = opaque; - GList *blockedrpcs = s->blockedrpcs; - GList *allowedrpcs = s->allowedrpcs; + GAState *state = opaque; + bool want = ga_command_is_allowed(cmd, state); + bool have = qmp_command_is_enabled(cmd); const char *name = qmp_command_name(cmd); - if (g_list_find_custom(blockedrpcs, name, ga_strcmp) == NULL) { - if (qmp_command_is_enabled(cmd)) { - return; - } - - if (allowedrpcs && - g_list_find_custom(allowedrpcs, name, ga_strcmp) == NULL) { - return; - } + if (want == have) { + return; + } + if (have) { + g_debug("disabling command: %s", name); + qmp_disable_command(&ga_commands, name, "the command is not allowed"); + } else { g_debug("enabling command: %s", name); qmp_enable_command(&ga_commands, name); } } -/* disable commands that aren't allowed */ -static void ga_disable_not_allowed(const QmpCommand *cmd, void *opaque) +static void ga_apply_command_filters(GAState *state) { - GList *allowedrpcs = opaque; - const char *name = qmp_command_name(cmd); - - if (g_list_find_custom(allowedrpcs, name, ga_strcmp) == NULL) { - g_debug("disabling command: %s", name); - qmp_disable_command(&ga_commands, name, "the command is not allowed"); - } + qmp_for_each_command(&ga_commands, ga_apply_command_filters_iter, state); } static bool ga_create_file(const char *path) @@ -509,15 +528,14 @@ void ga_set_frozen(GAState *s) if (ga_is_frozen(s)) { return; } - /* disable all forbidden (for frozen state) commands */ - qmp_for_each_command(&ga_commands, ga_disable_not_allowed_freeze, NULL); g_warning("disabling logging due to filesystem freeze"); - ga_disable_logging(s); s->frozen = true; if (!ga_create_file(s->state_filepath_isfrozen)) { g_warning("unable to create %s, fsfreeze may not function properly", s->state_filepath_isfrozen); } + ga_apply_command_filters(s); + ga_disable_logging(s); } void ga_unset_frozen(GAState *s) @@ -549,12 +567,12 @@ void ga_unset_frozen(GAState *s) } /* enable all disabled, non-blocked and allowed commands */ - qmp_for_each_command(&ga_commands, ga_enable_non_blocked, s); s->frozen = false; if (!ga_delete_file(s->state_filepath_isfrozen)) { g_warning("unable to delete %s, fsfreeze may not function properly", s->state_filepath_isfrozen); } + ga_apply_command_filters(s); } #ifdef CONFIG_FSFREEZE @@ -1086,13 +1104,6 @@ static void config_load(GAConfig *config, const char *confpath, bool required) split_list(config->aliststr, ",")); } - if (g_key_file_has_key(keyfile, "general", "block-rpcs", NULL) && - g_key_file_has_key(keyfile, "general", "allow-rpcs", NULL)) { - g_critical("wrong config, using 'block-rpcs' and 'allow-rpcs' keys at" - " the same time is not allowed"); - exit(EXIT_FAILURE); - } - end: g_key_file_free(keyfile); if (gerr && (required || @@ -1172,7 +1183,6 @@ static void config_parse(GAConfig *config, int argc, char **argv) { const char *sopt = "hVvdc:m:p:l:f:F::b:a:s:t:Dr"; int opt_ind = 0, ch; - bool block_rpcs = false, allow_rpcs = false; const struct option lopt[] = { { "help", 0, NULL, 'h' }, { "version", 0, NULL, 'V' }, @@ -1268,7 +1278,6 @@ static void config_parse(GAConfig *config, int argc, char **argv) } config->blockedrpcs = g_list_concat(config->blockedrpcs, split_list(optarg, ",")); - block_rpcs = true; break; } case 'a': { @@ -1278,7 +1287,6 @@ static void config_parse(GAConfig *config, int argc, char **argv) } config->allowedrpcs = g_list_concat(config->allowedrpcs, split_list(optarg, ",")); - allow_rpcs = true; break; } #ifdef _WIN32 @@ -1319,12 +1327,6 @@ static void config_parse(GAConfig *config, int argc, char **argv) exit(EXIT_FAILURE); } } - - if (block_rpcs && allow_rpcs) { - g_critical("wrong commandline, using --block-rpcs and --allow-rpcs at the" - " same time is not allowed"); - exit(EXIT_FAILURE); - } } static void config_free(GAConfig *config) @@ -1435,7 +1437,6 @@ static GAState *initialize_agent(GAConfig *config, int socket_activation) s->deferred_options.log_filepath = config->log_filepath; } ga_disable_logging(s); - qmp_for_each_command(&ga_commands, ga_disable_not_allowed_freeze, NULL); } else { if (config->daemonize) { become_daemon(config->pid_filepath); @@ -1459,25 +1460,6 @@ static GAState *initialize_agent(GAConfig *config, int socket_activation) return NULL; } - if (config->allowedrpcs) { - qmp_for_each_command(&ga_commands, ga_disable_not_allowed, config->allowedrpcs); - s->allowedrpcs = config->allowedrpcs; - } - - /* - * Some commands can be blocked due to system limitation. - * Initialize blockedrpcs list even if allowedrpcs specified. - */ - config->blockedrpcs = ga_command_init_blockedrpcs(config->blockedrpcs); - if (config->blockedrpcs) { - GList *l = config->blockedrpcs; - s->blockedrpcs = config->blockedrpcs; - do { - g_debug("disabling command: %s", (char *)l->data); - qmp_disable_command(&ga_commands, l->data, NULL); - l = g_list_next(l); - } while (l); - } s->command_state = ga_command_state_new(); ga_command_state_init(s, s->command_state); ga_command_state_init_all(s->command_state); @@ -1503,6 +1485,8 @@ static GAState *initialize_agent(GAConfig *config, int socket_activation) } #endif + ga_apply_command_filters(s); + ga_state = s; return s; }