From 53461b74df0576ec091275d1a5dbee00611df1ee Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 19 Dec 2013 03:02:45 +0100 Subject: [PATCH] driverd: implement AddMatch/RemoveMatch logic --- TODO | 4 +- src/bus-driverd/bus-driverd.c | 345 ++++++++++++++++++++++++++++--- src/libsystemd-bus/bus-control.c | 18 +- src/libsystemd-bus/bus-control.h | 3 + src/libsystemd-bus/bus-match.c | 40 ++++ src/libsystemd-bus/bus-match.h | 1 + src/systemd/sd-bus-protocol.h | 2 + 7 files changed, 369 insertions(+), 44 deletions(-) diff --git a/TODO b/TODO index 802516903..2e3becc3d 100644 --- a/TODO +++ b/TODO @@ -113,17 +113,15 @@ Features: * libsystemd-bus: - when kdbus doesn't take our message without memfds, try again with memfds - - implement translator service - implement monitor logic + - implement support for byebye ioctl - properly map matches with well-known names against messages with unique names - when triggering property change events, allow a NULL strv indicate that all properties listed as such are send out as changed - see if we can drop more message validation on the sending side - support "const" properties as flag - add API to clone sd_bus_message objects - SD_BUS_COMMENT() macro for inclusion in vtables, syntax inspired by gdbus - - sort out error codes for sd_bus_release_name(), distuingish: successful removal from foreign name, from non-existing name - kdbus: matches against source or destination pids for an "strace -p"-like feel. Problem: The PID info needs to be available in userspace too... - - kdbus: we need a way to distuingish messages we got due to monitoring from normal messages, since we want to bind methods only to the latter - kdbus: when we do "systemctl daemon-reexec" the call doesn't get properly cancelled - longer term: * priority queues diff --git a/src/bus-driverd/bus-driverd.c b/src/bus-driverd/bus-driverd.c index f28dc5738..d4126a99b 100644 --- a/src/bus-driverd/bus-driverd.c +++ b/src/bus-driverd/bus-driverd.c @@ -50,38 +50,318 @@ #include "hashmap.h" #include "def.h" #include "unit-name.h" +#include "bus-control.h" -/* - * TODO: - * - * AddMatch / RemoveMatch - */ +#define CLIENTS_MAX 1024 +#define MATCHES_MAX 1024 -static int driver_add_match(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) { +typedef struct Match Match; +typedef struct Client Client; +typedef struct Context Context; +struct Match { + Client *client; + char *match; + uint64_t cookie; + LIST_FIELDS(Match, matches); +}; + +struct Client { + Context *context; + uint64_t id; + uint64_t next_cookie; + Hashmap *matches; + unsigned n_matches; + char *watch; +}; + +struct Context { + sd_bus *bus; + sd_event *event; + Hashmap *clients; +}; + +static void match_free(Match *m) { + + if (!m) + return; + + if (m->client) { + Match *first; + + first = hashmap_get(m->client->matches, m->match); + LIST_REMOVE(matches, first, m); + if (first) + assert_se(hashmap_replace(m->client->matches, m->match, first) >= 0); + else + hashmap_remove(m->client->matches, m->match); + + m->client->n_matches--; + } + + free(m->match); + free(m); +} + +static int match_new(Client *c, struct bus_match_component *components, unsigned n_components, Match **_m) { + Match *m, *first; + int r; + + assert(c); + assert(_m); + + r = hashmap_ensure_allocated(&c->matches, string_hash_func, string_compare_func); + if (r < 0) + return r; + + m = new0(Match, 1); + if (!m) + return -ENOMEM; + + m->match = bus_match_to_string(components, n_components); + if (!m->match) { + r = -ENOMEM; + goto fail; + } + + m->cookie = ++c->next_cookie; + + first = hashmap_get(c->matches, m->match); + LIST_PREPEND(matches, first, m); + r = hashmap_replace(c->matches, m->match, first); + if (r < 0) { + LIST_REMOVE(matches, first, m); + goto fail; + } + + m->client = c; + c->n_matches++; + + *_m = m; + m = NULL; + + return 0; + +fail: + match_free(m); + return r; +} + +static int on_name_owner_changed(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error); + +static void client_free(Client *c) { + Match *m; + + if (!c) + return; + + if (c->context) { + if (c->watch) + sd_bus_remove_match(c->context->bus, c->watch, on_name_owner_changed, c); + + assert_se(hashmap_remove(c->context->clients, &c->id) == c); + } + + while ((m = hashmap_first(c->matches))) + match_free(m); + + hashmap_free(c->matches); + free(c->watch); + + free(c); +} + +static int on_name_owner_changed(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) { + Client *c = userdata; + + assert(bus); + assert(m); + + client_free(c); + return 0; +} + +static int client_acquire(Context *context, uint64_t id, Client **_c) { + char *watch = NULL; + Client *c; + int r; + + assert(context); + assert(_c); + + c = hashmap_get(context->clients, &id); + if (c) { + *_c = c; + return 0; + } + + if (hashmap_size(context->clients) >= CLIENTS_MAX) + return -ENOBUFS; + + r = hashmap_ensure_allocated(&context->clients, uint64_hash_func, uint64_compare_func); + if (r < 0) + return r; + + c = new0(Client, 1); + if (!c) + return -ENOMEM; + + c->id = id; + + r = hashmap_put(context->clients, &c->id, c); + if (r < 0) + goto fail; + + c->context = context; + + if (asprintf(&watch, + "type='signal'," + "sender='org.freedesktop.DBus'," + "path='/org/freedesktop/DBus'," + "interface='org.freedesktop.DBus'," + "member='NameOwnerChanged'," + "arg0=':1.%llu'", (unsigned long long) id) < 0) { + r = -ENOMEM; + goto fail; + } + + r = sd_bus_add_match(context->bus, watch, on_name_owner_changed, c); + if (r < 0) { + free(watch); + goto fail; + } + + c->watch = watch; + + *_c = c; + return 0; + +fail: + client_free(c); + return r; +} + +static int driver_add_match(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) { + + struct bus_match_component *components = NULL; + Context *context = userdata; + unsigned n_components = 0; + Match *m = NULL; + Client *c = NULL; char *arg0; + uint64_t id; int r; - r = sd_bus_message_read(m, "s", &arg0); + assert(bus); + assert(message); + assert(context); + + r = sd_bus_message_read(message, "s", &arg0); + if (r < 0) + return r; + + r = bus_kernel_parse_unique_name(message->sender, &id); if (r < 0) return r; - /* FIXME */ + r = client_acquire(context, id, &c); + if (r == -ENOBUFS) + return sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Reached limit of %u clients", CLIENTS_MAX); + if (r < 0) + return r; + + if (c->n_matches >= MATCHES_MAX) { + r = sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Reached limit of %u matches per client", MATCHES_MAX); + goto fail; + } + + r = bus_match_parse(arg0, &components, &n_components); + if (r < 0) { + r = sd_bus_error_setf(error, SD_BUS_ERROR_MATCH_RULE_INVALID, "Match rule \"%s\" is not valid", arg0); + goto fail; + } + + r = match_new(c, components, n_components, &m); + if (r < 0) + goto fail; + + r = bus_add_match_internal_kernel(bus, id, components, n_components, m->cookie); + if (r < 0) + goto fail; + + bus_match_parse_free(components, n_components); + + return sd_bus_reply_method_return(message, NULL); + +fail: + bus_match_parse_free(components, n_components); + + match_free(m); - return sd_bus_reply_method_return(m, NULL); + if (c->n_matches <= 0) + client_free(c); + + return r; } -static int driver_remove_match(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) { +static int driver_remove_match(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) { + + struct bus_match_component *components = NULL; + _cleanup_free_ char *normalized = NULL; + Context *context = userdata; + unsigned n_components = 0; + Client *c = NULL; + Match *m = NULL; char *arg0; + uint64_t id; int r; - r = sd_bus_message_read(m, "s", &arg0); + assert(bus); + assert(message); + assert(context); + + r = sd_bus_message_read(message, "s", &arg0); + if (r < 0) + return r; + + r = bus_kernel_parse_unique_name(message->sender, &id); if (r < 0) return r; - /* FIXME */ + c = hashmap_get(context->clients, &id); + if (!c) + return sd_bus_error_setf(error, SD_BUS_ERROR_MATCH_RULE_NOT_FOUND, "You have not registered any matches."); + + r = bus_match_parse(arg0, &components, &n_components); + if (r < 0) { + r = sd_bus_error_setf(error, SD_BUS_ERROR_MATCH_RULE_INVALID, "Match rule \"%s\" is not valid", arg0); + goto finish; + } + + normalized = bus_match_to_string(components, n_components); + if (!normalized) { + r = -ENOMEM; + goto finish; + } + + m = hashmap_get(c->matches, normalized); + if (!m) { + r = sd_bus_error_setf(error, SD_BUS_ERROR_MATCH_RULE_NOT_FOUND, "Match rule \"%s\" not found."); + goto finish; + } + + bus_remove_match_internal_kernel(bus, id, m->cookie); + match_free(m); - return sd_bus_reply_method_return(m, NULL); + r = sd_bus_reply_method_return(message, NULL); + +finish: + bus_match_parse_free(components, n_components); + + if (c->n_matches <= 0) + client_free(c); + + return r; } static int driver_get_security_ctx(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) { @@ -455,51 +735,46 @@ static const sd_bus_vtable driver_vtable[] = { SD_BUS_VTABLE_END }; -static int connect_bus(sd_event *event, sd_bus **_bus) { - _cleanup_bus_unref_ sd_bus *bus = NULL; +static int connect_bus(Context *c) { int r; - assert(event); - assert(_bus); + assert(c); - r = sd_bus_default_system(&bus); + r = sd_bus_default_system(&c->bus); if (r < 0) { log_error("Failed to create bus: %s", strerror(-r)); return r; } - if (!bus->is_kernel) { + if (!c->bus->is_kernel) { log_error("Not running on kdbus"); return -EPERM; } - r = sd_bus_add_object_vtable(bus, "/org/freedesktop/DBus", "org.freedesktop.DBus", driver_vtable, NULL); + r = sd_bus_add_object_vtable(c->bus, "/org/freedesktop/DBus", "org.freedesktop.DBus", driver_vtable, c); if (r < 0) { log_error("Failed to add manager object vtable: %s", strerror(-r)); return r; } - r = sd_bus_request_name(bus, "org.freedesktop.DBus", 0); + r = sd_bus_request_name(c->bus, "org.freedesktop.DBus", 0); if (r < 0) { log_error("Unable to request name: %s\n", strerror(-r)); return r; } - r = sd_bus_attach_event(bus, event, 0); + r = sd_bus_attach_event(c->bus, c->event, 0); if (r < 0) { - log_error("Error %d while adding bus to even: %s", r, strerror(-r)); + log_error("Error while adding bus to event loop: %s", strerror(-r)); return r; } - *_bus = bus; - bus = NULL; - return 0; } int main(int argc, char *argv[]) { - _cleanup_event_unref_ sd_event *event = NULL; - _cleanup_bus_unref_ sd_bus *bus = NULL; + Context context = {}; + Client *c; int r; log_set_target(LOG_TARGET_AUTO); @@ -512,25 +787,31 @@ int main(int argc, char *argv[]) { goto finish; } - r = sd_event_default(&event); + r = sd_event_default(&context.event); if (r < 0) { log_error("Failed to allocate event loop: %s", strerror(-r)); goto finish; } - sd_event_set_watchdog(event, true); + sd_event_set_watchdog(context.event, true); - r = connect_bus(event, &bus); + r = connect_bus(&context); if (r < 0) goto finish; - r = bus_event_loop_with_idle(event, bus, "org.freedesktop.DBus", DEFAULT_EXIT_USEC); + r = bus_event_loop_with_idle(context.event, context.bus, "org.freedesktop.DBus", DEFAULT_EXIT_USEC); if (r < 0) { log_error("Failed to run event loop: %s", strerror(-r)); goto finish; } finish: + while ((c = hashmap_first(context.clients))) + client_free(c); + + sd_bus_unref(context.bus); + sd_event_unref(context.event); + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; } diff --git a/src/libsystemd-bus/bus-control.c b/src/libsystemd-bus/bus-control.c index b51007d1e..b8f6360fb 100644 --- a/src/libsystemd-bus/bus-control.c +++ b/src/libsystemd-bus/bus-control.c @@ -851,7 +851,7 @@ static int add_name_change_match(sd_bus *bus, item = m->items; item->size = offsetof(struct kdbus_item, id_change) + sizeof(struct kdbus_notify_id_change); - item->id_change.id = name_id; + /* item->id_change.id = name_id; */ /* If the old name is unset or empty, then this can * match against added ids */ @@ -877,9 +877,9 @@ static int add_name_change_match(sd_bus *bus, return 0; } -static int bus_add_match_internal_kernel( +int bus_add_match_internal_kernel( sd_bus *bus, - const char *match, + uint64_t id, struct bus_match_component *components, unsigned n_components, uint64_t cookie) { @@ -898,7 +898,6 @@ static int bus_add_match_internal_kernel( int r; assert(bus); - assert(match); zero(bloom); @@ -1018,6 +1017,7 @@ static int bus_add_match_internal_kernel( m->size = sz; m->cookie = cookie; m->src_id = src_id; + m->id = id; item = m->items; @@ -1084,25 +1084,25 @@ int bus_add_match_internal( assert(match); if (bus->is_kernel) - return bus_add_match_internal_kernel(bus, match, components, n_components, cookie); + return bus_add_match_internal_kernel(bus, 0, components, n_components, cookie); else return bus_add_match_internal_dbus1(bus, match); } -static int bus_remove_match_internal_kernel( +int bus_remove_match_internal_kernel( sd_bus *bus, - const char *match, + uint64_t id, uint64_t cookie) { struct kdbus_cmd_match m; int r; assert(bus); - assert(match); zero(m); m.size = offsetof(struct kdbus_cmd_match, items); m.cookie = cookie; + m.id = id; r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_REMOVE, &m); if (r < 0) @@ -1139,7 +1139,7 @@ int bus_remove_match_internal( assert(match); if (bus->is_kernel) - return bus_remove_match_internal_kernel(bus, match, cookie); + return bus_remove_match_internal_kernel(bus, 0, cookie); else return bus_remove_match_internal_dbus1(bus, match); } diff --git a/src/libsystemd-bus/bus-control.h b/src/libsystemd-bus/bus-control.h index 2cac5d83a..b610bef84 100644 --- a/src/libsystemd-bus/bus-control.h +++ b/src/libsystemd-bus/bus-control.h @@ -25,3 +25,6 @@ int bus_add_match_internal(sd_bus *bus, const char *match, struct bus_match_component *components, unsigned n_components, uint64_t cookie); int bus_remove_match_internal(sd_bus *bus, const char *match, uint64_t cookie); + +int bus_add_match_internal_kernel(sd_bus *bus, uint64_t id, struct bus_match_component *components, unsigned n_components, uint64_t cookie); +int bus_remove_match_internal_kernel(sd_bus *bus, uint64_t id, uint64_t cookie); diff --git a/src/libsystemd-bus/bus-match.c b/src/libsystemd-bus/bus-match.c index 342819d9c..7638f2038 100644 --- a/src/libsystemd-bus/bus-match.c +++ b/src/libsystemd-bus/bus-match.c @@ -816,6 +816,46 @@ fail: return r; } +char *bus_match_to_string(struct bus_match_component *components, unsigned n_components) { + _cleanup_free_ FILE *f = NULL; + char *buffer = NULL; + size_t size = 0; + unsigned i; + + if (n_components <= 0) + return strdup(""); + + assert(components); + + f = open_memstream(&buffer, &size); + if (!f) + return NULL; + + for (i = 0; i < n_components; i++) { + char buf[32]; + + if (i != 0) + fputc(',', f); + + fputs(bus_match_node_type_to_string(components[i].type, buf, sizeof(buf)), f); + fputc('=', f); + fputc('\'', f); + + if (components[i].type == BUS_MATCH_MESSAGE_TYPE) + fputs(bus_message_type_to_string(components[i].value_u8), f); + else + fputs(components[i].value_str, f); + + fputc('\'', f); + } + + fflush(f); + if (ferror(f)) + return NULL; + + return buffer; +} + int bus_match_add( struct bus_match_node *root, struct bus_match_component *components, diff --git a/src/libsystemd-bus/bus-match.h b/src/libsystemd-bus/bus-match.h index 1d3812660..056082b90 100644 --- a/src/libsystemd-bus/bus-match.h +++ b/src/libsystemd-bus/bus-match.h @@ -90,3 +90,4 @@ enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n int bus_match_parse(const char *match, struct bus_match_component **_components, unsigned *_n_components); void bus_match_parse_free(struct bus_match_component *components, unsigned n_components); +char *bus_match_to_string(struct bus_match_component *components, unsigned n_components); diff --git a/src/systemd/sd-bus-protocol.h b/src/systemd/sd-bus-protocol.h index 1967fa8f0..439a77961 100644 --- a/src/systemd/sd-bus-protocol.h +++ b/src/systemd/sd-bus-protocol.h @@ -94,6 +94,8 @@ enum { #define SD_BUS_ERROR_UNIX_PROCESS_ID_UNKNOWN "org.freedesktop.DBus.Error.UnixProcessIdUnknown" #define SD_BUS_ERROR_INVALID_SIGNATURE "org.freedesktop.DBus.Error.InvalidSignature" #define SD_BUS_ERROR_INCONSISTENT_MESSAGE "org.freedesktop.DBus.Error.InconsistentMessage" +#define SD_BUS_ERROR_MATCH_RULE_NOT_FOUND "org.freedesktop.DBus.Error.MatchRuleNotFound" +#define SD_BUS_ERROR_MATCH_RULE_INVALID "org.freedesktop.DBus.Error.MatchRuleInvalid" _SD_END_DECLARATIONS; -- 2.30.2