From: Lennart Poettering Date: Thu, 9 May 2013 18:00:51 +0000 (+0200) Subject: bus: add API for appending/reading fixed arrays X-Git-Tag: v205~276 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=b3af9646f8ac23e73fe1d7af3b69e35b1547b13e bus: add API for appending/reading fixed arrays --- diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c index 835a9f9a4..afd4551b4 100644 --- a/src/libsystemd-bus/bus-message.c +++ b/src/libsystemd-bus/bus-message.c @@ -1438,6 +1438,7 @@ int sd_bus_message_open_container( struct bus_container *c, *w; uint32_t *array_size = NULL; char *signature; + size_t before; int r; if (!m) @@ -1459,6 +1460,11 @@ int sd_bus_message_open_container( if (!signature) return -ENOMEM; + /* Save old index in the parent container, in case we have to + * abort this container */ + c->saved_index = c->index; + before = m->header->body_size; + if (type == SD_BUS_TYPE_ARRAY) r = bus_message_open_array(m, c, contents, &array_size); else if (type == SD_BUS_TYPE_VARIANT) @@ -1481,7 +1487,8 @@ int sd_bus_message_open_container( w->signature = signature; w->index = 0; w->array_size = array_size; - w->begin = 0; + w->before = before; + w->begin = m->rindex; return 0; } @@ -1507,6 +1514,36 @@ int sd_bus_message_close_container(sd_bus_message *m) { return 0; } +static void message_abort_container(sd_bus_message *m) { + struct bus_container *c; + size_t delta; + + assert(m); + assert(!m->sealed); + assert(m->n_containers > 0); + + c = message_get_container(m); + + /* Undo appends */ + assert(m->header->body_size >= c->before); + delta = m->header->body_size - c->before; + m->header->body_size = c->before; + + /* Free container */ + free(c->signature); + m->n_containers--; + + /* Correct index of new top-level container */ + c = message_get_container(m); + c->index = c->saved_index; + + /* Correct array sizes all the way up */ + for (c = m->containers; c < m->containers + m->n_containers; c++) + if (c->array_size) { + assert(*c->array_size >= delta); + *c->array_size -= delta; + } +} typedef struct { const char *types; @@ -1762,6 +1799,68 @@ int sd_bus_message_append(sd_bus_message *m, const char *types, ...) { return r; } +int sd_bus_message_append_array_ptr(sd_bus_message *m, char type, size_t size, void **ptr) { + ssize_t align, sz; + void *a; + int r; + + if (!m) + return -EINVAL; + if (m->sealed) + return -EPERM; + if (!bus_type_is_trivial(type)) + return -EINVAL; + if (!ptr && size > 0) + return -EINVAL; + + align = bus_type_get_alignment(type); + sz = bus_type_get_size(type); + + assert_se(align > 0); + assert_se(sz > 0); + + if (size % sz != 0) + return -EINVAL; + + r = sd_bus_message_open_container(m, SD_BUS_TYPE_ARRAY, CHAR_TO_STR(type)); + if (r < 0) + return r; + + a = message_extend_body(m, align, size); + if (!a) { + r = -ENOMEM; + goto fail; + } + + r = sd_bus_message_close_container(m); + if (r < 0) + goto fail; + + *ptr = a; + return 0; + +fail: + message_abort_container(m); + return r; +} + +int sd_bus_message_append_array(sd_bus_message *m, char type, const void *ptr, size_t size) { + int r; + void *p; + + if (!ptr && size > 0) + return -EINVAL; + + r = sd_bus_message_append_array_ptr(m, type, size, &p); + if (r < 0) + return r; + + if (size > 0) + memcpy(p, ptr, size); + + return 0; +} + static int buffer_peek(const void *p, uint32_t sz, size_t *rindex, size_t align, size_t nbytes, void **r) { size_t k, start, n; @@ -1990,7 +2089,7 @@ int sd_bus_message_read_basic(sd_bus_message *m, char type, void *p) { assert_not_reached("Unknown basic type..."); } - m->rindex = rindex; + m->rindex = rindex; break; } @@ -2186,6 +2285,7 @@ int sd_bus_message_enter_container(sd_bus_message *m, char type, const char *con struct bus_container *c, *w; uint32_t *array_size = NULL; char *signature; + size_t before; int r; if (!m) @@ -2228,6 +2328,9 @@ int sd_bus_message_enter_container(sd_bus_message *m, char type, const char *con if (!signature) return -ENOMEM; + c->saved_index = c->index; + before = m->rindex; + if (type == SD_BUS_TYPE_ARRAY) r = bus_message_enter_array(m, c, contents, &array_size); else if (type == SD_BUS_TYPE_VARIANT) @@ -2250,6 +2353,7 @@ int sd_bus_message_enter_container(sd_bus_message *m, char type, const char *con w->signature = signature; w->index = 0; w->array_size = array_size; + w->before = before; w->begin = m->rindex; return 1; @@ -2284,6 +2388,28 @@ int sd_bus_message_exit_container(sd_bus_message *m) { return 1; } +static void message_quit_container(sd_bus_message *m) { + struct bus_container *c; + + assert(m); + assert(m->sealed); + assert(m->n_containers > 0); + + c = message_get_container(m); + + /* Undo seeks */ + assert(m->rindex >= c->before); + m->rindex = c->before; + + /* Free container */ + free(c->signature); + m->n_containers--; + + /* Correct index of new top-level container */ + c = message_get_container(m); + c->index = c->saved_index; +} + int sd_bus_message_peek_type(sd_bus_message *m, char *type, const char **contents) { struct bus_container *c; int r; @@ -2627,6 +2753,59 @@ int sd_bus_message_read(sd_bus_message *m, const char *types, ...) { return r; } +int sd_bus_message_read_array(sd_bus_message *m, char type, const void **ptr, size_t *size) { + struct bus_container *c; + void *p; + size_t sz; + ssize_t align; + int r; + + if (!m) + return -EINVAL; + if (!m->sealed) + return -EPERM; + if (!bus_type_is_trivial(type)) + return -EINVAL; + if (!ptr) + return -EINVAL; + if (!size) + return -EINVAL; + if (BUS_MESSAGE_NEED_BSWAP(m)) + return -ENOTSUP; + + align = bus_type_get_alignment(type); + if (align < 0) + return align; + + r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, CHAR_TO_STR(type)); + if (r < 0) + return r; + + c = message_get_container(m); + sz = BUS_MESSAGE_BSWAP32(m, *c->array_size); + + r = message_peek_body(m, &m->rindex, align, sz, &p); + if (r < 0) + goto fail; + if (r == 0) { + r = -EBADMSG; + goto fail; + } + + r = sd_bus_message_exit_container(m); + if (r < 0) + goto fail; + + *ptr = (const void*) p; + *size = sz; + + return 1; + +fail: + message_quit_container(m); + return r; +} + static int message_peek_fields( sd_bus_message *m, size_t *rindex, diff --git a/src/libsystemd-bus/bus-message.h b/src/libsystemd-bus/bus-message.h index 9c0829c7f..eafbb7c6c 100644 --- a/src/libsystemd-bus/bus-message.h +++ b/src/libsystemd-bus/bus-message.h @@ -34,10 +34,10 @@ struct bus_container { char enclosing; char *signature; - unsigned index; + unsigned index, saved_index; uint32_t *array_size; - size_t begin; + size_t before, begin; }; struct bus_header { diff --git a/src/libsystemd-bus/bus-type.c b/src/libsystemd-bus/bus-type.c index 055732808..6354c84f2 100644 --- a/src/libsystemd-bus/bus-type.c +++ b/src/libsystemd-bus/bus-type.c @@ -92,6 +92,23 @@ bool bus_type_is_basic(char c) { return !!memchr(valid, c, sizeof(valid)); } +bool bus_type_is_trivial(char c) { + static const char valid[] = { + SD_BUS_TYPE_BYTE, + SD_BUS_TYPE_BOOLEAN, + SD_BUS_TYPE_INT16, + SD_BUS_TYPE_UINT16, + SD_BUS_TYPE_INT32, + SD_BUS_TYPE_UINT32, + SD_BUS_TYPE_INT64, + SD_BUS_TYPE_UINT64, + SD_BUS_TYPE_DOUBLE + }; + + return !!memchr(valid, c, sizeof(valid)); +} + + bool bus_type_is_container(char c) { static const char valid[] = { SD_BUS_TYPE_ARRAY, diff --git a/src/libsystemd-bus/bus-type.h b/src/libsystemd-bus/bus-type.h index e26113608..122628c66 100644 --- a/src/libsystemd-bus/bus-type.h +++ b/src/libsystemd-bus/bus-type.h @@ -29,6 +29,7 @@ bool bus_type_is_valid(char c); bool bus_type_is_valid_in_signature(char c); bool bus_type_is_basic(char c); +bool bus_type_is_trivial(char c); bool bus_type_is_container(char c); int bus_type_get_alignment(char c); int bus_type_get_size(char c); diff --git a/src/libsystemd-bus/test-bus-marshal.c b/src/libsystemd-bus/test-bus-marshal.c index 20ae723fb..ac519531f 100644 --- a/src/libsystemd-bus/test-bus-marshal.c +++ b/src/libsystemd-bus/test-bus-marshal.c @@ -43,6 +43,7 @@ int main(int argc, char *argv[]) { void *buffer = NULL; size_t sz; char *h; + const int32_t integer_array[] = { -1, -2, 0, 1, 2 }, *return_array; r = sd_bus_message_new_method_call(NULL, "foobar.waldo", "/", "foobar.waldo", "Piep", &m); assert_se(r >= 0); @@ -77,6 +78,9 @@ int main(int argc, char *argv[]) { r = sd_bus_message_close_container(m); assert_se(r >= 0); + r = sd_bus_message_append_array(m, 'i', integer_array, sizeof(integer_array)); + assert_se(r >= 0); + r = bus_message_seal(m, 4711); assert_se(r >= 0); @@ -168,6 +172,11 @@ int main(int argc, char *argv[]) { assert_se(streq(x, "foobar")); assert_se(streq(y, "waldo")); + r = sd_bus_message_read_array(m, 'i', (const void**) &return_array, &sz); + assert_se(r > 0); + assert_se(sz == sizeof(integer_array)); + assert_se(memcmp(integer_array, return_array, sz) == 0); + r = sd_bus_message_peek_type(m, NULL, NULL); assert_se(r == 0); diff --git a/src/systemd/sd-bus.h b/src/systemd/sd-bus.h index c1ec50871..2dab93d91 100644 --- a/src/systemd/sd-bus.h +++ b/src/systemd/sd-bus.h @@ -41,15 +41,10 @@ extern "C" { #endif /* TODO: - * - add page donation logic - * - api for appending/reading fixed arrays * - merge busctl into systemctl or so? * - default policy (allow uid == 0 and our own uid) - * * - enforce alignment of pointers passed in * - negotiation for attach attributes - * - * - for kernel and unix transports allow setting the unix user/access mode for the node */ typedef struct sd_bus sd_bus; @@ -173,6 +168,11 @@ int sd_bus_message_exit_container(sd_bus_message *m); int sd_bus_message_peek_type(sd_bus_message *m, char *type, const char **contents); int sd_bus_message_rewind(sd_bus_message *m, int complete); +int sd_bus_message_append_array(sd_bus_message *m, char type, const void *ptr, size_t size); +int sd_bus_message_append_array_ptr(sd_bus_message *m, char type, size_t size, void **ptr); + +int sd_bus_message_read_array(sd_bus_message *m, char type, const void **ptr, size_t *size); + /* Convenience calls */ int sd_bus_emit_signal(sd_bus *bus, const char *path, const char *interface, const char *member, const char *types, ...);