diff options
| -rw-r--r-- | src/libsystemd-bus/bus-message.c | 142 |
1 files changed, 111 insertions, 31 deletions
diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c index 2d051e8aeb..12756bf53e 100644 --- a/src/libsystemd-bus/bus-message.c +++ b/src/libsystemd-bus/bus-message.c @@ -2091,14 +2091,89 @@ int sd_bus_message_rewind(sd_bus_message *m, int complete) { return !isempty(c->signature); } +typedef struct { + const char *types; + unsigned n_struct; + unsigned n_array; +} TypeStack; + +static int type_stack_push(TypeStack *stack, unsigned max, unsigned *i, const char *types, unsigned n_struct, unsigned n_array) { + assert(stack); + assert(max > 0); + + if (*i >= max) + return -EINVAL; + + stack[*i].types = types; + stack[*i].n_struct = n_struct; + stack[*i].n_array = n_array; + (*i)++; + + return 0; +} + +static int type_stack_pop(TypeStack *stack, unsigned max, unsigned *i, const char **types, unsigned *n_struct, unsigned *n_array) { + assert(stack); + assert(max > 0); + assert(types); + assert(n_struct); + assert(n_array); + + if (*i <= 0) + return 0; + + (*i)--; + *types = stack[*i].types; + *n_struct = stack[*i].n_struct; + *n_array = stack[*i].n_array; + + return 1; +} + static int message_read_ap(sd_bus_message *m, const char *types, va_list ap) { - const char *t; + unsigned n_array, n_struct; + TypeStack stack[BUS_CONTAINER_DEPTH]; + unsigned stack_ptr = 0; int r; assert(m); assert(types); - for (t = types; *t; t++) { + /* Ideally, we'd just call ourselves recursively on every + * complex type. However, the state of a va_list that is + * passed to a function is undefined after that function + * returns. This means we need to docode the va_list linearly + * in a single stackframe. We hence implement our own + * home-grown stack in an array. */ + + n_array = (unsigned) -1; + n_struct = strlen(types); + + for (;;) { + const char *t; + + if (n_array == 0 || (n_struct == 0 && n_array == (unsigned) -1)) { + r = type_stack_pop(stack, ELEMENTSOF(stack), &stack_ptr, &types, &n_struct, &n_array); + if (r < 0) + return r; + if (r == 0) + break; + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + continue; + } + + t = types; + if (n_array != (unsigned) -1) + n_array --; + else { + types ++; + n_struct--; + } + switch (*t) { case SD_BUS_TYPE_BYTE: @@ -2118,6 +2193,11 @@ static int message_read_ap(sd_bus_message *m, const char *types, va_list ap) { p = va_arg(ap, void*); r = sd_bus_message_read_basic(m, *t, p); + if (r < 0) + return r; + if (r == 0) + return -ENXIO; + break; } @@ -2129,29 +2209,30 @@ static int message_read_ap(sd_bus_message *m, const char *types, va_list ap) { return r; { - unsigned i, n; char s[k + 1]; - memcpy(s, t + 1, k); s[k] = 0; - t += k; r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, s); if (r < 0) return r; if (r == 0) return -ENXIO; + } - n = va_arg(ap, unsigned); - for (i = 0; i < n; i++) { - r = message_read_ap(m, s, ap); - if (r < 0) - return r; - } - - r = sd_bus_message_exit_container(m); + if (n_array == (unsigned) -1) { + types += k; + n_struct -= k; } + r = type_stack_push(stack, ELEMENTSOF(stack), &stack_ptr, types, n_struct, n_array); + if (r < 0) + return r; + + types = t + 1; + n_struct = k; + n_array = va_arg(ap, unsigned); + break; } @@ -2168,13 +2249,14 @@ static int message_read_ap(sd_bus_message *m, const char *types, va_list ap) { if (r == 0) return -ENXIO; - r = message_read_ap(m, s, ap); + r = type_stack_push(stack, ELEMENTSOF(stack), &stack_ptr, types, n_struct, n_array); if (r < 0) return r; - if (r == 0) - return -ENXIO; - r = sd_bus_message_exit_container(m); + types = s; + n_struct = strlen(s); + n_array = (unsigned) -1; + break; } @@ -2196,29 +2278,27 @@ static int message_read_ap(sd_bus_message *m, const char *types, va_list ap) { return r; if (r == 0) return -ENXIO; + } - t += k - 1; + if (n_array == (unsigned) -1) { + types += k - 1; + n_struct -= k - 1; + } - r = message_read_ap(m, s, ap); - if (r < 0) - return r; - if (r == 0) - return -ENXIO; + r = type_stack_push(stack, ELEMENTSOF(stack), &stack_ptr, types, n_struct, n_array); + if (r < 0) + return r; - r = sd_bus_message_exit_container(m); - } + types = t + 1; + n_struct = k - 2; + n_array = (unsigned) -1; break; } default: - r = -EINVAL; + return -EINVAL; } - - if (r < 0) - return r; - if (r == 0) - return -ENXIO; } return 1; |