#include <fcntl.h>

#include "util.h"

#include "bus-internal.h"

#include "bus-message.h"

#include "bus-kernel.h"

#define KDBUS_MSG_FOREACH_DATA(d, k) \

for ((d) = (k)->data; \

(uint8_t*) (d) < (uint8_t*) (k) + (k)->size; \

(d) = (struct kdbus_msg_data*) ((uint8_t*) (d) + ALIGN8((d)->size)))

static int parse_unique_name(const char *s, uint64_t *id) {

int r;

assert(s);

assert(id);

if (!startswith(s, ":1."))

return 0;

r = safe_atou64(s + 3, id);

if (r < 0)

return r;

return 1;

}

static void append_payload_vec(struct kdbus_msg_data **d, const void *p, size_t sz) {

assert(d);

assert(p);

assert(sz > 0);

(*d)->size = offsetof(struct kdbus_msg_data, vec) + sizeof(struct kdbus_vec);

(*d)->type = KDBUS_MSG_PAYLOAD_VEC;

(*d)->vec.address = (uint64_t) p;

(*d)->vec.size = sz;

*d = (struct kdbus_msg_data*) ((uint8_t*) *d + ALIGN8((*d)->size));

}

static void append_destination(struct kdbus_msg_data **d, const char *s, size_t length) {

assert(d);

assert(d);

(*d)->size = offsetof(struct kdbus_msg_data, data) + length + 1;

(*d)->type = KDBUS_MSG_DST_NAME;

memcpy((*d)->data, s, length + 1);

*d = (struct kdbus_msg_data*) ((uint8_t*) *d + ALIGN8((*d)->size));

}

static int bus_message_setup_kmsg(sd_bus_message *m) {

struct kdbus_msg_data *d;

bool well_known;

uint64_t unique;

size_t sz, dl;

int r;

assert(m);

assert(m->sealed);

assert(!m->kdbus);

if (m->destination) {

r = parse_unique_name(m->destination, &unique);

if (r < 0)

return r;

well_known = r == 0;

} else

well_known = false;

sz = offsetof(struct kdbus_msg, data);

/* Add in fixed header, fields header, fields header padding and payload */

sz += 4 * ALIGN8(offsetof(struct kdbus_msg_data, vec) + sizeof(struct kdbus_vec));

/* Add in well-known destination header */

if (well_known) {

dl = strlen(m->destination);

sz += ALIGN8(offsetof(struct kdbus_msg, data) + dl + 1);

}

m->kdbus = malloc0(sz);

if (!m->kdbus)

return -ENOMEM;

m->kdbus->flags =

((m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) |

((m->header->flags & SD_BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0);

m->kdbus->dst_id =

well_known ? 0 :

m->destination ? unique : (uint64_t) -1;

m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS1;

m->kdbus->cookie = m->header->serial;

m->kdbus->timeout_ns = m->timeout * NSEC_PER_USEC;

d = m->kdbus->data;

if (well_known)

append_destination(&d, m->destination, dl);

append_payload_vec(&d, m->header, sizeof(*m->header));

if (m->fields) {

append_payload_vec(&d, m->fields, m->header->fields_size);

if (m->header->fields_size % 8 != 0) {

static const uint8_t padding[7] = {};

append_payload_vec(&d, padding, 8 - (m->header->fields_size % 8));

}

}

if (m->body)

append_payload_vec(&d, m->body, m->header->body_size);

m->kdbus->size = (uint8_t*) m - (uint8_t*) m->kdbus;

assert(m->kdbus->size <= sz);

return 0;

}

int bus_kernel_take_fd(sd_bus *b) {

struct kdbus_cmd_hello hello = {};

int r;

assert(b);

r = ioctl(b->input_fd, KDBUS_CMD_HELLO, &hello);

if (r < 0)

return -errno;

if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello.id) < 0)

return -ENOMEM;

b->is_kernel = true;

r = bus_start_running(b);

if (r < 0)

return r;

return 1;

}

int bus_kernel_connect(sd_bus *b) {

assert(b);

assert(b->input_fd < 0);

assert(b->output_fd < 0);

assert(b->kernel);

b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);

if (b->input_fd < 0)

return -errno;

b->output_fd = b->input_fd;

return bus_kernel_take_fd(b);

}

int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m) {

int r;

assert(bus);

assert(m);

assert(bus->state == BUS_RUNNING);

r = bus_message_setup_kmsg(m);

if (r < 0)

return r;

r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);

if (r < 0)

return errno == EAGAIN ? 0 : -errno;

return 0;

}

static void close_kdbus_msg(struct kdbus_msg *k) {

struct kdbus_msg_data *d;

KDBUS_MSG_FOREACH_DATA(d, k) {

if (d->type != KDBUS_MSG_UNIX_FDS)

continue;

close_many(d->fds, (d->size - offsetof(struct kdbus_msg_data, fds)) / sizeof(int));

}

}

static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_message **ret) {

sd_bus_message *m = NULL;

struct kdbus_msg_data *d;

unsigned n_payload = 0, n_fds = 0;

_cleanup_free_ int *fds = NULL;

struct bus_header *h = NULL;

size_t total, n_bytes = 0, idx = 0;

int r;

assert(bus);

assert(k);

assert(ret);

if (k->payload_type != KDBUS_PAYLOAD_DBUS1)

return 0;

KDBUS_MSG_FOREACH_DATA(d, k) {

size_t l;

l = d->size - offsetof(struct kdbus_msg_data, data);

if (d->type == KDBUS_MSG_PAYLOAD) {

if (!h) {

if (l < sizeof(struct bus_header))

return -EBADMSG;

h = (struct bus_header*) d->data;

}

n_payload++;

n_bytes += l;

} else if (d->type == KDBUS_MSG_UNIX_FDS) {

int *f;

unsigned j;

j = l / sizeof(int);

f = realloc(fds, sizeof(int) * (n_fds + j));

if (!f)

return -ENOMEM;

fds = f;

memcpy(fds + n_fds, d->fds, j);

n_fds += j;

}

}

if (!h)

return -EBADMSG;

r = bus_header_size(h, &total);

if (r < 0)

return r;

if (n_bytes != total)

return -EBADMSG;

r = bus_message_from_header(h, sizeof(struct bus_header), fds, n_fds, NULL, NULL, 0, &m);

if (r < 0)

return r;

KDBUS_MSG_FOREACH_DATA(d, k) {

size_t l;

if (d->type != KDBUS_MSG_PAYLOAD)

continue;

l = d->size - offsetof(struct kdbus_msg_data, data);

if (idx == sizeof(struct bus_header) &&

l == BUS_MESSAGE_FIELDS_SIZE(m))

m->fields = d->data;

else if (idx == sizeof(struct bus_header) + ALIGN8(BUS_MESSAGE_FIELDS_SIZE(m)) &&

l == BUS_MESSAGE_BODY_SIZE(m))

m->body = d->data;

else {

sd_bus_message_unref(m);

return -EBADMSG;

}

idx += l;

}

r = bus_message_parse_fields(m);

if (r < 0) {

sd_bus_message_unref(m);

return r;

}

/* We take possession of the kmsg struct now */

m->kdbus = k;

m->free_kdbus = true;

m->free_fds = true;

fds = NULL;

*ret = m;

return 1;

}

int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {

struct kdbus_msg *k;

size_t sz = 128;

int r;

assert(bus);

assert(m);

for (;;) {

void *q;

q = realloc(bus->rbuffer, sz);

if (!q)

return -errno;

k = bus->rbuffer = q;

k->size = sz;

r = ioctl(bus->input_fd, KDBUS_CMD_MSG_RECV, bus->rbuffer);

if (r >= 0)

break;

if (errno == EAGAIN)

return 0;

if (errno != EMSGSIZE)

return -errno;

sz *= 2;

}

r = bus_kernel_make_message(bus, k, m);

if (r > 0)

bus->rbuffer = NULL;

else

close_kdbus_msg(k);

return r;

}

int bus_kernel_create(const char *name, char **s) {

struct kdbus_cmd_fname *fname;

size_t l;

int fd;

char *p;

assert(name);

assert(s);

fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);

if (fd < 0)

return -errno;

l = strlen(name);

fname = alloca(offsetof(struct kdbus_cmd_fname, name) + DECIMAL_STR_MAX(uid_t) + 1 + l + 1);

sprintf(fname->name, "%lu-%s", (unsigned long) getuid(), name);

fname->size = offsetof(struct kdbus_cmd_fname, name) + strlen(fname->name) + 1;

fname->kernel_flags = KDBUS_CMD_FNAME_ACCESS_WORLD;

fname->user_flags = 0;

p = strjoin("/dev/kdbus/", fname->name, "/bus", NULL);

if (!p)

return -ENOMEM;

if (ioctl(fd, KDBUS_CMD_BUS_MAKE, fname) < 0) {

close_nointr_nofail(fd);

free(p);

return -errno;

}

if (s)

*s = p;

return fd;

}