/**
* Try to retrieve data from the buffer associate with the file descriptor.
* The read buffer is filled if required. If a complete message is available
* it is returned. The message is passed through amsg_verify before it is
* returned.
*
* @param fd The file descriptor to read a message from.
* @return A complete message in malloced memory or NULL if there is no
* data or only an incomplete message. If this function returns NULL,
* it is guaranteed that data must be read from the file descriptor
* before a complete message can be returned. It is not guaranteed
* that all available data from the file descriptor was actuall read!
*/
struct anoubisd_msg *
get_msg(int fd)
{
struct msg_buf *mbp;
struct anoubisd_msg *msg;
struct anoubisd_msg *msg_r;
int copy;
if ((mbp = _get_mbp(fd)) == NULL) {
log_warnx("msg_buf not initialized");
return NULL;
}
if (mbp->rmsg) {
if ((int)mbp->rmsgoff != mbp->rmsg->size)
if (!_fill_buf(mbp))
goto eof;
if ((int)mbp->rmsgoff == mbp->rmsg->size) {
msg_r = mbp->rmsg;
mbp->rmsg = NULL;
mbp->rmsgoff = 0;
goto message;
}
return NULL;
}
/* we need at least the struct anoubisd_msg structure. */
if (mbp->rtailp - mbp->rheadp < (int)sizeof(struct anoubisd_msg))
if (!_fill_buf(mbp))
goto eof;
if (mbp->rtailp - mbp->rheadp < (int)sizeof(struct anoubisd_msg))
return NULL;
/* check for a complete message */
msg = (struct anoubisd_msg *)mbp->rheadp;
if (msg->size > MSG_SIZE_LIMIT
|| msg->size < (int)sizeof(struct anoubisd_msg)) {
log_warnx("get_msg: Bad message size %d", msg->size);
master_terminate();
}
if ((msg_r = malloc(msg->size)) == NULL) {
log_warn("get_msg: can't allocate memory");
master_terminate();
}
copy = mbp->rtailp - mbp->rheadp;
if (copy > msg->size)
copy = msg->size;
memcpy(msg_r, msg, copy);
mbp->rheadp += copy;
if (msg_r->size != copy) {
mbp->rmsg = msg_r;
mbp->rmsgoff = copy;
return NULL;
}
message:
amsg_verify(msg_r);
DEBUG(DBG_MSG_RECV, "get_msg: fd:%d size:%d", mbp->fd, msg_r->size);
return msg_r;
eof:
return NULL;
}
/*
Поскольку точное время жизненно важно для хранилища, то обращаться с ним
следует следующим образом:
- проведем базовую проверку сравнив в временем компиляции и установим
time_good если проверка пройдена.
- ждем, пока появится время GPS,
- проведем коррекцию. Если время RTC в прошлом - то просто добавим разницу
к текущему значению, в противном случае сбросим флаг time_good, будем ждать,
пока время GPS не догонит системное. Если разница больше чем
STORAGE_VOID_LIMIT_US - обнулим хранилище и начнем с начала.
*/
bool_t bnapStorageDoRecord(BnapStorage_t *bsp){
bool_t status;
int64_t timestamp = -1;
/* there is no sense to do something without normal time */
if (GlobalFlags.time_good != 1)
return CH_FAILED;
if (GlobalFlags.time_proved == 1){
timestamp = fastGetTimeUnixUsec();
if (bsp->mtime > timestamp){
if (bsp->mtime > (timestamp + STORAGE_VOID_LIMIT_US)){/* time too far in future */
bnapStorageWipe(bsp);
}
return CH_FAILED; /* wait until mtime be older than current system time */
}
}
_fill_buf(bsp->buf, ×tamp);
status = bsp->mmcp->vmt->write(bsp->mmcp, bsp->tip, bsp->buf, 1);
chDbgCheck(status == CH_SUCCESS, "write failed");
bsp->tip++;
if (bsp->tip >= bsp->mmcp->capacity)
bsp->tip = 0; /* wrap ring buffer */
bsp->used++;
if (bsp->used >= bsp->mmcp->capacity)
bsp->used = bsp->mmcp->capacity; /* clamp value */
bsp->mtime = timestamp;
return CH_SUCCESS;
}
/**
* Read an anoubis protocol message from a client connected to the session
* engine. A client message on the wire consists of a 32 bit length in
* network byte order followed by the actual message data. The length
* given includes the 32 length itself and the 32 bit checksum at the
* end of the message.
*
* @param fd The file descriptor to read from.
* @param msgp A complete message (if any) is stored here. This value
* must never be NULL. The pointer pointed to by msgp is either set
* to NULL or is set to point to the result message. The result message
* is allocated using anoubis_msg_new and must be freed by the caller
* with anoubis_msg_free.
* @return Zero if EOF is encountered. A negative error code if an error
* occured or a positive value in case of success.
* NOTE: Success does not mean that there is a complete message
* available. The message may still be incomplete. In this case
* NULL is stored in *msgp.
*/
int
get_client_msg(int fd, struct anoubis_msg **msgp)
{
struct msg_buf *mbp;
u_int32_t len;
struct anoubis_msg *m;
*msgp = NULL;
if ((mbp = _get_mbp(fd)) == NULL)
return 0;
if (mbp->rmsg) {
log_warnx("get_client_msg: Bad buffer state");
return 0;
}
if ((unsigned int)(mbp->rtailp - mbp->rheadp) < sizeof(len))
if (!_fill_buf(mbp))
return 0;
if ((unsigned int)(mbp->rtailp - mbp->rheadp) < sizeof(len))
return 1;
len = ntohl(*(u_int32_t*)mbp->rheadp);
if ((unsigned int)(mbp->rtailp - mbp->rheadp) < len)
if (!_fill_buf(mbp))
return 0;
if ((unsigned int)(mbp->rtailp - mbp->rheadp) < len)
return 1;
/*
* anoubis_msg_new expects the size of the message without
* the message length and without the trainling checksum (i.e.
* payload data only). However, m->length of the resulting
* message includes the checksum but not the message length.
* This is the reason for the somewhat surprising length calculations.
*/
m = anoubis_msg_new(len - sizeof(len) - CSUM_LEN);
if (!m)
return -ENOMEM;
memcpy(m->u.buf, mbp->rheadp+sizeof(len), m->length);
mbp->rheadp += len;
*msgp = m;
return 1;
}