uchar_ptr TFTP_read
(
uint_32_ptr size
/* [OUT] number of bytes read, or error code */
)
{ /* Body */
uint_32 sock;
sockaddr_in remote_addr;
uint_16 remote_size;
uint_16 ack_block;
uint_16 pkt_op, pkt_block;
uint_32 pkt_size;
uint_32 time_left;
boolean expired;
#if TFTP_TIMEOUT_RETRIES
uint_32 retries = 0;
#endif
ack_block = ntohs(TFTP_config.ACK.BLOCK);
TFTP_timeout_restart(&TFTP_config.TIMEOUT);
for (;;) {
/* Check for timeout */
time_left = TFTP_timeout_left(&TFTP_config.TIMEOUT, &expired);
if (expired) {
#if TFTP_TIMEOUT_RETRIES
retries++;
if (retries > TFTP_TIMEOUT_RETRIES) {
*size = RTCSERR_TFTP_TIMEOUT;
TFTP_close();
return NULL;
} /* Endif */
#endif
/* Retransmit the last packet */
TFTP_RESEND();
} /* Endif */
/* Wait for a packet */
sock = TFTP_WAIT(time_left);
/* Timeout -- retransmit last packet */
if (sock != TFTP_config.SOCK) {
continue;
} /* Endif */
remote_size = sizeof(remote_addr);
pkt_size = TFTP_RECV(TFTP_config.PACKET);
pkt_op = ntohs(TFTP_config.PACKET.HEAD.OP);
pkt_block = ntohs(TFTP_config.PACKET.HEAD.BLOCK);
/* Check source address of received packet */
if (remote_addr.sin_addr.s_addr != TFTP_config.SADDR.sin_addr.s_addr) {
continue;
} /* Endif */
/* Validate source port */
if (ack_block && remote_addr.sin_port != TFTP_config.SADDR.sin_port) {
TFTP_SEND(TFTP_config.SOCK, _tftp_error_tid, remote_addr);
continue;
} /* Endif */
/* Check size of received packet */
if (pkt_size < sizeof(TFTP_HEADER)) {
TFTP_SEND(TFTP_config.SOCK, _tftp_error_op, remote_addr);
*size = RTCSERR_TFTP_ERROR + TFTPERR_ILLEGAL_OP;
TFTP_close();
return NULL;
} /* Endif */
/* Check for error packet */
if (pkt_op == TFTPOP_ERROR) {
*size = RTCSERR_TFTP_ERROR + pkt_block;
TFTP_close();
return NULL;
} /* Endif */
/* Check for data packet */
if ((pkt_op != TFTPOP_DATA)
|| (pkt_size > sizeof(TFTP_PACKET))
|| (pkt_block < ack_block)
|| (pkt_block > ack_block+1)) {
TFTP_SEND(TFTP_config.SOCK, _tftp_error_op, remote_addr);
*size = RTCSERR_TFTP_ERROR + TFTPERR_ILLEGAL_OP;
TFTP_close();
return NULL;
} /* Endif */
/* Check for retransmitted packet */
if (pkt_block == ack_block) {
TFTP_timeout_restart(&TFTP_config.TIMEOUT);
TFTP_SEND(TFTP_config.SOCK, TFTP_config.ACK, TFTP_config.SADDR);
continue;
} /* Endif */
/* We have the next packet */
break;
} /* Endfor */
/* Update the adaptive timeout */
TFTP_timeout_update(&TFTP_config.TIMEOUT);
/* Free the original RRQ */
if (!ack_block) {
TFTP_config.SADDR.sin_port = remote_addr.sin_port;
_mem_free(TFTP_config.RRQ_PTR);
TFTP_config.RRQ_PTR = NULL;
} /* Endif */
/* ACK it */
ack_block++;
htons(TFTP_config.ACK.BLOCK, ack_block);
TFTP_SEND(TFTP_config.SOCK, TFTP_config.ACK, TFTP_config.SADDR);
TFTP_config.LAST = (pkt_size < sizeof(TFTP_PACKET));
/* Return the data */
*size = pkt_size - sizeof(TFTP_HEADER);
return TFTP_config.PACKET.DATA;
} /* Endbody */
unsigned char *TFTP_read
(
uint32_t *size
/* [OUT] number of bytes read, or error code */
)
{ /* Body */
uint32_t sock;
sockaddr_in remote_addr;
uint16_t remote_size;
uint16_t ack_block;
uint16_t pkt_op, pkt_block;
uint32_t pkt_size;
uint32_t time_left;
bool expired;
#if TFTP_TIMEOUT_RETRIES
uint32_t retries = 0;
#endif
ack_block = mqx_ntohs(TFTP_config.ACK.BLOCK);
TFTP_timeout_restart(&TFTP_config.TIMEOUT);
for (;;) {
/* Check for timeout */
time_left = TFTP_timeout_left(&TFTP_config.TIMEOUT, &expired);
if (expired) {
#if TFTP_TIMEOUT_RETRIES
retries++;
if (retries > TFTP_TIMEOUT_RETRIES) {
*size = RTCSERR_TFTP_TIMEOUT;
TFTP_close();
return NULL;
} /* Endif */
#endif
/* Retransmit the last packet */
TFTP_RESEND();
} /* Endif */
/* Wait for a packet */
sock = TFTP_WAIT(time_left);
/* Timeout -- retransmit last packet */
if (sock != TFTP_config.SOCK) {
continue;
} /* Endif */
remote_size = sizeof(remote_addr);
pkt_size = TFTP_RECV(TFTP_config.PACKET);
pkt_op = mqx_ntohs(TFTP_config.PACKET.HEAD.OP);
pkt_block = mqx_ntohs(TFTP_config.PACKET.HEAD.BLOCK);
/* Check source address of received packet */
if (remote_addr.sin_addr.s_addr != TFTP_config.SADDR.sin_addr.s_addr) {
continue;
} /* Endif */
/* Validate source port */
if (ack_block && remote_addr.sin_port != TFTP_config.SADDR.sin_port) {
TFTP_SEND(TFTP_config.SOCK, _tftp_error_tid, remote_addr);
continue;
} /* Endif */
/* Check size of received packet */
if (pkt_size < sizeof(TFTP_HEADER)) {
TFTP_SEND(TFTP_config.SOCK, _tftp_error_op, remote_addr);
*size = RTCSERR_TFTP_ERROR + TFTPERR_ILLEGAL_OP;
TFTP_close();
return NULL;
} /* Endif */
/* Check for error packet */
if (pkt_op == TFTPOP_ERROR) {
*size = RTCSERR_TFTP_ERROR + pkt_block;
TFTP_close();
return NULL;
} /* Endif */
/* Check for data packet */
if ((pkt_op != TFTPOP_DATA)
|| (pkt_size > sizeof(TFTP_PACKET))) {
TFTP_SEND(TFTP_config.SOCK, _tftp_error_op, remote_addr);
*size = RTCSERR_TFTP_ERROR + TFTPERR_ILLEGAL_OP;
TFTP_close();
return NULL;
} /* Endif */
/* Check for retransmitted packet */
if (pkt_block == ack_block) {
TFTP_timeout_restart(&TFTP_config.TIMEOUT);
TFTP_SEND(TFTP_config.SOCK, TFTP_config.ACK, TFTP_config.SADDR);
continue;
} /* Endif */
/* Aknowledge also packets with lower id, some servers do retransmit them until they get an ack */
if (pkt_block < ack_block) {
TFTP_timeout_restart(&TFTP_config.TIMEOUT);
mqx_htons(TFTP_config.ACK.BLOCK, pkt_block);
TFTP_SEND(TFTP_config.SOCK, TFTP_config.ACK, TFTP_config.SADDR);
mqx_htons(TFTP_config.ACK.BLOCK, ack_block); /* Restore id of last acknowledged packet */
continue;
} /* Endif */
/* Drop unexpected packets */
if (pkt_block > ack_block+1) {
/* Some server do send more than one packet at a time, these will eventually retransmitted */
continue;
}
/* We have the next packet */
break;
} /* Endfor */
/* Update the adaptive timeout */
TFTP_timeout_update(&TFTP_config.TIMEOUT);
/* Free the original RRQ */
if (!ack_block) {
TFTP_config.SADDR.sin_port = remote_addr.sin_port;
_mem_free(TFTP_config.RRQ_PTR);
TFTP_config.RRQ_PTR = NULL;
} /* Endif */
/* ACK it */
ack_block++;
mqx_htons(TFTP_config.ACK.BLOCK, ack_block);
TFTP_SEND(TFTP_config.SOCK, TFTP_config.ACK, TFTP_config.SADDR);
TFTP_config.LAST = (pkt_size < sizeof(TFTP_PACKET));
/* Return the data */
*size = pkt_size - sizeof(TFTP_HEADER);
return TFTP_config.PACKET.DATA;
} /* Endbody */