Does the rx packet that you copy from get freed somewhere else?
________________________________
From: [email protected]
[mailto:[email protected]] On Behalf Of
Justin Drake
Sent: 18 June 2012 15:31
To: [email protected]
Subject: [lwip-users] Problems freeing a packet buffer using pbuf_free
I am a function to send data packets. Each time a packet is receive, I create a
buffer using `pbuf_alloc`. I then send the packet using `upd_sendto`. Finally,
I free the buffer with `pbuf_free`.
For some reason, `pbuf_free` is not freeing the buffers. (I get a buffer
overflow after `n` packets, where `n` is the pool size.)
How can I have `pbuf_free` actually free my buffers? How is the buffer overflow
avoided?
Below is my implementation:
static err_t IAP_tftp_send_data_packet(struct udp_pcb *upcb, struct ip_addr
*to, int to_port, int block)
{
err_t err;
struct pbuf *pkt_buf;
char packet[TFTP_DATA_PKT_LEN_MAX];
int bytesRead;
int bytesToSend;
/* Specify that we are sending data. */
IAP_tftp_set_opcode(packet, TFTP_DATA);
/* Specify the block number that we are sending. */
IAP_tftp_set_block(packet, block);
bytesRead = IAP_tftp_set_data(packet, block);
if(bytesRead != 0) {
bytesToSend = TFTP_DATA_PKT_LEN_MAX - (512 - bytesRead + 1);
} else {
bytesToSend = TFTP_DATA_PKT_LEN_MAX - 512;
}
pkt_buf = pbuf_alloc(PBUF_TRANSPORT, bytesToSend, PBUF_POOL);
if (!pkt_buf)
{
print("(TFTP) Buffer overflow!\r\n");
}
/* Copy the file data onto pkt_buf. */
memcpy(pkt_buf->payload, packet, bytesToSend);
err = udp_sendto(upcb, pkt_buf, to, to_port);
/* free the buffer pbuf */
printf("%d\n\r", pbuf_free(pkt_buf));
return err;
}
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