// Helper function for send/sendto to handle TCP packets STATIC mp_uint_t lwip_tcp_send(lwip_socket_obj_t *socket, const byte *buf, mp_uint_t len, int *_errno) { // Check for any pending errors STREAM_ERROR_CHECK(socket); u16_t available = tcp_sndbuf(socket->pcb.tcp); if (available == 0) { // Non-blocking socket if (socket->timeout == 0) { *_errno = MP_EAGAIN; return MP_STREAM_ERROR; } mp_uint_t start = mp_hal_ticks_ms(); // Assume that STATE_PEER_CLOSED may mean half-closed connection, where peer closed it // sending direction, but not receiving. Consequently, check for both STATE_CONNECTED // and STATE_PEER_CLOSED as normal conditions and still waiting for buffers to be sent. // If peer fully closed socket, we would have socket->state set to ERR_RST (connection // reset) by error callback. // Avoid sending too small packets, so wait until at least 16 bytes available while (socket->state >= STATE_CONNECTED && (available = tcp_sndbuf(socket->pcb.tcp)) < 16) { if (socket->timeout != -1 && mp_hal_ticks_ms() - start > socket->timeout) { *_errno = MP_ETIMEDOUT; return MP_STREAM_ERROR; } poll_sockets(); } // While we waited, something could happen STREAM_ERROR_CHECK(socket); } u16_t write_len = MIN(available, len); err_t err = tcp_write(socket->pcb.tcp, buf, write_len, TCP_WRITE_FLAG_COPY); // If the output buffer is getting full then send the data to the lower layers if (err == ERR_OK && tcp_sndbuf(socket->pcb.tcp) < TCP_SND_BUF / 4) { err = tcp_output(socket->pcb.tcp); } if (err != ERR_OK) { *_errno = error_lookup_table[-err]; return MP_STREAM_ERROR; } return write_len; }
// Helper function for recv/recvfrom to handle TCP packets STATIC mp_uint_t lwip_tcp_receive(lwip_socket_obj_t *socket, byte *buf, mp_uint_t len, int *_errno) { // Check for any pending errors STREAM_ERROR_CHECK(socket); if (socket->incoming.pbuf == NULL) { // Non-blocking socket if (socket->timeout == 0) { if (socket->state == STATE_PEER_CLOSED) { return 0; } *_errno = MP_EAGAIN; return -1; } mp_uint_t start = mp_hal_ticks_ms(); while (socket->state == STATE_CONNECTED && socket->incoming.pbuf == NULL) { if (socket->timeout != -1 && mp_hal_ticks_ms() - start > socket->timeout) { *_errno = MP_ETIMEDOUT; return -1; } poll_sockets(); } if (socket->state == STATE_PEER_CLOSED) { if (socket->incoming.pbuf == NULL) { // socket closed and no data left in buffer return 0; } } else if (socket->state != STATE_CONNECTED) { assert(socket->state < 0); *_errno = error_lookup_table[-socket->state]; return -1; } } assert(socket->pcb.tcp != NULL); struct pbuf *p = socket->incoming.pbuf; if (socket->leftover_count == 0) { socket->leftover_count = p->tot_len; } u16_t result = pbuf_copy_partial(p, buf, ((socket->leftover_count >= len) ? len : socket->leftover_count), (p->tot_len - socket->leftover_count)); if (socket->leftover_count > len) { // More left over... socket->leftover_count -= len; } else { pbuf_free(p); socket->incoming.pbuf = NULL; socket->leftover_count = 0; } tcp_recved(socket->pcb.tcp, result); return (mp_uint_t) result; }
// Helper function for recv/recvfrom to handle TCP packets STATIC mp_uint_t lwip_tcp_receive(lwip_socket_obj_t *socket, byte *buf, mp_uint_t len, int *_errno) { // Check for any pending errors STREAM_ERROR_CHECK(socket); if (socket->incoming.pbuf == NULL) { // Non-blocking socket if (socket->timeout == 0) { if (socket->state == STATE_PEER_CLOSED) { return 0; } *_errno = MP_EAGAIN; return -1; } mp_uint_t start = mp_hal_ticks_ms(); while (socket->state == STATE_CONNECTED && socket->incoming.pbuf == NULL) { if (socket->timeout != -1 && mp_hal_ticks_ms() - start > socket->timeout) { *_errno = MP_ETIMEDOUT; return -1; } poll_sockets(); } if (socket->state == STATE_PEER_CLOSED) { if (socket->incoming.pbuf == NULL) { // socket closed and no data left in buffer return 0; } } else if (socket->state != STATE_CONNECTED) { assert(socket->state < 0); *_errno = error_lookup_table[-socket->state]; return -1; } } assert(socket->pcb.tcp != NULL); struct pbuf *p = socket->incoming.pbuf; mp_uint_t remaining = p->len - socket->recv_offset; if (len > remaining) { len = remaining; } memcpy(buf, (byte*)p->payload + socket->recv_offset, len); remaining -= len; if (remaining == 0) { socket->incoming.pbuf = p->next; // If we don't ref here, free() will free the entire chain, // if we ref, it does what we need: frees 1st buf, and decrements // next buf's refcount back to 1. pbuf_ref(p->next); pbuf_free(p); socket->recv_offset = 0; } else { socket->recv_offset += len; } tcp_recved(socket->pcb.tcp, len); return len; }