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zephyr/modusocket: Implement recv() for TCP sockets.

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Short read approach is taken - at most, the remaining data in the current
fragment will be returned.
This commit is contained in:
Paul Sokolovsky 2017-04-02 16:27:09 +03:00
parent bf51e2ff98
commit ca81c3ab0b
1 changed files with 77 additions and 0 deletions
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77
zephyr/modusocket.c
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@ -44,6 +44,13 @@ typedef struct _socket_obj_t {
mp_obj_base_t base;
struct net_context *ctx;
struct k_fifo recv_q;
struct net_buf *cur_buf;
#define STATE_NEW 0
#define STATE_CONNECTING 1
#define STATE_CONNECTED 2
#define STATE_PEER_CLOSED 3
int8_t state;
} socket_obj_t;
STATIC const mp_obj_type_t socket_type;
@ -103,6 +110,19 @@ static void sock_received_cb(struct net_context *context, struct net_buf *net_bu
}
DEBUG_printf("\n");
// if net_buf == NULL, EOF
if (net_buf == NULL) {
// TODO: k_fifo accessor for this?
struct net_buf *last_buf = (struct net_buf*)sys_slist_peek_tail(&socket->recv_q.data_q);
// We abuse "buf_sent" flag to store EOF flag
net_nbuf_set_buf_sent(last_buf, true);
DEBUG_printf("Set EOF flag on %p\n", last_buf);
return;
}
// Make sure that "EOF flag" is not set
net_nbuf_set_buf_sent(net_buf, false);
// net_buf->frags will be overwritten by fifo, so save it
net_nbuf_set_token(net_buf, net_buf->frags);
k_fifo_put(&socket->recv_q, net_buf);
@ -126,6 +146,8 @@ STATIC mp_obj_t socket_make_new(const mp_obj_type_t *type, size_t n_args, size_t
socket_obj_t *socket = m_new_obj_with_finaliser(socket_obj_t);
socket->base.type = type;
k_fifo_init(&socket->recv_q);
socket->cur_buf = NULL;
socket->state = STATE_NEW;
int family = AF_INET;
int socktype = SOCK_STREAM;
@ -226,6 +248,61 @@ STATIC mp_obj_t socket_recv(mp_obj_t self_in, mp_obj_t len_in) {
net_buf_gather(net_buf, vstr.buf, recv_len);
net_nbuf_unref(net_buf);
} else if (sock_type == SOCK_STREAM) {
do {
if (socket->state == STATE_PEER_CLOSED) {
return mp_const_empty_bytes;
}
unsigned header_len = 0;
if (socket->cur_buf == NULL) {
DEBUG_printf("TCP recv: no cur_buf, getting\n");
struct net_buf *net_buf = k_fifo_get(&socket->recv_q, K_FOREVER);
// Restore ->frags overwritten by fifo
net_buf->frags = net_nbuf_token(net_buf);
header_len = net_nbuf_appdata(net_buf) - net_buf->frags->data;
DEBUG_printf("TCP recv: new cur_buf: %p, hdr_len: %u\n", net_buf, header_len);
socket->cur_buf = net_buf;
}
struct net_buf *frag = socket->cur_buf->frags;
if (frag == NULL) {
printf("net_buf has empty fragments on start!\n");
assert(0);
}
net_buf_pull(frag, header_len);
unsigned frag_len = frag->len;
recv_len = frag_len;
if (recv_len > max_len) {
recv_len = max_len;
}
DEBUG_printf("%d data bytes in head frag, going to read %d\n", frag_len, recv_len);
vstr_init_len(&vstr, recv_len);
memcpy(vstr.buf, frag->data, recv_len);
if (recv_len != frag_len) {
net_buf_pull(frag, recv_len);
} else {
frag = net_buf_frag_del(socket->cur_buf, frag);
if (frag == NULL) {
DEBUG_printf("Finished processing net_buf %p\n", socket->cur_buf);
// If "buf_sent" flag was set, it's last packet and we reached EOF
if (net_nbuf_buf_sent(socket->cur_buf)) {
socket->state = STATE_PEER_CLOSED;
}
net_nbuf_unref(socket->cur_buf);
socket->cur_buf = NULL;
}
}
// Keep repeating while we're getting empty fragments
// Zephyr IP stack appears to feed empty net_buf's with empty
// frags for various TCP control packets.
} while (recv_len == 0);
} else {
mp_not_implemented("");
}