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#include <sys/socket.h>
#include <errno.h>
#include <stdint.h>
#include <wasi/api.h>
#include <wasi/descriptor_table.h>
#include <wasi/sockets_utils.h>
static ssize_t tcp_recvfrom(tcp_socket_t *socket, uint8_t *buffer,
size_t length, int flags, struct sockaddr *addr,
socklen_t *addrlen)
{
// TODO wasi-sockets: flags:
// - MSG_WAITALL: we can probably support these relatively easy.
// - MSG_OOB: could be shimmed by always responding that no OOB data is available.
// - MSG_PEEK: could be shimmed by performing the receive into a local socket-specific buffer. And on subsequent receives first check that buffer.
const int supported_flags = MSG_DONTWAIT;
if ((flags & supported_flags) != flags) {
errno = EOPNOTSUPP;
return -1;
}
if (addr != NULL || addrlen != NULL) {
errno = EISCONN;
return -1;
}
tcp_socket_state_connected_t connection;
if (socket->state.tag == TCP_SOCKET_STATE_CONNECTED) {
connection = socket->state.connected;
} else {
errno = ENOTCONN;
return -1;
}
bool should_block = socket->blocking;
if ((flags & MSG_DONTWAIT) != 0) {
should_block = false;
}
streams_borrow_input_stream_t rx_borrow =
streams_borrow_input_stream(connection.input);
while (true) {
wasip2_list_u8_t result;
streams_stream_error_t error;
if (!streams_method_input_stream_read(rx_borrow, length,
&result, &error)) {
if (error.tag == STREAMS_STREAM_ERROR_CLOSED) {
return 0;
} else {
// TODO wasi-sockets: wasi-sockets has no way to recover TCP stream errors yet.
errno = EPIPE;
return -1;
}
}
if (result.len) {
memcpy(buffer, result.ptr, result.len);
wasip2_list_u8_free(&result);
return result.len;
} else if (should_block) {
poll_borrow_pollable_t pollable_borrow =
poll_borrow_pollable(connection.input_pollable);
poll_method_pollable_block(pollable_borrow);
} else {
errno = EWOULDBLOCK;
return -1;
}
}
}
static ssize_t udp_recvfrom(udp_socket_t *socket, uint8_t *buffer,
size_t length, int flags, struct sockaddr *addr,
socklen_t *addrlen)
{
// TODO wasi-sockets: flags:
// - MSG_PEEK: could be shimmed by performing the receive into a local socket-specific buffer. And on subsequent receives first check that buffer.
const int supported_flags = MSG_DONTWAIT | MSG_TRUNC;
if ((flags & supported_flags) != flags) {
errno = EOPNOTSUPP;
return -1;
}
output_sockaddr_t output_addr;
if (!__wasi_sockets_utils__output_addr_validate(
socket->family, addr, addrlen, &output_addr)) {
errno = EINVAL;
return -1;
}
network_error_code_t error;
udp_borrow_udp_socket_t socket_borrow =
udp_borrow_udp_socket(socket->socket);
udp_socket_streams_t streams;
switch (socket->state.tag) {
case UDP_SOCKET_STATE_UNBOUND: {
// Unlike `send`, `recv` should _not_ perform an implicit bind.
errno = EINVAL;
return -1;
}
case UDP_SOCKET_STATE_BOUND_NOSTREAMS: {
if (!__wasi_sockets_utils__stream(socket, NULL, &streams,
&error)) {
errno = __wasi_sockets_utils__map_error(error);
return -1;
}
break;
}
case UDP_SOCKET_STATE_BOUND_STREAMING:
streams = socket->state.bound_streaming.streams;
break;
case UDP_SOCKET_STATE_CONNECTED:
streams = socket->state.connected.streams;
break;
default: /* unreachable */
abort();
}
bool return_real_size = (flags & MSG_TRUNC) != 0;
bool should_block = socket->blocking;
if ((flags & MSG_DONTWAIT) != 0) {
should_block = false;
}
udp_borrow_incoming_datagram_stream_t incoming_borrow =
udp_borrow_incoming_datagram_stream(streams.incoming);
while (true) {
udp_list_incoming_datagram_t datagrams;
if (!udp_method_incoming_datagram_stream_receive(
incoming_borrow, 1, &datagrams, &error)) {
errno = __wasi_sockets_utils__map_error(error);
return -1;
}
if (datagrams.len) {
udp_incoming_datagram_t datagram = datagrams.ptr[0];
size_t datagram_size = datagram.data.len;
size_t bytes_to_copy =
datagram_size < length ? datagram_size : length;
if (output_addr.tag != OUTPUT_SOCKADDR_NULL) {
__wasi_sockets_utils__output_addr_write(
datagram.remote_address, &output_addr);
}
memcpy(buffer, datagram.data.ptr, bytes_to_copy);
udp_list_incoming_datagram_free(&datagrams);
return return_real_size ? datagram_size : bytes_to_copy;
} else if (should_block) {
poll_borrow_pollable_t pollable_borrow =
poll_borrow_pollable(streams.incoming_pollable);
poll_method_pollable_block(pollable_borrow);
} else {
errno = EWOULDBLOCK;
return -1;
}
}
}
ssize_t recv(int socket, void *restrict buffer, size_t length, int flags)
{
return recvfrom(socket, buffer, length, flags, NULL, NULL);
}
ssize_t recvfrom(int socket, void *__restrict buffer, size_t length, int flags,
struct sockaddr *__restrict addr,
socklen_t *__restrict addrlen)
{
descriptor_table_entry_t *entry;
if (!descriptor_table_get_ref(socket, &entry)) {
errno = EBADF;
return -1;
}
if (buffer == NULL) {
errno = EINVAL;
return -1;
}
switch (entry->tag) {
case DESCRIPTOR_TABLE_ENTRY_TCP_SOCKET:
return tcp_recvfrom(&entry->tcp_socket, buffer, length, flags,
addr, addrlen);
case DESCRIPTOR_TABLE_ENTRY_UDP_SOCKET:
return udp_recvfrom(&entry->udp_socket, buffer, length, flags,
addr, addrlen);
default:
errno = EOPNOTSUPP;
return -1;
}
}
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