1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
#include "s2n.h"
int s2n_example_recv(struct s2n_connection *conn, uint8_t *buffer, size_t buffer_size)
{
s2n_blocked_status blocked = S2N_NOT_BLOCKED;
int bytes_read = 0;
while (bytes_read < buffer_size) {
int r = s2n_recv(conn, buffer + bytes_read, buffer_size - bytes_read, &blocked);
if (r > 0) {
/* `r` bytes were successfully received. Update `bytes_read` so the next `s2n_recv()`
* call writes into the buffer with the correct offset.
*/
bytes_read += r;
} else if (r == 0) {
/* The connection was closed. No more data will be received, so bail out of the loop. */
break;
} else if (s2n_error_get_type(s2n_errno) == S2N_ERR_T_BLOCKED) {
/* The return of `s2n_recv()` indicates an error. If this error is `S2N_ERR_T_BLOCKED`,
* the socket is blocked waiting to receive more data from the peer.
*
* In a typical non-blocking environment, `poll()` or `select()` would be used re-enter
* `s2n_example_recv()` and call `s2n_recv()` again after the socket has more data
* available. But this example just busy-waits, so we immediately call `s2n_recv()`
* again.
*/
continue;
} else {
/* `s2n_recv()` encountered an irrecoverable error. Log the error and return. */
fprintf(stderr, "Error: %s. %s\n", s2n_strerror(s2n_errno, NULL), s2n_strerror_debug(s2n_errno, NULL));
return -1;
}
}
fprintf(stdout, "Received: %.*s\n", bytes_read, buffer);
return 0;
}
int s2n_example_recv_echo(struct s2n_connection *conn, uint8_t *buffer, size_t buffer_size)
{
s2n_blocked_status blocked = S2N_NOT_BLOCKED;
while (true) {
int r = s2n_recv(conn, buffer, buffer_size, &blocked);
if (r == 0) {
fprintf(stdout, "End of data.\n");
return 0;
} else if (r > 0) {
fprintf(stdout, "Received: %.*s\n", r, buffer);
} else if (r < 0 && s2n_error_get_type(s2n_errno) != S2N_ERR_T_BLOCKED) {
fprintf(stderr, "Error: %s. %s\n", s2n_strerror(s2n_errno, NULL), s2n_strerror_debug(s2n_errno, NULL));
return -1;
}
}
}
|
