1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Handle the TLS Alert protocol
4 *
5 * Author: Chuck Lever <chuck.lever@oracle.com>
6 *
7 * Copyright (c) 2023, Oracle and/or its affiliates.
8 */
9
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/inet.h>
16
17 #include <net/sock.h>
18 #include <net/handshake.h>
19 #include <net/tls.h>
20 #include <net/tls_prot.h>
21
22 #include "handshake.h"
23
24 #include <trace/events/handshake.h>
25
26 /**
27 * tls_alert_send - send a TLS Alert on a kTLS socket
28 * @sock: open kTLS socket to send on
29 * @level: TLS Alert level
30 * @description: TLS Alert description
31 *
32 * Returns zero on success or a negative errno.
33 */
34 int tls_alert_send(struct socket *sock, u8 level, u8 description)
35 {
36 u8 record_type = TLS_RECORD_TYPE_ALERT;
37 u8 buf[CMSG_SPACE(sizeof(record_type))];
38 struct msghdr msg = { 0 };
39 struct cmsghdr *cmsg;
40 struct kvec iov;
41 u8 alert[2];
42 int ret;
43
44 trace_tls_alert_send(sock->sk, level, description);
45
46 alert[0] = level;
47 alert[1] = description;
48 iov.iov_base = alert;
49 iov.iov_len = sizeof(alert);
50
51 memset(buf, 0, sizeof(buf));
52 msg.msg_control = buf;
53 msg.msg_controllen = sizeof(buf);
54 msg.msg_flags = MSG_DONTWAIT;
55
56 cmsg = CMSG_FIRSTHDR(&msg);
57 cmsg->cmsg_level = SOL_TLS;
58 cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
59 cmsg->cmsg_len = CMSG_LEN(sizeof(record_type));
60 memcpy(CMSG_DATA(cmsg), &record_type, sizeof(record_type));
61
62 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, iov.iov_len);
63 ret = sock_sendmsg(sock, &msg);
64 return ret < 0 ? ret : 0;
65 }
66
67 /**
68 * tls_get_record_type - Look for TLS RECORD_TYPE information
69 * @sk: socket (for IP address information)
70 * @cmsg: incoming message to be parsed
71 *
72 * Returns zero or a TLS_RECORD_TYPE value.
73 */
74 u8 tls_get_record_type(const struct sock *sk, const struct cmsghdr *cmsg)
75 {
76 u8 record_type;
77
78 if (cmsg->cmsg_level != SOL_TLS)
79 return 0;
80 if (cmsg->cmsg_type != TLS_GET_RECORD_TYPE)
81 return 0;
82
83 record_type = *((u8 *)CMSG_DATA(cmsg));
84 trace_tls_contenttype(sk, record_type);
85 return record_type;
86 }
87 EXPORT_SYMBOL(tls_get_record_type);
88
89 /**
90 * tls_alert_recv - Parse TLS Alert messages
91 * @sk: socket (for IP address information)
92 * @msg: incoming message to be parsed
93 * @level: OUT - TLS AlertLevel value
94 * @description: OUT - TLS AlertDescription value
95 *
96 */
97 void tls_alert_recv(const struct sock *sk, const struct msghdr *msg,
98 u8 *level, u8 *description)
99 {
100 const struct kvec *iov;
101 u8 *data;
102
103 iov = msg->msg_iter.kvec;
104 data = iov->iov_base;
105 *level = data[0];
106 *description = data[1];
107
108 trace_tls_alert_recv(sk, *level, *description);
109 }
110 EXPORT_SYMBOL(tls_alert_recv);
111
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