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linux/net/handshake/alert.c
Chuck Lever b470985c76 net/handshake: Trace events for TLS Alert helpers
Add observability for the new TLS Alert infrastructure.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/169047947409.5241.14548832149596892717.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-28 14:07:59 -07:00

111 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Handle the TLS Alert protocol
*
* Author: Chuck Lever <chuck.lever@oracle.com>
*
* Copyright (c) 2023, Oracle and/or its affiliates.
*/
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/inet.h>
#include <net/sock.h>
#include <net/handshake.h>
#include <net/tls.h>
#include <net/tls_prot.h>
#include "handshake.h"
#include <trace/events/handshake.h>
/**
* tls_alert_send - send a TLS Alert on a kTLS socket
* @sock: open kTLS socket to send on
* @level: TLS Alert level
* @description: TLS Alert description
*
* Returns zero on success or a negative errno.
*/
int tls_alert_send(struct socket *sock, u8 level, u8 description)
{
u8 record_type = TLS_RECORD_TYPE_ALERT;
u8 buf[CMSG_SPACE(sizeof(record_type))];
struct msghdr msg = { 0 };
struct cmsghdr *cmsg;
struct kvec iov;
u8 alert[2];
int ret;
trace_tls_alert_send(sock->sk, level, description);
alert[0] = level;
alert[1] = description;
iov.iov_base = alert;
iov.iov_len = sizeof(alert);
memset(buf, 0, sizeof(buf));
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
msg.msg_flags = MSG_DONTWAIT;
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_TLS;
cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
cmsg->cmsg_len = CMSG_LEN(sizeof(record_type));
memcpy(CMSG_DATA(cmsg), &record_type, sizeof(record_type));
iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, iov.iov_len);
ret = sock_sendmsg(sock, &msg);
return ret < 0 ? ret : 0;
}
/**
* tls_get_record_type - Look for TLS RECORD_TYPE information
* @sk: socket (for IP address information)
* @cmsg: incoming message to be parsed
*
* Returns zero or a TLS_RECORD_TYPE value.
*/
u8 tls_get_record_type(const struct sock *sk, const struct cmsghdr *cmsg)
{
u8 record_type;
if (cmsg->cmsg_level != SOL_TLS)
return 0;
if (cmsg->cmsg_type != TLS_GET_RECORD_TYPE)
return 0;
record_type = *((u8 *)CMSG_DATA(cmsg));
trace_tls_contenttype(sk, record_type);
return record_type;
}
EXPORT_SYMBOL(tls_get_record_type);
/**
* tls_alert_recv - Parse TLS Alert messages
* @sk: socket (for IP address information)
* @msg: incoming message to be parsed
* @level: OUT - TLS AlertLevel value
* @description: OUT - TLS AlertDescription value
*
*/
void tls_alert_recv(const struct sock *sk, const struct msghdr *msg,
u8 *level, u8 *description)
{
const struct kvec *iov;
u8 *data;
iov = msg->msg_iter.kvec;
data = iov->iov_base;
*level = data[0];
*description = data[1];
trace_tls_alert_recv(sk, *level, *description);
}
EXPORT_SYMBOL(tls_alert_recv);