kTLS sockets use cmsg to report decryption errors and the need
for session re-keying. An "application data" message contains a ULP
payload, and that is passed along to the RPC client. An "alert"
message triggers connection reset. Everything else is discarded.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/net/tls.h | 2 ++
include/trace/events/sunrpc.h | 40 +++++++++++++++++++++++++++++++++
net/sunrpc/xprtsock.c | 49 +++++++++++++++++++++++++++++++++++++++--
3 files changed, 89 insertions(+), 2 deletions(-)
diff --git a/include/net/tls.h b/include/net/tls.h
index 6b1bf46daa34..54bccb2e4014 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -71,6 +71,8 @@ static inline struct tlsh_sock *tlsh_sk(struct sock *sk)
#define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type)
+#define TLS_RECORD_TYPE_ALERT 0x15
+#define TLS_RECORD_TYPE_HANDSHAKE 0x16
#define TLS_RECORD_TYPE_DATA 0x17
#define TLS_AAD_SPACE_SIZE 13
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 986e135e314f..d7d07f3b850e 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -1319,6 +1319,46 @@ TRACE_EVENT(xs_data_ready,
TP_printk("peer=[%s]:%s", __get_str(addr), __get_str(port))
);
+/*
+ * From https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml
+ *
+ * Captured March 2022. Other values are unassigned or reserved.
+ */
+#define rpc_show_tls_content_type(type) \
+ __print_symbolic(type, \
+ { 20, "change cipher spec" }, \
+ { 21, "alert" }, \
+ { 22, "handshake" }, \
+ { 23, "application data" }, \
+ { 24, "heartbeat" }, \
+ { 25, "tls12_cid" }, \
+ { 26, "ACK" })
+
+TRACE_EVENT(xs_tls_contenttype,
+ TP_PROTO(
+ const struct rpc_xprt *xprt,
+ unsigned char ctype
+ ),
+
+ TP_ARGS(xprt, ctype),
+
+ TP_STRUCT__entry(
+ __string(addr, xprt->address_strings[RPC_DISPLAY_ADDR])
+ __string(port, xprt->address_strings[RPC_DISPLAY_PORT])
+ __field(unsigned long, ctype)
+ ),
+
+ TP_fast_assign(
+ __assign_str(addr, xprt->address_strings[RPC_DISPLAY_ADDR]);
+ __assign_str(port, xprt->address_strings[RPC_DISPLAY_PORT]);
+ __entry->ctype = ctype;
+ ),
+
+ TP_printk("peer=[%s]:%s: %s", __get_str(addr), __get_str(port),
+ rpc_show_tls_content_type(__entry->ctype)
+ )
+);
+
TRACE_EVENT(xs_stream_read_data,
TP_PROTO(struct rpc_xprt *xprt, ssize_t err, size_t total),
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 0a521aee0b2f..c73af8f1c3d4 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -47,6 +47,8 @@
#include <net/checksum.h>
#include <net/udp.h>
#include <net/tcp.h>
+#include <net/tls.h>
+
#include <linux/bvec.h>
#include <linux/highmem.h>
#include <linux/uio.h>
@@ -350,13 +352,56 @@ xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
return want;
}
+static int
+xs_sock_process_cmsg(struct socket *sock, struct msghdr *msg,
+ struct cmsghdr *cmsg, int ret)
+{
+ if (cmsg->cmsg_level == SOL_TLS &&
+ cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {
+ u8 content_type = *((u8 *)CMSG_DATA(cmsg));
+
+ trace_xs_tls_contenttype(xprt_from_sock(sock->sk), content_type);
+ switch (content_type) {
+ case TLS_RECORD_TYPE_DATA:
+ /* TLS sets EOR at the end of each application data
+ * record, even though there might be more frames
+ * waiting to be decrypted. */
+ msg->msg_flags &= ~MSG_EOR;
+ break;
+ case TLS_RECORD_TYPE_ALERT:
+ ret = -ENOTCONN;
+ break;
+ default:
+ ret = -EAGAIN;
+ }
+ }
+ return ret;
+}
+
+static int
+xs_sock_recv_cmsg(struct socket *sock, struct msghdr *msg, int flags)
+{
+ union {
+ struct cmsghdr cmsg;
+ u8 buf[CMSG_SPACE(sizeof(u8))];
+ } u;
+ int ret;
+
+ msg->msg_control = &u;
+ msg->msg_controllen = sizeof(u);
+ ret = sock_recvmsg(sock, msg, flags);
+ if (msg->msg_controllen != sizeof(u))
+ ret = xs_sock_process_cmsg(sock, msg, &u.cmsg, ret);
+ return ret;
+}
+
static ssize_t
xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
{
ssize_t ret;
if (seek != 0)
iov_iter_advance(&msg->msg_iter, seek);
- ret = sock_recvmsg(sock, msg, flags);
+ ret = xs_sock_recv_cmsg(sock, msg, flags);
return ret > 0 ? ret + seek : ret;
}
@@ -382,7 +427,7 @@ xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
size_t count)
{
iov_iter_discard(&msg->msg_iter, READ, count);
- return sock_recvmsg(sock, msg, flags);
+ return xs_sock_recv_cmsg(sock, msg, flags);
}
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
