[PATCH 14/14] nvmet-tcp: control messages for recvmsg()
Hannes Reinecke
hare at suse.de
Thu Aug 3 03:51:02 PDT 2023
kTLS requires control messages for recvmsg() to relay any out-of-band
TLS messages (eg TLS alerts) to the caller.
Signed-off-by: Hannes Reinecke <hare at suse.de>
---
drivers/nvme/target/tcp.c | 87 +++++++++++++++++++++++++++++++++------
1 file changed, 74 insertions(+), 13 deletions(-)
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 7279c994abd6..e2db573d68d9 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -14,6 +14,7 @@
#include <net/sock.h>
#include <net/tcp.h>
#include <net/tls.h>
+#include <net/tls_prot.h>
#include <net/handshake.h>
#include <linux/inet.h>
#include <linux/llist.h>
@@ -118,6 +119,7 @@ struct nvmet_tcp_cmd {
u32 pdu_len;
u32 pdu_recv;
int sg_idx;
+ char recv_cbuf[CMSG_LEN(sizeof(char))];
struct msghdr recv_msg;
struct bio_vec *iov;
u32 flags;
@@ -1116,12 +1118,49 @@ static inline bool nvmet_tcp_pdu_valid(u8 type)
return false;
}
+static int nvmet_tcp_tls_record_ok(struct socket *sock, struct msghdr *msg, char *cbuf)
+{
+ struct cmsghdr *cmsg = (struct cmsghdr *)cbuf;
+ u8 ctype, level, description;
+ int ret = 0;
+
+ if (!IS_ENABLED(CONFIG_NVME_TARGET_TCP_TLS))
+ return 0;
+
+ ctype = tls_get_record_type(sock->sk, cmsg);
+ switch (ctype) {
+ case 0:
+ break;
+ case TLS_RECORD_TYPE_DATA:
+ break;
+ case TLS_RECORD_TYPE_ALERT:
+ tls_alert_recv(sock->sk, msg, &level, &description);
+ pr_err("TLS Alert level %u desc %u\n", level, description);
+ ret = (level == TLS_ALERT_LEVEL_FATAL) ?
+ -ENOTCONN : -EAGAIN;
+ break;
+ default:
+ /* discard this record type */
+ pr_err("TLS record %d unhandled\n", ctype);
+ ret = -EAGAIN;
+ break;
+ }
+ return ret;
+}
+
static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
{
struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
- int len;
+ int len, ret;
struct kvec iov;
- struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
+ char cbuf[CMSG_LEN(sizeof(char))] = {};
+ struct msghdr msg = {
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ .msg_control = cbuf,
+ .msg_controllen = sizeof(cbuf),
+#endif
+ .msg_flags = MSG_DONTWAIT
+ };
recv:
iov.iov_base = (void *)&queue->pdu + queue->offset;
@@ -1130,6 +1169,9 @@ static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
iov.iov_len, msg.msg_flags);
if (unlikely(len < 0))
return len;
+ ret = nvmet_tcp_tls_record_ok(queue->sock, &msg, cbuf);
+ if (ret < 0)
+ return ret;
queue->offset += len;
queue->left -= len;
@@ -1182,16 +1224,21 @@ static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
{
struct nvmet_tcp_cmd *cmd = queue->cmd;
- int ret;
+ int len, ret;
while (msg_data_left(&cmd->recv_msg)) {
- ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
+ len = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
cmd->recv_msg.msg_flags);
- if (ret <= 0)
+ if (len <= 0)
+ return len;
+ ret = nvmet_tcp_tls_record_ok(cmd->queue->sock,
+ &cmd->recv_msg,
+ cmd->recv_cbuf);
+ if (ret < 0)
return ret;
- cmd->pdu_recv += ret;
- cmd->rbytes_done += ret;
+ cmd->pdu_recv += len;
+ cmd->rbytes_done += len;
}
if (queue->data_digest) {
@@ -1209,20 +1256,30 @@ static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
{
struct nvmet_tcp_cmd *cmd = queue->cmd;
- int ret;
- struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
+ int ret, len;
+ char cbuf[CMSG_LEN(sizeof(char))] = {};
+ struct msghdr msg = {
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ .msg_control = cbuf,
+ .msg_controllen = sizeof(cbuf),
+#endif
+ .msg_flags = MSG_DONTWAIT
+ };
struct kvec iov = {
.iov_base = (void *)&cmd->recv_ddgst + queue->offset,
.iov_len = queue->left
};
- ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
+ len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
iov.iov_len, msg.msg_flags);
- if (unlikely(ret < 0))
+ if (unlikely(len < 0))
+ return len;
+ ret = nvmet_tcp_tls_record_ok(queue->sock, &msg, cbuf);
+ if (ret < 0)
return ret;
- queue->offset += ret;
- queue->left -= ret;
+ queue->offset += len;
+ queue->left -= len;
if (queue->left)
return -EAGAIN;
@@ -1389,6 +1446,10 @@ static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
if (!c->r2t_pdu)
goto out_free_data;
+ if (IS_ENABLED(CONFIG_NVME_TARGET_TCP_TLS)) {
+ c->recv_msg.msg_control = c->recv_cbuf;
+ c->recv_msg.msg_controllen = sizeof(c->recv_cbuf);
+ }
c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
list_add_tail(&c->entry, &queue->free_list);
--
2.35.3
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