[PATCH 5.15 35/84] tls: rx: factor out writing ContentType to cmsg

Greg Kroah-Hartman
2024-03-04T21:54:03Z

From: Jakub Kicinski <kuba@kernel.org>

[ Upstream commit 06554f4ffc2595ae52ee80aec4a13bd77d22bed7 ]

cmsg can be filled in during rx_list processing or normal
receive. Consolidate the code.

We don't need to keep the boolean to track if the cmsg was
created. 0 is an invalid content type.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: f7fa16d49837 ("tls: decrement decrypt_pending if no async completion will be called")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/tls/tls_sw.c | 91 +++++++++++++++++++-----------------------------
1 file changed, 36 insertions(+), 55 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index c491cde30504e..ca71a9f559b37 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1634,6 +1634,29 @@ static bool tls_sw_advance_skb(struct sock *sk, struct sk_buff *skb,
return true;
}

+static int tls_record_content_type(struct msghdr *msg, struct tls_msg *tlm,
+ u8 *control)
+{
+ int err;
+
+ if (!*control) {
+ *control = tlm->control;
+ if (!*control)
+ return -EBADMSG;
+
+ err = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
+ sizeof(*control), control);
+ if (*control != TLS_RECORD_TYPE_DATA) {
+ if (err || msg->msg_flags & MSG_CTRUNC)
+ return -EIO;
+ }
+ } else if (*control != tlm->control) {
+ return 0;
+ }
+
+ return 1;
+}
+
/* This function traverses the rx_list in tls receive context to copies the
* decrypted records into the buffer provided by caller zero copy is not
* true. Further, the records are removed from the rx_list if it is not a peek
@@ -1642,31 +1665,23 @@ static bool tls_sw_advance_skb(struct sock *sk, struct sk_buff *skb,
static int process_rx_list(struct tls_sw_context_rx *ctx,
struct msghdr *msg,
u8 *control,
- bool *cmsg,
size_t skip,
size_t len,
bool zc,
bool is_peek)
{
struct sk_buff *skb = skb_peek(&ctx->rx_list);
- u8 ctrl = *control;
- u8 msgc = *cmsg;
struct tls_msg *tlm;
ssize_t copied = 0;
-
- /* Set the record type in 'control' if caller didn't pass it */
- if (!ctrl && skb) {
- tlm = tls_msg(skb);
- ctrl = tlm->control;
- }
+ int err;

while (skip && skb) {
struct strp_msg *rxm = strp_msg(skb);
tlm = tls_msg(skb);

- /* Cannot process a record of different type */
- if (ctrl != tlm->control)
- return 0;
+ err = tls_record_content_type(msg, tlm, control);
+ if (err <= 0)
+ return err;

if (skip < rxm->full_len)
break;
@@ -1682,27 +1697,12 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,

tlm = tls_msg(skb);

- /* Cannot process a record of different type */
- if (ctrl != tlm->control)
- return 0;
-
- /* Set record type if not already done. For a non-data record,
- * do not proceed if record type could not be copied.
- */
- if (!msgc) {
- int cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
- sizeof(ctrl), &ctrl);
- msgc = true;
- if (ctrl != TLS_RECORD_TYPE_DATA) {
- if (cerr || msg->msg_flags & MSG_CTRUNC)
- return -EIO;
-
- *cmsg = msgc;
- }
- }
+ err = tls_record_content_type(msg, tlm, control);
+ if (err <= 0)
+ return err;

if (!zc || (rxm->full_len - skip) > len) {
- int err = skb_copy_datagram_msg(skb, rxm->offset + skip,
+ err = skb_copy_datagram_msg(skb, rxm->offset + skip,
msg, chunk);
if (err < 0)
return err;
@@ -1739,7 +1739,6 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
skb = next_skb;
}

- *control = ctrl;
return copied;
}

@@ -1761,7 +1760,6 @@ int tls_sw_recvmsg(struct sock *sk,
struct tls_msg *tlm;
struct sk_buff *skb;
ssize_t copied = 0;
- bool cmsg = false;
int target, err = 0;
long timeo;
bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
@@ -1778,8 +1776,7 @@ int tls_sw_recvmsg(struct sock *sk,
bpf_strp_enabled = sk_psock_strp_enabled(psock);

/* Process pending decrypted records. It must be non-zero-copy */
- err = process_rx_list(ctx, msg, &control, &cmsg, 0, len, false,
- is_peek);
+ err = process_rx_list(ctx, msg, &control, 0, len, false, is_peek);
if (err < 0) {
tls_err_abort(sk, err);
goto end;
@@ -1851,26 +1848,10 @@ int tls_sw_recvmsg(struct sock *sk,
* is known just after record is dequeued from stream parser.
* For tls1.3, we disable async.
*/
-
- if (!control)
- control = tlm->control;
- else if (control != tlm->control)
+ err = tls_record_content_type(msg, tlm, &control);
+ if (err <= 0)
goto recv_end;

- if (!cmsg) {
- int cerr;
-
- cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
- sizeof(control), &control);
- cmsg = true;
- if (control != TLS_RECORD_TYPE_DATA) {
- if (cerr || msg->msg_flags & MSG_CTRUNC) {
- err = -EIO;
- goto recv_end;
- }
- }
- }
-
if (async) {
/* TLS 1.2-only, to_decrypt must be text length */
chunk = min_t(int, to_decrypt, len);
@@ -1959,10 +1940,10 @@ int tls_sw_recvmsg(struct sock *sk,

/* Drain records from the rx_list & copy if required */
if (is_peek || is_kvec)
- err = process_rx_list(ctx, msg, &control, &cmsg, copied,
+ err = process_rx_list(ctx, msg, &control, copied,
decrypted, false, is_peek);
else
- err = process_rx_list(ctx, msg, &control, &cmsg, 0,
+ err = process_rx_list(ctx, msg, &control, 0,
decrypted, true, is_peek);
if (err < 0) {
tls_err_abort(sk, err);
--
2.43.0