[PATCH net-next v3 4/5] selftests: drv-net: psp: factor out psp connection setup

[Daniel Zahka <daniel.zahka@gmail.com>]

Lift out connection setup and PSP assoc uapi code in psp.py and
responder, so that the key exchange sequence can be used in other test
cases that start with a key exchange, but might choose to perform
additional tx/rx assoc calls afterwards.

The caller of conn_setup_psp() not handling errors was preexisting. Here
we are adding some more error paths, so we just handle errors by closing
the data sock to make the code a bit more robust.

Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
---
v3:
- take key lengths from the kernel's rx-assoc reply instead of a
  per-version table
- close the data socket in psp_responder if conn_setup_psp() fails
---
 tools/testing/selftests/drivers/net/psp.py         | 14 +++-
 .../testing/selftests/drivers/net/psp_responder.c  | 78 ++++++++++++++--------
 2 files changed, 63 insertions(+), 29 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/psp.py b/tools/testing/selftests/drivers/net/psp.py
index 473500901879..71eeade62ad2 100755
--- a/tools/testing/selftests/drivers/net/psp.py
+++ b/tools/testing/selftests/drivers/net/psp.py
@@ -447,10 +447,11 @@ def assoc_twice(cfg):
             ksft_eq(len(tx), 0)
 
 
-def _data_basic_send(cfg, version, ipver):
-    """ Test basic data send """
-    _init_psp_dev(cfg)
+def _establish_psp_conn(cfg, version, ipver=None):
+    """Establish a PSP connection and return after key exchange
 
+    Requires _init_psp_dev() to have been called first.
+    """
     # Version 0 is required by spec, don't let it skip
     if version:
         name = cfg.pspnl.consts["version"].entries_by_val[version].name
@@ -475,7 +476,14 @@ def _data_basic_send(cfg, version, ipver):
                         "version": version,
                         "tx-key": tx,
                         "sock-fd": s.fileno()})
+    return s
+
+
+def _data_basic_send(cfg, version, ipver):
+    """ Test basic data send """
+    _init_psp_dev(cfg)
 
+    s = _establish_psp_conn(cfg, version, ipver)
     data_len = _send_careful(cfg, s, 100)
     _check_data_rx(cfg, data_len)
     _close_psp_conn(cfg, s)
diff --git a/tools/testing/selftests/drivers/net/psp_responder.c b/tools/testing/selftests/drivers/net/psp_responder.c
index a26e7628bbb1..14b179e1aec8 100644
--- a/tools/testing/selftests/drivers/net/psp_responder.c
+++ b/tools/testing/selftests/drivers/net/psp_responder.c
@@ -37,20 +37,15 @@ static struct {
 	unsigned char rx;
 } psp_vers;
 
-static int conn_setup_psp(struct ynl_sock *ys, struct opts *opts, int data_sock)
+#define PSP_MAX_KEY_LEN		32
+
+static int
+rx_assoc(struct ynl_sock *ys, __u32 *spi, char *key, unsigned int *key_len,
+	 int data_sock)
 {
 	struct psp_rx_assoc_rsp *rsp;
 	struct psp_rx_assoc_req *req;
-	struct psp_tx_assoc_rsp *tsp;
-	struct psp_tx_assoc_req *teq;
-	char info[300];
-	int key_len;
-	ssize_t sz;
-	__u32 spi;
 
-	dbg("create PSP connection\n");
-
-	// Rx assoc alloc
 	req = psp_rx_assoc_req_alloc();
 
 	psp_rx_assoc_req_set_sock_fd(req, data_sock);
@@ -64,29 +59,28 @@ static int conn_setup_psp(struct ynl_sock *ys, struct opts *opts, int data_sock)
 		return -1;
 	}
 
-	// SPI exchange
-	key_len = rsp->rx_key._len.key;
-	memcpy(info, &rsp->rx_key.spi, sizeof(spi));
-	memcpy(&info[sizeof(spi)], rsp->rx_key.key, key_len);
-	sz = sizeof(spi) + key_len;
+	*key_len = rsp->rx_key._len.key;
+	memcpy(spi, &rsp->rx_key.spi, sizeof(*spi));
+	memcpy(key, rsp->rx_key.key, *key_len);
 
-	send(data_sock, info, sz, MSG_WAITALL);
 	psp_rx_assoc_rsp_free(rsp);
 
-	sz = recv(data_sock, info, sz, MSG_WAITALL);
-	if (sz < 0) {
-		perror("ERROR: failed to read PSP key from sock");
-		return -1;
-	}
-	memcpy(&spi, info, sizeof(spi));
+	return 0;
+}
+
+static int
+tx_assoc(struct ynl_sock *ys, __u8 version, __u32 spi, char *key,
+	 unsigned int key_len, int data_sock)
+{
+	struct psp_tx_assoc_rsp *tsp;
+	struct psp_tx_assoc_req *teq;
 
-	// Setup Tx assoc
 	teq = psp_tx_assoc_req_alloc();
 
 	psp_tx_assoc_req_set_sock_fd(teq, data_sock);
-	psp_tx_assoc_req_set_version(teq, psp_vers.tx);
+	psp_tx_assoc_req_set_version(teq, version);
 	psp_tx_assoc_req_set_tx_key_spi(teq, spi);
-	psp_tx_assoc_req_set_tx_key_key(teq, &info[sizeof(spi)], key_len);
+	psp_tx_assoc_req_set_tx_key_key(teq, key, key_len);
 
 	tsp = psp_tx_assoc(ys, teq);
 	psp_tx_assoc_req_free(teq);
@@ -99,6 +93,35 @@ static int conn_setup_psp(struct ynl_sock *ys, struct opts *opts, int data_sock)
 	return 0;
 }
 
+static int conn_setup_psp(struct ynl_sock *ys, struct opts *opts, int data_sock)
+{
+	char info[sizeof(__u32) + PSP_MAX_KEY_LEN];
+	unsigned int key_len;
+	ssize_t sz;
+	__u32 spi;
+
+	dbg("create PSP connection\n");
+
+	if (rx_assoc(ys, &spi, &info[sizeof(spi)], &key_len, data_sock))
+		return -1;
+
+	// SPI exchange
+	memcpy(info, &spi, sizeof(spi));
+	sz = sizeof(spi) + key_len;
+
+	send(data_sock, info, sz, MSG_WAITALL);
+
+	sz = recv(data_sock, info, sz, MSG_WAITALL);
+	if (sz < 0) {
+		perror("ERROR: failed to read PSP key from sock");
+		return -1;
+	}
+	memcpy(&spi, info, sizeof(spi));
+
+	return tx_assoc(ys, psp_vers.tx, spi, &info[sizeof(spi)], key_len,
+			data_sock);
+}
+
 static void send_ack(int sock)
 {
 	send(sock, "ack", 4, MSG_WAITALL);
@@ -282,7 +305,10 @@ run_session(struct ynl_sock *ys, struct opts *opts,
 				/* nothing to do */
 			} else if (accept_cfg == ACCEPT_CFG_PSP) {
 				dbg("new data sock: psp\n");
-				conn_setup_psp(ys, opts, data_sock);
+				if (conn_setup_psp(ys, opts, data_sock)) {
+					close(data_sock);
+					data_sock = -1;
+				}
 			} else {
 				fprintf(stderr, "WARN: new data sock but no config\n");
 			}

-- 
2.52.0