| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20250408233118.21452-7-ryazanov.s.a@gmail.com>
Date: Wed, 9 Apr 2025 02:31:18 +0300
From: Sergey Ryazanov <ryazanov.s.a@...il.com>
To: Loic Poulain <loic.poulain@....qualcomm.com>,
Johannes Berg <johannes@...solutions.net>
Cc: Andrew Lunn <andrew+netdev@...n.ch>,
Eric Dumazet <edumazet@...gle.com>,
"David S . Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
netdev@...r.kernel.org
Subject: [RFC PATCH 6/6] net: wwan: hwsim: support NMEA port emulation
Support NMEA port emulation for the WWAN core GNSS port testing purpose.
Emulator produces pair of GGA + RMC sentences every second what should
be enough to fool gpsd into believing it is working with a NMEA GNSS
receiver.
If the GNSS system is enabled then one NMEA port will be created
automatically for the simulated WWAN device. Manual NMEA port creation
is not supported at the moment.
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@...il.com>
---
drivers/net/wwan/wwan_hwsim.c | 128 +++++++++++++++++++++++++++++++++-
1 file changed, 126 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c
index 20277ba88433..5b5af2c9a63d 100644
--- a/drivers/net/wwan/wwan_hwsim.c
+++ b/drivers/net/wwan/wwan_hwsim.c
@@ -2,7 +2,7 @@
/*
* WWAN device simulator for WWAN framework testing.
*
- * Copyright (c) 2021, Sergey Ryazanov <ryazanov.s.a@...il.com>
+ * Copyright (c) 2021, 2025, Sergey Ryazanov <ryazanov.s.a@...il.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -12,8 +12,10 @@
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/spinlock.h>
+#include <linux/time.h>
#include <linux/list.h>
#include <linux/skbuff.h>
+#include <linux/timer.h>
#include <linux/netdevice.h>
#include <linux/wwan.h>
#include <linux/debugfs.h>
@@ -65,6 +67,9 @@ struct wwan_hwsim_port {
AT_PARSER_SKIP_LINE,
} pstate;
} at_emul;
+ struct {
+ struct timer_list timer;
+ } nmea_emul;
};
};
@@ -193,6 +198,108 @@ static const struct wwan_port_ops wwan_hwsim_at_emul_port_ops = {
.tx = wwan_hwsim_at_emul_tx,
};
+#if IS_ENABLED(CONFIG_GNSS)
+#define NMEA_MAX_LEN 82 /* Max sentence length */
+#define NMEA_TRAIL_LEN 5 /* '*' + Checksum + <CR><LF> */
+#define NMEA_MAX_DATA_LEN (NMEA_MAX_LEN - NMEA_TRAIL_LEN)
+
+static __printf(2, 3)
+void wwan_hwsim_nmea_skb_push_sentence(struct sk_buff *skb,
+ const char *fmt, ...)
+{
+ unsigned char *s, *p;
+ va_list ap;
+ u8 cs = 0;
+ int len;
+
+ s = skb_put(skb, NMEA_MAX_LEN + 1); /* +'\0' */
+ if (!s)
+ return;
+
+ va_start(ap, fmt);
+ len = vsnprintf(s, NMEA_MAX_DATA_LEN + 1, fmt, ap);
+ va_end(ap);
+ if (WARN_ON_ONCE(len > NMEA_MAX_DATA_LEN))/* No space for trailer */
+ return;
+
+ for (p = s + 1; *p != '\0'; ++p)/* Skip leading '$' or '!' */
+ cs ^= *p;
+ p += snprintf(p, 5 + 1, "*%02X\r\n", cs);
+
+ len = (p - s) - (NMEA_MAX_LEN + 1); /* exp. vs real length diff */
+ skb->tail += len; /* Adjust tail to real length */
+ skb->len += len;
+}
+
+static void wwan_hwsim_nmea_emul_timer(struct timer_list *t)
+{
+ /* 43.74754722298909 N 11.25759835922875 E in DMM format */
+ static const unsigned int coord[4 * 2] = { 43, 44, 8528, 0,
+ 11, 15, 4559, 0 };
+ struct wwan_hwsim_port *port = from_timer(port, t, nmea_emul.timer);
+ struct sk_buff *skb;
+ struct tm tm;
+
+ time64_to_tm(ktime_get_real_seconds(), 0, &tm);
+
+ mod_timer(&port->nmea_emul.timer, jiffies + HZ); /* 1 second */
+
+ skb = alloc_skb(NMEA_MAX_LEN * 2, GFP_KERNEL); /* GGA + RMC */
+ if (!skb)
+ return;
+
+ wwan_hwsim_nmea_skb_push_sentence(skb,
+ "$GPGGA,%02u%02u%02u.000,%02u%02u.%04u,%c,%03u%02u.%04u,%c,1,7,1.03,176.2,M,55.2,M,,",
+ tm.tm_hour, tm.tm_min, tm.tm_sec,
+ coord[0], coord[1], coord[2],
+ coord[3] ? 'S' : 'N',
+ coord[4], coord[5], coord[6],
+ coord[7] ? 'W' : 'E');
+
+ wwan_hwsim_nmea_skb_push_sentence(skb,
+ "$GPRMC,%02u%02u%02u.000,A,%02u%02u.%04u,%c,%03u%02u.%04u,%c,0.02,31.66,%02u%02u%02u,,,A",
+ tm.tm_hour, tm.tm_min, tm.tm_sec,
+ coord[0], coord[1], coord[2],
+ coord[3] ? 'S' : 'N',
+ coord[4], coord[5], coord[6],
+ coord[7] ? 'W' : 'E',
+ tm.tm_mday, tm.tm_mon + 1,
+ (unsigned int)tm.tm_year - 100);
+
+ wwan_port_rx(port->wwan, skb);
+}
+
+static int wwan_hwsim_nmea_emul_start(struct wwan_port *wport)
+{
+ struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport);
+
+ timer_setup(&port->nmea_emul.timer, wwan_hwsim_nmea_emul_timer, 0);
+ wwan_hwsim_nmea_emul_timer(&port->nmea_emul.timer);
+
+ return 0;
+}
+
+static void wwan_hwsim_nmea_emul_stop(struct wwan_port *wport)
+{
+ struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport);
+
+ timer_delete_sync(&port->nmea_emul.timer);
+}
+
+static int wwan_hwsim_nmea_emul_tx(struct wwan_port *wport, struct sk_buff *in)
+{
+ consume_skb(in);
+
+ return 0;
+}
+
+static const struct wwan_port_ops wwan_hwsim_nmea_emul_port_ops = {
+ .start = wwan_hwsim_nmea_emul_start,
+ .stop = wwan_hwsim_nmea_emul_stop,
+ .tx = wwan_hwsim_nmea_emul_tx,
+};
+#endif
+
static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev,
enum wwan_port_type type)
{
@@ -203,6 +310,10 @@ static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev,
if (type == WWAN_PORT_AT)
ops = &wwan_hwsim_at_emul_port_ops;
+#if IS_ENABLED(CONFIG_GNSS)
+ else if (type == WWAN_PORT_NMEA)
+ ops = &wwan_hwsim_nmea_emul_port_ops;
+#endif
else
return ERR_PTR(-EINVAL);
@@ -478,9 +589,10 @@ static int __init wwan_hwsim_init_devs(void)
list_add_tail(&dev->list, &wwan_hwsim_devs);
spin_unlock(&wwan_hwsim_devs_lock);
- /* Create a couple of ports per each device to accelerate
+ /* Create a few various ports per each device to accelerate
* the simulator readiness time.
*/
+
for (j = 0; j < 2; ++j) {
port = wwan_hwsim_port_new(dev, WWAN_PORT_AT);
if (IS_ERR(port))
@@ -490,6 +602,18 @@ static int __init wwan_hwsim_init_devs(void)
list_add_tail(&port->list, &dev->ports);
spin_unlock(&dev->ports_lock);
}
+
+#if IS_ENABLED(CONFIG_GNSS)
+ port = wwan_hwsim_port_new(dev, WWAN_PORT_NMEA);
+ if (IS_ERR(port)) {
+ dev_warn(&dev->dev, "failed to create initial NMEA port: %d\n",
+ (int)PTR_ERR(port));
+ } else {
+ spin_lock(&dev->ports_lock);
+ list_add_tail(&port->list, &dev->ports);
+ spin_unlock(&dev->ports_lock);
+ }
+#endif
}
return 0;
--
2.45.3
Powered by blists - more mailing lists