[PATCH bpf-next 1/2] net-tun: add type safety to tun_xdp_to_ptr() and tun_ptr_to_xdp()

Subsystems: networking drivers, the rest, tun/tap driver

STALE2205d LANDED

Landed in mainline as b558b6c24068 on 2020-08-19.

3 messages, 2 authors, 2020-08-19 · open the first message on its own page

[PATCH bpf-next 1/2] net-tun: add type safety to tun_xdp_to_ptr() and tun_ptr_to_xdp()

From: Maciej Żenczykowski <hidden>
Date: 2020-08-19 01:07:25

From: Maciej Żenczykowski <redacted>

This reduces likelihood of incorrect use.

Test: builds
Signed-off-by: Maciej Żenczykowski <redacted>
---
 drivers/net/tun.c      | 6 +++---
 include/linux/if_tun.h | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 3c11a77f5709..5dd7f353eeef 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c

@@ -225,13 +225,13 @@ bool tun_is_xdp_frame(void *ptr)
 }
 EXPORT_SYMBOL(tun_is_xdp_frame);
 
-void *tun_xdp_to_ptr(void *ptr)
+void *tun_xdp_to_ptr(struct xdp_frame *xdp)
 {
-	return (void *)((unsigned long)ptr | TUN_XDP_FLAG);
+	return (void *)((unsigned long)xdp | TUN_XDP_FLAG);
 }
 EXPORT_SYMBOL(tun_xdp_to_ptr);
 
-void *tun_ptr_to_xdp(void *ptr)
+struct xdp_frame *tun_ptr_to_xdp(void *ptr)
 {
 	return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
 }

diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 5bda8cf457b6..6c37e1dbc5df 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h

@@ -28,8 +28,8 @@ struct tun_xdp_hdr {
 struct socket *tun_get_socket(struct file *);
 struct ptr_ring *tun_get_tx_ring(struct file *file);
 bool tun_is_xdp_frame(void *ptr);
-void *tun_xdp_to_ptr(void *ptr);
-void *tun_ptr_to_xdp(void *ptr);
+void *tun_xdp_to_ptr(struct xdp_frame *xdp);
+struct xdp_frame *tun_ptr_to_xdp(void *ptr);
 void tun_ptr_free(void *ptr);
 #else
 #include <linux/err.h>

@@ -48,11 +48,11 @@ static inline bool tun_is_xdp_frame(void *ptr)
 {
 	return false;
 }
-static inline void *tun_xdp_to_ptr(void *ptr)
+static inline void *tun_xdp_to_ptr(struct xdp_frame *xdp)
 {
 	return NULL;
 }
-static inline void *tun_ptr_to_xdp(void *ptr)
+static inline struct xdp_frame *tun_ptr_to_xdp(void *ptr)
 {
 	return NULL;
 }

-- 
2.28.0.220.ged08abb693-goog

[PATCH bpf-next 2/2] net-tun: eliminate two tun/xdp related function calls from vhost-net

From: Maciej Żenczykowski <hidden>
Date: 2020-08-19 01:07:29

From: Maciej Żenczykowski <redacted>

This provides a minor performance boost by virtue of inlining
instead of cross module function calls.

Test: builds
Signed-off-by: Maciej Żenczykowski <redacted>
---
 drivers/net/tun.c      | 18 ------------------
 include/linux/if_tun.h | 15 ++++++++++++---
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 5dd7f353eeef..efaef83b8897 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c

@@ -219,24 +219,6 @@ struct veth {
 	__be16 h_vlan_TCI;
 };
 
-bool tun_is_xdp_frame(void *ptr)
-{
-	return (unsigned long)ptr & TUN_XDP_FLAG;
-}
-EXPORT_SYMBOL(tun_is_xdp_frame);
-
-void *tun_xdp_to_ptr(struct xdp_frame *xdp)
-{
-	return (void *)((unsigned long)xdp | TUN_XDP_FLAG);
-}
-EXPORT_SYMBOL(tun_xdp_to_ptr);
-
-struct xdp_frame *tun_ptr_to_xdp(void *ptr)
-{
-	return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
-}
-EXPORT_SYMBOL(tun_ptr_to_xdp);
-
 static int tun_napi_receive(struct napi_struct *napi, int budget)
 {
 	struct tun_file *tfile = container_of(napi, struct tun_file, napi);

diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 6c37e1dbc5df..2a7660843444 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h

@@ -27,9 +27,18 @@ struct tun_xdp_hdr {
 #if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
 struct socket *tun_get_socket(struct file *);
 struct ptr_ring *tun_get_tx_ring(struct file *file);
-bool tun_is_xdp_frame(void *ptr);
-void *tun_xdp_to_ptr(struct xdp_frame *xdp);
-struct xdp_frame *tun_ptr_to_xdp(void *ptr);
+static inline bool tun_is_xdp_frame(void *ptr)
+{
+       return (unsigned long)ptr & TUN_XDP_FLAG;
+}
+static inline void *tun_xdp_to_ptr(struct xdp_frame *xdp)
+{
+       return (void *)((unsigned long)xdp | TUN_XDP_FLAG);
+}
+static inline struct xdp_frame *tun_ptr_to_xdp(void *ptr)
+{
+       return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
+}
 void tun_ptr_free(void *ptr);
 #else
 #include <linux/err.h>

-- 
2.28.0.220.ged08abb693-goog

Re: [PATCH bpf-next 1/2] net-tun: add type safety to tun_xdp_to_ptr() and tun_ptr_to_xdp()

From: Alexei Starovoitov <hidden>
Date: 2020-08-19 21:09:41

On Tue, Aug 18, 2020 at 6:07 PM Maciej Żenczykowski
[off-list ref] wrote:

From: Maciej Żenczykowski <redacted>

This reduces likelihood of incorrect use.

Test: builds
Signed-off-by: Maciej Żenczykowski <redacted>

Applied. Thanks

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