Merge branch 'net-add-debug-checks-to-skb_reset_xxx_header'

kuba-moo · kuba-moo · commit c1ddfdbee369 · 2024-11-06T17:29:17.000-08:00
Eric Dumazet says: ==================== net: add debug checks to skb_reset_xxx_header() Add debug checks (only enabled for CONFIG_DEBUG_NET=y builds), to catch bugs earlier. ==================== Link: https://patch.msgid.link/20241105174403.850330-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
@@ -2909,9 +2909,19 @@ static inline void skb_reset_inner_headers(struct sk_buff *skb)
 	skb->inner_transport_header = skb->transport_header;
 }
 
+static inline int skb_mac_header_was_set(const struct sk_buff *skb)
+{
+	return skb->mac_header != (typeof(skb->mac_header))~0U;
+}
+
 static inline void skb_reset_mac_len(struct sk_buff *skb)
 {
-	skb->mac_len = skb->network_header - skb->mac_header;
+	if (!skb_mac_header_was_set(skb)) {
+		DEBUG_NET_WARN_ON_ONCE(1);
+		skb->mac_len = 0;
+	} else {
+		skb->mac_len = skb->network_header - skb->mac_header;
+	}
 }
 
 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
@@ -2927,7 +2937,10 @@ static inline int skb_inner_transport_offset(const struct sk_buff *skb)
 
 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
 {
-	skb->inner_transport_header = skb->data - skb->head;
+	long offset = skb->data - skb->head;
+
+	DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_transport_header))offset);
+	skb->inner_transport_header = offset;
 }
 
 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
@@ -2944,7 +2957,10 @@ static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
 
 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
 {
-	skb->inner_network_header = skb->data - skb->head;
+	long offset = skb->data - skb->head;
+
+	DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_network_header))offset);
+	skb->inner_network_header = offset;
 }
 
 static inline void skb_set_inner_network_header(struct sk_buff *skb,
@@ -2966,7 +2982,10 @@ static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
 
 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
 {
-	skb->inner_mac_header = skb->data - skb->head;
+	long offset = skb->data - skb->head;
+
+	DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_mac_header))offset);
+	skb->inner_mac_header = offset;
 }
 
 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
@@ -2988,7 +3007,10 @@ static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
 
 static inline void skb_reset_transport_header(struct sk_buff *skb)
 {
-	skb->transport_header = skb->data - skb->head;
+	long offset = skb->data - skb->head;
+
+	DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->transport_header))offset);
+	skb->transport_header = offset;
 }
 
 static inline void skb_set_transport_header(struct sk_buff *skb,
@@ -3005,7 +3027,10 @@ static inline unsigned char *skb_network_header(const struct sk_buff *skb)
 
 static inline void skb_reset_network_header(struct sk_buff *skb)
 {
-	skb->network_header = skb->data - skb->head;
+	long offset = skb->data - skb->head;
+
+	DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->network_header))offset);
+	skb->network_header = offset;
 }
 
 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
@@ -3014,11 +3039,6 @@ static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
 	skb->network_header += offset;
 }
 
-static inline int skb_mac_header_was_set(const struct sk_buff *skb)
-{
-	return skb->mac_header != (typeof(skb->mac_header))~0U;
-}
-
 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
 {
 	DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
@@ -3043,7 +3063,10 @@ static inline void skb_unset_mac_header(struct sk_buff *skb)
 
 static inline void skb_reset_mac_header(struct sk_buff *skb)
 {
-	skb->mac_header = skb->data - skb->head;
+	long offset = skb->data - skb->head;
+
+	DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->mac_header))offset);
+	skb->mac_header = offset;
 }
 
 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)

Original file line number	Diff line number	Diff line change
`@@ -2909,9 +2909,19 @@ static inline void skb_reset_inner_headers(struct sk_buff *skb)`
`2909`	`2909`	`skb->inner_transport_header = skb->transport_header;`
`2910`	`2910`	`}`
`2911`	`2911`
	`2912`	`+static inline int skb_mac_header_was_set(const struct sk_buff *skb)`
	`2913`	`+{`
	`2914`	`+ return skb->mac_header != (typeof(skb->mac_header))~0U;`
	`2915`	`+}`
	`2916`	`+`
`2912`	`2917`	`static inline void skb_reset_mac_len(struct sk_buff *skb)`
`2913`	`2918`	`{`
`2914`		`- skb->mac_len = skb->network_header - skb->mac_header;`
	`2919`	`+ if (!skb_mac_header_was_set(skb)) {`
	`2920`	`+ DEBUG_NET_WARN_ON_ONCE(1);`
	`2921`	`+ skb->mac_len = 0;`
	`2922`	`+ } else {`
	`2923`	`+ skb->mac_len = skb->network_header - skb->mac_header;`
	`2924`	`+ }`
`2915`	`2925`	`}`
`2916`	`2926`
`2917`	`2927`	`static inline unsigned char *skb_inner_transport_header(const struct sk_buff`
`@@ -2927,7 +2937,10 @@ static inline int skb_inner_transport_offset(const struct sk_buff *skb)`
`2927`	`2937`
`2928`	`2938`	`static inline void skb_reset_inner_transport_header(struct sk_buff *skb)`
`2929`	`2939`	`{`
`2930`		`- skb->inner_transport_header = skb->data - skb->head;`
	`2940`	`+ long offset = skb->data - skb->head;`
	`2941`	`+`
	`2942`	`+ DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_transport_header))offset);`
	`2943`	`+ skb->inner_transport_header = offset;`
`2931`	`2944`	`}`
`2932`	`2945`
`2933`	`2946`	`static inline void skb_set_inner_transport_header(struct sk_buff *skb,`
`@@ -2944,7 +2957,10 @@ static inline unsigned char skb_inner_network_header(const struct sk_buff skb)`
`2944`	`2957`
`2945`	`2958`	`static inline void skb_reset_inner_network_header(struct sk_buff *skb)`
`2946`	`2959`	`{`
`2947`		`- skb->inner_network_header = skb->data - skb->head;`
	`2960`	`+ long offset = skb->data - skb->head;`
	`2961`	`+`
	`2962`	`+ DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_network_header))offset);`
	`2963`	`+ skb->inner_network_header = offset;`
`2948`	`2964`	`}`
`2949`	`2965`
`2950`	`2966`	`static inline void skb_set_inner_network_header(struct sk_buff *skb,`
`@@ -2966,7 +2982,10 @@ static inline unsigned char skb_inner_mac_header(const struct sk_buff skb)`
`2966`	`2982`
`2967`	`2983`	`static inline void skb_reset_inner_mac_header(struct sk_buff *skb)`
`2968`	`2984`	`{`
`2969`		`- skb->inner_mac_header = skb->data - skb->head;`
	`2985`	`+ long offset = skb->data - skb->head;`
	`2986`	`+`
	`2987`	`+ DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_mac_header))offset);`
	`2988`	`+ skb->inner_mac_header = offset;`
`2970`	`2989`	`}`
`2971`	`2990`
`2972`	`2991`	`static inline void skb_set_inner_mac_header(struct sk_buff *skb,`
`@@ -2988,7 +3007,10 @@ static inline unsigned char skb_transport_header(const struct sk_buff skb)`
`2988`	`3007`
`2989`	`3008`	`static inline void skb_reset_transport_header(struct sk_buff *skb)`
`2990`	`3009`	`{`
`2991`		`- skb->transport_header = skb->data - skb->head;`
	`3010`	`+ long offset = skb->data - skb->head;`
	`3011`	`+`
	`3012`	`+ DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->transport_header))offset);`
	`3013`	`+ skb->transport_header = offset;`
`2992`	`3014`	`}`
`2993`	`3015`
`2994`	`3016`	`static inline void skb_set_transport_header(struct sk_buff *skb,`
`@@ -3005,7 +3027,10 @@ static inline unsigned char skb_network_header(const struct sk_buff skb)`
`3005`	`3027`
`3006`	`3028`	`static inline void skb_reset_network_header(struct sk_buff *skb)`
`3007`	`3029`	`{`
`3008`		`- skb->network_header = skb->data - skb->head;`
	`3030`	`+ long offset = skb->data - skb->head;`
	`3031`	`+`
	`3032`	`+ DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->network_header))offset);`
	`3033`	`+ skb->network_header = offset;`
`3009`	`3034`	`}`
`3010`	`3035`
`3011`	`3036`	`static inline void skb_set_network_header(struct sk_buff *skb, const int offset)`
`@@ -3014,11 +3039,6 @@ static inline void skb_set_network_header(struct sk_buff *skb, const int offset)`
`3014`	`3039`	`skb->network_header += offset;`
`3015`	`3040`	`}`
`3016`	`3041`
`3017`		`-static inline int skb_mac_header_was_set(const struct sk_buff *skb)`
`3018`		`-{`
`3019`		`- return skb->mac_header != (typeof(skb->mac_header))~0U;`
`3020`		`-}`
`3021`		`-`
`3022`	`3042`	`static inline unsigned char skb_mac_header(const struct sk_buff skb)`
`3023`	`3043`	`{`
`3024`	`3044`	`DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));`
`@@ -3043,7 +3063,10 @@ static inline void skb_unset_mac_header(struct sk_buff *skb)`
`3043`	`3063`
`3044`	`3064`	`static inline void skb_reset_mac_header(struct sk_buff *skb)`
`3045`	`3065`	`{`
`3046`		`- skb->mac_header = skb->data - skb->head;`
	`3066`	`+ long offset = skb->data - skb->head;`
	`3067`	`+`
	`3068`	`+ DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->mac_header))offset);`
	`3069`	`+ skb->mac_header = offset;`
`3047`	`3070`	`}`
`3048`	`3071`
`3049`	`3072`	`static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)`