Re: [PATCH 1/2] netfilter: fix - mistake to pass a pointer where array is required

[lizf <lizf@cn.fujitsu.com>]

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Patrick McHardy wrote:
>> Macros like SCTP_CHUNKMAP_XXX(chukmap) require chukmap to be an array,
>> We can see from below:
>>
>> #define ELEMCOUNT(x) (sizeof(x)/sizeof(x[0]))
>>
>> #define SCTP_CHUNKMAP_RESET(chunkmap)                \
>>     do {                            \
>>         int i;                        \
>>         for (i = 0; i < ELEMCOUNT(chunkmap); i++)    \
>>             chunkmap[i] = 0;            \
>>     } while (0)
>>
>> But match_packet() passes a pointer to these macros. Here's the patch.
>>
>> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> 
> 
> Thanks, but your mailer corrupted the patch by converting tabs to
> spaces. Please resend as attachment so I can apply it.
> 
> 

Sorry for the noise, I've configed my mailer according to a kernel doc,
but i'm still not sure whether it works. So here's the attachment.

Li Zefan


[-- Attachment #2: xt_sctp.patch --]
[-- Type: text/x-patch, Size: 2054 bytes --]

diff --git a/net/netfilter/xt_sctp.c b/net/netfilter/xt_sctp.c
index c002153..f65c71c 100644
--- a/net/netfilter/xt_sctp.c
+++ b/net/netfilter/xt_sctp.c
@@ -41,21 +41,22 @@ match_flags(const struct xt_sctp_flag_info *flag_info,
 static inline bool
 match_packet(const struct sk_buff *skb,
 	     unsigned int offset,
-	     const u_int32_t *chunkmap,
-	     int chunk_match_type,
-	     const struct xt_sctp_flag_info *flag_info,
-	     const int flag_count,
+	     const struct xt_sctp_info *info,
 	     bool *hotdrop)
 {
 	u_int32_t chunkmapcopy[256 / sizeof (u_int32_t)];
 	sctp_chunkhdr_t _sch, *sch;
 
+	int chunk_match_type = info->chunk_match_type;
+	const struct xt_sctp_flag_info *flag_info = info->flag_info;
+	int flag_count = info->flag_count;
+
 #ifdef DEBUG_SCTP
 	int i = 0;
 #endif
 
 	if (chunk_match_type == SCTP_CHUNK_MATCH_ALL)
-		SCTP_CHUNKMAP_COPY(chunkmapcopy, chunkmap);
+		SCTP_CHUNKMAP_COPY(chunkmapcopy, info->chunkmap);
 
 	do {
 		sch = skb_header_pointer(skb, offset, sizeof(_sch), &_sch);
@@ -72,7 +73,7 @@ match_packet(const struct sk_buff *skb,
 
 		duprintf("skb->len: %d\toffset: %d\n", skb->len, offset);
 
-		if (SCTP_CHUNKMAP_IS_SET(chunkmap, sch->type)) {
+		if (SCTP_CHUNKMAP_IS_SET(info->chunkmap, sch->type)) {
 			switch (chunk_match_type) {
 			case SCTP_CHUNK_MATCH_ANY:
 				if (match_flags(flag_info, flag_count,
@@ -103,7 +104,7 @@ match_packet(const struct sk_buff *skb,
 
 	switch (chunk_match_type) {
 	case SCTP_CHUNK_MATCH_ALL:
-		return SCTP_CHUNKMAP_IS_CLEAR(chunkmap);
+		return SCTP_CHUNKMAP_IS_CLEAR(info->chunkmap);
 	case SCTP_CHUNK_MATCH_ANY:
 		return false;
 	case SCTP_CHUNK_MATCH_ONLY:
@@ -147,9 +148,7 @@ match(const struct sk_buff *skb,
 			&& ntohs(sh->dest) <= info->dpts[1],
 			XT_SCTP_DEST_PORTS, info->flags, info->invflags)
 		&& SCCHECK(match_packet(skb, protoff + sizeof (sctp_sctphdr_t),
-					info->chunkmap, info->chunk_match_type,
-					info->flag_info, info->flag_count,
-					hotdrop),
+					info, hotdrop),
 			   XT_SCTP_CHUNK_TYPES, info->flags, info->invflags);
 }