Andrew Morton <[EMAIL PROTECTED]> wrote: > >> Filter incoming data, looking for ICMP messages: >> >> tcpdump -f "ip proto \icmp" >> >> Well, that catches nothing.
We aren't handling the reading of specific fields like the IP protocol field correctly. This patch should make it work again. I tried to move this logic into the new load_pointer function but it all came out messy so I simply rolled it back. Signed-off-by: Herbert Xu <[EMAIL PROTECTED]> Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- diff --git a/net/core/filter.c b/net/core/filter.c --- a/net/core/filter.c +++ b/net/core/filter.c @@ -36,7 +36,7 @@ #include <linux/filter.h> /* No hurry in this branch */ -static void *__load_pointer(struct sk_buff *skb, int k) +static void *load_pointer(struct sk_buff *skb, int k) { u8 *ptr = NULL; @@ -50,18 +50,6 @@ static void *__load_pointer(struct sk_bu return NULL; } -static inline void *load_pointer(struct sk_buff *skb, int k, - unsigned int size, void *buffer) -{ - if (k >= 0) - return skb_header_pointer(skb, k, size, buffer); - else { - if (k >= SKF_AD_OFF) - return NULL; - return __load_pointer(skb, k); - } -} - /** * sk_run_filter - run a filter on a socket * @skb: buffer to run the filter on @@ -177,7 +165,13 @@ int sk_run_filter(struct sk_buff *skb, s case BPF_LD|BPF_W|BPF_ABS: k = fentry->k; load_w: - ptr = load_pointer(skb, k, 4, &tmp); + if (k >= 0) + ptr = skb_header_pointer(skb, k, 4, &tmp); + else if (k < SKF_AD_OFF) + ptr = load_pointer(skb, k); + else + break; + if (ptr != NULL) { A = ntohl(*(u32 *)ptr); continue; @@ -186,7 +180,13 @@ int sk_run_filter(struct sk_buff *skb, s case BPF_LD|BPF_H|BPF_ABS: k = fentry->k; load_h: - ptr = load_pointer(skb, k, 2, &tmp); + if (k >= 0) + ptr = skb_header_pointer(skb, k, 2, &tmp); + else if (k < SKF_AD_OFF) + ptr = load_pointer(skb, k); + else + break; + if (ptr != NULL) { A = ntohs(*(u16 *)ptr); continue; @@ -195,7 +195,13 @@ int sk_run_filter(struct sk_buff *skb, s case BPF_LD|BPF_B|BPF_ABS: k = fentry->k; load_b: - ptr = load_pointer(skb, k, 1, &tmp); + if (k >= 0) + ptr = skb_header_pointer(skb, k, 1, &tmp); + else if (k < SKF_AD_OFF) + ptr = load_pointer(skb, k); + else + break; + if (ptr != NULL) { A = *(u8 *)ptr; continue; @@ -217,7 +223,9 @@ load_b: k = X + fentry->k; goto load_b; case BPF_LDX|BPF_B|BPF_MSH: - ptr = load_pointer(skb, fentry->k, 1, &tmp); + if (fentry->k < 0) + return 0; + ptr = skb_header_pointer(skb, fentry->k, 1, &tmp); if (ptr != NULL) { X = (*(u8 *)ptr & 0xf) << 2; continue; - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
