Attachment #49578 for bug #115846

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 [PATCH] 2.6.13 breaks libpcap (and tcpdump)
 
 [NET]: 2.6.13 breaks libpcap (and tcpdump)
 
 Patrick McHardy says:
 
   Never mind, I got it, we never fall through to the second switch
   statement anymore. I think we could simply break when load_pointer
   returns NULL. The switch statement will fall through to the default
   case and return 0 for all cases but 0 > k >= SKF_AD_OFF.
 
 Here's a patch to do just that.
 
 I left BPF_MSH alone because it's really a hack to calculate the IP
 header length, which makes no sense when applied to the special data.
 
 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
 Signed-off-by: David S. Miller <davem@davemloft.net>
 Signed-off-by: Chris Wright <chrisw@osdl.org>
 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
++ b/net/core/filter.c
-- a/net/core/filter.c

				A = ntohl(*(u32 *)ptr);
				continue;
			}
			break;
		case BPF_LD|BPF_H|BPF_ABS:
			k = fentry->k;
 load_h:

				A = ntohs(*(u16 *)ptr);
				continue;
			}
			break;
		case BPF_LD|BPF_B|BPF_ABS:
			k = fentry->k;
load_b:

				A = *(u8 *)ptr;
				continue;
			}
			break;
		case BPF_LD|BPF_W|BPF_LEN:
			A = skb->len;
			continue;

Return to bug 115846

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(-)file_not_specified_in_diff (-5 / +4 lines)
	[PATCH] 2.6.13 breaks libpcap (and tcpdump)		[PATCH] 2.6.13 breaks libpcap (and tcpdump)
1		1
2	[NET]: 2.6.13 breaks libpcap (and tcpdump)	2	[NET]: 2.6.13 breaks libpcap (and tcpdump)
3		3
4	Patrick McHardy says:	4	Patrick McHardy says:
5		5
6	Never mind, I got it, we never fall through to the second switch	6	Never mind, I got it, we never fall through to the second switch
7	statement anymore. I think we could simply break when load_pointer	7	statement anymore. I think we could simply break when load_pointer
8	returns NULL. The switch statement will fall through to the default	8	returns NULL. The switch statement will fall through to the default
9	case and return 0 for all cases but 0 > k >= SKF_AD_OFF.	9	case and return 0 for all cases but 0 > k >= SKF_AD_OFF.
10		10
11	Here's a patch to do just that.	11	Here's a patch to do just that.
12		12
13	I left BPF_MSH alone because it's really a hack to calculate the IP	13	I left BPF_MSH alone because it's really a hack to calculate the IP
14	header length, which makes no sense when applied to the special data.	14	header length, which makes no sense when applied to the special data.
15		15
16	Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>	16	Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
17	Signed-off-by: David S. Miller <davem@davemloft.net>	17	Signed-off-by: David S. Miller <davem@davemloft.net>
18	Signed-off-by: Chris Wright <chrisw@osdl.org>	18	Signed-off-by: Chris Wright <chrisw@osdl.org>
19	Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>	19	Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
20	--	20	++ b/net/core/filter.c
21	-- a/net/core/filter.c
Lines 182-188 int sk_run_filter(struct sk_buff *skb, s Link Here
182	A = ntohl((u32 )ptr);	182	A = ntohl((u32 )ptr);
183	continue;	183	continue;
184	}	184	}
185	return 0;	185	break;
186	case BPF_LD\|BPF_H\|BPF_ABS:	186	case BPF_LD\|BPF_H\|BPF_ABS:
187	k = fentry->k;	187	k = fentry->k;
188	load_h:	188	load_h:
Lines 191-197 int sk_run_filter(struct sk_buff *skb, s Link Here
191	A = ntohs((u16 )ptr);	191	A = ntohs((u16 )ptr);
192	continue;	192	continue;
193	}	193	}
194	return 0;	194	break;
195	case BPF_LD\|BPF_B\|BPF_ABS:	195	case BPF_LD\|BPF_B\|BPF_ABS:
196	k = fentry->k;	196	k = fentry->k;
197	load_b:	197	load_b:
Lines 200-206 load_b: Link Here
200	A = (u8 )ptr;	200	A = (u8 )ptr;
201	continue;	201	continue;
202	}	202	}
203	return 0;	203	break;
204	case BPF_LD\|BPF_W\|BPF_LEN:	204	case BPF_LD\|BPF_W\|BPF_LEN:
205	A = skb->len;	205	A = skb->len;
206	continue;	206	continue;