From 0b05b2a49e430220876f8faa7e4778dc7497033c Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Tue, 5 Jul 2005 14:10:21 -0700 Subject: [NET]: Consolidate common code in net/core/filter.c Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/core/filter.c | 90 ++++++++++++++++++++----------------------------------- 1 file changed, 33 insertions(+), 57 deletions(-) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index e1267b465de..3923428a840 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -36,7 +36,7 @@ #include /* No hurry in this branch */ -static u8 *load_pointer(struct sk_buff *skb, int k) +static void *__load_pointer(struct sk_buff *skb, int k) { u8 *ptr = NULL; @@ -50,6 +50,18 @@ static u8 *load_pointer(struct sk_buff *skb, int k) 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 @@ -64,15 +76,16 @@ static u8 *load_pointer(struct sk_buff *skb, int k) int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen) { - unsigned char *data = skb->data; /* len is UNSIGNED. Byte wide insns relies only on implicit type casts to prevent reading arbitrary memory locations. */ unsigned int len = skb->len-skb->data_len; struct sock_filter *fentry; /* We walk down these */ + void *ptr; u32 A = 0; /* Accumulator */ u32 X = 0; /* Index Register */ u32 mem[BPF_MEMWORDS]; /* Scratch Memory Store */ + u32 tmp; int k; int pc; @@ -168,67 +181,28 @@ int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen) case BPF_LD|BPF_W|BPF_ABS: k = fentry->k; load_w: - if (k < 0) { - u8 *ptr; - - if (k >= SKF_AD_OFF) - break; - ptr = load_pointer(skb, k); - if (ptr) { - A = ntohl(*(u32*)ptr); - continue; - } - } else { - u32 _tmp, *p; - p = skb_header_pointer(skb, k, 4, &_tmp); - if (p != NULL) { - A = ntohl(*p); - continue; - } + ptr = load_pointer(skb, k, 4, &tmp); + if (ptr != NULL) { + A = ntohl(*(u32 *)ptr); + continue; } return 0; case BPF_LD|BPF_H|BPF_ABS: k = fentry->k; load_h: - if (k < 0) { - u8 *ptr; - - if (k >= SKF_AD_OFF) - break; - ptr = load_pointer(skb, k); - if (ptr) { - A = ntohs(*(u16*)ptr); - continue; - } - } else { - u16 _tmp, *p; - p = skb_header_pointer(skb, k, 2, &_tmp); - if (p != NULL) { - A = ntohs(*p); - continue; - } + ptr = load_pointer(skb, k, 2, &tmp); + if (ptr != NULL) { + A = ntohs(*(u16 *)ptr); + continue; } return 0; case BPF_LD|BPF_B|BPF_ABS: k = fentry->k; load_b: - if (k < 0) { - u8 *ptr; - - if (k >= SKF_AD_OFF) - break; - ptr = load_pointer(skb, k); - if (ptr) { - A = *ptr; - continue; - } - } else { - u8 _tmp, *p; - p = skb_header_pointer(skb, k, 1, &_tmp); - if (p != NULL) { - A = *p; - continue; - } + ptr = load_pointer(skb, k, 1, &tmp); + if (ptr != NULL) { + A = *(u8 *)ptr; + continue; } return 0; case BPF_LD|BPF_W|BPF_LEN: @@ -247,10 +221,12 @@ load_b: k = X + fentry->k; goto load_b; case BPF_LDX|BPF_B|BPF_MSH: - if (fentry->k >= len) - return 0; - X = (data[fentry->k] & 0xf) << 2; - continue; + ptr = load_pointer(skb, fentry->k, 1, &tmp); + if (ptr != NULL) { + X = (*(u8 *)ptr & 0xf) << 2; + continue; + } + return 0; case BPF_LD|BPF_IMM: A = fentry->k; continue; -- cgit v1.2.3