X-Git-Url: http://git.bitcoin.ninja/index.cgi?p=flowspec-xdp;a=blobdiff_plain;f=xdp.c;h=3ebec88555e37bb82ac5ca6868e8ef0e0c5d20d5;hp=4e4d6c6308437ed759239c1f166f982dca36256c;hb=348583843f9499b0f1c335edc684a077bb2c2710;hpb=d05d679fa4de0002100a7cd806897a2d97d19b5f diff --git a/xdp.c b/xdp.c index 4e4d6c6..3ebec88 100644 --- a/xdp.c +++ b/xdp.c @@ -96,6 +96,7 @@ struct tcphdr { #elif defined(__BIG_ENDIAN) #define BIGEND128(a, b, c, d) ((((uint128_t)a) << 3*32) | (((uint128_t)b) << 2*32) | (((uint128_t)c) << 1*32) | (((uint128_t)d) << 0*32)) #define HTON128(a) (a) +#define BE16(a) ((uint16_t)a) #else #error "Need endian info" #endif @@ -117,6 +118,16 @@ static const uint32_t IHL_DROP = 2; static const uint32_t V6FRAG_DROP = 3; #define STATIC_RULE_CNT 4 +#define DO_RETURN(reason, ret) {\ + if (ret == XDP_DROP) { INCREMENT_MATCH(reason); } \ + return ret; \ + } + +// It seems (based on drop counts) that data_end points to the last byte, not one-past-the-end. +// This feels strange, but some documentation suggests > here as well, so we stick with that. +#define CHECK_LEN(start, struc) \ + if (unlikely((void*)(start) + sizeof(struct struc) > data_end)) DO_RETURN(PKT_LEN_DROP, XDP_DROP); + #ifdef TEST // 64 bit version of xdp_md for testing struct xdp_md { @@ -133,10 +144,7 @@ static const int XDP_PASS = 0; static const int XDP_DROP = 1; static long drop_cnt_map[RULECNT + STATIC_RULE_CNT]; -#define DO_RETURN(reason, ret) { \ - if (ret == XDP_DROP) drop_cnt_map[reason] += 1; \ - return ret; \ - } +#define INCREMENT_MATCH(reason) drop_cnt_map[reason] += 1; #else #include @@ -148,23 +156,14 @@ struct bpf_map_def SEC("maps") drop_cnt_map = { .value_size = sizeof(long), .max_entries = RULECNT + STATIC_RULE_CNT, }; -#define DO_RETURN(reason, ret) {\ - if (ret == XDP_DROP) { \ - long *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \ - if (value) \ - *value += 1; \ - } \ - return XDP_DROP; \ - } +#define INCREMENT_MATCH(reason) { \ + long *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \ + if (value) \ + *value += 1; \ +} SEC("xdp_drop") #endif - -// It seems (based on drop counts) that data_end points to the last byte, not one-past-the-end. -// This feels strange, but some documentation suggests > here as well, so we stick with that. -#define CHECK_LEN(start, struc) \ - if (unlikely((void*)(start) + sizeof(struct struc) > data_end)) DO_RETURN(PKT_LEN_DROP, XDP_DROP); - int xdp_drop_prog(struct xdp_md *ctx) { const void *const data_end = (void *)(size_t)ctx->data_end; @@ -210,7 +209,7 @@ int xdp_drop_prog(struct xdp_md *ctx) #ifdef NEED_V4_PARSE if (eth_proto == BE16(ETH_P_IP)) { CHECK_LEN(pktdata, iphdr); - const struct iphdr *ip = (struct iphdr*) pktdata; + struct iphdr *ip = (struct iphdr*) pktdata; #if PARSE_IHL == PARSE if (unlikely(ip->ihl < 5)) DO_RETURN(IHL_DROP, XDP_DROP); @@ -246,7 +245,7 @@ int xdp_drop_prog(struct xdp_md *ctx) #ifdef NEED_V6_PARSE if (eth_proto == BE16(ETH_P_IPV6)) { CHECK_LEN(pktdata, ip6hdr); - const struct ip6hdr *ip6 = (struct ip6hdr*) pktdata; + struct ip6hdr *ip6 = (struct ip6hdr*) pktdata; l4hdr = pktdata + 40; @@ -298,7 +297,7 @@ int xdp_drop_prog(struct xdp_md *ctx) #include #include -const char d[] = TEST; +char d[] = TEST; int main() { struct xdp_md test = { .data = (uint64_t)d,