X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=xdp.c;h=75a44ff2a16d0a22a3cd462107feeec7dd3997c1;hb=ac33c8518d541b228fc24efcb89858abca0fc75f;hp=8003b89e0066b4311fd8eb482a922718914166e4;hpb=ce7cb6545f4fd8872f08263733cb2188530e9420;p=flowspec-xdp diff --git a/xdp.c b/xdp.c index 8003b89..75a44ff 100644 --- a/xdp.c +++ b/xdp.c @@ -77,9 +77,12 @@ struct tcphdr { // Note that all operations on uint128s *stay* in Network byte order! #if defined(__LITTLE_ENDIAN) -#define BIGEND32(v) ((v >> 3*8) | ((v >> 8) & 0xff00) | ((v << 8) & 0xff0000) | (v << 3*8) & 0xff000000) +#define BIGEND32(v) (((((uint32_t)(v)) >> 3*8) & 0xff) | \ + ((((uint32_t)(v)) >> 1*8) & 0xff00) | \ + ((((uint32_t)(v)) << 1*8) & 0xff0000) | \ + ((((uint32_t)(v)) << 3*8) & 0xff000000)) #elif defined(__BIG_ENDIAN) -#define BIGEND32(v) (v) +#define BIGEND32(v) ((uint32_t)(v)) #else #error "Need endian info" #endif @@ -92,11 +95,11 @@ struct tcphdr { (((uint128_t)BIGEND32(a)) << 0*32)) #define HTON128(a) BIGEND128(a >> 3*32, a >> 2*32, a >> 1*32, a>> 0*32) // Yes, somehow macro'ing this changes LLVM's view of htons... -#define BE16(a) ((((uint16_t)(a & 0xff00)) >> 8) | (((uint16_t)(a & 0xff)) << 8)) +#define BE16(a) (((((uint16_t)a) & 0xff00) >> 8) | ((((uint16_t)a) & 0xff) << 8)) #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) +#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) ((uint128_t)(a)) +#define BE16(a) ((uint16_t)(a)) #else #error "Need endian info" #endif @@ -144,28 +147,38 @@ static const int XDP_PASS = 0; static const int XDP_DROP = 1; static long drop_cnt_map[RULECNT + STATIC_RULE_CNT]; -#define INCREMENT_MATCH(reason) drop_cnt_map[reason] += 1; +#define INCREMENT_MATCH(reason) { drop_cnt_map[reason] += 1; drop_cnt_map[reason] += data_end - pktdata; } -#else +#else /* TEST */ #include #include -struct bpf_map_def SEC("maps") drop_cnt_map = { - .type = BPF_MAP_TYPE_PERCPU_ARRAY, - .key_size = sizeof(uint32_t), - .value_size = sizeof(long), - .max_entries = RULECNT + STATIC_RULE_CNT, +struct match_counter { + uint64_t bytes; + uint64_t packets; }; +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(max_entries, RULECNT + STATIC_RULE_CNT); + __u32 *key; + struct match_counter *value; +} drop_cnt_map SEC(".maps"); + #define INCREMENT_MATCH(reason) { \ - long *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \ - if (value) \ - *value += 1; \ + struct match_counter *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \ + if (value) { \ + value->bytes += data_end - pktdata; \ + value->packets += 1; \ + } \ } #ifdef RATE_CNT struct ratelimit { struct bpf_spin_lock lock; - int64_t sent_bytes; + union { + int64_t sent_bytes; + int64_t sent_packets; + } rate; int64_t sent_time; }; struct { @@ -174,10 +187,42 @@ struct { __u32 *key; struct ratelimit *value; } rate_map SEC(".maps"); -#endif +#endif /* RATE_CNT */ + +// For per-source rate limiting, we have to use per-CPU hash maps as Linux +// doesn't support spinlocks inside of a LRU_HASH (see if block in +// map_check_btf as of Linux 5.10). +// This isn't exactly accurate, but at least its faster. +struct percpu_ratelimit { + union { + int64_t sent_bytes; + int64_t sent_packets; + } rate; + int64_t sent_time; +}; +#define V6_SRC_RATE_DEFINE(n, limit) \ +struct { \ + __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH); \ + __uint(max_entries, limit); \ + uint128_t *key; \ + struct percpu_ratelimit *value; \ +} v6_src_rate_##n SEC(".maps"); + +#define V4_SRC_RATE_DEFINE(n, limit) \ +struct { \ + __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH); \ + __uint(max_entries, limit); \ + __u32 *key; \ + struct percpu_ratelimit *value; \ +} v4_src_rate_##n SEC(".maps"); + +#include "maps.h" + +#ifndef HAVE_WRAPPER // Set this to call xdp_drop externally SEC("xdp_drop") -#endif +#endif /* HAVE_WRAPPER */ +#endif /* not TEST */ int xdp_drop_prog(struct xdp_md *ctx) { const void *const data_end = (void *)(size_t)ctx->data_end; @@ -186,30 +231,32 @@ int xdp_drop_prog(struct xdp_md *ctx) unsigned short eth_proto; { + // DO_RETURN in CHECK_LEN relies on pktdata being set to calculate packet length. + // That said, we don't want to overflow, so just set packet length to 0 here. + pktdata = data_end; CHECK_LEN((size_t)ctx->data, ethhdr); const struct ethhdr *const eth = (void*)(size_t)ctx->data; + pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr); #if PARSE_8021Q == PARSE if (likely(eth->h_proto == BE16(ETH_P_8021Q))) { CHECK_LEN((size_t)ctx->data, ethhdr_vlan); const struct ethhdr_vlan *const eth_vlan = (void*)(size_t)ctx->data; - + pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr_vlan); #ifdef REQ_8021Q if (unlikely((eth_vlan->tci & BE16(0xfff)) != BE16(REQ_8021Q))) DO_RETURN(VLAN_DROP, XDP_DROP); #endif - eth_proto = eth_vlan->h_proto; - pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr_vlan); #else if (unlikely(eth->h_proto == BE16(ETH_P_8021Q))) { + pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr_vlan); DO_RETURN(VLAN_DROP, PARSE_8021Q); #endif } else { #ifdef REQ_8021Q DO_RETURN(VLAN_DROP, XDP_DROP); #else - pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr); eth_proto = eth->h_proto; #endif } @@ -217,8 +264,7 @@ int xdp_drop_prog(struct xdp_md *ctx) const void *l4hdr = NULL; const struct tcphdr *tcp = NULL; - uint8_t ports_valid = 0; - uint16_t sport, dport; // Host Endian! Only valid with tcp || udp + int32_t sport = -1, dport = -1; // Host Endian! Only valid with tcp || udp #ifdef NEED_V4_PARSE if (eth_proto == BE16(ETH_P_IP)) { @@ -240,13 +286,11 @@ int xdp_drop_prog(struct xdp_md *ctx) tcp = (struct tcphdr*) l4hdr; sport = BE16(tcp->source); dport = BE16(tcp->dest); - ports_valid = 1; } else if (ip->protocol == IP_PROTO_UDP) { CHECK_LEN(l4hdr, udphdr); const struct udphdr *udp = (struct udphdr*) l4hdr; sport = BE16(udp->source); dport = BE16(udp->dest); - ports_valid = 1; } else if (ip->protocol == IP_PROTO_ICMP) { CHECK_LEN(l4hdr, icmphdr); icmp = (struct icmphdr*) l4hdr; @@ -287,13 +331,11 @@ int xdp_drop_prog(struct xdp_md *ctx) tcp = (struct tcphdr*) l4hdr; sport = BE16(tcp->source); dport = BE16(tcp->dest); - ports_valid = 1; } else if (v6nexthdr == IP_PROTO_UDP) { CHECK_LEN(l4hdr, udphdr); const struct udphdr *udp = (struct udphdr*) l4hdr; sport = BE16(udp->source); dport = BE16(udp->dest); - ports_valid = 1; } else if (v6nexthdr == IP6_PROTO_ICMPV6) { CHECK_LEN(l4hdr, icmp6hdr); icmpv6 = (struct icmp6hdr*) l4hdr;