diff options
| -rw-r--r-- | flow.c | 30 | ||||
| -rw-r--r-- | flow.h | 2 | ||||
| -rw-r--r-- | tcp.c | 33 |
3 files changed, 36 insertions, 29 deletions
@@ -455,16 +455,16 @@ static uint64_t flow_sidx_hash(const struct ctx *c, flow_sidx_t sidx) } /** - * flow_hash_probe() - Find hash bucket for a flow - * @c: Execution context + * flow_hash_probe_() - Find hash bucket for a flow, given hash + * @hash: Raw hash value for flow & side * @sidx: Flow and side to find bucket for * * Return: If @sidx is in the hash table, its current bucket, otherwise a * suitable free bucket for it. */ -static inline unsigned flow_hash_probe(const struct ctx *c, flow_sidx_t sidx) +static inline unsigned flow_hash_probe_(uint64_t hash, flow_sidx_t sidx) { - unsigned b = flow_sidx_hash(c, sidx) % FLOW_HASH_SIZE; + unsigned b = hash % FLOW_HASH_SIZE; /* Linear probing */ while (flow_sidx_valid(flow_hashtab[b]) && @@ -475,17 +475,35 @@ static inline unsigned flow_hash_probe(const struct ctx *c, flow_sidx_t sidx) } /** + * flow_hash_probe() - Find hash bucket for a flow + * @c: Execution context + * @sidx: Flow and side to find bucket for + * + * Return: If @sidx is in the hash table, its current bucket, otherwise a + * suitable free bucket for it. + */ +static inline unsigned flow_hash_probe(const struct ctx *c, flow_sidx_t sidx) +{ + return flow_hash_probe_(flow_sidx_hash(c, sidx), sidx); +} + +/** * flow_hash_insert() - Insert side of a flow into into hash table * @c: Execution context * @sidx: Flow & side index + * + * Return: raw (un-modded) hash value of side of flow */ -void flow_hash_insert(const struct ctx *c, flow_sidx_t sidx) +uint64_t flow_hash_insert(const struct ctx *c, flow_sidx_t sidx) { - unsigned b = flow_hash_probe(c, sidx); + uint64_t hash = flow_sidx_hash(c, sidx); + unsigned b = flow_hash_probe_(hash, sidx); flow_hashtab[b] = sidx; flow_dbg(flow_at_sidx(sidx), "Side %u hash table insert: bucket: %u", sidx.sidei, b); + + return hash; } /** @@ -229,7 +229,7 @@ static inline bool flow_sidx_eq(flow_sidx_t a, flow_sidx_t b) return (a.flowi == b.flowi) && (a.sidei == b.sidei); } -void flow_hash_insert(const struct ctx *c, flow_sidx_t sidx); +uint64_t flow_hash_insert(const struct ctx *c, flow_sidx_t sidx); void flow_hash_remove(const struct ctx *c, flow_sidx_t sidx); flow_sidx_t flow_lookup_af(const struct ctx *c, uint8_t proto, uint8_t pif, sa_family_t af, @@ -1294,28 +1294,16 @@ static void tcp_tap_window_update(struct tcp_tap_conn *conn, unsigned wnd) } /** - * tcp_seq_init() - Calculate initial sequence number according to RFC 6528 - * @c: Execution context - * @conn: TCP connection, with faddr, fport and eport populated + * tcp_init_seq() - Calculate initial sequence number according to RFC 6528 + * @hash: Hash of connection details * @now: Current timestamp */ -static void tcp_seq_init(const struct ctx *c, struct tcp_tap_conn *conn, - const struct timespec *now) +static uint32_t tcp_init_seq(uint64_t hash, const struct timespec *now) { - struct siphash_state state = SIPHASH_INIT(c->hash_secret); - const struct flowside *tapside = TAPFLOW(conn); - uint64_t hash; - uint32_t ns; - - inany_siphash_feed(&state, &tapside->faddr); - inany_siphash_feed(&state, &tapside->eaddr); - hash = siphash_final(&state, 36, - (uint64_t)tapside->fport << 16 | tapside->eport); - /* 32ns ticks, overflows 32 bits every 137s */ - ns = (now->tv_sec * 1000000000 + now->tv_nsec) >> 5; + uint32_t ns = (now->tv_sec * 1000000000 + now->tv_nsec) >> 5; - conn->seq_to_tap = ((uint32_t)(hash >> 32) ^ (uint32_t)hash) + ns; + return ((uint32_t)(hash >> 32) ^ (uint32_t)hash) + ns; } /** @@ -1488,6 +1476,7 @@ static void tcp_conn_from_tap(struct ctx *c, sa_family_t af, union sockaddr_inany sa; union flow *flow; int s = -1, mss; + uint64_t hash; socklen_t sl; if (!(flow = flow_alloc())) @@ -1584,11 +1573,10 @@ static void tcp_conn_from_tap(struct ctx *c, sa_family_t af, conn->seq_from_tap = conn->seq_init_from_tap + 1; conn->seq_ack_to_tap = conn->seq_from_tap; - tcp_seq_init(c, conn, now); + hash = flow_hash_insert(c, TAP_SIDX(conn)); + conn->seq_to_tap = tcp_init_seq(hash, now); conn->seq_ack_from_tap = conn->seq_to_tap; - flow_hash_insert(c, TAP_SIDX(conn)); - tcp_bind_outbound(c, conn, s); if (connect(s, &sa.sa, sl)) { @@ -2110,6 +2098,7 @@ static void tcp_tap_conn_from_sock(struct ctx *c, in_port_t dstport, union inany_addr saddr, daddr; /* FIXME: avoid bulky temporaries */ struct tcp_tap_conn *conn; in_port_t srcport; + uint64_t hash; inany_from_sockaddr(&saddr, &srcport, sa); tcp_snat_inbound(c, &saddr); @@ -2133,8 +2122,8 @@ static void tcp_tap_conn_from_sock(struct ctx *c, in_port_t dstport, conn->ws_to_tap = conn->ws_from_tap = 0; conn_event(c, conn, SOCK_ACCEPTED); - tcp_seq_init(c, conn, now); - flow_hash_insert(c, TAP_SIDX(conn)); + hash = flow_hash_insert(c, TAP_SIDX(conn)); + conn->seq_to_tap = tcp_init_seq(hash, now); conn->seq_ack_from_tap = conn->seq_to_tap; |