diff options
Diffstat (limited to 'tcp_internal.h')
| -rw-r--r-- | tcp_internal.h | 145 |
1 files changed, 125 insertions, 20 deletions
diff --git a/tcp_internal.h b/tcp_internal.h index 1b5dbed..d7b125f 100644 --- a/tcp_internal.h +++ b/tcp_internal.h @@ -8,7 +8,15 @@ #define MAX_WS 8 #define MAX_WINDOW (1 << (16 + (MAX_WS))) -#define MSS (USHRT_MAX - sizeof(struct tcphdr)) + +#define MSS4 ROUND_DOWN(IP_MAX_MTU - \ + sizeof(struct tcphdr) - \ + sizeof(struct iphdr), \ + sizeof(uint32_t)) +#define MSS6 ROUND_DOWN(IP_MAX_MTU - \ + sizeof(struct tcphdr) - \ + sizeof(struct ipv6hdr), \ + sizeof(uint32_t)) #define SEQ_LE(a, b) ((b) - (a) < MAX_WINDOW) #define SEQ_LT(a, b) ((b) - (a) - 1 < MAX_WINDOW) @@ -25,17 +33,108 @@ #define OPT_EOL 0 #define OPT_NOP 1 #define OPT_MSS 2 -#define OPT_MSS_LEN 4 #define OPT_WS 3 -#define OPT_WS_LEN 3 #define OPT_SACKP 4 #define OPT_SACK 5 #define OPT_TS 8 -#define CONN_V4(conn) (!!inany_v4(&(conn)->faddr)) +#define TAPSIDE(conn_) ((conn_)->f.pif[1] == PIF_TAP) +#define TAPFLOW(conn_) (&((conn_)->f.side[TAPSIDE(conn_)])) +#define TAP_SIDX(conn_) (FLOW_SIDX((conn_), TAPSIDE(conn_))) + +#define CONN_V4(conn) (!!inany_v4(&TAPFLOW(conn)->oaddr)) #define CONN_V6(conn) (!CONN_V4(conn)) -extern char tcp_buf_discard[MAX_WINDOW]; +/* + * enum tcp_iov_parts - I/O vector parts for one TCP frame + * @TCP_IOV_TAP tap backend specific header + * @TCP_IOV_ETH Ethernet header + * @TCP_IOV_IP IP (v4/v6) header + * @TCP_IOV_PAYLOAD IP payload (TCP header + data) + * @TCP_NUM_IOVS the number of entries in the iovec array + */ +enum tcp_iov_parts { + TCP_IOV_TAP = 0, + TCP_IOV_ETH = 1, + TCP_IOV_IP = 2, + TCP_IOV_PAYLOAD = 3, + TCP_NUM_IOVS +}; + +/** + * struct tcp_payload_t - TCP header and data to send segments with payload + * @th: TCP header + * @data: TCP data + */ +struct tcp_payload_t { + struct tcphdr th; + uint8_t data[IP_MAX_MTU - sizeof(struct tcphdr)]; +#ifdef __AVX2__ +} __attribute__ ((packed, aligned(32))); /* For AVX2 checksum routines */ +#else +} __attribute__ ((packed, aligned(__alignof__(unsigned int)))); +#endif + +/** struct tcp_opt_nop - TCP NOP option + * @kind: Option kind (OPT_NOP = 1) + */ +struct tcp_opt_nop { + uint8_t kind; +} __attribute__ ((packed)); +#define TCP_OPT_NOP ((struct tcp_opt_nop){ .kind = OPT_NOP, }) + +/** struct tcp_opt_mss - TCP MSS option + * @kind: Option kind (OPT_MSS == 2) + * @len: Option length (4) + * @mss: Maximum Segment Size + */ +struct tcp_opt_mss { + uint8_t kind; + uint8_t len; + uint16_t mss; +} __attribute__ ((packed)); +#define TCP_OPT_MSS(mss_) \ + ((struct tcp_opt_mss) { \ + .kind = OPT_MSS, \ + .len = sizeof(struct tcp_opt_mss), \ + .mss = htons(mss_), \ + }) + +/** struct tcp_opt_ws - TCP Window Scaling option + * @kind: Option kind (OPT_WS == 3) + * @len: Option length (3) + * @shift: Window scaling shift + */ +struct tcp_opt_ws { + uint8_t kind; + uint8_t len; + uint8_t shift; +} __attribute__ ((packed)); +#define TCP_OPT_WS(shift_) \ + ((struct tcp_opt_ws) { \ + .kind = OPT_WS, \ + .len = sizeof(struct tcp_opt_ws), \ + .shift = (shift_), \ + }) + +/** struct tcp_syn_opts - TCP options we apply to SYN packets + * @mss: Maximum Segment Size (MSS) option + * @nop: NOP opt (for alignment) + * @ws: Window Scaling (WS) option + */ +struct tcp_syn_opts { + struct tcp_opt_mss mss; + struct tcp_opt_nop nop; + struct tcp_opt_ws ws; +} __attribute__ ((packed)); +#define TCP_SYN_OPTS(mss_, ws_) \ + ((struct tcp_syn_opts){ \ + .mss = TCP_OPT_MSS(mss_), \ + .nop = TCP_OPT_NOP, \ + .ws = TCP_OPT_WS(ws_), \ + }) + +extern char tcp_buf_discard [MAX_WINDOW]; void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn, unsigned long flag); @@ -54,28 +153,34 @@ void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn, conn_event_do(c, conn, event); \ } while (0) -void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn); +void tcp_rst_do(const struct ctx *c, struct tcp_tap_conn *conn); #define tcp_rst(c, conn) \ do { \ flow_dbg((conn), "TCP reset at %s:%i", __func__, __LINE__); \ tcp_rst_do(c, conn); \ } while (0) - - -size_t tcp_fill_headers4(const struct ctx *c, - const struct tcp_tap_conn *conn, - struct iphdr *iph, struct tcphdr *th, - size_t plen, const uint16_t *check, - uint32_t seq); -size_t tcp_fill_headers6(const struct ctx *c, - const struct tcp_tap_conn *conn, - struct ipv6hdr *ip6h, struct tcphdr *th, - size_t plen, uint32_t seq); +struct tcp_info_linux; + +void tcp_update_check_tcp4(const struct iphdr *iph, + const struct iovec *iov, int iov_cnt, + size_t l4offset); +void tcp_update_check_tcp6(const struct ipv6hdr *ip6h, + const struct iovec *iov, int iov_cnt, + size_t l4offset); +void tcp_fill_headers4(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, struct iphdr *iph, + struct tcp_payload_t *bp, size_t dlen, + const uint16_t *check, uint32_t seq, bool no_tcp_csum); +void tcp_fill_headers6(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, struct ipv6hdr *ip6h, + struct tcp_payload_t *bp, size_t dlen, + uint32_t seq, bool no_tcp_csum); int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn, - int force_seq, struct tcp_info *tinfo); -int tcp_fill_flag_header(struct ctx *c, struct tcp_tap_conn *conn, int flags, - struct tcphdr *th, char *opts, size_t *optlen); + bool force_seq, struct tcp_info_linux *tinfo); +int tcp_prepare_flags(const struct ctx *c, struct tcp_tap_conn *conn, + int flags, struct tcphdr *th, struct tcp_syn_opts *opts, + size_t *optlen); #endif /* TCP_INTERNAL_H */ |