diff options
Diffstat (limited to 'net/tcp.c')
| -rw-r--r-- | net/tcp.c | 891 |
1 files changed, 691 insertions, 200 deletions
diff --git a/net/tcp.c b/net/tcp.c index 7c713a5ca56..a2941951834 100644 --- a/net/tcp.c +++ b/net/tcp.c @@ -24,9 +24,26 @@ #include <net.h> #include <net/tcp.h> -static int tcp_activity_count; +/* + * The start sequence number increment for the two sequently created + * connections within the same timer tick. This number must be: + * - prime (to increase the time before the same number will be generated) + * - larger than typical MTU (to avoid similar numbers for two sequently + * created connections) + */ +#define TCP_START_SEQ_INC 2153 /* just large prime number */ + +#define TCP_SEND_RETRY 3 +#define TCP_SEND_TIMEOUT 2000UL +#define TCP_RX_INACTIVE_TIMEOUT 30000UL +#define TCP_RCV_WND_SIZE (PKTBUFSRX * TCP_MSS) + +#define TCP_PACKET_OK 0 +#define TCP_PACKET_DROP 1 + static struct tcp_stream tcp_stream; -static tcp_incoming_filter *incoming_filter; + +static int (*tcp_stream_on_create)(struct tcp_stream *tcp); /* * TCP lengths are stored as a rounded up number of 32 bit words. @@ -35,12 +52,10 @@ static tcp_incoming_filter *incoming_filter; */ #define LEN_B_TO_DW(x) ((x) >> 2) #define ROUND_TCPHDR_LEN(x) (LEN_B_TO_DW((x) + 3)) +#define ROUND_TCPHDR_BYTES(x) (((x) + 3) & ~3) #define SHIFT_TO_TCPHDRLEN_FIELD(x) ((x) << 4) #define GET_TCP_HDR_LEN_IN_BYTES(x) ((x) >> 2) -/* Current TCP RX packet handler */ -static rxhand_tcp *tcp_packet_handler; - #define RANDOM_PORT_START 1024 #define RANDOM_PORT_RANGE 0x4000 @@ -62,6 +77,22 @@ static inline s32 tcp_seq_cmp(u32 a, u32 b) return (s32)(a - b); } +static inline u32 tcp_get_start_seq(void) +{ + static u32 tcp_seq_inc; + u32 tcp_seq; + + tcp_seq = (get_timer(0) & 0xffffffff) + tcp_seq_inc; + tcp_seq_inc += TCP_START_SEQ_INC; + + return tcp_seq; +} + +static inline ulong msec_to_ticks(ulong msec) +{ + return msec * CONFIG_SYS_HZ / 1000; +} + /** * tcp_stream_get_state() - get TCP stream state * @tcp: tcp stream @@ -84,31 +115,90 @@ static void tcp_stream_set_state(struct tcp_stream *tcp, tcp->state = new_state; } -void tcp_init(void) +/** + * tcp_stream_get_status() - get TCP stream status + * @tcp: tcp stream + * + * Return: TCP stream status + */ +enum tcp_status tcp_stream_get_status(struct tcp_stream *tcp) { - incoming_filter = NULL; - tcp_stream.state = TCP_CLOSED; + return tcp->status; } -void tcp_set_incoming_filter(tcp_incoming_filter *filter) +/** + * tcp_stream_set_status() - set TCP stream state + * @tcp: tcp stream + * @new_satus: new TCP stream status + */ +static void tcp_stream_set_status(struct tcp_stream *tcp, + enum tcp_status new_status) { - incoming_filter = filter; + tcp->status = new_status; } -static struct tcp_stream *tcp_stream_add(struct in_addr rhost, - u16 rport, u16 lport) +void tcp_stream_restart_rx_timer(struct tcp_stream *tcp) { - struct tcp_stream *tcp = &tcp_stream; - - if (tcp->state != TCP_CLOSED) - return NULL; + tcp->time_last_rx = get_timer(0); +} +static void tcp_stream_init(struct tcp_stream *tcp, + struct in_addr rhost, u16 rport, u16 lport) +{ memset(tcp, 0, sizeof(struct tcp_stream)); tcp->rhost.s_addr = rhost.s_addr; tcp->rport = rport; tcp->lport = lport; tcp->state = TCP_CLOSED; tcp->lost.len = TCP_OPT_LEN_2; + tcp->rcv_wnd = TCP_RCV_WND_SIZE; + tcp->max_retry_count = TCP_SEND_RETRY; + tcp->initial_timeout = TCP_SEND_TIMEOUT; + tcp->rx_inactiv_timeout = TCP_RX_INACTIVE_TIMEOUT; + tcp_stream_restart_rx_timer(tcp); +} + +static void tcp_stream_destroy(struct tcp_stream *tcp) +{ + if (tcp->on_closed) + tcp->on_closed(tcp); + memset(tcp, 0, sizeof(struct tcp_stream)); +} + +void tcp_init(void) +{ + static int initialized; + struct tcp_stream *tcp = &tcp_stream; + + tcp_stream_on_create = NULL; + if (!initialized) { + initialized = 1; + memset(tcp, 0, sizeof(struct tcp_stream)); + } + + tcp_stream_set_state(tcp, TCP_CLOSED); + tcp_stream_set_status(tcp, TCP_ERR_RST); + tcp_stream_destroy(tcp); +} + +void tcp_stream_set_on_create_handler(int (*on_create)(struct tcp_stream *)) +{ + tcp_stream_on_create = on_create; +} + +static struct tcp_stream *tcp_stream_add(struct in_addr rhost, + u16 rport, u16 lport) +{ + struct tcp_stream *tcp = &tcp_stream; + + if (!tcp_stream_on_create || + tcp->state != TCP_CLOSED) + return NULL; + + tcp_stream_init(tcp, rhost, rport, lport); + if (!tcp_stream_on_create(tcp)) + return NULL; + return tcp; } @@ -122,30 +212,226 @@ struct tcp_stream *tcp_stream_get(int is_new, struct in_addr rhost, tcp->lport == lport) return tcp; - if (!is_new || !incoming_filter || - !incoming_filter(rhost, rport, lport)) - return NULL; + return is_new ? tcp_stream_add(rhost, rport, lport) : NULL; +} - return tcp_stream_add(rhost, rport, lport); +void tcp_stream_put(struct tcp_stream *tcp) +{ + if (tcp->state == TCP_CLOSED) + tcp_stream_destroy(tcp); } -static void dummy_handler(struct tcp_stream *tcp, uchar *pkt, - u32 tcp_seq_num, u32 tcp_ack_num, - u8 action, unsigned int len) +u32 tcp_stream_rx_offs(struct tcp_stream *tcp) { + u32 ret; + + switch (tcp->state) { + case TCP_CLOSED: + case TCP_SYN_SENT: + case TCP_SYN_RECEIVED: + return 0; + default: + break; + } + + ret = tcp->rcv_nxt - tcp->irs - 1; + if (tcp->fin_rx && tcp->rcv_nxt == tcp->fin_rx_seq) + ret--; + + return ret; } -/** - * tcp_set_tcp_handler() - set a handler to receive data - * @f: handler - */ -void tcp_set_tcp_handler(rxhand_tcp *f) +u32 tcp_stream_tx_offs(struct tcp_stream *tcp) +{ + u32 ret; + + switch (tcp->state) { + case TCP_CLOSED: + case TCP_SYN_SENT: + case TCP_SYN_RECEIVED: + return 0; + default: + break; + } + + ret = tcp->snd_una - tcp->iss - 1; + if (tcp->fin_tx && tcp->snd_una == tcp->fin_tx_seq + 1) + ret--; + + return ret; +} + +static void tcp_stream_set_time_handler(struct tcp_stream *tcp, ulong msec, + void (*handler)(struct tcp_stream *)) +{ + if (!msec) { + tcp->time_handler = NULL; + return; + } + + tcp->time_handler = handler; + tcp->time_start = get_timer(0); + tcp->time_delta = msec_to_ticks(msec); +} + +static void tcp_send_packet(struct tcp_stream *tcp, u8 action, + u32 tcp_seq_num, u32 tcp_ack_num, u32 tx_len) +{ + tcp->tx_packets++; + net_send_tcp_packet(tx_len, tcp->rhost, tcp->rport, + tcp->lport, action, tcp_seq_num, + tcp_ack_num); +} + +static void tcp_send_repeat(struct tcp_stream *tcp) +{ + uchar *ptr; + u32 tcp_opts_size; + int ret; + + if (!tcp->retry_cnt) { + puts("\nTCP: send retry counter exceeded\n"); + tcp_send_packet(tcp, TCP_RST, tcp->retry_seq_num, + tcp->rcv_nxt, 0); + tcp_stream_set_status(tcp, TCP_ERR_TOUT); + tcp_stream_set_state(tcp, TCP_CLOSED); + tcp_stream_destroy(tcp); + return; + } + tcp->retry_cnt--; + tcp->retry_timeout += tcp->initial_timeout; + + if (tcp->retry_tx_len > 0) { + tcp_opts_size = ROUND_TCPHDR_BYTES(TCP_TSOPT_SIZE + + tcp->lost.len); + ptr = net_tx_packet + net_eth_hdr_size() + + IP_TCP_HDR_SIZE + tcp_opts_size; + + if (tcp->retry_tx_len > TCP_MSS - tcp_opts_size) + tcp->retry_tx_len = TCP_MSS - tcp_opts_size; + + /* refill packet data */ + ret = tcp->tx(tcp, tcp->retry_tx_offs, ptr, tcp->retry_tx_len); + if (ret < 0) { + puts("\nTCP: send failure\n"); + tcp_send_packet(tcp, TCP_RST, tcp->retry_seq_num, + tcp->rcv_nxt, 0); + tcp_stream_set_status(tcp, TCP_ERR_IO); + tcp_stream_set_state(tcp, TCP_CLOSED); + tcp_stream_destroy(tcp); + return; + } + } + tcp_send_packet(tcp, tcp->retry_action, tcp->retry_seq_num, + tcp->rcv_nxt, tcp->retry_tx_len); + + tcp_stream_set_time_handler(tcp, tcp->retry_timeout, tcp_send_repeat); +} + +static void tcp_send_packet_with_retry(struct tcp_stream *tcp, u8 action, + u32 tcp_seq_num, u32 tx_len, u32 tx_offs) +{ + tcp->retry_cnt = tcp->max_retry_count; + tcp->retry_timeout = tcp->initial_timeout; + tcp->retry_action = action; + tcp->retry_seq_num = tcp_seq_num; + tcp->retry_tx_len = tx_len; + tcp->retry_tx_offs = tx_offs; + + tcp_send_packet(tcp, action, tcp_seq_num, tcp->rcv_nxt, tx_len); + tcp_stream_set_time_handler(tcp, tcp->retry_timeout, tcp_send_repeat); +} + +static inline u8 tcp_stream_fin_needed(struct tcp_stream *tcp, u32 tcp_seq_num) +{ + return (tcp->fin_tx && (tcp_seq_num == tcp->fin_tx_seq)) ? TCP_FIN : 0; +} + +static void tcp_steam_tx_try(struct tcp_stream *tcp) { - debug_cond(DEBUG_INT_STATE, "--- net_loop TCP handler set (%p)\n", f); - if (!f) - tcp_packet_handler = dummy_handler; - else - tcp_packet_handler = f; + uchar *ptr; + int tx_len; + u32 tx_offs, tcp_opts_size; + + if (tcp->state != TCP_ESTABLISHED || + tcp->time_handler || + !tcp->tx) + return; + + tcp_opts_size = ROUND_TCPHDR_BYTES(TCP_TSOPT_SIZE + tcp->lost.len); + tx_len = TCP_MSS - tcp_opts_size; + if (tcp->fin_tx) { + /* do not try to send beyonds FIN packet limits */ + if (tcp_seq_cmp(tcp->snd_una, tcp->fin_tx_seq) >= 0) + return; + + tx_len = tcp->fin_tx_seq - tcp->snd_una; + if (tx_len > TCP_MSS - tcp_opts_size) + tx_len = TCP_MSS - tcp_opts_size; + } + + tx_offs = tcp_stream_tx_offs(tcp); + ptr = net_tx_packet + net_eth_hdr_size() + + IP_TCP_HDR_SIZE + tcp_opts_size; + + /* fill packet data and adjust size */ + tx_len = tcp->tx(tcp, tx_offs, ptr, tx_len); + if (tx_len < 0) { + puts("\nTCP: send failure\n"); + tcp_send_packet(tcp, TCP_RST, tcp->retry_seq_num, + tcp->rcv_nxt, 0); + tcp_stream_set_status(tcp, TCP_ERR_IO); + tcp_stream_set_state(tcp, TCP_CLOSED); + tcp_stream_destroy(tcp); + return; + } + if (!tx_len) + return; + + if (tcp_seq_cmp(tcp->snd_una + tx_len, tcp->snd_nxt) > 0) + tcp->snd_nxt = tcp->snd_una + tx_len; + + tcp_send_packet_with_retry(tcp, TCP_ACK | TCP_PUSH, + tcp->snd_una, tx_len, tx_offs); +} + +static void tcp_stream_poll(struct tcp_stream *tcp, ulong time) +{ + ulong delta; + void (*handler)(struct tcp_stream *tcp); + + if (tcp->state == TCP_CLOSED) + return; + + /* handle rx inactivity timeout */ + delta = msec_to_ticks(tcp->rx_inactiv_timeout); + if (time - tcp->time_last_rx >= delta) { + puts("\nTCP: rx inactivity timeout exceeded\n"); + tcp_stream_reset(tcp); + tcp_stream_set_status(tcp, TCP_ERR_TOUT); + tcp_stream_destroy(tcp); + return; + } + + /* handle retransmit timeout */ + if (tcp->time_handler && + time - tcp->time_start >= tcp->time_delta) { + handler = tcp->time_handler; + tcp->time_handler = NULL; + handler(tcp); + } + + tcp_steam_tx_try(tcp); +} + +void tcp_streams_poll(void) +{ + ulong time; + struct tcp_stream *tcp; + + time = get_timer(0); + tcp = &tcp_stream; + tcp_stream_poll(tcp, time); } /** @@ -240,7 +526,6 @@ int net_set_ack_options(struct tcp_stream *tcp, union tcp_build_pkt *b) * This returns the actual rounded up length of the * TCP header to add to the total packet length */ - return GET_TCP_HDR_LEN_IN_BYTES(b->sack.hdr.tcp_hlen); } @@ -300,18 +585,8 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int payload_len, "TCP Hdr:SYN (%pI4, %pI4, sq=%u, ak=%u)\n", &tcp->rhost, &net_ip, tcp_seq_num, tcp_ack_num); - tcp_activity_count = 0; net_set_syn_options(tcp, b); - tcp_seq_num = 0; - tcp_ack_num = 0; pkt_hdr_len = IP_TCP_O_SIZE; - if (tcp->state == TCP_SYN_SENT) { /* Too many SYNs */ - action = TCP_FIN; - tcp->state = TCP_FIN_WAIT_1; - } else { - tcp->lost.len = TCP_OPT_LEN_2; - tcp->state = TCP_SYN_SENT; - } break; case TCP_SYN | TCP_ACK: case TCP_ACK: @@ -328,21 +603,16 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int payload_len, &tcp->rhost, &net_ip, tcp_seq_num, tcp_ack_num); payload_len = 0; pkt_hdr_len = IP_TCP_HDR_SIZE; - tcp->state = TCP_FIN_WAIT_1; break; case TCP_RST | TCP_ACK: case TCP_RST: debug_cond(DEBUG_DEV_PKT, "TCP Hdr:RST (%pI4, %pI4, s=%u, a=%u)\n", &tcp->rhost, &net_ip, tcp_seq_num, tcp_ack_num); - tcp->state = TCP_CLOSED; break; /* Notify connection closing */ case (TCP_FIN | TCP_ACK): case (TCP_FIN | TCP_ACK | TCP_PUSH): - if (tcp->state == TCP_CLOSE_WAIT) - tcp->state = TCP_CLOSING; - debug_cond(DEBUG_DEV_PKT, "TCP Hdr:FIN ACK PSH(%pI4, %pI4, s=%u, a=%u, A=%x)\n", &tcp->rhost, &net_ip, @@ -382,7 +652,7 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int payload_len, * it is, then the u-boot tftp or nfs kernel netboot should be * considered. */ - b->ip.hdr.tcp_win = htons(PKTBUFSRX * TCP_MSS >> TCP_SCALE); + b->ip.hdr.tcp_win = htons(tcp->rcv_wnd >> TCP_SCALE); b->ip.hdr.tcp_xsum = 0; b->ip.hdr.tcp_ugr = 0; @@ -501,6 +771,7 @@ void tcp_hole(struct tcp_stream *tcp, u32 tcp_seq_num, u32 len) void tcp_parse_options(struct tcp_stream *tcp, uchar *o, int o_len) { struct tcp_t_opt *tsopt; + struct tcp_scale *wsopt; uchar *p = o; /* @@ -515,10 +786,13 @@ void tcp_parse_options(struct tcp_stream *tcp, uchar *o, int o_len) case TCP_O_END: return; case TCP_O_MSS: - case TCP_O_SCL: case TCP_P_SACK: case TCP_V_SACK: break; + case TCP_O_SCL: + wsopt = (struct tcp_scale *)p; + tcp->rmt_win_scale = wsopt->scale; + break; case TCP_O_TS: tsopt = (struct tcp_t_opt *)p; tcp->rmt_timestamp = tsopt->t_snd; @@ -533,129 +807,344 @@ void tcp_parse_options(struct tcp_stream *tcp, uchar *o, int o_len) } } -static u8 tcp_state_machine(struct tcp_stream *tcp, u8 tcp_flags, - u32 tcp_seq_num, int payload_len) +static int tcp_seg_in_wnd(struct tcp_stream *tcp, + u32 tcp_seq_num, int payload_len) { - u8 tcp_fin = tcp_flags & TCP_FIN; - u8 tcp_syn = tcp_flags & TCP_SYN; - u8 tcp_rst = tcp_flags & TCP_RST; - u8 tcp_push = tcp_flags & TCP_PUSH; - u8 tcp_ack = tcp_flags & TCP_ACK; - u8 action = TCP_DATA; + if (!payload_len && !tcp->rcv_wnd) { + if (tcp_seq_num == tcp->rcv_nxt) + return 1; + } + if (!payload_len && tcp->rcv_wnd > 0) { + if (tcp_seq_cmp(tcp->rcv_nxt, tcp_seq_num) <= 0 && + tcp_seq_cmp(tcp_seq_num, tcp->rcv_nxt + tcp->rcv_wnd) < 0) + return 1; + } + if (payload_len > 0 && tcp->rcv_wnd > 0) { + if (tcp_seq_cmp(tcp->rcv_nxt, tcp_seq_num) <= 0 && + tcp_seq_cmp(tcp_seq_num, tcp->rcv_nxt + tcp->rcv_wnd) < 0) + return 1; + tcp_seq_num += payload_len - 1; + if (tcp_seq_cmp(tcp->rcv_nxt, tcp_seq_num) <= 0 && + tcp_seq_cmp(tcp_seq_num, tcp->rcv_nxt + tcp->rcv_wnd) < 0) + return 1; + } + + return 0; +} + +static int tcp_rx_check_ack_num(struct tcp_stream *tcp, u32 tcp_seq_num, + u32 tcp_ack_num, u32 tcp_win_size) +{ + u32 old_offs, new_offs; + u8 action; + + switch (tcp->state) { + case TCP_SYN_RECEIVED: + if (tcp_seq_cmp(tcp->snd_una, tcp_ack_num) >= 0 || + tcp_seq_cmp(tcp_ack_num, tcp->snd_nxt) > 0) { + // segment acknowledgment is not acceptable + tcp_send_packet(tcp, TCP_RST, tcp_ack_num, 0, 0); + return TCP_PACKET_DROP; + } + tcp_stream_set_state(tcp, TCP_ESTABLISHED); + tcp->snd_wnd = tcp_win_size; + tcp->snd_wl1 = tcp_seq_num; + tcp->snd_wl2 = tcp_ack_num; + + if (tcp->on_established) + tcp->on_established(tcp); + + fallthrough; + + case TCP_ESTABLISHED: + case TCP_FIN_WAIT_1: + case TCP_FIN_WAIT_2: + case TCP_CLOSE_WAIT: + case TCP_CLOSING: + if (tcp_seq_cmp(tcp_ack_num, tcp->snd_nxt) > 0) { + // ACK acks something not yet sent + action = tcp_stream_fin_needed(tcp, tcp->snd_una) | TCP_ACK; + tcp_send_packet(tcp, action, tcp->snd_una, tcp->rcv_nxt, 0); + return TCP_PACKET_DROP; + } + + if (tcp_seq_cmp(tcp->snd_una, tcp_ack_num) < 0) { + old_offs = tcp_stream_tx_offs(tcp); + tcp->snd_una = tcp_ack_num; + new_offs = tcp_stream_tx_offs(tcp); + if (tcp->time_handler && + tcp_seq_cmp(tcp->snd_una, tcp->retry_seq_num) > 0) { + tcp_stream_set_time_handler(tcp, 0, NULL); + } + if (tcp->on_snd_una_update && + old_offs != new_offs) + tcp->on_snd_una_update(tcp, new_offs); + } + + if (tcp_seq_cmp(tcp->snd_una, tcp_ack_num) <= 0) { + if (tcp_seq_cmp(tcp->snd_wl1, tcp_seq_num) < 0 || + (tcp->snd_wl1 == tcp_seq_num && + tcp_seq_cmp(tcp->snd_wl2, tcp_seq_num) <= 0)) { + tcp->snd_wnd = tcp_win_size; + tcp->snd_wl1 = tcp_seq_num; + tcp->snd_wl2 = tcp_ack_num; + } + } + + if (tcp->state == TCP_FIN_WAIT_1) { + if (tcp->snd_una == tcp->snd_nxt) + tcp_stream_set_state(tcp, TCP_FIN_WAIT_2); + } + + if (tcp->state == TCP_CLOSING) { + if (tcp->snd_una == tcp->snd_nxt) + tcp_stream_set_state(tcp, TCP_CLOSED); + } + return TCP_PACKET_OK; + + case TCP_LAST_ACK: + if (tcp_ack_num == tcp->snd_nxt) + tcp_stream_set_state(tcp, TCP_CLOSED); + return TCP_PACKET_OK; + + default: + return TCP_PACKET_DROP; + } +} + +static int tcp_rx_user_data(struct tcp_stream *tcp, u32 tcp_seq_num, + char *buf, int len) +{ + int tmp_len; + u32 buf_offs, old_offs, new_offs; + u8 action; + + if (!len) + return TCP_PACKET_OK; + + switch (tcp->state) { + case TCP_ESTABLISHED: + case TCP_FIN_WAIT_1: + case TCP_FIN_WAIT_2: + break; + default: + return TCP_PACKET_DROP; + } + + tmp_len = len; + old_offs = tcp_stream_rx_offs(tcp); + buf_offs = tcp_seq_num - tcp->irs - 1; + if (tcp->rx) { + tmp_len = tcp->rx(tcp, buf_offs, buf, len); + if (tmp_len < 0) { + puts("\nTCP: receive failure\n"); + tcp_send_packet(tcp, TCP_RST, tcp->snd_una, + tcp->rcv_nxt, 0); + tcp_stream_set_status(tcp, TCP_ERR_IO); + tcp_stream_set_state(tcp, TCP_CLOSED); + tcp_stream_destroy(tcp); + return TCP_PACKET_DROP; + } + } + if (tmp_len) + tcp_hole(tcp, tcp_seq_num, tmp_len); + + new_offs = tcp_stream_rx_offs(tcp); + if (tcp->on_rcv_nxt_update && old_offs != new_offs) + tcp->on_rcv_nxt_update(tcp, new_offs); + + action = tcp_stream_fin_needed(tcp, tcp->snd_una) | TCP_ACK; + tcp_send_packet(tcp, action, tcp->snd_una, tcp->rcv_nxt, 0); + + return TCP_PACKET_OK; +} + +void tcp_rx_state_machine(struct tcp_stream *tcp, + union tcp_build_pkt *b, unsigned int pkt_len) +{ + int tcp_len = pkt_len - IP_HDR_SIZE; + u32 tcp_seq_num, tcp_ack_num, tcp_win_size; + int tcp_hdr_len, payload_len; + u8 tcp_flags, action; + + tcp_hdr_len = GET_TCP_HDR_LEN_IN_BYTES(b->ip.hdr.tcp_hlen); + payload_len = tcp_len - tcp_hdr_len; + + if (tcp_hdr_len > TCP_HDR_SIZE) + tcp_parse_options(tcp, (uchar *)b + IP_TCP_HDR_SIZE, + tcp_hdr_len - TCP_HDR_SIZE); /* - * tcp_flags are examined to determine TX action in a given state - * tcp_push is interpreted to mean "inform the app" - * urg, ece, cer and nonce flags are not supported. - * - * exe and crw are use to signal and confirm knowledge of congestion. - * This TCP only sends a file request and acks. If it generates - * congestion, the network is broken. + * Incoming sequence and ack numbers are server's view of the numbers. + * The app must swap the numbers when responding. */ - debug_cond(DEBUG_INT_STATE, "TCP STATE ENTRY %x\n", action); - if (tcp_rst) { - action = TCP_DATA; - tcp->state = TCP_CLOSED; - net_set_state(NETLOOP_FAIL); - debug_cond(DEBUG_INT_STATE, "TCP Reset %x\n", tcp_flags); - return TCP_RST; - } + tcp_seq_num = ntohl(b->ip.hdr.tcp_seq); + tcp_ack_num = ntohl(b->ip.hdr.tcp_ack); + tcp_win_size = ntohs(b->ip.hdr.tcp_win) << tcp->rmt_win_scale; - switch (tcp->state) { + tcp_flags = b->ip.hdr.tcp_flags; + +// printf("pkt: seq=%d, ack=%d, flags=%x, len=%d\n", +// tcp_seq_num - tcp->irs, tcp_ack_num - tcp->iss, tcp_flags, pkt_len); +// printf("tcp: rcv_nxt=%d, snd_una=%d, snd_nxt=%d\n\n", +// tcp->rcv_nxt - tcp->irs, tcp->snd_una - tcp->iss, tcp->snd_nxt - tcp->iss); + + switch (tcp->state) { case TCP_CLOSED: - debug_cond(DEBUG_INT_STATE, "TCP CLOSED %x\n", tcp_flags); - if (tcp_syn) { - action = TCP_SYN | TCP_ACK; - tcp->irs = tcp_seq_num; - tcp->rcv_nxt = tcp_seq_num + 1; - tcp->lost.len = TCP_OPT_LEN_2; - tcp->state = TCP_SYN_RECEIVED; - } else if (tcp_ack || tcp_fin) { - action = TCP_DATA; + if (tcp_flags & TCP_RST) + return; + + if (tcp_flags & TCP_ACK) { + tcp_send_packet(tcp, TCP_RST, tcp_ack_num, 0, 0); + return; } - break; - case TCP_SYN_RECEIVED: + + if (!(tcp_flags & TCP_SYN)) + return; + + tcp->irs = tcp_seq_num; + tcp->rcv_nxt = tcp->irs + 1; + + tcp->iss = tcp_get_start_seq(); + tcp->snd_una = tcp->iss; + tcp->snd_nxt = tcp->iss + 1; + tcp->snd_wnd = tcp_win_size; + + tcp_stream_restart_rx_timer(tcp); + + tcp_stream_set_state(tcp, TCP_SYN_RECEIVED); + tcp_send_packet_with_retry(tcp, TCP_SYN | TCP_ACK, + tcp->iss, 0, 0); + return; + case TCP_SYN_SENT: - debug_cond(DEBUG_INT_STATE, "TCP_SYN_SENT | TCP_SYN_RECEIVED %x, %u\n", - tcp_flags, tcp_seq_num); - if (tcp_fin) { - action = action | TCP_PUSH; - tcp->state = TCP_CLOSE_WAIT; - } else if (tcp_ack || (tcp_syn && tcp_ack)) { - action |= TCP_ACK; - tcp->irs = tcp_seq_num; - tcp->rcv_nxt = tcp_seq_num + 1; - tcp->state = TCP_ESTABLISHED; - - if (tcp_syn && tcp_ack) - action |= TCP_PUSH; - } else { - action = TCP_DATA; + if (!(tcp_flags & TCP_ACK)) + return; + + if (tcp_seq_cmp(tcp_ack_num, tcp->iss) <= 0 || + tcp_seq_cmp(tcp_ack_num, tcp->snd_nxt) > 0) { + if (!(tcp_flags & TCP_RST)) + tcp_send_packet(tcp, TCP_RST, tcp_ack_num, 0, 0); + return; } - break; + + if (tcp_flags & TCP_RST) { + tcp_stream_set_status(tcp, TCP_ERR_RST); + tcp_stream_set_state(tcp, TCP_CLOSED); + return; + } + + if (!(tcp_flags & TCP_SYN)) + return; + + /* stop retransmit of SYN */ + tcp_stream_set_time_handler(tcp, 0, NULL); + + tcp->irs = tcp_seq_num; + tcp->rcv_nxt = tcp->irs + 1; + tcp->snd_una = tcp_ack_num; + + tcp_stream_restart_rx_timer(tcp); + + /* our SYN has been ACKed */ + tcp_stream_set_state(tcp, TCP_ESTABLISHED); + + if (tcp->on_established) + tcp->on_established(tcp); + + action = tcp_stream_fin_needed(tcp, tcp->snd_una) | TCP_ACK; + tcp_send_packet(tcp, action, tcp->snd_una, tcp->rcv_nxt, 0); + tcp_rx_user_data(tcp, tcp_seq_num, + ((char *)b) + pkt_len - payload_len, + payload_len); + return; + + case TCP_SYN_RECEIVED: case TCP_ESTABLISHED: - debug_cond(DEBUG_INT_STATE, "TCP_ESTABLISHED %x\n", tcp_flags); - if (payload_len > 0) { - tcp_hole(tcp, tcp_seq_num, payload_len); - tcp_fin = TCP_DATA; /* cause standalone FIN */ + case TCP_FIN_WAIT_1: + case TCP_FIN_WAIT_2: + case TCP_CLOSE_WAIT: + case TCP_CLOSING: + case TCP_LAST_ACK: + if (!tcp_seg_in_wnd(tcp, tcp_seq_num, payload_len)) { + if (tcp_flags & TCP_RST) + return; + action = tcp_stream_fin_needed(tcp, tcp->snd_una) | TCP_ACK; + tcp_send_packet(tcp, action, tcp->snd_una, tcp->rcv_nxt, 0); + return; } - if ((tcp_fin) && - (!IS_ENABLED(CONFIG_PROT_TCP_SACK) || - tcp->lost.len <= TCP_OPT_LEN_2)) { - action = action | TCP_FIN | TCP_PUSH | TCP_ACK; - tcp->state = TCP_CLOSE_WAIT; - } else if (tcp_ack) { - action = TCP_DATA; + tcp_stream_restart_rx_timer(tcp); + + if (tcp_flags & TCP_RST) { + tcp_stream_set_status(tcp, TCP_ERR_RST); + tcp_stream_set_state(tcp, TCP_CLOSED); + return; } - if (tcp_syn) - action = TCP_ACK + TCP_RST; - else if (tcp_push) - action = action | TCP_PUSH; - break; - case TCP_CLOSE_WAIT: - debug_cond(DEBUG_INT_STATE, "TCP_CLOSE_WAIT (%x)\n", tcp_flags); - action = TCP_DATA; - break; - case TCP_FIN_WAIT_2: - debug_cond(DEBUG_INT_STATE, "TCP_FIN_WAIT_2 (%x)\n", tcp_flags); - if (tcp_ack) { - action = TCP_PUSH | TCP_ACK; - tcp->state = TCP_CLOSED; - puts("\n"); - } else if (tcp_syn) { - action = TCP_DATA; - } else if (tcp_fin) { - action = TCP_DATA; + if (tcp_flags & TCP_SYN) { + tcp_send_packet(tcp, TCP_RST, tcp_ack_num, 0, 0); + tcp_stream_set_status(tcp, TCP_ERR_RST); + tcp_stream_set_state(tcp, TCP_CLOSED); + return; } - break; - case TCP_FIN_WAIT_1: - debug_cond(DEBUG_INT_STATE, "TCP_FIN_WAIT_1 (%x)\n", tcp_flags); - if (tcp_fin) { - tcp->rcv_nxt++; - action = TCP_ACK | TCP_FIN; - tcp->state = TCP_FIN_WAIT_2; + + if (!(tcp_flags & TCP_ACK)) + return; + + if (tcp_rx_check_ack_num(tcp, tcp_seq_num, tcp_ack_num, + tcp_win_size) == TCP_PACKET_DROP) { + return; } - if (tcp_syn) - action = TCP_RST; - if (tcp_ack) - tcp->state = TCP_CLOSED; - break; - case TCP_CLOSING: - debug_cond(DEBUG_INT_STATE, "TCP_CLOSING (%x)\n", tcp_flags); - if (tcp_ack) { - action = TCP_PUSH; - tcp->state = TCP_CLOSED; - puts("\n"); - } else if (tcp_syn) { - action = TCP_RST; - } else if (tcp_fin) { - action = TCP_DATA; + + if (tcp_rx_user_data(tcp, tcp_seq_num, + ((char *)b) + pkt_len - payload_len, + payload_len) == TCP_PACKET_DROP) { + return; + } + + if (tcp_flags & TCP_FIN) { + tcp->fin_rx = 1; + tcp->fin_rx_seq = tcp_seq_num + payload_len + 1; + tcp_hole(tcp, tcp_seq_num + payload_len, 1); + action = tcp_stream_fin_needed(tcp, tcp->snd_una) | TCP_ACK; + tcp_send_packet(tcp, action, tcp->snd_una, tcp->rcv_nxt, 0); + } + + if (tcp->fin_rx && + tcp->fin_rx_seq == tcp->rcv_nxt) { + /* all rx data were processed */ + switch (tcp->state) { + case TCP_ESTABLISHED: + tcp_stream_set_state(tcp, TCP_LAST_ACK); + tcp_send_packet_with_retry(tcp, TCP_ACK | TCP_FIN, + tcp->snd_nxt, 0, 0); + tcp->snd_nxt++; + break; + + case TCP_FIN_WAIT_1: + if (tcp_ack_num == tcp->snd_nxt) + tcp_stream_set_state(tcp, TCP_CLOSED); + else + tcp_stream_set_state(tcp, TCP_CLOSING); + break; + + case TCP_FIN_WAIT_2: + tcp_stream_set_state(tcp, TCP_CLOSED); + break; + + default: + break; + } + } + + if (tcp->state == TCP_FIN_WAIT_1 && + tcp_stream_fin_needed(tcp, tcp->snd_una)) { + /* all tx data were acknowledged */ + tcp_send_packet_with_retry(tcp, TCP_ACK | TCP_FIN, + tcp->snd_una, 0, 0); } - break; } - return action; } /** @@ -667,9 +1156,6 @@ void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len) { int tcp_len = pkt_len - IP_HDR_SIZE; u16 tcp_rx_xsum = b->ip.hdr.ip_sum; - u8 tcp_action = TCP_DATA; - u32 tcp_seq_num, tcp_ack_num; - int tcp_hdr_len, payload_len; struct tcp_stream *tcp; struct in_addr src; @@ -713,54 +1199,59 @@ void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len) if (!tcp) return; - tcp_hdr_len = GET_TCP_HDR_LEN_IN_BYTES(b->ip.hdr.tcp_hlen); - payload_len = tcp_len - tcp_hdr_len; + tcp->rx_packets++; + tcp_rx_state_machine(tcp, b, pkt_len); + tcp_stream_put(tcp); +} - if (tcp_hdr_len > TCP_HDR_SIZE) - tcp_parse_options(tcp, (uchar *)b + IP_TCP_HDR_SIZE, - tcp_hdr_len - TCP_HDR_SIZE); - /* - * Incoming sequence and ack numbers are server's view of the numbers. - * The app must swap the numbers when responding. - */ - tcp_seq_num = ntohl(b->ip.hdr.tcp_seq); - tcp_ack_num = ntohl(b->ip.hdr.tcp_ack); +struct tcp_stream *tcp_stream_connect(struct in_addr rhost, u16 rport) +{ + struct tcp_stream *tcp; - /* Packets are not ordered. Send to app as received. */ - tcp_action = tcp_state_machine(tcp, b->ip.hdr.tcp_flags, - tcp_seq_num, payload_len); + tcp = tcp_stream_add(rhost, rport, random_port()); + if (!tcp) + return NULL; - tcp_activity_count++; - if (tcp_activity_count > TCP_ACTIVITY) { - puts("| "); - tcp_activity_count = 0; - } + tcp->iss = tcp_get_start_seq(); + tcp->snd_una = tcp->iss; + tcp->snd_nxt = tcp->iss + 1; - if ((tcp_action & TCP_PUSH) || payload_len > 0) { - debug_cond(DEBUG_DEV_PKT, - "TCP Notify (action=%x, Seq=%u,Ack=%u,Pay%d)\n", - tcp_action, tcp_seq_num, tcp_ack_num, payload_len); + tcp_stream_set_state(tcp, TCP_SYN_SENT); + tcp_send_packet_with_retry(tcp, TCP_SYN, tcp->snd_una, 0, 0); - (*tcp_packet_handler) (tcp, (uchar *)b + pkt_len - payload_len, - tcp_seq_num, tcp_ack_num, tcp_action, - payload_len); + return tcp; +} - } else if (tcp_action != TCP_DATA) { - debug_cond(DEBUG_DEV_PKT, - "TCP Action (action=%x,Seq=%u,Ack=%u,Pay=%d)\n", - tcp_action, tcp_ack_num, tcp->rcv_nxt, payload_len); - - /* - * Warning: Incoming Ack & Seq sequence numbers are transposed - * here to outgoing Seq & Ack sequence numbers - */ - net_send_tcp_packet(0, tcp->rhost, tcp->rport, tcp->lport, - (tcp_action & (~TCP_PUSH)), - tcp_ack_num, tcp->rcv_nxt); - } +void tcp_stream_reset(struct tcp_stream *tcp) +{ + if (tcp->state == TCP_CLOSED) + return; + + tcp_stream_set_time_handler(tcp, 0, NULL); + tcp_send_packet(tcp, TCP_RST, tcp->snd_una, 0, 0); + tcp_stream_set_status(tcp, TCP_ERR_RST); + tcp_stream_set_state(tcp, TCP_CLOSED); } -struct tcp_stream *tcp_stream_connect(struct in_addr rhost, u16 rport) +void tcp_stream_close(struct tcp_stream *tcp) { - return tcp_stream_add(rhost, rport, random_port()); + switch (tcp->state) { + case TCP_SYN_SENT: + tcp_stream_reset(tcp); + break; + case TCP_SYN_RECEIVED: + case TCP_ESTABLISHED: + tcp->fin_tx = 1; + tcp->fin_tx_seq = tcp->snd_nxt; + if (tcp_stream_fin_needed(tcp, tcp->snd_una)) { + /* all tx data were acknowledged */ + tcp_send_packet_with_retry(tcp, TCP_ACK | TCP_FIN, + tcp->snd_una, 0, 0); + } + tcp_stream_set_state(tcp, TCP_FIN_WAIT_1); + tcp->snd_nxt++; + break; + default: + break; + } } |