Daniele Lacamera
CDC/ECM driver for mbed, based on USBDevice by mbed-official. Uses PicoTCP to access Ethernet USB device. License: GPLv2
Fork of
USB_Ethernet
by 
Daniele Lacamera
Diff: modules/pico_tcp.c
- Revision:
- 2:540f6e142d59
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/modules/pico_tcp.c Sat Aug 03 13:16:14 2013 +0000
@@ -0,0 +1,2217 @@
+/*********************************************************************
+PicoTCP. Copyright (c) 2012 TASS Belgium NV. Some rights reserved.
+See LICENSE and COPYING for usage.
+
+.
+
+Authors: Daniele Lacamera, Philippe Mariman
+*********************************************************************/
+
+#include "pico_tcp.h"
+#include "pico_config.h"
+#include "pico_eth.h"
+#include "pico_socket.h"
+#include "pico_stack.h"
+#include "pico_socket.h"
+#include "pico_queue.h"
+#include "pico_tree.h"
+
+#define TCP_SOCK(s) ((struct pico_socket_tcp *)s)
+#define SEQN(f) (f?(long_be(((struct pico_tcp_hdr *)(f->transport_hdr))->seq)):0)
+#define ACKN(f) (f?(long_be(((struct pico_tcp_hdr *)(f->transport_hdr))->ack)):0)
+
+#define PICO_TCP_RTO_MIN 10
+#define PICO_TCP_RTO_MAX 120000
+#define PICO_TCP_IW 2
+#define PICO_TCP_SYN_TO 1000
+
+#define PICO_TCP_MAX_CONNECT_RETRIES 7
+
+#define PICO_TCP_LOOKAHEAD 0x00
+#define PICO_TCP_FIRST_DUPACK 0x01
+#define PICO_TCP_SECOND_DUPACK 0x02
+#define PICO_TCP_RECOVER 0x03
+#define PICO_TCP_BLACKOUT 0x04
+#define PICO_TCP_UNREACHABLE 0x05
+#define PICO_TCP_WINDOW_FULL 0x06
+
+/* check if the Nagle algorithm is enabled on the socket */
+#define IS_NAGLE_ENABLED(s) (!(!(!(s->opt_flags & (1 << PICO_SOCKET_OPT_TCPNODELAY)))))
+/* check if tcp connection is "idle" according to Nagle (RFC 896) */
+#define IS_TCP_IDLE(t) ((t->in_flight == 0) && (t->tcpq_out.size == 0))
+/* check if the hold queue contains data (again Nagle) */
+#define IS_TCP_HOLDQ_EMPTY(t) (t->tcpq_hold.size == 0)
+
+#ifdef PICO_SUPPORT_TCP
+#define tcp_dbg_nagle(...) do{}while(0)
+#define tcp_dbg_options(...) do{}while(0)
+
+
+#define tcp_dbg(...) do{}while(0)
+//#define tcp_dbg dbg
+
+
+#ifdef PICO_SUPPORT_MUTEX
+static void * Mutex = NULL;
+#define LOCK(x) {\
+ if (x == NULL) \
+ x = pico_mutex_init(); \
+ pico_mutex_lock(x); \
+}
+#define UNLOCK(x) pico_mutex_unlock(x);
+
+#else
+#define LOCK(x) do{}while(0)
+#define UNLOCK(x) do{}while(0)
+#endif
+
+
+static inline int seq_compare(uint32_t a, uint32_t b)
+{
+ uint32_t thresh = ((uint32_t)(-1))>>1;
+ if (((a > thresh) && (b > thresh)) || ((a <= thresh) && (b <= thresh))) {
+ if (a > b)
+ return 1;
+ if (b > a)
+ return -1;
+ } else {
+ if (a > b)
+ return -2;
+ if (b > a)
+ return 2;
+ }
+ return 0;
+}
+
+static int segment_compare(void * ka, void * kb)
+{
+ struct pico_frame *a = ka, *b = kb;
+ return seq_compare(SEQN(a), SEQN(b));
+}
+
+struct pico_tcp_queue
+{
+ struct pico_tree pool;
+ uint32_t max_size;
+ uint32_t size;
+ uint32_t frames;
+};
+
+static struct pico_frame *peek_segment(struct pico_tcp_queue *tq, uint32_t seq)
+{
+ struct pico_tcp_hdr H;
+ struct pico_frame f = {};
+ f.transport_hdr = (uint8_t *) (&H);
+ H.seq = long_be(seq);
+
+ return pico_tree_findKey(&tq->pool,&f);
+}
+
+static struct pico_frame *first_segment(struct pico_tcp_queue *tq)
+{
+ return pico_tree_first(&tq->pool);
+}
+
+static struct pico_frame *next_segment(struct pico_tcp_queue *tq, struct pico_frame *cur)
+{
+ if (!cur)
+ return NULL;
+ return peek_segment(tq, SEQN(cur) + cur->payload_len);
+}
+
+static int pico_enqueue_segment(struct pico_tcp_queue *tq, struct pico_frame *f)
+{
+ int ret = -1;
+ if (f->payload_len <= 0) {
+ tcp_dbg("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! TRIED TO ENQUEUE INVALID SEGMENT!\n");
+ //abort();
+ return -1;
+ }
+ LOCK(Mutex);
+ if ((tq->size + f->payload_len) > tq->max_size)
+ {
+ ret = 0;
+ goto out;
+ }
+ if (pico_tree_insert(&tq->pool,f) != 0)
+ {
+ ret = 0;
+ goto out;
+ }
+ tq->size += f->payload_len;
+ if (f->payload_len > 0)
+ tq->frames++;
+ ret = f->payload_len;
+
+out :
+ UNLOCK(Mutex);
+ return ret;
+}
+
+static void pico_discard_segment(struct pico_tcp_queue *tq, struct pico_frame *f)
+{
+ struct pico_frame *f1;
+ LOCK(Mutex);
+ f1 = pico_tree_delete(&tq->pool,f);
+ if (f1) {
+ tq->size -= f->payload_len;
+ if (f->payload_len > 0)
+ tq->frames--;
+ }
+ pico_frame_discard(f);
+ UNLOCK(Mutex);
+}
+
+/* Structure for TCP socket */
+struct tcp_sack_block {
+ uint32_t left;
+ uint32_t right;
+ struct tcp_sack_block *next;
+};
+
+struct pico_socket_tcp {
+ struct pico_socket sock;
+
+ /* Tree/queues */
+ struct pico_tcp_queue tcpq_in;
+ struct pico_tcp_queue tcpq_out;
+ struct pico_tcp_queue tcpq_hold; /* buffer to hold delayed frames according to Nagle */
+
+ /* tcp_output */
+ uint32_t snd_nxt;
+ uint32_t snd_last;
+ uint32_t snd_old_ack;
+ uint32_t snd_retry;
+ uint32_t snd_last_out;
+
+ /* congestion control */
+ uint32_t avg_rtt;
+ uint32_t rttvar;
+ uint32_t rto;
+ uint32_t in_flight;
+ uint8_t timer_running;
+ uint8_t keepalive_timer_running;
+ uint16_t cwnd_counter;
+ uint16_t cwnd;
+ uint16_t ssthresh;
+ uint16_t recv_wnd;
+ uint16_t recv_wnd_scale;
+
+ /* tcp_input */
+ uint32_t rcv_nxt;
+ uint32_t rcv_ackd;
+ uint32_t rcv_processed;
+ uint16_t wnd;
+ uint16_t wnd_scale;
+
+ /* options */
+ uint32_t ts_nxt;
+ uint16_t mss;
+ uint8_t sack_ok;
+ uint8_t ts_ok;
+ uint8_t mss_ok;
+ uint8_t scale_ok;
+ struct tcp_sack_block *sacks;
+ uint8_t jumbo;
+
+ /* Transmission */
+ uint8_t x_mode;
+ uint8_t dupacks;
+ uint8_t backoff;
+
+};
+
+/* Queues */
+static struct pico_queue tcp_in = {};
+static struct pico_queue tcp_out = {};
+
+/* If Nagle enabled, this function can make 1 new segment from smaller segments in hold queue */
+static struct pico_frame * pico_hold_segment_make(struct pico_socket_tcp *t);
+
+/* checks if tcpq_in is empty */
+int pico_tcp_queue_in_is_empty(struct pico_socket *s)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *) s;
+
+ if (t->tcpq_in.frames == 0)
+ return 1;
+ else
+ return 0;
+}
+
+/* Useful for getting rid of the beginning of the buffer (read() op) */
+static int release_until(struct pico_tcp_queue *q, uint32_t seq)
+{
+ struct pico_frame *head = first_segment(q);
+ int ret = 0;
+ while (head && (seq_compare(SEQN(head) + head->payload_len, seq) <= 0)) {
+ struct pico_frame *cur = head;
+ head = next_segment(q, cur);
+ tcp_dbg("Releasing %p\n", q);
+ pico_discard_segment(q, cur);
+ ret++;
+ }
+ return ret;
+}
+
+static int release_all_until(struct pico_tcp_queue *q, uint32_t seq)
+{
+ struct pico_frame *f = NULL, *tmp __attribute__((unused));
+ struct pico_tree_node * idx, * temp;
+ int ret = 0;
+
+ pico_tree_foreach_safe(idx,&q->pool,temp){
+ f = idx->keyValue;
+ if (seq_compare(SEQN(f) + f->payload_len, seq) <= 0) {
+ tcp_dbg("Releasing %p\n", f);
+ pico_discard_segment(q, f);
+ ret++;
+ } else
+ return ret;
+ }
+ return ret;
+}
+
+/* API calls */
+
+uint16_t pico_tcp_checksum_ipv4(struct pico_frame *f)
+{
+ struct pico_ipv4_hdr *hdr = (struct pico_ipv4_hdr *) f->net_hdr;
+ struct pico_tcp_hdr *tcp_hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+ struct pico_socket *s = f->sock;
+ struct pico_ipv4_pseudo_hdr pseudo;
+
+ if (s) {
+ /* Case of outgoing frame */
+ //dbg("TCP CRC: on outgoing frame\n");
+ pseudo.src.addr = s->local_addr.ip4.addr;
+ pseudo.dst.addr = s->remote_addr.ip4.addr;
+ } else {
+ /* Case of incomming frame */
+ //dbg("TCP CRC: on incomming frame\n");
+ pseudo.src.addr = hdr->src.addr;
+ pseudo.dst.addr = hdr->dst.addr;
+ }
+ pseudo.zeros = 0;
+ pseudo.proto = PICO_PROTO_TCP;
+ pseudo.len = short_be(f->transport_len);
+
+ return pico_dualbuffer_checksum(&pseudo, sizeof(struct pico_ipv4_pseudo_hdr), tcp_hdr, f->transport_len);
+}
+
+static void tcp_send_fin(struct pico_socket_tcp *t);
+static int pico_tcp_process_out(struct pico_protocol *self, struct pico_frame *f)
+{
+ struct pico_tcp_hdr *hdr;
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)f->sock;
+ hdr = (struct pico_tcp_hdr *)f->transport_hdr;
+
+ if (f->payload_len > 0) {
+ tcp_dbg("Process out: sending %p (%d bytes)\n",f, f->payload_len);
+ } else {
+ tcp_dbg("Sending empty packet\n");
+ }
+
+ if (f->payload_len > 0) {
+ if (seq_compare(SEQN(f) + f->payload_len, t->snd_nxt) > 0) {
+ t->snd_nxt = SEQN(f) + f->payload_len;
+ tcp_dbg("%s: snd_nxt is now %08x\n", __FUNCTION__, t->snd_nxt);
+ }
+ } else if (hdr->flags == PICO_TCP_ACK) { /* pure ack */
+ //hdr->seq = long_be(t->snd_nxt); /* XXX disabled this to not to mess with seq nrs of ACKs anymore */
+ } else {
+ tcp_dbg("%s: non-pure ACK with len=0, fl:%04x\n", __FUNCTION__, hdr->flags);
+ }
+
+ pico_network_send(f);
+ return 0;
+}
+
+int pico_tcp_push(struct pico_protocol *self, struct pico_frame *data);
+
+/* Interface: protocol definition */
+struct pico_protocol pico_proto_tcp = {
+ .name = "tcp",
+ .proto_number = PICO_PROTO_TCP,
+ .layer = PICO_LAYER_TRANSPORT,
+ .process_in = pico_transport_process_in,
+ .process_out = pico_tcp_process_out,
+ .push = pico_tcp_push,
+ .q_in = &tcp_in,
+ .q_out = &tcp_out,
+};
+
+static uint32_t pico_paws(void)
+{
+ static unsigned long _paws = 0;
+ _paws = pico_rand();
+ return long_be(_paws); /*XXX: implement paws */
+}
+
+static void tcp_add_options(struct pico_socket_tcp *ts, struct pico_frame *f, uint16_t flags, int optsiz)
+{
+ uint32_t tsval = long_be(pico_tick);
+ uint32_t tsecr = long_be(ts->ts_nxt);
+ int i = 0;
+ f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
+
+ memset(f->start, PICO_TCP_OPTION_NOOP, optsiz); /* fill blanks with noop */
+
+ if (flags & PICO_TCP_SYN) {
+ f->start[i++] = PICO_TCP_OPTION_MSS;
+ f->start[i++] = PICO_TCPOPTLEN_MSS;
+ f->start[i++] = (ts->mss >> 8) & 0xFF;
+ f->start[i++] = ts->mss & 0xFF;
+ f->start[i++] = PICO_TCP_OPTION_SACK_OK;
+ f->start[i++] = PICO_TCPOPTLEN_SACK_OK;
+ }
+
+ f->start[i++] = PICO_TCP_OPTION_WS;
+ f->start[i++] = PICO_TCPOPTLEN_WS;
+ f->start[i++] = ts->wnd_scale;
+
+ if (optsiz >= 12) {
+ f->start[i++] = PICO_TCP_OPTION_TIMESTAMP;
+ f->start[i++] = PICO_TCPOPTLEN_TIMESTAMP;
+ memcpy(f->start + i, &tsval, 4);
+ i += 4;
+ memcpy(f->start + i, &tsecr, 4);
+ i += 4;
+ }
+
+ if (flags & PICO_TCP_ACK) {
+ struct tcp_sack_block *sb;
+ int len_off;
+
+ if (ts->sack_ok && ts->sacks) {
+ f->start[i++] = PICO_TCP_OPTION_SACK;
+ len_off = i;
+ f->start[i++] = PICO_TCPOPTLEN_SACK;
+ while(ts->sacks) {
+ sb = ts->sacks;
+ ts->sacks = sb->next;
+ memcpy(f->start + i, sb, 2 * sizeof(uint32_t));
+ i += (2 * sizeof(uint32_t));
+ f->start[len_off] += (2 * sizeof(uint32_t));
+ pico_free(sb);
+ }
+ }
+ }
+ if (i < optsiz)
+ f->start[ optsiz - 1 ] = PICO_TCP_OPTION_END;
+}
+
+static void tcp_send_ack(struct pico_socket_tcp *t);
+
+static void tcp_set_space(struct pico_socket_tcp *t)
+{
+ int mtu, space;
+ int shift = 0;
+
+ mtu = t->mss + PICO_SIZE_TCPHDR + PICO_SIZE_TCPOPT_SYN ;
+ if (t->tcpq_in.max_size == 0) {
+ space = 1024 * 1024 * 1024; /* One Gigabyte, for unlimited sockets. */
+ } else {
+ space = ((t->tcpq_in.max_size - t->tcpq_in.size) / mtu) * t->mss;
+ }
+ if (space < 0)
+ space = 0;
+ while(space > 0xFFFF) {
+ space >>= 1;
+ shift++;
+ }
+ if ((space != t->wnd) || (shift != t->wnd_scale) || ((space - t->wnd) > (space>>2))) {
+ t->wnd = space;
+ t->wnd_scale = shift;
+ }
+}
+
+/* Return 32-bit aligned option size */
+static int tcp_options_size(struct pico_socket_tcp *t, uint16_t flags)
+{
+ int size = 0;
+ struct tcp_sack_block *sb = t->sacks;
+
+ if (flags & PICO_TCP_SYN) { /* Full options */
+ size = PICO_TCPOPTLEN_MSS + PICO_TCP_OPTION_SACK_OK + PICO_TCPOPTLEN_WS + PICO_TCPOPTLEN_TIMESTAMP;
+ } else {
+
+ /* Always update window scale. */
+ size += PICO_TCPOPTLEN_WS;
+
+ if (t->ts_ok)
+ size += PICO_TCPOPTLEN_TIMESTAMP;
+
+ size+= PICO_TCPOPTLEN_END;
+ }
+ if ((flags & PICO_TCP_ACK) && (t->sack_ok && sb)) {
+ size += 2;
+ while(sb) {
+ size += (2 * sizeof(uint32_t));
+ sb = sb->next;
+ }
+ }
+ size = (((size + 3) >> 2) << 2);
+ return size;
+}
+
+int pico_tcp_overhead(struct pico_socket *s)
+{
+ if (!s)
+ return 0;
+
+ return PICO_SIZE_TCPHDR + tcp_options_size((struct pico_socket_tcp *)s, 0); /* hdr + Options size for data pkt */
+
+}
+
+static void tcp_process_sack(struct pico_socket_tcp *t, uint32_t start, uint32_t end)
+{
+ struct pico_frame *f;
+ struct pico_tree_node * index, * temp;
+ int cmp;
+ int count = 0;
+
+ pico_tree_foreach_safe(index,&t->tcpq_out.pool,temp){
+ f = index->keyValue;
+ cmp = seq_compare(SEQN(f), start);
+ if (cmp > 0)
+ goto done;
+
+ if (cmp == 0) {
+ cmp = seq_compare(SEQN(f) + f->payload_len, end);
+ if (cmp > 0) {
+ tcp_dbg("Invalid SACK: ignoring.\n");
+ }
+
+ tcp_dbg("Marking (by SACK) segment %08x BLK:[%08x::%08x]\n", SEQN(f), start, end);
+ f->flags |= PICO_FRAME_FLAG_SACKED;
+ count++;
+
+ if (cmp == 0) {
+ /* that was last segment sacked. Job done */
+ goto done;
+ }
+ }
+ }
+
+done:
+ if (t->x_mode > PICO_TCP_LOOKAHEAD) {
+ if (t->in_flight > (count))
+ t->in_flight -= (count);
+ else
+ t->in_flight = 0;
+ }
+}
+
+static void tcp_rcv_sack(struct pico_socket_tcp *t, uint8_t *opt, int len)
+{
+ uint32_t start, end;
+ int i = 0;
+ if (len % 8) {
+ tcp_dbg("SACK: Invalid len.\n");
+ return;
+ }
+ while (i < len) {
+ start = long_from(opt + i);
+ i += 4;
+ end = long_from(opt + i);
+ i += 4;
+ tcp_process_sack(t, long_be(start), long_be(end));
+ }
+}
+
+static void tcp_parse_options(struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)f->sock;
+ uint8_t *opt = f->transport_hdr + PICO_SIZE_TCPHDR;
+ int i = 0;
+ f->timestamp = 0;
+ while (i < (f->transport_len - PICO_SIZE_TCPHDR)) {
+ uint8_t type = opt[i++];
+ uint8_t len;
+ if(i < (f->transport_len - PICO_SIZE_TCPHDR) && (type > 1))
+ len = opt[i++];
+ else
+ len = 1;
+ if (f->payload && ((opt + i) > f->payload))
+ break;
+ tcp_dbg_options("Received option '%d', len = %d \n", type, len);
+ switch (type) {
+ case PICO_TCP_OPTION_NOOP:
+ case PICO_TCP_OPTION_END:
+ break;
+ case PICO_TCP_OPTION_WS:
+ if (len != PICO_TCPOPTLEN_WS) {
+ tcp_dbg_options("TCP Window scale: bad len received (%d).\n", len);
+ i += len - 2;
+ break;
+ }
+ t->recv_wnd_scale = opt[i++];
+ tcp_dbg_options("TCP Window scale: received %d\n", t->recv_wnd_scale);
+ break;
+ case PICO_TCP_OPTION_SACK_OK:
+ if (len != PICO_TCPOPTLEN_SACK_OK) {
+ tcp_dbg_options("TCP option sack: bad len received.\n");
+ i += len - 2;
+ break;
+ }
+ t->sack_ok = 1;
+ break;
+ case PICO_TCP_OPTION_MSS: {
+ uint16_t mss;
+ if (len != PICO_TCPOPTLEN_MSS) {
+ tcp_dbg_options("TCP option mss: bad len received.\n");
+ i += len - 2;
+ break;
+ }
+ t->mss_ok = 1;
+ mss = short_from(opt + i);
+ i += sizeof(uint16_t);
+ if (t->mss > short_be(mss))
+ t->mss = short_be(mss);
+ break;
+ }
+ case PICO_TCP_OPTION_TIMESTAMP: {
+ uint32_t tsval, tsecr;
+ if (len != PICO_TCPOPTLEN_TIMESTAMP) {
+ tcp_dbg_options("TCP option timestamp: bad len received.\n");
+ i += len - 2;
+ break;
+ }
+ t->ts_ok = 1;
+ tsval = long_from(opt + i);
+ i += sizeof(uint32_t);
+ tsecr = long_from(opt + i);
+ f->timestamp = long_be(tsecr);
+ i += sizeof(uint32_t);
+ t->ts_nxt = long_be(tsval);
+ break;
+ }
+ case PICO_TCP_OPTION_SACK:
+ {
+ tcp_rcv_sack(t, opt + i, len - 2);
+ i += len - 2;
+ break;
+ }
+ default:
+ tcp_dbg_options("TCP: received unsupported option %u\n", type);
+ i += len - 2;
+ }
+ }
+}
+
+static int tcp_send(struct pico_socket_tcp *ts, struct pico_frame *f)
+{
+ struct pico_tcp_hdr *hdr= (struct pico_tcp_hdr *) f->transport_hdr;
+ struct pico_frame *cpy;
+ hdr->trans.sport = ts->sock.local_port;
+ hdr->trans.dport = ts->sock.remote_port;
+ if (!hdr->seq)
+ hdr->seq = long_be(ts->snd_nxt);
+
+ if (ts->rcv_nxt != 0) {
+ if ( (ts->rcv_ackd == 0) || (seq_compare(ts->rcv_ackd, ts->rcv_nxt) != 0) || (hdr->flags & PICO_TCP_ACK)) {
+ hdr->flags |= PICO_TCP_ACK;
+ hdr->ack = long_be(ts->rcv_nxt);
+ ts->rcv_ackd = ts->rcv_nxt;
+ }
+ }
+
+ if (hdr->flags & PICO_TCP_SYN) {
+ ts->snd_nxt++;
+ }
+ if (f->payload_len > 0) {
+ hdr->flags |= PICO_TCP_PSH | PICO_TCP_ACK;
+ hdr->ack = long_be(ts->rcv_nxt);
+ ts->rcv_ackd = ts->rcv_nxt;
+ ts->keepalive_timer_running = 2; /* XXX TODO check fix: added 1 to counter to postpone sending keepalive, ACK is in data segments */
+ }
+
+ f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
+ hdr->rwnd = short_be(ts->wnd);
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
+
+ /* TCP: ENQUEUE to PROTO ( Transmit ) */
+ cpy = pico_frame_copy(f);
+ if ((pico_enqueue(&tcp_out, cpy) > 0)) {
+ if (f->payload_len > 0) {
+ ts->in_flight++;
+ ts->snd_nxt += f->payload_len; /* update next pointer here to prevent sending same segment twice when called twice in same tick */
+ }
+ tcp_dbg("DBG> [tcp output] state: %02x --> local port:%d remote port: %d seq: %08x ack: %08x flags: %02x = t_len: %d, hdr: %u payload: %d\n",
+ TCPSTATE(&ts->sock) >> 8, short_be(hdr->trans.sport), short_be(hdr->trans.dport), SEQN(f), ACKN(f), hdr->flags, f->transport_len, (hdr->len & 0xf0) >> 2 , f->payload_len );
+ } else {
+ pico_frame_discard(cpy);
+ }
+ return 0;
+}
+
+//#define PICO_TCP_SUPPORT_SOCKET_STATS
+
+#ifdef PICO_TCP_SUPPORT_SOCKET_STATS
+static void sock_stats(unsigned long when, void *arg)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)arg;
+ tcp_dbg("STATISTIC> [%lu] socket state: %02x --> local port:%d remote port: %d queue size: %d snd_una: %08x snd_nxt: %08x timer: %d cwnd: %d\n",
+ when, t->sock.state, short_be(t->sock.local_port), short_be(t->sock.remote_port), t->tcpq_out.size, SEQN(first_segment(&t->tcpq_out)), t->snd_nxt, t->timer_running, t->cwnd);
+ pico_timer_add(2000, sock_stats, t);
+}
+#endif
+
+struct pico_socket *pico_tcp_open(void)
+{
+ struct pico_socket_tcp *t = pico_zalloc(sizeof(struct pico_socket_tcp));
+ if (!t)
+ return NULL;
+ t->mss = PICO_TCP_DEFAULT_MSS;
+
+ t->tcpq_in.pool.root = t->tcpq_hold.pool.root = t->tcpq_out.pool.root = &LEAF;
+ t->tcpq_hold.pool.compare = t->tcpq_in.pool.compare = t->tcpq_out.pool.compare = segment_compare;
+
+ t->tcpq_in.max_size = PICO_DEFAULT_SOCKETQ;
+ t->tcpq_out.max_size = PICO_DEFAULT_SOCKETQ;
+ t->tcpq_hold.max_size = 2*PICO_TCP_DEFAULT_MSS;
+
+ /* disable Nagle by default */
+ t->sock.opt_flags |= (1 << PICO_SOCKET_OPT_TCPNODELAY);
+
+#ifdef PICO_TCP_SUPPORT_SOCKET_STATS
+ pico_timer_add(2000, sock_stats, t);
+#endif
+ tcp_set_space(t);
+
+ return &t->sock;
+}
+
+int pico_tcp_read(struct pico_socket *s, void *buf, int len)
+{
+ struct pico_socket_tcp *t = TCP_SOCK(s);
+ struct pico_frame *f;
+ uint32_t in_frame_off, in_frame_len;
+ int tot_rd_len = 0;
+
+ while (tot_rd_len < len) {
+ /* To be sure we don't have garbage at the beginning */
+ release_until(&t->tcpq_in, t->rcv_processed);
+ f = first_segment(&t->tcpq_in);
+ if (!f) {
+ tcp_set_space(t);
+ goto out;
+ }
+
+ /* Hole at the beginning of data, awaiting retransmissions. */
+ if (seq_compare(t->rcv_processed, SEQN(f)) < 0) {
+ tcp_dbg("TCP> read hole beginning of data, %08x - %08x. rcv_nxt is %08x\n",t->rcv_processed, SEQN(f), t->rcv_nxt);
+ goto out;
+ }
+
+ if(seq_compare(t->rcv_processed, SEQN(f)) > 0) {
+ in_frame_off = t->rcv_processed - SEQN(f);
+ in_frame_len = f->payload_len - in_frame_off;
+ } else {
+ in_frame_off = 0;
+ in_frame_len = f->payload_len;
+ }
+ if ((in_frame_len + tot_rd_len) > len) {
+ in_frame_len = len - tot_rd_len;
+ }
+
+ if (in_frame_len > f->payload_len - in_frame_off)
+ in_frame_len = f->payload_len - in_frame_off;
+
+ memcpy((uint8_t *)buf + tot_rd_len, f->payload + in_frame_off, in_frame_len);
+ tot_rd_len += in_frame_len;
+ t->rcv_processed += in_frame_len;
+
+ if ((in_frame_len == 0) || (in_frame_len == f->payload_len)) {
+ pico_discard_segment(&t->tcpq_in, f);
+ }
+ }
+
+out:
+ tcp_set_space(t);
+ if (t->tcpq_in.size == 0) {
+ s->ev_pending &= (~PICO_SOCK_EV_RD);
+ }
+ return tot_rd_len;
+}
+
+int pico_tcp_initconn(struct pico_socket *s);
+static void initconn_retry(unsigned long when, void *arg)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)arg;
+ if (TCPSTATE(&t->sock) == PICO_SOCKET_STATE_TCP_SYN_SENT) {
+ if (t->backoff > PICO_TCP_MAX_CONNECT_RETRIES) {
+ tcp_dbg("TCP> Connection timeout. \n");
+ if (t->sock.wakeup)
+ t->sock.wakeup(PICO_SOCK_EV_ERR, &t->sock);
+ return;
+ }
+ tcp_dbg("TCP> SYN retry %d...\n", t->backoff);
+ t->backoff++;
+ pico_tcp_initconn(&t->sock);
+ } else {
+ tcp_dbg("TCP> Connection is already established: no retry needed. good.\n");
+ }
+}
+
+int pico_tcp_initconn(struct pico_socket *s)
+{
+ struct pico_socket_tcp *ts = TCP_SOCK(s);
+ struct pico_frame *syn;
+ struct pico_tcp_hdr *hdr;
+ int opt_len = tcp_options_size(ts, PICO_TCP_SYN);
+
+ syn = s->net->alloc(s->net, PICO_SIZE_TCPHDR + opt_len);
+ if (!syn)
+ return -1;
+ hdr = (struct pico_tcp_hdr *) syn->transport_hdr;
+
+ if (!ts->snd_nxt)
+ ts->snd_nxt = long_be(pico_paws());
+ ts->snd_last = ts->snd_nxt;
+ ts->cwnd = PICO_TCP_IW;
+ ts->ssthresh = 40;
+ syn->sock = s;
+ hdr->seq = long_be(ts->snd_nxt);
+ hdr->len = (PICO_SIZE_TCPHDR + opt_len) << 2 | ts->jumbo;
+ hdr->flags = PICO_TCP_SYN;
+ tcp_set_space(ts);
+ hdr->rwnd = short_be(ts->wnd);
+ tcp_add_options(ts,syn, PICO_TCP_SYN, opt_len);
+ hdr->trans.sport = ts->sock.local_port;
+ hdr->trans.dport = ts->sock.remote_port;
+
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(syn));
+
+ /* TCP: ENQUEUE to PROTO ( SYN ) */
+ tcp_dbg("Sending SYN... (ports: %d - %d) size: %d\n", short_be(ts->sock.local_port), short_be(ts->sock.remote_port), syn->buffer_len);
+ pico_enqueue(&tcp_out, syn);
+ pico_timer_add(PICO_TCP_SYN_TO << ts->backoff, initconn_retry, ts);
+ return 0;
+}
+
+static int tcp_send_synack(struct pico_socket *s)
+{
+ struct pico_socket_tcp *ts = TCP_SOCK(s);
+ struct pico_frame *synack;
+ struct pico_tcp_hdr *hdr;
+ int opt_len = tcp_options_size(ts, PICO_TCP_SYN | PICO_TCP_ACK);
+
+ synack = s->net->alloc(s->net, PICO_SIZE_TCPHDR + opt_len);
+ if (!synack)
+ return -1;
+ hdr = (struct pico_tcp_hdr *) synack->transport_hdr;
+
+ synack->sock = s;
+ hdr->len = (PICO_SIZE_TCPHDR + opt_len) << 2 | ts->jumbo;
+ hdr->flags = PICO_TCP_SYN | PICO_TCP_ACK;
+ hdr->rwnd = short_be(ts->wnd);
+ hdr->seq = long_be(ts->snd_nxt);
+ ts->rcv_processed = long_be(hdr->seq);
+ ts->snd_last = ts->snd_nxt;
+ tcp_set_space(ts);
+ tcp_add_options(ts,synack, hdr->flags, opt_len);
+ synack->payload_len = 0;
+ synack->timestamp = pico_tick;
+ tcp_send(ts, synack);
+ pico_frame_discard(synack);
+ return 0;
+}
+
+static void tcp_send_empty(struct pico_socket_tcp *t, uint16_t flags)
+{
+ struct pico_frame *f;
+ struct pico_tcp_hdr *hdr;
+ int opt_len = tcp_options_size(t, flags);
+ f = t->sock.net->alloc(t->sock.net, PICO_SIZE_TCPHDR + opt_len);
+ if (!f) {
+ return;
+ }
+ f->sock = &t->sock;
+ hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+ hdr->len = (PICO_SIZE_TCPHDR + opt_len) << 2 | t->jumbo;
+ hdr->flags = flags;
+ hdr->rwnd = short_be(t->wnd);
+ tcp_set_space(t);
+ tcp_add_options(t,f, flags, opt_len);
+ hdr->trans.sport = t->sock.local_port;
+ hdr->trans.dport = t->sock.remote_port;
+ hdr->seq = long_be(t->snd_nxt);
+ if ((flags & PICO_TCP_ACK) != 0)
+ hdr->ack = long_be(t->rcv_nxt);
+ t->rcv_ackd = t->rcv_nxt;
+
+ f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
+ hdr->rwnd = short_be(t->wnd);
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
+
+ /* TCP: ENQUEUE to PROTO */
+ pico_enqueue(&tcp_out, f);
+}
+
+static void tcp_send_ack(struct pico_socket_tcp *t)
+{
+ return tcp_send_empty(t, PICO_TCP_ACK);
+}
+
+static int tcp_send_rst(struct pico_socket *s, struct pico_frame *fr)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *) s;
+ struct pico_frame *f;
+ struct pico_tcp_hdr *hdr, *hdr_rcv;
+ int opt_len = tcp_options_size(t, PICO_TCP_RST);
+ int close;
+
+ tcp_dbg("TCP SEND_RST >>>>>>>>>>>>>>> START\n");
+
+ f = t->sock.net->alloc(t->sock.net, PICO_SIZE_TCPHDR + opt_len);
+
+ if (!f) {
+ return -1;
+ }
+
+ hdr_rcv = (struct pico_tcp_hdr *) fr->transport_hdr;
+
+ f->sock = &t->sock;
+ hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+ hdr->len = (PICO_SIZE_TCPHDR + opt_len) << 2 | t->jumbo;
+ hdr->flags = PICO_TCP_RST;
+ hdr->rwnd = short_be(t->wnd);
+ tcp_set_space(t);
+ tcp_add_options(t,f, PICO_TCP_RST, opt_len);
+ hdr->trans.sport = t->sock.local_port;
+ hdr->trans.dport = t->sock.remote_port;
+ hdr->seq = long_be(t->snd_nxt);
+
+ /* check if state is synchronized */
+ if (((s->state & PICO_SOCKET_STATE_TCP) > PICO_SOCKET_STATE_TCP_SYN_RECV)) {
+ /* in synchronized state: send RST with seq = ack from previous segment */
+ hdr->seq = hdr_rcv->ack;
+ close = 0;
+ } else {
+ /* non-synchronized state */
+ /* go to CLOSED here to prevent timer callback to go on after timeout */
+ (t->sock).state &= 0x00FFU;
+ (t->sock).state |= PICO_SOCKET_STATE_TCP_CLOSED;
+ close = 1;
+ }
+
+ hdr->ack = long_be(t->rcv_nxt);
+ t->rcv_ackd = t->rcv_nxt;
+ f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
+ hdr->rwnd = short_be(t->wnd);
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
+
+ /* TCP: ENQUEUE to PROTO */
+ pico_enqueue(&tcp_out, f);
+
+ /* goto CLOSED */
+ if (close) {
+ (t->sock).state &= 0xFF00U;
+ (t->sock).state |= PICO_SOCKET_STATE_CLOSED;
+
+ /* call EV_FIN wakeup before deleting */
+ if ((t->sock).wakeup)
+ (t->sock).wakeup(PICO_SOCK_EV_FIN, &(t->sock));
+
+ /* delete socket */
+ pico_socket_del(&t->sock);
+
+ tcp_dbg("TCP SEND_RST >>>>>>>>>>>>>>> DONE, deleted socket\n");
+ }
+
+ return 0;
+}
+
+int pico_tcp_reply_rst(struct pico_frame *fr)
+{
+ struct pico_tcp_hdr *hdr;
+ struct pico_frame *f;
+ int size = PICO_SIZE_TCPHDR;
+
+ tcp_dbg("TCP>>>>>>>>>>>>>>>> sending RST ... <<<<<<<<<<<<<<<<<<\n");
+
+ f = fr->sock->net->alloc(fr->sock->net, size);
+
+ /* fill in IP data from original frame */
+ // TODO if IPv4
+ ((struct pico_ipv4_hdr *)(f->net_hdr))->dst.addr = ((struct pico_ipv4_hdr *)(fr->net_hdr))->src.addr;
+ ((struct pico_ipv4_hdr *)(f->net_hdr))->src.addr = ((struct pico_ipv4_hdr *)(fr->net_hdr))->dst.addr;
+
+ /* fill in TCP data from original frame */
+ ((struct pico_tcp_hdr *)(f->transport_hdr))->trans.dport = ((struct pico_tcp_hdr *)(fr->transport_hdr))->trans.sport;
+ ((struct pico_tcp_hdr *)(f->transport_hdr))->trans.sport = ((struct pico_tcp_hdr *)(fr->transport_hdr))->trans.dport;
+ hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+ hdr->len = size << 2;
+ hdr->flags = PICO_TCP_RST | PICO_TCP_ACK;
+ hdr->rwnd = 0;
+ if (((struct pico_tcp_hdr *)(fr->transport_hdr))->flags & PICO_TCP_ACK) {
+ hdr->seq = ((struct pico_tcp_hdr *)(fr->transport_hdr))->ack;
+ } else {
+ hdr->seq = 0U;
+ }
+
+ hdr->ack = ((struct pico_tcp_hdr *)(fr->transport_hdr))->seq + short_be(fr->payload_len);
+
+ /* enqueue for transmission */
+ pico_ipv4_frame_push(f,&(((struct pico_ipv4_hdr *)(f->net_hdr))->dst),PICO_PROTO_TCP);
+
+ return 0;
+}
+
+static int tcp_nosync_rst(struct pico_socket *s, struct pico_frame *fr)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *) s;
+ struct pico_frame *f;
+ struct pico_tcp_hdr *hdr, *hdr_rcv;
+ int opt_len = tcp_options_size(t, PICO_TCP_RST | PICO_TCP_ACK);
+
+ tcp_dbg("TCP SEND RST (NON-SYNC) >>>>>>>>>>>>>>>>>> state %x\n",(s->state & PICO_SOCKET_STATE_TCP));
+ if (((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_LISTEN)) {
+ /* XXX TODO NOTE: to prevent the parent socket from trying to send, because this socket has no knowledge of dst IP !!! */
+ return pico_tcp_reply_rst(fr);
+ }
+
+ /***************************************************************************/
+ /* sending RST */
+ f = t->sock.net->alloc(t->sock.net, PICO_SIZE_TCPHDR + opt_len);
+
+ if (!f) {
+ return -1;
+ }
+
+ hdr_rcv = (struct pico_tcp_hdr *) fr->transport_hdr;
+
+ f->sock = &t->sock;
+ hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+ hdr->len = (PICO_SIZE_TCPHDR + opt_len) << 2 | t->jumbo;
+ hdr->flags = PICO_TCP_RST | PICO_TCP_ACK;
+ hdr->rwnd = short_be(t->wnd);
+ tcp_set_space(t);
+ tcp_add_options(t,f, PICO_TCP_RST | PICO_TCP_ACK, opt_len);
+ hdr->trans.sport = t->sock.local_port;
+ hdr->trans.dport = t->sock.remote_port;
+
+ /* non-synchronized state */
+ if (hdr_rcv->flags & PICO_TCP_ACK) {
+ hdr->seq = hdr_rcv->ack;
+ } else {
+ hdr->seq = 0U;
+ }
+
+ hdr->ack = hdr_rcv->seq + short_be(fr->payload_len);
+
+ t->rcv_ackd = t->rcv_nxt;
+ f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
+ hdr->rwnd = short_be(t->wnd);
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
+
+ /* TCP: ENQUEUE to PROTO */
+ pico_enqueue(&tcp_out, f);
+
+ /***************************************************************************/
+
+ tcp_dbg("TCP SEND_RST (NON_SYNC) >>>>>>>>>>>>>>> DONE, ...\n");
+
+ return 0;
+}
+
+static void tcp_send_fin(struct pico_socket_tcp *t)
+{
+ struct pico_frame *f;
+ struct pico_tcp_hdr *hdr;
+ int opt_len = tcp_options_size(t, PICO_TCP_FIN);
+ f = t->sock.net->alloc(t->sock.net, PICO_SIZE_TCPHDR + opt_len);
+ if (!f) {
+ return;
+ }
+ f->sock = &t->sock;
+ hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+ hdr->len = (PICO_SIZE_TCPHDR + opt_len) << 2 | t->jumbo;
+ hdr->flags = PICO_TCP_FIN | PICO_TCP_ACK;
+ hdr->ack = long_be(t->rcv_nxt);
+ t->rcv_ackd = t->rcv_nxt;
+ hdr->rwnd = short_be(t->wnd);
+ tcp_set_space(t);
+ tcp_add_options(t,f, PICO_TCP_FIN, opt_len);
+ hdr->trans.sport = t->sock.local_port;
+ hdr->trans.dport = t->sock.remote_port;
+ hdr->seq = long_be(t->snd_nxt); /* XXX TODO check correct ?? --> snd_last? otherwise maybe data after FIN */
+
+ f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
+ hdr->rwnd = short_be(t->wnd);
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
+ //tcp_dbg("SENDING FIN...\n");
+ /* TCP: ENQUEUE to PROTO ( Pure ACK ) */
+ pico_enqueue(&tcp_out, f);
+ t->snd_nxt++;
+}
+
+static void tcp_sack_prepare(struct pico_socket_tcp *t)
+{
+ struct pico_frame *pkt;
+ uint32_t left=0, right=0;
+ struct tcp_sack_block *sb;
+ int n = 0;
+ if (t->sacks) /* previous sacks are pending */
+ return;
+
+ pkt = first_segment(&t->tcpq_in);
+ while(n < 3) {
+ if (!pkt) {
+ if(left) {
+ sb = pico_zalloc(sizeof(struct tcp_sack_block));
+ if (!sb)
+ break;
+ sb->left = long_be(left);
+ sb->right = long_be(right);
+ n++;
+ sb->next = t->sacks;
+ t->sacks = sb;
+ left = 0;
+ right = 0;
+ }
+ break;
+ }
+ if ((SEQN(pkt) < t->rcv_nxt)) {
+ pkt = next_segment(&t->tcpq_in, pkt);
+ continue;
+ }
+ if (!left) {
+ left = SEQN(pkt);
+ right = SEQN(pkt) + pkt->payload_len;
+ pkt = next_segment(&t->tcpq_in, pkt);
+ continue;
+ }
+ if(SEQN(pkt) == (right + 1)) {
+ right += pkt->payload_len;
+ pkt = next_segment(&t->tcpq_in, pkt);
+ continue;
+ } else {
+ sb = pico_zalloc(sizeof(struct tcp_sack_block));
+ if (!sb)
+ break;
+ sb->left = long_be(left);
+ sb->right = long_be(right);
+ n++;
+ sb->next = t->sacks;
+ t->sacks = sb;
+ left = 0;
+ right = 0;
+ pkt = next_segment(&t->tcpq_in, pkt);
+ }
+ }
+}
+
+static int tcp_data_in(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+
+ if (((hdr->len & 0xf0) >> 2) <= f->transport_len) {
+ tcp_parse_options(f);
+ f->payload = f->transport_hdr + ((hdr->len & 0xf0) >>2);
+ f->payload_len = f->transport_len - ((hdr->len & 0xf0) >>2);
+ tcp_dbg("TCP> Received segment. (exp: %x got: %x)\n", t->rcv_nxt, SEQN(f));
+
+ if (seq_compare(SEQN(f), t->rcv_nxt) <= 0) {
+ struct pico_frame *nxt;
+ if (seq_compare(SEQN(f), t->rcv_nxt) == 0) { /* Exactly what we expected */
+ struct pico_frame *cpy = pico_frame_copy(f);
+ /* Enqueue: try to put into RCV buffer */
+ if(pico_enqueue_segment(&t->tcpq_in, cpy) <= 0) {
+ pico_frame_discard(cpy);
+ }
+ t->rcv_nxt = SEQN(f) + f->payload_len;
+ nxt = peek_segment(&t->tcpq_in, t->rcv_nxt);
+ while(nxt) {
+ tcp_dbg("scrolling rcv_nxt...%08x\n", t->rcv_nxt);
+ t->rcv_nxt += f->payload_len;
+ nxt = peek_segment(&t->tcpq_in, t->rcv_nxt);
+ }
+ t->sock.ev_pending |= PICO_SOCK_EV_RD;
+ t->rcv_nxt = SEQN(f) + f->payload_len;
+ } else {
+ tcp_dbg("TCP> lo segment. Uninteresting retransmission. (exp: %x got: %x)\n", t->rcv_nxt, SEQN(f));
+ }
+ } else {
+ tcp_dbg("TCP> hi segment. Possible packet loss. I'll dupack this. (exp: %x got: %x)\n", t->rcv_nxt, SEQN(f));
+ if (t->sack_ok) {
+ tcp_sack_prepare(t);
+ }
+ }
+ /* In either case, ack til recv_nxt. */
+ if ( ((t->sock.state & PICO_SOCKET_STATE_TCP) != PICO_SOCKET_STATE_TCP_CLOSE_WAIT) && ((t->sock.state & PICO_SOCKET_STATE_TCP) != PICO_SOCKET_STATE_TCP_SYN_SENT) && ((t->sock.state & PICO_SOCKET_STATE_TCP) != PICO_SOCKET_STATE_TCP_SYN_RECV)) {
+ //tcp_dbg("SENDACK CALLED FROM OUTSIDE tcp_synack, state %x\n",t->sock.state);
+ tcp_send_ack(t);
+ } else {
+ //tcp_dbg("SENDACK PREVENTED IN SYNSENT STATE\n");
+ }
+ return 0;
+ } else {
+ tcp_dbg("TCP: invalid data in pkt len, exp: %d, got %d\n", (hdr->len & 0xf0) >> 2, f->transport_len);
+ return -1;
+ }
+}
+
+static int tcp_ack_advance_una(struct pico_socket_tcp *t, struct pico_frame *f)
+{
+ int ret = release_all_until(&t->tcpq_out, ACKN(f));
+ if (ret > 0)
+ t->sock.ev_pending |= PICO_SOCK_EV_WR;
+ return ret;
+}
+
+static uint16_t time_diff(unsigned long a, unsigned long b)
+{
+ if (a >= b)
+ return (a - b);
+ else
+ return (b - a);
+}
+
+static void tcp_rtt(struct pico_socket_tcp *t, uint32_t rtt)
+{
+
+ uint32_t avg = t->avg_rtt;
+ uint32_t rvar = t->rttvar;
+ if (!avg) {
+ /* This follows RFC2988
+ * (2.2) When the first RTT measurement R is made, the host MUST set
+ *
+ * SRTT <- R
+ * RTTVAR <- R/2
+ * RTO <- SRTT + max (G, K*RTTVAR)
+ */
+ t->avg_rtt = rtt;
+ t->rttvar = rtt >> 1;
+ t->rto = t->avg_rtt + (t->rttvar << 4);
+ } else {
+ int var = (t->avg_rtt - rtt);
+ if (var < 0)
+ var = 0-var;
+ /* RFC2988, section (2.3). Alpha and beta are the ones suggested. */
+
+ /* First, evaluate a new value for the rttvar */
+ t->rttvar <<= 2;
+ t->rttvar -= rvar;
+ t->rttvar += var;
+ t->rttvar >>= 2;
+
+ /* Then, calculate the new avg_rtt */
+ t->avg_rtt <<= 3;
+ t->avg_rtt -= avg;
+ t->avg_rtt += rtt;
+ t->avg_rtt >>= 3;
+
+ /* Finally, assign a new value for the RTO, as specified in the RFC, with K=4 */
+ t->rto = t->avg_rtt + (t->rttvar << 2);
+ }
+ tcp_dbg(" -----=============== RTT CUR: %u AVG: %u RTTVAR: %u RTO: %u ======================----\n", rtt, t->avg_rtt, t->rttvar, t->rto);
+}
+
+static void tcp_congestion_control(struct pico_socket_tcp *t)
+{
+ if (t->x_mode > PICO_TCP_LOOKAHEAD)
+ return;
+ if (t->cwnd > t->tcpq_out.frames) {
+ tcp_dbg("Limited by app: %d\n", t->cwnd);
+ if (t->sock.wakeup)
+ t->sock.wakeup(PICO_SOCK_EV_WR, &t->sock);
+ return;
+ }
+ tcp_dbg("Doing congestion control\n");
+ if (t->cwnd < t->ssthresh) {
+ t->cwnd++;
+ } else {
+ t->cwnd_counter++;
+ if (t->cwnd_counter >= t->cwnd) {
+ t->cwnd++;
+ t->cwnd_counter = 0;
+ }
+ }
+ tcp_dbg("TCP_CWND, %lu, %u, %u, %u\n", pico_tick, t->cwnd, t->ssthresh, t->in_flight);
+}
+
+static void add_retransmission_timer(struct pico_socket_tcp *t, unsigned long next_ts);
+static void tcp_retrans_timeout(unsigned long val, void *sock)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *) sock;
+ struct pico_frame *f = NULL;
+ unsigned long limit = val - t->rto;
+ struct pico_tcp_hdr *hdr;
+ if( t->sock.net && ((t->sock.state & 0xFF00) == PICO_SOCKET_STATE_TCP_ESTABLISHED
+ || (t->sock.state & 0xFF00) == PICO_SOCKET_STATE_TCP_CLOSE_WAIT) )
+ {
+ tcp_dbg("\n\nTIMEOUT! backoff = %d\n", t->backoff);
+ /* was timer cancelled? */
+ if (t->timer_running == 0) {
+ add_retransmission_timer(t, 0);
+ return;
+ }
+ t->timer_running--;
+
+ f = first_segment(&t->tcpq_out);
+ while (f) {
+ if ((t->x_mode == PICO_TCP_WINDOW_FULL) ||
+ ((f->timestamp != 0) && (f->timestamp <= limit))) {
+ struct pico_frame *cpy;
+ hdr = (struct pico_tcp_hdr *)f->transport_hdr;
+ tcp_dbg("TCP BLACKOUT> TIMED OUT (output) frame %08x, len= %d rto=%d Win full: %d frame flags: %04x\n", SEQN(f), f->payload_len, t->rto, t->x_mode == PICO_TCP_WINDOW_FULL, f->flags);
+ if ((t->x_mode != PICO_TCP_WINDOW_FULL) ) {
+ t->x_mode = PICO_TCP_BLACKOUT;
+ tcp_dbg("Mode: Blackout.\n");
+ t->cwnd = PICO_TCP_IW;
+ t->in_flight = 0;
+ }
+ f->timestamp = pico_tick;
+ tcp_add_options(t, f, 0, f->transport_len - f->payload_len - PICO_SIZE_TCPHDR);
+ hdr->rwnd = short_be(t->wnd);
+ hdr->flags |= PICO_TCP_PSH;
+ hdr->ack = long_be(t->rcv_nxt);
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
+ /* TCP: ENQUEUE to PROTO ( retransmit )*/
+ cpy = pico_frame_copy(f);
+ if (pico_enqueue(&tcp_out, cpy) > 0) {
+ t->backoff++;
+ add_retransmission_timer(t, (t->rto << t->backoff) + pico_tick);
+ tcp_dbg("TCP_CWND, %lu, %u, %u, %u\n", pico_tick, t->cwnd, t->ssthresh, t->in_flight);
+ return;
+ } else {
+ add_retransmission_timer(t, (t->rto << t->backoff) + pico_tick);
+ pico_frame_discard(cpy);
+ }
+ }
+ f = next_segment(&t->tcpq_out, f);
+ }
+ t->backoff = 0;
+ add_retransmission_timer(t, 0);
+ if (t->tcpq_out.size < t->tcpq_out.max_size)
+ t->sock.ev_pending |= PICO_SOCK_EV_WR;
+ return;
+ }
+}
+
+static void add_retransmission_timer(struct pico_socket_tcp *t, unsigned long next_ts)
+{
+ struct pico_tree_node * index;
+
+ if (t->timer_running > 0)
+ return;
+
+ if (next_ts == 0) {
+ struct pico_frame *f;
+
+ pico_tree_foreach(index,&t->tcpq_out.pool){
+ f = index->keyValue;
+ if (((next_ts == 0) || (f->timestamp < next_ts)) && (f->timestamp > 0)) {
+ next_ts = f->timestamp;
+ }
+ }
+ }
+ if (next_ts > 0) {
+ if ((next_ts + t->rto) > pico_tick) {
+ pico_timer_add(next_ts + t->rto - pico_tick, tcp_retrans_timeout, t);
+ } else {
+ pico_timer_add(1, tcp_retrans_timeout, t);
+ }
+ t->timer_running++;
+ }
+}
+
+static int tcp_retrans(struct pico_socket_tcp *t, struct pico_frame *f)
+{
+ struct pico_frame *cpy;
+ struct pico_tcp_hdr *hdr;
+ if (f) {
+ hdr = (struct pico_tcp_hdr *)f->transport_hdr;
+ tcp_dbg("TCP> RETRANS (by dupack) frame %08x, len= %d\n", SEQN(f), f->payload_len);
+ f->timestamp = pico_tick;
+ tcp_add_options(t, f, 0, f->transport_len - f->payload_len - PICO_SIZE_TCPHDR);
+ hdr->rwnd = short_be(t->wnd);
+ hdr->flags |= PICO_TCP_PSH;
+ hdr->ack = long_be(t->rcv_nxt);
+ hdr->crc = 0;
+ hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
+ /* TCP: ENQUEUE to PROTO ( retransmit )*/
+ cpy = pico_frame_copy(f);
+ if (pico_enqueue(&tcp_out, cpy) > 0) {
+ t->in_flight++;
+ t->snd_last_out = SEQN(cpy);
+ add_retransmission_timer(t, pico_tick + t->rto);
+ } else {
+ pico_frame_discard(cpy);
+ }
+ return(f->payload_len);
+ }
+ return 0;
+}
+
+#ifdef TCP_ACK_DBG
+static void tcp_ack_dbg(struct pico_socket *s, struct pico_frame *f)
+{
+ uint32_t una, nxt, ack, cur;
+ struct pico_frame *una_f = NULL, *cur_f;
+ struct pico_tree_node *idx;
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ char info[64];
+ char tmp[64];
+ ack = ACKN(f);
+ nxt = t->snd_nxt;
+ tcp_dbg("===================================\n");
+ tcp_dbg("Queue out (%d/%d). ACKED=%08x\n", t->tcpq_out.size, t->tcpq_out.max_size, ack);
+
+ pico_tree_foreach(idx, &t->tcpq_out.pool) {
+ info[0] = 0;
+ cur_f = idx->keyValue;
+ cur = SEQN(cur_f);
+ if (!una_f) {
+ una_f = cur_f;
+ una = SEQN(una_f);
+ }
+
+ if (cur == nxt) {
+ strncpy(tmp, info, strlen(info));
+ snprintf(info,64, "%s SND_NXT", tmp);
+ }
+ if (cur == ack) {
+ strncpy(tmp, info, strlen(info));
+ snprintf(info,64, "%s ACK", tmp);
+ }
+ if (cur == una) {
+ strncpy(tmp, info, strlen(info));
+ snprintf(info,64, "%s SND_UNA", tmp);
+ }
+ if (cur == t->snd_last) {
+ strncpy(tmp, info, strlen(info));
+ snprintf(info,64, "%s SND_LAST", tmp);
+ }
+ tcp_dbg("%08x %d%s\n", cur, cur_f->payload_len, info);
+
+ }
+ tcp_dbg("SND_NXT is %08x, snd_LAST is %08x", nxt, t->snd_last);
+ tcp_dbg("===================================\n");
+ tcp_dbg("\n\n");
+}
+#endif
+
+static int tcp_ack(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_frame *f_new; /* use with Nagle to push to out queue */
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *) f->transport_hdr;
+ uint32_t rtt = 0;
+ int acked = 0;
+ struct pico_frame *una = NULL;
+ if ((hdr->flags & PICO_TCP_ACK) == 0)
+ return -1;
+
+#ifdef TCP_ACK_DBG
+ tcp_ack_dbg(s,f);
+#endif
+
+ tcp_parse_options(f);
+ t->recv_wnd = short_be(hdr->rwnd);
+
+ acked = tcp_ack_advance_una(t, f);
+ una = first_segment(&t->tcpq_out);
+
+ if ((t->x_mode == PICO_TCP_BLACKOUT) ||
+ ((t->x_mode == PICO_TCP_WINDOW_FULL) && ((t->recv_wnd << t->recv_wnd_scale) > t->mss))) {
+ tcp_dbg("Re-entering look-ahead...\n\n\n");
+ t->x_mode = PICO_TCP_LOOKAHEAD;
+ t->backoff = 0;
+ }
+
+ /* One should be acked. */
+// if ((acked == 0) && (t->in_flight > 0))
+ if ((acked == 0) && (f->payload_len == 0) && (t->in_flight > 0))
+ t->in_flight--;
+ if (!una || acked > 0) {
+ t->x_mode = PICO_TCP_LOOKAHEAD;
+ tcp_dbg("Mode: Look-ahead. In flight: %d/%d buf: %d\n", t->in_flight, t->cwnd, t->tcpq_out.frames);
+ t->backoff = 0;
+
+ /* Do rtt/rttvar/rto calculations */
+ /* First, try with timestamps, using the value from options */
+ if(f && (f->timestamp != 0)) {
+ rtt = time_diff(pico_tick, f->timestamp);
+ if (rtt)
+ tcp_rtt(t, rtt);
+ } else if(una && (una->timestamp != 0)) {
+ /* If no timestamps are there, use conservatve estimation on the una */
+ rtt = time_diff(pico_tick, una->timestamp);
+ if (rtt)
+ tcp_rtt(t, rtt);
+ }
+
+ tcp_dbg("TCP ACK> FRESH ACK %08x (acked %d) Queue size: %u/%u frames: %u cwnd: %u in_flight: %u snd_una: %u\n", ACKN(f), acked, t->tcpq_out.size, t->tcpq_out.max_size, t->tcpq_out.frames, t->cwnd, t->in_flight, SEQN(una));
+ if (acked > t->in_flight) {
+ tcp_dbg("WARNING: in flight < 0\n");
+ t->in_flight = 0;
+ } else
+ t->in_flight -= (acked);
+
+ } else if ((t->snd_old_ack == ACKN(f)) && /* We've just seen this ack, and... */
+ ((0 == (hdr->flags & (PICO_TCP_PSH | PICO_TCP_SYN))) &&
+ (f->payload_len == 0)) && /* This is a pure ack, and... */
+ (ACKN(f) != t->snd_nxt)) /* There is something in flight awaiting to be acked... */
+ {
+ /* Process incoming duplicate ack. */
+ if (t->x_mode < PICO_TCP_RECOVER) {
+ t->x_mode++;
+ tcp_dbg("Mode: DUPACK %d, due to PURE ACK %0x, len = %d\n", t->x_mode, SEQN(f), f->payload_len);
+ tcp_dbg("ACK: %x - QUEUE: %x\n",ACKN(f), SEQN(first_segment(&t->tcpq_out)));
+ if (t->x_mode == PICO_TCP_RECOVER) { /* Switching mode */
+ t->snd_retry = SEQN(first_segment(&t->tcpq_out));
+ if (t->ssthresh > t->cwnd)
+ t->ssthresh >>=2;
+ else
+ t->ssthresh = (t->cwnd >> 1);
+ if (t->ssthresh < 2)
+ t->ssthresh = 2;
+ }
+ } else if (t->x_mode == PICO_TCP_RECOVER) {
+ tcp_dbg("TCP RECOVER> DUPACK! snd_una: %08x, snd_nxt: %08x, acked now: %08x\n", SEQN(first_segment(&t->tcpq_out)), t->snd_nxt, ACKN(f));
+ if (t->in_flight <= t->cwnd) {
+ struct pico_frame *nxt = peek_segment(&t->tcpq_out, t->snd_retry);
+ if (!nxt)
+ nxt = first_segment(&t->tcpq_out);
+
+ while (nxt && (nxt->flags & PICO_FRAME_FLAG_SACKED) && (nxt != first_segment(&t->tcpq_out))) {
+ tcp_dbg("Skipping %08x because it is sacked.\n", SEQN(nxt));
+ nxt = next_segment(&t->tcpq_out, nxt);
+ }
+
+ if (nxt && (seq_compare(SEQN(nxt), t->snd_nxt)) > 0)
+ nxt = NULL;
+ if (nxt && (seq_compare(SEQN(nxt), SEQN(first_segment(&t->tcpq_out))) > (t->recv_wnd << t->recv_wnd_scale)))
+ nxt = NULL;
+
+ if(!nxt)
+ nxt = first_segment(&t->tcpq_out);
+ if (nxt) {
+ tcp_retrans(t, peek_segment(&t->tcpq_out, t->snd_retry));
+ t->snd_retry = SEQN(nxt);
+ }
+ }
+
+ if (++t->cwnd_counter > 1) {
+ t->cwnd--;
+ if (t->cwnd < 2)
+ t->cwnd = 2;
+ t->cwnd_counter = 0;
+ }
+ } else {
+ tcp_dbg("DUPACK in mode %d \n", t->x_mode);
+
+ }
+ } /* End case duplicate ack detection */
+
+ /* Do congestion control */
+ tcp_congestion_control(t);
+ if ((acked > 0) && t->sock.wakeup) {
+ if (t->tcpq_out.size < t->tcpq_out.max_size)
+ t->sock.wakeup(PICO_SOCK_EV_WR, &(t->sock));
+ //t->sock.ev_pending |= PICO_SOCK_EV_WR;
+ }
+
+ /* if Nagle enabled, check if no unack'ed data and fill out queue (till window) */
+ if (IS_NAGLE_ENABLED((&(t->sock)))) {
+ while (!IS_TCP_HOLDQ_EMPTY(t) && ((t->tcpq_out.max_size - t->tcpq_out.size) >= PICO_TCP_DEFAULT_MSS)) {
+ tcp_dbg_nagle("TCP_ACK - NAGLE add new segment\n");
+ f_new = pico_hold_segment_make(t);
+ if (f_new == NULL)
+ break; /* XXX corrupt !!! (or no memory) */
+ if (pico_enqueue_segment(&t->tcpq_out,f_new) <= 0)
+ // handle error
+ tcp_dbg_nagle("TCP_ACK - NAGLE FAILED to enqueue in out\n");
+ }
+ }
+
+ /* If some space was created, put a few segments out. */
+ tcp_dbg("TCP_CWND, %lu, %u, %u, %u\n", pico_tick, t->cwnd, t->ssthresh, t->in_flight);
+ if (t->x_mode == PICO_TCP_LOOKAHEAD) {
+ if ((t->cwnd >= t->in_flight) && (t->snd_nxt > t->snd_last_out)) {
+ pico_tcp_output(&t->sock, t->cwnd - t->in_flight);
+ }
+ }
+
+ t->snd_old_ack = ACKN(f);
+ return 0;
+}
+
+static int tcp_finwaitack(struct pico_socket *s, struct pico_frame *f)
+{
+ tcp_dbg("RECEIVED ACK IN FIN_WAIT1\nTCP> IN STATE FIN_WAIT2\n");
+
+ /* acking part */
+ tcp_ack(s,f);
+ /* update TCP state */
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_FIN_WAIT2;
+
+ return 0;
+}
+
+static void tcp_deltcb(unsigned long when, void *arg)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)arg;
+ if (TCPSTATE(&t->sock) == PICO_SOCKET_STATE_TCP_TIME_WAIT) {
+ tcp_dbg("TCP> state: time_wait, final timer expired, going to closed state\n");
+ /* update state */
+ (t->sock).state &= 0x00FFU;
+ (t->sock).state |= PICO_SOCKET_STATE_TCP_CLOSED;
+ (t->sock).state &= 0xFF00U;
+ (t->sock).state |= PICO_SOCKET_STATE_CLOSED;
+ /* call EV_FIN wakeup before deleting */
+ if (t->sock.wakeup) {
+ (t->sock).wakeup(PICO_SOCK_EV_FIN, &(t->sock));
+ }
+ /* delete socket */
+ pico_socket_del(&t->sock);
+ } else {
+ tcp_dbg("TCP> trying to go to closed, wrong state\n");
+ }
+}
+
+static int tcp_finwaitfin(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *) (f->transport_hdr);
+ tcp_dbg("TCP> received fin in FIN_WAIT2\n");
+ /* received FIN, increase ACK nr */
+ t->rcv_nxt = long_be(hdr->seq) + 1;
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_TIME_WAIT;
+ /* set SHUT_REMOTE */
+ s->state |= PICO_SOCKET_STATE_SHUT_REMOTE;
+ if (s->wakeup)
+ s->wakeup(PICO_SOCK_EV_CLOSE, s);
+ if (f->payload_len > 0) /* needed?? */
+ tcp_data_in(s,f);
+ /* send ACK */
+ tcp_send_ack(t);
+ /* set timer */
+ pico_timer_add(200, tcp_deltcb, t);
+ return 0;
+}
+
+static int tcp_closewaitack(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ tcp_dbg("TCP> received ack in CLOSING\n");
+ /* acking part */
+ tcp_ack(s,f);
+ /* update TCP state */
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_TIME_WAIT;
+ /* set timer */
+ pico_timer_add(200, tcp_deltcb, t);
+ return 0;
+}
+
+static int tcp_lastackwait(struct pico_socket *s, struct pico_frame *f)
+{
+ tcp_dbg("TCP> state: last_ack, received ack, to closed\n");
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_CLOSED;
+ s->state &= 0xFF00U;
+ s->state |= PICO_SOCKET_STATE_CLOSED;
+ /* call socket wakeup with EV_FIN */
+ if (s->wakeup)
+ s->wakeup(PICO_SOCK_EV_FIN, s);
+ /* delete socket */
+ pico_socket_del(s);
+ return 0;
+}
+
+static int tcp_syn(struct pico_socket *s, struct pico_frame *f)
+{
+ /* TODO: Check against backlog length */
+ struct pico_socket_tcp *new = (struct pico_socket_tcp *)pico_socket_clone(s);
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *)f->transport_hdr;
+ if (!new)
+ return -1;
+
+#ifdef PICO_TCP_SUPPORT_SOCKET_STATS
+ pico_timer_add(2000, sock_stats, s);
+#endif
+
+ new->sock.remote_port = ((struct pico_trans *)f->transport_hdr)->sport;
+#ifdef PICO_SUPPORT_IPV4
+ if (IS_IPV4(f)) {
+ new->sock.remote_addr.ip4.addr = ((struct pico_ipv4_hdr *)(f->net_hdr))->src.addr;
+ new->sock.local_addr.ip4.addr = ((struct pico_ipv4_hdr *)(f->net_hdr))->dst.addr;
+ }
+#endif
+#ifdef PICO_SUPPORT_IPV6
+ if (IS_IPV6(f)) {
+ new->sock.remote_addr.ip6 = ((struct pico_ipv6_hdr *)(f->net_hdr))->src;
+ new->sock.local_addr.ip6 = ((struct pico_ipv6_hdr *)(f->net_hdr))->dst;
+ }
+#endif
+
+ /* Set socket limits */
+ new->tcpq_in.max_size = PICO_DEFAULT_SOCKETQ;
+ new->tcpq_out.max_size = PICO_DEFAULT_SOCKETQ;
+ new->tcpq_hold.max_size = 2*PICO_TCP_DEFAULT_MSS;
+
+ f->sock = &new->sock;
+ tcp_parse_options(f);
+ new->mss = PICO_TCP_DEFAULT_MSS;
+ new->rcv_nxt = long_be(hdr->seq) + 1;
+ new->snd_nxt = long_be(pico_paws());
+ new->snd_last = new->snd_nxt;
+ new->cwnd = PICO_TCP_IW;
+ new->ssthresh = 40;
+ new->recv_wnd = short_be(hdr->rwnd);
+ new->jumbo = hdr->len & 0x07;
+ new->sock.parent = s;
+ new->sock.wakeup = s->wakeup;
+ /* Initialize timestamp values */
+ new->sock.state = PICO_SOCKET_STATE_BOUND | PICO_SOCKET_STATE_CONNECTED | PICO_SOCKET_STATE_TCP_SYN_RECV;
+ pico_socket_add(&new->sock);
+ tcp_send_synack(&new->sock);
+ tcp_dbg("SYNACK sent, socket added. snd_nxt is %08x\n", new->snd_nxt);
+ return 0;
+}
+
+static void tcp_set_init_point(struct pico_socket *s)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ t->rcv_processed = t->rcv_nxt;
+}
+
+static int tcp_synack(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *) s;
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *)f->transport_hdr;
+
+ if (ACKN(f) == (1 + t->snd_nxt)) {
+ t->rcv_nxt = long_be(hdr->seq);
+ t->rcv_processed = t->rcv_nxt + 1;
+ tcp_ack(s, f);
+
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_ESTABLISHED;
+ tcp_dbg("TCP> Established. State: %x\n", s->state);
+
+ if (s->wakeup)
+ s->wakeup(PICO_SOCK_EV_CONN, s);
+ s->ev_pending |= PICO_SOCK_EV_WR;
+
+ t->rcv_nxt++;
+ t->snd_nxt++;
+ tcp_send_ack(t); /* return ACK */
+
+ return 0;
+
+ } else {
+ tcp_dbg("TCP> Not established, RST sent.\n");
+ tcp_nosync_rst(s,f);
+ return 0;
+ }
+}
+
+static int tcp_first_ack(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ tcp_dbg("ACK in SYN_RECV: expecting %08x got %08x\n", t->snd_nxt, ACKN(f));
+ if (t->snd_nxt == ACKN(f)) {
+ tcp_set_init_point(s);
+ tcp_ack(s, f);
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_ESTABLISHED;
+ tcp_dbg("TCP: Established. State now: %04x\n", s->state);
+ if( !s->parent && s->wakeup) { /* If the socket has no parent, -> sending socket that has a sim_open */
+ tcp_dbg("FIRST ACK - No parent found -> sending socket\n");
+ s->wakeup(PICO_SOCK_EV_CONN, s);
+ }
+ if (s->parent && s->parent->wakeup) {
+ tcp_dbg("FIRST ACK - Parent found -> listening socket\n");
+ s->wakeup = s->parent->wakeup;
+ s->parent->wakeup(PICO_SOCK_EV_CONN, s->parent);
+ }
+ s->ev_pending |= PICO_SOCK_EV_WR;
+ tcp_dbg("%s: snd_nxt is now %08x\n", __FUNCTION__, t->snd_nxt);
+ return 0;
+ } else {
+ tcp_nosync_rst(s,f);
+ return 0;
+ }
+}
+
+static int tcp_closewait(struct pico_socket *s, struct pico_frame *f)
+{
+
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *) (f->transport_hdr);
+
+
+ if (f->payload_len > 0)
+ tcp_data_in(s,f);
+ if (f->flags & PICO_TCP_ACK)
+ tcp_ack(s,f);
+ if (seq_compare(SEQN(f), t->rcv_nxt) == 0) {
+ /* received FIN, increase ACK nr */
+ t->rcv_nxt = long_be(hdr->seq) + 1;
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_CLOSE_WAIT;
+ /* set SHUT_REMOTE */
+ s->state |= PICO_SOCKET_STATE_SHUT_REMOTE;
+ tcp_dbg("TCP> Close-wait\n");
+
+ if (s->wakeup){
+ if(f->payload_len>0){
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ t->sock.ev_pending |=PICO_SOCK_EV_CLOSE;
+ }else
+ s->wakeup(PICO_SOCK_EV_CLOSE, s);
+ }
+ } else {
+ tcp_send_ack(t); /* return ACK */
+ }
+ return 0;
+}
+
+/*static int tcp_fin(struct pico_socket *s, struct pico_frame *f)
+{
+ return 0;
+}*/
+
+static int tcp_rcvfin(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ tcp_dbg("TCP> Received FIN in FIN_WAIT1\n");
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_CLOSING;
+ t->rcv_processed = t->rcv_nxt + 1;
+ t->rcv_nxt++;
+ /* send ACK */
+ tcp_send_ack(t);
+ return 0;
+}
+
+static int tcp_finack(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ tcp_dbg("TCP> ENTERED finack\n");
+ t->rcv_nxt++;
+ /* send ACK */
+ tcp_send_ack(t);
+
+ /* call socket wakeup with EV_FIN */
+ if (s->wakeup)
+ s->wakeup(PICO_SOCK_EV_FIN, s);
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_TIME_WAIT;
+ /* set SHUT_REMOTE */
+ s->state |= PICO_SOCKET_STATE_SHUT_REMOTE;
+ pico_timer_add(2000, tcp_deltcb, t);
+
+ return 0;
+}
+
+static int tcp_rst(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *) s;
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *) (f->transport_hdr);
+
+ tcp_dbg("TCP >>>>>>>>>>>>>> received RST <<<<<<<<<<<<<<<<<<<<\n");
+ if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_SYN_SENT) {
+ /* the RST is acceptable if the ACK field acknowledges the SYN */
+ if ((t->snd_nxt + 1) == ACKN(f)) { /* valid, got to closed state */
+ /* update state */
+ (t->sock).state &= 0x00FFU;
+ (t->sock).state |= PICO_SOCKET_STATE_TCP_CLOSED;
+ (t->sock).state &= 0xFF00U;
+ (t->sock).state |= PICO_SOCKET_STATE_CLOSED;
+
+ /* call EV_FIN wakeup before deleting */
+ if ((t->sock).wakeup)
+ (t->sock).wakeup(PICO_SOCK_EV_FIN, &(t->sock));
+
+ /* call EV_ERR wakeup before deleting */
+ pico_err = PICO_ERR_ECONNRESET;
+ if ((t->sock).wakeup)
+ (t->sock).wakeup(PICO_SOCK_EV_ERR, &(t->sock));
+
+ /* delete socket */
+ pico_socket_del(&t->sock);
+ } else { /* not valid, ignore */
+ tcp_dbg("TCP RST> IGNORE\n");
+ return 0;
+ }
+ } else { /* all other states */
+ /* all reset (RST) segments are validated by checking their SEQ-fields,
+ a reset is valid if its sequence number is in the window */
+ if ((long_be(hdr->seq) >= t->rcv_ackd) && (long_be(hdr->seq) <= ((short_be(hdr->rwnd)<<(t->wnd_scale)) + t->rcv_ackd))) {
+ if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_SYN_RECV) {
+ /* go to closed */
+ (t->sock).state &= 0x00FFU;
+ (t->sock).state |= PICO_SOCKET_STATE_TCP_CLOSED;
+ (t->sock).state &= 0xFF00U;
+ (t->sock).state |= PICO_SOCKET_STATE_CLOSED;
+ /* call EV_ERR wakeup */
+ pico_err = PICO_ERR_ECONNRESET;
+ if ((t->sock).wakeup)
+ (t->sock).wakeup(PICO_SOCK_EV_ERR, &(t->sock));
+ tcp_dbg("TCP RST> SOCKET BACK TO LISTEN\n");
+ pico_socket_del(s);
+ } else {
+ /* go to closed */
+ (t->sock).state &= 0x00FFU;
+ (t->sock).state |= PICO_SOCKET_STATE_TCP_CLOSED;
+ (t->sock).state &= 0xFF00U;
+ (t->sock).state |= PICO_SOCKET_STATE_CLOSED;
+
+ /* call EV_FIN wakeup before deleting */
+ if ((t->sock).wakeup)
+ (t->sock).wakeup(PICO_SOCK_EV_FIN, &(t->sock));
+ /* call EV_ERR wakeup before deleting */
+ pico_err = PICO_ERR_ECONNRESET;
+ if ((t->sock).wakeup)
+ (t->sock).wakeup(PICO_SOCK_EV_ERR, &(t->sock));
+
+ /* delete socket */
+ pico_socket_del(&t->sock);
+ }
+ } else { /* not valid, ignore */
+ tcp_dbg("TCP RST> IGNORE\n");
+ return 0;
+ }
+ }
+
+ return 0;
+}
+
+struct tcp_action_entry {
+ uint16_t tcpstate;
+ int (*syn)(struct pico_socket *s, struct pico_frame *f);
+ int (*synack)(struct pico_socket *s, struct pico_frame *f);
+ int (*ack)(struct pico_socket *s, struct pico_frame *f);
+ int (*data)(struct pico_socket *s, struct pico_frame *f);
+ int (*fin)(struct pico_socket *s, struct pico_frame *f);
+ int (*finack)(struct pico_socket *s, struct pico_frame *f);
+ int (*rst)(struct pico_socket *s, struct pico_frame *f);
+};
+
+static struct tcp_action_entry tcp_fsm[] = {
+ /* State syn synack ack data fin finack rst*/
+ { PICO_SOCKET_STATE_TCP_UNDEF, NULL, NULL, NULL, NULL, NULL, NULL, NULL },
+ { PICO_SOCKET_STATE_TCP_CLOSED, NULL, NULL, NULL, NULL, NULL, NULL, NULL },
+ { PICO_SOCKET_STATE_TCP_LISTEN, &tcp_syn, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, NULL },
+ { PICO_SOCKET_STATE_TCP_SYN_SENT, &tcp_nosync_rst, &tcp_synack, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_SYN_RECV, NULL, &tcp_nosync_rst, &tcp_first_ack, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_ESTABLISHED, NULL, &tcp_ack, &tcp_ack, &tcp_data_in, &tcp_closewait, &tcp_closewait, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_CLOSE_WAIT, NULL, &tcp_ack, &tcp_ack, &tcp_send_rst, &tcp_closewait, &tcp_closewait, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_LAST_ACK, NULL, &tcp_ack, &tcp_lastackwait, &tcp_send_rst, &tcp_send_rst, &tcp_send_rst, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_FIN_WAIT1, NULL, &tcp_ack, &tcp_finwaitack, &tcp_data_in, &tcp_rcvfin, &tcp_finack, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_FIN_WAIT2, NULL, &tcp_ack, &tcp_ack, &tcp_data_in, &tcp_finwaitfin, &tcp_finack, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_CLOSING, NULL, &tcp_ack, &tcp_closewaitack, &tcp_send_rst, &tcp_send_rst, &tcp_send_rst, &tcp_rst },
+ { PICO_SOCKET_STATE_TCP_TIME_WAIT, NULL, &tcp_ack, &tcp_send_rst, &tcp_send_rst, &tcp_send_rst, &tcp_send_rst, &tcp_rst }
+};
+
+/*
+ NOTE: in SYN-RECV receiving syn when cloned by default (see yellow pos-it), should send reset.
+*/
+
+int pico_tcp_input(struct pico_socket *s, struct pico_frame *f)
+{
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *) (f->transport_hdr);
+ int ret = 0;
+ uint8_t flags = hdr->flags;
+ struct tcp_action_entry *action = &tcp_fsm[s->state >> 8];
+
+ f->payload = (f->transport_hdr + ((hdr->len & 0xf0) >> 2));
+ f->payload_len = f->transport_len - ((hdr->len & 0xf0) >> 2);
+
+ tcp_dbg("[%lu] TCP> [tcp input] socket: %p state: %d <-- local port:%d remote port: %d seq: %08x ack: %08x flags: %02x = t_len: %d, hdr: %u payload: %d\n", pico_tick,
+ s, s->state >> 8, short_be(hdr->trans.dport), short_be(hdr->trans.sport), SEQN(f), ACKN(f), hdr->flags, f->transport_len, (hdr->len & 0xf0) >> 2, f->payload_len );
+
+ /* This copy of the frame has the current socket as owner */
+ f->sock = s;
+
+ /* Those are not supported at this time. */
+ flags &= ~(PICO_TCP_CWR | PICO_TCP_URG | PICO_TCP_ECN);
+ if (flags == PICO_TCP_SYN) {
+ if (action->syn)
+ action->syn(s,f);
+ } else if (flags == (PICO_TCP_SYN | PICO_TCP_ACK)) {
+ if (action->synack)
+ action->synack(s,f);
+ } else {
+ if ((flags == PICO_TCP_ACK) || (flags == (PICO_TCP_ACK | PICO_TCP_PSH))) {
+ if (action->ack) {
+ action->ack(s,f);
+ }
+ }
+ if (f->payload_len > 0) {
+ ret = f->payload_len;
+ if (action->data)
+ action->data(s,f);
+ }
+ if (flags == PICO_TCP_FIN) {
+ if (action->fin)
+ action->fin(s,f);
+ }
+ if ((flags == (PICO_TCP_FIN | PICO_TCP_ACK)) || (flags == (PICO_TCP_FIN | PICO_TCP_ACK | PICO_TCP_PSH))) {
+ if (action->finack)
+ action->finack(s,f);
+ }
+ if (flags & PICO_TCP_RST) {
+ if (action->rst)
+ action->rst(s,f);
+ }
+ }
+
+//discard:
+ pico_frame_discard(f);
+ return ret;
+}
+
+static void tcp_send_keepalive(unsigned long when, void *_t)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)_t;
+ tcp_dbg("\n\nSending keepalive (%d), [State = %d]...\n", t->backoff,t->sock.state );
+ if( t->sock.net && ((t->sock.state & 0xFF00) == PICO_SOCKET_STATE_TCP_ESTABLISHED) )
+ {
+ tcp_send_ack(t);
+
+ if (t->keepalive_timer_running > 0) {
+ t->keepalive_timer_running--;
+ }
+
+ if (t->keepalive_timer_running == 0) {
+ t->keepalive_timer_running++;
+ tcp_dbg("[Self] Adding timer(retransmit keepalive)\n");
+ pico_timer_add(t->rto << (++t->backoff), tcp_send_keepalive, t);
+ }
+ }
+}
+
+int pico_tcp_output(struct pico_socket *s, int loop_score)
+{
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *)s;
+ struct pico_frame *f, *una;
+ struct pico_tcp_hdr *hdr;
+ int sent = 0;
+
+ una = first_segment(&t->tcpq_out);
+
+ f = peek_segment(&t->tcpq_out, t->snd_nxt);
+ while((f) && (t->cwnd >= t->in_flight)) {
+ hdr = (struct pico_tcp_hdr *)f->transport_hdr;
+ f->timestamp = pico_tick;
+ tcp_add_options(t, f, hdr->flags, tcp_options_size(t, hdr->flags));
+ if (seq_compare(SEQN(f) + f->payload_len, SEQN(una) + (t->recv_wnd << t->recv_wnd_scale)) > 0) {
+ t->cwnd = t->in_flight;
+ if (t->cwnd < 1)
+ t->cwnd = 1;
+ if (t->x_mode != PICO_TCP_WINDOW_FULL) {
+ tcp_dbg("TCP> RIGHT SIZING (rwnd: %d, frame len: %d\n",t->recv_wnd << t->recv_wnd_scale, f->payload_len);
+ tcp_dbg("In window full...\n");
+ t->snd_nxt = SEQN(una); /* XXX prevent out-of-order-packets ! */ /*DLA re-enabled.*/
+ t->snd_retry = SEQN(una); /* XXX replace by retry pointer? */
+
+ /* Alternative to the line above: (better performance, but seems to lock anyway with larger buffers)
+ if (seq_compare(t->snd_nxt, SEQN(una)) > 0)
+ t->snd_nxt -= f->payload_len;
+ */
+
+ t->x_mode = PICO_TCP_WINDOW_FULL;
+ if (t->keepalive_timer_running == 0) {
+ tcp_dbg("[Window full] Adding timer(send keepalive)\n");
+ tcp_send_keepalive(0, t);
+ }
+ }
+ break;
+ }
+ tcp_dbg("TCP> DEQUEUED (for output) frame %08x, acks %08x len= %d, remaining frames %d\n", SEQN(f), ACKN(f), f->payload_len,t->tcpq_out.frames);
+ tcp_send(t, f);
+ sent++;
+ loop_score--;
+ t->snd_last_out = SEQN(f);
+ if (loop_score < 1)
+ break;
+ if (f->payload_len > 0) {
+ f = next_segment(&t->tcpq_out, f);
+ } else {
+ f = NULL;
+ }
+ }
+ if (sent > 0) {
+ if (t->rto < PICO_TCP_RTO_MIN)
+ t->rto = PICO_TCP_RTO_MIN;
+ //if (s->wakeup)
+ // t->sock.wakeup(PICO_SOCK_EV_WR, &t->sock);
+ add_retransmission_timer(t, pico_tick + t->rto);
+ } else {
+ /* Nothing to transmit. */
+ }
+
+ if ((t->tcpq_out.frames == 0) && (s->state & PICO_SOCKET_STATE_SHUT_LOCAL)) { /* if no more packets in queue, XXX replacled !f by tcpq check */
+ if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_ESTABLISHED) {
+ tcp_dbg("TCP> buffer empty, shutdown established ...\n");
+ /* send fin if queue empty and in state shut local (write) */
+ tcp_send_fin(t);
+ /* change tcp state to FIN_WAIT1 */
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_FIN_WAIT1;
+ } else if ((s->state & PICO_SOCKET_STATE_TCP) == PICO_SOCKET_STATE_TCP_CLOSE_WAIT) {
+ /* send fin if queue empty and in state shut local (write) */
+ tcp_send_fin(t);
+ /* change tcp state to LAST_ACK */
+ s->state &= 0x00FFU;
+ s->state |= PICO_SOCKET_STATE_TCP_LAST_ACK;
+ tcp_dbg("TCP> STATE: LAST_ACK.\n");
+ }
+ }
+ return loop_score;
+}
+
+/* function to make new segment from hold queue with specific size (mss) */
+static struct pico_frame * pico_hold_segment_make(struct pico_socket_tcp *t)
+{
+ struct pico_frame *f_temp,*f_new;
+ struct pico_socket *s = (struct pico_socket *) &t->sock;
+ struct pico_tcp_hdr *hdr;
+ int total_len = 0, total_payload_len = 0;
+ int off = 0, test = 0;
+
+ off = pico_tcp_overhead(s);
+
+ /* init with first frame in hold queue */
+ f_temp = first_segment(&t->tcpq_hold);
+ total_len = f_temp->payload_len;
+ f_temp = next_segment(&t->tcpq_hold, f_temp);
+
+ /* check till total_len <= MSS */
+ while ((f_temp != NULL) && ((total_len+f_temp->payload_len) <= PICO_TCP_DEFAULT_MSS)) {
+ total_len += f_temp->payload_len;
+ f_temp = next_segment(&t->tcpq_hold, f_temp);
+ if (f_temp == NULL)
+ break;
+ }
+ /* alloc new frame with payload size = off + total_len */
+ f_new = pico_socket_frame_alloc(s, off + total_len);
+ if (!f_new) {
+ pico_err = PICO_ERR_ENOMEM;
+ return f_new;
+ }
+
+ hdr = (struct pico_tcp_hdr *) f_new->transport_hdr;
+ /* init new frame */
+ f_new->payload += off;
+ f_new->payload_len -= off;
+ f_new->sock = s;
+
+ f_temp = first_segment(&t->tcpq_hold);
+ hdr->seq = ((struct pico_tcp_hdr *)(f_temp->transport_hdr))->seq; /* get sequence number of first frame */
+ hdr->trans.sport = t->sock.local_port;
+ hdr->trans.dport = t->sock.remote_port;
+
+ /* check till total_payload_len <= MSS */
+ while ((f_temp != NULL) && ((total_payload_len + f_temp->payload_len) <= PICO_TCP_DEFAULT_MSS)) {
+ /* cpy data and discard frame */
+ test++;
+ memcpy(f_new->payload + total_payload_len, f_temp->payload, f_temp->payload_len);
+ total_payload_len += f_temp->payload_len;
+ pico_discard_segment(&t->tcpq_hold, f_temp);
+ f_temp = first_segment(&t->tcpq_hold);
+ }
+
+ hdr->len = (f_new->payload - f_new->transport_hdr) << 2 | t->jumbo;
+
+ tcp_dbg_nagle("NAGLE make - joined %d segments, len %d bytes\n",test,total_payload_len);
+
+ return f_new;
+}
+
+/* original behavior kept when Nagle disabled;
+ Nagle algorithm added here, keeping hold frame queue instead of eg linked list of data */
+int pico_tcp_push(struct pico_protocol *self, struct pico_frame *f)
+{
+ struct pico_tcp_hdr *hdr = (struct pico_tcp_hdr *)f->transport_hdr;
+ struct pico_socket_tcp *t = (struct pico_socket_tcp *) f->sock;
+ struct pico_frame *f_new;
+ int total_len = 0;
+
+ hdr->trans.sport = t->sock.local_port;
+ hdr->trans.dport = t->sock.remote_port;
+ hdr->seq = long_be(t->snd_last + 1);
+ hdr->len = (f->payload - f->transport_hdr) << 2 | t->jumbo;
+
+ if (f->payload_len > (t->tcpq_out.max_size - t->tcpq_out.size))
+ t->sock.ev_pending &= (~PICO_SOCK_EV_WR);
+
+ /***************************************************************************/
+
+ if (!IS_NAGLE_ENABLED((&(t->sock)))) {
+ /* TCP_NODELAY enabled, original behavior */
+ if (pico_enqueue_segment(&t->tcpq_out,f) > 0) {
+ tcp_dbg_nagle("TCP_PUSH - NO NAGLE - Pushing segment %08x, len %08x to socket %p\n", t->snd_last + 1, f->payload_len, t);
+ t->snd_last += f->payload_len;
+ return f->payload_len;
+ } else {
+ tcp_dbg("Enqueue failed.\n");
+ return 0;
+ }
+ }
+ /***************************************************************************/
+ else {
+ /* Nagle's algorithm enabled, check if ready to send, or put frame in hold queue */
+ if (IS_TCP_IDLE(t) && IS_TCP_HOLDQ_EMPTY(t)) { /* opt 1. send frame */
+ if (pico_enqueue_segment(&t->tcpq_out,f) > 0) {
+ tcp_dbg_nagle("TCP_PUSH - NAGLE - Pushing segment %08x, len %08x to socket %p\n", t->snd_last + 1, f->payload_len, t);
+ t->snd_last += f->payload_len;
+ return f->payload_len;
+ } else {
+ tcp_dbg("Enqueue failed.\n");
+ return 0;
+ }
+ } else { /* opt 2. hold data back */
+ total_len = f->payload_len + t->tcpq_hold.size;
+ if ((total_len >= PICO_TCP_DEFAULT_MSS) && ((t->tcpq_out.max_size - t->tcpq_out.size) >= PICO_TCP_DEFAULT_MSS)) {/* TODO check mss socket */
+ /* IF enough data in hold (>mss) AND space in out queue (>mss) */
+ /* add current frame in hold and make new segment */
+ if (pico_enqueue_segment(&t->tcpq_hold,f) > 0 ) {
+ tcp_dbg_nagle("TCP_PUSH - NAGLE - Pushed into hold, make new (enqueued frames out %d)\n",t->tcpq_out.frames);
+ t->snd_last += f->payload_len; /* XXX WATCH OUT */
+ f_new = pico_hold_segment_make(t);
+ } else {
+ tcp_dbg_nagle("TCP_PUSH - NAGLE - enqueue hold failed 1\n");
+ return 0;
+ }
+ /* and put new frame in out queue */
+ if ((f_new != NULL) && (pico_enqueue_segment(&t->tcpq_out,f_new) > 0)) {
+ return f_new->payload_len;
+ } else {
+ tcp_dbg_nagle("TCP_PUSH - NAGLE - enqueue out failed, f_new = %p\n",f_new);
+ return -1; /* XXX something seriously wrong */
+ }
+ } else {
+ /* ELSE put frame in hold queue */
+ if (pico_enqueue_segment(&t->tcpq_hold,f) > 0) {
+ tcp_dbg_nagle("TCP_PUSH - NAGLE - Pushed into hold (enqueued frames out %d)\n",t->tcpq_out.frames);
+ t->snd_last += f->payload_len; /* XXX WATCH OUT */
+ return f->payload_len;
+ } else {
+ tcp_dbg_nagle("TCP_PUSH - NAGLE - enqueue hold failed 2\n");
+ return 0;
+ }
+ }
+ }
+ }
+ /***************************************************************************/
+}
+#endif //PICO_SUPPORT_TCP
