debug("%p new state: %s\n", c->utcp, strstate[state]);
}
+static bool fin_wanted(struct utcp_connection *c, uint32_t seq) {
+ if(seq != c->snd.last)
+ return false;
+ switch(c->state) {
+ case FIN_WAIT_1:
+ case CLOSING:
+ case LAST_ACK:
+ return true;
+ default:
+ return false;
+ }
+}
+
static inline void list_connections(struct utcp *utcp) {
debug("%p has %d connections:\n", utcp, utcp->nconnections);
for(int i = 0; i < utcp->nconnections; i++)
// TODO: convert to ringbuffers to avoid memmove() operations.
// Store data into the buffer
-static ssize_t buffer_put(struct buffer *buf, const void *data, size_t len) {
+static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data, size_t len) {
if(buf->maxsize <= buf->used)
return 0;
- if(len > buf->maxsize - buf->used)
- len = buf->maxsize - buf->used;
- if(len > buf->size - buf->used) {
+
+ debug("buffer_put_at %zu %zu %zu\n", buf->used, offset, len);
+
+ size_t required = offset + len;
+ if(required > buf->maxsize) {
+ if(offset >= buf->maxsize)
+ return 0;
+ abort();
+ len = buf->maxsize - offset;
+ required = buf->maxsize;
+ }
+
+ if(required > buf->size) {
size_t newsize = buf->size;
- do {
- newsize *= 2;
- } while(newsize < buf->used + len);
+ if(!newsize) {
+ newsize = required;
+ } else {
+ do {
+ newsize *= 2;
+ } while(newsize < buf->used + len);
+ }
if(newsize > buf->maxsize)
newsize = buf->maxsize;
char *newdata = realloc(buf->data, newsize);
buf->data = newdata;
buf->size = newsize;
}
- memcpy(buf->data + buf->used, data, len);
- buf->used += len;
+
+ memcpy(buf->data + offset, data, len);
+ if(required > buf->used)
+ buf->used = required;
return len;
}
+static ssize_t buffer_put(struct buffer *buf, const void *data, size_t len) {
+ return buffer_put_at(buf, buf->used, data, len);
+}
+
// Get data from the buffer. data can be NULL.
static ssize_t buffer_get(struct buffer *buf, void *data, size_t len) {
if(len > buf->used)
static bool buffer_init(struct buffer *buf, uint32_t len, uint32_t maxlen) {
memset(buf, 0, sizeof *buf);
- buf->data = malloc(len);
- if(!len)
- return false;
+ if(len) {
+ buf->data = malloc(len);
+ if(!buf->data)
+ return false;
+ }
buf->size = len;
buf->maxsize = maxlen;
return true;
c->src = src;
c->dst = dst;
+#ifdef UTCP_DEBUG
+#warning debugging
+ c->snd.iss = 0;
+#else
c->snd.iss = rand();
+#endif
c->snd.una = c->snd.iss;
c->snd.nxt = c->snd.iss + 1;
c->rcv.wnd = utcp->mtu;
} *pkt;
pkt = malloc(sizeof pkt->hdr + c->utcp->mtu);
- if(!pkt->data)
+ if(!pkt)
return;
pkt->hdr.src = c->src;
c->snd.nxt += seglen;
left -= seglen;
- if(c->state != ESTABLISHED && seglen && c->snd.nxt == c->snd.last) {
- switch(c->state) {
- case FIN_WAIT_1:
- case CLOSING:
- seglen--;
- pkt->hdr.ctl |= FIN;
- break;
- default:
- break;
- }
+ if(seglen && fin_wanted(c, c->snd.nxt)) {
+ seglen--;
+ pkt->hdr.ctl |= FIN;
}
print_packet(c->utcp, "send", pkt, sizeof pkt->hdr + seglen);
pkt->hdr.dst = c->dst;
switch(c->state) {
- case LISTEN:
- // TODO: this should not happen
- break;
-
case SYN_SENT:
+ // Send our SYN again
pkt->hdr.seq = c->snd.iss;
pkt->hdr.ack = 0;
pkt->hdr.wnd = c->rcv.wnd;
break;
case SYN_RECEIVED:
+ // Send SYNACK again
pkt->hdr.seq = c->snd.nxt;
pkt->hdr.ack = c->rcv.nxt;
pkt->hdr.ctl = SYN | ACK;
case ESTABLISHED:
case FIN_WAIT_1:
+ case CLOSE_WAIT:
+ case CLOSING:
+ case LAST_ACK:
+ // Send unacked data again.
pkt->hdr.seq = c->snd.una;
pkt->hdr.ack = c->rcv.nxt;
pkt->hdr.ctl = ACK;
- uint32_t len = seqdiff(c->snd.nxt, c->snd.una);
- if(c->state == FIN_WAIT_1)
- len--;
+ uint32_t len = seqdiff(c->snd.last, c->snd.una);
if(len > utcp->mtu)
len = utcp->mtu;
- else {
- if(c->state == FIN_WAIT_1)
- pkt->hdr.ctl |= FIN;
+ if(fin_wanted(c, c->snd.una + len)) {
+ len--;
+ pkt->hdr.ctl |= FIN;
}
+ c->snd.nxt = c->snd.una + len;
buffer_copy(&c->sndbuf, pkt->data, 0, len);
print_packet(c->utcp, "rtrx", pkt, sizeof pkt->hdr + len);
utcp->send(utcp, pkt, sizeof pkt->hdr + len);
break;
- default:
- // TODO: implement
+ case CLOSED:
+ case LISTEN:
+ case TIME_WAIT:
+ case FIN_WAIT_2:
+ // We shouldn't need to retransmit anything in this state.
#ifdef UTCP_DEBUG
abort();
#endif
+ timerclear(&c->rtrx_timeout);
break;
}
}
int utcp_shutdown(struct utcp_connection *c, int dir) {
- debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c->snd.last);
+ debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c ? c->snd.last : 0);
if(!c) {
errno = EFAULT;
return -1;
return -1;
}
- // TODO: handle dir
- // TODO: check that repeated calls with the same parameters should have no effect
+ if(!(dir == UTCP_SHUT_RD || dir == UTCP_SHUT_WR || dir == UTCP_SHUT_RDWR)) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ // TCP does not have a provision for stopping incoming packets.
+ // The best we can do is to just ignore them.
+ if(dir == UTCP_SHUT_RD || dir == UTCP_SHUT_RDWR)
+ c->recv = NULL;
+
+ // The rest of the code deals with shutting down writes.
+ if(dir == UTCP_SHUT_RD)
+ return 0;
switch(c->state) {
case CLOSED:
- return 0;
case LISTEN:
+ errno = ENOTCONN;
+ return -1;
+
case SYN_SENT:
set_state(c, CLOSED);
return 0;
return diff;
}
+bool utcp_is_active(struct utcp *utcp) {
+ if(!utcp)
+ return false;
+
+ for(int i = 0; i < utcp->nconnections; i++)
+ if(utcp->connections[i]->state != CLOSED && utcp->connections[i]->state != TIME_WAIT)
+ return true;
+
+ return false;
+}
+
struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept, utcp_send_t send, void *priv) {
struct utcp *utcp = calloc(1, sizeof *utcp);
if(!utcp)
if(c)
c->poll = poll;
}
+
+void utcp_set_accept_cb(struct utcp *utcp, utcp_accept_t accept, utcp_pre_accept_t pre_accept) {
+ if(utcp) {
+ utcp->accept = accept;
+ utcp->pre_accept = pre_accept;
+ }
+}
projects / utcp / blobdiff